@PhDThesis{Casagrande:2017:SeIcSt,
author = "Casagrande, Fernanda",
title = "Sea ice study and Arctic polar amplification using BESM model",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2016-05-25",
keywords = "sea ice, coupled climate models, global climate change, Brazilian
Earth System Model, polar amplification, gelo marinho, modelos
clim{\'a}ticos acoplados, mudan{\c{c}}as clim{\'a}ticas
globais, modelo brasileiro do sistema terrestre,
amplifica{\c{c}}{\~a}o polar.",
abstract = "Important international reports and a significant number of
scientific publications have reported on the abrupt decline of the
Arctic sea ice, polar amplification and its impact on the Global
Climate System. In this thesis, we evaluate the ability of the
Brazilian Earth System Model (BESM) to represent the Arctic sea
ice and sensitivity to the atmospheric Carbon dioxide
(CO\$_{2}\$) forcing. We used decadal simulations (1980-2012),
future scenarios with Representative Concentration Pathway RCP 4.5
and RCP 8.5 (2006-2100) and quadrupling of the atmospheric
CO\$_{2}\$) concentration (2006-2300). We validated our results
with satellite observations and compared them to Coupled Model
Intercomparison Project, Phase 5 (CMIP5) for the same numerical
experiment designs. BESM results for the Arctic sea ice seasonal
cycle are consistent with CMIP5 models and observations. However,
almost all models tend to overestimate sea ice extent (SIE) in
March compared to observations. The correct evaluation of minimum
record of sea ice, in terms of time, spatial and area remains a
limitation in Coupled Global Climate Models (CGCM). Looking to
spatial patterns, we found a systematic model error in September
sea ice cover between the Beaufort Sea and East Siberia for most
models. Future scenarios show a decrease in SIE as response to an
increase in radiative forcing due to the increase of greenhouse
gases concentration for all models. From the year 2045 onwards,
all models show a dramatic shrinking in sea ice and consequent
expansion of ice-free conditions at the end of the melting season.
The projected future sea ice loss is explained by the combined
effects of both: the amplified warming in northern hemisphere high
latitudes and climate feedbacks. The quadrupling of CO\$_{2}\$)
concentration numerical experiment shows the amplified warming at
high latitudes as response to CO\$_{2}\$) forcing with strongest
warming in winter (DJF) and Autumn (SON). The Polar warming is
linked with changes in SIE and Sea Ice Thickness (SIT). The albedo
sea ice feedback reinforces the polar warming with marked
contributions from April to August. RESUMO: Importantes
relat{\'o}rios internacionais e um expressivo n{\'u}mero de
publica{\c{c}}{\~o}es cient{\'{\i}}ficas t{\^e}m reportado
sobre o abrupto decl{\'{\i}}nio do gelo marinho {\'A}rtico,
amplifica{\c{c}}{\~a}o polar e seus impactos no sistema
clim{\'a}tico global. Nessa tese n{\'o}s analisamos a habilidade
do Modelo Brasileiro do Sistema Terrestre (BESM) em representar o
gelo marinho {\'A}rtico e sensibilidade ao for{\c{c}}amento
radiativo de Di{\'o}xido de Carbono (CO\$_{2}\$), usando
simula{\c{c}}{\~o}es decenais (1980-2012), cen{\'a}rios futuros
usando Caminhos Representativos de Concentra{\c{c}}{\~a}o RCP
4.5 e RCP 8.5 (2006-2100) e quadruplicando a
concentra{\c{c}}{\~a}o de CO\$_{2}\$ (2006-2300). N{\'o}s
validados nossos resultados utilizando as observa{\c{c}}{\~o}es
de sat{\'e}lites e comparando com o Projeto de
Intercompara{\c{c}}{\~a}o de Modelos Acoplados, Fase 5 (CMIP5)
para o mesmo experimento num{\'e}rico. Os resultados do BESM para
o ciclo sazonal s{\~a}o consistentes com os modelos do CMIP5 e
observa{\c{c}}{\~o}es. No entanto, a maioria dos modelos tende a
superestimar a extens{\~a}o do gelo marinho (SIE) em Mar{\c{c}}o
comparado {\`a}s observa{\c{c}}{\~o}es. A correta an{\'a}lise
do m{\'{\i}}nimo registrado de gelo marinho em termos de
padr{\~a}o temporal, espacial e {\'a}rea continua sendo uma
limita{\c{c}}{\~a}o nos Modelos Clim{\'a}ticos Globais
Acoplados (CGCM). Avaliando o padr{\~a}o espacial, n{\'o}s
encontramos um erro sistem{\'a}tico na cobertura de gelo marinho
em Setembro entre o mar de Beaufort e Leste da Sib{\'e}ria para a
maioria dos modelos. Os cen{\'a}rios futuros mostram uma
diminui{\c{c}}{\~a}o do gelo marinho como resposta ao aumento do
for{\c{c}}amento radiativo devido ao aumento na
concentra{\c{c}}{\~a}o dos gases do efeito estufa para todos os
modelos. A partir do ano de 2045, todos os modelos mostram um
encolhimento dr{\'a}stico no gelo marinho e consequente aumento
das condi{\c{c}}{\~o}es de oceano livre de gelo no final da
esta{\c{c}}{\~a}o de derretimento. As proje{\c{c}}{\~o}es
futuras de retra{\c{c}}{\~a}o de gelo marinho s{\~a}o
explicadas por efeitos combinados: Aquecimento amplificado em
altas latitudes norte e os processos de
retroalimenta{\c{c}}{\~a}o clim{\'a}ticos. O experimento
num{\'e}rico quadruplicando a concentra{\c{c}}{\~a}o de
CO\$_{2}\$ mostra amplificado aquecimento em altas latitudes
como resposta ao for{\c{c}}amento radiativo do CO\$_{2}\$, com
aquecimento mais intenso no ver{\~a}o (DJF) e outono (SON). O
aquecimento polar esta relacionado com mudan{\c{c}}as na
extens{\~a}o de gelo marinho e espessura do gelo marinho (SIT). O
processo de retroalimenta{\c{c}}{\~a}o albedo gelo marinho
refor{\c{c}}a o aquecimento polar com acentuadas
contribui{\c{c}}{\~o}es de Abril at{\'e} Agosto.",
committee = "Souza, Ronald Buss de (presidente) and Nobre, Paulo (orientador)
and Capistrano, Vinicius Buscioli and Sim{\~o}es, Jefferson
Cardia and Camargo, Ricardo de",
copyholder = "SID/SCD",
englishtitle = "Estudo do gelo marinho e da amplifica{\c{c}}{\~a}o polar no
{\'A}rtico com o modelo BESM",
language = "en",
pages = "89",
ibi = "8JMKD3MGP3W34P/3LLUKM5",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3LLUKM5",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}