Atmospheres 2004 Technical Highlights: Section 4 Major Activities

The previous section outlined the science activities pursued in the Laboratory for Atmospheres. This section presents summary paragraphs of our major activities in measurements, field campaigns, data sets, data analysis, and modeling. In addition, we summarize the Laboratory's support for the National Oceanic and Atmospheric Administration’s (NOAA) remote sensing requirements. The section concludes with a listing of project scientists, a description of interactions with other scientific groups, and a statement of our interest in commercialization and technology transfer.

4.1 Measurements

Studies of the atmospheres of Earth and the planets require a comprehensive set of observations, relying on instruments borne on spacecraft, aircraft, balloons, or those that are ground-based. Our instrument systems 1) provide information leading to basic understanding of atmospheric processes, and 2) serve as calibration references for satellite instrument validation.

Many of the Laboratory’s activities involve developing concepts and designs for instrument systems for spaceflight missions, and for balloon-, aircraft-, and ground-based observations. Airborne instruments provide critical in situ and remote measurements of atmospheric trace gases, aerosol, ozone, and cloud properties. Airborne instruments also serve as stepping-stones in the development of spaceborne instruments, and serve an important role in validating spacecraft instruments.

Table 3 shows the principal instruments that were built in the Laboratory or for which a Laboratory scientist has had responsibility as Instrument Scientist. The instruments are grouped according to the scientific discipline each supports. Table 3 also indicates each instrument’s deployment—in space, on aircraft, balloons, on the ground, or in the laboratory. Instrument details are not presented here, but appear in a separate Laboratory technical publication, the “Instrument Systems Report,” NASA-TP-2005-212783.

Table 3: Principal instruments supporting scientific disciplines in the Laboratory for Atmospheres.


Structure and

Atmospheric Chemistry

Clouds and

Atmospheres/Solar Influences



Total Ozone Mapping Spectrometer (TOMS)

Earth Polychromatic Imaging Camera (EPIC)


Gas Chromatograph Mass Spectrometer (GCMS)–

Cassini Huygens Probe

Ion and Neutral Mass Spectrometer (INMS)–Cassini Orbiter


ER-2 Doppler Radar (EDOP)

Holographic Airborne

Rotating Lidar Instrument Experiment (HARLIE)

Air Goddard Lidar Observatory for Winds (Air GLOW )

Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTAL)

Raman Airborne Spectroscopic Lidar (RASL)

Cloud Physics Lidar (CPL)

cloud THickness from Offbeam Returns (THOR) Lida

Cloud Radar System (CRS)

UAV Cloud Physics Lidar (UAV CP Lidar)





Scanning Raman Lidar (SRL)

Goddard Lidar Observatory for Winds (GLOW)

Lightweight Rain Radiometer-X band


Stratospheric Ozone Lidar Trailer Experiment


Aerosol and Temperature Lidar (AT Lidar)

Brewer UV Spectrometer

Kiritimati Island Lidar Trailer (KILT )

Lagrange-2 Solar Viewing Interferometer Prototype (L2-SVIP) Instrument Incubator Program (IIP)

GeoSpec (IIP)

Micro-Pulse Lidar (MPL)

COmpact Visible Infrared Radiometer (COVIR)

Surface-Sensing Measurements for Atmospheric Radiative Transfer (SMART)—Chemical, Optical, and Microphysical Measurements of In situ Troposphere (COMMIT)


4.2 Field Campaigns

Field campaigns use the resources of NASA, other agencies, and other countries to carry out scientific experiments, to validate satellite instruments, or to conduct environmental impact assessments from bases throughout the world. Research aircraft, such as the NASA ER-2 and DC-8, serve as platforms from which remote sensing and in situ observations are made. Ground-based systems are also used for soundings, remote sensing, and other radiometric measurements. In 2004, Laboratory personnel supported many such activities as scientific investigators, or as mission participants, in the planning and coordination phases.

Aura Validation Experiment (AVE)

AVE is a measurement campaign designed to acquire correlative data needed for the validation of the Aura satellite instruments. Aura was launched in July 2004 with four instruments: OMI, TES, MLS, and HIRDLS. Aura has three science objectives: 1) analyze the recovery of the ozone layer, 2) assess air quality problems, and 3) determine how the Earth’s climate is changing.

The first component of the AVE mission (Pre-AVE) was conducted during January–February 2004. Measurements were made in the western U.S. and the tropics from San Jose, Costa Rica using the NASA WB-57F high altitude aircraft. The objective of Pre-AVE was to test concepts for using high-quality in situ and remote data sets for Aura validation. The high altitude NASA WB-57F carried 18 in situ instruments and 1 remote sensing instrument. During this campaign, a total of eight flights were conducted (one test, two mid-latitude flights, three equatorial flights, and two transit flights between Houston and San Jose, Costa Rica).

The second component of AVE (AVE-October) was conducted during October–November 2004. Again, measurements were made in the western U.S. and over the Gulf of Mexico in support of Aura. During AVE-October, the payload consisted of 11 instruments (8 in situ and 3 remote sensing). A total of eight flights were conducted that were precisely timed to coincide with the Aura overpass. For more information, contact Paul A. Newman (

Figure 4-1. Picture of the Galapagos Islands taken from the NASA WB-57F from an altitude of 60,000 feet on January 30, 2004. Photo by Brian J. Barnett (NASA JSC).

CPL Activities

During 2004, the Cloud Physics Lidar (CPL) was modified to operate on the NASA WB-57F aircraft. Historically the CPL has operated only on the ER-2 aircraft. Future missions, however, will require use of the WB-57F, so it became imperative to adapt CPL to that aircraft. Mechanical, thermal, and data system modifications were required for operation on the WB-57F.

After modifications were made, the CPL participated in the first Aura Validation Experiment (AVE) conducted from Ellington Field in Houston, TX from October 18 to November 12, 2004. The purpose of this experiment was to validate the instruments onboard the Aura satellite. A total of nine satellite underflights were performed under a variety of atmospheric conditions.

For more information on the CPL instrument, or for access to CPL data, visit, or contact Matthew McGill (

United Arab Emirates Unified Aerosol Experiment (UAE2)

The Goddard Surface-sensing Measurements for Atmospheric Radiative Transfer (SMART) facility deployed successfully in the United Arab Emirates Unified Aerosol Experiment (UAE2, from August–September 2004 near the oasis of Al Ain city, UAE. UAE2 was conducted by the regional scientists and authorities in concert with researchers from NASA AERONET, U.S. Naval Research Laboratory (NRL) aerosol group, and aircraft research team at the University of the Witwatersrand, South Africa. This experiment used ground-based and airborne instruments in the vicinity of the Persian Gulf to characterize the chemical, microphysical, optical and radiative properties of the regional dust and anthropogenic aerosols, and to aid in the satellite retrievals ( html) for assessing the aerosol impact on the regional-to-global climate. SMART ( is a mobile, ground-based remote sensing facility (8' ´ 8' ´ 20' weather-sealed trailer with thermostatic temperature control), which includes a sun photometer, a rotating shadow-band radiometer, a micropulse lidar, a solar spectrometer, an interferometer, a whole-sky imager, a microwave radiometer, an array of shortwave and longwave flux radiometers, and a system of surface meteorological probes. MPLNET supplied one of the lidars and performed data analysis on the lidars.

