![](media/image1.wmf){width="3.247916666666667in"
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> **FIRE Phase III:**
>
> **Cirrus**
>
> **Implementation Plan**
>
> **May 1996**

+-----------------------------------------------------------------------+
| **Cirrus Panel:**                                                     |
|                                                                       |
| **Tom Ackerman**                                                      |
|                                                                       |
| **William Cotton**                                                    |
|                                                                       |
| **Steven Cox(Chair)**                                                 |
|                                                                       |
| **Tony Del Genio**                                                    |
|                                                                       |
| **Leo Donner**                                                        |
|                                                                       |
| **Andrew Heymsfield**                                                 |
|                                                                       |
| **Michael King**                                                      |
|                                                                       |
| **Kuo-Nan Liou**                                                      |
|                                                                       |
| **Pat Minnis**                                                        |
|                                                                       |
| **William Rossow**                                                    |
|                                                                       |
| **David Starr**                                                       |
|                                                                       |
| **Graeme Stephens**                                                   |
+-----------------------------------------------------------------------+

Cover Image

Tropical cirrus anvils associated with deep convective clouds acquired

at 2315 UTC 31 January 1993 during the TOGA COARE campaign over the
Western Tropical Pacific Ocean (13.5˚ S 152˚ W). This image was acquired
by the MODIS Airborne Simulator (King et al. 1996, J. Atmos. Oceanic
Tech.) onboard the NASA ER-2 high altitude research aircraft. The image,
at a

visible wavelength of 0.66 µm, covered a total domain size of 37 by 82
km

and also showed developing cumulus congestus clouds around the cirrus

anvils (provided by S. C. Tsay and M. D. King at NASA Goddard Space
Flight

Center).

TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY

1.1 Primary Components

1.2 Strategies

1.3 Critical Questions

1.4 Programmatic Goals

1.5 Collaborative Programs

2.0 MULTIPLE CRITERIA APPLIED TO SELECTION OF IMPLEMENTATION PLAN GOALS

3.0 NEW PLATFORMS AND INSTRUMENTATION

3.1 Aircraft

3.2 Instruments

3.3 Satellites

4.0 CONTINUED EXPLOITATION OF EXISTING CIRRUS DATA SETS

4.1 GCM and Parameterization Evaluation and Validation

4.2 Characterization of Cloud Radiative Properties and Effects

4.3 Characterization of Cloud Microphysical Properties

4.4 Case Studies and Modeling of Cloud Development

4.5 Development, Validation, and Application of Satellite Remote Sensing
of Cloud Properties

4.6 Implementation Steps

5.0 REMOTE SENSING FOR FIRE III UPPER TROPOSPHERIC CLOUD RESEARCH

5.1. Continued analysis with datasets prior to FIRE III field campaigns

5.1.1 Ground‑based and airborne sensors

5.1.2 Theoretical studies

5.1.3 Satellite analyses

5.2 Implementation Steps

6.0 GCMS AND FIRE III

6.1 Implementation Steps

7.0 TROPICAL CIRRUS EXPERIMENT

7.1 Background

7.2 Tropical cirrus versus midlatitude cirrus

7.3 Key issues and questions

7.4 Limitations of past experiments

7.5 Experimental Design

7.5.1 Ground-Satellite Remote Sensing Experiment

7.5.2 A Radiation-Microphysics Experiment-An in-situ Experiment

7.5.3 Evolution of Non Precipitating Anvil and Isolated Cirrus Layers

7.5.4 Convection-Cirrus System Experiment

7.5.5 Ground-based Remote Sensing

7.5.6 Summary of Four Tropospheric Cirrus Experiments

7.5.7 Collaborative Programs

7.6 Implementation Steps

8.0 SUCCESS

8.1 FIRE Participation

8.2 Implementation Steps

9.0 SHEBA/FIRE III Stratus

9.1 SHEBA-FIRE Collaboration

9.2 Implementation Steps

10.0 COMPLIMENTARY PROGRAMS

10.1 Implementation Steps

APPENDIX A - REFERENCES A-

APPENDIX B - ACRONYMS, ABBREVIATIONS and NOTATIONS B-

APPENDIX C - FIRE SCIENTIFIC ORGANIZATION AND DATA MANAGEMENT C-

APPENDIX D - FIRE INVESTIGATOR'S RESEARCH ABSTRACTS D-

APPENDIX E - RESULTS OF CIRRUS IMPLEMENTATION STEPS SURVEY E-

1.0 EXECUTIVE SUMMARY

The First ISCCP Regional Experiment (FIRE) has conducted basic research
on climatically important cloud systems. FIRE was conceived in 1984 as a
national US research program responding to the needs of ISCCP
(International Satellite Cloud Climatology Project), an international
World Meteorological Organization program. Throughout its history, FIRE
has been especially interested in the cloud-climate connection. As a
result, integrated, interdisciplinary studies involving
experimentalists, theoreticians and modelers have been planned and
executed by the broad-based community of FIRE scientists. These
specialists span the fields of radiation, cloud microphysics and
dynamics ranging from cloud scale to the general circulation.

Previous FIRE research has centered on midlatitude cirrus cloud systems
and subtropical marine boundary layer cloud systems. It has enhanced our
ability to both monitor these systems from satellites and to include
their radiative effects in models of various scales. It has
significantly increased our understanding of the control of these cloud
systems by the large-scale circulation and has greatly enhanced our
ability to realistically simulate these systems in Global Circulation
models (GCM). Modeling studies and field campaigns have greatly enhanced
our understanding of these two climatically important cloud regimes.
FIRE GCM research has added to our understanding of the importance of
these cloud regimes in the climate system.

> There have been two previous phases of FIRE. FIRE-I (1984-1989)
> focused on midlatitude cirrus clouds in the upper U.S. and marine
> stratocumulus clouds in the eastern Pacific off the coast of
> California. FIRE-II (1989-1994) continued to study midlatitude cirrus
> clouds in the central US and the boundary layer clouds of the eastern
> Atlantic. The following document outlines the strategies, questions,
> and programmatic goals of the upper tropospheric component of FIRE-III
> (1995- ).
>
> 1.1 PRIMARY COMPONENTS.1 Primary Components
>
> FIRE Phase III has two primary components:
>
> An upper tropospheric cloud component which consists of continuing
> investigations of middle latitude cirrus cloud systems with a
> methodical transition of emphasis to tropical upper-tropospheric cloud
> systems;
>
> A boundary layer/arctic cloud component which consists of continuing
> investigations of subtropical marine stratocumulus systems and a new
> thrust aimed at Arctic cloud systems. A separate document, the Arctic
> Cloud Implementation Plan, describes this component.
>
> 1.2 STRATEGIES:..2 Strategies
>
> The FIRE III upper tropospheric cloud component will adopt the
> following strategies:
>
> 1\. The continued analysis and simulation of observations obtained
> during the FIRE Phases I and II field campaigns and the FIRE extended
> time observations. The FIRE Phase I and II model, theoretical, and
> field campaign results will be applied to the improvement and
> evaluation of cloud-system parameterizations employed in cloud
> resolving models (CRMs) and GCMs. They will also be used to develop
> and verify improved techniques for the inference of cloud radiative
> and microphysical properties from satellite and surface based data.
>
> 2\. Provide a methodical transition from FIRE Phases I and II
> accomplishments to a coherent research plan for the next generation of
> research on climatically important cloud systems.
>
> 3\. Define, design, test and implement new critically needed
> measurement systems to observe key microphysical and radiative
> properties of cirrus clouds. The inability to observe these properties
> is currently a barrier to a better understanding of cirrus cloud
> systems.
>
> 4\. The definition and execution of limited but highly-focused
> observational programs to complement our current understanding of
> cirrus cloud systems.
>
> 5\. The assessment of the need for and subsequent definition and
> execution of a major field campaign focused on tropical
> upper-tropospheric cloud systems.
>
> 1.3 CRITICAL QUESTIONS
>
> Critical questions to be addressed in the upper-tropospheric cloud
> component are:.3 Critical Questions

**What are the distributions and amounts of ice mass and total water in
the upper troposphere?**

• How can ice mass be determined from remote sensors and how can these
measurements be validated?

• How do the concentrations of ice particles, the total water, the ice
mass and their distributions depend on large-scale meteorological
parameters such as temperature, vertical motion, wind shear, etc.?

• How are the total water mass and ice mass distributions related to
detrainment from deep convective cloud systems?

• How do the local and regional evolutions of total water and cloud ice
mass distributions and their small-scale variability depend on the ice
formation process (e.g. synoptic ascent versus convective detrainment)
parameters?

**What are the microphysical properties of upper tropospheric clouds?**

• How do the particle sizes, shapes and phase depend on the large scale
environment?

• How does microphysical composition affect the evolution of the cloud
system and the tropospheric water budget (interactions between cloud
layers, vertical water transports, precipitation at the surface)?

• What are the microphysics of cirrus formed at extremely low
temperatures?

• How do aerosols impact the microphysical development of cirrus clouds?

**What are the radiative properties of upper-tropospheric clouds and how
do they relate to the ice mass, and the microphysical and macrophysical
characteristics of the cloud?**

• What are the scattering phase functions, asymmetry parameters, and
optical extinction parameters associated with microphysical
distributions?

• How can these radiative properties be directly and accurately observed
from airborne, satellite and surface-based platforms?

• Can these radiative properties be usefully expressed in terms of an
effective particle size that is consistent with cloud ice path and
optical depth?

• How do the vertical and horizontal structures of cirrus clouds affect
their bulk radiative properties and how does this impact the remote
sensing of cloud microphysical properties?

**How representative are midlatitude continental cirrus of upper
tropospheric clouds in other regions of the globe?**

• Will GCMs be able to use a single universal cirrus parameterization
for all latitudinal and regional domains?

• Are tropical cirrus cloud systems sufficiently different from their
midlatitude cousins to call for a tropical cirrus field campaign?

> 1.4 PROGRAMMATIC GOALS.4 Programmatic Goals
>
> Key programmatic goals that FIRE III must address include serving
> specific components of our science and technological communities.
> Among these components are the instrument/measurement technologies and
> strategies to be used to observe key radiative and microphysical cloud
> parameters. The term \"validation\" will be applied in reference to
> the assessment and improvement of remote sensing of microphysical,
> radiative and spatial properties of cloud systems; this continues to
> be a programmatic goal of high priority for FIRE III. Large scale
> models of the climate potentially represent one of the most powerful
> tools to explore the role of cloud systems in climate because of their
> ability to simulate the many feedback processes at work in the earth
> climate system; however, current model treatments of cloud systems are
> crude at best. FIRE has a responsibility and a vested interest in
> working closely with the modeling community to improve the ability of
> climate models to credibly represent and investigate cloud systems.
>
> 1.5 COLLABORATIVE PROGRAMS.5 Collaborative Programs
>
> In addressing the questions presented above, FIRE-III recognizes a
> strong common interest with other programs. Those most directly
> related include the National Aeronautics and Space Administration
> (NASA) Subsonic Assessment (SASS), Department of Energy (DOE)
> Atmospheric Radiation Measurements (ARM), National Science Foundation
> (NSF) Role of Clouds, Energy and Water (ROCEW), and NSF
> Stratosphere-Troposphere Experiments: Radiation, Aerosols, and Ozone -
> B (STERAO-B) programs. There is also considerable international
> activity in the cirrus cloud-climate research arena. Past FIRE
> collaboration with scientists from Europe and Japan is expected to
> continue. For example, researchers from the European Clouds and
> Radiation Experiment (EUCREX) and Japan Cloud Studies (JACCS)
> communities have expressed interest in possible future participation
> with FIRE-III. FIRE welcomes the collaboration with other programs and
> other countries in its quest to better understand the roles of clouds
> in the Earth\'s climate system.

**2.0 MULTIPLE CRITERIA APPLIED TO SELECTION OF IMPLEMENTATION** **PLAN
GOALS**

The development of an implementation plan for FIRE III is especially
challenging at this time. Not only must basic scientific goals be met,
specific programmatic goals consistent with the needs of multiple
constituencies must be addressed and the current fiscal realities faced
by sponsoring agencies further constrain the options. The FIRE Research
Plan identified the scientific goals for FIRE III. These were restated
in the previous section.

Key programmatic goals that FIRE III must address include serving
specific components of our science and technological communities. Among
these components are the instrument/measurement technologies and
strategies to be used to observe key radiative and microphysical cloud
parameters. The term \"validation\" has been applied in reference to the
assessment and improvement of remote sensing of microphysical, radiative
and spatial properties of cloud systems; this continues to be a
programmatic goal of high priority for FIRE III. Large scale models of
the climate potentially represent one of the most powerful tools to
explore the role of cloud systems in climate because of their ability to
simulate the many feedback processes at work in the earth climate
system; however, current model treatments of cloud systems are crude at
best. FIRE has a responsibility and a vested interest in working closely
with the modeling community to improve the ability of climate models to
credibly represent and investigate cloud systems.

The current fiscal climate is, to say the least, challenging! While all
goals in the FIRE III Research Plan have scientific merit, priorities
must be set and limited fiscal, logistic and human resources must be
focused on the most important elements; furthermore unnecessary
duplication and premature execution must be minimized.

The implementation plan that follows represents the best efforts of a
group of FIRE Science Team members to provide a plan which fits within
these multiple constraints and offers a high probability of successfully
achieving the stated goals of the FIRE Research Plan.

Section 3 lists some exciting new advances in both platform and
instrument development that are especially relevant and important to
future FIRE studies of cirrus clouds. Section 4 describes FIRE research
goals and activities that exploit existing FIRE datasets obtained in
previous field campaigns (Cirrus Intensive Field Observations (IFO)-I,
IFO-II, Extended Time Observations (ETO), Tropical Ocean and Global
Atmosphere - Coupled Ocean-Atmosphere Regional Experiment (TOGA-COARE),
Central Equatorial Pacific Experiment (CEPEX), etc.) Section 5 outlines
research strategies for satellite, airborne, and surface remote sensing
investigations that will focus on validation, cloud process studies, and
diagnostic analyses. These strategies include continued analyses of
previously obtained datasets, theoretical studies, and analyses of
future midlatitude and equatorial cirrus field campaigns. Section 6
describes the rationale and measurement requirements for tropical cirrus
experiments designed to test the hypothesis that **"radiative properties
of cirrus anvils are primarily controlled by the mass flux and vertical
velocities in associated cumulus convection."** This hypothesis will
provide a direct basis for the development of GCM parameterizations for
convective anvils. Section 7 outlines the unique characteristics of
tropical cirrus cloud systems, discusses the need for a focused
experimental program, and outlines a hierarchy of four experiments of
increasing complexity and demand on resources. These experiments include
a ground-satellite remote sensing experiment, an in situ
radiation-microphysics experiment, a non-precipitating anvil and cirrus
layer evolution experiment, and a convection-cirrus system experiment.
Section 8 outlines FIRE's collaborative participation in the Subsonic
Assessment: Contrail and Cloud Effects Special Study (SUCCESS),
conducted in Kansas, April - May, 1996, that will study the impact of
contrails and jet engine exhaust products on midlatitude cirrus. In
addition to specifying FIRE's contributions to SUCCESS, a number of
SUCCESS-funded instruments are identified that may have important roles
in future FIRE campaigns. Section 9 outlines FIRE's collaborative
participation in the Surface HEat Budget of the Arctic Ocean (SHEBA)
field experiment to be conducted in the Arctic ice domain, April 15 -
May 30, 1998. The FIRE cirrus component will focus on remote sensing of
ice and water clouds. Section 10 identifies additional complementary and
collaborative activities that FIRE is currently involved with or is
planning towards, such as with DOE ARM, Earth Observing System (EOS)
instruments (Moderate-resolution Imaging Spectrometer (MODIS),
Multi-angle Imaging Spectro-Radiometer (MISR), and Advanced Spaceborne
Thermal Emission and Reflection radiometer (ASTER)), NSF
Stratosphere-Troposphere Experiments: Radiation, Aerosols and Ozone
(STERAO), NASA Land Processes, Brazil Large-Scale Land Processes in the
Basin of the Amazon (LBA), EUCREX, and JACCS.

The plan also identifies a number of "Implementation Steps" for each of
the research strategies. These are listed at the ends of each section
(sections 4-10). The results of a survey soliciting participation from
the FIRE researchers in each of these implementation is given in
Appendix E.

Appendix A lists the references, B the acronyms, abbreviations, and
notations, C the FIRE-III organization and data management, and D the
individual research abstracts of the FIRE-III science team members

**3.0 NEW PLATFORMS AND INSTRUMENTATION**

Since FIRE II, a number of new advances in platform and instrumentation
have taken place. This has occurred, in part, through new aircraft
progress (e.g. SUCCESS, the ARM Unmanned aerospace vehicle (UAV)
program) and new satellite programs. Those relevant to the study of
cirrus clouds are summarized below.

**3.1 Aircraft**

The National Center for Atmospheric Research (NCAR) has recently
acquired the WB-57 high altitude aircraft. The ceiling of this aircraft
is approximately 20 km and it is able to penetrate most clouds (hard
convection excepted). The aircraft is also capable of carrying a payload
of about 910 kg. This aircraft clearly holds much promise for study of
upper tropospheric clouds; instrumentation packages are now under
development, although some of the packages planned for the WB-57 may be
\"borrowed\" from NASA\'s ER-2 or DC-8 making multiple aircraft missions
with common instrumentation somewhat problematic.

UAVs are now being used to study the atmosphere; leading efforts in
application of UAV\'s have come from the DOE ARM UAV program and the UAV
program of NASA. While high altitude UAVs have not yet carried science
payloads, flight of these aircraft to altitudes similar to the WB-57 is
imminent.

Recently the Strato 2C aircraft, designed and manufactured in Germany by
Burkhart Grob Lubt- und Raumfahrt Gmbh and Co., flew in some of its
early test flights. Although the early test flights were performed at
relatively low altitudes, this aircraft has been designed to perform
research missions at altitudes as high as 24 km with an endurance of 8
hours and carrying an 800 kg payload. Similarly the Strato 2C has an
endurance of 48 hours at 18 km altitude (payload 1000 kg). The
pressurized cabin accommodates 2 pilots and 2 mission scientists and has
an effective length of 5.5 meters and is 1.88 meters high. The aircraft
uses composite materials for a high strength to weight ratio and two
reverse mounted, compound engines; the term \"compound engine\" is used
to describe the combined 300 kW piston engine and the gas generator of a
2000 kW turboprop engine which serves as a turbocharger and provides
additional thrust. The Strato 2C should be very well suited for tropical
upper tropospheric cirrus research.

**3.2 Instruments**

Instrumentation development has advanced on a number of fronts. Table
3.1 summarizes the airborne instruments under development that have
potential application for cirrus cloud studies. Similar instruments are
listed for surface operations (table 3.2) and satellites (table 3.3).

Table 3.1 - Potential Airborne Instrumentation (Under Development**)**

+-----------------------+-----------------------+---------------------+
| **Instrument/**       | **Parameters**        | **Institution/**    |
|                       |                       |                     |
| **Platform**          |                       | **Investigators**   |
+-----------------------+-----------------------+---------------------+
| DIAL                  | Cirrus backscatter    | Langley             |
|                       |                       |                     |
| ER-2                  | water vapor profiles  | Browell             |
+-----------------------+-----------------------+---------------------+
| X-Band Doppler Radar  | Profiles of Z, IWC,   | NASA Goddard        |
|                       |                       |                     |
| ER-2                  | Air vertical velocity | Heymsfield          |
+-----------------------+-----------------------+---------------------+
| m-wave Radiometer     | water/ice profile     | GSFC                |
| (325 Ghz)             |                       |                     |
|                       |                       | Wang                |
| ER-2                  |                       |                     |
+-----------------------+-----------------------+---------------------+
| MISR Airborne         | TOA, cloud, and       | GSFC                |
| Simulator?            | surface reflectance   |                     |
|                       |                       |                     |
| ER -2                 |                       |                     |
+-----------------------+-----------------------+---------------------+
| SSFR                  | radiation             | ARC                 |
|                       |                       |                     |
| DC-8/ER-2             |                       | Pilewskie           |
+-----------------------+-----------------------+---------------------+
| 94 GHz Radar          | Profiles of Z, IWC    | JPL                 |
|                       |                       |                     |
| DC-8                  |                       | Li                  |
+-----------------------+-----------------------+---------------------+
| Submillimeter         | IWP, Particle size    | JPL, GSFC           |
| Radiometer            |                       |                     |
|                       |                       | Walks, Chang        |
| DC-8                  |                       |                     |
+-----------------------+-----------------------+---------------------+
| m-wave Radiometer     | water/ice profile     | JPL                 |
| (600 Ghz)             |                       |                     |
|                       |                       | Walters             |
| DC-8                  |                       |                     |
+-----------------------+-----------------------+---------------------+
| Lidar                 | cloud structure and   | NOAA ETL            |
|                       | profile               |                     |
| DC-8                  |                       | Eberhard            |
+-----------------------+-----------------------+---------------------+
| Ice Nuclei Counter    | Number concentration, | CSU                 |
|                       | species               |                     |
| DC-8                  |                       | Kreidenweis         |
+-----------------------+-----------------------+---------------------+
| p-Nephelometer        | microphysics,         | SPEC, Inc.          |
|                       | scattering phase      |                     |
| DC-8                  | function              | Lawson              |
+-----------------------+-----------------------+---------------------+
| CVI                   | microphysics,         | NCAR                |
|                       | water/ice content     |                     |
| DC-8                  |                       | Twohy               |
+-----------------------+-----------------------+---------------------+
| CCN Spectra           | CCN spectra           | NCAR                |
|                       |                       |                     |
| DC-8                  |                       | Cooper              |
+-----------------------+-----------------------+---------------------+
| Diode Laser           | water vapor           | LaRC                |
| Hygrometer            |                       |                     |
|                       |                       | Sachse              |
| DC-8                  |                       |                     |
+-----------------------+-----------------------+---------------------+
| Cloudscope            | large particle        | DRI                 |
|                       | spectra               |                     |
| DC-8                  |                       | Hallett             |
+-----------------------+-----------------------+---------------------+
| Gerber Probe (g       | IWC, particle size    | Gerber Scientific   |
| Meter)                |                       |                     |
|                       |                       | Gerber              |
| DC-8/WB-57            |                       |                     |
+-----------------------+-----------------------+---------------------+
| Broad Band            | Broad band fluxes     | Scripps             |
| Radiometers           |                       |                     |
|                       |                       | Valero              |
| ER                    |                       |                     |
| -2/DC-8/WB-57/surface |                       |                     |
+-----------------------+-----------------------+---------------------+
| Spectral Polarimeter  | Optical depth,        | CSU                 |
|                       | particle size, shape  |                     |
| UAV                   | index                 | Stephens            |
+-----------------------+-----------------------+---------------------+
| m-Wavelength Radar    | Backscatter profiles  | LLNL                |
|                       |                       |                     |
| UAV                   |                       |                     |
+-----------------------+-----------------------+---------------------+
| Advanced AVHRR MPIR   | Optical properties    | Sandia              |
|                       |                       |                     |
| UAV                   |                       |                     |
+-----------------------+-----------------------+---------------------+
| FTIR, FTS             | Optical properties in | Harvard             |
|                       | IR at 1.4 mm and in A |                     |
| UAV                   | band, in-situ water   | Anderson            |
+-----------------------+-----------------------+---------------------+
| A Band Spectrometer   | Cirrus and aerosol    | CSIRO/CSU           |
|                       | optical properties    |                     |
| UAV/WB-57             |                       | O\'Brien/Stephens   |
+-----------------------+-----------------------+---------------------+
| MODIS /ASTER Airborne | Land/surface          | GSFC                |
| Simulator (MASTER)?   | characteristics       |                     |
|                       |                       |                     |
| C-130                 |                       |                     |
+-----------------------+-----------------------+---------------------+

Table 3.2 - Potential Surface Instrumentation

+-----------------------+-----------------------+-----------------------+
| **Instrument**        | **Parameters**        | **Institution/**      |
|                       |                       |                       |
|                       |                       | **Investigator**      |
+-----------------------+-----------------------+-----------------------+
| MFOV 2                | Equivalent size,      | CSU                   |
|                       | transmittance         |                       |
|                       |                       | Cox                   |
+-----------------------+-----------------------+-----------------------+
| AERI                  | Downwelling spectral  | U Wisconsin           |
|                       | radiance              |                       |
|                       |                       | S. Ackerman           |
+-----------------------+-----------------------+-----------------------+
| 35 Ghz radar          | Cloud structure and   | NOAA ETL              |
|                       | profile               |                       |
|                       |                       | Eberhard              |
+-----------------------+-----------------------+-----------------------+
| SPFR                  | Hemispherical         | ARC                   |
|                       | spectral flux         |                       |
|                       |                       | Pilewskie             |
+-----------------------+-----------------------+-----------------------+
| m -pulse lidar        | Cloud structure and   | GSFC                  |
|                       | profile               |                       |
|                       |                       | Spinhirne             |
+-----------------------+-----------------------+-----------------------+

**3.3 Satellites**

The latter part of the decade will witness the launch of a number of
satellites carrying research payloads. The Tropical Rain Monitoring
Mission (TRMM) and EOS AM-1 satellites will carry the Clouds and the
Earth's Radiant Energy System (CERES) instrument. The Advanced Earth
Observing Satellite (ADEOS) and the AM-1 platform will fly spectral
radiometers, the Global Imager (GLI) and MODIS, with channels well
suited to the detection of cirrus. ADEOS will also carry the
Polarization and Directionality of Earth Reflectances (POLDER) and
Interferometric Monitor of Greenhouse Gases (IMG) sensors. The European
ERS-1 satellite is flying an advanced version of the Along-Track
Scanning Radiometer (ATSR).

Table 3.3 - Potential Satellite Instrumentation

+--------------+-----------------+---------------------------+--------+
| *            | **In            | **Measurement**           | **     |
| *Satellite** | strumentation** |                           | Launch |
|              |                 |                           | Date** |
+--------------+-----------------+---------------------------+--------+
| ERS-1        | ATSR            | IR, NIR multi-angular     | 1994   |
+--------------+-----------------+---------------------------+--------+
| ADEOS        | POLDER, IMG     | Solar wavelengths,        | 1996+  |
|              |                 | multi-angular             |        |
| (Japanese)   |                 |                           |        |
|              |                 | polarization              |        |
+--------------+-----------------+---------------------------+--------+
| ADEOS 2      | GLI, POLDER,    | Spectral, high spatial    | 2000+  |
|              | AMSR            | resolution                |        |
+--------------+-----------------+---------------------------+--------+
| TRMM         | CERES, LIS, PR, | Precipitation water       | 1997   |
|              | TMI, VIRS       | content                   |        |
+--------------+-----------------+---------------------------+--------+
| EOS AM-1     | CERES           | Broadband SW, IR          | 1998   |
+--------------+-----------------+---------------------------+--------+
| EOS AM-1     | MODIS           | Spectral, high spatial    | 1998   |
|              |                 | resolution                |        |
+--------------+-----------------+---------------------------+--------+
| EOS AM-1     | ASTER           | Similar to Landsat with   | 1998   |
|              |                 | both solar and infrared   |        |
|              |                 | bands                     |        |
+--------------+-----------------+---------------------------+--------+
| EOS AM-1     | MISR            | Multi-angle,              | 1998   |
|              |                 | multi-spectral,           |        |
|              |                 | bi-directional            |        |
|              |                 | reflectance               |        |
+--------------+-----------------+---------------------------+--------+
| EOS PM-1     | CERES, MODIS    | See above                 | 2000   |
+--------------+-----------------+---------------------------+--------+
| EOS PM-1     | MIMR (Microwave | Water content             | 2000   |
|              | Imager)         |                           |        |
+--------------+-----------------+---------------------------+--------+
| EOS PM-1     | AIRS (Infrared  | Temperature and moisture  | 2000   |
|              | Spectrometer)   | soundings                 |        |
+--------------+-----------------+---------------------------+--------+
| EOS AM-2     | EOSP            | Spectral, multi-angle,    | 2000   |
|              |                 | high-precision            |        |
|              |                 | measurements of radiance  |        |
|              |                 | and polarization          |        |
+--------------+-----------------+---------------------------+--------+
| EOS ALT      | GLAS (Lidar)    | Cloud top height          | 2002   |
+--------------+-----------------+---------------------------+--------+

**4.0 CONTINUED EXPLOITATION OF EXISTING CIRRUS DATA SETS**

Funded FIRE‑III research projects that address the FIRE‑III science
objectives on upper tropospheric clouds by utilizing existing
observations of cirrus clouds (Cirrus‑I, Cirrus‑II, FIRE ETO,
FIRE/TOGA‑COARE, CEPEX, etc.) fall into five basic areas:

• GCM and parameterization evaluation and validation,

• characterization of cloud radiative properties and effects,

• characterization of cloud microphysical properties,

• case studies and modeling of cloud development,

• development, validation and application of satellite remote sensing of
cloud properties.

At the present time, the analysis of existing FIRE observations has
progressed into the stage where collaborative studies using combined
analysis of multiple data sets in comparison with theory/model‑based
approaches are the rule. To a great extent, analysis and modeling in
each basic area supports the efforts in the others resulting in greatly
added value.

**4.1 GCM and Parameterization Evaluation and Validation**

Studies in this area are crucial to the achievement of one of the
long‑standing central goals of FIRE, i.e., to improve our understanding
of the role of cirrus in the global climate system and to improve our
capabilities to realistically simulate this system. Two specific
approaches are implemented where each makes considerable use of the
extensive large‑scale observations of atmospheric state obtained during
FIRE Cirrus‑II, and to a lessor extent during FIRE Cirrus‑I and
FIRE/TOGA‑COARE, as well as the cirrus cloud observations themselves
from satellites, ground and airborne remote sensors, and in situ
measurements.

First, ISCCP data will be compared with simulations using the Goddard
Institute for Space Science (GISS) GCM and Geophysics Fluid Dynamics
Laboratory (GFDL) Skyhi models to define regions of GCMs deficiencies in
cirrus properties and FIRE data will be used to explore the reasons for
the discrepancies. Synoptic conditions giving rise to cirrus formation
during FIRE Cirrus‑I and FIRE Cirrus‑II will be compared to those
generating cirrus in the GISS GCMs to understand the GCM\'s tendency to
over predict the altitude of cirrus formation. Simulated radiative
properties of midlatitude and tropical cirrus will also be compared and
validated against observations from Cirrus‑I, Cirrus‑II, TOGA‑COARE and
CEPEX. The distributions of cloud top/base pressure, optical thickness,
and particle size will be examined.

Second, diagnostics derived from wind profiler and radiosonde
observations, obtained during FIRE Cirrus‑II, will be used as input
parameters to drive a suite of GCM cloud parameterizations as in Mace et
al. (1995). A verification data set, derived from the FIRE Cirrus‑II
ground‑based and satellite observations, is being created for comparison
with the parameterization output. An extensive analysis of the
relationship between large‑scale forcing (meteorological conditions) and
cirrus formation and maintenance will be undertaken. To extend the
results from midlatitude cirrus to other geographical regions, data
collected during TOGA COARE, under the sponsorship of NASA and DOE, will
be examined in considerable detail in order to quantify the importance
of tropical cirrus to the local radiative energy budgets and identify
similarities and differences between tropical cirrus and their
midlatitude counterparts.

**4.2 Characterization of Cloud Radiative Properties and Effects**

One of the key areas of scientific investigation identified in the
FIRE‑III Research Plan is the characterization of the fundamental
radiative properties of cirrus clouds, specifically the scattering phase
functions, asymmetry parameters and optical extinction parameters, in
relationship to cloud microphysical properties. While a significant
effort will be made in FIRE‑III to develop and/or refine suitable new
instrumentation and to obtain appropriate measurements of these very
difficult to observe parameters, continued analysis of the existing
measurements will provide improvements in our knowledge of bulk cloud
radiative properties, that are useful for characterizing cloud radiative
effects, as well as supporting the development of new theories for
characterizing the more fundamental radiative properties, and new
techniques for retrieving cloud microphysical properties from
satellites.

In terms of bulk cloud radiative properties, continued analysis of
existing FIRE observations will be used to improve parameterizations of
longwave and shortwave radiative effects of cirrus based on
probabilities of cloud free lines of sight and the stochastic treatment
of cloud optical properties, respectively. In addition,
satellite-derived cloud radiative properties will be used to estimate
tropospheric heating and cooling caused by radiative processes,
including changes in radiative processes associated with the seasonal
cycle and with weather systems both in middle latitudes and in the
tropics where semi‑transparent cirrus clouds are the most numerous and
have the largest impact on the heat budget of the Earth.

Analysis of FIRE Cirrus‑II observations, both radiative and
microphysical, will be used to support development of unified theories
for light scattering by realistically‑shaped ice crystals using the
geometric ray‑tracing technique (Takano and Liou, 1995), the new
T‑matrix method (Mishchenko et al., 1996) and other techniques enabling
fast calculations of scattering by non‑spherical particles both in the
solar and infrared spectral regions over all size parameters in
extensive media comprised of gases and particles. Development of such
models is integral to the improvement of remote sensing techniques and
algorithms. Moreover, the results will be used in sophisticated
radiative transfer model calculations, including account of ice
scattering and absorption from the visible to the thermal infrared, to
assess the effects of cloud inhomogeneities on the results derived from
remote sensing algorithms which will then be compared to existing FIRE
observations. Effects of cloud inhomogeneity is a key unresolved issue
for FIRE‑III.

In support of the above line of research, a strong effort will be made
to characterize the angular distribution of reflected radiation derived
from Tilt Scan Coupled Charge Device (CCD) Camera observations obtained
during FIRE Cirrus‑II and FIRE/TOGA‑COARE. This instrument provides
observations of cloud bi‑directional reflectance, a critical parameter
involved in the reduction of satellite observations and a direct
manifestation of the integral effect of the scattering phase function.

