Articles | Volume 19, issue 15
Research article 12 Aug 2019
Research article | 12 Aug 2019
Speciated atmospheric mercury and sea–air exchange of gaseous mercury in the South China Sea
Chunjie Wang et al.
No articles found.
Jun Zhou, Zhangwei Wang, Xiaoshan Zhang, Charles T. Driscoll, and Che-Jen Lin
Atmos. Chem. Phys., 20, 16117–16133,Short summary
Mercury (Hg) emissions from natural resources have a large uncertainty, which is mainly derived from the forest. A long-term and multiplot (10) study of soil–air fluxes at subtropical and temperate forests was conducted. Forest soils are an important atmospheric Hg source, especially for subtropical forests. The compensation points imply that the atmospheric Hg concentration plays a critical role in inhibiting Hg emissions from the forest floor. Climate change can enhance soil Hg emissions.
Jun Zhou, Zhangwei Wang, Xiaoshan Zhang, Charles Driscoll, and Che-Jen Lin
Atmos. Chem. Phys. Discuss.,
Preprint withdrawnShort summary
Previous studies showed that Hg emissions from the natural resource exists large uncertainty, which was mainly derived from the forest with a large uncertainty range. Long-term and multi-plot (five) study of soil-air fluxes and the vertical distribution of Hg in a subtropical forest were conducted to reduce the uncertainty. Additionally, The Hg diffusion coefficients (Ds) between soil and atmosphere was investigated, which should provide a foundation for future model development.
Jun Zhou, Buyun Du, Zhangwei Wang, Lihai Shang, and Jing Zhou
Atmos. Chem. Phys. Discuss.,
Preprint withdrawnShort summary
The current knowledge concerning mercury budgets and pools of forest in China is reviewed, including THg and MeHg input fluxes by precipitation, throughfall and litterfall, output by runoffs and soil-atmosphere exchange fluxes, Hg storage in soils and biomass, and their risk assessment. The annual THg retentions at forests of China are about 1.2 to 7.9-fold higher compared to those in North America, and THg retention in forest is much high than that in global scale estimated by models.
Longfei Yu, Yihao Wang, Xiaoshan Zhang, Peter Dörsch, and Jan Mulder
Biogeosciences, 14, 3097–3109,Short summary
In this study, we applied phosphorus (P) to a nitrogen (N)-saturated forest in the Chinese subtropics and observed significant decreases in both N2O and CH4 emission from soil within 1.5 years. This was associated with a strong decrease of mineral N in soil water, likely due to stimulated N uptake. Our findings suggest that P limitation could be one important reason for large greenhouse gas emissions reported in the subtropical forests receiving excessive N input.
Zhijia Ci, Fei Peng, Xian Xue, and Xiaoshan Zhang
Atmos. Chem. Phys., 16, 14741–14754,Short summary
We performed field measurements and controlled field experiments to examine the flux, temporal variation and influencing factors of air–surface Hg(0) exchange at a high-altitude and remote site in the central Qinghai–Tibet Plateau. We found that the environmental conditions greatly influenced the air–surface Hg dynamics. Our results have important implications for the Hg biogeochemical cycle in the soils of Qinghai–Tibet Plateau under rapid climate warming and environmental change.
Z. W. Wang, J. C. Gallet, C. A. Pedersen, X. S. Zhang, J. Ström, and Z. J. Ci
Atmos. Chem. Phys., 14, 629–640,
Related subject area
Subject: Gases | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Measurement report: Characterization of uncertainties in fluxes and fuel sulfur content from ship emissions in the Baltic SeaLimitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions – a case study for methane in HeidelbergPositive and negative influences of typhoons on tropospheric ozone over southern ChinaDeclines and peaks in NO2 pollution during the multiple waves of the COVID-19 pandemic in the New York metropolitan areaSpatial and temporal variations of CO2 mole fractions observed at Beijing, Xianghe, and Xinglong in North ChinaThe CO2 integral emission by the megacity of St Petersburg as quantified from ground-based FTIR measurements combined with dispersion modellingAnthropogenic and natural controls on atmospheric δ13C-CO2 variations in the Yangtze River delta: insights from a carbon isotope modeling frameworkQuantifying variability, source, and transport of CO in the urban areas over the Himalayas and Tibetan PlateauNew methodology shows short atmospheric lifetimes of oxidized sulfur and nitrogen due to dry depositionUncertainties in eddy covariance air–sea CO2 flux measurements and implications for gas transfer velocity parameterisationsConvergent evidence for the pervasive but limited contribution of biomass burning to atmospheric ammonia in peninsular Southeast AsiaConcurrent variation in oil and gas methane emissions and oil price during the COVID-19 pandemicOzone variability induced by synoptic weather patterns in warm seasons of 2014–2018 over the Yangtze River Delta region, ChinaSeasonal patterns of atmospheric mercury in tropical South America as inferred by a continuous total gaseous mercury record at Chacaltaya station (5240 m) in BoliviaA mass-weighted isentropic coordinate for mapping chemical tracers and computing atmospheric inventoriesMethane mapping, emission quantification, and attribution in two European cities: Utrecht (NL) and Hamburg (DE)Ozone affected by a succession of four landfall typhoons in the Yangtze River Delta, China: major processes and health impacts4D dispersion of total gaseous mercury derived from a mining source: identification of criteria to assess risks related to high concentrations of atmospheric mercuryEstimating CH4, CO2 and CO emissions from coal mining and industrial activities in the Upper Silesian Coal Basin using an aircraft-based mass balance approachProfiling of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon: normalized excess mixing ratios and related emission factors in biomass burning plumesMeasurement report: Leaf-scale gas exchange of atmospheric reactive trace species (NO2, NO, O3) at a northern hardwood forest in MichiganA dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO2 and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modellingThe increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)Understanding nighttime methane signals at the Amazon Tall Tower Observatory (ATTO)Background heterogeneity and other uncertainties in estimating urban methane flux: results from the Indianapolis Flux Experiment (INFLUX)Methane emissions from the Munich OktoberfestA study of the influence of tropospheric subsidence on spring and summer surface ozone concentrations at the JRC Ispra station in northern ItalyLocal and synoptic meteorological influences on daily variability in summertime surface ozone in eastern ChinaVariability in a four-network composite of atmospheric CO2 differences between three primary baseline sitesQuantifying the impact of synoptic circulation patterns on ozone variability in northern China from April to October 2013–2017Multivariate statistical air mass classification for the high-alpine observatory at the Zugspitze Mountain, GermanyEvolution of anthropogenic air pollutant emissions in Guangdong Province, China, from 2006 to 2015Methane emissions from oil and gas platforms in the North SeaAssessing London CO2, CH4 and CO emissions using aircraft measurements and dispersion modelling2005–2017 ozone trends and potential benefits of local measures as deduced from air quality measurements in the north of the Barcelona metropolitan areaCountry-scale greenhouse gas budgets using shipborne measurements: a case study for the UK and IrelandIntercomparison of midlatitude tropospheric and lower-stratospheric water vapor measurements and comparison to ECMWF humidity dataEddy flux measurements of sulfur dioxide deposition to the sea surfaceQuantifying uncertainties from mobile-laboratory-derived emissions of well pads using inverse Gaussian methodsObserving local CO2 sources using low-cost, near-surface urban monitorsSpatiotemporal variability of NO2 and PM2.5 over Eastern China: observational and model analyses with a novel statistical methodSpatial–temporal patterns of inorganic nitrogen air concentrations and deposition in eastern ChinaPhenomenology of summer ozone episodes over the Madrid Metropolitan Area, central SpainShip-based MAX-DOAS measurements of tropospheric NO2, SO2, and HCHO distribution along the Yangtze RiverGradient flux measurements of sea–air DMS transfer during the Surface Ocean Aerosol Production (SOAP) experimentMeasurements of atmospheric ethene by solar absorption FTIR spectrometryOzone pollution around a coastal region of South China Sea: interaction between marine and continental airAbundance and sources of atmospheric halocarbons in the Eastern MediterraneanDiurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity areaAtmospheric carbonyl sulfide (OCS) measured remotely by FTIR solar absorption spectrometry
Jari Walden, Liisa Pirjola, Tuomas Laurila, Juha Hatakka, Heidi Pettersson, Tuomas Walden, Jukka-Pekka Jalkanen, Harri Nordlund, Toivo Truuts, Miika Meretoja, and Kimmo K. Kahma
Atmos. Chem. Phys., 21, 18175–18194,Short summary
Ship emissions play an important role in the deposition of gaseous compounds and nanoparticles (Ntot), affecting climate, human health (especially in coastal areas), and eutrophication. Micrometeorological methods showed that ship emissions were mainly responsible for the deposition of Ntot, whereas they only accounted for a minor proportion of CO2 deposition. An uncertainty analysis applied to the fluxes and fuel sulfur content results demonstrated the reliability of the results.
