来自沿海盐沼地的天然甲基化物和甲基化物排放
R C Rhew1, B R Miller, R F Weiss
1Scripps Institution of Oceanography, University of California at San Diego, La Jolla 92093-0244, USA. rob@gaslab.ucsd.edu
Nature
|February 5, 2000
概括
沿海盐沼是大气中甲基化物 (CH3Br) 和甲基化物 (CH3Cl) 的重要天然来源,对臭氧层的健康至关重要. 这些生态系统可能占全球排放量的10%,尽管它们的表面积很小.
科学领域:
- 大气中的化学成分
- 环境科学环境科学
- 生态生态学 生态生态学
背景情况:
- 大气中的甲基化物 (CH3Br) 和甲基化物 (CH3Cl) 都与平流层臭氧消耗有关.
- 目前对CH3Br和CH3Cl的排放估计与已知的损失过程不符,表明潜在的自然来源缺失.
- 据怀疑,陆地生态系统在这些化合物的全球预算中扮演着更重要的角色.
研究的目的:
- 研究沿海盐沼作为大气中甲基化物 (CH3Br) 和甲基化物 (CH3Cl) 的来源的作用.
- 量化CH3Br和CH3Cl的流量来自盐沼地的不同植被区.
- 评估盐沼对于大气CH3Br和CH3Cl预算的全球意义.
主要方法:
- 在两个沿海盐沼生态系统中进行了CH3Br和CH3Cl流量的现场测量.
- 测量了各种植被区的流动,以捕捉空间的变化.
- 监测了排放的日间和季节性变化.
主要成果:
- 从沿海盐沼地的所有被研究的植被区中检测到CH3Br和CH3Cl的大量流动.
- 测量流量达到了CH3Br的42微摩尔m(-2) d(-1) 和CH3Cl的570微摩尔m(-2) d(-1).
- 观察到CH3Br和CH3Cl流量之间存在强烈的正相关性,其摩尔比率约为1:20.
- 排放量表现出相当大的日间,季节和空间变化.
结论:
- 沿海盐沼是大气中CH3Br和CH3Cl的大量,以前被低估的自然来源.
- 尽管这些生态系统覆盖的全球面积很小 (<0.1%),但它们可能对全球CH3Br和CH3Cl排放贡献约10%.
- 这些发现强调了将盐沼排放纳入全球大气模型中,以研究臭氧损耗的重要性.
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