@article{anyah_semazzi_2007, title={Variability of East African rainfall based on multiyear RegCM3 simulations}, volume={27}, ISSN={["1097-0088"]}, DOI={10.1002/joc.1401}, abstractNote={The International Center for Theoretical Physics (ICTP) regional climate model version 3 (ICTP-RegCM3) multiyear simulations of East Africa rainfall during the October–December, short rains season are evaluated. Two parallel runs; based on NCEP reanalysis and NASA FvGCM lateral boundary conditions are performed. The simulated monthly and seasonal rainfall climatology as well as the interannual variability are found to be fairly consistent with the observations. The model climatology over specific homogeneous climate subregions, except central Kenya (CKE) highlands, also reasonably agrees with the observed. The latitude-time evolution (intraseasonal variability) of the simulated seasonal rainfall exhibits two distinct modes of behavior. The first is a quasistationary mode associated with high rainfall throughout the season within the equatorial belt between 1°S and 2°N. The second mode is associated with the intertropical convergence zone (ITCZ)-driven southward migration of regions of rainfall maxima as the season progresses, which is also consistent with the observed. Furthermore, observed rainfall variability over distinct homogeneous climate subregions is also fairly reproduced by the model, except over central Kenya highlands and northeastern parts of Kenya. The spatial correlation between the simulated seasonal rainfall and some of the global teleconnections (DMI and Nino3.4 indices) shows that the regional model conserves some of the observed regional ‘hot spots’ where rainfall-ENSO/DMI associations are strong. At the same time, unlike observations, the model reveals that along the East Africa Rift Valley and over western parts of the Lake Victoria Basin, the association is weak, perhaps an indication that nonlinear interactions between local forcing (captured by the model) and large-scale systems either suppress or obscur the dominant influence of the teleconnections on rainfall over certain parts. Copyright © 2006 Royal Meteorological Society.}, number={3}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Anyah, Richard O. and Semazzi, Fredrick H. M.}, year={2007}, month={Mar}, pages={357–371} } @article{anyah_semazzi_2006, title={Climate variability over the Greater Horn of Africa based on NCAR AGCM ensemble}, volume={86}, ISSN={["0177-798X"]}, DOI={10.1007/s00704-005-0203-7}, number={1-4}, journal={THEORETICAL AND APPLIED CLIMATOLOGY}, author={Anyah, R. O. and Semazzi, F. H. M.}, year={2006}, month={Sep}, pages={39–62} } @article{fall_semazzi_dutta_niyogi_anyah_bowden_2006, title={The spatiotemporal climate variability over Senegal and its relationship to global climate}, volume={26}, ISSN={["1097-0088"]}, url={http://dx.doi.org/10.1002/joc.1355}, DOI={10.1002/joc.1355}, abstractNote={Abstract Climate variability over Senegal (West Africa) and its relationship to global climate are examined for the period 1979–1998. Monthly observed rainfall for 20 stations and monthly CPC merged analysis precipitation (CMAP) over Senegal were averaged for the months of June, July, August, and September in order to generate seasonal rainfall totals for the wet season, as well as climate indices averaged over the study period. The spatial distribution patterns are mapped and analyzed using ArcGIS Spatial Analyst. Rainfall distribution over Senegal is dominated by a N–S gradient. To investigate the climate variability over Senegal, an empirical orthogonal function (EOF) analysis is performed for the 1979–1998 period, using rain‐gauge and CMAP rainfall data over Senegal, and CMAP data only for West Africa. The first West African mode agrees strongly with Lamb's rainfall index. One of our major findings is that EOF2 for West Africa is well correlated with EOF1 for rainfall in Senegal. This relationship is supported by the projection of winds on the EOF2 mode by the National Centers for Environmental Prediction (NCEP), as well as the grid‐point correlation between the time series of EOF2 over West Africa and the Atlantic sea‐surface temperature (SST). The typical circulation associated with positive anomalies over Senegal is a moisture convergence, which takes place over the Guinea Gulf, in conjunction with the warm waters in this area. The time series for rainfall over Senegal show positive correlations with the South Atlantic SST. Over the Pacific Ocean, the greatest correlation coefficients (up to −0.72) are observed during the April–July period, which provide a modest possibility of predicting Senegal's rainy season. Given the specificity of coastal West Africa, the traditional indices used by policy makers and end users for the whole Sahel–Sudan region will not work for Senegal. The CMAP data are robust and suitable for analyses over West Africa. On the basis of its reliability, CMAP data has proven to be a good validation for analyses based on rain‐gauge precipitation. Copyright © 2006 Royal Meteorological Society}, number={14}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Fall, Souleymane and Semazzi, Fredrick H. M. and Dutta, Dev and Niyogi, S. and Anyah, Richard O. and Bowden, Jared}, year={2006}, month={Nov}, pages={2057–2076} } @article{anyah_semazzi_2004, title={Simulation of the sensitivity of Lake Victoria basin climate to lake surface temperatures}, volume={79}, ISSN={["1434-4483"]}, DOI={10.1007/s00704-004-0057-4}, number={1-2}, journal={THEORETICAL AND APPLIED CLIMATOLOGY}, author={Anyah, RO and Semazzi, FHM}, year={2004}, month={Oct}, pages={55–69} }