<table style="width:100%;">
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</colgroup>
<tbody>
<tr class="odd">
<td colspan="5"><img src="media/image1.jpeg"
style="width:0.675in;height:0.58264in" /></td>
<td colspan="8"><p><u>Proposal Cover Page</u></p>
<p>Date: 6/12/2007</p></td>
<td colspan="4"><p>NNH07ZDA001N-ARCTAS</p>
<p>Proposal Number:</p>
<p>(Leave blank for NASA use)</p></td>
</tr>
<tr class="even">
<td colspan="6">Name of Submitting Institution:</td>
<td colspan="6">Bay Area Environmental Research Institute</td>
<td colspan="3"><strong>Congressional District:</strong></td>
<td colspan="2">California #1</td>
</tr>
<tr class="odd">
<td><strong>Proposal Title:</strong></td>
<td colspan="16"><strong>Airborne sunphotometer measurements of aerosols
and water vapor to study aerosol radiative forcing and boreal forest
fires in ARCTAS</strong></td>
</tr>
<tr class="even">
<td colspan="17"><p><strong><u>Certification of Compliance with
Applicable Executive Orders and US Code</u></strong></p>
<p>By submitting the proposal identified in this <em>Cover
Sheet/Proposal Summary</em> in response to this Research Announcement,
the Authorizing Official of the proposing institution (or the individual
proposer if there is no proposing institution) as identified below:</p>
<ul>
<li><p>certifies that the statements made in this proposal are true and
complete to the best of his/her knowledge;</p></li>
<li><p>agrees to accept the obligations to comply with NASA award terms
and conditions if an award is made as a result of this proposal;
and</p></li>
<li><p>confirms compliance with all provisions, rules, and stipulations
set forth in the two Certifications contained in this NRA [namely,
(i<em>) Assurance of Compliance with the NASA Regulations Pursuant to
Nondiscrimination in Federally Assisted Programs</em>, <em>and (ii)
Certifications, Disclosures, And Assurances Regarding Lobbying and
Debarment &amp; Suspension</em>]<em>.</em></p></li>
</ul>
<p>Willful provision of false information in this proposal and/or its
supporting documents, or in reports required under an ensuing award, is
a criminal offense (U.S. Code, Title 18, Section 1001).</p>
<p><strong><u>NASA PROCEDURE FOR HANDLING PROPOSALS</u></strong></p>
<p>This proposal shall be used and disclosed for evaluation purposes
only, and a copy of this Government notice shall be applied to any
reproduction or abstract thereof. Any authorized restrictive notices
that the submitter places on this proposal shall also be strictly
complied with. Disclosure of this proposal for any reason outside the
Government evaluation purposes shall be made only to the extent
authorized by the Government.</p></td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Principal Investigator Name:</strong></td>
<td colspan="5">Jens Redemann</td>
<td colspan="4"><strong>Authorized Institutional Official
Name:</strong></td>
<td colspan="4">Mark T. Sittloh</td>
</tr>
<tr class="even">
<td colspan="4"><strong>Organization:</strong></td>
<td colspan="5">Bay Area Environmental Research (BAER) Institute</td>
<td colspan="4"><strong>Organization:</strong></td>
<td colspan="4">Bay Area Environmental Research Institute</td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Mailing Address:</strong></td>
<td colspan="5">4742 Suffolk Ct.</td>
<td colspan="4"><strong>Mailing Address</strong></td>
<td colspan="4">560 3<sup>rd</sup> St. West</td>
</tr>
<tr class="even">
<td colspan="4"><strong>City, State Zip:</strong></td>
<td colspan="5">Ventura, CA 93003</td>
<td colspan="4"><strong>City, State Zip:</strong></td>
<td colspan="4">Sonoma, CA 95476-6502</td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Telephone Number:</strong></td>
<td colspan="5">(805) 658-2637</td>
<td colspan="4"><strong>Telephone Number:</strong></td>
<td colspan="4">(707) 938-9387</td>
</tr>
<tr class="even">
<td colspan="4"><strong>Fax Number:</strong></td>
<td colspan="5">(805) 658-2637</td>
<td colspan="4"><strong>Fax Number:</strong></td>
<td colspan="4">(707) 938-3984</td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Email Address:</strong></td>
<td colspan="5"><a
href="mailto:jredemann@mail.arc.nasa.gov">jredemann@mail.arc.nasa.gov</a></td>
<td colspan="4"><strong>Email Address:</strong></td>
<td colspan="4"><u>msittloh@baeri.org</u></td>
</tr>
<tr class="even">
<td colspan="4"><strong>Principal Investigator Signature:</strong></td>
<td colspan="5"></td>
<td colspan="4"><strong>Authorized Institutional Official
Signature:</strong></td>
<td colspan="4"></td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Date:</strong></td>
<td colspan="5"></td>
<td colspan="4"><strong>Date:</strong></td>
<td colspan="4"></td>
</tr>
<tr class="even">
<td colspan="17"><strong>Co-Investigators:</strong></td>
</tr>
<tr class="odd">
<td colspan="2"><strong>Name</strong></td>
<td colspan="5"><strong>Telephone</strong></td>
<td colspan="4"><strong>Email</strong></td>
<td colspan="2"><strong>Institution</strong></td>
<td colspan="4"><strong>Address</strong></td>
</tr>
<tr class="even">
<td colspan="2">Philip B. Russell</td>
<td colspan="5">650-604-5404</td>
<td colspan="4">Philip.B.Russell@nasa.gov</td>
<td colspan="3">NASA Ames</td>
<td colspan="3">Moffett Field, CA 94035</td>
</tr>
<tr class="odd">
<td colspan="2"></td>
<td colspan="5"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="3"></td>
</tr>
<tr class="even">
<td colspan="3"><strong>Budget:</strong></td>
<td colspan="5"></td>
<td colspan="2"><strong>BAER</strong></td>
<td colspan="6"><strong>NASA Ames</strong></td>
<td><strong>Total</strong></td>
</tr>
<tr class="odd">
<td colspan="8">Year 1 (Oct. 2007 – Sep. 2008):</td>
<td colspan="2"></td>
<td colspan="6"></td>
<td></td>
</tr>
<tr class="even">
<td colspan="8">Year 2 (Oct. 2008 – Sep. 2009):</td>
<td colspan="2"></td>
<td colspan="6"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="8">Year 3 (Oct. 2009 – Sep. 2010):</td>
<td colspan="2"></td>
<td colspan="6"></td>
<td></td>
</tr>
<tr class="even">
<td colspan="8"><strong>Total:</strong></td>
<td colspan="2"></td>
<td colspan="6"></td>
<td></td>
</tr>
</tbody>
</table>

**TABLE OF CONTENTS**

[ACRONYMS iii](#acronyms)

[1 ABSTRACT / EXECUTIVE SUMMARY 2](#abstract-executive-summary)

[2 BACKGROUND AND RATIONALE 3](#background-and-rationale)

[2.1 AATS-14 capabilities relevant to this proposal
3](#aats-14-capabilities-relevant-to-this-proposal)

[2.2 Aerosol Radiative Forcing Studies in previous field campaigns
4](#aerosol-radiative-forcing-studies-in-previous-field-campaigns)

[2.3 Comparisons of AATS measurements to satellite, in situ, and other
aircraft observations in previous field campaigns
5](#comparisons-of-aats-measurements-to-satellite-in-situ-and-other-aircraft-observations-in-previous-field-campaigns)

[2.3.1 Comparisons to satellite observations
5](#comparisons-to-satellite-observations)

[2.3.2 Comparisons to in situ observations
9](#comparisons-to-in-situ-observations)

[2.3.3 Comparisons to lidar measurements and synergy with other airborne
radiation sensors
12](#comparisons-to-lidar-measurements-and-synergy-with-other-airborne-radiation-sensors)

[2.4 Spatial variability of AOD based on AATS-14 measurements in
previous studies
12](#spatial-variability-of-aod-based-on-aats-14-measurements-in-previous-studies)

[3 Detailed description of proposed work
13](#detailed-description-of-proposed-work)

[3.1 AATS-14 instrument calibration, measurements, data reduction, and
archival for ARCTAS (April/July 2008)
14](#aats-14-instrument-calibration-measurements-data-reduction-and-archival-for-arctas-apriljuly-2008)

[3.1.1 Calibration 14](#calibration)

[3.1.2 Measurements 14](#measurements)

[3.1.3 Data reduction and archival 15](#data-reduction-and-archival)

[3.2 Integrated analyses for ARCTAS aerosol radiative effect studies
15](#integrated-analyses-for-arctas-aerosol-radiative-effect-studies)

[3.3 Integrated analyses for ARCTAS satellite validation studies
15](#integrated-analyses-for-arctas-satellite-validation-studies)

[4 SUMMARY OF PLANNED ACTIVITIES LISTED BY YEAR
17](#summary-of-planned-activities-listed-by-year)

[4.1 Year 1 (FY08) 17](#year-1-fy08)

[4.2 Year 2 (FY09) 17](#year-2-fy09)

[4.3 Year 3 (FY10) 17](#year-3-fy10)

[5 REFERENCES 17](#references)

[6 MANAGEMENT PLAN 21](#management-plan)

[6.1 Roles of Co-PIs and Co-I's 21](#roles-of-co-pis-and-co-is)

[7 CURRENT AND PENDING SUPPORT OF PI J. Redemann
21](#current-and-pending-support-of-pi-j.-redemann)

[8 BUDGET 22](#budget)

[8.1 Budget Justification: Narrative
22](#budget-justification-narrative)

[8.2 Budget Justification: Details 23](#budget-justification-details)

[8.3 Total Budget 23](#total-budget)

[8.4 Travel budget 24](#travel-budget)

[9 Biographical Sketches 25](#biographical-sketches)

[10 STATEMENTS OF COMMITMENT 28](#statements-of-commitment)

[10.1 Co-Investigator 28](#co-investigator)

[10.2 Collaborators 29](#collaborators)

[10.2.1 Prof. Peter Pilewskie, Univ. of Colorado
29](#prof.-peter-pilewskie-univ.-of-colorado)

[10.2.2 Dr. Ralph Kahn, JPL 30](#dr.-ralph-kahn-jpl)

