Formation and fate of freshwater on an ice floe in the Central Arctic

˜The œcryosphere, Год журнала: 2025, Номер 19(2), С. 619 - 644

Опубликована: Фев. 7, 2025

Abstract. The melt of snow and sea ice during the Arctic summer is a significant source relatively fresh meltwater. fate this freshwater, whether in surface ponds or thin layers underneath leads, impacts atmosphere–ice–ocean interactions their subsequent coupled evolution. Here, we combine analyses datasets from Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition (June–July 2020) process study on formation freshwater floes Central Arctic. Our budget suggest that high fraction (58 %) derived melt. Additionally, contribution stored precipitation (snowmelt) outweighs by 5 times input situ (rain). magnitude rate local meltwater production are remarkably similar to those observed prior Surface Heat Budget Ocean (SHEBA) campaign, where cumulative totaled around 1 m both. A small (10 remains ponds, which higher more deformed second-year (SYI) compared first-year (FYI) later summer. Most drains laterally vertically, with vertical drainage enabling storage internally freshening brine channels. In upper ocean, can accumulate transient order 0.1 thick leads under ice. presence such substantially system reducing bottom allowing false growth; heat, nutrient, gas exchange; influencing ecosystem productivity. Regardless, majority inferred be ultimately incorporated into ocean (75 (14 %). Terms as annual could used future work diagnostics global climate models. For example, range values CESM2 model roughly encapsulate total production, while underestimated about 50 %, suggesting pond terms key investigation.

Язык: Английский

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Dynamic ice–ocean pathways along the Transpolar Drift amplify the dispersal of Siberian matter

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Апрель 14, 2025

Abstract The Transpolar Drift (TPD) plays a crucial role in regulating Arctic climate and ecosystems by transporting fresh water key substances, such as terrestrial nutrients pollutants, from the Siberian Shelf across Ocean to North Atlantic. However, year-round observations of TPD remain scarce, creating significant knowledge gaps regarding influence sea ice drift ocean surface circulation on transport pathways associated matter. Using geochemical provenance tracer data collected over complete seasonal cycle, our study reveals substantial spatiotemporal variability dispersal matter along TPD. This reflects dynamic shifts contributions individual rivers they integrate into large-scale current system, followed their rapid extensive redistribution through combination ice–ocean exchanges divergent drift. These findings emphasize complexity highlight challenges forecasting dynamics light anticipated changes extent, river discharge, patterns.

Язык: Английский

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Ocean-sourced snow: An unaccounted process on Arctic sea ice

Research Square (Research Square), Год журнала: 2023, Номер unknown

Опубликована: Ноя. 20, 2023

The water isotope composition of the winter snow cover on Arctic sea ice is strongly enriched in heavy isotopes near snow-sea interface, incompatible with typical enrichment values through metamorphism processes alone. Our stratigraphic investigations from MOSAiC expedition, using computed tomography combined isotopic analyses snow, highlight that approximately 20% snowpack not meteoric origin but created ice. Here, we show sublimation under high-temperature gradients during produces a snow-like structure and significantly contributes to total equivalent This, until now, unaccounted oceanographic source “snow” furthers our understanding i) vapor fluxes gas exchange biogeochemistry applications, ii) formation saline contribution salt aerosols, iii) uncertainties mass balance physical properties iv) additional precipitation estimates when compared situ measurements. Ultimately, regional differences will result varying local temperature therefore different contributions ocean-sourced this essential for improving accuracy modeled predictions.

Язык: Английский

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Arctic Surface Snow Interactions with the Atmosphere: Spatio-Temporal Isotopic Variability During the MOSAiC Expedition

Опубликована: Март 20, 2024

Abstract. The Arctic Ocean’s snow cover is crucial in moderating interactions between sea-ice and the atmosphere, yet fully grasping its isotopic composition processes shaping it presents substantial challenges. This study employs a unique dataset from Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition to explore complex deposition post-depositional changes affecting on sea ice. By examining 911 individual isotope measurements collected over full year, we identify clear layering within snowpack: top layer, with lower δ18O values higher d-excess values, indicates fresh meteoric snowfall, while bottom affected by ice beneath, shows d- values. integrating these discrete samples continuous vapour data, our research provides insight into as well that alter signatures snow. We observe significant difference vapor during autumn, mainly due delays sampling after precipitation events, ranges suggesting impact Atlantic moisture. Winter months exhibit sharp differences indicating kinetic fractionation amid extreme cold RV Polarstern traverses Siberian sector Ocean. Conversely, summer display convergence signatures, reflecting conditions favouring equilibrium fractionation, highlighted increased air temperatures humidity levels. While readily responds temperature humidity, surface influenced more subsequent such sublimation wind-driven redistribution. Sublimation, intensified snow’s prolonged residence facilitated porosity snow, plays key role enrichment. Wind-driven redistribution, occurring 67 % winter, led homogenised depleted signal across spreading effect was especially pronounced ridge profiles, where layers showed uniform signal, stark contrast flat samples. Furthermore, distinct patterns were detected along MOSAiC route region close Samoylov Island Fram Straight near Ny-Ålesund. Snow exhibited notable seasonal variations, which indicative continental climate. In contrast, Ny-Ålesund displayed consistent fluctuations, steady

