> FIRE
>
> (First ISCCP Regional Experiment)
>
> IMPLEMENTATION PLAN
>
> Prepared by the FIRE Science Experiment
>
> July, 1985
>
> **[FOREWORD]{.underline}**
>
> Project FIRE (First ISCCP Regional Experiment) is a US experiment in
> the ISCCP context that seeks to address the issues of basic
> understanding and parameterizations of cirrus and marine stratocumulus
> cloud systems and ISCCP data products. The scientific guidance for the
> FIRE experiment is outlined in the FIRE Research Plan (National
> Climate Program Office, Rockville, Maryland, November, 1983). Project
> FIRE was formed in September, 1984 and is supported by the National
> Aeronautics and Space Administration (NASA), National Oceanic and
> Atmospheric Administration (NOAA), National Science Foundation (NSF),
> Department of Defense (DOD), and Department of Energy (DOE).
>
> Based on discussions at a series of FIRE Science Experiment Team
> meetings, an eleven‑person Drafting Panel has prepared two documents
> that outline an approach for implementing the FIRE goals of basic
> understanding and parameterizations. The first document, the FIRE
> Implementation Plan (Abridged), is a condensed version that consists
> of two parts, an Executive Summary and an Overview of the FIRE tasks,
> observations, organization, data management, and priorities. It is
> intended for those readers who want a broad perspective of the FIRE
> goals, objectives, and approach.
>
> The second document, the FIRE Implementation Plan, is similar to the
> Abridged version, but with expanded sections on the FIRE Research
> Tasks, Extended Time Observations, and Intensive Field Observations.
> It is intended for those readers who want a more detailed description
> of the research investigations and observations.
>
> Additional copies of both documents are available from Mr. David S.
> McDougal, FIRE Project Manager, Mail Stop 483, NASA Langley Research
> Center, Hampton, VA 23665.
>
> **[TABLE OF CONTENTS]{.underline}**

Page

> 1.0 EXECUTIVE SUMMARY 5
>
> 2.0 INTRODUCTION 7
>
> 3.0 FIRE RESEARCH TASKS 9
>
> 3.1 DEVELOPMENT OF CLOUD DESCRIPTION/CLASSIFICATION
>
> SCHEMES 9
>
> 3.2 IMPROVEMENT OF CLOUD RADIATION MODELS 10
>
> 3.3 IMPROVEMENT OF SATELLITE CLOUD RETRIEVAL
>
> TECHNIQUES 11
>
> 3.4 DESCRIPTION OF CLOUD SPACE/TIME STATISTICAL
>
> STRUCTURES 12
>
> 3.5 IMPROVEMENT OF CLOUD DYNAMICS MODELS 12
>
> 3.6 IMPROVEMENT OF GCM CLOUD PARAMETERIZATIONS 14
>
> 4.0 EXTENDED TIME OBSERVATIONS 15
>
> 4.1 EXTENDED AREA 15
>
> 4.11 Satellite Observations 15
>
> 4.12 Surface Observations 17
>
> 4.2 LIMITED AREA 18
>
> 4.21 Satellite Observations 18
>
> 4.22 Surface Observations 18
>
> 4.221 Cirrus Studies 18
>
> 4.222 Stratocumulus Studies 21
>
> 5.0 INTENSIVE FIELD OBSERVATIONS 23
>
> 5.1 CIRRUS INTENSIVE FIELD OBSERVATIONS 23
>
> 5.11 Specific Objectives 23
>
> 5.12 Schedule 23
>
> 5.13 Location 24
>
> 5.14 Satellite Observations 24
>
> 5.15 Aircraft Observations 24
>
> 5.151 NASA/ER‑2 Instrumentation 24
>
> 5.152 NASA/CV‑990 Instrumentation 25
>
> 5.153 NCAR King Air Instrumentation 26
>
> 5.16 Surface Based Observations 26
>
> 5.17 Operations 26
>
> 5.2 STRATOCUMULUS INTENSIVE FIELD OBSERVATIONS 27
>
> 5.21 Scientific Objectives 27
>
> 5.22 Schedule 27
>
> 5.23 Location 29
>
> 5.24 Satellite Observations 29
>
> 5.25 Aircraft Observations 29
>
> 5.26 Surface Observations 31
>
> 5.27 Operations 33
>
> 6.0 FIRE SCIENTIFIC ORGANIZATION 35
>
> 6.1 FIRE WORKING GROUPS 35
>
> 6.2 INTENSIVE FIELD PROGRAM MANAGEMENT 35
>
> 6.21 Operations Plan 35
>
> 6.22 Mission Selection Team 36
>
> 6.23 Mission Planning Team 36
>
> 6.24 Mission Scientist 36
>
> 6.3 INTERNATIONAL COLLABORATION POLICY 37
>
> 7.0 FIRE DATA MANAGEMENT 38
>
> 7.1 DATA MANAGEMENT RESPONSIBILITIES OF PRINCIPAL
>
> INVESTIGATORS 38
>
> 7.2 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE
>
> WORKING GROUPS 38
>
> 7.3 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE
>
> CENTRAL ARCHIVE 39
>
> 7.4 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE
>
> PROJECT OFFICE 39
>
> 7.5 FIRE DATA PROTOCOL 40
>
> 7.6 FIRE DATA CHARACTERISTICS 40
>
> 8.0 FIRE DATA ACQUISITION PRIORITIES 41
>
> REFERENCES 43
>
> APPENDIX A
>
> Description of NASA ER‑2 Instruments 46
>
> APPENDIX B
>
> Description of UW C131‑A Instruments 50
>
> APPENDIX C
>
> Description of NOAA WP‑3D Orion Instrumentation 51
>
> APPENDIX D
>
> Description of NASA CV‑990 Instruments 56
>
> APPENDIX E
>
> Description of NCAR King Air Instrumentation 57
>
> APPENDIX F
>
> Surface Measurements of San Nicolas Island 58
>
> APPENDIX G
>
> NOAA/WPL Ground‑Based Remote Sensors 60
>
> APPENDIX H
>
> Glossary of Acronyms 63
>
> APPENDIX I
>
> Schedule of Significant FIRE Events 65
>
> [1.0 EXECUTIVE SUMMARY]{.underline}
>
> The central objectives of FIRE are to quantify the capabilities of
> current models for large scale cloud systems and for their effects on
> radiation, and to obtain data and understanding necessary to improve
> these models. A secondary objective is to check and, where possible,
> improve the interpretation of global statistics on cloud parameters
> which will be collected by International Satellite Cloud Climatology
> Project (ISCCP) (Bretherton et al, 1983).
>
> A more restrictive definition of FIRE\'s goals focusing on cirrus in
> the midwestern U. S. and marine stratocumulus cloud systems off the
> west coast of the U.S. has been adopted in light of the resources
> likely to be available for FIRE; cirrus and marine stratocumulus cloud
> systems were singled out because of their very significant climatic
> influences and because of the likelihood that FIRE could achieve
> significant research progress in these areas.
>
> FIRE research and data acquisition will be performed by scientists
> from U. S. government agencies and from universities. NASA will serve
> as the lead agency with the FIRE Project Office located at the NASA
> Langley Research Center. A FIRE Science Experiment Team has been
> selected consisting of 36 scientists who have expressed strong
> interest in FIRE and who have participated in the planning of FIRE. In
> addition, FIRE Working Groups are to be formed to address some
> specific, complicated tasks requiring coordination of researchers with
> a variety of specializations and using multiple data sets.
>
> Physical process modeling, which includes all processes important to
> the characterization and evolution of cloud systems, and large scale
> GCM and climate modeling are critical to FIRE\'S success; these
> extremely important modeling components will be integrated into FIRE
> through the participation of modeling researchers in the FIRE Task
> Groups. In this way modelers will participate in all phases of FIRE.
>
> FIRE includes two basic data gathering components: [Extended Time
> Observations]{.underline} and [Intensive Field
> Observations.]{.underline} The Extended Time Observation data set
> consists of satellite data, meteorological analyses and data from a
> limited number of surface observing sites. Satellite data from 50° N
> to 50° S and from 60° to 140° W will be collected on a 6 day on‑ 9 day
> off schedule for a four‑year period beginning in January, 1986.
> Northern hemisphere meteorological analyses for this period will also
> be archived. In addition, at least three sites will be maintained
> which will include surface instrumentation measuring downwelling
> radiation components and meteorological variables. Two of these sites
> will have lidar installations. The sites chosen to date are San
> Nicolas Island for marine stratocumulus studies and Salt Lake City,
> Utah and Boulder, Colorado for cirrus studies.
>
> The Intensive Field Observations will consist of three‑ to six‑week
> field experiments concentrating on multiplatform, high space and time
> resolution observations of cirrus and marine stratocumulus cloud
> systems. The cirrus observations will be collected in the midwestern
> U. S. with the first experiment scheduled for Fall, 1986 in central
> Wisconsin. A second phase of the cirrus Intensive Field Observations
> will be conducted in early Spring, 1988; the exact site has not yet
> been chosen. The marine stratocumulus Intensive Field Observations
> will be conducted in the vicinity of San Nicolas Island, off the West
> Coast of the U. S.; the first marine stratocumulus experiment is
> scheduled for early Summer, 1987 with a second observation period in
> Summer, 1989.

The cirrus and marine stratocumulus Intensive Field Observations will
require extensive satellite data support. Both will rely upon air craft
for in situ sampling of microphysical, thermodynamic and radiative
properties of the cloud layers. Two NASA jet aircraft will be utilized
in both programs. Both programs would benefit from at least one
additional aircraft capable of measuring air motions and cloud
microphysics; aircraft from NCAR and NOAA are currently being sought to
fill this need. Both the cirrus and stratocumulus programs will require
surface observations of radiation and lidar information about the cloud
layer; a tethered balloon installation is crucial to the marine
stratocumulus experiment and a 50 MHz doppler sounding instrument
currently under development would be highly complementary to the cirrus
experiment. In addition, each experiment will require supplementary
rawinsonde accents.

> Satellite data and some routine meteorological data from the Extended
> Time Observation component of FIRE will be centrally archived. In
> addition, some of the surface lidar and radiation data will be
> submitted to an archive for use by the scientific community; this
> latter type of data will be of the value‑added variety where principal
> investigators have spent considerable effort in reducing subsets of
> their raw data for widespread utilization. From the Intensive Field
> Observations satellite data and selected value‑added data sets
> resulting from FIRE Working Groups\' activities will be centrally
> archived. Several institutions are currently being considered to hold
> both the Extended Time and Intensive Field Observation data sets;
> chief among the factors being considered in this selection are ease of
> access and quality assurance. From time to time, certified FIRE data
> will be transferred to EDIS and/or other organizations for permanent
> archive and for open access by the at‑large scientific community.
>
> FIRE will improve GCM cloud‑radiation parameterizations, for at least
> cirrus and marine stratocumulus clouds, by providing a better
> understanding of the link between small scale cloud processes and
> planetary scale climate processes. This goal will be accomplished by
> the extensive interaction in FIRE between scientists specializing in
> observational analysis and those with expertise in multiple scales of
> atmospheric modeling.
>
> [2.0 INTRODUCTION:]{.underline}
>
> The FIRE Science Experiment Team (FSET) has taken the charge \"\... to
> quantify the capabilities of current models for large scale cloud
> systems and for their effects on radiation, and to obtain data and
> understanding necessary to improve these models\...\", and focused it
> to produce a three‑pronged scientific experiment described in this
> document, THE FIRE IMPLEMENTATION PLAN. The three components are: 1)
> investigation of cirrus cloud systems; 2) investigation of marine
> stratocumulus cloud systems; and 3) investigation of interrelations
> between ISCCP data and higher time and space resolution cloud data. In
> this implementation plan specific objectives and strategies for each
> of these three components are set forth. In fact, the three components
> are highly interactive in all phases of planning, execution and
> analysis. Many activities cited in the marine stratocumulus and cirrus
> plans directly support the ISCCP intercomparison goals; the period of
> the cirrus and marine stratocumulus activities are designed to
> coincide with the period of the ISCCP program, which is expected to
> continue until 1988 or possibly 1989; and some data collected during
> the marine stratocumulus field program will be highly complementary to
> the cirrus program and vice versa. In fact, the three components of
> FIRE are so closely related that a common set of general goals and
> strategies for all three may be defined.
>
> These goals for FIRE may be simply stated as:
>
> [GOAL 1: BASIC UNDERSTANDING:]{.underline} The first goal common of
> the three components of FIRE is an understanding of roles played by
> physical processes in determining life cycles of cirrus and marine
> stratocumulus cloud systems and the radiative properties of these
> clouds during their life cycles. Specifically, FIRE has been designed
> to address the study of the formation, maintenance and dissipation of
> cirrus and marine stratocumulus cloud systems. In both types of cloud
> systems, cloud radiative properties play important roles in the energy
> budgets of the cloud layers themselves, in the planetary energy budget
> and in any cloud layer parameters inferred remotely from satellites.
> In this lest sense, this objective addresses needs of the ISCCP data
> set.
>
> [GOAL 2: PARAMETERIZATION:]{.underline} A second common goal among the
> FIRE components is a quest for relationships between large scale
> processes, or representations, and smaller scale processes, or
> representations; the primary reason for employing this approach is
> that we have a better physical understanding of and ability to
> investigate cloud scale phenomenae, although climate models cannot
> explicitly resolve these cloud scale processes. For the cirrus and
> stratocumulus cloud systems, relationships between the cloud scale
> processes and the climate scale model variables will become the future
> parameterizations in a GCM or climate model; in the case of ISCCP
> data, these relationships will lead to a better understanding of and
> increased utilization of ISCCP data by the scientific community.
>
> The FIRE IMPLEMENTATION PLAN outlines a series of investigations and
> observations designed to meet the goals of basic understanding and
> parameterization. In this plan, FIRE is not meant to solve \"all\" of
> the problems in the field of clouds and radiation. Rather, FIRE is
> meant to address the issues of basic understanding and
> parameterization of cirrus and marine stratocumulus cloud fields and
> ISCCP data products.
>
> Besides sharing a common set of goals, the three FIRE components share
> a general set of strategies adopted to achieve those goals. These
> three common strategies are briefly set out below:
>
> [Strategy 1: MODELING]{.underline} ‑ The modeling strategies for FIRE
> encompass several types of models. These models range from radiative
> transfer models which require cloud microphysical data as input, to
> cirrus and marine stratocumulus models capable of describing the time
> evolution of these cloud systems, to general circulation and climate
> models, which will ultimately utilize cloud parameterizations, and to
> the retrieval algorithm models utilized in ISCCP. All FIRE modeling
> strategies seek first to provide a means to compare our best current
> understanding of a phenomenon with observations of that phenomenon and
> second to provide a means to extend that understanding by utilizing
> the models to extrapolate to other conditions.
>
> [Strategy 2: EXTENDED TIME OBSERVATIONS]{.underline} ‑ We have much to
> learn from data bases already collected and those currently being
> collected; this is particularly true for satellite data and to a
> lesser extent for other types of data. The extended time observations
> of cloud systems will yield information on the phenomenology of these
> systems, on their variability in space and time, and on their bulk
> radiative properties. Since these data will generally be of higher
> spatial resolution than the ISCCP data set, they will be particularly
> useful for comparison with ISCCP products.
>
> [Strategy 3: INTENSIVE FIELD OPERATIONS]{.underline} ‑ Intensive field
> programs are currently planned to support all three components of
> FIRE. Four field programs of three to six weeks duration are planned.
> These field programs are designed to observe cloud systems with high
> resolution temporal and spatial sampling. The field programs will
> include satellite, aircraft, balloon borne and surface observations.
> The experiments will be concentrated in limited geographical areas for
> periods of three to six weeks. Four intensive field programs are
> planned; one each year beginning in Fall 1986. The 1986 and 1988 field
> programs would be staged in the continental U. S. with an emphasis on
> the study of cirrus systems; 1987 and 1989 experiment would emphasize
> marine stratocumulus systems and be staged near San Nicolas Island,
> off the west coast of California. Although the intensive field
> operations would emphasize the cirrus and marine stratocumulus
> objectives, they would also strongly contribute to the ISCCP
> intercomparison objective.
>
> [3.0 FIRE RESEARCH TASKS]{.underline}
>
> An obstacle to reliable predictions from first principles of cloud and
> their radiative effects in GCMs is the lack of understanding of the
> large scale statistics of turbulent atmospheric motions and the cloud
> formed by these motions. The ISCCP research strategy to overcome this
> obstacle is to coordinate a number of intensive, smaller scale
> projects with a global climatology effort. The goal of FIRE is to
> improve GCM cloud‑radiation parameterizations, for at least cirrus and
> marine stratocumulus clouds, by providing a link between the small
> scale cloud processes and the planetary scale climate processes. This
> goal is to be accomplished by the interaction of data analysis and
> modeling studies on a range of space/time scales. Progress comes
> through the iterative application of four steps:
>
> 1\. Improve cloud radiation models.
>
> 2\. Improve cloud dynamics models.
>
> 3\. Intercompare the ISCCP cloud climatology with FIRE cloud data.

