Impact of background error statistics on forecasting of tropical cyclones over the north Indian Ocean
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
Impact of background error statistics on forecasting of tropical cyclones over the north Indian Ocean
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| Creator |
V, Rakesh
Goswami, P |
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| Subject |
Climate Modelling
Meteorology and Climatology |
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| Description |
While the quality of background error statistics (BES) is recognized as one of the key components of assimilation, considerable uncertainties exist in prescribing BES, especially since the prescription and
impact of BES can also depend on the weather regime and geographical location. In this backdrop, it is
necessary to quantify the impact of different BES for particular weather systems; this is particularly true
for cyclones over the north Indian Ocean which have characteristics different from those over the
Atlantic and the Pacific. The objective of this work is to assess the relative improvement in forecasting
tropical cyclone track and intensity due to different BES. We have used global BES (GBES), computed
from global model forecasts for 357 cases distributed over a period of one year and regional BES
(RBES), generated from short-range forecasts with Weather Research and Forecasting (WRF) model for
a 30 day period. From a series of assimilation experiments using the WRF three-dimensional variational
(3D-Var) data assimilation system with different BES, and a number of parameters to quantify the impact
of BES, it is shown that the use of RBES in WRF 3D-Var significantly improves prediction of track as
compared to simulations with no assimilation or GBES. Further, the skill with RBES is comparable with,
or better than, many operational skills, although a strict comparison is difficult due to differences in the
events and the basins. While parallel and significant efforts are needed for the formulation and
incorporation of BES in assimilation systems in general, this study quantifies relative advantages of using
RBES in forecasting cyclones over the Indian ocean
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| Publisher |
American Geophysical Union
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| Date |
2011-07-28
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cir.cmmacs.ernet.in/85/1/JGR_2011.pdf
V, Rakesh and Goswami, P (2011) Impact of background error statistics on forecasting of tropical cyclones over the north Indian Ocean. Jounal of Geophysical Research. ISSN 0148–0227 (Print) ISSN 2156–2202 (Online) |
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| Relation |
http://www.agu.org/journals/jgr/
http://cir.cmmacs.ernet.in/85/ |
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