Ethane and propane are the most abundant non-methane hydrocarbons in the atmosphere. However, their emissions, atmospheric distribution, and trends in their atmospheric concentrations are insufficiently understood. Atmospheric model simulations using standard community emission inventories do not reproduce available measurements in the Northern Hemisphere. Here, we show that observations of pre-industrial and present-day ethane and propane can be reproduced in simulations with a detailed atmospheric chemistry transport model, provided that natural geologic emissions are taken into account and anthropogenic fossil fuel emissions are assumed to be two to three times higher than is indicated in current inventories. Accounting for these enhanced ethane and propane emissions results in simulated surface ozone concentrations that are 5–13% higher than previously assumed in some polluted regions in Asia. The improved correspondence with observed ethane and propane in model simulations with greater emissions suggests that the level of fossil (geologic + fossil fuel) methane emissions in current inventories may need re-evaluation.

乙烷和丙烷是大气中最丰富的非甲烷碳氢化合物。但是，对它们的排放，大气分布和大气浓度趋势的了解还不够。使用标准社区排放清单进行的大气模型模拟无法重现北半球的可用测量数据。在这里，我们表明，只要考虑到自然地质排放并将人为化石燃料排放假定为两个，则可以使用详细的大气化学迁移模型在模拟中重现工业前和当今乙烷和丙烷的观测结果。比当前库存量高出三倍。考虑到这些增加的乙烷和丙烷排放量，可得出模拟的表面臭氧浓度比亚洲某些受污染地区以前的估计值高5-13％。在模拟模型中观察到的乙烷和丙烷排放量更高的情况下，对应关系得到了改善，这表明可能需要对现有清单中化石（地质+化石燃料）甲烷的排放水平进行重新评估。