The use of IASI atmospheric composition data in the MACC-II data assimilation system, or Why Noise Matters!

MACC-II (Monitoring Atmospheric Composition and Climate) is the current pre-operational atmospheric service of the European Copernicus/ GMES programme funded by FP7. The service combines a state-of-the art transport and chemistry model with satellite data from various sensors to provide consistent analyses of 3-dimensional fields of atmospheric composition including ozone, carbon monoxide, nitrogen oxides, methane, and aerosols. The MACC-II system is run routinely and provides daily 5-day forecasts of atmospheric composition data. The MACC-II delayed mode system monitors greenhouse gases and aerosols six months behind real time, and MACC also provided a 10-year reanalysis of atmospheric composition covering the years 2003-2013. More details about MACC-II can be found on http://www.gmes-atmosphere.eu

This talk shows that atmospheric composition retrievals from IASI play an important part in the MACC data assimilation system. IASI CO retrievals from Metop-A (produced by LATMOS/ULB) were assimilated in the MACC reanalysis and are assimilated daily in the MACC NRT analysis. IASI CO retrievals from MetOp-B are monitored in the MACC NRT analysis at present and first assimilation tests are being carried out. Furthermore, IASI CH4 retrievals (produced by LMD) are assimilated in the MACC delayed mode analysis, assimilation tests with IASI O3 retrievals (produced by LATMOS/ULB) are on-going, and the dissemination of the operational IASI volcanic SO2 product is eagerly awaited. Any decisions about future IASI products and data dissemination should not forget the importance of the atmospheric composition products and their NRT delivery.