Investigating the Air-sea Interaction over Ocean Fronts and Eddies Using a Two-way Coupled Modeling System
Abstract
This study investigates the coupled processes of the atmosphere, ocean currents and waves using the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) modeling system. The impact of including the effects associated with air-sea interaction is examined through the use of the wind-current shear and the sea state in bulk flux formulas. Four one-month simulations over the east coast of the United States were performed: i) a control case that neglects the effects of both ocean currents and waves, (ii) an ocean-current case that considers the interaction between the atmosphere and ocean currents by using the wind-current shear in the bulk flux formulas, (iii) a wave case that considers the waves and the atmosphere interaction using Taylor and Yelland (2001) surface roughness scheme, and (iv) a current-wave case that considers the coupled processes of the atmosphere, ocean currents and waves. It was found that the monthly-averaged sea surface temperatures (SSTs) near the Gulf Stream (between 34N to 37.5 N) increase over 0.5 degree due to the ocean current. A heat budget analysis showed that latent heat flux (LHF) is the major contributor to the SST increase near the Gulf Stream. The mechanism of the surface heat and moisture fluxes change due to the ocean currents was investigated using the sensitivity test. It was found that LHF was more sensitive to the surface stability than the 10-m wind speed and 2-m humidity. Beside the LHF, an increase of the downward long wave radiation and a decrease of the downward short wave radiation was found near the Gulf Stream. The increase of cloudiness from atmospheric boundary layer to mid-troposphere due to the ocean currents was found to be the major contributor of the downward short wave radiation decrease at the surface. The result showed that waves also influences SST, and its impact has a larger spatial variability than for currents. A detailed analysis of the wave-atmosphere and wave-ocean-atmosphere interactions shows that the two-way coupling greatly modifies air-sea interaction and related processes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMOS22B..03S
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3337 Global climate models;
- ATMOSPHERIC PROCESSESDE: 4504 Air/sea interactions;
- OCEANOGRAPHY: PHYSICALDE: 4522 ENSO;
- OCEANOGRAPHY: PHYSICAL