Atmospheric Circulation Patterns During Glacial Inception: A Possible Candidate

• Published in: Quaternary Research
• Main Author: Crowley, Thomas J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1984
• Subjects: Davis Strait; Greenland; North Atlantic; Northwest Atlantic; Sea ice
• Online Access: http://dx.doi.org/10.1016/0033-5894(84)90093-0; http://api.elsevier.com/content/article/PII:0033589484900930?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:0033589484900930?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400016355

Models of atmospheric circulation in the North Atlantic sector during glacial inception can be expanded to a hemispheric scale with the aid of diagnostic studies of the present climate. The present “Greenland Above” (GA) atmospheric circulation type may be a candidate for the atmospheric circulation type required during glacial inception. The pattern is an amplification, with only minor phase shifts, of the present average winter circulation pattern in the extratropical Northern Hemisphere. Southerly flow in the northwest Atlantic is associated with warm ocean temperatures, low sea ice in the Davis Strait, and increased precipitation over northeast Canada. Evidence from modeling of the present climate indicates that the GA pattern could be maintained by increased snow cover over eastern North America. Enhanced snow cover, due to decreased Northern Hemisphere summer insolation, could cause a similar response on an ice-age time scale.