1992年大气甲烷增长速率异常 下降的模拟研究

应用初步建立的全球二维大气化学模式，模拟了甲烷、一氧化碳和OH自由基自工业革命以来的长期变化，对1992年大气中甲烷增长速率突然下降这一异常现象的可能原因如平流层O3下降，皮纳图博火山引起对流层温度下降、甲烷排放源减少等逐一进行了定量研究。研究还发现一氧化碳排放源的减少是另一重要影响因子，并进行了验证。结果表明，1992年甲烷增长速率急剧下降的主要原因来自甲烷和一氧化碳排放源的减少。

A Modeling of the Sudden Decrease in CH4 Growth Rate in 1992

A two-dimensional global chemistry model is developed to study the distribution and long-term trend of CH 4 . The model contains 34 species and 104 chemical and photochemical reactions. Using the model, the long history trends of CH 4 and OH in atmosphere is simulated, and a comparison between the model results and observations shows the simulation is successful. Experiments were done to investigate the causes of a dramatic decrease in the growth rate of CH 4 in 1992 such as stratospheric ozone depletion, decrease of temperature in the troposphere due to Mount Pinatubo eruption and descendant of CH 4 sources fluxes. A new explanation is proposed and verified by this model that the decrease of CO emission plays an important role in the abnormal growth rate of CH 4 in 1992. It shows that the decreases of emissions of CH 4 and CO are the main cause of the dramatic decrease in growth rate of CH 4 in 1992.