A51B-0754 0800h
Validation of Aqua AIRS/AMSU/HSB Precipitation Estimates
This paper compares Aqua AMSR-E retrievals of precipitation rates with concurrent AIRS/AMSU/HSB estimates based on the ``opaque-channel'' algorithm described by Chen and Staelin (IEEE Transactions on Geoscience and Remote Sensing, 41, 2, pp. 410-417). This algorithm uses the opaque channels in the oxygen and water vapor absorption bands in addition to four window channels and was trained using NEXRAD data over the eastern U.S. The training set consisted primarily of data from convective precipitation. Its systematic tendency to overestimate summer precipitation rates at high latitudes was quantified, permitting correction of the initial opaque-channel estimates. The climate-dependent biases determined for $5^\circ\times5^\circ$ cells were applied to the initial 15-km opaque-channel retrievals using a neural network trained with AMSR-E data, and the results were validated using 15-km resolution NEXRAD data at midlatitudes and global AMSR-E statistics. For this purpose, the climate was characterized by latitude and by the three dominant principal components representing the atmospheric temperature profile channels. The corrected retrieval results agree well with the concurrent validation data available on a global scale.
A51B-0755 0800h
Atmospheric Soundings From AIRS/AMSU in Partial Cloud Cover
Simultaneous use of AIRS/AMSU-A observations allow for the determination of accurate atmospheric soundings under partial cloud cover conditions. The methodology involves the determination of the radiances AIRS would have seen if the AIRS fields of view were clear, called clear column radiances, and use of these radiances to infer the atmospheric and surface conditions giving rise to these clear column radiances. Susskind et al., (2003) demonstrate via simulation that accurate temperature soundings and clear column radiances can be derived from AIRS/AMSU-A observations in cases of up to 80% partial cloud cover, with only a small degradation in accuracy compared to that obtained in clear scenes. Susskind and Atlas (2004) show that these findings hold for real AIRS/AMSU-A soundings as well. For data assimilation purposes, this small degradation in accuracy is more than offset by a significant increase in spatial coverage (roughly 50% of global cases were accepted, compared to 3.6% of the global cases being diagnosed as clear), and assimilation of AIRS temperature soundings in partially cloudy conditions resulted in a larger improvement in forecast skill than when AIRS soundings were assimilated only under clear conditions. Alternatively, derived AIRS clear column radiances under partial cloud cover could also be used for data assimilation purposes. Further improvements in AIRS sounding methodology have been made since the results shown in Susskind and Atlas (2004). A new version of the AIRS/AMSU-A retrieval algorithm, Version 4.0, will be delivered to the Goddard DAAC for production of AIRS derived products, including clear column radiances. Results will be shown of the accuracy and spatial distribution of temperature-moisture profiles and clear column radiances derived from AIRS/AMSU-A as a function of fractional cover using the Version 4.0 algorithm. References Susskind, J., C. D. Barnet, and J. M. Blaisdell, "Retrieval of Atmospheric and Surface Parameters from AIRS/AMSU/HSB Data in the Presence of Clouds," IEEE Transactions on Geoscience and Remote Sensing, Vol. 41, No. 2, 2003. Susskind, J., R. Altas, "Atmospheric Soundings from AIRS/AMSU/HSB," SPIE Defense and Security Symposium, Orlando, Florida, April 12-16, 2004.
A51B-0756 0800h
ARM Site Atmospheric State Best Estimates for AIRS Forward Model and Retrieval Validation
The high accuracy retrieval goals of AIRS (1K rms in 1km layers below 100mbar for temperature, 10% rms in 2km layers below 100 mbar for water vapor, 0.5K for surface skin temperature), combined with the large temporal and spatial variability of the atmosphere and difficulties in making accurate measurements of the atmospheric state, necessitates careful and detailed validation using well characterized ground based sites. As part of on-going AIRS Science Team efforts and a collaborative effort between NASA and ARM, data from various ARM and other observations are used to create best estimates of the atmospheric state at the Aqua overpass times. This draws upon previous and on-going studies and careful characterization of the ARM data streams. For some overpasses which meet specific view angle and weather related requirements, dedicated radiosondes are launched just before (~45 minutes) and at the overpass time. Estimates of the spectral surface emissivity and local skin temperatures are also constructed. These products and auxiliary plots are made available on the web for each satellite overpass. These profiles and collocated clear sky AIRS data are being used to study observed minus calculated AIRS spectra, aimed at evaluation of the AIRS forward model, AIRS radiances and retrievals, and the input atmospheric state. This paper presents material on how the best estimate profiles are constructed, analyses demonstrating the accuracy of the products, and example applications of the products, focusing on clear sky forward model and retrieval validation.
