Showing 11862 items
1 January, 2011 by Chester Sands, Sandra McInnes, Sandra McInnes
We assessed the available morphological evidence to see if this corroborates the paraphyly in the Parachela (Tardigrada) as suggested by recent molecular data. We reconcile molecular phylogenetics with alpha morphology,…Read more on Phylum Tardigrada: A re-evaluation of the Parachela
1 January, 2011 by Gareth Marshall
This study examines regional atmospheric circulation changes associated with a reversal in the sign of the relationship between the Southern Annular Mode (SAM) and near-surface temperatures at Halley station, East…1 January, 2011 by Louise Sime
We compare the present and last interglacial periods as recorded in Antarctic water stable isotope records now available at various temporal resolutions from six East Antarctic ice cores: Vostok, Taylor…Read more on A comparison of the present and last interglacial periods in six Antarctic ice cores
1 January, 2011
Lubchenco challenges scientists to: ‘‘ address the most urgent needs of society, in proportion to their importance; communicate their knowledge and understanding widely in order to inform decisions of individuals…1 January, 2011 by Peter Convey
The springtail Gomphiocephalus hodgsoni (Arthropoda: Collembola) has been the focus of extensive ecophysiological and molecular genetic work and is now arguably the most well-studied of the continental Antarctic springtails. Here,…1 January, 2011 by Povl Abrahamsen, Hugh Venables, Michael Meredith
Antarctic Bottom Water (AABW), the densest water in the global overturning circulation, has warmed in recent decades, most notably in the Atlantic. Time series recorded within the boundary currents immediately…1 January, 2011 by Keith Nicholls, Michael Meredith
A serendipitous > 8-month time series of hydrographic properties was obtained from the vicinity of the South Orkney Islands, Southern Ocean, by tagging a southern elephant seal (Mirounga leonine) on…1 January, 2011
The ecology of Earth's first large organisms is an unsolved problem in palaeontology. This experience report discusses the determination of which ecosystems could have been feasible, by considering the biological…1 January, 2011 by Lloyd Peck, Melody Clark, Simon Morley
The limpet, Nacella concinna, collected from the Antarctic Peninsula (67 S), was incubated at -0.3 degrees C and 2.9 degrees C for 9 months to test if the previously reported…1 January, 2011 by Peter Convey
It has long been maintained that the majority of terrestrial Antarctic species are relatively recent, post last glacial maximum, arrivals with perhaps a few microbial or protozoan taxa being substantially…1 January, 2011
Delayed sleep phase (and sometimes free-run) is common in the Antarctic winter (no natural sunlight) and optimizing the artificial light conditions is desirable. This project evaluated sleep when using 17…1 January, 2011 by David Newnham, David Maxfield, Mark Clilverd, Richard Horne
We report the first ground-based passive microwave observations made from Troll station, Antarctica, which show enhanced mesospheric nitric oxide (NO) volume mixing ratio reaching levels of 1.2 ppmv, or 2–3…1 January, 2011 by Kevin Newsham
P>Dark septate endophytes (DSE) frequently colonize roots in the natural environment, but the effects of these fungi on plants are obscure, with previous studies indicating negative, neutral or positive effects…Read more on A meta-analysis of plant responses to dark septate root endophytes
1 January, 2011 by Kevin Newsham
Previous studies have shown the leafy liverwort Cephaloziella varians to associate consistently with fungi, typically the ericoid mycorrhizal symbiont Rhizoscyphus ericae, across a wide latitudinal gradient in the maritime and…1 January, 2011
Radar studies of firn on the ice sheets have revealed complex folds on its internal layering that form from the interplay of snow accumulation and ice flow. A mathematical theory…1 January, 2011 by Melody Clark, Simon Morley
Animal physiology, ecology and evolution are affected by temperature and it is expected that community structure will be strongly influenced by global warming. This is particularly relevant in the tropics,…Read more on Upper temperature limits of tropical marine ectotherms: global warming implications
