Publication Date:
2019-07-17
Description:
Temperature changes in Antarctica over the last millennium are investigated using proxy records, a set of
simulations driven by natural and anthropogenic forcings and one simulation with data assimilation.
Over Antarctica, a long term cooling trend in annual mean is simulated during the period 1000-1850.
The main contributor to this cooling trend is the volcanic forcing, astronomical forcing playing a dominant
role at seasonal timescale. Since 1850, all the models produce an Antarctic warming in response to
the increase in greenhouse gas concentrations. We present a composite of Antarctic temperature,
calculated by averaging seven temperature records derived from isotope measurements in ice cores. This
simple approach is supported by the coherency displayed between model results at these data grid
points and Antarctic mean temperature. The composite shows a weak multi-centennial cooling trend
during the pre-industrial period and a warming after 1850 that is broadly consistent with model results.
In both data and simulations, large regional variations are superimposed on this common signal, at
decadal to centennial timescales. The model results appear spatially more consistent than ice core
records. We conclude that more records are needed to resolve the complex spatial distribution of
Antarctic temperature variations during the last millennium.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
