Articles | Volume 22, issue 22
https://doi.org/10.5194/acp-22-14631-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-22-14631-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Nov 2022
Research article |
| 18 Nov 2022
| 18 Nov 2022
Long-term declines in atmospheric nitrogen and sulfur deposition reduce critical loads exceedances at multiple Canadian rural sites, 2000–2018
Irene Cheng
CORRESPONDING AUTHOR
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Zhuanshi He
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Hazel Cathcart
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Daniel Houle
Aquatic Contaminants Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Montréal, Quebec H2Y 2E7, Canada
Amanda Cole
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Jian Feng
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Jason O'Brien
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Anne Marie Macdonald
Air Quality Research Division, Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
Julian Aherne
School of Environment, Trent University, Peterborough, Ontario K9L 0G2, Canada
Jeffrey Brook
Dalla Lana School of Public Health and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5T 3M7, Canada
Related authors
Irene Cheng, Amanda Cole, Leiming Zhang, and Alexandra Steffen
Atmos. Chem. Phys., 25, 8591–8611, https://doi.org/10.5194/acp-25-8591-2025, https://doi.org/10.5194/acp-25-8591-2025, 2025
Short summary
Short summary
Using the positive matrix factorization (PMF) model and observations, we showed that natural surface emission (wildfires and re-emitted Hg) dominated anthropogenic contributions to total gaseous mercury (TGM). Decreasing TGM was due to reduced shipping, local combustion, and regional emissions. Relative contributions from natural surface emissions increased by 0.3–1.8 % yr-1. Results showed Hg control measures have been effective, but greater attention is needed for monitoring surface re-emissions.
Irene Cheng, Amanda Cole, Leiming Zhang, and Alexandra Steffen
Atmos. Chem. Phys., 25, 8591–8611, https://doi.org/10.5194/acp-25-8591-2025, https://doi.org/10.5194/acp-25-8591-2025, 2025
Short summary
Short summary
Using the positive matrix factorization (PMF) model and observations, we showed that natural surface emission (wildfires and re-emitted Hg) dominated anthropogenic contributions to total gaseous mercury (TGM). Decreasing TGM was due to reduced shipping, local combustion, and regional emissions. Relative contributions from natural surface emissions increased by 0.3–1.8 % yr-1. Results showed Hg control measures have been effective, but greater attention is needed for monitoring surface re-emissions.
Anam M. Khan, Olivia E. Clifton, Jesse O. Bash, Sam Bland, Nathan Booth, Philip Cheung, Lisa Emberson, Johannes Flemming, Erick Fredj, Stefano Galmarini, Laurens Ganzeveld, Orestis Gazetas, Ignacio Goded, Christian Hogrefe, Christopher D. Holmes, László Horváth, Vincent Huijnen, Qian Li, Paul A. Makar, Ivan Mammarella, Giovanni Manca, J. William Munger, Juan L. Pérez-Camanyo, Jonathan Pleim, Limei Ran, Roberto San Jose, Donna Schwede, Sam J. Silva, Ralf Staebler, Shihan Sun, Amos P. K. Tai, Eran Tas, Timo Vesala, Tamás Weidinger, Zhiyong Wu, Leiming Zhang, and Paul C. Stoy
Atmos. Chem. Phys., 25, 8613–8635, https://doi.org/10.5194/acp-25-8613-2025, https://doi.org/10.5194/acp-25-8613-2025, 2025
Short summary
Short summary
Vegetation removes tropospheric ozone through stomatal uptake, and accurately modeling the stomatal uptake of ozone is important for modeling dry deposition and air quality. We evaluated the stomatal component of ozone dry deposition modeled by atmospheric chemistry models at six sites. We find that models and observation-based estimates agree at times during the growing season at all sites, but some models overestimated the stomatal component during the dry summers at a seasonally dry site.
Paul A. Makar, Philip Cheung, Christian Hogrefe, Ayodeji Akingunola, Ummugulsum Alyuz, Jesse O. Bash, Michael D. Bell, Roberto Bellasio, Roberto Bianconi, Tim Butler, Hazel Cathcart, Olivia E. Clifton, Alma Hodzic, Ioannis Kioutsioukis, Richard Kranenburg, Aurelia Lupascu, Jason A. Lynch, Kester Momoh, Juan L. Perez-Camanyo, Jonathan Pleim, Young-Hee Ryu, Roberto San Jose, Donna Schwede, Thomas Scheuschner, Mark W. Shephard, Ranjeet S. Sokhi, and Stefano Galmarini
Atmos. Chem. Phys., 25, 3049–3107, https://doi.org/10.5194/acp-25-3049-2025, https://doi.org/10.5194/acp-25-3049-2025, 2025
Short summary
Short summary
The large range of sulfur and nitrogen deposition estimates from air quality models results in a large range of predicted impacts. We used models and deposition diagnostics to identify the processes controlling atmospheric sulfur and nitrogen deposition variability. Controlling factors included the uptake of gases and aerosols by hydrometeors, aerosol inorganic chemistry, particle dry deposition, ammonia bidirectional fluxes, gas deposition via plant cuticles and soil, and land use data.
Dane Blanchard, Mark Gordon, Duc Huy Dang, Paul Andrew Makar, and Julian Aherne
Atmos. Chem. Phys., 25, 2423–2442, https://doi.org/10.5194/acp-25-2423-2025, https://doi.org/10.5194/acp-25-2423-2025, 2025
Short summary
Short summary
This study offers the first known evaluation of water-soluble brown carbon aerosols in the Athabasca oil sands region (AOSR), Canada. Fluorescence spectroscopy analysis of aerosol samples from five regional sites (collected during the summer of 2021) identified oil sands operations as a measurable brown carbon source. Industrial aerosol emissions were unlikely to impact regional radiative forcing. These findings show that fluorescence spectroscopy can be used to monitor brown carbon in the AOSR.
Tamara Emmerichs, Abdulla Al Mamun, Lisa Emberson, Huiting Mao, Leiming Zhang, Limei Ran, Clara Betancourt, Anthony Wong, Gerbrand Koren, Giacomo Gerosa, Min Huang, and Pierluigi Guaita
EGUsphere, https://doi.org/10.5194/egusphere-2025-429, https://doi.org/10.5194/egusphere-2025-429, 2025
Short summary
Short summary
The risk of ozone pollution to plants is estimated based on the flux through the plant pores which still has uncertainties. In this study, we estimate this quantity with 9 models at different land types worldwide. The input data stems from a database. The models estimated mostly reasonable summertime ozone deposition. The different results of the models varied by land cover which were mostly related to the moisture deficit. This is an important step for assessing the ozone impact on vegetation.
