Data assimilation of stratospheric constituents: a review W. A. Lahoz1,*, Q. Errera2, R. Swinbank3, and D. Fonteyn2,** 1Data Assimilation Research Centre, University of Reading, UK 2BIRA-IASB, Brussels, Belgium 3Met Office, Exeter, UK *now at: Norsk Institutt for Luftforskning, NILU, Norway **now at: Belgian Federal Science Office, Belgium
Abstract. The data assimilation of stratospheric constituents is reviewed. Several data
assimilation methods are introduced, with particular consideration to their
application to stratospheric constituent measurements. Differences from
meteorological data assimilation are outlined. Historically, two approaches
have been used to carry out constituent assimilation. One approach has
carried constituent assimilation out as part of a Numerical Weather
Prediction system; the other has carried it out in a standalone chemical
model, often with a more sophisticated representation of chemical processes.
Whereas the aim of the Numerical Weather Prediction approach has been to
improve weather forecasts, the aims of the chemical model approach have
included providing chemical forecasts and analyses of chemical constituents.
A range of constituent assimilation systems developed in these two areas is
presented and strengths and weaknesses discussed. The use of stratospheric
constituent data assimilation to evaluate models, observations and analyses,
and to provide analyses of constituents, monitor ozone, and make ozone
forecasts is discussed. Finally, the current state of affairs is assessed,
future directions are discussed, and potential key drivers identified.
Citation: Lahoz, W. A., Errera, Q., Swinbank, R., and Fonteyn, D.: Data assimilation of stratospheric constituents: a review, Atmos. Chem. Phys., 7, 5745-5773, doi:10.5194/acp-7-5745-2007, 2007.