Nutrient availability limits biological production in Arctic sea ice melt ponds

Dimethyl sulfide (DMS) production in the northern Arctic Ocean has been considered to be minimal because of high sea ice concentration and extremely low productivity.

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Meltwater sources and sinks for multiyear Arctic sea ice in summer

The Cryosphere ◽

10.5194/tc-15-4517-2021 ◽

2021 ◽

Vol 15 (9) ◽

pp. 4517-4525

Author(s):

Don Perovich ◽

Madison Smith ◽

Bonnie Light ◽

Melinda Webster

Keyword(s):

Sea Ice ◽

Heat Budget ◽

Arctic Sea Ice ◽

Sources And Sinks ◽

Ice Melt ◽

Ice Surface ◽

Melt Ponds ◽

Arctic Sea ◽

Ice Mass Balance ◽

Surface Heat Budget

Abstract. On Arctic sea ice, the melt of snow and sea ice generate a summertime flux of fresh water to the upper ocean. The partitioning of this meltwater to storage in melt ponds and deposition in the ocean has consequences for the surface heat budget, the sea ice mass balance, and primary productivity. Synthesizing results from the 1997–1998 SHEBA field experiment, we calculate the sources and sinks of meltwater produced on a multiyear floe during summer melt. The total meltwater input to the system from snowmelt, ice melt, and precipitation from 1 June to 9 August was equivalent to a layer of water 80 cm thick over the ice-covered and open ocean. A total of 85 % of this meltwater was deposited in the ocean, and only 15 % of this meltwater was stored in ponds. The cumulative contributions of meltwater input to the ocean from drainage from the ice surface and bottom melting were roughly equal.

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Inorganic carbon dynamics of melt pond-covered first year sea ice in the Canadian Arctic

Biogeosciences Discussions ◽

10.5194/bgd-11-7485-2014 ◽

2014 ◽

Vol 11 (5) ◽

pp. 7485-7519 ◽

Cited By ~ 3

Author(s):

N.-X. Geilfus ◽

R. J. Galley ◽

O. Crabeck ◽

T. Papakyriakou ◽

J. Landy ◽

...

Keyword(s):

Sea Ice ◽

Arctic Sea Ice ◽

The Arctic ◽

First Year ◽

Ice Melt ◽

Melt Pond ◽

Melt Ponds ◽

Arctic Sea ◽

Melt Water

Abstract. Melt pond formation is a common feature of the spring and summer Arctic sea ice. However, the role of the melt ponds formation and the impact of the sea ice melt on both the direction and size of CO2 flux between air and sea is still unknown. Here we describe the CO2-carbonate chemistry of melting sea ice, melt ponds and the underlying seawater associated with measurement of CO2 fluxes across first year landfast sea ice in the Resolute Passage, Nunavut, in June 2012. Early in the melt season, the increase of the ice temperature and the subsequent decrease of the bulk ice salinity promote a strong decrease of the total alkalinity (TA), total dissolved inorganic carbon (TCO2) and partial pressure of CO2 (pCO2) within the bulk sea ice and the brine. Later on, melt pond formation affects both the bulk sea ice and the brine system. As melt ponds are formed from melted snow the in situ melt pond pCO2 is low (36 μatm). The percolation of this low pCO2 melt water into the sea ice matrix dilutes the brine resulting in a strong decrease of the in situ brine pCO2 (to 20 μatm). As melt ponds reach equilibrium with the atmosphere, their in situ pCO2 increase (up to 380 μatm) and the percolation of this high concentration pCO2 melt water increase the in situ brine pCO2 within the sea ice matrix. The low in situ pCO2 observed in brine and melt ponds results in CO2 fluxes of −0.04 to −5.4 mmol m–2 d–1. As melt ponds reach equilibrium with the atmosphere, the uptake becomes less significant. However, since melt ponds are continuously supplied by melt water their in situ pCO2 still remains low, promoting a continuous but moderate uptake of CO2 (~ −1mmol m–2 d–1). The potential uptake of atmospheric CO2 by melting sea ice during the Arctic summer has been estimated from 7 to 16 Tg of C ignoring the role of melt ponds. This additional uptake of CO2 associated to Arctic sea ice needs to be further explored and considered in the estimation of the Arctic Ocean's overall CO2 budget.

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The contribution of melt ponds to enhanced Arctic sea-ice melt during the Last Interglacial

10.5194/tc-2021-6 ◽

2021 ◽

Author(s):

Rachel Diamond ◽

Louise C. Sime ◽

David Schroeder ◽

Maria-Vittoria Guarino

Keyword(s):

