Impact to AIRS Data Products

AMSU-A2 microwave instrument currently offline

Power to the AMSU-A2 microwave instrument onboard NASA's Aqua satellite was lost at 19:47 UT September 24, 2016, and the AMSU-A2 instrument remains offline. Relays that control power to AMSU-A2 are located on the Aqua spacecraft, and the Aqua Flight Operations Team is pursuing a recovery effort to restore power to the instrument. AMSU-A2 comprises two microwave channels: 23.8 GHz and 31.4 GHz.  The function of these channels is to identify precipitation and correct for surface emissivity, cloud liquid water and water vapor effects in the AIRS/AMSU retrieval algorithm.

Impact to AIRS data production

The AIRS project operates two parallel Level 2 retrieval algorithms: one using both IR and MW measurements (AIRS/AMSU) and the other using only IR measurements (AIRS). The production of AIRS/AMSU-based products has been suspended while the AMSU-A2 instrument is not operational.

Production of AIRS (IR only) data continues normally and these data products are available from September 2002 to the current date. The quality of these products are similar to that of the AIRS/AMSU products, as shown in the V6 Level 2 Performance and Test Report, which may be accessed at:

A more detailed report on the comparison between the AIRS/AMSU and AIRS retrieval products is currently under development and will be made available soon.

Production of these AIRS/AMSU-based data products has been suspended while AMSU-A2 is not operational:

Level 2

Level 3
AIRX3STD.006, AIRX3ST8.006, AIRX3STM.006, AIRX3SPD.006, AIRX3SP8.006, AIRX3SPM.006

Production of these AIRS (IR only) data products continue:

Level 2

Level 3
AIRS3STD.006, AIRS3ST8.006, AIRS3STM.006, AIRS3SPD.006, AIRS3SP8.006, AIRS3SPM.006

Production of Level 1B AIRABRAD.005 and AIRABRAD_NRT.005 continue

These products also contain AMSU-A1 radiances, which are valid.

If the AMSU-A2 instrument resumes operation

If the anomaly teams are successful in restoring power to AMSU-A2, AIRS/AMSU production will resume. Production of the AIRS (IR only) products will continue independently of the status of AMSU-A2.