Multiyear sea ice thermal regimes and oceanic heat flux derived from an ice mass balance buoy in the Arctic Ocean

A thermistor-string-based Snow and Ice Mass Balance Array (SIMBA) has been developed in recent years and used for monitoring snow and ice mass balance in the Arctic Ocean. SIMBA measures vertical environment temperature (ET) profiles through the air-snow-sea ice-ocean column using a thermistor string (5 m long, sensor spacing 2cm). Each thermistor sensor equipped with a small identical heating element. A small voltage was applied to the heating element so that the heat energy liberated in the vicinity of each sensor is the same. The heating time intervals lasted 60 s and 120 s, respectively. The heating temperatures (HT) after these two intervals were recorded. The ET was measured 4 times a day and once per day for the HT.A total 15 SIMBA buoys have been deployed in the Arctic Ocean during the Chinese National Arctic Research Expedition (CHINARE) 2018 and the Nansen and Amundsen Basins Observational System (NABOS) 2018 field expeditions in late autumn. We applied a recently developed SIMBA algorithm to retrieve snow and ice thickness using SIMBA ET and HT temperature data. We focus particularly on sea ice bottom evolution during Arctic winter.In mid-September 2018, 5 SIMBA buoys were deployed in the East Siberian Sea (NABOS2018) where snow was in practical zero cm and ice thickness ranged between 1.8 m &#8211; 2.6 m. By the end of May, those SIMBA buoys were drifted in the central Arctic where snow and ice thicknesses were around 0.05m - 0.2m and 2.6m &#8211; 3.2m, respectively. For those 10 SIMBA buoys deployed by the CHINARE2018 in the Chukchi Sea and Canadian Basin, the initial snow and ice thickness were ranged between 0.05m &#8211; 0.1cm and 1.5m &#8211; 2.5m, respectively. &#160;By the end of May, those SIMBA buoys were drifted toward the north of Greenland where snow and ice thicknesses were around 0.2m - 0.3m and 2.0m &#8211; 3.5m, respectively. The ice bottom evolution derived by SIMBA algorithm agrees well with SIMBA HT identified ice-ocean interfaces. We also perform a preliminary investigation of sea ice bottom evolution measured by several SIMBA buoys deployed during the MOSAiC leg1 field campaign in winter 2019/2020.&#160;&#160;

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Estimation of Oceanic Heat Flux Under Sea Ice in the Arctic Ocean

Journal of Ocean University of China ◽

10.1007/s11802-019-3877-7 ◽

2019 ◽

Vol 18 (3) ◽

pp. 605-614 ◽

Cited By ~ 1

Author(s):

Long Lin ◽

Jinping Zhao

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Arctic Ocean ◽

The Arctic ◽

Oceanic Heat Flux ◽

The Arctic Ocean

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Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean

Journal of Climate ◽

10.1175/jcli-d-19-0976.1 ◽

2020 ◽

Vol 33 (18) ◽

pp. 8107-8123 ◽

Cited By ~ 6

Author(s):

Igor V. Polyakov ◽

Tom P. Rippeth ◽

Ilker Fer ◽

Matthew B. Alkire ◽

Till M. Baumann ◽

...

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Arctic Ocean ◽

Mixed Layer ◽

Winter Season ◽

Atlantic Water ◽

The Arctic ◽

Surface Mixed Layer ◽

Winter Convection ◽

Oceanic Heat Flux

AbstractA 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback.

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A comparison of factors that led to the extreme sea ice minima in the 21st century in the Arctic Ocean

Journal of Climate ◽

10.1175/jcli-d-21-0199.1 ◽

2021 ◽

pp. 1-56

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Arctic Ocean ◽

Atmospheric Circulation ◽

21St Century ◽

Open Water ◽

The Arctic ◽

Area Loss ◽

The Arctic Ocean ◽

The Difference

Abstract The extreme Arctic sea ice minima in the 21st century have been attributed to multiple factors, such as anomalous atmospheric circulation, excess solar radiation absorbed by open ocean, and thinning sea ice in a warming world. Most likely it is the combination of these factors that drive the extreme sea ice minima, but it has not been quantified, how the factors rank in setting the conditions for these events. To address this question, the sea ice budget of an Arctic regional sea ice-ocean model forced by atmospheric reanalysis data is analyzed to assess the development of the observed sea ice minima. Results show that the ice area difference in the years 2012, 2019, and 2007 is driven to over 60% by the difference in summertime sea ice area loss due to air-ocean heat flux over open water. Other contributions are small. For the years 2012 and 2020 the situation is different and more complex. The air-ice heat flux causes more sea ice area loss in summer 2020 than in 2012 due to warmer air temperatures, but this difference in sea ice area loss is compensated by reduced advective sea ice loss out of the Arctic Ocean mainly caused by the relaxation of the Arctic Dipole. The difference in open water area in early August leads to different air-ocean heat fluxes, which distinguishes the sea ice minima in 2012 and 2020. Further, sensitivity experiments indicate that both the atmospheric circulation associated with the Arctic Dipole and extreme storms are essential conditions for a new low record of sea ice extent.

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Mechanism of seasonal Arctic sea ice evolution and Arctic amplification

The Cryosphere ◽

10.5194/tc-10-2191-2016 ◽

2016 ◽

Vol 10 (5) ◽

pp. 2191-2202 ◽

Cited By ~ 17

Author(s):

Kwang-Yul Kim ◽

Benjamin D. Hamlington ◽

Hanna Na ◽

Jinju Kim

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Arctic Ocean ◽

Turbulent Heat Flux ◽

Sea Surface ◽

The Arctic ◽

Turbulent Heat ◽

Arctic Amplification ◽

Atmospheric Column ◽

The Arctic Ocean

Abstract. Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents–Kara seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice reduction warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be free of ice. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents–Kara seas and Laptev, East Siberian, Chukchi, and Beaufort seas.

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