Toward the development of a seasonal climate prediction system for eastern Africa

Conference · Sat Nov 01 04:00:00 EST 1997

OSTI ID:535515

Sun, Liqiang; Semazzi, F H.M. ^[1]; Giorgi, F ^[2]

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1. North Carolina State Univ., Raleigh, NC (United States)
2. National Center for Atmospheric Research, Boulder, CO (United States)

This study reports customization of a regional climate model for application to portions of eastern Africa that are highly susceptible to drought. The model that being adapted is RegCM2 developed at the National Center for Atmospheric Research (NCAR). Six climatic subregions were used in the calibration of the model. Ten sensitivity experiments were conducted to test the performance of the cumulus convection scheme, moisture scheme, boundary layer formulation, surface physics, and the lateral boundary scheme in simulating climate, particularly rainfall, in eastern Africa. Results showed that: (1) the Grell cumulus scheme led to satisfactory results when precipitation efficiency and the location of the cloud base were appropriately specified; (2) the critical Richardson number was a key parameter in customizing the boundary layer scheme, and a value of 0.25 yielded satisfactory results; (3) the liquid water content in the radiative transfer scheme should be set to about half of the value adopted in the case of the midlatitudes; (4) it is desirable to specify the latern boundary forcing so that it is stronger over the upper troposphere and relatively weaker over the mid and low troposphere; and (5) the simulation of autumn rains were relatively insensitive for a fairly broad range of initial specification of soil wetness. 10 refs., 1 fig., 3 tabs.

• OSTI ID: 535515
• Report Number(s): CONF-970207--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AFRICA
CLIMATE MODELS
CLIMATIC CHANGE
DROUGHTS
R CODES
RAIN
REGIONAL ANALYSIS
SENSITIVITY ANALYSIS