**4.3 Characterization of Cloud Microphysical Properties**

Cirrus cloud microphysical properties provide the physical linkage
between, on the one hand, remote sensing and cloud radiative properties
and radiative effects, and, on the other hand, cloud formation, water
processing and atmospheric dynamics. As such, characterization of cloud
microphysical properties is a fundamental requirement for each of the
other basic research areas described herein. Further analysis,
emphasizing statistical summarization (means and variability) delineated
by cloud type and location within the cloud, will be made of the
mid‑latitude observations obtained during FIRE Cirrus‑II and the
tropical observations obtained during TOGA‑COARE and CEPEX. In addition
to directly supporting studies of cloud radiative properties and remote
sensing studies, these results will be used to develop and evaluate
conceptual models of cirrus cloud formation, to evaluate numerical
models (parcel models, LES models and GCM parameterizations) of cirrus
clouds, and be incorporated into multi‑sensor/multi‑parameter analysis
of individual observed cases of cirrus cloud development. As such,
continued analysis of the microphysical observations is a pivotal
element in developing an understanding of how cirrus clouds work, both
in mid‑latitude and in the tropics.

In terms of remote sensing, the results of analysis of the microphysical
observations will be used to advance and improve techniques for remotely
inferring cloud microphysical properties, including cloud ice water
content using passive high‑frequency microwave observations from
TOGA‑COARE, particle size and ice water content distributions from joint
analysis of ground‑based short wavelength radar and passive radiometer
observations from FIRE Cirrus‑II following Matrosov et al. (1992), and
techniques using existing satellite observations in the solar and
infrared spectral regions (Young et al., 1994 and Minnis et al., 1995).

The analysis of microphysical observations will also be used to further
define the observational requirements (in situ and remote sensing
instrumentation and observing strategies) for future field experiments
and to define the fundamental humidity conditions required for ice
nucleation in cirrus, especially with respect to indicating the relative
contributions of the homogeneous versus heterogeneous ice nucleation
processes. Resolution of the latter issue is central to assessment of
the potential global impact of anthropogenic (e.g., aircraft emissions)
and volcanic impacts on global climate through aerosol effects on
cirrus.

**4.4 Case Studies and Modeling of Cloud Development**

Integrated multi‑sensor/multi‑parameter analysis will be made of
additional cases from FIRE Cirrus‑II and FIRE/TOGA‑COARE. These studies
combine data spanning a wide range of scales from synoptic rawinsonde
observations to mesoscale profiler and aircraft measurements to the very
high resolution observations obtained by remote and in situ sensors into
a comprehensive description. These studies seek to define the
relationship between resolved dynamical processes and cloud physical
development and microphysical properties. Cirrus‑II cases of particular
interest that have not as yet been analyzed in detail include the
subtropical jet stream cases and a well‑observed case of a large, fairly
homogeneous appearing cirrus system. Though not nearly as comprehensive,
analysis of TOGA‑COARE and CEPEX cases will be used to explore the
workings of tropical cirrus systems.

Analysis of high‑resolution cloud model simulations will also be used to
develop improved understanding of the interaction of dynamical,
radiative and microphysical processes in cirrus clouds in both the
middle latitudes, as observed during FIRE Cirrus‑II, and also for the
tropical situations observed during TOGA‑COARE and CEPEX. In conjunction
with the case study analyses and observations, these studies will
provide the understanding needed to further develop improved GCM cirrus
cloud parameterizations and to define the issues and strategies for any
future tropical observing campaign.

A significant new focus for FIRE‑III is the emerging plan for
utilization of the extensive and high quality FIRE Cirrus‑II data sets
and analysis products in the systematic intercomparison of a broad range
of cirrus cloud models under the auspices of the GEWEX Cloud System
Studies (GCSS) Project Working Group on Cirrus Clouds (WG-2). While this
WG-2 activity is presently at the initial planning stage, the plan is to
follow the lead of GCSS WG-1 where FIRE Stratus and FIRE Atlantic
Stratocumulus Transition Experiment (ASTEX) data sets have played a
pivotal role in the organized intercomparison of models of stratus cloud
development. To date, the WG-1 intercomparisons have proven very
worthwhile to the participants and have resulted in significant gains in
understanding model performance, in the context of model
content/approach, versus the observations, a very necessary ingredient
for the improvement of models. The GCSS working groups are highly
international and encompass a much larger community than the FIRE
Science Team. The international cirrus modeling community has now
developed the sophistication and breadth required for a systematic
intercomparison project to be truly fruitful. At the same time, the FIRE
Cirrus‑II data sets and analysis products, both completed and still in
progress, uniquely provide the necessary observational basis for such an
effort. It is expected that these activities will constitute a major
contribution in advancing understanding of cirrus cloud processes and
defining issues and observational requirements during FIRE‑III. These
activities represent an integral step toward realization of the goal of
development and validation of suitable realistic GCM cloud
parameterizations.

**4.5 Development, Validation, and Application of Satellite Remote
Sensing of Cloud Properties**

Further analysis of FIRE‑II observations will be used to support
improvement and validation of techniques for remote sensing of cirrus
cloud properties from existing satellite observations, including the
ISCCP products. Remote sensing techniques are increasingly incorporating
recent and developing theoretical results on the scattering properties
of ice crystals (e.g., Minnis et al., 1993). The traditional retrieved
cloud properties include cloud optical depth, visible albedo, and
infrared emittance as well as cloud altitude. In addition, new
experimental retrievals of particle size and type (shape) and ice water
path are now being made. FIRE‑II observations offer a unique testbed for
evaluating these methods. Of particular importance are the \"ground
truth\" measurements of cloud altitude provided by active sensing
systems, that have been a cornerstone of FIRE including the ETO
observations, as well as the wealth of coincident in situ microphysical
observations obtained during FIRE Cirrus‑II and to a lessor extent
during TOGA‑COARE and CEPEX. It is expected that, as the results of
theoretical studies (Monte Carlo calculations) and analysis (Landsat) on
the effects of cirrus cloud inhomogeneity become available, they will
also be incorporated into the algorithms for application to FIRE‑II
data.

Besides the analysis of the results from the emerging techniques and
their integration into each of the other areas described here, such as
the case studies, special emphasis will be made on resolving differences
between various cloud systems, particularly between mid‑latitude and
tropical cirrus systems, in terms of the cloud microphysical and
radiative properties.

FIRE observations and analysis continue to provide strong support for
algorithm development and validation for EOS, especially products to be
derived from MODIS, MISR, and EOSP (Earth Observing Scanning
Polarimeter). Analysis of FIRE‑II observations will also continue to
specifically focus on ISCCP validation and application (e.g., Mishchenko
et al., 1995), including comparative global and inter‑regional studies.

**4.6 IMPLEMENTATION STEPS:**

In order to assure continued progress in the analysis and application of
previously collected FIRE data sets, two FST members will have the
responsibility for each of the following topics to coordinate
multi-investigator participation and to report on progress.

• GCM and parameterization evaluation and validation,

• characterization of cloud radiative properties and effects,

• characterization of cloud microphysical properties,

• case studies and modeling of cloud development,

• development, validation and application of satellite remote sensing of
cloud properties.

The FIRE project office should support the logistics of
multi-investigator participation pursing the above goals.

**5.0 REMOTE SENSING FOR FIRE III UPPER TROPOSPHERIC CLOUD RESEARCH**

Remote sensing plays an important role in quantifying the properties of
clouds over small, medium, and large spatial (0.001 ‑ 10 ‑ 1000 km) and
temporal scales (1 sec ‑ 15 min ‑ decades). Methods for deriving cloud
radiative and physical parameters from radiances ‑‑ measured by active
and passive sensors on the ground, on aircraft, and on satellites ‑‑ are
under continual development as new instruments and data sets become
available. Past FIRE data have played a critical role in advancing the
science of cloud remote sensing (Randall et al., 1995) and the
validation and improvement of the ISCCP global cloud products (Rossow et
al., 1993). Conversely, the remotely sensed cloud properties from FIRE
have been major contributors to better understanding of cloud processes
and to the validation and interpretation of meso‑ and synoptic scale
atmospheric circulation models, (Soden and Donner, 1994). This dual role
for remote sensing algorithms, as users of FIRE products for validation
and development and as providers of datasets for understanding clouds
and for model validation and interpretation, will continue during the
FIRE III period. The FIRE III scientific objectives will be addressed in
the remote sensing realm by implementing the following strategies:

> • analysis and development using currently available datasets;
>
> • theoretical sensitivity studies using new models of cloud particle
> size, shape, and vertical and horizontal distributions;
>
> • the execution of a limited midlatitude experiment focused primarily
> on contrails and cirrus over land, execution of other limited field
> experiments;
>
> • and the design and execution of a more extensive tropical upper
> tropospheric cloud experiment.

Remote sensing investigations during FIRE III focus on several areas,
such as validation, cloud process studies, and diagnostic analyses.
These endeavors frequently require collaboration with other FIRE
investigations.

In the validation area, the heterogeneous characteristics of available
and future instrumentation preclude a straightforward comparison of
different measurements. Rather a statistical comparison is required to
account for different sampling of smaller space and time scales. The
primary strategy is to use the in situ, higher resolution aircraft
measurements to validate the larger datasets that can be acquired from
surface remote sensing instruments. These larger datasets can then be
used to validate the satellite retrievals. Thus, a subset of the FIRE
team must conduct investigations that integrate a comprehensive
collection of coincident observations from aircraft, the surface and
satellites, where similar or \"identical\" quantities are retrieved, to
determine how well cloud properties can be determined from satellites
alone. Some examples of this type of study are Nakajima et al., (1991),
Wielicki et al., (1990), Minnis et al., (1990, 1992, 1993), Wylie
(1989), Rossow and Garder (1993a) and Han et al., (1994, 1995c), where
statistical comparisons are made between satellite and surface and/or
aircraft observations. Cloud process studies and circulation model
validations use a variety of remote sensing data for both evaluation and
understanding of the phenomena. Close collaboration between the modeling
and remote sensing investigators is important to ensure that the data
are provided in the most usable format. The collaborative approach were
quite successful during earlier FIRE studies (e.g., Wang et al., 1993;
Mace et al., 1995; Martin et al., 1995). Joint validation and process
efforts such as these will continue during FIRE III.

Measurements of the properties of clouds, surface and atmosphere allow
one to infer radiative fluxes, in principle. Several such analyses have
been done for the surface radiation (Darnell et al., 1992; Whitlock et
al., 1995; Rossow and Zhang, 1995) and for top‑of‑atmosphere (Rossow and
Zhang, 1995), but these calculations are much more detailed than
available validating datasets with the exception of top‑of‑atmosphere
fluxes that can be compared with NIMBUS‑7 Earth Radiation Budget (ERB)
and Earth Radiation Budget Experiment (ERBE) values. These calculations
can also be extended to heating/cooling profiles, if enough information
about cloud layer structure can be obtained. Aside from continued work
on reducing the uncertainties in how ice clouds are to be represented in
radiative transfer models, diagnostic studies are possible where
measured physical variables are used to calculate flux profiles that are
compared with observations of fluxes from the same aircraft or from
coordinated aircraft. The most important quantities in terms of
uncertainties are ice water content, particle size‑shape distributions
(shortwave mostly), and small‑scale vertical ‑ horizontal structures.
Some FIRE III studies will implement improved cloud and surface
retrievals and compare the calculated fluxes with available surface and
in situ measurements of spectral and broadband fluxes. Such tasks
require systematic analyses of the observations from as many instruments
over the whole time period as possible, rather than limited case‑study
analyses.

Other diagnostic efforts for FIRE III include cloud formation/decay
processes. Direct diagnosis requires measurements that resolve the
relevant space‑time scales of atmospheric motions and variations in
water, including phase changes and transports from lower altitudes. Such
a direct approach may not be entirely feasible at this time, so such
studies should be complemented by an indirect approach that examines
statistical variations of clouds, water vapor and atmospheric dynamics
on larger scales. Modeling studies will apply this approach with
information derived from satellite retrievals. Satellites are the best
tool for developing larger‑scale information, but more diagnostic
analyses are needed to obtain information about cloud processes.

**5.1. Continued analysis with datasets prior to FIRE III field
campaigns**

**5.1.1 Ground‑based and airborne sensors**

Datasets taken by ground‑based lidars, radars, and radiometers will be
analyzed further to examine the vertical and horizontal distributions of
ice and liquid water particle sizes and mass content and their radiative
effects. These datasets will also be used for satellite algorithm
verification and to address the differences between tropical midlatitude
cirrus clouds. Table 5.1 lists the FIRE III researchers who will be
providing information based on surface remote sensing instruments. Table
5.2 lists the FIRE III researchers who will be providing information
based on airborne remote sensing instruments. Table 5.3 delineates the
properties that can be derived from these measurements. Table 5.4
identifies satellite remote sensing thrusts.

Table 5.1. Surface remote sensing investigations for pre‑FIRE‑III

  ----------------- ------------------------------- ----------------------
  **Researchers**   **Instruments**                 **Data Sets**

  T. Ackerman       surface radar, lidar, microwave FIRE II Cirrus,
                    and flux radiometers            TOGA/COARE, ARM,
                                                    PSUCS\*

  Cox               lidar, IR interferometer, IR    FIRE II, ASTEX
                    radiometer, flux radiometers,   
                    wind profiler, rawinsonde       

  Sassen            surface polarization lidar,     FIRE ETO (Utah), FIRE
                    flux radiometers, scanning PDL, ‑I, II Cirrus
                    and 95 GHz polarimetric Doppler 
                    radar                           

  Uttal             surface radar, lidar, IR        FIRE‑II Cirrus, ASTEX,
                    radiometer                      DOE Pacific Cruise,
                                                    NOAA Arizona
                                                    Experiment
  ----------------- ------------------------------- ----------------------

\* Penn State University Continental Stratus

Table 5.2 Airborne remote sensing investigations for pre‑FIRE‑III

  ----------------- ------------------------------- ----------------------
  **Researchers**   **Instruments**                 **Data Sets**

  Sassen            airborne lidar                  TOGA/COARE

  Spinhirne         Airborne lidars, Tilt‑Scan      FIRE‑I and -II Cirrus,
                    Camera, microwave and flux      TOGA/COARE
                    radiometers, IR radiometer      

  Tsay              ER‑2 MAS                        SCAR‑B
  ----------------- ------------------------------- ----------------------

These investigators will perform validations of their derived parameters
through comparisons with in situ data, other sensors, and satellite
data. For example, vertical distributions of cloud phase, particle size,
and water content from radar measurements need in situ profiles of
similar quantities for verification. Integration of these quantities
should match liquid water path retrievals from microwave radiometers.
Thus, it is critical that all of the in situ measurements for the
experiments in Table 5.1 are analyzed as soon as possible. Initial
comparisons between lidar and radar cloud boundaries have already shown
some differences between the two types of measurements, apparently due
to the different particle size dependencies in the instruments-
operating spectral regimes. Airborne lidar and aircraft and satellite
thermal radiances provide a check for surface‑derived cloud‑top
altitudes in optically thick clouds. Radar, lidar, and microwave
radiometers provide verifications of aircraft‑derived phase, particle
size, and water path. Sunphotometers and interferometers are used to
validate optical depths determined from lidars in thin clouds.

With better quantification of the uncertainties in the surface and
air‑based remote sensing products, it will be possible to obtain more
reliable determinations of the distributions of ice mass in the upper
troposphere, of the radiative and microphysical properties of upper
tropospheric clouds and how they relate to each other. The measurements
taken in most of the experiments in Table 5.2 can be used to develop a
very representative statistical base for characterizing mid‑latitude
clouds. Radar, lidar, and MODIS Airborne Simulator (MAS) data obtained
during TOGA-COARE, CEPEX, and the upcoming DOE/NOAA cruise will provide
an initial database for characterizing micro physical, radiative
properties and spatial variability of tropical cirrus clouds. Because
the methods for deriving cloud base and top from radars and lidars are
relatively mature, the structural differences between tropical and
midlatitude cirrus can be examined in some detail. Although techniques
for determining ice mass and ice crystal size distributions are still
evolving, it is important to extract as much information as possible on
these quantities from the radar and lidar datasets.

Table 5.3. Cloud properties derived from surface and aircraft remote
sensing instruments

  ---------------- ------------------------------------------------------
  **Cloud          **Instruments**
  Parameter**      

  amount           surface radar, lidar; airborne lidar, MAS

  top altitude     surface lidar, scanning PDL, and 95 GHz radar;
                   airborne lidar

  base altitude    surface lidar, scanning PDL, and 95 GHz radar,
                   ceilometer; airborne lidar

  optical depth    surface lidar, sunphotometer; airborne lidar, MAS

  phase            surface radar, polarization lidar; airborne lidar, MAS

  albedo,          surface solar flux radiometers; airborne surface solar
  reflectance,     flux radiometers, Tilt Scan camera, MAS
  transmission     

  emissivity       surface IR radiometer, IR interferometer, flux
                   radiometer; airborne MAS, IR radiometer, IR
                   interferometer

  liquid water     surface radar, microwave radiometer
  path             

  ice water path   surface radar with IR radiometer or CO2 lidar

  horizontal       surface PDL, lidar, radars
  structure        

  vertical         surface lidars, radars; airborne lidars
  structure        
  ---------------- ------------------------------------------------------

**5.1.2 Theoretical studies**

The key uncertainties in the representation of clouds in radiative
transfer models are three: treatment of ice phase clouds, treatment of
small‑scale horizontal inhomogeneity, and treatment of cloud vertical
structure, particularly phase and particle size changes. Investigations
addressing these issues are summarized in Table 5.3. New ice crystal
models will be developed for use in satellite retrieval algorithms.
Theoretical limitations to retrieval methods will be determined and
combinations of remote sensing data and radiative transfer models will
be used to develop methods for understanding and accounting for vertical
and horizontal inhomogeneities in cloud structure.

The results of the theoretical scattering studies will be tested by some
FIRE III laboratory measurements and airborne nephelometer and g‑meter
measurements as well as by aircraft and satellite multiangle reflectance
and polarization data. Studies of new methods for treating vertical and
horizontal inhomogeneities will rely on radar, lidar, and satellite
radiances and polarization for verification.

Table 5.3. Theoretical studies for remote sensing applications

  ------------------- ---------------------------------------------------
  **Researcher**      **Thrust of Theoretical Research**

  Han and Welch       Inclusion of effective variance with effective size
                      in particle size retrievals

  Liou                Unified theory and methods for computing light
                      scattering properties of ice crystals

  Minnis              Sensitivity of effective particle size to vertical
                      distribution of particle size and shape; emittance
                      and reflectance parameterization; angular
                      sensitivity of derived sizes

  Mishchenko          T‑matrix and ray tracing methods for computing
                      scattering and absorption in ice clouds; test
                      renormalization method for retrieval of cloud
                      inhomogeneities

  Wielicki and Cox    Horizontal inhomogeneities in clouds using models
                      and archive data
  ------------------- ---------------------------------------------------

**5.1.3 Satellite analyses**

Comparisons of satellite analyses with surface and aircraft measurements
taken during FIRE I and II, ASTEX, TOGA/COARE, and CEPEX are being
completed to determine the state of the art for satellite cloud remote
sensing. Additional studies using these same datasets will the lay the
foundation for improved methods that can be tested using measurements
taken during FIRE III field programs. The improved methods will be
applied to large‑area, long‑term satellite data to provide climatologies
for answering the planning needs of FIRE III and for addressing some of
FIRE\'s main objectives. The FIRE III researchers participating in the
analysis of pre‑FIRE satellite data for upper tropospheric clouds are
given in Table 5.4 with the focus of their research.

Table 5.4. Satellite remote sensing studies for pre‑FIRE III datasets

  ---------------- ---------------------------------- --------------------
  **Researcher**   **Satellite or Instrument Data**   **Thrust**

  Han and Welch    AVHRR, ISCCP                       climatology,
                                                      validation

  Liou             AVHRR                              model validation

  Minnis           GOES Imager, AVHRR, SSM/I, SAGE I  climatology,
                   and II, GMS, Meteosat, LITE        validation,
                                                      algorithm
                                                      development

  Mishchenko       ISCCP                              model validation

  Rossow           ISCCP                              climatology,
                                                      validation

  Wielicki         Landsat, LITE                      spatial scales,
                                                      optical properties

  Wylie            HIRS, GOES Sounder                 climatology
  ---------------- ---------------------------------- --------------------

Satellite measurements of temperature and humidity profiles (by NOAA
TIROS Operational Vertical Sounder (TOVS) products) and cloud properties
(cover, top temperature and height, optical thickness by ISCCP, Rossow
and Schiffer, 1991) are routine products, but the accuracy of humidity
profiles and cloud properties in the upper troposphere need more work.
Results from earlier FIRE observations have already been used to improve
the ISCCP retrieval method for ice phase clouds (Minnis et al 1993) and
comparisons with Stratospheric Aerosol and Gas Experiment (SAGE) (Liao
et al 1995a, 1995b) and HIRS determinations not only quantify the
systematic errors in the ISCCP results but also provide, when combined
with ISCCP, a good first survey of cirrus occurrence. Methods for
retrieval of liquid water cloud, particle sizes (Han et al., 1994, Young
et al., 1994) and liquid water path over open water (Greenwald et al.,
1993; Liu and Curry, 1994; Lin and Rossow, 1994) are well‑developed, but
ideas for retrieving the same properties for ice phase clouds (Minnis et
al., 1994; Lin and Rossow, 1994) need more thorough testing. Several
investigations focus on improving these retrievals and validating them
with available pre‑FIRE III datasets. A key analysis concept that may
improve analyses of upper tropospheric clouds is to analyze observations
from many different instruments. In particular, the combination of
multi‑channel optical and microwave imagers and infrared and microwave
profilers has been suggested by some work, e.g. (Baum et al., 1992; Baum
et al., 1994) but is not fully developed. Several FIRE III
investigations focus on this possibility. Successful developments in
this case will provide the first comparisons of the properties of
upper‑level clouds between polar, midlatitude and tropical regions and
an assessment of their seasonal variations. The primary obstacle to
progress is lack of complete enough observations for validation of the
retrieval methods.

Multi-angle spectral measurements of polarization as well as radiance
will be provided by POLDER on ADEOS and EOSP on EOS AM-2. It has been
demonstrated that polarimetry is a promising remote sensing technique
for retrieving cloud and aerosol characteristics such as optical
thickness, cloud top altitude, and particle phase and size (e.g., Goloub
et al., 1994; Mishchenko et al., 1996). Additional studies are necessary
to further develop and validate polarization retrieval algorithms and to
examine the sensitivity of the retrieved characteristics to measurement
accuracy.

Validations of the satellite retrievals will use both direct and
indirect methods. Direct comparisons with in situ data will be exploited
whenever possible using appropriate statistical methods to account for
spatial and temporal sampling characteristics. Cloud fraction, top and
base altitudes, emissivity, albedo, liquid water path, ice water path,
and optical depth will be evaluated through direct comparisons with the
results from the measuring instrument in many cases. Other techniques
such as multiangle views from various platforms will be used to test
limitations and uncertainties in retrievals of several parameters such
as cloud amount, effective particle size, and optical depth.

Combined remote sensing datasets will be developed to improve the
retrieval of quantities such as ice and water paths, cloud thickness and
base, and cloud overlap. Considerable effort will be used to devise new
techniques for estimating these parameters and for determining the cloud
properties in multilayer and mixed phase conditions.

Datasets consisting of validated retrievals will be developed at time
and space resolutions desired by FIRE III modeling investigators for use
in diagnostic and cloud process studies. Such datasets will primarily be
focused on the field programs, but may include longer time periods. The
application of the retrieval algorithms to large time and space datasets
will provide some direction for a later tropical cirrus campaign and a
large‑scale evaluation of differences between tropical and midlatitude
cirrus clouds. Other more detailed satellite analyses will provide
additional insight in latitudinal cirrus variations.

FIRE III encourages the use of additional satellite instruments to
address the FIRE III upper tropospheric cloud issues. The only satellite
instruments that have been extensively used to study upper‑level
cloudiness are the imaging radiometers and infrared sounders on the
polar orbiting and geostationary weather satellites. The Along-Track
Scanning Radiometer (ATSR) sensor is a different type of imaging
radiometer in that it provides multi‑angle measurements, but these data
have not been released. For many years, several passive microwave
instruments have been making measurements that, together with the
imagers and sounders, might be analyzed together to increase retrieved
information. The microwave instruments may not sense the clouds
themselves, but they can help separate upper‑level ice clouds from
lower‑level liquid water clouds and improve cloud‑clear discrimination
in complicated situations. One or two preliminary studies like this have
been done with the Special Sensor Microwave/Imager (SSM/I) (Liu and
Curry, 1994; Lin and Rossow, 1994), but SSM/T and the new SSM/T2 have
not been used before.

**5.2 IMPLEMENTATION STEPS:**

• Design and conduct investigations that integrate a comprehensive
collection of coincident observations from aircraft, the surface and
satellites where similar or \"identical\" quantities are retrieved.

• Maintain close collaboration between modeling and remote sensing
investigators to insure maximum utilization of remote sensing data.

• Seek to establish how ice clouds may be most effectively and
efficiently represented in radiative transfer models. Specifically:

• small scale horizontal inhomogeneity

• cloud vertical structure

• phase and particle size/shape changes

• Provide validated retrievals of ice cloud and environmental parameters
to FIRE III modeling investigators for use in diagnostic and cloud
process studies.

• Explore the application of additional satellite data such as ATSR and
passive microwave radiometry to upper tropospheric cloud issues.

• Conduct studies which examine the statistical variability of clouds,
water vapor and atmospheric dynamics on larger scales in the tropics.

**6.0 GCMS AND FIRE III**

Mesoscale anvil clouds are emerging as one of the key unknowns in the
assessment of the tropical equilibrium energy budget and its
fluctuations on interannual and longer time scales. Unlike optically
thin cirrus, cumulus anvils have a substantial shortwave as well as
longwave impact, and so the sign of feedbacks due to changes in these
clouds is far from obvious. Unlike the deep convective clouds with which
they are associated, anvils occupy a sufficiently large area of the
tropics to affect the planetary radiation balance. Because of their
large physical thickness relative to other cirrus, the vertical
structure of their microphysical characteristics and resulting radiative
flux profiles may be complex and thus are not easily determined by
remote sensing alone.

It has been proposed that tropical sea surface temperatures (SSTs) in
the current climate are limited by shortwave reflection from
convectively generated anvils (Ramanathan and Collins, 1991), although
the importance of this mechanism to seasonal and interannual variations
of SST is a subject of controversy (Wallace, 1992; Fu et al., 1992;
Hartmann and Michelsen, 1993; Fu et al., 1994; Liu et al., 1994).
Idealized climate‑change simulations with some general circulation
models (GCMs) have further demonstrated that changes in cumulus anvil
radiative properties can significantly alter the global climate
sensitivity, depending on the nature of the interaction between the
convection, the underlying SST, and the tropical general circulation
(Del Genio, 1995).

Compared to the relatively thin cirrus observed during the FIRE‑I and
FIRE‑II field campaigns, cumulus anvils have significantly higher ice
water contents (Churchill and Houze, 1984) in addition to being
physically thicker and are therefore optically thicker. Furthermore,
anvils are subject to qualitatively different dynamical forcing than are
other cirrus: mesoscale updrafts, driven in part by condensation and
radiative heating within the anvil, control their radiative properties,
while the midlatitude cirrus of FIRE‑I and ‑II were controlled instead
by synoptic‑scale dynamical phenomena driven by unrelated energy
sources. Finally, unlike their thin cirrus counterparts, cumulus anvils
have an important external source of cloud water and ice, in the form of
condensate detrained from adjacent or embedded cumulus updrafts (Gamache
and Houze, 1983; Heymsfield and Platt, 1984; Churchill and Houze, 1984;
Heymsfield and Miloshevitch, 1995). Hence, it is unlikely that the
microphysical and radiative properties of cirrus observed by FIRE‑I and
‑II can simply by extrapolated to higher ice water contents to
characterize the properties of anvil clouds, and it would be dangerous
for cloud parameterizations in numerical models to assume that such
extrapolations are sufficient to deal with the problem. Because of these
distinctions, we must observe both the anvil microphysical and radiative
properties, and the dynamical environment in which they are created and
then dissipate, to understand how they differ form other high clouds.

Observational studies (Leary and Houze, 1980), along with
cloud‑system‑resolving models (Sui et al., 1994; Cotton et al., 1995)
and new developments in cumulus parameterizations for GCMs (Donner,
1993a), suggest a general hypothesis regarding the radiative properties
of anvils. **The hypothesis is: The radiative properties of cirrus
anvils are primarily controlled by the mass fluxes and vertical
velocities in associated cumulus convection.** This hypothesis is
consistent with highly active dynamics in the mesoscale precipitating
and non‑precipitating cloudiness associated with the convection. While
these constitute the primary controls, other factors, such as mesoscale
ascending motions slant wise in stratiform anvils, thermal
stratification and moisture characteristics in the volume where the
anvil forms, also play roles. Since ice can be transported great
distances under some circumstances, even cirrus clouds which appear to
be detached from convection are likely to require an understanding of
the convective anvils treated by this hypothesis, since these anvils are
the ultimate source for much of the water vapor and ice for the detached
cirrus. However, the large-scale environment, such as humidity and
vertical motion, also affect the characteristics of cirrus anvils.

We propose that a FIRE tropical cirrus experiment be designed to test
this hypothesis. In the process of doing so, an unprecedented
characterization of convective anvils and their sources and sinks will
be obtained. This hypothesis provides a direct basis for the development
of GCM parameterizations for convective anvils (Donner, 1993b). These
anvil parameterizations require both cumulus parameterizations and
treatment of ice advection and microphysics as well as vertical
velocities. Some basic elements of this hypothesis have been tested in
the cumulus parameterization at the European Centre for Medium‑Range
Weather Forecasts (Christian Jakob, personal communication), and there
are plans to use the Donner (1993a, b) parameterization in a GFDL GCM
shortly.

The basis for the convection/cirrus hypothesis lies in observational
studies which show substantial phase changes and water transport at the
scale of both cumulus cells and mesoscale cirrus anvils. These studies
also indicate substantial transport of water from the cumulus cells to
the anvils. Since this water transport includes both condensate and
vapor, in situ condensation within the anvil controlled by vertical
motions therein plays a critical role in determining its microphysical
and radiative properties. These results have also been obtained with
cloud‑system‑resolving models. The keys to quantifying the water
transport from the cumulus cells to the anvils are the mass transport in
the cumulus convection and the microphysical characteristics of the
water transported in the cumulus cells. The latter can be inferred from
microphysical theory, but the vertical velocities at cumulus scale are
required to do so. Mesoscale ascending motions play a key role in
determining in situ condensation and deposition.

Earlier cumulus parameterizations have been somewhat successful in
producing diagnosed large‑scale heat sources and moisture sinks (which
represent the sum of phase changes and eddy transports) without
including mesoscale anvils, but this may have been a result of
substituting excessive cell scale activity for the absent mesoscale
activity. Although the consequences may have been limited with respect
to heat sources and moisture sinks, this is not true for radiative
forcing associated with cirrus anvils. Treatment of the latter problem
will require parameterizations that treat the transport of water vapor
and condensate at the cell scale accurately. This will be true whether
the anvils are parameterized as subgrid phenomena in coarse‑resolution
GCMs or the anvils are calculated using prognostic microphysical
equations in very‑high‑resolution GCMs.

To test the convection/cirrus hypothesis, simultaneous characterization
of several statistical properties of deep cells and cirrus properties is
required. To characterize deep cumulus cells, information on cell scale
mass fluxes, vertical‑velocity distributions, liquid and ice contents,
turbulent kinetic energy, precipitation fluxes, and particle sizes is
required. For the mesoscale anvils, information on mass fluxes, vertical
velocities, ice content, particle sizes and habits, phase functions,
radiative fluxes, and spatial variability is required. Vertical profiles
are desirable. For the convective system as a whole, information on the
large‑scale apparent heat source and moisture sink is required. Platform
and instrument availability will constrain the accuracy and level of
detail with which these quantities can be inferred. For many quantities,
statistically significant samples are adequate.

The information on deep cumulus cells will permit assessing the portions
of the convection/cirrus hypothesis regarding the major water sources
for the anvils. Cell scale mass fluxes have long been established as an
important control on thermal and moisture interactions between
convection and larger scales (Arakawa and Schubert, 1974). Donner
(1993a) showed that, by adding vertical velocities at cell scale,
microphysics parameterizations can be used to determine the water supply
for convective anvils. Information on anvil mass fluxes, vertical
velocity, and water content can be used to examine anvil water budgets
and their relationships to deep cells (Leary and Houze, 1980). Anvil ice
contents, shapes, and sizes can be used to calculate radiative fluxes
(Liou et al., 1991; Mitchell and Arnott, 1994). Horizontal variability
on scales below those of GCM grids can be important in determining
GCM‑scale properties due to the nonlinearity in many microphysical and
radiative processes. It is important to diagnose large‑scale heat
sources and moisture sinks because they provide critical closure on the
aggregate effects of convective systems (Thompson, 1979).

Since much of the cirrus with strong radiative forcing occurs in the
tropics, there is a preference to site the experiment there. Both land
and oceanic convection are important (Brazil, western Pacific). However,
this may entail great expense for logistical reasons. There is presently
no set of experimental data with the simultaneous measurements required
to test the convection/cirrus hypothesis. Therefore, a mid‑latitude
experiment would also provide valuable data, should the tropical
location not be feasible.

**6.1 IMPLEMENTATION STEPS**:

• Reexamine historical cirrus data sets for supporting evidence of the
hypothesis: \"that the radiative properties of cirrus anvils are
primarily controlled by the mass fluxes and vertical velocities in
associated cumulus convection.\" Concurrent satellite-radar data may be
helpful.

• Integrate testing of the above hypothesis into the design of a FIRE
III cirrus campaign.

• Design a future FIRE Science Team (FST) meeting to specifically
address the interface between the modeling and experimental FST
constituencies.

**7.0 TROPICAL CIRRUS EXPERIMENT**

**7.1 Background**

Tropical cirrus are a ubiquitous feature of the tropical atmosphere.
Satellite and shuttle observations suggest that the fractional coverage
of cirrus in the tropics is in excess of 60% (Liao et al., 1995a; Wylie,
1994; Winker et al., 1995). Although the formation of cirrus is
generally related to deep convection, their lifecycle is complex and
poorly understood, being influenced both by local and large scale
controls. Our understanding of cirrus lifecycle and properties is
limited to a large extent by a lack of observations. The discussion
below outlines some of the unique characteristics of tropical cirrus and
the need for a focused experimental program.

