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在过去的2000年里,全球甲预算发生了意想不到的变化
D F Ferretti1, J B Miller, J W C White
1Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA. d.ferretti@niwa.co.nz
概括
在南极冰芯中测量稳定碳同位素的测量显示,在工业前全新纪晚期,甲预算发生了意想不到的变化. 生物质燃烧排放量大幅波动,影响全球甲预算.
科学领域:
- 古气候学 古气候学
- 大气化学 大气化学
- 地质化学 地质化学
背景情况:
- 在工业化前的Holocene时期的甲预算及其驱动因素尚未完全理解.
- 大气中的甲 (CH4) 在地球气候系统中起着重要作用.
- 在甲中稳定的碳同位素 (delta13CH4) 提供了对甲来源和沉积点的关键见解.
研究的目的:
- 使用南极冰芯数据重建了晚期工业前全新世甲预算.
- 调查甲来源的变化,特别是生物质燃烧排放.
- 评估人类活动和气候变化对工业化前甲排放的影响.
主要方法:
- 从2000年的南极冰核记录中分析大气甲 (delta13CH4) 中稳定的碳同位素.
- 模拟甲源分区以推断排放变化.
- 同位素数据与已知的气候和人类活动代理数据的比较.
主要成果:
- 在2000年期间观察到显著的delta13CH4变化.
- 甲同位素组成从公元0年到公元1000年被丰富,从公元1000年到1700年被耗尽.
- 模拟的源分区表明,在两个时期之间,生物质燃烧排放量减少了40%左右.
结论:
- 工业化前生物质燃烧排放量差异很大,以前被低估.
- 人为因素和自然气候变化都影响了这些排放.
- 在工业前全新纪晚期的甲预算比以前假设的更为动态.
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