Hazel Cathcart, Julian Aherne, Michael D. Moran, Verica Savic-Jovcic, Paul A. Makar, and Amanda Cole
Biogeosciences, 22, 535–554, https://doi.org/10.5194/bg-22-535-2025, https://doi.org/10.5194/bg-22-535-2025, 2025
Short summary
Short summary
Deposition from sulfur and nitrogen pollution can harm ecosystems, and recovery from this type of pollution can take decades or longer. To identify risk to Canadian soils, we created maps showing sensitivity to sulfur and nitrogen pollution. Results show that some ecosystems are at risk from acid and nutrient nitrogen deposition: 10 % of protected areas are receiving acid deposition beyond their damage threshold, and 70 % may be receiving nitrogen deposition that could cause biodiversity loss.
Zihan Song, Leiming Zhang, Chongguo Tian, Qiang Fu, Zhenxing Shen, Renjian Zhang, Dong Liu, and Song Cui
Atmos. Chem. Phys., 24, 13101–13113, https://doi.org/10.5194/acp-24-13101-2024, https://doi.org/10.5194/acp-24-13101-2024, 2024
Short summary
Short summary
A novel concept integrating crop cycle information into fire spot extraction was proposed. Spatiotemporal variations of open straw burning in Northeast China are revealed. Open straw burning in Northeast China emitted a total of 218 Tg of CO2-eq during 2001–2020. The policy of banning straw burning effectively reduced greenhouse gas emissions.
Pierluigi Renan Guaita, Riccardo Marzuoli, Leiming Zhang, Steven Turnock, Gerbrand Koren, Oliver Wild, Paola Crippa, and Giacomo Alessandro Gerosa
EGUsphere, https://doi.org/10.5194/egusphere-2024-2573, https://doi.org/10.5194/egusphere-2024-2573, 2024
Preprint archived
Short summary
Short summary
This study assesses the global impact of tropospheric ozone on wheat crops in the 21st century under various climate scenarios. The research highlights that ozone damage to wheat varies by region and depends on both ozone levels and climate. Vulnerable regions include East Asia, Northern Europe, and the Southern and Eastern edges of the Tibetan Plateau. Our results emphasize the need of policies to reduce ozone levels and mitigate climate change to protect global food security.
Xiaohong Yao and Leiming Zhang
Atmos. Chem. Phys., 24, 7773–7791, https://doi.org/10.5194/acp-24-7773-2024, https://doi.org/10.5194/acp-24-7773-2024, 2024
Short summary
Short summary
This study investigates long-term trends of criteria air pollutants, including NO2, CO, SO2, O3 and PM2.5, and NO2+O3 measured in 10 Canadian cities during the last 2 to 3 decades. We also investigate associated driving forces in terms of emission reductions, perturbations from varying weather conditions and large-scale wildfires, as well as changes in O3 sources and sinks.
Juanjuan Qin, Leiming Zhang, Yuanyuan Qin, Shaoxuan Shi, Jingnan Li, Zhao Shu, Yuwei Gao, Ting Qi, Jihua Tan, and Xinming Wang
Atmos. Chem. Phys., 24, 7575–7589, https://doi.org/10.5194/acp-24-7575-2024, https://doi.org/10.5194/acp-24-7575-2024, 2024
Short summary
Short summary
The present research unveiled that acidity dominates while transition metal ions harmonize with the light absorption properties of humic-like substances (HULIS). Cu2+ has quenching effects on HULIS by complexation, hydrogen substitution, or electrostatic adsorption, with aromatic structures of HULIS. Such effects are less pronounced if from Mn2+, Ni2+, Zn2+, and Cu2+. Oxidized HULIS might contain electron-donating groups, whereas N-containing compounds might contain electron-withdrawing groups.
Roya Ghahreman, Wanmin Gong, Paul A. Makar, Alexandru Lupu, Amanda Cole, Kulbir Banwait, Colin Lee, and Ayodeji Akingunola
Geosci. Model Dev., 17, 685–707, https://doi.org/10.5194/gmd-17-685-2024, https://doi.org/10.5194/gmd-17-685-2024, 2024
Short summary
Short summary
The article explores the impact of different representations of below-cloud scavenging on model biases. A new scavenging scheme and precipitation-phase partitioning improve the model's performance, with better SO42- scavenging and wet deposition of NO3- and NH4+.
Olivia E. Clifton, Donna Schwede, Christian Hogrefe, Jesse O. Bash, Sam Bland, Philip Cheung, Mhairi Coyle, Lisa Emberson, Johannes Flemming, Erick Fredj, Stefano Galmarini, Laurens Ganzeveld, Orestis Gazetas, Ignacio Goded, Christopher D. Holmes, László Horváth, Vincent Huijnen, Qian Li, Paul A. Makar, Ivan Mammarella, Giovanni Manca, J. William Munger, Juan L. Pérez-Camanyo, Jonathan Pleim, Limei Ran, Roberto San Jose, Sam J. Silva, Ralf Staebler, Shihan Sun, Amos P. K. Tai, Eran Tas, Timo Vesala, Tamás Weidinger, Zhiyong Wu, and Leiming Zhang
Atmos. Chem. Phys., 23, 9911–9961, https://doi.org/10.5194/acp-23-9911-2023, https://doi.org/10.5194/acp-23-9911-2023, 2023
Short summary
Short summary
A primary sink of air pollutants is dry deposition. Dry deposition estimates differ across the models used to simulate atmospheric chemistry. Here, we introduce an effort to examine dry deposition schemes from atmospheric chemistry models. We provide our approach’s rationale, document the schemes, and describe datasets used to drive and evaluate the schemes. We also launch the analysis of results by evaluating against observations and identifying the processes leading to model–model differences.
Mark Gordon, Dane Blanchard, Timothy Jiang, Paul A. Makar, Ralf M. Staebler, Julian Aherne, Cris Mihele, and Xuanyi Zhang
Atmos. Chem. Phys., 23, 7241–7255, https://doi.org/10.5194/acp-23-7241-2023, https://doi.org/10.5194/acp-23-7241-2023, 2023
Short summary
Short summary
Measurements of the gas sulfur dioxide (SO2) were made in a forest downwind of oil sands mining and production facilities in northern Alberta. These measurements tell us the rate at which SO2 is absorbed by the forest. The measured rate is much higher than what is currently used by air quality models, which is supported by a previous study in this region. This suggests that SO2 may have a much shorter lifetime in the atmosphere at this location than currently predicted by models.
