Publication Date:
2019-07-16
Description:
A quasi-geostrophic model of Southern Hemisphere’s
wintertime atmospheric circulation with horizontal
resolution T21 has been coupled to a global ocean circulation
model with a resolution of 2� ×2� and simplified
physics. This simplified coupled model reproduces qualitatively
some features of the first and the second EOF of atmospheric
833 hPa geopotential height in accordance with
NCEP data. The variability patterns of the simplified coupled
model have been compared with variability patterns simulated
by four complex state-of-the-art coupled CMIP5 models.
The first EOF of the simplified model is too zonal and
does not reproduce the right position of the centre of action
over the Pacific Ocean and its extension to the tropics. The
agreement in the second EOF between the simplified and the
CMIP5 models is better. The total variance of the simplified
model is weaker than the observational variance and those of
the CMIP5 models. The transport properties of the Southern
Ocean circulation are in qualitative accord with observations.
The simplified model exhibits skill in reproducing essential
features of decadal and multi-decadal climate variability
in the extratropical Southern Hemisphere. Notably, 800 yr
long coupled model simulations reveal sea surface temperature
fluctuations on the timescale of several decades in the
Antarctic Circumpolar Current region.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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