Banca de QUALIFICAÇÃO: MATHEUS HENRIQUE DE FREITAS LEITE

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MATHEUS HENRIQUE DE FREITAS LEITE
DATE: 15/10/2021
TIME: 09:00
LOCAL: videoconferência
TITLE:

INFLUENCE OF ZONAL AND SOUTHERN FLOWS ON THE JET CURRENT OF NORTH EAST

KEY WORDS:

Northeast Brazilian Jet Current; Circulations between hemispheres; Zonal and

Meridional Processes

PAGES: 51
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
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 circulations behave during
interactions 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 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). The classification was similar for CJSTHS with CJNEB. LI
calls (15 events) are the most common with a minimum duration of 1 to 13 days. The 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 HN 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. These results will be used to predict southern 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