Synoptic-Scale Air–Sea Flux Forcing in the Western North Pacific: Observations and Their Impact on SST and the Mixed Layer

Abstract

Abstract Decade-long surface meteorological measurements from a Japan Meteorological Agency buoy at 29°N, 135°E are analyzed to elucidate the surface air–sea flux forcing in the western North Pacific Ocean. Besides the well-defined annual cycles, the observed heat and momentum fluxes are dominated by signals related to synoptic-scale weather disturbances. The synoptic-scale heat flux signals have a dominant time scale of 3–14 days, whereas the wind stress signals have a scale of 2–8 days. A comparison between the heat fluxes estimated using the buoy measurements and those from the NCEP reanalysis reveals that the daily NCEP product overestimates both the incoming solar radiation at sea surface and the turbulent heat flux amplitude associated with the individual weather events. The rms amplitude of the synoptic-scale net heat flux of the NCEP product is found to be positively biased by 23%. Despite this amplitude bias, the NCEP product captures the timing and relative strength of the synoptic-scale net hea...