A regional climatography of West Nile, Uganda, to support human plague modeling

The U.S. Centers for Disease Control and Prevention is collaborating with the National Center for Atmospheric Research to quantitatively address the linkages between climate and human plague in this region. The aim of this paper is to advance knowledge of the climatic conditions required to maintain enzootic cycles and to trigger epizootic cycles and ultimately to target limited surveillance, prevention, and control resources.

A hybrid dynamical-statistical downscaling technique was applied to simulations from the Weather Research and Forecasting Model (WRF) to generate a multiyear 2-km climate dataset for modeling plague in the West Nile region. The resulting dataset resolves the spatial variability and annual cycle of temperature, humidity, and rainfall in West Nile relative to satellite-based and in situ records. Topography exerts a first-order influence on the climatic gradients in West Nile, which lies in a transition zone between the drier East African Plateau and the wetter Congo Basin, and between the unimodal rainfall regimes of the Sahel and the bimodal rainfall regimes characteristic of equatorial East Africa.