| Records |
| Author |
Karl-Ludwig Klein |
Title  |
Radio Astronomical Tools for the Study of Solar Energetic Particles II.Time-Extended Acceleration at Subrelativistic and Relativistic Energies |
Type |
Journal |
| Year |
2021 |
Publication |
Frontiers in Astronomy and Space Sciences |
Abbreviated Journal |
|
| Volume |
7 |
Issue |
|
Pages |
93 |
| Keywords |
|
| Abstract |
Solar energetic particle (SEP) events are commonly separated in two categories: numerous “impulsive” events of relatively short duration, and a few “gradual” events, where SEP-intensities may stay enhanced over several days at energies up to several tens of MeV. In some gradual events the SEP spectrum extends to relativistic energies (>1 GeV), over shorter durations. The two categories are strongly related to an idea developed in the 1960s based on radio observations: Type III bursts, which were addressed in a companion chapter, outline impulsive acceleration of electrons to subrelativistic energies, while the large and the relativistic SEP events were ascribed to a second acceleration process. At radio wavelengths, typical counterparts were bursts emitted by electrons accelerated at coronal shock waves (type II bursts) and by electron populations in large-scale closed coronal structures (type IV bursts). Both burst types are related to coronal mass ejections (CMEs). Type II bursts from metric to kilometric wavelengths tend to accompany large SEP events, which is widely considered as a confirmation that CME-driven shocks accelerate the SEPs. But type II bursts, especially those related to SEP events, are most often accompanied by type IV bursts, where the electrons are rather accelerated in the wake of the CME. Individual event studies suggest that although the CME shock is the most plausible accelerator of SEPs up to some yet unknown limiting energy, the relativistic SEP events show time structure that rather points to coronal acceleration related to type IV bursts. This chapter addresses the question what type II bursts tell us about coronal shock waves and how type II and type IV radio bursts are related with relativistic proton signatures as seen by particle detectors on the Earth and by their gamma-ray emission in the solar atmosphere, focusing on two relativistic SEP events, on 2005 Jan 20 and 2017 Sep 10. The importance of radio emissions as a complement to the upcoming SEP observations from close to the Sun is underlined. |
| Programme |
227 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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Place of Publication |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
2296-987X |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
|
Serial |
7777 |
| Permanent link to this record |
| |
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| |
| Author |
Yushiro Fujii, Kenji Satake, Shingo Watada, Tung-Cheng Ho |
| Title |
Re-examination of Slip Distribution of the 2004 Sumatra–Andaman Earthquake (Mw 9.2) by the Inversion of Tsunami Data Using Green’s Functions Corrected for Compressible Seawater Over the Elastic Earth |
Type |
Journal |
| Year |
2021 |
Publication |
Pure and Applied Geophysics |
Abbreviated Journal |
|
| Volume |
178 |
Issue |
12 |
Pages |
4777-4796 |
| Keywords |
2004 Sumatra–Andaman earthquake far-field tsunami waveform phase-corrected Green’s function slip distribution tsunami data inversion |
| Abstract |
We re-examined the slip distribution on faults of the 2004 Sumatra–Andaman (M 9.1 according to USGS) earthquake by the inversion of tsunami data with phase-corrected Green’s functions applied to linear long waves. The correction accounts for the effects of compressibility of seawater, elasticity of solid earth, and gravitational potential variation associated with the motion of mass to reproduce the delayed arrivals and the reversed phase of the first tsunami waves. We used sea surface height (SSH) data from satellite altimetry (SA) measurements along five tracks, and the tsunami waveforms recorded at tide gauges (TGs) and ocean bottom pressure gauges (OBPGs) in and around the Indian Ocean. The inversion results for both data sets for different rupture velocities (Vr) show that the reproducibility of the spatiotemporal SSHs and tsunami waveforms is improved by the phase corrections, although the effects are not so significant within the Indian Ocean. The best slip distribution model from joint inversion of SA, TG and OBPG data with Vr of 1.3 km/s shows the largest slips of 16–25 m off Sumatra Island, large slips of 2–11 m off the Nicobar Islands, and moderate slips of 2–6 m in the Andaman Islands. The inversion results reproduce the far-field tsunami waveforms well at distant stations even more than 13,000–25,000 km from the epicenter. The total source length is about 1400 km and the seismic moment is Mw 9.2, longer and larger than that of our previous estimates based on TG records. |
| Programme |
688 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
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| ISSN |
1420-9136 |
ISBN |
|
Medium |
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| Area |
|
Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8411 |
| Permanent link to this record |
| |
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| |
| Author |