Язык: Английский

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Comment on egusphere-2024-719

Опубликована: Апрель 21, 2024

Abstract. The Arctic Ocean’s snow cover is crucial in moderating interactions between sea-ice and the atmosphere, yet fully grasping its isotopic composition processes shaping it presents substantial challenges. This study employs a unique dataset from Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition to explore complex deposition post-depositional changes affecting on sea ice. By examining 911 individual isotope measurements collected over full year, we identify clear layering within snowpack: top layer, with lower δ¹⁸O values higher d-excess values, indicates fresh meteoric snowfall, while bottom affected by ice beneath, shows d- d-excess values. integrating these discrete samples continuous vapour data, our research provides insight into as well that alter signatures snow. We observe significant difference vapor during autumn, mainly due delays sampling after precipitation events, ranges suggesting impact Atlantic moisture. Winter months exhibit sharp differences indicating kinetic fractionation amid extreme cold RV Polarstern traverses Siberian sector Ocean. Conversely, summer display convergence signatures, reflecting conditions favouring equilibrium fractionation, highlighted increased air temperatures humidity levels. While readily responds temperature humidity, surface influenced more subsequent such sublimation wind-driven redistribution. Sublimation, intensified snow’s prolonged residence facilitated porosity snow, plays key role enrichment. Wind-driven redistribution, occurring 67 % winter, led homogenised depleted signal across spreading effect was especially pronounced ridge profiles, where layers showed uniform signal, stark contrast flat samples. Furthermore, distinct patterns were detected along MOSAiC route region close Samoylov Island Fram Straight near Ny-Ålesund. Snow exhibited notable seasonal variations, which indicative continental climate. In contrast, Ny-Ålesund displayed consistent fluctuations, steady

Язык: Английский

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Comment on egusphere-2024-719

Опубликована: Апрель 23, 2024

Abstract. The Arctic Ocean’s snow cover is crucial in moderating interactions between sea-ice and the atmosphere, yet fully grasping its isotopic composition processes shaping it presents substantial challenges. This study employs a unique dataset from Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition to explore complex deposition post-depositional changes affecting on sea ice. By examining 911 individual isotope measurements collected over full year, we identify clear layering within snowpack: top layer, with lower δ¹⁸O values higher d-excess values, indicates fresh meteoric snowfall, while bottom affected by ice beneath, shows d- d-excess values. integrating these discrete samples continuous vapour data, our research provides insight into as well that alter signatures snow. We observe significant difference vapor during autumn, mainly due delays sampling after precipitation events, ranges suggesting impact Atlantic moisture. Winter months exhibit sharp differences indicating kinetic fractionation amid extreme cold RV Polarstern traverses Siberian sector Ocean. Conversely, summer display convergence signatures, reflecting conditions favouring equilibrium fractionation, highlighted increased air temperatures humidity levels. While readily responds temperature humidity, surface influenced more subsequent such sublimation wind-driven redistribution. Sublimation, intensified snow’s prolonged residence facilitated porosity snow, plays key role enrichment. Wind-driven redistribution, occurring 67 % winter, led homogenised depleted signal across spreading effect was especially pronounced ridge profiles, where layers showed uniform signal, stark contrast flat samples. Furthermore, distinct patterns were detected along MOSAiC route region close Samoylov Island Fram Straight near Ny-Ålesund. Snow exhibited notable seasonal variations, which indicative continental climate. In contrast, Ny-Ålesund displayed consistent fluctuations, steady

Язык: Английский

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Reply on RC1

Опубликована: Июнь 7, 2024

Abstract. The Arctic Ocean’s snow cover is crucial in moderating interactions between sea-ice and the atmosphere, yet fully grasping its isotopic composition processes shaping it presents substantial challenges. This study employs a unique dataset from Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition to explore complex deposition post-depositional changes affecting on sea ice. By examining 911 individual isotope measurements collected over full year, we identify clear layering within snowpack: top layer, with lower δ¹⁸O values higher d-excess values, indicates fresh meteoric snowfall, while bottom affected by ice beneath, shows d- d-excess values. integrating these discrete samples continuous vapour data, our research provides insight into as well that alter signatures snow. We observe significant difference vapor during autumn, mainly due delays sampling after precipitation events, ranges suggesting impact Atlantic moisture. Winter months exhibit sharp differences indicating kinetic fractionation amid extreme cold RV Polarstern traverses Siberian sector Ocean. Conversely, summer display convergence signatures, reflecting conditions favouring equilibrium fractionation, highlighted increased air temperatures humidity levels. While readily responds temperature humidity, surface influenced more subsequent such sublimation wind-driven redistribution. Sublimation, intensified snow’s prolonged residence facilitated porosity snow, plays key role enrichment. Wind-driven redistribution, occurring 67 % winter, led homogenised depleted signal across spreading effect was especially pronounced ridge profiles, where layers showed uniform signal, stark contrast flat samples. Furthermore, distinct patterns were detected along MOSAiC route region close Samoylov Island Fram Straight near Ny-Ålesund. Snow exhibited notable seasonal variations, which indicative continental climate. In contrast, Ny-Ålesund displayed consistent fluctuations, steady

