Showing 11923 items
1 January, 2009
The paradigm of self-organized criticality (SOC) has found application in understanding scaling and bursty transport in driven, dissipative plasmas. SOC is, however, a limiting process that occurs as the ratio…Read more on Avalanching systems under intermediate driving rate
1 January, 2009 by Richard Horne
A three dimensional ray tracing of whistler-mode chorus is performed in a realistic magnetosphere using the HOTRAY code. A variety of important propagation characteristics are revealed associated with azimuthal density…1 January, 2009 by Richard Horne
The HOTRAY code is used to evaluate the path integrated gain of electromagnetic ion cyclotron (EMIC) waves as a function of frequency in two propagation bands above the O+ and…1 January, 2009 by Michael Dunn, Peter Convey
Soil bacterial diversity at environmentally distinct locations on Signy Island, South Orkney Islands was examined using the denaturing gradient gel profiling approach. A range of chemical variables in soils at…1 January, 2009 by Lloyd Peck, Melody Clark
The ability to understand and predict the effects of environmental stress on biodiversity is becoming increasingly important in our changing environment. Antarctic marine species are some of the most stenothermal…1 January, 2009 by Lloyd Peck, Melody Clark
The Antarctic limpet, Nacella concinna, exhibits the classical heat shock response, with up-regulation of duplicated forms of the inducible heat shock protein 70 (HSP70) gene in response to experimental manipulation…1 January, 2009 by Guy Hillyard, Michael Thorne, Roger Worland, Melody Clark
Background: Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the…1 January, 2009 by Mark Clilverd
We analyze in detail the February 2004 Global Ozone Monitoring by Occultation of Stars (GOMOS) NO2 observations in the northern polar latitudes during the springtime descent of NOx from the…1 January, 2009 by Mark Clilverd, Neil Cobbett
[1] The Antarctic-Arctic Radiation-belt (Dynamic) Deposition-VLF Atmospheric Research Konsortium (AARDDVARK) provides a network of continuous long-range observations of the lower ionosphere in the polar regions. Our ultimate aim is to…1 January, 2009
Rothera research station is a British Antarctic Survey (BAS) base on the Antarctic Peninsula that is operational year round. During the 8-month winter the 20 people living there are physically…1 January, 2009 by Peter Convey
As we draw towards the end of the massive effort that has been the International Polar Year (IPY), it is opportune to consider what impact it has had on Antarctic…Read more on Antarctic biology, the International Polar Year, and beyond
1 January, 2009 by Dominic Hodgson, John Turner, Peter Convey
The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from…Read more on Review. Antarctic climate change and the environment
1 January, 2009 by Peter Convey
Sub-Antarctic islands share many similarities in their history of human interaction and impacts before the mid-twentieth century. Large impacts on land were associated with marine exploitation industries of sealing and…1 January, 2009 by Andrew Clarke, Dominic Hodgson, David Barnes, Claus-Dieter Hillenbrand, Peter Convey
The evolutionary and biogeographic history of the contemporary Antarctic terrestrial and marine biotas reveals many components of ancient origin. For large elements of the terrestrial biota, long-term isolation over timescales…Read more on Exploring biological constraints on the glacial history of Antarctica
1 January, 2009 by Howard Roscoe
NO2 measurements during 1990-2007, obtained from a zenith-sky spectrometer in the Antarctic, are analysed to determine the long-term changes in NO2. An atmospheric photochemical box model and a radiative transfer…1 January, 2009
Subglacially erupted Neogene basaltic hyaloclastites in lava-fed deltas in Antarctica were found to contain putative endolithic microborings preserved in fresh glass along hydrous alteration boundaries. The location and existence over…1 January, 2009 by Geraint Tarling, Sally Thorpe
We model a summer snapshot of the behavior of Antarctic krill (Euphausia superba) during advection across the Scotia Sea. Individual krill respond to a changing landscape of predation risk and…1 January, 2009 by Emily Shuckburgh
A new diagnostic (the "Lyapunov diffusivity'') is presented that has the ability to quantify isentropic mixing in diffusion units and detects local mixing events by describing latitude-longitude variability. It is…1 January, 2009 by Huw Griffiths
The Southern Ocean is of unique ecological, biogeographic and political interest, as noted by your Editorial 'The way ahead for polar science' (Nature 457, 1057; 2009). Given the rate and…Read more on Polar science: bid for freely accessible biodiversity archive
1 January, 2009 by Dominic Hodgson
Recent data revealed that metazoans such as mites and springtails have persisted in Antarctica throughout several glacial-interglacial cycles, which contradicts the existing paradigm that terrestrial life was wiped out by…1 January, 2009 by Michael Thorne, Melody Clark
