Sea-salt aerosol transport patterns over the Northern Hemisphere inferred from two subarctic ice core records

AbstractIt has recently been shown that much sea-salt aerosol around the coast of Antarctica is generated not from open water, but from the surface of newly formed sea ice. Previous interpretations of ice-core records have disregarded the sea-ice surface as a source of sea salt. The majority of sea-salt aerosol at Halley research station originates from frost flowers rather than open water, and the seasonal cycle of sea salt in aerosol at Halley appears to be controlled by ice production in the Weddell Sea, as well as variations in wind speed. Frost flowers are also an important source of aerosol at Siple Dome, suggesting that variations in sea-salt concentrations in the core, and other cores drilled in similar locations, may be reflecting changes in sea-ice production rather than changes in transportation patterns. For Greenland cores, and those from low-accumulation inland sites in Antarctica, it is not simple to calculate the proportion of sea salt originating from frost flowers rather than open water. However, modelling studies suggest that a sea-ice surface source contributed much of the flux of sea salt to these sites in glacial periods, suggesting that interpretations of ice-core records from these locations should also be revisited.

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Seasonally resolved ice core records from West Antarctica indicate a sea ice source of sea-salt aerosol and a biomass burning source of ammonium

Journal of Geophysical Research Atmospheres ◽

10.1002/2013jd020720 ◽

2014 ◽

Vol 119 (14) ◽

pp. 9168-9182 ◽

Cited By ~ 14

Author(s):

Daniel R. Pasteris ◽

Joseph R. McConnell ◽

Sarah B. Das ◽

Alison S. Criscitiello ◽

Matthew J. Evans ◽

...

Keyword(s):

Sea Ice ◽

Biomass Burning ◽

Ice Core ◽

Sea Salt ◽

West Antarctica ◽

Sea Salt Aerosol ◽

Ice Core Records

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Exploring ice core sea ice proxies through process-based modelling

10.5194/egusphere-egu2020-9013 ◽

2020 ◽

Author(s):

Rachael Rhodes ◽

Xin Yang ◽

Eric Wolff

Keyword(s):

Sea Ice ◽

Atmospheric Chemistry ◽

Ice Core ◽

Ice Cores ◽

Sea Salt ◽

Atmospheric Composition ◽

The Arctic ◽

Sea Salt Aerosol ◽

Aerosol Emission ◽

The Impact

It is important to understand the magnitude and rate of past sea ice changes, as well as their timing relative to abrupt shifts in other components of Earth&#8217;s climate system. Furthermore, records of past sea ice over the last few centuries are urgently needed to assess the scale of natural (internal) variability over decadal timescales. By continuously recording past atmospheric composition, polar ice cores have the potential to document changing sea ice conditions if atmospheric chemistry is altered. &#160;Sea salt aerosol, specifically sodium (Na), and bromine enrichment (Brenr, Br/Na enriched relative to seawater ratio) are two ice core sea ice proxies suggested following this premise.Here we aim to move beyond a conceptual understanding of the controls on Na and Brenr in ice cores by using process-based modelling to test hypotheses. We present results of experiments using a 3D global chemical transport model (p-TOMCAT) that represents marine aerosol emission, transport and deposition. Critically, the complex atmospheric chemistry of bromine is also included. Three fundamental issues will be examined: 1) the partitioning of Br between gas and aerosol phases, 2) sea salt aerosol production from first-year versus multi-year sea ice, and 3) the impact of increased acidity in the atmosphere due to human activity in the Arctic.

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Review of: “Ice core records of biomass burning tracers (levoglucosan, dehydroabietic and vanillic acids) from Aurora Peak in Alaska since 1660s: A new dimension of forest fire activities in the Northern Hemisphere”

10.5194/acp-2019-139-rc1 ◽

2019 ◽

Author(s):

Anonymous

Keyword(s):

Northern Hemisphere ◽

Forest Fire ◽

Biomass Burning ◽

Ice Core ◽

Ice Core Records

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Sea ice as a source of sea salt aerosol to Greenland ice cores: a model-based study

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-9417-2017 ◽

2017 ◽

Vol 17 (15) ◽

pp. 9417-9433 ◽

Cited By ~ 20

Author(s):

