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CHANGES IN TRENDS OF ATMOSPHERIC COMPOSITION OVER URBAN AND BACKGROUND REGIONS OF EURASIA: ESTIMATES BASED ON SPECTROSCOPIC OBSERVATIONS

The analysis of the CO and CH4 total column (TC) as well as aerosol optical depth (AOD) data in urban and background regions of Eurasia for different seasons and periods from 1998 to 2016 years is presented. Trends estimates based on longterm spectroscopic datasets of OIAP RAS (Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences) for stations Moscow, Zvenigorod (ZSS, Moscow province), Zotino (ZOTTO, Central Siberia), Beijing (joint site of OIAP RAS and IAP CAS (Institute of Atmospheric Physics, Chinese Academy of Sciences)), SPbSU stations Peterhof and NDACC stations located in Eurasia were compared between themselves and with similar assessments obtained from satellite data. Significant decrease of anthropogenic CO in megacities Moscow (3.5±2.2%/yr) and Beijing (1.4±1.4%/yr) in autumn months of 1998−2016 were found according ground-based spectroscopic observations. In spite of total anthropogenic CO emissions decrease (for Europe and China) and absence of growth of wild-fires emissions in 2007−2016 we found that CO TC in background regions of Northern Eurasia has stabilized or increased in summer and autumn months of 2007−2016. Decrease of AOD over Central and Southern Europe and over China (1−5%/ yr) was observed after 2007. Since 2007 an increase in CH4 TC trends over Northern Europe as well as for tropical belt of Eurasia has been obtained. Analysis of satellite observations AIRS v6 of CO and CH4 TC and MODIS AOD data confirmed the ground-based estimates of trends.