# ACRONYMS {#acronyms .unnumbered}

+-------------------+--------------------------------------------------+
| AATS              | Ames Airborne Tracking Sunphotometer(s)          |
+-------------------+--------------------------------------------------+
| ACE               | Aerosol Characterization Experiment              |
+-------------------+--------------------------------------------------+
| AERONET           | Aerosol Robotic Network                          |
+-------------------+--------------------------------------------------+
| AOD               | Aerosol Optical Depth                            |
+-------------------+--------------------------------------------------+
| ARM               | Atmospheric Radiation Measurement                |
+-------------------+--------------------------------------------------+
| AVHRR             | Advanced Very High Resolution Radiometer         |
+-------------------+--------------------------------------------------+
| BRDF              | Bidirectional Reflectance Distribution Function  |
+-------------------+--------------------------------------------------+
| CALIOP            | Cloud-Aerosol LIdar with Orthogonal Polarization |
+-------------------+--------------------------------------------------+
| CALIPSO           | Cloud-Aerosol Lidar and Infrared Pathfinder      |
|                   | Satellite Observations                           |
+-------------------+--------------------------------------------------+
| CAR               | Cloud Absorption Radiometer                      |
+-------------------+--------------------------------------------------+
| CCSP              | Climate Change Science Program                   |
+-------------------+--------------------------------------------------+
| CIRPAS            | Center for Interdisciplinary Remotely Piloted    |
|                   | Aircraft Studies                                 |
+-------------------+--------------------------------------------------+
| CLAMS             | Chesapeake Lighthouse & Aircraft Measurements    |
|                   | for Satellites                                   |
+-------------------+--------------------------------------------------+
| COZ               | Columnar Ozone                                   |
+-------------------+--------------------------------------------------+
| CWV               | Columnar Water Vapor                             |
+-------------------+--------------------------------------------------+
| DIAL              | Differential Absorption Lidar                    |
+-------------------+--------------------------------------------------+
| DOE               | Department of Energy                             |
+-------------------+--------------------------------------------------+
| DU                | Dobson Unit (10^-3^ atm-cm)                      |
+-------------------+--------------------------------------------------+
| EOS               | Earth Observation System                         |
+-------------------+--------------------------------------------------+
| ESE               | Earth Science Enterprise                         |
+-------------------+--------------------------------------------------+
| EVE               | Extended-MODIS- Validation Experiment            |
+-------------------+--------------------------------------------------+
| HIRDLS            | High Resolution Dynamics Limb Sounder            |
+-------------------+--------------------------------------------------+
| HSRL              | High Spectral Resolution Lidar                   |
+-------------------+--------------------------------------------------+
| IGAC              | International Global Atmospheric Chemistry       |
+-------------------+--------------------------------------------------+
| INTEX or          | Intercontinental Chemical Transport              |
|                   | Experiment-North America                         |
| INTEX-NA          |                                                  |
+-------------------+--------------------------------------------------+
| INTEX-A or -B     | Phase A or B of INTEX-NA                         |
+-------------------+--------------------------------------------------+
| IOP               | Intensive Observation Period                     |
+-------------------+--------------------------------------------------+
| IR                | Infrared                                         |
+-------------------+--------------------------------------------------+
| ITCT              | Intercontinental Transport and Chemical          |
|                   | Transformation                                   |
+-------------------+--------------------------------------------------+
| MAS               | MODIS Airborne Simulator                         |
+-------------------+--------------------------------------------------+
| MASTER            | MODIS/ASTER Airborne Sensors                     |
+-------------------+--------------------------------------------------+
| MISR              | Multi-Angle Imaging Spectroradiometer            |
+-------------------+--------------------------------------------------+
| MODIS             | Moderate-resolution Imaging Spectroradiometer    |
+-------------------+--------------------------------------------------+
| OCO               | Orbiting Carbon Observatory                      |
+-------------------+--------------------------------------------------+
| OMI               | Ozone Monitoring Instrument                      |
+-------------------+--------------------------------------------------+
| PARASOL           | Polarization and Anisotropy of Reflectances for  |
|                   | Atmospheric Sciences coupled with Observations   |
|                   | from a Lidar                                     |
+-------------------+--------------------------------------------------+
| POLDER            | Polarization and Directionality of the Earth's   |
|                   | Reflectances                                     |
+-------------------+--------------------------------------------------+
| PRIDE             | Puerto Rico Dust Experiment                      |
+-------------------+--------------------------------------------------+
| PSAP              | Particle Soot Absorption Photometer              |
+-------------------+--------------------------------------------------+
| RSP               | Research Scanning Polarimeter                    |
+-------------------+--------------------------------------------------+
| SAFARI            | Southern African Regional Science Initiative     |
+-------------------+--------------------------------------------------+
| SGP               | Southern Great Plains                            |
+-------------------+--------------------------------------------------+
| SOLVE II          | SAGE III Ozone Loss and Validation Experiment II |
+-------------------+--------------------------------------------------+
| SSA               | Single Scattering Albedo                         |
+-------------------+--------------------------------------------------+
| SSFR              | Solar Spectral Flux Radiometer                   |
+-------------------+--------------------------------------------------+
| SZA               | Solar Zenith Angle                               |
+-------------------+--------------------------------------------------+
| TARFOX            | Tropospheric Aerosol Radiative Forcing           |
|                   | Observational Experiment                         |
+-------------------+--------------------------------------------------+
| TC^4^             | Tropical Composition, Cloud and Climate Coupling |
+-------------------+--------------------------------------------------+
| TCSP              | Tropical Cloud Systems and Processes             |
+-------------------+--------------------------------------------------+
| TES               | Tropospheric Emission Spectrometer               |
+-------------------+--------------------------------------------------+
| TOMS              | Total Ozone Mapping Spectrometer                 |
+-------------------+--------------------------------------------------+
| UV                | Ultraviolet                                      |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+
|                   |                                                  |
+-------------------+--------------------------------------------------+

#  {#section .unnumbered}

# ABSTRACT / EXECUTIVE SUMMARY

We propose airborne sunphotometer measurements and their combined
analysis with Terra and A-Train satellite aerosol data, and other
airborne observations to address the ARCTAS scientific objectives
regarding the spatial distribution and radiative impact of Arctic Haze
and biomass burning aerosol. Measurements will be made by the NASA Ames
Airborne Tracking Sunphotometer (AATS-14) on a profiling aircraft. In
particular, we plan to collect AATS-14 measurements of aerosol optical
depth (AOD), aerosol extinction, water vapor column content, and water
vapor concentration in two 4-week deployment periods in April and July
of 2008. The goals of our proposed work are:

1\) the preparation, calibration and field deployment of AATS-14 on a
profiling aircraft in two 4-week periods in ARCTAS;

2\) the processing and archival of AATS-14 data collected in ARCTAS;

3\) an integrated analysis of the horizontal and vertical distribution
of Arctic Haze aerosols and the emissions from boreal forest fires, with
an emphasis on the immediate vicinity of clouds;

4\) the combination of AATS-14 AOD measurements with solar irradiance
measurements on the same aircraft to determine aerosol direct radiative
effects; and

5\) the use and validation of aerosol observations from MODIS, MISR,
OMI, POLDER and CALIPSO in conjunction with AATS-14 measurements to
address ARCTAS science objectives.

The work proposed will build on the successful deployment of our group's
sunphotometers on a variety of aircraft in a large number of field
campaigns, including TARFOX (1996), ACE-2 (1997), SAFARI-2000 (2000),
PRiDE (2000), ACE-Asia (2001), CLAMS (2001), EVE (2004), INTEX-A (2004),
and INTEX-B (2006). Our proposed integrated analyses will build on the
experience gathered in these field campaigns, which have provided
important aerosol information used in the improvement of retrieval
algorithms for the MISR and MODIS sensors among others.

The combination of AATS-14 measurements of AOD with solar spectral
irradiance measurements from the Solar Spectral Flux Radiometers (SSFR,
PI: Peter Pilewskie, proposed separately) have resulted in the
development of techniques to study aerosol radiative forcing efficiency
and aerosol absorption. We plan to utilize these techniques to study
aerosol radiative effects in ARCTAS, thereby providing
observationally-based estimates of the aerosol radiative forcing of
climate by Arctic aerosols. If the aircraft that AATS-14 and SSFR are
deployed on also carries a suitable in situ instrumentation package,
comparisons and closure studies between the aerosol radiative properties
and the in situ measured optical and microphysical properties will be
carried out.

The research proposed here supports the strategic sub-goal 3A of the
NASA ROSES 2007 call, i.e., to "study Earth from space to advance
scientific understanding and meet societal needs". The scientific
question we seek to answer are those regarding changes in the global
Earth system, the primary causes for those changes, and how the Earth
system will change and respond to these changes in the future. Our work
will be responsive to the NASA research objectives loosely paraphrased
here: 3A.1 "Understand climate forcing associated with changes in
atmospheric composition"; 3A.5 "Understand the role of oceans,
atmosphere, and ice in the climate system and improve predictive
capability for its future evolution".

Because of our experience in the synergistic use of suborbital and
satellite aerosol observations, and because of the membership of the PI
of this proposal on the MODIS and CALIPSO science teams, we feel
uniquely qualified to perform the work proposed in response to this NRA.

# BACKGROUND AND RATIONALE 

Aerosols introduce major uncertainty into predictions of Earth's
climate. Atmospheric aerosols exert a direct effect on the Earth's
radiation balance by scattering and absorbing solar and longwave
radiation and an indirect effect through the modification of cloud
radiative properties, as well as cloud formation and maintenance. Both
effects can be studied using in situ \[e.g., *Redemann et al*., 2000,
2006; *Fiebig et al*., 2002\], satellite \[e.g., *Zhang et al*., 2005;
*Coakley et al*., 2002\] or suborbital remote sensing data \[e.g.,
*Hignett et al*., 1999; *Russell et al*., 1999; *Kim et al*., 2005\],
with advantages and drawbacks to each method. Satellite observations of
aerosols and their radiative effects in the Arctic are extremely
important due to the paucity of suborbital observations. At the same
time, these satellite observations are hampered by the vast spatial
extent of cloud cover, the lack of contrast between clouds and highly
reflective surfaces, as well as the persistently low sun angles and long
seasonal lack of solar illumination during NH winter.

The ARCTAS white paper \[*Jacob et al*., 2007\] identifies four
scientific themes: long-range transport of pollution to the Arctic,
boreal forest fires, aerosol radiative forcing and chemical processes.
Out of those scientific themes, the NASA Ames Airborne Tracking
Sunphotometer (AATS-14) is uniquely suited to contribute to at least two
areas, namely boreal forest fires and direct aerosol radiative forcing
of climate, including the proven ability to support satellite-based
observations for similar scientific objectives.

At the time this proposal is being prepared, the migration of radiation
sensors previously flown on the contracted J-31 aircraft in INTEX-A and
INTEX-B has commenced. The platform now designated for these sensors is
the NASA P-3. We assume here that at least the AATS-14, CAR and SSFR
sensors will be successfully installed on the NASA P-3 by the start of
the ARCTAS deployment. With the exception of instrument re-installation,
no costs for integrating AATS-14 on the P-3 platform are included here.

The research proposed here supports the strategic sub-goal 3A of the
NASA ROSES 2007 call, i.e., to "study Earth from space to advance
scientific understanding and meet societal needs". The scientific
question we seek to answer are those regarding changes in the global
Earth system, the primary causes for those changes, and how the Earth
system will change and respond to these changes in the future. Our work
will be responsive to the NASA research objectives loosely paraphrased
here: 3A.1 "Understand climate forcing associated with changes in
atmospheric composition"; 3A.5 "Understand the role of oceans,
atmosphere, and ice in the climate system and improve predictive
capability for its future evolution". As noted by the ROSES 2007 Summary
of Solicitation, NASA addresses these questions and objectives by using
an integrated observational strategy that combines observations from
space with suborbital and ground-based measurements.

In this proposal, we seek funding to carry out airborne sunphotometer
measurements of aerosol properties in ARCTAS to support aerosol
radiative forcing studies and to aid in the interpretations and
validation of measurements acquired with aerosol sensors aboard Terra
and the A-Train satellites, while addressing scientific goals of ARCTAS.
The following sections provide a summary of the capabilities of the NASA
Ames Airborne Tracking Sunphotometer (AATS-14), a brief description of
the relevant satellite sensors, their data products and validation
needs, a summary of ARCTAS, and some examples of previous AATS
measurements in relevant experiments.

## AATS-14 capabilities relevant to this proposal

The deployments of the NASA Ames Airborne Tracking Sunphotometers
(AATS-6 and AATS-14) in previous field campaigns have made significant
contributions to the airborne study of atmospheric aerosols. In addition
to the successful deployment of AATS-14 in the INTEX-A and INTEX-B field
campaigns, the fully analyzed AATS measurements from SAFARI (2000),
PRiDE (2000), ACE-Asia (2001), and CLAMS (2001), EVE (2004) and previous
experiments have been used extensively in radiative forcing assessments
and for the augmentation and validation of satellite sensors aboard the
NASA EOS platforms and other spacecraft.

