Preconditioning of Summer Melt Ponds From Winter Sea Ice Surface Temperature

Geophysical Research Letters, Год журнала: 2023, Номер 50(4)

Опубликована: Фев. 22, 2023

Abstract Comparing helicopter‐borne surface temperature maps in winter and optical orthomosaics summer from the year‐long Multidisciplinary drifting Observatory for Study of Arctic Climate expedition, we find a strong geometric correlation between warm anomalies melt pond location following summer. Warm are associated with thinner snow ice, that is, depression refrozen leads, allow water accumulation during melt. January were 0.3–2.5 K warmer on sea ice later formed ponds. A one‐dimensional steady‐state thermodynamic model shows observed differences line thickness depth. We demonstrate potential seasonal prediction coverage observations. threshold‐based classification achieves correct 41%

Язык: 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, Год журнала: 2024, Номер 12(1)

Опубликована: Янв. 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.

Язык: Английский

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Digital elevation models of the sea-ice surface from airborne laser scanning during MOSAiC

Scientific Data, Год журнала: 2023, Номер 10(1)

Опубликована: Окт. 20, 2023

Abstract Airborne laser scanners (ALS) are used to map the sea-ice surface at sub-meter resolution. We conducted 64 flights over Arctic sea ice between September 2019 and 2020 during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition measure elevation. The ranged from repeated, local-scale 5 × km 2 floe grid surveys regional-scale transects more than 100 long. provide data different processing levels: geolocated elevation point clouds gridded segments freeboard with a spatial resolution 0.5 m. latter product is corrected atmospheric backscatter, drift, offset in due degraded INS/GNSS solutions > 85° N. For surveys, all combined merged two-dimensional maps. Other provided parameters include reflectance echo width. presented offer unique possibility study temporal evolution, distribution, variability snow their properties addition validating satellite products.

Язык: Английский

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Observations of preferential summer melt of Arctic sea-ice ridge keels from repeated multibeam sonar surveys

˜The œcryosphere, Год журнала: 2023, Номер 17(11), С. 4873 - 4887

Опубликована: Ноя. 20, 2023

Abstract. Sea-ice ridges constitute a large fraction of the total Arctic sea-ice area (up to 40 %–50 %); nevertheless, they are least studied part ice pack. Here we investigate melt rates using rare, repeated underwater multibeam sonar surveys that cover period 1 month during advanced stage melt. Bottom increases with draft for first- and second-year level first-year ridge, an average 0.46, 0.55, 0.95 m snow in observation period, respectively. On average, ridge had 4.6 keel bottom draft, was 42 wide, 4 % macroporosity. While were 3.8 times higher than ice, surface almost identical but responsible decrease. Average cross-sectional ranged from 0.2 2.6 m, maximum point loss 6 showcasing its spatial variability. We attribute 57 (surface bottom) variability (36 %), slope (32 width (27 larger steeper slope, smaller width. The rate flanks proportional increased within 10 corners between these comparable ice.

Язык: Английский

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Sea ice melt pond bathymetry reconstructed from aerial photographs using photogrammetry: a new method applied to MOSAiC data

˜The œcryosphere, Год журнала: 2024, Номер 18(7), С. 2991 - 3015

Опубликована: Июль 2, 2024

Abstract. Melt ponds are a core component of the summer sea ice system in Arctic, increasing uptake solar energy and impacting ice-associated ecosystem. They were thus one key topics during 1-year drift campaign Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) Transpolar Drift 2019/2020. Pond depth is dominating factor describing surface meltwater volume; it necessary to estimate budgets used model parameterization simulate pond coverage evolution. However, observational data on spatially temporally strongly limited few situ measurements. bathymetry, which fully resolved, remains unexplored. Here, we present newly developed method derive bathymetry from aerial images. We determine photogrammetric multi-view reconstruction topography. Based images recorded dedicated grid flights facilitated assumptions, able obtain with mean deviation 3.5 cm compared manual observations. The independent color sky conditions, an advantage over recently radiometric airborne retrieval methods. It can furthermore be implemented any typical photogrammetry workflow. algorithm, including requirements recording survey planning, correction refraction at air–pond interface. In addition, show how retrieved topography synergizes initial image retrieve water level individual visually determined margins. use give profound overview MOSAiC floe, found unexpected steady volume. properties more than 1600 their size, volume, elevation above level, temporal scaling single measurements, discuss representativeness measurements importance such high-resolution new satellite retrievals, indications non-rigid bottoms. study points out great potential geometric emerging increasingly available visual uncrewed vehicles (UAVs) or aircraft, allowing integrated understanding improved formulation thermodynamic hydrological models.