Ingeborg Levin, Ute Karstens, Samuel Hammer, Julian DellaColetta, Fabian Maier, and Maksym Gachkivskyi
Atmos. Chem. Phys., 21, 17907–17926,Short summary
The radon tracer method is applied to atmospheric methane and radon observations from the upper Rhine valley to independently estimate methane emissions from the region. Comparison of our top-down results with bottom-up inventory data requires high-resolution footprint modelling and representative radon flux data. In agreement with inventories, observed emissions decreased, but only until 2005. A limitation of this method is that point-source emissions are not captured or not fully captured.
Zhixiong Chen, Jane Liu, Xugeng Cheng, Mengmiao Yang, and Hong Wang
Atmos. Chem. Phys., 21, 16911–16923,Short summary
Using a large ensemble of typhoons, we investigate the impacts of evolving typhoons on tropospheric ozone and address the linkages between typhoon-affected meteorological conditions and ozone variations. The influences of typhoon-induced stratospheric intrusions on lower-troposphere ozone are also quantified. Thus, the results obtained in this study have important implications for a full understanding of the multifaced roles of typhoons in modulating tropospheric ozone variation.
Maria Tzortziou, Charlotte Frances Kwong, Daniel Goldberg, Luke Schiferl, Róisín Commane, Nader Abuhassan, James Szykman, and Lukas Valin
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
The COVID-19 pandemic created an extreme natural experiment in which sudden changes in human behavior significantly impacted urban air quality. Using a combination of model, satellite, and ground-based data, we examine the impact of multiple waves and phases of the pandemic on atmospheric nitrogen pollution in the New York metropolitan area, and address the role of weather as a key driver of high pollution episodes observed even during – and despite – the stringent early lockdowns.
Yang Yang, Minqiang Zhou, Ting Wang, Bo Yao, Pengfei Han, Denghui Ji, Wei Zhou, Yele Sun, Gengchen Wang, and Pucai Wang
Atmos. Chem. Phys., 21, 11741–11757,Short summary
This study introduces the in situ CO2 measurement system installed in Beijing (urban), Xianghe (suburban), and Xinglong (rural) in North China for the first time. The spatial and temporal variations in CO2 mole fractions at the three sites between June 2018 and April 2020 are discussed on both seasonal and diurnal scales.
Dmitry V. Ionov, Maria V. Makarova, Frank Hase, Stefani C. Foka, Vladimir S. Kostsov, Carlos Alberti, Thomas Blumenstock, Thorsten Warneke, and Yana A. Virolainen
Atmos. Chem. Phys., 21, 10939–10963,Short summary
Megacities are a significant source of emissions of various substances in the atmosphere, including carbon dioxide, which is the most important anthropogenic greenhouse gas. In 2019–2020, the Emission Monitoring Mobile Experiment was carried out in St Petersburg, which is the second-largest industrial city in Russia. The results of this experiment, coupled with numerical modelling, helped to estimate the amount of CO2 emitted by the city. This value was twice as high as predicted.
Cheng Hu, Jiaping Xu, Cheng Liu, Yan Chen, Dong Yang, Wenjing Huang, Lichen Deng, Shoudong Liu, Timothy J. Griffis, and Xuhui Lee
Atmos. Chem. Phys., 21, 10015–10037,Short summary
Seventy percent of global CO2 emissions were emitted from urban landscapes. The Yangtze River delta (YRD) ranks as one of the most densely populated regions in the world and is an anthropogenic CO2 hotspot. Besides anthropogenic factors, natural ecosystems and croplands act as significant CO2 sinks and sources. Independent quantification of the fossil and cement CO2 emission and assessment of their impact on atmospheric δ13C-CO2 have potential to improve our understanding of urban CO2 cycling.
Youwen Sun, Hao Yin, Yuan Cheng, Qianggong Zhang, Bo Zheng, Justus Notholt, Xiao Lu, Cheng Liu, Yuan Tian, and Jianguo Liu
Atmos. Chem. Phys., 21, 9201–9222,Short summary
We quantified the variability, source, and transport of urban CO over the Himalayas and Tibetan Plateau (HTP) by using measurement, model simulation, and the analysis of meteorological fields. Urban CO over the HTP is dominated by anthropogenic and biomass burning emissions from local, South Asia and East Asia, and oxidation sources. The decreasing trends in surface CO since 2015 in most cities over the HTP are attributed to the reduction in local and transported CO emissions in recent years.
Katherine Hayden, Shao-Meng Li, Paul Makar, John Liggio, Samar G. Moussa, Ayodeji Akingunola, Robert McLaren, Ralf M. Staebler, Andrea Darlington, Jason O'Brien, Junhua Zhang, Mengistu Wolde, and Leiming Zhang
Atmos. Chem. Phys., 21, 8377–8392,Short summary
We developed a method using aircraft measurements to determine lifetimes with respect to dry deposition for oxidized sulfur and nitrogen compounds over the boreal forest in Alberta, Canada. Atmospheric lifetimes were significantly shorter than derived from chemical transport models with differences related to modelled dry deposition velocities. The shorter lifetimes suggest models need to reassess dry deposition treatment and predictions of sulfur and nitrogen in the atmosphere and ecosystems.
Yuanxu Dong, Mingxi Yang, Dorothee C. E. Bakker, Vassilis Kitidis, and Thomas G. Bell
Atmos. Chem. Phys., 21, 8089–8110,Short summary
Eddy covariance (EC) is the most direct method for measuring air–sea CO2 flux from ships. However, uncertainty in EC air–sea CO2 fluxes has not been well quantified. Here we show that with the state-of-the-art gas analysers, instrumental noise no longer contributes significantly to the CO2 flux uncertainty. Applying an appropriate averaging timescale (1–3 h) and suitable air–sea CO2 fugacity threshold (at least 20 µatm) to EC flux data enables an optimal analysis of the gas transfer velocity.
Yunhua Chang, Yan-Lin Zhang, Sawaeng Kawichai, Qian Wang, Martin Van Damme, Lieven Clarisse, Tippawan Prapamontol, and Moritz F. Lehmann
Atmos. Chem. Phys., 21, 7187–7198,Short summary
In this study, we integrated satellite constraints on atmospheric NH3 levels and fire intensity, discrete NH3 concentration measurement, and N isotopic analysis of NH3 in order to assess the regional-scale contribution of biomass burning to ambient atmospheric NH3 in the heartland of Southeast Asia. The combined approach provides a valuable cross-validation framework for source apportioning of NH3 in the lower atmosphere and will thus help to ameliorate predictions of biomass burning emissions.
David R. Lyon, Benjamin Hmiel, Ritesh Gautam, Mark Omara, Katherine A. Roberts, Zachary R. Barkley, Kenneth J. Davis, Natasha L. Miles, Vanessa C. Monteiro, Scott J. Richardson, Stephen Conley, Mackenzie L. Smith, Daniel J. Jacob, Lu Shen, Daniel J. Varon, Aijun Deng, Xander Rudelis, Nikhil Sharma, Kyle T. Story, Adam R. Brandt, Mary Kang, Eric A. Kort, Anthony J. Marchese, and Steven P. Hamburg
Atmos. Chem. Phys., 21, 6605–6626,Short summary
The Permian Basin (USA) is the world’s largest oil field. We use tower- and aircraft-based approaches to measure how methane emissions in the Permian Basin changed throughout 2020. In early 2020, 3.3 % of the region’s gas was emitted; then in spring 2020, the loss rate temporarily dropped to 1.9 % as oil price crashed. We find this short-term reduction to be a result of reduced well development, less gas flaring, and fewer abnormal events despite minimal reductions in oil and gas production.
Da Gao, Min Xie, Jane Liu, Tijian Wang, Chaoqun Ma, Haokun Bai, Xing Chen, Mengmeng Li, Bingliang Zhuang, and Shu Li
Atmos. Chem. Phys., 21, 5847–5864,Short summary
O3 has been increasing in recent years over the Yangtze River Delta region of China and is closely associated with dominant weather systems. Still, the study on the impact of changes in synoptic weather patterns (SWPs) on O3 variation is quite limited. This work aims to reveal the unique features of changes in each SWP under O3 variation and quantifies the effects of meteorological conditions on O3 variation. Our findings could be helpful in strategy planning for O3 pollution control.
Alkuin Maximilian Koenig, Olivier Magand, Paolo Laj, Marcos Andrade, Isabel Moreno, Fernando Velarde, Grover Salvatierra, René Gutierrez, Luis Blacutt, Diego Aliaga, Thomas Reichler, Karine Sellegri, Olivier Laurent, Michel Ramonet, and Aurélien Dommergue
Atmos. Chem. Phys., 21, 3447–3472,Short summary
The environmental cycling of atmospheric mercury, a harmful global contaminant, is still not sufficiently constrained, partly due to missing data in remote regions. Here, we address this issue by presenting 20 months of atmospheric mercury measurements, sampled in the Bolivian Andes. We observe a significant seasonal pattern, whose key features we explore. Moreover, we deduce ratios to constrain South American biomass burning mercury emissions and the mercury uptake by the Amazon rainforest.
