Vertical motion in the upper ocean from glider and altimetry data

Abstract

This study represents a first attempt to combine new glider technology data with altimetry measurements to understand the upper ocean dynamics and vertical exchanges in areas with intense horizontal density gradients. In July 2008, just two weeks after Jason-2 altimeter was launched, a glider mission took place along a satellite track in the Alboran Sea (Western Mediterranean). The mission was designed to be almost simultaneous with the satellite passage. Dynamic height from glider reveals a sharp gradient (~15 cm) and corresponds very well with the absolute dynamic topography from Jason-1 & Jason-2 tandem mission (r > 0.97, rms differences < 1.6 cm). We blend both data sets (glider and altimetry) to obtain a consistent and reliable 3D dynamic height field. Using quasi-geostrophic dynamics, we diagnose large-scale vertical motions (~1 m day-1) which may provide a local . mechanism for the subduction of the chlorophyll tongue observed by the glider Copyright 2009 by the American Geophysical Union.