Background: Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The…1 January, 2009 by Richard Horne
This special issue of the Journal of Atmospheric and Solar-Terrestrial Physics is devoted to research into high speed solar wind streams (HSSs) and their effects on the region of near-Earth…1 January, 2009
Sixty species of Ostracoda have been recovered from Cenomanian, Santonian and Maastrichtian strata in New Zealand, and late Campanian sediments on Snow Hill and James Ross islands in the Antarctic…1 January, 2009 by Michael Meredith
Monitoring the sources and fate of freshwater in the East Greenland Current (EGC) is important, as this water has the potential to suppress deep convection in the Nordic and Labrador…Read more on The sources and fate of freshwater exported in the East Greenland Current
1 January, 2009
Improved sampling technologies, international observing networks, and data synthesis efforts are providing an unprecedented view of the global patterns and decadal variability of surface-ocean partial pressure of carbon dioxide (pCO(2))…Read more on Surface-ocean CO2 variability and vulnerability
1 January, 2009 by Richard Hindmarsh, Richard Hindmarsh
Using the finite-element code Elmer, we show that the full Stokes modeling of the ice-sheet/ice-shelf transition we propose can give consistent predictions of grounding-line migration. Like other marine ice-sheet models…Read more on Full Stokes modeling of marine ice sheets: influence of the grid size
1 January, 2009 by Robert Larter
An animated reconstruction shows South Pacific plate kinematics, in the reference frame of West Antarctica, between 55 Ma and the present-day. The ocean floor in the region formed due to…1 January, 2009 by Robert Larter
Decades after the recognition of the West Antarctic Rift System, and in spite of its global importance, the location and nature of the plate boundary it formed at are unknown…Read more on West Antarctic Rift System in the Antarctic Peninsula
1 January, 2009
A tectonic model of the Weddell Sea is built by composing a simple circuit with optimized rotations describing the growth of the South Atlantic and SW Indian oceans. The model…Read more on Gondwana breakup and plate kinematics: Business as usual
1 January, 2009
The breeding and feeding grounds of most humpback whale populations are well known. Their preference for shallow, subtropical waters in winter, where they calve and mate (Clapham 1996), often brings…Read more on Feeding grounds of the western South Atlantic humpback whale population
1 January, 2009
Fatty acids profiles of Emiliania huxleyi strain CCMP1516 were determined in a virus-induced culture crash with E. huxleyi virus 86 (EhV-86). As cell numbers declined in the infected cultures due…1 January, 2009 by Fausto Ferraccioli
New aeromagnetic data image the extent and spatial distribution of Cenozoic magmatism and older basement features over the Admiralty Block of the Transantarctic Mountains. Digital enhancement techniques image magmatic and…1 January, 2009 by Fausto Ferraccioli, Hugh Corr, Tom Jordan
The Wilkes Subglacial Basin represents all approximately 1400 kin-long and Lip to 600 kill wide Subglacial depression, buried beneath the over 3 km-thick East Antarctic Ice Sheet. Contrasting models, including…1 January, 2009
The presence of major crystalline basement provinces at depth in NW Ireland is inferred from in situ Hf isotope analysis of zircons from granitoid rocks that cut structurally overlying metasedimentary…1 January, 2009 by Gareth Marshall
This second paper examines the Southern Hemisphere annular mode (SAM) variability from reconstructions, observed indices, and simulations from 17 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) models…1 January, 2009 by Iain Staniland, Jaume Forcada
Correctly quantifying the impacts of rare apex marine predators is essential to ecosystem-based approaches to fisheries management, where harvesting must be sustainable for targeted species and their dependent predators. This…1 January, 2009 by Jaume Forcada, Philip Trathan
Penguins are adapted to live in extreme environments, but they can be highly sensitive to climate change, which disrupts penguin life history strategies when it alters the weather, oceanography and…Read more on Penguin responses to climate change in the Southern Ocean
1 January, 2009 by Elaina Ford
A dynamical link is demonstrated between the equatorial quasi-biennial oscillation (QBO) and high-latitude mesospheric zonal winds recorded by an Imaging Doppler Interferometer (IDI) at Halley, Antarctica. Above ~80 km eastward…Read more on QBO effects on Antarctic mesospheric winds and polar vortex dynamics
1 January, 2009 by Richard Phillips
The Black-browed Albatross Thalassarche melanophris is a long-lived procellariiform that typically nests colonially and exhibits low fecundity. Previous studies on albatrosses have focussed on the bottom-up effects of food supply…1 January, 2009
