Rare and new for Antarctica species of algae from the continental waterbodies of Schirmacher Oasis

2021 ◽  
Vol 55 (2) ◽  
pp. 335-347
Author(s):  
S. V. Smirnova ◽  
T. V. Safronova ◽  
A. F. Luknitskaya ◽  
O. N. Boldina
Keyword(s):  
East Antarctica ◽  
Algal Flora ◽  
Schirmacher Oasis ◽  
The Antarctic

One rare (Dinobryon cylindricum) and two new (Gonium pectorale, Staurastrum orbiculare) for the Antarctic algal flora species were found in the waterbodies of Schirmacher Oasis (East Antarctica). Their locations are described. Data on morphology, ecology and distribution of the recorded species are summarized.

New and rare species of algae for Antarctica from the waterbodies of the Schirmacher Oasis (East Antarctica)

2021 ◽  
pp. 144-147
Author(s):  
Svetlana V. Smirnova ◽  
Olga Ya. Chaplygina ◽  
Aliya F. Luknitskaya ◽  
Olga N. Boldina
Keyword(s):  
Rare Species ◽  
Algal Species ◽  
East Antarctica ◽  
The Other ◽  
Algal Flora ◽  
Schirmacher Oasis

Three algal species new to algal flora of the Schirmacher oasis are given: Dactylothamnos antarcticus, Staurastrum orbiculare, Gonium pectorale. One of them – D. antarcticus is an endemic to Antarctica, the other two are first recorded for Antarctica. Their location is described. Data on their morphology and distribution are summarized.

scholarly journals Mass balance of the Antarctic ice sheet 1992–2016: reconciling results from GRACE gravimetry with ICESat, ERS1/2 and Envisat altimetry

2021 ◽  
pp. 1-27
Author(s):  
H. Jay Zwally ◽  
John W. Robbins ◽  
Scott B. Luthcke ◽  
Bryant D. Loomis ◽  
Frédérique Rémy
Keyword(s):  
Mass Balance ◽  
Antarctic Peninsula ◽  
East Antarctica ◽  
Mantle Material ◽  
West Antarctica ◽  
Mantle Viscosity ◽  
Grounding Line ◽  
The Antarctic ◽  
Total Gain

Abstract GRACE and ICESat Antarctic mass-balance differences are resolved utilizing their dependencies on corrections for changes in mass and volume of the same underlying mantle material forced by ice-loading changes. Modeled gravimetry corrections are 5.22 times altimetry corrections over East Antarctica (EA) and 4.51 times over West Antarctica (WA), with inferred mantle densities 4.75 and 4.11 g cm−3. Derived sensitivities (Sg, Sa) to bedrock motion enable calculation of motion (δB0) needed to equalize GRACE and ICESat mass changes during 2003–08. For EA, δB0 is −2.2 mm a−1 subsidence with mass matching at 150 Gt a−1, inland WA is −3.5 mm a−1 at 66 Gt a−1, and coastal WA is only −0.35 mm a−1 at −95 Gt a−1. WA subsidence is attributed to low mantle viscosity with faster responses to post-LGM deglaciation and to ice growth during Holocene grounding-line readvance. EA subsidence is attributed to Holocene dynamic thickening. With Antarctic Peninsula loss of −26 Gt a−1, the Antarctic total gain is 95 ± 25 Gt a−1 during 2003–08, compared to 144 ± 61 Gt a−1 from ERS1/2 during 1992–2001. Beginning in 2009, large increases in coastal WA dynamic losses overcame long-term EA and inland WA gains bringing Antarctica close to balance at −12 ± 64 Gt a−1 by 2012–16.

scholarly journals An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 217
Author(s):  
Jiangping Zhu ◽  
Aihong Xie ◽  
Xiang Qin ◽  
Yetang Wang ◽  
Bing Xu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Antarctic Peninsula ◽  
Austral Summer ◽  
Correlation Coefficients ◽  
East Antarctica ◽  
West Antarctica ◽  
Austral Spring ◽  
Reanalysis Dataset ◽  
Near Surface ◽  
The Antarctic

The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in Antarctica, we compare the near-surface temperature data from ERA5 and ERA-Interim with the measured data from 41 weather stations. ERA5 has a strong linear relationship with monthly observations, and the statistical significant correlation coefficients (p < 0.05) are higher than 0.95 at all stations selected. The performance of ERA5 shows regional differences, and the correlations are high in West Antarctica and low in East Antarctica. Compared with ERA5, ERA-Interim has a slightly higher linear relationship with observations in the Antarctic Peninsula. ERA5 agrees well with the temperature observations in austral spring, with significant correlation coefficients higher than 0.90 and bias lower than 0.70 °C. The temperature trend from ERA5 is consistent with that from observations, in which a cooling trend dominates East Antarctica and West Antarctica, while a warming trend exists in the Antarctic Peninsula except during austral summer. Generally, ERA5 can effectively represent the temperature changes in Antarctica and its three subregions. Although ERA5 has bias, ERA5 can play an important role as a powerful tool to explore the climate change in Antarctica with sparse in situ observations.

