Investigating the Contribution of Mesoscale Convective Complexes to Monthly Rainfall Totals in West Africa

It is postulated that in West Africa, mesoscale convective complexes (MCCs) significantly contribute to the monthly rainfall totals. MCCs are meteorologically small-scaled (~ 100, 000 squared kilometers), short-lived (between 9 to 24 hours), high precipitation events that possess an undefined capacity to alter regional mass, moisture and heat fluxes and thus global energy and water distributions. Additionally, the non-discriminatory socio-economic geospatial distribution of these features correlates with currently and projected densely populated locations, and thus MCCs present considerable socio-economic impacts to local and international disaster response agencies. However, quantifying their contribution to monthly or seasonal totals has been difficult in spite of the formal observation of these features since 1980 because of untimely and subjective manual-based methods for identifying them in infrared satellite datasets and limited datasets at the appropriate high resolution for characterizing them. With increasing observational datasets at various resolutions for multiple variables, the issue of MCCs is again in the forefront as their convective nature raises questions regarding the seasonal variability and frequency in current and future climates, amongst others. In this study, we characterize the amount of rainfall associated with MCCs in West Africa during summer 2006 using hourly infrared satellite data, and TRMM satellite rainfall data. We further demonstrate a method for conducting the fully automated analysis of long periods of high-resolution heterogeneous observational datasets that leverages functionality from the existing climate evaluation project Apache Open Climate Workbench (http://climate.apache.org/).