Hybrid Mass Balance/4D‐Var Joint Inversion of NOx and SO2 Emissions in East Asia

Qu, Zhen; Henze, D. K.; Theys, Nicolas; Wang, Jun; Wang, Wei

doi:10.1029/2018jd030240

Cited by 36 publications

(29 citation statements)

References 104 publications

(179 reference statements)

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“…These are related to the distribution of SO 2 sources over too few point sources in bottom-up inventories (Liu et al, 2018), lower SO 2 column densities in OMI retrievals compared to simulations, and small sources that are not detectable in OMI retrievals when the signal is comparable to the noise. The constraints from the prior emissions in the mass balance method (more details in Qu et al (2017) and Qu et al (2019) further limit the posterior emissions from deviating too much beyond the prior emissions, which were for 2010.…”

Section: Discussionmentioning

confidence: 99%

“…The global mean OH concentration in GEOS-Chem ranges from 10 × 10 15 to 13 × 10 15 molec/cm 3 from version 8 to version 12 (http://wiki.seas.harvard.edu/geos-chem/index.php/Mean_OH_concentration). Our subsequent study incorporates multiple species observations to synergistically change O 3 and OH concentration, and thus provide more accurate constraints on SO 2 emission estimates (Qu et al, 2019).…”

Section: 1029/2019jd030243mentioning

confidence: 99%

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SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

Henze

et al. 2019

JGR Atmospheres

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SO2 column densities from Ozone Monitoring Instrument provide important information on emission trends and missing sources, but there are discrepancies between different retrieval products. We employ three Ozone Monitoring Instrument SO2 retrieval products (National Aeronautics and Space Administration (NASA) standard (SP), NASA prototype, and BIRA) to study the magnitude and trend of SO2 emissions. SO2 column densities from these retrievals are most consistent when viewing angles and solar zenith angles are small, suggesting more robust emission estimates in summer and at low latitudes. We then apply a hybrid 4D‐Var/mass balance emission inversion to derive monthly SO2 emissions from the NASA SP and BIRA products. Compared to HTAPv2 emissions in 2010, both posterior emission estimates are lower in United States, India, and Southeast China, but show different changes of emissions in North China Plain. The discrepancies between monthly NASA and BIRA posterior emissions in 2010 are less than or equal to 17% in China and 34% in India. SO2 emissions increase from 2005 to 2016 by 35% (NASA)–48% (BIRA) in India, but decrease in China by 23% (NASA)–33% (BIRA) since 2008. Compared to in situ measurements, the posterior GEOS‐Chem surface SO2 concentrations have reduced NMB in China, the United States, and India but not in South Korea in 2010. BIRA posteriors have better consistency with the annual growth rate of surface SO2 measurement in China and spatial variability of SO2 concentration in China, South Korea, and India, whereas NASA SP posteriors have better seasonality. These evaluations demonstrate the capability to recover SO2 emissions using Ozone Monitoring Instrument observations.

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Section: Discussionmentioning

confidence: 99%

Section: 1029/2019jd030243mentioning

confidence: 99%

SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

Henze

et al. 2019

JGR Atmospheres

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“…Our study here using OMPS thus touches an important issue, which is whether or not there would be any artificial trends in our climate data record of atmospheric SO2 and NO2 due to the transition of satellite sensors. Our study is also different from past studies (Wang et al, 2016;Qu et al, 2017;Qu et al, 2019a;Qu et al, 2019b) that have applied the 4D-Var technique to OMI data with the GEOS-Chem adjoint model, but did not include evaluation with independent satellite data. Qu et al (2019b) showed joint inversion using OMI SO2 and NO2 benefits from simultaneous adjustment of OH and O3 concentrations, which supports assimilating OMPS SO2 and NO2 observations simultaneously in this study.…”

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confidence: 72%

Inverse modeling of SO2 and NOx emissions over China using multi-sensor satellite data: 1. formulation and sensitivity analysis

Wang¹,

Wang²,

Xu³

et al. 2019

Preprint

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Abstract. SO2 and NO2 observations from the Ozone Mapping and Profiler Suite (OMPS) sensor are used for the first time in conjunction with GEOS-Chem adjoint model to optimize both SO2 and NOx emission estimates over China for October 2013. OMPS SO2 and NO2 observations are first assimilated separately to optimize emissions of SO2 and NOx, respectively. Posterior emissions, compared to the prior, yield improvements in simulating columnar SO2 and NO2, in comparison to measurements from OMI and OMPS. The posterior SO2 and NOx emissions from separate inversions are 748 Gg S and 672 Gg N, which are 36 % and 6 % smaller than prior MIX emissions, respectively. In spite of the large reduction of SO2 emissions over the North China Plain, the simulated sulfate-nitrate-ammonium Aerosol Optical Depth (AOD) only decrease slightly, which can be attributed to (a) nitrate rather than sulfate as the dominant contributor to AOD and (b) replacement of ammonium sulfate with ammonium nitrate as SO2 emissions are reduced. Both data quality control and the weight given to SO2 relative to NO2 observations can affect the spatial distributions of the joint inversion results. When the latter is properly balanced, the posterior emissions from assimilating OMPS SO2 and NO2 jointly yield a difference of −3 % to 15 % with respect to the separate assimilations for total anthropogenic SO2 emissions and ± 2 % for total anthropogenic NOx emissions; but the differences can be up to 100 % for SO2 and 40 % for NO2 in some grid cells. Improvements on SO2 and NO2 simulations evaluated with OMPS and OMI measurements from the joint inversions are overall consistent with those from separate inversions. Moreover, the joint assimilations save ~ 50 % of the computational time than assimilating SO2 and NO2 separately when computational resources are limited to run one inversion at a time sequentially. The sensitivity analysis shows that a perturbation of NH3 to 50 % (20 %) of the prior emission inventory: (a) has negligible impact on the separate SO2 inversion, but can lead to decrease of posterior SO2 emissions over China by −2.4 % (−7.0 %) in total and up to −9.0 % (−27.7 %) in some grid cells in the joint inversion with NO2; (b) yield posterior NOx emissions over China decrease by −0.7 % (−2.8 %) for the separate NO2 inversion and by −2.7 % (−5.3 %) in total and up to −15.2 % (−29.4 %) in some grid cells for the joint inversion. The large reduction of SO2 between 2010 and 2013, however, only leads to ~ 10 % decrease of aerosol optical depth regionally; reducing surface aerosol concentration requires the reduction of emissions of NH3 as well.