4\. Conduct comparisons of GCMs with the improved cloud‑radiation,
dynamics models and with the FIRE and ISCCP observations.

> Each of these steps is to be carried out for marine stratocumulus and
> cirrus clouds as part of two types of studies: (1) The intensive field
> observations programs (IFO) will collect and analyze limited area/time
> data focused on the diagnosis of cloud processes at smaller scales;
> (2) Extended time observations (ETO) will collect and analyze
> regional, multi‑year data to bridge the gap between IFO and ISCCP
> data. The unique attribute of the FIRE IFOs is the coordination of
> satellite, aircraft and ground observations. This section outlines the
> specific tasks planned as part of FIRE.
>
> [3.1 DEVELOPMENT OF CLOUD DESCRIPTION/CLASSIFICATION
> SCHEMES]{.underline}
>
> (Steps 1,2,3, and 4)
>
> Comparisons of data and models on many different scales require a
> common description or classification of cloud types to insure
> comparison of the same cloud phenomena. Selection of case studies from
> a larger data set also requires a method for rapid identification of
> cases involving a particular cloud type. Most cloud classifications
> (e.g., WMO instructions for ground observers) are based on cloud
> morphology on scales \~0.1‑10 km; however, for FIRE the cloud type
> definitions must be applicable to all space and time scales covered by
> the different observations. Improvement of GCM cloud parameterization
> also begins with identification of the cloud types which behave in
> distinctly different ways.
>
> Available studies have identified four crucial properties of clouds
> that distinguish the effects of different clouds on observed
> radiances, namely, (1) cloud size distribution, (2) cloud element
> shape and texture, and (3) internal variability within a cloud
> element, and (4) cloud microphysical structure. Cloud size
> distribution describes the characteristic size (or size range) of
> individual cloud elements; e.g., cumulus and stratus clouds exhibit a
> very different relation of cloud element size to the mesoscale or
> synoptical scales of atmospheric motions. Cloud element shape and
> texture significantly affect the angular distribution of reflected
> solar radiation (Busygin et al., 1973; McKee and Cox, 1976; Davis and
> Cox, 1982; Harshvardan, 1982; Welch and Wielicki, 1984; Schmetz, 1984
> and Davies, 1984) and of emitted thermal radiation (Naber and Weinman,
> 1984). Variations in liquid water content between cloud elements or
> within individual elements can have similar effects (Coakley and
> Bretherton, 1982; Wielicki and Welch, 1985). Cloud microphysical
> structure‑‑as represented by particle composition, size, shape, phase,
> and possible internal inhomogeneity (or the distribution functions for
> these parameters)‑‑determine the particle scattering and absorption
> properties as functions of wavelength, and thereby plays a role in
> determining the cloud\'s large scale radiative properties (Wiscombe et
> al, 1984).
>
> Development of a cloud classification scheme will be a continuing
> effort throughout FIRE. Data collected during FIRE that provides a
> measure of the four parameters described above must be compared with
> other classifications and modeling studies to identify the key
> patterns that meaningfully distinguish cloud types. A link to the
> familiar morphological cloud types will be provided by photography
> from all ground‑based and aircraft‑based observing platforms.
>
> [3.2 IMPROVEMENT OF CLOUD RADIATION MODELS]{.underline}
>
> (Step 1 and 4)
>
> This task addresses the problem of calculating the radiative effects
> of clouds given a specification of cloud properties. The primary
> issues are to determine which properties are most crucial to accurate
> calculations of radiation and to ascertain the sensitivity of
> radiative calculations to cloud parameters that are difficult to
> measure. Since most cloud radiation models involve approximations, for
> example ignoring small scale variations in liquid water content, this
> task is also concerned with testing such approximations. The strategy
> for FIRE is to assemble data sets which contain both specifications of
> cloud and atmospheric properties and independent verification
> measurements of the radiation field produced by the clouds. The former
> are needed to define the clouds in the radiative transfer model
> (input) and the latter are used to verify the calculated radiation
> (output). The observations must be balanced between input and output
> parameters to provide definitive tests of model performance. These
> data will be used to test various types of radiative models,
> particularly column models and full three‑dimensional models.
> Intercomparisons of the models provides further insight for
> parameterization of cloud‑radiation effects in GCMs.
>
> The key parts of this task are as follows:

i\. Determine cloud radiance directionality both instantaneously and in
time/space averaged sense. The largest uncertainty in understanding the
relation between large scale cloud properties and the radiation field is
probably associated with neglect of three dimensional cloud structure on
the radiation (cf., Davies, 1984; Welch and Wielicki, 1984; Naber and
Weinman, 1984; Davies et aI., 1984). FIRE observations can be used to
test the capability of current column and full three‑dimensional models
to calculate radiance directionality, given a specification of three
dimensional cloud structure. Sensitivity studies can then determine the
cloud‑shape detail required to calculate the large scale radiation
directionality accurately. An essential element of this study will be
the measurement of Simultaneous multiple viewing angle radiances using
satellite and/or aircraft observations.

ii\. Determine effects of cloud fractional cover. Since most models
parameterize cloud effects on radiation at scales larger than typical
scales of cloud elements, the effects of cloud shape are mixed with the
effects of cloud fractional cover in modeling the radiation. Various
methods of treating fractional cloud cover in column models will be
compared with actual FIRE data, to see which, if any is best. Extension
of the comparisons of models and observations to mesoscale and synoptic
scales is then required for improving GCM and climate model
parameterization schemes.

iii\. Diagnose spectrally‑dependent cloud‑radiation interactions.
Attempts to compare observed and calculated cloud absorption (Twomey and
Cocks, 1982) cast some doubt on the accuracy of current models to
reproduce spectrally integrated fluxes. FIRE measurements can verify
model calculations over the whole spectrum by examining the relation
between various narrowband and broadband radiances and the variation of
angular dependence with wavelength.

iv\. Determine effects of cloud particle shape and orientation on
cirrus‑radiation interactions. Cirrus clouds are composed of particles
with a variety of non‑spherical shapes which alter the angular and
spectral dependences from those calculated assuming spherical shapes.
This may also cause variations in radiative properties among cirrus
clouds of differing predominate crystal habits, but otherwise similar
bulk properties. Comparisons of model calculations to measured radiances
at multiple angles and wavelengths (see Reynolds and Vonder Haar, 1977;
Platt, 1983; Griffith et aI., 1980) must be coordinated with
measurements of ice particle shape to determine the importance of
particle shape for the radiation.

v\. Measure effects of cloud diurnal variations. Many climate model
radiative calculations integrate over the diurnal cycle. FIRE
observations can be used to test the validity of this approach not only
by verifying the angular dependence of reflected (absorbed) solar
radiation but also by determining the correlation of diurnal radiation
variations with cloud variations.

vi\. Investigate the time and space averaged radiative properties of
cloud fields on scales representative of those used in GCMs. Since
radiation computations are typically made only once every few time steps
in GCMs and over grid spacing intervals of one to two hundred
kilometers, it is essential to represent cloud radiative properties on
these same scales. High resolution FIRE observations and modeling
efforts will be used to address this task. This task is closely related
to Item ii., Section 3.24.

> [3.3 IMPROVEMENT OF SATELLITE CLOUD RETRIEVAL TECHNIQUES]{.underline}
>
> (Steps 1, 3 and 4)
>
> This task addresses the problem of inferring cloud properties from
> measured radiances that is central to the analysis of FIRE
> observations and constitutes a major contribution to the
> interpretation of the ISCCP cloud climatology. Improvement of
> radiative models that relate cloud properties to observed radiances is
> not only intimately linked to the general understanding of the
> cloud‑radiation interaction in Steps 1 and 4, but also includes
> specific problems raised by the analysis of satellite data in ISCCP.
> Satellite‑measured radiances are generally limited in spatial and
> temporal resolution, angular coverage, and spectral coverage; thus,
> retrieved cloud parameters using current methods depend on these
> factors (Rossow et aI., 1985). These factors also present a challenge
> to the coordination of satellite data with other observations for
> retrieval validation. The IFO observations must be coordinated to
> provide a balanced set of input radiances and output cloud properties
> to test retrieval techniques. Limited intercomparisons using
> ground‑based and aircraft observations must also be extended to larger
> scales by statistical comparisons of mufti‑satellite data. Comparisons
> of retrievals by different techniques applied to the same FIRE and
> ISCCP data are a key to development of better methods.
>
> Key cloud properties retrieved by current methods that will benefit
> from intercomparisons are:
>
> i\. Cloud cover fraction and cloud size distribution. More accurate
> measures of cloud cover fraction can be achieved with higher
> resolution observations but this is currently impractical. FIRE
> observations can be used to measure the statistical variation of cloud
> cover fraction and derive statistical descriptions of cloud size
> distributions which may improve longer resolution monitoring of cloud
> cover changes.
>
> ii\. Cloud top height. Cloud top height is usually inferred from
> measurements of thermal radiation; results depend primarily on cloud
> element shape or the topography of the top for broken cloud types and
> on cloud optical thickness and vertical structure for thin cirrus
> clouds. Detection and measurement of precise cloud top altitudes for
> marine stratocumulus clouds are further complicated by the low
> radiance contras\" between cloud tops and haze and water vapor‑laden
> clear areas. FIRE \"round and aircraft observations of both cloud
> types can be compared to satellite retrievals to improve their
> interpretation.
>
> iii\. Cloud optical thickness. Cloud optical thickness (or other
> measures of the cloud extinction) influences the amount of reflected
> and transmitted solar radiation; its retrieval is strongly dependent
> on proper modeling of radiance directionality. As discussed in Section
> 3.2, the effects of cloud shape and as well as internal variations of
> liquid water content, must studied on a local, instantaneous basis and
> in a statistical sense during FIRE to allow proper interpretation of
> satellite radiance measurements.
>
> iv\. Cloud microphysical structure. While specific parameters of the
> microphysical structure are not retrievable from satellite
> measurements, an index that distinguishes \~5 categories, ranging from
> large ice particles to small liquid droplets, can be extracted from
> AVHRR data using the visible, 11 um, and 3.7 um charnels (Arking and
> Childs, 1985). In situ observations with aircraft will help establish
> the validity of this kind of information for satellite classification
> of cloud type.
>
> v\. Diurnal variation of cloudiness. Diurnal variations in cloud
> properties are difficult to monitor with current techniques because
> most satellite observations of clouds at night must rely solely on
> thermal radiance measurements which cannot reliably detect low, broken
> clouds. FIRE observations can be used to explore new techniques,
> especially multi‑channel methods. These data can also be used to
> identify new cloud properties that are crucial to retrieval accuracy
> and to develop new techniques employing them.
>
> [3.4 DESCRIPTION OF CLOUD SPACE/TIME STATISTICAL
> STRUCTURES]{.underline}
>
> (Steps 1, 2, 3 and 4)­
>
> The FIRE IFOs provide the coordinated observations of target cloud
> types (marine stratocumulus and cirrus) from \"round, aircraft and
> spacecraft needed to obtain the nearly simultaneous and coincident
> measurements of cloud properties and radiances to test radiative and
> cloud dynamics models. The ETO extends these detailed results to
> larger space and time scales using very high resolution observations
> and connects them to the more extensive, but longer resolution ISCCP
> and ERBE results. This extension is necessary to determine the
> representativeness of the results and to provide the type of
> information needed by radiative and cloud dynamical models that
> parameterize the smaller‑scale cloud property variations. Close
> coordination between the IFO and ETO is required.
>
> Key parts of this task are as follows:
>
> i\. Characterize the spatial variations of mesoscale and synoptic
> scale cloud systems in terms of cloud size distribution or other
> statistics of cloud cover variation. Although systematic descriptions
> of the spatial scales of cloud cover variation within marine
> stratocumulus fields are not available (sec, however, Agee et aI.,
> 1973; Coakley and Bretherton, 1982), coordinated analyses of satellite
> data with IFO data can identify the processes responsible for the
> different modes of cloud cover observed to occur. Little is known of
> the statistics of cirrus cloud cover, so that the ETO is an important
> component of the FIRE cirrus program.
>
> ii\. Determine the statistics of radiance directionality on GCM scales
> for marine stratocumulus and cirrus clouds. These statistics are not
> only necessary for the development of GCM cloud‑radiation
> parameterizations but also crucial to improved interpretation of ISCCP
> and ERBE data. The intercomparison of ISCCP and ERBE results will
> further constrain GCM cloud radiative models and indicate the role
> played by marine stratocumulus and cirrus in the planetary and surface
> radiation budgets. This task is closely related to Item vi., Section
> 3.22.
>
> iii\. Characterize cloud property variations on diurnal and seasonal
> time scales. In addition to obtaining a systematic description of the
> time variations of marine stratocumulus, FIRE can provide statistics
> on the resulting variations of the radiation budget in the boundary
> layer which may be instrumental in determining the structure and
> variation of these clouds (cf., Nicholls, 1984). Extended observations
> of cirrus variations can be related to corresponding variations in the
> state of the upper troposphere in order to formulate GCM‑scale
> parameterizations. Since the interaction of radiation and cirrus also
> plays a role in determining cirrus variations (Starr and Cox, 1985),
> these observations can be correlated with changes in the radiation
> fields observed by satellites.
>
> [3.5 IMPROVEMENT OF CLOUD DYNAMICS MODELS]{.underline}
>
> (Steps 2 and 4)
>
> This task concerns the understanding of the processes that produce
> clouds from particular atmospheric stases. The special emphasis of
> FIRE is to extend our understanding of the workings of these processes
> on the smaller space/time scales of individual clouds to cloud
> structures and the state of the atmosphere on meso‑ and synoptic
> scales. The primary data for this task will be that obtained during
> the IFOs targeted on marine stratocumulus and cirrus; however, the
> ETO, based largely on satellite data, is necessary to link small
> scales to large scales. This task also depends on radiative model
> improvements to increase the detail retrieved form the IFO and ETO
> data. The emphasis is on model comparisons to data to diagnose
> processes and to improve modeling of these two cloud types.
>
> Cirrus clouds exhibit significant horizontal and vertical structure
> and a strong coupling to radiation (Starr and Cox, 1985). Little is
> known about the distribution of cirrus, the conditions required to
> produce them, or their life cycles. The primary focus of this task is
> to improve understanding of the coupling of cirrus clouds, radiation,
> and atmospheric dynamics by comparisons of models to coordinated
> measurements of all of these quantifies. Models that will be employed
> for these studies include two‑dimensional (horizontal/vertical) time
> dependent process models, high‑resolution, Iimited‑area models and
> GCMs. The coordination of \"round, aircraft and satellite observations
> during the IFOs, as well as the extension of the IFO results to the
> ETO and ISCCP scales, is crucial to this task.
>
> Key issues to be studied are as follows:
>
> i\. Space/time structure of cloud properties.
>
> Diagnosis of cirrus processes depends on adequate description of cloud
> variability from scales associated with turbulence to the mesoscale.
> The difficulties of satellite detection of cirrus with current
> techniques make proper measurements of cirrus distributions especially
> crucial for FIRE. FIRE research will result in improved cirrus
> detection techniques from satellites. Obtaining a limited‑area
> climatology of cirrus cloud systems for FIRE will improve the utility
> of the ISCCP results for the whole globe.
>
> ii\. Coupling of cloud structure, dynamics and radiation.
>
> The important influence of radiation on the dynamics, structure and
> properties of cirrus clouds implies a strong feedback between cloud
> scale processes and larger scale radiative effects (Starr and Cox,
> 1985). This complexity requires careful coordination of many
> observation platforms to document relationships between cloud
> properties, atmospheric state and motions, and radiation fields for
> each target cloud. Improvement of our understanding of cloud processes
> requires careful comparisons between model results and FIRE
> observations.
>
> iii\. Diurnal cycle of cirrus.
>
> An important test of the role of radiation in cirrus life cycles can
> be obtained by observations of the diurnal cycle of cirrus, about
> which little is known. Validation of methods to detect nighttime
> cirrus from satellites is vital to understanding the processes
> controlling cirrus structure.
>
> iv\. Large scale relationship of atmospheric state and cirrus cloud
> ice/water budget. Extensions of the IFO results to understanding the
> large scale ice/water budget is important to understanding the
> processes that produce cirrus and developing improved cirrus cloud
> parameterizations.
>
> Marine stratocumulus clouds exhibit considerable structure from the
> smallest scales (\~1 km) resolved by satellites (Coakley and
> Bretherton, 1982) to mesoscale/synoptic scale (Agee et aI., 1973).
> However, only a few modeling and in situ observational studies have
> focused on fractional cloudiness (Sommeria and Deardorff, 1977;
> Albrecht, 1981; Bougeault, 1982). A major focus of this task is to
> elucidate the processes responsible for determining fractional cloud
> cover through comparisons of models to FIRE data. A broad spectrum of
> dynamical models will be employed, including simple mixed‑layer
> models, \"large\" eddy models that explicitly resolve the primary
> turbulent motion scales, high resolution, limited area dynamical
> models and GCMs that include boundary layer and cloud
> parameterizations. Microphysical models will also be used to
> investigate the coupling between dynamics and radiation through cloud
> radiative properties.
>
> Key issues to be studied are as follows:

i\. Space/time structure of cloud cover. Marine stratocumulus exhibit
cloud cover variations organized on turbulent boundary layer scales,
mesoscales, and synoptic scales that are probably controlled by dynamic
interaction of boundary layer turbulence and planetary scale wave
motions. Description of the statistics of the space/time structures and
variations and their association with particular modes of motion are
crucial for model validation.

ii\. Role of cloud top entrainment instability. Mesoscale changes in the
contrast in air parcel properties across the inversion layer near cloud
and boundary layer top can lead to changes in the stability of the cloud
layer (Squires, 1958; Lilly, 1968; Randall, 1980). FIRE IFO data will be
used to diagnose the role of cloud top entrainment instability in
determining the mesoscale marine stratocumulus structure by coordinating
satellite observations of mesoscale cloud structure with IFO
measurements of boundary layer properties.

iii\. Diurnal cycle of cloud properties. The role of radiation in
determining the marine stratocumulus structures and variations
(Nicholls, 1984) can be further studied by examining the diurnal
variation of the cloud properties. Observations and modeling studies
have indicated a large amplitude diurnal cycle for these clouds (Short
and Wallace, 1980; Brill and Albrecht, 1982; Minnis and Harrison, 1984).
FIRE IFOs can characterize the differences between daytime and nocturnal
structure of the cloud topped boundary layer.

iv\. Coupling of entrainment and cloud structure. The difficulty of
measuring entrainment rate calls for application of multiple,
independent measurement techniques in the IFOs. Relating these
measurements to the mesoscale cloud structures observed from satellites
can provide an improved understanding of the entrainment process for
cloud dynamical models and a new remote sensing tool to monitor marine
atmospheric boundary layer properties.

v\. Role of boundary layer aerosol in cloud behavior. Monitoring of
subcloud and between‑cloud aerosols associated with in situ cloud
droplet measurements can elucidate the role of such aerosols in
determining the optical properties of marine stratocumulus clouds.

