Intercontinental transport and deposition patterns of atmospheric mercury from anthropogenic emissions

Abstract. Global policies that regulate anthropogenic mercury emissions to the environment require quantitative and comprehensive source–receptor relationships for mercury emissions, transport and deposition among major continental regions. In this study, we use the GEOS-Chem model to establish source–receptor relationships among eleven major continental regions worldwide. Source–receptor relationships for surface mercury concentrations (SMC) show that some regions (e.g. East Asia, the Indian subcontinent and Europe) should be responsible for their local surface Hg(II) and Hg(P) concentrations because of near-field transport and deposition contributions from their local anthropogenic emissions (up to 64% and 71% for Hg(II) and Hg(P), respectively, over East Asia). We define region of primary influence (RPI) and region of secondary influence (RSI) to establish intercontinental influence patterns. Results indicate that East Asia is SMC RPI for almost all other regions, while Europe, Russia and the Indian subcontinent also make some contributions to SMC over some receptor regions because they are dominant RSI source regions. Source–receptor relationships for mercury deposition show that approximately 16% and 17% of dry and wet deposition, respectively, over North America originate from East Asia, indicating that trans-pacific transport of East Asian emissions is the major foreign source of mercury deposition in North America. Europe, Southeast Asia and the Indian subcontinent are also important mercury deposition sources for some receptor regions because they are dominant RSI. We also quantify seasonal variation on mercury deposition contributions over other regions from East Asia. Results show that mercury deposition (including dry and wet) contributions from East Asia over the Northern Hemisphere receptor regions (e.g. North America, Europe, Russia, Middle East and Middle Asia) vary seasonally, with the maximum values in summer and minimum values in winter. The opposite seasonal pattern occurs on mercury dry deposition contributions over Southeast Asia and the Indian subcontinent.

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Intercontinental transport and deposition patterns of atmospheric mercury from anthropogenic emissions

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-10163-2014 ◽

2014 ◽

Vol 14 (18) ◽

pp. 10163-10176 ◽

Cited By ~ 26

Author(s):

L. Chen ◽

H. H. Wang ◽

J. F. Liu ◽

Y. D. Tong ◽

L. B. Ou ◽

...

Keyword(s):

North America ◽

Southeast Asia ◽

East Asia ◽

Transport Model ◽

Indian Subcontinent ◽

Atmospheric Mercury ◽

Anthropogenic Emissions ◽

Mercury Deposition ◽

Mercury Emissions ◽

Source Receptor Relationships

Abstract. Global policies that regulate anthropogenic mercury emissions to the environment require quantitative and comprehensive source–receptor relationships for mercury emissions, transport and deposition among major continental regions. In this study, we use the GEOS-Chem global chemical transport model to establish source–receptor relationships among 11 major continental regions worldwide. Source–receptor relationships for surface mercury concentrations (SMC) show that some regions (e.g., East Asia, the Indian subcontinent, and Europe) should be responsible for their local surface Hg(II) and Hg(P) concentrations due to near-field transport and deposition contributions from their local anthropogenic emissions (up to 64 and 71% for Hg(II) and Hg(P), respectively, over East Asia). We define the region of primary influence (RPI) and the region of secondary influence (RSI) to establish intercontinental influence patterns. Results indicate that East Asia is the SMC RPI for almost all other regions, while Europe, Russia, and the Indian subcontinent also make some contributions to SMC over some receptor regions because they are dominant RSI source regions. Source–receptor relationships for mercury deposition show that approximately 16 and 17% of dry and wet deposition, respectively, over North America originate from East Asia, indicating that transpacific transport of East Asian emissions is the major foreign source of mercury deposition in North America. Europe, Southeast Asia, and the Indian subcontinent are also important mercury deposition sources for some receptor regions because they are the dominant RSIs. We also quantify seasonal variation on mercury deposition contributions over other regions from East Asia. Results show that mercury deposition (including dry and wet) contributions from East Asia over the Northern Hemisphere receptor regions (e.g., North America, Europe, Russia, the Middle East, and Middle Asia) vary seasonally, with the maximum values in summer and minimum values in winter. The opposite seasonal pattern occurs on mercury dry deposition contributions over Southeast Asia and the Indian subcontinent.

