Coupled ocean-cloud-resolving simulations of the air-sea interaction
over the equatorial western Pacific
JOURNAL OF THE ATMOSPHERIC SCIENCES, 58 (22):
3357-3375 (2001)DOI: 10.1175/1520-0469(2001)058<3357:COCRSO>2.0.CO;2
Abstract
A cloud-resolving model coupled to an ocean model with high vertical
resolution is used to investigate air-sea interactions in 10-day long
simulations. Modeled fields showed good agreement with two different
convective regimes during the Tropical Ocean Global Atmosphere Coupled
Ocean-Atmosphere Research Experiment (TOGA COARE) Intensive Observing
Period. The model simulates the formation of precipitation-produced,
stable freshwater lenses at the top of the ocean mixed layer, with a
variety of horizontal dimensions and lifetimes. The simulated fresh
anomalies show realistic features, such as a positive correlation
between salinity and temperature, the development of a surface jet in
the direction of the wind, and, as a consequence, downwelling
(upwelling) on its downwind (upwind) edge. The dataset generated by the
coupled model is used to evaluate the contribution from several factors
(ocean currents, gustiness, and correlations between wind speed and air
temperature, wind speed and water vapor mixing ratio, and wind speed and
SST) to the surface heat fluxes. Gustiness was shown to be a major
contribution to the simulated surface heat fluxes, especially when
convection is active. In a multiday average, the contributions from the
other effects (currents and wind speed-air temperature, wind speed-water
vapor mixing ratio, and wind speed-SST correlations) are small; however,
they cannot be neglected under certain circumstances.