Yu Lin, Leiming Zhang, Qinchu Fan, He Meng, Yang Gao, Huiwang Gao, and Xiaohong Yao
Atmos. Chem. Phys., 22, 16073–16090, https://doi.org/10.5194/acp-22-16073-2022, https://doi.org/10.5194/acp-22-16073-2022, 2022
Short summary
Short summary
In this study, we analyzed 7-year (from May 2014 to April 2021) concentration data of six criteria air pollutants (PM2.5, PM10, O3, NO2, CO and SO2) as well as the sum of NO2 and O3 in six cities in South China. Three different analysis methods were used to identify emission-driven interannual variations and perturbations from varying weather conditions. In addition, a self-developed method was further introduced to constrain analysis uncertainties.
Hui Zhang, Xuewu Fu, Ben Yu, Baoxin Li, Peng Liu, Guoqing Zhang, Leiming Zhang, and Xinbin Feng
Atmos. Chem. Phys., 21, 15847–15859, https://doi.org/10.5194/acp-21-15847-2021, https://doi.org/10.5194/acp-21-15847-2021, 2021
Short summary
Short summary
Our observations of speciated atmospheric mercury at the Waliguan GAW Baseline Observatory show that concentrations of gaseous elemental mercury (GEM) and particulate bound mercury (PBM) were elevated compared to the Northern Hemisphere background. We propose that the major sources of GEM and PBM were mainly related to anthropogenic emissions and desert dust sources. This study highlights that dust-related sources played an important role in the variations of PBM in the Tibetan Plateau.
Zhiyong Wu, Leiming Zhang, John T. Walker, Paul A. Makar, Judith A. Perlinger, and Xuemei Wang
Geosci. Model Dev., 14, 5093–5105, https://doi.org/10.5194/gmd-14-5093-2021, https://doi.org/10.5194/gmd-14-5093-2021, 2021
Short summary
Short summary
A community dry deposition algorithm for modeling the gaseous dry deposition process in chemistry transport models was extended to include an additional 12 oxidized volatile organic compounds and hydrogen cyanide based on their physicochemical properties and was then evaluated using field flux measurements over a mixed forest. This study provides a useful tool that is needed in chemistry transport models with increasing complexity for simulating an important atmospheric process.
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, https://doi.org/10.5194/acp-21-8377-2021, https://doi.org/10.5194/acp-21-8377-2021, 2021
Short summary
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.
Xuewu Fu, Chen Liu, Hui Zhang, Yue Xu, Hui Zhang, Jun Li, Xiaopu Lyu, Gan Zhang, Hai Guo, Xun Wang, Leiming Zhang, and Xinbin Feng
Atmos. Chem. Phys., 21, 6721–6734, https://doi.org/10.5194/acp-21-6721-2021, https://doi.org/10.5194/acp-21-6721-2021, 2021
Short summary
Short summary
TGM concentrations and isotopic compositions in 10 Chinese cities showed strong seasonality with higher TGM concentrations and Δ199Hg and lower δ202Hg in summer. We found the seasonal variations in TGM concentrations and isotopic compositions were highly related to regional surface Hg(0) emissions, suggesting land surface Hg(0) emissions are an important source of atmospheric TGM that contribute dominantly to the seasonal variations in TGM concentrations and isotopic compositions.
Xiaofei Qin, Leiming Zhang, Guochen Wang, Xiaohao Wang, Qingyan Fu, Jian Xu, Hao Li, Jia Chen, Qianbiao Zhao, Yanfen Lin, Juntao Huo, Fengwen Wang, Kan Huang, and Congrui Deng
Atmos. Chem. Phys., 20, 10985–10996, https://doi.org/10.5194/acp-20-10985-2020, https://doi.org/10.5194/acp-20-10985-2020, 2020
Short summary
Short summary
The uncertainties in mercury emissions are much larger from natural sources than anthropogenic sources. A method was developed to quantify the contributions of natural surface emissions to ambient GEM based on PMF modeling. The annual GEM concentration in eastern China showed a decreasing trend from 2015 to 2018, while the relative contribution of natural surface emissions increased significantly from 41 % in 2015 to 57 % in 2018, gradually surpassing those from anthropogenic sources.
E. Morris, X. Liu, A. Manwar, D. Y. Zang, G. Evans, J. Brook, B. Rousseau, C. Clark, and J. MacIsaac
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., VI-4-W2-2020, 119–126, https://doi.org/10.5194/isprs-annals-VI-4-W2-2020-119-2020, https://doi.org/10.5194/isprs-annals-VI-4-W2-2020-119-2020, 2020
Cited articles
Aherne, J. and Jeffries, D.:
Critical Load Assessments and Dynamic Model Applications for Lakes in North America, in: Critical Loads and Dynamic Risk Assessments, series Environmental Pollution, vol. 25, edited by: de Vries, W., Hettelingh, J. P., and Posch, M., Springer, Dordrecht, https://doi.org/10.1007/978-94-017-9508-1_19, 2015.
Altshuller, A.:
Model predictions of the rates of homogeneous oxidation of sulfur dioxide to sulfate in the troposphere, Atmos. Environ., 13, 1653–1661, 1979.
Anastasopolos, A. T., Sofowote, U. M., Hopke, P. K., Rouleau, M., Shin, T., Dheri, A., Peng, H., Kulka, R., Gibson, M. D., Farah, P. M., and Sundar, N.:
Air quality in Canadian port cities after regulation of low-sulphur marine fuel in the North American Emissions Control Area, Sci. Total. Environ., 791, 147949, https://doi.org/10.1016/j.scitotenv.2021.147949, 2021.
Benish, S. E., Bash, J. O., Foley, K. M., Appel, K. W., Hogrefe, C., Gilliam, R., and Pouliot, G.:
Long-term regional trends of nitrogen and sulfur deposition in the United States from 2002 to 2017, Atmos. Chem. Phys., 22, 12749–12767, https://doi.org/10.5194/acp-22-12749-2022, 2022.
Bergström, A. K. and Jansson, M.:
Atmospheric nitrogen deposition has caused nitrogen enrichment and eutrophication of lakes in the Northern Hemisphere, Glob. Change Biol., 12, 635–643, 2006.