During UAE2, we devoted a great deal of effort to characterize the surface radiative properties of deserts by using in-house, custom-built instruments. The differential warming/cooling effects exerted by atmospheric aerosols constitute one of the most uncertain factors in climate change related research. This is especially true over regions of bright-reflecting surface, such as desert areas. Furthermore, one of the key ingredients for achieving accurate aerosol retrievals from satellite observations is a comprehensive understanding of surface spectral-bidirectional reflectance. Working under daytime dead heat of ~35–45°C and a wide range of relative humidity (~10–80%), we have acquired many first-hand, first-class data sets of surface radiative properties. Currently, the compilation of these spectral-bidirectional reflectances of desert surface is underway for community use. For further information, contact Si-Chee Tsay (

Figure 4-2. “Light through a Camel’s Eyes” What is seen in a camel’s eyes through reflected sunlight by hazy desert? To assist satellite retrievals of aerosol properties over desert regions, we deployed our “camel robot”—a spectroradiometer mounted on a tripod seen in the center panel. The team of NASA/University researchers are shown in the left panel. The color of the surface ranged from dull white near the coast (the remains of oceanic wash-up) to pinkish-red inland (pictures in the right panel). One of the key ingredients for achieving accurate aerosol retrievals from satellite observations is a comprehensive understanding of surface spectral Bidirectional Reflectance Factors (BRFs), defined as a ratio of radiance measurements reflected from a targeted surface and from a spectral-angular featureless referencing plate (cf. instrument setup in the center panel). Shown in the bottom panel is the spectral (350–2500 nm) characteristics of BRF’s acquired at one of the inland sites around 13:20 local time on October 1, 2004.

4.3 Data Sets

In the previous discussion, we examined the array of instruments and some of the field campaigns that produce the atmospheric data used in our research. The raw and processed data from these instruments and campaigns is used directly in scientific studies. Some of this data, plus data from additional sources, is arranged into data sets useful for studying various atmospheric phenomena. The major data sets are described in the following paragraphs.

50-Year Chemical Transport Model (CTM) Output

A 50-year simulation of stratospheric constituent evolution has been completed using the Code 916 three-dimensional chemistry and transport model. Boundary conditions were specified for chlorofluorocarbons, methane, and N2O appropriate for the period 1973–2023. Sulfate aerosols were also specified, and represent the eruptions of El Chichón and Mt. Pinatubo. Simulations with constant chlorine and without the volcanic aerosols have also been completed to help distinguish chemical effects from effects of interannual variability in meteorological fields. The model output from all simulations is available on the Code 916 science system; software to read the output is also available. Although the CTM itself is run at 2° ´ 2.5° latitude/longitude horizontal resolution; the output is stored at 4° ´ 5° latitude/longitude. Higher resolution files are available from UniTree, the Code 930 archive. The model output stored on the science system is for 6 days each month (1, 5, 10, 15, 20, 25); daily fields are saved on UniTree. Details about this and other CTM simulations are available from the Code 916 Web site at 3D/exp.html. Questions or comments should be addressed to Anne Douglass (

Aerosol Products from TOMS and OMI

Laboratory scientists are generating a unique new data set of atmospheric aerosol by reanalyzing the 17-year data record of Earth’s ultraviolet albedo as measured by TOMS. Since 1996, Laboratory staff members have developed techniques for extracting aerosol information from measured UV radiances. TOMS aerosol detection capability is based on the change in spectral contrast of upwelling near-UV radiances at the top of an aerosol-laden atmosphere. The spectral contrast variability is measured in relation to that of a pure molecular atmosphere. The near-UV technique differs from conventional visible methods of aerosol detection in that the UV measurements can separate UV-absorbing aerosol (such as desert dust, smoke from biomass burning, and volcanic ash) from nonabsorbing aerosol (such as sulfates, sea salt, and ground-level fog). In addition, the UV technique can detect aerosol over water and land surfaces, including deserts where traditional visible and near-IR methods do not work. TOMS aerosol data are currently available in the form of a contrast index and as near-UV extinction optical depth.

The aerosol index is a qualitative parameter that provides excellent information about absorbing aerosol sources, transport, and seasonal variation of a variety of aerosol types. The aerosol index is the only known remote-sensing technique capable of detecting desert dust, smoke, and volcanic ash aerosol over snow or ice and clouds. The most recent version of the data, based on Version 8 reprocessing, has been released.

The science value of the TOMS aerosol information has been enhanced by the application of an inversion procedure to the TOMS measured radiances to derive the near-UV extinction optical depth and single-scattering albedo of aerosol. The combination of these two products yields the aerosol absorption optical depth. Figure 4-3 shows the retrieved TOMS extinction optical depth and single scattering albedo of the dense smoke plume formed during the fires in California in October 2003. The third panel shows the resulting aerosol absorption optical depth.

Figure 4-3. TOMS retrievals of aerosol extinction optical depth, single scattering albedo, and absorption optical depth of the aerosol layer produced by fires in Southern California in late October 2003.

The TOMS aerosol algorithm has been applied to the entire TOMS record to produce the longest available data set on aerosol optical depth over the oceans and the continents at a 1° ´ 1° resolution. The TOMS aerosol optical depth record (available at is a useful data set for the analysis of aerosol trends, especially over land areas, where aerosol sources are located, and no other long-term records are available.

Analysis of the TOMS long-term record on aerosol optical depth has detected the existence of statistically significant trends in the atmospheric aerosol load over China and India, as shown in Figure 4-4. The TOMS aerosol record indicates that an increasing trend of 17% per decade in the winter aerosol load has taken place in the China coastal plain. A similar analysis also shows a 7% per decade trend in aerosol concentration in India. These TOMS observed trends in aerosol optical depth are consistent with observed increases of SO2 emissions associated with anthropogenic activities in these regions.

For more information on the TOMS aerosol optical depth and single-scattering albedo products, contact Omar Torres (

Figure 4-4. Trends in aerosol optical depth in China and India as derived from TOMS observations

The near-UV record of aerosol properties will be extended into the future making use of observations by the Ozone Monitoring Instrument (OMI) on the Aura spacecraft, launched on July 2004. Figure 4-5 shows preliminary retrieval results of aerosols over Australia derived from OMI observations.

Figure 4-5. OMI retrieved optical depth and single scattering albedo over Australia on 11-10-2004.

Figure 4-6. Polar image and partial day data set updated for March 8, 2004. The latest daily image and a full-day data set are updated once each day (when we have a full day of data). This near-real time system is automated.

Global Precipitation

An up-to-date, long, continuous record of global precipitation is vital to a wide variety of scientific activities. These include initializing and validating numerical weather prediction and climate models, providing input for hydrological and water cycle studies, supporting agricultural productivity studies, and diagnosing climatic fluctuations and trends on regional and global scales.

At the international level, the Global Energy and Water Cycle Experiment (GEWEX) component of the World Climate Research Programme (WCRP) established the Global Precipitation Climatology Project (GPCP) to develop such global data sets. Scientists working in the Laboratory have led the GPCP effort to merge microwave data from low-Earth–orbit satellites, infrared data from geostationary satellites, and data from ground-based rain gauges to produce the best estimates of global precipitation.

Version 2 of the GPCP merged data set provides global, monthly precipitation estimates for the period, January 1979 to the present. Updates are being produced on a quarterly basis. The release includes input fields, combination products, and error estimates for the rainfall estimates. The data set is archived at World Data Center A (located at the National Climatic Data Center in Asheville, North Carolina) and at the Goddard Distributed Active Archive Center (DAAC). Evaluation is ongoing for this long-term data set in the context of climatology, El Niño Southern Oscillation (ENSO)-related variations, and regional and global trends. The seven-year TRMM data set is being used in the assessment of the longer GPCP data set.

