Banca de DEFESA: MATHEUS HENRIQUE DE FREITAS LEITE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MATHEUS HENRIQUE DE FREITAS LEITE
DATE: 05/09/2022
TIME: 14:00
LOCAL: videoconferência
TITLE:

ANALYSIS OF BRAZILIAN NORTHEAST JET CURRENT AND ITS INFLUENCE ON FLOWS
ZONES AND SOUTHERN

KEY WORDS:

 Northeast Brazilian Jet Current; Circulations between hemispheres; Zonal and
Meridional Processes

PAGES: 63
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SUMMARY:

The Brazilian Northeast jet stream (CJNEB), internationally recognized in 2017, is
located between 0ºS and 20ºS with a speed greater than 20m/s. CJNEB is a mechanism of
interaction and circulation between the hemispheres, but they are still poorly studied. The aim
of this study is to analyze and classify how global circulation behave during interaction with
CJNEB. Three study areas were used: area I includes AS (70ºN - 70ºS and 0-90ºW); Areas 2
and 3 encompass the entire planet between latitudes 70-30oS to 70-30oN for two hemispheres,
respectively. The data used for the years 2018 to 2020 were: 1) NCEP/NCAR reanalysis data,
with horizontal resolution of 2.5 ºx2.5º and 17 pressure levels (between 1000hPa - 100hPa); 2)
satellite images gridded in the infrared and water vapor channels of the GIBBS (Global ISCCP
B1). CJNEB was identified by its location and winds velocity above 20 m/s at the 200 hPa level.
The events of inter-hemispheric linkages were chosen: (a) through advancement of the CJSTHN
to latitudes 0-5ºN and (b) the existence of the link with the CJNEB. There was a total of 671
occurrences of advances (a), which resulted in 266 occurrences of connections (b). Connections
lasting one and more days (16 events) were analyzed in detail from formation to dissipation.
These events were classified as Complete (LC) and Incomplete (LI) Bindings: 1) when
CJSTHN (CJSTHS) together with CJNEB enters HS (HN) but does not join CJSTHS
(CJSTHN) (LI) and 2) when CJSTHN (CJSTHS) with CJNEB enters HS (HN) and joins with
CJSTHS (CJSTHN) (LC). North’s incomplete bindings (14 events) are the most common with
a duration of 1 to 13 days. Zonal and meridional processes were identified by 1) number of
geopotential height anomaly nuclei (nuclei) and 2) families of baroclinic cyclones in satellite
images (families). The shape of the H N current has always been meridional and the HS has
generally changed from zonal to meridional. The number of nuclei/families is 5/6 in the HS
while in the HN they can reach 6/7, that is, the southern circulation in the HN was more intense
than in the HS. Upper Tropospheric Cyclonic Vortex and Trough of Bolivian High had a strong
influence on the interhemispheric connection. Conceptual models, which show the conditions
for the interhemispheric connection, were elaborated. These results will be used in operational
practice to forecast meridional processes influenced by the circulation from HN to HS.

BANKING MEMBERS:
Interno - 4421297 - HELIOFABIO BARROS GOMES
Externo à Instituição - HENRIQUE FUCHS BUENO REPINALDO - UNESP
Presidente - 1099304 - NATALIA FEDOROVA