Chlorophyllain Antarctic sea ice from historical ice core data

AbstractUsing results stemming from the International Trans-Antarctic Scientific Expedition (ITASE) ice-core array plus data from ice cores from the South Pole and Siple Dome we investigate the use of sodium (Na+), non-sea-salt sulfate (nssSO42–) and methylsulfonate (MS–) as proxies for Antarctic sea-ice extent (SIE). Maximum and mean annual chemistry concentrations for these three species correlate significantly with maximum, mean and minimum annual SIE, offering more information and clarification than single ice-core and single species approaches. Significant correlations greater than 90% exist between Na+ and maximum SIE; nssSO42– with minimum and mean SIE; and MS– with mean SIE. Correlations with SIE within large geographic regions are in the same direction for all ice-core sites for Na+ and nssSO42– but not MS–. All ice cores display an SIE correlation with nssSO42– and MS–, but not all correlate with Na+. This multi-core multi-parameter study provides the initial step in determining which chemical species can be used reliably and in which regions as a building block for embedding other ice-core records. Once established, the resulting temporal and spatial matrix can be used to relate ice extents, atmospheric patterns, biological productivity and site conditions.

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Technical Note: On the use of the mushy-layer Rayleigh number for the interpretation of sea-ice-core data

The Cryosphere Discussions ◽

10.5194/tcd-7-3209-2013 ◽

2013 ◽

Vol 7 (4) ◽

pp. 3209-3230 ◽

Cited By ~ 8

Author(s):

M. Vancoppenolle ◽

D. Notz ◽

F. Vivier ◽

J. Tison ◽

B. Delille ◽

...

Keyword(s):

Quantitative Analysis ◽

Rayleigh Number ◽

Sea Ice ◽

Standard Method ◽

Ice Core ◽

Active Regions ◽

Technical Note ◽

Mushy Layer ◽

Core Data ◽

Specific Formulation

Abstract. We examine some practical aspects of using a mushy-layer Rayleigh number for the interpretation of sea-ice-core data. In principle, such analysis should allow one to determine convectively active regions within the ice core by identifying those regions in which the mush-Rayleigh number is super-critical. In practice, however, a quantitative analysis is complicated by uncertainties regarding the specific formulation of both the mush-Rayleigh number itself and of the sea-ice permeability that is crucial for quantifying the Rayleigh number. Additionally, brine loss from highly permeable sections of the ice core, in particular close to the ice–ocean interface, and typically weekly ice core sampling, limit the practical applicability of the Rayleigh number for ice-core interpretation. We here quantify these uncertainties, suggest a standard method for the computation of the Rayleigh number for sea ice and discuss possibilities and limitations of ice-core interpretation based on the Rayleigh number.

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Ice Core Evidence for Antarctic Sea Ice Decline Since the 1950s

Science ◽

10.1126/science.1087888 ◽

2003 ◽

Vol 302 (5648) ◽

pp. 1203-1206 ◽

Cited By ~ 218

Author(s):

M. A. J. Curran

Keyword(s):

Sea Ice ◽

Ice Core ◽

Antarctic Sea Ice ◽

Sea Ice Decline ◽

The 1950S

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Sea Salt Sodium Record in a Shallow Ice Core from East Antarctica as a Potential Proxy of the Antarctic Sea Ice Extent in Southern Indian Ocean

Journal of Ocean University of China ◽

10.1007/s11802-019-4084-2 ◽

2019 ◽

Vol 18 (6) ◽

pp. 1351-1359 ◽

Cited By ~ 1

Author(s):

Jiao Yang ◽

Zhiheng Du ◽

Cunde Xiao

Keyword(s):

Indian Ocean ◽

Sea Ice ◽

Ice Core ◽

Sea Salt ◽

East Antarctica ◽

Southern Indian Ocean ◽

Sea Ice Extent ◽

Antarctic Sea Ice ◽

The Antarctic

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Surface properties and processes of perennial Antarctic sea ice in summer

Journal of Glaciology ◽

10.3189/172756501781831864 ◽

2001 ◽

Vol 47 (159) ◽

pp. 613-625 ◽

Cited By ~ 85

Author(s):

Christian Haas ◽

David N. Thomas ◽

Jörg Bareiss

Keyword(s):

