大气阻塞和大西洋多十年的海洋变化
Sirpa Häkkinen1, Peter B Rhines, Denise L Worthen
1National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Code 615, Greenbelt, MD 20771, USA. sirpa.hakkinen@nasa.gov
概括
北大西洋的大气阻塞事件影响海洋循环,导致更温暖,更的亚极海洋. 这种联系解释了海洋的长期变化,包括过去的变暖趋势.
科学领域:
- 气候学和海洋学
- 大气科学 大气科学
- 海洋与大气层的相互作用
背景情况:
- 大气阻隔隔绝了大气区域从长时间 (≥5天) 的强风中隔离出来.
- 这些阻塞事件显著影响北大西洋风力模式,并因此影响海洋循环和性质.
研究的目的:
- 研究北大西洋大气阻塞与海洋循环和性质之间的关系.
- 确定大气阻塞是否解释了观测到的海洋变暖和盐度模式,包括十年和多十年的变化.
主要方法:
- 对北大西洋北部大气阻塞频率和位置的分析.
- 阻塞事件与海洋学数据的相关性,重点关注亚极海洋温度和盐度.
- 检查与阻塞系统相关的风力强迫及其对海洋旋转和热交换的影响.
主要成果:
- 格陵兰岛和西欧之间的频繁的大气阻塞集群与更温暖,更的亚极海洋条件相对应.
- 这种相关性在最近的十年时期 (例如,1996-2010年) 和更长的时间尺度中很明显.
- 来自阻塞的风力强迫系统削弱了海洋旋转和热交换,导致大西洋多年周期变化 (AMV) 的温暖阶段.
结论:
- 大气阻塞是北大西洋海洋变化的关键驱动因素,影响短期和长期气候模式.
- 这项研究证实了阻塞风和更温暖的海洋状态之间的联系,解释了像20世纪中叶温室气体变暖前的现象.
- 了解这些海洋-大气相互作用对于预测未来的气候变化和海洋行为的重要.
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