Development of data sets with finer time resolution (daily and 3 h) is proceeding. A daily, global analysis for the period 1997–present has also been completed for the GPCP and is available from the archives. A quasi-global, 3 h resolution rainfall analysis combining TRMM and other satellite data is being produced in real time, with images and data available through the TRMM Web site. A research version of this 3 h data set will soon be available. For more information, contact Robert Adler (

Merged TOMS/SBUV Data Set

We have recently updated our merged satellite total ozone data set to include the Version 8 TOMS and SBUV data. We have transferred the calibration from the original six satellite instruments to the NOAA 16 SBUV/2. This allows us to extend the record despite issues with the calibration of the Earth Probe TOMS (EP-TOMS) for the last few years. The data sets now extend through the end of 2003. We have added a merged profile data set from the SBUV instruments. The data, and information about how they were constructed, can be found at It is expected that these data will be useful for trend analyses for ozone assessments and for scientific studies in general. During 2005, we will update the data through the end of 2004 and will incorporate the data from the OMI instrument on Aura as soon as it has gone through its calibration checks. For further information, contact Richard Stolarski ( or Stacey Frith (

MPLNET Data Sets

The Micro-Pulse Lidar Network (MPLNET) is composed of ground-based lidar systems, co-located with sun–sky photometer sites in the NASA Aerosol Robotic Network (AERONET). The MPLNET project uses the MPL system, which is a compact and eye-safe lidar capable of determining the range of aerosols and clouds continuously in an autonomous fashion. The unique capability of this lidar to operate unattended in remote areas makes it an ideal instrument to use for a network. The primary purpose of MPLNET is to acquire long-term observations of aerosol and cloud vertical structure at key sites around the world. These types of observations are required for several NASA satellite validation programs, and are also a high priority in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The combined lidar and sun photometer measurements are able to produce quantitative aerosol and cloud products, such as optical depth, sky radiance, vertical structure, and extinction profiles. MPLNET results have contributed to studies of dust, biomass, marine, and continental aerosol properties, the effects of soot on cloud formation, aerosol transport processes, and polar clouds and snow. MPLNET data has also been used to validate results from NASA satellite sensors, such as the Multi-Angle Imaging Spectroradiometer (MISR) and TOMS, and to help construct algorithms used to interpret space-based lidar data from GLAS. MPLNET sites will be used as ground calibration/validation sites for NASA’s next satellite lidar—CALIPSO. Further information on the MPLNET project, and access to data, is available online at For questions on the MPLNET project contact Judd Welton (

Multiyear Global Surface Wind Velocity Data Set

The Special Sensor Microwave Imagers (SSM/I) aboard Defense Meteorological Satellite Program (DMSP) satellites have provided a large data set of surface wind speeds over the global oceans from July 1987 to the present. These data are characterized by high resolution, coverage, and accuracy, but their application was limited by the lack of directional information. In an effort to extend the applicability of these data, our scientists developed methodology to assign directions to the SSM/I wind speeds and to produce analyses using these data. This methodology has been used since 1987 to generate global SSM/I wind vectors. These data are currently being used in a variety of atmospheric and oceanic applications and are available to interested investigators. In addition, a new higher resolution integrated data set in which data from all SSM/I and available scatterometers from 1987 to the present is now being produced. For more information, contact Robert Atlas (

Southern Hemisphere ADditional OZonesondes (SHADOZ) Data Set

Initiated by NASA’s Goddard Space Flight Center in 1998, in collaboration with NOAA and meteorological and space agencies from around the world, SHADOZ augments balloonborne ozonesonde launches in the tropics and subtropics. SHADOZ presently includes 13 sites, including 2 that are north of the equator (Suriname and Malaysia). Launches are usually weekly at each station. SHADOZ archives ozone and temperature profile data at a user-friendly, open Web site: SHADOZ ozone data are used for a number of purposes:

(1) Satellite algorithm retrievals and validation of satellite measurements,

(2) Mechanistic studies of processes affecting ozone distributions in the tropical stratosphere and troposphere, and

(3) Evaluation of photochemical and dynamical models that simulate ozone.

SHADOZ has led to significant scientific advances. For example, satellite retrievals are using longitudinal and seasonal variations in tropical ozone for the first time. By having so many profiles, it has been possible to improve accuracy and precision of the ozonesonde measurement under tropical conditions. All SHADOZ stations fly a radiosonde electrochemical concentration cell (ECC) ozonesonde combination. The World Meteorological Organization (WMO) uses SHADOZ as the paradigm for developing new ozone sounding stations in WMO’s Global Atmospheric Watch (GAW) program. In 2004, SHADOZ methods were tested in a field campaign called BESOS: Balloon Experiment on Standards for Ozonesondes. For additional details, contact Anne Thompson ( The archive URL is located at

Skyrad Ground-Based Observations

Skyrad, a ground-based measurement program to observe the zenith sky, continues to investigate radiative transfer properties of the atmosphere in the near-UV and visible (300–500 nm). The purpose of these observations is to test the accuracy of the Laboratory’s highly regarded radiative transfer models, to improve ozone algorithms (for both ground and space), and to validate orbiting satellite instruments, which also operate in this wavelength range. There are now several U.S. and international instruments in orbit (Aura, TOMS, and Envisat) operating in this wavelength range. The observations are taken from the Laboratory’s Radiometric Calibration and Development Facility (RCDF), which houses several ground-based instruments, notably the Shuttle Solar Backscatter Ultraviolet (SSBUV) and a double monochromator Brewer instrument. This location is ideally suited for these studies because several instruments measuring aerosols (AERONET and sun photometers) are located near the RCDF.

Nearly three years of zenith sky data have been taken over a range of sky conditions using SSBUV. In addition, an accurate set of tables of expected zenith sky radiances were calculated for conditions over Goddard including a range of aerosol characteristics and ozone amounts. Comparisons of observations and models resulted in differences of less than 3%. The zenith data are also being used to derive ozone column amounts and aerosol characteristics in the ultraviolet at high solar zenith angles. Accurate ground-based measurements of ozone under these conditions are desperately needed for validation of satellite data. Errors in satellite observation are the largest at high solar zenith angles, a critical region for observing ozone trends. The GSFC Brewer monochromator has been modified and further calibrated to measure, in addition to ozone, nitrogen dioxide, sulfur dioxide, and the absorbing properties of aerosols, which is a new application for this instrument. These measurements are being proposed for local air-quality observations and for validating the Ozone Monitoring Instrument (OMI) flying on Aura as well as similar instruments flying on European satellites. For more information, contact Ernest Hilsenrath ( and Jay Herman (

TIROS Operational Vertical Sounder Pathfinder

The Pathfinder Projects are joint NOAA–NASA efforts to produce multiyear climate data sets using measurements from instruments on operational satellites. One such satellite-based instrument suite is TOVS. TOVS is composed of three atmospheric sounding instruments: the High Resolution Infrared Sounder-2 (HIRS-2), the Microwave Sounding Unit (MSU), and the Spectral Sensor Unit (SSU). These instruments have flown on the NOAA Operational Polar Orbiting Satellite since 1979. We have reprocessed TOVS data from 1979 to the present, using an algorithm developed in the Laboratory to infer temperature and other surface and atmospheric parameters from TOVS observations.

The TOVS Pathfinder Path A data set covers the period 1979–2004 and consists of global fields of surface skin and atmospheric temperatures, atmospheric water vapor, cloud amount, and cloud height, Outgoing Longwave Radiation (OLR) and clear sky OLR, and precipitation estimates. The data set includes data from TIROS N, and NOAA 6, 7, 8, 9, 10, 11, 12, and 14. Equivalent future data sets will be produced from AIRS data on EOS Aqua. We have demonstrated with the 25-year TOVS Pathfinder Path A data set that TOVS data can be used to study interannual variability and trends of surface and atmospheric temperatures and humidity, cloudiness, OLR, and precipitation. The TOVS precipitation data is being incorporated in the monthly and daily GPCP precipitation data sets.

