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

˜The œcryosphere, Journal Year: 2025, Volume and Issue: 19(2), P. 619 - 644

Published: Feb. 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.

Language: Английский

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Impacts of air fraction increase on Arctic sea ice density, freeboard, and thickness estimation during the melt season

˜The œcryosphere, Journal Year: 2025, Volume and Issue: 19(3), P. 1259 - 1278

Published: March 17, 2025

Abstract. Arctic sea ice has undergone significant changes over the past 50 years. Modern large-scale estimates of thickness and volume come from satellite observations. However, these have limited accuracy, especially during melt season, making it difficult to compare state year year. Uncertainties in density lead high uncertainties retrieval its freeboard. During Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition, we observed a first-year (FYI) freeboard increase 0.02 m, while decreased by 0.5 m season June–July 2020. Over same period, FYI 910 880 kg m−3, air fraction increased 1 % 6 %, due void expansion controlled internal melt. This substantially affected Due differences thermodynamic (such as salinity temperature), is less pronounced second-year (SYI) smaller impact on evolution SYI ridges. We validated our discrete measurements coring using co-located topography observations underwater sonar an airborne laser scanner. Despite decreasing thickness, similar counterintuitive increasing was entire 0.9 km2 MOSAiC floe, with stronger than saline SYI. The surrounding area experienced slightly lower 0.01 July 2020, despite comparable rates obtained mass balance buoys. defines rapid decrease density, complicates altimeters underlines importance considering algorithms.

Language: Английский

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The Eurasian Arctic Ocean along the MOSAiC drift in 2019–2020: An interdisciplinary perspective on physical properties and processes

Elementa Science of the Anthropocene, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, 2019–2020), a year-long drift with sea ice, has provided scientific community an unprecedented, multidisciplinary dataset from Eurasian Ocean, covering high atmosphere to deep ocean across all seasons. However, heterogeneity data and superposition spatial temporal variability, intrinsic campaign, complicate interpretation observations. In this study, we have compiled quality-controlled physical hydrographic best spatio-temporal coverage derived core parameters, including mixed layer depth, heat fluxes over key layers, friction velocity. We provide comprehensive accessible overview conditions encountered along MOSAiC drift, discuss their interdisciplinary implications, compare common climatologies these new data. Our results indicate that, most part, variability was dominated by regional rather than seasonal signals, carrying potentially strong implications biogeochemistry, ecology, even atmospheric conditions. Near-surface properties were strongly influenced relative position sampling, within or outside river-water Transpolar Drift, warming meltwater input. Ventilation down Atlantic Water in Nansen Basin allowed stronger connectivity between subsurface ice surface via elevated upward fluxes. Yermak Plateau Fram Strait regions characterized heterogeneous water mass distributions, energetic currents, lateral gradients frontal regions. Together presented offer context research, fostering improved understanding complex, coupled System.

Language: Английский

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Sea ice mass balance during the MOSAiC drift experiment: Results from manual ice and snow thickness gauges

Elementa Science of the Anthropocene, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Precise measurements of Arctic sea ice mass balance are necessary to understand the rapidly changing cover and its representation in climate models. During Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition, we made repeat point snow thickness on primarily level first- second-year (FYI, SYI) using ablation stakes gauges. This technique enabled us distinguish surface bottom (basal) melt characterize importance oceanic versus atmospheric forcing. We also evaluated time series growth context other MOSAiC observations historical from Surface Heat Budget (SHEBA) campaign North Pole Environmental (NPEO). Despite similar freezing degree days, average at was greater FYI (1.67 m) SYI (1.23 than SHEBA (1.45 m, 0.53 m), due part initially thinner conditions MOSAiC. Our estimates effective thermal conductivity, which agree with results observations, unlikely explain difference. On MOSAiC, grew more faster SYI, demonstrating a feedback loop that acts increase production after multi-year loss. (mean 0.50 NPEO (0.18 considerable spatial variability correlated albedo variability. Basal relatively small 0.12 higher (0.07 m). Finally, present showing false bottoms reduced basal rates some cases, agreement These detailed will allow further investigation into connections between carefully observed energy budget, ocean heat fluxes, ice, ecosystem during campaigns.