Sea Ice ◽

Ocean Circulation ◽

Arctic Sea Ice ◽

Sea Surface ◽

Last Interglacial ◽

Ice Melt ◽

Melt Pond ◽

Melt Ponds ◽

Arctic Sea ◽

Thermodynamic Processes

Abstract. HadGEM3 is the first coupled climate model to simulate an ice-free Arctic during the Last Interglacial (LIG), 127 000 years ago. This simulation appears to yield accurate Arctic surface temperatures during the summer season. Here, we investigate the causes and impacts of this extreme simulated ice loss. We find that the summer ice melt is predominantly driven by thermodynamic processes: atmospheric and ocean circulation changes do not significantly contribute to the ice loss. We demonstrate these thermodynamic processes are significantly impacted by melt ponds, which form on average 8 days earlier during the LIG than during the pre-industrial control (PI) simulation. This relatively small difference significantly changes the LIG surface energy balance, and strengthens the albedo feedback. Compared to the PI simulation: in mid-June, of the absorbed flux at the surface over ice-covered cells (ice concentration > 0.15), ponds account for 45–50 %, open water 45 %, and bare ice and snow 5–10 %. We show that the simulated ice loss leads to large Arctic sea surface salinity and temperature changes. The sea surface temperature and salinity signals we identify here provide a means to verify, in marine observations, if and when an ice-free Arctic occurred during the LIG. Strong LIG correlations between spring melt pond and summer ice area indicate that, as Arctic ice continues to thin in future, the spring melt pond area will likely become an increasingly reliable predictor of the September sea-ice area. Finally, we note that models with explicitly modelled melt ponds seem to simulate particularly low LIG sea ice extent. These results show that models with explicit (as opposed to parameterised) melt ponds can simulate very different sea-ice behaviour under forcings other than the present-day. This is of concern for future projections of sea-ice loss.

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The contribution of melt ponds to enhanced Arctic sea-ice melt during the Last Interglacial

10.5194/egusphere-egu21-9239 ◽

2021 ◽

Author(s):

Rachel Diamond ◽

Louise Sime ◽

David Schroeder ◽

Maria-Vittoria Guarino

Keyword(s):

Sea Ice ◽

Ocean Circulation ◽

Arctic Sea Ice ◽

Sea Surface ◽

Last Interglacial ◽

Ice Melt ◽

Melt Pond ◽

Melt Ponds ◽

Arctic Sea ◽

Thermodynamic Processes

<p>HadGEM3 is the first coupled climate model to simulate an ice-free Arctic during the Last Interglacial (LIG), 127 000 years ago. This simulation appears to yield accurate Arctic surface temperatures during the summer season. Here, we investigate the causes and impacts of this extreme simulated ice loss. We find that the summer ice melt is predominantly driven by thermodynamic processes: atmospheric and ocean circulation changes do not significantly contribute to the ice loss. We demonstrate these thermodynamic processes are significantly impacted by melt ponds, which form on average 8 days earlier during the LIG than during the pre-industrial control (PI) simulation. This relatively small difference significantly changes the LIG surface energy balance, and strengthens the albedo feedback. Compared to the PI simulation: in mid-June, of the absorbed flux at the surface over ice-covered cells (ice concentration>0.15), ponds account for 45-50%, open water 45%, and bare ice and snow 5-10%. We show that the simulated ice loss leads to large Arctic sea surface salinity and temperature changes. The sea surface temperature and salinity signals we identify here provide a means to verify, in marine observations, if and when an ice-free Arctic occurred during the LIG. Strong LIG correlations between spring melt pond and summer ice area indicate that, as Arctic ice continues to thin in future, the spring melt pond area will likely become an increasingly reliable predictor of the September sea-ice area. Finally, we note that models with explicitly modelled melt ponds seem to simulate particularly low LIG sea-ice extent. These results show that models with explicit (as opposed to parameterised) melt ponds can simulate very different sea-ice behaviour under forcings other than the present-day. This is of concern for future projections of sea-ice loss.</p>

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Inorganic carbon dynamics of melt-pond-covered first-year sea ice in the Canadian Arctic

Biogeosciences ◽

10.5194/bg-12-2047-2015 ◽

2015 ◽

Vol 12 (6) ◽

pp. 2047-2061 ◽

Cited By ~ 18

Author(s):

N.-X. Geilfus ◽

R. J. Galley ◽

O. Crabeck ◽

T. Papakyriakou ◽

J. Landy ◽

...

Keyword(s):