[3.6 IMPROVEMENT OF GCM CLOUD PARAMETERIZATIONS]{.underline} (Step 4)

> This task includes many of the activities discussed above but the
> emphasis is on the climate GCM calculation of radiative flux
> divergences from a particular large scale atmospheric state involving
> clouds. The FIRE concept breaks this calculation into two parts:
> calculation of cloud properties from an atmospheric state and
> calculation of radiation fields from cloud properties. The primary
> focus of this task within FIRE is to define [quantitative]{.underline}
> methods for comparison of data and models; this is an appropriate FIRE
> task because of the detailed study within FIRE to understand the
> linkage between IFO and ETO data and between these data and specific
> process models. The FIRE data sets allow for GCM tests in both
> prognostic and diagnostic modes. FIRE and ISCCP data, together,
> provide a check of the statistical behavior of GCMs, while FIRE and
> ERBE provide a check on the statistics of the GCM radiation budget.
> Comparisons of data to GCMs must build on the FIRE developments that
> link multi‑scale observations and model results and develop methods
> for comparison of cloud properties, radiation quantifies, and the
> space/time statistics of these.
>
> [4.0 EXTENDED TIME OBSERVATIONS]{.underline}
>
> The Extended Time Observation (ETO) program will directly support the
> ISCCP and GCM validation efforts. The ETO data will consist of
> satellite observations, special \"round stations with lidar and
> surface radiation measurements, and conventional meteorological
> observations. These data will provide a means of extending the results
> derived in the more detailed Intensive Field Observation Program
> intercomparison studies to larger time and space scales.
>
> The Extended Time Observations are subdivided into two space scales:
> Extended area and Limited area. The extended area data set is meant to
> provide data over a large geographical area where occurrences of
> cirrus and stratocumulus cloud systems may be found in a variety of
> geographical locations; and to allow for mufti‑satellite,
> multiple‑vie\" observations of these systems. The limited area data
> set is geographically specific to the location and surrounding area of
> surface observing sites being maintained throughout the FIRE
> experiment.
>
> The specific objectives of the ETO are:

i\. to provide a statistical description of existing cirrus and
stratocumulus cloud fields,

ii\. to characterize the horizontally averaged radiative characteristics
(\~250 km)^2^ of cirrus and stratocumulus cloud fields, and

iii\. to relate cirrus and stratocumulus cloud fields to accompanying
larger scale meteorological fields, as in a GCM.

> Statistical descriptions of cirrus and marine stratocumulus cloud
> fields will be multi‑dimensional frequency distributions on a spatial
> scale of (250 km)^2^ . These distributions will characterize cloud
> field properties including areal cloud fraction, cloud top height and
> temperature, cloud visible reflectance and shortwave albedo and cloud
> infrared emittance.
>
> [4.1 EXTENDED AREA]{.underline}
>
> [4.11 SATELLITE OBSERVATIONS]{.underline}
>
> Data will be collected for a spatial area 100° latitude by 80°
> longitude bounded by 50°S to 50°N latitude and 60°W to 140°W longitude
> as shown in Fig. 1. This area is chosen to include a wide range of
> cloud types, including the Intertropical Convergence Zone, South
> American and California stratocumulus, Brazilian cumulonimbus, East
> Coast U.S. stratocumulus, and cirrus at both low and middle latitudes.
> While the primary focus of FIRE is on marine stratocumulus and
> continental cirrus cloud systems, the ETO data set must support the
> intercomparison of ISCCP cloud properties over a wide range of cloud
> types and locations. In addition, later studies of GCM cloud
> parameterizations can then be compared to observations over a wider
> range of atmospheric conditions. Finally, validation of bidirectional
> reflectance models using simultaneous GOES and AVHRR data requires a
> wide range of solar zenith, viewing zenith, and viewing azimuth angles
> with sufficient samples to ensure stable statistics.
>
> Within each month of the year, data will be collected for 6 days on, 9
> days off, and 6 days on, etc. This sampling will allow some time
> dependent studies of cloud evolution, while obtaining independent
> synoptic meteorological samples. The 6 days on and 9 days off cycle is
> dictated by the NOAA polar orbiter ground track repeat cycle of 9.5
> days. By allowing 9 days off between sampled for any geographic area
> within one month. In order to simplify data collection planning, the
> two 6 day periods will be taken on the 5th to 10th days and the 20th
> to 25th of each month.
>
> ![](media/image1.wmf){width="7.694444444444445in"
> height="8.930555555555555in"}
>
> The satellite data to be included in the FIRE ETO-EA archive is given
> below:
>
> i\. AVHRR GAC Data, 5 spectral channels, 2 satellites, day and night,
> giving four samples per day. Data volume is 1.5 6250 BPI
> tapes/observation day.
>
> ii\. HIRS Sounder Data, 20 spectral channels, 2 satellites, day and
> night, giving four samples per day. Data volume is approximately 0.2
> tapes/observation day.
>
> iii\. GOES VAS Imager Data, 8 km spatial resolution, 2 spectral
> channels, GOES East and West, every 3 hours. Data volume is 0.5 6250
> BPI tapes/observation day.
>
> iv\. GOES VAS Sounder Data, 16 km spatial resolution, 2 to 4 spectral
> channels, GOES East and West, every four hours.
>
> v\. ERBE broadband data, 2 channels, scanner and nonscanner, up to 3
> satellites, day and night, six times per day.
>
> vi\. ISCCP B3 data, 3 hourly, GOES East and GOES West, analyzed cloud
> property data.
>
> Data for extended area, extended time satellite observations will be
> extracted from the NOAA/NESDIS archive on an as needed basis. It is
> expected that data for multiple-satellite, multiple-view studies of
> the directional properties of the cloud radiance field will focus on
> daytime only data and of that only conjunctions of satellite
> observations that allow simultaneous views of individual cloud
> systems. Such a study compacts the overall extended area, extended
> time observations to a set of approximately 20 6250 BPI tapes/year
> containing the required AVHRR, HIRS, VISSR/VAS data.
>
> **[4.12 SURFACE OBSERVATIONS]{.underline}**
>
> The description of the downwelling radiation fields and the
> conventional meteorological fields will be constructed primarily from
> observations and analyses which are routinely available. The NOAA/NWS
> and northern hemisphere international rawinsonde networks (\~90 sites)
> and the U.S. Solar Radiation Network (NOAA/ERL) will provide the
> extended area surface and upper air data. However, satellite derived
> information on standard meteorological fields (soundings and wind
> fields) will be incorporated into the data sets for the regions within
> the FIRE domain which are not well‑sampled by the rawinsonde network;
> this is currently clone operationally by the NOAA/NMC using products
> provided by NOAA/NESDIS. These data are operationally archived by NOAA
> and will be added to the FIRE archive when acquired for specific FIRE
> studies.
>
> The surface observation data sets are:

i\. Full vertical resolution rawinsonde observations for all launch
sites within the FIRE domain (temperature, humidity, and horizontal wind
speed and direction as functions of pressure);

ii\. Standard NMC gridded analyses over the FIRE domain (fields of
temperature, humidity, horizontal wind speed and direction, and vertical
motion at standard pressure levers);

iii\. Gridded analyses of daily total and direct solar radiation at the
surface.

> [4.2 LIMITED AREA]{.underline}
>
> [4.21 SATELLITE OBSERVATIONS]{.underline}
>
> The Extended Time Observation, Limited Area satellite data sets will
> contain data for the cirrus and stratocumulus IFO regions (recall
> Fig. 1) and for the two regions covering the surface lidar sites. Data
> will be collected for the same 6‑day on 9‑day off cycle used in the
> ETO‑EA data set to give a total of 12 days per month for all 12 months
> of the year. Data to be included in these data sets in addition to
> that listed in Section 4.11 include:

i\. AVHRR LAC data, 1 km resolution, 5 charnels, afternoon polar orbit
only, day and night 2 samples per day. Data volume is 0.75 6250BPI tapes
per day.

ii\. GOES VAS imager data, 1 km visible charnel and 8 km infrared
charnel data, hourly data for both GOES East and GOES West taken on the
hour and 15 minutes after the hour. Data volume is 0.5 tapes per day.

iii\. Sage II and Landsat/5 data as available.

> Note that HIRS‑2, VAS Sounder, ERBE, AVHRR‑GAC, and ISCCP data can be
> obtained for the same times using a subset of the ETO‑EA data set.
>
> While the \]imited area extended time observations represent a
> sizeable archive (‑200 6250 BPI tapes/year), it is recognized that
> intensive analyses will be limited to a 10‑20% subset of this data;
> over a four year period this subset will contain approximately 100
> statistically independent samples of appropriate cirrus and
> stratocumulus cloud systems.
>
> [4.22 SURFACE OBSERVATIONS]{.underline}
>
> Ground‑based measurements from a limited number of locations offer a
> variety of advantages for the study of the radiative behavior of
> clouds. They can be made in a nearly continuous manner as the overhead
> atmosphere\'s properties change, and they can represent a time
> averaged measurement at a point in space as well. The measurements are
> usually inexpensive compared to aircraft and balloon methods, although
> the ground‑based measurements by no means replace in situ
> measurements.
>
> [4.221 CIRRUS STUDIES]{.underline}
>
> Two classes of surface based observing sites are defined for cirrus
> studies. Class I sites incorporate a lidar cirrus cloud detecting
> system as part of the site observing system. Class II sites do not.
>
> [I. Class I Sites]{.underline}
>
> The approximate locations of the three proposed class I observing
> sites are Salt Lake City, Utah; Hampton, Virginia; and Boulder,
> Colorado. Other potential class I observing sites exist both within
> the United States and in other countries. It is recommended that
> observations be taken at these locations and analyzed according to the
> strategy and objectives of this program to the extent that this is
> possible.
>
> Class I sites will be operated throughout the duration of FIRE (4
> years). Observations will be taken when cirrus clouds are present and
> generally unobstructed by extensive underlying cloud layers. At each
> site, observations will be taken at one second intervals during at
> least one continuous three hour time period on at least three days of
> most weeks subject to the occurrence of suitable conditions. Observing
> times should be coordinated with the 6‑day on phase of the satellite
> observing schedules when possible in order to maximize the acquisition
> of coincident satellite and surface based observations.
>
> In order to document suspected day‑night differences in the structure
> and properties of cirrus, 25% of the schedule observing periods should
> be at night. Thus, a sample of \~2500 hours of observations with 500
> of these occurring at night is planned (9 hours/week for \~35
> weeks/year over 4 years at 3 sites.
>
> [Class I Site Measurements and Instrumentation]{.underline}
>
> Details of the instrumentation, which will be in place at the class I
> observing sites, is somewhat site specific. However, the following
> instrumentation and support facilities will exist at each of the
> sites:
>
> i\. pyranometers
>
> ii\. pyrheliometer (solar tracking)
>
> iii\. NWS rawinsonde site (close proximity)
>
> iv\. data logging and real time data processing and display facilities
> access to NWS analysis and forecast products
>
> vi\. access to satellite imagery in near real time.
>
> These instrumentation facilities will provide measurements of the
> direct and total downwelling solar radiation at the surface and
> vertical profiles of environmental pressure, temperature, humidity,
> and horizontal winds. Occasional supplementary rawinsonde launches
> will be required in addition to the usual, twice daily, routine
> launches. On average, one supplementary launch per week per site is
> likely to be required. A minimum 12 hour advance notice for a special
> launch will be needed from the special observing sites. The lest two
> items, which are support facilities, will assist a local 12‑36 hour
> forecast to be made at the site. This will be used in scheduling
> observing periods, requesting special rawinsonde launches and
> coordinating with satellite observations. Details of the additional
> site‑specific instrumentation are given below for each site.
>
> [Salt Lake City, Utah Site]{.underline}
>
> i\. scanning ruby (694 nm) lidar with dual polarization receiver
>
> ii\. scanning narrow beam infrared (10‑12 µm) radiometer
>
> iii\. all‑sky, 35 mm fisheye camera
>
> iv\. K~a~‑band (0.8 cm) radar (occasionally).
>
> The corresponding directly calculable cloud physical properties are
> (i) cloud base and top heights, areal cloud fraction, particle phase
> and ice crystal orientation, and cloud optical depth at .694 µm; (iii)
> cloud type and amount. The corresponding inferentially calculable
> cloud properties are (i) broadband visible cloud optical thickness and
> ice crystal habits; (ii) cloud emittance at 10‑12 um and broadband
> infrared cloud emittance; (iv) cloud (ice) water content
> (occasionally).
>
> [Hampton, VA Site]{.underline}
>
> i\. scanning ruby, doubled ruby and doubled Nd YAG lidar (694, 347,
> 532 nm) with dual polarization receiver.
>
> ii\. scanning, narrow beam, visible (0.4 ‑ 0.75 µm) radiometer
>
> iii\. scanning, narrow beam, near infrared (1.04 ‑ 2.2 µm) radiometer
>
> iv\. precision spectral pyranometers
>
> v\. cloud imaging cameras
>
> The corresponding directly calculable cloud properties are (i) cloud
> base and top heights, areal cloud fraction, particle phase and ice
> crystal orientation and cloud optical thickness at 694, 347, and 532
> nm; (ii‑iii) cloud optical thickness at multiple wavelengths from
> 0.4‑2.2 µm; (iv) surface radiation budget (v) cloud type and amount.
>
> [Boulder, Colorado Site]{.underline}

i\. scanning ruby, doubled ruby and doubled Nd lidar (694, 347, 532 nm)
with dual polarization receiver

ii\. scanning CO2 doppler lidar (9‑11 µm)

iii\. vertically pointing, narrow beam, infrared (10‑12 µm) radiometer

iv\. narrow beam, visible, sun photometer (solar tracking)

v\. PROFS mesoscale solar radiation network (23 stations with
pyranometers).