In this study the authors apply a recently developed clustering method for the systematic identification of metastable atmospheric regimes in high-dimensional datasets generated by atmospheric models. The novelty of this…Read more on Systematic Metastable Atmospheric Regime Identification in a AGCM
1 January, 2009 by Mervyn Freeman
Superposed epoch analyses have shown that, on average, the interplanetary magnetic field (IMF) turns northward close to substorm onset. This has been commonly accepted as evidence for the substorm onset…1 January, 2009 by Alexander Tate, Mark Belchier, Peter Fretwell
We introduce a new bathymetric compilation of the area around South Georgia in the Southern Ocean. Using a variety of data sources including multi and single-beam swath bathymetry we have…Read more on Compilation of a new bathymetric dataset of South Georgia
1 January, 2009 by Philip Trathan, Peter Fretwell
Aim To map and assess the breeding distribution of emperor penguins (Aptenodytes forsteri) using remote sensing. Location Pan-Antarctic. Methods Using Landsat ETM satellite images downloaded from the Landsat Image Mosaic…Read more on Penguins from space: faecal stains reveal the location of emperor penguin colonies
1 January, 2009 by Andrew Clarke, Lloyd Peck
Widespread recognition of the importance of biological studies at large spatial and temporal scales, particularly in the face of many of the most pressing issues facing humanity, has fueled the…1 January, 2009 by Ed King
A structural glaciological description and analysis of surface morphological features of the Larsen C ice shelf, Antarctic Peninsula, is derived from satellite images spanning the period 1963-2007. The data are…Read more on Surface structure and stability of the Larsen C ice shelf, Antarctic Peninsula
1 January, 2009 by Vsevolod Afanasyev
To test the potential effects of winds on the migratory detours of shearwaters, transequatorial migrations of 3 shearwaters, the Manx Puffin us puffinus, the Cory's Calonectris diomedea, and the Cape…Read more on Influence of sea surface winds on shearwater migration detours
1 January, 2009 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
The presence of a complex bedform arrangement on the sea floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related…1 January, 2009 by Richard Phillips
Several species of seabirds show cyclic patterns of attendance at their nesting colonies. We examined the patterns of variation in the numbers of Cory's shearwater at three colonies (two oceanic…1 January, 2009 by Katrin Linse
The Census of Antarctic Marine Life (CAML) aims to collate DNA barcode data for Antarctic marine species. DNA barcoding is a technique that uses a short gene sequence from a…1 January, 2009
We measured daily energy expenditure (DEE) continuously for a whole year in a free ranging bird, the macaroni penguin Eudyptes chrysolophus. We combined these measurements with concurrently recorded foraging behaviour,…1 January, 2009
The movement of marine vertebrates has been tracked using a variety of techniques, all of which depend on the external attachment of a transmitting or recording device. However, these devices…Read more on Tracking macaroni penguins during long foraging trips using ‘behavioural geolocation’
1 January, 2009 by David Barnes, Huw Griffiths, Katrin Linse
To investigate whether the biogeographical regions proposed by J. W. Hedgpeth and widely adopted by other authors hold true, are an oversimplification or with further data might show a unified…Read more on Towards a generalized biogeography of the Southern Ocean benthos
1 January, 2009 by Adrian Jenkins, Hilmar Gudmundsson
Surface ice-flow velocities measured at stakes on Rutford Ice Stream, West Antarctica, covering a period of similar to 25 years are analysed for evidence of temporal variations in flow. No…1 January, 2009 by Richard Phillips
The migratory movements of seabirds (especially smaller species) remain poorly understood, despite their role as harvesters of marine ecosystems on a global scale and their potential as indicators of ocean…1 January, 2009 by Howard Roscoe
More than 40 years of radiosonde data from two Antarctic stations are examined for changes in the date of the final stratospheric warming that occurs each year as the vortex…1 January, 2009
Life-time records of the trophic sources of carbon, nitrogen and of growth rate can be generated from biogenic structures that show accretionary growth, including fish scales, whale baleen and the…1 January, 2009 by Lloyd Peck
The cost of overcoming prey defenses relative to the value of internal tissues is a key criterion in predator/prey interactions. Optimal foraging theory predicts: (1) specific sizes of prey will…1 January, 2009
This study has investigated the three-dimensional movement of clasts within deformation till, using embedded wireless probes. These probes were part of an environmental sensor network, which measured subglacial properties (temperature,…1 January, 2009 by Elaine Fitzcharles, Philip Trathan
