从大气辐射传输模型正演和反演两个角度,探究CO₂观测时地表高程的敏感性。SRTM地表高程数据表明,在北京附近的平原地区,卫星指向不准导致的地表高程均值的误差较小,在偏移量为0.1~10.0 km的情况下,误差极大值约为10 m;而在北京附近山区以及平原与山区交界区内,地表高程均值的误差较大,误差极大值分别为713.98,515.61 m。CO₂反演结果表明:高程值每变化100 m,CO₂柱浓度偏差为3.29×10 ^-6;在大气CO₂高精度反演中,地表高程偏差是一个关键因素。

The influence of surface elevation on atmospheric CO2 observations is explored from the perspective of forward and inversion of the atmospheric radiation transfer model in this work. The surface elevation data from the shuttle radar topography mission (SRTM) show that the error of the mean surface elevation due to inaccurate satellite pointing in the plains near Beijing is small, with a maximum error of approximately 10 m for a pointing offset of 0.1-10 km. However, in the mountainous areas and in the boundaries between mountainous areas and plains, the error of the mean surface elevation is large, with the maximum errors of 713.98 and 515.61 m, respectively. The CO2 inversion results show that for an elevation change of 100 m, the CO2 column density deviates by 3.29×10 -6. Thus, the research results show that the surface elevation deviation is a critical factor in performing atmospheric CO2 inversion with high precision.