> The corresponding directly calculable cloud properties are (i) cloud
> base and top heights, areal cloud fraction, particle phase and ice
> crystal orientation and cloud optical thickness at 694, 347, and 532
> nm; (ii) ice particle fall speeds, turbulent intensity and vertical
> profiles of horizontal convergence/divergence; (iv) broadband visible
> cloud optical thickness. The corresponding inferentially calculable
> cloud properties are (i) broadband visible cloud optical thickness and
> ice crystal habits; (ii) local vertical profile of vertical wind
> speeds and ice crystal habits; (iii) cloud emittance at 10‑12 µm and
> broadband infrared cloud emittance; (iv) areal cloud fraction.
>
> [II. Class II Sites]{.underline}
>
> Class II sites will be operated continuously during daylight hours
> throughout the duration of the FIRE ( 4 years). Seven class II sites
> are planned. Proposed class II sites are:
>
> [Class II Sites]{.underline}
>
> [Location]{.underline}
>
> Boulder, Colorado
>
> Champaign, Illinois
>
> Hampton, Virginia
>
> Mauna Loa, Hawaii
>
> Madison, Wisconsin
>
> Palisades, New York
>
> Salt Lake City,‑Utah
>
> West Lafayette, Indiana
>
> It should be noted that the Utah and Boulder class I sites are
> colocated with a class II site. This colocation will provide an
> observational basis for developing inferential relationships between
> cloud properties deduced from Lidar observations and the passive
> measurements made at a Class II site.
>
> [Class II Site Measurements and Instrumentation]{.underline}
>
> At each of the class II special observing sites, most of the following
> instrumentation and support facilities will be in place:
>
> i\. multiple field‑of‑view, solar (visible) radiometer
>
> ii\. pyranometers
>
> iii\. NWS rawinsonde site (close proximity)
>
> iv\. data logging facilities.
>
> These instruments will provide a direct measurement of (i, ii) the
> broadband visible cloud optical depth and the direct and diffuse
> components of downwelling visible radiation; (ii) the total
> downwelling solar radiation at the surface, and (iii) the
> environmental profiles of pressure, temperature, humidity, and
> horizontal winds ‑ no special launches required. Inferentially, an
> estimate of local cloud cover or cloud structure (variability of
> visible optical depth over sky) may be made based on observations (i).
>
> [4.222 STRATOCUMULUS STUDIES]{.underline}
>
> The Naval Postgraduate School and the Naval Research Laboratory are
> planning to cooperate with several universities in a multi‑year field
> program of nearly continuous Cloud Top Boundary Layer (CTBL) studies
> at SNI, involving the installation of a three wind component Doppler
> Sodar, and augmentation of the tower with a full suite of longwave and
> shortwave surface radiation measurements. An existing network of
> radiosonde stations (two island, four coastal) will be used to define
> horizontal variability and longer tropospheric thermodynamics.
>
> NOAA/ERL is planning to make extended‑time surface radiometric
> measurements at SNI. Automated pyranometers and pyrheliometers will be
> located at the vertices and at the center of a 5‑point square network
> occupying approximately a two square mile area. More complex and some
> manually‑operated instruments will also be located at the center of
> the network to make additional measurements for giving more detailed
> spectral information. Portable, independent, and weather‑proof data
> acquisition systems will be located at each vertex. Spectral
> measurements of solar transmission will also be made. An automated
> scanning radiometer with three spectral charnels will be used. Also,
> pyrogeometer measurements of the downwelling longwave flux will be
> made. Depending on the success of testing now in progress, solar
> radiometersondes may be periodically flown vertically through the
> stratus deck to obtain the vertical upwelling and downwelling flux
> profiles for comparison with model calculations.
>
> A summary of planned observations is given in Table 1
>
> ![](media/image2.wmf){width="7.611111111111111in"
> height="10.472222222222221in"}
>
> **[5.0 INTENSIVE FIELD OBSERVATIONS]{.underline}**
>
> Intensive Field Observation (IFO) programs are planned to support
> research tasks requiring high time and space resolution information on
> cirrus and marine stratocumulus cloud systems. In addition to
> supporting the cirrus and marine stratocumulus studies, these data
> will be instrumental in the development of a better understanding of
> ISCCP data products. The intensive field observations will be gathered
> from a variety of platforms on a relatively local, but regionally
> representative, geographical scale. Data will be collected from
> multiple satellites, aircraft, balloon and surface‑based
> instrumentation. The intensive data collection periods will be
> approximately three to six weeks in length and will be scheduled
> annually starting in the fall of 1986.
>
> The sampling strategy involves obtaining observations of the same
> targets from multiple platforms. Synchronized high resolution
> multispectral satellite observations will be obtained from multiple
> platforms viewing the scene from different angles. Coincident
> observations will also be obtained from aircraft where one is
> essentially a satellite platform simulator with additional
> capabilities and the other aircraft are equipped with in situ
> radiative, microphysical and air motion sensing instrumentation.
> Special lidar, radar and radiometric observations will be obtained
> from surface based sites as will conventional observations of
> meteorological parameters. The strategy calls for high density
> observations over limited times (2‑3 hours) both in small (10 km)^2^
> fixed regions where surface based observations are being collected and
> over surrounding regions as weather and satellite operations permit.
> Observations over the fixed region will serve the purposes of the
> intensive case Studies while missions over the surrounding regions,
> particularly over water, will provide important data for cloud
> retrieval algorithm intercomparison.
>
> **[5 1 CIRRUS INTENSIVE FIELD OBSERVATIONS]{.underline}**
>
> **[5.11 SPECIFIC OBJECTIVES]{.underline}**
>
> The central objective of the FIRE program of cirrus cloud studies is
> to develop quantitative relationships between the properties of cirrus
> cloud fields and the associated radiative fields as functions of the
> large scale meteorological environment.
>
> Since relatively little is known about cirrus clouds, it is
> appropriate to pose a number of key questions that will require
> answering before the central objective can be met. These questions
> include:

o What roles do radiative processes play in the evolution of cirrus
cloud fields?

o Is wind shear an important factor in providing a driving mechanism for
the small scale vertical motion field?

o What scales and magnitudes of vertical motion are found within cirrus
cloud fields?

o What is the particle size distribution within cirrus layers? What is
it dependent upon?

o Are there \'characteristic\' large scale environments favorable to
cirrus formation that can be reliably identified?

> The above list is not meant to be exclusive; it is offered only to
> illustrate how much is [not]{.underline} presently known about cirrus
> clouds and therefore, how much we have to gain from the FIRE cirrus
> component.
>
> **[5.12 SCHEDULE]{.underline}**
>
> Two field experiments are planned with the first in the Fall, 1986 and
> the second in early Spring, 1988. Each will be three to six weeks in
> duration. A target of sixteen case study samples should be attainable
> in this two stage experiment setting. The observing periods will
> provide the opportunity to sample pre‑warm frontal and jet stream
> cirrus in 1986 and convectively generated cirrus and jet stream cirrus
> in 1988. Furthermore, the two observational periods will provide an
> opportunity for researchers to revise strategies and instrumentation
> based on the experience and results of the first experiment. This is
> particularly important for the cirrus observational studies since this
> will mark the first major experimental effort concentrating on cirrus
> cloud systems.
>
> **[5.13 LOCATION]{.underline}**
>
> The preliminary site selected for the first experiment will be a
> (\~100 km)^2^ area in central Wisconsin (see Figure 1). This site was
> chosen for a number of reasons. Climatologically, this area has a
> relatively high and reliable frequency of cirrus cloud occurrence
> (\~35%) especially pre‑warm frontal cirrus during this fall time
> period. The northerly location together with the selected time period
> will ensure that cloud overflights are possible with at least two
> research aircraft, i.e., relatively low cirrus layers (\<12 km) will
> occur. Furthermore, complications in the analysis of vertical motion
> fields due to orographic effects are minimized by using this site.
> This site is within the view of both GOES satellites and is close to
> Lake Superior and Lake Michigan, which provide uniform backgrounds for
> aircraft‑satellite cloud data intercomparisons.
>
> The site for the second phase of the experiment has not yet been
> selected. Possible locations are a longer latitude location in the
> Midwest U.S. or even the same site as the first experiment. This
> decision will be made following the experience obtained in the first
> experiment.
>
> **[5.14 SATELLITE OBSERVATIONS]{.underline}**
>
> The satellite platforms, measurement systems, and data products for
> the program of intensive field observations are the same as previously
> described (See Sections 4.11 and 4.21). Satellite data is to be
> collected [every day]{.underline} during the IFO time periods. It
> should be noted that obtaining coincident data from multiple platforms
> operating at maximum capacity (spectral and spatial resolution) is an
> even higher priority item in the Intensive Field Observation setting,
> e.g., NOAA‑PO AVHRR/LAC, and HIRS‑2, GOES VAS, ERBS ERBE and SAGE II
> and LANDSAT/5 TM.
>
> **[5.15 AIRCRAFT OBSERVATIONS]{.underline}**
>
> A minimum of two highly instrumented research aircraft will be
> deployed during the intensive field observing program. The NASA/ER‑2
> aircraft will be used primarily as a high lever (well above Cloud top)
> areal cloud mapping platform. Besides allowing high resolution
> definition of the cloud and upwelling radiance fields, it will also
> obtain data spectrally comparable to a number of satellite systems.
> This will permit detailed intercomparisons with the satellite systems.
> The NASA/CV‑990 aircraft will be used in two modes. The primary mode
> of operation will be in the vicinity of the cloud layer with the
> purpose of obtaining in situ data on the microphysical, thermodynamic
> and radiative structure of the target cloud field. Flight levers just
> above, within and below the target cloud will be required in order to
> measure spectral radiances, irradiances and the cloud layer
> microphysical properties. In this mode, multiple flight levers will be
> used in order to sample the vertical profiles of radiative fluxes and
> meteorological state parameters. A secondary mode of operation is to
> perform areal cloud mapping functions from flight levers more than 2
> km above and below cloud top and base respectively. The NCAR King Air
> Aircraft will be used for profiling and as an in situ sampling
> platform. The NCAR King Air will specialize in microphysical
> measurements and air motion sensing within the cirrus cloud layer. Its
> capabilities represent an important addition to describing the cirrus
> cloud layer properties.
>
> **[5.151 NASA/ER‑2 Instrumentation]{.underline}**
>
> The following instrumentation is available for operation from the ER‑2
> platform (See Appendix A for more details):

i\. Cloud Lidar System (CLS) ‑ a downward pointing Nd and doubled Nd
(1.064 and 0.532 µm)

dual polarization lidar with \~7.5 m vertical resolution and a 50 m
horizontal sampling interval.

ii\. Multispectral Cloud Radiometer (MCR) ‑ a scanning (45° cross‑track)
multispectral (0.754, 0.760, 0.763, 1.644, 1.713, 2.164, 10.070 µm)
radiometer with resolution of about \~100 m at the nadir, sample
synchronized with CLS and simultaneous in all charnels.

iii\. Thematic Mapper Simulator (TMS) ‑ a scanning (84° cross‑track)
multispectral (6 visible, 0.83, 0.98, 3.7, 11, 12.5 um) radiometer with
resolution of about \~50m at the nadir, channelization allows use as a
NOAA‑PO AVHRR/LAC simulator in addition to its use as a LANDSAT/5
thematic mapper simulator.

iv\. Hemispheric Flux Radiometers ‑ upward and downward pointing solar
(0.26 ‑ 2.6 um) and infrared (5‑40 µm) broadband flux radiometers.

v\. Two channel IR broadband hemispherical flux radiometer

vi\. Narrow spectral bandpass, narrow field of view downlooking 2
charnel IR radiometer.

vii\. Hemispherical solar flux radiometers upward and downward looking.

viii\. Narrow spectral bandpass hemispherical solar flux radiometer. ix
. Advanced Microwave moisture Sounder (AMMS)

x\. Temperature and Pressure Probes

xi\. INS Wind System

xii\. Down‑looking Photography

> **[5.152 NASA/CV‑990 Instrumentation]{.underline}**
>
> The following instrumentation will be available and operated from the
> CV‑99O platform (See Appendix D for more details):

i\. Laser particle size spectrometers ‑ particle size distributions from
0.25 to 1200 um and crystal habit from 200 um to 800 um.

ii\. Hemispheric Flux Radiometers ‑ upward and downward pointing solar
(0.20‑2.6 µm) and infrared (5‑40 um) broadband flux radiometers.

iii\. Reversing field of view Hemispherical Flux Radiometers broadband
solar (0.20‑2.6 µm).

iv\. Reversing field of view Hemispherical Flux Radiometers IR (5‑40
µm).

v\. Solar tracking photometer (380‑1060 um) 6 charnels.

vi\. 2 narrow beam narrow spectral bandpass IR radiometers (2 charnels
each); upward and downward pointing.

vii\. Reversing field of view multichannel (4 or 5 charnels) narrow
spectral bandpass solar radiometer.

viii\. Airborne Lidar System (ALS) ‑ upward pointing ruby, Nd, and
doubled Nd (0.694, 1.060,

0.530 µm) dual polarization cloud lidar and downward pointing Nd dual
polarization lidar ‑ spatial resolution \~10^l^‑10^2^m.

ix\. Temperature and Pressure Probes

x\. INS Wind System

xi\. Frost point hygrometer

xii\. Multiangular visible radiance radiometer (Bugeye)

xiii\. Spectral radiance radiometer .35 ‑ 15 µm; zenith \< 0¡ to 180¡;
FOV 6 mr.

xiv\. Ice water content

xv\. Cloud photography

> It should be noted that the nominal horizontal resolution/sampling
> interval is ‑100 m or less for most airborne systems. The cloud lidars
> will generate a high resolution description of cloud base and top
> heights, areal cloud fraction, particle phase and orientation and
> cloud optical depths at the sampled wavelengths. Other radiometric
> instrumentation will serve to define the upwelling and downwelling
> broadband fluxes and spectral radiances. The aircraft observations
> will also permit direct analysis of the fine‑scale structure of the
> upper lever humidity and motion fields.
>
> **[5.153 NCAR KING AIR INSTRUMENTATION]{.underline}**
>
> The following instrumentation is available on the NC AR King Air.
>
> Table 2
>
> [Parameters Instrument]{.underline}
>
> winds Gust probe, inertial navigation system
>
> temperature Rosemount, NCAR, reverse flow, fast response,
>
> radiation
>
> water vapor Lyman‑Alpha hygrometer
>
> liquid water Knollenberg, and Johnson‑Williams liquid
>
> droplet distribution water
>
> shortwave and longwave Barnes PRT‑5, Eppley pyranometers and
>
> irradiances pyrgeometers
>
> sea surface temp Barnes PRT‑5
>
> ozone Pearson‑Stedman (see Lenschow et aI., 1981)
>
> **[5.16 SURFACE BASED OBSERVATIONS]{.underline}**
>
> There are two components of the surface based observing system: cloud
> lidar/radiometric sites and meteorological sounding systems. The cloud
> lidar/radiometric instrumentation from the (class I sites) will be
> redeployed to the field site. Efforts are underway to obtain a
> narrow‑beam, multispectral (multiple solar and infrared charnels)
> scanning radiometer to be incorporated into the surface based
> observing systems at the field site.
>
> Because of the importance of relating the observed cloud and radiative
> fields to the large scale meteorological conditions and the difficulty
> of obtaining good estimates of large scale vertical motion at cirrus
> cloud levers, it is proposed that two independent wind sounding
> systems be deployed over the intensive field observing region. The
> first is the conventional rawinsonde network that will be operated by
> NOAA/NWS. Coordinated on‑demand launches will be required of all these
> sites during times when aircraft missions are in progress. The
> affected stations would be St. Cloud, MN; International Falls, MN;
> Green Bay, WI; Peoria, IL; Sault St. Marie, MI; and Flint, MI. In
> addition, two special stations would be required in the observing
> ‑region (western edge). These supplementary rawinsonde sites will
> permit consistency checks between vertical motion computed from
> observed horizontal divergence determined over triangular regions
> encompassing the field region and its nearby environment as well as
> corrections for sonde drift.
>
> The second upper‑level wind system is a VHF wind profiling system
> (Appendix G) being developed by NOAA/ERL. These systems are unaffected
> by problems of sonde tracking and drift and may provide an accurate
> direct measurement of ambient vertical motion over each unit. In
> addition, horizontal wind speeds and directions can be observed which
> may then be used to infer larger scale vertical motions in much the
> same way as is clone for rawinsonde observations. Continuous sampling
> allows time averaging that ensures a much greater degree of
> representativeness than rawinsonde observations offer To achieve high
> accuracy at cirrus cloud levers, wind profilers should be operated at
> a frequency of 50 MHz. Ideally three of these sites would be operated
> within the field region provided resources can be found to support
> this activity. At the very least, one profiler would be very useful to
> provide a detailed description of the convective structure of the
> overlying cirrus cloud.
>
> **[5 17 OPERATIONS]{.underline}**
>
> Preliminary estimates of times of potential coincident satellite
> observations within the field site and surrounding region, (82.5¡W to
> 102.5¡W and 37.5¡N to 47.5¡N) should be included in the operations
> plan. Special attention should be given to coincident observations by
> NOAA satellites and LANDSAT/5 and/or ERBS. Two weeks before the actual
> experiment, these estimates should be updated. This will allow
> targeting of specific \"most opportune\" times for aircraft
> operations. The operations of the satellites should be firmly
> scheduled at that time, i.e., NOAA, AVHRR/LAC, GOES VAS, ERBS ERBE and
> SAGE II and LANDSAT/5 TM. It is important to know precisely where and
> when data will be collected by various satellites in order that
> coordinated aircraft operations may be planned.
>
> A forecasting capability is crucially important to field operations.
> Specific forecasting responsibilities will be assumed by members of
> FSET. Facilities at the University of Wisconsin at Madison will be
> utilized., i.e., McIDAS, to enable 12‑36 hour forecasts and longer
> range outlooks to be generated for the observing region. In this
> respect, it should be noted that quick look data sets will be
> available from all observing systems in the field to facilitate
> mission planning. Aircraft missions may be flown on successive days or
> on a day/night sequence as may be required by weather conditions and
> satellite operations. All surface observing systems will be maintained
> in an on call basis throughout the field experiment period.
>
> **[5.2 STRATOCUMULUS INTENSIVE FIELD OBSERVATIONS]{.underline}**
>
> **[5.21 SCIENTIFIC OBJECTIVES]{.underline}**
>
> The intensive field observations of the stratocumulus component of
> FIRE will support the general goals of improving GCM and climate model
> cloud‑radiation parameterizations and increasing utilization and
> understanding of ISCCP data ; in addition answers to a number of
> specific questions will be sought from the intensive observation data
> set. Some of the more significant questions are:
>
> o What determines the fractional cloudiness and cloud morphology?

o What is the role of cloud‑top entrainment instability in determining
cloud type?

