Long-Term Trends of Carbon Monoxide Total Columnar Amount in Urban Areas and Background Regions: Ground-and Satellite-based Spectroscopic Measurements

摘要

A comparative study was carried out to explore carbon monoxide total columnar amount (CO TC) in background and polluted atmosphere,including the stations of ZSS (Zvenigorod),ZOTTO (Central Siberia),Peterhof,Beijing,and Moscow,during 1998-2014,on the basis of ground-and satellite-based spectroscopic measurements.Interannual variations of CO TC in different regions of Eurasia were obtained from ground-based spectroscopic observations,combined with satellite data from the sensors MOPITT (2001 14),AIRS (2003-14),and IASI MetOp A (2010-13).A decreasing trend in CO TC (1998-2014) was found at the urban site of Beijing,where CO TC decreased by 1.14％ ± 0.87％ yr-1.Meanwhile,at the Moscow site,CO TC decreased remarkably by 3.73％ ± 0.39％ yr 1.In the background regions (ZSS,ZOTTO,Peterhof),the reduction was 0.9％-1.7％ yr-1 during the same period.Based on the AIRSv6 satellite data for the period 2003-14,a slight decrease (0.4％-0.6％ yr-1) of CO TC was detected over the midlatitudes of Eurasia,while a reduction of 0.9％-1.2％ yr 1 was found in Southeast Asia.The degree of correlation between the CO TC derived from satellite products (MOPITTv6 Joint,AIRSv6 and IASI MetOp-A) and ground-based measurements was calculated,revealing significant correlation in unpolluted regions.While in polluted areas,IASI MetOp-A and AIRSv6 data underestimated CO TC by a factor of 1.5-2.8.On average,the correlation coefficient between ground-and satellite-based data increased significantly for cases with PBL heights greater than 500 m.