Sounds and vibrations recorded on and beneath landfast sea ice during construction of an artificial gravel island for oil production in the Alaska Beaufort Sea

Abstract The surface spectral albedo was measured over coastal landfast sea ice in Prydz Bay (off Zhongshan Station), East Antarctica from 5 October to 26 November of 2016. The mean albedo decreased from late-spring to early-summer, mainly responding to the change in surface conditions from dry (phase I) to wet (phase II). The evolution of the albedo was strongly influenced by the surface conditions, with alternation of frequent snowfall events and katabatic wind that induce snow blowing at the surface. The two phases and day-to-day albedo variability were more pronounced in the near-infrared albedo wavelengths than in the visible ones, as the near-infrared photons are more sensitive to snow metamorphism, and to changes in the uppermost millimeters and water content of the surface. The albedo diurnal cycle during clear sky conditions was asymmetric with respect to noon, decreasing from morning to evening over full and patchy snow cover, and decreasing more rapidly in the morning over bare ice. We conclude that snow and ice metamorphism and surface melting dominated over the solar elevation angle dependency in shaping the albedo evolution. However, we realize that more detailed surface observations are needed to clarify and quantify the role of the various surface processes.

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Albedo of Melting Sea Ice in the Southern Beaufort Sea

Journal of Glaciology ◽

10.3189/s0022143000013022 ◽

1971 ◽

Vol 10 (58) ◽

pp. 101-104 ◽

Cited By ~ 1

Author(s):

M.P. Langleben

Keyword(s):

Sea Ice ◽

Northwest Territories ◽

Beaufort Sea ◽

Ice Cover ◽

Short Wave ◽

Wave Radiation ◽

Short Wave Radiation ◽

Melting Period ◽

Fast Ice ◽

Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

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Increasing Multiyear Sea Ice Loss in the Beaufort Sea: A New Export Pathway for the Diminishing Multiyear Ice Cover of the Arctic Ocean

10.1002/essoar.10509833.1 ◽

2021 ◽

Author(s):

David Gareth Babb ◽

Ryan J. Galley ◽

Stephen E. L. Howell ◽

Jack Christopher Landy ◽

Julienne Christine Stroeve ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Beaufort Sea ◽

Ice Cover ◽

The Arctic ◽

Export Pathway ◽

The Arctic Ocean ◽

Multiyear Ice

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Seasonal evolution and salt/freshwater fluxes of first-year sea ice: Comparison between pack ice and landfast sea ice

10.5194/egusphere-egu21-10798 ◽

2021 ◽

Author(s):

Marc Oggier ◽

Hajo Eicken ◽

Robert Rember ◽

Allison Fong ◽

Dmitry V. Divine ◽

...

Keyword(s):

Sea Ice ◽

Ice Cores ◽

Upper Ocean ◽

First Year ◽

Ice Melt ◽

Ice Surface ◽

Freshwater Fluxes ◽

Exchange Processes ◽

Bulk Salinity ◽

Landfast Sea Ice

<p>Sea ice affects the exchange of energy and matter between the atmosphere and the ocean from local to hemispheric scales. Salt fluxes across the ice-ocean interface that drive thermohaline mixing beneath growing sea ice are important elements of upper ocean nutrient and carbon exchange. Sea-ice melt releases freshwater into the upper ocean and results in formation of melt ponds that affect gas and energy transfer across the atmosphere-ice interface. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) provided an opportunity to follow sea-ice evolution and exchange processes over a full seasonal cycle in a rapidly changing ice cover. To this end, approximately 25 sea-ice cores were collected at 2 distinct sites, representing first-year and multi-year ice, to monitor physical, biological and geochemical processes relevant to atmosphere-ice-ocean exchange processes. Here we compare the growth and decay of first-year ice in the Central Arctic during the winter 2019-2020 to that of landfast first-year ice at Utqia&#289;vik, Alaska, from 1998 to 2016. Ice stratigraphy was similar at both sites with about 15 cm of granular ice on top of columnar ice, with a comparable growth history with a similar maximum ice thickness of 1.6-1.7 m. We aggregated the sea-ice bulk salinity and temperature profiles using a degree-day approach, and examined brine and freshwater fluxes at lower and upper interfaces of the ice, respectively. Preliminary results show lower sea-ice bulk salinity during the growth season and greater desalination at the ice surface during the melt season at the MOSAiC floe in comparison to Utqia&#289;vik.</p>

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Physical controls on the storage of methane in landfast sea ice

The Cryosphere ◽

10.5194/tc-8-1019-2014 ◽

2014 ◽

Vol 8 (3) ◽

pp. 1019-1029 ◽

Cited By ~ 9

Author(s):

J. Zhou ◽

J.-L. Tison ◽

G. Carnat ◽

N.-X. Geilfus ◽

B. Delille

Keyword(s):

