Arctic-North Pacific coupled impacts on the late autumn cold in North America

• Published in: Environmental Research Letters
• Main Authors: Mi-Kyung Sung, Baek-Min Kim, Eun-Hyuk Baek, Young-Kwon Lim, Seong-Joong Kim
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing 2016
• Subjects: Pacific decadal oscillation; arctic warming; Arctic–midlatitude interaction; Environmental technology. Sanitary engineering; TD1-1066; Environmental sciences; GE1-350; Science; Q; Physics; QC1-999; Arctic; East Siberian Sea; Pacific; Chukchi
• Online Access: https://doi.org/10.1088/1748-9326/11/8/084016; https://doaj.org/article/689b86c4c65c4bcfaf0d31d301fe4ff1

The Pacific decadal oscillation (PDO) is known to bring an anomalously cold (warm) period to southeastern (northwestern) North America during the cold season of its positive phase through a Rossby wave linkage. This study provides evidence that the remote connection between the North Pacific and the downstream temperature over central North America is strengthened by the warm arctic conditions over the Chukchi and East Siberian Sea, especially in the late autumn season. The modulation effect of the Arctic manifests itself as an altered Rossby wave response to a transient vorticity forcing that results from an equatorward storm track shift, which is induced collaboratively by the PDO and the warm Arctic. This observational finding is supported by two independent modeling experiments: (1) an idealized coupled GCM experiment being nudged toward the warm arctic surface condition and (2) a simple stationary wave model experiment forced by transient eddy forcing.