We have also developed the methodology used by the AIRS science team to generate products from AIRS for weather and climate studies, and continue to improve the AIRS science team retrieval algorithm. A new algorithm, Version 4.0, was recently delivered to JPL. The Goddard DAAC has been producing AIRS level-2 soundings since September 2002 using an early version of the AIRS science team retrieval algorithm. The DAAC will begin producing improved AIRS level-2 soundings starting in February 2005 based on the Version 4.0 AIRS Science Team retrieval algorithm. All products obtained in the TOVS Pathfinder data set will also be produced from AIRS, including precipitation estimates. In joint work with Robert Atlas, AIRS temperature profiles derived using this improved retrieval algorithm have been assimilated into the Laboratory forecast analysis system and have shown a significant improvement in weather prediction skill. For more information, contact Joel Susskind (

TOMS Data Sets

Since the Atmospheric Chemistry and Dynamics Branch first formed, it has been tasked with making periodic ozone assessments. Through the years the Branch has led the science community in conducting ozone research by making measurements, analyzing data, and modeling the chemistry and transport of trace gases that control the behavior of ozone. This work has resulted in a number of ozone and related data sets based on the TOMS instrument. The first TOMS instrument flew onboard the Nimbus-7 spacecraft and produced data for the period from November 1978 through May 6, 1993 when the instrument failed. Data are also available from the Meteor-3 TOMS instrument (August 1991–December 1994) and from the TOMS that flew on the Earth Probe spacecraft (July 1996–present).

TOMS data are given as daily files of ozone, reflectivity, aerosol index, and erythemal UV flux at the ground. A new Version 8 algorithm was released in 2004 that addresses errors associated with extreme viewing conditions. These data sets are described on the Atmospheric Chemistry and Dynamics Branch Web site, which is linked to the Laboratory Web site, Click on the Code 916 Branch site, and then click on Data Services. The TOMS spacecraft and data sets are then found by clicking on TOMS Total Ozone data. Alternatively, TOMS data can be accessed directly from

Tropospheric O3 Studies

In 2004, our branch members developed a long record (1979–present time) of tropospheric and stratospheric ozone from TOMS satellite measurements, extending from the tropics to the high latitudes in both hemispheres. In a recently submitted paper in the Journal of Geophysical Research, this data set was used to determine long-term changes in ozone in both the troposphere and stratosphere. The paper discusses the important issues of stratospheric ozone recovery and the long-term increase in tropospheric ozone related to an increase in industrial pollution. Also in 2004, satellite measurements of tropospheric ozone were used to characterize the ozone pollution in the Northern Hemisphere. This study indicated that ozone values over surface emission-free regions of the Atlantic and Pacific Oceans are relatively high (50–60 DU) and are comparable to industrial regions of North America, Europe, and Asia where surface emissions of NOx from industrial sources are significantly high. For more information, contact Jerry Ziemke (

4.4 Data Analysis

A considerable effort by our scientists is spent in analyzing the data from a vast array of instruments and field campaigns. This section details some of the major activities in this endeavor.

Aerosol and Water Cycle Dynamics

Aerosol can influence the regional and possibly the global water cycle by changing the surface energy balance, and altering cloud and rainfall patterns via direct and indirect effects. On the other hand, condensation heating from rainfall, and radiative heating from clouds and water vapor associated with fluctuations of the water cycle drive circulation, which determines the residence time, and transport of aerosols, and their interaction with the water cycle. Understanding the mechanisms and dynamics of aerosol-clouds-precipitation, and eventually implementing realistic aerosol-cloud microphysics in climate models are clearly important pathways to improve the reliability of predictions by climate and Earth system models. Laboratory scientists are involved in analyses of the interrelationships among satellite derived quantities such as cloud optical properties, effective cloud radii, aerosol optical thickness (MODIS, TOMS, Cloudsat, and CALIPSO) in conjunction with rainfall, water vapor, cloud liquid water (TRMM, AMSR), with large scale circulation, moisture convergence (ECMWF and NCEP re-analyses) in different climatic regions of the world, including the semi-arid regions of southwest U.S., the Middle East, Northern Africa, and central and western Asia, as well as the extremely wet monsoon regions of South and East Asia, South America and West Africa. The empirical studies will be coordinated with modeling studies, using global and regional climate models, as well cloud resolving models, coupled to land surface and vegetation models, and ocean models. A major goal of this research is to develop a fully interactive climate-aerosol climate system model, including data assimilation, so that atmospheric water cycle dynamics can be studied in a unified modeling and observational framework. This research also calls for the need to organize and coordinate field campaigns for aerosol and water cycle measurements in conjunction with GEWEX, CLIVAR, and other WCRP international programs on aerosols and water cycle studies. For more information, contact William Lau (, Mian Chin (, Lorraine Remer (, or W.K. Tao (

Atmospheric Hydrologic Processes and Climate

One of the main thrusts in climate research in the Laboratory is to identify natural variability on seasonal, interannual, and interdecadal time scales, and to isolate the natural variability from the human-made global-change signal. Climate diagnostic studies use a combination of remote-sensing data, historical climate data, model output, and assimilated data. Diagnostic studies are combined with modeling studies to unravel physical processes underpinning climate variability and predictability. The key areas of research include ENSO, monsoon variability, intraseasonal oscillation, air–sea interaction, and water vapor and cloud feedback processes. More recently, the possible impact of anthropogenic aerosol on regional and global atmospheric water cycle is also included. A full array of standard and advanced analytical techniques, including wavelets transform, multivariate empirical orthogonal functions, singular value decomposition, canonical correlation analysis, nonlinear system analysis, and satellite orbit-related sampling calculations are used. Maximizing the use of satellite data for better interpretation, sampling, modeling, and eventually prediction of geophysical and hydroclimate systems is a top priority of research in the Laboratory.

Satellite-derived data sets for key hydroclimate variables such as rainfall, water vapor, clouds, surface wind, sea surface temperature, sea level heights, and land surface characteristics are obtained from a number of different projects: the EOS Terra and Aqua series; TRMM, Quick Scatterometer Satellite (QuikSCAT) and Topography Experiment (TOPEX)/Poseidon; the Earth Radiation Budget Experiment (ERBE); Clouds and the Earth’s Radiant Energy System (CERES); the International Satellite Cloud Climatology Project (ISCCP); Advanced Very High Resolution Radiometer (AVHRR); TOMS; SSM/I; MSU; and TOVS Pathfinder. Diagnostic and modeling studies of diurnal and seasonal cycles of various geophysical parameters will be conducted using satellite data to validate climate model outputs, and to improve physical parameterization in models. For more information, contact William Lau ( or Yogesh Sud (

Atmospheric Ozone Research

The Clean Air Act Amendment of 1977 assigned NASA the major responsibility for studying the ozone layer.

Data from many ground-based, aircraft, and satellite missions are combined with meteorological data to understand the factors that influence the production and loss of atmospheric ozone. Analysis is conducted over different temporal and spatial scales, ranging from studies of transient filamentary structures that play a key role in mixing the chemical constituents of the atmosphere to investigations of global-scale features that evolve over decades.

The principal goal of these studies is to understand the complex coupling between natural phenomena, such as volcanic eruptions and atmospheric motions, with human-made pollutants, such as those generated by agricultural and industrial activities. These nonlinear couplings have been shown to be responsible for the development of the well-known Antarctic ozone hole.