A51B-0757 0800h
Validation of AIRS Land Surface Temperature and Infrared Emissivity Products
The University of Wisconsin Space Science and Engineering Center (UW-SSEC) is evaluating the accuracy and utility of the NASA AIRS land surface temperature and infrared emissivity products in cooperation with the EOS AIRS science team. Validation of the AIRS operational Level 2 (L2) algorithm over ocean scenes has occurred during the last two years and a validated algorithm will soon be used to reprocess the AIRS data. The AIRS operational L2 algorithm is now being evaluated for accuracy over land scenes. The validation effort for land scenes described here is focused on the comparison of "preliminary" AIRS land products to measurements made by ground-based, aircraft-based, and other satellite-based sensors. Comparison will be made to AIRS products over the U.S. Department of Energy Atmospheric Radiation Measurement (DOE ARM) program Southern Great Plains (SGP) site in north central Oklahoma where a ground-based network exists for validation of land surface products. The particular ground-based and aircraft-based sensors considered here are the UW-SSEC Atmospheric Emitted Radiance Interferometer (AERI) and the Scanning-High spectral resolution Interferometer Sounder (S-HIS). Comparison will also be made to Aqua MODIS land products produced by the MODIS Land team and made available through the MODIS Land Discipline web site. In addition to these instrument sensor inter-comparisons, we will compare the AIRS L2 land products with a UW-SSEC research product that uses atmospheric state data from the European Center for Medium Range Forecasting (ECMWF) to perform an atmospheric correction and thereby directly obtain the land surface temperature and infrared emissivity from the AIRS observations for cloud-free scenes.
A51B-0758 0800h
AIRS retrievals of atmospheric profiles of temperature and humidity - comparisons with radiosondes and ship-based remote sensing during AEROSE
The World Meteorological Organization (WMO) has determined that significantly improving weather forecasting would require global temperature and moisture soundings with at least the accuracy of the current radiosondes. The Atmospheric Infrared Sounder (AIRS) on board of the NASA EOS Aqua satellite, launched in 2002, is designed to provide high-accuracy atmospheric profiles of temperature and humidity. The validation of the AIRS atmospheric profile retrieval scheme is a continuing effort, and has so far been based mostly on dedicated and operational radiosonde measurements. The University of Miami's Marine-Atmosphere Emitted Radiance Interferometer (M-AERI) is a sea-going instrument that measures spectra of atmospheric infrared radiation with ~10 min time resolution. These spectra can be used to retrieve profiles of temperature and humidity in the lowest 3km of the atmosphere (see presentation in session H.20). Thus M-AERI measurements provide another validation dataset for AIRS profile retrievals. An M-AERI was deployed on NOAA Ship Ronald H. Brown during the 2004 Aerosol and Ocean Science Expedition (AEROSE), a multidisciplinary campaign conducted in the tropical North Atlantic Ocean from 29 February to 26 March 2004. This study presents the comparison of atmospheric temperature and moisture profiles derived from a) radiosondes, b) M-AERI and c) AIRS measurements.
A51B-0759 0800h
Study of Water Vapor in the Tropical Tropopause Layer using the JPL Laser Hygrometer and Validation of the Atmospheric Infrared Sounder (AIRS) instrument on the EOS-Aqua satellite.
The Pre-Aura Validation Experiment (Pre-AVE) was a NASA aircraft mission to characterize the composition of the Tropical Tropopause Layer (TTL). In January, 2004, the high-altitude NASA WB-57 aircraft made three flights from San Jose, Costa Rica, into the equatorial TTL. These flights were characterized by unusually cold and dry conditions near the tropical tropopause. We will present in situ water vapor measurements made during these flights made by the JPL Laser Hygrometer (JLH)with the goal being a better understanding how air becomes dehydrated in this region. Temperature measurements from the Atmospheric Infrared Sounder (AIRS) instrument suite on EOS-Aqua will be used to place these in situ measurements in a regional context. Additionally, we report here in situ water vapor measurements made by JLH during the NASA Middle Latitude Cirrus Experiment (MidCiX) flights of 2 May and 6 May 2004. On these flights, the WB-57 aircraft flew spatially and temporally close to the overpass track of the EOS-Aqua satellite. Water vapor measurements taken by the JPL Laser Hygrometer (JLH) on-board the WB-57 will be compared with water retrievals from the AIRS instrument for validation purposes.
