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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:08 |
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Conference: Bucharest University Faculty of Physics 2018 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Contributions to thermal convection forecast over Romanian teritory
Authors:
Dorinel VISOIU(1), Cristian Valer VRACIU(1)
*
Affiliation:
1) University of Bucharest, The Faculty of Physics, 405 Atomistilor Street, BO Box 11, Magurele, Ilfov, Romania, 077125
E-mail
dorinel.visoiu@gmail.com
Keywords:
sailplane, thermal convection, Gold`s method
Abstract:
As weather and climate models move towards higher resolution, there is growing interest about potential future improvements in the understanding and prediction of atmospheric convection and its interaction with larger-scale phenomena. Short-term forecasts of thermal convection remain poor, with biases that have not been removed by increasing resolution in current operational forecast models (Lin et al., 2012). Particularly, the depth of the convective layer and its diurnal variation is still a debatable subject and a lot of studies have been initiated in that respect. Thermal convection consists of plumes or thermals of warm air that rises and cold air that sinks within the boundary layer due to buoyancy forces. Usually, the dimensions of rising thermals are large enough to allow sailplanes to circle inside their boundaries and to climb with them during the cross-country flights. The development of the convective boundary layer is mainly connected with the diurnal variation of the surface temperature and, ultimately, to forecast the evolution of the convective layer depth means to forecast the environment temperature at the ground level. The present study used the methodology of the British meteorologist Gold E.(1933) to forecast the evolution of the thermal convection during the daytime, expressed in the depth (in hPa) of the convective layer. Gold developed a solar heating table for Great Britain area, respectively for 52 deg. N, which contains the hourly values of the depth of boundary layer (in hPa) changed to an adiabatic state by insolation. In the present study are provided similar values obtained for the Romanian territory, respectively 45 deg. N lat. The main benefit of this study is improving the forecast of thermal convection for a limited area during national and international gliding competitions organized in Romania.
References:
Lin Y, Donner LJ, Petch J, Bechtold P, Boyle J, Klein SA, Komori T, Wapler K, Willett M, Xie X, Zhao M, Xie S, McFarlane SA, Schumacher C. 2012: TWP-ICE global atmospheric model intercomparison: convection responsiveness and resolution impact. Journal of Geophysical Research 117: D09111, DOI: 10.1029/2011JD017018.
Gold E., 1933: Maximum day temperatures and the tephigram. Prof. Notes Met Office, London, No.63.
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