AATS-14 measures direct solar beam transmission in 14 narrow channels
using detectors in a tracking head that rotates in two axes. Azimuth and
elevation motors controlled by differential sun sensors rotate the
tracking head, keeping detectors normal to the solar beam. The tracking
head mounts outside the aircraft skin to minimize blockage by aircraft
structures and also to avoid data contamination by aircraft-window
effects. From the transmission measurements we derive AOD at 13
wavelengths (354, 380, 453, 499, 519, 604, 675, 778, 865, 1019, 1241,
1558, 2139 nm) and columnar water vapor (CWV). Under suitable conditions
(see below) we also derive columnar ozone (COZ). Vertical
differentiation of AOD and CWV data in suitable flight patterns yields
aerosol extinction spectra and water vapor concentration. In previous
field campaigns, the AATS-14 AOD measurements in the UV, visible, and
near IR (out to 1 m) have been extensively compared to ground-based
AERONET measurements, yielding very strong correlations (r^2^\>0.99) and
rms-differences generally less than 10% (e.g., *Schmid et al*., 2003a;
*Livingston et al.,* 2003, *Redemann et al*., 2005). Measurements of
AATS CWV agreed with other CWV measurements at least to within 10%
\[*Schmid et al*., 2001; *Livingston et al.*, 2007, see also below\].

For COZ the accuracy of AATS retrievals depends critically on two
factors: (1) the relative magnitudes of the overlying AOD and ozone
optical depth, both near 600 nm (the peak of the Chappuis ozone
absorption band) and (2) solar zenith angle (SZA). For AATS-14 data
acquired at aircraft altitudes near 10 km during the SOLVE II mission,
COZ retrievals to better than 3% accuracy (\~10 DU) were achieved
because AOD at 600 nm was less than or comparable to the ozone OD there
(\~0.04), and because the instrument calibration uncertainty was
minimized by large airmass values due to SZAs \>83° (*Livingston et
al.*, 2005). For the proposed AATS measurements in ARCTAS, data will
usually be taken at smaller SZAs from an aircraft often flying near the
surface, and with overlying AOD likely to exceed overlying ozone optical
depth significantly. Thus, it is unrealistic to expect AATS COZ
retrieval accuracies of better than 10% (\~30 DU), except when the AATS
aircraft flies at higher altitudes (i.e., above most AOD) and SZA is
large.

## Aerosol Radiative Forcing Studies in previous field campaigns

For the study of aerosol--climate interactions, we are mainly interested
in aerosol effects on the atmospheric radiation balance. Hence, an
actual measurement of atmospheric irradiance is preferable to methods
which require the deduction of the aerosol effect on irradiance based on
in situ aerosol properties or measurements of satellite radiances. The
preferred way to study the aerosol radiative forcing of climate uses
simultaneous measurements of the aerosol amount and the affected
radiation field. In several recent field campaigns, AATS-14 derived AOD
has been used in conjunction with measurements of the spectral
irradiance by SSFR (*Pilewskie et al*., 2000) to determine the direct
impact of aerosols on the radiation balance. For example, *Redemann et
al*. \[2006a\] used the aerosol gradient method to derive the direct
aerosol radiative forcing efficiency in 10 case studies during flights
conducted as part of the INTEX-A and ITCT field studies in 2004. This
method requires the determination of the change in AOD and the
associated change in net spectral irradiance (see Figure 1). The
combination of coincident AATS-14 and SSFR measurements yielded plots of
net (downwelling minus upwelling) spectral irradiance as a function of
aerosol optical depth (AOD) as measured along horizontal flight legs. By
definition, the slope of these plots yields the instantaneous change in
net irradiance per unit AOD change and is referred to as the
instantaneous spectral aerosol radiative forcing efficiency, *E~i~*, \[W
m^-2^ nm^-1^\]. Numerical integration over a given spectral range yields
the instantaneous broadband aerosol radiative forcing efficiency \[W
m^-2^\]. This technique for deriving *E~i~* is called the aerosol
gradient method because it actually requires gradients in AOD and net
irradiance.

Within 10 case studies considered suitable for their analysis, *Redemann
et al*. \[2006a\] found a high variability in the derived instantaneous
aerosol forcing efficiencies for the visible wavelength range (350-700
nm), with a mean of -79.6 W m^-2^ and a standard deviation of 21.8 W
m^-2^(27%). *Redemann et al.* \[2006a\] further presented spectrally
resolved aerosol forcing efficiencies between 350 and 1670 nm, estimates
of the midvisible aerosol single scattering albedo (SSA) and a
comparison of observed broadband forcing efficiencies to previously
reported values. Their estimates of aerosol SSA showed that aerosol
absorption was larger early in the 12 July-8 August 2006 period than
later, consistent with independent trajectory analyses and satellite
imagery that showed the stronger influence of smoke aerosols from Alaska
fires during the early period.

![](media/image2.png){width="4.6402777777777775in"
height="3.4118055555555555in"}

**Figure 1.** a) Regression plot of binned broadband visible net
irradiance shown in versus midvisible aerosol optical depth for a case
study (July 21, 2004) in INTEX-A and two spectral ranges (350-1700nm and
250-700nm, respectively). The slope of the regression line yields the
instantaneous aerosol radiative forcing efficiency, *~i~E*.

## Comparisons of AATS measurements to satellite, in situ, and other aircraft observations in previous field campaigns

### Comparisons to satellite observations

Satellite sensors of aerosols \[*Kaufman et al.*, 2002; *Ramanathan et
al*., 2002\] are essential to developing an accurate description of the
regional and global distribution of aerosols and their variability.
Spaceborne aerosol sensors launched in the past few years, such as
MODIS, MISR, POLDER, OMI and CALIOP, have the potential to advance our
understanding of aerosol processes at global and regional scales alike.
However, for these satellite aerosol observations to be most useful for
the study of climate, an extensive validation effort is required to
ensure their continuous reliability and assess their accuracy.

AATS measurements of aerosol optical depth and water vapor have been
used extensively in the interpretation and validation of satellite-based
observations. The notable advantages of the AATS-14 instrument for this
purpose include its deployment on airborne platforms (which allows the
validation of satellite observations over dark water), a well-documented
instrument calibration record, and extensive coverage of the spectral
range of current satellite sensors. Note that the AATS-14 spectral range
extends to the MODIS channel at 2.1 m, a channel that carries abundant
information on aerosol particle size. AATS-14 is one of the very few
sensors that can measure AOD at 2.1 m, and the only airborne one \[e.g.,
*Levy et al*., 2005, *Redemann et al*., 2005\]. Table 1 summarizes
satellite aerosol validation studies that have used an AATS instrument.
To date, nine published studies have compared AATS measurements to
retrievals by MODIS or MISR aboard the EOS Terra and Aqua satellites,
and two publications led by the AATS team included validation of
TOMS-derived AOD. In addition, a publication dealing with the validation
of two distinct OMI aerosol retrieval algorithms (see below) in the
context of INTEX-B \[*Livingston et al*., 2007\] is in preparation.

**Table 1.** Validation of satellite derived aerosol properties
published by the proposing team.

+------+----------+-----------+-------+-----------+-----------------+
| **   | **Ca     | *         | *     | *         | **Publication** |
| Sens | mpaign** | *Region** | *Surf | *Period** |                 |
| or** |          |           | ace** |           |                 |
+------+----------+-----------+-------+-----------+-----------------+
| A    | TARFOX   | US East   | Ocean | July 1996 | Veefkind et     |
| VHRR |          | Coast     |       |           | al., 1999       |
+------+----------+-----------+-------+-----------+-----------------+
| A    | ACE 2    | Canary    | Ocean | June/July | Durkee et al.,  |
| VHRR |          | Islands   |       | 1997      | 2000            |
|      |          |           |       |           |                 |
|      |          |           |       |           | Livingston et   |
|      |          |           |       |           | al., 2000       |
|      |          |           |       |           |                 |
|      |          |           |       |           | Schmid et al.,  |
|      |          |           |       |           | 2000            |
+------+----------+-----------+-------+-----------+-----------------+
| AT   | TARFOX   | US East   | Ocean | July 1996 | Veefkind et     |
| SR-2 |          | Coast     |       |           | al., 1999       |
+------+----------+-----------+-------+-----------+-----------------+
| AT   | SAFARI   | Namibian  | Ocean | September | Schmid et al.,  |
| SR-2 | 2000     | Coast     |       | 2000      | 2003b           |
+------+----------+-----------+-------+-----------+-----------------+
| G    | ACE-Asia | Eastern   | Ocean | April     | Wang et al,     |
| MS-5 |          | Asia      |       | 2001      | 2003b           |
+------+----------+-----------+-------+-----------+-----------------+
| GO   | PRIDE    | Puerto    | Ocean | June/July | Livingston et   |
| ES-8 |          | Rico      |       | 2000      | al., 2003       |
|      |          |           |       |           |                 |
|      |          |           |       |           | Wang et al.,    |
|      |          |           |       |           | 2003a           |
+------+----------+-----------+-------+-----------+-----------------+
| MAS  | TARFOX   | US East   | Ocean | July 1996 | Tanré et al.    |
|      |          | Coast     |       |           | 1999            |
+------+----------+-----------+-------+-----------+-----------------+
| MISR | SAF      | Southern  | Ocean | September | Schmid et al.,  |
|      | ARI-2000 | Africa    | &     | 2000      | 2003b           |
|      |          |           | Land  |           |                 |
+------+----------+-----------+-------+-----------+-----------------+
| MISR | ACE-Asia | Eastern   | Ocean | April     | Kahn et al.,    |
|      |          | Asia      |       | 2001      | 2004            |
+------+----------+-----------+-------+-----------+-----------------+
| MISR | CLAMS    | US East   | Ocean | July/Aug. | Redemann et     |
|      |          | Coast     |       | 2001      | al., 2005       |
+------+----------+-----------+-------+-----------+-----------------+
| MISR | INTEX-A  | US East   | Ocean | July 2004 | Russell et al., |
|      |          | Coast     |       |           | 2007            |
+------+----------+-----------+-------+-----------+-----------------+
| M    | PRIDE    | Puerto    | Ocean | June/July | Livingston et   |
| ODIS |          | Rico      |       | 2000      | al., 2003       |
|      |          |           |       |           |                 |
|      |          |           |       |           | Levy et al.,    |
|      |          |           |       |           | 2003            |
+------+----------+-----------+-------+-----------+-----------------+
| M    | SAF      | Southern  | Ocean | September | Schmid et al.,  |
| ODIS | ARI-2000 | Africa    | &     | 2000      | 2003b           |
|      |          |           | Land  |           |                 |
+------+----------+-----------+-------+-----------+-----------------+
| M    | CLAMS    | US East   | Ocean | Ju        | Levy et al.,    |
| ODIS |          | Coast     |       | ly/August | 2005 Redemann   |
|      |          |           |       | 2001      | et al., 2005    |
+------+----------+-----------+-------+-----------+-----------------+
| M    | ACE-Asia | Eastern   | Ocean | April     | Chu et al.,     |
| ODIS |          | Asia      |       | 2001      | 2004            |
+------+----------+-----------+-------+-----------+-----------------+
| M    | ACE-Asia | Eastern   | Ocean | April     | Anderson et     |
| ODIS |          | Asia      |       | 2001      | al., 2006       |
+------+----------+-----------+-------+-----------+-----------------+
| M    | EVE      | US CA     | Ocean | April     | Redemann et     |
| ODIS |          | Coast     |       | 2004      | al., 2006       |
+------+----------+-----------+-------+-----------+-----------------+
| M    | INTEX-A  | US East   | Ocean | July 2004 | Russell et al., |
| ODIS |          | Coast     |       |           | 2007            |
+------+----------+-----------+-------+-----------+-----------------+
| POAM | SOLVE-2  | Arctic    | Ocean | Jan/Feb   | Russell et al., |
|      |          |           | &     | 2003      | 2005            |
|      |          |           | Land  |           |                 |
+------+----------+-----------+-------+-----------+-----------------+
| SAGE | SOLVE-2  | Arctic    | Ocean | Jan/Feb   | Russell et al., |
| 3    |          |           | &     | 2003      | 2005            |
|      |          |           | Land  |           |                 |
+------+----------+-----------+-------+-----------+-----------------+
| Sea  | ACE-Asia | Eastern   | Ocean | April     | Hsu et al.,     |
| WiFS |          | Asia      |       | 2001      | 2002            |
+------+----------+-----------+-------+-----------+-----------------+
| TOMS | PRIDE    | Puerto    | Ocean | June/July | Livingston et   |
|      |          | Rico      |       | 2000      | al., 2003       |
+------+----------+-----------+-------+-----------+-----------------+
| TOMS | SAF      | Southern  | Land  | September | Schmid et al.,  |
|      | ARI-2000 | Africa    |       | 2000      | 2003b           |
+------+----------+-----------+-------+-----------+-----------------+

These AATS results have provided important aerosol information used in
the improvement of retrieval algorithms for MISR \[*Kahn et al*., 2001,
*Martonchik et al*., 1998\] and MODIS \[*Martins et al*., 2002, *Levy et
a*l., 2005; *Chu et al*., 2005\]. Additional examples of AATS
measurements are given in *Russell et al*., 1999, *Schmid et al*., 2000,
2003a, *Livingston et al*., 2003, and *Redemann et al*., 2006b.

