Estimating city NOX emissions from TROPOMI high spatial resolution observations – A case study on Yangtze River Delta, China

Xue, Ruibin; Wang, Shanshan; Zhang, Sanbao; He, Songbai; Liu, Jiaqi; Tanvir, Aimon; Zhou, Bin

doi:10.1016/j.uclim.2022.101150

Cited by 12 publications

(7 citation statements)

References 30 publications

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“…At last, NO 2 emission can be obtained by dividing NO 2 mass by its lifetime and further converted to NO X emission by an empirical conversion coefficient of 1.32 [31,32]. A detailed evaluation on the uncertainty of the EMG method for quantifying NO 2 lifetime and NO X emission can be found in the study by Xue et al [29].…”

Section: Exponentially-modified Gaussian (Emg) Methodsmentioning

confidence: 99%

“…The tropospheric NO 2 and HCHO VCDs were extracted and filtered with quality flags exceeding 0.75 and 0.5, respectively. The pixels were further re-gridded into 0.01 • × 0.01 • , which can be referred to the study of Xue et al [29]. For each HCHO grid, a 24 km averaging radius was applied to smoothen the data for less noise [10,30].…”

Section: Tropomi Observationsmentioning

confidence: 99%

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Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

et al. 2022

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An unprecedented city-wide lockdown took place in Shanghai from April to May 2022 to curb the spread of COVID-19, which caused socio-economic disruption but a significant reduction of anthropogenic emissions in this metropolis. However, the ground-based monitoring data showed that the concentration of ozone (O3) remained at a high level. This study applied Tropospheric Monitoring Instrument (TROPOMI) observations to examine changes in tropospheric vertical column density (VCD) of nitrogen dioxide (NO2) and formaldehyde (HCHO), which are precursors of O3. Compared with the same period in 2019–2021, VCDs of NO2 and HCHO decreased respectively by ~50% and ~20%. Multiple regression analysis showed that the lockdown effect played a dominant role in this dramatic decline rather than meteorological impacts. Using the exponentially-modified Gaussian method, this study quantified nitrogen oxides (NOX) emission in Shanghai as 32.60 mol/s with a decrease of 50–80%, which was mainly contributed by the transportation and industrial sectors. The significant reduction of NOX emission in Shanghai is much higher than that of volatile organic compounds (VOCs), which led to dramatic changes in formaldehyde-to-nitrogen dioxide ratio (HCHO/NO2, FNR). Thus, when enforcing regulation on NOx emission control in the future, coordinately reducing VOCs emission should be implemented to mitigate urban O3 pollution.

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Section: Exponentially-modified Gaussian (Emg) Methodsmentioning

confidence: 99%

Section: Tropomi Observationsmentioning

confidence: 99%

Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

et al. 2022

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“…Additionally, the pixel values for HCHO and NO2 products were further resampled to a grid of 5 km × 5 km. For the HCHO data, an additional 25 km smoothing radius was applied to reduce noise in the data [3,4,53,54].…”

Section: Data Description and Preprocessingmentioning

confidence: 99%

Machine Learning to Characterize Biogenic Isoprene Emissions and Atmospheric Formaldehyde with Their Environmental Drivers in the Marine Boundary Layer

