Development of a Coupled Regional Climate Simulation Model for the Lake Victoria Basin

摘要: A three dimensional dynamical model for Lake Victoria based on the Princeton Ocean Model (POM) has been developed. In this formulation standard version of POM is modified by replacing open boundaries with a closed coastline and adopting bathymetry Victoria. The lake 9 equal vertical sigma levels horizontal resolution 20 km. model’s upper boundary conditions are momentum, sensible heat radiative energy fluxes derived from double-nested simulations NCAR regional climate (RegCM2) or idealized surface forcing. 360-day to investigate, (i) sensitivity lake’s circulation variations in shear direction wind stress forcing, (ii) response abrupt change forcing assess memory lake, (iii) its temperature stratification. RegCM2 output used constructing October-November-December seasonal “short-rains” eastern Africa. these experiments we apply selective systematic suppression radiation, momentum contributions determine their relative importance. results show that geometry play fundamental role determining climatology regions upwelling downwelling determined nearshore bathymetry. about two weeks long. There exists Kelvin wave like disturbances thermocline trapped along coast propagate clockwise around periodicity 30 days. oscillations entirely disappear case isothermal conditions. characterized anti-clockwise circular motion predominantly easterly winds. three-dimensional produces pattern indicative water mixing spiral field. This associated spreading pool warm across northern section lake. not present one-dimensional model. Comparison simulation one thermal diffusion model, indicates former more realistic results.