In order to simplify our discussion, we have adopted the following
definitions of cloud types: (a) isolated cirrus: high-level ice clouds
isolated in space and time from cumulus convection rooted in the
boundary layer; (b) non-precipitating anvil: high-level ice cloud
contiguous in space and/or time with cumulus convection rooted in the
boundary layer but not precipitating; (c) precipitating anvil: the same
as the previous category but precipitating stratiform regions, and
possibly including mixed phase microphysics; (d) cells: deep cumulus
convection elements rooted in the boundary layer. The generic term
\"anvil\" includes both categories (b) and (c). \"Isolated cirrus\" can
be the debris left by decayed cumulonimbi and mesoscale convective
systems or can be cirrus formed in situ (perhaps aided by moisture
pumped by active systems days prior) by large-scale vertical motions or
radiation/turbulence interactions. The optical thickness of
non-precipitating anvil and isolated cirrus may vary considerably from
quite thick to tenuous in the case of extensive invisible cirrus\'
(Prabhakara et al., 1993; Barton, 1993). \"Precipitating anvils\" are
generally associated with dynamically active mesoscale convective
systems where the term \"precipitating\" refers to liquid or ice water
substance that actually arrives at the ground. \"Attached anvils\" are
defined as anvils linked at a given time to cells, while \"detached
anvils\" are identifiable anvils produced by earlier cells or MCCs that
may have subsequently dissipated.

**7.2 Tropical cirrus versus midlatitude cirrus**

Tropical cirrus clouds are unique and important in a number of ways:

Tropical cirrus are partly a product clouds directly affect both thermal
and solar radiative transfer through their optical properties. (This
broad effect is often referred to as cloud‑climate radiative forcing.)
Unlike mid‑latitude cirrus, the large extent of these clouds, as well as
their vertical location, imposes large scale radiative effects at the
surface and in the atmosphere. Climate model simulations of the
tropospheric component of the cloud radiative forcing indicate net
heating of the atmosphere. Various studies suggest that the longwave
heating of cirrus is a principal component of this net heating and that
the amount of this heating is sensitive to the optical properties and
altitude of the cirrus (e.g. Ackerman et al., 1988; Stackhouse and
Stephens, 1991; Fu and Liou, 1993, Wong et al, 1994). Because of the
high altitude and cold temperature of tropical cirrus, the effects of
cirrus on the radiative budget of the atmosphere are thought to be more
pronounced in the tropics than in midlatitudes.

Tropical cirrus are a product of the transport of water from the
tropical boundary layer to the upper troposphere via deep convection.
The feedback between the concentration of water vapor in the upper
troposphere and other changes in the physical climate system is a
crucial issue. Both the effect of clouds on radiation and the effect of
clouds on the water budget are controversial issues and our
understanding of them is poorly constrained by the existing
observational data. Little or no data exist relating tropical cirrus to
a regional water budget, whereas results from the recent FIRE I and II
experiments, as well as a higher density of conventional observations in
midlatitudes, has enhanced our understanding of midlatitude cirrus.

It has been suggested that tropical cirrus clouds produce a particular
kind of feedback in the context of climate change. For example, cirrus
clouds concentrated over the Pacific warm pool associated with the deep
convection are thought to impact significantly the surface energy budget
by reducing the amount of solar radiation reaching the ocean surface,
thus creating a feedback loop among clouds, radiation, and SST
(Ramanathan and Collins, 1991). Also, the atmospheric radiative heating
produced by these clouds is thought to feed back onto large scale
stability and convection (Fowler and Randall, 1994). Both effects (one
in the atmosphere and one at the surface) are central to cloud‑climate
feedback mechanisms. The low temperatures of tropical cirrus impact
cirrus microphysics and, consequently, cloud albedo and the infrared
radiative exchange.

**7.3 Key issues and questions**

• What is the relationship between upper tropospheric cirrus and
mesoscale convection? How do we parameterize the lifecycle of cirrus and
its impact on large-scale forcing in the context of climate models?

• What is the impact of cirrus on the upper tropospheric water budget?
What are the distributions and amounts of ice mass and total water in
the upper tropical troposphere?

• What are the relationships between cloud microphysics and radiative
properties? To what extent do the radiative properties of these clouds
depend on environmental conditions including the extent of the
surrounding deep convection? What are the microphysical properties of
tropical cirrus and how are these related to their environment?

• What is the impact of cirrus on the tropical radiation budget? Are
current model parameterizations an adequate representation of tropical
cirrus effects?

• To what extent and with what accuracy can the properties of cirrus be
determined by satellite remote sensing? Are there new techniques and
instruments that can be applied to the problem?

**7.4 Limitations of past experiments**

Very limited coincident data on ice microphysics, radiation, and
environmental parameters for tropical cirrus exist at this point.
Although some microphysical and radiation data are available from GARP
Atlantic Tropical Experiment (GATE), TOGA COARE and CEPEX, they are
extremely limited. Because of the limited ceiling of the DC-8 (10 - 11
km) and Lear Jet (13 km) which were used in the TOGA-COARE and CEPEX
experiments, complete profiles of ice microphysics could not be
obtained. The sampling strategies did not address the lifecycle
(formation, maintenance, and dissipation) of cirrus. Sampling of the
regional environment was not of sufficient density to allow studies of
the water budget of the tropical upper troposphere and theoretical
interpretation of the radiometric measurements is limited due to the
lack of adequate microphysics observations. These experiments were also
not closely coordinated with the orbiting meteorological satellites,
notably the NOAA series, so that remote sensing validation was highly
problematic. Finally, these experiments were primarily focused on an
understanding of surface heat fluxes and convection (COARE) and
large-scale statistics (CEPEX). Consequently, the volume of data that is
directly applicable to the cirrus radiation and microphysics problem is
extremely limited. While it is imperative that these data be analyzed, a
coordinated and comprehensive experiment focusing on the tropical cirrus
is urgently needed in the near future to answer many very fundamental
questions.

**7.5 Experimental Design**

The preceding discussion provides a framework within which we can now
outline a hierarchy of tropical cirrus experiments of increasing
complexity and demand on resources.

**7.5.1 Ground-Satellite Remote Sensing Experiment**

The continuing acquisition of coordinated ground based and satellite
remotely sensed tropical cirrus data and the analysis of previously
acquired data from FIRE II, TOGA-COARE, CEPEX and ARM will provide
valuable information on the radiative, microphysical and spatial
properties of tropical cirrus cloud systems. The successful analysis of
these data sets depends upon an opportunistic selection of cases where
cirrus clouds are present over the ground based locations. The ARM
deployment in Kavieng is probably the most ideally located site in terms
of deep tropical convection and its anvil outflow. However, in
summertime, midlatitude locations typically experience episodic
\"tropical conditions\" with high humidities and tropopause heights in
excess of sixteen kilometers; these opportunities may be exploited on a
case by case basis by individual or small groups of investigators as we
build our tropical cirrus database. While ground based systems lack the
maneuverability afforded by aircraft, these sites afford a rather
complete suite of observations extending over a considerable depth of
the atmosphere. The availability of coincident surface based radiation
measurements (from solar through microwave wavelengths), lidar
measurements, rawinsonde measurements and satellite observations over an
extended period of time from multiple locations would represent a
powerful set of data. Of course this ground-satellite experiment can be
optimized by the addition of in situ aircraft observations of cloud
microphysics.

Table 7.1 - Ground Satellite Experiment Measurement Requirements

+-----------------------------+----------------------------------------+
| **Minimum**                 | **Desirable**                          |
+-----------------------------+----------------------------------------+
| **Satellite**               | microwave, water vapor imagery         |
|                             |                                        |
| Geostationary imagery       | infrared temperature, temperature      |
|                             |                                        |
|                             | retrievals, radiation budget,          |
|                             |                                        |
|                             | multispectral imagery                  |
+-----------------------------+----------------------------------------+
| **Surface**                 | cloud radar, profiler, DIAL            |
|                             |                                        |
| Lidar, spectral radiation   |                                        |
| (solar and infrared),       |                                        |
| fluxes, rawinsonde          |                                        |
+-----------------------------+----------------------------------------+
| **In situ**                 | Aircraft with the following:           |
|                             |                                        |
|                             | complete microphysics, spectral        |
|                             | radiation, water vapor                 |
+-----------------------------+----------------------------------------+

**7.5.2 A Radiation-Microphysics Experiment-An in-situ Experiment**

This experiment is aimed at understanding the relationship between the
microphysics and the radiative properties of tropical cirrus cloud
systems.; in essence, this is an experiment intended to describe the
nature of tropical cirrus. The targets of this experiment is isolated
and non-precipitating anvil cirrus. The fundamental strategy is the
concurrent measurement of cirrus microphysics and radiative properties
by aircraft with simultaneous remote sensing by satellite. The
experiment is best carried out over the ocean to take advantage of the
well-characterized and uniform background of the sea surface.

Resources required for such an experiment are two aircraft, one to serve
as a local remote sensing platform, as well as measure the radiative
fluxes above cloud, and the second to serve as an in situ platform for
microphysics and, alternatively, to measure fluxes below cloud. US
scientific aircraft which would fulfill these requirements include the
NASA ER-2 and NCAR WB-57. Instrumentation needed for the ER-2 includes
active remote sensors such as the Doppler cloud radar and cloud lidar, a
scanning imager such as the MAS, and broad-band and narrow-band flux
radiometers. The cloud radar, especially 95 Ghz, can be used to address
the issue of the water budget by using reflectivity and vertical
velocity to map out the ice water content distribution across the entire
range of cirrus right into the cell itself. The WB-57 needs
instrumentation to measure the complete size distribution of cirrus
crystals, ambient meteorology, and broad and narrow-band fluxes. There
is also a critical need for turbulence information within the cirrus.
Dropsondes capability are under consideration to be included, however a
network of rawinsonde stations surrounding the area of flight operations
would be preferred. Flight coordination with both geostationary and
polar orbiting satellites is also a necessity.

The location of the experiment is relatively flexible as long as it
occurs in a region of prevalent deep convection, preferably over open
ocean.

Table 7.2 - Radiation-Microphysics Experiment Measurement Requirements

+-----------------------------------+-----------------------------------+
| **Minimum**                       | **Desirable**                     |
+-----------------------------------+-----------------------------------+
| **Satellite**                     | Microwave, water vapor imagery    |
|                                   | infrared temperature, temperature |
| Geostationary imagery             | retrievals, radiation budget,     |
|                                   | multispectral imagery             |
+-----------------------------------+-----------------------------------+
| **Surface**                       | Lidar, spectral radiances (solar  |
|                                   | and infrared), fluxes,            |
|                                   | rawinsonde, cloud radar,          |
|                                   | profiler, DIAL                    |
+-----------------------------------+-----------------------------------+
| **In situ**:                      | Dropwinsondes                     |
|                                   |                                   |
| Aircraft with the following:      |                                   |
|                                   |                                   |
| complete microphysics, spectral   |                                   |
| radiation, water vapor (DC-8,     |                                   |
| WB-57)                            |                                   |
+-----------------------------------+-----------------------------------+
| Aircraft with a complement of     |                                   |
| remote sensing radiation          |                                   |
| observations (ER-2)               |                                   |
+-----------------------------------+-----------------------------------+

**7.5.3 Evolution of Non Precipitating Anvil and Isolated Cirrus
Layers**

The next experimental step is to investigate the evolution of
non-precipitating anvil and isolated cirrus. The goal of this experiment
is to understand the lifecycle of tropical cirrus from formation to
dissipation. Observation of tropical cirrus, particularly from the
vantage point of satellite, shows its longevity, evolution, and
formation in the upper troposphere. The mechanism of formation apart
from deep convection may be either radiative forcing within an existing
cirrus layer or forcing of moist layers by large-scale dynamics. In
either case, the long lifetime and formation issues are climatologically
important because they exert a strong influence on the overall radiative
impact of the cirrus. Required observations include all the microphysics
and radiation of the previous experiment, but these observations are now
needed in a temporally constrained fashion that follows the evolution
and development of cirrus from its initial extrusion from a convective
system or in situ formation through its demise. Furthermore, because the
environment plays a significant role in this lifecycle, observations of
the upper troposphere meteorological properties are needed.

The resources needed for this experiment include both the ER-2 and WB-57
with the instrument complement noted earlier. Another possible
alternative is to measure water vapor by DIAL since reliable
measurements of upper troposphere relative humidity are a crucial, and
difficult, requirement. The incorporation of the NCAR Electra with the
Electra Doppler Radar (ELDORA), or possibly one of the NOAA P-3s with
Doppler radar, to this experiment is a powerful addition. ELDORA is
capable of mapping the dynamics of convection both within cells and
precipitating anvil regions. In addition, a first order estimate of ice
mass can be made from the reflectivities. This addition permits an
investigation of the convective processes leading to the
non-precipitating anvil formation and a good estimate of the amount of
ice in that anvil. Satellite remote sensing is an integral component of
this experiment in order to place the aircraft operations in the context
of the cirrus evolution.

The preferred location for such an experiment is again over the ocean
because flight operations are generally easier in that environment and
remote sensing from above is simplified by the ocean background.
Convection also is generally less intense in an oceanic environment,
which makes flight operations somewhat safer for the tropospheric
aircraft.

Table 7.3 - Evolution Experiment Measurement Requirements

+-----------------------------------+-----------------------------------+
| **Minimum**                       | **Desirable**                     |
+-----------------------------------+-----------------------------------+
| **Satellite**                     | Microwave, water vapor imagery    |
|                                   | infrared temperature, temperature |
| Geostationary imagery             | retrievals, radiation budget,     |
|                                   | multispectral imagery             |
+-----------------------------------+-----------------------------------+
| **Surface**                       | Lidar, spectral radiances (solar  |
|                                   | and infrared), fluxes, rawinsonde |
|                                   | network, cloud radar, profiler    |
|                                   | network (3), DIAL                 |
+-----------------------------------+-----------------------------------+
| **In situ:**                      | Aircraft Doppler radar w/lidar    |
|                                   | (NCAR Electra)                    |
| Aircraft with the following:      |                                   |
|                                   | Dropwinsondes                     |
| complete microphysics, spectral   |                                   |
| radiation, water vapor (DC-8,     |                                   |
| WB-57)                            |                                   |
+-----------------------------------+-----------------------------------+
| Aircraft with a complement of     |                                   |
| remote sensing radiation          |                                   |
| observations (ER-2)               |                                   |
+-----------------------------------+-----------------------------------+

**7.5.4 Convection-Cirrus System Experiment**

The most complete level of characterization of anvils requires certain
information about the cells and precipitating anvils in addition to the
information described above for non-precipitating anvils and isolated
cirrus. The cells comprise the major water source for the anvils. Both
vapor and condensed water are important, and the water source may be
direct or indirect. (\"Direct\" refers to the horizontal transport of
condensate into an attached anvil; \"indirect\" refers to condensation
of vapor in the active anvil or total water generally in the detached
anvil.) Knowledge of the water source is critical for calculating the
microphysical and radiative properties of the anvils.

The additional information required for this level of characterization
includes information on cell-scale mass fluxes, vertical velocity
distributions, liquid and ice contents, and particle sizes. To
characterize the convective system as a whole, the large-scale heat
source and moisture sink are required. The information required to
calculate the large-scale source and sink includes local temperature and
moisture tendencies, and temperature and moisture advection averaged
over spatial scales of 100-200 km with temporal resolution on the order
of a few hours. The heat source and moisture sink are computed as the
residuals when these large-scale contributions to the budget are summed
and are assumed to represent the aggregate effects of the smaller scale
motions on the large scale. In addition, for anvils, information on mass
fluxes, vertical velocities, ice content, particle sizes and habits,
phase functions, radiative heating profiles, and spatial variability of
these quantities is required.

This level of characterization clearly involves cell-scale information
and large-scale atmospheric characterization that FIRE by itself is not
well-suited to obtain. Collaboration with a large-scale experiment would
therefore be necessary to implement the complete experiment as
described. But we underscore that this level of characterization does
not presently exist from any field experiments that have been conducted
to date. (Previous experiments have focused on either convection or
cirrus in isolation but have not recognized that anvil cirrus are
intrinsically linked to convection and cannot be studied meaningfully in
isolation.) Satellite and GCM studies indicate that this is the
predominant component of the radiative forcing in the tropics and that
the forcing is sensitive to perturbations in this process.

The resources needed for this experiment from the FIRE perspective
include the ER-2, WB-57, and Electra discussed above. In addition, a
platform, such as possibly the DC-8, is required to make the
penetrations of the precipitating anvil and cells required to document
the microphysical properties and radiative heating profiles in these
regions. Measurement needs include standard microphysical instruments
and flux radiometers, but also include precipitation radar and microwave
radiometers to assess the hydrologic budget with the cells and
precipitating anvils, see Table 7.4.

The location of such an experiment is problematic. In order to
characterize the atmosphere at the required detail, this experiment
would almost certainly require land-based instrumentation. However, land
convection tends to be more intense with stronger updrafts and a
propensity for lightning. This in turn makes the aircraft operations
more difficult and may preclude penetration of the cells themselves, but
not of the precipitating anvil. One possibility is a monsoonal flow
environment where the convection may be less intense than in more
isolated land convection.

Table 7.4 - Convection Cirrus System Experiment Measurement Requirements

+-----------------------------------+-----------------------------------+
| **Minimum**                       | **Desirable**                     |
+-----------------------------------+-----------------------------------+
| **Satellite**                     | microwave, water vapor imagery    |
|                                   |                                   |
| Geostationary imagery             | infrared temperature, temperature |
|                                   |                                   |
|                                   | retrievals, radiation budget,     |
|                                   |                                   |
|                                   | multispectral imagery             |
+-----------------------------------+-----------------------------------+
| **Surface**                       | cloud radar, profiler network     |
|                                   | (3), DIAL                         |
| Lidar, spectral radiances (solar  |                                   |
|                                   |                                   |
| and infrared), fluxes, rawinsonde |                                   |
|                                   |                                   |
| network                           |                                   |
+-----------------------------------+-----------------------------------+
| **In situ:**                      | dropwinsondes                     |
|                                   |                                   |
| Aircraft with the following:      | Aircraft Doppler radar w/lidar    |
|                                   | (NCAR Electra)                    |
| complete microphysics, spectral   |                                   |
|                                   |                                   |
| radiation, water vapor (DC-8,     |                                   |
| WB-57)                            |                                   |
+-----------------------------------+-----------------------------------+
| Aircraft with a complement of     |                                   |
| remote sensing radiation          |                                   |
| observations (ER-2)               |                                   |
+-----------------------------------+-----------------------------------+

**7.5.5 Ground-based Remote Sensing**

The most appropriate role of ground-based remote sensing in ocean based
tropical experiments is difficult to assess. To a very large extent, the
utility of ground-based systems will be determined by the specific
location and objectives of the proposed experiment. The strengths of
ground-based remote sensing are the continuity of the data record, the
ability to provide a complete altitude coverage from near ground to the
tropopause and the capability of clustering many different types of
instrumentation which may not be adaptable to aircraft. The biggest
difficulties encountered with ground based observations in maritime
tropical field experiments are the expense of site preparation and
deployment and the uncertainty of cirrus cloud occurrence over a
specific geographic point during the course of the experiment. The
latter issue represents a significant problem in the case of limited
time and space deployments. Because the location of convection maybe
somewhat random in nature and movement of convection can be slow or
practically non-existent, one can imagine a situation in which a ground
site was largely devoid of thick anvil coverage for the majority of a
month-long campaign. When selecting locations for surface based
installations, it is critical that a climatology of cirrus clouds,
likely constructed from satellite data, be used. While this offers no
guarantee of cirrus cloud occurrence in the future, it is probably the
best guide to surface site selection. In order to meet the requirement
of measuring the regional thermodynamic and dynamic environments, these
surface sites should include rawinsonde and 400 or 90 MHz wind profiler
observations.

**7.5.6 Summary of Four Tropospheric Cirrus Experiments**

The importance of upper tropospheric clouds in the understanding and
simulation of the Earth's climate demands a focused modeling and
observation/analysis research program. This program must satisfy the
needs for improvements in capabilities for remote sensing both from
space and from the surface, in basic understanding of physical processes
contributing to evolution of the clouds, in knowledge of the cloud
radiative and microphysical properties and the relationships between,
and in the representation of theses clouds in large-scale models used
for climate simulation.

A key area where improvements are critically needed is for tropical
cirrus clouds. This conclusion arises both from their importance to the
global climate system and the lack of adequate observations. In
particular, tropical cirrus are highly coupled to deep convective
systems which supply copious ice and vapor mass to the upper
troposphere. Significant advancement in understanding of the physical
processes and in the treatment of tropical cirrus in large-scale models
critically depends on the acquisition and analysis of appropriate
observations. Specifically, quantitative observations of the convective
mass flux in relationship to the ice mass detrainment into the anvil are
sorely needed.

Four distinct and graduated observational approaches were defined in
this Implementation Plan. They differ in scope and scientific emphasis.
While each observational approach offers significant contributions to
achieving FIRE III objectives, it is the strongly held position of the
FIRE Science Team that a minimum requirement to address the key issue of
tropical cirrus clouds is to implement the "cirrus evolution"
experimental approach. The "cloud system approach offers additional and
substantive advantages such as definition of convective mass flux in
relationship to large-scale environmental conditions and integration to
the cloud system scale. This is highly desirable for the purpose of
parameterization development and even more important for model
validation. Ideally, the "cirrus evolution" approach is fully
incorporated within the "cloud system" approach in a single coordinated
observational/analysis effort.

Conduct of the recommended experimental approach does not preclude the
other observational approaches. Theses may be of particular benefit if
an early implementation can be achieved. However, the FST emphasizes the
importance of conducting the combined evolution/cloud system program
because this is the only avenue which affords the opportunity to achieve
the FIRE III objectives. Table 7.5 summarizes the objectives addressed
by each of the four component observational programs. On a more global
scale, the FIRE III science team notes that no other currently proposed
research plan within NASA or by other agencies addresses the tropical
upper tropospheric cloud issue with sufficient focus to provide the
progress required to monitor and to effectively include those clouds in
contemporary GCM and climatic models.

Table 7.5 - Experiment Objectives for Four Candidate Experiments

+-------------+-------------+-------------+-------------+-------------+
|             | Remote      | Basic       | Radiation   | Large-Scale |
|             |             |             | and         |             |
|             | Sensing     | Un          |             | Model       |
|             |             | derstanding | M           |             |
|             |             |             | icrophysics | Param       |
|             |             | of          |             | eterization |
|             |             | Evolution   |             |             |
+-------------+-------------+-------------+-------------+-------------+
| Ground      | √           |             | **/**       |             |
| Satellite   |             |             |             |             |
|             |             |             |             |             |
| Remote      |             |             |             |             |
| Sensing     |             |             |             |             |
|             |             |             |             |             |
| Experiment  |             |             |             |             |
+-------------+-------------+-------------+-------------+-------------+
| A           | √           | **/**       | √           | **/**       |
| Radiation-  |             |             |             |             |
|             |             |             |             |             |
| M           |             |             |             |             |
| icrophysics |             |             |             |             |
|             |             |             |             |             |
| Experiment  |             |             |             |             |
| -           |             |             |             |             |
|             |             |             |             |             |
| An In-Situ  |             |             |             |             |
|             |             |             |             |             |
| Experiment  |             |             |             |             |
+-------------+-------------+-------------+-------------+-------------+
| Evolution   | √           | √           | √           | **/**       |
| of          |             |             |             |             |
|             |             |             |             |             |
| Non-        |             |             |             |             |
|             |             |             |             |             |
| Pr          |             |             |             |             |
| ecipitating |             |             |             |             |
|             |             |             |             |             |
| Anvil and   |             |             |             |             |
|             |             |             |             |             |
| Isolated    |             |             |             |             |
| Cirrus      |             |             |             |             |
|             |             |             |             |             |
| Layers      |             |             |             |             |
+-------------+-------------+-------------+-------------+-------------+
| Convection- | √           | √           | √           | √           |
|             |             |             |             |             |
| Cirrus      |             |             |             |             |
| System      |             |             |             |             |
|             |             |             |             |             |
| Experiment  |             |             |             |             |
+-------------+-------------+-------------+-------------+-------------+

**7.5.7 Collaborative Programs**

The cost and complexity of tropical deployments makes it almost
inevitable that FIRE must develop collaborations with other interested
parties. The simplest radiation-microphysics experiment involves a
collaboration between NASA and NCAR such as proposed Panama experiment
in 1997. Increasing the resource requirements for more complex
experiments increases the need for shared resources. In particular, the
complete life cycle experiment requires collaboration with a large
program such as LBA, which is aimed at understanding surface and
meteorological components of the hydrologic cycle. FIRE, because of its
developed expertise in clouds and radiation, can contribute a great deal
to such efforts. An active component of the planning of any FIRE
tropical experiment must be the search for other interested
collaborators.

**7.6 IMPLEMENTATION STEPS:**

> • Continue analysis of previously collected data on
> tropical/subtropical cirrus cloud systems.
>
> • Continue instrumentation and technique development to observe and/or
> infer radiative and microphysical properties of cirrus clouds.
>
> • Continue collection of radiative and microphysical data on tropical
> and subtropical cirrus cloud systems on a target of opportunity basis.
>
> • Develop monthly upper tropospheric cloud climatologies from
> historical satellite data over the region extending from 10°S to 30°N
> latitude and from 35°W to 135°W longitude.
>
> • Determine collaborative possibilities with other programs such as
> LBA in order to optimize scope of a FIRE III cirrus campaign.
>
> • Design a modular FIRE III cirrus field experiment capable of
> addressing the scientific questions outlined in Sections 1 - 6.
>
> • Submit a letter of intent to the NSF OFAP by June 1996 indicating
> the likelihood of a request to use the WB-57 and the Electra in a
> 45-day tropical cirrus field campaign in CY 1999.
>
> • Submit a letter of intent to NASA by June 1996 indicating the
> likelihood of a request to use the ER-2 and DC-8 in a 45 day tropical
> cirrus field campaign in CY 1999. The NCAR WB-57, NCAR Electra, NASA
> ER-2, and NASA DC-8 would be part of a Convective Cirrus experiment
> (section 7.5.4).

**8.0 SUCCESS**

The Atmospheric Effects of Aviation Program (AEAP) SASS program
sponsored by the NASA Office of Aeronautics will conduct the SUCCESS
field mission in April 1996 based in Salina, Kansas. FIRE Cirrus and the
NASA Radiation Science Program is a full partner in this campaign. In
addition, planned flight operations will be focused on the ARM Cloud and
Atmospheric Radiation Testbed (CART) site near Lamont, Oklahoma, where
the usual ARM ground‑based instrumentation will be supplemented by
various active remote sensors (95 GHz radar and dual‑polarization lidar)
and coordinated with a UAV Intensive Observation Period (IOP) focused on
cloud radiative properties.

The goals of SASS are to assess the present and future impact of the
subsonic aircraft fleet on the Earth\'s radiation budget and climate.
Areas of prime concern for the SUCCESS mission are:

• radiative effects of contrails,

• direct radiative effects of aircraft exhaust (water vapor, soot,
etc.),

• indirect radiative effects of aircraft exhaust through modification of
cirrus, and

• resultant changes in radiatively active gases such as ozone.

FIRE\'s interest is primarily in the remote sensing and impact of
contrails and in the potential impact of aircraft exhaust on cirrus.
Contrails provide a very interesting remote sensing target. Early in
their lifetime, they exhibit a very high density of very small particles
and relatively large optical depth in contrast to more generic cirrus.
These properties evolve in time and persisting (spreading) contrails
appear to lose this distinct identity as time goes on. From a remote
sensing perspective, they present an extreme cases for detection of high
altitude ice cloud properties. Assessment of the global radiative impact
relies on satellite‑based detection of contrail coverage and radiative
properties, which is a significant challenge given their small
transverse scale.

Direct contrail modification of ambient cirrus is also an issue of
concern. Potentially more significant are the effects of aircraft
emissions on the aerosol budget of the upper troposphere and its
potential widespread effect on cirrus cloud microphysical and radiative
properties by altering the relative importance of the operating
nucleation modes (ice nuclei versus homogeneous or heterogeneous
nucleation). Such an aerosol effect has been well‑documented for stratus
clouds during FIRE Stratus and ASTEX and has long been evident in the
contrast between continental and maritime clouds in the lower
troposphere. Sassen et al. (1995) present results indicating a strong
modification of cirrus associated with incorporation of volcanic aerosol
into a cirrus cloud during FIRE Cirrus‑II. By analogy, aircraft effects
on the upper tropospheric aerosol budget, that preliminary assessments
indicate is quite significant on a global basis, could have a similar
effect. On a more fundamental level, modeling studies using FIRE
Cirrus‑II data have reached the point where more detailed knowledge of
the operating nucleation modes are essential for further progress, i.e.,
-reasonable assumptions about nucleation mode can significantly impact
the results (Jensen et al., 1994) and present data is inadequate to
resolve this issue. Thus, SASS presents a good opportunity to advance
basic knowledge about this important aspect of cirrus clouds. In
addition to potential aircraft effects, assessment of possible global
impacts due to volcanic activity also require increased knowledge of
cirrus cloud microphysical processes and their relationship to aerosols
(Song et al., 1996).

The FIRE contribution to SUCCESS is comprised of the NASA ER‑2 platform
and associated instruments and investigators, i.e.,

\- MAS

\- High‑spectral resolution Interferometer Spectrometer (HIS)

\- Radiation Airborne Measurement System (RAMS)

\- Cloud Lidar System (CLS)

\- Microwave Imaging Radiometer (MIR)

\- Tilt‑scan CCD Camera

\- RC-10 Camera

This instrument package is nearly identical, with some improvements, to
that employed for FIRE Cirrus‑II. The MIR is a new addition that was
flown during TOGA‑COARE but that has now been enhanced through the
addition of an additional high frequency (325 GHz) channel for the
detection of cirrus ice water content. It is expected that a significant
portion of the SUCCESS missions will involve measurements of cirrus in
addition to contrail missions. Some remote sensing missions will be
flown over the Gulf of Mexico to address specific remote sensing issues
for FIRE Cirrus, specifically evaluation of the high frequency microwave
observations and observations of cloud bi‑directional reflectance using
the Tilt‑scan CCD Camera in conjunction with the other measurements
enabling estimation of cloud optical depth and particle size.

The NASA DC‑8 will be the primary in situ observing system and is
sponsored by AEAP/SASS. Some FIRE investigators are also sponsored under
SASS and will be participating on the DC‑8 during SUCCESS. Some of the
ground‑based instrumentation are also sponsored, at least partially, by
SASS. The DC‑8 instrumentation includes in situ measurements of:

\- standard meteorological parameters (e.g., temperature)

\- water vapor (multiple techniques)

\- aerosol size distribution and composition, including Cloud Nuclei
(CN), Cloud

Condensation Nuclei (CCN) and ice nuclei, by a variety of sensors

\- ice particle size distributions, including replicators

\- cloud ice water content (new NCAR counterflow virtual impactor (CVI)
and

Gerber probe)

\- ice crystal scattering phase function by nephelometer

\- a variety of chemical species including NOx, NOy, O3, HNO3, SO2, Odd

Hydrogen, PAN, and organics

AEAP/SASS has made a significant investment in the development of some
of these instruments. This instrument package represents, by far, the
most comprehensive attempt ever made to fully observe upper tropospheric
aerosols in conjunction with cloud microphysical properties. FIRE will
benefit both through the data obtained during SUCCESS as well as through
data obtained in future field missions (e.g., many of these instruments
are proposed for integration on the new NCAR WB‑57 high altitude
aircraft in association with the proposed STERAO missions).

**8.1 FIRE Participation**

FIRE has already established a collaborative effort to study cirrus and
contrails over the central U.S. during Spring 1996. FIRE remote sensing
researchers and their participation in SUCCESS are summarized in Table
8.1. FIRE III will provide satellite and meteorological support for
SUCCESS in addition to the use of the NASA ER‑2. The SUCCESS
investigations should improve our understanding of midlatitude cirrus
clouds and the effects of aircraft on their optical properties.

Table 8.1 FIRE III Investigations during SUCCESS

  ---------------- --------------------------- --------------------------
  **Researcher**   **Instrument**              **Thrust**

  T. Ackerman      surface radar, microwave    contrail and cirrus
                   radiometer, flux            radiative properties and
                   radiometers                 structure

  S. Ackerman,     ER‑2 MAS, HIS, surface AERI contrail and cirrus
  Tsay                                         radiative properties,
                                               contrail/cirrus dependence
                                               on UT water vapor

  Eberhard         surface Doppler lidar and   contrail and cirrus
                   cloud radar                 structure and microphysics

  Gerber           DC-8 g-meter (PVM-100A)     contrail and cirrus
                                               microphysics

  Hallett, Hudson  DC-8 in situ microphysics   contrail and cirrus
                                               microphysics

  Heymsfield       DC-8 in situ microphysics   contrail and cirrus
                                               microphysics

  Kreidenweis      ice nuclei                  observe ice nuclei
                                               concentration, composition
                                               and efficiency

  Lawson           p-Nephelometer              contrail and cirrus
                                               microphysics

  Liou             AVHRR                       model validation

  Minnis           GOES Imager, AVHRR          algorithm validation;
                                               cirrus and contrail
                                               radiative properties

  Mishchenko       ISCCP                       model validation

  Rossow           ISCCP                       climatology, validation

  Sassen           surface lidar               cirrus and contrail
                                               structure

  Stephens, etc.   surface radiometers         contrail and cirrus
                                               radiative properties

  Spinhirne        ER‑2 lidar, IR radiometer,  cirrus bidirectional
                   TSC, surface lidar          reflectance; contrail and
                                               cirrus structure and
                                               optical properties

  Toon             airborne radiometers        cirrus and contrail
                                               radiative effects

  Valero,          Surface, ER-2, and DC-8     contrail and cirrus
  Pilewskie        radiometers                 radiative properties
  ---------------- --------------------------- --------------------------

In summary, SUCCESS will advance FIRE Cirrus objectives through
evaluation and resulting improvements to remote sensing techniques for
cloud ice water content, particle size, and optical properties. The hope
is that SUCCESS will result in a major advance in knowledge of upper
tropospheric aerosols, their sources and sinks, and their effects of
cirrus clouds both locally and, through extrapolation, globally. The
present observational data base on upper tropospheric aerosols is paltry
at best and SUCCESS should do much to alleviate this situation. Many
measurements taken during SUCCESS have never been attempted before in
the upper troposphere.