A51B-0760 0800h
Comparison of Upper Tropospheric Water Vapor from AIRS and Cryogenic Frostpoint Hygrometers
Upper tropospheric water vapor (UTWV) from the Atmospheric Infrared Sounder (AIRS) experiment on NASA's Aqua spacecraft has the potential of addressing several important climate questions. The specified AIRS system measurement uncertainty for water vapor is 20 percent absolute averaged over 2 km layers. Cryogenic frostpoint hygrometers (CFH) are balloon-borne water vapor sensors responsive from the surface into the lower stratosphere. Several dozen coincident, collocated CFH profiles have been obtained for AIRS validation. The combination of CFH sensitivity and sample size offers a statistically compelling picture of AIRS UTWV measurement capability. We present a comparison between CFH observations and AIRS retrievals. We focus on the altitude range from the middle troposphere up to heights at the limits of AIRS sensitivity to water vapor, believed to be around 100-150 hPa.
A51B-0761 0800h
Over Ocean Atmospheric Validation of AIRS Temperature/Moisture Profiles and Radiances
A suite of in situ and remote sensing meteorological instrumentation is in continuous operation on the commercial cruise ship Explorer of the Seas. This suite has been routinely monitoring atmospheric state and downwelling cloud cleared high-resolution radiances during concurrent Aqua satellite overpass times since Aqua launch. The instrumentation includes well calibrated research grade radiosonde launches for tropospheric temperature and moisture profiles and Marine Atmospheric Emitted Radiance Interferometer (M-AERI) uplooking radiance measurements for radiance validation. The M-AERI also provides highly accurate measurement of ocean surface skin temperature and high temporal resolution planetary boundary layer retrievals of temperature and moisture. This data set is being used to validate AIRS measured upwelling radiances and derived thermodynamic profiles during Aqua overpass times. Preliminary validation results between the shipborne instrumentation and AIRS datasets will be shown for clear sky conditions from 2002 - current.
A51B-0762 0800h
Validation of AIRS ozone column and profile retrievals
The Atmospheric Infrared Sounder (AIRS) currently on the EOS-Aqua platform retrieves ozone column and profile information from nadir viewing of IR emittance in the 10 $\mu$m band. Using an updated channel selection, we report on comparisons of ozone column with TOMS. We also examine AIRS sensitivity in retrieving tropospheric ozone columns, and present preliminary validations with co-incident ozonesondes.
A51B-0763 0800h
Optimization of the Atmospheric Infrared Sounder (AIRS) Carbon Monoxide Retrievals
Since the first light of the Atmospheric Infrared Sounder (AIRS) onboard NASA's EOS Aqua satellite in the summer of 2002, a new method for retrieving atmospheric constituents, one which can be done in the presence of clouds, has been in use by the AIRS science team. This physical retrieval technique combines linear least squares with singular value decomposition to minimize the dependence of the final solution on the first-guess inputs and their associated errors. Combining AIRS wide swath width with its cloud clearing capability results in more comprehensive daily global coverage than previously possible. By implementing this retrieval method on the 4.67 $\mu$m (2180 cm$^{-1}$) spectral region we can retrieve tropospheric carbon monoxide. Through channel and function selection, and damping criteria, we have optimized the carbon monoxide retrieval using in situ aircraft profiles from the Climate Modeling and Diagnostic Laboratory (CMDL) as truth. These in situ profiles were collected from various locations around the globe over a 15 month period and therefore are spatially and temporally representative of the CO variability in the troposphere. Comparisons of the in situ and retrieved carbon monoxide profiles, including sensitivity functions, as well as global CO maps will be presented.