Yuming Jin, Ralph F. Keeling, Eric J. Morgan, Eric Ray, Nicholas C. Parazoo, and Britton B. Stephens
Atmos. Chem. Phys., 21, 217–238,Short summary
We propose a new atmospheric coordinate (Mθe) based on equivalent potential temperature (θe) but with mass as the unit. This coordinate is useful in studying the spatial and temporal distribution of long-lived chemical tracers (CO2, CH4, O2 / N2, etc.) from sparse data, like airborne observation. Using this coordinate and sparse airborne observation (HIPPO and ATom), we resolve the Northern Hemisphere mass-weighted average CO2 seasonal cycle with high accuracy.
Hossein Maazallahi, Julianne M. Fernandez, Malika Menoud, Daniel Zavala-Araiza, Zachary D. Weller, Stefan Schwietzke, Joseph C. von Fischer, Hugo Denier van der Gon, and Thomas Röckmann
Atmos. Chem. Phys., 20, 14717–14740,Short summary
Methane accounts for ∼ 25 % of current climate warming. The current lack of methane measurements is a barrier for tracking major sources, which are key for near-term climate mitigation. We use mobile measurements to identify and quantify methane emission sources in Utrecht (NL) and Hamburg (DE) with a focus on natural gas pipeline leaks. The measurements resulted in fixing the major leaks by the local utility, but coordinated efforts are needed at national levels for further emission reductions.
Chenchao Zhan, Min Xie, Chongwu Huang, Jane Liu, Tijian Wang, Meng Xu, Chaoqun Ma, Jianwei Yu, Yumeng Jiao, Mengmeng Li, Shu Li, Bingliang Zhuang, Ming Zhao, and Dongyang Nie
Atmos. Chem. Phys., 20, 13781–13799,Short summary
The Yangtze River Delta (YRD) region has been suffering from severe ozone (O3) pollution in recent years. Synoptic systems, like typhoons, can have a significant effect on O3 episodes. However, research on landfall typhoons affecting O3 in the YRD is limited. This work aims to reveal the main processes of landfall typhoons affecting surface O3 and estimate health impacts of O3 during the study period in the YRD, which can be useful for taking reasonable pollution control measures in this area.
José M. Esbrí, Pablo L. Higueras, Alba Martínez-Coronado, and Rocío Naharro
Atmos. Chem. Phys., 20, 12995–13010,Short summary
The aim of this work was to identify criteria to obtain the minimum amount of data with the maximum meaning and representativeness in order to delimit risk areas, both in a spatial and temporal respect. We have constructed a model of vertical mercury movements which could be used to predict the location and timing of mercury inhalation risk. Also, we have designed a monitoring strategy to identify the relevant criteria, which involved the measurement of gaseous mercury in a vertical section.
Alina Fiehn, Julian Kostinek, Maximilian Eckl, Theresa Klausner, Michał Gałkowski, Jinxuan Chen, Christoph Gerbig, Thomas Röckmann, Hossein Maazallahi, Martina Schmidt, Piotr Korbeń, Jarosław Neçki, Pawel Jagoda, Norman Wildmann, Christian Mallaun, Rostyslav Bun, Anna-Leah Nickl, Patrick Jöckel, Andreas Fix, and Anke Roiger
Atmos. Chem. Phys., 20, 12675–12695,Short summary
A severe reduction of greenhouse gas emissions is necessary to fulfill the Paris Agreement. We use aircraft- and ground-based in situ observations of trace gases and wind speed from two flights over the Upper Silesian Coal Basin, Poland, for independent emission estimation. The derived methane emission estimates are within the range of emission inventories, carbon dioxide estimates are in the lower range and carbon monoxide emission estimates are slightly higher than emission inventory values.
Flora Kluge, Tilman Hüneke, Matthias Knecht, Michael Lichtenstern, Meike Rotermund, Hans Schlager, Benjamin Schreiner, and Klaus Pfeilsticker
Atmos. Chem. Phys., 20, 12363–12389,Short summary
The presented study reports on airborne measurements of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon basin and lays a special focus on the influence of biomass burning emissions on the atmospheric profiles of these carbonyl compounds within the planetary boundary layer as well as in the free and upper troposphere.
Wei Wang, Laurens Ganzeveld, Samuel Rossabi, Jacques Hueber, and Detlev Helmig
Atmos. Chem. Phys., 20, 11287–11304,Short summary
Trees exchange with the atmosphere nitrogen oxides and ozone, affecting the tropospheric composition and consequently air quality and ecosystem health. We examined the leaf-level gas exchanges for four typical tree species (pine, maple, oak, aspen) found in northern Michigan, US. The leaves largely absorb the gases, showing little evidence of emission. We measured the uptake rates that can be used to improve model studies of the source and sink processes controlling these gases in forests.
Ingeborg Levin, Ute Karstens, Markus Eritt, Fabian Maier, Sabrina Arnold, Daniel Rzesanke, Samuel Hammer, Michel Ramonet, Gabriela Vítková, Sebastien Conil, Michal Heliasz, Dagmar Kubistin, and Matthias Lindauer
Atmos. Chem. Phys., 20, 11161–11180,Short summary
Based on observations and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling, a sampling strategy has been developed for tall tower stations of the Integrated Carbon Observation System (ICOS) research infrastructure atmospheric station network. This strategy allows independent quality control of in situ measurements, provides representative coverage of the influence area of the sites, and is capable of automated targeted sampling of fossil fuel CO2 emission hotspots.
Peter G. Simmonds, Matthew Rigby, Alistair J. Manning, Sunyoung Park, Kieran M. Stanley, Archie McCulloch, Stephan Henne, Francesco Graziosi, Michela Maione, Jgor Arduini, Stefan Reimann, Martin K. Vollmer, Jens Mühle, Simon O'Doherty, Dickon Young, Paul B. Krummel, Paul J. Fraser, Ray F. Weiss, Peter K. Salameh, Christina M. Harth, Mi-Kyung Park, Hyeri Park, Tim Arnold, Chris Rennick, L. Paul Steele, Blagoj Mitrevski, Ray H. J. Wang, and Ronald G. Prinn
Atmos. Chem. Phys., 20, 7271–7290,Short summary
Sulfur hexafluoride (SF6) is a potent greenhouse gas which is regulated under the Kyoto Protocol. From a 40-year record of measurements, collected at five global monitoring sites and archived air samples, we show that its concentration in the atmosphere has steadily increased. Using modelling techniques, we estimate that global emissions have increased by about 24 % over the past decade. We find that this increase is driven by the demand for SF6-insulated switchgear in developing countries.
Santiago Botía, Christoph Gerbig, Julia Marshall, Jost V. Lavric, David Walter, Christopher Pöhlker, Bruna Holanda, Gilberto Fisch, Alessandro Carioca de Araújo, Marta O. Sá, Paulo R. Teixeira, Angélica F. Resende, Cleo Q. Dias-Junior, Hella van Asperen, Pablo S. Oliveira, Michel Stefanello, and Otávio C. Acevedo
Atmos. Chem. Phys., 20, 6583–6606,Short summary
A long record of atmospheric methane concentrations in central Amazonia was analyzed. We describe events in which concentrations at 79 m are higher than at 4 m. These events are more frequent during the nighttime of dry season, but we found no association with fire signals. Instead, we suggest that a combination of nighttime transport and a nearby source could explain such events. Our research gives insights into how methane is transported in the complex nocturnal atmosphere in Amazonia.
Nikolay V. Balashov, Kenneth J. Davis, Natasha L. Miles, Thomas Lauvaux, Scott J. Richardson, Zachary R. Barkley, and Timothy A. Bonin
Atmos. Chem. Phys., 20, 4545–4559,Short summary
An accurate independent verification methodology to estimate methane (a powerful greenhouse gas) emissions is essential for the effective implementation of policies that aim to reduce the impacts of climate change. In this paper, four uncertainties that complicate the independent estimation of urban methane emissions are identified: the definition of urban domain, background heterogeneity, emissions temporal variability, and missing sources. Ways to improve emission estimates are suggested.
Jia Chen, Florian Dietrich, Hossein Maazallahi, Andreas Forstmaier, Dominik Winkler, Magdalena E. G. Hofmann, Hugo Denier van der Gon, and Thomas Röckmann
Atmos. Chem. Phys., 20, 3683–3696,Short summary
We demonstrate for the first time that large festivals can be significant methane sources, though they are not included in emission inventories. We combined in situ measurements with a Gaussian plume model to determine the Oktoberfest emissions and show that they are not due solely to human biogenic emissions, but are instead primarily fossil fuel related. Our study provides the foundation to develop reduction policies for such events and new pathways to mitigate fossil fuel methane emissions.