> o What determines the magnitude of the entrainment rate?

o How is the diurnal radiation cycle transmitted into a diurnal behavior
of the cloud layer?

o How do maritime aerosols relate to droplet distributions in the
stratocumulus clouds?

> The intensive phase will provide the opportunity for a three‑platform
> intercomparison study. Ground, aircraft and satellite measurements
> will be combined to infer the effects of processes that are extremely
> difficult to measure directly. For example, aircraft radiation
> measurements taken above the clouds will be combined with satellite
> measurements to deduce free‑atmospheric radiative heating/cooling
> rates; likewise, \"round and aircraft data will be used to deduce
> whole boundary layer heating rates.
>
> **[5.22 SCHEDULE]{.underline}**
>
> Table 3 shows a time fine for the activities of the experiment. Four
> types of activity are listed: 1) theoretical and modeling studies, 2)
> satellite observations, 3) field experiments, and 4) analysis. . These
> activities will make use of both previous and concurrent experiments
> with related objectives. These include DYCOMS (Dynamics and Chemistry
> of Marine Stratocumulus), which is planned for August 1985, off the
> California coast; NOAA P3 flights concurrent with DYCOMS; and a
> Doppler radar experiment to be performed at Santa Barbara in September
> 1985.
>
> A full spectrum of modeling studies will continue throughout the
> experiment. There will be many opportunities for comparisons of field
> observations with model results.
>
> The use of satellite observations to characterize the CTBL can begin
> immediately, using archived data. The field experiments, however, will
> be preceded by a period of preparation, in order to allow time for the
> planning and development of suitable data acquisition and processing
> techniques.
>
> ![](media/image3.wmf){width="7.583333333333333in"
> height="8.472222222222221in"}
>
> TABLE 3. SCHEDULE OF ACTIVITIES FOR THE FIRE STRATOCUMULUS SUBPROGRAM.
>
> 1985 1986 1987 1988 1989 1990
>
> THEORETICAL AND MODELING STUDIES X X X X X X
>
> EXTENDED‑TIME OBSERVATIONS (SATELLITE) X X X
>
> INTENSIVE FIELD‑EXPERIMENTS X X
>
> ANALYSIS OF OBSERVATIONS X X X X
>
> **[5.23 LOCATION]{.underline}**
>
> The site selected for the marine stratocumulus Intensive Field
> Observations is San Nicolas Island (SNI) located approximately 100 km.
> west of Los Angeles, California (see Figure 1). San Nicolas Island was
> chosen for a number of reasons. The island is relatively small and
> minimally disrupts the marine boundary layer flow; climatological data
> show that the northwest tip of the island receives marine flow more
> than 60% of the time; marine stratocumulus clouds occur approximately
> 38% of the time during the month of June. As part of the Pacific
> Missile Test Center, the island has very good support facilities for
> scientists and their experiments; the restricted airspace around the
> island will eliminate any conflict with commercial air traffic.
> Collaboration with the Naval Post Graduate School and Naval Research
> Laboratory personnel will be optimized as a result of their access and
> previous utilization of the SNI facilities.
>
> **[5.24 SATELLITE OBSERVATIONS]{.underline}**
>
> The satellite platforms, measurement systems, and data products for
> the program of intensive field observations are the same as previously
> described for the Extended Time Observations (Sections 4.11, 4.21).
>
> Experimental planning during the intensive period will be greatly
> facilitated by the use of an interactive satellite data processing and
> display system available at SNI. The facility can also be used for
> limited data archival.
>
> **[5.25 AIRCRAFT OBSERVATIONS]{.underline}**
>
> Studies of marine stratiform clouds by means of island‑based
> observations offer the decisive advantage of providing long time
> series, but they suffer from the disadvantage that the island itself
> and the nearby continent may significantly influence the structure of
> CTBL. Diurnal variations, for example, are much larger over land than
> over the ocean, and mesoscale land/sea circulations may be
> significant. Air craft will be used to study the horizontal
> variability of the CTBL in the vicinity of SNI and several hundred km
> upstream and downstream in order to determine the representativeness
> of the island‑based observations. The aircraft can and will probe the
> CTBL, the capping inversion, and the overlying free atmosphere. Both
> horizontal and vertical variations in boundary layer structure will be
> measured.
>
> Table 4 lists the aircraft that will potentially be available to the
> FIRE Stratocumulus IFO program. A wide variety of instruments will be
> carried on the various aircraft, which will fly at levers ranging from
> the surface layer to the longer stratosphere. The key observational
> capabilities of the aircraft can be summarized as follows:

i\. fast response (\~10 Hz bandwidth) measurements of air velocity
components and scalar variables to be used for turbulence flux estimates
and other turbulence statistics;

ii\. mean in situ measurements of wind and scalar variables;

iii\. remote sensing with radiometers and lidars; and

iv\. accurate horizontal and vertical aircraft positioning.

> Two turbulence aircraft that are most likely to be available for
> FIRE\'s stratocumulus segment are the NOAA/OAO WP‑3D and the NC AR
> King Air. The P3 is described in Appendix C, and the King Air is
> discussed in Appendix E. Each aircraft is equipped with a
> nose‑boom‑mounted gust probe system for turbulence measurements, as
> well as a wide variety of other sensors, including cloud microphysics
> and radiation instruments, that will complement both the groundbased
> and satellite observations. They will be used in FIRE to make
> cross‑wind and along‑wind measurements in the vicinity of SNI in
> cooperation with the \"round and satellite work.
>
> Fast‑response fluctuations in velocity components, temperature, and
> humidity can be measured with sufficient accuracy that vertical fluxes
> of these variables can be estimated throughout the CTBL including the
> entrainment zone. Following the methods of Lenschow et al. (1982),
> measurements of the ozone flux and mean concentration profiles through
> the boundary layer and its capping inversion will be used to estimate
> the entrainment velocity at the top of the boundary layer. Humidity
> fluctuations will be measured from aircraft by ultraviolet absorption
> (the Lyman‑alpha fine) and microwave refractometry.
>
> Measurement of divergence in the marine boundary layer by integrating
> the mean horizontal wind field around a closed flight path may not be
> feasible because of time changes that can occur during the flight
> (Brost et aI., 1982a). Possibly this problem can be solved by using
> several aircraft simultaneously. Alternatively, by invoking the PBL
> mass budget, the vertically averaged PBL divergence can be estimated
> from the entrainment velocity and the time rate of change of the PBL
> depth.
>
> A downward pointing lidar and a multispectral cloud radiometer will
> fly on the NASA ER‑2 in the longer stratosphere, for the purpose of
> mapping the structure of the cloud‑top surface. This will provide
> high‑resolution data on the entrainment process at the cloud top, and
> will also give quantitative information about the small scale
> structures of in‑cloud turbulent elements. It will be particularly
> useful in cases where the cloud is in the process of breaking apart.
> The ER‑2 will also be instrumented with a multispectral cloud
> radiometer, to measure cloud optical and radiative properties, and a
> thematic mapper simulator that mimics the AVHRR satellite instrument.
> ER‑2 flights will be coordinated with coincident flights by the
> University of Washington C‑131A cloud/ aerosol research aircraft that
> will provide the necessary in situ measurements to allow the cloud
> microphysics and radiative properties to be related.
>
> The principal instruments on the ER‑2 are the Multispectral Cloud
> Radiometer (MCR), Cloud Lidar System (CLS), and modified version of
> the Thematic Mapper Simulator (TMS) radiometer to provide high
> resolution measurements at AVHRR wavelengths. (A brief description of
> these instruments is given in Appendix A.) An important application
> for the high altitude aircraft experiment is to provide \"ground
> truth\" for satellite derivations of cloud fraction and cloud top
> altitude. Specifically, the aircraft observations will be compared
> with satellite AVHRR observations. A second application is to provide
> simultaneous multi‑angle radiance observations for radiative model
> tests using the aircraft and satellite data (e.g. LANDSAT/5 TM and TMS
> simulator).
>
> Even though marine stratocumulus clouds occur at low levels,
> observations with the high altitude aircraft will be extremely useful.
> A high altitude aircraft will be needed to provide an adequate swath
> width for the scanning radiometers. The capabilities of the ER‑2
> platform will permit full coverage of a 200‑by‑200 km area in a 3‑hour
> period by the onboard scanning radiometers. Within the sampled area,
> the TMS will provide observations at 50 m or greater resolution at the
> simulated AVHRR wavelengths, and the lidar measurements will give
> extensive coverage of the height structure of the cloud systems.
> Moreover, the presence of cirrus clouds, which are expected to very
> frequently overlie the CTBL, can be detected and quantified by
> downward observations from the high altitude aircraft.
>
> ER‑2 lidar studies will concentrate on deriving the cloud‑top altitude
> and cloud morphology of maritime stratus and stratocumulus clouds, as
> well as the spatial distribution of cloud optical thickness. Two
> current problems of particular interest are the \"cloud absorption
> paradox\" and the \"cloud optical depth paradox\" discussed in Section
> 3.22. To address these two problems in situations where the surface
> albedo and the fractal structure of clouds are the least troublesome,
> a full complement of measurements will be obtained during episodes of
> thick and horizontally extensive coastal stratus or stratocumulus
> cloudiness.
>
> In order to accomplish these objectives, the ER‑2 flights will be
> coordinated with in situ cloud microphysics and cloud radiation
> observations made by the University of Washington\'s C‑131A cloud and
> aerosol research aircraft, as well as the other FIRE research
> aircraft. The C‑131A will provide information on the cloud particle
> size distribution, thermodynamic phase and liquid water and ice water
> contents . Through a combination of these data, the
> cloud-radiometer‑derived optical thickness will be compared to that
> predicted from the cloud microphysics observations. These data will
> help to address the relationship between the effective optical depth
> of a cloud for radiative transfer purposes, and the optical depth
> predicted from the integration of the measured liquid water content
> and effective particle size.
>
> In addition to cloud microphysics observations, the University of
> Washington C‑131A includes a multichannel scanning radiometer designed
> to derive the spectral single scattering albedo of clouds. The concept
> behind the cloud absorption measurements is the diffusion domain
> method described by King (1981). (A brief description of the Cloud
> Absorption Radiometer and the cloud microphysics measurement
> capabilities of the UW C‑131A are given in Appendix B.)
>
> Upward and downward pointing lidar systems will be flown on NASA \'s
> CV‑990. The aircraft will also carry a PRT‑5 radiometer (looking
> clown), a 70 mm camera, a Rosemount 102 air temperature sensor, and a
> General Eastern 1011 dew/frost point hygrometer. The measurements will
> be coordinated with data from GOES and LANDSAT, as well as other
> aircraft data. Plans call for three 4‑hour flights per day, to allow
> good sampling of diurnal variability.
>
> Narrowband measurements, made with a minimum number of instruments (to
> minimize intercalibration problems) will also fly on the CV‑990, as
> will a sun‑ tracking photometer (which can give important values of
> cloud optical depth) and a PMS system. Much of this equipment has been
> flown on a P‑3, and the possibility of combining the systems is being
> explored.
>
> A description of the instruments to be flown on the CV‑990 is given in
> Appendix D.
>
> Finally, a small, highly maneuverable Queen Air aircraft, operated by
> the NOSC in San Diego, will make aerosol and meteorological
> measurements in the profiling mode, to provide high‑resolution aerosol
> concentration observations and vertical profiles of boundary‑layer
> variables.
>
> Table 5 summarizes the aircraft observations.
>
> **[5.26 SURFACE OBSERVATIONS]{.underline}**
>
> During the IFO period, the extended time activities at SNI described
> in Section 4.222 will be augmented by a variety of direct and remote
> sensing systems. Short‑wavelength (8‑18 mm) Doppler radars will
> provide observations of the variability of cloud‑top height for
> comparison with the satellite deduced variability. Small scale
> fluctuations of cloud‑top height and cloud‑top vertical velocity will
> be measured. This data will provide checks on satellite derived
> quantifies, and they will also help to identify episodes of cloud‑top
> entrainment instability. Current technology allows measurements of
> cloud‑top morphology and kinematics within a 3‑15 km radius
> surrounding the radar site, depending on conditions.
>
> . .
>
> Table 5: SUMMARY OF INTENSIVE OBSERVATIONS
>
> 1 Aircraft:
>
> a\. Direct Observations
>
> i\. Entrainment rate (through inversion budgets)
>
> ii\. Thermodynamic profiles, particularly for adjacent cloudy and
> cloud‑free environments.
>
> iii\. Radiative flux profiles Cloud drop size distribution
> Photography, particularly showing details of cloud top morphology
>
> vi\. Test the degree to which island‑based observations represent
> boundary‑layer conditions over the open ocean.
>
> b\. Validation platform for remotely sensed parameters
>
> i\. Lidar, cloud top morphology
>
> ii\. Radiometry, satellite calibration
>
> iii\. Microphysical probes, cloud liquid water structure
>
> iv\. Turbulent flux probes, particularly for the buoyancy flux
>
> 2\. Surface‑Based Observations:
>
> a\. Radar and lidar
>
> i\. Cloud morphology
>
> ii\. Variability of liquid water within cloud system
>
> iii\. Cloud and subcloud layer kinematics (doppler), with particular,
> emphasis on mesoscale divergence field, velocity statistics. that
> contribute to the turbulence kinetic energy budget, and measurement of
> the entrainment rate.
>
> b\. Tethered balloon
>
> i\. Turbulence measurements
>
> ii\. Radiometric measurements
>
> iii\. Microphysical measurements
>
> The measurement of cloud liquid water and water vapor is an important
> part of the envisioned measurement program. Liquid water mixing ratios
> will be inferred from the radar reflectivity factor; in situ
> measurements of liquid water content and droplet spectra will also be
> made to infer the relationship between liquid water and reflectivity.
> Ground‑based scanning dual ‑ channel microwave radiometers will be
> used to continuously monitor the temporal and spatial variability of
> total liquid water and water vapor overhead, for comparison with
> satellite‑observed cloud reflectivity.
>
> A Doppler radar will provide information about the turbulent
> kinematics of the cloud layer, including profiles of horizontal and
> vertical wind components, convergence, and the turbulent fluxes of
> momentum within the cloud layer. Such profiles are generated from
> cortical scan data (Browning and Wexler, 1968). The elevation angle
> chosen for such a scan depends on the quantity to be measured; low
> elevation (\<15¡) are best for convergence measurements, an elevation
> angle of 45¡ minimizes the error in measuring the vertical flux of
> momentum, and near vertical elevations optimize the measurement of
> vertical velocity and its variance. Horizontal wind profiles can be
> measured with good accuracy at elevation angles below 75¡.
>
> Similar velocity measurement techniques will be applied below cloud
> base and several hundred meters into the cloud by means of pulsed
> infrared Doppler lidar, which uses atmospheric aerosols for scatterers
> (Hall et al., 1984). Instruments currently being tested have an
> effective range of 20 km or more in the subcloud layer of the CTBL.
> Such systems, operating in the cortical scan mode, have already
> demonstrated their ability to observe wind profiles and turbulence in
> the dry planetary boundary layer.
>
> It is anticipated that a Doppler radar and a Doppler lidar will be
> operated at SNI each day for 5 hours during the afternoon, and again
> for 5 hours after midnight. A sequence of 4 or 5 RHI scans at various
> azimuths will be followed by a sequence of 4 or 5 PPI scans at various
> elevation angles ranging from \~10¡ to 90¡. The 90¡ scan will allow
> measurement of the vertical motion field at cloud‑top. These, combined
> with measurements of the actual lime‑rate‑of‑change of cloud‑top
> height, would allow determination of the entrainment rate. This
> strategy will be tested using data collected prior to FIRE.
>
> An array of ground‑based remote sensors at SNI will document various
> aspects of the cloud dynamics and microphysics. Particle sizes and
> shapes will be probed using a dual‑polarization lidar system, and
> simultaneous measurements of surface infrared and solar radiation will
> provide a means of relating these particle spectra to cloud radiative
> properties. The cloud LWC will be monitored by a dual‑charnel
> microwave radimeter; this data will be compared with LWC observations
> from the satellite platform. The cloud microphysical data will be
> complemented by tower measurements (using a PMS system) of subcloud
> aerosols.
>
> Two candidate tethered balloon systems are planned for use in the FIRE
> Stratocumulus Subprogram. The first has been developed for the U.S.
> Navy by a private contractor (LTA International), and was flown in
> 1984 by NRL at SNI. It is 17 m long, has a volume of 220 m^3^, and
> under conditions of zero wind can lift a payload of approximately 20
> kg to an altitude of 1 km. It is capable of operating in
> flight‑altitude winds of 20 m s^‑1^. A cloud physics instrument
> package (including temperatures and winds) has been developed by NRL
> for use with the balloon.
>
> The second, significantly larger candidate tethered balloon has been
> developed by the Wallops Flight Facility of the NASA/Goddard Space
> Flight Center. It is portable, and has flown at various sites
> including Virginia and Alaska. It is 31.6 m long, has a volume of 1275
> m^3^, and under zero‑wind conditions can lift a payload of
> approximately 400 kg to an altitude of 1 km. It is capable of
> operating in flight‑altitude winds exceeding 25 m s^-1^. This balloon
> is large enough to lift the comprehensive instrument package developed
> by the British Meteorological Office (Slingo et al., 1982; Caughey et
> al., 1982; and Roach et al., 1982, Caughey and Kitchen, 1984). This
> package consists of an optical scattering droplet spectrometer (ASSP),
> two CSIRO net radiometers, a turbulence probe, a microwave radiometer
> to measure integrated liquid water content, and a pressure sensor for
> height measurement. These instruments are strung along a cable 40‑50 m
> below the balloon. The instrument package includes its own telemetry
> system. The balloon can remain aloft for up to 72 consecutive hours,
> after which the batteries must be changed. It will be used both at
> fixed levers and to make soundings.
>
> Both tethered balloons can be deployed on SNI and operated at
> different levers or in different modes (e.g. sounding mode vs.
> constant lever mode) to investigate the vertical coupling of various
> boundary layer processes. Alternatively they can be deployed at
> different locations (e.g. San Nicolas and San Clemente Islands) to
> gain additional information about the role of horizontal advective
> processes.
>
> In addition to broadband net radiation measurements at the surface, a
> three spectral bandpass scanning radiometer will be used to measure
> sky and \"round radiance in the visible and near infrared wavelengths.
>
> A summary of surface observations appears in Table 1, Section 4.222.
>
> **[5.27 OPERATIONS]{.underline}**
>
> The U.S. Navy\'s Pacific Missile Test Center has been using SNI for
> some time as an observation post. An operations groups at Pt. Mugu
> airfield not only controls the airspace around SNI but also has access
> to the Island\'s facilities. Elliott et al. (1983) give further
> information. SNI has dormitories, a cafeteria, and modest
> entertainment facilities, as well as powered field sites and an
> airfield. A tethered balloon system has been used at SNI with
> considerable success, and the meteorological tower, on the upwind
> (northwest) tip of the island is a proven facility. The ground‑based
> observation systems will have to be protected against the extremely
> harsh marine environment. Rosenthal (1983) gives further information.
>
> **[6.0 FIRE SCIENTIFIC ORGANIZATION]{.underline}**
>
> **[6.1 FIRE WORKING GROUPS]{.underline}**
>
> FIRE has been designed to address a number of complicated scientific
> problems. The FIRE strategy is to assemble those members of the
> scientific community with interests in these problems and to create an
> environment which encourages them to collectively pursue these
> problems. Two FIRE working groups representing the themes of cirrus
> cloud systems and marine stratocumulus cloud systems will be
> constituted from the FSET membership:
>
> i\. Cirrus Working Group
>
> ii\. Marine Stratocumulus Working Group.
>
> It is clear that physical process modeling, which includes all
> processes important to the maintenance and to the characterization of
> cloud systems, and large scale GCM and climate modeling are critical
> to the successful attainment of FIRE\'s goals; it is extremely
> important that these modeling components be integrated with the
> observational components of FIRE. For this reason, FIRE investigators
> with modeling interests will play important roles in both the cirrus
> and stratocumulus working groups.
>
> The cirrus and marine stratocumulus working groups will accept the
> following responsibilities:

