HR: 0800h
AN: H31E-0700    [Abstracts]
TI: Preciptation Parameterization for Idealized Land-Atmosphere Sahel Models
AU: * Eshel, G
EM: geshel@gmail.com
AF: Bard College at Simon's Rock, Div. od Sci., Math. and Computing 84 Alford Rd., Great Barrington, MA 01230, United States
AU: Stieglitz, M
EM: marc.stieglitz@ce.gatech.edu
AF: Georgia Institute of Technology, Department of Civil and Environmental Engineering 790 Atlantic Drive, Atlanta, GA 30332-0355, United States
AB: The lead author has previously devised a simple yet powerful numerical model of land-ocean-atmosphere dynamic interactions near a coastline (Eshel and Heavens 2007, Paleoceanography, in press). The model dynamical core, tested extensively against observations in the northern Red Sea, performs well and tracks closely disparate observations while illuminating underlying physics. However, to be useful for studying land-ocean-atmosphere interactions in the western Sahel off the subtropical North Atlantic, the model must incorporate moist thermodynamics. To that end, a water vapor equation is needed, and it must include adequate representation of moisture sources and sinks. That is, precipitation parameterization is required. And while numerous parameterization schemes exist, they often require input variables that are absent from simplified, idealized models, like Eshel and Heavens'. Put differently, idealized models' highly truncated state vectors do not include as state variables the necessary input arguments into most precipitation schemes. As a result, such schemes cannot be used in the context of idealized models. Here we present a precipitation parameterization scheme for the Sahel region of subtropical western Africa. Sufficiently simple to be used in idealized models such as Eshel and Heavens', the scheme's predictions are surprisingly powerful, and compare extremely well with Sahel precipitation observations. In this talk, we present the scheme, test it against observations, and interpret its skill dynamically and physically.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1847 Modeling
DE: 1854 Precipitation (3354)
DE: 1872 Time series analysis (3270, 4277, 4475)
SC: Hydrology [H]
MN: 2007 Fall Meeting