The A-Train constellation includes six satellites, all with equator
crossing times within a 30 minute time frame. The six satellites are
Aqua, CloudSat, CALIPSO, PARASOL, Aura and OCO. Aboard these six
satellites are at least four instruments with a key goal of measuring
aerosols: the MODIS instrument on Aqua, CALIOP on CALIPSO, POLDER on
PARASOL, and OMI on Aura. Many A-Train instruments also measure water
vapor, including TES, HIRDLS, and MLS on Aura, and AIRS and MODIS on
Aqua. Table 2 contains a list of the Terra and A-Train satellite
instruments and derived data products especially relevant to this
proposal. The following paragraphs give more information on specific
instruments targeted by this proposal.

**Table 2.** Satellite sensors relevant to this proposal

+---------+---------+-------------------------------+-----------------+
| Sa      | Ins     | Data products                 | Coverage /      |
| tellite | trument |                               | Resolution /    |
|         |         |                               | Comments        |
+---------+---------+-------------------------------+-----------------+
| Aqu     | MODIS   | AOD (ocean - 7, 470-2130 nm,  | 10x10km, nadir  |
| a+Terra |         | land - 2, 470 + 660 nm),      |                 |
|         |         | column H~2~O                  |                 |
+---------+---------+-------------------------------+-----------------+
| CALIPSO | CALIOP  | Aerosol extinction profiles   | 333 / 30 m      |
|         |         | (2, 532 + 1064 nm)            | (horiz./vert.), |
|         |         |                               | Level-2         |
|         |         | AOD (2, 532 + 1064 nm)        | profile/curtain |
|         |         |                               | with 40km       |
|         |         |                               | horiz.          |
+---------+---------+-------------------------------+-----------------+
| Terra   | MISR    | AOD, aerosol type, particle   | 17.6km,         |
|         |         | shape indication (ocean and   | operational,    |
|         |         | land - 4, 470-865 nm)         | 1km research    |
|         |         |                               | mode            |
+---------+---------+-------------------------------+-----------------+
| PARASOL | POLDER  | AOD (2, 670 + 865 nm)         | 20x20km         |
+---------+---------+-------------------------------+-----------------+
| Aura    | OMI     | AOD + ssa (17, 330-500 nm),   | 13x24 km,       |
|         |         | column O~3~                   | 13x12km (zoom   |
|         |         |                               | mode)           |
+---------+---------+-------------------------------+-----------------+
| Aura    | TES     | Water vapor profiles, surface | 0.5x5 km / 4    |
|         |         | to 33 km                      | to5 km          |
|         |         |                               | (horizontal /   |
|         |         |                               | vertical),      |
|         |         |                               | nadir mode      |
+---------+---------+-------------------------------+-----------------+
| Aqu     | CERES   | Broadband solar and           | 20km, nadir     |
| a+Terra |         | terrestrial radiative fluxes  | horizontal, and |
|         |         | in three channels             | flux profiles   |
+---------+---------+-------------------------------+-----------------+
| Aqua    | AIRS    | Water vapor profiles, surface | 50 km / 2km     |
|         |         | to 100 mb                     | (horizontal /   |
|         |         |                               | vertical)       |
|         |         | Column water vapor,           |                 |
|         |         | troposphere                   |                 |
+---------+---------+-------------------------------+-----------------+

OMI is a hyperspectral imager that measures UV and visible radiation
scattered back by the Earth-atmosphere system. A major OMI advantage is
its ability to derive aerosol optical depth and single scattering albedo
over land, by using the small land surface reflectivity in the UV. This
technique, developed by *Herman et al.* \[1997\] and *Torres et al.*
\[1998\], is sensitive to aerosols that absorb in the near-UV, such as
mineral dust, volcanic ash and carbonaceous particles. Whereas
measurements of AOD and SSA by OMI's predecessor, TOMS, were limited to
a few bands in the near UV, OMI measures radiances from 270 to 500 nm,
with resolution \~0.5 nm. Because of strong absorption below 330 nm by
ozone, OMI-derived aerosol properties range from the near-UV to the
mid-visible (330-500 nm) at 17 discrete wavelengths \[*Torres et al*.,
2002\], chosen in part to match wavelength bands of other satellite
sensors such as MODIS. By incorporating wavelengths longer than TOMS,
OMI bridges the gap to retrievals by MODIS, MISR and AVHRR. OMI also has
finer spatial resolution than TOMS, aiding in cloud-screening.
Operationally, OMI AOD and SSA are derived by two methods, a
multi-wavelength method and the aforementioned near UV-technique. One of
the main purposes of this proposal is the validation of OMI AOD from
both techniques, by using AATS-14 in ARCTAS, similar to our efforts in
INTEX-B (see also Figure 2).

MODIS is one of four Earth-observing satellites aboard the Terra
satellite and one of six aboard the Aqua satellite. MODIS views the
entire Earth\'s surface every 2 days, acquiring data in 36 spectral
bands. The MODIS aerosol product (MOD04_L2) is derived from radiance
measurements in channels 1-7 and 20 of the 36 MODIS bands. Over the
ocean the measured radiances are inverted into the aerosol optical
depths at 466, 553, 644, 855, 1243, 1632 and 2119 nm and volume
distribution (in the range of 0.08-5 µm radius). In the inversion, it is
assumed that the aerosol size distribution is bi-modal log-normal
\[*Remer et al*., 2005\]. AOD, fine mode fraction and other aerosol data
are retrieved and stored at a resolution of nominally 10x10km at nadir
\[*Kaufman et al.*, 1997\].

MISR produces 36 simultaneous views of Earth, in a combination of nine
angles varying from +70° to --70° in the along-track direction, in four
spectral bands centered at 446, 558, 672 and 867 nm \[*Diner et al*.,
1998\]. It takes seven minutes for all nine MISR cameras to view a fixed
line on the surface, which sets the effective temporal resolution for
coincident observations. At midlatitudes, a given location is imaged
about once per week in Global Mode, providing 275 m resolution data in
all four nadir channels, and in the red channels of the other eight
cameras. The remaining 24 channels of data are averaged on board the
spacecraft to 1.1 km resolution. During major field campaigns locations
in the MISR swath can be designated "MISR Local Mode sites", 300 km
along-track by 360 km cross-track, over which data are acquired at 275 m
resolution in all 36 channels. Due to the wide range of scattering
angles sampled (about 50° to 160° at midlatitudes), MISR offers tight
constraints on AOD, particle shape, size distribution, and single
scattering albedo, particularly over dark, uniform ocean surfaces
\[*Kahn et al.,* 2001; *Martonchik et al.,* 1998\].

Within the A-Train, the CALIPSO satellite carries an aerosol-cloud lidar
(CALIOP), a three-channel imaging infrared radiometer (IIR) and a
wide-field camera (WFC). The CALIPSO suite of instruments is designed to
provide a global set of data on aerosol and cloud properties, enabling
new observationally-constrained estimates of the radiative effects of
aerosols and clouds on climate. The key instrument for this proposal is
CALIOP, a two-wavelength (532 and 1064nm), polarization-sensitive lidar
that produces profiles of aerosol extinction and backscattering with a
single-shot vertical and horizontal resolution of 30 and 333 m,
respectively. The CALIPSO aerosol algorithm selects a "best-match" lidar
ratio (i.e., the ratio of aerosol extinction to aerosol backscatter,
*Klett* \[1985\]) based on optical characteristics, geolocation and
season from a look-up table that is based on a cluster analysis of
AERONET data and in situ observations, respectively \[*Vaughan et al*.,
2004, *Omar et al*., 2005\]. To fulfill feature finding and layer
classification requirements, the current CALIPSO level-2 algorithm
yields an aerosol [layer]{.underline} product at a horizontal resolution
of 5 km and an aerosol [profile]{.underline} product at a horizontal
resolution of 40 km.

As an example of previous, multi-grid cell validation studies with
AATS-14, Figure 2 shows the comparison of spectral AOD by two different
OMI retrieval algorithms ("MW": using radiances of 17 channels from UV
to vis.; "UV": using only UV radiances) and by the standard MODIS
aerosol retrieval algorithm to an average AATS-14 spectral AOD during a
low-level flight leg on March 10, 2006, over the Gulf of Mexico in
INTEX-B. There is good agreement between AATS-14 and MODIS-derived
spectral AOD and less good agreement between AATS-14 and the two OMI
retrievals. The exact causes of this disagreement are being studied;
indeed, the resolution of individual retrieval grid cells allows a much
closer investigation of the exact causes for potential disagreement of
satellite and suborbital AOD measurements (e.g., surface
characteristics, cloud contamination, etc.) than the comparison of
temporally-averaged ground-based observations to spatially-averaged
satellite observations affords.

![](media/image3.png){width="5.240277777777778in"
height="2.964583333333333in"}

![](media/image4.png){width="5.427083333333333in"
height="3.8895833333333334in"}

Figure 2: Comparisons of multi-grid cell retrievals of spectral AOD by
two different OMI retrieval algorithms ("MW": using radiances of 17
channels from UV to vis.; "UV": using only UV radiances) and by the
standard MODIS aerosol retrieval algorithm to AATS-14 measurements
during a low-level flight leg on March 10, 2006, over the Gulf of Mexico
in INTEX-B.

### Comparisons to in situ observations

Aerosol closure studies test the consistency of different measurements
that are linked by one or more models. Because the linking models (e.g.,
of aerosol growth in humidity, of light scattering by mixed aerosols)
are often used as components of the chemical transport models or general
circulation models that predict aerosol effects on climate, closure
studies provide important assessments of both the measurements and the
models that undergird our current understanding of aerosol effects on
climate.

Aerosol extinction closure studies have revealed important insights
about aerosol sampling and inadvertent modification in such previous
experiments as TARFOX (*Hegg et al*., 1997; *Hartley et al*. 2000),
ACE-2 (*Collins et al*., 2000; *Schmid et al*., 2000), SAFARI 2000
(*Magi et al*., 2003), ACE-Asia (*Schmid et al*., 2003a, *Redemann et
al*., 2003) and CLAMS (*Magi et al*., 2005).