i\. Define specific goals to be collectively pursued; these include but
are not limited to the following:

a\. satellite intercomparisons;

b\. satellite‑in situ intercomparisons;

c\. case studies;

d\. GCM parameterizations.

ii\. Identify responsible individuals in each of the collective study
areas referred to in item i and monitor the progress of the collective
research.

iii\. Define data sources, requirements and schedules essential to
working group studies.

iv\. Exchange data among FSET and working group members.

v\. Oversee publication of joint research results from tasks identified
in item i.

vi\. Establish a data management subcommittee to perform duties defined
in section 7.3.

> Since some data sets will be common to both working groups, a single
> principal investigator may be expected to participate actively in both
> groups; this presents a potential problem of over commitment. To
> partially alleviate this problem some resources should be set aside to
> support postdoctoral associates to work with overcommitted principal
> investigators.
>
> **[6.2 INTENSIVE FIELD PROGRAM MANAGEMENT]{.underline}**
>
> **[6.21 OPERATIONS PLANS]{.underline}**
>
> The FIRE Project Office will prepare detailed operations plans for the
> three observational components of FIRE: Extended Time Observations;
> Cirrus Intensive Field Observations and; Stratocumulus Intensive Field
> Observations. These plans must be developed as soon as possible in
> light of the short lead time on the initiation of the Extended Time
> Observations and the first phase of the Cirrus Intensive Field
> Observations.
>
> **[6.22 MISSION SELECTION TEAM]{.underline}**
>
> During the intensive field phases of the cirrus and stratocumulus
> programs a Mission Selection Team (MST) will be formed. The MST will
> be comprised of no more than five FSET scientists representing the
> multiple goals of FIRE as listed in Section 6.1, item i; it will be
> chaired by the FSET chairman or his designee and have the following
> responsibilities immediately prior to and during the intensive field
> observation periods. The MST will accept the following
> responsibilities.

i\. solicit and represent ideas of other FIRE scientists in operations
decisions and scheduling.

ii\. review on a daily basis the candidate missions proposed by the MPT
(see Section 6.23) and select the planned operations and scheduling of
all FIRE platforms for the following day.

iii\. select on a daily basis a Mission Scientist (MS) and an alternate
mission scientist (see section 6.24) to plan and carry out operations
selected by the MST.

iv\. assemble forecast information for use in daily operations
planning.\*

v\. maintain up‑to‑date experiment accomplishment records for use in
daily operations planning.\*

vi\. maintain current statue reports on all data gathering components
throughout the experiment.\*

vii\. review daily post mission reports prepared by the Mission Planning
Team (see section 6.23).

\* assisted by the FIRE project office.

> All deliberations of the Miss ion Selection Team will be open and in
> the lack of a clear consensus among its members, the chairman will
> assume responsibility for making operations decisions.
>
> On issues concerning specific platforms such as aircraft or special
> rawinsonde accents, an appropriate spokesperson from the contributing
> organization will be given the opportunity to advise the MST and to
> participate on the MPT.
>
> **[6.23 MISSION PLANNING TEAM]{.underline}**
>
> A Mission Planning Team (MPT) will be active during the cirrus and
> marine stratocumulus Intensive Field Observation Phases. The Mission
> Planning Team will contain at least three FSET members, individuals
> representing participating aircraft facilities and FIRE Project Office
> support personnel. The MPT members for the following day will be
> identified on a daily basis by the MST. Ideally, on any given day, the
> MPT will contain candidate mission scientists for the following day\'s
> operations. It will not be uncommon for members of the MST to also
> serve as members of the MPT. The MPT\'s responsibilities are listed
> below.

i\. Prepare three candidate missions for the following day\'s operations
and present these to the MST for consideration.

ii\. Following a decision by the MST, support the Mission Scientist in
preparing a detailed mission plan for the following day\'s operations.

iii\. Prepare a post mission summary of each day\'s operations including
an evaluation of the success of the operations. This daily summary will
be made available to the FIRE Project Office and the MST and become a
part of the FIRE data archive.

> **[6.24 MISSION SCIENTIST]{.underline}**
>
> A Mission Scientist (MS) will be identified on a daily basis by the
> MST at the same time the following day\'s mission is selected. In the
> event that the MS plans to be aboard an aircraft during the mission,
> an alternate mission scientist will be selected by the MST and will
> perform ground‑based functions during the execution of the mission.
> The MS will be in charge of the detailed planning of the following
> day\'s operations and the execution of that plan. He will be
> responsible for making any real time decisions required during the
> execution of the plan.
>
> A Mission Scientist must have an overall grasp of the scientific
> objectives of FIRE as well as an appreciation of operational
> constraints of the various platforms and personnel.
>
> **[6.3 INTERNATIONAL COLLABORATION POLICY]{.underline}**
>
> FIRE is an experiment being conducted by U.S. scientists to provide a
> U.S. national contribution to the International Satellite Cloud
> Climatology Project (ISCCP) of the World Climate Research Program. In
> the sense that the scientific problems addressed by FIRE are truly
> international, it is in the best interests of FIRE to encourage the
> free exchange of information with our international colleagues.
> Although resources do not permit direct support of foreign
> participation in FIRE, ways will be sought to allow such
> participation. 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 which is responsible for this function under the Joint
> Scientific Committee of WMO and ICSU. Reports of FIRE activities will
> be made at the annual ISCCP WG/DM meetings.
>
> **[7.0 FIRE DATA MANAGEMENT]{.underline}**
>
> Data management is an ongoing activity, beginning immediately in the
> pre‑experiment phase and continuing through the end of FIRE. Most of
> the data management tasks will be performed by the FIRE Investigators
> acting individually or as members of the Working Groups (see section
> 6.1). The FIRE working groups will be the foci for identifying and
> coordinating items relating to the acquisition and use of data as a
> communal resource, working closely with other groups dealing with
> scheduling of platforms, identification of calibration and
> intercomparison needs, colocation requirements, and selection of case
> studies and integrated analyses.
>
> 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 individual FIRE
> investigators, (2) the FIRE Working Groups, (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]{.underline} 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]{.underline} source of information and
> copies of data which are centrally archived, whereas the FIRE Working
> Groups, composed of the investigators, will coordinate the
> [decentralized]{.underline} data reduction and analysis activities. In
> addition, the FIRE Central Archive will transfer, from time to time,
> certified FIRE data to EDIS and/or other organizations for permanent
> archive and for open access by the scientific community.
>
> **[7.1 DATA MANAGEMENT RESPONSIBILITIES OF PRINCIPAL
> INVESTIGATORS]{.underline}**
>
> All data reduction and analysis functions in FIRE reside with the
> scientists carrying out their research as part of FIRE. To encourage
> the interaction of these researchers needed to integrate the various
> observations and models into a more comprehensive understanding of
> clouds, FIRE investigators will have free access to all data sets
> collected during FIRE, either by individual principal investigators or
> collected from satellites. Coordination of data analysis and modeling
> activities requires all FIRE principal investigators to perform
> certain other tasks as part of the FIRE data management. These
> functions are:

\(1\) To provide to the FIRE Central Archive information concerning data
holdings, including all data collected as part of FIRE and other data
deemed relevant to FIRE research.

\(2\) To save all data collected during FIRE in un‑reduced form for five
years so that reduction of data can be repeated if necessary.

\(3\) To provide to the FIRE Central Archive copies of all
[reduced]{.underline} FIRE observations in a mutually agreed upon
format, accompanied by complete instrument, reduction algorithm and data
format documentation.

\(4\) To provide, within nine months after acquisition, to the FIRE
Central Archive copies of any data [analysis products]{.underline}
deemed relevant to the accomplishment of FIRE objectives, accompanied by
appropriate documentation.

\(5\) To provide to other FIRE investigators or the FIRE Central
Archive, upon request, copies of other data sets acquired for FIRE
research, that are relevant to other FIRE studies.

\(6\) To provide to other FIRE investigators reasonable access to
[un‑reduced]{.underline} observations to facilitate particularly crucial
mufti‑data analyses.

> **[7.2 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE WORKING
> GROUPS]{.underline}**
>
> There are two FIRE Working Groups ‑ a Cirrus Working Group and a
> Marine Stratocumulus Working Group (see section 6.1). These working
> groups 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, so the FIRE Working Groups must
> govern these individual activities to insure progress toward the FIRE
> science objectives. The data management functions of the two FIRE
> Working Groups are:

\(1\) To determine the content and format of all principal investigator
data sets to be submitted to the FIRE Central Archive.

\(2\) To set standards for data quality control, documentation of all
data sets, and certification criteria for data products that will be
transferred to the permanent FIRE Data Archive.

\(3\) To select case study data sets for special intensive processing
(including re‑formatting) by all relevant principal investigators and to
identify other additional processing of data to accomplish FIRE
objectives.

\(4\) To coordinate data management decisions, through a standing
sub‑working group on data management, to insure uniform FIRE data
characteristics.

\(5\) To certify, within 18 months after acquisition, those data
products from the Central Archive that will be transferred to the
permanent FIRE Data Archive.

> **[7.3 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE CENTRAL
> ARCHIVE]{.underline}**
>
> The FIRE Central Archive provides a centralized data holding and data
> cataloguing service in order to facilitate easy access to all FIRE
> data by all FIRE investigators. Since most of the satellite data are
> not collected directly by FIRE principal investigators, the Central
> Archive will also be responsible for the collection of the satellite
> data sets required for FIRE research from the relevant satellite
> operating agencies. The specific data management functions of the
> Central Archive are:

\(1\) To collect all reduced observations and data analysis products
submitted by individual principal investigators or groups of principal
investigators upon the request of the FIRE Working Groups.

\(2\) To collect all satellite data sets required for FIRE as specified
by the FIRE Working Groups.

\(3\) To provide for archival of all submitted data sets by producing
back‑up copies of all data and taking other necessary precautions to
insure the preservation of the FIRE data throughout the duration of
FIRE.

\(4\) To provide, upon request, copies of any data sets to FIRE
investigators (et affordable cost to investigators).

\(5\) To produce a catalog of the complete FIRE data holdings of the
archive and the individual principal investigators indicating the
current analysis statue of these data. The catalog entries should
provide information about the location ‑of the data holding, the
instrument(s) performing the observations, the resolution and areal
coverage of the data, the date, time and location of the observations,
and the format of the data.

\(6\) To update the catalog (item 5) every six months and to disseminate
it to FIRE investigators in both hard copy and electronic (on‑line
dial‑up data set) form.

\(7\) To transfer, on an annual basis, certified FIRE data from the
Central Archive to EDIS and/or other organizations for permanent
archive, called the FIRE Data Archive, and for access by the at‑large
scientific community.

\(8\) To publish a FIRE Data Archive Users Manual that describes the
contents of the FIRE Data Archive, data formats, data request
information, and other pertinent descriptive material.

> **[7.4 DATA MANAGEMENT RESPONSIBILITIES OF THE FIRE PROJECT
> OFFICE]{.underline}**
>
> The 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 liason among these different groups. The specific data
> management functions are:

\(1\) To provide liason 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 liason between the FIRE Central Archive and the
satellite and other data collecting agencies 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.

> **[7.5 FIRE DATA PROTOCOL]{.underline}**
>
> The FIRE Working Groups are responsible for the certification of data
> submitted to a permanent FIRE Data Archive. The certification process
> will normally take 18 months after acquisition. During the
> certification process period, a set of data protocol and publication
> \"round rules will be agreed upon and abided to by all FSET members as
> a condition of their participation in the FIRE working groups.
>
> **[7.6 FIRE DATA CHARACTERISTICS]{.underline}**
>
> There are three types of data acquisition activities in FIRE involving
> different combinations of observing platforms. There are four
> Intensive Field Programs (IFP) scheduled, two concentrating on cirrus
> and two concentrating on marine stratocumulus. These include
> collection of data from the surface, aircraft and satellites. FIRE
> observations are extended in space and time by the Extended Time
> Observations ‑ Limited Area (ETO‑LA), which include observations from
> the surface and satellites for the duration of FIRE. Finally, the
> larger scale is covered by Extended Time Observations ‑ Extended Area
> (ETO‑EA) from satellites. The FIRE data archive will contain the
> following types of information obtained from these different
> activities:
>
> \(1\) Reduced data‑‑observations converted to the physical quantity
> directly sensed by the instrument with quality control inspection and
> removal of bad data
>
> \(2\) Calibration, quality and navigation information‑‑describes the
> conversion to physical units, the conditions of observation and the
> location of the observation
>
> \(3\) Instrument documentation and data tape format description
>
> \(4\) Analysis products‑‑physical quantifies derived from the
> observations, including documentation on the analysis algorithm and
> any auxiliary data sets used in the analysis
>
> \(5\) Data for special case studies which have been arranged for
> intercomparison of multi‑platform observations
>
> \(6\) Data selected for special processing to facilitate model studies
>
> \(7\) Bibliography of FIRE publications
>
> The estimated data volumes for the different FIRE data acquisition
> activities are given below as a number of 6250 bpi density data tapes
> per year:
>
> IFP (assumes one IFP per year) 280
>
> ETO‑LA (four regions) 300
>
> ETO‑EA 20
>
> The complete ETO‑EA data set will reside in the ISCCP archive
> currently being acquired and maintained by NOAA. Only specific subsets
> of the NOAA archive will be transferred to the FIRE Central Archive as
> the specific needs and priorities of FIRE are identified by FIRE
> investigators and working groups. The twenty tape per year entry in
> the above table represents the estimated volume of the subsets to be
> acquired by the **FIRE Central** Archive and is less than
> one‑twentieth of the total ETO‑EA data volume which will reside in the
> ISCCP archive.
>
> **[8.0 FIRE DATA ACQUISITION PRIORITIES]{.underline}**
>
> The FIRE Implementation Plan describes six major data acquisition
> activities designed to support studies of cirrus and stratocumulus
> cloud systems and ultimately to parameterize these systems in general
> circulation models. These same data will support intercomparisons with
> ISCCP data.
>
> Each of the data acquisition activities is important to achieving the
> goals of FIRE; however, resource planning and the natural
> chronological sequence of tasks in pursuing a scientific investigation
> dictate the need for some relative prioritization of these tasks. The
> data acquisition activities and the relative priorities assigned to
> each by the FIRE Science Experiment Team are listed below.
>
> [OBSERVATIONAL COMPONENT PRIORITY]{.underline}
>
> (1 = highest)
>
> Cirrus Intensive Field Observations
>
> Phase I 1
>
> Extended Time ‑ Limited Area Observations 1