**8.2 IMPLEMENTATION STEPS:**

• In light of the many related goals of FIRE III and SUCCESS, promote
communication of SUCCESS accomplishments to FST scientists. Perhaps
common or serial meetings could achieve this.

• A successful FIRE III tropical field campaign will depend upon a
number of instrumentation development projects in SUCCESS. As a result,
FIRE III management should maintain a close liaison with SUCCESS
management on the progress and success of these development programs.

**9.0 SHEBA/FIRE III Stratus**

Commencing in August 1997 and continuing for approximately one year,
SHEBA will mount a field campaign on the pack ice in the Arctic Ocean.
In addition the ARM site at Barrow, Alaska should be activated by this
time and will provide an additional surface based set of radiation and
cloud observations. The SHEBA expedition will consist of an array of
surface based instrumentation in place for the duration of the
experiment and probably two aircraft expeditions, each with a duration
on the order of one month. The two aircraft campaigns are tentatively
scheduled for August, 1997 and April 1998. FIRE III scientists plan to
participate extensively in the April 1998 aircraft campaign.

Owing to the relatively shallow depths of the troposphere and cold
temperatures of the Arctic, there may be relatively little difference
between lower and middle tropospheric stratiform clouds and upper
tropospheric cirrus. Nonetheless, the dynamics (vertical motions) that
contribute to upper tropospheric Arctic cirrus cloud formation may be
different from lower tropospheric Arctic stratus resulting in differing
cloud properties as well. While the primary focus of the SHEBA
experiment is upon the surface and boundary layer, the heat and energy
budgets at the surface are dependent upon cloud structures both within
and above the boundary layer. Likewise, the ability to observe the
surface and lower atmospheric layers from satellite is impaired by
clouds at all levels in the arctic atmosphere. It becomes apparent that
the FIRE III/SHEBA mutual goals may be best served by including cloud
systems at all levels in the arctic atmosphere within the scope of the
experiment objectives.

**9.1 SHEBA-FIRE Collaboration**

The SHEBA-FIRE collaboration will involve several FIRE remote sensing
groups (Table 9.1) whose investigations will examine both ice and liquid
clouds in the polar regions. The results will provide additional
information for the temperature and latitudinal variability of ice
clouds and their optical properties. The experiment will also be
valuable for validating MODIS and CERES cloud retrievals.

Table 9.1 Remote Sensing Investigators Evaluating Polar Ice Clouds
During SHEBA

  ---------------- ----------------------------- -----------------------------
  **Researcher**   **Instrument**                **Thrust**

  T. Ackerman      surface radar, microwave      contrail and cirrus radiative
                   radiometer, flux radiometers  properties and structure

  Fairall          Surface lidar, microwave      cloud structure, phase
                   radiometer, wind profiler     

  Han and Welch    AVHRR                         algorithm validation, cloud
                                                 mask development, optical
                                                 properties

  Hobbs, King,     C‑130 CAR, lidar, flux        algorithm validation,
  Tsay             radiometers; ER‑2 MAS, lidar  cloud/clear discrimination,
                                                 optical properties,
                                                 bidirectional reflectance

  Minnis           AVHRR, MODIS                  polar ice cloud retrieval
                                                 algorithm validation, cloud
                                                 properties, climatology

  Rossow           ISCCP, HIS, SSM/T2            polar ice cloud retrieval
                                                 algorithm development and
                                                 validation, radiative
                                                 properties, climatology

  Uttal            Surface 35 GHz radar, lidar,  cloud structure, emittance,
                   IR radiometer                 and microphysical properties,
                                                 ice mass

  Wielicki         Landsat                       cloud optical properties,
                                                 horizontal variability, and
                                                 validation

  Wylie            HIRS                          cloud optical depth and
                                                 height, algorithm validation
  ---------------- ----------------------------- -----------------------------

It is therefore strongly urged that SHEBA-FIRE III Stratus component
include measurements of middle and upper tropospheric cirrus. Aircraft
measurements of cirrus microphysics and radiative properties should be
made on an occasional basis to compare with their lower tropospheric
cousins and mid latitude and tropical counterparts. In addition, when
lower tropospheric stratus is absent but cirrus is present, ground‑based
measurement systems such as lidars, radiometers, millimeter wavelength
radars, and sounding systems should be operated to obtain measurements
when Arctic cirrus is present.

**9.2 IMPLEMENTATION STEPS:**

• Maintain active liaison between the FIRE III SHEBA and FIRE III
Tropical cirrus components.

• Encourage FIRE III SHEBA principals to include middle and upper
tropospheric ice clouds in the Arctic within the experiment\'s scope.

**10.0 COMPLIMENTARY PROGRAMS**

FIRE researchers are actively engaged in a number of scientific
endeavors, involving other programs, that will advance FIRE Cirrus
objectives during FIRE‑III. Already described elsewhere in this document
are the joint FIRE‑AEAP SUCCESS field mission (section 6.0) and FIRE
participation in and critical support of the model intercomparison
activities of the GCSS WG-2 (section 4.0). Other complimentary programs
and opportunities are described below.

In addition to the SUCCESS field mission and associated analysis and
modeling, AEAP/SASS will conduct one or more additional field missions
during FIRE‑III. While these missions are highly focused on
heterogeneous chemistry and near‑field aircraft wake studies, useful
observations of cirrus clouds will also be obtained, especially with
respect to resolving the potentially important effect of aerosols on
cirrus and fundamental ice particle scattering properties. It is
expected that members of the FIRE Science Team will participate in these
missions and that FIRE will benefit from the knowledge gained. The
continuing AEAP/SASS support of development of critical instrumentation
for aerosol and ice physics measurements and cloud radiative properties
measurements will also benefit future FIRE missions.

The DOE ARM program is also highly complimentary with FIRE with a number
a researchers actively involved in both programs. FIRE and ARM are
highly synergistic with FIRE providing the benefits of its efforts to
improve satellite‑based and ground‑based remote sensing techniques for
cirrus cloud characterization, studies of cloud development processes
and large‑scale analysis of cloud data sets; and ARM providing the
extended‑time collection of cloud and atmospheric observations with
enhanced collections during IOPs along with its systematic program of
single‑column model (as in a single GCM grid cell) and radiative model
testing and evaluation using the collected data. ARM has also strongly
supported the development and improvement of sophisticated sensors, both
ground‑based and deployed on UAVs, for application to cloud‑radiative
research. Airborne observations, involving both UAVs and manned
aircraft, are collected during some IOPs. FIRE and ARM are very mutually
beneficial with data, results and expertise flowing freely between the
programs.

Activities of the Mission To Planet Earth (MTPE) EOS Instrument Teams
also constitute a significant opportunity to advance FIRE Cirrus
objectives during FIRE‑III. Elements of these teams are committed to
providing detailed global cloud observations derived from EOS
observations. In the near term, the MISR and ASTER teams will develop
(expected within 2 years) and collect cloud observations with airborne
simulator instruments much the way that the MAS has done during FIRE‑II.
When developed, the MISR simulator, that will be deployed on the NASA
ER‑2, will provide a new capability for obtaining observations enabling
much improved definition of multi‑spectral cloud bi‑directional
reflectance, models of which are an essential ingredient in
satellite‑based cloud retrieval algorithms. Though focused on land
surface studies, ASTER simulator, that will be deployed on the NASA
C‑130, will provide a capability to obtain very high spatial resolution
multi‑spectral cloud scene data of very high quality. Such data sets
would be very useful in assessing effects of cloud inhomogeneity and
significantly improve the quality of the available data for such studies
(presently relying on Landsat observations).

The MAS has provided crucial data to FIRE. Similarly, FIRE data has
proven very important to the MODIS team for algorithm development and
validation. For example, the incorporation of the 1.3 mm channel on
MODIS for cirrus detection resulted from analysis of MAS and Airborne
Visible/Infrared Imaging Spectrometer (AVIRIS) data collected during
FIRE Cirrus‑II. There is a close relationship between the
MODIS‑Atmosphere and FIRE teams. Additional MAS data collections are
expected during FIRE‑III as the MODIS team continues its algorithm
development and validation activities in preparation for the AM‑1 launch
scheduled for 6/98. Where appropriate, FIRE will seek to incorporate
those data and results to further understanding of cirrus cloud
properties and processes. Similar close relationships should be promoted
between the MISR and ASTER teams and the FIRE Cirrus community.

In the longer term, the EOS instrument teams will conduct intensive data
validation exercises in the post AM‑1 launch era (after 6/98). The teams
are presently developing their EOS Science Data Validation Plans. It
will be imperative for FIRE and those teams to seek opportunities for
mutually beneficial field deployments and analysis efforts. This will
significantly enhance the scientific value of these activities by
broadening their scientific purpose beyond the highly focused on remote
sensing objectives of the EOS instrument teams.

NSF may support a series of field deployments (NCAR aircraft) focused on
the upper troposphere (STERAO). There is an opportunity for FIRE and NSF
to join resources to conduct a campaign targeted on tropical cirrus. The
NSF program also focuses on upper tropospheric chemistry in addition to
its cirrus cloud focus. As with the AEAP program, this may provide
opportunities for collection of data on cirrus clouds during FIRE‑III.
It should be noted that the NSF program strongly benefits from
instrument development during FIRE‑II and AEAP/SASS. NCAR personnel have
also been very instrumental in some of these efforts. NSF\'s present
efforts to deploy a new highly capable resource for upper tropospheric
research, the WB‑57, will surely have a major positive impact on cirrus
cloud research during FIRE‑III.

Other possible synergism that will be explored are with the NASA Land
Surface Processes Program which is planning a major field campaign, the
Large-Scale Land Processes in the Basin of the Amazon (LBA), in Brazil
in 1998 or 1999. A joint FIRE mission to this tropical convective
environment in conjunction with the substantial planned data collections
could prove to be the best possible opportunity to address the issue of
coupling between deep convection and upper tropospheric cloudiness which
is a major issue confronting the GCM community, as described in section
6.

FIRE will also explore opportunities for useful exchange of data and
expertise with the EUCREX community. It is expected that the European
community will be highly involved in the GCSS WG-2 activities (section
4.4) and that this may provide the forum for useful interaction between
FIRE and EUCREX. Possibilities for joint cooperative field activities
will continue to be explored.

**10.1 IMPLEMENTATION STEPS**

• Explore collaboration with international partners in a tropical upper
tropospheric cloud experiment.

• Participate in and provide crucial data sets in support of the cirrus
cloud model intercomparison activities of the GCSS WG-2.

• Maintain communication with other international partners performing
independent research on upper tropospheric cloud systems and their
relationship to climate.

• Explore collaboration with other funded projects in order to provide a
more comprehensive field campaign capable of addressing the goals of
FIRE III.

**APPENDIX A - REFERENCES**

Ackerman, S. A., H. Chung, S. K. Cox, L. Herman, W. L. Smith, and D. P.
Wylie, Comparison of NOAA-9 ERBE measurements with cirrus IFO satellite
and aircraft measurements, *FIRE Science Team Meeting*, Vail, CO, 1988.

Albrecht, B. A., C. S. Bretherton, D. Johnson, W. H. Schubert, and A. S.
Frisch, The Atlantic Stratocumulus Transition Experiment \--ASTEX, *Bul.
Amer. Meteor. Soc., 76*, 889-904, 1995.

Arakawa, A., and W. H. Schubert, Interaction of a cumulus cloud ensemble
with the large‑scale environment: Part 1, *J. Atmos. Sci., 31*, 674‑701,
1974.

Arnott, W. P., Y. Y. Dong, J. Hallett, and M. R. Poellot, Observations
and importance of small ice crystals in a cirrus cloud from FIRE II
data, *J. Geophys. Res., 99*, 1371--1381, 1994.

Arnott, W. P., Y. Y. Dong, R. Purcell, and J. Hallett, Direct airborne
sampling of small ice crystals and the concentration and phase of haze
particles, Ninth Symposium on Meteorological Observations and
Instrumentation, Charlotte, North Carolina, 27-31 March 1995, 415--420,
1995.

Baum, B. A., B. A. Wielicki, P. Minnis, and L. Parker, Cloud property
retrieval using merged HIRS and AVHRR data, *J. Appl. Meteor., 31*,
351-369, 1992.

Baum, B. A., R. F. Arduini, B. A. Wielicki, P. Minnis, and S. C. Tsay,
Multilevel cloud retrieval using multispectral HIRS and AVHRR data:
Nighttime oceanic analysis, *J. Geophys. Res., 99*, 5499-5514, 1994.

Barton, 1993.

Blyth, 1986

Churchill, D. D., and R. A. Houze, Mesoscale updraft magnitude and
cloud‑ice content deduced from the ice budget of the stratiform region
of a tropical cloud cluster, *J. Atmos. Sci., 41*, 1717‑1725, 1984.

Cotton W. R., G. D. Alexander, R. Hertenstein, R. L. Walko, R. L.
McAnelly, M. Nicholls, Cloud venting ‑‑ A review and some new global
annual estimates, *Earth Science Reviews*, in press, 1995.

Darnell, W. L., W. F. Staylor, S. K. Gupta, F. M. Denn, N. A. Ritchey,
and A. C. Wilber, Seasonal variation of surface radiation budget derived
from International Satellite Cloud Climatology Project C1 data, *J.
Geophys. Res., 97*, 15741-15760, 1992.

Derr et al, *J. Atmos. Sci., 47*, 2287-2783, 1990.

Del Genio, A. D., M.‑S. Yao, W. Kovari, and K. K.‑W. Lo, A prognostic
cloud water parameterization for global climate models, in press, 1995.

Donner, L. J., A cumulus parameterization including mass fluxes,
vertical momentum dynamics, and mesoscale effects, *J. Atmos. Sci., 50*,
889‑906, 1993a.

Donner, L. J., Parameterization of convection for GCMs, Clouds and
Climate, Advanced Study Program, National Center for Atmospheric
Research, 367‑387, 1993b.

Foster, T., W. P. Arnott, J. Hallett, J. G. Hudson, and R. Pueschel,
Measurements of ice particles in tropical cirrus anvils: Importance in
radiation balance, AMS Conference on Cloud Physics, January 15-20, 1995,
Dallas, Texas, 419--424, 1995.

Fowler and Randall, 1994.

Fu, Q., and K. N. Liou, Parameterization of the radiative properties of
cirrus clouds*, J. Atmos. Sci., 50*, 2008-2025, 1993.

Fu, R., A. D. Del Genio, W. B. Rossow, and W. T. Liu, Cirrus‑cloud
thermostat for tropical sea surface temperatures tested using satellite
data, *Nature, 358*, 394‑397, 1992.

Fu, R., A. D. Del Genio, and W. B. Rossow, Influence of ocean surface
conditions on atmospheric vertical thermodynamic structure and deep
convection, *J. Climate, 7*, 1092‑1108,. 1994

Gamache, J. F., and R. A. Houze, Jr., Water budget of a mesoscale
convective system in the tropics, *J. Atmos. Sci., 40*, 1835‑1850, 1983.

Goloub, P., J. L. Deuze, M. Herman, and Y. Fouquart, Analysis of the
POLDER polarization measurements performed over cloud covers, IEEE
Trans. GE-32, 78-88, 1994.

Han, Q.-Y., Global survey of effective particle size in liquid water
cloud by satellite observations, Ph.D. Dissertation, Columbia
University, New York, 205 pp. \[Available from University Microfilms
International, 305 N. Zeeb Rd., Ann Arbor, MI 48106\], 1992.

Han, Q.-Y., W. B. Rossow, and A. A. Lacis, Initial survey of cloud
particle sizes using ISCCP data, *Preprints, 5th Conf. on Climate
Variations, Denver, AMS*, 372-375, 1991.

Han, Q.-Y., W. B. Rossow, and A. A. Lacis, Near-global survey of
effective cloud droplet radii in liquid water clouds using ISCCP data,
*J. Climate, 7*, 465-497, 1994.

Han, Q.-Y., W. B. Rossow, R. Welch, A. White, and J. Chou, Validation of
satellite retrievals of cloud microphysics and liquid water path using
observations from FIRE, *J. Atmos. Sci., 52*, 4183-4195, 1995a.

Han, Q.-Y., W. B. Rossow, R. Welch, A. White, and J. Chou, Validation of
satellite retrievals of cloud microphysics and liquid water path, *J.
Climate*, submitted, 1995b.

Han, Q-Y., R. M. Welch, and J. Chou, Retrieval of cirrus microphysics
over oceans on a near-global scale using ISCCP data, *Preprints, Conf.
Cloud Physics*, 15-20 Jan 1995, Dallas, TX, Amer. Meteor. Soc., 65-69,
1995c.

Hartmann, D. L., and M. L. Michelsen, Large‑scale effects on the
regulation of tropical sea surface temperature, *J. Climate, 6*,
2049‑2062, 1993.

Heymsfield, A. J., and L. M. Miloshevich, Relative humidity and
temperature influences on cirrus formation and evolution: Observations
from wave clouds and FIRE II, *J. Atmos. Sci* ., *52,* 4302-4326, 1995.

Heymsfield, A. J., and C. Platt, A parameterization of the particle size
spectrum of ice clouds in terms of the ambient temperature and the ice
water content, *J. Atmos. Sci., 41*, 846--855, 1984.

Hudson, J. G., An instantaneous CCN spectrometer, *J. Atmos. Oceanic
Technol., 6*, 1055--1065, 1989.

Hudson, J. G., and X. Da, Volatility and size of cloud condensation
nuclei. *J. Geophys. Res*., in press, 1995.

Hudson, J. G., and H. Li, Microphysical contrasts in Atlantic stratus,
*J. Atmos. Sci., 52*, 3031--3040, 1995.

Hudson, J. G., and G. Svensson, The microphysics of California marine
stratus clouds, J. Appl. Meteor., in press, 1995.

Jensen, E. J., O. B. Toon, D. L. Westphal, S. Kinne, and A. J
Heymsfield, Microphysical modeling of cirrus. Part II: Sensitivity
studies, *J. Geophys. Res., 99-D5*, 10,443-10,454, 1994.

King, et al., 1996

Krueger, S. K., Numerical simulation of tropical cumulus clouds and
their interaction with the subcloud layer, *J. Atmos. Sci., 45*,
2221-2250, 1988.

Leary, C. A., and R. A. Houze, Jr., The contribution of mesoscale
motions to the mass and heat fluxes of an intense tropical convective
system, *J. Atmos. Sci., 37*, 784‑796, 1980.

Liao, X., W. B. Rossow, and D. Rind, Comparison between SAGE II and
ISCCP high-level cloud amounts. Part I: Global and zonal mean cloud
amounts, *J. Geophys. Res., 100*, 1121-1135, 1995a.

Liao, X., W. B. Rossow, and D. Rind, Comparison between SAGE II and
ISCCP high-level cloud amounts. Part II: Locating cloud tops, *J.
Geophys. Res., 100*, 1137-1147, 1995b.

Lin, B., and W. B. Rossow, Observations of cloud liquid water path over
oceans: Optical and microwave remote sensing methods, *J. Geophys. Res.,
99*, 20907-20927, 1994.

Liou, K. N., J. L. Lee, S. C. Ou, Q. Fu, and Y. Takano, Ice cloud
microphysics, radiative transfer, and large‑scale cloud processes,
*Meteorol. Atmos. Phys., 46*, 41‑50, 1991.

Liu, G., and J. A. Curry, Determination of characteristic features of
cloud liquid water from satellite microwave measurements, *J. Geophys.
Res., 98*, 5069-5092, 1994.

Liu, W. T., A. Zhang, and J. K. B. Bishop, Evaporation and solar
irradiance as regulators of sea surface temperature in annual and
interannual changes, *J. Geophys. Res., 99*, 12623‑12637, 1994.

Mace, G. G., D. O\'C. Starr, T. P. Ackerman, and P. Minnis, Examination
of coupling between an upper tropospheric cloud system and
synoptic-scale dynamics diagnosed from wind profiler and radiosonde
data, *J. Atmos. Sci., 52*, (in press), 1995.

Macke, A., M. I. Mishchenko, K. Muinonen, and B. E. Carlson, Scattering
of light by large nonspherical particles: Ray tracing approximation
versus T-matrix method. *Opt. Lett., 20*, 1934-1936, 1995.

Martin, G. M., D. W. Johnson, and A. Spice, The measurement and
parameterization of effective radius of droplets in warm stratocumulus
clouds, *J. Atmos. Sci., 51*, 1823--1842, 1994.

Martin, G. M., D. W. Johnson, D. P. Rogers, P. R. Jonas, P. Minnis, and
D. A. Hegg, Observations of the interaction between cumulus clouds and
warm stratocumulus clouds in the marine boundary layer during ASTEX, *J.
Atmos. Sci., 52*, 2902-2922, 1995.

Matrosov, S. Y., T. Uttal, J. B. Snider, and R. A. Kropfli, Estimation
of ice cloud parameters from ground-based infrared radiometer and radar
measurements, *J. Geophys. Res., 97*, 11,567-11,574, 1992.

Minnis, P., D. F. Young, K. Sassen, J. M. Alvarez, and C. J. Grund, The
27-28 October 1986 FIRE IFO Cirrus Case Study: Cirrus parameter
relationships derived from satellite and lidar data, *Mon. Wea. Rev.,
118*, 2402-2425, 1990.

Minnis, P., P. W. Heck, D. F. Young, C. W. Fairall, and J. B. Snider,
Stratocumulus cloud properties derived from simultaneous satellite and
island-based instrumentation during FIRE, *J. Appl. Meteor., 31*,
317-339, 1992.

Minnis, P., P. W. Heck, and D. F. Young, Inference of cirrus cloud
properties from satellite-observed visible and infrared radiances. Part
II: Verification of theoretical radiative properties, *J. Atmos. Sci.,
50*, 1305-1322, 1993.

Minnis, P., D. F. Young, D. P. Garber, Y. Takano, and K.-N. Liou,
Effects of cloud particle size and shape on satellite remote sensing of
cloud properties, *Proc. 8th Conf. Atmos. Radiation, Nashville, TN, Jan.
23-28, 1994*, 418-420, 1994.

Minnis, P., D. P. Kratz, J. A. Coakley, Jr., M. D. King, R. Arduini, D.
P. Garber, P. W. Heck, S. Mayor, E. Schmidt, W. L. Smith, Jr., and D. F.
Young, Cloud optical property retrieval (Subsystem 4.3). "Clouds and the
Earth's radiant energy system(CERES) algorithm theoretical basis
document, Volume III: Cloud analyses and radiance inversions (Subsystem
4)", NASA RP 1376 Vol. 3, edited by the CERES Science Team, in press,
1995.

Mishchenko, M. I., and L. D. Travis, Satellite retrieval of aerosol
properties over the ocean using polarization as well as intensity of
reflected sunlight, J. Geophys. Res., submitted, 1996. Greenwald, T. J.,
G. L. Stephens, T. H. Vonder Haar, and D. L. Jackson, A physical
retrieval of cloud liquid water over the global oceans using Special
Sensor Microwave/Imager (SSM/I) observations, *J. Geophys. Res., 98*,
18,471-18,488, 1993.

Mishchenko, M. I. and A. Macke, Scattering of light by large
nonspherical particles: ray-tracing approximation versus T- matrix
method, MISR Science Team Meeting, JPL, Pasadena, June 5-9, 1995.

Mishchenko, M. I., W. B. Rossow, A. Macke, and A. A. Lacis, Sensitivity
of cirrus cloud albedo, bidirectional reflectance, and optical thickness
retrieval accuracy to ice-particle shape, J. Geophys. Res., submitted,
1995.

Mishchenko, M. I., L. D. Travis, and D. W. Mackowski, T-matrix
computations of light scattering by nonspherical particles: a review, J.
Quant. Spectrosc. Radiat. Transfer, in press, 1996.

Mitchell, D. L., and W. P. Arnott, A model predicting the evolution of
ice particle size spectra and radiative properties of cirrus clouds.
Part II: Dependence of absorption and extinction on ice crystal
morphology, *J. Atmos. Sci., 51*, 817‑832, 1994.

Nakajima, T., M. D. King, J. D. Spinhirne, and L. F. Radke,
Determination of the optical thickness and effective particle radius of
clouds from reflected solar radiation measurements. Part II: Marine
stratocumulus, *J. Atmos. Sci., 48*, 728-750, 1991.

Prabhakara et al, 1993.

Ramanathan, V., and W. Collins, Thermodynamic regulation of ocean
warming by cirrus clouds deduced from the 1987 El Nino, *Nature, 351*,
27‑32, 1991.

Randall, D. A., Q. Sao, and C.-H. Moeing, A second-order bulk
boundary-layer model, *J. Atmos. Sci., 49*, 1903-1923, 1992.

Randall, D., B. Albrecht, S. Cox, D. Johnson, P. Minnis, W. Rossow, and
D. Starr, On FIRE at Ten, *Rev Geophys.*, in press,. 1995

Rawlins, F., and J. S. Foot, Remotely sensed measurements of
stratocumulus properties during FIRE using the C130 aircraft
multi-channel radiometer, *J. Atmos. Sci., 47*, 2488-2503, 1990.

Raymond, D. J., and A. M. Blyth, A stochastic mixing model for
nonprecipitating cumulus clouds, *J. Atmos. Sci., 43*, 2708-2718, 1986.

Rossow, W. B., and L. C. Garder, Cloud detection using satellite
measurements of infrared and visible radiances for ISCCP, *J. Climate,
6*, 2341-2369, 1993a.

Rossow, W. B., and L. C. Garder, Validation of ISCCP cloud detections,
J*. Climate, 6*, 2370-2393, 1993b.

Rossow, W. B., and R. A. Schiffer, ISCCP cloud data products, *Bull.
Amer. Meteorol. Soc., 72*, 2-20, 1991.

Rossow, W. B., and Y.-C. Zhang, Calculation of surface and top of
atmosphere radiative fluxes from physical quantities based on ISCCP
data, 2, Validation and first results, *J. Geophys. Res., 100*,
1166-1184, 1995.

Rossow, W. B., A. W. Walker, and L. C. Garder, Comparison of ISCCP and
other cloud amounts. *J. Clim., 6*, 2394-2418, 1993.

Sassen, K., D. Starr, and T. Uttal, Mesoscale and microscale structure
of cirrus clouds: Three case studies, *J. Atmos. Sci., 43*, 371--396,
1989.

Sassen, K., D. O\'C. Starr, G. G. Mace, M. R. Poellot, S. H. Melfi, W.
L. Eberhard, J. D. Spinhirne, E. W. Eloranta, D. E. Hagen, and J.
Hallett, The 5-6 December 1991 FIRE IFO II jet stream cirrus case study:
The influence of volcanic aerosols, *J. Atmos. Sci., 52*, 97-123, 1995.

Soden, B. J., and L. J. Donner, Evaluation of a GCM cirrus
parameterization using satellite observations, *J. Geophys. Res., 99*,
14,401-14,413, 1994.

Song, N., D. O\'C. Starr, D. J. Wuebbles, K. Kunkel, A. Williams, and S.
M. Larson, Effects of volcanic aerosols on global cloudiness, *J.
Climate*, (submitted), 1996.

Stackhouse and Stephens, 1991

Sui, C. H., K. M. Lau, W. K. Tao, J. Simpson, The tropical water and
energy cycles in a cumulus ensemble model. Part II: Equilibrium climate,
*J. Atmos. Sci., 51*, 711‑728, 1994.

Takano, Y., and K. N. Liou Radiative transfer in cirrus clouds. Part
III: Light scattering by irregular ice crystals, *J. Atmos. Sci., 52*,
818-837, , 1995.

Tiedtke, M., Representation of clouds in large-scale models, *Mon. Wea.
Rev., 117*,1641-1657, 1993.

Thompson, R. M., S. W. Payne, E. E. Recker, and R. J. Reed, Structure
and properties of synoptic‑scale wave disturbances in the intertropical
convergence zone of the eastern Atlantic, *J. Atmos. Sci., 36*, 53‑72,
1979.

Twohy, C. H., and J. G. Hudson, Measurements of cloud condensation
nuclei spectra within maritime cumulus cloud droplets, *J. Appl.
Meteor., 34*, 815--833, 1995.

Wallace, J. M., Effect of deep convection on the regulation of tropical
sea surface temperature, *Nature, 357*, 230‑231, 1992.

Wang, P.-H., P. Minnis, and G. K. Yue, 1994: Extinction (1-mm)
properties of high-altitude clouds from solar occultation measurements
(1985-1990): Evidence of volcanic aerosol effect. Submitted J. Geophys.
Res.

Wang, S., Modeling marine boundary-layer clouds with a two-layer model:
A one-dimensional simulation, *J. Atmos. Sci., 43*, 2373-2391, 1993.

Wang, S., B. A. Albrecht, and P. Minnis, Regional modeling of marine
boundary layer clouds, *J. Atmos. Sci., 50*, 4022-4043, 1993.

Whitlock, C. H., T. P. Charlock, W. F. Staylor, R. T. Plnker, I. Laszlo,
A. Ohmura, H. Gilgen, T. Konzelman, R. C. DiPasquale, C. D. Moats, S. R.
LeCroy, and N. A. Ritchey, First global WCRP shortwave surface radiation
budget dataset, *Bul. Amer. Met. Soc., 76*, 905-922, , 1995.

Wielicki, B. A., J. T. Suttles, A. J. Heymsfield, R. M. Welch, J. D.
Spinhirne, M. L. Wu, D. O\'C. Starr, L. Parker, and R. F. Arduini, The
27-28 October 1986 FIRE IFO Cirrus Case Study: Comparison of radiative
transfer theory with observations by satellite and aircraft, *Mon. Wea.
Rev., 118*, 2356-2376, 1990.

Winker et al, 1995.

Wylie, 1994.

Wylie, D. P., and W. P. Menzel, Two years of cloud cover statistics
using VAS, *J. Climate, 2*, 380-392, 1989.

Young, D. F., S. Mayor, P. Minnis, J. M. Intrieri, S. Matrosov, and J.
Snider, Comparison of satellite and surface-based remote sensing of
cloud microphysical properties during FIRE Cirrus Phase II, *Proc. 8th
Conf. Atmos. Radiation, Nashville, TN, Jan. 23-28, 1994*, 231-233, 1994.

**APPENDIX B - ACRONYMS, ABBREVIATIONS and NOTATIONS**

  ------------------- ---------------------------------------------------
  2D                  two dimensional

  2D-C                PMS optical array probe; 25 micron to 1 millimeter

  2D-P                PMS optical array probe; 100 micron to 6 millimeter

  ACE-1               Atmospheric Chemistry Experiment; first mission

  ADEOS               Advanced Earth Observing Satellite (Japan)

  AEAP                Atmospheric Effects of Aviation Program

  AEM-B               second Application Explorer Mission

  AES                 Atmospheric Environment Service (Canada)

  AIDJEX              Arctic Ice Dynamics Joint Experiment

  AIRS                Atmospheric Infrared Sounder

  AMS                 American Meteorological Society

  AMSR                Advanced Microwave Scanning Radiometer

  ARC                 Ames Research Center

  ARM                 Atmospheric Radiation Program

  ARMCAS              Arctic Radiation, Microphysics, Clouds, and
                      Aerosols Study

  ASAP                as soon as possible

  ASCII               American Standard Code for Information Interchange

  ASTER               Advanced Spaceborne Thermal Emission and Reflection
                      radiometer

  ASTEX               Atlantic Stratocumulus Transition Experiment

  ATSR                Along-Track Scanning Radiometer

  AVHRR               Advanced Very High Resolution Radiometer

  AVIRIS              Airborne Visible/Infrared Imaging Spectrometer

  BASE                Beaufort Arctic Seas Experiment

  BRDF                bi-directional reflectance distribution function

  Bull. Amer. Meteor. Bulletin of the American Meteorological Society
  Soc.                

  C                   cirrus, centigrade

  C1                  ISCCP hourly cloud analyses

  C-130               NCAR airplane

  C-131A              University of Washington airplane

  CAR                 Cloud Absorption Radiometer

  CART                Cloud and Atmospheric Radiation Testbed

  CARSS               Center for Atmospheric and Remote Sounding Studies

  CCD                 charged-couple device

  CCN                 cloud consendation nuclei

  CD-ROM              compact disk-read only memory

  CEPEX               Central Equatorial Pacific Experiment

  CERES               Clouds and the Earth's Radiant Energy System

  CFD                 continuos flow diffusion

  CIMMS               Cooperative Institute for Mesoscale Meteorological
                      Studies

  CIRES               Cooperative Institute for Research in Environmental
                      Sciences

  Cirrus-I            Cirrus IFO-I (Wisconsin 1986)

  Cirrus-II           Cirrus IFO-II (Kansas 1991)

  CLS                 Cloud Lidar System

  cm                  centimeter (10-2)

  CN                  cloud nuclei

  COARE               Coupled Ocean-Atmosphere Regional Experiment

  CO2                 carbon dioxide

  conf                conference

  CRM                 cloud resolving model

  CSIRO               Commonwealth Scientific and Industrial Research
                      Organization (Australia)

  CSU                 Colorado State University

  CVI                 counterflow virtual impactor

  CV-580              University of Washington aircraft

  CY                  calendar year

  DAAC                Distributed Active Archive Center (EOS)

  DAT                 digital archival tape

  DC-8                NASA ARC aircraft

  DIAL                Differential Absorption Lidar

  DMA                 differential mobility analyzer

  DMS                 daily mission scientist

  DMWG                Data Management Working Group

  DOD                 Department of Defense

  DOE                 Department of Energy

  DRI                 Desert Research Institute

  ECMWF               European Center for Medium-Range Weather Forecasts

  EDX                 energy-dispersive x-ray

  ELDORA              Electra Doppler Radar

  EOS                 Earth Observing System

  EOS-AM (AM-1)       first launch in NASA EOS series (mid-1998)

  EOSDIS              Earth Observing System Data and Information System

  EOS-PM              second launch in NASA EOS series (late 2000)

  EOSP                Earth Observing Scanning Polarimeter

  ERB                 Earth Radiation Budget instrument ( NIMBUS 6 & 7)

  ERBE                Earth Radiation Budget Experiment (ERBS)

  ERBS                Earth Radiation Budget Satellite

  ER-2                NASA ARC aircraft

  ERS-1               European Remote-Sensing Satellite-1

  ETL                 Environmental Technology Laboratory (NOAA)

  ETO                 extended time observation

  EUCREX              European Cloud Radiation Experiment

  FARS                Facility for Atmospheric Research (U. of Utah)

  FAX                 facsimile

  FIRE                First ISCCP Regional Experiment

  FIRE Stratus        Marine Stratocumulus IFO (California 1987)

  FIRE I              FIRE phase I (1984-1989)

  FIRE II             FIRE phase II (1990-1994)

  FIRE III            FIRE phase III (1995- ??)