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Estimating mercury emission outflow from East Asia using CMAQ-Hg

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-21285-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 21285-21315

Author(s):

C.-J. Lin ◽

L. Pan ◽

D. G. Streets ◽

S. K. Shetty ◽

C. Jang ◽

...

Keyword(s):

North America ◽

East Asia ◽

East Asian ◽

Source Region ◽

Atmospheric Mercury ◽

Mercury Deposition ◽

Mercury Emission ◽

Mercury Emissions ◽

Mercury Transport ◽

Balance Analysis

Abstract. East Asia contributes nearly 50% of the global anthropogenic mercury emissions into the atmosphere. Recently, there are concerns for the long-range transport of mercury from East Asia to North America, which may lead to enhanced dry and wet depositions in North America. In this study, we performed four monthly simulations (January, April, July and October in 2005) using CMAQ-Hg v4.6 in an East Asian model domain. Coupled with a mass balance analysis and a number of emission inventory scenarios, the chemical transport of atmospheric mercury, the seasonal mercury transport budgets and mercury emission outflow from the East Asian region were investigated. The total annual mercury deposition in the region for the modeling year is estimated to be 821 Mg, with 396 Mg contributed by wet deposition and 425 Mg contributed by dry deposition. Regional mercury transport budgets show strong seasonal variability, with a net removal of RGM (7~5 Mg mo−1) and PHg (13~21 Mg mo−1), and a net export of GEM (60~130 Mg mo−1) from the study domain. The annual outflow caused by the East Asian emission is estimated to be in the range of 1369~1671 Mg yr−1, primarily in the form of GEM. This represents about 75% of the total mercury emissions (anthropogenic and natural) in the region. The emission outflow from this source region would contribute to 20~30% of mercury deposition in areas remote from anthropogenic emission sources.

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GNAQPMS-Hg v1.0, a global nested atmospheric mercury transport model: model description, evaluation and application to trans-boundary transport of Chinese anthropogenic emissions

Geoscientific Model Development ◽

10.5194/gmd-8-2857-2015 ◽

2015 ◽

Vol 8 (9) ◽

pp. 2857-2876 ◽

Cited By ~ 8

Author(s):

H. S. Chen ◽

Z. F. Wang ◽

J. Li ◽

X. Tang ◽

B. Z. Ge ◽

...

Keyword(s):

North America ◽

East Asia ◽

Aqueous Phase ◽

Wet Deposition ◽

Transport Model ◽

Atmospheric Mercury ◽

Model Description ◽

Anthropogenic Emissions ◽

Comparison Results ◽

Western Asia

Abstract. Atmospheric mercury (Hg) is a toxic pollutant and can be transported over the whole globe due to its long lifetime in the atmosphere. For the purpose of assessing Hg hemispheric transport and better characterizing regional Hg pollution, a global nested atmospheric Hg transport model (GNAQPMS-Hg – Global Nested Air Quality Prediction Modeling System for Hg) has been developed. In GNAQPMS-Hg, the gas- and aqueous-phase Hg chemistry representing the transformation among three forms of Hg: elemental mercury (Hg(0)), divalent mercury (Hg(II)), and primary particulate mercury (Hg(P)) are calculated. A detailed description of the model, including mercury emissions, gas- and aqueous-phase chemistry, and dry and wet deposition is given in this study. Worldwide observations including extensive data in China have been collected for model evaluation. Comparison results show that the model reasonably simulates the global mercury budget and the spatiotemporal variation of surface mercury concentrations and deposition. Overall, model predictions of annual total gaseous mercury (TGM) and wet deposition agree with observations within a factor of 2, and within a factor of 5 for oxidized mercury and dry deposition. The model performs significantly better in North America and Europe than in East Asia. This can probably be attributed to the large uncertainties in emission inventories, coarse model resolution and to the inconsistency between the simulation and observation periods in East Asia. Compared to the global simulation, the nested simulation shows improved skill at capturing the high spatial variability of surface Hg concentrations and deposition over East Asia. In particular, the root mean square error (RMSE) of simulated Hg wet deposition over East Asia is reduced by 24 % in the nested simulation. Model sensitivity studies indicate that Chinese primary anthropogenic emissions account for 30 and 62 % of surface mercury concentrations and deposition over China, respectively. Along the rim of the western Pacific, the contributions from Chinese sources are 11 and 15.2 % over the Korean Peninsula, 10.4 and 8.2 % over Southeast Asia, and 5.7 and 5.9 % over Japan. But for North America, Europe and western Asia, the contributions from China are all below 5 %.