Stratocumulus Intensive Field Observations, Phase I 2

Cirrus Intensive Field Observations Phase II 3

Extended Time‑ Extended Area Observations 4

Stratocumulus Intensive Field Observations, Phase II 5

> Although many factors were considered in the assignment of the above
> priorities, the overriding considerations are summarized below.
>
> The Cirrus (Ci) Intensive Field Observations, Phase I was given the
> highest priority because relatively little previous work has been
> reported on this climatologically important cloud system; a lack of
> observations of Ci is often cited as the reason for the embryonic
> state of research on cirrus cloud systems. As a result there is much
> to be learned and much to be gained from this initial set of
> observations and subsequent studies. This same argument also applies
> to the Extended Time‑Limited Area observations of both cirrus and
> stratocumulus systems.
>
> The Stratocumulus (Sc) Intensive Field Observations, Phase I was given
> the second highest priority. Substantial progress in making Sc
> observations and in modeling Sc systems has allowed researchers to
> formulate very specific questions designed to elucidate the behavior
> of these systems. These observations will fill gaps in previous
> observational programs and address specific questions to promote an
> effective GCM parameterization of this phenomenon.
>
> The Ci Intensive Field Observations, Phase II was given the third
> highest priority. Because of the primitive state of our understanding
> of Ci cloud systems,‑a two stage Ci observation program is essential.
> Phase II will be designed around what is learned from the Phase I
> observations and subsequent model developments. The Phase II program
> will possibly shift its focus to more complex cirrus cloud systems and
> to a geographical region different from that of Cirrus, Phase I
> studies.
>
> The Extended Time ‑ Extended Area observations were given the fourth
> highest priority. This priority was assigned based on the fact that
> the data are being archived routinely by U. S. government agencies.
> Therefore, these data may be accessed from these independent archives
> at a later time. This is not meant to imply that the ET‑EA data set is
> expendable; it is not. It should be noted that a substantial satellite
> data archive will be accumulated in the Priority 1 activity, Extended
> Time ‑ Limited Area observation data set.
>
> The fifth priority was assigned to the Sc Intensive Field
> Observations, Phase II. While there will undoubtedly be much to gain
> by conducting these observations, the FSET assigned higher relative
> priorities to other components to bring about a parity in the
> understanding of cirrus and stratocumulus cloud systems and in their
> parameterizations.
>
> The FSET emphasizes that all FIRE observational components are
> important to the attainment of FIRE goals. Means of acquiring the
> resources for all components of FIRE must be actively pursued. The
> priorities assigned above are offered only in the context of assisting
> the formulation of a plan to accomplish [all]{.underline} of FIRE\'s
> goals.
>
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upside-down.‑ [J. Atmos. Sci., 37]{.underline}, 125‑130.

Reynolds, D. W. and T. H. Vonder Haar, 1977: A bi‑spectral method for
cloud parameter determination. [Mon. Wea. Rev., 105]{.underline}
446‑457.

Roach, W. T., R. Brown, S. J. Caughey, B. A. Crease, and A. Slingo,
1982: A field study of nocturnal stratocumulus: I. Mean structure and
budgets. [Quart. J. Roy. Met. Soc., 108]{.underline}, 103‑123.

Rosenthal, J. S., 1983: Some perspectives in establishing an atmospheric
transmission facility based on experiences at San Nicolas Island.
[Pacific Missile Test Center]{.underline}. Rept. No. TP 000009, 64 pp.

Rossow, W. B., F. Mosher, E. Kinsella, A. Arking, M. Desbois, E.
Harrison, P. Minnis, E. Ruprecht, G. Seze, C. Simmer and E. Smith, 1985:
ISCCP‑cloud algorithm intercomparison. [J. Climate Appl.
Meteor.]{.underline} (in press).

Schmetz, J., 1984: On the parameterization of the radiative properties
of broken clouds [Tellus, 36]{.underline}, 417‑432.

Short, D. A. and J. M. Wallace, 1980: Satellite‑inferred
morning‑to-evening cloudiness changes. [Mon. Wea. Rev.,
108]{.underline}, 1160‑1169.

Slingo, A., S. Nicholls, and J. Schmetz, 1982: Aircraft observations of
marine stratocumulus during JASIN. [Quart. J. Roy. Meteor.
Soc.]{.underline}, [108]{.underline}, 833‑856.

Sommeria, G. and J. W. Deardorff, 1977: Subgrid scale condensation in
models of non‑precipitating clouds. [J. Atmos. Sci., 34]{.underline}
345‑355.

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LANDSAT data. [J. Climate Appl. Meteor.]{.underline} (in press).

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large drops on cloud absorption. Part I: Parcel models. [J. Atmos.
Sci]{.underline}., [41]{.underline}, 1336‑1355.

> **APPENDIX A**
>
> DESCRIPTION OF NASA ER‑2 INSTRUMENTS
>
> [1. Cloud Lidar System]{.underline} (See also Section 5.151)
>
> A unique element of the proposed radiation investigation is a lidar
> instrument which provided absolute range resolved measurements to
> complement passive observations. The lidar system operated at dual
> wavelengths and dual polarization. Backscattered return signals are
> digitized with a 7.S m vertical range resolution and, at the nominal
> pule repetition rate of 3.47 Hz, a return signal is acquired every 50
> m of horizontal distance. The system characteristics are summarized in
> Table A.1. The lidar system has been flown on the NASA WB‑57F aircraft
> and is currently integrated to and operational from the NASA ER‑2
> aircraft. The lidar system is mounted in the forward section of an
> ER‑2 superpod which also contains the Multispectral Cloud Radiometer
> (MCR). Support systems for both instruments include the data system
> and tape recorder, mounting facilities, power system, and navigation
> and timing information. The co‑location in a single pod permits a
> direct optical alignment and time synchronization between the lidar
> measurements and the cloud radiometer nadir pixels. A full description
> of the CIS is given by Spinhirne [et al]{.underline}. (1982).
> Representative results from an earlier field program are described by
> Spinhirne [et al.]{.underline} (1983).
>
> 2\. [Multispectral Cloud Radiometer]{.underline}

The Multispectral Cloud Radiometer is a seven‑channel scanning
radiometer whose spectral characteristics are summarized in Table A.2.
The spectral charnels were specifically selected from remote sensing of
cloud properties. The instrument was designed so that it scans through
nadir in a plane perpendicular to the velocity vector of the aircraft,
where the scan extends up to 45¡ on either side of nadir. All channels
are sampled simultaneously in order to permit a high degree of
registration among wavelengths.

> Table A.1. ER‑2 LIDAR SYSTEM CHARACTERISTICS
>
> [Transmitter]{.underline}
>
> Laser Nd: YAG, I + II
>
> Wavelength 1.064, 0.532 µm
>
> Pulse energy 100, 50 mJ
>
> Pulse repetition rate 3.47 Hz
>
> Beam divergence l mrad
>
> [Receiver]{.underline}
>
> Telescope Cassegrainian
>
> Aperature 18 cm
>
> Dectors 0.532 µm PMT, dual polarization
>
> 1.064 µm APD
>
> Filters 1 um FWHM
>
> [Data Acquisition]{.underline}
>
> Pre‑amplifiers 40 MHz, 4 decade logarithmic
>
> Digitizer 8 bit, 20 MHz
>
> Data words 2048 dual charnel
>
> The optical system of the cloud radiometer is of the non‑dispersive
> filter-dichroic configuration. The optical path consists of a 12.38 by
> 17.5 cm scan mirror, canted 45¡ to the long axis of the instrument; a
> 12.38 cm Dall‑Kirkham (Cassegrainian) telescope; ant a complex
> configuration of dichroic filters, mirrors, lenses, filters and a
> single prism. The instantaneous field of view of the radiometer is 7
> mrad, resulting in a \"round resolution at nadir of 133 m. A more
> complete description of the MCR is given by Curran [et
> al.]{.underline} (1983).
>
> [Table A.2. DESCRIPTION OF SPECTRAL CHANNELS OF MULTISPECTRAL CLOUD
> RADIOMETER.]{.underline}
>
> Central Central Spectral
>
> Channel wavenumber wavenumber resolution Principal Function
>
> number (cm-l) (Um) (Um)
>
> 1 13271 0.75350 0.00108 Optical thickness
>
> 2 13146 0.76070 0.00121 O~2~ A‑band altimetry, volume
>
> scattering coefficient
>
> 3 13099 0.76339 0.00112 O~2~ A‑band altimetry, volume
>
> scattering coefficient
>
> 4 6093 1.6412 0.0641 Cloud phase, particle size
>
> 5 5836 1.7136 0.0457 Cloud phase, particle size
>
> 6 4630 2.1599 0.0894 Cloud phase, particle size
>
> 7 932 10.73 0.90 Temperature
>
> 3\. [Thematic Mapper Simulator]{.underline}
>
> The Thematic Mapper Simulator is a multispectral scanner which may be
> flown in the Q‑bay of the ER‑2 aircraft, and which simulates the
> spatial and spectral characteristics of the Landsat‑4 Thematic Mapper
> bands. The Advanced Microwave Moisture Sounder (AMMS), which has flown
> in the peat in the aircraft Q‑bay, is not being proposed as part of
> the present study. The U‑2 modified TMS will be the Q‑bay instrument
> for our study. This version of the TMS is available with a 11 µm split
> window charnel and a 6.7 µm charnel. For the proposed experiment, the
> 6.7 µm charnel will be replaced with a 3.7 µm charnel. The TMS will
> then serve the function of a high resolution imager with bands similar
> to the AVHRR satellite instrument. The characteristics of the TMS as
> configured for the experiment are listed in Table A.3.
>
> ![](media/image4.wmf){width="7.777777777777778in" height="5.0in"}
>
> **APPENDIX B**
>
> DESCRIPTION OF UW C131‑A INSTRUMENTS
>
> 1\. [The Cloud Absorption Radiometer]{.underline}
>
> The Cloud Absorption Radiometer (CAR) is a thirteen‑channel scanning
> radiometer whose spectral characteristics are summarized in Table B.
> l. All of the wavelengths were selected to avoid the molecular
> absorption bands, so that the anticipated absorption would be due
> solely to water or ice particles and aerosol particles. The instrument
> scans in a vertical plane from 5¡ before zenith to 5¡ peat nadir (190¡
> aperture). This permits observations of the internal scattered
> radiation field [within]{.underline} clouds in both zenith and nadir
> directions with as much as a 5¡ aircraft roll.
>
> The optical system of the CAR is of the non‑dispersive, filter
> dichroic configuration (Fig. 4). The optical path consists of a 12.4
> by 17.5 cm scan mirror, canted 45¡ to the long axis of the instrument,
> a 12.4 cm Dall‑Kirkham (Cassegrainian) telescope, and a complex
> configuration of dichroic filters, collimating lenses, mirrors, beam
> splitters, filters and a filter wheel. The filter wheel contains
> optical charnels 8 through 13. Every fourth scan the filter wheel
> rotates to measure a new wavelength interval. With this configuration
> the first seven channels are continuously and simultaneously sampled,
> while the eighth registered charnel is selected from among the six
> charnels on the filter wheel. The instantaneous field of view of the
> radiometer is 1¡ (17.5 mrad). A more complete description of the
> instrument as well as initial observations are given by King et al.
> (1985).
>
> 2\. The University of Washington\'s Airborne Research Facility
>
> For the past fourteen years the UW has utilized a B‑23 aircraft for
> cloud and aerosol research. The CAR was integrated into this facility
> in 1983, and it was aboard this aircraft that the CAR was
> flight‑tested and the first measurements with the CAR were obtained.
>
> The B‑23 has recently been replaced by a Convair‑131A. This aircraft
> is now being equipped for clout ant aerosol research and the CAR is
> being mounted onto it. The instrumentation on the C‑131A can be
> sub-divided into the following broad categories: navigational and
> flight characteristics, meteorological (including radiation), cloud
> physics, aerosol, cloud and atmospheric chemistry and data processing
> and display.
>
> ![](media/image5.wmf){width="7.958333333333333in"
> height="4.861111111111111in"}
>
> \(a\) [Aerosol]{.underline}
>
> Aerosol in the size range of 0.01‑45 µm are measured using several
> instruments that are all fed from a common batch sampler of air aboard
> the aircraft. The batch sampler consists of a stainless steel cylinder
> 90 liter in volume and 1.5 m high which has a freely‑floating piston.
> Electric valves control the filling and emptying of ambient air
> samples into and from this cylinder. Ram air pressure forces the
> piston upwards, filling the cylinder with ambient air ant closing the
> air inlet valve. Since the piston offers negligible resistance to the
> in‑rushing air (the pressure above the piston is reduced), sampling of
> particles is close to isokinetic.
>
> After the cylinder is full, air from its base pesses into the various
> instruments. The instruments size the particles after any water on
> them has been evaporated by passage through a diffusion drier. Hence,
> these instruments provide the dry size spectra of particles from 0.01
> to 11 µm. The Royco 245, on the other hand, measures particles in the
> size range 2 to 45 µm without any significant drying.
>
> When such measurements are made in clouds, the particles that enter
> the diffusion drier, and are subsequently sized, are primarily cloud
> interstitial aerosol. This is because the cloud drops are removed by a
> cyclone which is switched into the first bend in the air inlet
> sampling tube for interstitial sampling. (The large bag sampler
> employed for filter sampling, on the other hand, removes cloud
> droplets greater than \~5 µm radius via impaction.)
>
> This system has been successfully used to measure cloud interstitial
> aerosol for several years (Radke, 1983).
>
> \(b\) [Cloud physics]{.underline}
>
> The critical questions which the cloud physics instrumentation must
> resolve are 1) what is the liquid water content (LWC) and droplet size
> distribution and 2) does the cloud include hydrometeors and, if BO, in
> what phase?
>
> We measure the LWC by three independent techniques, The
> Johnson‑Williams (J-W) hot wire, a new King/CSIRO hot wire and a PMS
> FSSP. The FSSP gives the droplet size distribution and the LWC is
> calculated. The FSSP and J‑W values of LWC have historically been in
> excellent agreement. We have had no flight experience with the King
> probe, but it is believed to have even less drift and error than the
> J‑W.
>
> The nature of the hydrometeors and the concentrations of ice are
> determine from the 1‑D and 2‑D PMS Cloud (C) and precipitation (P)
> probes and the UW ice particle counter. These five probes provide both
> automatic and visual confirmation of the presence of ice particles and
> hydrometeors. The OAP‑2D C and P probes provide visual identification
> of crystal habit and some indication of crystal riming.
>
> The aircraft is also equipped with bulk cloud water samplers. We
> intend to filter the cloud water and analyze the filter optically, as
> described by Clarke (1982), as another approach to examining the
> cloud\'s optical absorption characteristics.
>
> **APPENDIX C**
>
> DESCRIPTION OF NO M WP‑3D ORION INSTRUMENTATION
>
> The Lockheed WP‑3D Orion (hereafter, the \"P3\") is a long‑range
> turboprop aircraft, originally developed for Naval submarine
> surveillance work, that has been equipped by NOAA/0AO for
> meteorological research. As configured for the Stratocumulus
> Subprogram of FIRE, the P3 will cruise (et high altitude for ferrys)
> at \~350 knots; the nominal operating speed for boundary‑layer
> turbulence work is 200 knots (100 m s^‑1^) ± 10%. Depending on load
> factors and altitude, the P3 can remain aloft for about 9 hours for a
> maximum‑range mission. The instruments to be used in FIRE, listed
> below, will allow 8‑10 scientists, plus the NOAA/OAO crew, to
> participate. The instrumentation is moat conveniently grouped by
> response time.
>
> 1\. Standard Flight Instruments (1 Hz sampling)
>
> The main flight data recording computer records standard flight
> variables and some custom instruments at 1 sample per second. These
> are given in fable C.1. In addition, several other derived variables
> (for example, potential temperature, water vapor mixing ratio and air
> density) are calculated and recorded. \[Some post‑flight data
> reduction is necessary to convert the radiometric observations to SI
> units, and post‑flight calibration corrections are sometimes
> necessary.\] A ten‑hour mission can generally be reduced to one
> 9‑track high‑density tape.
>
> 2\. Gust probe instruments (nominal 20 Hz sampling)
>
> The noseboom mounted gust‑probe turbulence system is maintained by
> NOAA/ ERL/ESG, and contracted to OAO by individual investigators. The
> gust probe instruments include vanes to sense the three wind
> components, a bead thermistor for temperature fluctuations, and a
> microwave refractometer for humidity. The INS is also used, at a
> longer sampling rate, to stabilize the wind measurement. The
> gust‑probe sensors are sampled first at 80 Hz, then averaged and
> processed to 20 Hz, producing a nominal spatial resolution of 5 m. The
> data are reduced to standard nine‑track tape format at NOAA/ERC/ESG.
> The data volume depends on the amount of time during a mission during
> which the gust probe is \"on\"; for some missions three high‑density
> tapes have been produced.
>
> ![](media/image6.wmf){width="7.472222222222222in"
> height="8.583333333333334in"}
>
> 3\. Knollenberg PMS
>
> The fastest-responding instruments on the P3 are contained in the
> cloud microphysics package, consisting of FSSP and 2‑D systems from
> PMS. This system has a dedicated recording system that operates only
> when the system encounters cloud drops large enough to sense. This is
> a standard PMS system described extensively elsewhere.
>
> 4\. Miscellaneous
>
> The P3 also has Omega dropwindsonde (ODW) and airborne expendable
> bathythermograph (AXBT) capability. ODW data are recorded on a
> separate (cassette) recorder and processed by NOAA/ERL/HRD in Miami,
> and the AXBT data is recorded by the main flight computer. Three
> AXBT's can be recorded simultaneously.
>
> In addition to the radar and flight radars, the P3 can be equipped
> with a Doppler radar (for rainfall data) with a dedicated computer.
>
> **APPENDIX D**
>
> DESCRIPTION OF NASA CV‑990 INSTRUMENTS
>
> (See also Section 5.152)
>
> 1\. [Airborne Lidar System]{.underline}
>
> The CV‑990 will carry a lidar system composed of two independent
> lidars, a ruby laser (λ = 0.6943 µm), and a ND: YAG laser (λ 1.06 µm)
> One laser is uplooking (zenith) while the other is downlooking
> (nadir). The lasers are interchangeable, so that either can be used on
> the uplooking or downlooking mode. In addition, their second harmonic
> (doubled frequency) can be used simultaneously making each a
> two‑wavelength lidar. Each lidar has its own computer‑driver data
> acquisition system, capable of handling two‑wavelength or
> two‑polarization data. Real‑time profile and intensity modulated
> diaplays are available, to assist decision\--making in the field. The
> lidar measurements will provide cloud top height, cloud thickness (for
> optical depths leas than about 3, such as over‑lying cirrus), and
> cloud optical depth for thin clouds.
>
> 2\. [Flux sensors]{.underline}
>
> The CV‑990 will also carry a newly developed 2π sr flux sensor for
> longwave radiative flux density measurements. This instrument, to be
> mounted on the wing tip of the aircraft, will be able to be rapidly
> flipped between an uplooking and downlooking mode such that net
> infrared flux measurements can be made above the clouds with a single
> instrument. This instrument has not yet been constructed. In addition,
> 2 shortwave flat plate flux sensors will be mounted on the fuselage
> one in an uplooking mode and one in a down‑looking mode. A
> nadir‑viewing PRT‑5 infrared radiometer (9.5‑11.5 µm) will d so be
> flown.
>
> 3\. [Spectral Scanning Radiometer]{.underline}
>
> Either one of two possible spectrally scanning radiometers will be
> flown
>
> on the CV‑990. One of these radiometers, developed at CSIRO, was
> recently flow on the CSIRO Focker Friendship aircraft. It i6 a
> nadir‑viewing instrument with circular variable filter capable of
> rapidly scanning in wavelength from 0.5t2.3 um in order to provide a
> detailed spectra of reflected radiation. It could be modified to look
> upward as well. The other possible instrument is an Israeli instrument
> recently acquired by CSU. It scans in a vertical plane from zenith to
> nadir and also contains a circular variable filter. It is capable of
> observing spectral radiance from .35 to 20 µm using modular detectors.
> Neither of these instruments has previously been integrated on the
> CV‑990.
>
> 4\. [Bugeye Radiometer]{.underline}
>
> This instrument is a multi‑angle fixed field of view instrument which
> measures the reflected intensity (radiance) in 1 wavelength band
> (0.3‑0.9 µm). This instrument has flown during MONEX.
>
> 5\. [Sunphotometer]{.underline}
>
> The CV‑990 ,has recently flown with a sunphotometer capable of
> measuring the spectral optical depth of aerosols and thin cirrus
> clouds above the aircraft. The sunphotometer is mounted externally to
> the airframe and has automatic suntracking capability.
>
> 6\. [Ancillary data]{.underline}
>
> The CV‑990 also carries a 70 mm camera, a Rosemont 102 air‑temperature
> probe, and a General Eastern 1011 dew/frost point hygrometer.
>
> **APPENDIX E**
>
> DESCRIPTION OF NCAR KING AIR INSTRUMENTATION
>
> The NCAR Ring Air is a twin‑engine turboprop aircraft. It can remain
> aloft for 4‑5 hours at 75 m sec^‑l^. Its range with full fuel ant
> optimum altitude is 3300 km. It carries the instruments listed in
> Table E.1. Further information is given by Phillips and Friesen
> (1984).