Bobbink, R. and Hicks, W. K.:
Factors Affecting Nitrogen Deposition Impacts on Biodiversity: An Overview, in: Nitrogen Deposition, Critical Loads and Biodiversity, edited by: Sutton, M. A., Mason, K. E., Sheppard, L. J., Sverdrup, H., Haeuber, R., and Hicks, W. K., Springer, Dordrecht, https://doi.org/10.1007/978-94-007-7939-6_14, 127–138, 2014.
Bobbink, R., Braun, S., Nordin, A., Power, S., Schutz, K., Strengbom, J., Weijters, M., and Tomassen, H: Review and revision of empirical critical loads and dose-response relationships, in: Proceedings of an expert workshop, Noordwijkerhout, 23–25 June 2010, edited by: Bobbink, R. and Hettelingh, J.-P., 21–28, 2011.
Brakke, D. F., Henriksen, A., and Norton, S. A.:
A variable F-factor to explain changes in base cation concentration as a function of strong acid deposition, Verh. Int. Verein. Limnol., 24, 146–149, 1990.
Brook, J. R., Samson, P. J., and Sillman, S.:
A meteorology-based approach to detecting the relationship between changes in SO2 emission rates and precipitation concentrations of sulfate, J. Appl. Meteorol. Clim., 33, 1050–1066, 1994.
Burns, D. A., Bhatt, G., Linker, L. C., Bash, J. O., Capel, P. D., and Shenk, G. W.:
Atmospheric nitrogen deposition in the Chesapeake Bay watershed: A history of change, Atmos. Environ., 251, 118277, https://doi.org/10.1016/j.atmosenv.2021.118277, 2021.
Butler, T., Vermeylen, F., Lehmann, C. M., Likens, G. E., and Puchalski, M.:
Increasing ammonia concentration trends in large regions of the USA derived from the NADP/AMoN network, Atmos. Environ., 146, 132–140, 2016.
Carslaw, D. C. and Ropkins, K.:
Openair – an R package for air quality data analysis, Environ. Modell. Softw., 27–28, 52–61, 2012.
Cheng, I. and Zhang, L.:
Long-term air concentrations, wet deposition, and scavenging ratios of inorganic ions, HNO3, and SO2 and assessment of aerosol and precipitation acidity at Canadian rural locations, Atmos. Chem. Phys., 17, 4711–4730, https://doi.org/10.5194/acp-17-4711-2017, 2017.
Cheng, I., Zhang, L., Cole, A., Cathcart,
H., and Houle, D.: 2000–2018 annual total deposition fluxes of nitrogen and sulfur at CAPMoN sites, Environment and Climate Change Canada, Government of Canada Open Data Portal [data set], https://open.canada.ca/data/en/dataset/89a1e52c-d24e-4840-904f-fd6f2cb92648, last access: 7 November 2022.
CLRTAP: Manual on Methodologies and Criteria for Modelling and Mapping Critical Loads and Levels and Air Pollution Effects, Risks and Trends, CLRTAP, http://www.icpmapping.org (last access: 15 September 2021), 2004.
de Vries, W., Hettlingh, J.-P., and Posch, M. (Eds.): Critical Loads and Dynamic Risk Assessments: Nitrogen, Acidity and Metals in Terrestrial and Aquatic Ecosystems, series Environmental Pollution, vol. 25, Springer Dordrecht, https://doi.org/10.1007/978-94-017-9508-1, 2015.
Driscoll, C. T., Lawrence, G. B., Bulger, A. J., Butler, T. J., Cronan, C. S., Eagar, C., Lambert, K. F., Likens, G. E., Stoddard, J. L., and Weathers, K. C.:
Acidic Deposition in the Northeastern United States: Sources and Inputs, Ecosystem Effects, and Management Strategies, BioScience., 51, 180–198, 2001.
Du, E., de Vries, W., Galloway, J. N., Hu, X., and Fang, J.:
Changes in wet nitrogen deposition in the United States between 1985 and 2012, Environ. Res. Lett., 9, 9, https://doi.org/10.1088/1748-9326/9/9/095004, 2014.
Ellis, R. A., Jacob, D. J., Sulprizio, M. P., Zhang, L., Holmes, C. D., Schichtel, B. A., Blett, T., Porter, E., Pardo, L. H., and Lynch, J. A.:
Present and future nitrogen deposition to national parks in the United States: critical load exceedances, Atmos. Chem. Phys., 13, 9083–9095, https://doi.org/10.5194/acp-13-9083-2013, 2013.
Environment and Climate Change Canada (ECCC): 2004 Canadian Acid Deposition Science Assessment, Meteorological Services of Canada [data set], http://www.publications.gc.ca/pub?id=9.688243&sl=0 (last access: 7 November 2022), 2004.
Environment and Climate Change Canada (ECCC): Canadian Air and Precipitation Monitoring Network (CAPMoN), Government of Canada Open Data Portal [data set], https://open.canada.ca/data/en/dataset/4baa2ee4-a8aa-457a-af26-aa13e96ee2f4 (last access: 7 November 2022), 2017.
Environment and Climate Change Canada (ECCC): Canada's Air Pollutant Emissions Inventory, Government of Canada Open Data Portal [data set], https://open.canada.ca/data/en/dataset/fa1c88a8-bf78-4fcb-9c1e-2a5534b92131 (last access: 7 November 2022), 2021a.
Environment and Climate Change Canada (ECCC): Major ions, Government of Canada Open Data Portal [data set], https://open.canada.ca/data/en/dataset/9974e51f-2616-42bf-8b40-ed12de91a304 (last access: 7 November 2022), 2021b.
Environment and Climate Change Canada (ECCC): Major ions and acidifying gases, Government of Canada Open Data Portal [data set], https://open.canada.ca/data/en/dataset/10ec2a54-9b6d-4dd7-9b05-5c30b9fa4920 (last access: 7 November 2022), 2021c.
Feng, J., Chan, E., and Vet, R.:
Air quality in the eastern United States and Eastern Canada for 1990–2015: 25 years of change in response to emission reductions of SO2 and NOx in the region, Atmos. Chem. Phys., 20, 3107–3134, https://doi.org/10.5194/acp-20-3107-2020, 2020.
Feng, J., Vet, R., Cole, A., Zhang, L., Cheng, I., O'Brien, J., and Macdonald, A. M.:
Inorganic chemical components in precipitation in the eastern US and Eastern Canada during 1989–2016: Temporal and regional trends of wet concentration and wet deposition from the NADP and CAPMoN measurements, Atmos. Environ., 254, 118367, https://doi.org/10.1016/j.atmosenv.2021.118367, 2021.
