The measurements of one of the major greenhouse gases, carbon dioxide (CO₂), are being made using dedicated satellite remote sensing since the launch of the greenhouse gases observing satellite (GOSAT) by a three-way partnership between the Japan Aerospace Exploration Agency (JAXA), the Ministry of Environment (MoE) and the National Institute for Environmental Studies (NIES), and the National Aeronautics and Space Administration (NASA) Orbiting Carbon Observatory-2 (OCO-2). In the past 10 years, estimation of CO₂ fluxes from land and ocean using the earth system models (ESMs) and inverse modelling of in situ atmospheric CO₂ data have also made significant progress. We attempt, for the first time, to evaluate the CO₂ fluxes simulated by an earth system model (MIROC-ES2L) and the fluxes estimated by an inverse model (MIROC4-Inv) using in situ data by comparing with GOSAT and OCO-2 observations. Both MIROC-ES2L and MIROC4-Inv fluxes are used in the MIROC4-atmospheric chemistry transport model (referred to as ACTM_ES2LF and ACTM_InvF, respectively) for calculating total column CO₂ mole fraction (XCO₂) that are sampled at the time and location of the satellite measurements. Both the ACTM simulations agreed well with the GOSAT and OCO-2 satellite observations, within 2 ppm for the spatial maps and time evolutions of the zonal mean distributions. Our results suggest that the inverse model using in situ data is more consistent with the OCO-2 retrievals, compared with those of the GOSAT XCO₂ data due to the higher accuracy of the former. This suggests that the MIROC4-Inv fluxes are of sufficient quality to evaluate MIROC-ES2L simulated fluxes. The ACTM_ES2LF simulation shows a slightly weaker seasonal cycle for the meridional profiles of CO₂ fluxes, compared with that from the ACTM_InvF. This difference is revealed by greater XCO₂ differences for ACTM_ES2LF vs GOSAT, compared with those of ACTM_InvF vs GOSAT. Using remote sensing–based global products of leaf area index (LAI) and gross primary productivity (GPP) over land, we show a weaker sensitivity of MIROC-ES2L biospheric activities to the weather and climate in the tropical regions. Our results clearly suggest the usefulness of XCO₂ measurements by satellite remote sensing for evaluation of large-scale ESMs, which so far remained untested by the sparse in situ data.

自从日本宇航局三方合作发射温室气体观测卫星（GOSAT）以来，就一直使用专用的卫星遥感技术对一种主要的温室气体二氧化碳（CO ₂）进行测量。 JAXA），环境部（MoE）和国家环境研究所（NIES），以及美国国家航空航天局（NASA）的绕行碳观测站2（OCO-2）。在过去的10年中，利用地球系统模型（ESM）估算陆地和海洋中的CO ₂通量以及就地大气CO ₂数据进行逆向建模也取得了重大进展。我们首次尝试评估CO ₂地球系统模型（MIROC-ES2L）模拟的磁通量和逆模型（MIROC4-Inv）使用原位数据通过与GOSAT和OCO-2观测值进行比较估算的磁通量。MIROC4-ES2L和MIROC4-Inv通量都用于MIROC4-大气化学传输模型（分别称为ACTM_ES2LF和ACTM_InvF），以计算在色谱柱的时间和位置取样的总色谱柱CO ₂摩尔分数（XCO ₂）。卫星测量。ACTM模拟都与GOSAT和OCO-2卫星观测非常吻合，在2 ppm以内的空间图和纬向平均分布的时间演变。我们的结果表明，与GOSAT XCO ₂相比，使用原位数据的反演模型与OCO-2检索更加一致。数据由于前者的准确性较高。这表明MIROC4-Inv通量的质量足以评估MIROC-ES2L模拟通量。与ACTM_InvF相比，ACTM_ES2LF模拟显示出CO ₂通量子午线轮廓的季节周期略弱。与ACTM_InvF与GOSAT相比，ACTM_ES2LF与GOSAT的XCO ₂差异更大，表明了这种差异。使用基于遥感的全球叶面积指数（LAI）和陆地初级生产力（GPP）的全球产品，我们发现MIROC-ES2L生物圈活动对热带地区天气和气候的敏感性较弱。我们的结果清楚地表明了XCO ₂的有用性 通过卫星遥感进行的测量，以评估大规模的ESM，到目前为止，尚未通过稀疏的现场数据进行测试。