Important evidence of constant low CO2 windows and impacts on the non-closure of the greenhouse effect

Jing Zhao; Guoqing Li; Weihong Cui; Qianqian Cao; Haoping Zhang

doi:10.1038/s41598-019-41562-x

Important evidence of constant low CO₂ windows and impacts on the non-closure of the greenhouse effect

Sci Rep. 2019 Mar 22;9(1):5033. doi: 10.1038/s41598-019-41562-x.

Authors

Jing Zhao^{1

2}, Guoqing Li^{3

4}, Weihong Cui^{5

6}, Qianqian Cao^{1

2}, Haoping Zhang⁷

Affiliations

¹ Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, 100094, P. R. China.
² University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
³ Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, 100094, P. R. China. ligq@aircas.ac.cn.
⁴ Hainan Key Laboratory of Earth Observation, Sanya, 572029, P. R. China. ligq@aircas.ac.cn.
⁵ National Engineering Center for Geoinformatics, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, 100010, P. R. China.
⁶ International Eurasian Academy of Sciences (IEAS), Beijing, 100010, P. R. China.
⁷ China Centre for Resources Satellite Data and Application, Beijing, 100094, P. R. China.

Abstract

The CO₂ distribution in the atmosphere remains unclear for the complexity of the long-range vertical transport process and other influencing factors. In this work, regression analysis was used to verify the accuracy of CO₂ concentrations datasets. Geostatistical analyses were used to investigate the spatiotemporal distributions of CO₂ at 7 levels from near the surface to the mid-troposphere (0~5 km). Spatial correlation and time series analyses were used to further determine the diffusion characteristics of the CO₂ concentration based on the horizontal wind (NCEP R2), which is one of the main driving factors. The results showed that the horizontal, not vertical, diffusion of CO₂ becomes increasingly more prominent with the decrease in atmospheric pressure to the mid-troposphere, whereas many regions, such as the Rocky Mountains and Qinghai-Tibet Plateau, have constant low values throughout the year due to the influence of high topography (up to 10.756 ppmv lower than that near the surface). These areas form low CO₂ concentration 'windows' keeping letting thermal infrared energy out into space. This study is the first to question the existing view of the closure of the 'greenhouse effect'. Future research studies should more precisely determine the closure threshold and the uncertainties about the surface fluxes.