@Article{RosaFerrGanMach:2013:EnCyEv,
author = "Rosa, Marcelo Barbio and Ferreira, Nelson Jesuz and Gan, Manoel
Alonso and Machado, L{\'u}cia Helena Ribas",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)}",
title = "Energetics of cyclogenesis events over the southern coast of
Brazil / Energ{\'e}tica de eventos de ciclog{\^e}neses na costa
sul do Brasil",
journal = "Revista Brasileira de Meteorologia",
year = "2013",
volume = "28",
number = "3",
pages = "231--245",
keywords = "energ{\'e}tica, ciclog{\^e}nese, barocl{\'{\i}}nia, energetic,
cyclogenesis, baroclinic.",
abstract = "Neste estudo {\'e} feita uma an{\'a}lise de 58 casos de
ciclog{\^e}nese ocorridos entre 2003-2011 sobre a costa do sul do
Brasil, focando o ciclo de energia. Nesta an{\'a}lise foram
utilizados dados do National Centers for Environmental Prediction
(NCEP) para criar os campos compostos dos dias selecionados e das
esta{\c{c}}{\~o}es de transi{\c{c}}{\~a}o (primavera e outono
austral), quando foi verificado um elevado n{\'u}mero de
ciclones. Observou-se um aprofundamento de um cavado
pr{\'e}-existente em superf{\'{\i}}cie sobre o Paraguai, dois
dias antes (D-2) da press{\~a}o na superf{\'{\i}}cie atingir o
seu m{\'{\i}}nimo sobre a costa da regi{\~a}o sul do Brasil.
Tipicamente, o processo de ciclog{\^e}nese come{\c{c}}a sobre
esta regi{\~a}o e se propaga para sudeste, intensificando ao
longo de sua trajet{\'o}ria. Em D-2 a corrente de jato est{\'a}
quase zonalmente orientada, mas adquire uma curvatura
cicl{\^o}nica, com um n{\'u}cleo no setor SE e o outro {\`a} NW
quando o ciclone est{\'a} completamente formado (D0). Quando a
anomalia de geopotencial para ondas curtas (Gh) entra em fase com
a anomalia para ondas longas (Gl), em D-1, ocorre o aumento de
PhKh, que se torna dominante. Durante todas as fases de
evolu{\c{c}}{\~a}o, os termos mais importantes foram o
barocl{\'{\i}}nico (PlPh e PhKh), seguido pelo barotr{\'o}pico
(KlKh). O termo de atrito (RKh) teve um papel secund{\'a}rio, e o
termo de fonte/sumidouro de energia e fluxo de energia potencial
dispon{\'{\i}}vel (RPh) n{\~a}o contribuiu para o
aprofundamento de baixa superf{\'{\i}}cie, mostrando que este
{\'u}ltimo n{\~a}o depende da atividade convectiva local.
Durante os meses de transi{\c{c}}{\~a}o, n{\~a}o foram
observadas diferen{\c{c}}as significativas nos mecanismos de
desenvolvimento ciclogen{\'e}tico e manuten{\c{c}}{\~a}o,
exceto por haver uma maior disponibilidade de energia
cin{\'e}tica (Kh) e potencial (Ph), e tamb{\'e}m por haver uma
maior troca de energia por convers{\~a}o barocl{\'{\i}}nica e
barotr{\'o}pica durante o outono austral. ABSTRACT: An analysis
of 58 cyclogenesis cases occurred from 2003 to 2011 over the
southern Brazilian coast is presented focusing on the energy cycle
proposed. For this analysis the National Centers for Environmental
Prediction (NCEP) data was utilized to create the composite fields
of all selected days as also to that of transitional seasons
(austral spring and autumn), when it was verified a high number of
cyclones. In the analysis, a deepening of a pre-existing surface
trough over Paraguay was observed two days (D-2) before the
surface pressure had reached its minimum over the southern
Brazilian coast. Typically, the cyclogenetic process begins on the
southern Brazil coast and spreads in a NW-SE direction,
strengthening along its path. On D-2 the jet stream is almost
zonally oriented and then when the cyclone is completely formed
(D0), this acquire a cyclonic curvature, with two cores: one
strongest in the SE and the other one in the NW direction. As soon
as the geopotential anomaly for short waves (Gh) is in phase with
anomaly for long waves (Gl) on D-1, the PhKh term increases in
magnitude, becoming the dominant one. During all evolution stages,
the dominant terms were the baroclinic (PlPh and PhKh), followed
by the barotropic (KlKh) term. The friction term (RKh) had a
secondary role and the source/sink of non conservative energy and
flux of the available potential energy (RPh) did not contributed
to the deepening of the surface low, which is not depending of the
convective activity inside it. Significant differences were not
observed in the mechanisms of cyclogenesis development and
maintenance during the transition months, except for a greater
availability of kinetic (Kh) and potential (Ph) energy and
baroclinic and barotropic conversion terms during the austral
autumn.",
doi = "10.1590/S0102-77862013000300001",
url = "http://dx.doi.org/10.1590/S0102-77862013000300001",
issn = "0102-7786",
label = "scopus 2013-11",
language = "en",
targetfile = "01.pdf",
urlaccessdate = "16 maio 2024"
}