RTIASI-4: a new version of the ECMWF fast radiative transfer model for the infrared atmospheric sounding interferometer
نویسنده
چکیده
An improved version of RTIASI, the ECMWF fast radiative transfer model for the Infrared Atmospheric Sounding Interferometer, has been developed. In the new version of RTIASI (RTIASI-4) the accuracy of the fast transmittance model has been improved by including 4 more molecules (HNO3, CCl4, CF4 and OCS) in the line-by-line computations and by using the year 2000 release of the HITRAN molecular database. By using a revised set of water vapour training profiles in the stratosphere, the condition of the regression has been improved so that unphysical oscillations observed in the stratospheric water vapour Jacobians have been virtually eliminated. RTIASI-4 features a revised vertical pressure grid that allows the integration of the radiative transfer equation to be performed with significantly increased accuracy. The water vapour transmittance model has been significantly improved by weighting the data prior to performing the regression and by introducing a dedicated transmittance model for the continuum absorption. Minor adjustments to the predictors for water vapour have also been made. A significant improvement to the previous versions of the model is the inclusion of CO, CH4, N2O and CO2 as profile variables. Finally, a solar term has been introduced to evaluate the solar radiance reflected by a land or water surface in a non-scattering atmosphere.
منابع مشابه
The inclusion of aerosols and clouds in RTIASI, the ECMWF fast radiative transfer model for the infrared atmospheric sounding interferometer
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