Benjamin Pohl, Thomas Saucède, Vincent Favier, Julien Pergaud, Deborah Verfaillie, Jean-Pierre Féral, Ylber Krasniqi, Yves Richard |
| Title |
Recent Climate Variability around the Kerguelen Islands (Southern Ocean) Seen through Weather Regimes |
Type |
Journal |
| Year |
2021 |
Publication |
Journal of Applied Meteorology and Climatology |
Abbreviated Journal |
|
| Volume |
60 |
Issue |
5 |
Pages |
711-731 |
| Keywords |
|
| Abstract |
Daily Weather Regimes Are Defined Around The Kerguelen Islands (Southern Ocean) On The Basis Of Daily 500-hpa Geopotential Height Anomalies Derived From The Era5 Ensemble Reanalysis Over The Period 1979–2018. Ten Regimes Are Retained As Significant. Their Occurrences Are Highly Consistent Across Reanalysis Ensemble Members. Regimes Show Weak Seasonality And Nonsignificant Long-term Trends In Their Occurrences. Their Sequences Are Usually Short (1–3 Days), With Extreme Persistence Values Above 10 Days. Seasonal Regime Frequency Is Mostly Driven By The Phase Of The Southern Annular Mode Over Antarctica, Midlatitude Dynamics Over The Southern Ocean Such As The Pacific–south American Mode, And, To A Lesser Extent, Tropical Variability, With Significant But Weaker Relationships With El Niño–southern Oscillation. At The Local Scale Over The Kerguelen Islands, Regimes Have A Strong Influence On Measured Atmospheric And Oceanic Variables, Including Minimum And Maximum Air Temperature, Mostly Driven By Horizontal Advections, Seawater Temperature Recorded 5 M Below The Surface, Wind Speed, And Sea Level Pressure. Relationships Are Weaker For Precipitation Amounts. Regimes Also Modify Regional Contrasts Between Observational Sites In Kerguelen, Highlighting Strong Exposure Contrasts. The Regimes Allow Us To Improve Our Understanding Of Weather And Climate Variability And Interactions In This Region; They Will Be Used In Future Work To Assess Past And Projected Long-term Circulation Changes In The Southern Midlatitudes. |
| Programme |
688,1044,1048 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Summary Language |
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Original Title |
|
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
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| ISSN |
1558-8424 |
ISBN |
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Medium |
|
| Area |
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Expedition |
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Conference |
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| Notes |
|
Approved |
yes |
| Call Number |
|
Serial |
8003 |
| Permanent link to this record |
| |
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| |
| Author |
Akers P., Savarino, J., Caillon, N. |
| Title |
Reconstructing Antarctic snow accumulation using nitrogen isotopes of nitrate |
Type |
Communication |
| Year |
2021 |
Publication |
EGU General Assembly, 19-30 April 2021 |
Abbreviated Journal |
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| Volume |
|
Issue |
|
Pages |
|
| Keywords |
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| Abstract |
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| Programme |
1177 |
| Campaign |
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| Address |
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Thesis |
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Place of Publication |
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Editor |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Medium |
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| Area |
|
Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
|
Serial |
7866 |
| Permanent link to this record |
| |
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| |
| Author |
Ishino S., Hattori S., Savarino J., Jourdain B., Legrand M., Preunkert S., Alexander B., Yoshida N., Huang J. |
| Title |
Regional characteristics of atmospheric sulfate formation in East Antarctica imprinted on 17O-excess signature |
Type |
Book Chapter |
| Year |
2021 |
Publication |
EGU General Assembly, 19-30 April 2021 |
Abbreviated Journal |
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| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Programme |
1177 |
| Campaign |
|
| Address |
|
| Corporate Author |
|
Thesis |
Bachelor's thesis |
| Publisher |
|
Place of Publication |
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Editor |
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| Language |
|
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
|
ISBN |
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Medium |
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| Area |
|
Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7869 |
| Permanent link to this record |
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| |
| Author |
S. Ishino, S. Hattori, M. Legrand, Q. Chen, B. Alexander, J. Shao, J. Huang, L. Jaeglé, B. Jourdain, S. Preunkert, A. Yamada, N. Yoshida, J. Savarino |
| Title |
Regional Characteristics of Atmospheric Sulfate Formation in East Antarctica Imprinted on 17O-Excess Signature |
Type |
Journal |
| Year |
2021 |
Publication |
Journal of Geophysical Research: Atmospheres |
Abbreviated Journal |
|
| Volume |
126 |
Issue |
6 |
Pages |
e2020JD033583 |
| Keywords |
aerosols Antarctica isotope methanesulfonate sulfate |