  FST                 FIRE III Science Team

  FTIR                fourier transform interferometer radiometer

  ftp                 file transfer protocol

  FTS                 fourier transform spectrometer

  GARP                Global Atmospheric Research Program

  GATE                GARP Atlantic Tropical Experiment

  GCM                 general circulation model; global climate model

  GCSS                GEWEX Cloud System Studies

  Geophys. Res. Lett. Geophysical Research Letters

  GEWEX               Global Energy and Water Cycle Experiment

  GFDL                Geophysical Fluids Dynamics Laboratory

  GHz                 gigahertz (10+9)

  GISS                Goddard Institute for Space Studies

  GLAS                Geoscience Laser Altimeter System

  GLI                 Global Imager

  GMS                 Global Meteorological Satellite (Japan)

  GOES                Geostationary Operational Environmental Satellite

  GSFC                Goddard Space Flight Center

  HDF/netCDF          hierarchical data format/net common data format

  HIRS                High Resolution Infrared Radiation Sounder

  HIS                 High-resolution Interferometric Sounder

  HNO3                nitric acid

  hz                  hertz

  IFO                 intensive field observations

  IMG                 Interferometric Monitor of Greenhouse Gases

  IN                  ice nuclei

  INDOEX              Indian Ocean Experiment

  IOP                 intensive observing period

  IR                  infrared

  ISCCP               International Satellite Cloud Climatology
                      Experiment

  IWC                 ice water content

  IWP                 ice water path

  J. Appl. Meteor.    Journal of Applied Meteorology

  J. Atmos. Sci.      Journal of the Atmospheric Sciences

  J. Atmos. Oceanic   Journal of Atmospheric and Oceanic Technology
  Technol.            

  J. Climate          Journal of Climate

  J. Geophy. Res.     Journal of Geophysical Research

  JPL                 Jet Propulsion Laboratory

  kg                  kilogram (10+3)

  kHz                 kilohertz (10+3)

  km                  kilometer (10+3)

  kW                  kilowatts (10+3)

  l                   liter

  Landsat             NASA Earth observing satellite series

  LaRC                Langley Research Center

  LBA                 Large-Scale Land Processes in the Basin of the
                      Amazon

  LEADEX              Lead Experiment

  LES                 large eddy simulation

  Lidar               light detection and ranging

  LIS                 Lightning Imaging Sensor

  LITE                Lidar In-space Technology Experiment

  LLNL                Lawrence Livermore National Laboratory

  LWC                 liquid water content

  m                   meter

  MAS                 MODIS Airborne Simulator

  MAST                Monterey Area Ship Track Experiment

  MASTER              MODIS/ASTER Airborne Simulator

  MCC                 Mesoscale Convective Complex

  Meteorol. Atmos.    Meteorological and Atmospheric Physics
  Phys.               

  Meteosat            geosynchronous meteorology satellite (ESA)

  MFOV 2              Multi-Field of View 2 radiometer

  Mhz                 megahertz (10+6)

  MIMR                Multifrequency Imaging Microwave Radiometer

  min                 minute

  MIR                 Microwave Imaging Radiometer

  MISR                Multi-angle Imaging Spectro-Radiometer

  MODIS               Moderate-resolution Imaging Spectrometer

  Mon. Wea. Rev.      Monthly Weather Review

  MPIR                Multispectral Pushbroom Imaging Radiometer

  mrad                milliradian (10-3)

  MSFC                Marshal Space Flight Center

  MST                 Mission Selection Team

  MTPE                Mission To Planet Earth

  N                   North

  NaCl                sodium chloride

  NASA                National Aeronautics and Space Administration

  NCAR                National Center for Atmospheric Research

  NCEP                National Centers for Environmental Prediction

  NCSA                National Center for Super Computing Applications

  NIMBUS              NASA meteorological satellite series (1-7)

  NIR                 near infrared

  nm                  nanometer (10-9)

  NOAA                National Oceanic and Atmospheric Administration

  NOx                 nitrogen oxides (NO, NO2, NO3)

  NOy                 total active nitrogen

  NSF                 National Science Foundation

  N.W.T.              Northwest Territories

  OFAP                Observational Facilities Advisory Panel

  OGP                 Office of Global Programs

  ONR                 Office of Naval Research

  Opt. Lett.          Optics Letters

  O3                  ozone

  P3                  NOAA aircraft

  P-3B                NASA Wallops aircraft

  PAN                 peroxyacetyl nitrate

  PDL                 Polarization Diversity Lidar

  Ph. D.              Doctor of Philosophy

  PI                  principal investigator

  PMS                 Particle Measurement Systems, Inc., Boulder, CO

  PR                  Precipitation Radar

  Proc                proceedings

  PSA                 particle surface area

  PSU                 Penn State University

  PSUCS               Penn State University Continental Stratus

  POLDER              Polarization and Directionality of Earth
                      Reflectances

  PVM                 Particulate Volume Monitor

  RAMS                Radiation Airborne Measurment System

  Rev. Geophys.       Reviews of Geophysics

  RH                  relative humidity

  ROCEW               Role of Clouds, Energy and Water (NSF)

  RP                  research publication (NASA)

  S                   stratus, South

  s, sec              second

  SAGE I & II         Stratospheric Aerosol and Gas Experiment (I-AEM-B;
                      II-ERBS)

  SASS                Subsonic Assessment Program (part of AEAP)

  SBIR                Small Business Innovative Research

  Sc                  stratocumulus

  SCAR B              Smoke, Clouds And Radiation-Brazil

  SCMS                small cumulus microphysical study

  SDSMT               South Dakota School of Mines and Technology

  SEM                 scanning electron microscopy

  SHEBA               Surface HEat Budget of the Arctic Ocean

  Skyhi               atmospheric model used at GISS

  SOCEX I & II        Southern Ocean Cloud Experiments

  SO2                 sulfur dioxide

  SPEC                Stratton Park Engineering Co. Inc.

  SPFR                Spectral Flux Radiometer

  SSFR                Solar Spectral Flux Radiometer

  SSM/I               Special Sensor Microwave/Imager

  SSM/T               Special Sensor Microwave/Temperature sounder

  SSM/T2              Special Sensor Microwave/Temperature Sounder;
                      version 2

  SST                 sea surface temperature

  Strato 2C           German UAV for atmospheric measurements

  STERAO              Stratosphere-Troposphere Experiments: Radiation,
                      Aerosols and Ozone

  SW                  shortwave

  SUCCESS             Subsonic Aircraft: Contrail and Cloud Effects
                      Special Study

  TEM                 transmission electron microscopy

  TIROS               Television Infrared Observation Satellite

  TMI                 TRMM Microwave Imager

  TOGA                Tropical Ocean and Global Atmosphere

  TOVS                TIROS Operational Vertical Sounder

  TRMM                Tropical Rainfall Measuring Mission

  TSCC                Tilt-Scan CCD Camera

  TWP                 Tropical Western Pacific

  T-39                NASA Langley aircraft

  U, Univ             university

  UAV                 unmanned aerospace vehicles

  UHF                 ultra-high frequency

  UND                 University of North Dakota

  URL                 Uniform Resource Locator (Internet)

  US                  United States

  UT                  upper troposphere

  UTC                 Universal Time Coordinated

  VAS                 VISSR Atmospheric Sounder

  VCR                 video cassette recorder

  VIRS                Visible and Infrared Scanner

  VISSR               Visible/Infrared Spin-Scan Radiometer

  vol                 volume

  W                   West

  WB-57F              NCAR aircraft

  WCRP                World Climate Research Program

  WG                  working group of GCSS

  WPDN                Wind Profiler Demonstration Network

  X-Band              frequency range from 5.2 to 10.9 GHz

  Z                   altitude

                      

                      
  ------------------- ---------------------------------------------------

**Appendix C: FIRE Scientific Organization and Data Management**

**TABLE OF CONTENTS**

1.0 LEAD MANAGEMENT 1

2.0 PROJECT MANAGEMENT 2

3.0 FIRE‑III SCIENCE TEAM 3

3.1 FIRE Working Groups 4

4.0 DATA MANAGEMENT 7

4.1 Data Management Responsibilities 8

4.1.1 Working Groups 8

4.1.2 Principal Investigators 9

4.1.3 Langley DAAC 10

4.1.4 Project Office 13

4.2 Data Products 13

4.3 Data Categories 15

4.4 Data Protocol and Publications Plan 15

4.4.1 Data Protocol 16

4.4.2 Data Publication 17

5.0 FIRE MISSION/MEETING MILESTONES 18

6.0 NATIONAL AND INTERNATIONAL COLLABORATIONS 18

**Appendix C: FIRE Scientific Organization and Data Management**

**1.0 LEAD MANAGEMENT**

FIRE has been a multi‑agency effort since its inception. The goals of
FIRE are not bounded by a single agency\'s mission; neither is the
talent base required to address the complex problems of cloud‑climate
research. Close interagency cooperation in the past has made possible
FIRE\'s advancements in our understanding of these climatically
important cloud systems. It is intention of FIRE\'s participants to
maintain and further refine this spirit of interagency cooperation.

While NASA will continue to serve as the lead agency for FIRE‑III, other
federal agencies including National Science Foundation (NSF), Office of
Naval Research (ONR), Department of Energy (DOE), Department of Defense
(DOD), and National Oceanic and Atmospheric Administration (NOAA) will
remain strong participants in FIRE‑III. The Radiation Sciences Program,
Atmospheric Science Branch, NASA Headquarters, will provide overall
cognizance of the FIRE project and will represent FIRE to the Working
Group on Data Management for WCRP Radiation Projects. Contact points are
located at the following offices:

Dr. Robert Curran Dr. Robert Abbey, Jr. Dr. Michael Ledbetter

Atmospheric Science Branch Office of Naval Research Arctic Systems
Science Program

NASA Headquarters/YS Code 1122 MM Office of Polar Programs

Washington, DC 20546 800 N. Quincy Street National Science Foundation

Arlington, VA 22217 2401 Wilson Boulevard

Arlington, VA 22230

Dr. Jay Fein Dr. Pam Stephens Dr. Richard Lawford

Atmospheric Sciences Atmospheric Sciences NOAA/OGP

National Science Foundation National Science Foundation Mail Stop GP

1800 G Street, NW 1800 G Street, NW 1100 Wayne Avenue

Washington, DC 20550 Washington, DC 20550 Silver Spring, MD 20910

Dr. Pat Crowley Dr. Rex Fleming

Department of Energy Director, Climate Observations

Environmental Sciences Division NOAA/ERL

Research ER‑74 3300 Mitchell Lane, Suite 175

Washington, DC 20585 Boulder, CO 80301

**2.0 PROJECT MANAGEMENT**

The FIRE project activities will be managed by the FIRE Project Office
at NASA\'s Langley Research Center. The FIRE project manager will be
responsible for the overall management, coordination, and reporting of
the project activities. These responsibilities will include interacting
with the Radiation, Dynamics, and Hydrology Branch and Physical Climate
and Hydrology Branch management at NASA Headquarters, the Meteorology
Research Program management at ONR, and the other agency
representatives; overall cognizance of project planning, schedules, and
field operations; and allocation of approved funding to support the
scientific objectives. The project manager will be assisted by a project
scientist and a project staff, which will include: an Operations
Manager, a Data Manager, and a Project Coordinator.

Project Scientist ‑ The FIRE Project Scientist will be responsible for
all scientific aspects of FIRE. The project scientist will (a) act as a
scientific advisor to the project manager, (b) represent the members of
the science team in their relationship with the project manager, (c)
maintain an oversight of the scientific integrity of the project; (d)
review and make recommendations of proposed modifications to selected
proposals as warranted; and (e) participate in negotiations regarding
allocations of specialized project resources among approved
investigations.

Operations Manager ‑ The Operations Manager will have overall
responsibility for organizing, scheduling, and conducting field
operations, preparation of mission plans, establishing mission
objectives with the MST Chairman, determining special support
requirements, conducting planning and debriefing sessions, and
operational procedures. The Operations Manager is also responsible for
designing the specific and facilitating operationally feasible flight
profiles to meet the scientific objectives and for coordinating the
experimental requirements of measurement platforms for resources,
testing, and integration for all field measurements. Lastly, the
Operations Manager is responsible for the setup, testing, and operation
of the mission operations site.

Data Manager ‑ The Data Manager will be responsible for coordinating the
types, scope, and quantity of data collected during the intensive field
and extended‑time activities and its archiving. The Data Manager will
serve as the Chairperson for the Data Management Working Group. The Data
Manager will ensure that the data is submitted as required to the FIRE
Central Archive and eventually released to the scientific community.

Project Coordinator ‑ The Project Coordinator will provide
administrative support to the FIRE Project Office, including logistical
and reimbursement support in the planning and conducting of FST meetings
and field missions as required.

**3.0 FIRE‑III SCIENCE TEAM**

The FIRE‑III Science Team (FST) will be comprised of the principal
investigators of those agency‑approved proposals directly related to
FIRE III research. Appointment to the FST will be based on the
recommendation of the supporting agency. The term of participation on
the team will continue as long as the approved research continues. The
team shall determine its own structure and method for interaction. Ex
officio members may be appointed to the team, as needed, by the project
manager.

The FST will be responsible for implementing the broad scientific
objectives of the project in accordance with the selected investigators.
Additional responsibilities will be to:

> a\. Develop implementation plans for FIRE research including:
>
> 1\. field experiments.
>
> 2\. data management.
>
> 3\. research programs.
>
> b\. Recommend and perform coordinated research activities, including
> the interface of modeling and experiments.
>
> c\. Conduct individual investigations in accordance with approved
> proposals.
>
> d\. Hold meetings and workshops, as needed, to plan and assess
> research programs.
>
> e\. Designate the makeup and responsibilities of special working
> group, as needed, to address special task areas.
>
> f\. Establish a data protocol that will promote the timely publication
> and dissemination of scientific results.

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> ![](media/image4.wmf){width="7.75in" height="9.86111111111111in"}
>
> iii\. Define data sources, requirements and schedules essential to
> working group studies.
>
> iv\. Exchange data among PST and working group members.
>
> v\. Oversee publication of joint research results from tasks
> identified in item i.

The Data Management Working Group (DMWG) will be comprised of key
members from the Cirrus and Arctic working group, as well as from the
FIRE Central Archive. The FIRE Data Manager will chair the DMWG. The
responsibilities of the DMWG are:

> i\. provide interaction and coordinate data management decisions among
> the FIRE data gathering working group, the FIRE Central Archive, and
> the principal investigators.
>
> ii\. ensure uniform FIRE data characteristics (throughout all working
> group and FIRE researchers)
>
> iii\. define listings of uniform parameter units and conventions for
> reduced data products.
>
> iv\. oversee the plans, progress, and performance of the FIRE Central
> Archive (see section 4.1.3).

**4.0 DATA MANAGEMENT**

Data management is an ongoing activity, beginning immediately in the
pre‑experiment phase and continuing through the end of FIRE‑III.
Collaboration and data exchange of data among FIRE investigators will be
required to produce integrated analyses of multi‑platform, multi‑scale,
and mufti‑spectral data sets; these integrated analyses are central to
the accomplishment of the FIRE‑III science objectives. In addition, the
data management activities will seek to ensure the availability of FIRE
data and analysis products to the entire science community. To maximize
these data management goals, the FST will develop a data management and
protocol plan consistent with the supporting agencies\' goals for the
sharing of the data, the rapid dissemination of results, and
documentation of measurements obtained.

At a minimum, the data management activities will disperse most of the
data reduction and processing functions to the FIRE investigators
engaged in collecting and analyzing the data, but to hold the resultant
data sets and analysis products centrally for ready access by all FIRE
investigators. The FIRE Central Archive, located at the Langley Research
Center EOSDIS Distributed Data Active Archive (DAAC), and the FIRE
Project Office will provide a centralized source of information and
copies of data which are centrally archived. The FST, composed of the
investigators , will coordinate the decentralized data reduction and an
analysis activities . In addition , the FIRE Central Archive will
transfer, from time to time, certified FIRE data to the scientific
community.

Data management activities in FIRE will insure the exchange of data
among FIRE investigators that is required to produce the integrated
analyses of multi‑platform, multi‑scale, and mufti‑spectral data sets;
these integrated analyses are central to the accomplishment of the FIRE
science objectives. In addition, the data management activities will
insure the availability of FIRE data and analysis products to the entire
science community. These activities will be carried out by four
organizational components within FIRE:

> \(1\) the Cirrus and Arctic Working Group,
>
> \(2\) the individual FIRE principal investigators,
>
> \(3\) the FIRE Central Archive, and
>
> \(4\) the FIRE Project Office.

The strategy embodied in this organization is to disperse most of the
data reduction and processing functions to the FIRE investigators
engaged in collecting and analyzing the data, but to

hold the resultant data sets and analysis products centrally for ready
access by all FIRE

investigators. The FIRE Central Archive and the FIRE Project Office will
provide a centralized

source of information and copies of data which are centrallv archived,
whereas the FIRE Working

Groups, composed of the investigators, will coordinate the decentralized
data reduction and

analysis activities. In addition, the FIRE Central Archive will
transfer, from time to time, certified

FIRE data to EOSDIS and for other organizations for permanent archive
and for open access by the scientific community.

**4.1 Data Management Responsibilities**

**4.1.1 Working Groups**

There are two data‑gathering FIRE working group ‑ a Cirrus Working
Group, and an Arctic Working Group. These working group will be composed
of FIRE principal investigators pursuing research relevant to that
working group. The data management responsibilities of the individual
principal investigators, as dispersed elements of the FIRE data
processing system, could become onerous if not coordinated properly.
Therefore, the FIRE Working Groups must govern these individual
activities to insure progress toward the FIRE science objectives. The
data management functions of the FIRE Working Groups are:

1\. To determine the content and format of all principal investigator
data sets to be submitted to

the Langley Research Center Distributed Active Archive System (LaRC
DAAC). If requested,

only FIRE‑III researchers will have access to data in the LaRC DAAC
during the time period for

data certification.

2\. To set standards for data quality, documentation of all data sets,
and certification criteria for data products that will be released to
the at‑large scientific community.

3\. To assign a data category\" (section 8.5) to each data parameter
that reflects it\'s usefulness

to subsequent data analysis and whether and when it should be archived.

4\. To select case study data sets for special intensive processing
(including reformatting) by all relevant principal investigators and to
identify other additional processing of data to accomplish FIRE‑III
objectives.

5\. To coordinate data management decisions and ensure uniform FIRE‑III
data characteristics.

6\. To certify, within 6‑24 months after acquisition, those data
products from the LaRC DAAC

that will be released to the scientific community.

**4.1.2 Principal Investigators**

All data reduction and analysis functions in FIRE‑III reside with the
scientists carrying out their research as part of the program. To
encourage the interactions of these researchers needed to integrate the
various observations and models into a more comprehensive understanding
of clouds and their effects, FIRE iii investigators will have free and
timely access to all data collected during FIRE‑III, either by
individual principal investigators or collected from satellites.
Coordination of data analysis and modeling activities requires all
principal investigators to perform certain other tasks as part of the
FIRE‑iii data management scheme. These functions are:

1\. To provide to the LaRC DAAC written information concerning data
holdings, including all

data collected as part of FIRE‑III and other data deemed relevant to
FIRE‑III research.

2\. To save all data collected in unreduced form for five years so that
reduction of data can be repeated if necessary.

3\. To provide to the LaRC DAAC copies of all category 1, 2, 3 (when
practical), and 4 (if desired) observations in a mutually‑agreed upon
format (see section 7.2 for definition of data category) accompanied by
complete instrument, reduction algorithm and data format documentation.

4\. To provide, within 9 months after acquisition, to the LaRC DAAC
copies of any data analysis products deemed relevant to the
accomplishment of FIRE‑III objectives, accompanied by appropriate
documentation .

5\. To provide for archival of all submitted data sets by producing
back‑up copies of all data and taking other necessary precautions to
ensure the preservation of the FIRE‑III data.

6\. To provide to other FIRE‑III investigators or the LaRC DAAC, upon
request, copies of other data sets acquired for FIRE‑III research, that
are relevant to other FIRE‑III studies.

7\. To provide to other FIRE-III investigators reasonable access to
unreduced observations to facilitate particularly crucial mufti‑data
analyses.

**4.1.3 Langley DAAC**

The LaRC DAAC will serve as the FIRE‑III Central Archive. The LaRC DAAC
is responsible for archiving and distributing NASA science data in the
areas of radiation budget, clouds, aerosols, and tropospheric chemistry.
It will also archive some of the data sets which result from the EOS
program and other elements of Mission to Planet Earth.

The DAAC has developed an on‑line computer system which allows the user
to logon, search through the DAAC\'s data inventory, choose desired data
sets, and place an order. Data may be received either electronically
(via FTP) or on media such as 4 mm tape, 8 mm tape, or CD‑ROM
(prepackaged datasets only).

Users with an X‑Windows terminal (e.g., Motif) or a Sun Open Windows
display system with access to Internet, may log onto the system by
entering:

> xhost + eosdis.larc.nasa.gov
>
> (or: xhost + 192.107.191.17)
>
> telnet eosdis.larc.nasa.gov
>
> login name: ims password: larcims

At the prompts, enter x for the X‑Windows interface and then your
display name (name of your workstation followed by \": 0\" or internet
address followed by \": 0\").

Users with access to NCSA Mosaic can use the following URL address:

> http://eosdis.larc.nasa.gov/

Users without access to a terminal with an X‑Windows display system but
who have access to Internet may log onto the system by entering:

> telnet eosdis.larc.nasa.gov
>
> login name: ims password: larcims

At the prompt, enter c for the character interface and then press
return.

Users who cannot access the system or who have questions concerning the
Langley DAAC may contact:

> Langley DAAC User and Data Services
>
> Mail Stop 157B
>
> NASA Langley Research Center
>
> Hampton, VA 23681‑0001
>
> Phone: (804) 864‑8656 FAX: (804) 864‑8807
>
> email: larc@eos.nasa.gov
>
> For further information on LaRC DAAC contact Ms. Sue Sorlie, Langley
> Research Center, 804‑864‑8660, s.e.sorlie@larc.nasa.gov or John Olson
> at 804‑864‑8609, olson@magician.larc.nasa.gov.
>
> The LaRC DAAC will provide a centralized data holding and on‑line
> system in order to facilitate easy access to all FIRE‑III data by all
> FIRE‑m investigators. Since most of the satellite data are not
> collected directly by FIRE‑m principal investigators, the LaRC DAAC
> will also be responsible for holding of the satellite data sets
> required for FIRE‑m research from the relevant satellite operating
> agencies. The specific data management functions of the FIRE‑III Data
> Archive are:
>
> 1\. To hold all reduced observations and data analysis products
> submitted by individual
>
> principal investigators or group of principal investigators upon the
> request of the FIRE‑III
>
> Science
>
> Team.
>
> 2\. To hold all satellite data sets required for FIRE‑III as specified
> by the FIRE‑III Science
>
> Team.
>
> 3\. To provide, upon request, copies of any data sets to FIRE‑III
> investigators (et minimal cost
>
> to investigators).
>
> 4\. To produce a data ingest request of the complete FIRE‑III data
> holdings of the archive and
>
> the individual principal investigators indicating the current analysis
> statue of these data. The data
>
> ingest request entries should provide information about the location
> of the data holding, the
>
> instrument(s) performing the observations, the temporal and spatial
> resolution of the data, and the
>
> format of the data.
>
> 5\. To update the data ingest request every year and to make it
> available to FIRE‑III
>
> investigators in both hard copy and electronically (on‑line dial‑up)
> form.
>
> 6\. To restrict access to the data products in the LaRC DAAC to only
> researchers associated with the FIRE‑III project, if so requested by
> the FST. The at‑large scientific community will not then have access
> to these data sets until they are released.

7\. To \"release\", on an annual basis, certified FlRE‑III data from the
permanent archive for

unrestricted access by the at‑large scientific community. The
\"transfer\" process removes the access

restraints to the at‑large scientific community.

8\. To provide for archival of the permanent FIRE‑III data in the data
archive by producing

back‑up copies of all data and taking other necessary precautions to
ensure the preservation of the

data.

9\. To publish documentation, such as a FIRE‑III Data Archive Users
Manual that describes

the contents of the FIRE‑III Data Archive, data formats, data request
information, and other

pertinent descriptive material.

**4.1.4 Project Office**

FIRE data management structure vests the primary data processing
function with the individual scientific investigators, the information
and archival functions with the Central Archive, and the decision‑making
with the FIRE Working Groups. The Project Office must provide for
liaison among these different group. The specific data management
functions of the project office are:

> 1\. To provide liaison between the FIRE Working Groups (and individual
> principal investigators) and the data collecting agencies and agencies
> operating observing platforms required by FIRE.
>
> 2\. To provide liaison between the FIRE Central Archive and the
> satellite and other data collecting group to facilitate the
> acquisition of the data sets needed for FIRE.
>
> 3 .To provide for a close working relationship among the FIRE Working
> Groups and the Central Archive by including a representative of the
> Central Archive on the Project Office staff who can attend FIRE
> Science Team meetings.

**4.2 Data Products**

There are several types of data products that will be acquired,
submitted, and archived at the LaRC DAAC. These products, which will be
obtained from a variety of instruments onboard satellite, airborne, or
surface‑based platforms during the field experiment, are as follows:

1\. Guide/Summary‑‑written information about the data holdings of the
individual PI\'s,

including location of the data holdings instrument(s) performing the
observations; resolution and

area coverage of the data; date, time, and location of the observations;
format of the data; and

analysis statue of these data.

2\. Raw data‑‑original observations acquired by the instrument, in
instrument units (voltages,

etc.).

3\. Reduced data‑‑observations converted to the physical quantity
directly sensed by the

instrument with quality control inspection and removal of bad data.

4\. Value‑added products‑‑physical quantifies derived from the
observations, including

documentation on the analysis algorithm and any auxiliary data sets used
in the analysis.

5\. Calibration, quality, and navigation information‑‑describes the
conversion to physical

units, the conditions of observation and the location of the
observation.

6\. Instrument documentation and data tape format description.

7\. Data for special case studies which have been arranged for
intercomparison of multi­

platform observations.

8\. Data selected for special processing to facilitate model studies.

9\. Status and bibliography of FIRE‑III publications.

The data acquired by the individual experimenters will be reduced to
final values and forwarded to the LaRC DAAC. The format for the
submittal of data to the archive must be in ASCII or HDF/netCDF (see
Appendix F). In addition, a written description of the readme file or
pertinent remarks should be included in the data file or in a separate
file to be submitted with the data. The Langley DAAC will assist data
producers putting data into HDF.

Transfer of the final data between the investigators and the LaRC DAAC
may be accomplished by electronic data transfer using ftp.

Transfer of the data from the data archive to the investigators will be
clone either physically (using DATs, 9‑track tapes or floppy disks) or
interactively (via electronic transfer) where such systems are available
(email or ftp).

**4.3 Data Categories**

Each of the data products will be assigned a data \"category\" by the
science team which will reflect its usefulness to subsequent data
analysis and whether and when it should be archived. Table 2 outlines
the definition of the four data categories. The FIRE‑III Science Team
will be responsible for these assignments, coordinated with the
responsible PIs.

Table 2 ‑ Definition of Data \"Categories\"

> [Category]{.underline} [Definition]{.underline}
> [Usefulness]{.underline} [Archive?]{.underline}
>
> 1 Fundamental measured Critical ASAP or 3‑6 months
>
> parameter
>
> 2 Fundamental measured \"A lot of people will use it\" 9‑18 months
>
> parameter
>
> 3 Reduced or value‑added Useful Welcomed; not
>
> parameter required

**4.4 Data Protocol and Publications Plan**

The FIRE-III data protocol and publication plan has been prepared to
encourage an orderly and timely analysis, interpretation, and
publication of the data obtained during FIRE‑III. It is hoped that the
development and distribution of this plan will enhance the science
output by promoting cooperation among the investigators and encouraging
the early publication of results, thereby enriching the scientific
interpretation of the data obtained from single and ensemble of
instruments.

The FIRE ‑III Science Team (FST) is responsible for the certification of
data submitted to the permanent FIRE‑III data archive located at the
Langley Research Center (LaRC) Distributed Active Archive Center (DAAC).
The certification process will normally take 6 -24 months after
acquisition. During the certification process period, the following set
of data protocol and publication ground rules will be agreed upon and
abided to by all FST members as a condition of their participation in
the FIRE‑III project.

**4.4.1 Data Protocol**

1\. FST members will have free and timely access to all FIRE‑III data
acquired during the project. The normal vehicle for data dissemination
will be a transfer of data via the LaRC DAAC; however, direct transfer
of data between investigators is also encouraged.

2\. Each investigator\'s data is proprietary until the data appear in
publication or, if the data are included in the LaRC DAAC, until this
archive is published/released to the scientific community. FST members
who collect FIRE‑III data are responsible for the reduction, analysis,
interpretation and publication of their data and research results.

3\. An investigator whose unpublished data are to be used in an
investigation has the right to be included among the authors of any
resulting publication. The investigator may refuse co­ authorship but not
the use of this data. The investigator must provide information
concerning the quality of the data and may require that suitable caveats
regarding the data be included in the publication. It is the
responsibility of the sponsoring investigator to solicit the
participation of the investigator whose data are to be used as early as
possible during the formative stages of the investigation.

4\. FST members may release their own data to whomever they wish. They
may not release the data of other investigators without consent.

5\. Selected sets of reduced data obtained by investigators
participating in collaborative research will be made available to FST
participants within 9 months following acquisition.

6\. The FST will normally provide the forum in which collaborative
investigations are planned and executed; however, this is not meant to
discourage collaborative investigations outside the scope of FIRE‑III.

7\. Any data sets resulting from collaborative investigations among FST
members will be made available to the LaRC DAAC. This includes all
collaborative efforts both within and outside the FST.

8\. Scientists who are not FST members, co investigators, or associates
may participate in investigations using unpublished FIRE‑III data
provided they are sponsored by a FST member and they make available
whatever data they plan to use to the LaRC DAAC at the beginning of the
participation. Co‑investigators and associates may participate in the
investigation of a FST member.

**4.4.2 Data Publication**

Early publication of results from FIRE‑III research is strongly
encouraged. Towards this goal, the following minimum publication plan
has been developed:

1\. An overview synopsis of the FIRE‑III program will be prepared by
program personnel and key FST researchers for publication in an
appropriate journal. The paper will describe the scientific objectives,
operational plans, and potential results of the major FIRE‑III
activities to the scientific community during the early stages of
FlRE‑III.

2\. A synopsis of the key operational activities and possible results
from the FIRE‑III field experiment will be prepared by project personnel
and key FST researchers for publication in an appropriate journal. This
paper will be designed to be a \"quick look\" publication to inform the
scientific community at an early stage of the implementation of the
mission and possible highlighted observations.

3\. Publication of results from the FIRE‑III Field experiment may be in
a special issue of an appropriate journal. The special issue decision
will be made by the FST. The issue will contain (a) an overview paper
and (b) science papers.

The overview paper will be co‑authored by program personnel and key
researchers and will include a statement of the goals of the particular
field mission. It will describe the field site, the instrumentation
involved in the deployment, flight plans, and other operational
activities.

The science papers will be contributions from the FIRE‑III
investigators. They will be \"stand alone\" papers that the
investigators will prepare summarizing measurements, data
interpretation, and data correlations. Collaborative papers between
different group are strongly encouraged.

4\. A firm timetable for the publication of the special issue papers
will be established whereby all of the papers will be submitted for
publication prior to a mutually agreed date, usually within a year after
the field experiment completion.

5\. Oral presentations of selected results by the investigators and the
project may be presented together at an appropriate conference.

6\. Additional publications or presentations by FIRE‑III investigators
beyond those identified above are expected and encouraged. Other
publications should, however, be in harmony with the data protocol and
publication plan contained in this document.

**5.0 FIRE MISSION/MEETING MILESTONES**

The listing of the key FIRE missions and meetings is given in table 3.
An attempt has been made to coordinate the various meetings between the
Cirrus and Arctic working group so that those researchers who are
participating in both missions can attend. Whenever the two group hold
coincident meetings, a full‑up FST meeting will also be held so as to
integrate the extended time and modeling activities as much as possible.
The milestone list reflects a minimum meeting schedule; other meetings
may be scheduled (i.e., meetings to plan for/review Tropical Cirrus
Mission) as required. Also included are some key cirrus collaborative
experiments, such as the Subsonic Aircraft Contrail and Cloud Special
Study (SUCCESS) and the Stratospheric Tropospheric Experiment:
Radiation, Aerosols, and Ozone (STERAO). Table 4 lists several field
experiments and satellite launches that are pertinent to FIRE planning.
At a minimum, the entire FST will meet at least once per year.