![](media/image7.wmf){width="7.319444444444445in"
height="4.333333333333333in"}

> **APPENDIX F**
>
> SURFACE MEASUREMENTS ON SAN NICOLAS ISLAND
>
> 1\. Penn State Facilities
>
> The Department of Meteorology of the Pennsylvania State University
> maintains for research use a comprehensive array of micrometeorology
> sensors, processing and logging systems suitable for complete energy
> budget or surface layer turbulence analysis. Radiation sensors and
> calibration standards are as follows:
>
> a\. Sensors
>
> Precision Spectral Pyranometers
>
> 2 each: 0295‑3 µn
>
> 0.395‑3 µm
>
> 0.695‑3 µm
>
> Pyranometers
>
> 2 each: Epply Model 8‑48
>
> Pyrgeometers
>
> 2 each: 4‑60 µm
>
> Si cell Radiometer
>
> Li‑Cor Pyranometer
>
> Net Radiometers
>
> 2 each: Swissteco S‑1
>
> b\. Standard
>
> Linke-Ruessner Pyrheliometer
>
> The department also has a system for combined
> wind‑temperature‑humidity profiling using remote sensors, and a dual
> charnel (20 and 30 GHz) water vapor/ liquid radiometer, and a
> six‑channel (60 Hz) radiometer for temperature profiles. A water‑vapor
> radiometer is planned for FY86 funds, and the system will be
> operational in FY87. The first major field deployment of the
> water‑vapor system will be the FIRE project at SNI. This equipment
> will be used during the intensive phase only.
>
> 2\. Naval Postgraduate School Facilities
>
> METEOROLOGICAL MEASUREMENTS/OBSERVATION
>
> Frequency of
>
> [Measurements Sensor/System Measurement]{.underline}
>
> Radiation (down Long/short wave Continuous
>
> and reflected) radiometers
>
> Sea Surface Temp‑ Floating thermister Continuous
>
> erature
>
> Mean surface layer:
>
> Wind (speed, Cup anemometer Continuous
>
> direction) vane
>
> Temperature Resistance thermo‑ Continuous
>
> meter
>
> Humidity Dew cell Continuous
>
> (cool mirror)
>
> Aerosols\* Optical Counters Continuous
>
> (.3 to 300)
>
> Turbulent Kinetic\* Hot film/ Continuous
>
> Energy Dissipation Miniature Cups
>
> Rate
>
> Inversion Height, Doppler Sodar Continuous
>
> Turbulence
>
> Temperature, Humidity, Buekers 2 to 8/day
>
> and Wind Profiles\* Radiosonde
>
> Sky and Sea\* Visual observations Hourly
>
> Conditions
>
> \* Primarily for intensive data periods

**APPENDIX G**

NOAA/WPL Ground‑Based Remote Sensors

> During FIRE IFO\'s, ground‑based sensor systems will play an important
> role in obtaining both in situ and remote measurements for satellite
> comparison and validation as well as for completing the physical
> picture of meteorological conditions that occur. The second role
> applies especially to the NOAA/ERL/Wave Propagation Laboratory\'s
> ground‑based remote sensor systems. These are described briefly in the
> following sections. The first three systems are described in more
> detail in the May, 1983 issue of [Journal of Climate and Applied
> Meteorology]{.underline} in articles by Pasqualucci et al., Hogg et
> al. (p.789) and Hogg et al. (p. 807), respectively, and the lidar
> system capabilities are described fully in articles by Hall et al. and
> Post et al. in the 1 August 1984 issue of [Applied
> Optics.]{.underline}
>
> i\) K~a~ ‑band Doppler radar.
>
> Operating at a somewhat shorter wavelength than conventional
> meteorological radars allows the Ka ‑band radar to detect the presence
> of particles smaller than raindrops. Although this causes strong
> attenuation in the presence of heavy precipitation, motions in
> non‑precipitating clouds can be observed by the detection of
> large‑non-precipitating cloud droplets. This will be a valuable (and
> in fact the only) tool during the FIRE stratocumulus IFO\'s for
> observing mesoscale divergence fields.
>
> Table G‑1
>
> Description of NOAA/WPL Ka‑band radar
>
> The following table summarizes the operating characteristics of the
> WPL
>
> K~a~ ‑band Doppler radar:
>
> wavelength 8.66 mm (35 GHz)
>
> peak power 100.00 KW
>
> pulse duration .30 µs
>
> average power 50.00 w
>
> antenna diameter 1.2 m
>
> system gain 48.00 dB
>
> beamwidth 0.5 deg.
>
> minimum detectable reflectivity at 10 km ‑26.00 dBz
>
> The computer controlled antenna can rotate continuously in azimuth at
> fixed elevation (PPI mode) to provide continuous profiles of the three
> wind components, turbulent fluxes and variances, and the height of the
> echo top. It can also scan in elevation through the zenith at fixed
> azimuth (RHI mode) to provide a vertical cross‑section of the echo. A
> wide variety of other scan options is available. The radar has a dual
> charnel receiver for measurements of linear or circuler depolarization
> ratio. The minimum range for reliable velocity measurements is about
> 200 m and the maximum range is adjustable by controlling the radar
> pulsing sequence. Nominal vertical resolution can be as small as 40 m.
> A puise‑pair algorithm has been implemented in a real time digital
> processor which removes the DC spectral fine for partial \"round
> clutter suppression. Other modes of operation allow time‑series data
> to be recorded for off‑line spectral processing.
>
> ii\) Steerable Microwave Radiometer
>
> The two‑channel microwave radiometer is designed to sense remotely the
> integrated amounts of liquid water and water vapor in the atmospheric
> column (either vertical or slant patin). This instrument will be used
> during the stratocumulus IFO\'s to provide time series estimates of
> cloua water and atmospheric water vapor. Steerability allows
> slant‑path measurements to be made. Essential characteristics are
> listed in Table G‑2.
>
> Table G‑2
>
> Microwave Radiometer Characteristics
>
> Radiometer 1 Radiometer 2
>
> Center wavelength 14.7 mm (20.6 GHz) 9.59 mm (31.6 GHz)
>
> Bandwidth 1.O GHz 1.O GHz
>
> Receiver Noise Temp. 680° K 725° K
>
> Sensitivity 0.26° K 0.26° K
>
> The system can operate in three modes: 1) fixed azimuth and elevation
> angles; 2) continuous 360 degree azimuth scans at fixed elevations;
> and 3) variable azimuth and elevation scans. The sampling rate for
> each mode is 10 Hz and averaging times are ten seconds for mode 1 and
> one second for modes 2 and 3.
>
> iii\) VHF Doppler Radar
>
> Large aperature (for sensivity) radar systems of appropriate
> wavelength are capable of detecting backscatter from atmospheric
> turbulence in optically clear air. The WPL 6‑m (VHF) Doppler system is
> designed to provide vertical profiles of the three‑di\'mensional wind
> vector. This instrument will be an important comportent of the cirrus
> IFO\'s for vertical motion studies. Combined with the lidar system
> (below), it will enable mapping of the relationships between
> cloud‑scale and large‑scale motions. The VHF radar characteristics are
> given in Table G‑3.
>
> Table G‑3
>
> VHF Radar Characteristics
>
> Wavelength 6.o m (49.9 MHz)
>
> Pulse Width 16.0 µs
>
> Pulse Repetition Period 2.4 ms
>
> Peak Power 10.0 kW
>
> Range Spacing 1500 m (10 ps)
>
> Levels Observed 13
>
> Minimum Range \~2 km above ground
>
> The radar\'s capability for vertical wind measurements would be
> augmented considerably by an array of three (or more) radars. Using
> such an arrangement, area‑ and time‑averaged divergences coula be
> compared with point measurements. It is worth remarking here that the
> NOAA/WPL wind profiles is one comportent of a complete profiler system
> that also obtains temperature and humidity profiles. These are also
> described in the second of the articles by Hogg et al. ‑
>
> iv\) IR Doppler Lidar
>
> The 10.6 pm pulsed infrared Doppler lidar system is capable of
> detecting atmospheric aerosols, winds and cirrus cloua particles.
> Recently the system\'s capabilities have been upgraded to include dual
> polarization sensitivity. Since cirrus ice particles are frequently
> transparent to solar radiation, the IR lidar is an important part of
> the cirrus program. System characteristics are listed in Table G‑4.
>
> Table G‑4
>
> IR Doppler Lidar Characteristics
>
> Wavelength 10.6 µm
>
> Power per Pulse 0.25 J
>
> Pulse Repetition Rate 1 ‑ 100 Hzµ
>
> Pulse Duration 1 ‑ 4 us
>
> Trans./Recv. Telescope 0.25 m Aperture (off axis)
>
> Scan Capability Alt‑Azimuth
>
> Minimum Range 0.5 km
>
> Maximum Range 20+ km
>
> Depending on the pulse repetition rate, the ranging can be as small as
> about 200 m. The potential for polarization studies has great
> significance for FIRE as it will give information about cirrus
> particle shapes and/or orientation.
>
> **APPENDIX H**
>
> GLOSSARY OF ACRONYMS
>
> AVHRR Advanced Very High Resolution Radiometer
>
> CTBL Cloud‑Topped Boundary Layer
>
> EDIS Environmental Data Information Service
>
> ERBE Earth Radiation Budget Experiment
>
> ERBS Earth Radiation Budget System
>
> ETO Extended Time Observations
>
> ETO‑EA Extended Time Observations ‑ Extended Area
>
> ETO‑LA Extended Time Observations ‑ Limited Area
>
> FIRE First ISCCP Regional Experiment
>
> FSET FIRE Science Experiment Team
>
> GAC Global Area Coverage
>
> GCM General Circulation Model
>
> GOES Geostationary Operational Environmental Satellite
>
> HIRS High Resolution Infrared Sounder
>
> IFO Intensive Field Observations
>
> ISCCP International Satellite Cloud Climatology Project
>
> LAC Local Area Coverage
>
> LANDSAT TM LANDSAT Thematic Mapper
>
> NASA National Aeronautics and Space Administration
>
> NESDIS National Environmental Satellite Data and Information
>
> Service
>
> NMC National Meteorological Center
>
> NOAA National Oceanic and Atmospheric Administration
>
> NOAA/OAO NOAA/Office of Aircraft Operations
>
> NRL Naval Research Laboratory
>
> NWS National Weather Service
>
> PROFS Prototype Regional Observing and Forecasting Service
>
> PMS Particle Measuring Systems, Inc.
>
> SAGE Stratospheric Aerosol and Gas Experiment
>
> SNI San Nicolas Island
>
> TOVS TIROS Operational Vertical Sounder
>
> VAS Vertical Atmospheric Sounder
>
> WPL Wave Propagation Laboratory
>
> **APPENDIX I**
>
> Schedule of Significant FIRE EVENTS
>
> [Date Location Activity]{.underline}
>
> 1 June, 1985 Submit FIRE Implementation Plan
>
> 1 September, 1985 Form Initial Task Groups
>
> 1 November, 1985 Complete Cirrus Observations Plan
>
> Complete Extended Time
>
> Observations Plan
>
> 1 January, 1986 Begin Extended Time Observations
>
> 1 June, 1986 Complete Marine Stratocumulus
>
> Observations Plan
>
> 1 November, 1986 Cirrus Intensive Field Observations
>
> 1 January, 1987 Fort Collins, CO FSET REVIEW MEETING
>
> 1 June, 1987 Marine Stratocumulus Intensive
>
> Field Observations
>
> 1 January, 1988 Hampton, VA FSET REVIEW MEETING
>
> 1 March, 1988 Cirrus Intensive Field Observations
>
> 1 January, 1989 Washington, D. C. FSET REVIEW MEETING
>
> 1 June, 1989 Marine Stratocumulus Intensive
>
> Field Observations
>
> 1 January, 1990 Washington, D. C. FSET REVIEW MEETING
>
> In addition, each field mission will have planning meetings
> approximately twelve months and six months before each mission, a
> preliminary data workshop three months after each mission, and a
> review of results nine months after each mission. These meetings will
> be coordinated and combined as much as possible with other mission
> activities. For example, preliminary estimates indicate that all
> mission planning/reviews, field missions, and FSET reviews can be
> consolidated into thirteen meetings over the next six years.