Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Zhuang Jiang, Becky Alexander, Joel Savarino, Joseph Erbland, Lei Geng doi  openurl
  Title Impacts of the photo-driven post-depositional processing on snow nitrate and its isotopes at Summit, Greenland: a model-based study Type (down) Journal
  Year 2021 Publication The Cryosphere Abbreviated Journal  
  Volume 15 Issue 9 Pages 4207-4220  
  Keywords  
  Abstract Abstract. Atmospheric Information Embedded In Ice-core Nitrate Is Disturbed By Post-depositional Processing. Here We Used A Layered Snow Photochemical Column Model To Explicitly Investigate The Effects Of Post-depositional Processing On Snow Nitrate And Its Isotopes (δ15n And Δ17o) At Summit, Greenland, Where Post-depositional Processing Was Thought To Be Minimal Due To The High Snow Accumulation Rate. We Found Significant Redistribution Of Nitrate In The Upper Snowpack Through Photolysis, And Up To 21 % Of Nitrate Was Lost And/or Redistributed After Deposition. The Model Indicates Post-depositional Processing Can Reproduce Much Of The Observed δ15n Seasonality, While Seasonal Variations In δ15n Of Primary Nitrate Are Needed To Reconcile The Timing Of The Lowest Seasonal δ15n. In Contrast, Post-depositional Processing Can Only Induce Less Than 2.1 ‰ Seasonal Δ17o Change, Much Smaller Than The Observation (9 ‰) That Is Ultimately Determined By Seasonal Differences In Nitrate Formation Pathway. Despite Significant Redistribution Of Snow Nitrate In The Photic Zone And The Associated Effects On δ15n Seasonality, The Net Annual Effect Of Post-depositional Processing Is Relatively Small, Suggesting Preservation Of Atmospheric Signals At The Annual Scale Under The Present Summit Conditions. But At Longer Timescales When Large Changes In Snow Accumulation Rate Occur This Post-depositional Processing Could Become A Major Driver Of The δ15n Variability In Ice-core Nitrate.  
  Programme 1177  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1994-0416 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8375  
Permanent link to this record
 

 
Author Peter S. Ungar, Lindsay Saylor, Aleksandr A. Sokolov, Natalia A. Sokolova, Olivier Gilg, Sophie Montuire, Aurélien Royer doi  openurl
  Title Incisor microwear of Arctic rodents as a proxy for microhabitat preference Type (down) Journal
  Year 2021 Publication Mammalian Biology Abbreviated Journal  
  Volume 101 Issue 6 Pages 1033-1052  
  Keywords Arctic Environment Habitats Narrow-headed vole Russia Siberian lemming Tooth wear Tundra Yamal Peninsula  
  Abstract Changing environmental conditions in the Arctic make it important to document and understand habitat preferences and flexibility of vulnerable high-latitude mammals. Indirect proxies are especially useful for elusive species, such as rodents. This study explores incisor microwear as an indicator of variation in behavior and microhabitat use in Siberian lemmings (Lemmus sibiricus) and narrow-headed voles (Lasiopodomys gregalis) from the Yamal Peninsula, Russia. Fifty-nine individuals were sampled at four sites along a latitudinal gradient from forest-tundra ecotone to high-Arctic tundra. Lemmings are present at the northernmost site, voles at the southernmost site, and both species at the middle two. Lemmus sibiricus prefers wet, mossy lowland, whereas La. gregalis favors drier thickets and more open microhabitats and burrows underground. Feature-based analyses indicate higher densities of features and more uniformly oriented striations for voles than lemmings at sites with both species. The species also differ significantly in microwear texture attributes suggesting larger features for lemmings, and smaller ones, but more of them, for voles. While no texture differences were found between sites within species, voles from sites with open tundra have higher striation densities than those from the forest-tundra ecotone. Furthermore, lemmings from open tundra sites have higher striation densities than those from the water-saturated, moss-covered northernmost site. While microhabitat preferences and burrowing by voles likely contribute to differences between species, variation within seems to reflect habitat variation given differences in abrasive loads between sites. This suggests that incisor microwear patterning can be used to track microhabitat differences among Arctic rodent populations.  
  Programme 1036  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-1476 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8377  
Permanent link to this record
 

 
Author Alberto Baudena, Enrico Ser-Giacomi, Donatella D’Onofrio, Xavier Capet, Cedric Cotté, Yves Cherel, Francesco D’Ovidio doi  openurl
  Title Fine-scale structures as spots of increased fish concentration in the open ocean Type (down) Journal
  Year 2021 Publication Scientific Reports Abbreviated Journal  
  Volume 11 Issue 1 Pages 15805  
  Keywords Fisheries Marine biology Physical oceanography  
  Abstract Oceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.  
  Programme 109  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8384  
Permanent link to this record
 