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GNAQPMS-Hg v1.0, a global nested atmospheric mercury transport model: model description, evaluation and application to trans-boundary transport of Chinese anthropogenic emissions

Geoscientific Model Development Discussions ◽

10.5194/gmdd-7-6949-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 6949-6996

Author(s):

H. S. Chen ◽

Z. F. Wang ◽

J. Li ◽

X. Tang ◽

B. Z. Ge ◽

...

Keyword(s):

North America ◽

East Asia ◽

Aqueous Phase ◽

Wet Deposition ◽

Transport Model ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Model Description ◽

Anthropogenic Emissions ◽

Comparison Results

Abstract. Atmospheric mercury (Hg) is a toxic pollutant and can be transported over the whole globe due to its long lifetime in the atmosphere. For the purpose of assessing Hg hemispheric transport and better characterizing regional Hg pollution, a global nested atmospheric Hg transport model (GNAQPMS-Hg) has been developed. In GNAQPMS-Hg, the gas and aqueous phase Hg chemistry representing the transformation among three forms of Hg: elemental mercury (Hg(0)), divalent mercury (Hg(II)), and primary particulate mercury (Hg(P)) are calculated. A detailed description of the model, including mercury emissions, gas and aqueous phase chemistry, and dry and wet deposition is given in this study. Worldwide observations including extensive data in China have been collected for model evaluation. Comparison results show that the model reasonably simulates the global mercury budget and the spatial–temporal variation of surface mercury concentrations and deposition. Overall, model predictions of annual total gaseous mercury (TGM) and wet deposition agree with observations within a factor of two, and within a factor of five for oxidized mercury and dry deposition. The model performs significantly better in North America and Europe than in East Asia. This can probably be attributed to the large uncertainties in emission inventories, coarse model resolution and to the inconsistency between the simulation and observation periods in East Asia. Compared to the global simulation, the nested simulation shows improved skill at capturing the high spatial variability of Hg concentrations and deposition over East Asia. In particular, the root mean square error (RMSE) of simulated Hg wet deposition over East Asia is reduced by 24% in the nested simulation. Model sensitivity studies indicate that Chinese primary anthropogenic emissions account for 30 and 62% of surface mercury concentrations and deposition over China, respectively. Along the rim of the western Pacific, the contributions from Chinese sources are 11 and 15.2% over the Korean Peninsula, 10.4 and 8.2% over Southeast Asia, and 5.7 and 5.9% over Japan. But for North America, Europe and West Asia, the contributions from China are all below 5%.

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Gaseous mercury in coastal urban areas

Environmental Chemistry ◽

10.1071/en10088 ◽

2010 ◽

Vol 7 (6) ◽

pp. 537 ◽

Cited By ~ 3

Author(s):

Anne L. Soerensen ◽

Henrik Skov ◽

Matthew S. Johnson ◽

Marianne Glasius

Keyword(s):

Urban Areas ◽

Marine Boundary Layer ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Mercury Deposition ◽

Mercury Emissions ◽

Gaseous Elemental Mercury ◽

Gaseous Mercury ◽

Range Transport ◽

Aquatic Food

Environmental context Mercury is a neurotoxin that bioaccumulates in the aquatic food web. Atmospheric emissions from urban areas close to the coast could cause increased local mercury deposition to the ocean. Our study adds important new data to the current limited knowledge on atmospheric mercury emissions and dynamics in coastal urban areas. Abstract Approximately 50% of primary atmospheric mercury emissions are anthropogenic, resulting from e.g. emission hotspots in urban areas. Emissions from urban areas close to the coast are of interest because they could increase deposition loads to nearby coastal waters as well as contribute to long range transport of mercury. We present results from measurements of gaseous elemental mercury (GEM) and reactive gaseous mercury (RGM) in 15 coastal cities and their surrounding marine boundary layer (MBL). An increase of 15–90% in GEM concentration in coastal urban areas was observed compared with the remote MBL. Strong RGM enhancements were only found in two cities. In urban areas with statistically significant GEM/CO enhancement ratios, slopes between 0.0020 and 0.0087 ng m–3 ppb–1 were observed, which is consistent with other observations of anthropogenic enhancement. The emission ratios were used to estimate GEM emissions from the areas. A closer examination of data from Sydney (Australia), the coast of Chile, and Valparaiso region (Chile) in the southern hemisphere, is presented.