Sea Ice ◽

Arctic Sea Ice ◽

The Arctic ◽

First Year ◽

Co2 Fluxes ◽

Ice Melt ◽

Melt Pond ◽

Melt Ponds ◽

Arctic Sea

Abstract. Melt pond formation is a common feature of spring and summer Arctic sea ice, but the role and impact of sea ice melt and pond formation on both the direction and size of CO2 fluxes between air and sea is still unknown. Here we report on the CO2–carbonate chemistry of melting sea ice, melt ponds and the underlying seawater as well as CO2 fluxes at the surface of first-year landfast sea ice in the Resolute Passage, Nunavut, in June 2012. Early in the melt season, the increase in ice temperature and the subsequent decrease in bulk ice salinity promote a strong decrease of the total alkalinity (TA), total dissolved inorganic carbon (TCO2) and partial pressure of CO2 (pCO2) within the bulk sea ice and the brine. As sea ice melt progresses, melt ponds form, mainly from melted snow, leading to a low in situ melt pond pCO2 (36 μatm). The percolation of this low salinity and low pCO2 meltwater into the sea ice matrix decreased the brine salinity, TA and TCO2, and lowered the in situ brine pCO2 (to 20 μatm). This initial low in situ pCO2 observed in brine and melt ponds results in air–ice CO2 fluxes ranging between −0.04 and −5.4 mmol m−2 day−1 (negative sign for fluxes from the atmosphere into the ocean). As melt ponds strive to reach pCO2 equilibrium with the atmosphere, their in situ pCO2 increases (up to 380 μatm) with time and the percolation of this relatively high concentration pCO2 meltwater increases the in situ brine pCO2 within the sea ice matrix as the melt season progresses. As the melt pond pCO2 increases, the uptake of atmospheric CO2 becomes less significant. However, since melt ponds are continuously supplied by meltwater, their in situ pCO2 remains undersaturated with respect to the atmosphere, promoting a continuous but moderate uptake of CO2 (~ −1 mmol m−2 day−1) into the ocean. Considering the Arctic seasonal sea ice extent during the melt period (90 days), we estimate an uptake of atmospheric CO2 of −10.4 Tg of C yr−1. This represents an additional uptake of CO2 associated with Arctic sea ice that needs to be further explored and considered in the estimation of the Arctic Ocean's overall CO2 budget.

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Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds

Physical Review Letters ◽

10.1103/physrevlett.120.148701 ◽

2018 ◽

Vol 120 (14) ◽

Cited By ~ 7

Author(s):

Predrag Popović ◽

B. B. Cael ◽

Mary Silber ◽

Dorian S. Abbot

Keyword(s):

Sea Ice ◽

Arctic Sea Ice ◽

Ice Melt ◽

Melt Ponds ◽

Arctic Sea ◽

Simple Rules

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The contribution of melt ponds to enhanced Arctic sea-ice melt during the Last Interglacial

The Cryosphere ◽

10.5194/tc-15-5099-2021 ◽

2021 ◽

Vol 15 (11) ◽

pp. 5099-5114

Author(s):

Rachel Diamond ◽

Louise C. Sime ◽

David Schroeder ◽

Maria-Vittoria Guarino

Keyword(s):

Sea Ice ◽

Ocean Circulation ◽

Arctic Sea Ice ◽

Sea Surface ◽

Last Interglacial ◽

Ice Melt ◽

Melt Pond ◽

Melt Ponds ◽

Arctic Sea ◽

Thermodynamic Processes

Abstract. The Hadley Centre Global Environment Model version 3 (HadGEM3) is the first coupled climate model to simulate an ice-free Arctic during the Last Interglacial (LIG), 127 000 years ago. This simulation appears to yield accurate Arctic surface temperatures during the summer season. Here, we investigate the causes and impacts of this extreme simulated ice loss. We find that the summer ice melt was predominantly driven by thermodynamic processes: atmospheric and ocean circulation changes did not significantly contribute to the ice loss. We demonstrate these thermodynamic processes were significantly impacted by melt ponds, which formed on average 8 d earlier during the LIG than during the pre-industrial control (PI) simulation. This relatively small difference significantly changed the LIG surface energy balance and impacted the albedo feedback. Compared to the PI simulation: in mid-June, of the absorbed flux at the surface over ice-covered cells (sea-ice concentration > 0.15), ponds accounted for 45 %–50 %, open water 35 %–45 %, and bare ice and snow 5 %–10 %. We show that the simulated ice loss led to large Arctic sea surface salinity and temperature changes. The sea surface temperature and salinity signals we identify here provide a means to verify, in marine observations, if and when an ice-free Arctic occurred during the LIG. Strong LIG correlations between spring melt pond and summer ice area indicate that, as Arctic ice continues to thin in future, the spring melt pond area will likely become an increasingly reliable predictor of the September sea-ice area. Finally, we note that models with explicitly modelled melt ponds seem to simulate particularly low LIG sea-ice area. These results show that models with explicit (as opposed to parameterised) melt ponds can simulate very different sea-ice behaviour under forcings other than the present day. This is of concern for future projections of sea-ice loss.

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Freshwater Sources and Sinks for Arctic Sea Ice in Summer

10.5194/tc-2021-114 ◽

2021 ◽

Author(s):

Don Perovich ◽

Madison Smith ◽

Bonnie Light ◽

Melinda Webster

Keyword(s):

Sea Ice ◽

Heat Budget ◽

Arctic Sea Ice ◽

Freshwater Input ◽

Sources And Sinks ◽

Ice Melt ◽

Ice Surface ◽

Melt Ponds ◽

Arctic Sea ◽

Ice Mass Balance

Abstract. On Arctic sea ice, the melt of snow and sea ice generate a summertime flux of fresh water to the upper ocean. The partitioning of this freshwater to storage in melt ponds and deposition in the ocean has consequences for the surface heat budget, the sea ice mass balance, and primary productivity. Synthesizing results from the SHEBA field experiment, we calculate the sources and sinks of freshwater produced during summer melt. The total freshwater input to the system from snow melt, ice melt, and precipitation from 1 June to 9 August was equivalent to a layer of water 80 cm thick over the ice-covered and open ocean. 85 % of this freshwater was deposited in the ocean and only 15 % of this freshwater was stored in ponds. The cumulative contributions of freshwater input to the ocean from drainage from the ice surface and bottom melting were roughly equal.

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