Page History

...

Anchor
_heading h.vx1227

(3) How is the uncertainty estimate obtained? Which sources of uncertainty does it account for and which does it omit?
The uncertainty estimation for CARRA is obtained from ensembles used in the derivation of the error statistics for the data assimilation schemes. See https://datastore.copernicus-climate.eu/documents/reanalysis-carra/CARRAUncertainty%20estimationFinal.pdf Copernicus Arctic Regional Reanalysis (CARRA): Uncertainty estimation method for details on how this is computed. It addresses some of the uncertainties of the model and data assimilation system, but not everything. It is based on using the weather forecast model to evolve initial uncertainties, represented as scaled random perturbations, forward in time and also using perturbations in the lateral boundary conditions. With this method, some of the systematic errors in the weather forecast model will not be accounted for.

...