Welcome on the
GRUAN Processor webpage.
The characterisation of uncertainties in Numerical Weather Prediction (NWP) models is a major challenge that is addressed as part of the Horizon 2020 GAIA-CLIM project. In that regard, observations from the radiosonde GCOS reference upper-air network (
) are being used at the Met Office and ECMWF to assess uncertainties associated with model data. A stand-alone module, decoupled from the NWP systems at the Met Office and ECMWF, is being developed based on a core radiative transfer modelling capability built around two existing open-source software packages (EUMETSAT's
RTTOV fast radiative transfer model, and the NWP SAF Radiance Simulator). This software, referred to as the GRUAN Processor, enables the comparison of collocated geophysical fields and simulated brightness temperature between radiosonde and model fields.
Data shown on this webpage are monthly averages of the differences NWP-GRUAN in observation space (T and q) and in simulated brightness temperature (Tb) space, processed with the GRUAN Processor (version 6.1). Both graphic-based (.eps) and text based (.txt) files are (or will soon be) available. Short or partial radiosonde ascents have been taken out of the averages. Cloud/clear or day/night profiles are not discriminated. The total uncertainty (red bars) represents the GRUAN standard errors in observation space, and the maximum total uncertainty (with k=1 from eq (6) Immler et al., 2010) propagated in Tb space (accounting for GRUAN standard error in P, q, and T, and model uncertainty at the surface due to the horizontal interpolation of model grid). A preliminary
are available on the GAIA-CLIM
, further up-to-date documents are in preparation.
For any queries, please contact
Note: Figures and data on this webpage are preliminary and made available only as a demonstrator.
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HIRS (NOAA 19)