A51B-0764 0800h
A fast radiative transfer model for infrared hyperspectral application to cloudy atmospheres
When clouds are present, the atmospheric infrared (IR) spectral signatures contain a wealth of information about cloud macrophysical, microphysical, and optical properties. To infer cloud optical thickness and effective particle size from the IR spectral measurements, accurate forward radiative transfer (RT) modeling is required. The conventional approach for the forward RT modeling simulation is based on a combination of the line-by-line model (LBLM) and a rigorous multiple scattering RT method such as the well-known Discrete Ordinates Radiative Transfer (DISORT) model. However, this approach is impractical in terms of CPU requirements for a hyperspectral imager application. Strow et al. (1998) developed a fast clear-sky RT model with very high accuracy when compared to the results from the LBLM. In this study, we develop a fast cloudy-sky RT model to compute the outgoing radiance observed at the top of the atmosphere. The code is capable of dealing with single-layered (plane parallel) clouds as well as a two-layered cloud system, such as an ice cloud overlying a water cloud. For ice clouds, the single-scattering properties of ice crystals are computed from a composite method that is based on the finite-difference time-domain (FDTD) technique, an improved geometric optics method (IGOM), the T-matrix method, and the Lorenz-Mie method. A number of pristine and complex ice crystal habits are considered, and include aggregates, hexagonal columns, hexagonal plates, three-dimensional bullet rosettes, hexagonal hollow columns, spheroids, and droxtals. Based on the ice single-scattering properties, a look-up library is generated of cloud reflectances and transmittances for a range of cloud optical thicknesses, effective particle sizes, and viewing angles. The outgoing radiances can be computed both efficiently and accurately using the pre-computed look-up library. The accuracy of the fast cloudy-sky radiative transfer model has been assessed through comparison with rigorous RT computations based on the LBLM and DISORT models.
A51B-0765 0800h
Nighttime cirrus detection in the AIRS/AMSU suite: Global application and comparison to cirrus climatologies
We use the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite onboard EOS-Aqua for the detection of cirrus clouds at nighttime. The proposed technique utilizes carefully selected infrared (IR) window channels near 3.8 and 10.4 microns and total column precipitable water (PW) measurements, derived from the synergistic AIRS and AMSU-A water vapor retrievals. We constrain the brightness temperature difference (dBT) using the PW measurements in order to determine if cirrus clouds are present. Simulated dBTs initialized with radiosonde profiles of temperature and humidity are used to define the boundaries between "cloudy sky" and "uncertain sky" categories, which contain both cloudy and clear footprints. Considerations of the impact of IR channel noise, surface emissivity, skin and air temperature differences, temperature and relative humidity profile variations, and instrument view angle are made. Simulations of cirrus clouds indicate this technique detects most all cirrus with tau(IR) greater than 0.1 over the tropical and subtropical oceans, and some (but not all) of the cirrus with tau(IR) less than 0.1. An analysis of coincident observations using Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site cloud boundaries and the proposed technique applied to the AIRS/AMSU suite indicates agreement for 82-84 percent of the cases. Most of the disagreements are explained well by AIRS footprint-scale heterogeneity compared to ARM point measurements, possible mixed phase microphysics in midlevel clouds, and significant IR channel noise for cold BT scenes over deep convective towers. We develop climatological maps of detected cirrus for select periods of time over the tropical and subtropical oceanic regions of the world, and make comparisons to other cirrus cloud climatologies. Discussion and analysis of the results will emphasize the frequency of occurrence of cirrus clouds.
A51B-0766 0800h
AIRS Cloud Products: Comparisons of AIRS VIS, AIRS IR, ARM and MODIS
The Atmospheric Infrared Sounder (AIRS) experiment on NASA's Earth Observing System Aqua spacecraft is a combination of infrared and microwave instruments designed for remote sensing of the atmosphere in the presence of clouds. The instruments and associated ground-based processing system have been in near full-time operation since September 2002, and have generated over 300,000 retrievals daily. The primary retrieved products are daily global fields of surface temperature, cloud height and fraction, and height-resolved humidity, temperature and minor gases. This work will focus on the cloud products from AIRS. We will show comparisons of the cloud fraction as seen in AIRS visible and infrared data and compare the cloud heights from AIRS retrievals with those reported in the ARM cloud lidar data. In addition, cloud parameters from MODIS will be compared with those from the AIRS retrieval. This work will illustrate cloud types where there is consistency among the measurements, and situations where the instrument's different sensitivities are more apparent.
