Abstract
Anthropogenic and natural emissions contribute to enhanced concentrations of aerosols in the Arctic winter and early spring, with most attention being paid to anthropogenic aerosols that contribute to so-called Arctic haze. Less-well-studied wintertime sea-spray aerosols (SSAs) under Arctic haze conditions are the focus of this study, since they can make an important contribution to wintertime Arctic aerosol abundances. Analysis of field campaign data shows evidence for enhanced local sources of SSAs, including marine organics at Utqiaġvik (formerly known as Barrow) in northern Alaska, United States, during winter 2014. Models tend to underestimate sub-micron SSAs and overestimate super-micron SSAs in the Arctic during winter, including the base version of the Weather Research Forecast coupled with Chemistry (WRF-Chem) model used here, which includes a widely used SSA source function based on . Quasi-hemispheric simulations for winter 2014 including updated wind speed and sea-surface temperature (SST) SSA emission dependencies and sources of marine sea-salt organics and sea-salt sulfate lead to significantly improved model performance compared to observations at remote Arctic sites, notably for coarse-mode sodium and chloride, which are reduced. The improved model also simulates more realistic contributions of SSAs to inorganic aerosols at different sites, ranging from 20%-93% in the observations. Two-thirds of the improved model performance is from the inclusion of the dependence on SSTs. The simulation of nitrate aerosols is also improved due to less heterogeneous uptake of nitric acid on SSAs in the coarse mode and related increases in fine-mode nitrate. This highlights the importance of interactions between natural SSAs and inorganic anthropogenic aerosols that contribute to Arctic haze. Simulation of organic aerosols and the fraction of sea-salt sulfate are also improved compared to observations. However, the model underestimates episodes with elevated observed concentrations of SSA components and sub-micron non-sea-salt sulfate at some Arctic sites, notably at Utqiaġvik. Possible reasons are explored in higher-resolution runs over northern Alaska for periods corresponding to the Utqiaġvik field campaign in January and February 2014. The addition of a local source of sea-salt marine organics, based on the campaign data, increases modelled organic aerosols over northern Alaska. However, comparison with previous available data suggests that local natural sources from open leads, as well as local anthropogenic sources, are underestimated in the model. Missing local anthropogenic sources may also explain the low modelled (sub-micron) non-sea-salt sulfate at Utqiaġvik. The introduction of a higher wind speed dependence for sub-micron SSA emissions, also based on Arctic data, reduces biases in modelled sub-micron SSAs, while sea-ice fractions, including open leads, are shown to be an important factor controlling modelled super-micron, rather than sub-micron, SSAs over the north coast of Alaska. The regional results presented here show that modelled SSAs are more sensitive to wind speed dependence but that realistic modelling of sea-ice distributions is needed for the simulation of local SSAs, including marine organics. This study supports findings from the Utqiaġvik field campaign that open leads are the primary source of fresh and aged SSAs, including marine organic aerosols, during wintertime at Utqiaġvik; these findings do not suggest an influence from blowing snow and frost flowers. To improve model simulations of Arctic wintertime aerosols, new field data on processes that influence wintertime SSA production, in particular for fine-mode aerosols, are needed as is improved understanding about possible local anthropogenic sources.
Original language | English |
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Pages (from-to) | 5641-5678 |
Number of pages | 38 |
Journal | Atmospheric Chemistry and Physics |
Volume | 23 |
Issue number | 10 |
Early online date | 22 May 2023 |
DOIs | |
Publication status | Published - May 2023 |
Bibliographical note
Funding Information:Eleftherios Ioannidis was supported by the PhD programme of the Make Our Planet Great Again (MOGPA) French initiative. We also received support from the French Agence National de Recherche (ANR) CASPA (Climate-relevant Aerosols and Sources in the Arctic) project (project no. ANR- 21-CE01-0017).
Funding Information:
Eleftherios Ioannidis was supported by the French Make Our Planet Great Again (MOPGA) PhD programme. The French authors also acknowledge support from the French space agency CNES, MERLIN project. Computer modelling was performed by Eleftherios Ioannidis, who benefited from access to IDRIS HPC resources (GENCI allocations A009017141 and A011017141) and the IPSL mesoscale computing centre (CICLAD: Calcul Intensif pour le Climat, l'Atmosphère et la Dynamique). We acknowledge the use of the MOZART-4 global model output, which is available at http://www.acom.ucar.edu/wrf-chem/mozart.shtml (last access: 2019). We acknowledge the use of the WRF-Chem preprocessor tool mozbc provided by the Atmospheric Chemistry Observations and Modeling Lab (ACOM) of NCAR. We would like to thank the Arctic Monitoring and Assessment Programme AMAP and Zbigniew Klimont for the ECLIPSE v6b anthropogenic emissions. We would like to acknowledge the following European Commission 7th Framework funded projects: (i) ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants – project no. 282688), (ii) PEGASOS (Pan-European Gas-Aerosols-Climate Interaction Study – project no. 265148), and (iii) Assessment of hemispheric air pollution on EU air policy (contract no. 07.0307/2011/605671/SER/C3). Kerri A. Pratt acknowledges funding from the US National Science Foundation (grant no. OPP-1724585). This is PMEL contribution no. 5366. Lucia M. Upchurch acknowledges the Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CIOCES) under NOAA Cooperative Agreement no. NA20OAR4320271 (contribution no. 2022-1224). Louis Marelle was supported by the European Union's Horizon 2020 research and innovation programme under grant agreement no. 101003826, project CRIceS. Also, we would like to acknowledge the IMPROVE database for the aerosol observations in Alaska. IMPROVE is a collaborative association of state, tribal, and federal agencies and international partners. The US Environmental Protection Agency is the primary funding source, with contracting and research support from the National Park Service. The Air Quality Group at the University of California, Davis, is the central analytical laboratory, with the ion analysis having been provided by the Research Triangle Institute and the carbon analysis having been provided by the Desert Research Institute. We would like to thank Josh Jones, University of Alaska, for providing us with detailed maps of sea-ice fraction plots from the radar at Utqiaġvik. The Villum Foundation is gratefully acknowledged for financing the establishment of the Villum Research Station. We also thank Aas Wenche (Norwegian Institute for Air Research) and Sharma Sangeeta (Environment and Climate Change Canada, Science and Technology Branch, Toronto, Canada) for providing us with EBAS observations at Zeppelin and Alert, respectively. We thank the Canadian Forces Services, Alert, NU, for maintaining the site. The observations at Zeppelin have been supported by the Norwegian Environment Agency (grant no. 17078061).
