Water column structure and statistics of Denmark Strait Overflow Water cyclones

摘要: Abstract Data from seven moorings deployed across the East Greenland shelfbreak and slope 280 km downstream of Denmark Strait are used to investigate characteristics dynamics Overflow Water (DSOW) cyclones. On average, a cyclone passes mooring array every other day near 900 m isobath, dominating variability boundary current system. There is considerable variation in both frequency location cyclones on slope, but no apparent seasonality. Using year-long data set September 2007 October 2008, we construct composite DSOW that reveals average scales features. The consists lens dense overflow water bottom, up 300 m thick, with cyclonic flow above lens. azimuthal intensified middle upper part column has shape Gaussian eddy peak depth-mean speed 0.22 m/s at radius 7.8 km. advected by mean 0.27 m/s self propagates 0.45 m/s, consistent topographic Rossby wave Nof speed. total translation velocity along 0.72 m/s. self-propagation exceeds swirl speed, indicating cannot kinematically trap fluid This implies anomaly dynamically linked, line previous theory. Satellite sea surface temperature (SST) investigated study expression Disturbances SST field found propagate less quickly than situ cyclones, raising possibility propagation signatures not directly associated