Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry
As sources of reactive halogens, snowpacks in sea ice regions control the oxidative capacity of the Arctic atmosphere. However, measurements of snowpack halide concentrations remain sparse, particularly in the high Arctic, limiting our understanding of and ability to parameterize snowpack participat...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BioOne
2019-05-01
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| Series: | Elementa: Science of the Anthropocene |
| Subjects: | |
| Online Access: | https://www.elementascience.org/articles/352 |
| _version_ | 1828750953346498560 |
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| author | Peter K. Peterson Mark Hartwig Nathaniel W. May Evan Schwartz Ignatius Rigor Wendy Ermold Michael Steele James H. Morison Son V. Nghiem Kerri A. Pratt |
| author_facet | Peter K. Peterson Mark Hartwig Nathaniel W. May Evan Schwartz Ignatius Rigor Wendy Ermold Michael Steele James H. Morison Son V. Nghiem Kerri A. Pratt |
| author_sort | Peter K. Peterson |
| collection | DOAJ |
| description | As sources of reactive halogens, snowpacks in sea ice regions control the oxidative capacity of the Arctic atmosphere. However, measurements of snowpack halide concentrations remain sparse, particularly in the high Arctic, limiting our understanding of and ability to parameterize snowpack participation in tropospheric halogen chemistry. To address this gap, we measured concentrations of chloride, bromide, and sodium in snow samples collected during polar spring above remote multi-year sea ice (MYI) and first-year sea ice(FYI) north of Greenland and Alask, as well as in the central Arctic, and compared these measurements to a larger dataset collected in the Alaskan coastal Arctic by Krnavek et al. (2012). Regardless of sea ice region, these surface snow samples generally featured lower salinities, compared to coastal snow. Surface snow in FYI regions was typically enriched in bromide and chloride compared to seawater, indicating snowpack deposition of bromine and chlorine-containing trace gases and an ability of the snowpack to participate further in bromine and chlorine activation processes. In contrast, surface snow in MYI regions was more often depleted in bromide, indicating it served as a source of bromine-containing trace gases to the atmosphere prior to sampling. Measurements at various snow depths indicate that the deposition of sea salt aerosols and halogen-containing trace gases to the snowpack surface played a larger role in determining surface snow halide concentrations compared to upward brine migration from sea ice. Calculated enrichment factors for bromide and chloride, relative to sodium, in the MYI snow samples suggests that MYI regions, in addition to FYI regions, have the potential to play an active role in Arctic boundary layer bromine and chlorine chemistry. The ability of MYI regions to participate in springtime atmospheric halogen chemistry should be considered in regional modeling of halogen activation and interpretation of satellite-based tropospheric bromine monoxide column measurements. |
| first_indexed | 2024-12-10T20:46:08Z |
| format | Article |
| id | doaj.art-4e2c73c46e5c41a9ad32b7f6b7c84c12 |
| institution | Directory Open Access Journal |
| issn | 2325-1026 |
| language | English |
| last_indexed | 2024-12-10T20:46:08Z |
| publishDate | 2019-05-01 |
| publisher | BioOne |
| record_format | Article |
| series | Elementa: Science of the Anthropocene |
| spelling | doaj.art-4e2c73c46e5c41a9ad32b7f6b7c84c122022-12-22T01:34:14ZengBioOneElementa: Science of the Anthropocene2325-10262019-05-017110.1525/elementa.352324Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistryPeter K. Peterson0Mark Hartwig1Nathaniel W. May2Evan Schwartz3Ignatius Rigor4Wendy Ermold5Michael Steele6James H. Morison7Son V. Nghiem8Kerri A. Pratt9Department of Chemistry, University of Michigan, Ann Arbor, Michigan, US; Applied Physics Laboratory, University of Washington, Seattle, WashingtonDepartment of Chemistry, University of Michigan, Ann Arbor, MichiganDepartment of Chemistry, University of Michigan, Ann Arbor, MichiganDepartment of Chemistry, University of Michigan, Ann Arbor, Michigan; now at Department of Chemistry, Whittier College, Whittier, CaliforniaApplied Physics Laboratory, University of Washington, Seattle, WashingtonApplied Physics Laboratory, University of Washington, Seattle, WashingtonApplied Physics Laboratory, University of Washington, Seattle, WashingtonApplied Physics Laboratory, University of Washington, Seattle, WashingtonJet Propulsion Laboratory, California Institute of Technology, Pasadena, CaliforniaDepartment of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MichiganAs sources of reactive halogens, snowpacks in sea ice regions control the oxidative capacity of the Arctic atmosphere. However, measurements of snowpack halide concentrations remain sparse, particularly in the high Arctic, limiting our understanding of and ability to parameterize snowpack participation in tropospheric halogen chemistry. To address this gap, we measured concentrations of chloride, bromide, and sodium in snow samples collected during polar spring above remote multi-year sea ice (MYI) and first-year sea ice(FYI) north of Greenland and Alask, as well as in the central Arctic, and compared these measurements to a larger dataset collected in the Alaskan coastal Arctic by Krnavek et al. (2012). Regardless of sea ice region, these surface snow samples generally featured lower salinities, compared to coastal snow. Surface snow in FYI regions was typically enriched in bromide and chloride compared to seawater, indicating snowpack deposition of bromine and chlorine-containing trace gases and an ability of the snowpack to participate further in bromine and chlorine activation processes. In contrast, surface snow in MYI regions was more often depleted in bromide, indicating it served as a source of bromine-containing trace gases to the atmosphere prior to sampling. Measurements at various snow depths indicate that the deposition of sea salt aerosols and halogen-containing trace gases to the snowpack surface played a larger role in determining surface snow halide concentrations compared to upward brine migration from sea ice. Calculated enrichment factors for bromide and chloride, relative to sodium, in the MYI snow samples suggests that MYI regions, in addition to FYI regions, have the potential to play an active role in Arctic boundary layer bromine and chlorine chemistry. The ability of MYI regions to participate in springtime atmospheric halogen chemistry should be considered in regional modeling of halogen activation and interpretation of satellite-based tropospheric bromine monoxide column measurements.https://www.elementascience.org/articles/352ArcticSnowSea iceBromineChlorineHalogen |
| spellingShingle | Peter K. Peterson Mark Hartwig Nathaniel W. May Evan Schwartz Ignatius Rigor Wendy Ermold Michael Steele James H. Morison Son V. Nghiem Kerri A. Pratt Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry Elementa: Science of the Anthropocene Arctic Snow Sea ice Bromine Chlorine Halogen |
| title | Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry |
| title_full | Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry |
| title_fullStr | Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry |
| title_full_unstemmed | Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry |
| title_short | Snowpack measurements suggest role for multi-year sea ice regions in Arctic atmospheric bromine and chlorine chemistry |
| title_sort | snowpack measurements suggest role for multi year sea ice regions in arctic atmospheric bromine and chlorine chemistry |
| topic | Arctic Snow Sea ice Bromine Chlorine Halogen |
| url | https://www.elementascience.org/articles/352 |
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