The basis for these studies is the measurement of aerosol optical depth
and columnar water vapor with an Ames Airborne Tracking Sunphotometer
(AATS-14 or AATS-6), because inlet effects (e.g., loss or enhancement of
large particles, shrinkage by evaporation of water, organics, or
nitrates) and filter effects that may decrease the quality of in situ
measurements are not present in the sunphotometer observations. As
pointed out above, the differentiation of AOD vertical profiles yields
profiles of spectral aerosol extinction (see Figure 3) and water vapor
density. Measuring solar beam attenuation by an AATS on the same
aircraft as in situ sensors allows a close match in the aerosol layers
described by the attenuation and in situ measurements. Such a match
allows the best-defined comparison between attenuation and in situ
results. It avoids the ambiguity that occurred in previous experiments
when the sunphotometer measurements were taken from the ground and thus
provided no information on what fraction of column optical depth was
above the aircraft's maximum sampling height.

![](media/image5.png){width="3.8743055555555554in"
height="3.454861111111111in"}

**Figure 3.** Comparison of aerosol extinction derived from AATS-14
measurement, aerosol size distributions, and lidar measurements on R/V
Ron Brown (*Wang et al*., 2003b).

An example from ACE-Asia where the in situ extinction is computed from
in situ size distribution and chemical composition measurements is shown
in Figure 3 \[*Wang et al*., 2003b\]. In the uppermost layer, the
underestimate of Mie-predicted extinction compared to the AATS-14 result
is attributed to nonspherical dust particles there, which are undersized
by the in situ mobility analyzer (*Wang et al.*, 2003b). In addition to
the AATS-14 and in situ derived extinction, Figure 3 further shows a
lidar-derived profile of midvisible aerosol extinction, which reproduces
the AATS and in situ derived aerosol layer structure well.In a recent
study, *Schmid et al*. \[2006\] compared a variety of ways to derive
aerosol extinction, including in situ, airborne sunphotmeter and lidar
observations. They concluded that even well proven measurement
techniques produce bias differences in midvisible aerosol extinction of
15-20%, with potentially larger differences in the UV and SWIR. Because
the observational circumstances are different for every aircraft, it is
particularly important for airborne platforms that are newly equipped
with in situ aerosol instrumentation to devote a significant portion of
flights towards flight patterns suitable for assessing the consistency
of the in situ measurements and the date from the available radiation
sensors, such as AATS-14, SSFR, and RSP. Since the P-3 platform to be
used in ARCTAS is a new platform for the radiation sensors and some of
the in situ instrumentation, we propose to carry out closure studies
between AATS-14 and the relevant in situ sensors.

![](media/image6.wmf){width="5.583333333333333in"
height="4.631944444444445in"}

**Figure 4**. Comparison of water vapor measurements on the Twin Otter
in ACE-Asia by AATS-14 and in situ sensors. (i-l) Examples of vertical
profiles. (m) Comparison of layer water vapor for 26 profiles. Error
bars are based on horizontal distance spanned by a profile, combined
with average horizontal variability of CWV in ACE-Asia flights. (n)
Comparison of water vapor density for the 26 profiles. (*Schmid et al.*,
2003b).

In addition to spectral AOD, AATS-14 measures the overlying column water
vapor (CWV) using a channel in the 940-nm water vapor absorption band
\[e.g., *Schmid et al*., 2000, 2001, *Livingston et al*., 2007\].
Vertical differentiation of AATS CWV profiles in aircraft ascents or
descents yields profiles of water vapor concentration. Our previous
closure studies have included many comparisons between the AATS water
vapor results and those from a variety of other measurement techniques
(e.g., *Schmid et al*., 2000, 2001). Fig. 4 shows examples for AATS-14
in ACE-Asia. In addition to the satellite validation work proposed here,
the continuously measured CWV results are useful in radiative transfer
calculations and in assessing any CWV changes associated with measured
AOD changes aloft.

### Comparisons to lidar measurements and synergy with other airborne radiation sensors

In addition to the in situ closure studies mentioned in the previous
section, AATS-14 results have been compared abundantly to, and used
synergistically with, lidar aerosol observations. These studies include
the investigation of massive aerosol layers in SAFARI-2000 \[*Schmid et
al*., 2003\], the combined use of lidar, sunphotometer and in situ size
distribution data to estimate aerosol refractive indices in TARFOX
\[*Redemann et al*., 2000a,b\], and the validation of the Raman lidar at
the ARM Southern Great Plains Site \[*Ferrare et al*., 2006\]. In
ARCTAS, the investigation of the vertical distribution of Arctic haze
aerosols and aerosol emissions from boreal forest fires will benefit
greatly from the availability of the CALIOP lidar measurements aboard
the CALIPSO satellite and from the planned deployment of the HSRL (High
Spectral Resolution Lidar) aboard the Langley King Air B-200 aircraft.
We propose to support the cross-validation of the CALIOP and HSRL
measurements through the measurements of vertical profiles of aerosol
extinction obtained from AATS-14.

Besides the potential in situ observation aboard the P-3 itself, the
lidar measurements on other aircraft, and the satellite observations, a
fourth class of sensors that will benefit from the deployment of AATS-14
on the P-3 are the other radiation sensors flown aboard the P-3. At the
time this proposal is being written, efforst are beoing made to
integrate the GSFC Cloud Absorption Radiometer (CAR) on the P-3; there
is also a possibility that one of the Research Scanning Polarimeters
(RSP) will be available to fly aboard the P-3. In previous deployments,
most notably SAFARI, CLAMS, INTEX-A and INTEX-B, the RSP and the CAR
teams have used AATS-14 measurements to constrain \[*Chowdhary et al*.,
2005\] and to validate their own retrievals of aerosol properties
\[*Gatebe et al*., 2005\].

## Spatial variability of AOD based on AATS-14 measurements in previous studies

Spatial variability in radiance fields observed by passive satellite
sensors is frequently used in the separation of cloud and aerosol
signals, under the assumption that most clouds exhibit larger spatial
variability than aerosols. In clear regions, AOD spatial variability
contributes significantly to the variability in the satellite-observed
radiance field. AOD variability can only be assessed on the relevant
scales (of a few hundred meters, comparable to the satellite sensor
resolution) from suborbital platforms that move fast by comparison to
wind speeds and only with instruments that provide data at appropriate
rates (1 Hz being equivalent to a spatial resolution of \~100m at an
aircraft speed of 200 knots). AATS-14 samples at 3 Hz and typically
averages 9 samples, recording a 3-second average every 4 seconds.
Because AATS-14 measures the direct solar beam transmission (unaffected
by surface properties), and because it is deployed on relatively
fast-moving platforms, it is well suited for studies of AOD spatial
variability.

For example, the cloud mask used in the MODIS aerosol retrieval
algorithm computes the standard deviation of 553 nm reflectances in
every group of 3 by 3 pixels within a box \[*Martins et al.,* 2002\]. If
any group of 9 contiguous pixels has a standard deviation greater than
0.0025, the center pixel is labeled as \'cloudy\' and discarded. This
test separates aerosol from most cloud types, but may fail at the
centers of large, thick clouds and with cirrus, both of which can be
spatially homogeneous. An example of the cloud mask thus derived is
shown in the lower right hand panel of Figure 5 for a scene sampled on
April 30, 2004, off the California coast (the 500m pixels that exhibit
variability with respect to their neighbors in excess of the criterion
above have white borders). The question arises whether the variability
in the vicinity of clouds could be due to 3-D radiative effects or even
the variability in aerosol properties rather than actual cloud
contamination. To answer this question, we have started to apply the
MODIS standard aerosol retrieval algorithm, usually applied only to
MODIS radiance spectra averaged over 10x10km, to the individual 500m
pixel radiances shown in the upper left panel of Figure 5 \[*Redemann et
al*., 2007\] to produce fine-scale maps of aerosol retrievals (see lower
left panel of Figure 5). We expect to compare these fine-scale aerosol
retrievals to the AATS-14 measurements obtained along the colored flight
path also shown in Figure 5 to elucidate whether a less stringent cloud
screening, for example the standard MODIS cloud mask shown in the upper
right panel of Figure 5, would produce a cloud filter that would not
suppress aerosol information in the immediate vicinity of clouds. We
propose similar studies in ARCTAS as outlined in section 3.3 below.

  ---------------------------------------------------- ---------------------------------------------------
  ![](media/image7.png){width="3.1368055555555556in"   ![](media/image8.png){width="3.615972222222222in"
  height="2.422222222222222in"}                        height="2.4159722222222224in"}

  ![](media/image9.png){width="3.51875in"              ![](media/image10.png){width="3.51875in"
  height="2.6020833333333333in"}                       height="2.6020833333333333in"}
  ---------------------------------------------------- ---------------------------------------------------

**Figure 5.** Upper Left - Flight track of EVE flight CIR06 (red), April
30, 2004, superimposed on MODIS-Aqua true color image. Upper Right --
Standard MODIS cloud mask, MYD35. Lower left -- AOD (553nm) computed by
applying the MODIS standard algorithm to 500m pixel radiances. Lower
right -- same as lower left, but with MODIS 500m pixels that would be
sorted out by variability criterion outlined with white borders.

# Detailed description of proposed work

For the reasons given in the preceding sections, we propose to make
measurements with AATS-14 on the NASA P-3 aircraft in ARCTAS and to
perform integrated analyses that address ARCTAS science goals. The
following subsections provide more specifics on the proposed
measurements and analyses.

## AATS-14 instrument calibration, measurements, data reduction, and archival for ARCTAS (April/July 2008)

### Calibration

Standard procedure for the preparation of AATS-14 for field deployment
is the pre- and post-mission calibration of the instrument at Mauna Loa
Observatory. These calibration trips are usually scheduled for a 10-day
span in an attempt to obtain a minimum of 5 suitable Langley plots per
trip. Because the ARCTAS deployment schedule calls for two 4-week
deployments (currently P-3 operations in Phase-A assumed to be from
Fairbanks, AK and Phase-B from Alberta, Canada) we will schedule three
calibration trips, with the second calibration trip serving as the
post-mission calibration for the Phase-A deployment and as the
pre-mission calibration for the Phase-B deployment. Previous
calibrations have shown very good stability of AATS-14 calibration on
time scales of a few months and therefore three calibration trips should
suffice.

### Measurements

Our proposed AATS-14 experimental work will emphasize measurements of:
(a) AOD spectra (354-2139 nm) and CWV on horizontal transects, (b)
aerosol extinction spectra and water vapor density in vertical profiles,
and (c) when conditions are appropriate, column ozone. Flights will be
coordinated with overpasses of A-Train satellites, as well as with other
ARCTAS platforms, so as to best address the combined science goals (see
below). Our ARCTAS flights will also include underflights of Terra,
permitting a renewal of our previous correlative measurements for MISR
aerosol validation, which have been very fruitful.

![](media/image11.wmf){width="5.220138888888889in"
height="3.435416666666667in"}

**Fig. 6.** Illustration of the low-altitude aircraft flight patterns
proposed for AATS measurements in ARCTAS to support combined suborbital
and satellite aerosol radiative effect studies. (1) Survey Vertical
Profile. (2) Minimum-Altitude Transect. (3) Parking Garage. (4)
Above-Cloud Transect.

Our experience from INTEX-A&B and many previous experiments has shown
that success in accomplishing the dual goals of satellite validation and
radiative effect science is critically dependent on flying the necessary
aircraft flight patterns. Fig. 6 shows the types of flight patterns
flown in INTEX-A&B, which we also propose to fly in ARCTAS. More
detailed flight patterns are proposed to be developed in a companion
proposal led by Dr. Russell, submitted separately to this NRA.