 
Author Casey Youngflesh, Yun Li, Heather J. Lynch, Karine Delord, Christophe Barbraud, Rubao Ji, Stephanie Jenouvrier doi  openurl
  Title Lack of synchronized breeding success in a seabird community: extreme events, niche separation, and environmental variability Type (down) Journal
  Year 2021 Publication Oikos Abbreviated Journal  
  Volume 130 Issue 11 Pages 1943-1953  
  Keywords Antarctica environmental indicators extreme events global change niche separation synchrony  
  Abstract Synchrony in ecological systems, the degree to which elements respond similarly over time or space, can inform our understanding of how ecosystems function and how they are responding to global change. While studies of ecological synchrony are often focused on within-species dynamics, synchrony among species may provide important insights into how dynamics of one species are indicative of conditions relevant to the larger community, with both basic and applied implications. Ecological theory suggests there may be conditions under which communities might exhibit increased synchrony, however, the degree to which these patterns are borne out in natural systems is currently unknown. We used long-term breeding success data from a community of Antarctic seabirds to assess the degree of interspecific, community synchrony, and the role that extreme events play in driving these dynamics. We assessed theoretical links between community synchrony, niche separation, and environmental variability using data from this and three other seabird communities as well as a simulation study. Results show that reproductive success for individual species in the Antarctic seabird community fluctuated relatively independently from one another, resulting in little synchrony across this community, outside of extreme years. While an exceptionally poor year for a given species was not necessarily associated with an exceptionally poor year for any other species, one community-wide extreme year existed. When compared to other seabird communities, this group of Antarctic seabirds exhibited lower overall synchrony and higher estimated niche separation, supporting theoretical predictions. Empirical and simulation-derived results suggest that communities where temporal variation is small for conditions in which species respond substantially differently, and large for conditions in which species respond similarly, may exhibit more synchronous dynamics. Identifying where and why synchronous dynamics might be more apparent has the potential to inform how ecological communities might respond to future global change.  
  Programme 109  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1600-0706 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8385  
Permanent link to this record
 

 
Author Eeva M. Soininen, Isabel C. Barrio, Ragnhild Bjørkås, Katrín Björnsdóttir, Dorothee Ehrich, Kelly Hopping, Elina Kaarlejärvi, Anders Lorentzen Kolstad, Svetlana Abdulmanova, Robert G. Björk, C. Guillermo Bueno, Isabell Eischeid, Rebecca Finger Higgens, Jennifer Sorensen Forbey, Charles Gignac, Olivier Gilg, Michael den Herder, Hildur Søndergaard Holm, Bernice C. Hwang, Jane Uhd Jepsen, Stefaniya Kamenova, Ilona Kater, Amanda M. Koltz, Jeppe Aagaard Kristensen, Chelsea J. Little, Petr Macek, Karen Marie Mathisen, Daniel Metcalfe, Jesper Bruun Mosbacher, Martin Alfons Mörsdorf, Taejin Park, Jeffrey Propster, Aradhana Roberts, Emmanuel Serrano Ferron, Marcus P. Spiegel, Mariana Tamayo, Maria W. Tuomi, Megha Verma, Katariina Elsa Maria Vuorinen, Maria Väisänen, René Van der Wal, Megan Wilcots, Nigel Yoccoz, James D. M. Speed doi  openurl
  Title Location of studies and evidence of effects of herbivory on Arctic vegetation: a systematic map Type (down) Journal
  Year 2021 Publication Environmental Evidence Abbreviated Journal  
  Volume 10 Issue 1 Pages 25  
  Keywords Browsing Defoliation Forest-tundra Grazing Grubbing Invertebrate Plant–herbivore interaction Tundra Vertebrate  
  Abstract Herbivores modify the structure and function of tundra ecosystems. Understanding their impacts is necessary to assess the responses of these ecosystems to ongoing environmental changes. However, the effects of herbivores on plants and ecosystem structure and function vary across the Arctic. Strong spatial variation in herbivore effects implies that the results of individual studies on herbivory depend on local conditions, i.e., their ecological context. An important first step in assessing whether generalizable conclusions can be produced is to identify the existing studies and assess how well they cover the underlying environmental conditions across the Arctic. This systematic map aims to identify the ecological contexts in which herbivore impacts on vegetation have been studied in the Arctic. Specifically, the primary question of the systematic map was: “What evidence exists on the effects of herbivores on Arctic vegetation?”.  
  Programme 1036  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2047-2382 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8386  
Permanent link to this record
 

