Technical Bulletins

Why is IASI important?

The IASI instrument has led to an increase in knowledge of atmospheric composition monitoring, as well as volcanic ash detection. It was observed that during volcanic eruptions SO2 values exceeded initial expectations.

Dieter Klaes, EPS Programme Scientist at EUMETSAT, explains: “When first launched on Metop-A, in 2006, IASI was a world-leading instrument. It was the first polar-orbiting interferometer providing huge amounts of operational data. The impact on NWP was enormous, much higher than anticipated.”

Cathy Clerbaux, from the SAF on Ozone and Atmospheric Chemistry Monitoring, said: “IASI has provided unprecedented atmospheric chemistry data, allowing near-real-time mapping of chemical species and aerosols, contributing to air traffic safety and to our understanding of atmospheric transport processes.

“Observations from IASI have unexpectedly allowed the detection from space of volatile chemical species, providing an ability to map sources and sinks of gases, such as ammonia. It has already been shown that IASI exhibits sensitivity to the change in quantities of greenhouse gases, can be used to study cloud and aerosol properties, and will provide information on a range of other climate variables.”

Global ammonia distribution derived from infrared satellite observations (Nature, fee required)

Dieter Klaes added: "Additional products derived from IASI include Sea Surface Temperature (SST) at a high accuracy, and Surface Emissivity, the latter still a matter of further research and improvement. The continuity provided by Metop-B, for the coming years (its nominal life time is five years), means we can continue the valuable service to our users and continue to develop more products for and with our users.

"For weather forecasters worldwide the data IASI on Metop-B will provide, along with similar data from the new CrIS (Cross-track Infrared Sounder) instrument on Suomi-NPP — in cooperation with our partner NOAA — will be invaluable.”

Last Updated:  Thursday, 21 January 2016