An emerging area of research is to understand the transport of chemically active trace gases across the tropopause boundary, both into the stratosphere from the troposphere, and out of the stratosphere to the troposphere. It has been suggested that changes in atmospheric circulation caused by greenhouse warming may affect this transport and, thus, delay the anticipated recovery of the ozone layer in response to phase-out of CFCs. For more information, contact Paul A. Newman (

First Measurements of Trace Gases (NO2, SO2, HCHO, O3) Amounts Using a Brewer Double Monochromator

O3, NO2, HCHO, and SO2 column amounts were measured by using a modified double Brewer spectrometer in direct-sun mode. A new “bootstrap” solar irradiance method of solar calibration has enabled the Brewer spectrometer to detect NO2, HCHO, and SO2 with a sensitivity of approximately 0.4 DU. The method for obtaining the column amounts uses a modified DOAS (spectral fitting) technique having the advantage that measured direct sun slant-column amounts can be accurately converted into vertical column amounts without needing to know the height distribution or making the unlikely assumption of horizontal homogeneity, especially in urban areas. The method described in this study can be applied to the worldwide Brewer network to obtain global distributions of pollution related trace gas amounts. For more information, contact Jay Herman (

First Simultaneous UV and Visible Wavelength Measurements of Aerosol Scattering and Absorption Properties

Very little is known about aerosol absorption in UV compared to the visible spectral region. Without such information, it is impossible to quantify the causes of the observed discrepancy between modeled and measured UV irradiances and photolysis rates. We have performed an aerosol UV absorption closure experiment using a UV-shadowband radiometer and a well-calibrated CIMEL sun–sky run side-by-side continuously for 17 months at the NASA GSFC site in Greenbelt, Maryland. The new combination of the two instruments has enabled the first determination of consistent aerosol scattering and absorption properties in both the visible and UV wavelength regions. For more information, contact Jay Herman (

Impact of Aerosols on Atmospheric Heating and Rainfall

The impact of smoke aerosols generated from biomass burning activities in Southeast Asia on the total reflected solar and emitted thermal radiation (direct and indirect effects) from clouds was investigated using satellite data. Narrowband radiance measurements were combined with broadband irradiance measurements to quantify how smoke aerosols modulate the cloud radiative forcing. Results show that smoke in Southeast Asia is frequently present over large areas of cloud-covered regions during boreal spring. Depending on the loading of the smoke aerosols, the reflected solar (emitted thermal) radiation from clouds was reduced by as much as 100 W m-2 or enhanced by as much 20 W m-2 during spring conditions.

The effect of smoke aerosols produced by agricultural practice from the Indochina peninsula on the precipitation over Southern China was carried out using long-term (~20 years) measurements of cloud fraction, precipitation, wind circulation, and aerosols from the combined satellite and model reanalysis data sets. We found that there are statistically significant indirect effects from smoke aerosols on clouds and precipitation in Southeast and East Asia region. Results show that the precipitation increased downstream from the peak aerosol concentrations and decreased in regions of high aerosol loading. This is caused by aerosols absorption of short wave radiation increasing air temperature and stabilizing the atmosphere in the area with high aerosol loading. These patterns are consistently observed during March through early May when more aerosols are produced from biomass burning. Mean southwesterly winds transport aerosols from biomass burning regions over dry Indochina to southern China where the mean climate is wetter in the pre-monsoon season spring of each year. Based on current measurements we find that the southern China monsoon now starts a couple weeks earlier than the climatological mean onset date because of precipitation increased by aerosol–cloud interaction. We also found that the increase is not due to a northward shift of tropical cloud systems. These results help us understand the impact of large-scale biomass burning on the fresh water distribution in Southeast Asia and also help in the prediction of the onset of the tropical monsoon system. For more information, contact Jay Herman (

Observing System Simulation Experiments

Observing system simulation experiments (OSSEs) are an important tool for designing spaceborne meteorological sensors, developing optimum methods for using satellite soundings and winds, and assessing the influence of satellite data on weather prediction and climate research. At the present time, OSSEs are being conducted to (1) provide a quantitative assessment of the potential impact of currently proposed space-based observing systems on global change research, (2) evaluate new methodology for assimilating specific observing systems, and (3) evaluate tradeoffs in the design and configuration of these observing systems. Specific emphasis over the past year has been on space-based lidar winds and other advanced passive sensors. For more information, contact Robert Atlas (

Rain Estimation Techniques from Satellites

Rainfall information is a key element in studying the hydrologic cycle. A number of techniques have been developed to extract rainfall information from current and future spaceborne sensor data, including the TRMM satellite and the Advanced Microwave Scanning Radiometer (AMSR) on EOS Aqua.

The retrieval techniques include the following:

The satellite-based rainfall information has been used to study the global distribution of atmospheric latent heating, the impact of ENSO on global-scale and regional precipitation patterns, the climatological contribution of tropical cyclone rainfall, and the validation of global models. For more information, contact Robert Adler (

Rain Measurement Validation for TRMM

The objective of the TRMM Ground Validation Program (GVP) is to provide reliable, instantaneous area- and time-averaged rainfall data from several representative tropical and subtropical sites worldwide for comparison with TRMM satellite measurements. Rainfall measurements are made at Ground Validation (GV) sites equipped with weather radar, rain gauges, and disdrometers. A range of data products derived from measurements obtained at GV sites is available via the Goddard DAAC. With these products, the validity of TRMM measurements is being established with accuracies that meet mission requirements. For more information, contact Robert Adler (

Unified Onboard Processing and Spectrometry

Increasingly, scientists agree that spectrometers are the wave of the future in passive Earth remote sensing. The difficulty, however, stems from the vast volume of data generated by an imaging spectrometer sampling in the spatial and spectral dimensions. The data volume from an advanced spectrometer could easily require 10 times the present EOS Data Information System (EOSDIS) capacity—something NASA simply cannot afford. A group of scientists and engineers at GSFC, led by Si-Chee Tsay, is funded (3rd year) by ESTO Advanced Component Technologies (ACT), which is a project to unify onboard processing techniques with compact, low-power, low-cost, Earth-viewing spectrometers being developed for eventual space missions. The philosophy is that spectrometry and its onboard processing algorithms must advance in lockstep, and eventually unite in an indistinguishable fashion. We envision a future in which archives of the spectrometer output will not be a monstrous data dump of spectra, but rather the information content of those spectra, undoubtedly a much smaller and more valuable data stream. In the meantime, we must quickly find ways to losslessly compress (onboard) spectra, using a combination of physics-based removal and proximal differencing, to the maximum extent possible. A system of hyperspectral imager (Quantum Well Infrared Photodetectors) has been integrated and flight-tested in a Navy research aircraft for building a testbed. Currently, we are analyzing an effective flat-fielding algorithm, which will be applied to the Field Programmable Processor Array, also known as Reconfigurable Data Path Processor (FPPA/RDPP) software simulator. In the meantime, we are implementing a cloud-detection algorithm in the FPPA/RDPP software simulator. The final goal is to demonstrate both flat-fielding and cloud-detection in “Real Time.” We are also exploring lossy compressions for specific applications in Earth sciences. For further information, contact Si-Chee Tsay (

4.5 Modeling

Modeling is an important aspect of our research, and is the path to understanding the physics and chemistry of our environment. Models are intimately connected with the data measured by our instruments: models are used to interpret data, and the data is combined with models in data assimilation. Our modeling activities are highlighted below.

Aerosol Modeling (GOCART)

Aerosol radiative forcing is one of the largest uncertainties in assessing global climate change. Aerosol is also a key component determining air quality. To understand the various processes that control aerosol properties and to understand the role of aerosol in atmospheric chemistry and climate, we have developed an atmospheric aerosol model, the GOCART model. This model uses the meteorological fields produced by the Goddard Global Modeling and Assimilation Office (GMAO, Code 900.3), and includes major types of aerosols: sulfate, dust, black carbon, organic carbon, and sea salt. Among these, sulfate, and black- and organic carbon originate mainly from human activities—such as fossil fuel combustion and biomass burning—while dust and sea salt are mainly generated by natural processes, for example, uplifting dust from deserts by strong winds.