A51B-0767 0800h
Retrieval of cloud properties from Atmospheric Infrared Sounder (AIRS) data
This study reports on the inference of cloud top properties (cloud top pressure, thermodynamic phase, optical thickness, and effective particle size) from radiometric measurements and atmospheric profiles generated from the Atmospheric Infrared Sounder (AIRS) onboard the EOS AQUA platform. The CO2 slicing method is applied to infer cloud top pressure from AIRS Level 1B (L1B) radiances; additional use is made of Level-2 (L2) Support products. Since there are 2378 wavenumber channels available within the infrared spectral region, more channels are used to find cloud top pressure than with the method as applied to MODIS 15-micron band data. In this study, the CO2 slicing method uses forward calculations based on the Stand-Alone AIRS Radiative Transfer Algorithm (SARTA); it has 100 vertical pressure layers from 0.005 to 1100 hPa and is considered a fast and accurate radiative transfer model. The cloud thermodynamic phase is inferred from a bispectral method based on the 8.5- and 11-micron channels similar to that used by the MODIS atmospheres team. Based on the cloud top pressure and phase information in addition to a look-up database of ice particle scattering properties, optical thickness and effective particle size are inferred. Examples will be shown for both ice cloud and water cloud cases.
A51B-0768 0800h
Clouds from AIRS/AMSU: An Evaluation Based On Intercomparisons with MODIS/AQUA Retrievals
Unlike conventional atmospheric sounding schemes, the AIRS/AMSU (flying on the EOS-AQUA satellite) sounding retrieval methodology allows for the retrieval of key atmospheric/surface parameters under partially cloudy conditions (Susskind et al., 2003). In addition, cloud parameters are also derived from the AIRS/AMSU observations. Within each AIRS footprint, cloud parameters at up to 2 cloud layers are determined with differing cloud top pressures and "effective" (product of infrared emissivity at 11 microns and physical cloud fraction) cloud fractions. However, so far the AIRS cloud product has not been rigorously evaluated/validated. Fortunately, collocated/coincident radiances measured by MODIS/AQUA (at a much lower spectral resolution but roughly an order of-magnitude higher spatial resolution than that of AIRS) are used to determine analogous cloud products from MODIS. This allows us for a rather rare and interesting possibility: the intercomparisons and mutual validation of imager vs. sounder-based cloud products obtained from the same satellite positions. We will present results of small- (granules) to large (global)-scale intercomparisons, assessing potential statistical differences related to the land/ocean or the day/night nature of the intercomparisons. We will investigate what type of cloud systems are retrieved most consistently (if any) with both retrieval schemes, and attempt to assess reasons behind possible statistically significant differences. We will also evaluate differences of monthly means and interannual variability of cloud cover and cloud top pressure as presented by the two cloud data sets. References Susskind, J., C, D. Barnet, and J. M. Blaisdell, Retrieval of Atmospheric and Surface Parameters from AIRS/AMSU/HSB Data in the Presence of Clouds, IEEE Transactions on Geoscience and Remote Sensing, Vol. 41, No. 2, 2003.
A51B-0769 0800h
Spatial and spectral variability of the outgoing thermal IR spectra: A case study of July 2003
AIRS (Atmospheric Infrared Sounder) provides measurements of the outgoing thermal IR spectra with unprecedented data quality and coverage. Here we present a survey of the spatial variability in different climate zones seen from AIRS data using the spectral EOF analysis. Over the tropical and subtropical oceans, the first principal component (PC1) is mostly due to the thermal contrast between surface and thick cold cloud tops. The second principal component (PC2) is mainly due to the spatial variation of the lower tropospheric humidity (LTH) and the low clouds. The signature of dust aerosol over the Arabian Sea and the Atlantic off the coast of North Africa in the summertime can be clearly seen in the PC2. Both the PC1 and the PC2 capture the variations in the upper tropospheric water vapor due to the forced orthogonality of EOFs. The third principal component (PC3) is mainly due to the spatial variation of the lower stratospheric temperature. Over the midlatitude oceans, the PC1 is still due to the thermal contrast of emission temperature. During wintertime, the PC2 is mainly due to stratospheric temperature variations. In the summer, the PC2 over the northern-hemisphere midlatitude oceans is mainly due to the variations of the LTH and the low clouds; the PC2 over the southern-hemisphere midlatitude oceans is mainly due to the stratospheric temperature variations. Parallel studies using synthetic spectra based on NCAR CAM2 and GFDL AM2 simulation are also presented. The major discrepancies between the simulation and AIRS observations are identified and discussed. This study demonstrates the potential of AIRS data for future climate studies.
