Correlated observation errors in data assimilation

International Journal for Numerical Methods in Fluids - Tập 56 Số 8 - Trang 1521-1527 - 2008
Laura Stewart, Sarah L. Dance, Nancy Nichols

Tóm tắt

AbstractData assimilation provides techniques for combining observations and prior model forecasts to create initial conditions for numerical weather prediction (NWP). The relative weighting assigned to each observation in the analysis is determined by its associated error. Remote sensing data usually has correlated errors, but the correlations are typically ignored in NWP. Here, we describe three approaches to the treatment of observation error correlations. For an idealized data set, the information content under each simplified assumption is compared with that under correct correlation specification. Treating the errors as uncorrelated results in a significant loss of information. However, retention of an approximated correlation gives clear benefits. Copyright © 2007 John Wiley & Sons, Ltd.

Từ khóa


Tài liệu tham khảo

10.1175/1520-0493(1977)105<1211:AADAOA>2.0.CO;2

10.1175/1520-0493(2003)131<0706:TSSOOE>2.0.CO;2

CollardA.On the choice of observation errors for the assimilation of AIRS brightness temperatures: a theoretical study. ECMWF Report AC/90 2004.

BergerH ForsytheM. Satellite Wind Superobbing. Forecasting Research Technical Report vol. 451. Met Office 2004.

10.1256/003590002320373337

10.1256/qj.03.193

FisherM.Accounting for correlated observation error in the ECMWF analysis. ECMWF Technical Memoranda MF/05106 2005.

Rodgers C, 2000, Inverse Methods of Atmospheric Sounding, Theory and Practice, 10.1142/3171

StewartL DanceS NicholsN. Correlated observation errors in data assimilation. Numerical Analysis Report 3/05 University of Reading 2005. Available at:http://www.maths.rdg.ac.uk/research/publications/Na_reports.asp.

FisherM.Estimation of entropy reduction and degrees of freedom for signal for large variational analysis systems. ECMWF Technical Memoranda 397 2003.

Thông tin
Thông tin xuất bản

International Journal for Numerical Methods in Fluids

Tập 56 Số 8

1521-1527

Thông tin tác giả