Sea surface temperture measurements with the Atmospheric Infrared Sounder (AIRS) and aerosol

Atmospheric Infrared Sounder (AIRS) measurements of the sea surface temperature at 2616cm-1 show an unexpected cold bias compared to the NCEP Global Real Time SST. This cold bias, which is distributed in large scale patterns which are stable on the time scale of several months, has a satellite zenith angle (sza) dependent and a sza independent component. The sza independent component is strongly temperature dependent, and is most likely related to a larger than expected gradient between the bulk and the skin temperature, possibly due to not understood regional or seasonal weather patterns. The sza dependent component of about 0.4K is most likely due to some form of aerosol which is not included in the radiative transfer. AIRS was launched 4 May 2002 on the EOS Aqua into polar orbit.