@PhDThesis{Morais:2016:EsObNu,
author = "Morais, Michelyne Duarte Coutinho de",
title = "V{\'o}rtices cicl{\^o}nicos de altos n{\'{\i}}veis que atuam
no nordeste do Brasil: estudo observacional e num{\'e}rico",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2016",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2016-02-22",
keywords = "v{\'o}rtices cicl{\^o}nicos de altos n{\'{\i}}veis, nordeste
do Brasil, simula{\c{c}}{\~o}es, observa{\c{c}}{\~o}es, upper
tropospheric cyclonic vortices, northeastern Brazil, simulations,
observations.",
abstract = "Aspectos evolutivos dos V{\'o}rtices Cicl{\^o}nicos de Altos
N{\'{\i}}veis (VCANs) do Nordeste do Brasil como estrutura
vertical, precipita{\c{c}}{\~a}o associada e efeitos do
aquecimento por condensa{\c{c}}{\~a}o na regi{\~a}o da
periferia e proximidades s{\~a}o escassos na literatura. Com esta
pesquisa desenvolveu-se um estudo observacional e num{\'e}rico da
estrutura f{\'{\i}}sico-din{\^a}mica durante a
evolu{\c{c}}{\~a}o destes sistemas. Inicialmente, examinaram-se
as principais caracter{\'{\i}}sticas em diferentes est{\'a}gios
do ciclo de vida atrav{\'e}s de uma climatologia objetiva para o
per{\'{\i}}odo de 1984 a 2013, usando os dados das
rean{\'a}lises do ERA-Interim. Verificou-se que na camada 200-500
hPa, a intensidade destes sistemas {\'e} maior e mais
vari{\'a}vel do que na camada 500-1000 hPa e que a maioria
n{\~a}o apresentou inclina{\c{c}}{\~a}o ou a
inclina{\c{c}}{\~a}o {\'e} para leste com a altura. Houve
domin{\^a}ncia de sistemas que permanecem no n{\'{\i}}vel de
200 hPa durante o desenvolvimento, contudo no est{\'a}gio de
profundidade m{\'a}xima tamb{\'e}m predominaram v{\'o}rtices na
camada 200-400 hPa. Em uma segunda etapa, um novo modelo
conceitual foi elaborado por meio da t{\'e}cnica de campos
compostos usando dados do ERA-Interim e do \emph{Prediction
Center Morphing Method} (CMORPH), de 2003 a 2013. Este modelo
descreve a evolu{\c{c}}{\~a}o do comportamento m{\'e}dio de
vari{\'a}veis atmosf{\'e}ricas na troposfera entre o centro e a
periferia de quatro grupos de v{\'o}rtices (profundos, rasos,
lentos e r{\'a}pidos). Notou-se que os profundos mostraram
consider{\'a}veis varia{\c{c}}{\~o}es horizontais de vento,
temperatura, umidade e omega entre o centro e a periferia acima do
n{\'{\i}}vel de 700 hPa. Essas varia{\c{c}}{\~o}es horizontais
foram mais fracas e semelhantes entre os lentos e r{\'a}pidos,
que se diferenciaram em termos din{\^a}micos. Em
adi{\c{c}}{\~a}o, verificou-se que os profundos foram mais
intensos e est{\~a}o associados {\`a} precipita{\c{c}}{\~a}o
substancial. Por outro lado, os rasos foram mais fracos e se
associaram a precipita{\c{c}}{\~a}o amena. Constatou-se que o
desenvolvimento de convec{\c{c}}{\~a}o no centro dos
v{\'o}rtices e proximidades {\'e} um poss{\'{\i}}vel
indicativo para a dissipa{\c{c}}{\~a}o. Simula{\c{c}}{\~o}es
num{\'e}ricas para um caso profundo foram executados com o modelo
\emph{Weather Research and Forecasting} (WRF), for{\c{c}}ado com
dados de an{\'a}lises do Global Forecast System (GFS).
