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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:52 |
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Conference: Bucharest University Faculty of Physics 2018 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
The evolution of thermal and dynamic tropopause height along the trajectory of cyclones that reach Romania and causes severe weather
Authors:
Meda Daniela ANDREI(1,2), Mihaela CAIAN(2), Sabina ȘTEFAN(1)
*
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
meda.georgescu@gmail.com
Keywords:
dynamic tropopause, thermal tropopause, potential vorticity, forecast, cyclogenesis
Abstract:
In this paper were determined the trajectories of some cyclones, which during the year 2017 crossed Europe and reached Romania. Were chosen those cases in which large amounts of water or strong winds were recorded. Along these trajectories, using the ERA-Interim data, the heights (and pressures) of thermal and dynamic tropopause, as well as the variation of the mean sea level pressure, were calculated. It is known that tropopause folds play an important role in most cases of cyclogenesis, and their tracking may be of great use in forecasting cyclone evolution. The goal of this analyze was to study the height variation of the two tropopauses, in parallel with the mean sea level pressure, throughout cyclone life, in order to see which one can provide a better signal in the prognosis of their generation, developing and decay. For this were analyzed times series of tropopause heights at zero and +/- 6-12 hours lead/delay at each cyclone centre along trajectories. Particular attention was paid to the momentum of cyclone generation, maximal deepening and decay to see if any of these tropopauses can be considered a precursor to cyclogenesis.
References:
Nielsen-Gammon (2001), J. W., A visualization of the global dynamic tropopause, Bull. Am. Meteorol. Soc., 82, 1151–1167;
Reichler, T., Dameris, M., & Sausen, R. (2003). Determining the tropopause height from gridded data. Geophysical Research Letters, 30(20), 2042;
Wirth, V., (2000), Thermal versus dynamical tropopause in upper tropospheric balanced flow anomalies, Q. J. R. Meteorol. Soc., 126, 299– 317.
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