In:
Quarterly Journal of the Royal Meteorological Society, Wiley, Vol. 131, No. 606 ( 2005-01), p. 437-458
Abstract:
A recent version of the European Centre for Medium‐Range Weather Forecasts four‐dimensional variational (4D‐Var) assimilation system (40 km horizontal resolution with a 12‐hour window) is used to examine the comparative impact of including satellite‐derived rainfall rates from SSM/I and TMI radiometers within the tropics. The methodology is similar to the one proposed by Marécal and Mahfouf (2002) where Total Column Water Vapour (TCWV) retrievals in rainy areas from a simplified 1D‐Var assimilation are introduced in the 4D‐Var system. An improved methodology for the estimation of rain rate retrieval errors proposed by Bauer et al. (2002) is used. Three one‐month experiments are undertaken: a control run (no rain rate assimilation), a TMI run (assimilation of TMI‐derived rain rates) and a SSM/I run (assimilation of SSM/I‐derived rain rates). The corrections of TCWV in rainy areas introduced in the 4D‐Var are very similar between SSM/I and TMI because they are dominated by the ‘no rain’ information. The impact of TMI and SSM/I assimilations is positive on forecast scores, both in the extratropics and in the tropics. Results from the SSM/I run show a larger positive impact which tends to demonstrate the benefit of the increased number of data from the SSM/I with respect to TMI. Copyright © 2005 Royal Meteorological Society.
Type of Medium:
Online Resource
ISSN:
0035-9009
,
1477-870X
Language:
English
Publisher:
Wiley
Publication Date:
2005
detail.hit.zdb_id:
3142-2
detail.hit.zdb_id:
2089168-4
SSG:
14
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