Atmospheric CO₂ is one of key parameters to estimate air-sea CO₂ flux. The Orbiting Carbon Observatory-2 (OCO-2) satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide (XCO₂) since 2014. In this study, the OCO-2 XCO₂ products were compared between in-situ data from the Total Carbon Column Network (TCCON) and Global Monitoring Division (GMD), and modeling data from CarbonTracker2019 over global ocean and land. Results showed that the OCO-2 XCO₂ data are consistent with the TCCON and GMD in situ XCO₂ data, with mean absolute biases of 0.25×10⁻⁶ and 0.67×10⁻⁶, respectively. Moreover, the OCO-2 XCO₂ data are also consistent with the CarbonTracker2019 modeling XCO₂ data, with mean absolute biases of 0.78×10⁻⁶ over ocean and 1.02×10⁻⁶ over land. The results indicated the high accuracy of the OCO-2 XCO₂ product over global ocean which could be applied to estimate the air-sea CO₂ flux.

大气CO ₂是估算海气CO ₂通量的关键参数之一。Orbiting Carbon Observatory-2 (OCO-2) 卫星自 2014 年以来观测了全球大气二氧化碳 (XCO ₂ )的柱平均干空气摩尔分数。在本研究中，OCO-2 XCO ₂产品在-来自总碳柱网络 (TCCON) 和全球监测司 (GMD) 的现场数据，以及来自 CarbonTracker2019 的全球海洋和陆地建模数据。结果表明，OCO-2 XCO ₂数据与TCCON和GMD原位XCO ₂数据一致，平均绝对偏差为0.25×10 ^-6和0.67×10^-6，分别。此外，OCO-2 XCO ₂数据也与CarbonTracker2019建模XCO ₂数据一致，海洋上的平均绝对偏差为0.78×10 ^-6，陆地上的平均绝对偏差为1.02×10 ^-6。结果表明，OCO-2 XCO ₂产品在全球海洋上的准确性很高，可用于估算海气CO ₂通量。