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IASI (Infrared Atmospheric Sounder Interferometer) is flying on the European MetOp series of weather satellites. Besides acquiring temperature and humidity data, IASI also observes the infrared emission of the main minor and trace atmospheric components with high precision. The retrieval of these gases would be highly beneficial to the efforts of scientists monitoring Earths climate. IASI retrieval capability and algorithms have been mostly driven by Numerical Weather Prediction centers, whose limited resources for data transmission and computing is hampering the full exploitation of IASI information content. The quest for real or nearly real time processing has affected the precision of the estimation of minor and trace gases, which are normally retrieved on a very coarse spatial grid. The paper presents the very first retrieval of the complete suite of IASI target parameters by exploiting all its 8461 channels. The analysis has been exemplified for sea surface and the target parameters will include sea surface temperature, temperature profile, water vapour and HDO profiles, ozone profile, total column amount of CO, CO2, CH4, N2O, SO2, HNO3, NH3, OCS and CF4. Concerning CO2, CH4 and N2O, it will be shown that their colum amount can be obtained for each single IASI IFOV (Instantaneous Field of View) with a precision better than 1-2%, which opens the possibility to analyze, e.g., the formation of regional patterns of greenhouse gases. To assess the quality of the retrieval, a case study has been set up which considers two years of IASI soundings over the Hawaii, Manua Loa validation station. [ABSTRACT FROM AUTHOR]

In the context of the development by EUMETSAT of a new generation of meteorological satellites, we have built the new σ-IASI-as (where "as" stands for "all sky") radiative transfer code. Unlike its predecessor σ-IASI, the code is able to calculate both clear and cloudy sky radiances, as well as their Jacobians with respect to any desired geophysical parameter. In addition, σ-IASI-as can perform calculations to simulate the extinction effect of the most common types of atmospheric aerosols and of clouds via ab-initio Mie calculations. We briefly describe the analytical scheme on which the model is based, and have a glance to its potentialities illustrating some sample calculations. Overall, the new model is a complete and fast radiative transfer tool for IASI, and already available for IASI-NG and MTG-IRS. [ABSTRACT FROM AUTHOR]

The paper illustrates the impact of new water vapor continuum coefficients in the far infrared on spectral cooling rates and integrated atmospheric fluxes. The analysis has been based on data and results obtained within the ECOWAR project (Earth Cooling by Water vapor Radiation). A novel methodology has been developed, implemented and used to retrieve foreign-broadened water vapor continuum absorption coefficients from atmospheric emitted spectral radiance observations in the spectral range 240 to 590 cm-1. The impact of these new coefficients on spectral cooling rates has been assessed. The new coefficients show that the lower troposphere tends to cool down at a rate larger than that predicted by the state-of-art Mlawer, Tobin-Clough, Kneizys, Davies (MT_CKD) continuum. [ABSTRACT FROM AUTHOR]

The paper illustrates the new features of the line-by-line radiative transfer model σIASI. The new features are mainly based on the computational optimization of the code and its parallelization. The paper also presents and discusses retrieval for temperature, water vapor and ozone profiles from spectra measured by the Infrared Atmospheric Sounding Interferometer in the tropical belt. Comparison with the ECMWF analysis is also provided, which shows the good quality and accuracy of IASI retrieval products. [ABSTRACT FROM AUTHOR]