Язык: 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, Год журнала: 2024, Номер 12(1)

Опубликована: Янв. 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.

Язык: Английский

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Automated Detection and Depth Determination of Melt Ponds on Sea Ice in ICESat-2 ATLAS Data—The Density-Dimension Algorithm for Bifurcating Sea-Ice Reflectors (DDA-Bifurcate-Seaice)

IEEE Transactions on Geoscience and Remote Sensing, Год журнала: 2023, Номер 61, С. 1 - 22

Опубликована: Янв. 1, 2023

As climate warms and the transition from a perennial to seasonal Arctic sea-ice cover is imminent, understanding melt ponding central changes in new Arctic. NASA's Ice, Cloud land Elevation Satellite (ICESat-2) has capacity provide measurements monitoring of onset on progression. Yet ponds are currently not identified ICESat-2 standard products, which only single surface determined. The objective this paper introduce mathematical algorithm that facilitates automated detection ATLAS data, retrieval two heights, pond bottom, depth width ponds. With Advanced Topographic Laser Altimeter System (ATLAS), carries first space-borne multi-beam micro-pulse photon-counting laser altimeter system, operating at 532 nm frequency. data recorded as clouds discrete photon points. Density-Dimension Algorithm for bifurcating reflectors (DDA-bifurcate-seaice) an auto-adaptive solves problem near 0.7 m nominal along-track spacing utilizing radial basis function calculation density field threshold automatically adapts background, apparent reflectance some instrument effects. DDA-bifurcate-seaice applied large sets 2019 2020 seasons multi-year region. Results evaluated by comparison those manually forced algorithm.

Язык: 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), Год журнала: 2023, Номер unknown

Опубликована: Сен. 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.

Язык: Английский

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Seasonality of spectral radiative fluxes and optical properties of Arctic sea ice during the spring–summer transition

Elementa Science of the Anthropocene, Год журнала: 2024, Номер 12(1)

Опубликована: Янв. 1, 2024

The reflection, absorption, and transmittance of shortwave solar radiation by sea ice play crucial roles in physical biological processes the ice-covered Arctic Ocean atmosphere. These sea-ice optical properties, particularly during melt season, significantly impact energy fluxes within total budget coupled atmosphere-ice-ocean system. We analyzed data from autonomous drifting stations to investigate seasonal evolution spectral albedo, transmittance, absorptivity for different sea-ice, snow, surface conditions measured MOSAiC expedition 2019–2020. spatial variability these properties was small spring increased strongly after onset on May 26, 2020, when liquid water content increased, largely accounting enhanced variability. temporal albedo mostly event-driven, thus containing episodic elements. Melt ponds reduced local 31%–45%. Over melting single ponding events deposition 35% compared adjacent bare ice. Thus, may summer as much over 1 month. Absorptivity showed strong variabilities independently conditions, possibly due internal under-ice processes. differences shown impacted partitioning radiation. This study shows that formation development ponds, reducing a third sites, can notably increase heat deposition. vastly evolutions, timing duration need be considered comparing in-situ observations with large-scale satellite remote sensing datasets, which we suggest help improve numerical models.

Язык: Английский

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Observing the evolution of summer melt on multiyear sea ice with ICESat-2 and Sentinel-2

˜The œcryosphere, Год журнала: 2023, Номер 17(9), С. 3695 - 3719

Опубликована: Авг. 31, 2023

Abstract. We investigate sea ice conditions during the 2020 melt season, when warm air temperature anomalies in spring led to early onset, an extended and second-lowest September minimum Arctic extent observed. focus on region of most persistent cover examine pond depth retrieved from Ice, Cloud, land Elevation Satellite-2 (ICESat-2) using two distinct algorithms concert with a time series fraction concentration derived Sentinel-2 imagery obtain insights about melting surface three dimensions. find study increased rapidly June, mean peaking at 16 % ± 6 24 June 2020, followed by slow decrease 8 3 July, remained below 10 for remainder season through 15 September. Sea was consistently high (>95 %) beginning until 4 as floes disintegrated, it decreased 70 30 July then became more variable, ranging 75 90 season. Pond steadily median 0.40 m 0.17 peaked 0.97 0.51 even had already started decrease. Our results demonstrate that combining high-resolution passive active remote sensing we now have ability track evolving observe changes throughout summer

Язык: Английский

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