North Atlantic and the Barents Sea variability contribute to the 2023 extreme fire season in Canada

• 成果类型: Article
• 署名作者: Liu, Guanyu; Li, Jing; Li, Xichen; Ying, Tong
• 署名单位: Peking University; Chinese Academy of Sciences; Institute of Atmospheric Physics, CAS
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9036
• DOI: 10.1073/pnas.2414241121
• 发表日期: 2024-12-03
• 关键词: weather index system; CLIMATE-CHANGE; simulations; emissions; wildfire; trend; dust; RISK; ice

摘要

In the late spring to summer season of 2023, Canada witnessed unprecedented wildfires, with an extensive burning area and smoke spreading as far as the East Coast of the United States and Europe. Here, using multisource data analysis and climate model simulations, we show that an abnormally warm North Atlantic, as well as an abnormally low Barents Sea ice concentration (SIC), are likely key climate drivers of this Canadian fire season, contributing to similar to 80% of the fire weather anomaly over Canada from June to August 2023. Specifically, the warm North Atlantic forms an anomalous regional zonal cell with ascending air over the Atlantic and descending air encircling Canada, creating hot and dry local conditions. Meanwhile, reduced Barents SIC leads to a high-pressure center and reinforces the dry northern winds in Canada through Rossby wave dynamics. These exacerbated dry and hot conditions create a favorable environment for the ignition and spread of fires, thus contributing to the prolonged and extreme fire season in Canada. These teleconnections can extend to decadal scales and have important implications for understanding and predicting decadal fire activity in Canada and the surrounding regions.