Influence of Hurricane Michael (2018) on Upper Ocean Circulation in the Gulf of Mexico
Abstract
Hurricane Michael (2018) is the most intense storm to form in the Gulf of Mexico, with the strongest maximum sustained wind speeds to make landfall in the contiguous United States since Hurricane Andrew in 1992. A multivariate analysis of this event explores the role of heat fluxes from the ocean surface and how this thermodynamic influence impacts the dynamic response via sea surface height anomalies and mixed layer depth. To assess the cause and thermodynamic forcings that contributed to the observed storm rapid intensification between October 3 and 11, 2018, we use AVHRR SST, ASCAT winds, AVISO sea level anomalies and surface ocean currents, GPM precipitation, and HYCOM simulations. A notable feature of the dynamic response in this analysis is that of a Loop Current anticyclonic eddy that propagates ahead of the path of Hurricane Michael. This anticyclonic eddy detachment deepened the mixed layer ahead of Hurricane Michael, which correlated well with observed values of oceanic heat content. Regions of upwelling associated with the strongest low-level cyclonic winds of the hurricane are identified using satellite-derived Ekman pumping, finding the spatial extent of wind-driven upwelling that causes mixed layer shoaling and anticyclonic features from the Loop Current, which cause mixed layer deepening. It is also found that a persistent cold wake in SSTs from upwelling is formed on October 10 and largely remains through the remainder of the month off the Gulf Coast of Florida, resulting in a maximum SST temperature change of 3°C from storm formation to demise.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMNH13E..03B
- Keywords:
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- 4313 Extreme events;
- NATURAL HAZARDS