STERIC AND WIND-INDUCED CHANGES IN TOPEX POSEIDON LARGE-SCALE SEA-SURFACE TOPOGRAPHY OBSERVATIONS/

Three years of TOPEX/POSEIDON altimeter data are analyzed with respect to large-scale fluctuations in sea surface height observations and un derlying physical processes. In midlatitudes the most conspicuous feat ure in the large-scale changes in sea surface height are related to su rface buoyancy fluxes, predominantly surface heat fluxes. The next pro minent variability on subannual timescales is the adjustment of the oc ean to varying winds stress fields in terms of planetary waves. The de gree to which basin-scale sea surface height variations relative to th e steric component can be described as a time-dependent Sverdrup balan ce is addressed for the Pacific Ocean. If a flat bottom ocean is assum ed, a significant correlation of meridional mass transport variations inferred from TOPEX/POSEIDON and a simple Sverdrup model can be found in the Pacific Ocean north of 40 degrees N, but it fails elsewhere. Nu merical ocean general circulation models show a good agreement with th e TOPEX/POSEIDON observations in all those components of ocean variabi lity and allow further insight into the dynamics that govern observed sea, surface height changes.