The NASA African Monsoon Multidisciplinary Analysis Mission: balloon-borne radiosonde results from Cape Verde

Easterly waves that may develop into damaging hurricanes as they move westward over the southern Atlantic Ocean was the subject of the research mission occurring between 15 August 2006 and 14 September 2006. To study West African-originating easterly wave activity, balloon-borne radiosondes were released as one part of the NASA African Monsoon Multi-disciplinary Analyses (NAMMA) mission, a component of the multi-national mission (AMMA). Radiosondes with Global Positioning System (GPS) capability were released every 4 hours from Praia, Cape Verde Islands and obtained 4-D position information (time, altitude, latitude, and longitude). High-resolution measurements of temperature, relative humidity, and wind at a vertical resolution of 4-6 meters effectively captured significant temporal features of convective and easterly wave activity. Five African Easterly Waves clearly were present during the observational period and are discussed. The axes of these waves in the low-level tropical easterly flow passed over Praia on August 22, 26, and September 3, 9, and 13. We will also present time-series analysis of selected meteorological parameters covering the 30-day campaign period; the interaction of the Saharan Aerosol Layer (SAL); and, the mid-level easterly jet. The radiosone data are an important part of the overall measurement mission contributing to understanding the morphology of easterly wave development, movement, and their sustainment.