Examining the impact of outgoing long wave radiation on precipitation over Uganda

Abstract

Weather forecasting is very important especially in developing countries like Uganda where rain fed agriculture is the main source of livelihood. Precipitation is arguably the meteorological phenomenon that has the greatest impact on human activity yet it remains one of the most elusive elements to predict therefore having an appropriate approach for rainfall prediction makes it possible to take preventive and mitigation measures especially its extremes. The purpose of the study was to contribute to prediction of rainfall in Uganda using Outgoing Longwave Radiation as one of the forecasting tools and the main objective of the study was to assess the impact of outgoing longwave radiation on precipitation over Uganda. The study found out that there were increasing temporal trends of OLR during study period for most of the stations such as Arua, Entebbe, Kabale, Mbarara, Soroti, Kotido, Masindi, Makerere, Kasese, Jinja, Gulu and Lira while only Tororo showed decreasing temporal trends of OLR during study period. Increasing temporal and spatial trends of OLR are associated with decreasing rainfall while decreasing trends are associated with increasing rainfall. The study also found out that there was a relationship between OLR and rainfall over different study stations such as Arua, Soroti, Kotido, Masindi, Makerere, Kasese, Jinja, Gulu, Tororo and Lira over Uganda during study period with these stations showing a negative correlation. This inverse relationship is an indication that presence of clouds and precipitation are responsible for lower OLR valves. Therefore, the use of OLR in these stations can be further explored to improve on rainfall forecasting in these regions.