3-DIMENSIONAL MODEL SYNTHESIS OF THE GLOBAL METHANE CYCLE
3-DIMENSIONAL MODEL SYNTHESIS OF THE GLOBAL METHANE CYCLE
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DOI：
10.1029/91jd01247
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发表时间：
1991-07-20
影响因子：
4.4
通讯作者：
FRASER, PJ
中科院分区：
文献类型：
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作者：
FUNG, I;JOHN, J;FRASER, PJ
利用甲烷通量测量和能源和农业统计数据，结合全球陆面特征和人类活动数字数据库，汇编了大气甲烷主要源和汇的地理和季节排放分布。大气中甲烷的化学破坏是使用Spivakovsky等人每隔5天获取的三维OH场来计算的。(1990a，b)。使用全球三维示踪剂传输模型模拟了大气中每个源和汇的特征。根据甲烷及其碳同位素的质量平衡，构建了候选甲烷收支情景。这些场景的真实性是通过它们再现大气中观测到的甲烷的经向梯度和季节变化的能力来测试的。几个预算方案同时满足了所有大气观测施加的限制。优先预算包括每年的破坏率：羟基氧化的年破坏率为450Tg，土壤吸收的年破坏率为10Tg，化石来源的年排放量为80Tg，家畜的年排放量为80Tg，湿地和北纬50度的冻土带的年排放量为35Tg。垃圾填埋场、热带沼泽、稻田、生物质燃烧和白蚁的排放量总计295Tg；然而，由于缺乏对这些来源集中地区的直接通量和大气甲烷变化的测量，这些术语的单独贡献不能唯一确定。
The geographic and seasonal emission distributions of the major sources and sinks of atmospheric methane were compiled using methane flux measurements and energy and agricultural statistics in conjunction with global digital data bases of land surface characteristics and anthropogenic activities. Chemical destruction of methane in the atmosphere was calculated using three-dimensional OH fields every 5 days taken from Spivakovsky et al. (1990a, b). The signatures of each of the sources and sinks in the atmosphere were simulated using a global three-dimensional tracer transport model. Candidate methane budget scenarios were constructed according to mass balance of methane and its carbon isotopes. The verisimilitude of the scenarios was tested by their ability to reproduce the meridional gradient and seasonal variations of methane observed in the atmosphere. Constraints imposed by all the atmospheric observations are satisfied simultaneously by several budget scenarios. A preferred budget comprises annual destruction rates of 450 Tg by OH oxidation and 10 Tg by soil absorption and annual emissions of 80 Tg from fossil sources, 80 Tg from domestic animals, and 35 Tg from wetlands and tundra poleward of 50-degrees-N. Emissions from landfills, tropical swamps, rice fields, biomass burning, and termites total 295 Tg; however, the individual contributions of these terms cannot be determined uniquely because of the lack of measurements of direct fluxes and of atmospheric methane variations in regions where these sources are concentrated.