@MastersThesis{Silva:2012:InFlCa,
author = "Silva, Aline Bilhalva da",
title = "Influ{\^e}ncia dos fluxos de calor em superf{\'{\i}}cie no
in{\'{\i}}cio e no final da esta{\c{c}}{\~a}o chuvosa sobre a
regi{\~a}o Centro-Oeste do Brasil",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2012",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2012-09-03",
keywords = "fluxo de calor em superf{\'{\i}}cie, in{\'{\i}}cio e final da
esta{\c{c}}{\~a}o chuvosa, mon{\c{c}}{\~a}o, surface heat
flux, beginning and ending of the rainy season, monsoon.",
abstract = "O principal objetivo deste estudo {\'e} avaliar a influ{\^e}ncia
dos fluxos de calor latente e sens{\'{\i}}vel em
superf{\'{\i}}cie sobre a regi{\~a}o Centro-Oeste do Brasil
durante o in{\'{\i}}cio e final da esta{\c{c}}{\~a}o chuvosa.
Para garantir uma consist{\^e}ncia na an{\'a}lise realizou-se
uma valida{\c{c}}{\~a}o das rean{\'a}lises Era-Interim e
Climate Forecast System Reanalysis (CFSR) a partir da an{\'a}lise
de precipita{\c{c}}{\~a}o de Brant Liebmann. Em
fun{\c{c}}{\~a}o da diferen{\c{c}}a de resolu{\c{c}}{\~a}o
espacial entre os conjuntos de dados mencionados anteriormente,
foi calculada a m{\'e}dia espacial para a regi{\~a}o
Centro-Oeste (\$10°\$-\$20°\$S e \$50°\$-\$60°\$W),
visando aplicar aos tr{\^e}s conjuntos de dados os testes
estat{\'{\i}}sticos Vi{\'e}s e EMQ (Erro M{\'e}dio
Quadr{\'a}tico), para per{\'{\i}}odos de acumulados de
precipita{\c{c}}{\~a}o: mensal, trimestral, anual,
esta{\c{c}}{\~a}o chuvosa e climatologia mensal, durante os anos
de 1989 a 2008. Estes testes foram aplicados para verificar qual
das duas rean{\'a}lises tem a melhor representatividade da
an{\'a}lise de precipita{\c{c}}{\~a}o de Liebmann. Os
resultados indicaram que sobre a regi{\~a}o Centro-Oeste do
Brasil, a rean{\'a}lise Era-Interim conseguiu simular melhor os
campos de precipita{\c{c}}{\~a}o da an{\'a}lise de Liebmann,
pois apresentou menores valores de Vi{\'e}s e EMQ (em todos os
per{\'{\i}}odos analisados), indicando que os dados s{\~a}o
mais precisos e menos dispersos que os campos da rean{\'a}lise
CFSR. Aplicou-se o m{\'e}todo de p{\^e}ntadas sobre m{\'e}dias
espaciais calculadas para a regi{\~a}o Centro-Oeste do Brasil,
para v{\'a}rias vari{\'a}veis durante o per{\'{\i}}odo de 1989
a 2010. A partir dos campos de precipita{\c{c}}{\~a}o m{\'e}dia
espacial pentadal que superaram o limiar m{\'e}dio anual de 2
mm/dia por 75\% de 8 p{\^e}ntadas subsequentes foi estabelecida
o in{\'{\i}}cio (final) da esta{\c{c}}{\~a}o chuvosa.
