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Kurz AY, Blum JD, Gratz LE, Jaffe DA. Contrasting Controls on the Diel Isotopic Variation of Hg 0 at Two High Elevation Sites in the Western United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:10502-10513. [PMID: 32786593 DOI: 10.1021/acs.est.0c01918] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The atmosphere is a significant global reservoir for mercury (Hg) and its isotopic characterization is important to understand sources, distribution, and deposition of Hg to the Earth's surface. To better understand Hg isotope variability in the remote background atmosphere, we collected continuous 12-h Hg0 samples for 1 week from two high elevation sites, Camp Davis, Wyoming (valley), and Mount Bachelor, Oregon (mountaintop). The samples collected at Camp Davis displayed strong diel variation in δ202Hg values of Hg0, but not in Δ199Hg or Δ200Hg values. We attribute this pattern to nightly atmospheric inversions trapping Hg in the valley and the subsequent nighttime uptake of Hg by vegetation, which depletes Hg from the atmosphere. At Mount Bachelor, the samples displayed diel variation in both δ202Hg and Δ199Hg, but not Δ200Hg. We attribute this pattern to differences in the vertical distribution of Hg in the atmosphere as Mount Bachelor received free tropospheric air masses on certain nights during the sampling period. Near the end of the sampling period at Mount Bachelor, the observed diel pattern dissipated due to the influence of a nearby forest fire. The processes governing the Hg isotopic fractionation differ across sites depending on mixing, topography, and vegetation cover.
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Affiliation(s)
- Aaron Y Kurz
- Department of Earth and Environmental Sciences, University of Michigan, 1100 N University Avenue, Ann Arbor, Michigan 48109, United States
| | - Joel D Blum
- Department of Earth and Environmental Sciences, University of Michigan, 1100 N University Avenue, Ann Arbor, Michigan 48109, United States
| | - Lynne E Gratz
- Environmental Studies Program, Colorado College, Colorado Springs, Colorado 80903, United States
| | - Daniel A Jaffe
- School of Science, Technology, Engineering & Mathematics, University of Washington Bothell, Bothell, Washington 98011, United States
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Sommar J, Osterwalder S, Zhu W. Recent advances in understanding and measurement of Hg in the environment: Surface-atmosphere exchange of gaseous elemental mercury (Hg 0). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137648. [PMID: 32182462 DOI: 10.1016/j.scitotenv.2020.137648] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 05/26/2023]
Abstract
The atmosphere is the major transport pathway for distribution of mercury (Hg) globally. Gaseous elemental mercury (GEM, hereafter Hg0) is the predominant form in both anthropogenic and natural emissions. Evaluation of the efficacy of reductions in emissions set by the UN's Minamata Convention (UN-MC) is critically dependent on the knowledge of the dynamics of the global Hg cycle. Of these dynamics including e.g. red-ox reactions, methylation-demethylation and dry-wet deposition, poorly constrained atmosphere-surface Hg0 fluxes especially limit predictability of the timescales of its global biogeochemical cycle. This review focuses on Hg0 flux field observational studies, namely the theory, applications, strengths, and limitations of the various experimental methodologies applied to gauge the exchange flux and decipher active sub-processes. We present an in-depth review, a comprehensive literature synthesis, and methodological and instrumentation advances for terrestrial and marine Hg0 flux studies in recent years. In particular, we outline the theory of a wide range of measurement techniques and detail the operational protocols. Today, the most frequently used measurement techniques to determine the net Hg0 flux (>95% of the published flux data) are dynamic flux chambers for small-scale and micrometeorological approaches for large-scale measurements. Furthermore, top-down approaches based on Hg0 concentration measurements have been applied as tools to better constrain Hg emissions as an independent way to e.g. challenge emission inventories. This review is an up-dated, thoroughly revised edition of Sommar et al. 2013 (DOI: 10.1080/10643389.2012.671733). To the tabulation of >100 cited flux studies 1988-2009 given in the former publication, we have here listed corresponding studies published during the last decade with a few exceptions (2008-2019). During that decade, Hg stable isotope ratios of samples involved in atmosphere-terrestrial interaction is at hand and provide in combination with concentration and/or flux measurements novel constraints to quantitatively and qualitatively assess the bi-directional Hg0 flux. Recent efforts in the development of relaxed eddy accumulation and eddy covariance Hg0 flux methods bear the potential to facilitate long-term, ecosystem-scale flux measurements to reduce the prevailing large uncertainties in Hg0 flux estimates. Standardization of methods for Hg0 flux measurements is crucial to investigate how land-use change and how climate warming impact ecosystem-specific Hg0 sink-source characteristics and to validate frequently applied model parameterizations describing the regional and global scale Hg cycle.