We have been using the GOCART model to study intercontinental transport, global air quality, aerosol radiative forcing, and aerosol–chemistry–climate interactions. It has also been used to support aircraft and satellite observations and for analyzing satellite and atmospheric measurement data. The output of the model is used by many groups worldwide for studies of air pollution, radiation budget, tropospheric chemistry, hydrological cycles, and climate change. For more information, contact Mian Chin (, or go to the Web site

Cloud and Mesoscale Modeling

The mesoscale model 5 (MM5) and cloud-resolving (Goddard Cumulus Ensemble–[GCE]) models are used in a wide range of studies, including investigations of the dynamic and thermodynamic processes associated with cyclones, hurricanes, winter storms, cold rainbands, tropical and mid-latitude deep convective systems, surface (i.e., ocean and land, and vegetation and soil) effects on atmospheric convection, cloud–chemistry interactions, cloud–aerosol interactions, and stratospheric–tropospheric interaction. Other important applications include long-term integrations of the models that allow for the study of air–sea, cloud–aerosol, cloud–chemistry (transport) and cloud–radiation interactions and their role in cloud–climate feedback mechanisms. Such simulations provide an integrated system-wide assessment of important factors such as surface energy, precipitation efficiency and radiative exchange processes, and diabatic heating and water budgets associated with tropical, subtropical, and mid-latitude weather systems. Data collected during several major field programs, GATE, (1974), PRESTORM (1985), TOGA COARE (1992–1993), ARM (1997, 2000), SCSMEX (1998), TRMM LBA (1999), TRMM KWAJEX (1999), WMO01 (2001), CAMEX4 (2001), CRYSTAL (2002), and IHOP (2002) has been used to improve, as well as to validate, the GCE and MM5 model. The MM5 was also improved in order to study regional climate variation, hurricanes, and severe weather events (i.e., flash floods in central U.S. and China). The models also are used to develop retrieval algorithms. For example, GCE model simulations are being used to provide TRMM investigators with four-dimensional cloud data sets to develop and improve TRMM rainfall and latent heating retrieval algorithms, and moist processes represented in large-scale models (i.e., weather forecast model and climate model). Both Open MultiProcessing (OpenMP) and Message Passing Interface (MPI) versions of the GCE model are developed and can be efficiently run on different computing platforms. This allows the GCE model to be used in many applications related to NASA missions.

Several Goddard Microphysical schemes (2ICE, 3ICE), Goddard radiation (including explicitly calculated cloud optical properties), Goddard Land Information System (LIS, including the CLM and NOAH land surface models), rainfall and bogus vortex assimilation techniques and diagnostics are being implemented into the Weather Research and Forecast (WRF). The WRF is the next generation regional-scale model that will replace MM5 and the NOAA NCEP numerical prediction model. In addition, a coupled Goddard fvGCM and GCE model is being developed. The use of the fvGCM will enable global coverage, and the use of a high-resolution GCE model will allow for better and more sophisticated physical parameterization.

The scientific output of the modeling activities was again exceptional in 2004 with 12 new papers published and many more submitted. For more information, contact Wei-Kuo Tao (

Global Modeling Initiative

The Global Modeling Initiative (GMI) was initiated under the auspices of the Atmospheric Effects of Aircraft Program in 1995. The goal of GMI is to develop and maintain a state-of-the-art modular 3-D chemistry and transport model (CTM) that can be used for assessment of the impact of various natural and anthropogenic perturbations on atmospheric composition and chemistry, including, but not exclusively, the effect of aircraft. The GMI model also serves as a testbed for model improvements. The goals of the GMI effort are to:

At present, the GMI model exists in separate tropospheric, stratospheric, and aerosol versions. Stratospheric simulations ozone trends have been carried out from 1995 to 2030 using the winds from the NASA Finite Volume General Circulation Model (fvGCM) and the NASA Finite Volume Data Assimilation System (fvDAS). Additional simulations for the years 1973–2025 have been carried out using a “warm” and “cold” realization of fvGCM meteorological fields. Tropospheric simulations have been carried out for 1997 conditions, utilizing winds from GMAO, as well as the Middle Atmosphere Community Climate Model (MACCM version 3), and the Goddard Institute for Space Studies (GISS-II'). The results have been evaluated by comparing them to existing ground-based, aircraft, and remotely-sensed measurements. Sensitivities of a new aerosol model (University of Michigan) to meteorological fields and chemical inputs are also being tested. For more information, contact Jose Rodriguez (

Physical Parameterization in Atmospheric GCM

The development of submodels of physical processes (physical parameterizations) is an integral part of better preparing the climate models for addressing the remaining outstanding climate change issues. Laboratory scientists are actively involved in developing and improving physical parameterizations of the moist processes affecting land–atmosphere interaction, as well as clouds and cloud-radiation and cloud-aerosol interactions. The accuracy of such process-interactions is extremely important for eliminating climate-model biases, which is vital to a better understanding of the global water and energy cycles.

For atmospheric radiation, we are developing efficient, accurate, and modular longwave and shortwave radiation codes with parameterized direct effects of man-made and natural aerosols. The radiation codes allow efficient computation of climate sensitivities to water vapor, cloud microphysics, and optical properties of clouds and aerosols. The codes also allow us to compute the global warming potentials of carbon dioxide and various trace gases.

The second key area of climate model development is the cloud physics itself. Almost all of the state-of-the-art models of our times develop large simulation biases, that are often larger than the outstanding climate change issues which need to be assessed by these models; it is primarily due to the biased heating and moistening fields simulated by the model’s cloud physics. We are evaluating and eliminating such simulation biases of McRAS, an in-house prognostic cloud-scale dynamics and cloud water substance scheme that includes representation of source and sink terms of cloud-scale condensation, microphysics of precipitation and evaporation, as well as horizontal and vertical advection of cloud water substance. Our cloud scheme incorporates attributes from physically based cloud life cycles, effects of convective updrafts and downdrafts, cloud microphysics within convective towers and anvils, cloud-radiation interactions, cloud-aerosol interactions, and cloud inhomogeneity corrections for radiative transfers. The boundary-layer clouds are based on the physics of boundary-layer convection. We are evaluating coupled radiation and the prognostic water schemes with in situ observations from the ARM Cloud and Radiation Test Bed (ARM-CART) and TOGA COARE IOPs, as well as satellite data. Recently, GCM-simulated diurnal cycle of rainfall, that shows significantly different characteristics in different regions of the world, has become an active area of research; TRMM satellite rainfall retrievals provide the essential validation statistics.

For land surface, we are using the Land Information System (LIS) for comparing state-of-the-art algorithms used for representing hydrologic, snow-cover, and evapotranspiration processes for different biomes in each land model. Moreover, the soil moisture prediction in our own model, called HYdrology and Simple Biosphere (HY-SiB) is extended down to 5 m, which often goes through the groundwater table. Two-year long integration with Global Soil Wetness Project (GSWP) forcing data from analysis of observations from 1987 and 1988 have revealed several salient characteristics of each land model that would significantly impact climate change studies. All these improvements have been found to better represent the hydrologic cycle in climate simulation studies. Currently, we are performing objective intercomparisons of different parameterization concepts (applied to models and satellite data retrievals) within the GSFC laboratories. NCAR and GISS scientists are our active collaborators. For more information, contact Yogesh Sud (

Trace Gas Modeling

The Atmospheric Chemistry and Dynamics Branch has developed two- and three-dimensional (2-D and 3-D, respectively) models to understand the behavior of ozone and other atmospheric constituents. We use the 2-D models primarily to understand global scale features that evolve in response to both natural effects, such as variations in solar luminosity in ultraviolet, volcanic emissions, or solar proton events, and human effects, such as changes in chlorofluorocarbons (CFCs), nitrogen oxides, and hydrocarbons. Three-dimensional stratospheric chemistry and transport models simulate the evolution of ozone and trace gases that affect ozone. The constituent transport is calculated using meteorological fields (winds and temperatures) generated by the GMAO or using meteorological fields that are output from a GCM. These calculations are appropriate to simulate variations in ozone and other constituents for time scales ranging from several days or weeks to seasonal, annual, and multiannual. The model simulations are compared with observations, with the goal of illuminating the complex chemical and dynamical processes that control the ozone layer, thereby improving our predictive capability.

