Author(s)

H. Elbern and H. Schmidt

Abstract

Four Dimensional Data Assimilation for a Eulerian Chemistry Transport Model A contribution to subproject GLOREAM H. Elbern and H. Schmidt University of Cologne, Institute for Geophysics and Meteorology, Project EURAD, AachenerStr. 201-209, 50931 Ksln, Germany Objective and method Using observations the model skill can be quantified by a suitable predefined scalar function /, giving a measure of distance between observed and modelled quantities. Minimising this cost function by variation of a selected parameter set leads to an improvement of model skill, provided that the observations are representative. Potential candidates for optimisation parameters are e.g. initial and boundary values of the species, emission rates, and deposition velocities. In the present study the initial values of the model are taken as control (optimisation) parameters. The method applied is the four dimensional variati

Keywords