Estimation of turbulent heat fluxes and exchange coefficients for heat at Dumont d'Urville, East Antarctica

1999 ◽  
Vol 11 (1) ◽  
pp. 93-99 ◽  
Author(s):  
S. Argentini ◽  
G. Mastrantonio ◽  
A. Viola
Keyword(s):  
Boundary Layer ◽  
Heat Fluxes ◽  
East Antarctica ◽  
Turbulent Heat ◽  
Convective Boundary ◽  
Doppler Sodar ◽  
Turbulent Heat Fluxes ◽  
Unstable Boundary Layer ◽  
Sodar Measurements ◽  
The Antarctic

Simultaneous acoustic Doppler sodar and tethersonde measurements were used to study some of the characteristics of the unstable boundary layer at Dumont d'Urville, Adélie Land, East Antarctica during the summer 1993–94. A description of the convective boundary layer and its behaviour in connection with the wind regime is given along with the frequency distribution of free convection episodes. The surface heat flux has been evaluated using the vertical velocity variance derived from sodar measurements. The turbulent exchange coefficients, estimated by coupling sodar and tethered balloon measurements, are in strong agreement with those present in literature for the Antarctic regions.

Palaeomagnetic results from the middle Tertiary Meander Intrusives of northern Victoria Land, East Antarctica

1996 ◽  
Vol 8 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Elena Belluso ◽  
Roberto Lanza
Keyword(s):  
Remanent Magnetization ◽  
Ross Sea ◽  
East Antarctica ◽  
Magnetic Mineralogy ◽  
Tilt Correction ◽  
Palaeomagnetic Data ◽  
Victoria Land ◽  
Geological Models ◽  
Laboratory Investigations ◽  
The Antarctic

The Tertiary stocks (Meander Intrusives) cropping out along the coasts of the Ross Sea were sampled for a palaeomagnetic study during the sixth Italian expedition to northern Victoria Land. Laboratory investigations concerned magnetic mineralogy and remanent magnetization. Minerals of the magnetiteulvöspinel series occur in the rocks from all stocks, with low-Ti titanomagnetite usually prevalent. Haematite and goethite occur in small amounts as alteration products. Large secondary components commonly screen the characteristic remanent magnetization and were removed by thermal or AF demagnetization at temperatures or peak-fields higher than 360°C and 20 mT respectively. A total of 10 VGPs were obtained from radiometrically dated rocks (42–22 Ma); the averaged position (69°S, 334°E; α95=9.9°) is the first middle Tertiary palaeomagnetic pole for East Antarctica, and gives evidence for a reversal in the course of the APW path. This evidence is not substantially altered by a supposed tilt-correction consistent with geophysical and geological models for the uplift of the Transantarctic Mountains. No definite conclusion about relative movements between East Antarctica and the Antarctic Peninsula can be drawn from the existing palaeomagnetic data.

Diving behaviour of two Ross seals off east Antarctica

2005 ◽  
Vol 32 (1) ◽  
pp. 63 ◽  
Author(s):  
Colin Southwell
Keyword(s):  
Continental Shelf ◽  
Additional Data ◽  
Prey Species ◽  
Current Knowledge ◽  
East Antarctica ◽  
Maximum Depth ◽  
Diving Behaviour ◽  
Sea Floor ◽  
Transmission Period ◽  
The Antarctic

The Ross seal (Ommatophoca rossii) is the least frequently sighted and least known of the Antarctic pinnipeds. Current knowledge of foraging and diving behaviour is based on observations of a single seal over <2 days. The current study provides some additional data on the diving behaviour of two Ross seals off east Antarctica over periods of 31 and 12 days during December–January 1999–2000 using satellite-linked dive recorders. Both seals remained over the continental shelf for these times, the female remaining some distance from the coast and the male moving close to the coast approximately half-way through his transmission period. Most dives by the female reached depths >150 m (maximum depth 372 m) and the modal duration was 10–11 min. The male’s dives were slightly shallower (most >100 m) and shorter (mode 6–7 min) when distant from the continental coast, and were truncated to a depth of 180 m when close to the coast, presumably by the sea floor. These dive patterns suggest that their prey species, thought to comprise mostly fish and squid, were relatively unavailable at depths <100 m.

scholarly journals Meltwater flux and climate change record of last 18.5 ka from Schirmacher Oasis, East Antarctica

Polar Science ◽  
2018 ◽  
Vol 18 ◽  
pp. 135-141 ◽  
Author(s):  
Pawan Govil ◽  
Abhijit Mazumder ◽  
Raghu Ram ◽  
Dhruv Sen Singh ◽  
Syed Azharuddin
Keyword(s):  
Climate Change ◽  
East Antarctica ◽  
Schirmacher Oasis
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