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| Titel |
WRF simulation of a precipitation event over the Tibetan Plateau, China – an assessment using remote sensing and ground observations |
| VerfasserIn |
F. Maussion, D. Scherer, R. Finkelnburg, J. Richters, W. Yang, T. Yao |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 6 ; Nr. 15, no. 6 (2011-06-10), S.1795-1817 |
| Datensatznummer |
250012852
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| Publikation (Nr.) |
 copernicus.org/hess-15-1795-2011.pdf |
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| Zusammenfassung |
| Meteorological observations over the Tibetan Plateau (TiP) are scarce, and
precipitation estimations over this remote region are difficult. The
constantly improving capabilities of numerical weather prediction (NWP)
models offer the opportunity to reduce this problem by providing
precipitation fields and other meteorological variables of high spatial and
temporal resolution. Longer time periods of years to decades can be simulated
by NWP models by successive model runs of shorter periods, which can be
described by the term "regional atmospheric reanalysis". In this paper,
we assess the Weather Research and Forecasting (WRF) models capacity in
retrieving rain- and snowfall on the TiP in such a configuration using a
nested approach: the simulations are conducted with three nested domains at
spatial resolutions of 30, 10, and 2 km. A validation study is carried out
for a one-month period with a special focus on one-week (22–28 October 2008), during which strong rain- and snowfall was observed on the TiP. The
output of the model in each resolution is compared to the Tropical Rainfall
Measuring Mission (TRMM) data set for precipitation and to the Moderate
Resolution Imaging Spectroradiometer (MODIS) data set for snow extent. TRMM
and WRF data are then compared to weather-station measurements. Our results
suggest an overall improvement from WRF over TRMM with respect to
weather-station measurements. Various configurations of the model with
different nesting and forcing strategies, as well as physical
parameterisation schemes are compared to propose a suitable design for a
regional atmospheric reanalysis over the TiP. The WRF model showed good
accuracy in simulating snow- and rainfall on the TiP for a one-month
simulation period. Our study reveals that there is nothing like an optimal
model strategy applicable for the high-altitude TiP, its fringing
high-mountain areas of extremely complex topography and the low-altitude land
and sea regions from which much of the precipitation on the TiP is
originating. The choice of the physical parameterisation scheme will thus be
always a compromise depending on the specific purpose of a model simulation.
Our study demonstrates the high importance of orographic precipitation, but
the problem of the orographic bias remains unsolved since reliable
observational data are still missing. The results are relevant for anyone
interested in carrying out a regional atmospheric reanalysis. Many
hydrological analyses and applications like rainfall-runoff modelling or the
analysis of flood events require precipitation rates at daily or even hourly
intervals. Thus, our study offers a process-oriented alternative for
retrieving precipitation fields of high spatio-temporal resolution in regions
like the TiP, where other data sources are limited. |
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