A geostrophic empirical mode based on altimetric sea surface height

作者：Zhang Lin; Sun Che^*

来源：Science China Earth Sciences, 2012, 55(7): 1193-1205.

DOI：10.1007/s11430-011-4293-z

• eta-GEM
• altimetry
• SSH

Recent discovery of low-dimensional coherent structure in oceanic currents along with a new merged altimeter product called Absolute Dynamic Topography (ADT) makes it possible to derive subsurface ocean information from satellite remote sensing data. An altimetric geostrophic empirical mode (eta-GEM) is developed in this study by projecting hydrographic transects onto the ADT sea surface height coordinate, based on which the four-dimensional thermohaline and velocity structures of oceanic currents are reconstructed from satellite surface observations. In the WOCE/SR3 area, the eta-GEM fields capture more than 95% of the total thermal variance. The GEM-derived flow has equivalent-barotropic structure and represents the velocity profile better than traditional dynamic modes. Comparison with mooring observations also demonstrates that the eta-GEM provides good estimates of the deep thermohaline fields.

• 出版日期2012-7
• 单位中国科学院海洋研究所