Abstract :
[en] We use the Earth system model of intermediate complexity LOVECLIM to show the effect of
coupling interactive ice sheets on the climate sensitivity of the model on a millennial time scale. We
compare the response to a 2xCO2 warming scenario between fully coupled model versions including
interactive Greenland and Antarctic ice sheet models and model versions with fixed ice sheets. For this
purpose an ensemble of different parameter sets have been defined for LOVECLIM, covering a wide
range of the model's sensitivity to greenhouse warming, while still simulating the present-day climate
and the climate evolution over the last millennium within observational uncertainties. Additional
freshwater fluxes from the melting ice sheets have a mitigating effect on the model's temperature
response, leading to generally lower climate sensitivities of the fully coupled model versions. The
mitigation is effectuated by changes in heat exchange within the ocean and at the sea-air interface,
driven by freshening of the surface ocean and amplified by sea-ice-related feedbacks. The strength of
the effect depends on the response of the ice sheets to the warming and on the model's climate
sensitivity itself. With the ensemble approach in this study we cover a wide range of possible model
responses.
Disciplines :
Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others
Scopus citations®
without self-citations
18