Associations between circulation pattern frequencies and sea ice minima in the western Arctic

ABSTRACTThe Arctic marine environment is undergoing a transition from thick multi-year to first-year sea-ice cover with coincident lengthening of the melt season. Such changes are evident in the Baffin Bay-Davis Strait-Labrador Sea (BDL) region where melt onset has occurred ~8 days decade−1 earlier from 1979 to 2015. A series of anomalously early events has occurred since the mid-1990s, overlapping a period of increased upper-air ridging across Greenland and the northwestern North Atlantic. We investigate an extreme early melt event observed in spring 2013. (~6σ below the 1981–2010 melt climatology), with respect to preceding sub-seasonal mid-tropospheric circulation conditions as described by a daily Greenland Blocking Index (GBI). The 40-days prior to the 2013 BDL melt onset are characterized by a persistent, strong 500 hPa anticyclone over the region (GBI >+1 on >75% of days). This circulation pattern advected warm air from northeastern Canada and the northwestern Atlantic poleward onto the thin, first-year sea ice and caused melt ~50 days earlier than normal. The episodic increase in the ridging atmospheric pattern near western Greenland as in 2013, exemplified by large positive GBI values, is an important recent process impacting the atmospheric circulation over a North Atlantic cryosphere undergoing accelerated regional climate change.

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Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean

Biogeosciences ◽

10.5194/bg-11-1705-2014 ◽

2014 ◽

Vol 11 (7) ◽

pp. 1705-1716 ◽

Cited By ~ 35

Author(s):

A. Fujiwara ◽

T. Hirawake ◽

K. Suzuki ◽

I. Imai ◽

S.-I. Saitoh

Keyword(s):

Community Structure ◽

Sea Ice ◽

Arctic Ocean ◽

Phytoplankton Community ◽

Phytoplankton Community Structure ◽

Western Arctic Ocean ◽

Phytoplankton Communities ◽

Ice Retreat ◽

Western Arctic ◽

Sea Ice Retreat

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analysed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years–the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.

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Sources of sediment found in sea ice from the western Arctic Ocean, new insights into processes of entrainment and drift patterns

Journal of Geophysical Research Atmospheres ◽

10.1029/2002jc001350 ◽

2003 ◽

Vol 108 (C8) ◽

Cited By ~ 85

Author(s):

Dennis A. Darby

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Western Arctic Ocean ◽

Western Arctic

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Surface Waves Under the Sea Ice in the Western Arctic During 2019 R/V Mirai Cruise

Volume 2A: Structures, Safety, and Reliability ◽

10.1115/omae2020-18547 ◽

2020 ◽

Author(s):

Tsubasa Kodaira ◽

Takuji Waseda ◽

Takehiko Nose ◽

Jun Inoue ◽

Kazutoshi Sato ◽

...

Keyword(s):

Sea Ice ◽

Surface Waves ◽

Ocean Waves ◽

Arctic Sea Ice ◽

The Arctic ◽

Wave Transformation ◽

Sea Ice Extent ◽

Marginal Ice Zone ◽

Western Arctic ◽

Arctic Climate Change

Abstract Surface ocean waves are one of the potential processes that influence on the Arctic sea-ice extent. A better understanding of the generation, propagation, and attenuation of ocean waves under the sea ice is necessary to discuss the future Arctic climate change. We deployed two drifting wave buoys in the marginal ice zone in the western Arctic. Since the surface wave observation in the marginal ice zone is rare, the obtained data are useful for validation of the numerical modeling of the surface waves under the sea ice. The first buoy was deployed in the pancake-ice covered area and the second one in the open ocean. The distance between the two buoys at the deployment was about 40km, and the second buoy was deployed approximately 5 hours after the first deployment. The comparison of the wave bulk statistic measured by the two buoys shows the wave transformation under the sea ice. In general, the significant wave height decreases, and the mean wave periods increase by the presence of the sea ice.

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Coastal acidification induced by biogeochemical processes driven by sea-ice melt in the western Arctic ocean

Polar Science ◽

10.1016/j.polar.2020.100504 ◽

2020 ◽

Vol 23 ◽

pp. 100504

Author(s):

Di Qi ◽

Baoshan Chen ◽

Liqi Chen ◽

Hongmei Lin ◽

Zhongyong Gao ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Biogeochemical Processes ◽

Western Arctic Ocean ◽

Ice Melt ◽

Western Arctic ◽

Coastal Acidification

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Evolution of supercooling under coastal Antarctic sea ice during winter

Antarctic Science ◽

10.1017/s0954102011000265 ◽

2011 ◽

Vol 23 (4) ◽

pp. 399-409 ◽

Cited By ~ 30

Author(s):

Gregory H. Leonard ◽

Patricia J. Langhorne ◽

Michael J.M. Williams ◽

Ross Vennell ◽

Craig R. Purdie ◽

...

Keyword(s):

Sea Ice ◽

Freezing Point ◽

Circulation Pattern ◽

Late Winter ◽

Ice Shelf ◽

Mcmurdo Sound ◽

The North ◽

Antarctic Sea Ice ◽

Ice Production

AbstractHere we describe the evolution through winter of a layer of in situ supercooled water beneath the sea ice at a site close to the McMurdo Ice Shelf. From early winter (May), the temperature of the upper water column was below its surface freezing point, implying contact with an ice shelf at depth. By late winter the supercooled layer was c. 40 m deep with a maximum supercooling of c. 25 mK located 1–2 m below the sea ice-water interface. Transitory in situ supercooling events were also observed, one lasting c. 17 hours and reaching a depth of 70 m. In spite of these very low temperatures the isotopic composition of the water was relatively heavy, suggesting little glacial melt. Further, the water's temperature-salinity signature indicates contributions to water mass properties from High Salinity Shelf Water produced in areas of high sea ice production to the north of McMurdo Sound. Our measurements imply the existence of a heat sink beneath the supercooled layer that extracts heat from the ocean to thicken and cool this layer and contributes to the thickness of the sea ice cover. This sink is linked to the circulation pattern of the McMurdo Sound.

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