Pavlos Kalabokas, Niels Roland Jensen, Mauro Roveri, Jens Hjorth, Maxim Eremenko, Juan Cuesta, Gaëlle Dufour, Gilles Foret, and Matthias Beekmann
Atmos. Chem. Phys., 20, 1861–1885,Short summary
The influence of tropospheric ozone on the surface measurements at a regional air pollution station in the pre-Alpine area of northern Italy is investigated. During such episodes the local air pollution parameters show generally very low values, while the ozone levels reach high values, occasionally exceeding the ozone air quality standards. Better understanding of ozone variability over the examined region will help in the formulation of more effective policies for the environment and climate.
Han Han, Jane Liu, Lei Shu, Tijian Wang, and Huiling Yuan
Atmos. Chem. Phys., 20, 203–222,Short summary
We statistically assessed the impacts of local and synoptic meteorology on daily surface ozone in eastern China in summer during 2013–2018. The results show that the meteorology described by a multiple linear regression model explains 43 % of variations in surface ozone. The most important local meteorological factors vary with location in eastern China. The maximum impact of the predominant synoptic pattern on surface ozone can reach ± 8 µg m-3 or ± 16 % of the daily mean over some regions.
Roger J. Francey, Jorgen S. Frederiksen, L. Paul Steele, and Ray L. Langenfelds
Atmos. Chem. Phys., 19, 14741–14754,Short summary
25-year composites of interhemispheric baseline CO2 differences demonstrate close agreement between 4 monitoring networks. Variability from monthly to multiyear time frames mostly reflects variability in upper troposphere dynamical indices chosen to represent eddy and mean transport interhemispheric exchange. Monthly interhemispheric atmospheric fluxes are much larger than air–surface terrestrial exchanges. The composite differences offer unusual constraints on transport in global carbon models.
Jingda Liu, Lili Wang, Mingge Li, Zhiheng Liao, Yang Sun, Tao Song, Wenkang Gao, Yonghong Wang, Yan Li, Dongsheng Ji, Bo Hu, Veli-Matti Kerminen, Yuesi Wang, and Markku Kulmala
Atmos. Chem. Phys., 19, 14477–14492,Short summary
We analyzed the surface ozone variation characteristics and quantified the impact of synoptic and local meteorological factors on northern China during the warm season based on multi-city, in situ ozone and meteorological data, as well as meteorological reanalysis. The results of quantitative exploration on synoptic and local meteorological factors influencing both interannual and day-to-day ozone variations will provide the scientific basis for evaluating emission reduction measures.
Armin Sigmund, Korbinian Freier, Till Rehm, Ludwig Ries, Christian Schunk, Anette Menzel, and Christoph K. Thomas
Atmos. Chem. Phys., 19, 12477–12494,Short summary
Air masses at the Schneefernerhaus mountain site at Zugspitze Mountain, Germany, were classified with respect to the atmospheric layer from which they originated and their degree of pollution. Measurements of several gases, particulate matter, and standard meteorological quantities indicated that polluted air was lifted to the site in 31 % of cases and clean air descended to the site in approximately 14 % cases while most of the remaining cases were ambiguous.
Yahui Bian, Zhijiong Huang, Jiamin Ou, Zhuangmin Zhong, Yuanqian Xu, Zhiwei Zhang, Xiao Xiao, Xiao Ye, Yuqi Wu, Xiaohong Yin, Cheng Li, Liangfu Chen, Min Shao, and Junyu Zheng
Atmos. Chem. Phys., 19, 11701–11719,Short summary
During 2006–2015, emissions of SO2, NOx, PM2.5 and PM10 saw an obvious downtrend. However, most emissions still have large reduction potential. On-road mobile sources and solvent use are the two key sources that should receive more effective control measures in GD. Also, controls measures on VOC and NH3 should be weighted since they still increased in 2006–2015. Since most control measures focused on PRD rather than non-PRD in GD, emissions in non-PRD were increasingly important.
Stuart N. Riddick, Denise L. Mauzerall, Michael Celia, Neil R. P. Harris, Grant Allen, Joseph Pitt, John Staunton-Sykes, Grant L. Forster, Mary Kang, David Lowry, Euan G. Nisbet, and Alistair J. Manning
Atmos. Chem. Phys., 19, 9787–9796,Short summary
Currently, bottom-up methods estimate that 0.13 % of methane produced by UK North Sea oil and gas installations is lost. Here we measure emissions from eight platforms in the North Sea and, when considered collectively, the methane loss is estimated at 0.19 % of gas production. As this ambient loss is not explicitly accounted for in the bottom-up approach, these measured emissions represent significant additional emissions above previous estimates.
Joseph R. Pitt, Grant Allen, Stéphane J.-B. Bauguitte, Martin W. Gallagher, James D. Lee, Will Drysdale, Beth Nelson, Alistair J. Manning, and Paul I. Palmer
Atmos. Chem. Phys., 19, 8931–8945,Short summary
This paper presents a new method to assess inventory estimates of greenhouse gas and air pollutant emissions for large cities and their surrounding regions. A case study using data sampled by a research aircraft around London was used to test the method. We found that the UK national inventory agrees with our observations for CO but needed lower emissions for CH4 to agree with the measured data. Repeated studies could help determine how these emissions vary on different timescales.
Jordi Massagué, Cristina Carnerero, Miguel Escudero, José María Baldasano, Andrés Alastuey, and Xavier Querol
Atmos. Chem. Phys., 19, 7445–7465,
Carole Helfter, Neil Mullinger, Massimo Vieno, Simon O'Doherty, Michel Ramonet, Paul I. Palmer, and Eiko Nemitz
Atmos. Chem. Phys., 19, 3043–3063,Short summary
We present a novel approach to estimate the annual budgets of carbon dioxide (881.0 ± 128.5 Tg) and methane (2.55 ± 0.48 Tg) of the British Isles from shipborne measurements taken over a 3-year period (2015–2017). This study brings independent verification of the emission budgets estimated using alternative products and investigates the seasonality of these emissions, which is usually not possible.
Stefan Kaufmann, Christiane Voigt, Romy Heller, Tina Jurkat-Witschas, Martina Krämer, Christian Rolf, Martin Zöger, Andreas Giez, Bernhard Buchholz, Volker Ebert, Troy Thornberry, and Ulrich Schumann
Atmos. Chem. Phys., 18, 16729–16745,Short summary
We present an intercomparison of the airborne water vapor measurements during the ML-CIRRUS mission. Although the agreement of the hygrometers significantly improved compared to studies from recent decades, systematic differences remain under specific meteorological conditions. We compare the measurements to model data, where we observe a model wet bias in the lower stratosphere close to the tropopause, likely caused by a blurred humidity gradient in the model tropopause.
Jack G. Porter, Warren De Bruyn, and Eric S. Saltzman
Atmos. Chem. Phys., 18, 15291–15305,Short summary
Deposition to the sea surface is a major loss pathway for highly soluble atmospheric trace gases. These fluxes are important to biogeochemical cycles, climate, and air quality. Here we report measurements of air–sea fluxes of sulfur dioxide, sensible heat, and momentum to coastal waters. Transfer velocities derived from the data show a dependence on molecular diffusivity, demonstrating the importance of diffusion in the interfacial layer on the atmospheric side of the air–sea interface.
Dana R. Caulton, Qi Li, Elie Bou-Zeid, Jeffrey P. Fitts, Levi M. Golston, Da Pan, Jessica Lu, Haley M. Lane, Bernhard Buchholz, Xuehui Guo, James McSpiritt, Lars Wendt, and Mark A. Zondlo
Atmos. Chem. Phys., 18, 15145–15168,Short summary
Mobile laboratory measurements have been widely used to quantify methane emissions from point sources such as oil and gas wells, but the emission uncertainties are poorly constrained. We designed a hierarchical measurement strategy to sample natural gas emissions in the Marcellus Shale play based upon high-resolution modeling of select sites. Our study quantifies the largest sources of error with this approach and provides guidance on how to best implement mobile laboratory sampling protocols.
Alexis A. Shusterman, Jinsol Kim, Kaitlyn J. Lieschke, Catherine Newman, Paul J. Wooldridge, and Ronald C. Cohen
Atmos. Chem. Phys., 18, 13773–13785,Short summary
We describe the diversity and heterogeneity of urban CO2 levels observed using the BErkeley Atmospheric CO2 Observation Network, a distributed instrument of > 50 CO2 sensors stationed every ~ 2 km across the San Francisco Bay Area. We demonstrate that relatively simple mathematical techniques, applied to these observations, can be used to detect the small changes in highway CO2 emissions expected to result from upcoming fuel economy regulations, affirming the policy relevance of low-cost sensors.
