Intercomparison of the performance of MM5/WRF with and without satellite data assimilation in short-range forecast applications over the Indian region
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
Intercomparison of the performance of MM5/WRF
with and without satellite data assimilation in short-range
forecast applications over the Indian region
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| Creator |
V, Rakesh
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| Subject |
Meteorology and Climatology
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| Description |
The present study is conducted to verify the
short-range forecasts from mesoscale model version5
(MM5)/weather research and forecasting (WRF) model
over the Indian region and to examine the impact of
assimilation of quick scatterometer (QSCAT) near surface
winds, spectral sensor microwave imager (SSM/I) wind
speed and total precipitable water (TPW) on the forecasts
by these models using their three-dimensional variational
(3D-Var) data assimilation scheme for a 1-month period
during July 2006. The control (without satellite data
assimilation) as well as 3D-Var sensitivity experiments
(with assimilating satellite data) using MM5/WRF were
made for 48 h starting daily at 0000 UTC July 2006. The
control run is analyzed for the intercomparison of MM5/
WRF short-range forecasts and is also used as a baseline
for assessing the MM5/WRF 3D-Var satellite data sensitivity
experiments. As compared to the observation, the
MM5 (WRF) control simulations strengthened (weakened)
the cross equatorial flow over southern Arabian sea near
peninsular India. The forecasts from MM5 and WRF
showed a warm and moist bias at lower and upper levels
with a cold bias at the middle level, which shows that the
convective schemes of these models may be too active
during the simulation. The forecast errors in predicted
wind, temperature and humidity at different levels are
lesser in WRF as compared to MM5, except the
temperature prediction at lower level. The rainfall pattern
and prediction skill from day 1 and day 2 forecasts by WRF
is superior to MM5. The spatial distribution of forecast
impact for wind, temperature, and humidity from 1-month
assimilation experiments during July 2006 demonstrated
that on average, for 24 and 48-h forecasts, the satellite data improved the MM5/WRF initial condition, so that model
errors in predicted meteorological fields got reduced.
Among the experiments, MM5/WRF wind speed prediction
is most benefited from QSCAT surface wind and
SSM/I TPW assimilation while temperature and humidity
prediction is mostly improved due to latter. The largest
improvement in MM5/WRF rainfall prediction is due to the
assimilation of SSM/I TPW. The assimilation of SSM/I
wind speed alone in MM5/WRF degraded the humidity and
rainfall prediction. In summary the assimilation of satellite data showed similar impact on MM5/WRF prediction;
largest improvement due to SSM/I TPW and degradation
due to SSM/I wind speed.
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| Publisher |
Springer
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| Date |
2009-09-03
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cir.cmmacs.ernet.in/78/1/map.pdf
V, Rakesh (2009) Intercomparison of the performance of MM5/WRF with and without satellite data assimilation in short-range forecast applications over the Indian region. Meteorology Atmospheric Physics, 105 (3-4). pp. 133-155. ISSN 0177-7971 (print version) ISSN: 1436-5065 (electronic version) |
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| Relation |
http://www.springerlink.com/content/0w76675l44715014/
http://cir.cmmacs.ernet.in/78/ |
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