1 January, 2011 by Vsevolod Afanasyev
Ten geolocators (light-level data loggers) were attached to Common Terns (Sterna hirundo) at a breeding site in the northeastern USA in 2007 and 2008; six were retrieved (five with useful…Read more on Migrations and winter quarters of five common terns tracked using geolocators
1 January, 2011 by David Barnes, Lloyd Peck, Melody Clark, Simon Morley
The Antarctic intertidal zone is one of the world's most extreme marine environments. As well as having a typically high annual temperature variation (~ 30 °C), it is affected by…Read more on Antarctic intertidal limpet ecophysiology: a winter-summer comparison
1 January, 2011 by Stephen Roberts
Quantitative climate reconstructions are fundamental to understand long-term trends in natural climate variability and to test climate models used to predict future climate change. Recent advances in molecular geochemistry have…1 January, 2011 by Lloyd Peck
There is great concern currently over environmental change and the biotic responses, actual or potential, to that change. There is also great concern over biodiversity and the observed losses to…Read more on Organisms and responses to environmental change
1 January, 2011 by Dominic Hodgson, Peter Convey
Cultivation techniques were used to study the heterotrophic bacterial diversity in two microbial mat samples originating from the littoral zone of two continental Antarctic lakes (Forlidas Pond and Lundstrom Lake)…1 January, 2011 by Richard Phillips
Considerable attention has focused on inter- and intraspecific variation in trophic niches of marine predators. Although this has revealed evidence for sexual segregation in distribution in some species, few studies…1 January, 2011 by Richard Phillips
Gadfly petrels are strictly oceanic seabirds that range very far from their breeding grounds. Foraging movements outside the breeding season are poorly described. We used global location sensing (GLS) to…1 January, 2011 by Michael Meredith
Antarctic coastal waters undergo major physical alterations during summer. Increased temperatures induce sea-ice melting and glacial melt water input, leading to strong stratification of the upper water column. We investigated…1 January, 2011 by Alistair Crame
We report on the discovery of a new outcrop of fossiliferous Neogene sediments on northern James Ross Island, northern Antarctic Peninsula. Approximately 100 specimens of the pectinid bivalve Austrochlamys anderssoni…1 January, 2011 by Geraint Tarling
We study the composition and biophysical properties of wax esters extracted from the Antarctic copepod, Calanoides acutus, to explore if these factors adjust buoyancy in diapausing copepods. Levels of wax…Read more on Phase transitions of wax esters adjust buoyancy in diapausing Calanoides acutus
1 January, 2011 by Peter Ward
Fatty acid biomarker analysis of the Cyclopoid copepods Oithona similis and Oithona frigida sampled from the Southern Ocean during the austral summer has indicated differences in diet between the two…Read more on Importance of diatoms for Oithona in Antarctic waters
1 January, 2011 by Roger Worland
The Arctic springtail Megaphorura arctica (Tullberg, 1876) employs a strategy known as cryoprotective dehydration to survive winter temperatures as low as -25 degrees C. During cryoprotective dehydration, water is lost…1 January, 2011 by Martin Collins
We review information from scientific trawl surveys carried out between 1977 and 2002 in the Porcupine Seabight and Abyssal Plain area of the Northeast Atlantic (240-4865 m water depth). Since…1 January, 2011 by Andrew Fleming, Hamish Pritchard
Satellite remote sensing has come to dominate the measurement of glacier and ice-sheet change. Three independent methods now exist for assessing ice-sheet mass balance and we focus on progress in…Read more on Understanding ice-sheet mass balance: progress in satellite altimetry and gravimetry
1 January, 2011
Diatom-rich sediments are common in several oceanic regions, especially the Southern Ocean. Some of these are strongly affected by bottom currents and are expected to be sorted by the flow.…1 January, 2011 by Roger Worland, Melody Clark
