4D-VAR chemical data assimilation of ENVISAT chemical products (BASCOE): validation support issues

RESUME A 4D-VAR chemical data assimilation system, BASCOE, is used to assimilate the chemical observations taken by the three dedicated instruments onboard Envisat. For the first time data assimilation takes active part in the validation of chemical atmospheric observations. Here we present the results of the assimilation of MIPAS NLE products and NRT products. It is shown that the MIPAS constrained analyses are representative of the MIPAS observed state. The comparison with HALOE show that MIPAS O3, H2O, CH4, NOx are in very good agreement with HALOE and these results are inline with the current understanding of both instruments.