A51B-0770 0800h
Small-Scale Waves in AIRS Radiances and Temperature Retrievals
Small-scale gravity waves are ubiquitous features in atmospheric temperature observations. In satellite observations, these waves have been traditionally difficult to resolve. Recent advances in satellite instrument resolution coupled to innovative analysis techniques have lead to some new global data sets on these waves. Realization of the import effects of these small-scale waves in a wide variety of atmospheric processes has grown in tandem with the observations. These effects include wave-forcing of the general circulation, and initiation and modulation of tropical convection, among others. Their scales are in general too small to be quantified in the global radiosonde network, and too small to be modeled with accuracy in global atmospheric models. Although they appear with sometimes large amplitude in high-resolution versions of global forecasting and assimilation models, their properties are often unrealistic. The models can suffer from insufficient horizontal and vertical resolution, and can also generate gravity waves anomalously via large amplitude forecast model adjustments following data insertation. In this paper we present examples of the occurrence of short horizontal-scale waves appearing in AIRS radiance measurements and examine the corresponding temperature retrievals and high-resolution atmospheric assimilation temperature fields for similar wave structures. In some cases, the wave scales are too small to be resolved in the assimilation, while in other cases, waves appear in the assimilation where none appear in the data. We will examine the sources of the waves in both the model and data. Through our case studies, we will also test both the horizontal and vertical resolution in the temperature retrievals.
A51B-0771 0800h
Using AIRS Water Vapor and Ozone Data to Study UTLS Transport in the South Asian Monsoon Region
The South Asian monsoon circulation has a strong influence on upper troposphere - lower stratosphere (UTLS) transport during NH summer. We are using AIRS water vapor and ozone retrievals to study climatology and variability of the monsoon region, and making detailed comparisons to chemical transport model (CTM) simulations (using MOZART). Climatological comparisons (based on 2 years of AIRS data) show enhanced water vapor and reduced ozone in the UTLS monsoon region, in reasonable agreement with MOZART results. Studies of daily, synoptic variability are focused on quantifying the influence of monsoon 'eddy-shedding' events in the UTLS.
A51B-0772 0800h
An Analysis of AIRS Ozone and Water Vapor in the Upper Troposphere and Lower Stratosphere Associated With Intensification of Tropical Cyclones
We use Atmospheric Infrared Sounder (AIRS) and in situ ozone and water vapor measurements in the tropical and subtropical upper troposphere and lower stratosphere (UT/LS) to investigate the conditions under which tropical cyclones intensify. Ozone and water vapor measurements can be used as indicators of stratosphere-troposphere exchange, which may influence tropical storm intensification through modification of the radiative balance of the UT. AIRS provides unique vertical profiles of ozone and water vapor in the UT/LS over the entire globe each day. We will perform a statistical analysis of these trace gases in the region of tropical cyclones during the intensification or de-intensification period for a number of storms starting in 2002, when the AIRS instrument began taking data. We will also use in situ aircraft trace gas measurements, when available, to observe finer scale details of tracer distributions near tropical storms.
A51B-0773 0800h
AIRS Data Subsetting Service at the Goddard Earth Sciences (GES) DISC/DAAC
The AIRS mission, as a combination of the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), brings climate research and weather prediction into 21st century. From NASA' Aqua spacecraft, the AIRS/AMSU/HSB instruments measure humidity, temperature, cloud properties and the amounts of greenhouse gases. The AIRS also reveals land and sea surface temperatures. Measurements from these three instruments are analyzed jointly to filter out the effects of clouds from the IR data in order to derive clear-column air-temperature profiles and surface temperatures with high vertical resolution and accuracy. Together, they constitute an advanced operational sounding data system that have contributed to improve global modeling efforts and numerical weather prediction; enhance studies of the global energy and water cycles, the effects of greenhouse gases, and atmosphere-surface interactions; and facilitate monitoring of climate variations and trends. The high data volume generated by the AIRS/AMSU/HSB instruments and the complexity of its data format (Hierarchical Data Format, HDF) are barriers to AIRS data use. Although many researchers are interested in only a fraction of the data they receive or request, they are forced to run their algorithms on a much larger data set to extract the information of interest. In order to better server its users, the GES DISC/DAAC, provider oflong-term archives and distribution services as well science support for the AIRS/AMSU/HSB data products, has developed various tools for performing channels, variables, parameter, spatial and derived products subsetting, resampling and reformatting operations. This presentation mainly describes the web-enabled subsetting services currently available at the GES DISC/DAAC that provide subsetting functions for all the Level 1B and Level 2 data products from the AIRS/AMSU/HSB instruments. Designed upon standardized web interface specifications, these on-line services allow users to access the AIRS/AMSU/HSB data in interoperable, personalized, real-time, on-demand and on-the-fly manners, facilitating the use of AIRS/AMSU/HSB data in research and application communities.