Cold hardiness in the Arctic Collembola Megaphorura arctica (Tullberg), formerly Onychiurus arcticus, has been the subject of extensive studies over the last decade. This species employs an unusual strategy known…1 January, 2011 by Hilmar Gudmundsson
The determination of basal properties on ice streams from surface data is formulated as a Bayesian statistical inference problem. The theory is applied to a flowline on Rutford Ice Stream,…1 January, 2011 by Richard Phillips
Pelagic seabirds are highly mobile, reducing the likelihood of allopatric speciation where disruption of gene flow between populations is caused by physically insurmountable, extrinsic barriers. Spatial segregation during the non-breeding…1 January, 2011 by Claus-Dieter Hillenbrand, Robert Larter
Sediment cores from cross-shelf troughs on the NE Antarctic Peninsula shelf recovered tills with variable shear strengths that represent different subglacial depositional regimes. In addition to detailed qualitative micromorphological descriptions,…1 January, 2011 by Claus-Dieter Hillenbrand, Robert Larter
Acoustic sub-bottom profiler surveys on the northeast Antarctic Peninsula shelf indicate that parts of the seabed are underlain by an acoustically transparent layer that is thin on the inner shelf…1 January, 2011 by Anje-Margriet Neutel
Global and regional climate models, such as those used in IPCC assessments, are the best tools available for climate predictions. Such models typically account for large-scale land-atmosphere feedbacks. However, these…Read more on Local ecosystem feedbacks and critical transitions in the climate
1 January, 2011 by David Vaughan, Hugh Corr
We assess basal roughness beneath Pine Island Glacier (PIG), West Antarctica, based on a recent airborne radio-echo sounding dataset. We identify a clear relationship between faster ice flow and decreased…Read more on The basal roughness of Pine Island Glacier, West Antarctica
1 January, 2011
The diets of Antarctic toothfish Dissostichus mawsoni and Patagonian toothfish Dissostichus eleginoides were examined around the South Sandwich Islands in the Southern Ocean, one of few regions with overlapping populations…1 January, 2011 by Dominic Hodgson, Stephen Roberts
The recent disintegration of Antarctic Peninsula ice shelves, and the associated accelerated discharge and retreat of continental glaciers, has highlighted the necessity of quantifying the current rate of Antarctic ice…1 January, 2011 by Howard Roscoe
Previous work showed a near-continuous increase in stratospheric water vapour between the 1950s and 1990s from a variety of instruments, without recourse to fits between instruments. We reassess the trend…Read more on Revisiting the lower stratospheric water vapour trend from the 1950s to 1970s
1 January, 2011 by Andy Smith, Ed King, Hugh Corr, Richard Hindmarsh, Richard Hindmarsh
We analyze Holocene ice flow using global positioning system and radio-echo sounding data acquired near the Amundsen-Weddell ice divide, between Pine Island Glacier and the Institute Ice Stream, West Antarctica.…Read more on Holocene stability of the Amundsen-Weddell ice divide, West Antarctica
1 January, 2011
Understanding the connectivity between breeding and nonbreeding populations of migratory birds is fundamental to our knowledge of biological phenomena such as population dynamics and dispersal. Moreover, our ability to quantify…1 January, 2011
Surface cross-stream eddy diffusion in the Southern Ocean is estimated by monitoring dispersion of particles numerically advected with observed satellite altimetry velocity fields. To gain statistical significance and accuracy in…Read more on Mean-flow and topographic control on surface eddy-mixing in the Southern Ocean
1 January, 2011 by Jean-Baptiste Sallee
The divergence of the eddy mass flux in the surface layer of the Southern Ocean makes an important contribution to subduction of fluid through the base of the mixed layer.…Read more on Parameterization of eddy-induced subduction in the Southern Ocean surface-layer
1 January, 2011
We use the 3-D FinROSE chemistry transport model (CTM) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) observations to study connections between atmospheric dynamics and middle atmospheric NOx (NOx =…1 January, 2011
The question of whether Pliocene climate was warm enough to support a substantial vegetation cover on Antarctica is of great significance to the ongoing and controversial debate on the stability…1 January, 2011
