AIRS level-3 12-hourly standard retrieval product (AIRS only) Version 6 (AIRS3STD.006)

AIRS 12-hourly products

The Atmospheric Infrared Sounder (AIRS) is a grating spectrometer (R = 1200) aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. In combination with the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), AIRS constitutes an innovative atmospheric sounding group of visible, infrared, and microwave sensors. The AIRS Only Level 3 Daily Gridded Product contains standard retrieval means, standard deviations and input counts. Each file covers a temporal period of 24 hours for either the descending (equatorial crossing North to South @1:30 AM local time) or ascending (equatorial crossing South to North @1:30 PM local time) orbit. The data starts at the international dateline and progresses westward (as do the subsequent orbits of the satellite) so that neighboring gridded cells of data are no more than a swath of time apart (about 90 minutes). The two parts of a scan line crossing the dateline are included in separate L3 files, according to the date, so that data points in a grid box are always coincident in time. The edge of the AIRS Level 3 gridded cells is at the date line (the 180E/W longitude boundary). When plotted, this produces a map with 0 degrees longitude in the center of the image unless the bins are reordered. This method is preferred because the left (West) side of the image and the right (East) side of the image contain data farthest apart in time. The gridding scheme used by AIRS is the same as used by TOVS Pathfinder to create Level 3 products. The daily Level 3 products have gores between satellite paths where there is no coverage for that day. The geophysical parameters have been averaged and binned into 1 x 1 deg grid cells, from -180.0 to +180.0 deg longitude and from -90.0 to +90.0 deg latitude.
Detail description of this dataset can be obtained from GSFC: Version 6

Global coverage is obtained twice daily (day and night) on a 1:30pm sun synchronous orbit from a 705-km altitude. In this dataset, 0z and 12z are set to the ascending and descending orbits, respectively.

Variables
12 level water vapor mass mixing ratio(gm/kg),Outgoing longwave radiation flux (W/M**2), 12 level Relative humidity profile (percent), Surface Air temperature(°K), Surface skin temperature(°K),24 level Air temperature (°K),Precipitable water (kg/M**2), Surface pressure (mb)
ZonalGlobal by 1.0 deg
MeridionalGlobal by 1.0 deg
Verticalsurface, and 1000,925,850,700,600,500,400,300,250,200,150,100,70, 50,30, 20,15, 10,7,5,3,2,1.5,1 (mb)  
Temporal Aug 31, 2002 to Jul 31, 2022 0z and 12z are set to the ascending and descending orbits, respectively
Static?no
Volume9.65 G Bytes/year
Server public:
Sourcehttps://disc.gsfc.nasa.gov/datasets/AIRS3STD_V006/summary?keywords=airs%20version%206
Acquired June 29, 2018 (Updated Aug 2022)
APDRC contact
SupplementsREADME.AIRS_V6.pdf