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	Author	Charlène Gémard, Víctor Planas-Bielsa, Francesco Bonadonna, Thierry Aubin
	Title	Contextual variations in calls of two nonoscine birds: the blue petrel Halobaena caerulea and the Antarctic prion Pachyptila desolata			Type	Journal
	Year	2021	Publication	Behavioral Ecology	Abbreviated Journal
	Volume	32	Issue	4	Pages	769-779
	Keywords
	Abstract	Bird vocalizations are critical cues in social interactions as they convey temporary information varying with the social context, for example, the signaler motivation when facing a rival or a potential mate. To date, literature mainly focused on learning birds. Burrowing petrels (Procellariidae) are nonlearning birds with a limited vocal repertoire. Bachelor males communicate with conspecifics with a single call emitted in three situations: in the absence of a certain auditory (spontaneous calls), toward females (female-directed calls), and toward males (male-directed calls). We first hypothesized that, although the call structure is preserved, temporal and spectral parameters vary between the three call types of bachelor males, translating different motivations (Motivation Hypothesis). To go further, we hypothesized that acoustic variations in male-directed calls indicate the signaler’s aggressive motivation and, therefore, the variations are similar whether calls are produced by breeder or bachelor males (Breeding Status Hypothesis). We tested the two hypotheses performing field playback experiments on two petrel species: the blue petrel (Halobaena caerulea) and the Antarctic prion (Pachyptila desolata). Despite the obvious call stereotypy, we observed temporal variations and frequency shifts when males react to a female or a male, which may translate the sexual or aggressive motivation of the signaler. Furthermore, the similarity of variations in male-directed calls of both breeder and bachelor males suggests the aggressive motivation. So far, vocal plasticity in nonlearning birds has been greatly underestimated. Here, we highlighted the expression of different motivations through vocal variations and the ability to produce frequency variations in species with genetically coded vocalizations.
	Programme	354
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	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1045-2249	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8259
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	Author	David Byrne, Jeff Polton, Colin Bell
	Title	Creation of a global tide analysis dataset: Application of NEMO and an offline objective analysis scheme			Type	Journal
	Year	2021	Publication	Journal of Operational Oceanography	Abbreviated Journal
	Volume		Issue		Pages	1-14
	Keywords
	Abstract	The accurate prediction of tides is vital for the operation of many industries, early warning of coastal flooding and scientific understanding of ocean processes. In this paper, we describe the creation method of a global dataset of tidal harmonics using NEMO (Nucleus for European Modelling of the Ocean) for the first time and an offline objective analysis scheme. Data are assimilated as part of a post-processing step, reducing the computational resources required. A reduced ensemble of tidal harmonics is generated, where each member is run for a shorter period of time than a central background state. This ensemble is used to estimate a single background covariance state, which is used for analysis. Output is validated using an ensemble of objective analyses. For each ensemble member, random selections of observations are omitted and validation is performed at these locations. Improvements in both Mean Absolute Error (MAE) and correlation coefficients (R2) are seen across all 6 of the largest diurnal and semi-diurnal constituents. MAEs in amplitude and phase are reduced by up to 78% and 89%, respectively, and correlations by as much as 0.14. In addition, the majority of locations (between 70 and 80%) see significant improvement.
	Programme	688
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	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1755-876X	ISBN	1755-876X	Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8338
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	Author	Natasha Roy, James Woollett, Najat Bhiry, Isabel Lemus-Lauzon, Ann Delwaide, Dominique Marguerie
	Title	Anthropogenic and climate impacts on subarctic forests in the Nain region, Nunatsiavut: Dendroecological and historical approaches			Type	Journal
	Year	2021	Publication	Écoscience	Abbreviated Journal
	Volume	28	Issue	3-4	Pages	361-376
	Keywords	approches historiques croissance démographique Dendrochronologie Dendrochronology détente de croissance radiale growth release historical approaches Nain Nunatsiavut population growth
	Abstract	Several recent dendrochronological, macrofossil and palynological studies have surveyed modern spruce forests at multiple locations in the Nain region of coastal Nunatsiavut (north-central Labrador) in order to reconstruct past forest composition, growth rates, species diversity and harvesting patterns. The present paper synthesizes original and previously collected data to evaluate the extent to which the dynamics of the region’s spruce forests over the past five centuries have been related to anthropogenic impacts. In three key case studies, Picea growth release events demonstrate multiple isolated forest disturbances prior to the late 19th century. In general, these events correspond to the local human settlement history rather than to regional climatic trends, suggesting that ongoing human impacts on the forest extend as far back as the 17th century. Disturbance regimes accelerated by ca 1875 and afterward in all of the study sites. This increase in forest disturbance corresponds to increased demands for wood triggered by socio-economic changes experienced by the region’s Inuit and Settler communities. Ongoing surveys demonstrate the presence of markers of human exploitation of forests throughout the study region, and especially in coastal locations, suggesting that anthropogenic impacts are in fact generalised and not limited to specific areas of recent settlement.
