On the multiple time scales of variability in the Northeast Pacific Ocean

[摘要] The spatial and temporal sea surface height energy distribution ofthe Northeast Pacific Ocean is described and discussed. Using analtimetric data set covering 15 years (1993–2007), the energywithin the 3–9 month band is primarily located within 10° ofthe coast. In the Gulf of Alaska, this energy signal is on theshelf, while further south, west of the California/Oregon coast, thesignificant energy in this band is west of the shelf break. In bothcases, it is primarily forced by the local wind. Within the 2–3year band, the signal reflects energy generated by local changes tothe wind stress from large atmospheric shifts indicated by thePacific North American Index and by advective or propagatingprocesses related to El Niño-Southern Oscillation. Over the two4–6 year periods within this data set, the change is primarily dueto the large scale shift in atmospheric systems north of about30° N which also affect changes in current strengths. Basedon the distribution of the energy signal and its variability, a setof three winter-time indices are suggested to characterize thedistinct differences in the SSH anomalies in these areas.

[学科分类] 海洋学与技术