The MSDOL project: Assimilation of Gomos Ozone Data in a 3-D chemistry-transport model

In the frame of the preparation of the use of ENVISAT data, the EEC is supp orting the MSDOL project: Monitoring of the Stratospheric Depletion of the Ozone Layer. The purpose is to assimilate the 400 vertical profiles of Ozon e recorded each day by the experiment GOMOS ton the future ESA ENVISAT spac ecraft) in a 3-D chemistry-transport model, where the winds are the ECMWF a nalysis. The sequentially assimilated model will better represent the reali ty since all single measurements are extrapolated in space and time through chemistry and transport. The assimilated model will serve at least two pur poses : the comparison with other data sets, and the estimate of the evolut ion of ozone as a function of time and space. The 3-D model is derived from the stratospheric chemistry-transport Rose model, in which the internally generated dynamics is replaced by the actual wind field. (C) 1999 Elsevier Science Ltd. All rights reserved.