The Kuroshio, with a surface flow speed of 1 2 m/s and a heat transport exceeding 10(exp 15)W, is the most powerful current in the North Pacific. On abutting the southward-flowing Oyashio cold current, it separates from the southern coast of Japan at 140°E and 35°N to become the eastward-flowing Kuroshio Extension. Our knowledge of the Kuroshio and its Extension has increased steadily over the past fifteen years. However, among the important remaining questions are the magnitude and seasonal change in the Kuroshio's heat transport. This is a challenging problem on which observational agreement to date has been elusive.
The above figures show new satellite calculations of the Kuroshio surface geostrophic heat transport based on the advective method. Our calculation combines sea-surface temperature (SST) data from the ATSR (Along-Track Scanning Radiometer) instrument on ERS-1 with absolute surface geostrophic velocity fields derived using Topex altimetry data. Monthly averages of the surface (top 1 m) geostrophic heat transport for the region shown have been calculated from October 1992 to September 1995. The figures display these calculations for two months close to the maximum (September 93) and minimum (April 94) in surface geostrophic heat transport. The difference between maximum and minimum for the eastward component shown is 77%. This is due largely to the change in SST. Data gaps are displayed as grey.
The ATSR data are the copyright of ESA/ CCLRC/BNSC/NERC and are produced by the UK Rutherford Appleton Laboratory. CNES's AVISO team is acknowledged for providing the Topex data.
ESA EOQ 52