2010-2018 global methane emissions inferred from GOSAT satellite observations

The dataset includes gridded methane emission fluxes from a global inversion of GOSAT methane (CH4) observations by Zhang et al. (2021) (https://doi.org/10.5194/acp-21-3643-2021). Monthly prior and posterior sectoral emissions from 2010-2018 are reported on a 4x5 degree grid. Source sectors include anthropogenic (oil exploitation, gas exploitation, coal mining, livestock, rice cultivation, wastewater treatment, landfills, and other anthropogenic sources) and natural (wetlands, geological seeps, termites, and biomass burning). The total methane flux is also reported. Usually small differences exist between the total methane flux and the sum of sectoral fluxes, which is due to the soil absorption flux.The monthly gridded sectoral emission flux product presented in this dataset are derived from an inversion by Zhang et al. (2021). Original inversion results (including posterior scaling factors, error covariance, and averaging kernel matrix) are archived at https://doi.org/10.5281/zenodo.4052518 Although monthly gridded sectoral emissions are reported here, this does not mean that the inversion can resolve emissions for each 4x5 degree grid cell by sector on a monthly basis. See the description below and Zhang et al. (2021) for the inversion configuration. The main purpose of creating this dataset is to facilitate follow-up transport model simulations and analysis. A brief description of the inversion configuration: The inversion is performed with the GEOS-Chem model for the period of 2010-2018 with GOSAT CO2-proxy CH4 retrievals from Parker and Boesch (2020). The inversion optimizes mean and trend of non-wetland emissions, monthly wetland emissions for 14 subcontinental regions, and annual hemispheric OH concentrations (methane loss rates). Sector attribution of posterior non-wetland emissions in a 4x5 degree grid cell is done on the basis of the relative contribution of a sector to prior emissions in the grid cell. Detailed description of the methodology can be found in Zhang et al. (2021).

本数据集收录了张等（2021年）基于GOSAT甲烷（CH4）观测数据进行的全球反演得到的网格化甲烷排放通量。2010-2018年每月的先验及后验各行业排放量以4x5度网格形式呈现。源行业包括人为源（石油开采、天然气开采、煤炭开采、畜牧业、水稻种植、废水处理、垃圾填埋场及其他人为源）和自然源（湿地、地质泄漏、白蚁及生物质燃烧）。同时，总甲烷通量亦被报告。通常，总甲烷通量与各行业通量之和之间存在微小差异，此差异源于土壤吸收通量。本数据集中所提供的每月网格化行业排放通量产品，源自张等（2021年）的反演结果。原始反演结果（包括后验缩放因子、误差协方差及平均核矩阵）存档于https://doi.org/10.5281/zenodo.4052518。尽管此处报告了每月网格化行业排放量，但这并不意味着反演能够按月解析每个4x5度网格单元的行业排放。具体配置请参见下文及张等（2021年）的描述。创建本数据集的主要目的是为了促进后续的传输模型模拟和分析。以下是反演配置的简要描述：反演采用GEOS-Chem模型，针对2010-2018年期间，利用帕克和博什（2020年）的GOSAT CO2-proxy CH4检索结果进行。反演优化了非湿地排放的均值和趋势、14个次大陆区域的月湿地排放量以及半球OH浓度（甲烷损失速率）。在4x5度网格单元中，后验非湿地排放的行业归属基于各行业对网格单元先验排放的相对贡献。详细的方法论描述可参考张等（2021年）。