@MastersThesis{Ramirez:1996:PaClVó,
author = "Ramirez, Maria Cleof{\'e} Valverde",
title = "Padr{\~o}es clim{\'a}ticos dos v{\'o}rtices cicl{\^o}nicos em
altos n{\'{\i}}veis no Nordeste do Brasil",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "1996",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "1996-12-04",
keywords = "climatologia, nordeste do Brasil, Atl{\^a}ntico Tropical Sul,
sat{\'e}lites meteorol{\'o}gicos, previs{\~a}o de tempo,
padr{\~o}es de circula{\c{c}}{\~a}o, v{\'o}rtices, ciclones,
fun{\c{c}}{\~o}es ortogonais, weather, northeastern Brazil,
South Tropical Atlantic Ocean, meteorological satellites, weather,
circulation patterns, vortices, cyclones, orthogonal functions.",
abstract = "Neste trabalho foram estudados os padr{\~o}es de
circula{\c{c}}{\~a}o associados aos v{\'o}rtices
cicl{\^o}nicos de altos n{\'{\i}}veis (VCAN's) sobre o Nordeste
do Brasil e Atl{\^a}ntico Tropical Sul. Utilizou-se as analises
di{\'a}rias do modelo de previs{\~a}o de tempo do ECMWF e
imagens de sat{\'e}lite meteorol{\'o}gicos. Os resultados
climatol{\'o}gicos para o per{\'{\i}}odo janeiro de 1980 -
dezembro de 1989 confirmam que os VCAN's formam-se na alta
troposfera, apresentando m{\'a}xima vorticidade cicl{\^o}nica em
200 hPa e um centro frio em 300 hPa. A maioria dos VCAN's
origina-se sobre o Atl{\^a}ntico Tropical sendo mais frequentes
nos meses de ver{\~a}o. Geralmente os VCAN's estendem-se para
baixo ate 500 hPa, e raramente chegam ate 700 hPa. Eles
inclinam-se com a altura para o oeste, e o centro frio esta
localizado a leste ou sudeste do centro do v{\'o}rtice. O tempo
de vida m{\'e}dio e de 7,1 dias. Nos anos de {"}El Nino{"} os
VCAN's s{\~a}o mais profundos na vertical, enquanto nos anos de
{"}La Nina{"} s{\~a}o confinados nos altos n{\'{\i}}veis.
Confirmou-se que os VCAN's originam-se a partir da
amplifica{\c{c}}{\~a}o da crista associada a Alta da
Bol{\'{\i}}via (AB). Essa amplifica{\c{c}}{\~a}o pode ser
causada pela incurs{\~a}o de sistemas frontais de latitudes
medias, ou por cavados do Pac{\'{\i}}fico Norte ou do
Atl{\^a}ntico Norte que se alinham com a AB na
dire{\c{c}}{\~a}o NW-SE ou NE-SW. Os VCAN's podem ter um
deslocamento regular ou irregular. Cavados de latitudes medias
associados a sistemas frontais e uma bifurca{\c{c}}{\~a}o inter
hemisf{\'e}rica a noroeste da Am{\'e}rica do Sul podem causar
deslocamento irregular. Para VCAN's com deslocamento regular e
comum observar a presen{\c{c}}a de um anticiclone nos altos
n{\'{\i}}veis do Atl{\^a}ntico Sul relacionado com a Zona de
Converg{\^e}ncia do Atl{\^a}ntico Sul. O primeiro modo da
analise das Fun{\c{c}}{\~o}es Ortogonais Emp{\'{\i}}ricas da
vorticidade relativa em 200 hPa apresenta um padr{\~a}o de ondas
estendendo-se desde a costa leste sul americana ate o
Atl{\^a}ntico Sul com orienta{\c{c}}{\~a}o SW-NE. Este modo
representa o cavado de latitudes medias, crista amplificada e
VCAN, sugerindo que ocorre transfer{\^e}ncia de momentum e
energia na dire{\c{c}}{\~a}o SW-NE. Para uma {\'a}rea menor
inserida no dom{\'{\i}}nio de estudo, o primeiro modo representa
o VCAN sobre o oceano e para o segundo modo, o VCAN sobre o
Nordeste. Mapas das correla{\c{c}}{\~o}es entre as amplitudes
destes modos e as series temporais da vorticidade relativa
filtrada para toda a {\'a}rea de estudo, indicam uma
rela{\c{c}}{\~a}o entre o cavado do Pac{\'{\i}}fico Sul (120°W
e 140°W) e o padr{\~a}o de ondas no leste da Am{\'e}rica do Sul.
Assim a presen{\c{c}}a deste cavado teria alguma
contribui{\c{c}}{\~a}o na forma{\c{c}}{\~a}o do VCAN.
ABSTRACT: In this work the circulation patterns associated with
cyclonic vortices (UTCV's) over Northeast Brazil and South
Tropical Atlantic was used for the analyzes of daily weather
forecast and ECMWF meteorological satellite images of the model
were studied. The climatological data for the period January 1980
- December 1989 confirm that VCAN's form in the upper troposphere,
with maxima ciclonic vorticity at 200 hPa and a cold center at 300
hPa. Most VCAN 's originates on the Tropical Atlantic are more
frequent in summer months. VCAN 's usually extend down to 500 hPa,
and rarely get to 700 hPa. They lean to the height to the west ,
and the cold center is located to the east or southeast of the
center of the vortex. The lifetime average and 7.1 days. In the
years of {"}El Nino{"} VCAN's are the deepest vertical, while in
years of {"}La Nina{"} are confined to high levels. It was
confirmed that the VCAN's originate from the associated
amplification of the Bolivian High (AB) crest. This amplification
can be caused by the incursion of frontal systems from middle
latitudes, or dug by North Pacific and North Atlantic that align
with AB in the direction NW-SE or NE-SW. The VCAN's can have a
regular or irregular displacement. Dug in the middle latitudes
associated with frontal systems and interhemispheric northwest of
South America bifurcation can cause irregular displacement. To
VCAN's with regular and common offset observe the presence of an
anticyclone in the high levels associated with the South Atlantic
Convergence Zone of the South Atlantic The first mode of EOF
analysis of the relative vorticity at 200 hPa shows a pattern of
waves extending up from the South American east coast until the
South Atlantic with SW-NE orientation. This is way trough the
middle latitudes, amplified ridge and VCAN, suggesting that
transfer occurs momentum and energy in the SW-NE direction. For a
smaller area inserted in the field of study, the first mode
represents the VCAN over the ocean and to the second mode, the
VCAN over the Northeast. Maps of correlations between the
amplitudes of these modes and the time series of filtered relative
vorticity for the entire study area, indicate a relationship
between the trough of the South Pacific (120°W and 140°W) and the
pattern of waves in eastern America South Thus the presence of
this trough would have some contribution in shaping the VCAN.",
committee = "Cavalcanti, Iracema Fonseca de Albuquerque (presidente) and
Kayano, Mary Toshie (orientadora) and Ferreira, Nelson Jesus
(orientador) and Gan, Manoel Alonso and Silva Dias, Pedro Leite
da",
copyholder = "SID/SCD",
englishtitle = "Climatic patters of upper level cyclonic vortix over Northeast
Brazil",
language = "pt",
pages = "132",
ibi = "6qtX3pFwXQZGivnJSY/Htyhr",
url = "http://urlib.net/ibi/6qtX3pFwXQZGivnJSY/Htyhr",
targetfile = "publicacao.pdf",
urlaccessdate = "20 maio 2024"
}