| Abstract |
17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of Δ17O of non-sea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d'Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although Δ17O(SO42−)nss at both sites showed consistent seasonality with summer minima (∼1.0‰) and winter maxima (∼2.5‰) owing to sunlight-driven changes in the relative importance of O3 oxidation to OH and H2O2 oxidation, significant intersite differences were observed in austral spring–summer and autumn. The cooccurrence of higher Δ17O(SO42−)nss at inland (2.0‰ ± 0.1‰) than the coastal site (1.2‰ ± 0.1‰) and chemical destruction of methanesulfonate (MS–) in aerosols at inland during spring–summer (October–December), combined with the first estimated Δ17O(MS–) of ∼16‰, implies that MS– destruction produces sulfate with high Δ17O(SO42−)nss of ∼12‰. If contributing to the known postdepositional decrease of MS– in snow, this process should also cause a significant postdepositional increase in Δ17O(SO42−)nss over 1‰, that can reconcile the discrepancy between Δ17O(SO42−)nss in the atmosphere and ice. The higher Δ17O(SO42−)nss at the coastal site than inland during autumn (March–May) may be associated with oxidation process involving reactive bromine and/or sea-salt particles around the coastal region. |
| Programme |
1177 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
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| ISSN |
2169-8996 |
ISBN |
|
Medium |
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| Area |
|
Expedition |
|
Conference |
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| Notes |
|
Approved |
yes |
| Call Number |
|
Serial |
8412 |
| Permanent link to this record |
| |
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| |
| Author |
Rob Harcourt, Mark A. Hindell, Clive R. McMahon, Kimberly T. Goetz, Jean-Benoit Charrassin, Karine Heerah, Rachel Holser, Ian D. Jonsen, Michelle R. Shero, Xavier Hoenner, Rose Foster, Baukje Lenting, Esther Tarszisz, Matthew Harry Pinkerton |
| Title |
Regional Variation in Winter Foraging Strategies by Weddell Seals in Eastern Antarctica and the Ross Sea |
Type |
Journal |
| Year |
2021 |
Publication |
Frontiers in Marine Science |
Abbreviated Journal |
|
| Volume |
8 |
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
The relative importance of intrinsic and extrinsic determinants of animal foraging is often difficult to quantify. The most southerly breeding mammal, the Weddell seal, remains in the Antarctic pack-ice year-round. We compared Weddell seals tagged at three geographically and hydrographically distinct locations in East Antarctica (Prydz Bay, Terre Adélie, and the Ross Sea) to quantify the role of individual variability and habitat structure in winter foraging behaviour. Most Weddell seals remained in relatively small areas close to the coast throughout the winter, but some dispersed widely. Individual utilisation distributions (UDi, a measure of the total area used by an individual seal) ranged from 125 to 20,825 km2. This variability was not due to size or sex but may be due to other intrinsic states for example reproductive condition or personality. The type of foraging (benthic vs. pelagic) varied from 56.6 ± 14.9% benthic dives in Prydz Bay through 42.1 ± 9.4% Terre Adélie to only 25.1 ± 8.7% in the Ross Sea reflecting regional hydrographic structure. The probability of benthic diving was less likely the deeper the ocean. Ocean topography was also influential at the population level; seals from Terre Adélie, with its relatively narrow continental shelf, had a core (50%) UD of only 200 km2, considerably smaller than the Ross Sea (1650 km2) and Prydz Bay (1700 km2). Sea ice concentration had little influence on the time the seals spent in shallow coastal waters, but in deeper offshore water they used areas of higher ice concentration. Marine Protected Areas (MPAs) in the Ross Sea encompass all the observed Weddell seal habitat, and future MPAs that include the Antarctic continental shelf are likely to effectively protect key Weddell seal habitat. |
| Programme |
1182 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2296-7745 |
ISBN |
2296-7745 |
Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
|
Approved |
yes |
| Call Number |
|
Serial |
8609 |
| Permanent link to this record |
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| |
| Author |
Benjamin Pohl, Vincent Favier, Jonathan Wille, Danielle G Udy, Tessa R Vance, Julien Pergaud, Niels Dutrievoz, Juliette Blanchet, Christoph Kittel, Charles Amory, Gerhard Krinner, Francis Codron |
| Title |
Relationship Between Weather Regimes and Atmospheric Rivers in East Antarctica |
Type |
Journal |
| Year |
2021 |
Publication |
Journal of Geophysical Research: Atmospheres |
Abbreviated Journal |
|
| Volume |
126 |
Issue |
24 |
Pages |
e2021JD035294 |
| Keywords |
atmospheric rivers East Antarctica snowfall amounts temperature anomalies weather regimes |
| Abstract |