Variscan Central Iberian Zone lamprophyre dikes cut synorogenic to late orogenic peraluminous S-type granitoids marking an important shift in regional tectonic regime from earlier, 350-290 Ma, extension-related crustal melting to…1 January, 2011 by Claire Allen, Geraint Tarling, Sophie Fielding
A compilation of more than 30 studies shows that adult Antarctic krill (Euphausia superba) may frequent benthic habitats year-round, in shelf as well as oceanic waters and throughout their circumpolar…1 January, 2011 by Jonathan Shanklin
1 January, 2011 by Richard Horne
The outer radiation belt is often enhanced during storms while the inner belt is usually considered to be unaffected by geomagnetic activity. During the most recent Halloween superstorms, the extreme…Read more on Profound change of the near-Earth radiation environment caused by solar superstorms
1 January, 2011 by Emily Shuckburgh
The modulation of air-sea heat fluxes by geostrophic eddies due to the stirring of temperature at the sea surface is discussed and quantified. It is argued that the damping of…Read more on Mixed layer lateral eddy fluxes mediated by air-sea interaction
1 January, 2011 by Eric Wolff, Louise Sime
The resemblance of the orbitally filtered isotope signal from the past 340 kyr in Antarctic ice cores to Northern Hemisphere summer insolation intensity has been used to suggest that the…1 January, 2011 by Hugh Corr, Louise Sime, Richard Hindmarsh, Richard Hindmarsh
We present a novel automated processing method for obtaining layer dip from radio-echo sounding (RES) data. The method is robust, easily applicable and can be used to process large (several…Read more on Automated processing to derive dip angles of englacial radar reflectors in ice sheets
1 January, 2011 by David Barnes, Lloyd Peck
Significant warming has been observed in every ocean, yet our ability to predict the consequences of oceanic warming on marine biodiversity remains poor. Experiments have been severely limited because, until…Read more on Turning on the heat: ecological response to simulated warming in the sea
1 January, 2011
Late Miocene (c. 13-5 Ma) volcanic sequences of the Hallett Volcanic Province (HVP) crop out along > 250 km of western Ross Sea coast in northern Victoria Land. Eight primary…1 January, 2011 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
The Amundsen Sea Embayment (ASE) drains approximately 35% of the West Antarctic Ice Sheet (WAIS) and is one of the most rapidly changing parts of the cryosphere. In order to…Read more on Deglacial history of the West Antarctic Ice Sheet in the western Amundsen Sea Embayment
1 January, 2011
The study of Glacial Isostatic Adjustment (GIA) is gaining an increasingly im-portant role within the geophysical community. Understanding the response of the Earth to loading is crucial in various contexts,…Read more on A benchmark study for glacial-isostatic adjustment codes
1 January, 2011
The 2007 International Polar Year (IPY) in the Antarctic was distinguished by strong regional and seasonal ice-atmosphere-ocean anomalies associated with an overall weakening of the prevailing westerly circulation. Here we…1 January, 2011 by Iain Staniland, Jaume Forcada
We compared Antarctic fur seals Arctocephalus gazella breeding at 2 contrasting sites on South Georgia: one high density colony at Bird Island and one lower density colony at Cooper Bay.…1 January, 2011 by Robert Mulvaney
Ice-core records of climate from Greenland and Antarctica show asynchronous temperature variations on millennial timescales during the last glacial period(1). The warming during the transition from glacial to interglacial conditions…1 January, 2011
Rhyolite eruptions in Iceland mostly take place at long-lived central volcanoes, examples of which are found associated with each of the present-day rift-zone ice caps. Subglacial eruptions at Kerlingarfjöll central…Read more on Explosive rhyolite tuya formation: classic examples from Kerlingarfjoll, Iceland
1 January, 2011 by Katrin Linse
Many members of the benthic fauna of the Antarctic continental shelf share close phylogenetic relationships to the deep-sea fauna adjacent to Antarctica and in other ocean basins. It has been…1 January, 2011 by Lloyd Peck
