Time and space scales of some oceanic and atmospheric parameters in the Gulf of Alaska

Abstract

Time series of monthly means up to 65 years long were examined to determine the time and spatial scales of variablity in the Gulf of Alaska. Sea level, sea level pressure (SLP), air temperature, fresh water discharge, sea surface temperature (SST) and the Southern Oscillation Index (SOI) are the variables chosen to gain insight into local and global responses in the gulf. This study reports four major results. 1) Sea level anomalies (variations from the annual cycle) are driven by wind and fresh water; temperature effects in sea level are not seen. 2) SST anomalies cannot be predicted from sea level data, but SLP in southeastern Alaska and air temperature in Seward may be useful indicators on a two to three month time scale. 3) On the whole, anomalies in coastal and interior Alaska weather occur together, with SLP 180° out of phase with air temperature and precipitation. Using empirical orthogonal functions, the Southeast and Southcoast district can be separated. 4) A statistically significant SOI signal is seen is both SLP (p>0.995, Seward) and sea level (p>0.995) records.