**6.0 NATIONAL AND INTERNATIONAL COLLABORATIONS**

FIRE Phase III is a research project to be conducted by U.S. scientists
to provide a U.S. national contribution to the ISCCP of the World
Climate Research Program. In the sense that the scientific problems
addressed by FIRE‑m are truly international, it is in the best interests
of FIRE III to encourage the free exchange of information with our
national and international colleagues. Although resources do not permit
direct support of foreign participation in FIRE-III, ways will be sought
to allow collaboration, such as full participation and data sharing as
members of the FS T. Other forms of collaboration will also be
encouraged. Cooperation and coordination with the research projects of
other countries will be accomplished through the ISCCP Working Group on
Data Management (DMWG), which is responsible for this function under the
Joint Scientific

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**APPENDIX D ‑ FIRE INVESTIGATORS\' ABSTRACTS**

Arctic Clouds and Marine Stratus Proposals 1

Coordinated Parameterization Development and Large Eddy Simulation for
Marine

and Arctic Cloud‑Topped Boundary Layers 1

C. S. Bretherton

University of Washington

Application of LES to Understanding and Parameterizing the Arctic Cloudy
Boundary Layer 1

Judith Curry^1^ and William Cotton^2^

^1^University of Colorado, ^2^Colorado State University

Boundary‑Layer Dynamics and Cloud‑radiative Studies in SHEBA:
Development of an

Atmospheric Lidar and a Wind Profiler 2

C. W. Fairall, C. Grund, and R. G. Strauch

NOAA Environmental Technology Laboratory

FIRE III Research 2

Peter Hobbs

University of Washington

FIRE III Research 3

James Hudson

Desert Research Institute

Canadian Participation in FIRE III 4

George Isaac

Atmospheric Environment Service

Remote Sensing and Retrieval of Arctic Stratus Clouds and Surface
Characteristics 4

Michael King and Si‑Chee Tsay

NASA Goddard Space Flight Center

Study of midlatitude and Arctic aerosol‑cloud‑radiation feedbacks based
on LES model

with explicit ice and liquid phase microphysics 5

Yefim Kogan^1^ and Douglas Lilly^2^

^1^Cooperative Institute for Mesoscale Meteorological Studies, ^2^School
of

Meteorology, University of Oklahoma

Cloud‑Scale Numerical Modeling of the Arctic Boundary Layer 5

Steven Krueger

Dept. of Meteorology, University of Utah

Intended FIRE‑III Research 6

D. H. Lenschow and Q. Wang

National Center for Atmospheric Research

FIRE III Research 7

Dave Randall

Colorado State University

> Radiative Energy Exchanges In The Polar Regions \.....7
>
> William Rossow and Barbara Carlson
>
> Institute for Space Studies, Goddard Space Flight Center
>
> Studies of the Radiative and Microphysical Properties of Cloud,
>
> Aerosol and Surface Bi‑Directional Reflectance \.....8
>
> Si‑Chee Tsay and Michael King
>
> NASA Goddard Space Flight Center
>
> FIRE III Research \.....8
>
> Tanneil Utta1
>
> NOAA Environmental Technology Laboratory
>
> A Parameterization Study of Marine Boundary‑Layer Clouds \.....9
>
> Shouping Wang
>
> NASA Marshall Space Flight Center
>
> Tropical Cirrus Proposals \.....9
>
> Application of Fire Phase I and II Results to Model Parameterizations
>
> and Extension to other Geographic Locales \.....9
>
> T. Ackerman and G. Mace
>
> Pennsylvania State University
>
> FIRE III Research \.....10
>
> Leo Donner
>
> NOAA Geophysical Fluid Dynamics Laboratory
>
> Aircraft Cloud Studies: FIRE III \.....10
>
> John Hallett
>
> Desert Research Institute
>
> .
>
> Abstract of Intended FIRE‑III Research \.....11
>
> A. J. Heymsfield and L. M. Miloshevich
>
> National Center for Atmospheric Research
>
> FIRE III Research \...\...12
>
> Paul Lawson
>
> SPEC Inc.
>
> Radiative Transfer and Satellite Remote Sensing of Cirrus Clouds
>
> Using FIRE‑II IFO Data \...\...13
>
> K. N. Liou
>
> University of Utah/CARSS
>
> Physically Based Retrieval of Ice Cloud Properties \...\...14
>
> Michael Mishchenko, Brian Cairns, and Andreas Macke
>
> Goddard Institute for Space Studies
>
> Analysis of Cirrus Cloud Microphysical Data \...\...15
>
> Michael Poellot
>
> University of North Dakota
>
> FARS Cirrus and Anvil Research for FIRE III \....16

Kenneth Sassen

University of Utah

FIRE Cirrus Cloud Studies 16

David Starr

NASA Goddard Space Flight Center

Cirrus Cloud Properties from Aircraft 17

Graeme Stephens

Colorado State University

Theoretical and Experimental Studies of the Interactions between Clouds
and Aerosols 17

Owen Toon, Andrew Ackerman, Joelle Champney, Eric Jensen, Irina Sokolik

NASA Ames Research Center

Joint Arctic Clouds and Marine Stratus and Tropical Cirrus Proposals 18

Participation of MAS and HIS in SUCCESS Campaign 18

Steve Ackerman^1^, Paul Menzel^1^, Si‑Chee Tsay^2^, and Steve Platnick
^2^

^1^University of Wisconsin, ^2^NASA Goddard Space Flight Center

Improvement of NCEP\'s Analysis/Forecast System Through Use of FIRE Data
Sets 19

Kenneth Campana, Qingyun Zhao, Yutai Hou

National Centers for Environmental Prediction (NCEP)

FIRE III Research 20

Steve Cox

Colorado State University

Development and Validation of a GCM Cloud Parameterization Using FIRE
and ISCCP Data

Sets 20

Anthony Del Genio

Goddard Institute for Space Studies

FIRE III Research 21

Hermann E. Gerber

Gerber Scientific

FIRE III Research 21

Qingyuan Han and Ronald Welch

South Dakota School of Mines and Technology

FIRE III Research 23

Sonia Kreidenweis, Paul DeMott, David Rogers

Colorado State University

Satellite Remote Sensing Studies 23

Patrick Minnis

NASA Langley Research Center

A Near‑Infrared Spectroradiometer for FIRE III 24

Peter Pilewskie

NASA Ames Research Center

A Cloud Observing Experiment: Remote Sensing for the Radiation and
Physical

Parameters of Clouds 25

James Spinhirne and James Wang

NASA Goddard Space Flight Center

Cloud Radiative and Physical Properties Inferred using Landsat 26

Bruce Wielicki

NASA Langley Research Center

FIRE III Research 27

Donald Wylie

Space Science and Engineering Center, University of Wisconsin‑Madison

Miscellaneous Proposals not funded by FIRE III 27

FIRE III Research 27

Howard Hanson

CIRES

Modeling of Cloud Scale Turbulent Transport 28

W. S. Lewellen and D. C. Lewellen

West Virginia University

**[Arctic Clouds and Marine Stratus Proposals]{.underline}**

**Coordinated Parameterization Development and Large-Eddy Simulation
for**

**Marine and Arctic Cloud-Topped Boundary Layers**

C. S. Bretherton

University of Washington

Large-eddy simulations of subtropical and summertime Arctic cloud-topped
boundary layers will be carried Out. The subtropical boundary layer
simulations will focus On two issues: (1) improving entrainment closures
based on in-cloud turbulent kinetic energy and cloud-top Jumps, which
are currently quite uncertain, and ascertaining what resolution in the
entrainment zone is required for an LES to reliably predict entrainment,
and (2) assessing the role of penetrative cumulus entrainment in
stratocumulus breakup. We hope to incorporate key findings in both of
these areas to improve current GCM parameterizations of the cloud-topped
boundary layer. A third area of study will be testing the feasibility of
several proposed mechanisms for multiple cloud layering in the
Summertime Arctic in an LES and comparing against field data

**Application of LES to Understanding and Parameterizing the Arctic
Cloudy**

**Boundary Layer**

Judith Curry^1^ and William Cotton^2^

^1^University of Colorado, ^2^Colorado State University

The goal of this research is to improve our understanding of physical
processes occurring in the arctic cloudy boundary layer and our ability
to parameterize them in climate models. The approach taken here is to
use Large-Eddy Simulation (LES) to interpret the interactions among
turbulence, cloud microphysics and radiative transfer in the following
different arctic cloudy boundary layer types: warm-season layered clouds
with decoupled mixed layers; and wintertime ice crystal plumes emanating
from leads. The LES results will be compared with observations, and
parameterizations suitable for large-scale models will be developed. The
results will be evaluated in the context of the forthcoming Arctic FIRE
experiment, particularly the optimal measurements to be obtained from
aircraft (including flight patterns) and the large-scale measurements
required to interpret cloud life-cycles. Specifically, we propose to
accomplish the following:

• develop and implement a new subgrid-scale parameterization and other
modifications for

the LES to accommodate the stable boundary layers that are present in
the Arctic;

• introduce new parameterizations into the LES related to the impact of
turbulence on

droplet spectra and the influence of droplet spectra on the radiation
fluxes;

• simulate and interpret the interactions among turbulence, cloud
microphysics and

radiative transfer in the different arctic cloudy boundary layer types;

• compare the LES output with case studies obtained from the Arctic
Stratus Experiment

and BASE;

• evaluate the importance of diabatic terms in second-moment equations,
and develop a

parameterization for these terms for second-order closure models if
necessary;

• evaluate the applicability of existing cloud fractional coverage
schemes to Arctic stratus

and develop a new scheme if necessary; and

• examine scale interactions using the LES nested in a mesoscale model
(RAMS).

**Boundary‑Layer Dynamics and Cloud‑radiative Studies in SHEBA:**

**Development of an Atmospheric Lidar and a Wind Profiler**

C. W. Fairall, C. Grund, and R. G. Strauch

NOAA Environmental Technology Laboratory

This is an NSF SHEBA Phase‑1 project to develop, construct, and test a
lidar and wind profiler for future deployment in the main ice camp of
the Surface Heat Budget of the Arctic Ocean (SHEBA) program, planned for
an 12‑month field program beginning in March 1997. These systems will be
used in conjunction with other surface‑based remote sensors (e.g.,
Doppler cloud radar, microwave radiometer, Doppler sodar, FTIR
radiometers) and in situ sensors for studies of boundary‑layer and
cloud/aerosol/radiative effects on the ice surface energy budget. The
work will be coordinated with the FIRE‑III Arctic Cloud research
program.

The wind profiler will be a portable, scaled clown version of the NOAA
network UHF profilers and be designed to provide wind and temperature
profiles continuously to 2.5 km altitude. Through additional data
processing, it will also provide information on velocity and scalar
turbulence profiles and precipitation. Based on an analysis of LEADEX
data, most of the temporal variability in the vertical gradients of
temperature, dew point, and (to a lesser extent) winds occurs below this
altitude. The lidar will be a derivative of a system being developed for
cloud and aerosol monitoring and will measure optical depth and provide
cloud ice/water discrimination. It will feature both vertically pointing
and zenith angle scan capabilities. The scanning capability is shown to
be critical for obtaining information about complex ice crystal habit
and structure. Both systems will feature high reliability in Arctic
conditions and will operate \"unattended\" except for occasional
changing of storage media or transfer of data. In the first year of the
project, the lidar will be designed and constructed. An existing
prototype radar (being developed for another program) and the lidar then
will be tested in Alaska for one month. In the second year of the
project the radar will be constructed following evaluation of the test
results . Both systems will be field tested in Alaska a second tune then
deployed on the main ice camp for SHEBA.

**FIRE III Research**

Peter Hobbs

University of Washington

Subject to the availability of funding, the Cloud and Aerosol Research
Group at the University of Washington intends to bring\" its new
twin‑engine, turbo‑prop, Convair‑580 research aircraft to the Arctic to
participate in a portion of the 6-week FIRE‑m intensive field project.
The aircraft will be instrument for state‑of‑the‑art measurements of
aerosols, cloud microstructures, and cloud radiative properties,
including the NASA‑built CAR 13---wavelength radiometer and lidar.

Our proposed research, which will be carried out in collaboration with
Drs. Michael King and Si‑Chee Tsay, includes the following:

\(1\) Measurements of cloud‑active aerosols and their precursors.

\(2\) Measurements of the statistical properties of the microphysical
structures of arctic stratus and other Clouds.

\(3\) Direct measurements of the spectral radiative properties of arctic
stratus, and comparisons with values derived from simultaneous
measurements of cloud structure.

\(4\) Comparisons of in situ measurements of cloud properties remote
sensing measurements from the ER‑2 and satellites.

We expect also to carry out a number of measurements concerned with the
radiative properties of sea‑ice, snow, tundra etc., and the energy
balance of the arctic. However, since these are more related to SHEBA,
they are not discussed here.

**FIRE III Research**

James Hudson

Desert Research Institute

I plan to mount both of the DRI instantaneous CCN spectrometers (Hudson
1989) aboard a research aircraft and operate them throughout the
project. The most likely aircraft is the NCAR C‑130, where they have
been in two previous projects---Telford California stratus project
(December 1994) and SCMS (July‑August 1995). Two spectrometers are
desirable in order to efficiently do sample processing upstream of one
of the CCN spectrometers. This allows the other instrument to
continuously monitor the ambient CCN spectrum. Continuous ambient
spectra are vital in aircraft operations where the concentrations change
rapidly with position (e.g., there are often vertical differences in
concentration and/or spectral slope that are significant for cloud
microphysics; also horizontal differences due to scavenging and
production). The sample processing mechanisms include:

\(1\) Volatility---subjecting the sample to various temperatures to
indirectly estimate particle composition (Hudson and Da 1995) especially
with respect to NaCl, sulfates, and carbon.

\(2\) Size vs. supersaturation---classifying the sample according to dry
particle size with an electrostatic classifier (DMA). This allows an
estimate of the relative solubility of the particles. Hudson and Da
(1995) showed that CCN from polluted air masses tend to act as though
they have more insoluble material internally‑mixed with the soluble
material that makes them CCN. CCN from cleaner air masses, however, act
like pure soluble substances. These two techniques are complementary;
when taken together they derive significant information about CCN
composition.

\(3\) Different inlets---The CCN spectra of droplet residue material
from the counterflow virtual impactor (CVI) can be used to determine the
effects of entrainment on cloud droplet spectra (Twohy and Hudson 1995).
If the CVI is not available then a cloud interstitial inlet can also
produce similar information about the effects of cloud dynamics on cloud
droplet spectra.

When both spectrometers monitor the ambient there is increased
confidence in the measurements not to mention the enhanced reliability
of two instruments.

In addition to comparing the cloud droplet and CCN concentrations I am
keenly interested in comparing the shapes of the two spectra. Martin et
al. (1994) suggested that the shape of the cloud droplet spectrum is
related to the shape of the CCN spectrum. Indeed Hudson and Li (1995)
found significant differences in the shape of the CCN spectra in
polluted and clean air masses; this is an additional difference to the
well‑known difference in number concentration. However this may or may
not go the same way in the Arctic. The shape (breadth) of the droplet
spectrum is very important for the initiation of drizzle
(autoconversion), which has been suggested to be related to CCN
concentrations (e.g., Albrecht et al. 1995). Drizzle initiation may also
depend on CCN spectral shape, testing this requires measurements at
supersaturations longer than the actual cloud supersaturations, which
are generally quite low for stratus Clouds anyway (e.g., Hudson and
Svensson 1995). Such low supersaturations (\<0.1%) are only possible
with the DRI spectrometer.

We expect significant variations in CCN concentrations, spectral shape,
and composition during FIRE‑III. CCN spectral measurements are necessary
in order to keep separate the effects on cloud microphysics of
differences in cloud dynamics from the differences in the aerosol.
Comparisons with identical CCN measurements in several other stratus
projects--- FIRE, ASTEX, SOCEX‑1 and 2, MAST, ACE‑1---will be
indispensable.

**Canadian Participation in FIRE III**

George Isaac

Atmospheric Environment Service

Observations collected by the Canadian PIs, together with the other FIRE
III data, will be used to understand Arctic cloud formation,
development, and their effect on climate change. Special emphasis will
be put on the interaction of Clouds with Arctic aerosols, the influence
of the aerosol chemistry upon cloud microphysical characteristics, and
the general role Clouds play in redistributing, transforming, and
transporting Arctic chemical constituents. Using the observations,
microphysical, chemical, dynamical and radiative properties, as well as
the vertical and horizontal spatial distribution characteristics, of the
Clouds studied will be determined. Parameterizations will be developed,
describing these properties, that might be used in GCMs. Where possible,
these parameterizations will be tested and evaluated in column models,
cloud resolving models and full scale GCMs.

It is anticipated that the National Research Council Convair 580 will be
involved and would fly out of Inuvik, NWT Some specialized \"round
instrumentation, such as lidars and radars, might also the used. The
possibility of placing instrumentation for measuring chemical
constituents on the ice flow and other surface sites will be explored.
This research will involve a large number of Canadian scientists and is
dependent upon Canadian funding approval. Formal plans for this work,
including PIs designated for each task, have yet to be developed.

**Remote Sensing and Retrieval of Arctic Stratus Clouds and Surface
Characteristics**

Michael King and Si‑Chee Tsay

NASA Goddard Space Flight Center

This investigation continues studies of the radiative and microphysical
properties of Arctic stratus Clouds and snow/sea ice surface. The
Moderate Resolution Imaging Spectroradiometer (MODIS), being developed
as part of the Earth Observing System (EOS) and scheduled to be launched
in 1998 on the EOS AM platform, is a NASA facility instrument designed
to meet the scientific needs for satellite remote sensing of Clouds,
aerosols, water vapor, and land and ocean surface properties. To support
the development of MODIS remote sensing and retrieval algorithms, the
MODIS Airborne Simulator (MAS) was developed for NASA\'s high‑altitude
ER‑2 aircraft. This airborne sensor is capable of providing narrowband
spectral coverage similar to MODIS of reflected solar and emitted
thermal radiation. Over the past few years, MAS has flown in many field
campaigns throughout the world, including recently in Alaska. These
diverse data sets provide critical measurements for assessing the
scientific capability and usefulness of MODIS charnel s , as well as
enabling unique information to be acquired from studies of the Earth\'s
atmosphere and surface. Analyses of various cases obtained during
previous FIRE‑I and II experiments are an important element of this
investigation.

The intent of this investigation is to support our participation in the
FIRE‑III field campaigns and to analyze data obtained by MAS during
previous campaigns. Specifically, we intend to:

\(1\) participate in flight planning and direction of the NASA ER‑2
aircraft over Arctic stratus Clouds off the north slope of Alaska during
the 1998 field campaign,

\(2\) build a well‑calibrated and feature‑rich data set to improve MODIS
cloud masking algorithms,

\(3\) distinguish Clouds from snow covered tundra and sea ice surfaces,

\(4\) retrieve stratus cloud properties (i.e., optical thickness and
effective particle radius) over highly reflecting surfaces, and

\(5\) perform statistical analyses of stratus cloud properties by using
high spatial resolution MAS data.

**Study of midlatitude and Arctic aerosol‑cloud‑radiation feedbacks
based on**

**LES model with explicit ice and liquid phase microphysics**

Yefim Kogan^1^ and Douglas Lilly^2^

^1^Cooperative Institute for Mesoscale Meteorological Studies, ^2^School
of Meteorology,

University of Oklahoma

The complexity of cloud‑radiation problem results in large uncertainties
in estimating the cloud forcing in global climate models. Of particular
importance are cloud‑radiation feedbacks in midlatitude, subtropical,
and high‑latitude low lever Clouds. Continuing investigation of these
cloud systems is a major goal of the FIRE III program.

The proposed work will have two major thrusts:

\(1\) Continuing the study of marine stratocumulus Clouds using LES
simulations based on FIRE I and FIRE II/ASTEX observational data. The
data will be used to validate the CIMMS LES model and to improve our
understanding of the interaction between the microphysical, radiative,
and thermodynamical processes. Validation of the model against
observations will result in further refinement and improvement in the
model physical and numerical formulation.

\(2\) Large‑eddy simulations of arctic cloud systems, including low
lever stratus with liquid and mixed phase microphysics.

The modeling part of the research will be based on the CIMMS 3‑D LES
model of a stratocumulus cloud layer that includes an explicit
formulation of aerosol and cloud drop size‑resolving microphysics and
radiation. The study of mixed phase Clouds will use the new version of
the CIMMS model which includes also explicit formulation of the
ice‑phase microphysics. Depending on the physics and the scale of the
studied phenomena, the model may be also formulated in a 2‑D framework
with bulk treatment of microphysics.

In accordance with the FIRE m objectives, model simulations and data
analysis will aim at the improvement of existing parameterizations of
cloud and radiative processes in LES and GCM models. The analysis of
ASTEX and FIRE III observational data sets will be made in collaboration
with the researchers from British Meteorological Office, University of
British Columbia and University of Colorado.

**Cloud‑Scale Numerical Modeling of the Arctic Boundary Layer**

Steven Krueger

Dept. of Meteorology, University of Utah

> The interactions between sea ice, open ocean, atmospheric radiation,
> and clouds over the Arctic Ocean
>
> exert a strong influence on global climate. Uncertainties in the
> formulation of interactive air‑sea‑ice processes in global climate
> models (GCMs) result in large differences between the Arctic and
> global climates simulated by different models. Arctic stratus clouds
> are not well‑simulated by GCMs, yet exert a strong influence on the
> surface energy budget of the Arctic. Leads (charnels of open water in
> sea ice) have significant impacts on the large‑ scale budgets during
> the Arctic winter, when they contribute about 50 percent of the
> surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of
> its area. Convective plumes generated by wide leads may penetrate the
> surface inversion and produce condensate that spreads up to 250 km
> downwind of the lead, and may significantly affect the longwave
> radiative fluxes at the surface and thereby the sea ice thickness. The
> effects of leads and boundary layer clouds must be accurately
> represented in climate models to allow possible feedbacks between them
> and the sea ice thickness.
>
> The FIRE III Arctic boundary layer clouds field program, in
> conjunction with the SHEBA ice camp and the ARM North Slope of Alaska
> and Adjacent Arctic Ocean site, will offer an unprecedented
> opportunity to greatly improve our ability to parameterize the
> important effects of leads and boundary layer clouds in GCMs.
>
> We will make extensive use of FIRE III measurements and a
> high‑resolution numerical model, the University of Utah Cloud
> Resolving Model, to increase our understanding of the physical
> processes that determine (1) the formation and structure of Arctic
> stratus clouds and (2) how leads over the Arctic Ocean affect the
> large‑ scale budgets of sensible heat, water vapor, and condensate.
> This is necessary before developing lead and boundary layer cloud
> parameterizations based on general physical principles. We will:

\(1\) Determine in detail how large‑scale processes, in combination with
cloud‑scale radiative, microphysical, and dynamical processes, govern
the formation and multilayered structure of Arctic stratus clouds.

\(2\) Quantitatively determine the effects of leads on the large‑scale
budgets of sensible heat, water vapor, and condensate in a variety of
Arctic winter conditions.

**Intended FIRE‑III Research**

D. H. Lenschow and Q. Wang

National Center for Atmospheric Research

> Our intended FIRE‑III research will utilize previous field
> observations of Arctic clouds, boundary layer, and ice surface to
> perform integrated analyses of both the Arctic clouds and boundary
> layer, and evaluate instrument capabilities for making measurements in
> the Arctic environment. We plan to use the data set obtained from the
> Beaufort and Arctic Seas Experiment (BASE) as the primary data source
> for two important reasons. First, BASE obtained measurements in the
> Arctic boundary layer during the fall/winter transition sea son which
> is not well documented Several types of structure were measured during
> this experiment, including stably‑stratified boundary layers,
> mixed‑phase boundary‑layer clouds, boundary layers modified by leads
> and polynyas, and multi‑layered cloud structures. Second, a primary
> platform for BASE was the newly‑instrumented NCAR C130 which will
> likely be deployed in FIRE‑III/SHEBA. Evaluation of the capability of
> the instruments on the C‑130 to measure in the Arctic is an essential
> step in preparing for FIRE‑III/SHEBA.

In addition to the BASE data set, we plan to analyze measurements from
the Arctic Stratus Experiment and the Arctic Ice Dynamics Joint
Experiment (AIDJEX) which measured the summertime Arctic boundary layer,
and from the Lead Experiment (LEADEX) which measured the effects of open
leads during winter/spring. Although these detests (excluding BASE) have
been studied by other researchers, our analyses will focus on addressing
problems that were uncovered during and after these experiments with a
view towards improving measurements in FIRE‑III/SHEBA.

The primary objectives of the proposed research are to:

\(1\) understand the Arctic cloud and boundary layer structure,
especially the interactions among cloud microphysics, turbulence, and
radiation using in situ aircraft measurements;

\(2\) understand the moisture, heat, and momentum exchange between the
atmosphere and the Arctic ocean water/ice surface;

\(3\) assess the instrumentation capability on the newly‑deployed NCAR
C‑130 for making measurements in the Arctic environment and provide a
basis for improved measurement capabilities for the FIRE‑III/SHEBA field
campaign;

\(4\) optimize the aircraft measurement strategy in the Arctic for
FIRE-III/SHEBA;

\(5\) provide analyses from in situ measurements useful for interpreting
and validating satellite remote sensing and retrieval algorithms, and
for validating results from numerical modeling of the Arctic clouds and
boundary layer (in collaboration with Judith Curry, University of
Colorado).

**FIRE III Research**

Dave Randall

Colorado State University

We propose to investigate the Arctic climate simulated by the current
version of the CSU GCM, with particular attention to cloudiness and the
surface energy budget. We propose to develop a one‑dimensional model of
the Arctic atmosphere‑sea ice‑ocean system, which will exist in two
versions, which differ only in their treatment of the atmosphere. The
first version will be based on the second‑order bulk model developed by
Randall et al. (1992), and the second will use a one‑dimensional version
of the third‑order closure developed by Krueger (1988). These
one‑dimensional models will be tested using the FIRE Arctic data in
\"single‑column model\" mode. Following these tests, at least one of the
two versions will be transferred to the CSU GCM, and used in simulations
of the present climate and of climate change due to increasing CO2.

**Radiative Energy Exchanges In The Polar Regions**

William Rossow and Barbara Carlson

Institute for Space Studies, Goddard Space Flight Center

Some evaluations of the surface energy balance in the polar regions,
that currently maintains a persistent sea and land ice cover, suggest
that it may be very sensitive to climate perturbations; however, little
change in polar ice/snow cover over the past century has been
documented, even though global temperatures have changed somewhat. This
situation reflects a generally poor understanding of the polar energy
balance and the feedback processes controlling it. There has been recent
significant progress in quantitative methods for analysis of satellite
measurements of the atmosphere, clouds and surface; however, the paucity
of quality in situ observations has prevented verification of these
methods under more difficult polar conditions. Very few of these methods
have even been applied to study of the polar regions. As one step
towards determining the polar energy balance and the key controlling
processes, we propose to combine all of the available satellite
measurements into a single consistent analysis that measures the key
properties of the atmosphere, clouds and surface required to infer the
surface and top‑of‑atmosphere radiation balance and its seasonal
variations. Building and improving upon the ISCCP analysis of imaging
radiometer data, we will add measurements by infrared and micro‑wave
sounders to deal with the complex variations of surface and cloud
properties. Using energy balance models, together with these
observations, we can infer the required energy transports (mostly by the
atmosphere) required to balance radiative fluxes and examine the
sensitivity of ice and snow cover to variations in these fluxes. If this
work is funded as part of a U.S. contribution to the Canadian GEWEX
experiment called BASE and a new project called SHEBA, then the value of
our combined satellite analysis will be greatly enhanced by comparison
with coordinated surface and aircraft observations and more complete
atmospheric and sea ice modeling efforts of collaborators.

**Studies of the Radiative and Microphysical Properties of Cloud,
Aerosol**

**and Surface Bi‑Directional Reflectance**

Si‑Chee Tsay and Michael King

NASA Goddard Space Flight Center

This investigation continues studies of the microphysical, optical and
radiative properties of Arctic clouds and aerosols, and characterizes
the anisotropy of various types of Arctic surfaces. Tools of this
investigation include a multispectral scanning radiometer (CAR; Cloud
Absorption Radiometer), which is mounted on the University of
Washington\'s C131A aircraft for the purpose of measuring the angular
distribution of scattered radiation deep within a cloud layer, from
which the single‑scattering albedo of clouds can be determined as a
function of wavelength. Recent improvements in the CAR further advance
its capability in characterizing the radiative properties of aerosols
and surfaces. Over the past few years, the CAR has flown in many
national and international field campaigns, providing unique information
in studies of cloud, aerosol and surface properties. Analyses of various
cases obtained during previous experiments are an important element of
this investigation.

The intent of this investigation is to participate in the 1997 FIRE‑III
and upcoming SCAR-B (Smoke, Cloud And Radiation ‑ Brazil) field
campaigns, and to analyze data obtained by the CAR as well as other
ancillary and coordinated microphysics/radiation data sets during
previous campaigns. Specifically, we intend to:

\(1\) validate experimentally the relationship between cloud
single‑scattering albedo and effective particle radius from CAR
radiation measurements in the diffusion domain,

\(2\) determine the radiative properties (i.e., optical thickness,
single‑scattering albedo and phase function) of aerosol from CAR
radiation measurements for use in developing atmospheric corrections,
and

\(3\) characterize the bi-directional reflectance distribution function
(BRDF) over Arctic snow and sea ice surfaces, as well as other types of
surfaces, to develop physically based surface BRDF models.

**FIRE III Research**

Tanneil Uttal

NOAA Environmental Technology Laboratory

The National Oceanic and Atmospheric Administration (NOAA) Environmental
Technology

Laboratory (ETL) is presently involved in studies of radiatively
important cloud properties,

utilizing data from the First ISCCP Radiation Experiment (FIRE II) and
the Atlantic

Stratocumulus Transition Experiment (ASTEX). Important remote sensing
techniques

based on radar, lidar and IR radiometer measurements have been developed
at ETL that

remote sensing of profiles of cloud properties such as particle
concentrations, sizes , LWC ,

and IWC from the \"round that were not possible even a few years ego.
The proposed work includes analysis of FIRE II and ASTEX data sets with
an emphasis on comparison of cloud properties between different climatic
regimes. In addition, NOAA/ETL has received separate funding for FY96 to
conduct a similar measurement campaign in the tropical Western Pacific
as part of the DOE/ARM program.

In this proposal we also plan to augment the mid‑latitude, sub‑tropical
and tropical data sets with an arctic data set collected in conjunction
with the FIRE III and SHEBA programs in 1997. Deployment of a 35 GHz
radar, lidar, and IR radiometer will allow characterization of arctic
clouds, haze, and aerosol which will be directly comparable to FIRE III,
ASTEX, and TWP results. This will provide the radiation/climate
community with an unprecedented data set for four major climatic zones.
The emphasis in this study will be on the intercomparison of cloud
properties to answer important questions of global variations of upper
tropospheric and boundary layer clouds.

**A Parameterization Study of Marine Boundary‑Layer Clouds**

Shouping Wang

NASA Marshall Space Flight Center

The goal of the proposed research is to formulate a new parameterization
of marine boundary‑layer clouds for a large‑scale model. We propose to
develop a model based on the buoyancy sorting concept developed by
Raymond and Blyth (1986), mass flux‑layered model of Wang (1993), and
the prognostic cloud scheme developed by Tiedtke (1993). For the
application in the marine boundary layer, we need to improve the
representation of the cloud‑top entrainment, large‑scale condensation
and evaporation in the cloud scheme. We also emphasize the interaction
between the cumulus and stratocumulus clouds in the boundary layer. In
the processes, some large‑eddy simulation runs will be conducted to
study the interaction that is crucial to our new parameterization. We
will also implement the new prognostic cloud scheme into a traditional
second‑order turbulence closure model. Thus, the stratocumulus,
trade‑wind cumulus regimes and the transition between them can be
predicted with a unified cloud scheme. All the one‑dimensional models
will be tested with ASTEX and FIRE data. Following the tests, we plan to
implement the models into a general circulation model.

**[Tropical Cirrus Proposals]{.underline}**

**Application of FIRE Phase I and II Results to Model Parameterizations
and**

**Extension to other Geographic Locales**

T. Ackerman and G. Mace

Pennsylvania State University

The ultimate goal of the proposed research is to improve
parameterization of cirrus in large­

scale models. Our intent is to use the Cirrus II data set to drive a
suite of GCM cloud parameterizations using the WPDN wind profiler and
radiosonde‑diagnostics as input parameters. A verification data set
derived from the Cirrus II ground‑based and satellite data is being
created for comparison with the parameterization output. An
extensivanalysis of the relationship between large‑scale forcing and
cirrus formation and maintenance will also be undertaken. In order to
supplement the temporally limited Cirrus II results, we will conducting
limited observational campaigns at our Pennsylvania field site taking
advantage of our unique suite of instruments, including radar, lidar,
microwave radiometer, and flux radiometers. To extend the results from
midlatitude cirrus to other geographical regions, data collected during
TOGA COARE under the sponsorship of NASA and the U. S. Department of
Energy will be examined in considerable detail in order to quantify the
importance of tropical cirrus to the local radiative energy budgets and
identify similarities and differences between tropical cirrus and their
midlatitude counterparts. A recently completed cirrus cloud model that
couples ice microphysics, radiative transfer, and cloud‑scale dynamics
will be used to simulate the COARE data, as well as carry out
simulations relevant to proposed tropical cirrus experiments.

**FIRE III Research**

Leo Donner

NOAA Geophysical Fluid Dynamics Laboratory

My FIRE‑III research will focus on cirrus anvils associated with deep
convection. I have developed a GCM parameterization for deep convection
(Donner, 1993a), which includes a method for determining the ice source
for cirrus anvils. The parameterization can be used either
diagnostically or in conjunction with a prognostic ice scheme in a GCM.
A field experiment to characterize simultaneously the thermodynamic,
hydrological, microphysical, and radiative properties of deep convective
systems and their associated anvils has not been conducted. Such an
experiment is necessary to provide a fundamental understanding of these
systems and to permit the validation and further development of
parameterizations such as that mentioned. The parameterization provides
a number of testable hypotheses regarding deep convective systems and
their interactions with larger scales by thermodynamic and radiative
mechanisms which can be tested in a convective cirrus experiment of the
type under discussion in FIRE III.

**Aircraft Cloud Studies: FIRE III**

John Hallett

Desert Research Institute

It is proposed to utilize currently available instrumentation and new
instrumentation on aircraft participation in the Arctic stratus
experiment and also in the proposed high lever tropical cirrus
experiment. The purpose is to examine extremes of the particle spectra
which are responsible for remote sensing signals, radiative and
precipitation properties of such clouds. Such instrumentation is capable
of mounting in a PMS pod, and can be readily installed on the NCAR C‑130
or University of Washington 580; it can be modified for mounting on
WB-57F or (cloudscopes) miniaturized for mounting on a smaller remotely
piloted vehicle. The overall purpose is to gain insight into the
processes leading to cloud formation and differences in the optical
properties of such clouds.

