Water vapor products from Meteosat-8 SEVIRI: An information content analysis for climate purposes

Within EUMETSAT's Satellite Application Facility on Climate Monitoring (CM-SAF) Meteosat-8 SEVIRI data is being used to derive fields of water vapor column amount and layer water vapor. This information is retrieved from SEVIRI infrared observations for the full Meteosat disk. Within this presentation we give an overview on these products and their validation status.

We also assess the information content of MSG SEVIRI data for water vapor products in the framework of climate applications using as stringent optimum estimation information content analysis. We show that the long-term stability of the absolute calibration of SEVIRI is the most crucial ingredient for stable long-term estimates of water vapor. Additionally, we assess possible dry biases in clear-sky infrared-only products compared to all-sky microwave products. The results of our study indicate that for climatological purposes a blended product based on SEVIRI and passive microwave data will yield best and most stable estimates of atmospheric water vapor, if systematic errors in the individual datasets are known from validation against independent reference data and corrected for beforehand.