Field, C. D., Dise, N. B., Payne, R. J., Britton, A. J., Emmett, B. A., Helliwell, R. C., Hughes, S., Jones, L., Lees, S., Leake, J. R., Leith, I. D., Phoenix, G. K., Power, S. A., Sheppard, L. J., Southon, G. E., Stevens, C. J., and Caporn, S. J. M.:
The Role of Nitrogen Deposition in Widespread Plant Community Change Across Semi-natural Habitats, Ecosystems, 17, 864–877, https://doi.org/10.1007/s10021-014-9765-5, 2014.
Flechard, C. R., Nemitz, E., Smith, R. I., Fowler, D., Vermeulen, A. T., Bleeker, A., Erisman, J. W., Simpson, D., Zhang, L., Tang, Y. S., and Sutton, M. A.:
Dry deposition of reactive nitrogen to European ecosystems: a comparison of inferential models across the NitroEurope network, Atmos. Chem. Phys., 11, 2703–2728, 2011.
Forsius, M., Posch, M., Holmberg, M., Vuorenmaa, J., Kleemola, S., Augustaitis, A., Beudert, B., Bochenek, W., Clarke, N., deWit, H. A., Dirnböck, T., Frey, J., Grandin, U., Hakola, H., Kobler, J., Krám, P., Lindroos, A.-J., Löfgren, S., Pecka, T., Rönnback, P., Skotak, K., Szpikowski, J., Ukonmaanaho, L., Valinia, S., and Váňa, M.:
Assessing critical load exceedances and ecosystem impacts of anthropogenic nitrogen and sulphur deposition at unmanaged forested catchments in Europe, Sci. Total. Environ., 753, 141791, https://doi.org/10.1016/j.scitotenv.2020.141791, 2021.
Fowler, D., Smith, R. I., Muller, J. B. A., Hayman, G., and Vincent, K. J.:
Changes in the atmospheric deposition of acidifying compounds in the UK between 1986 and 2001, Environ. Pollut., 137, 15–25, 2005.
Gasset, N., Fortin, V., Dimitrijevic, M., Carrera, M., Bilodeau, B., Muncaster, R., Gaborit, É., Roy, G., Pentcheva, N., Bulat, M., Wang, X., Pavlovic, R., Lespinas, F., Khedhaouiria, D., and Mai, J.:
A 10 km North American precipitation and land-surface reanalysis based on the GEM atmospheric model, Hydrol. Earth Syst. Sci., 25, 4917–4945, https://doi.org/10.5194/hess-25-4917-2021, 2021.
GAW (Precipitation Chemistry Science Advisory Group): Global Atmosphere Watch: Manual for the GAW Precipitation Chemistry Programme, Guidelines Data Quality Objectives and Standard Operating Procedures, No. 160, World Meteorological Organization (WMO), Geneva, Switzerland, 2004.
Gloser, V. and Gloser, J.:
Nitrogen and base cation uptake in seedlings of Acer pseudoplatanus and Calamagrostis villosa exposed to an acidified environment, in: Recent Advances of Plant Root Structure and Function, edited by: Gašparíková, O., Čiamporová, M., Mistrík, I., and Baluška, F., Springer, Dordrecht, https://doi.org/10.1007/978-94-017-2858-4_12, 103–109, 2001.
Hall, J., Reynolds, B., Aherne, J., and Hornung, M.:
The importance of selecting appropriate criteria for calculating acidity critical loads for terrestrial ecosystems using the simple mass balance equation, Water Air Soil Poll., 1, 29–41, 2001.
Hazlett, P. W., Emilson, C. E., Lawrence, G. B., Fernandez, I. J., Ouimet, R., and Bailey, S. W.:
Reversal of forest soil acidification in the northeastern United States and eastern Canada: Site and soil factors contributing to recovery, Soil Syst., 4, 54, https://doi.org/10.3390/soilsystems4030054, 2020.
Holland, E. A., Braswell, B. H., Sulzman, J., and Lamarque, J. F.:
Nitrogen deposition onto the United States and Western Europe: synthesis of observations and models, Ecol. Appl., 15, 38–57, 2005.
Houle, D., Augustin, F., and Couture, S.:
Rapid improvement of lake acid-base status in Atlantic Canada following steep decline in precipitation acidity, Can. J. Fish. Aquat. Sci., https://doi.org/10.1139/cjfas-2021-0349, online first, 2022.
Hu, C., Griffis, T. J., Frie, A., Baker, J. M., Wood, J. D., Millet, D. B., Yu, Z., Yu, X., and Czarnetzki, A. C.:
A multiyear constraint on ammonia emissions and deposition within the US corn belt, Geophys. Res. Lett., 48, e2020GL090865, https://doi.org/10.1029/2020GL090865, 2021.
Jeffries, D. S., Clair, T. A., Couture, S., Dillon, P. J., Dupont, J., Keller, W., McNicol, D. K., Turner, M. A., Vet, R., and Weeber, R.:
Assessing the Recovery of Lakes in Southeastern Canada from the Effects of Acidic Deposition, Ambio, 32, 176–182, 2003.
Jeffries, D. S., Semkin, R. G., Gibson, J. J., and Wong, I.:
Recently surveyed lakes in northern Manitoba and Saskatchewan, Canada: characteristics and critical loads of acidity, J. Limnol., 69, 45–55, 2010.
Kharol, S. K., Shephard, M. W., McLinden, C. A., Zhang, L., Sioris, C. E., O'Brien, J. M., Vet, R., Cady-Pereira, K. E., Hare, E., Siemons, J., and Krotkov, N. A.:
Dry deposition of reactive nitrogen from satellite observations of ammonia and nitrogen dioxide over North America, Geophys. Res. Lett., 45, 1157–1166, 2018.
Lawrence, G. B., Hazlett, P. W., Fernandez, I. J., Ouimet, R., Bailey, S. W., Shortle, W. C., Smith, K. T., and Antidormi, M. R.:
Declining Acidic Deposition Begins Reversal of Forest-Soil Acidification in the Northeastern U. S. and Eastern Canada, Environ. Sci. Technol., 49, 13103–13111, 2015.
Lee, C., Martin, R. V., van Donkelaar, A., Lee, H., Dickerson, R. R., Hains, J. C., Krotkov, N., Richter, A., Vinnikov, K., and Schwab, J. J.:
SO2 emissions and lifetimes: Estimates from inverse modeling using in situ and global, space-based (SCIAMACHY and OMI) observations, J. Geophys. Res.-Atmos., 116, D06304, https://doi.org/10.1029/2010JD014758, 2011.