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Affiliation(s)
- Jonas Sommar
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China.
| | - Stefan Osterwalder
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble INP, Grenoble, France
| | - Wei Zhu
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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Tong Y, Yin X, Lin H, Wang H, Deng C, Chen L, Li J, Zhang W, Schauer JJ, Kang S, Zhang G, Bu X, Wang X, Zhang Q. Recent Decline of Atmospheric Mercury Recorded by Androsace tapete on the Tibetan Plateau. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:13224-13231. [PMID: 27993077 DOI: 10.1021/acs.est.6b04632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We combined the mercury passive sampling method and plant biomonitoring together to understand the long-term changes of atmospheric mercury concentrations on the Tibetan Plateau. Through the analysis of leaves of Androsace tapete that represent growing periods spanning the past decade, we explored the historical records of atmospheric mercury from 2006 to 2015. Mercury concentration was stable in the leaves of Androsace tapete during the period between 2006 and 2009, while a significant decrease occurred after the year of 2010. The decreasing trend is consistent with the monitoring data of the ground-based stations in other regions globally. Despite the potential uncertainties using a passive sampling method and biomonitoring technique, we suggest that Androsace tapete is a potential biomarker that could provide reliable and effective historical records of atmospheric mercury concentrations and offer new perspectives in monitoring mercury and perhaps other atmospheric pollutants in regions where long-term active monitoring was missing.
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Affiliation(s)
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences , Lanzhou, 730000 P.R. China
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
- University of Chinese Academy of Sciences , Beijing, 100049 P.R. China
| | - Huiming Lin
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Huanhuan Wang
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Chunyan Deng
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Long Chen
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Jinling Li
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Wei Zhang
- School of Environment and Natural Resources, Renmin University of China , Beijing, 100872 P.R. China
| | - James Jay Schauer
- Civil & Environmental Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53703, United States
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences , Lanzhou, 730000 P.R. China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences , Beijing, 100101 P.R. China
| | - Guoshuai Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
| | | | - Xuejun Wang
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences , Beijing, 100101 P.R. China
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Bieser J, De Simone F, Gencarelli C, Geyer B, Hedgecock I, Matthias V, Travnikov O, Weigelt A. A diagnostic evaluation of modeled mercury wet depositions in Europe using atmospheric speciated high-resolution observations. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:9995-10012. [PMID: 24764005 DOI: 10.1007/s11356-014-2863-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/01/2014] [Indexed: 05/24/2023]
Abstract
This study is part of the Global Mercury Observation System (GMOS), a European FP7 project dedicated to the improvement and validation of mercury models to assist in establishing a global monitoring network and to support political decisions. One key question about the global mercury cycle is the efficiency of its removal out of the atmosphere into other environmental compartments. So far, the evaluation of modeled wet deposition of mercury was difficult because of a lack of long-term measurements of oxidized and elemental mercury. The oxidized mercury species gaseous oxidized mercury (GOM) and particle-bound mercury (PBM) which are found in the atmosphere in typical concentrations of a few to a few tens pg/m(3) are the relevant components for the wet deposition of mercury. In this study, the first European long-term dataset of speciated mercury taken at Waldhof/Germany was used to evaluate deposition fields modeled with the chemistry transport model (CTM) Community Multiscale Air Quality (CMAQ) and to analyze the influence of the governing parameters. The influence of the parameters precipitation and atmospheric concentration was evaluated using different input datasets for a variety of CMAQ simulations for the year 2009. It was found that on the basis of daily and weekly measurement data, the bias of modeled depositions could be explained by the bias of precipitation fields and atmospheric concentrations of GOM and PBM. A correction of the modeled wet deposition using observed daily precipitation increased the correlation, on average, from 0.17 to 0.78. An additional correction based on the daily average GOM and PBM concentration lead to a 50% decrease of the model error for all CMAQ scenarios. Monthly deposition measurements were found to have a too low temporal resolution to adequately analyze model deficiencies in wet deposition processes due to the nonlinear nature of the scavenging process. Moreover, the general overestimation of atmospheric GOM by the CTM in combination with an underestimation of low precipitation events in the meteorological models lead to a good agreement of total annual wet deposition besides the large error in weekly deposition estimates. Moreover, it was found that the current speciation profiles for GOM emissions are the main factor for the overestimation of atmospheric GOM concentrations and might need to be revised in the future. The assumption of zero emissions of GOM lead to an improvement of the mean normalized bias for three-hourly observations of atmospheric GOM from 9.7 to 0.5, Furthermore, the diurnal correlation between model and observation increased from 0.01 to 0.64. This is a strong indicator that GOM is not directly emitted from primary sources but is mainly created by oxidation of GEM.
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Affiliation(s)
- J Bieser
- Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502, Geesthacht, Germany,
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Cai Y, Montague DC, Deshler T. Comparison of measured and calculated scattering from surface aerosols with an average, a size-dependent, and a time-dependent refractive index. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd014607] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gustin M, Jaffe D. Reducing the uncertainty in measurement and understanding of mercury in the atmosphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2222-2227. [PMID: 20184358 DOI: 10.1021/es902736k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Elucidating the extent of mercury in the atmosphere requires deployment of robust and sensitive instruments.
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Affiliation(s)
- Mae Gustin
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, USA.
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