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Evaluation of global EMEP MSC-W (rv4.34) WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements

Geoscientific Model Development ◽

10.5194/gmd-14-7021-2021 ◽

2021 ◽

Vol 14 (11) ◽

pp. 7021-7046

Author(s):

Yao Ge ◽

Mathew R. Heal ◽

David S. Stevenson ◽

Peter Wind ◽

Massimo Vieno

Keyword(s):

North America ◽

Southeast Asia ◽

East Asia ◽

Atmospheric Chemistry ◽

Wet Deposition ◽

Global Analysis ◽

Monitoring Networks ◽

Model Framework ◽

Annual Total ◽

Model Measurement

Abstract. Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (Nr) species, especially of reduced N (gaseous NH3, particulate NH4+). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of Nr chemistry and its potential mitigation. Here we undertake the first evaluation of the global version of the EMEP MSC-W ACTM driven by WRF meteorology (1∘×1∘ resolution), with a focus on surface concentrations and wet deposition of N and S species relevant to investigation of atmospheric Nr and secondary inorganic aerosol (SIA). The model–measurement comparison is conducted both spatially and temporally, covering 10 monitoring networks worldwide. Model simulations for 2010 compared use of both HTAP and ECLIPSEE (ECLIPSE annual total with EDGAR monthly profile) emissions inventories; those for 2015 used ECLIPSEE only. Simulations of primary pollutants are somewhat sensitive to the choice of inventory in places where regional differences in primary emissions between the two inventories are apparent (e.g. China) but are much less sensitive for secondary components. For example, the difference in modelled global annual mean surface NH3 concentration using the two 2010 inventories is 18 % (HTAP: 0.26 µg m−3; ECLIPSEE: 0.31 µg m−3) but is only 3.5 % for NH4+ (HTAP: 0.316 µg m−3; ECLIPSEE: 0.305 µg m−3). Comparisons of 2010 and 2015 surface concentrations between the model and measurements demonstrate that the model captures the overall spatial and seasonal variations well for the major inorganic pollutants NH3, NO2, SO2, HNO3, NH4+, NO3-, and SO42- and their wet deposition in East Asia, Southeast Asia, Europe, and North America. The model shows better correlations with annual average measurements for networks in Southeast Asia (mean R for seven species: R7‾=0.73), Europe (R7‾=0.67), and North America (R7‾=0.63) than in East Asia (R5‾=0.35) (data for 2015), which suggests potential issues with the measurements in the latter network. Temporally, both model and measurements agree on higher NH3 concentrations in spring and summer and lower concentrations in winter. The model slightly underestimates annual total precipitation measurements (by 13 %–45 %) but agrees well with the spatial variations in precipitation in all four world regions (0.65–0.94 R range). High correlations between measured and modelled NH4+ precipitation concentrations are also observed in all regions except East Asia. For annual total wet deposition of reduced N, the greatest consistency is in North America (0.75–0.82 R range), followed by Southeast Asia (R=0.68) and Europe (R=0.61). Model–measurement bias varies between species in different networks; for example, bias for NH4+ and NO3- is largest in Europe and North America and smallest in East Asia and Southeast Asia. The greater uniformity in spatial correlations than in biases suggests that the major driver of model–measurement discrepancies (aside from differing spatial representativeness and uncertainties and biases in measurements) are shortcomings in absolute emissions rather than in modelling the atmospheric processes. The comprehensive evaluations presented in this study support the application of this model framework for global analysis of current and potential future budgets and deposition of Nr and SIA.

