The CAMS interim Reanalysis of Carbon Monoxide, Ozone and Aerosol for 2003–2015Report as inadecuate

The CAMS interim Reanalysis of Carbon Monoxide, Ozone and Aerosol for 2003–2015 - Download this document for free, or read online. Document in PDF available to download.

1 ECMWF - European Centre for Medium-Range Weather Forecasts 2 KNMI - Royal Netherlands Meteorological Institute 3 LMD - Laboratoire de Météorologie Dynamique 4 Department of Meteorology - Climatology, School of Geology Aristotle University of Thessaloniki, University Campus, Thessaloniki, Greece

Abstract : A new global reanalysis data set of atmospheric composition AC for the period 2003–2015 has been produced by the Copernicus Atmosphere Monitoring Service CAMS. Satellite observations of total column TC carbon monoxide CO and aerosol optical depth AOD, as well as several TC and profile observations of ozone, have been assimilated with the Integrated Forecasting System for Composition C-IFS of the European Centre for Medium-Range Weather Forecasting. Compared to the previous Monitoring Atmospheric Composition and Climate MACC reanalysis MACCRA, the new CAMS interim reanalysis CAMSiRA is of a coarser horizontal resolution of about 110 km, compared to 80 km, but covers a longer period with the intent to be continued to present day. This paper compares CAMSiRA with MACCRA and a control run experiment CR without assimilation of AC retrievals. CAMSiRA has smaller biases than the CR with respect to independent observations of CO, AOD and stratospheric ozone. However, ozone at the surface could not be improved by the assimilation because of the strong impact of surface processes such as dry deposition and titration with nitrogen monoxide NO, which were both unchanged by the assimilation. The assimilation of AOD led to a global reduction of sea salt and desert dust as well as an exaggerated increase in sulfate. Compared to MACCRA, CAMSiRA had smaller biases for AOD, surface CO and TC ozone as well as for upper stratospheric and tropospheric ozone. Finally, the temporal consistency of CAMSiRA was better than the one of MACCRA. This was achieved by using a revised emission data set as well as by applying careful selection and bias correction to the assimilated retrievals. CAMSiRA is therefore better suited than MACCRA for the study of interannual variability, as demonstrated for trends in surface CO.

Author: Johannes Flemming - Angela Benedetti - Antje Inness - Richard J. Engelen - Luke Jones - Vincent Huijnen - Samuel Remy - Mark Parr



Related documents