A composite look at short‐time‐scale sea‐surface temperature changes in the western North Pacific based on ships and buoys

Abstract

A simple method of interpolating sea-surface temperature (SST) and its measurement method is applied to western North Pacific ship and buoy observations taken between 1970 and 2000. Comparisons are made between the resulting quasidaily in situ analyses and more inclusive analyses based mainly on satellite infrared observations. In terms of analysis differences, spatial correlation, and temporal spectra, the in situ analyses are found to be of moderate quality and are taken to be appropriate for composite diagnoses. This use is illustrated in a novel comparison of short-time-scale SST changes observed during the passage of two groups of midlatitude cold-season cyclones.Transient cooling is found to be preferentially associated with the stronger of the two cyclone groups. The significance of this cooling is quantified and the possibility of oceanic mixed-layer cooling and heat loss from bucket observations is explored. Although the bias in bucket observations is confirmed using composites