Brief descriptions and rationales for the four patterns shown in Figure
6 are as follows: (1) Survey Vertical Profile, often flown when first
arriving at a measurement site, provides profiles of AOD, aerosol
extinction, CWV, and water vapor density, often used for determining
aerosol and water vapor layer heights for further measurements in
subsequent patterns. (2) Minimum Altitude Transect, usually flown at or
near satellite overpass time, provides AOD and CWV measurements of the
full column viewed by the satellite. Long transects can measure
gradients and other spatial structure in the satellite scene. (3)
Parking Garage, or stepped profile, includes horizontal legs and linking
ramps. The horizontal legs permit measurements of radiative fluxes
and/or collection of long-duration samples, at altitudes chosen on the
basis of the Survey Vertical Profile. (4) Above-Cloud Transect provides
measurements of AOD spectra and CWV above cloud. Such measurements
contribute to studies of aerosol indirect (i.e., cloud-mediated)
effects. For example, above-cloud AOD spectra are difficult to determine
from space, but they affect satellite retrievals of cloud OD and droplet
effective radius---two important measures of aerosol indirect effects.
Radiative flux spectra from above-cloud transects also permit retrievals
of cloud OD and droplet effective radius from SSFR and RSP measurements.

### Data reduction and archival

We will reduce the AATS-14 data in the field and provide it to the
project archive on project schedules as we did in INTEX-A&B (see the
data archived at <http://www-air.larc.nasa.gov/cgi-bin/arcstat>.). Our
experience has shown that our initial data reduction in the field
produces data that is within a few percent of final data processing,
with the exception of rare changes in the calibration of select
channels, which can only be detected during the post-mission calibration
trip and therefore need to be included in later processing.

## Integrated analyses for ARCTAS aerosol radiative effect studies

The range of integrated analyses possible with the ARCTAS AATS-14 data
set will depend somewhat on whether and which other instruments fly on
the P-3 aircraft with AATS-14. As pointed out above, the inclusion of an
in situ aerosol instrumentation package on the P-3 would necessitate a
focus on aerosol closure studies, such as those described in section
2.3.2 above.

The radiative impacts of Arctic Haze aerosol and boreal forest fire
smoke depend critically on their vertical distributions and on the
albedo of the underlying surface. Therefore, as a first step to the
radiative effects studies proposed here, we plan to assess the vertical
structure of aerosol optical properties during aircraft profiles.
Depending on the observational circumstances, we propose to then either
make measurements conducive to the aerosol gradient method for the
assessment of aerosol radiative forcing efficiency or to fly stacked
parking garage patterns to allow the derivation of aerosol absorption
from the measurement of layer AOD from AATS and flux divergence from the
SSFR (see above).

## Integrated analyses for ARCTAS satellite validation studies

Satellite sensors of aerosols \[*Kaufman et al.*, 2002; *Ramanathan et
al*., 2002\] are essential for developing an accurate description of
their regional and global distribution and variability. In particular in
the Arctic, spaceborne aerosol sensors launched in the past few years,
such as MODIS, MISR, POLDER, OMI and CALIOP, have the potential to
advance our understanding of aerosol processes in an environment that is
otherwise difficult to access. Together the new sensors are beginning to
advance our understanding of aerosol-climate interactions.

It is noteworthy that the ARCTAS white paper \[Jacob et al., 2007\]
contains a detailed vision for the synergy of satellite and suborbital
observations of Arctic haze and boreal forest fires. The suborbital
platforms need the satellite-based measurements to assess the spatial
context of their detailed observations, while the satellite measurements
require the suborbital measurements for validation purposes and to
provide the satellite studies with aerosol information not currently
accessible from space.

Of particular interest to the validation of OMI data products are
observations that include information on aerosol absorbing properties,
because aerosol single scattering albedo (SSA) is one of the data
products to be derived from OMI radiances. In the past, observations of
AOD by AATS-14 were successfully combined with measurements of
spectrally resolved total irradiances by the NASA Ames SSFR (Solar
Spectral Flux Radiometer) to derive the spectral aerosol single
scattering albedo \[e.g., *Bergstrom et al*., 2003\]. In INTEX-A, the
AATS and SSFR measurements were combined to estimate aerosol radiative
forcing from an aerosol gradient method - as shown in Fig. 1. In this
proposal we only request funding to support the deployment of the NASA
AATS-14 instrument and associated analyses. However, the addition of
SSFR to measure upwelling and downwelling, spectrally resolved total
irradiances will enable the validation of OMI-derived SSA.

The particular interests of the MISR aerosol team in ARCTAS are (i) to
study Boreal Fire Plume Height, Optical Depth, and Smoke Type, (ii) to
quantify MISR\'s ability to retrieve Aerosol Optical Depth Over Snow and
Ice, (iii) to contribute MISR maps of high-latitude Aerosol Optical
Depth, Air Mass Type & Extent, as much as possible, (iv) to contribute
MISR multi-angle maps of high-latitude Surface Structure, and (v) to
work collaboratively to realize the aerosol transport and aerosol
forcing campaign goals.

The ARCTAS goals of the MODIS aerosol team led by Dr. Lorraine Remer are
(i) to study emission sources and transport of aerosols (dust,
pollution, smoke) and CO to the Arctic region, (ii)
inter-compare/validate aerosols and CO between GOCART model outputs,
satellite retrievals, and aircraft measurements to assess influxes of
aerosol and CO to the Arctic region in a global perspective, (iii)
advance satellite retrievals over snow/ice/cloud surface using airborne
measurements of aerosol chemical compositions and CO vertical
distributions currently unavailable or less accurate, and (iv) to
evaluate aerosol radiative effects in the complex environments
(snow/ice/clouds) using GOCART model simulations and MODIS satellite
measurements on Terra and Aqua.

As described in section 2, the observations of aerosols and their
radiative effects by MODIS, MISR and OMI in the Arctic are extremely
important due to the paucity of suborbital observations. At the same
time, these satellite observations are hampered by the vast spatial
extent of cloud cover, the lack of contrast between clouds and highly
reflective surfaces, as well as the persistently low sun angles and long
seasonal lack of solar illumination. We propose here to fly low-level
horizontal transects over the Arctic snow- and ice-cover to measure
spectral AOD with AATS-14 for a validation of the retrievals by the
passive aerosol remote sensors.

Among the challenges for the passive remote sensors described above,
only the persistence of low cloud cover in the Arctic presents an
observational challenge to CALIPSO. Because of the relatively higher
frequency of CALIPSO overpasses in the Arctic (by comparison to lower
latitudes), we expect to have ample opportunities for the comparison of
AATS-14 derived aerosol extinction profiles to the extinction profiles
derived from the CALIOP lidar. Even when low clouds are present,
AATS-measured AODs and extinction profiles above the clouds can be
compared to corresponding CALIPSO results. Both the above-cloud and
cloud-free comparisons of AATS and CALIPSO should be useful for the
investigation of the spatial distribution of Arctic haze and boreal
forest fires, which in turn is important for assessing the transport of
pollutants to the Arctic.

Finally, we propose to use the AATS-14 observations of AOD near clouds
in partly cloudy satellite scenes to study the spatial variability of
AOD as a function of distance from cloud edges. We plan to use these
observations to study the effectiveness with which the passive remote
sensors separate aerosols from clouds and we plan to incorporate both
satellite (CALIOP) and suborbital (HSRL) data to investigate where
changes in full column AOD as seen by AATS occurred in the vertical
column relative to the vertical extent of clouds.

# SUMMARY OF PLANNED ACTIVITIES LISTED BY YEAR

## Year 1 (FY08)

1)  Preparation for participation of AATS-14 in ARCTAS including
    replacement of deteriorated filters, installation of AATS on P-3
    (assuming that initial integration, funded by other sources, is
    successful), participation in pre-deployment test flights,
    coordination of deployment schedule, flight planning, etc.;

2)  Participation of AATS-14 in two ARCTAS deployments(April and July
    2008);

3)  Pre-, between-, and post-mission calibration of AATS-14 at MLO
    (March, June, August 2008);

4)  Preliminary analysis and archival of AOD, CWV and COZ data collected
    in ARCTAS on ARCTAS website by Sept. 30, 2008;

## Year 2 (FY09)

1)  Final archival of data collected in ARCTAS, based on post-mission
    calibration;

2)  Detailed validation studies for MODIS, MISR and OMI based on AATS-14
    data collected in ARCTAS; publication of validation results.

3)  Collaborative studies to test closure among suborbital sensors and
    chemical transport models using AATS multi-wavelength extinction
    profiles. Derivation of CALIOP validation profiles from the
    extinction closure study cases. Publication of results.

## Year 3 (FY10)

1)  Integrated analyses of data collected during ARCTAS, including
    comparison of coincident data products from various Terra and
    A-Train sensors in the context of collocated suborbital
    measurements, and assessment of regional aerosol radiative effects.
    Publication of results.

2)  Studies of the spatial distribution of Arctic haze aerosols and
    emissions from boreal forest fires, based on the combined use of
    suborbital in situ and remote sensing data with satellite aerosol
    retrieval maps to provide the scene context of the suborbital
    measurements. Publication of results.

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Multi-Grid-Cell Validation of Satellite Aerosol Property Retrievals in
INTEX/ITCT/ICARTT 2004, *J. Geophys. Res., 112*, D12S09,
doi:10.1029/2006JD007606, 2007.

Schmid, B., J. M. Livingston, P. B. Russell, P. A. Durkee, H. H.
Jonsson, D. R. Collins, R. C. Flagan, J. H. Seinfeld, S. Gassó, D. A.
Hegg, E. Öström, K. J. Noone, E. J. Welton, K. J. Voss, H. R. Gordon, P.
Formenti, and M. O. Andreae, Clear sky closure studies of lower
tropospheric aerosol and water vapor during ACE 2 using airborne
sunphotometer, airborne in-situ, space-borne, and ground-based
measurements, *Tellus*, B 52, 568-593, 2000.

Schmid B., J.J. Michalsky, D.W. Slater, J.C. Barnard, R.N. Halthore,
J.C. Liljegren, B.N. Holben, T.F. Eck, J.M. Livingston, P.B. Russell, T.
Ingold, and I. Slutsker. Comparison of columnar water-vapor measurements
from solar transmittance methods. *Applied Optics,* Vol. 40, No. 12,
1886-1896, 2001.

Schmid, B., D. A. Hegg, J. Wang, D. Bates, J. Redemann, P. B. Russell,
J. M. Livingston, H. H. Jonsson, E. J. Welton, J. H. Seinfeld, R. C.
Flagan, D. S. Covert, O. Dubovik, A. Jefferson, Column closure studies
of lower tropospheric aerosol and water vapor during ACE-Asia using
airborne sunphotometer, airborne in-situ and ship-based lidar
measurements, *J. Geophys. Res.*, Vol. 108 D23,
doi:10.1029/2002JD003361, 2003a.

Schmid B., J. Redemann, P. B. Russell, P. V. Hobbs, D. L. Hlavka, M. J.
McGill, B. N. Holben, E. J. Welton, J. Campbell, O. Torres, R. A. Kahn,
D. J. Diner, M. C. Helmlinger, D. A. Chu, C. Robles Gonzalez, and G. de
Leeuw, Coordinated airborne, spaceborne, and ground-based measurements
of massive, thick aerosol layers during the dry season in Southern
Africa, *J. Geophys. Res*, 108, doi:10.1029/2002JD002297, 2003b.

Schmid B., R. Ferrare, C. Flynn, R. Elleman, D. Covert, A. Strawa, E.
Welton, D. Turner, H. Jonsson, J. Redemann, J. Eilers, K. Ricci, A. G.
Hallar, M. Clayton, J. Michalsky, A. Smirnov, B. Holben, J. Barnard. How
well can we measure the vertical profile of tropospheric aerosol
extinction?, *J. Geophys. Res.* Vol. 111, D05S07
doi:10.1029/2005JD005837, 2006.

Tanré, D., Remer, L. A., Kaufman, Y. J.; Mattoo, S.; Hobbs, P. V.;
Livingston, J. M.; Russell, P. B.; Smirnov, A. Retrieval of aerosol
optical thickness and size distribution over ocean from the MODIS
airborne simulator during TARFOX. *J. Geophys. Res*. 104 (D2) 2261-2278,
1999.

