The Role of Oceanic Mesoscale Features on the Tropical Cyclone–Induced Mixed Layer Response: A Case Study
- 1 April 2003
- journal article
- Published by American Meteorological Society in Journal of Physical Oceanography
- Vol. 33 (4), 649-676
- https://doi.org/10.1175/1520-0485(2003)33<649:troomf>2.0.co;2
Abstract
Oceanic mixed layer (ML) response to Hurricane Gilbert in the western Gulf of Mexico is investigated in this paper using the Miami Isopycnic Coordinate Ocean Model (MICOM). Three snapshots of oceanic observations indicated that a Loop Current Warm Core Eddy (LCWCE) contributed significantly to the ML heat and mass budgets. To examine the time evolution of different physical processes in the ML, MICOM is initialized with realistic, climatological, and quiescent conditions for the same realistic forcing. The ML evolves differently for the realistic background condition with the LCWCE in the domain; differences between climatological and quiescent conditions remain small. Mixed layer temperature (MLT) and ML depth (MLD) differences of up to 1°C and 30 m are directly attributed to horizontal advective processes in the LCWCE regime due to preexisting velocities. Comparison of simulated temperatures using realistic conditions in the model shows improved agreement with profiler observations. Using four entrainment mixing parameterizations, the spatial and temporal ML evolution is investigated in MICOM simulations. Although the rates of simulated cooling and deepening differ for the four schemes, the overall pattern remains qualitatively similar. For the three schemes that use surface-induced turbulence to predict entrainment rate, the cooling pattern extends farther away from the track. Based on linear regression analysis, MLTs simulated using the bulk Richardson number closure fit the observed temperatures better than did the other schemes. Averaged surface fluxes ranged from 10% to 30% in the directly forced region, with larger values in the LCWCE regime. Overall, entrainment mixing remains the dominant mechanism in controlling the heat and mass budgets.Keywords
This publication has 24 references indexed in Scilit:
- The 3D Oceanic Mixed Layer Response to Hurricane GilbertJournal of Physical Oceanography, 2000
- Numerical simulations of tropical cyclone‐ocean interaction with a high‐resolution coupled modelJournal of Geophysical Research: Solid Earth, 1993
- Velocity and hydrographic structure of two Gulf of Mexico warm‐core ringsJournal of Geophysical Research: Oceans, 1990
- Mixed Layer-Thermocline Interaction in a Three-Dimensional Isopycnic Coordinate ModelJournal of Physical Oceanography, 1989
- Modeling the Seasonal Cycle of the Upper OceanJournal of Physical Oceanography, 1988
- A Multi-Limit Mixed-Layer Entrainment FormulationJournal of Physical Oceanography, 1983
- Anticyclonic Rings in the Gulf of MexicoJournal of Physical Oceanography, 1982
- Numerical Simulations of the Ocean's Nonlinear, Baroclinic Response to Translating hurricanesJournal of Physical Oceanography, 1978
- A mixed layer model of the oceanic thermal response to hurricanesJournal of Geophysical Research, 1976
- Linear theory of the response of a two layer ocean to a moving hurricane‡Geophysical Fluid Dynamics, 1970