The following instruments and measurements are to be emphasized:

• Continuous Ice Crystals Replicator (few µm to 250 µm)

This provides a continuous record of particles in a plastic formvar film
which can consequently be examined by optical microscopy or other
techniques. The formvar replicator may be modified to detect
sulfate/nitrate containing particles; it is to be used in parallel with
2D‑C probe. Sample volume 1 l s^‑1^; spatial resolution a few m. Gives
concentration, size, habit, phase of particles (Foster et al. 1995);
some automation of analysis is available (Arnott et al. 1995).

• Cloudscope, high resolution (few µm)

This instrument has a sample volume of 100 cm3 s‑1 and uses a VCR to
record particles impacting on a small (500 ¥ 500 µm) optical flat facing
the air stream at stagnation conditions. In cirrus cloud, with many
smaller ice particles, it can give size and shape distribution, and
together with a mass and density of each particle direct from
evaporation time. Spatial resolution \~5 m; maximum particle size \~ 250
µm (Arnott et al. 1995).

It can also be used to show presence of a few large aerosol particles in
clear air. Such particles (a few to 10 \~m size) impact on the optical
flat and may crystallize at the stagnation relative humidity confirming
a hygroscopic component. Visual analysis of real time video gives
concentrations of such large aerosol particles. These are important for
radiation and cloud physics considerations, they may lead to the
presence of large cloud droplets which may precipitate or freeze. Such
measurements would be made above the cloud of an Arctic stratus
inversion to show their importance in producing large droplets as the
overlaying aerosol is clown mixed into the cloud below. This is proposed
for ASTEX and would be related to CCN and droplet measurements (as
proposed by J. Hudson). The measurements are also important for
investigating the structure and origin of high lever, low visibility
cirrus; this is proposed for a tropical cirrus experiment. It is
anticipated that different composition particles (nitric acid trihydrate
compared with ice) will behave differently in evaporation and some
estimates of the presence of these components at low temperature could
be obtained .

• Cloudscope, low resolution

A similar concept instrument is supposed to seek the presence of low
concentration of large particles responsible for radar echoes. The
principle is identical to the high resolution instruments, only it uses
a forward facing flat of 10 ¥ 10 cm, giving a volume sample rate of
several m3 s\~ 1. Small particles (10 \~m) will not be collected at all,
and large particles (few mm) collected uniformly . Some information on
intermediate size particles may be obtained from variation in collected
particles from the center to the edge of the collecting flat. This would
be used for detecting occasional large ice particles in Arctic stratus
or tropical cirrus, to give estimates of radar reflectivity and also an
estimate of sizes which dominate mass.

**Abstract of Intended FIRE‑III Research**

A. J. Heymsfield and L. M. Miloshevich

National Center for Atmospheric Research

In summary, our intended F\~ m research will include: development of a
conceptual and quantitative model of cirrus formation and evolution,
based on our FIRE I, II and m studies to date; continued acquisition and
analysis of cirrus microphysical measurements from our balloon‑borne ice
crystal replicators; acquisition and analysis of aircraft measurements
for the FIRE experimenters involved in radar operations at the ARM site
during SUCCESS; and development of a strategy for a possible FIRE-III
tropical cirrus experiment.

> Thus Far during FIRE III we have completed reprocessing of the King
> Air and Sabreliner relative
>
> humidity(RH) and 2D probe data. A preliminary look at the RH data
> seems to confirm the hypothesis put forth in Heymsfield and
> Miloshevich, 1995, that cirrus clouds can be represented by a
> three‑layer model: a highly ice‑supersaturated ice crystal generation
> zone at cloud top, a mid‑level ice‑saturated growth zone, and a longer
> ice‑subsaturated zone of ice crystal sublimation. We will use the FIRE
> II RH, 2D, and replicator data, the aircraft data collected during our
> pre‑FIRE II wave cloud experiment, and the replicator data described
> below, to define: (1) the fundamental RH condition required for ice
> nucleation in cirrus, (2) the thickness and representative
> microphysical and thermodynamic properties of the three distinct
> regions in cirrus, and (3) insights into the relative contributions of
> the homogeneous versus heterogeneous ice nucleation processes. We will
> prepare a publication in the formal literature reporting our results.
>
> We have acquired high‑quality data from our ice crystal replicator
> during the first year of FIRE III. Cases include: two cirrus wave
> clouds, a stratiform ice cloud, two deep cirrus thunderstorm anvils,
> two liquid water clouds, two multi‑layer cloud cases, and a winter
> storm case. The first three cases were collected together with high
> quality RH measurements from a balloon‑borne cryogenic hygrometer,
> making them particularly valuable in assessing the dependence of
> cirrus formation and evolution on RH. The two liquid water cases
> provide data on the efficiency with which the replicator collects
> small particles, an important aspect of the quantitative performance
> of the replicator. The lest launch was a successful test of an
> improved prototype instrument. One of us (LMM) is preparing a paper
> that assesses the qualitative and quantitative performance of the
> replicator. We will be analyzing these measurements and the FIRE II
> replicator measurements using efficient image processing techniques we
> are developing. During the remainder of FIRE III we will attempt to
> launch one replicator per month on average, focusing on summertime
> cirrus anvils, about which little is known.
>
> During the NASA SUCCESS program, the DC‑8 will be overflying the ARM
> CART site, with several flights dedicated to remote sensing
> objectives. A number of FIRE researchers, including Ackerman, Sassen
> and Minnis, will be using lidar, radar and satellites to study cirrus
> cloud microphysical properties. One of us (A\]H) will be installing a
> PMS 2D‑P probe on the DC‑8 for the intercomparison and validation
> objectives. We will acquire and process the 2D‑P data, and make it
> available to FIRE researchers.
>
> One of us (AJH) is involved in the formulation of a tropical cirrus
> study under consideration in the vicinity of Panama during the summer
> of 1997. AJH is also involved in the development of INDOEX, a program
> that includes a cirrus component being organized by the Scripps Center
> for Clouds, Chemistry, and Climate, presently planned for
> winter/spring 1998. We will work toward including FIRE investigators
> in the Panama experiment or, alternatively, work to conduct a FIRE
> experiment prior to or after INDOEX.

**FIRE III Research**

Paul Lawson

SPEC Inc.

> Analysis of Existing Data

During the course of SPEC\'s LaRC SBIR contract, we recorded digital
holograms and scattering measurements from thousands of ice crystals in
the CSU dynamic cloud chamber. The dynamic cloud chamber performs a
predictable adiabatic expansion that produces ice crystals with
consistent habits and sizes as the pressure and temperature in the
chamber decreases. The crystal habits include stellars, dendrites,
plates, columns and a few rosettes (‑10 \> T \> 40 •C) and the size
range varied from about 30 to 250 gm. Ice crystals were extracted from
the chamber and accelerated through the sample volume of the
Pi‑Nephelometer. Holograms and scattering measurements of thousand of
ice crystals were recorded This data set encompasses more than 100
Mbytes of measurements. Also, in‑focus video of the ice crystals is
available from video photography of a moving tape that collects crystals
as they fall to the bottom of the chamber. The SBIR effort was intended
to provide a proof‑of‑concept demonstration that the Pi‑Nephelometer was
capable of making digital holography and scattering phase function
measurements. This task was accomplished, however, there were no funds
to analyze the massive amount of collected data. As a part of our FIRE
III effort, we will statistically correlate the scattering measurements
with holography images and video photography of crystal size and shape.
This effort will include the development of additional software to
process, analyze and display the measurements.

Modifications to LaRC Pi‑Nephelometer

The optics in the LaRC Pi‑Nephelometer will be modified to increase the
acceptance angle of the solid‑state camera, install a new generation m
image intensifier and to provide a separate reference beam. These
modifications are intended to improve the capability to reconstruct
images of holograms where there is a high percentage of light
transmitted through a crystal.

New Measurements in the CSU Cloud Chamber.

We will conduct limited additional tests in the CSU cloud chamber. These
tests will focus on crystal types not included in the previous data set
(primarily bullet rosettes) and repeats of some other crystal types. The
additional tests will be used to supplement the existing data set and to
determine the improvement in the ability of the Pi‑Nephelometer to
record holograms of ice crystals and reconstruct images.

Scattering Phase Function and Radiative Parameters

The cloud chamber and flight measurements of scattering phase function
will be used to determine representative phase functions for various
habits of crystals typically found in cirrus clouds in the mid‑latitudes
and the tropics. We plan to work with Dr. Heymsfield and Dr. Liou
(available through other FIRE III funding) to integrate our measurements
with existing data collected over the lest twenty years by Dr.
Heymsfield. Typical phase functions can be estimated for various types
of ice crystals.

**Radiative Transfer and Satellite Remote Sensing of Cirrus Clouds
Using**

**FIRE‑II IFO Data**

K. N. Liou

University of Utah

We will use the replicator sonde, atmospheric sounding, and satellite
data associated with five cirrus cloud cases (22, 26, 28, and 29
November and 5 December 1991) during FIRE II‑IFO to determine and
parameterize the radiative properties of cirrus clouds and to validate
the satellite retrieval algorithm developed for the mapping of the
optical depth and ice crystal size for these clouds based on AVHRR
channels.

Specifically, we will carry out the following research:

\(1\) Analysis of the ice crystal size distribution and shape including
small ice crystals from the replicator sonde data obtained in
FIRE‑II‑IFO. Development of the representative ice crystal size
distributions and shapes for midlatitude and tropical cirrus for
application to radiation/climate modeling.

\(2\) Development of a light scattering program for aggregate and
irregular‑shaped crystals based on Monte Carlo/geometric ray‑tracing
method. Development of a scattering and absorption program for small ice
crystals on the basis of a novel hybrid geometric optics method. Use of
the \"exact\" FDTD method to calibrate the efficient modified geometric
optics approximation.

\(3\) Validation of a detection scheme for the identification of clear,
cirrus, low cloud, cirrus/low cloud cases in multilayer cloudy
conditions using FIRE‑II‑IFO lidar, radar, and sounding observations.
Validation of a satellite AVHRR retrieval algorithm for the mapping of
cirrus optical depth, temperature, and mean ice crystal size, employing
the FIRE‑II‑IFO replicator and sounding data for the aforementioned five
days during which extensive cirrus occurred.

**Physically Based Retrieval of Ice Cloud Properties**

Michael Mishchenko, Brian Cairns, and Andreas Macke

Goddard Institute for Space Studies

Previous analyses of the FIRE measurements have been interpreted as
indicative of ice particle asymmetry parameters smaller than 0.75 at
solar wavelengths. This is consistent with the results obtained by ray
tracing calculations for realistic fractal particle shapes.
Alternatively , the effect of cloud inhomogeneities can be equivalent to
choosing a more isotropic phase function in the standard horizontally
homogeneous plane‑parallel model. Because of these ambiguities, we are
undertaking a broad‑minded research effort aimed at improving our
understanding of ice clouds and based on self-consistent use of
state‑of‑the-art modeling techniques.

The unique aspect of our approach is the use of ray tracing and T‑matrix
methods to accurately compute light scattering and absorption by ice
crystals with size parameters ranging from zero to infinity. Recent
dramatic improvements in the T‑matrix method have made it applicable to
size parameters as large as 100, thus, potentially, covering the gap
between the domain of applicability of the Rayleigh (size parameters
less than 1) and geometric optics (size parameters larger than 100)
approximations. This result is especially important since the T‑matrix
method is many orders of magnitude faster than any alternative technique
for rigorously computing nonspherical scattering. We are now in the
process of examining in detail the convergence of results obtained with
the T‑matrix and ray tracing methods at size parameters less than 100
for different nonspherical shapes (spheroids and cylinders with varying
aspect ratios). This research will result in the complete size-parameter
coverage with only two techniques. Both of these techniques are combined
with line‑by‑line and K‑distribution techniques to retrieve the
properties of physically realistic, vertically extensive, clouds
containing a mixture of gas and particles. At thermal infrared
wavelengths, light scattering depends primarily on the particles\'
overall departure from sphericity and is computed using the T‑matrix
approach. Analysis of infrared spectral measurements permits the
retrieval of effective particle size, the vertical distribution of cloud
opacity, and cloud temperature. Light scattering at visible wavelengths
is very sensitive to particle shape, in particular, to its irregularity,
but nearly independent of particle size. In this spectral range the ray
tracing technique is an accurate means to retrieve particle shape/phase
function information. Both techniques are applicable in the infrared
which allows us to transfer the physical parameters retrieved from
thermal infrared data to the phase function/shape information retrieved
from visible data. We plan to use the results of this work in improving
radiative treatment of ice‑cloud particles in the GISS GCM and the ISCCP
retrieval algorithm.

The ambiguities in the interpretation of FIRE results introduced by
cloud inhomogeneities are addressed using a renormalization method. This
method allows the effects of cloud inhomogeneities to be included in a
standard plane‑parallel model, with renormalized single‑scatter albedo,
phase function and optical depth. These renormalized quantifies depend
in a simple way on the single‑scattering properties calculated using
T‑matrix and ray tracing calculations and on the variability in particle
density, with the usual single scattering properties being retrieved in
the limit of no variability. Comparisons with Monte Carlo calculations
indicate that this renormalization method is valid over a wide range of
variability. We can therefore readily examine the sensitivity of
retrieved microphysical properties to the presence of inhomogeneities
and check the consistency of these retrievals with microphysics probe
measurements when allowance is made for the presence of cloud
inhomogeneities. The renormalization method allows the effect of cloud
inhomogeneities to be included in calculations that treat ice scattering
and absorption accurately and take proper account of gaseous scattering
and absorption from the visible to the thermal infrared.

**Analysis of Cirrus Cloud Microphysical Data**

Michael Poellot

University of North Dakota

The objectives of the proposed work are to: (1) characterize the cirrus
clouds sampled by the University of North Dakota (UND) Citation aircraft
during the FIRE Cirrus IFO‑II in terms of particle size distributions,
crystal habit and ice water content; (2) analyze the spatial variation
of cirrus clouds; and (3) participate in limited collaborative case
study analysis of IFO data.

\(1\) Microphysical characterization of cirrus

The method of analysis will follow that of Heymsfield and Platt (1984;
hereafter referred to as HP), where pass average values of particle
concentrations by size are calculated. Data from the DRI (Desert
Research Institute) replicator will be used to determine particle
characteristics for the smaller particles and PMS 2\~C data for the
larger particles. Following HP, the size distributions will be
parameterized for each 5 •C temperature range analyzed, and the pass
average IWC used to normalize the spectra. Values obtained for the
clouds sampled in this study will be compared with those derived by HP.
In addition to the stratification by temperature, an effort will be m\~
to determine relationships between the microphysical and macrophysical
cloud properties such as cloud depth, distance from cloud boundary, and
large‑scale forcing. It will not be within the scope of this proposal to
analyze all of the replicator data; rather, portions of the film from a
representative portion of each data leg will be processed. The bulk of
the replicator data processing will be performed under subcontract with
DRI.

\(2\) Analysis of the spatial variation of cirrus clouds

It is planned to do a spectral analysis (similar to that of Sassen et
al. 1989) of the vertical velocities derived from the UND Citation IFO
data for the legs flown in cirrus. This will also be clone for several
of the cirrus microphysical parameters (e. g. , ice crystal
concentration and size) derived from the 2D‑C data. The output of this
work will be a description of the variation of these parameters as a
function of scale. This will allow us to see if the apparent
fluctuations in vertical velocity at the 1 km scale are indicative of
fluctuations in cloud microphysical characteristics of the same scale.

\(3\) Limited collaborative case studies

Not all of the significant observational missions from this IFO have
been thoroughly analyzed, including a subtropical cirrus case from
November 30 and a multiple‑aircraft satellite underpass mission on
December 7. It is expected that UND will become involved in one or two
such case study analyses.

**FARS Cirrus and Anvil Research for FIRE m**

Kenneth Sassen

University of Utah

High cloud remote sensing research at the University of Utah Facility
for Atmospheric Research (FARS) in support of the Project FIRE Extended
Time Observations (ETO) component began in December 1986, and now
comprises \~1900 hours of polarization lidar (0.694 \~m wavelength)
observations. These measurements are invaluable as \"groundtruth\" data
in statistically defining cloud heights for helping to evaluate and
improve the algorithm used in the extensive ISCCP program data set to
identify and characterize various clouds from satellite radiance data.
Importantly, a strong improvement in the FARS remote sensing
capabilities has occurred since 1991, involving initially a
comprehensive suite of surface radiation budget radiometers and a
narrow‑beam midinfrared (9.5 ‑ 11.5 gm) radiometer, and more recently an
advanced two‑color (0.532 and 1.06 μm) scanning Polarization Diversity
Lidar (PDL) and a 95 GHz (3.2 mm) polarimetric Doppler radar. We intend
to utilize the entire FARS state‑of‑the‑art remote sensor ensemble to
support further ETO high cloud case studies on a selective bias,
particularly under optically‑dense cirrus and anvil cloud conditions to
help assess the effects of optical extinction on our extended dataset.
Anvil cirrus clouds will receive particular attention, because previous
FARS studies suggest that Great Basin anvils display significant
scattering departures from other cirrus in the visible, infrared, and
microwave spectral regions, and in recognition of the fact that anvils
in other climatic regimes (i.e., the tropics) may differ significantly
in their properties. In this regard, we are performing a retrospective
polarization lidar data analysis program of western‑central Pacific
Ocean anvil/cirrus cloud data collected aboard the NASA DC‑8 platform
during the TOGA/COARE intensive field phase a. D. Spinhirne, NASA
co‑investigator). This study is yielding statistical information on
tropical cirrus cloud physical and scattering properties, as well as
providing case studies to delineate the effects on cirrus of the fallout
of sulfuric acid aerosol from the June 1991 Pinatubo eruptions. We will
also continue to identify for analysis and publication cirrus cloud case
studies from our growing FIRE ETO and IFO datasets.

**FIRE Cirrus Cloud Studies**

David Starr

NASA Goddard Space Flight Center

This research project focuses on the following fundamental questions
concerning physical processes in upper tropospheric clouds: What is the
role of large‑scale, mesoscale and small‑scale dynamical processes in
determining the physical properties of cirrus clouds? and What is the
role of microphysical and radiative processes in determining the
physical properties of cirrus clouds and how are they modulated by and
how do they interact with dynamical processes at various scales?
Improved understanding of the interaction of dynamical, microphysical
and radiative processes in determining the net ice water budget and
associated vertical transports in cirrus clouds is essential to efforts
to develop and corroborate representations of cirrus cloud processes for
application in large‑scale models used for climate studies. The approach
that will be taken is to continue our analysis of the wealth of
observations obtained during the 1991 FIRE Cirrus‑II field campaign and
the FIRE Pilot tropical Cirrus Experiment during TOGA‑COARE integrated
with renewed efforts to investigate cirrus cloud development using a
very high resolution numerical cirrus cloud model. This project will
also support proposed FIRE‑III field activities (experiment design and
execution) and utilize the data obtained. We will continue our active
collaboration with and support of other FIRE researchers by providing
analysis and data products, as we have in the past. Dr. Starr will
contribute substantially to the development of plans for the
implementation of FIRE‑m and an eventual FIRE tropical cirrus
experiment. Dr. Starr is also heavily committed to the planning and
execution (mission scientist) of the joint NASA AEAP/FIRE SUCCESS
mission scheduled for April 1996 in Kansas/Oklahoma that is concerned
with the possible effects of aircraft emissions, including contrails and
also possible aerosol effects, on cirrus clouds and global climate.

Our proposed analyses of FIRE Cirrus‑II and other observations will
define the dynamical and thermodynamic environment and internal
structure of observed cirrus cloud systems and characterize the
macrophysical and microphysical structure of the clouds. We will
investigate the interactions between cloud processes and larger scale
atmospheric controls. These results will be used to guide our modeling
efforts. A number of significant improvements to our cirrus cloud model
are underway including implementation of a new dynamical package,
incorporation of an advanced explicit cloud microphysics package
enabling explicit consideration of nucleation processes, and improvement
in treatment of cloud radiative processes.

We will extend our studies to consider three topics of central
importance to FIRE‑III: a) anvil cirrus both in the middle latitudes and
in the tropics, b) the role of nucleation processes in determining
cirrus cloud properties, and c) contrasting cirrus development
associated with the subtropical jet stream versus other cirrus
situations in the middle latitudes.

**Cirrus Cloud Properties from Aircraft**

Graeme Stephens

Colorado State University

This proposal describes research aimed at the development of new
techniques for both remote sensing of ice cloud properties and for
measurement of their shortwave radiative properties. The approach
proposes to develop and fly new spectrometers principally in the near
infrared region (a high resolution A‑band spectrometer and a scanning
spectral polarimeter), as well as the use of a new airborne radar and mm
microwave radiometer. The aim is to deploy these instruments in a
proposed field experiment and carry out analyses of the data and
supporting theoretical research.

**Theoretical and Experimental Studies of the Interactions between
Clouds**

**and Aerosols**

Owen Toon, Andrew Ackerman, Joelle Champney, Eric Jensen, Irina Sokolik

NASA Ames Research Center

Our work is aimed at better assessing the indirect effects of aerosols
on. We have developed one and two‑dimensional models of the interactions
between tropospheric aerosols and clouds. Marine stratus clouds have
been shown to be sensitive to the abundance of aerosols in the marine
boundary layer. Our work has shown that the depth of the boundary layer
and the optical thickness of stratus can be controlled by the abundance
of aerosols. We have also been able to simulate many of the properties
of ship tracks, including the albedo change in the clouds, as well as
the liquid water and drizzle rate changes that are induced by adding
aerosols to the marine boundary layer from ship exhaust. We have also
developed models of cirrus clouds and their sensitivity to ambient
nuclei concentrations. We have shown that cirrus clouds are not as
sensitive to changes in ambient aerosol concentrations as are stratus.
However, even cirrus will respond if aerosols with unusual properties
are introduced. At the present time we are working to construct an LES
model for both marine boundary layer and cirrus clouds so that more
realistic simulations can be conducted.

In addition to theoretical studies we have participated in a number of
FIRE sponsored field programs, as well as the NavyÕs MAST program to
investigate ship tracks. At the present time the PI is the project
scientist for SUCCESS. SUCCESS is a joint program between FIRE and
NASA\'s Atmospheric Effects of Aviation Program. SUCCESS has a number of
goals including improving our understanding of the radiative properties
of cirrus clouds and of contrails, characterizing the aerosols in the
upper troposphere, determining the formation mechanisms of cirrus clouds
and determining the role of aircraft exhaust in modifying cirrus.
SUCCESS will involve the NASA DC‑8, ER‑2 and T‑39 aircraft in a
coordinated field program. The aircraft will be based in Salina, Kansas
during April 1996 and concentrate many of their measurements over the
DOE ARM site in Oklahoma The SUCCESS program coincides with a DOE
intensive operational period in which DOE aircraft equipped with
radiometers will also be operating. The ER‑2 will be equipped with
remote sensing instruments similar to those used in previous FIRE field
programs.

The DC‑8 and T‑39 will be used as in situ sampling platforms to
determine cloud optical, microphysical and chemical properties.

**[Joint Arctic Clouds and Marine Stratus and Tropical Cirrus
Proposals]{.underline}**

**Participation of MAS and HIS in SUCCESS Campaign**

Steve Ackerman^1^, Paul Menzel^1^, Si‑Chee Tsay^2^, and Steve Platnick
^2^

^1^University of Wisconsin, ^2^NASA Goddard Space Flight Center

Scientific Goals

\(1\) Collect a well‑calibrated data set of high spectral and spatial
resolution radiation measurements to support the objective of SUCCESS
and the development of cirrus cloud masking algorithm.

Our major goal is to determine the radiative properties of cirrus
contrails, and contras\" them with naturally occurring cirrus. To assess
the radiative impact of these clouds requires a well‑calibrated set of
radiation measurements and \"ground (or in-situ) truth\" observations.
We propose to acquire MAS and HIS multispectral observations from the
NASA ER‑2 aircraft by coordinating over flights of the ER‑2 with in situ
aircraft and \"ground based measurements. Several studies have
demonstrated the sensitivity of the MAS and HIS spectral observations to
cloud microphysical properties.

The MAS/HIS measurements will address the very important relationship
between the cirrus radiative properties and the thermodynamic
environment (atmospheric temperature and moisture conditions) wherein
cirrus forms and is maintained. The HIS will provide accurate
measurements of the atmospheric thermodynamical properties supporting
the cirrus life cycle and the MAS will measure the cirrus aerial extent
and radiative properties.

Future observations from satellite platforms, such as MODIS and AIRS,
are well suited to study these clouds. Participation of MAS and HIS
instruments on the ER‑2 is a unique opportunity to provide measurements
that can be used to develop remote sensing techniques for the future
MODIS and AIRS instruments. The HIS spectral region covers the
wavelengths of all the current and near future infrared instruments
flying in space, and therefore provides a data set for testing any
infrared retrieval technique. The MAS has many spectral charnels that
are similar to the future MODIS.

Observations made from the MAS and HIS during this experiment will be
used to develop techniques to detect the presence of cirrus using
multispectral observations. Particular emphasis will be placed on
developing and validating methods of detecting tropospheric clouds and
defining their aerial extent with infrared (e.g., 13.9 µm) and near
infrared (e.g., 1.88 µm) charnels; these are similar to the MODIS
charnels and the MAS cirrus detection have relevance to the MODIS cloud
mask.

Well calibrated radiances are essential for the development of accurate
cloud retrieval algorithm. The calibration of the HIS is such that it
serves as a reference for line‑by‑line radiative transfer models. The
MAS infrared charnels are calibrated through two onboard blackbody
sources that are viewed once every scan. Calibration of the IR MAS
charnels will be augmented through vicarious calibration with the HIS.
The MAS solar charnels are calibrated in the field, using an integrating
sphere, before and after each ER‑2 flight mission.

\(2\) Perform a statistical characterization of the spectral properties
of contrails and naturally occurring cirrus clouds.

Several studies have demonstrated the sensitivity of spectral radiances
to cloud particle size and shape distributions. The MAS and HIS
instruments provide accurate spectral measurements that can be used to
assess differences in the radiative signatures between contrails and
naturally occurring cirrus clouds. One difficulty in assessing the
impact of the high‑altitude subsonic aircraft on cirrus
formation/modification is the natural variability of the atmosphere and
the potentially small signal of the radiative perturbation. Variations
in the atmospheric spectral properties for contrail! and natural cirrus
conditions will be assessed with the two ER‑2 instruments in conjunction
with in situ and ground‑based observations.

\(3\) Participate in the flight planning and direction of the NASA ER‑2
aircraft during field campaigns.

One goal of the NASA FIRE and SASS programs is to determine the
radiative impact of contrails. Field experiments, such as SUCCESS, which
include observations of the radiative characteristics of contrails from
a suite of ground‑based, aircraft and satellite platforms are crucial to
achieving this goal. Such a field program requires the field
coordination of a science team. The authors have participated in the
execution of a wide variety of national and international field
programs, with emphasis on the coordination of the ER‑2 flight plans. We
will work cooperatively with the science team in the design and
execution of the field experiment.

\(4\) Map the environmental upper tropospheric water vapor distributions
around contrails and cirrus.

The HIS was designed to provide accurate, high‑spectral resolution
observations to support algorithm development that will improve our
capabilities of passive remote sensing the temperature and moisture
structure of the atmosphere. With appropriate ER‑2 flight tracks, the
HIS measurements will be used to characterize the upper tropospheric
temperature and moisture for environments in which contrails are
imbedded.

**Improvement of NCEP\'s Analysis/Forecast System Through Use of FIRE**

**Data Sets**

Kenneth Campana, Qingyun Zhao, Yutai Hou

National Centers for Environmental Prediction (NCEP)

We intend to make use of the various FIRE data sets to validate and
improve the global and

> regional model cloud and radiation parameterizations in NCEP\'s
> operations. These model\'s are generally used for routine short‑term
> NWP forecasts, but the global model is used for extended (up to 6
> months) forecasts in a coupled ocean/atmosphere environment. We intend
> to use the data to identify deficiencies in the model\'s predicted
> upper‑level and boundary‑layer cloud. It is expected that improved
> cloud/radiative processes will result in improved model predictions,
> especially near the earth\'s surface.
>
> The current (diagnostic) cloud scheme in NCEP\'s global model does not
> attempt to parameterize clouds in the lowest 10 percent of the model
> atmosphere, except in suspected marine stratus regions, because of
> large values, and diffuse horizontal gradients, of the relative
> humidity in the longer layers. Additionally, comparison of upper‑level
> clouds with U.S. Air Force Real‑Time Nephanalyses, show this modeled
> cloud to be excessive; however, we are concerned that the analysis,
> itself, may not be reliable at these levers. The regional model
> employs an explicit cloud water parameterization and the global model
> will soon adopt a similar scheme (currently being tested). Since we
> have not subjected this parameterization to any rigorous comparison
> with boundary‑layer or \'reliable\' upper‑level cloud observations,
> the FIRE data provides us with a unique opportunity to do sot
> Specifically, we plan to study the cloud water parameterization in the
> following manner:
>
> 1\. We will use the FIRE data to regionally validate the model\'s
> cloud parameters, e. g. fractional coverage, liquid‑water and ice
> particles, vertical extent, and optical depth. We intend to discern
> whether the model can successfully simulate these cloud types, and if
> not, how the parameterization might be improved.
>
> 2\. We will attempt to isolate the effects of upper‑level cirrus cloud
> on the development of lower‑level cloud (via ice‑fall \'seeding\'),
> and subsequently on model convective and stratiform precipitation,
> through a series of sensitivity experiments.
>
> 3\. We intend to use any FIRE‑observed differences in the properties
> of tropical and midlatitude upper‑level clouds to adjust our
> parameterization of their radiative properties.
>
> 4\. We will use the SHEBA data to investigate the ability of our
> models to simulate the Arctic environment (clouds and
> temperature/moisture structure) in an often‑neglected region of the
> globe.

**FIRE III Research**

Steve Cox

Colorado State University

> A research effort is proposed which transitions the investigation of
> the radiative characteristics of upper tropospheric cloudiness begun
> during FIRE I and II into the era of FIRE III. The work is envisioned
> as both a continuation of the previous efforts and the development of
> new research strategies which will enhance future studies. The
> proposed research addresses four major areas. Improved
> parameterizations of longwave and shortwave radiative effects based
> respectively on probabilities of cloud free fines of sight and the
> stochastic treatment of cloud optical properties are proposed. An
> improved algorithm for inferring the infrared emissivity of cirrus
> clouds is discussed. New interpretation algorithm for remotely sensing
> the visible optical thickness and cloud microphysical properties are
> presented. Hardware efforts are highlighted by the deployment and
> testing of a near‑IR interferometer, completion of a precise and
> \"smart\" instrument pointing device and design and construction of a
> new multiple field of view sun photometer. In addition to a continued
> attention to data currently archived, activities will include a
> linkage in data acquisition and analysis leading into future field
> experiment deployments.

**Development and Validation of a GCM Cloud Parameterization Using
FIRE**

**and ISCCP Data Sets**

Anthony Del Genio

Goddard Institute for Space Studies

We intend to compare ISCCP data to GISS GCM simulations to define
regions of GCM deficiencies in cirrus and stratus properties, and use
FIRE data to explore the reasons for the discrepancies. For cirrus, we
will compare the synoptic conditions giving rise to cirrus during FIRE I
and II to those generating cirrus in the GCM to understand the GCM\'s
tendency to overpredict the altitude of cirrus formation. We will
compare the simulated radiative properties of midlatitude and tropical
cirrus and validate them against observations from FIRE III and‑the FIRE
Pilot Tropical Cirrus Experiment. We will also explore the factors
controlling tropical cumulus anvil ice content and radiative properties
in the GCM in order to justify and define the science requirements for a
possible FIRE III tropical cirrus field experiment. For stratus clouds,
we will explore the sensitivity of marine stratus breakup in the GISS
GCM to vertical resolution, forcing a single column version of the model
with ASTEX data. We will try to isolate factors controlling optical
thickness ‑ temperature correlations, focusing on cloud physical
thickness and static/ moist convective stability variations. In the
third year of research, we will compare the properties of simulated
Arctic clouds to those observed during the FIRE III Arctic Cloud
Experiment. We will examine distributions of cloud top/base pressure,
optical thickness, and particle size, and for the latter, we will
compare ice particle characteristics to those for midlatitude cirrus.

**FIRE III Research**

Hermann E. Gerber

Gerber Scientific

The planned research consists of two parts: The first part will entail
the development of an asymmetry and backscatter meter (!\'g meter\").
This new optical instrument will be based on the reciprocal nephelometer
principle, and will be designed for aircraft deployment. Feasibility,
design and breadboarding are efforts of the first year, testing of the g
meter under controlled conditions the principal effort the second year,
and deployment on the U. of Washington aircraft during the Arctic FIRE
III the effort of the third year. The second part of the planned
research consists of continued analysis of the ASTEX Sc data base, as
well as analysis of the SOCEX I and SOCEX II Sc experiments conducted
under Sc baseline conditions south of Australia Cloud‑property scaling
relationships, 2 kHz microphysical data (LWC, PSA, and effective
radius), and entrainment features will be studied. Analysis of optical
and microphysical data collected during the FIRE m experiment will
follow.

**FIRE III Research**

Qingyuan Han and Ronald Welch

South Dakota School of Mines and Technology

The proposed investigation is focused upon two main areas. First is the
validation of ISCCP cirrus cloud property retrievals using the two
cirrus FIRE lFOs over the U.S., the TOGA‑COARE and CEPEX results, and
the upcoming polar (including SHEBA) observations. Second, it is
proposed to use ISCCP data to characterize the cirrus ice crystal
particle size retrievals in various regions of the world, including over
land and oceans, and especially for the tropical, mid‑latitude and polar
regions.

> This proposal specifically addresses the following critical questions
> posed by the \"First ISCCP Regional Experiment‑m Program\"
> Announcement of Opportunity on page A‑4:

1\) Where are the distributions and amounts of ice mass and total water
in the upper troposphere? Specifically, how can ice mass be determined
from remote sensors and how can these measurements be validated?

2\) What are the microphysical properties of tropospheric clouds?
Specifically, how do the particle sizes, shapes and phase depend on the
large scale environment?

3\) What are the radiative properties of upper‑tropospheric clouds and
how do they relate to the ice mass, and the microphysical and
macrophysical characteristics of the cloud? Specifically, can these
radiative properties be usefully expressed in terms of an effective
particle size that is consistent with cloud ice path and optical depth?

