根据10Be和14C记录推断的年轻德里亚斯事件期间深水形成的变化
R Muscheler1, J Beer, G Wagner
1Department of Surface Waters, EAWAG, Dübendorf, Switzerland. muscheler@eawag.ch
Nature
|December 16, 2000
概括
年轻干旱时期大气中放射性碳 (14C) 的波动主要是由生产速率的变化驱动的,而不仅仅是碳循环. 使用-10 (10Be) 数据的分析显示,深水形成的变化也影响了14C水平.
科学领域:
- 古气候学 古气候学
- 地质化学 地质化学
- 大气科学 大气科学
背景情况:
- 大气中的放射性碳 (14C) 变化受到碳循环变化和放射性核素生产速度的影响,这些都受到太阳活动和地球磁场的影响.
- 10 (10Be) 度直接反映了生产速度,使其成为分离14C的影响的有价值工具.
- 在年轻德里亚斯寒冷时期显著的14C波动的原因仍然不清楚.
研究的目的:
- 为了研究大气14C在较年轻的Dryas.期间的大规模波动的驱动因素.
- 区分碳循环效应和14C度的生产速度变化.
- 评估深水形成对14C变化的作用.
主要方法:
- 利用来自GISP2冰芯的10Be记录来重建过去的放射性核素生产率.
- 基于重建的生产率,模拟大气中的14C度.
- 分析了测量和建模的14C之间的残余差异,以推断碳循环变化.
主要成果:
- 在新干旱时期的大多数大气14C波动都归因于放射性核化物生产速度的变化.
- 考虑到生产速度后,剩余14C变化的很大一部分可以通过碳循环的变化来解释.
- 最可能的碳循环变化是深水形成速度的变化.
结论:
- 生产速度的变化是影响年轻德里亚斯时期大气14C的主要因素.
- 深水形成的变化可能在调节14C度方面发挥了次要作用.
- 这项研究成功地解开了生产率和碳循环对过去14C水平的影响.
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