A comparison of TOVS ocean skin and surface air temperatures with other data sets

A data set of geophysical fields has been processed at the Goddard Laboratory for Atmospheres from Tiros operational vertical sounder (TOVS) high‐resolution infrared sounder 2 (HIRS2) and microwave sounding unit (MSU) radiance observations. The retrieval system is the physically based Pathfinder Path A methodology. The data set currently covers the period 1985–1995. We compare monthly means of TOVS skin temperature T s and surface air temperature T a to the Tropical Ocean Global Atmosphere (TOGA) buoy observations, National Center for Environmental Prediction (NCEP) T s and the Comprehensive Ocean Atmosphere Data Set (COADS) T s and T a for the time period 1987–1989. We also compare the T a data to the European Center for Medium‐Range Weather Forecasts (ECMWF) 2 m temperature. The TOVS Ts has a mean cold bias of ≤0.5 K relative to NCEP T s , while the T a has a mean cold bias of ≤1.0 K in the tropics relative to both ECMWF and COADS T a . The bias in the TOVS T a is largely due to the diurnal sampling of NOAA 10 observations. The bias in the T s has additional contributions from a possible cool skin effect as well as retrieval errors associated with cloud clearing and accounting for water vapor attenuation and reflected solar radiation. Because of the holistic retrieval of TOVS T s and T a there is a near cancellation of biases due to diurnal sampling and cloud clearing, so that the derived T s ‐ T a have higher accuracy than the individual T s and T a and give a more realistic representation of the evolution of known features of the ocean surface circulation than does the COADS. These results indicate that TOVS T s and T a may be suitable for climate variability studies involving air‐sea interactions. The data set is available on a daily, 5‐daily, or monthly mean basis with a spatial resolution of 1° by 1°.