Spatial And Temporal Variation Characteristics Of Atmospheric Carbon Dioxide Concentration And Its Influencing Factors In China

Carbon dioxide?CO₂?is one of the major greenhouse gases in the global atmosphere.According to the measured results of the Hawaiian atmospheric background station,atmospheric CO₂ concentration has increased by 28.7%in the past 60 years,which significantly affects global warming and the formation of extreme climate.In the past 15years,China has been the largest emitter of carbon dioxide.The research on atmospheric CO₂ concentration monitoring,spatial and temporal changes,carbon sources and carbon sinks has become one of the hotspots in the field of atmospheric environment.This study took the concentrations of atmospheric tropospheric CO₂ column of China as the research object,selected the world's first dedicated atmospheric gas observation satellite?Global Greenhouse Gas Observation by Satellite,GOSAT?as the main data source to establish a atmospheric tropospheric CO₂ concentration database in 0.1ospatial resolution of China from April 2009 to December 2016 by using space Kriging interpolation.After verification by surface measured data,we established the correlations between tropospheric atmospheric CO₂ concentration and NDVI,land surface temperature,monthly precipitation,power energy consumption,fossil fuel CO₂ emissions and biomass burning CO₂ emissions per-pixel in China during growing season from 2009 to 2016.Finally,we quantified the effects of biomass burning emissions,fossil fuel emissions,and NDVI on the spatial and temporal variation of CO₂ concentrations.This study has a great significance for understanding and mastering the spatial and temporal variation characteristics of atmospheric carbon dioxide concentration and the relative contribution rate of carbon source/carbon sink at different scales in China,and has important reference value for the implementation of regional sustainable development theory.The main research results of this paper are as follows:?1?The average concentration of atmospheric CO₂ reached 392.28 ppm in China during 2009-2016 vegetation growing season.In April 2016,the atmospheric tropospheric CO₂ concentration reached 404.9 ppm,an increase of 4.35%from April2009.Meanwhile,the atmospheric CO₂ concentration had a significant seasonal variation in China.The highest value area appeared in the Yangtze River Delta in spring;The lowest value region appeared in the northeast high latitudes in summer.The average annual change of atmospheric CO₂ concentration was 6.78 ppm,of which the seasonal change of bare land was the smallest,only 5.11 ppm,and the maximum change was in agricultural land,reached 8.26 ppm.?2?The annual increase of atmospheric CO₂ concentration in China was slowed down by 0.4 ppm per decade.The interannual growth rate of atmospheric CO₂concentration in Northwest China and Northeast China has slowed significantly?-0.1ppm/a?and South China was at an accelerated growth stage?+0.19 ppm/a?.?3?The average center of atmospheric CO₂ concentration in China showed two abnormal fluctuations in 2010 and 2014,which were shifted from the previous year to the northeast and southwest by 178.5 km and 180.7 km,respectively.At the same time,the standard deviation ellipse azimuth showed a counterclockwise rotation of 2.25oand a clockwise rotation of 2.2o.?4?Atmospheric CO₂ concentration and NDVI had a significant negative correlation belt?r<-0.7?from northeast to southwest direction;the correlation with surface temperature in Heilongjiang Province and Sichuan-Yunnan region was higher,but other regions were affected by latitude changes.Precipitation showed a weak correlation in the high latitudes of Northwest China,similar to that in southern China.The impact of human active fossil fuel combustion was mainly distributed in densely populated areas,but weak in Shandong and Henan.Biomass burning emissions showed large areas of correlation in Heilongjiang Province and Yunnan Province.?5?The contribution of the three main driving factors selected in this paper has significant spatial and temporal heterogeneity.The atmospheric CO₂ concentration in China was mainly controlled by NDVI.Human activities fossil fuel combustion has a high contribution rate to atmospheric CO₂ concentration in spring and autumn,which was the main driving factor of atmospheric CO₂ in these regions.The biomass burning emission had a great contribution and influence on the atmospheric CO₂ change in the low latitudes of South China in autumn and the Yunnan Province in spring,respectively.