Measurement of Sea Surface Temperature by the NOAA 2 Satellite

Abstract

Sea surface temperature (Ts) may be inferred to a useful accuracy from satellite measurements of infrared radiances in the atmospheric windows. However, even in the absence of clouds, the slight opacity produced by water vapor continuum, carbon dioxide, ozone and aerosol absorption causes the temperature ?seen? by the satellite to be lower than that measured by ships or aircraft. The difference between Ts and the temperature inferred from infrared radiances when looking vertically through a cloud-free atmosphere is estimated to about ±0.5 K for the 10.5?12.5 ?m window of the scanning radiometer of NOAA 2 when data on certain atmospheric variables are available. A simple parametric formula in terms of integrated water vapor content gave about that accuracy while saving considerable computation time. It was found that Ts may be estimated to an accuracy of about ±1 K within about 500 km of the subsatellite track in the Mid-Ocean Dynamics Experiment area in a comparison of satellite data with ship and aircraft measurements, despite various sources of possible error. An area represented by each mapped Ts of about 40 km ? 40 km could be attained for areas that were nearly cloud-free.