A numerical study of a TOGA-COARE squall-line using a coupled mesoscale atmosphere-ocean model
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An atmosphere-ocean coupled mesoscale modeling system is developed and used to investigate the interactions between a squall line and the upper ocean observed over the western Pacific warm pool during the Tropical Ocean/Global Atmosphere Coupled Ocean and Atmosphere Response Experiment (TOGA-COARE). The modeling system is developed by coupling the Advanced Regional Prediction System (ARPS) to the Princeton Ocean Model (POM) through precipitation and two-way exchanges of momentum, heat, and moisture across the air-sea interface. The results indicate that the interaction between the squall-line and the upper ocean produced noticeable differences in the sensible and latent heat fluxes, as compared to the uncoupled cases. Precipitation, which is often ignored in air-sea heat flux estimates, played a major role in the coupling between the mesoscale convective system and the ocean. Precipitation affected the air-sea interaction through both freshwater flux and sensible heat flux. The former led to the formation of a thin stable ocean layer underneath and behind the precipitating atmospheric convection. The presence of this stable layer resulted in a more significant convection-induced sea surface temperature (SST) change in and behind the precipitation zone. However, convection-induced SST changes do not seem to play an important role in the intsensification of the existing convective system that resulted in the SST change, as the convection quickly moved away from the region of original SST response.
Key wordsair-sea interaction mesoscale modeling squall line coupled ocean-atmosphere modeling
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- Barnes, G., 1994: Summary report of the TOGA COARE international data workshop. Toulouse, France.Google Scholar
- Blumberg, A. F., and G. L. Mellor, 1987: A description of a three dimensional coastal ocean circulation model.Three Dimensional Coastal Ocean Models, N. Heaps, Ed., American Geophysical Union, 208pp.Google Scholar
- Curry, J. A., and P. J. Webster, 1999:Thermodynamics of Atmospheres and Oceans. Academic Press, 254pp.Google Scholar
- Jorgensen, D. P., T. J. Matejka, and M. A. Le Mone, 1995: Structure and momentum fluxes within a TOGA COARE squall line system observed by airborne Dopplar radar.21st Conference On Hurricane and Tropical Meteorology, Miami, FL, Amer. Meteor. Soc., 579–581.Google Scholar
- Kantha, L. H., and C. A. Clayson, 2000:Numerical Models of Oceansand Oceanic Processes. Academic Press, 940pp.Google Scholar
- Kessler, E., 1969: On the distribution and continuity of water substance in atmospheric circulation.Meteor. Monogr.,32(10), 84pp.Google Scholar
- Levitus, S., and T. P. Boyer, 1994:World Ocean Atlas 1994. Volume 4: Temperature. NOAA Atlas NESDIS 4, 129pp.Google Scholar
- Levitus, S., R. Burgett, and T. Boyer, 1994:World Ocean Atlas 1994. Volume 3: Salinity. NOAA Atlas NESDIS 3, 111pp.Google Scholar
- Xie, L., L. J. Pietrafesa, and S. Raman, 1999: Coastal ocean-atmosphere coupling.Coastal and Estuarine Studies: Coastal Ocean Prediction. American Geophysical Union, 101–123.Google Scholar