Язык: Английский

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Reply on RC2

Опубликована: Июнь 7, 2024

Abstract. The Arctic Ocean’s snow cover is crucial in moderating interactions between sea-ice and the atmosphere, yet fully grasping its isotopic composition processes shaping it presents substantial challenges. This study employs a unique dataset from Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition to explore complex deposition post-depositional changes affecting on sea ice. By examining 911 individual isotope measurements collected over full year, we identify clear layering within snowpack: top layer, with lower δ¹⁸O values higher d-excess values, indicates fresh meteoric snowfall, while bottom affected by ice beneath, shows d- d-excess values. integrating these discrete samples continuous vapour data, our research provides insight into as well that alter signatures snow. We observe significant difference vapor during autumn, mainly due delays sampling after precipitation events, ranges suggesting impact Atlantic moisture. Winter months exhibit sharp differences indicating kinetic fractionation amid extreme cold RV Polarstern traverses Siberian sector Ocean. Conversely, summer display convergence signatures, reflecting conditions favouring equilibrium fractionation, highlighted increased air temperatures humidity levels. While readily responds temperature humidity, surface influenced more subsequent such sublimation wind-driven redistribution. Sublimation, intensified snow’s prolonged residence facilitated porosity snow, plays key role enrichment. Wind-driven redistribution, occurring 67 % winter, led homogenised depleted signal across spreading effect was especially pronounced ridge profiles, where layers showed uniform signal, stark contrast flat samples. Furthermore, distinct patterns were detected along MOSAiC route region close Samoylov Island Fram Straight near Ny-Ålesund. Snow exhibited notable seasonal variations, which indicative continental climate. In contrast, Ny-Ålesund displayed consistent fluctuations, steady

Язык: Английский

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Arctic Freshwater Sources and Ocean Mixing Relationships Revealed With Seawater Isotopic Tracing

Journal of Geophysical Research Oceans, Год журнала: 2024, Номер 129(7)

Опубликована: Июнь 29, 2024

Abstract The Arctic Ocean and adjacent seas are undergoing increased freshwater influx due to enhanced glacial sea ice melt, precipitation, runoff. Accurate delineation of these sources is vital as they critically modulate ocean composition circulation with widespread varied impacts. Despite this, the using physical oceanographic measurements (e.g., temperature, salinity) alone challenging there a requirement improve partitioning water masses their mixing relationships. Here, we complement traditional continuous surface seawater isotopic analysis (δ 18 O deuterium excess) across transect extending from coastal Alaska Baffin Bay Labrador Sea conducted US Coast Guard Cutter Healy in Autumn 2021. We find that diverse signatures sources, coupled high proportion marine systems, facilitates detailed fingerprinting partitioning. observe highest Beaufort Amundsen Gulf regions, heightened content eastern West Greenland. apply delineate revealing Western inputs dominated by meteoric inputs—specifically Mackenzie River—with smaller meltwater component primary local precipitation discharge. demonstrate such cannot be achieved temperature‐salinity relationships alone, highlight potential tracers assess roles importance evolving sources.

Язык: Английский

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Formation and fate of freshwater on an ice floe in the Central Arctic

Опубликована: Июль 9, 2024

Abstract. The melt of snow and sea ice during the Arctic summer is a significant source relatively fresh meltwater in central Arctic. fate this freshwater – whether surface ponds, or thin layers underneath leads impacts atmosphere-ice-ocean interactions their subsequent coupled evolution. Here, we combine analyses datasets from Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition (June–July, 2020) to understand key drivers budget Central water over time. Freshwater suggest that high fraction (58 %) derived melt. Additionally, contribution stored precipitation (snowmelt) significantly outweighs by five times input situ (rain). magnitude rate local production are remarkably similar observed on prior Surface Heat Budget Ocean (SHEBA) campaign. A small (10 remains which higher more deformed second-year compared first-year later summer. Most drains via lateral vertical drainage channels, with enabling storage internally freshening brine channels. In upper ocean, can accumulate transient order 10 cm 1 m thick under ice. presence such substantially system reducing bottom allowing false growth, heat, nutrient gas exchange, influencing ecosystem productivity. Regardless, majority inferred be ultimately incorporated into ocean (75 (14 %). Comparison sink terms estimates CESM2 climate model simulated ponds dramatically underestimated. This suggests pond should investigated as likely explanation.

Язык: Английский

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