Investigou-se a influ{\^e}ncia do aquecimento por
condensa{\c{c}}{\~a}o oriundo da convec{\c{c}}{\~a}o cumulus e
da microf{\'{\i}}sica de nuvens na periferia do v{\'o}rtice e
proximidades durante o desenvolvimento. Evid{\^e}ncias mostraram
que os efeitos da redu{\c{c}}{\~a}o deste aquecimento foram:
redu{\c{c}}{\~a}o do acumulado de precipita{\c{c}}{\~a}o e dos
gradientes horizontais da temperatura e umidade entre o centro e a
periferia do v{\'o}rtice. Entretanto, quando a
redu{\c{c}}{\~a}o do aquecimento foi oriundo da
convec{\c{c}}{\~a}o cumulus, o v{\'o}rtice se enfraqueceu, a
profundidade se manteve, a inclina{\c{c}}{\~a}o com a altura foi
vari{\'a}vel e o campo de vento em 200 hPa foi mais fraco e
alterado. Ao contr{\'a}rio, quando este aquecimento foi derivado
da microf{\'{\i}}sica de nuvens, o v{\'o}rtice se intensificou
com profundidade maior, o campo de vento em 200 hPa mudou pouco e
a inclina{\c{c}}{\~a}o do v{\'o}rtice com a altura foi similar
{\`a} simula{\c{c}}{\~a}o controle. As simula{\c{c}}{\~o}es
sem aquecimento latente reproduziram o v{\'o}rtice, embora aquela
inicializada previamente gerou o VCAN em decorr{\^e}ncia da
propaga{\c{c}}{\~a}o de energia cin{\'e}tica atrav{\'e}s de um
trem de ondas. Essas simula{\c{c}}{\~o}es e a com 50\% de
redu{\c{c}}{\~a}o do aquecimento latente pela
convec{\c{c}}{\~a}o cumulus mantiveram o sistema por meio do
trem de ondas, conduzindo a inferir que casos sem calor latente ou
com nebulosidade associada podem ser mantidos por este processo
din{\^a}mico. ABSTRACT: Information about the evolutionary
aspects of the upper tropospheric cyclonic vortices (UTCVs) in
northeastern Brazil, such as vertical structure, associated
precipitation and over effects of heating by condensing in the
periphery and nearby region is scarce in the literature. In this
research is developed an observational and numerical study of the
physical-dynamic structure and evolution of these systems.
Initially, the UTCVs main features were examined in different life
cycle stages through objective climatology, for the period from
1984 to 2013, using data from ERA-Interim reanalysis. As noted,
UTCVs in the 200-500 hPa layer had greater and more variable
intensity than those in the 500-1000 hPa layer and majority
presented no tilt or tilt to the east with height. There was
dominance of UTCVs that remained at 200 hPa during evolution.
However, in the hours of maximum depth, vortices also predominated
in the 200-400 hPa layer. In the second phase of the study, a new
conceptual model was formulated through composite fields technique
using ERA-Interim data and the Prediction Center Morphing Method
(CMORPH), from 2003 to 2013. This model describes the evolution of
the average behavior of the atmospheric variables in the
troposphere, between center and periphery, of four groups of the
UTCVs (deep, shallow, slow and fast). We noted that the deep cases
showed considerable horizontal wind, temperature, humidity and
omega horizontal gradients between the center and periphery, above
the 700 hPa level. These horizontal gradients were weaker and
similar, between the slow and fast cases, which differed in
dynamic terms. In addition, the deep cases were more intense,
vertically extended and associated with considerable
precipitation. On the other hand, the shallow cases were weaker
with a lower vertical extension and milder precipitation. The
development of convection in the center and closeness of UTCVs is
a possible indication of dissipation. Numerical simulations, for
one case of the deep vortex, were performed with the Weather
Research and Forecasting (WRF) model, with data from Global
Forecast System analyses (GFS). The Influence of heating by
condensation from cumulus convection and cloud microphysics on the
closeness and periphery of UTCVs was investigated. Evidence showed
that the effects of this heating involve reduction of the
cumulative precipitation and horizontal gradients of temperature
and moisture between the center and vortex edge. However, when the
reduction of the heating was derived from cumulus convection, the
UTCV weakened, the depth remained the same and the wind field at
200 hPa was weaker. In contrast, when this heating was derived
from cloud microphysics, the vortex intensified, with greater
depth, and the wind field at 200 hPa changed little. The vortex
tilt with height was similar to the simulation control. The
simulations without latent heating produced the vortex, although
the one initialized previously generated the system as a result of
kinetic energy propagating trough of a train of waves. These
simulations and 50\% reduction of the latent heat by cumulus
convection maintained the system through this wave train, leading
to the inference that dry cases or those associated with
cloudiness can be maintained by this dynamic process.",
committee = "Ferreira, Nelson Jesuz (presidente) and Gan, Manoel Alonso
(orientador) and Fernandez, Julio Pablo Reyes (orientador) and
Rivero, Silvio Nilo Figueroa and Gandu, Adilson Wagner and Souza,
Enio Pereira de",
copyholder = "SID/SCD",
englishtitle = "Upper tropospheric cyclonic vortices act in the northeastern
Brazil: observational and numerical study",
language = "pt",
pages = "261",
ibi = "8JMKD3MGP3W34P/3L3FGTS",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3L3FGTS",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}