Banca de QUALIFICAÇÃO: JEAN SOUZA DOS REIS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : JEAN SOUZA DOS REIS
DATE: 28/02/2020
TIME: 14:00
LOCAL: Auditório CCET
TITLE:

DYNAMIC AND CLIMATOLOGICAL ASPECTS OF EXTRATROPICAL CYCLONS IN SOUTH AMERICA

KEY WORDS:

Cyclone. Tracking. Dynamic. Extratropical

PAGES: 68
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Meteorologia Sinótica
SUMMARY:

Extratropical cyclones are meteorological systems of great influence at medium and high latitudes, they are considered essential components in global atmospheric circulation. In South America, they are the most important systems in modulate the weather and climate due to formation of clouds, rain, intense winds and abrupt changes in temperature. Currently, there are two conceptual models of extratropical cyclone, the Bjerknes and Solberg model and the Shapiro-Keyser model, with evolutionary and morphological characteristics specific. About Shapiro-Keyser conceptual model, a presence of a mesoscale phenomenon calls Sting Jet called attention of the scientific community in the Northern Hemisphere because of intense winds capable of causing great damage and monetary losses, but few studies have been carried out in the Southern Hemisphere. In this study is, will carry out the first climatology of each conceptual model of extratropical cyclone and will analyze how dynamic and synoptic characteristics are applied through robust climatology. Determined the climatology of each conceptual model, will be analyzed the cyclone three-dimensional structure. In cases of Shapiro-Keyser model the presence of the Sting Jet will be studied. In addition, it will be assessed how each cyclone conceptual model influences in occurrence of natural disasters in the regions South and Southeast of Brazil. The Reanalyzed data from the ERA5 set from the European Center for Medium-Term Meteorological Forecasts (ECMWF) will be used, with a spatial resolution of 0.125 ° x 0.125 °, 2.5 ° x2.5 ° of 6-hour in period of 1979 to 2019. Natural disaster data contains extreme events such as floods, flash floods and landslides was kindly provided by the National Center for Monitoring and Natural Disaster Alerts (CEMADEN). For identification of extratropical cyclones, an automatic method of cyclone identification will be used in mean sea level pressure data of the ERA5. A subroutine will be created for identifying the conceptual model of cyclone Shapiro-Keyser using the wind spin at 925 hPa and the potential temperature in the system's occlusion phase, to identify the warm core of cyclone seclusion. An analysis of the three-dimensional structure and the core of the cyclone will be made using the cyclone phase diagram. A methodology for identifying the Sting Jet is show based in previous studies, using the frontogenetic functions and magnitude of the wind in surface. Preliminary results show good agreement with the climatological properties observed in previous studies in South America. The average lifetime of extratropic cyclones was 3.4 days and in 40% of cases, the cyclones had a lifetime between 1 and 5 days. There is no evident of seasonal variation in the lifetime of cyclones considering the winter and summer seasons. The average speed of extratropical cyclones was 21 km/h in winter and 19 km/h in summer. An analysis of deepening rate and minimum pressure in the center of the cyclone indicates these systems are more intense in winter than in summer.

BANKING MEMBERS:
Presidente - 1164414 - WEBER ANDRADE GONCALVES
Interno - 2086472 - BERGSON GUEDES BEZERRA
Interno - 1752417 - CLAUDIO MOISES SANTOS E SILVA
Interno - 1858120 - DAVID MENDES