在过去的650年中,南半球生物质燃烧的巨大变化
1Institute for Terrestrial and Planetary Atmospheres/School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.
概括
大气中的一氧化碳水平在650年内大幅波动,这是由于南半球生物质燃烧造成的. 冰芯数据揭示了燃烧活动的重大变化,影响了CO度和同位素比率.
科学领域:
- 古气候学 古气候学
- 大气化学 大气化学
背景情况:
- 大气中的一氧化碳 (CO) 是一个关键的温室气体,也是大气过程的标志物.
- 了解过去的CO变化对于气候建模和评估人为影响至关重要.
研究的目的:
- 从南极冰芯中重建650年的大气一氧化碳 (CO) 度和同位素组成 (δ(13) C和 δ(18) O) 的记录.
- 调查二氧化碳变化的历史驱动因素,特别是南半球生物质燃烧.
主要方法:
- 对南极冰芯进行分析,以确定二氧化碳度和同位素比 (δ(13) C和δ(18) O).
- 应用同位素质量平衡模型来推断生物质燃烧的变化.
- 一个650年大气记录的重建.
主要成果:
- 从13世纪中叶到16世纪,二氧化碳度下降了约25%,然后在18世纪末恢复.
- 同位素比 (δ(13) C 和 δ(18) O) 显示相应的下降和随后的增加,反映了CO度的变化.
- 南半球的生物质燃烧在1600年代下降了50%左右,到1800年代末增加了100%左右,到今天下降了70%左右.
结论:
- 南半球生物质燃烧一直是过去大气CO变化的主要驱动因素.
- 在过去的650年里,生物质燃烧发生了显著的十年到百年规模的波动.
- 冰芯记录提供了关于历史大气组成和生物地球化学循环的宝贵见解.
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