453 African easterly jet in the ECMWF integrated forecast system: 4DVar analysis A. M. Tompkins1, A. Diongue2, D. J. Parker3 and C. D. Thorncroft4 Research Department 1 ECMWF 2 Direction de la Meteorologie Nationale, Dakar-Yoff, Senegal 3 Institute for Atmospheric Science, University of Leeds, Leeds, UK 4 Department of Earth and Atmospheric Science, University at Albany, New York, USA Submitted to Q.J. Roy. Meteor. Soc. December 2004 Series: ECMWF Technical Memoranda A full list of ECMWF Publications can be found on our web site under: http://www.ecmwf.int/publications/ Contact:
[email protected] c Copyright 2004 European Centre for Medium-Range Weather Forecasts Shinfield Park, Reading, RG2 9AX, England Literary and scientific copyrights belong to ECMWF and are reserved in all countries. This publication is not to be reprinted or translated in whole or in part without the written permission of the Director. Appropriate non-commercial use will normally be granted under the condition that reference is made to ECMWF. The information within this publication is given in good faith and considered to be true, but ECMWF accepts no liability for error, omission and for loss or damage arising from its use. African easterly jet in 4DVar analysis Abstract In August 2000, the Met Office C130 research flight aircraft conducted four sorties over the Western Sahel region, making dropsonde measurements at an unprecedented resolution. These were used as an independent validation source to assess the quality of the analysis of the African easterly jet (AEJ) in the European Centre for medium range forecasts (ECMWF) integrated forecast system.