人为活动排放的以 CO 2 和 CH 4 为主的大量温室气体是造成全球增温的主要因素。由于地面观测站点稀少, 卫星遥感为监测 CO 2 和 CH 4 的时空分布及变化趋势提供了新的技术手段。本文验证了 GOSAT、OCO-2 卫星的大气 CO 2 和 CH 4 柱浓度遥感产品 XCO 2 和 XCH 4 的精度, 并分析了我国 XCO 2 和 XCH 4 的时空分布和变化趋势, 主要结论如下: (1) 在所用 XCO 2 遥感产品中, OCO-2_ACOS 与地面观测的相关性最高 (达 0.93); 而 XCH 4 产品中 GOSAT_OCPR 的相关性最高 (达 0.78)。(2) 在研究的时间跨度内, XCO 2 浓度呈逐年上升趋势, 如我国 OCO-2 XCO 2 年均浓度由 2014 年的 396.92 × 10 －6 增长到 2021 年的 414.72 × 10 －6 ; CO 2 浓度高值主要分布在城市和工业集中的中国东部地区, 西北地区塔克拉玛干沙漠的高值与气溶胶散射影响有关; 同时, 受人为源和自然源的季节变化影响, XCO 2 具有冬春高、夏秋低的时间特征。(3) XCH 4 浓度同样呈逐年上升趋势, 但与 XCO 2 不同, XCH 4 浓度高值主要分布在天然气和煤炭开采集中的四川东部、重庆西部、陕西与山西的中部地区, 以及工业集中的华北地区,季浓度呈现夏秋高、春冬低的特征。(4) 2020 年 XCO 2 高值区发生偏移; 相对于 2020 年, 2021 年 CO 2 增速有所回升, 但增幅相对于 2019 年之前仍有所减小。

The large amount of greenhouse gases, mainly CO 2 and CH 4 , emitted by human activities is a major contributor to global warming. Due to the scarcity of ground-based observation sites, satellite remote sensing provides a new technical means to monitor the spatial and temporal distribution and trends of CO 2 and CH 4 . In this paper, we verify the accuracy of XCO 2 and XCH 4 , the remote sensing products of atmospheric CO 2 and CH 4 column concentrations from GOSAT and OCO-2 satellites, and analyze the spatial and temporal distributions and trends of XCO 2 and XCH 4 in China. The main conclusions are as follows. (1) Among XCO 2 remote sensing products, OCO-2_ACOS has the highest correlation with ground observation (up to 0.93); while GOSAT_OCPR has the highest correlation with XCH 4 products (up to 0.78). (2) In the years of study, XCO 2 concentration increases year by year, for example, the annual average OCO-2 XCO 2 concentration in China increases from 396.92 × 10 －6 in 2014 to 414.72 × 10 －6 in 2021. The high values of CO 2 concentration are mainly distributed in urban and industrial concentrated East China, and the high values in the Taklamakan Desert in Northwest China are related to the influence of aerosol scattering. And in the other hand, influenced by the seasonality of anthropogenic and natural sources, XCO 2 has the temporal characteristics of high in winter and spring and low in summer and autumn. (3) The concentration of XCH 4 also increases year by year. Unlike XCO 2 , the high concentration of XCH 4 is distributed in central areas of China such as eastern Sichuan, western Chongqing, centralShaanxi and Shanxi where natural gas and coal mining are concentrated, and the northern China where industry is concentrated. And the seasonal concentration of XCH 4 is high in summer and autumn and low in spring and winter. (4) In 2020, the XCO 2 high value area shifts. Compared with 2020, the CO 2 growth rate of 2021 increases a little, but the increase is still reduced compared with that before 2019.