Physiology of sea ice diatoms. II. Dark survival of three polar diatoms

1983 ◽  
Vol 29 (1) ◽  
pp. 157-160 ◽  
Author(s):  
Anna C. Palmisano ◽  
Cornelius W. Sullivan
Keyword(s):  
Sea Ice ◽  
Dark Incubation ◽  
Winter Conditions ◽  
Dark Survival ◽  
Polar Diatoms ◽  
Dark Transition

Three polar sea ice diatoms were exposed to 5 months of darkness at −2 °C to simulate polar winter conditions. Cells were tested monthly for the ability to initiate growth of a population. A critical percentage (~1–100%) of a nonaxenic population of each diatom remained viable after 5 months of dark incubation. Survival was generally enhanced by preconditioning cells with a simulated summer–winter transition (decreasing light and temperature, increasing salinity) or a simple light–dark transition; however, preconditioning was not essential to the survival of sea ice diatom cultures under winter conditions.

Growth, Metabolism, and Dark Survival in Sea Ice Microalgae

Sea Ice Biota ◽  
2018 ◽  
pp. 131-146 ◽  
Author(s):  
Anna C. Palmisano ◽  
Cornelius W. Sullivan
Keyword(s):  
Sea Ice ◽  
Dark Survival ◽  
Growth Metabolism

scholarly journals Variability of the Arctic sea ice microwave emission at 89 GHz under winter conditions

2018 ◽  
Vol 15 (3) ◽  
pp. 139-147
Author(s):  
E.V. Zabolotskikh ◽  
◽  
M.A. Zhivotovskaya‎ ◽  
N.Yu.‎ Zakhvatkina‎ ◽  
B. Chapron ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Microwave Emission ◽  
The Arctic ◽  
Winter Conditions ◽  
Arctic Sea

scholarly journals Improving Sea Ice Characterization in Dry Ice Winter Conditions Using Polarimetric Parameters from C- and L-Band SAR Data

2017 ◽  
Vol 9 (12) ◽  
pp. 1270 ◽  
Author(s):  
Mohammed Dabboor ◽  
Benoit Montpetit ◽  
Stephen Howell ◽  
Christian Haas
Keyword(s):  
Sea Ice ◽  
Dry Ice ◽  
Winter Conditions ◽  
L Band ◽  
Sar Data

DATA ON THE COMPOSITION AN DARK SURVIVAL OF FOUR SEA-ICE MICROALGAE1

1972 ◽  
Vol 17 (3) ◽  
pp. 458-461 ◽  
Author(s):  
J. S. BUNT ◽  
C. C. LEE
Keyword(s):  
Sea Ice ◽  
Dark Survival

scholarly journals Comparison of sea‐ice thickness measurements under summer and winter conditions in the Arctic using a small electromagnetic induction device

Geophysics ◽  
1997 ◽  
Vol 62 (3) ◽  
pp. 749-757 ◽  
Author(s):  
Christian Haas ◽  
Sebastian Gerland ◽  
Hajo Eicken ◽  
Heinz Miller
Keyword(s):  
Sea Ice ◽  
Pore Space ◽  
Ice Core ◽  
The Arctic ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Archie’S Law ◽  
Apparent Conductivity ◽  
Winter Conditions ◽  
Em Induction

Drillhole‐determined sea‐ice thickness was compared with values derived remotely using a portable small‐offset loop‐loop steady state electromagnetic (EM) induction device during expeditions to Fram Strait and the Siberian Arctic, under typical winter and summer conditions. Simple empirical transformation equations are derived to convert measured apparent conductivity into ice thickness. Despite the extreme seasonal differences in sea‐ice properties as revealed by ice core analysis, the transformation equations vary little for winter and summer. Thus, the EM induction technique operated on the ice surface in the horizontal dipole mode yields accurate results within 5 to 10% of the drillhole determined thickness over level ice in both seasons. The robustness of the induction method with respect to seasonal extremes is attributed to the low salinity of brine or meltwater filling the extensive pore space in summer. Thus, the average bulk ice conductivity for summer multiyear sea ice derived according to Archie's law amounts to 23 mS/m compared to 3 mS/m for winter conditions. These mean conductivities cause only minor differences in the EM response, as is shown by means of 1-D modeling. However, under summer conditions the range of ice conductivities is wider. Along with the widespread occurrence of surface melt ponds and freshwater lenses underneath the ice, this causes greater scatter in the apparent conductivity/ice thickness relation. This can result in higher deviations between EM‐derived and drillhole determined thicknesses in summer than in winter.

scholarly journals Use of organic exudates from two polar diatoms by bacterial isolates from the Arctic Ocean

2020 ◽  
Vol 378 (2181) ◽  
pp. 20190356 ◽  
Author(s):  
Lucas Tisserand ◽  
Laëtitia Dadaglio ◽  
Laurent Intertaglia ◽  
Philippe Catala ◽  
Christos Panagiotopoulos ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Model Systems ◽  
The Arctic ◽  
Bacterial Strains ◽  
Biological Communities ◽  
Polar Diatoms

Global warming affects primary producers in the Arctic, with potential consequences for the bacterial community composition through the consumption of microalgae-derived dissolved organic matter (DOM). To determine the degree of specificity in the use of an exudate by bacterial taxa, we used simple microalgae–bacteria model systems. We isolated 92 bacterial strains from the sea ice bottom and the water column in spring–summer in the Baffin Bay (Arctic Ocean). The isolates were grouped into 42 species belonging to Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. Forty strains were tested for their capacity to grow on the exudate from two Arctic diatoms . Most of the strains tested (78%) were able to grow on the exudate from the pelagic diatom Chaetoceros neogracilis , and 33% were able to use the exudate from the sea ice diatom Fragilariopsis cylindrus . 17.5% of the strains were not able to grow with any exudate, while 27.5% of the strains were able to use both types of exudates. All strains belonging to Flavobacteriia ( n  = 10) were able to use the DOM provided by C. neogracilis , and this exudate sustained a growth capacity of up to 100 times higher than diluted Marine Broth medium, of two Pseudomonas sp. strains and one Sulfitobacter strain. The variable bioavailability of exudates to bacterial strains highlights the potential role of microalgae in shaping the bacterial community composition. This article is part of the theme issue ‘The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

scholarly journals The One Two Punch – Warm Alaskan Winters – Global Warming

2019 ◽  
Vol 2 (3) ◽  
Keyword(s):  
High Pressure ◽  
Global Warming ◽  
Sea Ice ◽  
Heat Waves ◽  
The Real ◽  
Average Temperature ◽  
The Poor ◽  
Winter Conditions ◽  
The One ◽  
The Antarctic

People in Alaska have been suffering due to the absence of sea ice and the warm Winters of 2017-18 and 2018-19 affecting their livelihood. The weather has taken to very unusual conditions in the winter. Weathermen have done an excellent job of reporting the occurring conditions. The high pressure ridges of weather school 101 have been blamed for the poor winter conditions. The real reason for the trouble is the impacts of exploding stars discussed in a number of papers as the SNIT theory. The major exploding stars being considered also cause heat waves in Sweden, Pakistan, and India with deaths and drought in Pakistan and India at the same time they are melting sea ice in the Antarctic. The variation of Earth’s average temperature confirms the SNIT theory.

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