This review describes outcomes of a 2010 horizon-scanning exercise building upon the first exercise conducted in 2009. The aim of both horizon scans was to identify emerging issues that could…Read more on A horizon scan of global conservation issues for 2011
1 January, 2011 by Richard Horne
Effects of density decrease in plasma injection regions and a latitude-dependent wave normal angle distribution on the energization of electrons by whistler mode waves at Jupiter are investigated. Previous work…1 January, 2011 by Philip Trathan
How top avian predators are distributed at sea during the inter-breeding period remains poorly known. Here we focused on the pelagic seabird that is the single greatest avian consumer of…Read more on Inter-population segregation in the wintering areas of macaroni penguins
1 January, 2011 by Philip Trathan
For land-breeding marine organisms such as seabirds, knowledge about their habitat use has mainly been gained through studies of breeding individuals that are constrained to return frequently to their breeding…1 January, 2011 by Michael Thorne, Roger Worland, Melody Clark
The Arctic springtail, Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola), is one of the few organisms known to survive the extreme stresses of its environment by using cryoprotective dehydration. We have…1 January, 2011 by Philip Leat
The South Sandwich volcanic arc is sited on a young oceanic crust, erupts low-K tholeiitic rocks, is characterized by unexotic pelagic and volcanogenic sediments on the down-going slab, and simple…1 January, 2011 by Philip Trathan, Peter Fretwell
In 1948, a small colony of emperor penguins Aptenodytes forsteri was discovered breeding on Emperor Island (67 degrees 51' 52 '' S, 68 degrees 42' 20 '' W), in the…1 January, 2011 by Richard Phillips
Currently, 17 of 22 albatross species are listed as Vulnerable, Endangered, or Critically endangered by the International Union for the Conservation of Nature (IUCN). Incidental mortality in fisheries is by…Read more on An assessment of seabird-fishery interactions in the Atlantic Ocean
1 January, 2011 by Jonathan Shanklin
The Antarctic ozone holes of 2008 and 2009 are reviewed from various perspectives, making use of a range of Australian data and analyses. In both years, ozone holes formed that…1 January, 2011
In the face of stochastic climatic perturbations, the overall stability of an ecosystem will be determined by the balance between its resilience and its resistance, but their relative importance is…1 January, 2011 by David Vaughan, David Barnes, Peter Fretwell
The West Antarctic ice sheet (WAIS) has long been considered vulnerable to rapid retreat and today parts are rapidly losing ice. Projection of future change in WAIS is, however, hampered…1 January, 2011 by Dominic Hodgson, Gareth Marshall, Stephen Roberts
We review the post-glacial climate variability along the East Antarctic coastline using terrestrial and shallow marine geological records and compare these reconstructions with data from elsewhere. Nearly all East Antarctic…1 January, 2011 by Michael Thorne, Melody Clark
Background Fish scales are an important reservoir of calcium and phosphorus and together with the skin function as an integrated barrier against environmental changes and external aggressors. Histological studies have…Read more on Skin healing and scale regeneration in fed and unfed sea bream, Sparus auratus
1 January, 2011 by Alistair Crame
Laocoetis piserai n. sp. (Hexactinellida, Porifera) from the mid-Cretaceous (i.e., Albian–Cenomanian) of James Ross Island is the first record of a fossil sponge from Antarctica. This new occurrence of a…Read more on First fossil sponge from Antarctica and its palaeobiogeographical significance
1 January, 2011 by Philip Trathan, Richard Phillips
Telemetry methods and remote sensing now make it possible to record the spatial usage of wide-ranging marine animals and the biophysical characteristics of their pelagic habitats. Furthermore, recent statistical advances…1 January, 2011 by Dominic Hodgson, Peter Fretwell, Robert Larter, Stephen Roberts
Precise relative sea level (RSL) data are important for inferring regional ice sheet histories, as well as helping to validate numerical models of ice sheet evolution and glacial isostatic adjustment.…Read more on A new Holocene relative sea level curve for the South Shetland Islands, Antarctica