Mengyao Liu, Jintai Lin, Yuchen Wang, Yang Sun, Bo Zheng, Jingyuan Shao, Lulu Chen, Yixuan Zheng, Jinxuan Chen, Tzung-May Fu, Yingying Yan, Qiang Zhang, and Zhaohua Wu
Atmos. Chem. Phys., 18, 12933–12952,Short summary
Eastern China is heavily polluted by NO2, PM2.5, and other air pollutants. Our study uses EOF–EEMD to analyze the spatiotemporal variability of ground-level NO2, PM2.5, and their associations with meteorological processes. Their regular diurnal cycles are mainly affected by human activities, while irregular day-to-day variations are dominated by weather processes representing synchronous variation or north–south opposing changes over Eastern China.
Wen Xu, Lei Liu, Miaomiao Cheng, Yuanhong Zhao, Lin Zhang, Yuepeng Pan, Xiuming Zhang, Baojing Gu, Yi Li, Xiuying Zhang, Jianlin Shen, Li Lu, Xiaosheng Luo, Yu Zhao, Zhaozhong Feng, Jeffrey L. Collett Jr., Fusuo Zhang, and Xuejun Liu
Atmos. Chem. Phys., 18, 10931–10954,Short summary
Our main results demonstrate that atmospheric Nr pollution in eastern China is more serious in the northern region than in the southern region. Any effects of current emission controls are not yet apparent in Nr pollution. NH3 emissions from fertilizer use were the largest contributor (36 %) to total inorganic Nr deposition. Our results provide useful information for policy-makers that mitigation of NH3 emissions should be a priority to tackle serious N deposition.
Xavier Querol, Andrés Alastuey, Gotzon Gangoiti, Noemí Perez, Hong K. Lee, Heeram R. Eun, Yonghee Park, Enrique Mantilla, Miguel Escudero, Gloria Titos, Lucio Alonso, Brice Temime-Roussel, Nicolas Marchand, Juan R. Moreta, M. Arantxa Revuelta, Pedro Salvador, Begoña Artíñano, Saúl García dos Santos, Mónica Anguas, Alberto Notario, Alfonso Saiz-Lopez, Roy M. Harrison, Millán Millán, and Kang-Ho Ahn
Atmos. Chem. Phys., 18, 6511–6533,Short summary
We show the main drivers of high O3 episodes in and around Madrid. High levels of ultrafine particles (UFPs) are evidenced, but we demonstrate that most O3 arises from the fumigation of high atmospheric layers, whereas UFPs are generated inside the PBL. O3 contributions from the fumigation of the vertical recirculation of regional air masses, hemispheric transport, and horizontally from direct urban plume transport are shown. Complexity arises from the need to quantify them to abate surface O3.
Qianqian Hong, Cheng Liu, Ka Lok Chan, Qihou Hu, Zhouqing Xie, Haoran Liu, Fuqi Si, and Jianguo Liu
Atmos. Chem. Phys., 18, 5931–5951,Short summary
We presented ship-based MAX-DOAS measurements of tropospheric trace gases' distribution along the eastern part of the Yangtze River during winter 2015. Tropospheric VCDs of NO2, SO2, and HCHO were retrieved from MAX-DOAS measurement spectra. Enhanced tropospheric NO2 and SO2 VCDs were detected over downwind areas of industrial zones over the Yangtze River. Our results indicate that different pollution control strategies should be applied in different provinces.
Murray J. Smith, Carolyn F. Walker, Thomas G. Bell, Mike J. Harvey, Eric S. Saltzman, and Cliff S. Law
Atmos. Chem. Phys., 18, 5861–5877,Short summary
The transfer of gases across the air–sea interface has a significant influence on climate. During a research voyage in the South Pacific we measured the transfer rate of the biogenic gas dimethyl sulfide (DMS) from the ocean using two independent methods. The agreement between the techniques provides confidence in their use in compilations of global gas transfer. We also identified physical conditions under which the observations are not well predicted by a standard gas transfer model.
Geoffrey C. Toon, Jean-Francois L. Blavier, and Keeyoon Sung
Atmos. Chem. Phys., 18, 5075–5088,Short summary
Remote sensing measurements of ethene have been made from the ground and from balloons. Ethene can be measured at low altitudes in polluted regions, such as the Los Angeles basin. Here ethene amounts have decreased by a factor of 3 over the past 25 years due to increasingly strict emission control regulations (e.g., on vehicle exhaust).
Hao Wang, Xiaopu Lyu, Hai Guo, Yu Wang, Shichun Zou, Zhenhao Ling, Xinming Wang, Fei Jiang, Yangzong Zeren, Wenzhuo Pan, Xiaobo Huang, and Jin Shen
Atmos. Chem. Phys., 18, 4277–4295,Short summary
While oceanic air is generally thought to be clean, the air pollution over waters in proximity to the coasts is not well recognized. This research indicated that ozone was higher over South China Sea (SCS) than that in the adjacent continental area, while continental anticyclone, tropical cyclone and land breeze favored O3 formation over SCS. In addition, weaker NO titration and stronger atmospheric oxidative capacity led to higher O3 production efficiency over SCS.
Fabian Schoenenberger, Stephan Henne, Matthias Hill, Martin K. Vollmer, Giorgos Kouvarakis, Nikolaos Mihalopoulos, Simon O'Doherty, Michela Maione, Lukas Emmenegger, Thomas Peter, and Stefan Reimann
Atmos. Chem. Phys., 18, 4069–4092,Short summary
Anthropogenic halocarbon emissions contribute to stratospheric ozone depletion and global warming. We measured atmospheric halocarbons for 6 months on Crete to extend the coverage of the existing observation network to the Eastern Mediterranean. The derived emission estimates showed a contribution of 16.8 % (13.6–23.3 %) and 53.2 % (38.1–84.2 %) of this region to the total HFC and HCFC emissions of the analyzed European domain and a reduction of the underlying uncertainties by 40–80 %.
Irène Xueref-Remy, Elsa Dieudonné, Cyrille Vuillemin, Morgan Lopez, Christine Lac, Martina Schmidt, Marc Delmotte, Frédéric Chevallier, François Ravetta, Olivier Perrussel, Philippe Ciais, François-Marie Bréon, Grégoire Broquet, Michel Ramonet, T. Gerard Spain, and Christophe Ampe
Atmos. Chem. Phys., 18, 3335–3362,Short summary
Urbanized and industrialized areas are the largest source of fossil CO2. This work analyses the atmospheric CO2 variability observed from the first in situ network deployed in the Paris megacity area. Gradients of several ppm are found between the rural, peri-urban and urban sites at the diurnal to the seasonal scales. Wind direction and speed as well as boundary layer dynamics, correlated to highly variable urban emissions, are shown to be key regulator factors of the observed CO2 records.
Geoffrey C. Toon, Jean-Francois L. Blavier, and Keeyoon Sung
Atmos. Chem. Phys., 18, 1923–1944,Short summary
OCS is the main form of atmospheric sulfur. It is produced near the earth's surface and destroyed primarily in the stratosphere, where it is converted to stratospheric sulfate aerosol (SSA). SSA plays an important role in atmospheric chemistry and transport and so it is important to better understand the factors that regulate OCS and hence SSA. Ground-based and balloon-borne infrared spectra observed over the past 30 years are analyzed to provide an improved OCS dataset.
Ahn, M. C., Kim, B., Holsen, T. M., Yi, S. M., and Han, Y. J.: Factors influencing concentrations of dissolved gaseous mercury (DGM) and total mercury (TM) in an artificial reservoir, Environ. Pollut., 158, 347–355, https://doi.org/10.1016/j.envpol.2009.08.036, 2010.
Amos, H. M., Jacob, D. J., Holmes, C. D., Fisher, J. A., Wang, Q., Yantosca, R. M., Corbitt, E. S., Galarneau, E., Rutter, A. P., Gustin, M. S., Steffen, A., Schauer, J. J., Graydon, J. A., Louis, V. L. St., Talbot, R. W., Edgerton, E. S., Zhang, Y., and Sunderland, E. M.: Gas-particle partitioning of atmospheric Hg(II) and its effect on global mercury deposition, Atmos. Chem. Phys., 12, 591–603, https://doi.org/10.5194/acp-12-591-2012, 2012.
Andersson, M. E., Gårdfeldt, K., Wängberg, I., Sprovieri, F., Pirrone, N., and Lindqvist, O.: Seasonal and daily variation of mercury evasion at coastal and off shore sites from the Mediterranean Sea, Mar. Chem., 104, 214–226, https://doi.org/10.1016/j.marchem.2006.11.003, 2007.
Angot, H., Barret, M., Magand, O., Ramonet, M., and Dommergue, A.: A 2-year record of atmospheric mercury species at a background Southern Hemisphere station on Amsterdam Island, Atmos. Chem. Phys., 14, 11461–11473, https://doi.org/10.5194/acp-14-11461-2014, 2014.
