Sunday, 9 January 2005
Synoptic Analysis of 2001-2004 "Long Rains" on Mt. Kilimanjaro, Tanzania
Recently, ice cores covering the last 10,000 years have been recovered from Mt. Kilimanjaro. Studies have suggested that East African precipitation is primarily driven by local-scale processes rather than large-scale atmospheric circulation. Interestingly, the changes seen in the Kilimanjaro ice cores closely resemble other climatic records from a large area in Africa as well as the Indian monsoon areas. So far, studies are further complicated by the lack of in situ data. To advance understanding of modern East African climate, this study focused on station data directly from Mt. Kilimanjaro's summit. First, these local measurements were compared to NCEP/NCAR reanalysis data to validate the global reanalysis in this particular region. Overall, the correspondence was reasonably good, opening the possibility for future studies, expanding the time frame over the past 50 years. Second, the use of both data sets allowed for an examination of commonalities of precipitation events during the “long rains” season (February – May) in 2001-2004 on Mt. Kilimanjaro and identified the key precipitation-causing processes. Results suggest that Kilimanjaro precipitation is related to strong convective activity over the Indian Ocean near Madagascar accompanied with anomalous airflow towards the continent where strong rising motion is responsible for the precipitation. In addition, the Indian Ocean appears to be the dominant source of moisture for Mt. Kilimanjaro snowfall. These findings provide a preliminary interpretation of the governing processes that control precipitation on Mt. Kilimanjaro, which contributes to a better understanding of current regional climate and aids in an improved interpretation of paleoclimatic records.
Supplementary URL: