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在过去的11万年中,大气中甲度的快速变化
1E. J. Brook and J. Orchardo, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA. T. Sowers, 447 Deike Building, Geosciences Department, Pennsylvania State University, University Park, PA 16802, USA.
概括
大气中的甲度在过去的11万年里大幅波动,与格陵兰岛的变暖事件相关. 北半球的阳光照射似乎影响了这些甲转移,影响了陆地生物圈.
科学领域:
- 古气候学 古气候学
- 冰芯分析 冰芯分析
- 大气化学 大气化学
背景情况:
- 千年规模的气候变化已经被记录在古气候记录中.
- 格陵兰岛的冰芯提供了过去大气条件的高分辨率档案.
- 丹斯加尔德-奥斯格尔事件代表了最后一个冰川时期的突然变暖时期.
研究的目的:
- 通过GISP2冰核记录,分析过去11万年间千年规模的甲变化.
- 研究大气甲度变化与Dansgaard-Oeschger事件之间的关系.
- 探索北半球阳光对冰川时期甲动态的潜在影响.
主要方法:
- 从GISP2冰核中分析甲度.
- 甲数据与Dansgaard-Oeschger事件时间相关.
- 甲转移量与北半球夏季阳光照射记录的比较.
主要成果:
- 吉斯普2冰芯显示了过去11万年间千年规模的甲变化.
- 甲度的急剧变化 (50-300 ppb) 与大多数丹斯加德-奥什格尔变暖事件相吻合.
- 甲转移的幅度在较长的时间尺度上有所变化,与北半球夏季阳光照射相关.
结论:
- 千年规模的甲变化是过去11万年的重要特征.
- 丹斯加尔德-奥什格尔事件伴随着大气中甲的快速变化.
- 北半球的阳光照射可能调节了气候变化对陆地生物圈甲产生的影响.
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