Localized Strong Warming and Humidification Over Winter Japan Tied to Sea Ice Retreat

• Published in: Geophysical Research Letters
• Main Authors: K. Tamura, T. Sato
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: winter; East Asia; climate change; regional climate; Geophysics. Cosmic physics; QC801-809; Sea ice
• Online Access: https://doi.org/10.1029/2023GL103522; https://doaj.org/article/93ca2218d9dc42fe89e34e1e96ca10b2

Abstract East Asian winter weather has altered dramatically in response to progressing climate change. However, analysis of time‐averaged atmospheric fields might obscure climate change signals that could relate to specific types of events. This study aimed to detect climate change signals for various background atmospheric fields by applying classification to daily surface pressure patterns. We found a pronounced trend of increase in surface air temperature over Japan since the 1980s, stronger than the seasonal mean trend, when dominating cold air advection from the Sea of Okhotsk. This cold air was warmed and humidified by the retreat of sea ice in the Sea of Okhotsk. In contrast, the warming trend was mitigated when warm air advection was dominant. These results highlight the importance of daily background atmospheric conditions in amplifying and localizing the impact of regional climate change.