Publisher Copyright:
© 2023 Eleftherios Ioannidis et al.
Funding
Eleftherios Ioannidis was supported by the PhD programme of the Make Our Planet Great Again (MOGPA) French initiative. We also received support from the French Agence National de Recherche (ANR) CASPA (Climate-relevant Aerosols and Sources in the Arctic) project (project no. ANR- 21-CE01-0017). Eleftherios Ioannidis was supported by the French Make Our Planet Great Again (MOPGA) PhD programme. The French authors also acknowledge support from the French space agency CNES, MERLIN project. Computer modelling was performed by Eleftherios Ioannidis, who benefited from access to IDRIS HPC resources (GENCI allocations A009017141 and A011017141) and the IPSL mesoscale computing centre (CICLAD: Calcul Intensif pour le Climat, l'Atmosphère et la Dynamique). We acknowledge the use of the MOZART-4 global model output, which is available at http://www.acom.ucar.edu/wrf-chem/mozart.shtml (last access: 2019). We acknowledge the use of the WRF-Chem preprocessor tool mozbc provided by the Atmospheric Chemistry Observations and Modeling Lab (ACOM) of NCAR. We would like to thank the Arctic Monitoring and Assessment Programme AMAP and Zbigniew Klimont for the ECLIPSE v6b anthropogenic emissions. We would like to acknowledge the following European Commission 7th Framework funded projects: (i) ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants – project no. 282688), (ii) PEGASOS (Pan-European Gas-Aerosols-Climate Interaction Study – project no. 265148), and (iii) Assessment of hemispheric air pollution on EU air policy (contract no. 07.0307/2011/605671/SER/C3). Kerri A. Pratt acknowledges funding from the US National Science Foundation (grant no. OPP-1724585). This is PMEL contribution no. 5366. Lucia M. Upchurch acknowledges the Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CIOCES) under NOAA Cooperative Agreement no. NA20OAR4320271 (contribution no. 2022-1224). Louis Marelle was supported by the European Union's Horizon 2020 research and innovation programme under grant agreement no. 101003826, project CRIceS. Also, we would like to acknowledge the IMPROVE database for the aerosol observations in Alaska. IMPROVE is a collaborative association of state, tribal, and federal agencies and international partners. The US Environmental Protection Agency is the primary funding source, with contracting and research support from the National Park Service. The Air Quality Group at the University of California, Davis, is the central analytical laboratory, with the ion analysis having been provided by the Research Triangle Institute and the carbon analysis having been provided by the Desert Research Institute. We would like to thank Josh Jones, University of Alaska, for providing us with detailed maps of sea-ice fraction plots from the radar at Utqiaġvik. The Villum Foundation is gratefully acknowledged for financing the establishment of the Villum Research Station. We also thank Aas Wenche (Norwegian Institute for Air Research) and Sharma Sangeeta (Environment and Climate Change Canada, Science and Technology Branch, Toronto, Canada) for providing us with EBAS observations at Zeppelin and Alert, respectively. We thank the Canadian Forces Services, Alert, NU, for maintaining the site. The observations at Zeppelin have been supported by the Norwegian Environment Agency (grant no. 17078061).
Funders | Funder number |
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Cooperative Institute for Climate | |
European Commission 7th Framework | 282688 |
French Agence National de Recherche | ANR- 21-CE01-0017 |
French Make Our Planet Great Again | |
French space agency CNES | |
MOGPA | |
MOPGA | |
Make Our Planet Great Again | |
Pan-European Gas-Aerosols-Climate Interaction Study | 265148, 07.0307/2011/605671/SER/C3 |
National Science Foundation | OPP-1724585 |
U.S. Environmental Protection Agency | |
National Oceanic and Atmospheric Administration | 2022-1224, NA20OAR4320271 |
National Park Service | |
Horizon 2020 | 101003826 |
Miljødirektoratet | 17078061 |