On the Loop Current eddy shedding variability

摘要

Analysis of observations of the Loop Current (LC) northward penetration and LC area, from satellite sea surface temperature, Topex/Poseidon (TP) sea surface height anomaly, and results from numerical simulations shows that when a relatively large cyclone remains north of the LC, the shedding period between two consecutive eddies may increase. It is shown that the interaction between the LC and the cyclone produces leakage of mass from the current and pushes the LC towards the West Florida Shelf escarpment, where mass is also redistributed due to the generation of a pressure gradient and a jet along the shelf edge. This process delays the northward penetration of the LC and the enlargement of its area, increasing the time between eddy shedding. This happened in 1998, when the largest registered period between eddy shedding since 1973 occurred, and the largest cyclone of the TP era was north of the LC.