1 January, 2011
In this study we examined the hypothesis that, under conditions of replete macronutrients and iron in the Southern Ocean, phytoplankton abundance and specific N uptake rates are influenced strongly by…1 January, 2011 by Huw Griffiths, Katrin Linse, Rowan Whittle
Limopsis is one of the most speciose and widespread bivalve genera in the Southern Ocean at the present day. However, the fossil record of the genus is poorly known from…1 January, 2011
A discrete-element model of sea ice is used to study how a 900 change in wind direction alters the pattern of faults generated through mechanical failure of the ice. The…Read more on Modelling the reorientation of sea-ice faults as the wind changes direction
1 January, 2011 by Eric Wolff
Predicting how climate will change in the future requires a sound understanding of physical processes. This is underpinned by observation of how and why climate has changed in the past.…1 January, 2011 by Eric Wolff
The rising trend in atmospheric concentrations of methane over the past 5,000 years has been attributed to human agency. A modelling study, of a power that has only now become…1 January, 2011 by Eric Wolff
While the trends in greenhouse gas concentrations in recent decades are clear, their significance is only revealed when viewed in the context of a longer time period. Fortunately, the air…Read more on Greenhouse gases in the earth system: a palaeoclimate perspective
1 January, 2011 by Richard Phillips
Cephalopods are components of the diet of many predators worldwide. They are identified mainly using their chitinized upper and lower beaks, but because it has been assumed that the number…1 January, 2011 by Philip Trathan
As the spatial distribution of marine organisms is often affected by seasonal changes, pelagic seabirds may change their foraging areas in response to seasonal changes in the marine environment. Here,…1 January, 2011 by Eugene Murphy, Emma Young, Michael Meredith
The marine ecosystem on the shelf and open ocean adjacent to South Georgia is extraordinarily rich, with a history of commercial exploitation. Although much progress has been made, attempts at…1 January, 2011 by Melody Clark
Insects in the field are exposed to multiple bouts of cold, and there is increasing evidence that the fitness consequences of repeated cold exposure differ from the impacts of a…1 January, 2011 by Nigel Meredith, Richard Horne
Understanding the dynamics of the Earth's radiation belts is important for modeling and forecasting the intensities of energetic electrons in space. Wave diffusion processes are known to be responsible for…Read more on Effects of energy and pitch angle mixed diffusion on radiation belt electrons
22 December, 2010 by Adrian Jenkins, Keith Makinson, Pierre Dutrieux
Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic data sets have turned…16 December, 2010 by Liz Thomas, Louise Sime, Robert Mulvaney, Thomas Bracegirdle
This study uses ice core methanesulphonic acid (MSA) records from the Antarctic Peninsula, where temperatures have been warming faster than anywhere else in the Southern Hemisphere, to reconstruct the 20th…14 December, 2010
We present statistical methods to determine climate regimes for the last glacial period using three temperature proxy records from Greenland: measurements of δ18O from the Greenland Ice Sheet Project 2…1 December, 2010 by Mark Clilverd
AARDDVARK data from a radio wave receiver in Sodankyla, Finland have been used to monitor transmissions across the auroral oval and just into the polar cap from the very low…1 December, 2010 by Mark Clilverd
We report a comparison of Solar Anomalous Magnetospheric Particle Explorer detected relativistic electron microbursts and short-lived subionospheric VLF perturbations termed FAST events, observed at Sodankyl Geophysical Observatory, Finland, during 2005.…1 December, 2010 by John King, Paul Holland
The winter advance of the sea ice edge in the Bellingshausen Sea is frequently interrupted by periods of rapid retreat lasting a few days. The frequency and duration of such…Read more on Analysis of a rapid sea ice retreat event in the Bellingshausen Sea