 
Author M. Afroosa, B. Rohith, Arya Paul, Fabien Durand, Romain Bourdallé-Badie, P. V. Sreedevi, Olivier de Viron, Valérie Ballu, S. S. C. Shenoi doi  openurl
  Title Madden-Julian oscillation winds excite an intraseasonal see-saw of ocean mass that affects Earth’s polar motion Type (down) Journal
  Year 2021 Publication Communications Earth & Environment Abbreviated Journal  
  Volume 2 Issue 1 Pages 1-8  
  Keywords Physical oceanography  
  Abstract Strong large-scale winds can relay their energy to the ocean bottom and elicit an almost immediate intraseasonal barotropic (depth independent) response in the ocean. The intense winds associated with the Madden-Julian Oscillation over the Maritime Continent generate significant intraseasonal basin-wide barotropic sea level variability in the tropical Indian Ocean. Here we show, using a numerical model and a network of in-situ bottom pressure recorders, that the concerted barotropic response of the Indian and the Pacific Ocean to these winds leads to an intraseasonal see-saw of oceanic mass in the Indo-Pacific basin. This global-scale mass shift is unexpectedly fast, as we show that the mass field of the entire Indo-Pacific basin is dynamically adjusted to Madden-Julian Oscillation in a few days. We find this large-scale ocean see-saw, induced by the Madden-Julian Oscillation, has a detectable influence on the Earth’s polar axis motion, in particular during the strong see-saw of early 2013.  
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2662-4435 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8387  
Permanent link to this record
 

 
Author Petra Zemunik, Jadranka Šepić, Havu Pellikka, Leon Ćatipović, Ivica Vilibić doi  openurl
  Title Minute Sea-Level Analysis (MISELA): a high-frequency sea-level analysis global dataset Type (down) Journal
  Year 2021 Publication Earth system science data Abbreviated Journal  
  Volume 13 Issue 8 Pages 4121-4132  
  Keywords  
  Abstract

Abstract. Sea-level observations provide information on a variety of processes occurring over different temporal and spatial scales that may contribute to coastal flooding and hazards. However, global research on sea-level extremes is restricted to hourly datasets, which prevent the quantification and analyses of processes occurring at timescales between a few minutes and a few hours. These shorter-period processes, like seiches, meteotsunamis, infragravity and coastal waves, may even dominate in low tidal basins. Therefore, a new global 1 min sea-level dataset – MISELA (Minute Sea-Level Analysis) – has been developed, encompassing quality-checked records of nonseismic sea-level oscillations at tsunami timescales (T<2 h) obtained from 331 tide-gauge sites (https://doi.org/10.14284/456, Zemunik et al., 2021b). This paper describes data quality control procedures applied to the MISELA dataset, world and regional coverage of tide-gauge sites, and lengths of time series. The dataset is appropriate for global, regional or local research of atmospherically induced high-frequency sea-level oscillations, which should be included in the overall sea-level extremes assessments.

 
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1866-3508 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8392  
Permanent link to this record
 

 
Author A. Barbero, J. Savarino, R. Grilli, C. Blouzon, G. Picard, M. M. Frey, Y. Huang, N. Caillon doi  openurl
  Title New Estimation of the NOx Snow-Source on the Antarctic Plateau Type (down) Journal
  Year 2021 Publication Journal of Geophysical Research: Atmospheres Abbreviated Journal  
  Volume 126 Issue 20 Pages e2021JD035062  
  Keywords Antarctic Plateau flux chamber nitrate photolysis snowpack emissions  
  Abstract To fully decipher the role of nitrate photolysis on the atmospheric oxidative capacity in snow-covered regions, NOx flux must be determined with more precision than existing estimates. Here, we introduce a method based on dynamic flux chamber measurements for evaluating the NOx production by photolysis of snowpack nitrate in Antarctica. Flux chamber experiments were conducted for the first time in Antarctica, at the French-Italian station Concordia, Dome C (75°06'S, 123°20’E, 3233 m a.s.l) during the 2019–2020 summer campaign. Measurements were gathered with several snow samples of different ages ranging from newly formed drifted snow to 6-year-old firn. Contrary to existing literature expectations, the daily average photolysis rate coefficient, , did not significantly vary between differently aged snow samples, suggesting that the photolabile nitrate in snow behaves as a single-family source with common photochemical properties, where a = (2.37 0.35) × 10−8 s−1 (1) has been calculated from December 10th 2019 to January 7th 2020. At Dome C summer daily average NOx flux, , based on measured NOx production rates was estimated to be (4.3 1.2) × 108 molecules cm−2 s−1, which is 1.5–7 times less than the net NOx flux observed previously above snow at Dome C using the gradient flux method. Using these results, we extrapolated an annual continental snow sourced NOx budget of 0.017 0.003 TgN y−1, 2 times the nitrogen budget, (N-budget), of the stratospheric denitrification previously estimated for Antarctica. These quantifications of nitrate photolysis using flux chamber experiments provide a road-map toward a new parameterization of the product that can improve future global and regional models of atmospheric chemistry.  
  Programme 1177  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2169-8996 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8393  
Permanent link to this record
 

 
Author Yushiro Fujii, Kenji Satake, Shingo Watada, Tung-Cheng Ho doi  openurl
  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 (down) 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  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1420-9136 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8411  
Permanent link to this record
 

 
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 doi  openurl
  Title Regional Characteristics of Atmospheric Sulfate Formation in East Antarctica Imprinted on 17O-Excess Signature Type (down) 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  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2169-8996 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8412  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print