Ariya, P. A., Amyot, M., Dastoor, A., Deeds, D., Feinberg, A., Kos, G., Poulain, A., Ryjkov, A., Semeniuk, K., Subir, M., and Toyota, K.: Mercury physicochemical and biogeochemical transformation in the atmosphere and at atmospheric interfaces: A review and future directions, Chem. Rev., 115, 3760–3802, https://doi.org/10.1021/cr500667e, 2015.
Athanasopoulou, E., Tombrou, M., Pandis, S. N., and Russell, A. G.: The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas, Atmos. Chem. Phys., 8, 5755–5769, https://doi.org/10.5194/acp-8-5755-2008, 2008.
Auzmendi-Murua, I., Castillo, Á., and Bozzelli, J. W.: Mercury oxidation via chlorine, bromine, and iodine under atmospheric conditions: Thermochemistry and kinetics, J. Phys. Chem. A, 118, 2959–2975, https://doi.org/10.1021/jp412654s, 2014.
Bowman, K. L., Hammerschmidt, C. R., Lamborg, C. H., and Swarr, G.: Mercury in the North Atlantic Ocean: The U.S. GEOTRACES zonal and meridional sections, Deep-Sea Res. Pt. II, 116, 251–261, https://doi.org/10.1016/j.dsr2.2014.07.004, 2015.
Cheng, I., Zhang, L., Blanchard, P., Graydon, J. A., and Louis, V. L. St.: Source-receptor relationships for speciated atmospheric mercury at the remote Experimental Lakes Area, northwestern Ontario, Canada, Atmos. Chem. Phys., 12, 1903–1922, https://doi.org/10.5194/acp-12-1903-2012, 2012.
Cheng, I., Zhang, L., Blanchard, P., Dalziel, J., Tordon, R., Huang, J., and Holsen, T. M.: Comparisons of mercury sources and atmospheric mercury processes between a coastal and inland site, J. Geophys. Res., 118, 2434–2443, https://doi.org/10.1002/jgrd.50169, 2013.
Ci, Z. J., Zhang, X. S., Wang, Z. W., Niu, Z. C., Diao, X. Y., and Wang, S. W.: Distribution and air-sea exchange of mercury (Hg) in the Yellow Sea, Atmos. Chem. Phys., 11, 2881–2892, https://doi.org/10.5194/acp-11-2881-2011, 2011.
Ci, Z., Wang, C., Wang, Z., and Zhang, X.: Elemental mercury (Hg(0)) in air and surface waters of the Yellow Sea during late spring and late fall 2012: Concentration, spatial-temporal distribution and air/sea flux, Chemosphere, 119, 199–208, https://doi.org/10.1016/j.chemosphere.2014.05.064, 2015.
de Foy, B., Tong, Y., Yin, X., Zhang, W., Kang, S., Zhang, Q., Zhang, G., Wang, X., and Schauer, J. J.: First field-based atmospheric observation of the reduction of reactive mercury driven by sunlight, Atmos. Environ., 134, 27–39, https://doi.org/10.1016/j.atmosenv.2016.03.028, 2016.
Draxler, R. R. and Rolph, G. D.: HYSPLITModel access via NOAA ARL READY Website, NOAA Air Resources Laboratory, Silver Spring, MD, available at: https://www.arl.noaa.gov/ready/hysplit4.html (last access: 7 August 2019), 2012.
Engle, M. A., Tate, M. T., Krabbenhoft, D. P., Kolker, A., Olson, M. L., Edgerton, E. S., DeWild, J. F., and McPherson, A. K.: Characterization and cycling of atmospheric mercury along the central US Gulf Coast, Appl. Geochem., 23, 419–437, https://doi.org/10.1016/j.apgeochem.2007.12.024, 2008.
Feddersen, D. M., Talbot, R., Mao, H., and Sive, B. C.: Size distribution of particulate mercury in marine and coastal atmospheres, Atmos. Chem. Phys., 12, 10899–10909, https://doi.org/10.5194/acp-12-10899-2012, 2012.
Fu, X., Feng, X., Zhang, G., Xu, W., Li, X., Yao, H., Liang, P., Li, J., Sommar, J., Yin, R., and Liu, N.: Mercury in the marine boundary layer and seawater of the South China Sea: Concentrations, sea/air flux, and implication for land outflow, J. Geophys. Res., 115, D06303, https://doi.org/10.1029/2009JD012958, 2010.
Fu, X., Feng, X., Qiu, G., Shang, L., and Zhang, H.: Speciated atmospheric mercury and its potential source in Guiyang, China, Atmos. Environ., 45, 4205–4212, https://doi.org/10.1016/j.atmosenv.2011.05.012, 2011.
Fu, X. W., Feng, X., Liang, P., Deliger, Zhang, H., Ji, J., and Liu, P.: Temporal trend and sources of speciated atmospheric mercury at Waliguan GAW station, Northwestern China, Atmos. Chem. Phys., 12, 1951–1964, https://doi.org/10.5194/acp-12-1951-2012, 2012.
Giorgi, F.: Dry deposition velocities of atmospheric aerosols as inferred by applying a particle dry deposition parameterisation to a general circulation model, Tellus, 40B, 23–41, https://doi.org/10.1111/j.1600-0889.1988.tb00210.x, 1988.
Gratz, L. E., Ambrose, J. L., Jaffe, D. A., Shah, V., Jaegle, L., Stutz, J., Festa, J., Spolaor, M., Tsai, C., Selin, N. E., Song, S., Zhou, X., Weinheimer, A. J., Knapp, D. J., Montzka, D. D., Flocke, F. M., Campos, T. L., Apel, E., Hornbrook, R., Blake, N. J., Hall, S., Tyndall, G. S., Reeves, M., Stechman, D., and Stell, M.: Oxidation of mercury by bromine in the subtropical Pacific free troposphere, Geophys. Res. Lett., 42, 10494–10502, https://doi.org/10.1002/2015GL066645, 2015.
Gustin, M. S., Huang, J., Miller, M. B., Peterson, C., Jaffe, D. A., Ambrose, J., Finley, B. D., Lyman, S. N., Call, K., Talbot, R., Feddersen, D., Mao, H., and Lindberg, S. E.: Do we understand what the mercury speciation instruments are actually measuring? Results of RAMIX, Environ. Sci. Technol., 47, 7295–7306, https://doi.org/10.1021/es3039104, 2013.
Hedgecock, I. and Pirrone, N.: Mercury and photochemistry in the marine boundary layer-modelling studies suggest the in situ production of reactive gas phase mercury, Atmos. Environ., 35, 3055–3062, https://doi.org/10.1016/S1352-2310(01)00109-1, 2001.
Holmes, C. D., Jacob, D. J., and Yang, X.: Global lifetime of elemental mercury against oxidation by atomic bromine in the free troposphere, Geophys. Res. Lett., 33, L20808, https://doi.org/10.1029/2006gl027176, 2006.
Holmes, C. D., Jacob, D. J., Mason, R. P., and Jaffe, D. A.: Sources and deposition of reactive gaseous mercury in the marine atmosphere, Atmos. Environ., 43, 2278–2285, https://doi.org/10.1016/j.atmosenv.2009.01.051, 2009.
Holmes, C. D., Jacob, D. J., Corbitt, E. S., Mao, J., Yang, X., Talbot, R., and Slemr, F.: Global atmospheric model for mercury including oxidation by bromine atoms, Atmos. Chem. Phys., 10, 12037–12057, https://doi.org/10.5194/acp-10-12037-2010, 2010.
Horowitz, H. M., Jacob, D. J., Zhang, Y., Dibble, T. S., Slemr, F., Amos, H. M., Schmidt, J. A., Corbitt, E. S., Marais, E. A., and Sunderland, E. M.: A new mechanism for atmospheric mercury redox chemistry: implications for the global mercury budget, Atmos. Chem. Phys., 17, 6353–6371, https://doi.org/10.5194/acp-17-6353-2017, 2017.
Horvat, M., Kotnik, J., Logar, M., Fajon, V., Zvonarić, T., and Pirrone, N.: Speciation of mercury in surface and deep-sea waters in the Mediterranean Sea, Atmos. Environ., 37, S93–S108, https://doi.org/10.1016/S1352-2310(03)00249-8, 2003.
Howard, D., Nelson, P. F., Edwards, G. C., Morrison, A. L., Fisher, J. A., Ward, J., Harnwell, J., van der Schoot, M., Atkinson, B., Chambers, S. D., Griffiths, A. D., Werczynski, S., and Williams, A. G.: Atmospheric mercury in the Southern Hemisphere tropics: seasonal and diurnal variations and influence of inter-hemispheric transport, Atmos. Chem. Phys., 17, 11623–11636, https://doi.org/10.5194/acp-17-11623-2017, 2017.
Huang, J., Miller, M. B., Edgerton, E., and Sexauer Gustin, M.: Deciphering potential chemical compounds of gaseous oxidized mercury in Florida, USA, Atmos. Chem. Phys., 17, 1689–1698, https://doi.org/10.5194/acp-17-1689-2017, 2017.