Here, we define weather regimes in the East Antarctica—Southern Ocean sector based on daily anomalies of 700 hPa geopotential height derived from ERA5 reanalysis during 1979–2018. Most regimes and their preferred transitions depict synoptic-scale disturbances propagating eastwards off the Antarctic coastline. While regime sequences are generally short, their interannual variability is strongly driven by the polarity of the Southern Annular Mode (SAM). Regime occurrences are then intersected with atmospheric rivers (ARs) detected over the same region and period. ARs are equiprobable throughout the year, but clearly concentrate during regimes associated with a strong atmospheric ridges/blockings on the eastern part of the domain, which act to channel meridional advection of heat and moisture from the lower latitudes towards Antarctica. Both regimes and ARs significantly shape climate variability in Antarctica. Regimes favorable to AR occurrences are associated with anomalously warm and humid conditions in coastal Antarctica and, to a lesser extent, the hinterland parts of the Antarctic plateau. These anomalies are strongly enhanced during AR events, with warmer anomalies and dramatically amplified snowfall amounts. Large-scale conditions favoring AR development are finally explored. They show weak dependency to the SAM, but particularly strong atmospheric ridges/blockings over the Southern Ocean appear as the most favorable pattern, in which ARs can be embedded, and to which they contribute. |
| Programme |
411 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2169-8996 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
|
Approved |
yes |
| Call Number |
|
Serial |
8430 |
| Permanent link to this record |
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| |
| Author |
Alexander Kokhanovsky, Simon Gascoin, Laurent Arnaud, Ghislain Picard |
| Title |
Retrieval of Snow Albedo and Total Ozone Column from Single-View MSI/S-2 Spectral Reflectance Measurements over Antarctica |
Type |
Journal |
| Year |
2021 |
Publication |
Remote Sensing |
Abbreviated Journal |
|
| Volume |
13 |
Issue |
21 |
Pages |
4404 |
| Keywords |
albedo inverse problems light scattering radiative transfer snow snow grain size |
| Abstract |
We proposed a simple algorithm to retrieve the total ozone column and snow properties (spectral albedo and effective light absorption path) using the high spatial resolution single–view MSI/S-2 measurements over Antarctica. In addition, the algorithm allows the retrieval of the snow grain size on a scale of 10–20 m. This algorithm should be useful for the understanding of intra-pixel total ozone and snow albedo variability in complement to satellite observations performed on a much coarser spatial resolution scale (0.3–1 km and even larger spatial scales). |
| Programme |
1110 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2072-4292 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8305 |
| Permanent link to this record |
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| Author |
Andrés Barbosa, Arvind Varsani, Virginia Morandini, Wray Grimaldi, Ralph E. T. Vanstreels, Julia I. Diaz, Thierry Boulinier, Meagan Dewar, Daniel González-Acuña, Rachael Gray, Clive R. McMahon, Gary Miller, Michelle Power, Amandine Gamble, Michelle Wille |
| Title |
Risk assessment of SARS-CoV-2 in Antarctic wildlife |
Type |
Journal |
| Year |
2021 |
Publication |
Science of The Total Environment |
Abbreviated Journal |
|
| Volume |
755 |
Issue |
|
Pages |
143352 |
| Keywords |
Antarctica Coronavirus COVID-19 Mitigation measures Reverse zoonoses Transmission |
| Abstract |
The coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pathogen has spread rapidly across the world, causing high numbers of deaths and significant social and economic impacts. SARS-CoV-2 is a novel coronavirus with a suggested zoonotic origin with the potential for cross-species transmission among animals. Antarctica can be considered the only continent free of SARS-CoV-2. Therefore, concerns have been expressed regarding the potential human introduction of this virus to the continent through the activities of research or tourism to minimise the effects on human health, and the potential for virus transmission to Antarctic wildlife. We assess the reverse-zoonotic transmission risk to Antarctic wildlife by considering the available information on host susceptibility, dynamics of the infection in humans, and contact interactions between humans and Antarctic wildlife. The environmental conditions in Antarctica seem to be favourable for the virus stability. Indoor spaces such as those at research stations, research vessels or tourist cruise ships could allow for more transmission among humans and depending on their movements between different locations the virus could be spread across the continent. Among Antarctic wildlife previous in silico analyses suggested that cetaceans are at greater risk of infection whereas seals and birds appear to be at a low infection risk. However, caution needed until further research is carried out and consequently, the precautionary principle should be applied. Field researchers handling animals are identified as the human group posing the highest risk of transmission to animals while tourists and other personnel pose a significant risk only when in close proximity (< 5 m) to Antarctic fauna. We highlight measures to reduce the risk as well as identify of knowledge gaps related to this issue. |
| Programme |
1151 |
| Campaign |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0048-9697 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
|
Serial |
7960 |
| Permanent link to this record |
