That the ENSO system delivers a signal to the African continent has been known for a long time. During the southern summer, the atmospheric response to remote forcing in the African sector is complicated by the propensity for the atmosphere to develop tropical-temperate interactions between African convection and transients in the southern oceans. Nevertheless, the tropical atmosphere's steady response to SST anomalies may reasonably be expressed by linear dissipative shallow water models, the basic mechanisms of which appear as Rossby and Kelvin waves. Two simple theories exist to explain this response: 1) The Matsuno-Gill mechanism and 2) the Lindzen-Nigam mechanism.

With a view to clarifying structure of the atmosphere during periods of atmospheric response to SSTs, the state of convection in El Nino and La Nina years over the western Pacific, Indian Ocean and Africa is examined by means of zonal cross sections of omega fields between 20 E and 160 E. The profiles are spaced at 5 degree latitude intervals between 10 N and 20 S and extend from the boundary layer to 200 hPa. We compare the large scale structure for individual years as well as El Nino and La Nina averaged years. Data from NCEP/NCAR Reanalysis and the ERA-40 Reanalysis is compared with integrations of the Unified Model (HadAM3) to reveal the most consistent picture associated with the remote delivery of ENSO to Africa.