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contributor authorWattrelot, Eric
contributor authorCaumont, Olivier
contributor authorMahfouf, Jean-François
date accessioned2017-06-09T17:31:27Z
date available2017-06-09T17:31:27Z
date copyright2014/05/01
date issued2014
identifier issn0027-0644
identifier otherams-86691.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4230276
description abstracthis paper presents results from radar reflectivity data assimilation experiments with the nonhydrostatic limited-area model Application of Research to Operations at Mesoscale (AROME) in an operational context. A one-dimensional (1D) Bayesian retrieval of relative humidity profiles followed by a three-dimensional variational data assimilation (3D-Var) technique is adopted. Several preprocessing procedures of raw reflectivity data are presented and the use of the nonrainy signal in the assimilation is widely discussed and illustrated. This two-step methodology allows the authors to build up a screening procedure that takes into account the evaluation of the results from the 1D Bayesian retrieval. In particular, the 1D retrieval is checked by comparing a pseudoanalyzed reflectivity to the observed reflectivity. Additionally, a physical consistency between the reflectivity innovations and the 1D relative humidity increments is imposed before assimilating relative humidity pseudo-observations with other observations. This allows the authors to counteract the difficulty of the current 3D-Var system to correct strong differences between model and observed clouds from the crude specification of background-error covariances. Assimilation experiments of radar reflectivity data in a preoperational configuration are first performed over a 1-month period. Positive impacts on short-term precipitation forecast scores are systematically found. The evaluation shows improvements on the analysis and also on objective conventional forecast scores, in particular for the model wind field up to 12 h. A case study for a specific precipitating system demonstrates the capacity of the method for improving significantly short-term forecasts of organized convection.
publisherAmerican Meteorological Society
titleOperational Implementation of the 1D+3D-Var Assimilation Method of Radar Reflectivity Data in the AROME Model
typeJournal Paper
journal volume142
journal issue5
journal titleMonthly Weather Review
identifier doi10.1175/MWR-D-13-00230.1
journal fristpage1852
journal lastpage1873
treeMonthly Weather Review:;2014:;volume( 142 ):;issue: 005
contenttypeFulltext


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