Kim, S. H., Han, Y. J., Holsen, T. M., and Yi, S. M.: Characteristics of atmospheric speciated mercury concentrations (TGM, Hg(II) and Hg(p)) in Seoul, Korea, Atmos. Environ., 43, 3267–3274, https://doi.org/10.1016/j.atmosenv.2009.02.038, 2009.
Kim, P. R., Han, Y. J., Holsen, T. M., and Yi, S. M.: Atmospheric particulate mercury: Concentrations and size distributions, Atmos. Environ., 61, 94–102, https://doi.org/10.1016/j.atmosenv.2012.07.014, 2012.
Kuss, J.: Water–air gas exchange of elemental mercury: An experimentally determined mercury diffusion coefficient for Hg0 water–air flux calculations, Limnol. Oceanogr., 59, 1461–1467, https://doi.org/10.4319/lo.2014.59.5.1461, 2014.
Kuss, J. and Schneider, B.: Variability of the gaseous elemental mercury sea-air flux of the Baltic Sea, Environ. Sci. Technol., 41, 8018–8023, https://doi.org/10.1021/es0716251, 2007.
Kuss, J., Zülicke, C., Pohl, C., and Schneider, B.: Atlantic mercury emission determined from continuous analysis of the elemental mercury sea-air concentration difference within transects between 50∘ N and 50∘ S, Global Biogeochem. Cy., 25, GB3021, https://doi.org/10.1029/2010GB003998, 2011.
Kuss, J., Krüger, S., Ruickoldt, J., and Wlost, K.-P.: High-resolution measurements of elemental mercury in surface water for an improved quantitative understanding of the Baltic Sea as a source of atmospheric mercury, Atmos. Chem. Phys., 18, 4361–4376, https://doi.org/10.5194/acp-18-4361-2018, 2018.
Laurier, F. J. G., Mason, R. P., Whalin, L., and Kato, S.: Reactive gaseous mercury formation in the North Pacific Ocean's marine boundary layer: A potential role of halogen chemistry, J. Geophys. Res., 108, 4529, https://doi.org/10.1029/2003JD003625, 2003.
Laurier, F. and Mason, R.: Mercury concentration and speciation in the coastal and open ocean boundary layer, J. Geophys. Res., 112, D06302, https://doi.org/10.1029/2006JD007320, 2007.
Lee, G.-S., Kim, P.-R., Han, Y.-J., Holsen, T. M., Seo, Y.-S., and Yi, S.-M.: Atmospheric speciated mercury concentrations on an island between China and Korea: sources and transport pathways, Atmos. Chem. Phys., 16, 4119–4133, https://doi.org/10.5194/acp-16-4119-2016, 2016.
Lindberg, S. E., Brooks, S., Lin, C. J., Scott, K. J., Landis, M. S., Stevens, R. K., Goodsite, M., and Richter, A.: Dynamic oxidation of gaseous mercury in the Arctic troposphere at polar sunrise, Environ. Sci. Technol., 36, 1245–1256, https://doi.org/10.1021/es0111941, 2002.
Liss, P. W. and Slater, P. G.: Flux of gases across the air-sea interface, Nature, 247, 181–184, https://doi.org/10.1038/247181a0, 1974.
Liu, B., Keeler, G. J., Dvonch, J. T., Barres, J. A., Lynam, M. M., Marsik, F. J., and Morgan, J. T.: Temporal variability of mercury speciation in urban air, Atmos. Environ., 41, 1911–1923, https://doi.org/10.1016/j.atmosenv.2006.10.063, 2007.
Liu, B., Keeler, G. J., Dvonch, J. T., Barres, J. A., Lynam, M. M., Marsik, F. J., and Morgan, J. T.: Urban-rural differences in atmospheric mercury speciation, Atmos. Environ., 44, 2013–2023, https://doi.org/10.1016/j.atmosenv.2010.02.012, 2010.
Liu, N., Qiu, G., Landis, M., Feng, X., Fu, X., and Shang, L.: Atmospheric mercury species measured in Guiyang, Guizhou province, southwest China, Atmos. Res., 100, 93–102, https://doi.org/10.1016/j.atmosres.2011.01.002, 2011.
Mamane, Y., Perrino, C., Yossef, O., and Catrambone, M.: Source characterization of fine and coarse particles at the East mediterranean coast, Atmos. Environ., 42, 6114–6130, https://doi.org/10.1016/j.atmosenv.2008.02.045, 2008.
Mao, H., Talbot, R., Hegarty, J., and Koermer, J.: Speciated mercury at marine, coastal, and inland sites in New England – Part 2: Relationships with atmospheric physical parameters, Atmos. Chem. Phys., 12, 4181–4206, https://doi.org/10.5194/acp-12-4181-2012, 2012.
Mao, H., Cheng, I., and Zhang, L.: Current understanding of the driving mechanisms for spatiotemporal variations of atmospheric speciated mercury: a review, Atmos. Chem. Phys., 16, 12897–12924, https://doi.org/10.5194/acp-16-12897-2016, 2016.
Mao, H., Hall, D., Ye, Z., Zhou, Y., Felton, D., and Zhang, L.: Impacts of large-scale circulation on urban ambient concentrations of gaseous elemental mercury in New York, USA, Atmos. Chem. Phys., 17, 11655–11671, https://doi.org/10.5194/acp-17-11655-2017, 2017.
Marumoto, K. and Imai, S.: Determination of dissolved gaseous mercury in seawater of Minamata Bay and estimation for mercury exchange across air-sea interface, Mar. Chem., 168, 9–17, https://doi.org/10.1016/j.marchem.2014.09.007, 2015.
Mason, R. P., Choi, A. L., Fitzgerald, W. F., Hammerschmidt, C. R., Lamborg, C. H., Soerensen, A. L., and Sunderland, E. M.: Mercury biogeochemical cycling in the ocean and policy implications, Environ. Res., 119, 101–117, https://doi.org/10.1016/j.envres.2012.03.013, 2012.
Mason, R. P., Hammerschmidt, C. R., Lamborg, C. H., Bowman, K. L., Swarr, G. J., and Shelley, R. U.: The air-sea exchange of mercury in the low latitude Pacific and Atlantic Oceans, Deep-Sea Res. Pt. I, 122, 17–28, https://doi.org/10.1016/j.dsr.2017.01.015, 2017.
Narukawa, M., Sakata, M., Marumoto, K., and Asakura, K.: Air-sea exchange of mercury in Tokyo Bay, J. Oceanogr., 62, 249–257, https://doi.org/10.1007/s10872-006-0049-3, 2006.
Nho-Kim, E. Y., Michou, M., and Peuch, V. H.: Parameterization of size-dependent particle dry deposition velocities for global modeling, Atmos. Environ., 38, 1933–1942, https://doi.org/10.1016/j.atmosenv.2004.01.002, 2004.
Poissant, L., Pilote, M., Xu, X., Zhang, H., and Beauvais, C.: Atmospheric mercury speciation and deposition in the Bay St. François wetlands, J. Geophys. Res., 109, D11301, https://doi.org/10.1029/2003JD004364, 2004.
Pryor, S. C. and Sorensen, L. L.: Nitric acid-sea salt reactions: Implications for nitrogen deposition to water surfaces, J. Appl. Meteorol., 39, 725–731, https://doi.org/10.1175/1520-0450-39.5.725, 2000.
Radke, L. F., Friedli, H. R., and Heikes, B. G.: Atmospheric mercury over the NE Pacific during spring 2002: Gradients, residence time, upper troposphere lower stratosphere loss, and long-range transport, J. Geophys. Res., 112, D19305, https://doi.org/10.1029/2005JD005828, 2007.
Read, K. A., Neves, L. M., Carpenter, L. J., Lewis, A. C., Fleming, Z. L., and Kentisbeer, J.: Four years (2011–2015) of total gaseous mercury measurements from the Cape Verde Atmospheric Observatory, Atmos. Chem. Phys., 17, 5393–5406, https://doi.org/10.5194/acp-17-5393-2017, 2017.
Rutter, A. P. and Schauer, J. J.: The effect of temperature on the gas–particle partitioning of reactive mercury in atmospheric aerosols, Atmos. Environ., 41, 8647–8657, https://doi.org/10.1016/j.atmosenv.2007.07.024, 2007.
Sander, R., Keene, W. C., Pszenny, A. A. P., Arimoto, R., Ayers, G. P., Baboukas, E., Cainey, J. M., Crutzen, P. J., Duce, R. A., Hönninger, G., Huebert, B. J., Maenhaut, W., Mihalopoulos, N., Turekian, V. C., and Van Dingenen, R.: Inorganic bromine in the marine boundary layer: a critical review, Atmos. Chem. Phys., 3, 1301–1336, https://doi.org/10.5194/acp-3-1301-2003, 2003.
