Abstract

This study aims at estimating errors to be accounted for in atmospheric inversions of methane (CH₄) emissions at the European scale. Four types of errors are estimated in the concentration space over the model domain and at selected measurement sites. Furthermore, errors in emission inventories are estimated at country and source sector scales. A technically ready method is used, which is implemented by running a set of simulations of hourly CH₄ mixing ratios for 2015 using two area-limited transport models at three horizontal resolutions with multiple data sets of emissions and boundary and initial conditions as inputs. The obtained error estimates provide insights into how these errors could be treated in an inverse modelling system for inverting CH₄ emissions over Europe. The main results show that sources of transport errors may better be controlled alongside the emissions, which differs from usual inversion practices. The average total concentration error is estimated at 29 ppb. The assessed error of total CH₄ emissions is 22% and emission errors are heterogeneous at sector (23–49%) and country scales (16–124%), with largest errors occurring in the waste sector due to uncertainties in activity data and emission factors and in Finland due to uncertainties in natural wetland emissions.

摘要

这项研究旨在估算在欧洲范围内，大气中甲烷（CH ₄）排放量反演中应考虑的误差。在模型域和所选测量位置的浓度空间中，估计出四种类型的误差。此外，排放清单的误差是根据国家和来源部门的规模估算的。使用了一种技术上可行的方法，该方法是通过使用两个区域受限的运输模型以三个水平分辨率运行多个2015年每小时CH ₄混合比的模拟来实现的，并使用多个排放量数据集以及边界和初始条件作为输入。所获得的误差估计值提供了有关如何在逆向建模系统的逆CH _4中如何处理这些误差的见解。欧洲的排放量。主要结果表明，可以更好地控制运输错误的来源以及排放，这与通常的反演方法不同。平均总浓度误差估计为29 ppb。CH ₄排放总量的评估误差为22％，排放误差在行业（23–49％）和国家规模（16–124％）上是不同的，由于活动数据和排放的不确定性，在废物部门发生的误差最大因素和芬兰由于自然湿地排放的不确定性。