Sea Ice ◽

Bubble Formation ◽

Gas Bubble ◽

Physical Processes ◽

Ice Melt ◽

Physical Controls ◽

The Difference ◽

Landfast Sea Ice ◽

Ice Water ◽

Brine Concentration

Abstract. We report on methane (CH4) dynamics in landfast sea ice, brine and under-ice seawater at Barrow in 2009. The CH4 concentrations in under-ice water ranged from 25.9 to 116.4 nmol L−1sw, indicating a supersaturation of 700 to 3100% relative to the atmosphere. In comparison, the CH4 concentrations in sea ice ranged from 3.4 to 17.2 nmol L−1ice and the deduced CH4 concentrations in brine from 13.2 to 677.7 nmol L−1brine. We investigated the processes underlying the difference in CH4 concentrations between sea ice, brine and under-ice water and suggest that biological controls on the storage of CH4 in ice were minor in comparison to the physical controls. Two physical processes regulated the storage of CH4 in our landfast ice samples: bubble formation within the ice and sea ice permeability. Gas bubble formation due to brine concentration and solubility decrease favoured the accumulation of CH4 in the ice at the beginning of ice growth. CH4 retention in sea ice was then twice as efficient as that of salt; this also explains the overall higher CH4 concentrations in brine than in the under-ice water. As sea ice thickened, gas bubble formation became less efficient, CH4 was then mainly trapped in the dissolved state. The increase of sea ice permeability during ice melt marked the end of CH4 storage.

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Chlorophyll-a in Antarctic Landfast Sea Ice: A First Synthesis of Historical Ice Core Data

Journal of Geophysical Research Oceans ◽

10.1029/2018jc014245 ◽

2018 ◽

Vol 123 (11) ◽

pp. 8444-8459 ◽

Cited By ~ 11

Author(s):

K. M. Meiners ◽

M. Vancoppenolle ◽

G. Carnat ◽

G. Castellani ◽

B. Delille ◽

...

Keyword(s):

Sea Ice ◽

Chlorophyll A ◽

Ice Core ◽

Core Data ◽

Landfast Sea Ice

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Investigation of spatiotemporal variability of melt pond fraction and its relationship with sea ice extent during 2000–2017 using a new data

10.5194/tc-2019-208 ◽

2019 ◽

Author(s):

Yifan Ding ◽

Xiao Cheng ◽

Jiping Liu ◽

Fengming Hui ◽

Zhenzhan Wang

Keyword(s):

Sea Ice ◽

Arctic Basin ◽

Beaufort Sea ◽

Arctic Sea Ice ◽

Spatiotemporal Variability ◽

First Year ◽

Spatial And Temporal Variability ◽

Sea Ice Extent ◽

Melt Pond ◽

Melt Ponds

Abstract. The accurate knowledge of variations of melt ponds is important for understanding Arctic energy budget due to its albedo-transmittance-melt feedback. In this study, we develop and validate a new method for retrieving melt pond fraction (MPF) from the MODIS surface reflectance. We construct an ensemble-based deep neural network and use in-situ observations of MPF from multi-sources to train the network. The results show that our derived MPF is in good agreement with the observations, and relatively outperforms the MPF retrieved by University of Hamburg. Built on this, we create a new MPF data from 2000 to 2017 (the longest data in our knowledge), and analyze the spatial and temporal variability of MPF. It is found that the MPF has significant increasing trends from late July to early September, which is largely contributed by the MPF over the first-year sea ice. The analysis based on our MPF during 2000–2017 confirms that the integrated MPF to late June does promise to improve the prediction skill of seasonal Arctic sea ice minimum. However, our MPF data shows concentrated significant correlations first appear in a band, extending from the eastern Beaufort Sea, through the central Arctic, to the northern East Siberian and Laptev Seas in early-mid June, and then shifts towards large areas of the Beaufort Sea, Canadian Arctic, the northern Greenland Sea and the central Arctic basin.

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Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea

10.5194/bg-2017-318 ◽

2017 ◽

Author(s):

Jacoba Mol ◽

Helmuth Thomas ◽

Paul G. Myers ◽

Xianmin Hu ◽

Alfonso Mucci

Keyword(s):

Sea Ice ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Beaufort Sea ◽

Total Alkalinity ◽

The Arctic ◽

Surface Mixed Layer ◽

Saturation State ◽

Carbon Transfer ◽

Mackenzie Shelf

Abstract. The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries inorganic carbon and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world oceans. Upwelling carries dissolved inorganic carbon (DIC) and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of inorganic carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of inorganic carbon are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) framework. A strong upwelling event prior to sampling on the Mackenzie Shelf is analyzed and the resulting influence on the carbonate system, including the saturation state of waters with respect to aragonite and pH, is investigated. TA and the oxygen isotope ratio of water (δ18O) are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of carbon dioxide (CO2) in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis for understanding how it will respond to the aforementioned climate-induced changes.

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