Schroeder, W. H. and Munthe, J.: Atmospheric mercury – An overview, Atmos. Environ., 32, 809–822, https://doi.org/10.1016/S1352-2310(97)00293-8, 1998.
Selin, N. E., Jacob, D. J., Park, R. J., Yantosca, R. M., Strode, S., Jaeglé, L., and Jaffe, D.: Chemical cycling and deposition of atmospheric mercury: Global constraints from observations, J. Geophys. Res., 112, D02308, https://doi.org/10.1029/2006JD007450, 2007.
Shah, V., Jaeglé, L., Gratz, L. E., Ambrose, J. L., Jaffe, D. A., Selin, N. E., Song, S., Campos, T. L., Flocke, F. M., Reeves, M., Stechman, D., Stell, M., Festa, J., Stutz, J., Weinheimer, A. J., Knapp, D. J., Montzka, D. D., Tyndall, G. S., Apel, E. C., Hornbrook, R. S., Hills, A. J., Riemer, D. D., Blake, N. J., Cantrell, C. A., and Mauldin III, R. L.: Origin of oxidized mercury in the summertime free troposphere over the southeastern US, Atmos. Chem. Phys., 16, 1511–1530, https://doi.org/10.5194/acp-16-1511-2016, 2016.
Sheu, G. R. and Mason, R. P.: An examination of the oxidation of elemental mercury in the presence of halide surfaces, J. Atmos. Chem., 48, 107–130, https://doi.org/10.1023/B:JOCH.0000036842.37053.e6, 2004.
Slemr, F., Angot, H., Dommergue, A., Magand, O., Barret, M., Weigelt, A., Ebinghaus, R., Brunke, E.-G., Pfaffhuber, K. A., Edwards, G., Howard, D., Powell, J., Keywood, M., and Wang, F.: Comparison of mercury concentrations measured at several sites in the Southern Hemisphere, Atmos. Chem. Phys., 15, 3125–3133, https://doi.org/10.5194/acp-15-3125-2015, 2015.
Soerensen, A. L., Skov, H., Jacob, D. J., Soerensen, B. T., and Johnson, M. S.: Global concentrations of gaseous elemental mercury and reactive gaseous mercury in the marine boundary layer, Environ. Sci. Technol., 44, 7425–7430, https://doi.org/10.1021/es903839n, 2010a.
Soerensen, A. L., Sunderland, E. M., Holmes, C. D., Jacob, D. J., Yantosca, R. M., Skov, H., Christensen, J. H., Strode, S. A., and Mason, R. P.: An improved global model for air-sea exchange of mercury: high concentrations over the North Atlantic, Environ. Sci. Technol., 44, 8574–8580, https://doi.org/10.1021/es102032g, 2010b.
Soerensen, A. L., Mason, R. P., Balcom, P. H., Jacob, D. J., Zhang, Y., Kuss, J., and Sunderland, E. M.: Elemental mercury concentrations and fluxes in the tropical atmosphere and ocean, Environ. Sci. Technol., 48, 11312–11319, https://doi.org/10.1021/es503109p, 2014.
Sprovieri, F. and Pirrone, N.: Spatial and temporal distribution of atmospheric mercury species over the Adriatic Sea, Environ. Fluid Mech., 8, 117–128, https://doi.org/10.1007/s10652-007-9045-4, 2008.
Sprovieri, F., Pirrone, N., Gärdfeldt, K., and Sommar, J.: Mercury speciation in the marine boundary layer along a 6000 km cruise path around the Mediterranean Sea, Atmos. Environ., 37, S63–S71, https://doi.org/10.1016/S1352-2310(03)00237-1, 2003.
Sprovieri, F., Hedgecock, I. M., and Pirrone, N.: An investigation of the origins of reactive gaseous mercury in the Mediterranean marine boundary layer, Atmos. Chem. Phys., 10, 3985–3997, https://doi.org/10.5194/acp-10-3985-2010, 2010.
Steffen, A., Lehnherr, I., Cole, A., Ariya, P., Dastoor, A., Durnford, D., Kirk, J., and Pilote, M.: Atmospheric mercury measurements in the Canadian Arctic Part 1: A review of recent field measurements, Sci. Total Environ., 509–510, 3–15, https://doi.org/10.1016/j.scitotenv.2014.10.109, 2015.
Strode, S. A., Jaeglé, L., Selin, N. E., Jacob, D. J., Park, R. J., Yantosca, R. M., Mason, R. P., and Slemr, F.: Air-sea exchange in the global mercury cycle, Global Biogeochem. Cy., 21, GB1017, https://doi.org/10.1029/2006GB002766, 2007.
Tseng, C. M., Liu, C. S., and Lamborg, C.: Seasonal changes in gaseous elemental mercury in relation to monsoon cycling over the northern South China Sea, Atmos. Chem. Phys., 12, 7341–7350, https://doi.org/10.5194/acp-12-7341-2012, 2012.
UNEP: Global Mercury Assessment: Sources, Emissions, Releases and Environmental Transport, UNEP Chemicals Branch, Geneva, Switzerland, 2013.
Valente, R. J., Shea, C., Humes, K. L., and Tanner, R. L.: Atmospheric mercury in the Great Smoky Mountains compared to regional and global levels, Atmos. Environ., 41, 1861–1873, https://doi.org/10.1016/j.atmosenv.2006.10.054, 2007.
Wang, C., Wang, Z., Ci, Z., Zhang, X., and Tang, X.: Spatial-temporal distributions of gaseous element mercury and particulate mercury in the Asian marine boundary layer, Atmos. Environ., 126, 107–116, https://doi.org/10.1016/j.atmosenv.2015.11.036, 2016a.
Wang, C., Ci, Z., Wang, Z., Zhang, X., and Guo, J.: Speciated atmospheric mercury in the marine boundary layer of the Bohai Sea and Yellow Sea, Atmos. Environ., 131, 360–370, https://doi.org/10.1016/j.atmosenv.2016.02.021, 2016b.
Wang, C., Ci, Z., Wang, Z., and Zhang, X.: Air-sea exchange of gaseous mercury in the East China Sea, Environ. Pollut., 212, 535–543, https://doi.org/10.1016/j.envpol.2016.03.016, 2016c.
Wang, S., Schmidt, J. A., Baidar, S., Coburn, S., Dix, B., Koenig, T. K., Apel, E., Bowdalo, D., Campos, T. L., Eloranta, E., Evans, M. J., DiGangi, J. P., Zondlo, M. A., Gao, R. S., Haggerty, J. A., Hall, S. R., Hornbrook, R. S., Jacob, D., Morley, B., Pierce, B., Reeves, M., Romashkin, P., ter Schure, A., and Volkamer, R.: Active and widespread halogen chemistry in the tropical and subtropical free troposphere, P. Natl. Acad. Sci. USA, 112, 9281–9286, https://doi.org/10.1073/pnas.1505142112, 2015.
Wang, Y. Q., Zhang, X. Y., and Draxler, R. R.: TrajStat: GIS-based software that uses various trajectory statistical analysis methods to identify potential sources from long-term air pollution measurement data, Environ. Model. Softw., 28, 938–939, https://doi.org/10.1016/j.envsoft.2009.01.004, 2009.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean, J. Geophys. Res., 97, 7373–7382, https://doi.org/10.1029/92JC00188, 1992.
Witt, M. L. I., Mather, T. A., Baker, A. R., De Hoog, J. C. M., and Pyle, D. M.: Atmospheric trace metals over the south-west Indian Ocean: Total gaseous mercury, aerosol trace metal concentrations and lead isotope ratios, Mar. Chem., 121, 2–16, https://doi.org/10.1016/j.marchem.2010.02.005, 2010.
Ye, Z., Mao, H., Lin, C.-J., and Kim, S. Y.: Investigation of processes controlling summertime gaseous elemental mercury oxidation at midlatitudinal marine, coastal, and inland sites, Atmos. Chem. Phys., 16, 8461–8478, https://doi.org/10.5194/acp-16-8461-2016, 2016.
Zhu, J., Wang, T., Talbot, R., Mao, H., Yang, X., Fu, C., Sun, J., Zhuang, B., Li, S., Han, Y., and Xie, M.: Characteristics of atmospheric mercury deposition and size-fractionated particulate mercury in urban Nanjing, China, Atmos. Chem. Phys., 14, 2233–2244, https://doi.org/10.5194/acp-14-2233-2014, 2014.
A low GEM level indicated that the SCS suffered less anthropogenic influence. There was no significant difference in GEM and HgP2.5 values between day and night, but the RGM level was higher in daytime than in nighttime. The size distribution of HgP in PM10 was observed to be bi-modal, but the coarse modal was the dominant size. The annual emission flux of Hg0 from the SCS was estimated to be 159 ton yr-1. The dry deposition was an important pathway for the input of atmospheric Hg to the SCS.
A low GEM level indicated that the SCS suffered less anthropogenic influence. There was no...