Verificou-se que de forma geral, a rean{\'a}lise Era-Interim
adiantou o in{\'{\i}}cio (final) da esta{\c{c}}{\~a}o chuvosa
na maioria dos anos analisados e conseguiu reproduzi-los de forma
satisfat{\'o}ria e coerente. O m{\'e}todo de compostos permitiu
acompanhar o avan{\c{c}}o da banda de precipita{\c{c}}{\~a}o da
regi{\~a}o equatorial em dire{\c{c}}{\~a}o a regi{\~a}o
centro-sul do pa{\'{\i}}s, durante o in{\'{\i}}cio da
esta{\c{c}}{\~a}o chuvosa; bem como seu movimento inverso
durante a esta{\c{c}}{\~a}o seca. Al{\'e}m disso, durante as
p{\^e}ntadas que antecedem o in{\'{\i}}cio da
esta{\c{c}}{\~a}o chuvosa sobre o Brasil Centro-Oeste, nota-se
que a atmosfera come{\c{c}}a a se desestabilizar atrav{\'e}s do
elevado aquecimento nas baixas camadas atmosf{\'e}ricas e isso
impulsiona o aumento dos fluxos de calor sens{\'{\i}}vel do solo
em dire{\c{c}}{\~a}o {\`a} atmosfera. {\`A} medida que os
movimentos verticais come{\c{c}}am a se intensificar, e a umidade
e calor superficial s{\~a}o propagados para altos n{\'{\i}}veis
da atmosfera, h{\'a} o desenvolvimento das c{\'e}lulas
convectivas associadas ao in{\'{\i}}cio da esta{\c{c}}{\~a}o
chuvosa. Durante este per{\'{\i}}odo, nota-se a
redu{\c{c}}{\~a}o dos fluxos de calor sens{\'{\i}}vel e
aumento dos fluxos de calor latente, em decorr{\^e}ncia da
satura{\c{c}}{\~a}o do solo e aumento da evapora{\c{c}}{\~a}o
sobre as regi{\~o}es onde h{\'a} presen{\c{c}}a de
precipita{\c{c}}{\~a}o. Com rela{\c{c}}{\~a}o ao final da
esta{\c{c}}{\~a}o chuvosa, nota-se que o recuo da banda
precipitante em dire{\c{c}}{\~a}o {\`a} regi{\~a}o equatorial
inicia apenas a partir da terceira p{\^e}ntada posterior a
p{\^e}ntada zero. Associado a isso, verifica-se a
redu{\c{c}}{\~a}o dos fluxos de calor latente sobre as
regi{\~o}es sem atua{\c{c}}{\~a}o da banda precipitante e
aumento dos fluxos de calor sens{\'{\i}}vel e temperatura em 925
hPa decorrentes da maior incid{\^e}ncia de radia{\c{c}}{\~a}o
solar. ABSTRACT: The main objective of this study is to evaluate
the influence of latent and sensible surface heat flux over the
West-Central Brazil region during the onset and the ending of
rainy season. It was carried out a validation of Era-Interim and
Climate Forecast System Reanalysis (CFSR) from the analysis of
Brant Liebmann precipitation. Due to the difference in spatial
resolution between the data sets mentioned previously, the spatial
average for the West-Central Brazil (\$10°\$-\$20°\$S e
\$50°\$-\$60°\$W) was calculated, in order to apply for these
three datasets, the statistics tests called BIAS and MSE (Mean
Square Error), for periods of accumulated precipitation: monthly,
quarterly, annual, rainy season and monthly climatology, from 1989
to 2008.These tests were applied for verify which of the two
reanalysis has the best representativeness of precipitation
analysis of Liebmann. The results indicated that over the
West-Central Brazil, the Era-Interim reanalysis simulated better
the analysis of Liebmann precipitation fields, because showed
lower values of BIAS and MSE (in all the analyzed periods),
indicating that the data are more accurate and less dispersed that
the CFSR fields. The identification of the onset pentads was
applied for the West-Central Brazil for several variables during
the period 1989 to 2008. From the spatial average pentadal
precipitation fields that exceeded the threshold annual average of
2 mm/day for 75\% of 8 subsequent pentads, it was established
onset (end) of the rainy season. It was found that in general
form, the Era-Enterim anteciped the onset (end) rainy season in
the majority of years analyzed and it was able to reproduce them
satisfactory and consistent form. The precipitation band was
tracked by the compost method from the equatorial region to
central south of country, during the rainy season; as well as its
return during dry season. Furthermore, during the pentads that
precede the onset of rainy season over West-Central Brazil, the
atmosphere starts to destabilize through the high heating in low
atmospheric layers and this leads the increase of the sensible
heat fluxes from the soil to the atmosphere. As soon as the
vertical movements begin to intensify, the humidity and
superficial heat propagate to higher atmospheric levels, an
impulse of convective cells associated beginning of rainy season
is observed. During this period, the reduction of sensible heat
flux and increase of latent heat flux, due of soil saturation and
increase of evaporation over the regions are observed where there
are precipitation. When the rainy season end, the precipitant band
retreatment into equatorial region only starts from the third
pentad after the zero pentad. Associated to this, it is observed
the reduction of latent flux heat over the regions without action
of precipitant band and the sensible heat flux and temperature in
925 hPa increase as result of higher solar radiation incidence.",
committee = "Ferreira, Nelson Jesuz (presidente) and Gan, Manoel Alonso
(orientador) and Silva, Adma Raia",
copyholder = "SID/SCD",
englishtitle = "Influence of surface heat flux in the beginning and ending of the
rainy season on the Center-West region of Brazil",
language = "pt",
pages = "201",
ibi = "8JMKD3MGP7W/3CF22S2",
url = "http://urlib.net/ibi/8JMKD3MGP7W/3CF22S2",
targetfile = "publicacao.pdf",
urlaccessdate = "11 maio 2024"
}