Lehmann, C. M., Bowersox, V. C., Larson, R. S., and Larson, S. M.:
Monitoring long-term trends in sulfate and ammonium in US precipitation: Results from the National Atmospheric Deposition Program/National Trends Network, Water Air Soil Poll., 7, 59–66, https://doi.org/10.1007/s11267-006-9100-z, 2007.
Li, Y., Schichtel, B. A., Walker, J. T., Schwede, D. B., Chen, X., Lehmann, C. M., Puchalski, M. A., Gay, D. A., and Collett, J. L.:
Increasing importance of deposition of reduced nitrogen in the United States, P. Natl. Acad. Sci. USA, 113, 5874–5879, 2016.
Likens, G. E., Butler, T. J., Claybrooke, R., Vermeylen, F., and Larson, R..:
Long-term monitoring of precipitation chemistry in the US: Insights into changes and condition, Atmos. Environ., 245, 118031, https://doi.org/10.1016/j.atmosenv.2020.118031, 2021.
Liu, X., Zhang, Y., Han, W., Tang, A., Shen, J., Cui, Z., Vitousek, P., Erisman, J. W., Goulding, K., Christie, P., Fangmeier, A., and Zhang, F.:
Enhanced nitrogen deposition over China, Nature, 494, 459–462, 2013.
Makar, P. A., Akingunola, A., Aherne, J., Cole, A. S., Aklilu, Y.-A., Zhang, J., Wong, I., Hayden, K., Li, S.-M., Kirk, J., Scott, K., Moran, M. D., Robichaud, A., Cathcart, H., Baratzedah, P., Pabla, B., Cheung, P., Zheng, Q., and Jeffries, D. S.:
Estimates of exceedances of critical loads for acidifying deposition in Alberta and Saskatchewan, Atmos. Chem. Phys., 18, 9897–9927, https://doi.org/10.5194/acp-18-9897-2018, 2018.
McHale, M. R., Ludtke, A. S., Wetherbee, G. A., Burns, D. A., Nilles, M. A., and Finkelstein, J. S.:
Trends in precipitation chemistry across the US 1985–2017: Quantifying the benefits from 30 years of Clean Air Act amendment regulation, Atmos. Environ., 247, 118219, https://doi.org/10.1016/j.atmosenv.2021.118219, 2021.
McKendry, I. G., Macdonald, A. M., Leaitch, W. R., van Donkelaar, A., Zhang, Q., Duck, T., and Martin, R. V.:
Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B, Atmos. Chem. Phys., 8, 6297–6307, https://doi.org/10.5194/acp-8-6297-2008, 2008.
McMillan, A. C., MacIver, D., and Sukloff, W. B.:
Atmospheric environmental information – an overview with Canadian examples, Environ. Modell. Softw., 15, 245–248, 2000.
Moran, M. D., Lupu, A., Zhang, J., Savic-Jovcic, V., and Gravel, S.:
A Comprehensive Performance Evaluation of the Next Generation of the Canadian Operational Regional Air Quality Deterministic Prediction System, in: Air Pollution Modeling and its Application XXV, edited by: Mensink, C. and Kallos, G., Springer, Cham, https://doi.org/10.1007/978-3-319-57645-9_12, 75–81, 2018.
Nilsson, J. and Grennfelt, P.:
Critical loads for sulphur and nitrogen, Report from a workshop held at Skokloster, Sweden, Miljørapport, Nordic Council of Ministers, Copenhagen, Denmark, 31 pp., 1988.
Nopmongcol, U., Beardsley, R., Kumar, N., Knipping, E., and Yarwood, G.:
Changes in United States deposition of nitrogen and sulfur compounds over five decades from 1970 to 2020, Atmos. Environ., 209, 144–151, 2019.
Olsen, A. R., Voldner, E. C., Bigelow, D. S., Chan, W. H., Clark, T. L., Lusis, M. A., Misra, P. K., and Vet, R. J.:
Unified wet deposition data summaries for North America: data summary procedures and results for 1980–1986, Atmos. Environ., 24, 661–672, 1990.
Pan, D., Benedict, K. B., Golston, L. M., Wang, R., Collett, J. L., Tao, L., Sun, K., Guo, X., Ham, J., Prenni, A. J., Schichtel, B. A., Mikoviny, T., Muller, M., Wisthaler, A., and Zondlo, M. A.:
Ammonia Dry Deposition in an Alpine Ecosystem Traced to Agricultural Emission Hotpots, Environ. Sci. Technol., 55, 7776–7785, 2021.
Pan, Y. P., Wang, Y. S., Tang, G. Q., and Wu, D.:
Wet and dry deposition of atmospheric nitrogen at ten sites in Northern China, Atmos. Chem. Phys., 12, 6515–6535, https://doi.org/10.5194/acp-12-6515-2012, 2012.
Pardo, L. H., Fenn, M. E., Goodale, C. L., Geiser, L. H., Driscoll, C. T., Allen, E. B., Baron, J. S., Bobbink, R., Bowman, W. D., Clark, C. M., Emmett, B., Gilliam, F. S., Greaver, T. L., Hall, S. J., Lilleskov, E. A., Liu, L., Lynch, J. A., Nadelhoffer, K. J., Perakis, S. S., Robin-Abbott, M. J., Stoddard, J. L., Weathers, K. C., and Dennis, R. L.:
Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States, Ecol. Appl., 21, 3049–3082, 2011.
Payne, R. J., Dise, N. B., Field, C. D., Dore, A. J., Caporn, S. J., and Stevens, C. J.:
Nitrogen deposition and plant biodiversity: Past, present, and future, Front. Ecol. Environ., 15, 431–436. https://doi.org/10.1002/fee.1528, 2017.
Posch, M., Kämäri, J., Johansson, M., and Forsius, M.:
Displaying inter-and intra-regional variability of large-scale survey results, Environmetrics, 4, 341–352, 1993.
Posch, M., de Vries, W., and Sverdrup, H. U.:
Mass Balance Models to Derive Critical Loads of Nitrogen and Acidity for Terrestrial and Aquatic Ecosystems, in: Critical Loads and Dynamic Risk Assessments: Nitrogen, Acidity and Metals in Terrestrial and Aquatic Ecosystems, edited by: de Vries, W., Hettelingh, J.-P., and Posch, M., Springer, Dordrecht, https://doi.org/10.1007/978-94-017-9508-1_6, 171–205, 2015.
