The 2005–2016 Trends of Formaldehyde Columns Over China Observed by Satellites: Increasing Anthropogenic Emissions of Volatile Organic Compounds and Decreasing Agricultural Fire Emissions

Abstract

We use 2005–2016 observations of formaldehyde (HCHO) columns over China from the OMI, GOME‐2, and SCIAMACHY satellite instruments to evaluate long‐term trends in emission inventories of volatile organic compounds (VOCs) that affect air quality. The observations show large increases over 2005–2016 in the North China Plain (+1.1 ± 0.5% a−1 relative to 2005) and the Yangtze River Delta region (+1.5 ± 0.4% a−1 relative to 2005), consistent with the trend of anthropogenic VOC emissions in the Multi‐resolution Emission Inventory for China (MEIC). Unlike other pollutants, VOC emissions have not been decreasing in recent years. An exception is the Huai River Basin in rural eastern China where the satellite data show rapidly decreasing VOC emissions since the early 2010s that appear to reflect bans on agricultural fires.

An Inversion of NO<sub><i>x</i></sub> and NMVOC Emissions using Satellite Observations during the KORUS-AQ Campaign and Implications for Surface Ozone over East Asia

“…We do not see a significant deviation in the model from the observations over this region indicating that no noticeable efforts on controlling VOC emissions in NCP and YRD have been made which is very likely due to the fact that the recent regulations over China have overlooked cutting emissions from several industrial sectors 310 prior to 2016 ]. This finding lines up with results reported by Souri et al [2017] and Shen et al [2019]. We observe both underestimated and overestimated values in the simulated HCHO columns over areas in South Korea and Japan.…”

“…In contrast, enhancements of the emissions are evident at higher latitudes. We observe that the dominantly anthropogenic VOC emissions over NCP increase (~25%) after the adjustment highlighting the minimal efforts made 390 to reduce this particular source of emissions [Souri et al, 2017;Shen et al, 2019]. For instance, Stavrakou et al [2017] reported ~6% increases in anthropogenic VOC emissions over China from 2010 to 2014.…”

“…This significant pollutant is not confined to the source, as it spreads hemispherically 60 through the air, affecting background concentrations as far away as U.S. A study by Lin et al [2017] provided modeling evidence of enhancements of springtime surface ozone levels (+0.5 ppbv yr -1 ) in the western U.S. in 1980-2014 solely due to the tripling of Asian anthropogenic emissions over the period. As more studies have informed the impact of ozone pollution on both human health and crop yields, Chinese governmental regulatory agencies have begun to take action 65 on cutting the amount of NOx (NO+NO2) emissions since 2011-2012 [Gu et al, 2013;Reuter et al, 2014;Krotkov et al, 2016;de Foy et al, 2016;Souri et al, 2017]; however no effective policy on volatile organic compound (VOC) emissions, emitted from various sources such as solvent use, mobile, and chemical industries [Liu et al, 2008a,b], had been put into the effect prior to 2016 [Stavrakou et al, 2017;Souri et al, 2017;Shen et al, 2019;, with an exception to 70 Pearl River Delta (PRD) [Zhong et al 2013]. In addition to China, a number of governments including those of Malaysia and Taiwan have put a great deal of effort into shifting their energy pattern from consuming fossil fuels to renewable sources [Trappey el al., 2012;Chua and Oh, 2011].…”

Global atmospheric carbon monoxide budget 2000–2017 inferred from multi-species atmospheric inversions

“…S7, S8, and S9. The TCCON stations include Indianapolis (Iraci et al, 2017a), Manaus (Dubey et al, 2017a), Sodankylä (Kivi et al, 2017), Lauder (Sherlock et al, 2017a, b), Burgos (Morino et al, 2018), Ascension Island (Feist et al, 2017) Author contributions. BZ, FC, and PC designed the study.…”

Constraining Emissions of Volatile Organic Compounds Over the Indian Subcontinent Using Space‐Based Formaldehyde Measurements

“…Here, the OMI and GOME-2A observational operators (a priori profiles and averaging kernels) are applied to the model, so that the HCHO profile assumptions are indeed consistent in both cases. Recent work by Shen et al (2019) concluded that the Zhu et al (2016) correction was also valid over China, suggesting that it may be uniform and thus likewise apply over India. A comparison of the updated QA4ECV HCHO products (used here) versus the v14 products (evaluated previously) over our Indian domain yields a slope of 1.31 (d[QA4ECV]/d[v14]) and correlation of 0.92 for OMI and a slope of 1.13 and correlation of 0.84 for GOME-2A.…”