data products are available from the GES DISC DAAC. Data from the UARS MLS instrument (Sept. 1991 - July 1999) are also available.
to order data -
Satellite Instruments
The Microwave Limb Sounder (MLS) experiments measure naturally-occurring microwave thermal emission from the limb (edge) of Earth's atmosphere to remotely sense vertical profiles of atmospheric gases, temperature, pressure, and cloud ice. The overall objective of these experiments is to provide information that will help improve our understanding of Earth's atmosphere and global change. The first MLS experiment in space (UARS MLS) was on NASA's Upper Atmosphere Research Satellite (UARS) launched 12 Sept 1991. After March 1994, the UARS MLS measurements became increasingly intermittent due to conserving satellite power and the MLS scan mechanism lifetime. The last data were obtained on 25 August 2001 (for more information go to UARS MLS data). The second (EOS MLS) is on the NASA Earth Observing System (EOS) Aura mission launched 15 July 2004. EOS MLS began full-up atmospheric science observations on 13 August 2004, with excellent performance to date in all portions of the instrument. Provisional and Stage I validated data are now publicly available (for information go to EOS MLS data). The Microwave Limb Sounder (MLS) views microwave emissions at the 118, 190, 240 and 640 GHz, and 2.5 THz spectral regions from the stratosphere into the upper troposphere. These measurements are used to derive vertical profiles of O3, H2O, BrO, ClO, HCl, HOCl, OH, HO2, HCN, CO, HNO3, N2O, and SO2 mixing ratios, as well as relative humidty with respect to ice, cloud water/ice content, geopotential height and temperature. The vertical resolution of these data is about 3 km, and the spatial coverage is near-global (-82° to +82°), with each profile spaced about 165 km along the orbit track (every 24.7 seconds).
Cuddy, David T.
EOS MLS Project Manager; Science Software and Data Production Manager
mail stop 183-701, Jet Propulsion Laboratory 4800 Oak Grove Drive, Pasadena, California USA 91109-8099
Measurment TypeMicrowave-occultation
Platform TypeMLS
OrbitSun synchronous
Spectral Coveragemicrowave
Scan PatternStare
Variablesozone and ozone precursor, upper troposphere water vapor
Repeat Time
Wavelength118 to 2250GHz
Number of Bands5- 118, 190, 240, 640 and 2250 GHz
Start DateAug 2004
Temporal Coverage~ 13 orbits a day
Swath Width1, 3.2, 10, 32, 100, 147 hPa (vertical res. 3 km)
Resolution 13km
Listed here are peer-reviewed scientific publications which include use of MLS data, have directly contributed to development and validation of the experiments (including related aircraft and balloon experiments) and/or their data, or have been authored by members of the MLS Science Team as part of their scientific research.
The Earth Observing System (EOS) Microwave Limb Sounder (MLS) is one of four instruments on the NASA's EOS Aura satellite, launched on July 15th 2004. MLS makes measurements of atmospheric composition, temperature, humidity and cloud ice that are needed to (1) track stability of the stratospheric ozone layer, (2) help improve predictions of climate change and variability, and (3) help improve understanding of global air quality. MLS observes thermal microwave emission from Earth's 'limb' (the edge of the atmosphere edge) viewing forward along the Aura spacecraft flight direction, scanning its view from the ground to ~90 km every ~25 seconds. Aura is in a near-polar 705 km altitude orbit. As Earth rotates underneath it, the Aura orbit stays fixed relative to the sun; to give daily global coverage with ~13 orbits per day. Aura is part of NASA's A-train group of Earth observing satellites. These satellites fly in formation with the different satellites making measurements within a short time of each other. The MLS measurements are made globally day and night. A feature of the MLS technique is that its measurements can be obtained in the presence of ice clouds and aerosol that prevent measurements by shorter-wavelength infrared, visible and ultraviolet techniques.
3 Sep 2009 13:47