The AMMA radiosonde programme and its implications for the future of atmospheric monitoring over Africa

This presentation describes the upper air observational programme which is being carried out as part of the African Monsoon Multidisciplinary Analysis (AMMA). An important goal of AMMA is to evaluate the impact of the upper-air data on weather and climate prediction for West Africa, and for the hurricane genesis regions of the tropical Atlantic. Since 2004, AMMA scientists have been working with operational agencies in Africa to reactivate silent radiosonde stations, to renovate unreliable stations, and to install new stations in regions of particular climatic importance. A comprehensive upper air network of 21 stations, including four GCOS Upper Air Network (GUAN) stations, is now active over West Africa, and during the AMMA Special Observing Period (SOP) June to September 2006 some 7000 soundings were made in the region, representing the greatest density of upper air observations ever since in the region, exceeding even the number of soundings made during the GATE programme of 1974. AMMA also encompassed a short, intensive campaign on a network of PILOT stations in the western part of the region, centered on Senegal. This activity both exposed the dilapidated state of the operational PILOT network in the region, and demonstrated that important upper air data can be collected at relatively low cost through PILOT soundings. Many operational lessons were learned in AMMA, involving technical problems in the harsh environment of sub-Saharan Africa and issues of funding, coordination and communication among the many nations and agencies involved. From these lessons we are able to make firm recommendations for the maintenance and operation of a useful upper air network in WMO Region I in the future.