Premium
Flow dependence of background errors and their vertical correlations for radiance‐data assimilation
Author(s) -
Hess Reinhold
Publication year - 2010
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.570
Subject(s) - radiosonde , radiance , data assimilation , meteorology , environmental science , climatology , depth sounding , troposphere , numerical weather prediction , atmospheric sciences , geology , remote sensing , geography , oceanography
This article examines the dependence of background‐error statistics on synoptic conditions and flow patterns. Error variances and vertical correlations of background temperatures as used for variational radiance‐data assimilation are estimated for two different weather regimes over Europe using the NMC method. The results are validated with real observations, i.e. radiosonde data and microwave satellite radiances and generalised with half a year of global data from the ECMWF forecasting system, where weather conditions are distinguished using model fields of wind speed, mean sea level pressure, and relative vorticity. Strong winds, low pressure, and cyclonic flow generally induce larger background errors of 500 hPa temperature than calm winds, high pressure, and anticyclonic flow, and also broader temperature correlations in the vertical with other tropospheric levels. Copyright © 2010 Royal Meteorological Society