Abstract:

GRACE satellites have observed strong ocean-bottom-pressure (OBP) signals in the high-latitudes of northern Pacific, but data has been only available since their launch in May 2002. Here we use a non-Boussinesq ocean model to simulate the OBP from 1948 to 2004 using NCEP/NCAR reanalysis data. It is found that the OBP time-series of the subarctic region of northern Pacific, from both GRACE and the model, have pronounced interannual variability signals, closely correlating with the Nino3.4 SST index. The GRACE and model results have been cross-verified by available TOPEX/Poseidon data and in-situ measurements of the western boundary currents.