Understanding the nature of tropical monsoon systems is essential for improving model forecasts in the tropics and the quality of life for billions of people living within the monsoon regions. Monsoon systems are forced by the distribution of solar heating and affect the tropical circulation by directly modulating the regional radiative energy balance. Understanding the spatial and temporal variability of the radiation budget in these monsoon regions is therefore essential for understanding these monsoon systems.

This study will examine the observed radiative energy budget of African monsoons using the NASA Clouds and the Earth's Radiant Energy System (CERES) measurements. Analyses will include examination of the outgoing longwave radiation (OLR) and reflected solar radiation (RSR) on daily, seasonal, and annual time scale over the African monsoon regions. Plots of OLR and RSR radiation as functions of latitude and time for selected longitude show clearly the annual variations. These observations will be compared directly with the simulated radiative energy budget from the NOAA NCEP Reanalysis 2 system. Inefficiency in the NCEP modeled results for these monsoon systems will be discussed.