High Latitude Impacts on Deglacial CO_\textrm2 : Southern Ocean Westerly Winds and Northern Hemisphere Permafrost Thawing
Résumé
Climate in the high latitudes changed massively during the last deglaciation. Temperature rose due to the polar amplification more than twice as much as in the global mean leading predominately to the shrinking of various parts of the cryosphere: decline of northern hem- ispheric (NH) land ice sheets and permafrost thawing, and a reduction in sea ice extent in both hemispheres. It is thus a rather natural choice to also analyse how changes in these polar regions might influence the global carbon cycle and atmospheric CO2. Here we use carbon cy- cle models to analyse two examples of the impact of high latitude climate change on deglacial CO2: (i) changes in the position of the westerly winds in the Southern Ocean during the Last Glacial Maximum (LGM) (based on Völker and Köhler 2013); (ii) Northern Hemisphere permafrost thawing at the onset of the Bølling/Allerød (B/A) around 14.6 ka ago (based on Köhler et al. 2014).