Dimorphism in various morphological traits is widely used to sex birds. However, when a threshold is set and there is overlap in the distribution of traits between sexes, there will…1 January, 2009 by Martin Collins
A study of the reproductive biology of the loliginid squid, Alloteuthis subulata in the North Sea, Irish Sea and Portuguese waters was carried out. A predominance of small squid (1 January, 2009
The mid-Pliocene warm period (ca. 3 to 3.3 million years ago) has become an important interval of time for palaeoclimate modelling exercises, with a large number of studies published during…1 January, 2009 by Michael Meredith
The polar foraminifera Neogloboquadrina pachyderma (sinistral) dominates assemblages from the high latitude Southern Ocean, which plays a key role in determining past climate due to the tight linkage between Antarctic…1 January, 2009 by Roger Worland
Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires special adaptations. To withstand such environmental conditions, tardigrades, as well as some nematodes and rotifers, enter a…Read more on High-temperature tolerance in anhydrobiotic tardigrades is limited by glass transition
1 January, 2009 by Roger Worland
Many limno-terrestrial tardigrades live in unstable habitats where they experience extreme environmental conditions such as drought, heat and subzero temperatures. Although their stress tolerance is often related only to the…1 January, 2009 by Philip Trathan, Simeon Hill
The ecosystem approach to fisheries attempts to define objectives for target species, the wider ecosystem, and critically, the fishery itself. Proposals for implementing the approach often include spatial restrictions on…1 January, 2009 by Claus-Dieter Hillenbrand, Robert Larter
The Belgica Trough and the adjacent Belgica Trough Mouth Fan in the southern Bellingshausen Sea (Pacific sector of the Southern Ocean) mark the location of a major outlet for the…1 January, 2009 by Claus-Dieter Hillenbrand
Modern global warming is likely to cause future melting of Earth's polar ice sheets that may result in dramatic sea-level rise. A possible collapse of the West Antarctic Ice Sheet…1 January, 2009 by Richard Hindmarsh, Richard Hindmarsh
A finite-difference model for the calculation of radar layer geometries in large ice masses is presented. Balance velocities are used as coefficients in the age equation and in the heat…Read more on A large-scale numerical model for computing isochrone geometry
1 January, 2009 by Dominic Hodgson
In this paper we present geological evidence from the Larsemann Hills (Lambert Glacier – Amery Ice Shelf region, East Antarctica) of marine sediments at an altitude of c. 8 m…1 January, 2009 by Dominic Hodgson, James Smith, Stephen Roberts
Direct exploration of subglacial lakes buried deep under the Antarctic Ice Sheet has yet to be achieved. However, at retreating margins of the ice sheet, there are a number of…Read more on Exploring former subglacial Hodgson Lake, Antarctica. Paper II: palaeolimnology
1 January, 2009 by Andreas Cziferszky, Dominic Hodgson, James Smith, Joanne Johnson, Stephen Roberts
At retreating margins of the Antarctic Ice Sheet, there are a number of locations where former subglacial lakes are emerging from under the ice but remain perennially ice-covered. This paper…1 January, 2009 by Jaume Forcada
Twinning in natural pinniped populations is often inferred from observations of suckling behavior, but this approach has been criticized because nonfilial nursing occurs at high frequencies in many seal species.…Read more on Genetic analysis of twinning in Antarctic fur seals (Arctocephalus gazella)
1 January, 2009 by Adrian Jenkins, David Vaughan, Hugh Corr, Paul Holland
It is argued that Larsen Ice Shelf contains marine ice formed by oceanic freezing and other mechanisms. Missing basal returns in airborne radar soundings and observations of a smooth and…1 January, 2009 by Mai Mai Lam, Richard Horne
Relativistic electron precipitation changes the chemistry of the upper atmosphere and depletes ozone, but the spatial and temporal distributions are poorly known. Here we survey more than 9 years of…1 January, 2009 by Richard Horne
While policy-makers discuss the benefits of manned spaceflight to the moon and beyond, scientists and engineers are considering how to protect astronauts from the harsh realities of space. During the…1 January, 2009 by Andrew Clarke
Sea-to-air emissions of bromocarbon gases are known to play an important role in atmospheric ozone depletion. In this study, seawater concentrations of bromoform (CHBr3) and dibromomethane (CH2Br2) were measured regularly…1 January, 2009
Solar radiation management (SRM) geoengineering has been proposed as one means of helping avoid the occurrence of dangerous climate change and undesirable state transitions ('tipping points') in the Earth system.…Read more on The fate of the Greenland Ice Sheet in a geoengineered, high CO2 world
