Hyperspectral Earth Observation from IASI: Five Years of Accomplishments

Abstract

The Infrared Atmospheric Sounding Interferometer (IASI) forms the main infrared sounding component of the European Organisation for the Exploitation of Meteorological Satellites's (EUMETSAT's) Meteorological Operation (MetOp)-A satellite (Klaes et al. 2007), which was launched in October 2006. This article presents the results of the first 4 yr of the operational IASI mission. The performance of the instrument is shown to be exceptional in terms of calibration and stability. The quality of the data has allowed the rapid use of the observations in operational numerical weather prediction (NWP) and the development of new products for atmospheric chemistry and climate studies, some of which were unexpected before launch. The assimilation of IASI observations in NWP models provides a significant forecast impact; in most cases the impact has been shown to be at least as large as for any previous instrument. In atmospheric chemistry, global distributions of gases, such as ozone and carbon monoxide, can be produced in near–real time, and short-lived species, such as ammonia or methanol, can be mapped, allowing the identification of new sources. The data have also shown the ability to track the location and chemistry of gaseous plumes and particles associated with volcanic eruptions and fires, providing valuable data for air quality monitoring and aircraft safety. IASI also contributes to the establishment of robust long-term data records of several essential climate variables. The suite of products being developed from IASI continues to expand as the data are investigated, and further impacts are expected from increased use of the data in NWP and climate studies in the coming years. The instrument has set a high standard for future operational hyperspectral infrared sounders and has demonstrated that such instruments have a vital role in the global observing system.

Observation of tropospheric δD by IASI over western Siberia: comparison with a general circulation model

“…It records radiance from the Earth's surface and the atmosphere with an apodized spectral resolution of 0.5 cm −1 , spectrally sampled at 0.25 cm −1 . It has a low noise of 0.1-0.4 K for a reference blackbody at 280 K (Hilton et al, 2012), with the lower noise values in the range used for δD retrievals (e.g. Lacour et al, 2012).…”

Intercomparison of polar ozone profiles by IASI/MetOp sounder with 2010 Concordiasi ozonesonde observations

“…The nadir radiances are collected and distributed in near real time to operational weather forecasting centers (Hilton et al, 2012;Collard and McNally, 2009) as well as for the monitoring of atmospheric composition changes (Clerbaux et al, 2009). IASI is a Fourier transform spectrometer on board the MetOp-A polar-orbiting satellite providing data on each location at least twice a day since June 2007.…”

Using the full IASI spectrum for the physical retrieval of temperature, H2O, HDO, O3, minor and trace gases

“…In this paper we present an original retrieval methodology, which exploits the full IASI (Infrared Atmospheric Sounder Interferometer, [1]) information content in order to estimate the atmospheric parameters. These include the main contributors to the formation of the Earth infrared emission spectrum: surface parameters (emissivity ) and surface temperature (T s ), vertical profiles of temperature (T ), of water vapour mixing ratio (Q), of ozone mixing ratio (O), of HDO mixing ratio (D) and average column abundances of CO 2 , CO, CH 4 , N 2 O, HNO 3 , SO 2 , NH 3 OCS and CF 4 .…”