来自热带沿海陆地的大气中甲基化物的强有力的来源
Y Yokouchi1, Y Noijiri, L A Barrie
1National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan. yokouchi@nies.go.jp
Nature
|February 5, 2000
概括
甲基化物 (CH3Cl) 是一个重要的大气环氧碳. 新的研究表明温暖的沿海土地,特别是热带岛屿,是主要的来源,挑战了以前的海洋排放理论.
科学领域:
- 大气化学 大气化学
- 环境科学 环境科学
- 环氧碳研究 环氧碳研究
背景情况:
- 甲基化物 (CH3Cl) 是大气中最丰富的环氧碳化合物,也是平流层的天然来源.
- 估计CH3Cl的全球流量为3.5 Tg,由于OH基反应,大气寿命为1.5年.
- 以前,海洋排放被认为是主要来源,生物质燃烧作为次要来源.
研究的目的:
- 为了调查大气中甲基化物 (CH3Cl) 的来源,鉴于最近发现海洋流量不足.
- 为了确定CH3Cl排放的其他重要来源.
主要方法:
- 进行了大气CH3Cl度的全球监测研究.
- 在不同地点进行点位测量.
- 分析了CH3Cl与陆地植物生物化合物之间的相关性.
- 检查了CH3Cl度的OH相关季节性.
主要成果:
- 最近的海水测量表明,海洋流量仅占全球CH3Cl流量的12%.
- 有证据表明,来自温暖的沿海地区,特别是热带岛屿的CH3Cl排放量很大.
- 在热带地区观察到大气中CH3Cl的增强.
- 在CH3Cl度和陆地植物生物化合物之间发现了强烈的相关性.
- 在中高度地区检测到OH相关的季节性.
结论:
- 温暖的沿海土地,特别是热带岛屿,是大气中甲基化物的重要,以前被低估的来源.
- 强大的赤道CH3Cl来源可以解释其在半球之间均分布.
- 全球CH3Cl来源的重新评估是必要的,不仅仅是海洋和生物质燃烧来源.
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