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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:25 |
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Conference: Bucharest University Faculty of Physics 2017 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Sensitivity of model’s horizontal resolution for precipitation- Case study: rapid cyclogenesis developed over the Black Sea
Authors:
Mirela PIETRIȘI(1,2), Meda Daniela ANDREI (1,2), Alexandra CRǍCIUN (2)
*
Affiliation:
1) University of Bucharest, Faculty of Physics, P.O.BOX MG 11, Magurele, Bucharest, Romania
2) National Meteorological Administration, Bucuresti-Ploiesti Ave., No. 97, 013686, Bucharest, Romania
E-mail
mirela.niculae@gmail.com
Keywords:
resolution, limited area model, lateral boundary conditions
Abstract:
During the last decades, the NWP models have been used by the forecasters as an important tool to predict severe meteorological events, such as wind gusts or large precipitation amounts. Even though a continuous effort was putted in the developing of NWP models, still they don’t accurately capture the observed events. One cause for an inaccurate prediction could be related to the model’s ability to resolve features that depends not only on spatial resolution but also on the domain’s size. In order to verify this for ALARO limited area model, several sensitivities studies were perform to assess the impact of horizontal resolution on precipitation field. For this purpose, we have used a synoptic situation that happened on 20 February 2017, when over the Black Sea basin rapidly formed and evolved a cyclone who affected the southeastern part of Romania. The simulations were made for two different domains and resolutions. The configuration that runs operationally at NMA does not capture the spatial distribution of the precipitation field nor the observed amount, maybe because the integration domain doesn’t cover the Black Sea entirely. Further, an extended domain that covers the Black Sea was used to account the exchange of sea-atmosphere fluxes, together with a fine horizontal resolution (5 km and 2.5 km) to account for sub-grid microphysics variability. These latest configurations capture the cyclone formed over the Black Sea, as well as the spatial distribution of precipitation, even though it not captures the precipitation peak. Hence, we assessed the NWP to accurately predict the observed precipitation field and we have found that the use of a fine resolution over a given domain leads to better results than the use of a coarse horizontal resolution.
Acknowledgement:
The authors would like to acknowledge Prof. Dr. Sabina Stefan for valuable suggestions and fruitful discussions.
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