	Programme	1080
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	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1195-6860	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8251
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	Author	Alain Royer, Florent Domine, Alexandre Roy, Alexandre Langlois, Nicolas Marchand, Gautier Davesne
	Title	New northern snowpack classification linked to vegetation cover on a latitudinal mega-transect across northeastern Canada			Type	Journal
	Year	2021	Publication	Écoscience	Abbreviated Journal
	Volume		Issue		Pages	1-18
	Keywords	classification de la couverture de neige Gradient latitudinal interactions neige-végétation Latitudinal gradient propriétés de la neige snow cover classification snow–vegetation interaction snowpack properties
	Abstract	Changes in mass, extent, duration, and physical properties of snow are key elements for studying associated climate change feedbacks in northern regions. In this study, we analyzed snowpack physical properties along a ‘mega’ transect from 47°N to 83°N (4,000 km) in northeastern Canada, which includes marked transitions between ecozones from boreal forest to subarctic and arctic ecosystems. Our unique dataset of 391 detailed snowpits acquired over the last 20 years, complemented with snow data from weather stations, shows that snowpack properties such as snow water equivalent, snow depth, density, grain size and basal depth hoar fraction (DHF) are strongly linked to vegetation type. Based on these results, we propose an updated classification of snow types in three classes: boreal forest snow (47–58°N), tundra snow (58–74°N) and polar desert snow (74–83°N), which is more appropriate to the study area than the general north hemisphere classification commonly used. We also show that shrub presence along the transect contributes to a significant increase in DHF development which contributes most strongly to the thermal insulation properties of the snowpack. Overall, our analysis suggests that snow–vegetation interactions have a positive feedback effect on warming at northern latitudes.
	Programme	1042
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	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1195-6860	ISBN	1195-6860	Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	7971
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	Author	Helena P. Baird, Seunggwan Shin, Rolf G. Oberprieler, Maurice Hullé, Philippe Vernon, Katherine L. Moon, Richard H. Adams, Duane D. McKenna, Steven L. Chown
	Title	Fifty million years of beetle evolution along the Antarctic Polar Front			Type	Journal
	Year	2021	Publication	Proceedings of the National Academy of Sciences	Abbreviated Journal
	Volume	118	Issue	24	Pages
	Keywords	Antarctica herbivory island biogeography paleoclimate species radiation
	Abstract	Global cooling and glacial–interglacial cycles since Antarctica’s isolation have been responsible for the diversification of the region’s marine fauna. By contrast, these same Earth system processes are thought to have played little role terrestrially, other than driving widespread extinctions. Here, we show that on islands along the Antarctic Polar Front, paleoclimatic processes have been key to diversification of one of the world’s most geographically isolated and unique groups of herbivorous beetles—Ectemnorhinini weevils. Combining phylogenomic, phylogenetic, and phylogeographic approaches, we demonstrate that these weevils colonized the sub-Antarctic islands from Africa at least 50 Ma ago and repeatedly dispersed among them. As the climate cooled from the mid-Miocene, diversification of the beetles accelerated, resulting in two species-rich clades. One of these clades specialized to feed on cryptogams, typical of the polar habitats that came to prevail under Miocene conditions yet remarkable as a food source for any beetle. This clade’s most unusual representative is a marine weevil currently undergoing further speciation. The other clade retained the more common weevil habit of feeding on angiosperms, which likely survived glaciation in isolated refugia. Diversification of Ectemnorhinini weevils occurred in synchrony with many other Antarctic radiations, including penguins and notothenioid fishes, and coincided with major environmental changes. Our results thus indicate that geo-climatically driven diversification has progressed similarly for Antarctic marine and terrestrial organisms since the Miocene, potentially constituting a general biodiversity paradigm that should be sought broadly for the region’s taxa.
