基于卫星高度计沿轨数据的南海北部陆架地转流异常反演OA北大核心CSCDCSTPCD

This study analyzes the cross-shelf characteristics of sea surface height anomaly data over the northern South China Sea shelf.For this purpose,it applies empirical orthogonal function decomposition(EOF)to these data from along-track satellite-altimeter measurements for 1993-2020.The results reveal clear seasonal and interannual variations in sea surface height anomalies and geostrophic current anomalies across the northern South China Sea.At the seasonal scale,sea surface height anomalies differ between the summer half-year(March-August)and the winter half-year(September-February).The amplitude of sea surface height anomalies on the nearshore side is ap-proximately 0.3 m in the winter half-year and-0.4 m in the summer half-year.At the interannual scale,there are clear fluctuations in sea surface height anomalies in 1997,2003,2007,and 2016.The EOF results reveal a tilted cross-shelf structure of sea surface height anomalies,with the amplitude reaching the maximum(minimum)value in October(May)each year.The geostrophic current anomaly retrieved from monthly sea surface height data is about 0.2 m/s,and the current flows in opposite directions in winter(westward)and summer(eastward).The fourth mode indicates that the geostrophic current anomaly on the continental shelf may be influenced by other dynamic pro-cesses.This paper expands the application of sea surface height anomaly data from along-track satellite altimeters to shallow continental shelf waters and provides valuable insights into regional ocean dynamics and climate re-search.