New research overseen by University of Arizona researchers may have unraveled two mysteries that have stunned paleo-climate experts for a long time. ‘Where did the ice sheets that rang in the last ice age more than 100,000 years ago come from, and how could they grow so quickly?’
The new research, circulated in the Nature Geoscience, explains the rapid development of the ice sheets that coated much of the Northern Hemisphere during the most recent ice age. The outcomes could also apply to other glacial periods throughout Earth’s past.
Scandinavia should have mainly remained ice-free because of the North Atlantic Current, which fetches warm water to the coasts of northwestern Europe. Although the two regions are positioned along similar latitudes, the Scandinavian summer temperatures are are are far above freezing. In contrast, the temperatures in large parts of the Canadian Arctic remain below freezing through the summer, according to the researchers. “Because of this discrepancy, climate models have struggled to account for the extensive glaciers that advanced in northern Europe and marked the beginning of the last ice age,” explained the study’s lead author, Marcus Lofverstrom.
To reveal answers, Lofverstrom helped build an incredibly complicated Earth-system model called the Community Earth System Model, which enabled his team to realistically recreate the conditions that prevailed at the beginning of the most recent glacial period.
The simulations demonstrated that as long as the ocean gateways in the Canadian Arctic Archipelago stay open, Earth’s orbital configuration cooled the Northern Hemisphere adequately to allow ice sheets to form in Northern Canada and Siberia, but not in Scandinavia.