CO 2 in Beijing and Xianghe Observed by Ground-Based FTIR Column Measurements and Validation to OCO-2/3 Satellite Observations.

Zhou, Minqiang; Ni, Qichen; Cai, Zhaonan; Langerock, Bavo; Nan, Weidong; Yang, Yang; Che, Ke; Yang, Dongxu; Wang, Ting; Liu, Yi; Wang, Pucai

Monitoring the atmospheric CO 2 columns inside and around a city is of great importance to understand the temporal–spatial variation of XCO 2 near strong anthropogenic emissions. In this study, we use two FTIR CO 2 column measurements in Beijing (Bruker EM27/SUN) and Xianghe (Bruker IFS 125HR) between 2019 and 2021 to investigate the differences of XCO 2 between Beijing (urban) and Xianghe (suburb) in North China and to validate the OCO-2 and OCO-3 satellite XCO 2 retrievals. The mean and standard deviation (std) of the Δ XCO 2 between Beijing and Xianghe (Beijing–Xianghe) observed by two FTIR instruments are 0.206 ± 1.736 ppm, which has a seasonal variation and varies with meteorological conditions (wind speed and wind direction). The mean and std of the XCO 2 differences between co-located satellite and FTIR measurements are −0.216 ± 1.578 ppm in Beijing and −0.343 ± 1.438 ppm in Xianghe for OCO-2 and 0.637 ± 1.594 ppm in Beijing and 1.206 ± 1.420 ppm in Xianghe for OCO-3. It is found that the OCO-3 snapshot area mode (SAM) measurements can capture the spatial gradient of XCO 2 between urban and suburbs well. However, the FTIR measurements indicate that the OCO-3 SAM measurements are about 0.9–1.4 ppm overestimated in Beijing and Xianghe.

BEIJING (China); COLUMNS; ATMOSPHERIC carbon dioxide; CARBON dioxide; WIND speed; TELECOMMUNICATION satellites

Remote Sensing, 2022, Vol 14, Issue 15, p3769

2072-4292

Academic Journal

10.3390/rs14153769