TITLE:
Arctic Sea Ice: Decadal Simulations and Future Scenarios Using BESM-OA
AUTHORS:
Fernanda Casagrande, Paulo Nobre, Ronald Buss de Souza, Andre Lanfer Marquez, Etienne Tourigny, Vinicius Capistrano, Raquel Leite Mello
KEYWORDS:
Arctic Sea Ice, Climate Models, Brazilian Earth System Model
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.6 No.2,
April
29,
2016
ABSTRACT: Important
international reports and a significant number of scientific publications have
reported on the abrupt decline of Arctic sea ice and its impact on the Global
Climate System. In this paper, we evaluated the ability of the newly
implemented Brazilian Earth System Model (BESM-OA) to represent Arctic sea ice
and sensitivity to CO2 forcing, using decadal simulations
(1980-2012) and future scenarios (2006-2100). We validated our results with
satellite observations and compared them to Coupled Model Intercomparison
Project, Phase 5 (CMIP5) for the same numerical experiment. BESM results for
the seasonal cycle are consistent with CMIP5 models and observations. However,
almost all models tend to overestimate sea ice extent 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.
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 sea ice extent in response to an increase in
radiative forcing for all models. From the year 2045 onwards, all models show a
dramatic shrinking in sea ice and ice free conditions at the end of the melting
season. The projected future sea ice loss is explained by the combined effects
of the amplified warming in northern hemisphere high latitudes and feedbacks
processes.