Short Note: Extracellular Export and Consumption of Glucose in Antarctic Sea Ice

Mapping Intimacies ◽

10.21203/rs.3.rs-654891/v1 ◽

2021 ◽

Author(s):

Fraser Kennedy ◽

Andrew McMinn ◽

Andrew Martin

Keyword(s):

Sea Ice ◽

Short Note ◽

Algal Community ◽

Antarctic Sea Ice ◽

Extracellular Glucose

Abstract Glucose microsensors were used to measure extracellular glucose exudation and consumption in a sea ice algal community. Glucose export increased with increasing irradiance between 15 and 512 µmol photons m− 2 s− 1. This export correlated with declining FvFm values and increasing NPQ values, implying that glucose export resulted from exposure to above optimal irradiances. Glucose concentrations in samples treated with DCMU to block photosynthesis, declined at all irradiances. Bacterial consumption of glucose was between 6% and 34% of extracellular export per hour.

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The use of oxygen microelectrodes to determine the net production by an Antarctic sea ice algal community

Antarctic Science ◽

10.1017/s0954102098000066 ◽

1998 ◽

Vol 10 (1) ◽

pp. 39-44 ◽

Cited By ~ 23

Author(s):

A. McMinn ◽

C. Ashworth

Keyword(s):

Sea Ice ◽

Photosynthetic Capacity ◽

Algal Community ◽

Diffusive Boundary Layer ◽

Chl A ◽

Antarctic Sea Ice ◽

Oxygen Microelectrodes ◽

Fast Ice ◽

Diffusive Boundary ◽

Algal Mat

Oxygen microelectrodes were used to measure the photosynthetic rates of Antarctic fast ice algal mats. Using the oxygen flux across the diffusive boundary layer below the fast ice at Davis, a productivity range of 0–1.78 mg C m−2 h−1 was measured. This is at the lower end of fast ice productivity estimates and suggests that conventional 14C techniques may overestimate sea ice algal mat productivity. Photosynthetic capacity (P max) approached 0.05 mg C. (mg chl a)−1 h −1. Onset of photosynthesis saturation, E k, was found at c. 14 μmol photons m −2 s −1. The irradiance of photoinhibition onset, E inh, was c. 20 μmol photons m −2 s −1 and the irradiance at the compensation point, E c, was 4 μmol photons m −2 s −1.

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Physical and biological properties of early winter Antarctic sea ice in the Ross Sea

Annals of Glaciology ◽

10.1017/aog.2020.43 ◽

2020 ◽

pp. 1-19

Author(s):

Jean-Louis Tison ◽

Ted Maksym ◽

Alexander D. Fraser ◽

Matthew Corkill ◽

Noriaki Kimura ◽

...

Keyword(s):

Sea Ice ◽

Ross Sea ◽

Thickness Distribution ◽

Biological Properties ◽

Weddell Sea ◽

Algal Community ◽

Early Winter ◽

Ice Growth ◽

Antarctic Sea Ice ◽

Spatial Differences

Abstract This work presents the results of physical and biological investigations at 27 biogeochemical stations of early winter sea ice in the Ross Sea during the 2017 PIPERS cruise. Only two similar cruises occurred in the past, in 1995 and 1998. The year 2017 was a specific year, in that ice growth in the Central Ross Sea was considerably delayed, compared to previous years. These conditions resulted in lower ice thicknesses and Chl-a burdens, as compared to those observed during the previous cruises. It also resulted in a different structure of the sympagic algal community, unusually dominated by Phaeocystis rather than diatoms. Compared to autumn-winter sea ice in the Weddell Sea (AWECS cruise), the 2017 Ross Sea pack ice displayed similar thickness distribution, but much lower snow cover and therefore nearly no flooding conditions. It is shown that contrasted dynamics of autumnal-winter sea-ice growth between the Weddell Sea and the Ross Sea impacted the development of the sympagic community. Mean/median ice Chl-a concentrations were 3–5 times lower at PIPERS, and the community status there appeared to be more mature (decaying?), based on Phaeopigments/Chl-a ratios. These contrasts are discussed in the light of temporal and spatial differences between the two cruises.

