Banca de DEFESA: MICEJANE DA SILVA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MICEJANE DA SILVA COSTA
DATA : 28/02/2018
HORA: 08:00
LOCAL: Sala 4, Escola de Ciências e Tecnologia (ECT)
TÍTULO:

SYNOTIC PATTERN OF WEAK AND INTENSE PRECIPITATION EVENTS IN THE NORTHEAST SEMARIATE OF BRAZIL

PALAVRAS-CHAVES:

Trend, composition of anomalies, Fortracc and climatic variability

PÁGINAS: 200
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Meteorologia
ESPECIALIDADE: Meteorologia Sinótica
RESUMO:

The semi - arid region of the Northeast of Brazil (NEBSA) has complex climatic characteristics which allows a great variation in the spatial distribution of precipitation, related to different rainfall regimes. Therefore, studies on atmospheric systems related to precipitation are relevant since they are associated with disasters that cause great social and economic impacts. Within this context the doctoral thesis is divided into articles format, thus: (i) The first article had the task to verify if there are trends in events of weak precipitation (WRE) and events of intense precipitation (HRE) for the periods less rainy and rainy during the years 1961 to 2011. Firstly, to define extreme precipitation events, the percentile tool (P) with values below P5 representing precipitation events weak (WRE) and above P95 intense (HRE), with a threshold of 5% in each percentile analyzed. The Mann-Kendall test allowed us to identify increasing and / or decreasing trends among extreme rainfall events. The results showed significant trends for the two extremes in both periods. The intensity of precipitation in the WRE and HRE had a statistical significance of 5% in the months of June, July, August, October, November and December. (ii) The second article aimed to define the beginning and end of the rainy season for each homogeneous rainfall sub-region of NEBSA during the period from 1979 to 2013. For this purpose, cluster analysis was used to define homogeneous regions of precipitation. And then, it was used pentad to identify the beginning and the end rainy in each subregion. As a result, five homogeneous sub-regions of precipitation were identified, with different periods of rainy onset, with the exception of the S2 and S3 sub-regions that coincide on November 27 to December 1, possibly due to the activities of ZCIT and VCAN. The months from November to April are the rainiest throughout NEBSA. With higher accumulated per pentad occur in the month of March and the smaller ones in the month of September.  (iii) Subsequently, the third article addresses the main theme of this, to identify existing differences in the dynamic characteristics of the atmosphere over NEBSA, with performance of each meteorological system in situations WRE and HRE for the period 1961-2011. For that, the Conceptual Model (MC) was adopted as the main tool for capturing extreme events associated to different meteorological systems, taking into account the duration in days and months of greater performance of each system. In order to support the investigation of the methodology applied in this thesis, the objective methods of Coutinho 2010 were used to select VCAN and ForTraCC for SCM. The anomaly compositions were analyzed for the day of the event and up to four days prior to the event, using meteorological variables provided by NCEP / NCAR, according to the need of each system. In summary, the results of this study broaden our global understanding of the role of seven atmospheric systems operating in different regions of NEBSA, whether or not they influence the total precipitation. In the anomaly compounds of each system associated to WRE and HRE days, it was possible to identify the location of its performance as well as to identify the systems that influenced or acted together. In relation to the extremes, it was observed that the events have similarities with each other, in relation to the behavior of the atmosphere, and what differs is the intensity of the event. In relation to SCM, it was seen that they are always associated with one or more systems.  (iv) Finally, the fourth article studied the mesoscale convective systems operating on NEBSA in the period from 2010 to 2011, a differentiated contribution of this thesis, whose objective was to identify the main physical and morphological characteristics of the atmosphere, when the SCM associated with the WRE and HRE events. For this, a software was created that tracked the results provided by ForTraCC, allowing to separate only the SCM that were acting on the station located inside the NEBSA. The results showed that the SCM have similar physical and morphological characteristics when they were classified as WRE and HRE and both events occur more frequently in the period of OND and JFM.  When analyzing the periods of each event, it was possible to verify that the HRE occurred more frequently in all quarters analyzed, possibly due to the greater intensity of the system, to be favored by the characteristics of the NEBSA region.

 

MEMBROS DA BANCA:
Presidente - 1914304 - KELLEN CARLA LIMA
Interno - 1346630 - LARA DE MELO BARBOSA ANDRADE
Interno - 1164414 - WEBER ANDRADE GONCALVES
Externo ao Programa - 2411669 - JONATHAN MOTA DA SILVA
Externo à Instituição - JOSÉ IVALDO BARBOSA DE BRITO - UFCG
Externo à Instituição - JOSÉ MARIA BRABO ALVES - UECE