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“…For example, satellite nitrogen dioxide (NO 2 ) columns have been used to constrain urban and shipping emissions of nitrogen oxides (NO x ; e.g., Huang et al, 2014;Vinken et al, 2014;Lu et al, 2015;Ding et al, 2018;Goldberg et al, 2019), namely, NO 2 and nitric oxide (NO), which are important contributors to secondary aerosol production in East Asian populated regions during warm seasons (e.g., Dong et al, 2014;Ge et al, 2013). However, satellite-observation-constrained emission estimates may be associated with variable levels of uncertainty depending on the emission inverse modeling approaches and the characteristics of the integrated satellite observations (e.g., Ding et al, 2017;Huang et al, 2014;Qu et al, 2019). It is therefore necessary to carefully evaluate the available satellite-observation-derived emissions, as well as their impacts on atmospheric conditions and atmosphere-biosphere interactions, for example, using stateof-the-art models and high-accuracy observations.…”

Section: Introductionmentioning

confidence: 99%

Impact of Aerosols From Urban and Shipping Emission Sources on Terrestrial Carbon Uptake and Evapotranspiration: A Case Study in East Asia

et al. 2020

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This study quantifies the immediate influences of aerosols from urban anthropogenic and shipping emission sources on carbon and water fluxes in East Asia on a cloudy day in spring 2016 when strong regional pollution transport occurred and intensive field campaign measurements are available. Within National Aeronautics and Space Administration (NASA)'s Land Information System (LIS), a long‐term offline Noah‐multiparameterization (MP) simulation with dynamic vegetation is performed. Modeled soil moisture and leaf area index are evaluated with satellite observations to ensure that land surface conditions are moderately well reproduced. The LIS output is then used to initialize several coupled NASA‐Unified Weather Research and Forecasting model simulations with online chemistry in which urban anthropogenic and shipping emissions are (1) largely based on the Hemispheric Transport of Air Pollution Phase 2 inventory for 2010, (2) reduced by 20% and 50% for all chemical species, and (3) adjusted only for nitrogen oxides (NOx) using satellite observations. Overall, modeled gross primary productivity and evapotranspiration almost linearly increase with the all‐species emission reductions, but their responses to emission‐induced aerosol optical depth (AOD) changes show strong spatial variability resulting from combined radiation and temperature impacts. Using satellite‐observation‐constrained NOx emissions, modeled nitrogen species and AOD better match various measurements at some locations/times. All‐species and NOx‐only emission adjustments lead to different gross primary productivity and evapotranspiration changes with AOD, especially over South Korea. This study demonstrates the importance of accurately quantifying emission impacts on atmosphere‐biosphere interactions. Improving more species' emission inputs for Earth system models, including applying effective chemical data assimilation methods, is strongly encouraged.

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Hybrid Mass Balance/4D‐Var Joint Inversion of NO_x and SO₂ Emissions in East Asia

Cited by 36 publications

References 104 publications

SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

Inverse modeling of SO<sub>2</sub> and NO<sub><i>x</i></sub> emissions over China using multi-sensor satellite data: 1. formulation and sensitivity analysis

Impact of Aerosols From Urban and Shipping Emission Sources on Terrestrial Carbon Uptake and Evapotranspiration: A Case Study in East Asia

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Hybrid Mass Balance/4D‐Var Joint Inversion of NOx and SO2 Emissions in East Asia

Cited by 36 publications

References 104 publications

SO2 Emission Estimates Using OMI SO2 Retrievals for 2005–2017

SO2 Emission Estimates Using OMI SO2 Retrievals for 2005–2017

Inverse modeling of SO&lt;sub&gt;2&lt;/sub&gt; and NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; emissions over China using multi-sensor satellite data: 1. formulation and sensitivity analysis

Impact of Aerosols From Urban and Shipping Emission Sources on Terrestrial Carbon Uptake and Evapotranspiration: A Case Study in East Asia

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Product

Resources

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Hybrid Mass Balance/4D‐Var Joint Inversion of NO_x and SO₂ Emissions in East Asia

SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

SO₂ Emission Estimates Using OMI SO₂ Retrievals for 2005–2017

Inverse modeling of SO<sub>2</sub> and NO<sub><i>x</i></sub> emissions over China using multi-sensor satellite data: 1. formulation and sensitivity analysis