A Comparison of the Annual Cycle of Two Sea Surface Temperature Climatologies of the World Ocean

Abstract

Abstract A comparison of the annual cycle of two monthly sea surface temperature climatologies for the world ocean is presented. One set of the climatological fields used consist of one-degree objectively analyzed monthly means, based on approximately 1.5 million temperature soundings held by the National Oceanographic Data Center, Washington, DC. The second climatology used is based on monthly objective analyses of a subset of the 70 million historical merchant ship reports from the Cooperative Ocean–Atmosphere Data Set. The comparison is performed by examining the amplitude and phase of the first two harmonics of each climatology, as well as the percent variance contributed by each harmonic to the annual cycle. There is excellent agreement between the two sea surface temperature climatologies in the first two harmonics. In the Northern Hemisphere, maxima in the amplitude of the first harmonic are found off Japan (approximately 7.5°C–8.0°C) and off the east coast of the United States (8.0°C–9.0°C off Cap...