Satellites can provide an ideal platform to study the Earth-atmosphere system on practically all spatial and temporal scales. Thus, one may expect that their rapidly growing datasets could provide crucial insights not only for short-term weather processes/predictions but into the ongoing and future climate change processes as well. For example, outgoing longwave radiation [OLR], probably the most important parameter to assess global climate change (since the Earth-atmosphere system has to adjust to the new energy balance), is well suited for satellite monitoring. Though Earth-observing satellites have been around for decades, extracting climatically reliable information from their widely varying datasets faces rather formidable challenges.

Here, first we present validation efforts and trend analyses of TOVS Path-A-retrieved cloud top pressures [Pc] and “effective” (the product of infrared emissivity at 11 microns and physical cloud cover) cloud fractions [Aeff], which are key parameters for influencing OLR, and are available since 1979. For example, the TOVS and ISCCP (available since 1983) cloud top pressures correlate strongly. Decadal trends in Pc and cloud cover are also similar. It is particularly encouraging that when only the AVHRR-based ISCCP analyses are compared with TOVS (for the cloud fraction), even the geographical patterns of the decadal trends are very similar.

We also present preliminary, AIRS-retrievals-based (based on 4 full years, since Sept. 2002 was the first full Month of operationally available AIRS analyses) grid-scale trend analyses of important atmospheric parameters (e. g., temperature and moisture fields, in addition to OLR and cloud fields) and investigate their interrelationships.

TOVS and AIRS outgoing OLR validation effort results are also presented. OLR interannual spatial variabilities from the available state-of-the-art CERES measurements and both from the AIRS and TOVS OLR computations are in remarkably good agreement. Global mean Monthly CERES and TOVS OLR time series show very good agreement in absolute values also.