HR: 14:55h
AN: H12F-06    [PDF]
TI: Impact of Mesoscale Surface Heterogeneity on Larger Scale Precipitation and the Surface Water and Energy Balances
AU: * Georgescu, M
EM: matt1@cep.rutgers.edu
AF: Rutgers University - Center for Environmental Prediction, 14 College Farm Road, New Brunswick, NJ 08901
AU: Weaver, C P
EM: weaver@cep.rutgers.edu
AF: Rutgers University - Center for Environmental Prediction, 14 College Farm Road, New Brunswick, NJ 08901
AB: High-resolution summertime simulations that capture storm-scale dynamics over many diurnal cycles and over several 100 x 100 km2 regions are conducted over the central United States using the Regional Atmospheric Modeling System (RAMS). The focus is on two different synoptic regimes in order to quantify the impact of clouds and precipitation associated with atmospheric dynamical systems on soil moisture and surface fluxes, both domain averages and spatial heterogeneity: one where large-scale dynamic forcing is strong and one where it is weak. The evolution of the surface water and energy balances controls mesoscale circulations that subsequently impact future convection and precipitation. This mesoscale surface heterogeneity is both relatively static (i.e., resulting from land cover and topographic features) and time-varying (i.e., resulting from spatial variability in rainfall and hence soil moisture). Control simulations, validated against observations, including rainfall, soil moisture, and surface fluxes, show that RAMS has the ability to capture the relevant processes during both synoptic regimes. The three-way interaction between large-scale atmospheric dynamics and precipitation, surface-forced mesoscale circulations, and the surface water and energy balances over multiple diurnal cycles controls the overall hydrologic evolution within the model domain. An improved understanding of this linkage is important for improving our ability to model hydrologic processes on basin scales.
DE: 3314 Convective processes
DE: 3322 Land/atmosphere interactions
DE: 3329 Mesoscale meteorology
DE: 3354 Precipitation (1854)
SC: Hydrology [H]
MN: 2003 Fall Meeting