HR: 08:45h
AN: PP41C-04 INVITED     [Abstracts]
TI: Buoyancy Budget of the Northern Red Sea
AU: * Eshel, G
EM: geshel@uchicago.edu
AF: Dept. of Geophysics, Univ. of Chicago, 5734 S. Ellis Ave., Chicago, IL 60637 United States
AU: Heavens, N
EM: heavens@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, Caltech, Pasadena, CA 91125 United States
AB: The northern and central Red Sea are sites of vigorous atmosphere-ocean exchanges and interactions of widely diverse kinds. While modern surface fluxes of liquid water and heat have been characterized quantitatively both climatologically and transiently, the role of the atmospheric boundary layer in modifying these fluxes is poorly understood. In particular, while past authors, among them the current presenter, GE, have assumed infinite capacity of the boundary layer to absorb water vapor, this is clearly an oversimplification; evaporation increases the boundary layer specific humidity, and most often its relative humidity as well. Enhanced relative humidity, in turn, suppresses evaporation. Thus the buoyancy budget of the lowermost atmosphere is clearly a central, and dynamically responsive, element of the totality of air-sea interactions in general, and those in the Red Sea in particular. exploring, describing and quantifying this budget is the centerpiece of the presented work. We identify two distinct regimes. The first, dominant in the northernmost Red Sea, is dominated by evaporation and mixing of the marine boundary layer air with adjacent dry desert air. The second regime, dominant in the transition zone (around 22°N), is dominated by both heat and water vapor exchanges, and is mostly associated with the presence of the convergence zone to the south (~ 18°N) and the accompanying tilted isentropes.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3307 Boundary layer processes
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005