VARIABILITY IN THE GULF OF ALASKA FROM GEOSAT ALTIMETRY DATA

Satellite altimetry was used to examine annual and interannual variabi lity in the Gulf of Alaska region. Crossover data from the Geosat Geod etic Mission (GM) and collinear data from the Exact Repeat Mission (ER M) were processed separately to form sea surface height anomalies at g rid points. The time series from the GM and ERM were then combined to produce a 3.75-year data set. The time series from the ERM data set ag reed fairly well with hydrographic dynamic heights at several location s, with an average correlation of 0.70 between the two data sets. The combined and ERM altimetric data sets were analyzed using empirical or thogonal functions (EOFs). These revealed variability that occurs prim arily on annual and interannual time scales. A comparison with EOF ana lysis of the atmospheric pressure field during the same time periods s howed that the annual variation in pressure seemed to be reflected in both the combined and ERM altimetric data sets. The amplitude time ser ies of the first mode in the combined data set was very similar to the North Pacific pressure index during the 1985-1989 time frame. The max imum correlation was at a lag of 250 days. Finally, an interannual mod e was present in all three data sets which was closely linked to the b aroclinic variations measured by the hydrographic data.