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Why very good in India might be pretty good in North America

International Journal of Corpus Linguistics ◽

10.1075/ijcl.17063.wag ◽

2019 ◽

Vol 24 (4) ◽

pp. 445-489

Author(s):

Susanne Wagner

Keyword(s):

North America ◽

Southeast Asia ◽

North American ◽

Corpus Linguistics ◽

Indian Subcontinent ◽

World Englishes ◽

Web Based ◽

Variationist Sociolinguistics ◽

The Future ◽

Trajectories Of Change

Abstract Situated at the interface of several sub-disciplines (corpus linguistics, World Englishes, variationist sociolinguistics), this study investigates patterns of adjectival amplification (very good, so glad, pretty cool) in the Corpus of Global Web-Based English (GloWbE). It highlights regional distributions/preferences of amplifier-adjective 2-grams and the idiosyncratic status of certain bigrams according to their frequency status. Globally, clear regional preferences in amplification patterns as well as possible trends concerning change are identified. Regionally, L1 varieties contrast starkly with some regions (Africa, Indian subcontinent) but – maybe unexpectedly – not with others (Southeast Asia). The results offer insights into current trajectories of change concerning the investigated amplifiers in certain regions and 2-grams: North American varieties are leading a trend away from very towards so and possibly pretty in the future.

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Evaluation of global EMEP MSC-W (rv4.34)-WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements

10.5194/gmd-2021-166 ◽

2021 ◽

Author(s):

Yao Ge ◽

Mathew R. Heal ◽

David S. Stevenson ◽

Peter Wind ◽

Massimo Vieno

Keyword(s):

North America ◽

Southeast Asia ◽

East Asia ◽

Atmospheric Chemistry ◽

Wet Deposition ◽

Global Analysis ◽

Monitoring Networks ◽

Model Framework ◽

Annual Total ◽

Model Measurement

Abstract. Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (Nr) species, especially of reduced N (gaseous NH3, particulate NH4+). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of Nr chemistry and its potential mitigation. Here we undertake the first evaluation of the global version of the EMEP MSC-W ACTM driven by WRF meteorology (1° × 1° resolution), with a focus on surface concentrations and wet deposition of N and S species relevant to investigation of atmospheric Nr and secondary inorganic aerosol (SIA). The model-measurement comparison is conducted both spatially and temporally, covering 9 monitoring networks worldwide. Model simulations for 2010 compared use of both HTAP and ECLIPSEE (ECLIPSE annual total with EDGAR monthly profile) emissions inventories; those for 2015 used ECLIPSEE only. Simulations of primary pollutants are somewhat sensitive to the choice of inventory in places where regional differences in primary emissions between the two inventories are apparent (e.g. China), but much less so for secondary components. For example, the difference in modelled global annual mean surface NH3 concentration using the two 2010 inventories is 18 % (HTAP: 0.26 μg m−3; ECLIPSEE: 0.31 μg m−3) but only 3.5 % for NH4+ (HTAP: 0.316 μg m−3; ECLIPSEE: 0.305 μg m−3). Comparisons of 2010 and 2015 surface concentrations between model and measurement demonstrate that the model captures well the overall spatial and seasonal variations of the major inorganic pollutants NH3, NO2, SO2, HNO3, NH4+, NO3−, SO42−, and their wet deposition in East Asia, Southeast Asia, Europe and North America. The model shows better correlations with annual average measurements for networks in Southeast Asia (Mean R for 7 species: = 0.73), Europe ( = 0.67) and North America ( = 0.63) than in East Asia ( = 0.35) (data for 2015), which suggests potential issues with the measurements in the latter network. Temporally, both model and measurement agree on higher NH3 concentrations in spring and summer, and lower concentrations in winter. The model slightly underestimates annual total precipitation measurements (by 13–34 %) but agrees well with the spatial variations in precipitation in all four world regions (0.65–0.78 R range). High correlations between measured and modelled NH4+ precipitation concentrations are also observed in all regions except East Asia. For annual total wet deposition of reduced N, the greatest consistency is in North America (R = 0.75), followed by Southeast Asia (R = 0.68) and Europe (R = 0.61). Model-measurement bias varies between species in different networks; for example, bias for NH4+ and NO3− is most in Europe and North America and least in East and Southeast Asia. The greater uniformity in spatial correlations than in biases suggests that the major driver of model-measurement discrepancies (aside from differing spatial representativeness and uncertainties and biases in measurements) are shortcomings in absolute emissions rather than in modelling the atmospheric processes. The comprehensive evaluations presented in this study support the application of this model framework for global analysis of current and potential future budgets and deposition of Nr and SIA.

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