The modeling effort has evolved in the following directions:

(1) Lagrangian models are used to calculate the chemical evolution of an air parcel along a trajectory. The Lagrangian modeling effort is primarily used to interpret aircraft and satellite chemical observations.

(2) Two-dimensional noninteractive models have comprehensive chemistry routines, but use specified, parameterized dynamics. They are used in both data analysis and multidecadal chemical assessment studies.

(3) Two-dimensional interactive models include interactions among photochemical, radiative, and dynamical processes, and are used to study the dynamical and radiative impact of major chemical changes.

(4) Three-dimensional CTMs have a complete representation of photochemical processes and use input meteorological fields from either the data assimilation system or from a general circulation model for transport.

The constituent fields calculated using winds from a new GCM developed jointly by the GMAO and NCAR exhibit many observed features. We have coupled this GCM with the stratospheric photochemistry from the CTM to produce a fully interactive 3-D model that is appropriate for assessment calculations. We are also using output from this GCM in the current CTM for multidecadal simulations. The CTM is being improved by implementation of a chemical mechanism suitable for both the upper troposphere and lower stratosphere. This capability is needed for interpretation of data from EOS Aura, which was launched in July 2004.

The Branch uses trace gas data from sensors on the Upper Atmosphere Research Satellite (UARS), on other satellites, from ground-based platforms, from balloons, and from various NASA-sponsored aircraft campaigns to test model processes. The integrated effects of processes such as stratosphere troposphere exchange, not resolved in 2-D or 3-D models, are critical to the reliability of these models. For more information, contact Anne Douglass (

4.6 Support for NOAA Operational Satellites

In the preceding pages, we examined the Laboratory for Atmosphere’s Research and Development work in measurements, data sets, data analysis, and modeling. In addition, Goddard supports NOAA’s operational remote sensing requirements. Laboratory project scientists support the NOAA Polar Orbiting Environmental Satellite (POES) and the Geostationary Operational Environmental Satellite (GOES) Project Offices. Project scientists ensure scientific integrity throughout mission definition, design, development, operations, and data analysis phases for each series of NOAA platforms. Laboratory scientists also support the NOAA SBUV/2 ozone measurement program. This program is now operational within the NOAA/National Environmental Satellite Data and Information Service (NESDIS). A series of SBUV/2 instruments fly on POES. Postdoctoral scientists work with the project scientists to support development of new and improved instrumentation and to perform research using NOAA’s operational data.

Laboratory members are actively involved in the NPOESS Internal Government Studies (IGS) and support the Integrated Program Office (IPO) Joint Agency Requirements Group (JARG) activities. Likewise, the Laboratory is supporting the formulation phase for the next generation GOES mission, known as GOES-R, which will supply a hundredfold increase in real-time data. Laboratory scientists are involved in specifying the requirements for the GOES-R advanced imager, high-resolution sounding suite, solar imaging suite, and in-situ sensors. They participate in writing each Request for Proposal (RFP), and serve on each Source Evaluation Board (SEB) for the engineering formulation of these instruments. For more information, contact Dennis Chesters (


GSFC project engineering and scientific personnel support NOAA for GOES. GOES supplies images and soundings to monitor atmospheric processes in real time, such as moisture, winds, clouds, and surface conditions. GOES observations are used by climate analysts to study the diurnal variability of clouds and rainfall, and to track the movement of water vapor in the upper troposphere. The GOES satellites also carry an infrared multichannel radiometer, which NOAA uses to make hourly soundings of atmospheric temperature and moisture profiles over the United States to improve numerical forecasts of local weather. The GOES project scientist at Goddard provides free public access to real-time weather images via the World Wide Web ( For more information, contact Dennis Chesters (


The first step in instrument selection for NPOESS was completed with Laboratory personnel participating on the Source Evaluation Board as technical advisors. Laboratory personnel were involved in evaluating proposals for the Ozone Mapper and Profiler System (OMPS) and the Crosstrack Infrared Sounder (CrIS), which will accompany the Advanced Technology Microwave Sounder (ATMS), an Advanced Microwave Sounding Unit (AMSU)-like crosstrack microwave sounder. Collaboration with the IPO continues through the Sounder Operational Algorithm Team (SOAT) and the Ozone Operational Algorithm Team (OOAT), which will provide advice on operational algorithms and technical support on various aspects of the NPOESS instruments. In addition to providing an advisory role, members of the Laboratory are conducting internal studies to test potential technology and techniques for NPOESS instruments. We have conducted numerous trade studies involving CrIS and ATMS, the advanced infrared and microwave sounders, which will fly on NPP and NPOESS. Simulation studies were conducted to assess the ability of AIRS to determine atmospheric CO2, CO, and CH4. These studies indicate that total CO2 can be obtained to 2 ppm (0.5%) from AIRS under clear conditions, total CH4 to 1%, and total CO to 15%. This shows that AIRS should be able to produce useful information about atmospheric carbon. For more information, contact Joel Susskind (

CrIS for NPP

CrIS is a high-spectral resolution interferometer infrared sounder with capabilities similar to those of AIRS. AIRS was launched with AMSU-A and the Humidity Sounder for Brazil (HSB) on the EOS Aqua platform on March 5, 2002. Scientific personnel have been involved in developing the AIRS Science Team algorithm to analyze the AIRS/AMSU/HSB data. Current results with AIRS/AMSU/HSB data demonstrate that the temperature sounding goals for AIRS, i.e., root mean squared (RMS) accuracy of 1K in 1 km layers of the troposphere under partial cloud cover, are being met over the ocean. The AIRS soundings will be used in a pseudo-operational mode by NOAA/NESDIS and the NOAA/National Center for Environmental Prediction (NCEP). Simulation studies were conducted for the IPO to compare the expected performance of AIRS/AMSU/HSB with that of CrIS, as a function of instrument noise, together with AMSU/HSB. The simulations will help in assessing the noise requirements for CrIS to meet the NASA sounding requirements for the NPP bridge mission in 2006. Trade studies have also been done for ATMS, which will accompany CrIS on the NPP mission and replace AMSU/HSB. For more information, contact Joel Susskind (

Ozone Mapper Profiler Suite (OMPS)

OMPS will become the next U.S. operational ozone sounder to fly on NPOESS. The instrument suite has heritage from TOMS and SBUV for total ozone mapping and ozone profiling. The need for high performance profiles providing better vertical resolution in the lower stratosphere resulted in the addition of a limb scattering profiler to the suite. The limb scattering profiler instrument has heritage from the two SOLSE/LORE shuttle demonstration flights in 1997 and 2002. These missions were developed by our Laboratory with partial support by the IPO. Data from these experimental flights are being used by Laboratory staff personnel to characterize the OMPS instrument and algorithm.