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High single-cell metabolic activity in Antarctic sea ice bacteria

Aquatic Microbial Ecology ◽

10.3354/amea1205 ◽

2008 ◽

Author(s):

A Martin ◽

JA Hall ◽

R O’Toole ◽

SK Davy ◽

KG Ryan

Keyword(s):

Sea Ice ◽

Single Cell ◽

Metabolic Activity ◽

Cell Metabolic Activity ◽

Antarctic Sea Ice

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RESPONSE OF SOUTHERN HEMISPHERE PRECIPITATION TO ANTARCTIC SEA ICE OSCILLATION ANOMALIES

CHINESE JOURNAL OF POLAR RESEARCH ◽

10.3724/sp.j.1084.2013.00045 ◽

2014 ◽

Vol 25 (1) ◽

pp. 45-52

Author(s):

Tingfeng Dou ◽

Cunde Xiao

Keyword(s):

Sea Ice ◽

Southern Hemisphere ◽

Antarctic Sea Ice

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Salinity effects on cultured Neogloboquadrina pachyderma (sinistral) from high latitudes: new paleoenvironmental insights

Geo-Marine Letters ◽

10.1007/s00367-020-00677-1 ◽

2021 ◽

Vol 41 (1) ◽

Author(s):

Jacqueline Bertlich ◽

Nikolaus Gussone ◽

Jasper Berndt ◽

Heinrich F. Arlinghaus ◽

Gerhard S. Dieckmann

Keyword(s):

Sea Ice ◽

Cold Water ◽

Weddell Sea ◽

Wall Thickening ◽

High Latitudes ◽

Neogloboquadrina Pachyderma ◽

Antarctic Sea Ice ◽

The Antarctic ◽

Water Species ◽

Cold Water Species

AbstractThis study presents culture experiments of the cold water species Neogloboquadrina pachyderma (sinistral) and provides new insights into the incorporation of elements in foraminiferal calcite of common and newly established proxies for paleoenvironmental applications (shell Mg/Ca, Sr/Ca and Na/Ca). Specimens were collected from sea ice during the austral winter in the Antarctic Weddell Sea and subsequently cultured at different salinities and a constant temperature. Incorporation of the fluorescent dye calcein showed new chamber formation in the culture at salinities of 30, 31, and 69. Cultured foraminifers at salinities of 46 to 83 only revealed chamber wall thickening, indicated by the fluorescence of the whole shell. Signs of reproduction and the associated gametogenic calcite were not observed in any of the culture experiments. Trace element analyses were performed using an electron microprobe, which revealed increased shell Mg/Ca, Sr/Ca, and Na/Ca values at higher salinities, with Mg/Ca showing the lowest sensitivity to salinity changes. This study enhances the knowledge about unusually high element concentrations in foraminifera shells from high latitudes. Neogloboquadrina pachyderma appears to be able to calcify in the Antarctic sea ice within brine channels, which have low temperatures and exceptionally high salinities due to ongoing sea ice formation.

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DASSO: a data assimilation system for the Southern Ocean that utilizes both sea-ice concentration and thickness observations

Journal of Glaciology ◽

10.1017/jog.2021.57 ◽

2021 ◽

pp. 1-6

Author(s):

Hao Luo ◽

Qinghua Yang ◽

Longjiang Mu ◽

Xiangshan Tian-Kunze ◽

Lars Nerger ◽

...

Keyword(s):

Data Assimilation ◽

Southern Ocean ◽

Sea Ice ◽

Coupled Model ◽

Sea Ice Concentration ◽

Model Free ◽

Antarctic Sea Ice ◽

Ice Concentration ◽

Data Assimilation System ◽

Assimilation System

Abstract To improve Antarctic sea-ice simulations and estimations, an ensemble-based Data Assimilation System for the Southern Ocean (DASSO) was developed based on a regional sea ice–ocean coupled model, which assimilates sea-ice thickness (SIT) together with sea-ice concentration (SIC) derived from satellites. To validate the performance of DASSO, experiments were conducted from 15 April to 14 October 2016. Generally, assimilating SIC and SIT can suppress the overestimation of sea ice in the model-free run. Besides considering uncertainties in the operational atmospheric forcing data, a covariance inflation procedure in data assimilation further improves the simulation of Antarctic sea ice, especially SIT. The results demonstrate the effectiveness of assimilating sea-ice observations in reconstructing the state of Antarctic sea ice, but also highlight the necessity of more reasonable error estimation for the background as well as the observation.

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