Sea Ice ◽

Water Level ◽

Ice Core ◽

Temperature Gradients ◽

Coarse Grained ◽

Heuristic Model ◽

Initial Formation ◽

Antarctic Sea Ice ◽

Upward Growth ◽

Standing Stocks

AbstractIce-core and snow data from the Amundsen, Bellingshausen and Weddell Seas, Antarctica, show that the formation of superimposed ice and the development of seawater-filled gap layers with high algal standing stocks is typical of the perennial sea ice in summer. The coarse-grained and dense snow had salinities mostly below 0.1‰. A layer of fresh superimposed ice had a mean thickness of 0.04–0.12 m. Gap layers 0.04–0.08 m thick extended downwards from 0.02 to 0.14 m below the water level. These gaps were populated by diatom standing stocks up to 439 μg L−1 chlorophyll a. We propose a comprehensive heuristic model of summer processes, where warming and the reversal of temperature gradients cause major transformations in snow and ice properties. The warming also causes the reopening of incompletely frozen slush layers caused by flood-freeze cycles during winter. Alternatively, superimposed ice forms at the cold interface between snow and slush in the case of flooding with negative freeboard. Combined, these explain the initial formation of gap layers by abiotic means alone. The upward growth of superimposed ice above the water level competes with a steady submergence of floes due to bottom and internal melting and accumulation of snow.

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South Pole Ice Core Reveals History of Antarctic Sea Ice

Eos ◽

10.1029/2021eo158303 ◽

2021 ◽

Vol 102 ◽

Author(s):

Elizabeth Thompson

Keyword(s):

Sea Ice ◽

Ice Core ◽

South Pole ◽

Permanent Record ◽

Antarctic Sea Ice ◽

Trace Back ◽

History Of

Every summer, most of the sea ice near Antarctica melts away, but its saltiness leaves a permanent record that scientists can trace back for millennia.

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An ice-core record of Antarctic sea-ice extent in the southern Indian Ocean for the past 300 years

Annals of Glaciology ◽

10.3189/2015aog69a719 ◽

2015 ◽

Vol 56 (69) ◽

pp. 451-455 ◽

Cited By ~ 4

Author(s):

C. Xiao ◽

T. Dou ◽

S.B. Sneed ◽

R. Li ◽

I. Allison

Keyword(s):

Indian Ocean ◽

Sea Ice ◽

Ice Core ◽

Ice Age ◽

Southern Indian Ocean ◽

The Arctic ◽

Sea Ice Extent ◽

Antarctic Sea Ice ◽

Ice Core Record ◽

Decadal Variations

AbstractThe differing response of ice extent in the Arctic and Antarctic to global average temperature change, over approximately the last three decades, highlights the importance of reconstructing long-term sea-ice history. Here, using high-resolution ice-core records of methane-sulfonate (MS–) from the East Antarctic ice sheet in Princess Elizabeth Land, we reconstruct southern Indian Ocean sea-ice extent (SIE) for the sector 62–92° E for the period AD 1708–2000. Annual MS– concentration positively correlates in this sector with satellite-derived SIE for the period 1979–2000 (r2 = 0.25, P < 0.02). The 293 year MS– record of proxy SIE shows multi-decadal variations, with large decreases occurring in two warm intervals during the Little Ice Age, and during the 1940s. It is very likely that the global temperature is the controlling factor of Antarctic sea-ice variation at the centennial scale, although there has been a change in phase between them in recent decades.

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Antarctic Sea Ice Proxies from Marine and Ice Core Archives Suitable for Reconstructing Sea Ice over the Past 2000 Years

Geosciences ◽

10.3390/geosciences9120506 ◽

2019 ◽

Vol 9 (12) ◽

pp. 506 ◽

Cited By ~ 3

Author(s):

Elizabeth R. Thomas ◽

Claire S. Allen ◽

Johan Etourneau ◽

Amy C. F. King ◽

Mirko Severi ◽

...

Keyword(s):

Sea Ice ◽

20Th Century ◽

Climate Models ◽

Ross Sea ◽

Ice Core ◽

Ice Cores ◽

Weddell Sea ◽

The Past ◽

Antarctic Sea Ice ◽

Past 2000 Years

Dramatic changes in sea ice have been observed in both poles in recent decades. However, the observational period for sea ice is short, and the climate models tasked with predicting future change in sea ice struggle to capture the current Antarctic trends. Paleoclimate archives, from marine sedimentary records and coastal Antarctic ice cores, provide a means of understanding sea ice variability and its drivers over decadal to centennial timescales. In this study, we collate published records of Antarctic sea ice over the past 2000 years (2 ka). We evaluate the current proxies and explore the potential of combining marine and ice core records to produce multi-archive reconstructions. Despite identifying 92 sea ice reconstructions, the spatial and temporal resolution is only sufficient to reconstruct circum-Antarctic sea ice during the 20th century, not the full 2 ka. Our synthesis reveals a 90 year trend of increasing sea ice in the Ross Sea and declining sea ice in the Bellingshausen, comparable with observed trends since 1979. Reconstructions in the Weddell Sea, the Western Pacific and the Indian Ocean reveal small negative trends in sea ice during the 20th century (1900–1990), in contrast to the observed sea ice expansion in these regions since 1979.

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