4\) How representative are midlatitude continental cirrus of upper
tropospheric clouds in other regions of the globe? Specifically, will
GCMs be able to use a single universal cirrus parameterization for all
latitude and regional domain, and are tropical cirrus cloud systems
sufficiently different from their midlatitude cousins to call for a
tropical cirrus field campaign?

> A major focus of this proposed investigation is the validation of the
> ISCCP cloud property retrievals using data acquired during the FIRE
> field campaigns. Cloud optical thickness and cloud top temperature
> retrieval algorithm using ISCCP data have been developed by Rossow and
> Garder (1993a,b) and Rossow et al (1993). Particle size and revised
> optical thickness algorithm for cirrus and marine stratocumulus have
> been developed by Han (1992) and Han et al (1991, 1994, 1995a,b).
> While various efforts have been made to compare satellite retrieved
> cloud properties with in situ measurements (e.g., Nakajima et al 1991;
> Minnis et al, 1992; Wielicki et al, 199\~, Rawlins and Foot, 1990),
> there are few direct validations of ISCCP analysis (Rossow and Garder,
> 1993b, Han et al, 1994, 1995a). The second major focus of this
> proposed investigation is the retrieval of cirrus ice crystal
> effective diameters for both land and ocean regions and for the
> tropics, mid‑latitudes and polar regions. It is expected that there
> are important regional, seasonal and diurnal differences in the cirrus
> cloud optical properties which will be important for global climate
> models and global cloud feedback sensitivity studies.
>
> Some specific questions involve differences between mid‑latitude
> cirrus as observed in the previous FIRE IFOs and tropical anvils and
> thin polar clouds. What are typical values in each region, and what is
> the typical variability in properties in each region and season?
>
> The specific objectives of this investigation include:

1\) Quantitative validation of ISCCP cirrus cloud retrievals will be
made using the FIRE, TOGA‑COARE and upcoming polar (FIRE and SHEBA)
results.

2\) The cirrus cloud algorithm will be extended for retrievals over the
continents; this requires the inclusion of seasonal and temporal
variations of surface reflectance in the AVHRR charnels 1‑3.

3\) A special focus of this investigation is the retrieval of cirrus
properties over the polar regions; this requires a significant
improvement in the polar cloud mask and inclusion of high reflectance
surfaces.

4\) Cirrus cloud retrievals will include a wide range of new crystal
habits and size distributions; in particular, preliminary studies
suggest that effective variance of the cirrus size distributions should
be included with effective size.

**FIRE III Research**

Sonia Kreidenweis, Paul DeMott, David Rogers

Colorado State University

Global climate studies have shown that clouds strongly influence the
Earth\'s radiation balance, but many of the factors that are thought to
control these influences are not well understood. Ice nuclei (1N)
populations are especially important for determining cola cloud
microphysical characteristics. Anthropogenic emissions, including
aircraft exhaust and long-range transport of pollution, may affect
climate through their effects upon ice nuclei abundance and thus upon
natural cloud processes. The assessment of the potential for such
climate effects is limited by the lack of appropriate measurements that
characterize ice nuclei in both relatively unperturbed (\"background\")
air masses, and in air masses strongly influenced by anthropogenic
activities.

Our contribution to the cirrus/contrail elements of FIRE III is through
our funded participation in the NASA SASS program. The focus of our
project is the measurement and characterization of IN in the upper
troposphere and longer stratosphere. We are currently finalizing the
design of the airborne version of the CSU continuous flow diffusion
(CFD) chamber, used to detect IN at controlled temperatures and
humidifies. We will use this device in the planned SUCCESS measurement
campaigns in Spring 1996, where our contributions will be (1) the
measurement of the number concentrations of IN in background air, and in
aircraft exhaust regions; (2) the measurement of total number
concentrations of particles less than 3 \~m in diameter, to determine
the fraction of those particles active as IN; and (3) the separation of
the IN and non‑IN fractions, and subsequent determination of the
elemental composition and morphologies of both fractions. To accomplish
item (3), we exploit the rapid growth of activated IN to
supermicron‑sized ice crystals in the CFD, which permits inertial
separation of the activated from the nonactivated particles. Each
fraction is then impacted onto appropriate substrates and analyzed using
scanning and transmission electron microscopy (SEM and TEM) and
energy-dispersive x‑ray (EDX) spectrometry. Our results will provide a
continuous flight record of IN abundance, which can be used to assess
whether IN concentrations have been perturbed in aircraft‑influenced air
masses.

Ice nuclei probably also play an important role in the formation and
properties of boundary layer clouds in the Arctic. The availability and
relative abundance of IN could be quite important in determining the
water phase in such clouds, which in turn has a significant effect upon
their radiative properties. The presence of mixed‑phase clouds at only
moderately supercooled cloud temperatures in springtime conditions
underscores the potential role of IN. In predominantly ice‑phase clouds
in winter time, the nature of IN may be quite different or profoundly
influenced by pollution during episodes of Arctic haze. Continuous
measurements of Arctic boundary‑layer IN abundance and chemistry, using
our CFD system as described above for the SUCCESS campaign, would be a
valuable contribution to the stratus/Arctic Cloud component of FIRE III.
We are presently pursuing funding for our participation in the Arc tic
Cloud Experiment.

**Satellite Remote Sensing Studies**

Patrick Minnis

NASA Langley Research Center

This proposed research is primarily designed to validate, develop, and
apply techniques for

the remote sensing of cloud properties to address many of the FIRE m
goals as outlined in

the FIRE m Research Plan. The research will continue analyses of FIRE‑II
datasets in the

early stages of FIRE‑III and will continue theoretical studies supported
by additional data analysis. Measurements from other experiments will be
examined to address some of the FIRE‑III objectives. The proposed
research includes participation in the Arctic field program and other
field experiments to be developed under FIRE‑III.

The basic objectives of this research effort are as follows:

\(1\) Quantify the uncertainties in satellite‑derived cloud and
radiation properties:

\(a\) by comparing derived values to other datasets based on
measurements having known uncertainties and accuracies (e.g., in situ,
lidar, radar, ceilometer, etc.),

\(b\) through sensitivity studies using theoretical computations, and

\(c\) by intercomparing results from various algorithm, especially the
ISCCP method, using results having quantified errors arising from (la)
above.

\(2\) Develop and improve techniques to derive cloud amount, phase,
effective particle size, optical depth, top and base height, thickness,
water path, radiative fluxes, and cloud layering and overlap using
multispectral satellite data during both day and night by

\(a\) using radiative transfer computations to develop parameterizations
of reflectance and emittance for various wavelengths and macro and
microphysical cloud configurations,

\(b\) developing empirical‑theoretical methods using satellite data
combined with measurements from other sources (e.g., radar, microwave
radiometers, etc.), and

\(c\) improving computer‑interactive tools for real‑time analysis of
field experiment satellite data.

\(3\) Apply improved analysis methods to various geostationary and
polar‑orbiting satellite datasets to

\(a\) develop cloud parameter products for understanding the temporal
and spatial variability of cloud and radiation fields during field
experiments, for validating mesoscale model predictions of cloud
properties for specified meteorological conditions, and for validating
similar parameters derived from EOS satellites,

\(b\) address outstanding scientific issues related to the absorption of
solar radiation by clouds, the tropospheric ice and liquid water budget,
the impact of clouds on the polar radiation budget, and the effects of
aerosols on cloud properties, and

\(c\) provide large‑scale, validated cloud parameter datasets to
evaluate GCM and ISCCP results.

**A Near‑Infrared Spectroradiometer for FIRE III**

Peter Pilewskie

NASA Ames Research Center

The current lever of understanding of the radiative properties of clouds
is incomplete, in part due to the lack of solar spectral data. The near‑
infrared region of the solar spectrum has proven to be one of the most
useful for cloud remote sensing, owing to liquid water and ice
absorption that is strong enough to reduce the scattering by cloud
particles, yet not to the degree which would make signal detection
difficult. Furthermore , the spectral nature of liquid and ice
absorption is different enough from water vapor absorption to allow
inferences of cloud properties in the vapor transparent near‑infrared
bands. While numerous remote sensing studies have capitalized on those
qualifies, the same spectral absorption properties of liquid, ice, and
vapor make the near‑infrared the most important spectral region for
determining cloud absorption. Our FIRE phase m research effort focuses
on developing instruments to match the lever of accuracy achieved by
broadband sensors, but with continuous spectral coverage. We have
defined the following detector specifications for the Spectral Flux
Radiometer (SPFR):

• 0.25 ‑ 2.5 µm spectral range

• hemispheric or narrow field of view (1 mrad)

• 10-20 nm resolution

• 1 Hz spectral sampling rate integrating sphere, standard lamp,
standard diffuser calibrated

• surface‑based (zenith viewing); aircraft platform (zenith and nadir
viewing)

We will obtain the following data products:

• solar spectral radiance or irradiance

• spectral transmission, reflection; bi-directional transmission,
reflection

• reduced products: cloud water phase, optical depth, particles size,
liquid/ice water path, 1iquid/ice water content

This research includes the design and development of the prototype in
our laboratory , calibration, field testing, flight testing, and field
deployment. We have successfully deployed, at surface sites, a
narrow‑field of view prototype. Note that in the characteristics listed
above we are also providing for a hemispheric field of view irradiance
measurement, requiring a different optical system. The desired optical
system will thus depend on the primary scientific objectives: irradiance
measurements are more appropriate for cloud energetics, while radiance
measurements are better suited for remote sensing.

We have set the following timetable:

Year 1: Complete mechanical and optical design of the SPFR. Procure
optical elements and begin work on mechanical components. Integrate
optics with housings and mounting components. Refine data control, data
transfer, and data storage software.

Year 2: Perform laboratory calibrations and field calibrations (if
necessary; remote site, such as the NOAA Observatory on Mauna Loa) for
spectral, energy, and angular response. Field test the prototype at
surface site during the SUCCESS mission; aircraft testflights in
June/July 1995. Develop software for data reduction, processing, and
analysis.

Year 3: Prepare instrument for FIRE m field study phase. Calibrate.
Refine data analysis routines. Prepare to deploy identical instrument
pair on an aircraft platform and surface site. Analyze collected data

**A Cloud Observing Experiment: Remote Sensing for the Radiation and**

**Physical Parameters of Clouds**

James Spinhirne and James Wang

NASA Goddard Space Flight Center

The proposal is for a continuation existing studies whereby instruments
on a high altitude aircraft are applied for the study, application and
development of cloud remote sensing. Previous work emphasized the
retrieval of important cloud radiation parameters for clouds. The basic
direction of the proposed work is to continue to develop and apply
remote sensing of radiation parameters and add a strong focus on the
retrieval of the cloud physical parameters that relate to cloud
radiation. The science objective is improved cloud remote sensing and
cloud parameterization for models. The estimate of the cloud ice water
content of cirrus clouds from combined passive and active sensing would
be specially studied. The proposed work is to involve: (i) the continued
analysis of previous observations from FIRE and of extensive
observations of tropical clouds from TOGA/COARE, (ii) improvements in
instrumentation, and (iii) participation in future field experiments.

An emphasis is the angular distribution of reflected radiation from
clouds. Shortwave reflectance functions are a fundamentally important
factor for cloud remote sensing and cloud radiation. There are few
experimental measurements especially for cirrus clouds. In the previous
four years an instrument, the Tilt Scan CCD Camera, was developed and
flown on the NASA ER‑2 aircraft for observation of the bi-directional
reflectance of cloud. Data were acquired in large scale field
experiments for mid latitude and tropical cirrus and marine stratus
clouds. A principal objective of this proposal is to provide support to
continue the analysis and reporting of the existing data. Limitations in
the current instrument have been found. Instrument improvement and
participation in a focused cirrus field experiment is proposed.

The combination of high frequency microwave radiometer measurements with
multispectral visible and near infrared radiometer measurements and
active cloud profiling is to be studied for retrieval of the ice/water
content of high clouds and other cloud physical parameters. Data of this
type were acquired during observations of tropical clouds in the 1993
TOGA/COARE project and are to be analyzed. Since 1993 the highest
frequency of the ER‑2 microwave radiometer was increased from 220 to 325
GHz. Study and tests of the 325 GHz charnel for cirrus remote sensing is
proposed.

A dedicated and focused cirrus remote sensing and radiation experiment
is proposed. Participation in a possible high latitude cloud study is
also proposed. In addition, basic field deployment and data processing
for the use of the ER‑2 cloud lidar and TSCC as support instruments in
other cloud and radiation field experiments is covered

**Cloud Radiative and Physical Properties Inferred using Landsat**

Bruce Wielicki

NASA Langley Research Center

An investigation is proposed to examine both boundary layer and cirrus
clouds using high resolution Landsat data. The study addresses issues in
three areas critical to FIRE III objectives:

• Satellite Based Cloud Remote Sensing Validation

• Comparison of Landsat results to Cloud Scale Dynamical Models

• Implications of Landsat data for Global Radiative Modeling

Landsat data provide a unique perspective to examine cloud systems
across spatial scales from 30 m to 180 km. The high spatial resolution
is important for comparisons to cloud scale dynamical models, as well as
to the elimination of uncertainties which result from varying amounts of
sub‑pixel scale cloud in typical meteorological satellite data Landsat
spectral coverage also provides a test bed for examining the
capabilities of the next generation of space‑borne cloud imagers. The
proposed studies involve analysis of three types of data:

• Existing FIRE I and FIRE II data sets

• New extended time and space observations to test FIRE I and II
conclusions in related cloud regimes (land and polar boundary layer,
topical cirrus)

• FIRE III field experiment data (SHEBA and tropical cirrus)

Many of the studies will involve cooperative work with other FIRE
investigators. While these collaborations are not explicitly named as
Co‑Investigators on this proposal, such collaborations are critical to
the success of FIRE III and will be pursued as part of this proposal.

Because FIRE III is part of the NASA Mission to Planet Earth program, a
major focus of this investigation will be on verification of cloud
remote sensing techniques and data/model intercomparisons considered to
be examples of the types of global capabilities available with the Earth
Observing System (EOS) MODIS imager beginning with the launch of EOS-AM
in 1998.

**FIRE III Research**

Donald Wylie

Space Science and Engineering Center, University of Wisconsin‑Madison

Don Wylie intends to participate in FIRE‑III in two areas: 1) The SHEBA
experiment in the Arctic and 2) global studies of the radiative
properties of clouds A cirrus cloud climatology is currently being
compiled at the University of Wisconsin‑Madison using the mufti‑spectral
HIRS data from the polar orbiting NOAA satellites. Over six years have
been collected. This is an adjunct to the International Satellite Cloud
Climatology Project (ISCCP). The SHEBA experiment will help both ISCCP
and the Wisconsin Cirrus Climatology by providing an opportunity for in
situ data in the Arctic. Polar regions have few good data for improving
these cloud climatologies. The cloud and radiation data from SHEBA will
be used to refine both satellite cloud climatologies.

Global studies of the radiative properties of cirrus clouds are being
clone using the data sets from the Wisconsin Cirrus Climatology and the
ISCCP. Both data sets are known for their estimates of the height of the
cloud tops. However, both also obtain information on the optical depths
of clouds. The Wisconsin Climatology measures optical depths in the
infrared 11 μm window region of the spectrum for semi‑transparent cirrus
clouds while the ISCCP measures optical depths at visible wavelengths.
Both data can be used to estimate tropospheric heating and cooling
caused by radiative processes. Changes in the radiative processes in the
seasonal cycles and weather systems also will be studied. FIRE data from
the aircraft flights in the TOGA/COARE experiment will be used to
understand the satellite derived radiative quantifies in the tropics,
which is where semi‑transparent clouds are the most numerous and have
the largest impact on the heat budget of the earth.

**[Miscellaneous Proposals not funded by FIRE III]{.underline}**

**FIRE III Research**

Howard Hanson

CIRES

I\'m working with Vern Derr and a couple of other NOAA/CIRES people to
\'rescue\' the 10plus‑year time series of collocated Eppley pyranometer
& NOAA microwave radiometer data that was accumulated at Stapleton
Airport in Denver. (Some of these data were used in a paper by Derr et
al. in J. Atmos. Sci., 47, 2774‑2783, 1990.) The instruments have been
at Stapleton since about 1983, and have a reasonably good record of
calibration by the NOAA labs; also, there\'s a more recent part of the
dataset that includes NOAA profiler data. This constitutes \'rescue\'
because, with Stapleton being decommissioned, the instruments are going
away. This decade‑long time series of downward solar radiation at the
surface with simultaneous cloud water data is too good to let slip
through the cracks. The job involves , essentially , reading some old
tapes and finding where other bits and pieces of the dataset are and
putting it all into one standard file system.

The actual grunt work is being clone by a student of mine and by one of
the NOAA/CIRES guys on the side, since it\'s all unfunded. Once we get
the dataset assembled, my student and I will try some simple time‑series
analyses of it, just to see if there\'s anything obvious of interest.

**Modeling of Cloud Scale Turbulent Transport**

W. S. Lewellen and D. C. Lewellen

West Virginia University

Our long term goals for ONR are to understand the dynamics of cloud
motions on scales of 10 kilometers and less in sufficient detail to be
able to provide a consistent subgrid scale turbulent closure for
mesoscale models, and to be able to utilize simulated variances as a
measure of forecast predictability. During FIRE III we expect to first
concentrate on the issue of cloud top entrainment. We will be utilizing
the ASTEX data set as part of this effort.

The goal of our research for NASA is to gain a better understanding of
the role of turbulent mixing on the dispersion and chemistry of the
wakes of subsonic aircraft flying in the neighborhood of the tropopause
and to provide valid subgrid parameterizations of this effect for the
larger scale climate models needed to assess the environmental impact of
the projected fleet of subsonic aircraft. We are utilizing numerical
Large‑Eddy Simulations (LES) of the turbulence to represent mixing
during the period from several seconds to almost an hour after wake
generation. During FIRE III we expect to make comparisons with the early
wake results to be obtained in SUCCESS. Our research will necessarily
involve ice microphysics of cirrus as we extend the time covered by our
simulation.

**APPENDIX E ‑ RESULTS OF CIRRUS IMPLEMENTATION STEPS SURVEY**

The following lists are based on responses to a questionnaire that was
distributed to the FIRE science community soliciting participation in
the implementation steps identified in the Cirrus Implementation Plan.
Lead researchers responsible for coordinating the multi‑investigator
participation and reporting on progress are identified in brackets. The
FIRE participants are listed as Participant (P), Liaison (L), or Neither
(N)

**4.0 CONTINUED EXPLOITATION OF EXISTING CIRRUS DATA SETS**

4.6‑1 GCM and parameterization evaluation and validation,

(Tony Del Genio, Leo Donner)

P L N

Del Genio Cox Cairns

M.Miller McDougal Gerber

Hallett Minnis Liou

G. Mace Rossow Pilewskie

G. Stephens Uttal Eberhard

Heymsfield Hlavka

S. Kinne Lawson

Poellot A. Macke

Sassen Arnott

Asano

4.6‑2 Characterization of cloud radiative properties and effects,

(Peter Pilewskie, Jim Spinhirne)

P L N

Cairns Gerber Del Genio

Cox McDougal Asano

Liou M. Miller

Minnis Rossow

Pilewskie Uttal

Eberhard Heymsfield

Hallett Poellot

Hlavka Sassen

S. Kinne

Lawson

G. Mace

A. Macke

G. Stephens

Arnott

4.6‑3 Characterization of cloud microphysical properties,

(Leo Donner, Andy Heymsfield)

P L N

Liou Gerber Cairns

Minnis McDougal Cox

Uttal M. Miller Del Genio

Eberhard Rossow Pilewskie

Hallett Hlavka Asano

Heymsfield A. Macke

S. Kinne Sassen

Lawson Starr

G. Mace

Poellot

G. Stephens

Arnott

4.6‑4 Case studies and modeling of cloud development,

(David Starr, Bill Cotton)

P L N

Cairns Cox Gerber

Liou Del Genio Pilewskie

M. Miller (?) McDougal Uttal

Minnis Rossow Hlavka

Heymsfield Eberhard A. Macke

G. Mace Hallett Asano

Sassen S. Kinne

Starr Lawson

Poellot

G. Stephens

Arnott

4.6‑5 Development, validation and application of satellite remote
sensing of cloud properties.

(Pat Minnis, Bill Rossow)

P L N

Liou Cairns Del Genio

Minnis Cox Gerber

Rossow McDougal Asano

Uttal M. Miller

Hallett Pilewskie

Heymsfield Eberhard

A. Macke Hlavka

Sassen S. Kinne

G. Stephens Lawson

G. Mace

Poellot

Arnott

4.6‑6 The FIRE project office should support the logistics of
multi‑investigator participation pursing the above goals.

(David McDougal)

P L N

McDougal Cairns Del Genio

Heymsfield Cox Gerber

Minnis M. Miller (?),

Rossow Pilewskie

Uttal Liou

Hallett Eberhard

G. Mace Hlavka

Poellot S. Kinne

G. Stephens Lawson

A. Macke

Arnott

Asano

**5.0 REMOTE SENSING FOR FIRE III UPPER TROPOSPHERIC CLOUD RESEARCH**

5.2‑1 Design and conduct investigations that integrate a comprehensive
collection of coincident observations from aircraft, the surface and
satellites where similar or \"identical\" quantifies are retrieved.

(Andy Heymsfield, Ken Sassen, Bruce Wielicki)

P L N

Liou Cairns M. Miller

Minnis Cox

Uttal Del Genio

Hallett McDougal

Heymsfield Pilewskie

S. Kinne (?) Rossow

G. Mace Gerber

A. Macke Eberhard

Poellot Hlavka

Sassen S. Kinne (?)

G. Stephens Lawson

Starr

Arnott

Asano

5.2‑2 Maintain close collaboration between modeling and remote sensing
investigators to in sure maximum utilization of remote sensing data.

(William Rossow, William Cotton)

P L N

Minnis Cox Cairns

Rossow Del Genio Liou

Uttal McDougal Pilewskie

G. Mace M.Miller Gerber

A. Macke Hlavka Eberhard

Sassen S. Kinne Hallett

G. Stephens Starr Heymsfield

Arnott Lawson

Poellot

Asano

5.2‑3 Seek to establish how ice clouds may be most effectively and
efficiently represented in radiative transfer models. Specifically:

• small scale horizontal inhomogeneity

• cloud vertical structure

• phase and particle size/shape changes

(Ron Welch, Si‑Chee Tsay)

P L N

Cairns Cox Del Genio

Liou McDougal Pilewskie

Minnis M. Miller Gerber

Hallett Rossow

Heymsfield Uttal

S. Kinne Eberhard

Lawson Hlavka

A. Macke G. Mace

G. Stephens Poellot

Arnott Sassen

Asano

5.2‑4 Provide validated retrievals of ice cloud and environmental
parameters to FIRE III modeling investigators for use in diagnostic and
cloud process studies.

(Leo Donner, Bruce Wielicki, J. Hallett)

P L N

Minnis Cox Cairns

Rossow Del Genio Liou

Uttal McDougal Pilewskie

Hallett M.Miller Gerber

G. Mace Eberhard Heymsfield

Starr Hlavka S. Kinne

G. Stephens Lawson

Arnott A. Macke

Poellot

Sassen

Asano

5.2‑5 Explore the application of additional satellite data such as ATSR
and passive microwave radiometry to upper tropospheric cloud issues.
(Don Wylie, Graeme Stephens)

> P L N
>
> Minnis **Cox Cairns**
>
> G. Stephens McDougal Del Genio
>
> M. Miller Liou
>
> Rossow Pilewskie
>
> Hallett Uttal
>
> Heymsfield Gerber
>
> Poellot Eberhard
>
> Hlavka
>
> S. Kinne
>
> Lawson
>
> G. Mace
>
> A. Macke
>
> Arnott
>
> Asano

5.2‑6 Conduct studies which examine the statistical variability of
clouds, water vapor and atmospheric dynamics on larger scales in the
tropics. (David Starr, Don Wylie)

> P L N
>
> Cairns Cox Del Genio
>
> Minnis McDougal Liou
>
> Rossow M.Miller Pilewskie
>
> S. Kinne Eberhard Uttal
>
> G. Mace Hallett Gerber
>
> Sassen Heymsfield Hlavka
>
> Starr Poellot Lawson
>
> G. Stephens A. Macke
>
> Arnott
>
> Asano
>
> 6.0 GCMs AND FIRE III

6.1‑1 Reexamine historical cirrus data sets for supporting evidence of
the hypothesis: **\"that the radiative properties of cirrus anvils are
primarily controlled by the mass fluxes and vertical velocities in
associated cumulus** convection.\" Concurrent satellite‑radar data may
be helpful. (Leo Donner, David Starr)

> P L N
>
> Minnis Cox Cairns
>
> Rossow Del Genio Liou
>
> Uttal McDougal Pilewskie
>
> Lawson M. Miller Gerber
>
> Sassen Hallett Eberhard
>
> Heymsfield Hlavka
>
> G. Mace S. Kinne
>
> Starr A. Macke
>
> G. Stephens Poellot
>
> Arnott
>
> Asano

6.1‑2 Integrate testing of the above hypothesis into the design of a
FIRE‑ m cirrus campaign.

(Leo Donner, William Cotton)

P L N

Cox Del Genio Cairns

Lawson McDougal Liou

Starr Minnis M. Miller

Rossow Pilewskie

Uttal Gerber

Eberhard Hallett

Heymsfield Hlavka

G. Mace S. Kinne

Sassen A. Macke

G. Stephens Poellot

Arnott

Asano

6.1‑3 Design a future FST meeting to specifically address the interface
between the modeling and experimental FST constituencies.

(David Starr, Tony Del Genio, Bruce Albrecht)

P L N

Del Genio Cox Cairns

Uttal McDougal Liou

G. Mace M. Miller Pilewskie

Starr Minnis Rossow

Hallett Gerber

Hlavka Eberhard

Lawson Heymsfield

Sassen S. Kinne

G. Stephens A. Macke

Poellot

Arnott

Asano

**7.0 TROPICAL CIRRUS EXPERIMENT**

7.6‑1 Continue analysis of previously collected data on
tropical/subtropical cirrus cloud systems.

(David Starr)

P L N

Cox Cairns M. Miller

Liou Del Genio Pilewskie

Minnis McDougal Uttal

Rossow Lawson Gerber

Hallett A. Macke Eberhard

Heymsfield Poellot Asano

Hlavka

S. Kinne (?)

G. Mace

Sassen

Starr (HELP)

G. Stephens

Arnott

7.6‑2 Continue instrumentation and technique development to observe
and/or infer radiative and microphysical properties of cirrus clouds.
(Graeme Stephens, Jim Spinhirne)

P L N

Cairns McDougal Del Genio

Cox Rossow Liou

Minnis Eberhard M.Miller

Pilewskie Poellot S. Kinne

Uttal Sassen

Gerber Asano

Hallett

Heymsfield

Hlavka

Lawson

G. Mace

A. Macke

G. Stephens

Arnott

7.6‑3 Continue collection of radiative and microphysical data on
tropical and subtropical cirrus cloud systems on a target of opportunity
basis.

(Tom Ackerman, Andy Heymsfield)

P L N

Cox McDougal Cairns

Liou M. Miller Del Genio

Minnis Rossow Gerber

Pilewskie Hlavka

Uttal A. Macke

Eberhard Sassen

Hallett Asano

Heymsfield

S. Kinne

Lawson

G. Mace

Poellot

G. Stephens

Arnott

7.6‑4 Develop monthly upper tropospheric cloud climatologies from
historical satellite data over the region extending from 10•S to 30•N
latitude and from 35•W to 135•W longitude.

(Tony Del Genio, Pat Minnis)

P L N

Minnis Cox Cairns

Rossow Del Genio Liou

McDougal Pilewskie

M. Miller Uttal

G. Stephens Gerber

Eberhard

Hallett

Heymsfield

Hlavka

S. Kinne

Lawson

G. Mace

A. Macke

Poellot

Arnott

Asano

7.6‑5 Determine collaborative possibilities with other programs such as
LBA in order to optimize scope of a FIRE III cirrus campaign

(David Starr, Steve Cox)

P L N

Cox McDougal Cairns

Rossow M. Miller Del Genio

A. Macke Minnis Liou

Starr Heymsfield Pilewskie

G. Stephens Lawson Uttal

G. Mace Gerber

Poellot Eberhard

Hallett

Hlavka

S. Kinne

Arnott

Asano

7.6‑6 Design a modular FIRE III cirrus field experiment capable of
addressing the scientific questions outlined in Sections 1 ‑ 6

(Tom Ackerman, Kuo‑Nan Liou, David Starr)

P L N

Cox Del Genio Cairns

Liou McDougal M.Miller

Minnis Pilewskie Rossow

Heymsfield Uttal Gerber

G. Mace A. Macke Eberhard

Sassen Poellot Hlavka

Starr Asano S. Kinne

G. Stephens Lawson

Arnott

7.6‑7 Submit a letter of intent to the NSF OFAP by June 1996 indicating
the likelihood of a request to use the WB‑57 and the Electra in a 45 day
tropical cirrus field campaign in CY 1999.

(Steve Cox, David McDougal)

P L N

Cox Minnis Cairns

McDougal Lawson Del Genio

Hallett G.Mace Liou

Heymsfield M. Miller

Sassen Pilewskie

G. Stephens Rossow

Uttal

Gerber

Eberhard

Hlavka

S. Kinne

A. Macke

Poellot

Arnott

Asano

7.6‑8 Submit a letter of intent to NASA by June 1996 indicating the
likelihood of a request to use the ER‑2 and DC‑8 in a 45 day tropical
cirrus field campaign in CY 1999. The NCAR WB‑57, NCAR Electra, NASA
ER‑2, and NASA DC‑8 would be part of a Convective Cirrus experiment
(section 7.5.4).

(Jim Spinhirne, David McDougal)

P L N

Cox Hlavka Cairns

McDougal Lawson Del Genio

Heymsfield G. Mace Liou

G. Stephens M. Miller

Minnis

Pilewskie

Rossow

Uttal

Gerber

Eberhard

S. Kinne

A. Macke

Poellot

Arnott

Asano

**8.0 SUCCESS**

8.2‑1 In light of the many related goals of FIRE III and SUCCESS,
promote communication of SUCCESS accomplishments to FST scientists.
Perhaps common or serial meetings could achieve this.

(Brian Toon, David Starr)

P L N

Liou Cairns Del Genio

Hallett Cox M.Miller

G. Mace McDougal Pilewskie

Sassen Minnis Rossow

Starr Gerber Uttal

Eberhard Heymsfield

Hlavka A. Macke

S. Kinne Poellot

Lawson Arnott

G. Stephens Asano

8.2‑2 A successful FIRE III tropical field campaign will depend upon a
number of instrumentation development projects in SUCCESS. As a result,
FIRE III management should maintain a close liaison with SUCCESS
management on the progress and success of these development programs.

(McDougal)

P L N

Hallett Cairns Del Genio

Heymsfield Cox Liou

McDougal M. Miller

Minnis Pilewskie

Hlavka Rossow

S. Kinne Uttal

Sassen Gerber

G. Stephens Eberhard

Lawson

G. Mace

A. Macke

Poellot

Arnott

Asano

> 09 . O SHEBA/FIRE III STRATUS

9.2‑1 Maintain active liaison between the FIRE m SHEBA and FIRE m
Tropical cirrus components.

> (Mike King, David Randall)
>
> P L N
>
> Rossow Cox Cairns
>
> Del Genio Liou
>
> McDougal Pilewskie
>
> M. Miller Gerber
>
> Minnis Hallett
>
> Uttal Heymsfield
>
> Eberhard S. Kinne
>
> Hlavka A. Macke
>
> Lawson Poellot
>
> G. Mace Arnott
>
> G. Stephens
>
> Asano

9.2‑2 Encourage FIRE III SHEBA principals to include middle and upper
tropospheric ice clouds in the Arctic within the experiment\'s scope.

> (Mike King, Bruce Wielicki)
>
> P L N
>
> Minnis Cox Cairns
>
> Rossow McDougal Del Genio
>
> Uttal Gerber Liou
>
> Heymsfield Eberhard M. Miller
>
> Arnott Hallett Pilewskie
>
> Hlavka Hallett
>
> Lawson S. Kinne
>
> G. Mace Poellot
>
> G. Stephens
>
> Arnott
>
> Asano
>
> **10.0 COMPLEMENTARY PROGRAMS**

10.1‑1 Explore collaboration with international partners in a tropical
upper tropospheric cloud experiment.

> (David Starr, Steve Cox)
>
> P L N
>
> Cox McDougal Cairns
>
> Liou M. Miller Del Genio
>
> Heymsfield Minnis Pilewskie
>
> A. Macke Rossow Uttal
>
> Starr Lawson Gerber
>
> G. Stephens G.Mace Eberhard
>
> Sassen Hlavka
>
> Asano S. Kinne
>
> Poellot
>
> Arnott

10.1‑2 Participate in and provide crucial data sets in support of the
cirrus cloud model intercomparison activities of the GCSS WG#2.

(David Starr)

P L N

Del Genio Cox Cairns

Liou McDougal Pilewskie

M. Miller Eberhard Gerber

Minnis Heymsfield A. Macke

Rossow Hlavka Arnott

Uttal Lawson

G. Mace Asano

Sassen

Starr

G. Stephens

10.1‑3 Maintain communication with other international partners
performing independent research on upper tropospheric cloud systems and
their relationship to climate.

(David Starr, Tom Ackerman)

P L N

Liou Cox Cairns

S. Kinne McDougal Del Genio

G. Mace M.Miller Minnis

A. Macke Gerber Pilewskie

Starr Heymsfield Rossow

G. Stephens Sassen Uttal

Asano Eberhard

Hlavka

Lawson

Poellot

Arnott

10.1‑4 Explore collaboration with other funded projects in order to
provide a more comprehensive field campaign capable of addressing the
goals of FIRE m.

(Steve Cox, Bob Curran)

P L N

Cox McDougal Cairns

Hallett Minnis Del Genio

Heymsfield Gerber Liou

G. Mace Hlavka M.Miller

Lawson Pilewskie

G. Stephens Rossow

Asano Uttal

Eberhard

S. Kinne

A. Macke

Poellot

Arnott