在全新世纪时代,美国东北部的千年规模的风暴变化
Anders J Noren1, Paul R Bierman, Eric J Steig
1Department of Geology, University of Vermont, Burlington, Vermont 05405, USA. anders.noren@alumni.carleton.edu
Nature
|October 25, 2002
概括
极端风暴事件,如暴雨,在过去的13,000年中显示出规律的3000年周期. 北美和欧洲的这种模式与北极振荡的变化有关,这是一个主要的气候驱动因素.
科学领域:
- 古气候学 古气候学
- 气候科学 气候科学
- 四年纪地质学四年纪地质学
背景情况:
- 记录自然气候变化对于理解人类对气候变化的影响至关重要.
- 研究过去的极端气候事件,如强烈的暴雨风暴,带来了重大挑战.
- 以前使用单个湖泊沉积物核心的方法受到当地环境偏差的限制.
研究的目的:
- 为了重建过去的风暴,并确定长期的变化模式.
- 研究大气模式对全新纪气候变化的影响.
- 为了确定过去13,000年来美国东北部的风暴时间表.
主要方法:
- 从13个湖泊收集的沉积物核心中分析了土著的浸泡层.
- 沉积物核心的年代测定,以确定过去事件的精确时间表.
- 风暴频率数据与长期气候振荡的相关性.
主要成果:
- 美国东北部的风暴相关洪水频率在过去13,000年中以规律的周期变化,周期大约为3,000年.
- 在过去的14,000年里,已经确定了四个不同的风暴峰值.
- 观察到的风暴模式与北极振荡的长期变化保持一致.
结论:
- 极端风暴事件的频率表现出由主要大气模式影响的周期性模式.
- 北极振荡在调节北美和欧洲的全新世气候变化方面发挥着重要作用.
- 这项研究提供了过去风暴活动的强大,多湖重建,克服了单个地点研究的局限性.
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