Laboratory scientists continue to support the Integrated Program Office (IPO) through the Ozone Operational Algorithm Team (OOAT) and the NPP mission science team. Laboratory scientists are conducting algorithm research, advising on pre- and postlaunch calibration procedures, and providing recommendations for validation. They participate in reviews for the OMPS instrument contractor and the NPOESS system integrator. The Laboratory staff members are also assessing OMPS data for climate research. An algorithm has been developed to analyze the Stratospheric Aerosol and Gas Experiment (SAGE) III data when SAGE III operates in a limb scattering mode, which will simulate retrievals expected from the OMPS profiler. This work is an extension of the retrievals used for the SOLSE-1 and SOLSE-2 missions. The advanced ultraviolet and visible radiative transfer models developed in the Laboratory over the last two decades enable this research. The two decades of experience in TOMS and SBUV calibration and validation will also be applied to OMPS. For more information, contact Ernest Hilsenrath ( or Richard McPeters (

Holographic Scanning Lidar Telescope Technology

The Integrated Program Office supports the development of Holographic Scanning Lidar Telescope technology as a risk reduction for lidar applications on NPOESS, including direct detection wind lidar systems. Currently used in ground-based and airborne lidar systems, holographic scanning telescopes operating in the visible and near-infrared wavelength region have reduced the size and weight of scanning receivers by a factor of three. We are currently investigating extending the wavelength region to the ultraviolet, increasing aperture sizes to 1 m and larger, and eliminating all mechanical moving components by optically addressing multiplexed holograms in order to perform scanning. This last development should reduce the weight of large aperture scanning receivers by another factor of three. To date, two conical scanning lidar instruments have been developed in this Lab: the Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS) and the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE). PHASERS is located in Manchester, New Hampshire and operated by Saint Anselm College. HARLIE is operated by GSFC and is currently being modified for use at a wavelength of 355 nm and interfaced to a Doppler receiver for atmospheric wind measurements. For more information on this technology, visit the Web site at, or contact Geary Schwemmer (

Tropospheric Wind Profile Measurements

Measurements of tropospheric wind profiles from ground, air and spaceborne platforms are important for understanding atmospheric dynamics on a variety of time scales. Numerous studies have shown that direct measurement of global winds will greatly improve numerical weather prediction. Because of this importance, the operational weather forecasting communities have identified global tropospheric winds as the number one unmet measurement requirement in the Integrated Operational Requirements Document (IORD-1) for NPOESS, the next generation polar orbiting weather satellite. The Laboratory is using these requirements to develop new Direct Detection Doppler Lidar technologies and systems to measure tropospheric wind profiles, first from the ground and on high altitude aircraft and then from satellites. The ground and airborne Doppler lidar systems provide critical validation of new technologies proposed for eventual spaceborne operation. The NPOESS Integrated Program Office is supporting the effort. For more information, contact Bruce Gentry (

4.7 Project Scientists

Spaceflight missions at NASA depend on cooperation between two upper-level managers, the project scientist and the project manager, who are the principal leaders of the project. The project scientist provides continuous scientific guidance to the project manager while simultaneously leading a science team and acting as the interface between the project and the scientific community at large. Table 4 lists project and deputy project scientists for current missions; Table 5 lists the validation and mission scientists for various campaigns.

Table 4: Laboratory for Atmospheres project and deputy project scientists.

Project Scientists

Mission and Deputy Project Scientists





Robert Adler


Anne Douglass


Pawan K. Bhartia


Ernest Hilsenrath

EOS Aura

Robert Cahalan


Hans Mayr


Dennis Chesters


Matt McGill


James Gleason


Matt McGill


Jay Herman


Steve Platnick

EOS Aqua

Charles Jackman


Marshall Shepherd


Eric Smith


Si-Chee Tsay

EOS Terra

Joel Susskind




Table 5: Laboratory for Atmospheres campaigns and mission scientists.

EOS Validation Scientist

Field/Aircraft Campaigns





David Starr


Matt McGill




Paul Newman




Si-Chee Tsay




Judd Welton


4.8 Interactions with Other Scientific Groups

The Laboratory relies on collaboration with university scientists to achieve its goals. Such relationships make optimum use of government facilities and capabilities and those of academic institutions. These relationships also promote the education of new generations of scientists and engineers. Educational programs include summer programs for faculty and students, fellowships for graduate research, and associateships for postdoctoral studies. A number of Laboratory members teach courses at nearby universities and give lectures and seminars at U.S. and foreign universities. (See Section 6 for more details on the education and outreach activities of our Laboratory). The Laboratory frequently supports workshops on a wide range of scientific topics of interest to the academic community.

NASA and non-NASA scientists work together on NASA missions, experiments, and instrument and system development. Similarly, several Laboratory scientists work on programs residing at universities or other federal agencies.

The Laboratory routinely makes its facilities, large data sets, and software available to the outside community. The list of refereed publications, presented in Appendix A3, reflects our many scientific interactions with the outside community; over 85% of the publications involve coauthors from institutions outside the Laboratory.

A prime example of the collaboration between the academic community and the Laboratory is given in this list of collaborative relationships via Memoranda of Understanding or cooperative agreements:

These collaborative relationships have been organized to increase scientific interactions between the Earth Sciences Directorate at GSFC, and the faculty and students at the participating universities.

In addition, university and other outside scientists visit the Laboratory for periods ranging from one day to as long as two years. Some of these appointments are supported by Resident Research Associateships offered by the National Research Council (NRC) of the National Academy of Sciences; others, by the Visiting Scientists and Visiting Fellows Programs currently managed by the GEST Center. Visiting Scientists are appointed for up to two years and perform research in pre-established areas. Visiting Fellows are appointed for up to one year and are free to carry out research projects of their own design.

Interactions with Other NASA Centers and Federal Laboratories

The Laboratory maintains strong, productive interactions with other NASA Centers and Federal laboratories.

Our ties with the other NASA Centers broaden our knowledge base. They allow us to complement each other’s strengths, thus increasing our competitiveness while minimizing duplication of effort. They also increase our ability to reach the Agency’s scientific objectives.

Our interactions with other Federal laboratories enhance the value of research funded by NASA. These interactions are particularly strong in ozone and radiation research, data assimilation studies, water vapor and aerosol measurements, ground-truth activities for satellite missions, and operational satellites. An example of interagency interaction is the NASA/NOAA/National Science Foundation (NSF) Joint Center for Satellite Data Assimilation (JCSDA), which is building on prior collaborations between NASA and NCEP to exploit the assimilation of satellite data for both operational and research purposes.

Interactions with Foreign Agencies

The Laboratory has cooperated in several ongoing programs with non-U.S. space agencies. These programs involve many of the Laboratory scientists.

Major efforts include TRMM, with the Japanese National Space Development Agency (NASDA); the Huygens Probe GCMS, with the ESA (Centre Nationale d’Etudes Spatiales [CNES]); the TOMS Program, with NASDA and the Russian Scientific Research Institute of Electromechanics (NIIEM); the Neutral Mass Spectrometer (NMS) instrument, with the Japanese Institute of Space and Aeronautical Science (ISAS); and climate research with various institutes in Europe, South America, Africa, and Asia. Another example of international collaboration was in the SOLVE II (SAGE III Ozone Loss and Validation Experiment) campaign, which was conducted in close collaboration with the Validation of International Satellites and study of Ozone Loss (VINTERSOL) campaign sponsored by the European Commission. More than 350 scientists from the United States, the European Union, Canada, Iceland, Japan, Norway, Poland, Russia, and Switzerland participated in this joint effort, which took place in January 2003. In 2004, another international collaboration started with the upload of instruments for the Polar Aura Validation Experiment (PAVE). PAVE is an Aura satellite validation involving instruments on the DC-8. Many of the experimenters from SOLVE II are involved in this campaign, which took place in late January and early February of 2005.

Laboratory scientists interact with about 20 foreign agencies, about an equal number of foreign universities, and several foreign companies. The collaborations vary from extended visits for joint missions, to brief visits for giving seminars, or working on joint science papers.

4.9 Commercialization and Technology Transfer

The Laboratory for Atmospheres fully supports Government–Industry partnerships, SBIR projects, and technology transfer activities. Successful technology transfer has occurred on a number of programs in the past and new opportunities will become available in the future. Past examples include the MPL, holographic optical scanner technology, and Circle to Point Conversion Detector. Industry now uses these innovations for topographic mapping, medical imaging, and for multiplexing in telecommunications. New research proposals involving technology development will have strong commercial partnerships wherever possible.