Schwede, D., Zhang, L., Vet, R., and Lear, G.:
An intercomparison of the deposition models used in the CASTNET and CAPMoN networks, Atmos. Environ., 45, 1337–1346, 2011.
Shao, S., Driscoll, C. T., Sullivan, T. J., Burns, D. A., Baldigo, B., Lawrence, G. B., and McDonnell, T. C.:
The response of stream ecosystems in the Adirondack region of New York to historical and future changes in atmospheric deposition of sulfur and nitrogen, Sci. Total. Environ., 716, 137113, https://doi.org/10.1016/j.scitotenv.2020.137113, 2020.
Sickles II, J. E. and Shadwick, D. S.:
Air quality and atmospheric deposition in the eastern US: 20 years of change, Atmos. Chem. Phys., 15, 173–197, https://doi.org/10.5194/acp-15-173-2015, 2015.
Simkin, S. M., Allen, E. B., Bowman, W. D., Clark, C. M., Belnap, J., Brooks, M. L., Cade, B. S., Collins, S. L., Geiser, L. H., Gilliam, F. S., and Jovan, S. E.:
Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States, P. Natl. Acad. Sci. USA, 113, 4086–4091, 2016.
Sirois, A. and Fricke, W.:
Regionally representative daily air concentrations of acid-related substances in Canada; 1983–1987, Atmos. Environ., 26, 593–607, 1992.
Sirois, A., Vet, R., and Lamb, D.:
A comparison of the precipitation chemistry measurements obtained by the CAPMoN and NADP/NTN networks, Environ. Monit. Assess., 62, 273–303, 2000.
Skeffington, R. A., Hall, J. R., Heywood, E., Wadsworth, R. A., Whitehead, P., Reynolds, B., Abbott, J., and Vincent, K.:
Uncertainty in critical load assessment models, Science Report: SC030172/SR, Technical Report, Environment Agency, Bristol, 2007.
Smith, V. H., Tilman, G. D., and Nekola, J. C.:
Eutrophication: Impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems, Environ. Pollut., 100, 179–196, https://doi.org/10.1016/S0269-7491(99)00091-3, 1999.
Staelens, J., Wuyts, K., Adriaenssens, S., Van Avermaet, P., Buysse, H., Van den Bril, B., Roekens, E., Ottoy, J. P., Verheyen, K., Thas, O., and Deschepper, E.:
Trends in atmospheric nitrogen and sulphur deposition in northern Belgium, Atmos. Environ., 49, 186–196, 2012.
Sutton, M. A., Reis, S., Riddick, S. N., Dragosits, U., Nemitz, E., Theobald, M. R., Tang, Y. S., Braban, C. F., Vieno, M., Dore, A. J., Mitchell, R. F., Wanless, S., Daunt, F., Fowler, D., Blackall, T. D., Milford, C., Flechard, C. R., Loubet, B., Massad, R., Cellier, P., Personne, E., Coheur, P. F., Clarisse, L., Van Damme, M., Ngadi, Y., Clerbaux, C., Skjøth, C. A., Geels, C., Hertel, O., Wichink Kruit, R. J., Pinder, R. W., Bash, J. O., Walker, J. T., Simpson, D., Horváth, L., Misselbrook, T. H., Bleeker, A., Dentener, F., and de Vries, W.:
Towards a climate-dependent paradigm of ammonia emission and deposition, Philos. T. R. Soc. B., 368, 20130166, https://doi.org/10.1098/rstb.2013.0166, 2013.
Suutari, R., Amann, M., Cofala, J., Klimont, Z., Posch, M., and Schöpp, W.:
From economic activities to ecosystem protection in Europe: An uncertainty analysis of two scenarios of the RAINS integrated assessment model, CIAM/CCE Rep. 1/2001, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria, 2001.
Sverdrup, H.:
The kinetics of base cation release due to chemical weathering, Lund University Press, Lund, Sweden, ISBN 91-7966-109-2, 1990.
Sverdrup, H. and De Vries, W.:
Calculating critical loads for acidity with the simple mass balance method, Water Air Soil Poll., 72, 143–162, https://doi.org/10.1007/BF01257121, 1994.
Tan, J., Fu, J. S., and Seinfeld, J. H.:
Ammonia emission abatement does not fully control reduced forms of nitrogen deposition, P. Natl. Acad. Sci. USA, 117, 9771–9775, 2020.
USEPA: Air pollutant emissions trends data, USEPA [data set], https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data (last access: 8 November 2022), 2021.
Vet, R., Artz, R. S., Carou, S., Shaw, M., Ro, C. U., Aas, W., Baker, A., Bowersox, V. C., Dentener, F., Galy-Lacaux, C.,Hou, A., Pienaar, J. J., Gillett, R., Forti, M. C., Gromov, S., Hara, H., Khodzher, T., Mahowald, N. M., Nickovic, S., Rao, P. S. P., and Reid, N. W.:
A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus, Atmos. Environ., 93, 3–100, 2014.
Walker, J. T., Beachley, G., Amos, H. M., Baron, J. S., Bash, J., Baumgardner, R., Bell, M. D., Benedict, K. B., Chen, X., Clow, D. W., Cole, A., Coughlin, J. G., Cruz, K., Daly, R. W., Decina, S. M., Elliott, E. M., Fenn, M. E., Ganzeveld, L., Gebhart, K., Isil, S. S., Kerschner, B. M., Larson, R. S., Lavery, T., Lear, G. G., Macy, T., Mast, M. A., Mishoe, K., Morris, K. H., Padgett, P. E., Pouyat, R. V., Puchalski, M., Pye, H., Rea, A. W., Rhodes, M. F., Rogers, C. M., Saylor, R., Scheffe, R., Schichtel, B. A., Schwede, D. B., Sexstone, G. A., Sive, B. C., Sosa, R., Templer, P. H., Thompson, T., Tong, D., Wetherbee, G. A., Whitlow, T. H., Wu, Z., Yu, Z., and Zhang, L.:
Toward the improvement of total nitrogen deposition budgets in the United States, Sci. Total Environ., 691, 1328–1352, 2019a.
Walker, J. T., Bell, M. D., Schwede, D., Cole, A., Beachley, G., Lear, G., and Wu, Z.:
Aspects of uncertainty in total reactive nitrogen deposition estimates for North American critical load applications, Sci. Total Environ., 690, 1005–1018, 2019b.
Walker, J. T., Beachley, G., Zhang, L., Benedict, K. B., Sive, B. C., and Schwede, D. B.:
A review of measurements of air-surface exchange of reactive nitrogen in natural ecosystems across North America, Sci. Total Environ., 698, 133975, https://doi.org/10.1016/j.scitotenv.2019.133975, 2020.