1 January, 2009 by Mervyn Freeman
With the arrival of the Cassini spacecraft at Saturn in July 2004, there have been quasi-continuous observations of Saturn kilometric radiation (SKR) emissions. Exploration of the nightside magnetosphere has revealed…1 January, 2009 by Roger Worland
It is widely held both in the physiological literature, and more generally, that the average characteristics of species within an assemblage differ among sites. Such generalizations should be based on…1 January, 2009
A novel technique is used to examine northern hemisphere midlatitude longitudinal variations in ionospheric long-term trends. Differences in hour-by-hour monthly median ionospheric parameters between equilatitudinal observatory pairs are analysed for…Read more on Longitudinal variation in E- and F-region ionospheric trends
1 January, 2009 by Joanne Johnson
Knowledge of the thickness, extent and basal thermal conditions of ice cover on Antarctica during past climatic fluctuations is essential if we are to accurately predict the contribution from the…1 January, 2009 by Gareth Marshall
Seasonal reconstructions of the Southern Hemisphere annular mode (SAM) index are derived to extend the record before the reanalysis period, using station sea level pressure (SLP) data as predictors. Two…Read more on Historical SAM variability. Part I: Century-length seasonal reconstructions
1 January, 2009 by Eric Wolff
This review of late-Holocene palaeoclimatology represents the results from a PAGES/CLIVAR Intersection Panel meeting that took place in June 2006. The review is in three parts: the principal high-resolution proxy…1 January, 2009 by Fausto Ferraccioli, Hugh Corr, Tom Jordan
Understanding Antarctic volcanoes is important as they provide a window on magmatic and tectonic processes of the Antarctic plate and contain datable records of ice-sheet changes. We present the results…Read more on Airborne gravity reveals interior of Antarctic volcano
1 January, 2009 by David Vaughan
We use models constrained by remotely sensed data from Pine Island and Thwaites Glaciers, West Antarctica, to infer basal properties that are difficult to observe directly. The results indicate strong…1 January, 2009 by Chester Sands, David Barnes
Concerted efforts are being made to understand the current and past processes that have shaped Antarctic biodiversity. However, high rates of new species discoveries, sampling patchiness and bias make estimation…1 January, 2009 by David Vaughan, Hugh Corr
This paper presents an overview of internal layering across Pine Island Glacier, West Antarctica, as measured from airborne-radar data acquired during a survey conducted by the British Antarctic Survey and…1 January, 2009 by Gareth Marshall
The southern annular mode (SAM) has a well-established impact on climate in the Southern Hemisphere. The strongest response in surface air temperature (SAT) is observed in the Antarctic, but the…Read more on Climate impacts of the southern annular mode simulated by the CMIP3 models
1 January, 2009 by Victoria Peck
Three dissolution events ca. 16 Ma, 15.5 Ma, and 14.3 Ma ago have been identified in sediments from the Congo Fan. Multiproxy benthic foraminiferal and sedimentary records suggest an expanded…1 January, 2009 by Ed King
Rutford Ice Stream, West Antarctica, drains a catchment of >45 000 km(2) into the Ronne Ice Shelf through a 26 km wide, 2.4 km deep subglacial trough adjacent to the…1 January, 2009 by Ed King, Richard Hindmarsh, Richard Hindmarsh
Most discharge from large ice sheets takes place through fast-flowing ice streams and their speed is strongly modulated by interactions between the ice and the underlying sediments. Seismic surveys and…Read more on Formation of mega-scale glacial lineations observed beneath a West Antarctic ice stream
1 January, 2009
The accurate estimation of scaling exponents is central in the observational study of scale-invariant phenomena. Natural systems unavoidably provide observations over restricted intervals; consequently, a stationary stochastic process time series…Read more on Pseudononstationarity in the scaling exponents of finite-interval time series
1 January, 2009 by Thomas Bracegirdle
The spatial and temporal distributions of marine cold air outbreaks (MCAOs) over the northern North Atlantic have been investigated using re-analysis data for the period from 1958 to 2007. MCAOs…1 January, 2009
A comparison was made of the ground-based and satellite total ozone content (TOC) measurements in the atmosphere over the Antarctic stations Vernadsky, Halley and Amundsen–Scott and the Arctic station Barrow.…1 January, 2009 by David Barnes
Three new cheilostome bryozoans species were discovered in the collections of the BIOPEARL I cruise to the Scotia Arc. The species were found on boulders from the continental slope and…Read more on A new genus and three new species of Antarctic cheilostome Bryozoa