Rachael H. Rhodes ◽

Xin Yang ◽

Eric W. Wolff ◽

Joseph R. McConnell ◽

Markus M. Frey

Keyword(s):

Sea Ice ◽

Atmospheric Chemistry ◽

Transport Model ◽

Ice Core ◽

Ice Cores ◽

Open Ocean ◽

Sea Salt ◽

The Arctic ◽

Sea Salt Aerosol ◽

Annual Variability

Abstract. Growing evidence suggests that the sea ice surface is an important source of sea salt aerosol and this has significant implications for polar climate and atmospheric chemistry. It also suggests the potential to use ice core sea salt records as proxies for past sea ice extent. To explore this possibility in the Arctic region, we use a chemical transport model to track the emission, transport, and deposition of sea salt from both the open ocean and the sea ice, allowing us to assess the relative importance of each. Our results confirm the importance of sea ice sea salt (SISS) to the winter Arctic aerosol burden. For the first time, we explicitly simulate the sea salt concentrations of Greenland snow, achieving values within a factor of two of Greenland ice core records. Our simulations suggest that SISS contributes to the winter maxima in sea salt characteristic of ice cores across Greenland. However, a north–south gradient in the contribution of SISS relative to open-ocean sea salt (OOSS) exists across Greenland, with 50 % of winter sea salt being SISS at northern sites such as NEEM (77° N), while only 10 % of winter sea salt is SISS at southern locations such as ACT10C (66° N). Our model shows some skill at reproducing the inter-annual variability in sea salt concentrations for 1991–1999, particularly at Summit where up to 62 % of the variability is explained. Future work will involve constraining what is driving this inter-annual variability and operating the model under different palaeoclimatic conditions.

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Ice-Core Study of the Link between Sea-Salt Aerosol, Sea-Ice Cover and Climate in the Antarctic Peninsula Area

Climatic Change ◽

10.1007/s10584-004-0708-6 ◽

2004 ◽

Vol 67 (1) ◽

pp. 63-86 ◽

Cited By ~ 17

Author(s):

Alberto J. Aristarain ◽

Robert J. Delmas ◽

Michel Stievenard

Keyword(s):

Sea Ice ◽

Antarctic Peninsula ◽

Ice Core ◽

Ice Cover ◽

Sea Salt ◽

Sea Salt Aerosol ◽

Core Study ◽

The Antarctic

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Sea ice as a source of sea salt aerosol to Greenland ice cores: a model-based study

10.5194/acp-2017-100 ◽

2017 ◽

Cited By ~ 1

Author(s):

Rachael H. Rhodes ◽

Xin Yang ◽

Eric W. Wolff ◽

Joseph R. McConnell ◽

Markus M. Frey

Keyword(s):

Sea Ice ◽

Atmospheric Chemistry ◽

Transport Model ◽

Ice Core ◽

Ice Cores ◽

Open Ocean ◽

Sea Salt ◽

The Arctic ◽

Sea Salt Aerosol ◽

Annual Variability

Abstract. Growing evidence suggests that the sea ice surface is an important source of sea salt aerosol and this has significant implications for polar climate and atmospheric chemistry. It also offers the opportunity to use ice core sea salt records as proxies for past sea ice extent. To explore this possibility in the Arctic region, we use a chemical transport model to track the emission, transport and deposition of sea salt from both the open ocean and the sea ice, allowing us to assess the relative importance of each. Our results confirm the importance of sea ice sea salt (SISS) to the winter Arctic aerosol burden. For the first time, we explicitly simulate the sea salt concentrations of Greenland snow and find they match high resolution Greenland ice core records to within a factor of two. Our simulations suggest that SISS contributes to the winter maxima in sea salt characteristic of ice cores across Greenland. A north-south gradient in the contribution of SISS relative to open ocean sea salt (OOSS) exists across Greenland, with 50 % of sea salt being SISS at northern sites such as NEEM, while only 10 % of sea salt is SISS at southern locations such as ACT10C. Our model shows some skill at reproducing the inter-annual variability in sea salt concentrations for 1991–1999 AD, particularly at Summit where up to 62 % of the variability is explained. Future work will involve constraining what is driving this inter-annual variability and operating the model under different paleoclimatic conditions.

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