Science. 1988 Mar 4;239(4844):1129-31. doi: 10.1126/science.239.4844.1129.
The average worldwide tropospheric mixing ratio of methane has increased by 11% from 1.52 parts per million by volume (ppmv) in January 1978 to 1.684 ppmv in September 1987, for an increment of 0.016 +/- 0.001 ppmv per year. Within the limits of our measurements, the global tropospheric mixing ratio for methane over the past decade is consistent either with a linear growth rate of 0.016 +/- 0.001 ppmv per year or with a slight lessening of the rate of growth over the past 5 years. No indications were found of an effect of the El Niño-Southern Oscillation-El Chichon events of 1982-83 on total global methane, although severe reductions were reported in the Pacific Northwest during that time period. The growth in tropospheric methane may have increased the water concentration in the stratosphere by as much as 28% since the 1940s and 45% over the past two centuries and thus could have increased the mass of precipitable water available for formation of polar stratospheric clouds.
自 1978 年 1 月的 1.52 百万分率（ppm）到 1987 年 9 月的 1.684 ppm，全球平流层甲烷混合比平均增加了 11%，每年递增 0.016 +/- 0.001 ppm。根据我们的测量结果，在过去十年中，全球平流层甲烷混合比，或者是以每年 0.016 +/- 0.001 ppm 的线性增长率增长，或者是过去 5 年增长率略有放缓。尽管 1982-83 年的厄尔尼诺-南方涛动-埃尔奇琼事件对全球甲烷总量有影响，但并未发现有任何迹象。在此期间，太平洋西北地区的甲烷浓度虽有所下降，但仍在可报告范围之内。自 20 世纪 40 年代以来，平流层中甲烷的增加可能使水蒸气浓度增加了 28%，过去两个世纪增加了 45%，这可能增加了形成极地平流层云的可降水量。
