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Volume 8, Issue 9 (Suppl)
J Earth Sci Clim Change
ISSN: 2157-7617 JESCC, an open access journal
Climate Congress 2017
October 16-17, 2017
October 16-17, 2017 Dubai, UAE
3
rd
World Congress on
Climate Change and Global Warming
Sea ice study and Arctic polar amplification using CMIP5 models
Fernanda Casagrande, Ronald Buss de Souza and Paulo Nobre
National Institute for Space Research-INPE, Brazil
I
mportant 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 work, we have evaluated the ability of
Coupled Model Intercomparison Project, Phase 5 (CMIP5), specially the Brazilian Earth System Model (BESM) to represent
the Arctic sea ice changes and sensitivity to the atmospheric carbon dioxide (CO
2
) forcing. We have 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 re-analyses data
set. 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 CO2
forcing with strongest warming in winter (DJF) and autumn (SON). The polar warming is linked with changes in SIE and Sea
IceThickness (SIT). The albedo sea ice feedback reinforces the polar warming with marked contributions fromApril to August.
fernanda.casagrande@inpe.brJ Earth Sci Clim Change 2017, 8:9 (Suppl)
DOI: 10.4172/2157-7617-C1-034