	Programme	136
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	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0027-8424, 1091-6490	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8087
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	Author	Mike Lockwood, Carl Haines, Luke A. Barnard, Mathew J. Owens, Chris J. Scott, Aude Chambodut, Kathryn A. McWilliams
	Title	Semi-annual, annual and Universal Time variations in the magnetosphere and in geomagnetic activity: 4. Polar Cap motions and origins of the Universal Time effect			Type	Journal
	Year	2021	Publication	Journal of Space Weather and Space Climate	Abbreviated Journal
	Volume	11	Issue		Pages	15
	Keywords
	Abstract	We use the am, an, as and the aσ geomagnetic indices to the explore a previously overlooked factor in magnetospheric electrodynamics, namely the inductive effect of diurnal motions of the Earth’s magnetic poles toward and away from the Sun caused by Earth’s rotation. Because the offset of the (eccentric dipole) geomagnetic pole from the rotational axis is roughly twice as large in the southern hemisphere compared to the northern, the effects there are predicted to be roughly twice the amplitude of those in the northern hemisphere. Hemispheric differences have previously been discussed in terms of polar ionospheric conductivities generated by solar photoionization, effects which we allow for by looking at the dipole tilt effect on the time-of-year variations of the indices. The electric field induced in a geocentric frame is shown to also be a significant factor and gives a modulation of the voltage applied by the solar wind flow in the southern hemisphere that is typically a ±30% diurnal modulation for disturbed intervals rising to ±76% in quiet times. For the northern hemisphere these are 15% and 38% modulations. Motion away from/towards the Sun reduces/enhances the directly-driven ionospheric voltages and reduces/enhances the magnetic energy stored in the tail and we estimate that approximately 10% of the effect appears in directly driven ionospheric voltages and 90% in changes of the rate of energy storage or release in the near-Earth tail. The hemispheric asymmetry in the geomagnetic pole offsets from the rotational axis is shown to be the dominant factor in driving Universal Time (UT) variations and hemispheric differences in geomagnetic activity. Combined with the effect of solar wind dynamic pressure and dipole tilt on the pressure balance in the near-Earth tail, the effect provides an excellent explanation of how the observed Russell-McPherron pattern with time-of-year F and UT in the driving power input into the magnetosphere is converted into the equinoctial F-UT pattern in average geomagnetic activity (after correction is made for dipole tilt effects on ionospheric conductivity), added to a pronounced UT variation with minimum at 02–10 UT. In addition, we show that the predicted and observed UT variations in average geomagnetic activity has implications for the occurrence of the largest events that also show the nett UT variation.
	Programme	139
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	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2115-7251	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8076
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	Author	M. A. Kenworthy, S. N. Mellon, J. I. Bailey, R. Stuik, P. Dorval, G. J. J. Talens, S. R. Crawford, E. E. Mamajek, I. Laginja, M. Ireland, B. Lomberg, R. B. Kuhn, I. Snellen, K. Zwintz, R. Kuschnig, G. M. Kennedy, L. Abe, A. Agabi, D. Mekarnia, T. Guillot, F. Schmider, P. Stee, Y. de Pra, M. Buttu, N. Crouzet, P. Kalas, J. J. Wang, K. Stevenson, E. de Mooij, A.-M. Lagrange, S. Lacour, A. Lecavelier des Etangs, M. Nowak, P. A. Strøm, Z. Hui, L. Wang
	Title	The β Pictoris b Hill sphere transit campaign – I. Photometric limits to dust and rings			Type	Journal
	Year	2021	Publication	Astronomy & Astrophysics	Abbreviated Journal
	Volume	648	Issue		Pages	A15
	Keywords
