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Modelling of forecast errors in geophysical fluid flows
Author(s) -
Bannister R. N.,
Katz D.,
Cullen M. J. P.,
Lawless A. S.,
Nichols N. K.
Publication year - 2007
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1618
Subject(s) - uncorrelated , data assimilation , representation (politics) , numerical weather prediction , mathematics , probability density function , meteorology , computer science , statistics , geography , politics , political science , law
A method is sought to decompose errors in numerical forecasts of the atmosphere into components that are uncorrelated. This can simplify the representation of the probability density function of forecast errors so that it can be used in data assimilation. A new method based on potential vorticity (PV) is used to partition errors into balanced and unbalanced variables that are thought to be mutually uncorrelated. The effectiveness of the PV method is compared with a simpler method. A toy model and an operational forecasting model are used to show that the PV‐based variables are usually less correlated than those of the simpler approach. Copyright © 2007 John Wiley & Sons, Ltd.