MULTICLIM - From CHAMP towards Multi-Satellite Climate Monitoring Based on the MetOp and COSMIC Missions

The overarching goal of the MULTICLIM project was to prepare for global monitoring of the climate evolution of the Earth’s atmosphere with high accuracy and consistency and thereby help to improve the ability to detect, attribute, and predict climate variability and change.

Short Description

The key datasets for this purpose are radio occultation data (CHAMP, COSMIC, MetOp missions) and Infrared Atmospheric Sounder Interferometer (IASI) data (from MetOp), of which the latter were in the focus of the MULTICLIM project.

One of the primary objectives of the IASI sensor on board the European MetOp satellites (the first satellite MetOp-A being in orbit since October 2006) is the improvement of the vertical resolution of temperature and water vapor profiles to about 1– 2 km in the troposphere as well as to improve the retrieval accuracy to within 1 K in temperature and about 10% in humidity.

A main scientific motivation for this is the key role played by water vapor in the upper troposphere and its effects on the global climate, since only small changes in humidity and its trends have serious implications on the amount of thermal energy escaping to space and thus on the strength of the Earth’s greenhouse effect. IASI is expected to supply more accurate quantification of climate variability and change and, additionally, the IASI data promise to greatly assist numerical weather prediction in delivering accurate and frequent temperature and humidity profiles for operational meteorology needs.

Contributing in the framework of the joint ESA and EUMETSAT MetOp Research Announcement of Opportunity, the MULTICLIM project undertook to advance IASI retrieval algorithms and to prepare IASI climatology processing for climatologies at high horizontal resolution, but also with horizontal grids matching radio occultation climatologies. Furthermore, retrieved temperature, humidity, and ozone profiles as well as sea surface temperature data from a “test orbit” of real MetOp IASI data were validated against co-located data from analysis fields of the European Centre for Medium-Range Weather Forecasts (ECMWF).

The project was valuable in contributing to the validation of IASI data during the MetOp-A satellite commissioning phase as well as it paved the way to further advancement and broader application of the IASI retrieval system for climate studies.

Project Partners


Wegener Center for Climate and Global Change, University of Graz - Prof. Gottfried Kirchengast


  • Meteorological Division, EUMETSAT Darmstadt - Dr. Peter Schlüssel
  • European Centre for Medium-Range Weather Forecasts ECMWF Reading, U.K. - Dr. Marco Matricardi
  • Space Science and Engineering Center, University of Wisconsin, Madison - Dr. Elisabeth Weisz

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