One of major challenges facing Earth's science in the next decade and beyondis the development of an accurate long term observational data set to study global change. To accomplish this, a wide range of observations will be required to provide both new measurements, not previously achievable and measurements with a greater degreee of accuracy and resolution than the ones which are presently and currently available. Among the parameters that are currently retrieved from satellite vertical sounding observations, temperature and moisture profiles are the most important for the description of the thermodynamic state of the medium. Other parameters, like those describing the cloud fields, the surface state or the conditions close to the surface are also key parameters for meteorology and climatology. A new generation of high spectral atmospheric sounders in the infrared has recently been designed to provide both new and more accurate data about the atmosphere, land and oceans for application to climate studies. Among the important observations that these instruments should contribute to the climate data set are day and night global measurements of: atmospheric temperature profiles; relative humidity profiles; cloud field parameters; total ozone burden of the atmosphere; distribution of minor atmospehric gases (methane, carbonmonoxide and nitrous oxide).

Inhalt
1 Review of future programs from 1994 ATOVS) to the EOS era.- Historical background for IASI.- IASI, infrared interferometer for operations and research.- Requirements for an Operational Interferometer Thermal Sounder.- Development of a Fourier Transform Infrared sounder. IMG.- 2 Next generation IR sounders . temperature and moisture analysis.- The Advanced-3I (Improved Initialization Inversion) method for the processing of next generation sounder observations.- Extraction of atmospheric signals from radiance measurements : some limitations.- GLA and LMD approaches to the processing of AIRS and IASI observations.- The impact of the initial guess on the accuracy of satellite retrievals.- Vertical sounding capabilities with high spectral resolution atmospheric radiation measurements. A demonstration with the High resolution Interferometer Sounder (HIS).- 3 Next generation IR sounders and cloud field analysis.- Determination of temperature and moisture profiles in a cloudy atmosphere using AIRS/AMSU.- Topics in optimal inversion schemes applied to atmospheric structure retrieval.- Retrieval of cloud parameters by multiple high spectral resolution observations in the near infrared under conditions of varying solar illumination.- Spectral variability of light scattering by atmospheric ice crystals.- Detection of Polar Stratospheric Clouds with next generation IR sounders.- Problems in cloud identification and clearing.- The potential of medium resolution spectral infrared measurements for high cloud studies.- Modelling reflecting and semi-transparent cloud for infrared sounding.- 4 Next generation IR Sounder and surface characteristics analysis.- Infrared remote sensing of surface temperature and surface spectral emissivities.- Effects of spectral resolution onsatellite surface temperature retrieval.- Investigation of infrared emissivities of Sahara dust powders and quartz from space.- 5 Next Generation IR sounders and trace gas analysis.- Trace gas remote sounding from near IR sun glint observation with tunable etalons.- High resolution observation of the Earth's atmosphere in the far infrared.- Remote sensing of atmospheric trace constituents using MID-IR Fourier transform spectrometry.- The measurement of global carbon monoxide using the Atmospheric Infrared Radiation Sounder (AIRS).- 6 Next generation IR observations : impact on weather and climate analysis.- Direct use of satellite sounding radiances in numerical weather prediction.- Retrieval and assimilation : system considerations.- On measuring the greenhouse effect of Earth.- Multi-year statistics of total cloud amounts from the Nimbus-7, ISCCP and Goads data sets.- 7 Forward modelling.- Transmittance coefficient generation for fast radiative transfer models. Application to new satellite sounding systems 431.- Review of existing spectral line data catalogs.- CO2 Q-branch spectral line shapes for atmospheric remote sensing.- Optimal spectral estimation algorithms for Michelson interferometer spectrometers.