| dc.description.abstract | Antarctic sea ice is considered a fundamental element in the analysis of the global
climate, due to its performance as a thermal insulator, registered as heat
exchanges between the ocean and the atmosphere. In addition, a distribution of
sea ice is an important factor in the formation of transient atmospheric systems,
such as extratropical cyclones, especially those originating on the continental
edge of Antarctica. Extratropic cyclones are targets for study due to the impact
on the weather conditions of the regions where they pass, and savings in the
transport of heat, water vapor and time. Therefore, the objective of this study was
to evaluate the behavior of extratropic cyclones in the Southern Hemisphere (HS)
and the atmospheric circulation in front of the Antarctic sea ice, for the period
from 1979 to 2015, through two simulations using the General Circulation Model
of the SPEED Atmosphere. One of the simulations, the Antarctic sea ice was
removed and the other Antarctic sea ice was maintained, both at a regular rating
of 3.75 ° x 3.75 ° and temporal resolution of 24 hours. The data used for the
scalable analysis of the atmospheric circulation of the HS were the fields of
surface temperature, albedo, sea surface temperature, mean sea level pressure,
geopotential height and zonal wind at 200 hPa. For analysis and detection of
extratropic cyclones in the HS, use a pressure at medium sea level. The results
show that the influence of Antarctic sea ice on atmospheric circulation and
extratopic cyclones is clear, considering what happens with the removal of
Antarctic sea ice, which can be observed if, as the climatic variables significantly
affected, mainly where gradients are more intense; the most common
atmospheric patterns showed more intensity in the simulation without ice than in
the simulation with ice; and as cyclone responses to the change without ice, if
they are stronger and less frequent, or if it was detected in the change with ice. | |