Warner, J. X., Dickerson, R. R., Wei, Z., Strow, L. L., Wang, Y., and Liang, Q.:
Increased atmospheric ammonia over the world's major agricultural areas detected from space, Geophys. Res. Lett., 44, 2875–2884, 2017.
Wen, Z., Xu, W., Li, Q., Han, M., Tang, A., Zhang, Y., Luo, X., Shen, J., Wang, W., Li, K., Pan, Y., Zhang, L., Li, W., Collett, J. R., Zhong, B., Wang, X., Goulding, K., Zhang, F., and Liu, X.:
Changes of nitrogen deposition in China from 1980 to 2018, Environ. Int., 144, 106022, https://doi.org/10.1016/j.envint.2020.106022, 2020.
Wright L. P., Zhang L., Cheng I., Aherne J., and Wentworth G. R.:
Impacts and effects indicators of atmospheric deposition of major pollutants to various ecosystems – A review, Aerosol Air Qual. Res., 18, 1953–1992, 2018.
Xu, W., Luo, X. S., Pan, Y. P., Zhang, L., Tang, A. H., Shen, J. L., Zhang, Y., Li, K. H., Wu, Q. H., Yang, D. W., Zhang, Y. Y., Xue, J., Li, W. Q., Li, Q. Q., Tang, L., Lu, S. H., Liang, T., Tong, Y. A., Liu, P., Zhang, Q., Xiong, Z. Q., Shi, X. J., Wu, L. H., Shi, W. Q., Tian, K., Zhong, X. H., Shi, K., Tang, Q. Y., Zhang, L. J., Huang, J. L., He, C. E., Kuang, F. H., Zhu, B., Liu, H., Jin, X., Xin, Y. J., Shi, X. K., Du, E. Z., Dore, A. J., Tang, S., Collett Jr., J. L., Goulding, K., Sun, Y. X., Ren, J., Zhang, F. S., and Liu, X. J.:
Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China, Atmos. Chem. Phys., 15, 12345–12360, https://doi.org/10.5194/acp-15-12345-2015, 2015.
Yao, X. and Zhang, L.:
Trends in atmospheric ammonia at urban, rural, and remote sites across North America, Atmos. Chem. Phys., 16, 11465–11475, https://doi.org/10.5194/acp-16-11465-2016, 2016.
Yao, X. and Zhang, L.:
Causes of large increases in atmospheric ammonia in the last decade across North America, ACS Omega, 4, 22133–22142, https://doi.org/10.1021/acsomega.9b03284, 2019.
Yu, F., Nair, A. A., and Luo, G.:
Long-term trend of gaseous ammonia over the United States: Modeling and comparison with observations, J. Geophys. Res.-Atmos., 123, 8315–8325, https://doi.org/10.1029/2018JD028412, 2018.
Yu, G., Jia, Y., He, N., Zhu, J., Chen, Z., Wang, Q., Piao, S., Liu, X., He, H., Guo, X., Wen, Z., Li, P., Ding, G., and Goulding, K.:
Stabilization of atmospheric nitrogen deposition in China over the past decade, Nat. Geosci., 12, 424–429, 2019.
Zbieranowski, A. L. and Aherne, J.:
Long-term trends in atmospheric reactive nitrogen across Canada: 1988–2007, Atmos. Environ., 45, 5853–5862, 2011.
Zhang, L. and He, Z.:
Technical Note: An empirical algorithm estimating dry deposition velocity of fine, coarse and giant particles, Atmos. Chem. Phys., 14, 3729–3737, https://doi.org/10.5194/acp-14-3729-2014, 2014.
Zhang, L., Brook, J. R., and Vet, R.:
A revised parameterization for gaseous dry deposition in air-quality models, Atmos. Chem. Phys., 3, 2067–2082, https://doi.org/10.5194/acp-3-2067-2003, 2003.
Zhang, L., Vet, R., Wiebe, A., Mihele, C., Sukloff, B., Chan, E., Moran, M. D., and Iqbal, S.:
Characterization of the size-segregated water-soluble inorganic ions at eight Canadian rural sites, Atmos. Chem. Phys., 8, 7133–7151, https://doi.org/10.5194/acp-8-7133-2008, 2008.
Zhang, L., Vet, R., O'Brien, J. M., Mihele, C., Liang, Z., and Wiebe, A.:
Dry deposition of individual nitrogen species at eight Canadian rural sites, J. Geophys. Res.-Atmos., 114, D02301, https://doi.org/10.1029/2008JD010640, 2009.
Zhang, L., Wright, L. P., and Asman, W. A. H.:
Bi-directional air-surface exchange of atmospheric ammonia – A review of measurements and a development of a big-leaf model for applications in regional-scale air-quality models, J. Geophys. Res.-Atmos., 115, D20310, https://doi.org/10.1029/2009JD013589, 2010.
Zhang, L., He, Z., Wu, Z., Macdonald, A. M., Brook, J. R., and Kharol, S.:
A database of modeled gridded dry deposition velocities for 45 gaseous species and three particle size ranges across North America, J. Environ. Sci., 127, 264–272, https://doi.org/10.1016/j.jes.2022.05.030, 2023.
Zhang, Y., Mathur, R., Bash, J. O., Hogrefe, C., Xing, J., and Roselle, S. J.:
Long-term trends in total inorganic nitrogen and sulfur deposition in the US from 1990 to 2010, Atmos. Chem. Phys., 18, 9091–9106, https://doi.org/10.5194/acp-18-9091-2018, 2018.
Zhao, Y., Zhang, L., Chen, Y., Liu, X., Xu, W., Pan, Y., and Duan, L.:
Atmospheric nitrogen deposition to China: A model analysis on nitrogen budget and critical load exceedance, Atmos. Environ., 153, 32–40, 2017.
Short summary
Nitrogen (N) and sulfur (S) deposition decreased significantly at 14 Canadian sites during 2000–2018. The greatest decline was observed in southeastern Canada owing to regional SO2 and NOx reductions. Wet deposition was more important than dry deposition, comprising 71–95 % of total N and 45–89 % of total S deposition. While critical loads (CLs) were exceeded at a few sites in the early 2000s, acidic deposition declined below CLs after 2012, which signifies recovery from legacy acidification.
Nitrogen (N) and sulfur (S) deposition decreased significantly at 14 Canadian sites during...
Altmetrics
Final-revised paper
Preprint