Wang,

Xue

et al. 2024

Atmosphere

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Oceanic biogenic emissions exert a significant impact on the atmospheric environment within the marine boundary layer (MBL). This study employs the extreme gradient boosting (XGBoost) machine learning method and clustering method combined with satellite observations and model simulations to discuss the effects of marine biogenic emissions on MBL formaldehyde (HCHO). The study reveals that HCHO columnar concentrations peaked in summer with 8.25 × 1015 molec/cm2, but the sea–air exchange processes controlled under the wind and sea surface temperature (SST) made marine biogenic emissions represented by isoprene reach their highest levels in winter with 95.93 nmol/m2/day. Analysis was conducted separately for factors influencing marine biogenic emissions and affecting MBL HCHO. It was found that phytoplankton functional types (PFTs) and biological degradation had a significant impact on marine biogenic emissions, with ratio range of 0.07~15.87 and 1.02~5.42 respectively. Machine learning methods were employed to simulate the conversion process of marine biogenic emissions to HCHO in MBL. Based on the SHAP values of the learning model, the importance results indicate that the factors influencing MBL HCHO mainly included NO2, as well as temperature (T) and relative humidity (RH). Specifically, the influence of NO2 on atmospheric HCHO was 1.3 times that of T and 1.6 times that of RH. Wind speed affected HCHO by influencing both marine biogenic emission and the atmospheric physical conditions. Increased marine biogenic emissions in air masses heavily influenced by human activities can reduce HCHO levels to some extent. However, in areas less affected by human activities, marine biogenic emissions can lead to higher levels of HCHO pollution. This research explores the impact of marine biogenic emissions on the HCHO status of the MBL under different atmospheric chemical conditions, offering significant insights into understanding chemical processes in marine atmospheres.

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“…Currently, these two satellite data sources dominate the studies on NO 2 concentrations (Van Geffen et al 2020, Ding et al 2022, Zhang et al 2023b. Various inversion methods such as plume and box models, mass balance, 4D-Var, and integrated Kalman filters employ satellite observations and atmospheric chemical transport models (CTM) to estimate atmospheric pollutant emissions (Martin et al 2003, Lamsal et al 2011, Duncan et al 2013, Ding et al 2015, Qu et al 2017, Gaubert et al 2020, Xue et al 2022. Several studies analyzed recent anthropogenic NO x emission trends using satellite observations (Forster et al 2020, 2021, Doumbia et al 2021, Chen et al 2022, Tzortziou et al 2022, but most focus on localized areas around the time of the first COVID-19 outbreak, leaving unexplored changes in global anthropogenic NO x emission trends in the years following the outbreak of COVID-19 and other factors influencing emissions.…”

Section: Introductionmentioning

confidence: 99%

Anthropogenic NO _x emissions of China, the U.S. and Europe from 2019 to 2022 inferred from TROPOMI observations

Mao,

Wang,

Jiang

et al. 2024

Environ. Res. Lett.

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Anthropogenic nitrogen oxide (NOx) emissions are closely associated with human activities. In recent years, global human activity patterns have changed significantly owing to the COVID‐19 epidemic and international energy crisis. However, their effects on NOx emissions are not yet fully understood. In this study, we developed a two-step inversion framework using NO2 observations from the TROPOMI satellite and the GEOS-Chem global atmospheric chemical transport model, and inferred global anthropogenic NOx emissions from 2019 to 2022, focusing on China, the United States (U.S.), and Europe. Our results indicated an 16.8% reduction in NOx emissions in 2020 and a 3.95% rebound in 2021 across all regions. China rebounded faster than the others, surpassing its 2019 levels by July 2020. In 2022, emissions declined in all regions, driven mainly by the Omicron variant, energy shortages, and clean energy policies. Our findings provide valuable insights for the development of effective future emission management strategies.

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Estimating city NOX emissions from TROPOMI high spatial resolution observations – A case study on Yangtze River Delta, China

Cited by 12 publications

References 30 publications

Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

Machine Learning to Characterize Biogenic Isoprene Emissions and Atmospheric Formaldehyde with Their Environmental Drivers in the Marine Boundary Layer

Anthropogenic NO _x emissions of China, the U.S. and Europe from 2019 to 2022 inferred from TROPOMI observations

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Estimating city NOX emissions from TROPOMI high spatial resolution observations – A case study on Yangtze River Delta, China

Cited by 12 publications

References 30 publications

Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

Ozone Pollution of Megacity Shanghai during City-Wide Lockdown Assessed Using TROPOMI Observations of NO2 and HCHO

Machine Learning to Characterize Biogenic Isoprene Emissions and Atmospheric Formaldehyde with Their Environmental Drivers in the Marine Boundary Layer

Anthropogenic NO x emissions of China, the U.S. and Europe from 2019 to 2022 inferred from TROPOMI observations

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Product

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Anthropogenic NO _x emissions of China, the U.S. and Europe from 2019 to 2022 inferred from TROPOMI observations