Sea surface temperature climate analyses derived from aerosol bias-corrected satellite data

This work describes daytime sea surface temperature (SST) climate analyses derived from 16 years (1985-2000) of reprocessed Advanced Very High Resolution Radiometer (AVHRR) Pathfinder Atmospheres (PATMOS) multichannel radiometric data (after Nalli and Reynolds, 2005). Two satellite bias correction methods are employed, the first being an aerosol correction, the second being an in situ correction of satellite bias. The aerosol correction is derived from observed statistical relationships between the slant-path aerosol optical depth and AVHRR multichannel SST (MCSST) depressions for elevated levels of aerosol. Weekly analyses of SST are produced on a 1 degree equal-angle grid using optimum interpolation (OI) methodology. Four separate OI analyses are derived using: (1) MCSST without satellite-bias correction, (2) MCSST with aerosol satellite-bias correction, (3) MCSST with in situ correction of satellite bias, and (4) MCSST with both aerosol and in situ corrections of satellite bias. These analyses are compared against two quasi-independent data sets. OI Analysis 1 exhibits significant negative and positive Biases as expected. Analysis 2, derived exclusively from satellite data, reduces globally the negative bias associated with elevated atmospheric aerosol, and reveals pronounced variations in diurnal warming consistent with recently published works. Analyses 3 and 4, derived from in situ correction of satellite biases, alleviates biases (positive and negative) associated with both aerosol and diurnal warming, and also reduces the dispersion. The PATMOS OISST 1985-2000 daytime climate analyses presented here provide a high resolution (1 degree weekly) empirical database for studying seasonal and interannual climate processes.