	Abstract	Aims. Photometric monitoring of β Pic in 1981 showed anomalous fluctuations of up to 4% over several days, consistent with foreground material transiting the stellar disk. The subsequent discovery of the gas giant planet β Pic b and the predicted transit of its Hill sphere to within a 0.1 au projected separation of the planet provided an opportunity to search for the transit of a circumplanetary disk (CPD) in this 21 ± 4 Myr-old planetary system. We aim to detect, or put an upper limit on, the density and nature of the material in the circumplanetary environment of the planet via the continuous photometric monitoring of the Hill sphere transit that occurred in 2017 and 2018.Methods. Continuous broadband photometric monitoring of β Pic requires ground-based observatories at multiple longitudes to provide redundancy and to provide triggers for rapid spectroscopic follow-up. These include the dedicated β Pic monitoring bRing observatories in Sutherland and Siding Springs, the ASTEP400 telescope at Concordia, and the space observatories BRITE and the Hubble Space Telescope (HST). We search the combined light curves for evidence of short-period transient events caused by rings as well as for longer-term photometric variability due to diffuse circumplanetary material.Results. We find no photometric event that matches with the event seen in November 1981, and there is no systematic photometric dimming of the star as a function of the Hill sphere radius.Conclusions. We conclude that the 1981 event was not caused by the transit of a CPD around β Pic b. The upper limit on the long-term variability of β Pic places an upper limit of 1.8 × 10^{22^{g of dust within the Hill sphere (comparable to the ~100 km radius asteroid 16 Psyche). Circumplanetary material is either condensed into a disk that does not transit β Pic, condensed into a disk with moons that has an obliquity that does not intersect with the path of β Pic behind the Hill sphere, or is below our detection threshold. This is the first time that a dedicated international campaign has mapped the Hill sphere transit of an extrasolar gas giant planet at 10 au.}}
	Programme	1066
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	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0004-6361, 1432-0746	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8195
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	Author	M. Afroosa, B. Rohith, Arya Paul, Fabien Durand, Romain Bourdallé-Badie, P. V. Sreedevi, Olivier de Viron, Valérie Ballu, S. S. C. Shenoi
	Title	Madden-Julian oscillation winds excite an intraseasonal see-saw of ocean mass that affects Earth’s polar motion			Type	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
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	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
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	Author	Alberto Baudena, Enrico Ser-Giacomi, Donatella D’Onofrio, Xavier Capet, Cedric Cotté, Yves Cherel, Francesco D’Ovidio
	Title	Fine-scale structures as spots of increased fish concentration in the open ocean			Type	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
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	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
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	Author	Jan Grimsrud Davidsen, Xavier Bordeleau, Sindre Håvarstein Eldøy, Frederick Whoriskey, Michael Power, Glenn T. Crossin, Colin Buhariwalla, Philippe Gaudin
	Title	Marine habitat use and feeding ecology of introduced anadromous brown trout at the colonization front of the sub-Antarctic Kerguelen archipelago			Type	Journal
	Year	2021	Publication	Scientific Reports	Abbreviated Journal
	Volume	11	Issue	1	Pages	11917
	Keywords	Animal migration Behavioural ecology Ecology Stable isotope analysis
	Abstract	In 1954, brown trout were introduced to the Kerguelen archipelago (49°S, 70°E), a pristine, sub-Antarctic environment previously devoid of native freshwater fishes. Trout began spreading rapidly via coastal waters to colonize adjacent watersheds, however, recent and unexpectedly the spread has slowed. To better understand the ecology of the brown trout here, and why their expansion has slowed, we documented the marine habitat use, foraging ecology, and environmental conditions experienced over one year by 50 acoustically tagged individuals at the colonization front. Trout mainly utilized the marine habitat proximate to their tagging site, ranging no further than 7 km and not entering any uncolonized watersheds. Nutritional indicators showed that trout were in good condition at the time of tagging. Stomach contents and isotope signatures in muscle of additional trout revealed a diet of amphipods (68%), fish (23%), isopods (6%), and zooplankton (6%). The small migration distances observed, presence of suitable habitat, and rich local foraging opportunities suggest that trout can achieve their resource needs close to their home rivers. This may explain why the expansion of brown trout at Kerguelen has slowed.
	Programme	1041
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	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	2045-2322	Medium
	Area		Expedition		Conference
	Notes				Approved	yes
	Call Number				Serial	8180
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