Torres, O., P.K. Bhartia, J.R. Herman, Z. Ahmad and J. Gleason,
Derivation of aerosol properties from satellite measurements of
backscattered ultraviolet radiation, Theoretical Basis, *J. Geophys.
Res*.,103, 17099-17110, 1998.

Torres, O., Decae, R., Veefkind, P., de Leeuw, G., OMI Aerosol Retrieval
Algorithm, ATBD-OMI-03, Version 2.0, August, 2002.

Vaughan, M. et al., Fully automated analysis of space-based lidar data:
an overview of the CALIPSO retrieval algorithms and data products, in
"Laser Radar Techniques for Atmospheric Sensing", U. N. Singh (ed.),
*Proc. SPIE*, Vol. 5575, doi: 10.1117/12.572024, 2004.

Veefkind J. P., G. de Leeuw, P. A. Durkee, P. B. Russell, P. V. Hobbs,
and J. M. Livingston, Aerosol optical depth retrieval using ATSR-2 and
AVHRR data during TARFOX, *J. Geophys. Res.*, *104*, 2253-2260, 1999.

Wang, J., S. A. Christopher, J. S. Reid, H. B. Maring , D. L. Savoie ,
B. N. Holben, J. M. Livingston, P. B. Russell and S-K. Yang, GOES-8
retrieval of dust aerosol optical thickness over the Atlantic Ocean
during PRIDE, *J. Geophys. Res.* , 108 D19, doi: 10.1029/2002JD002494,
2003.a.

Wang, J., S.A. Christopher, F. Brechtel, J. Kim, B. Schmid, J. Redemann,
P.B. Russell, P. Quinn, and B.N. Holben, Geostationary Satellite
Retrievals of Aerosol Optical Thickness during ACE-Asia, *J. Geophys.
Res.*, *108*, doi:10.1029/2003JD003580, 2003b.

Zhang, J., S.A. Christopher, L.A. Remer and Y.J. Kaufman, Shortwave
Aerosol Cloud-Free Radiative Forcing from Terra, II: Global and Seasonal
Distributions, *J. Geophys. Res.*, D10, S24, doi:10.1029/2004jd005009,
2005.

# MANAGEMENT PLAN

## Roles of Co-PIs and Co-I's

Dr. Jens Redemann will be Principal Investigator. He will be responsible
for the overall scientific direction, project management,
administration, and communications with NASA HQ. He will be responsible
for completing the work on time and within budget. Dr. Philip Russell
will be Co-Investigator. He will be responsible for the project
management on the NASA Ames part of this proposal, and he will
participate scientifically. Mr. Roy Johnson, the AATS engineer, will
prepare AATS-14 for deployment and provide engineering support in the
field. Mr. John Livingston has been a member of the NASA Ames
Sunphotometer Group for more than two decades and will assist in the
deployment of AATS-14 and in the detailed analysis of its data. Mrs.
Ramirez and Mrs. Zhang will aid in the analysis of AATS-14 and satellite
data during and after the ARCTAS deployments.

NASA Ames Research Center and BAER Institute will furnish additional
personnel necessary to accomplish the research.

# CURRENT AND PENDING SUPPORT OF PI J. Redemann

+--------------------------+-----------------------+------------------+
| **Short Title**          | **Agency/Task No.**   | **Duration / WY  |
|                          |                       | for J.           |
|                          | **Total award**       | Redemann**       |
+--------------------------+-----------------------+------------------+
| Current:                 |                       |                  |
+--------------------------+-----------------------+------------------+
| NASA EOS Program:        | NASA HQ / NNG04GM63G  | 7/2004--8/2007 / |
|                          |                       |                  |
| "Spatial variability of  | \$340.7k (Co-PI)      | 0.2 WY           |
| MODIS and MISR derived   |                       |                  |
| data products".          |                       |                  |
+--------------------------+-----------------------+------------------+
| NASA INTEX-B:            | NASA                  | 10/2005-9/2008   |
|                          | AURA/04-0000-0297     |                  |
| "Airborne Sunphotometry  |                       | 0.15 WY          |
| in INTEX-B: Measurements | \$1106.4k (Co-I)      |                  |
| and Analyses..."         |                       |                  |
+--------------------------+-----------------------+------------------+
| A combination of         | NNH05ZDA001N-CCST     | 10/2006-9/2009   |
| mesoscale aerosol        |                       |                  |
| transport modeling,      | \$TBD (PI)            | 0.2-0.35 WY      |
| suborbital data, CALIPSO |                       | (est.)           |
| and other A-Train        |                       |                  |
| aerosol observations to  |                       |                  |
| study the vertical       |                       |                  |
| structure of aerosol     |                       |                  |
| radiative effects        |                       |                  |
+--------------------------+-----------------------+------------------+
|                          |                       |                  |
+--------------------------+-----------------------+------------------+
| Pending:                 |                       |                  |
+--------------------------+-----------------------+------------------+
| Using MODIS, MISR and    | NNH06ZDA001N-EOS      | 10/2006-9/2009   |
| suborbital aerosol       |                       |                  |
| products in the vicinity | \$554.8k (PI)         | 0.30 WY          |
| of clouds and in clear   |                       |                  |
| skies to assess aerosol  |                       |                  |
| radiative effects        |                       |                  |
+--------------------------+-----------------------+------------------+
| Supplemental Analyses of | NNH06ZDA001N-ACRM     | 10/2006-9/2009   |
| INTEX-B J31              |                       |                  |
| Sunphotometry:           | \$950.0k (Co-I)       | 0.25 WY          |
| Collaborative Studies of |                       |                  |
| Aerosol, Cloud and       |                       |                  |
| Surface Radiative        |                       |                  |
| Properties and Effects   |                       |                  |
+--------------------------+-----------------------+------------------+

# BUDGET

## Budget Justification: Narrative

As specified by Section IV of the ROSES 2007 NRA, this section includes
the *Table of Proposed Work Effort* and the description of facilities
and equipment, as well as the rationale and basis of estimate for all
components of cost including procurements, travel, publication costs,
and all subawards/subcontracts. The *Table of Proposed Work Effort*
includes the names and/or titles of all personnel necessary to perform
the proposed investigation. The number of person-months each person is
expected to devote to the project must be given for each year.

**Table of Proposed Work Effort**

![](media/image12.wmf)

The work commitments shown in this section for the PI, Co-I and other
investigators are based on our best estimate of the work required to
conduct the proposed work and bring the effort to a successful
conclusion via flights, data archival, presentations and publications.

The trips shown (below) are to ARCTAS planning meetings, ARCTAS
deployment sites, data workshops, and open scientific conferences, where
the named investigators will need to attend to confer on plans and to
present interim and final results.

Justification for the other costs (listed in Section 3.2, Budget
Justification: Details per the ROSES 2007 call) is as follows:

**Network and computer support:** This is an allocation to the proposed
project of a share of charges billed to Dr. Russell's group for
maintaining the network and system administration in Ames Building 245.
These costs are not covered by Ames G&A or Allocated Service Pools but
are billed to research tasks.

**Publications:** This is our best estimate of the journal page charges
and conference abstract fees required to describe the research results
at conferences and in the peer-reviewed literature. Other included
support costs identified are for Directorate and Division operating
accounts.

## Budget Justification: Details

As specified by Section IV of the ROSES 2007 NRA, this section includes
the detailed proposed budget including all of the Other Direct Costs and
Other Applicable Costs specified in the *NASA Guidebook for Proposers*.
As required for this NRA, the *Budget Justification: Narrative* and the
*Budget Justification: Details* do not specify the Total Estimated Cost,
the cost of Direct Labor, or any Administrative Costs

(e.g., overhead).

![](media/image13.wmf)

## Total Budget

As specified by Section IV of the ROSES 2007 NRA, the *Total Budget*
file, which specifies the complete set of cost components including all
costs discussed in the *Budget Narrative* and *Budget Details*, as well
as the Total Estimated Cost, cost of Direct Labor, and Administrative
Costs (overhead), is provided in a file called "totalbudget.pdf," which
is uploaded as a separate attachment in NSPIRES.

## Travel budget

![](media/image14.wmf)

# Biographical Sketches

**(a) Jens Redemann, PI**

> **Abbreviated Curriculum Vitae**

Professional Experience

  --------------------- ----------------- --------------------------------
  Senior Research       BAERI, Sonoma, CA **Sept. 006 to present**
  Scientist, Group                        
  Leader                                  

  Senior Research       BAERI, Sonoma, CA **April 1999 to Sept. 2006**
  Scientist                               

  Research Assistant    UCLA, CA          **May 1995 to March 1999**

  Lecturer              UCLA, CA          **Jan. 1999 to present**

  Research Assistant    FU Berlin,        **June 1994 to April 1995**
                        Germany           
  --------------------- ----------------- --------------------------------

Education

+---------------------------------+------------------------------------+
| Ph.D. in Atmospheric Sciences,  | > **1999**                         |
| UCLA.                           |                                    |
+---------------------------------+------------------------------------+
| M.S. in Atmospheric Sciences,   | > **1997**                         |
| UCLA.                           |                                    |
+---------------------------------+------------------------------------+
| M.S. in Physics, FU Berlin,     | > **1995**                         |
| Germany.                        |                                    |
+---------------------------------+------------------------------------+

**Relevant Research Experience**

-   PI for a grant to study the vertical distribution of aerosol
    radiative effects from a combination of CALIPSO, MODIS and MISR
    data. CALIPSO and MODIS science team member.

-   Co-Principal Investigator for the study of the spatial variability
    of aerosol products in the vicinity of clouds from MODIS and MISR.
    MODIS science team member.

-   Mission Principal Investigator and Mission Scientist for the
    Extended-MODIS- Validation Experiment (EVE) in 2004, an airborne
    field campaign to validate MODIS near-IR AOD measurements of Asian
    dust transported across the Pacific basin.

-   PI, NASA New Investigator Program (NIP), 2003-2005.

-   PI for the participation of AATS-14 (an airborne sunphotometer) in
    the CLAMS satellite validation study (July 2001). Responsible for
    proposal writing and experiment design, instrument integration, as
    well as scheduling and supervision of three group members. Member of
    the CLAMS science team.

-   Related airborne sunphotometer, lidar and spectral solar flux
    radiometer measurements to in situ measurements of atmospheric
    aerosols and gases to model and derive the vertical structure of
    aerosol-induced radiative flux changes in Earth's atmosphere.

-   Participated in the SAFARI-2000, ACE-Asia, PRIDE, CLAMS, ADAM , ARM
    Aerosol IOP, EVE and INTEX-A&B field experiments aimed at
    investigating atmospheric aerosols. Responsible for daily flight
    planning and platform coordination in CLAMS, INTEX and EVE.

-   Utilized satellite derived aerosol optical depth fields and aerosol
    properties from the ACE-Asia campaign to determine the aerosol
    radiative forcing of climate in the Pacific Basin troposphere.

-   Developed a coupled aerosol microphysics and chemistry model to
    study the dependence of the aerosol single scattering albedo on
    ambient relative humidity.

