LARGE-SCALE RESPONSE OF THE OCEAN TO ATMOSPHERIC FORCING AT LOW-FREQUENCIES

Estimates of the time-dependent sea surface topography on large space (500-2500 km) and time (30 days to 2 years) scales from altimetry and tide gauge data are compared with estimates of the surface meteorological fields (winds and pressure) on the same scales. The comparisons are made in the North Pacific and North Atlantic. Despite the obvious remaining high noise level in the sea surface topography, there is a significant correlation between the atmosphere and the time-varying ocean circulation. These relations are quantified using simple multichannel regression models. With no time lags, typically 50% of the sea level variance can be described by the wind curl and divergence and the pressure field. Some areas produce classical static inverted barometer effects, but others suggest an amplified response. The motions are believed to characterize most of the water column.