Long‐term (2005–2014) trends in formaldehyde (HCHO) columns across North America as seen by the OMI satellite instrument: Evidence of changing emissions of volatile organic compounds

Zhu, Lei; Mickley, Loretta J.; Jacob, Daniel J.; Marais, Eloïse A.; Sheng, Jianxiong; Hu, Lu; Abad, G. González; Chance, K.

doi:10.1002/2017gl073859

Cited by 97 publications

(91 citation statements)

References 70 publications

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“…The daily HCHO columns are then averaged on a 0.5° × 0.5° grid to yield a 12‐year monthly product for 2005–2016. We focus on May–September when prompt oxidation of VOCs provides the strongest HCHO signal (Zhu, Mickley, et al, ; Zhu, Jacob, et al, ). Lower oxidant concentrations in winter leads to smearing and dilution of the signal below the detection limit of 1 × 10 16 molecules cm −2 (González Abad et al, ; Zhu et al, ).…”

Section: Methodsmentioning

confidence: 99%

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

Shen

Jacob

Zhu

et al. 2019

Geophysical Research Letters

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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.

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Section: Methodsmentioning

confidence: 99%

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

Shen

Jacob

Zhu

et al. 2019

Geophysical Research Letters

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“…The moving average technique and time series decomposition are beneficial for differentiating trends and extracting cyclical patterns [33,37,38]. The lower sub-plots demonstrate the results of time series decomposition (i.e., the trend component, seasonal component and the residual component).…”

Section: Spatiotemporal Distribution Features Of Hcho Throughout Beijmentioning

confidence: 99%

“…Regarding the potential instrumental error, HCHO over the remote Pacific Ocean has been taken into consideration. As reported, HCHO over the western Pacific Ocean (i.e., the HCHO background area) was used to validate corresponding satellite-based measurements, and no trend was found [33,34]. Linear least squares regression adopted in this study is the approach to infer the potential trends exhibited in HCHO images.…”

Section: Spatiotemporal Distribution Features Of Hcho Throughout Beijmentioning

confidence: 99%

Spatiotemporal Variations in Satellite-Based Formaldehyde (HCHO) in the Beijing-Tianjin-Hebei Region in China from 2005 to 2015

Zhu

et al. 2018

Atmosphere

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Abstract:The widespread distribution and strong seasonal pattern of highly concentrated summertime formaldehyde (HCHO) were observed using data from the Ozone Monitoring Instrument (OMI) onboard Aura satellite from 2005 to 2015 in Beijing-Tianjin-Hebei, China. The large-scale HCHO concentrations and its close connection with the surface O 3 pollution made the study of summertime HCHO patterns and its major contributors necessary. Accordingly, time series decomposition, Moran's I and Pearson correlation coefficient (PCC) were adopted to investigate the spatiotemporal variations of HCHO. We found that the HCHO columns regionally increased from 2005 to 2010 and decreased in the north (e.g., Chengde) from 2010 to 2015. Additionally, HCHO Vertical Column Densities (VCDs) exhibited higher values in urban areas. Despite the strong possibilities of major biogenic contributions, anthropogenic sources represented larger spatial PCCs and larger total emission rates. Industrial sources exhibited a large increasing emission amount, and the most similar distribution to HCHO was found in residential sources. By comparison, power-based emissions accounted for a relatively small fraction, and transportation emissions declined rapidly. In conclusion, anthropogenic VOCs might contribute to the summertime HCHO concentrations as well as isoprene, and controls on VOCs and HCHO would be greatly assisted by the satellite-based observations.

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“…Environmental factor dependences are better understood, the dominant factor of variability being temperature (Palmer et al, 2006). Isoprene emissions can undergo large change over decadal scales in response to changing land cover (Purves et al, 2004;Zhu et al, 2017a).…”

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confidence: 99%

High-resolution inversion of OMI formaldehyde columns to quantify isoprene emission on ecosystem-relevant scales: application to the Southeast US

Kaiser¹,

Jacob²,

Zhu³

et al. 2017

Preprint

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Abstract. Isoprene emissions from vegetation have a large effect on atmospheric chemistry and air quality. isoprene emission inventories used in atmospheric models are based on limited vegetation information and uncertain land cover data, leading to potentially large errors. Satellite observations of atmospheric formaldehyde (HCHO), a high-yield isoprene oxidation product, provide 'top-down' information to evaluate isoprene emission inventories through inverse analyses. Past inverse analyses have however been hampered by uncertainty in the HCHO satellite data, uncertainty in the time-and NO x -dependent yield of HCHO from isoprene oxidation, and coarse resolution of the atmospheric models used for 30 the inversion. Here we demonstrate the ability to use HCHO satellite data from OMI in a high-resolution inversion to 2 to correct model NO x biases, which was done here using SEAC 4 RS observations but can be done more generally using satellite NO 2 data concurrently with HCHO. We find in our inversion that isoprene emissions from the widely-used MEGAN v2.1 inventory are biased high over the Southeast US by 40% on average, although the broad-scale distributions are correct including maximum emissions in Arkansas/Louisiana and high base emission factors in the oak-covered Ozarks of Southeast Missouri. A particularly large discrepancy is in the Edwards Plateau of Central Texas where MEGAN v2.1 is too high by a 5 factor of 3, possibly reflecting errors in land cover. The lower isoprene emissions inferred from our inversion, when implemented into GEOS-Chem, decrease surface ozone over the Southeast US by 1-3 ppb and decrease the isoprene contribution to organic aerosol from 40% to 20%.

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Long‐term (2005–2014) trends in formaldehyde (HCHO) columns across North America as seen by the OMI satellite instrument: Evidence of changing emissions of volatile organic compounds

Cited by 97 publications

References 70 publications

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

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

Spatiotemporal Variations in Satellite-Based Formaldehyde (HCHO) in the Beijing-Tianjin-Hebei Region in China from 2005 to 2015

High-resolution inversion of OMI formaldehyde columns to quantify isoprene emission on ecosystem-relevant scales: application to the Southeast US

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