A comparison of satellite-observed sea-surface temperatures with ground truth in the Indian Ocean

Daily worldwide sea-surface temperature maps are produced by the National Environmental Satellite Service. For the first half of 1975, sea-surface temperatures recorded on these maps were compared with concurrent ship observations in the Indian Ocean. Additional comparisons were made with historical data. These show systematic differences between the satellite and sea-surface observations. The satellite-derived temperatures appear to be too low along the equator and along the East African coast in the vicinity of the equator. Furthermore, in April, May, and June the areas off the equator (and not along the coast) appear to have temperatures that are too high. Although the mean differences are not large (1°-2°C), the fact that the errors vary in time and space made it difficult to apply the satellite data for oceanographic interpretations. concurrent ship observations in the Indian Ocean. Additional comparisons were made with historical data. These show systematic differences between the satellite and sea-surface observations. The satellite-derived temperatures appear to be too low along the equator and along the East African coast in the vicinity of the equator. Furthermore, in April, May, and June the areas off the equator (and not along the coast) appear to have temperatures that are too high. Although the mean differences are not large (1°-2°C), the fact that the errors vary in time and space made it difficult to apply the satellite data for oceanographic interpretations. Ants Leetmaa, Matthew Cestari. Prepared by Atlantic Oceanographic and Meteorological Laboratories. Also available online in PDF via the NOAA Central Library. Includes bibliographical references.