Honors / Organizations

+----------------------------------------------------------+-----------+
| AGU Fall meeting invited presentation                    | ##        |
|                                                          | ## **2005 |
|                                                          | ** {#sect |
|                                                          | ion-1 .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| NASA Group Achievement Awards -- INTEX-A Science Team    | ##        |
|                                                          | ## **2005 |
|                                                          | ** {#sect |
|                                                          | ion-2 .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| Member of technical committee: NASA Earth System         | ##        |
| Scholars Network                                         | ## **June |
|                                                          |  2004 -** |
|                                                          |  {#june-2 |
|                                                          | 004-- .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| NASA Group Achievement Awards - SOLVE II Science Team    | ##        |
|                                                          | ## **2004 |
|                                                          | ** {#sect |
|                                                          | ion-3 .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| Invited Presentation at the 5^th^ International APEX     | #### **   |
| workshop, Miyazaki, Japan.                               | July 2002 |
|                                                          | ** {#july |
|                                                          | -2002 .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| Invited Presentation at the Atmospheric Chemistry        | ##        |
| Colloquium for Emerging Senior Scientists (ACCESS V).    | ## **1999 |
|                                                          | ** {#sect |
|                                                          | ion-4 .un |
|                                                          | numbered} |
+----------------------------------------------------------+-----------+
| Outstanding Student Paper Award, AGU Fall meeting.       | **1998**  |
+----------------------------------------------------------+-----------+
| NASA Global Change Research Fellowship Awards.           | **19      |
|                                                          | 95-1998** |
+----------------------------------------------------------+-----------+
| UCLA Neiburger Award for excellence in teaching of the   | **1997**  |
| atmospheric sciences.                                    |           |
+----------------------------------------------------------+-----------+

Summary of bibliography: 40 peer-reviewed journal articles (10
first-authored), 100+ conference presentations (50+ first-authored).

Publications relevant to this NRA are listed in section 6 of this
proposal. A complete list of publications can be found at
http://geo.arc.nasa.gov/sgg/AATS-website/CV_info/redemann.html.

**(b) Philip B. Russell**

**Abbreviated Curriculum Vitae**

**Scientific Contributions**

Leadership of many studies of atmospheric aerosol and trace gas effects
on radiation and climate, using remote and in situ measurements from
space, air, ground, and ship platforms.

Development of the NASA Ames Airborne Tracking Sunphotometers (AATS,
U.S. Patent 4,710,618) and leadership of their worldwide, diverse uses
ranging from validation of satellites and models through studies of
aerosol radiative forcing of climate.

Membership on many satellite science teams, including Earth Observing
System Inter-Disciplinary Science (EOS-IDS), Solar Occultation
Satellites (SOSST), Stratospheric Aerosol and Gas Experiment (SAGE), and
Stratospheric Aerosol Measurement (SAM) II.

**Professional Experience**

[NASA Ames Research Center]{.underline}: Research Scientist
(1995-present); Chief, Atmospheric Chemistry and Dynamics Branch
(1989-95); Acting Chief, Earth System Science Division (1988-89); Chief,
Atmospheric Experiments Branch (1982-89). Project Manager,
Stratosphere-Troposphere Exchange Project (STEP, 1982-93).

[SRI International]{.underline} (1972-82): Physicist to Senior
Physicist, Atmospheric Science Center.

[National Center for Atmospheric Research]{.underline} (1971-72, at
University of Chicago and NCAR): Postdoctoral Appointee.

**Education**

Ph.D. and M.S., Physics, Stanford University (1971 and 1967, Atomic
Energy Commission Fellow).

M.S., Management, Stanford University (1990, NASA Sloan Fellow).

B.A., Physics, Wesleyan University (1965, Magna cum Laude; Highest
Honors).

**Honors and Awards**

NASA Ames Honor Award (2002, for excellence in scientific research).
NASA Ames Associate Fellow (1995, for excellence in atmospheric
research; Ames's highest annual award). NASA Exceptional Service Medal
(1988, for managing Stratosphere-Troposphere Exchange Project). NASA
Space Act Award (1989, for inventing Airborne Autotracking
Sunphotometer). NASA Group Achievement Awards (1989-2006).

Member, Phi Beta Kappa and Sigma Xi.

**Scientific Societies/Committees**

Fellow, American Association for the Advancement of Science (elected
2005 for "pioneering work and scientific leadership in the measurement
of aerosol properties and the effects of haze on the Earth's energy
budget and climate"). Editor-in-Chief (1994-95) and Editor (1993, 1996),
*Geophysical Research Letters*; Member, Board of Editors and Atmospheric
Science Executive Committee, American Geophysical Union. Guest Editor,
*Journal of Geophysical Research* Special Issues (1988-1993). Chair,
American Meteorological Society International Committee on Laser
Atmospheric Studies (1979-82, Member, 1978-82). Member, National
Research Council Committee on Army Basic Research (1979-81). Member,
American Meteorological Society Committee on Radiation Energy (1979-81).

1987\)

**Publications**

Over 125 peer-reviewed publications. Selected publications relevant to
this NRA are listed below.

Russell, P. B., et al., Multi-grid-cell validation of satellite aerosol
property retrievals in INTEX/ITCT/ICARTT 2004, *J. Geophys. Res., 112*,
D12S09, doi:10.1029/2006JD007606, 2007

Russell, P., et al., Aerosol optical depth measurements by airborne Sun
photometer in SOLVE II: Comparisons to SAGE III, POAM III and airborne
spectrometer measurements, *Atmos. Chem. Phys*., *5*, 1311--1339, 2005
(SRef-ID: 1680-7324/acp/2005-5-1311,
[www.atmos-chem-phys.org/acp/5/1311/](http://www.atmos-chem-phys.org/acp/5/1311/)).

Russell, P. B., et al, Sunlight transmission through desert dust and
marine aerosols: Diffuse light corrections to Sun photometry and
pyrheliometry, *J. Geophys. Res*., 109, D08207,
doi:10.1029/2003JD004292, 2004.

Schmid B., J. Redemann, P. B. Russell, et al., Coordinated airborne,
spaceborne, and ground-based measurements of massive, thick aerosol
layers during the dry season in Southern Africa, *J. Geophys. Res*.,
108(D13)8496, doi:10.1029/2002JD002297, 2003.

Russell, P. B., et al., Comparison of aerosol single scattering albedos
derived by diverse techniques in two North Atlantic experiments, *J.
Atmos. Sci.,* *59*, 609-619, 2002.

Redemann, J., P. B. Russell, and P. Hamill, Dependence of aerosol light
absorption and single scattering albedo on ambient relative humidity for
sulfate aerosols with black carbon cores, *J. Geophys. Res.*, *106*,
27,485-27,495, 2001.

Russell, P. B., and J. Heintzenberg, An overview of the ACE-2 Clear Sky
Column Closure Experiment (CLEARCOLUMN), *Tellus B 52*, 463-483, 2000.

Schmid, B., Livingston, J. M., Russell, P. B., et al. Clear sky closure
studies of lower tropospheric aerosol and water vapor during ACE 2 using
airborne sunphotometer, airborne in-situ, space-borne, and ground-based
measurements. *Tellus B 52*, 568-593, 2000.

Bergstrom, R. W., and P. B. Russell, Estimation of aerosol radiative
effects over the mid-latitude North Atlantic region from satellite and
in situ measurements. *Geophys. Res. Lett., 26*, 1731-1734, 1999.

Russell, P. B., P. V. Hobbs, and L. L. Stowe, Aerosol properties and
radiative effects in the United States Mid-Atlantic haze plume: An
overview of the Tropospheric Aerosol Radiative Forcing Observational
Experiment (TARFOX), *J. Geophys. Res*., *104*, 2213-2222, 1999a.

Russell, P. B., et al., Aerosol-induced radiative flux changes off the
United States Mid-Atlantic coast: Comparison of values calculated from
sunphotometer and in situ data with those measured by airborne
pyranometer, *J. Geophys. Res.,* 104, 2289-2307, 1999b.

Russell, P. B., S. Kinne and R. Bergstrom, Aerosol climate effects:
Local radiative forcing and column closure experiments, *J. Geophys.
Res.,* *102*, 9397-9407, 1997.

Russell, P. B., et al., Global to microscale evolution of the Pinatubo
volcanic aerosol, derived from diverse measurements and analyses. *J.
Geophys. Res.*, *101*, 18,745-18,763, 1996a.

Russell, P.B., et al., The tropical experiment of the
Stratosphere-Troposphere Exchange Project (STEP): Science objectives,
operations, and summary findings. *J. Geophys. Res.*, *98*, 8563-8589,
1993.

Russell, P.B., et al., Post-Pinatubo optical depth spectra vs. latitude
and vortex structure: Airborne tracking sunphotometer measurements in
AASE II. *Geophys. Res. Lett.*, *20*, 2571-2574, 1993.

Russell, P.B., and M.P. McCormick. SAGE II aerosol data validation and
initial data use: An introduction and overview. *J. Geophys. Res.*,
*94*, 8335-8338, 1989.

Russell, P.B., et al. Satellite and correlative measurements of the
stratospheric aerosol: III. Comparison of measurements by SAM II, SAGE,
dustsondes, filters, impactors, and lidar.\" *J. Atmos. Sci.*, *41*,
1791-1800, 1984.

Russell, P.B., and B.M. Morley, 1982: \"Orbiting Lidar Simulations: II.
Density, Temperature, Aerosol and Cloud Measurements by a
Wavelength-Combining Technique,\" *Applied Optics*, *21*, 1554-1563.

Russell, P.B., et al. \"Satellite and correlative measurements of the
stratospheric aerosol: I. An optical model for data conversions.\" *J.
Atmos. Sci.,* *38*, 1270-1294, 1981.

Russell, P.B., J.M. Livingston, and E.E. Uthe. \"Aerosol-induced albedo
change: measurement and modeling of an incident.\" *J. Atmos. Sci.*,
*36,* 1587-1608, 1979.

Russell, P.B., and G.W. Grams, 1975: Application of soil dust optical
properties in analytical models of climate change, *J. Appl. Meteorol*.,
*14*, 1037-1043.

# STATEMENTS OF COMMITMENT

## Co-Investigator

TO: Jens Redemann

FROM: Philip Russell

I acknowledge that I am identified by name as Co-Investigator to the
investigation entitled "Airborne

sunphotometer measurements of aerosols and water vapor to study aerosol
radiative forcing and boreal forest fires in ARCTAS**"**, that is
submitted by Dr. Jens Redemann to the NASA Research Announcement
NNH07ZDA001N-ARCTYAS, and that I intend to carry out all
responsibilities identified for me in this proposal. I understand that
the extent and justification of my participation as stated in this
proposal will be considered during peer review in determining in part
the merits of this proposal.

Signed:

  ---------------------------------------------------- -- -- -------------------------------
  ![](media/image15.png){width="2.032638888888889in"         
  height="0.35347222222222224in"}                            

  **Philip Russell**                                         

  **Date:**                                                  
  ---------------------------------------------------- -- -- -------------------------------

## Collaborators

### Prof. Peter Pilewskie, Univ. of Colorado

**Subject:** Letter of support for ARCTAS collaboration

**From:** Peter Pilewskie \<Peter.Pilewskie@lasp.colorado.edu\>

**Date:** Tue, 05 Jun 2007 13:26:33 -0600

**To:** Jens Redemann <jredemann@mail.arc.nasa.gov>

Dear Jens,

I acknowledge that I am identified by name as a Collaborator to the
investigation entitled "Airborne

sunphotometer measurements of aerosols and water vapor to study aerosol
radiative forcing and boreal forest fires in ARCTAS", that is submitted
by Dr. Jens Redemann to the NASA Research Announcement
NNH07ZDA001-N-ARCTAS, and that I intend to carry out all
responsibilities identified for me in this proposal. I understand that
the extent and justification of my participation as stated in this
proposal will be considered during peer review in determining in part
the merits of this proposal.

Sincerely,

Peter Pilewskie

\--

Peter Pilewskie

Laboratory for Atmospheric and Space Physics

Department of Atmospheric and Oceanic Sciences

Duane Physics, Rm D-317

Campus Box 311

University of Colorado

Boulder, CO 80309-0311

303 492 5724

peter.pilewskie@lasp.colorado.edu

### Dr. Ralph Kahn, JPL

![](media/image16.jpeg){width="6.99375in" height="7.60625in"}