Atmospheric Infrared Sounder

Atmospheric Infrared Sounder
NASA · Public domain · source
Name	Atmospheric Infrared Sounder
Operator	National Aeronautics and Space Administration / Jet Propulsion Laboratory
Manufacturer	Boeing / Honeywell International
Mission type	Earth observation
Launch date	July 4, 2002
Launch vehicle	Delta II
Launch site	Cape Canaveral Space Force Station
Orbit	Sun-synchronous
Instrument type	Infrared spectrometer
Mass	145 kg

Atmospheric Infrared Sounder The Atmospheric Infrared Sounder instrument aboard a NASA satellite provides high-spectral-resolution infrared observations to retrieve atmospheric temperature, humidity, and trace gas profiles, supporting weather forecasting and climate research. Developed by teams at the Jet Propulsion Laboratory, California Institute of Technology, and industry partners including Boeing and Honeywell International, the instrument complements other spaceborne missions such as MODIS, Aqua, and Suomi NPP. Its data have been assimilated by major centers like the European Centre for Medium-Range Weather Forecasts, National Centers for Environmental Prediction, and Japan Meteorological Agency.

Overview

AIRS operates from the Aqua platform, launched aboard a Delta II rocket from Cape Canaveral Space Force Station into a sun-synchronous orbit designed to provide global coverage. The program involved collaborations among NASA, the Jet Propulsion Laboratory, the National Oceanic and Atmospheric Administration, and industrial contractors including Boeing and Honeywell International. AIRS forms part of a constellation of instruments on Aqua alongside Advanced Microwave Scanning Radiometer-EOS, MODIS, and CERES to enable synergistic retrievals used by operational centers like ECMWF, NCEP, and research groups at NOAA and NSF-funded laboratories.

Instrument Design and Specifications

The AIRS suite comprises a high-resolution infrared grating spectrometer developed at Jet Propulsion Laboratory with contributions from Lockheed Martin and tested at facilities associated with Caltech and Pasadena. It uses a cryogenically cooled detector array with components from firms such as Raytheon and Boeing Satellite Systems, dispersing radiation across multiple focal plane modules. The design parameters include spectral coverage spanning mid- to far-infrared channels to detect emissions from gases like water vapor, carbon dioxide, ozone, and methane; spatial sampling consistent with sun-synchronous orbits used by NOAA-15 and resolution competitive with instruments on MetOp platforms. Engineering verification occurred at JPL laboratories and at test ranges coordinated with NASA's Goddard Space Flight Center.

Data Products and Processing

AIRS produces Level 1 radiances, Level 2 retrieved profiles, and Level 3 gridded products distributed through archives managed by NASA Goddard Space Flight Center and mirrored at servers used by ECMWF and NOAA. Processing chains involve radiative transfer models developed in collaboration with teams at University of Wisconsin–Madison, Colorado State University, and Massachusetts Institute of Technology. Products include atmospheric temperature and humidity profiles, surface temperature, cloud properties, and trace gas concentrations used within assimilation systems at NCEP, UK Met Office, and research centers like NCAR. Data formats adhere to standards from Committee on Earth Observation Satellites and are integrated with tools from University Corporation for Atmospheric Research and the Goddard Earth Sciences Data and Information Services Center.

Mission History and Operations

The project inception traces to proposals submitted to NASA programs in the 1990s, with instrument development coordinated by JPL under program management involving NASA Headquarters and payload integration supported by Lockheed Martin Space Systems. Launched in 2002, operations have been sustained by flight teams at NASA JPL, with routine commanding through Mission Control Center networks and data handling by GSFC. AIRS has persisted through on-orbit anomalies addressed via collaboration with contractors including Honeywell International, with cross-calibration campaigns involving agencies such as ESA and missions like AIRS paired with AMSU. Operational use expanded with assimilation by ECMWF and national services like JMA for improved numerical weather prediction.

Scientific Applications

AIRS data have advanced research at institutions such as Caltech, Harvard University, Princeton University, MIT, Scripps Institution of Oceanography, and University of Oxford in studies of atmospheric dynamics, climate variability, and composition. Applications include monitoring of El Niño–Southern Oscillation impacts, investigations of stratospheric ozone trends, tracking of volcanic ash plumes, and assessments of greenhouse gas distributions including CO2 and methane. Studies published by teams associated with NOAA, NASA Ames Research Center, National Center for Atmospheric Research, and international groups at CNRS and Max Planck Institute for Meteorology have used AIRS to examine processes relevant to Intergovernmental Panel on Climate Change assessments and to inform policy discussions at venues like United Nations Framework Convention on Climate Change forums.

Validation and Calibration

Pre-launch calibration involved facilities at Jet Propulsion Laboratory and NASA Goddard, with in-flight validation campaigns coordinated with field programs from NOAA labs, NCAR, and university groups such as University of Colorado Boulder and Texas A&M University. Validation used radiosonde networks maintained by national services including UK Met Office, Japan Meteorological Agency, and Australian Bureau of Meteorology, as well as lidar and microwave sounder comparisons from missions like COSMIC and MetOp. Cross-calibration exercises engaged ESA missions and instrument teams from EUMETSAT to ensure continuity with IASI and other hyperspectral sounders.

Legacy and Future Developments

AIRS established a benchmark for hyperspectral infrared sounding adopted by successors in programs from NOAA, ESA, JAXA, and industry partners including Ball Aerospace. Lessons influenced instruments such as CrIS on Suomi NPP and upcoming missions planned by NASA Earth Science Division and international consortia including EUMETSAT and JAXA. The AIRS heritage persists in algorithm frameworks used at ECMWF and research centers like NCAR and in training programs at institutions including Stanford University and University of Cambridge. Category:Earth observation satellites