Language: Английский

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The Eurasian Arctic Ocean along the MOSAiC drift in 2019-2020: An interdisciplinary perspective on physical properties and processes

EarthArXiv (California Digital Library), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 7, 2023

The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, 2019--2020), a year-long drift with sea ice, has provided scientific community an unprecedented, multidisciplinary dataset from Eurasian Ocean, covering high atmosphere to deep ocean across all seasons. However, heterogeneity data and superposition spatial temporal variability, intrinsic campaign, complicate interpretation observations. In this study, we have compiled quality-controlled physical hydrographic best spatio-temporal coverage derived core parameters, including mixed layer depth, heat fluxes over key layers, friction velocity. We provide comprehensive accessible overview conditions encountered along MOSAiC drift, discuss their interdisciplinary implications, compare common climatologies these new data. Our results indicate that, most part, variability was dominated by regional rather than seasonal signals, carrying potentially strong implications biogeochemistry, ecology, even atmospheric conditions. Near-surface properties were strongly influenced relative position sampling, within or outside river-water Transpolar Drift, warming meltwater input. Ventilation down Atlantic Water in Nansen Basin allowed stronger connectivity between subsurface ice surface via elevated upward fluxes. Yermak Plateau Fram Strait regions characterized heterogeneous water mass distributions, energetic currents, lateral gradients frontal regions. Together presented offer context research, fostering improved understanding complex, coupled System.

Language: Английский

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Novel methods to study sea ice deformation, linear kinematic features and coherent dynamic clusters from imaging remote sensing data

˜The œcryosphere, Journal Year: 2025, Volume and Issue: 19(3), P. 1135 - 1151

Published: March 11, 2025

Abstract. Satellite synthetic aperture radar (SAR) data are commonly utilized for calculating sea ice displacements and, consequently, deformation strain rates. However, rate calculations often suffer from a poor signal-to-noise ratio, especially products with spatial resolution higher than 1 km. In this study, new filtering method to derived Sentinel-1 SAR image pairs of 800 m was applied. Subsequently, power law evaluate the rates at decreasing resolutions employed assess quality filtered data. Upon positive evaluation data, two innovative methods assessment were introduced. The first method, named “damage parcel” tracking, involved combined analysis and monitor divergence convergence within cover. Additionally, term describe behavior winter pack proposed: “coherent dynamic clusters” (CDCs). CDCs cohesive clusters plates that move coherently along linear kinematic features (LKFs). second novel developed in study focused on exploring geometrical properties these CDCs. Both applied January–February collection imagery available during N-ICE2015 campaign. damage parcels continuously tracked over period 3 weeks, including major storm, revealing slow healing process existing LKFs. Furthermore, CDC demonstrated presence elongated density ranging 5 20 per 100 km by km, shortest distance between LKFs found be 5–10

Language: Английский

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Under-ice environment observations from a remotely operated vehicle during the MOSAiC expedition

Scientific Data, Journal Year: 2025, Volume and Issue: 12(1)

Published: June 5, 2025

Language: Английский

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Overview of the MOSAiC expedition: Ecosystem

EarthArXiv (California Digital Library), Journal Year: 2023, Volume and Issue: unknown

Published: Dec. 8, 2023

An international and interdisciplinary sea ice drift expedition, the ‘The Multidisciplinary drifting Observatory for Study of Arctic Climate‘ (MOSAiC), was conducted from October 2019 to September 2020. The aim MOSAiC study interconnected physical, chemical biological characteristics processes atmosphere deep central system. ecosystem team addressed current knowledge gaps explored unknown properties over a complete seasonal cycle focusing on three major research areas: biodiversity, biogeochemical cycles linkages environment. In addition coverage core along cycle, dedicated projects covered specific habitats, or organisms higher taxonomic temporal resolution. A wide range sampling approaches sampling, coring, lead CTD rosette-based water plankton nets, ROVs acoustic buoys applied address science objectives. Further, process-related measurements e.g. productivity patterns, migrations diversity shifts were both in situ onboard RV Polarstern. This paper provides detailed overview used main It highlights program examples two habitat- process-specific projects. First results presented include high activities winter time discovery hotspots underexplored habitats. unique interconnectivity coordinated efforts also revealed insights into cross-disciplinary interactions like impact biota cloud formation. further presents lessons learned conducting such demanding field campaign an outlook spin-off be next years.

Language: Английский

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Relationship of physical and mechanical properties of sea ice during the freeze-up season in Nansen Basin

Cold Regions Science and Technology, Journal Year: 2024, Volume and Issue: unknown, P. 104353 - 104353

Published: Oct. 1, 2024

Language: Английский

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

Published: July 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.

Language: Английский

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