Hypersensitivity of glacial summer temperatures in Siberia

• DOI: 10.5194/cp-16-371-2020
• Publication Date: 2020-02-18T12:09:03Z
• Authors: Pepijn Bakker; Irina Rogozhina; Ute Merkel; Matthias Prange
• Keywords: Last Glacial Maximum; Paleoclimatology; Circumpolar star

Abstract. Climate change in Siberia is currently receiving a lot of attention because large permafrost-covered areas could provide strong positive feedback to global warming through the release carbon that has been sequestered there on glacial–interglacial timescales. Geological evidence and climate model experiments show Siberian region also played an exceptional role during glacial periods. The known for its harsh cold did not experience major glaciations last ice age, including severest stages around Last Glacial Maximum (LGM). On contrary, it thought summer temperatures were comparable present day. However, glaciation found several older We combine LGM from second third phases Paleoclimate Modelling Intercomparison Project (PMIP2 PMIP3) with sensitivity using Community Earth System Model (CESM). Together, these reveal intermodel spread much larger than any other globe suggest are highly susceptible changes imposed boundary conditions, included feedbacks processes, physics different components model. find circumpolar atmospheric stationary wave pattern associated northward heat transport drive local snow vegetation this combination explains susceptibility Siberia. This suggests small difference between two periods terms climate, buildup or their respective evolution towards maximum conditions can lead strongly divergent Siberia, allowing sheet some periods, while others, above-freezing preclude multi-year snowpack forming.