Assimilation of 3D ozone field in global chemistry-transport models using Kalman filter

In this paper, data assimilation approach for the estimation of the 3 dimensional global ozone based on the global transport model TM3 is presented. TM3 uses the meteorological data from ECMWF (European Center for Medium-Range Weather Forecasts) to transport the 3D ozone field and includes simplified parameterized chemistry scheme for ozone (Cariolle and Déqueé, 1986). The retrieved ozone profiles used in the assimilation are products of the fast-delivery service of GOME (Global Ozone Monitoring Experiment) products at KNMI. The Kalman filter technique is chosen as a data assimilation technique since it not only estimates the ozone distribution globally but also quantifies the uncertainty in its estimate. The data assimilation is demonstrated for the period of March–April 1997. Results and validation of the assimilated 3D ozone fields with the available ozone sondes for this period are discussed and verified.