Showing 11862 items
1 December, 2010 by Mark Clilverd
The full potential of whistlers for monitoring plasmaspheric electron density variations has not yet been realized. The primary reason is the vast human effort required for the analysis of whistler…1 December, 2010 by David Barnes, Huw Griffiths, Lloyd Peck, Simon Morley
Antarctic marine invertebrates from the Western Antarctic Peninsula (WAP) are generally stenothermal, with three-month survival and activity limits above the average maximum summer seawater temperature (1.0 degrees C) of 1-6…1 December, 2010 by Mark Clilverd
It has long been recognized that whistler-mode waves can be trapped in plasmaspheric whistler ducts which guide the waves. For nonguided cases these waves are said to be "nonducted", which…1 December, 2010
During winter the ocean surface in polar regions freezes over to form sea ice. In the summer the upper layers of sea ice and snow melts producing meltwater that accumulates…1 December, 2010 by Richard Horne
Strong electron cyclotron harmonic (ECH) waves have been observed by Cassini associated with local plasma injection regions in the Saturnian magnetosphere. Using measured electron distributions from the Cassini plasma spectrometer,…23 November, 2010 by Howard Roscoe
In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring…19 November, 2010 by Liz Thomas
Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry.…Read more on Observed 20th century desert dust variability: impact on climate and biogeochemistry
17 November, 2010 by Nigel Meredith
This study explores the manner in which the plasmapause is responsible for dictating which magnetospheric source regions of ELF/VLF chorus are able to propagate to and be received by midlatitude…Read more on Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus
11 November, 2010 by Richard Horne
Plasmaspheric plumes created during disturbed geomagnetic conditions have been suggested as a major cause of increased occurrences of electromagnetic ion cyclotron (EMIC) waves at these times. We have catalogued occurrences…1 November, 2010 by Anna Jones
A modelling study of radical chemistry in the coastal Antarctic boundary layer, based upon observations performed in the course of the CHABLIS (Chemistry of the Antarctic Boundary Layer and the…Read more on Coupling of HOx, NOx and halogen chemistry in the Antarctic boundary layer
1 November, 2010 by Richard Horne
Coupling between the Rice Convection Model and Ring Current-Atmospheric Interactions Model codes is used to simulate the dynamical evolution of ring current ion phase space density and the thermal electron…Read more on Global simulation of magnetosonic wave instability in the storm time magnetosphere
1 November, 2010 by Mark Clilverd
Geomagnetic storms triggered by coronal mass ejections and high-speed solar wind streams can lead to enhanced losses of energetic electrons from the radiation belts into the atmosphere, both during the…1 October, 2010 by John King, Thomas Lachlan-Cope
Polynyas play an important role in the regional meteorology and oceanography of the high latitudes and in the global ocean circulation. Unique low-level observations of an Antarctic coastal polynya, the…Read more on Convective heat transfer over thin ice covered coastal polynyas
1 October, 2010
A discrete element model is used to study shear rupture of sea ice under convergent wind stresses. The model includes compressive, tensile, and shear rupture of viscous elastic joints connecting…Read more on Effect of shear rupture on aggregate scale formation in sea ice
15 September, 2010 by Hilmar Gudmundsson
The advance of a glacier over a deforming sediment layer is analysed numerically. We treat this problem as a contact problem involving two slowly-deforming viscous bodies. The surface evolution of…Read more on A numerical study of glacier advance over deforming till
10 September, 2010 by Gareth Chisham, Mervyn Freeman
The open-closed magnetic field line boundary (OCB) delimits the region of open magnetic flux forming the polar cap in the Earth’s ionosphere. We present a reliable, automated method for determining…7 September, 2010 by Richard Phillips
* 1. The global decline of albatrosses (Diomedidae: Procellariiformes) is thought to have occurred largely as a direct result of fishery-related mortality. Albatrosses and other large petrels interact with fisheries…1 September, 2010 by David Vaughan, Liz Thomas, Robert Arthern, Robert Mulvaney
We describe in situ measurements of the compaction of Antarctic snow. At three different sites in Antarctica, the rate of compaction was measured hourly, over various depth intervals, for up…Read more on In situ measurements of Antarctic snow compaction compared with predictions of models
1 September, 2010 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
Multibeam swath bathymetry and sub-bottom profiler data are used to establish constraints on the flow and retreat history of a major palaeo-ice stream that carried the combined discharge from the…1 September, 2010 by Richard Horne
Chorus, a naturally occurring magnetospheric electromagnetic wave, is believed to be the result of a long chain of physical processes starting with supergranular circulation at the sun. The interaction of…Read more on Introduction to the special section on Chorus: Chorus and its role in space weather
24 August, 2010 by Anna Jones, Eric Wolff, Gareth Marshall, Howard Roscoe, Neil Brough, Steve Colwell
The majority of tropospheric ozone depletion event (ODE) studies have focussed on time-series measurements, with comparatively few studies of the vertical component. Those that exist have almost exclusively used free-flying…21 August, 2010 by Peter Kirsch, Richard Horne
The slot-region between Earth's inner and outer electron radiation belts was observed on 24 February 2004 by the satellite STSAT-1 to be populated by quasi-trapped electrons of energy 100-400 keV.…1 August, 2010 by Mark Clilverd, Paul Breen, Tracy Moffat-Griffin
Transmissions from three U.S. VLF (very low frequency) transmitters were received at Churchill, Canada, during an event study in May to November, 2007. This period spans four cycles of recurrent…Read more on Energetic outer radiation belt electron precipitation during recurrent solar activity
1 August, 2010 by Nigel Meredith
Wave-particle interactions can play a key role in the process of transfer of energy between different electron populations in the outer Van Allen radiation belt. We present a case study…Read more on Wave-particle interactions in the equatorial source region of whistler-mode emissions
1 August, 2010 by Claire Allen, Claus-Dieter Hillenbrand, James Smith
Cores from a contourite drift on the continental slope in the NW Weddell Sea, Antarctica, contain up to four sandy foraminifer-rich layers (WA1–4), with dispersed ice-rafted debris (IRD), interbedded with…16 July, 2010 by Howard Roscoe
The passive tracer method is used to estimate ozone loss from ground-based measurements in the Antarctic. A sensitivity study shows that the ozone depletion can be estimated within an accuracy…Read more on Estimation of Antarctic ozone loss from ground-based total column measurements
1 July, 2010
Geological constraints on ice-sheet deglaciation are essential for improving the modelling of ice masses and understanding their potential for future change. Here we present a detailed interpretation of depositional environments…1 July, 2010 by Adrian Jenkins, Pierre Dutrieux
Thinning ice in West Antarctica, resulting from acceleration in the flow of outlet glaciers, is at present contributing about 10% of the observed rise in global sea level. Pine Island…1 July, 2010 by Richard Horne
The global distribution and spectral properties of electromagnetic ion cyclotron (EMIC) waves in the He+ band are simulated for the 21 April 2001 storm using a combination of three different…1 July, 2010 by Richard Hindmarsh, Richard Hindmarsh
Increase in ice-shelf melting is generally presumed to have triggered recent coastal ice-sheet thinning. Using a full-Stokes finite element model which includes a proper description of the grounding line dynamics,…Read more on Coupling of ice-shelf melting and buttressing is a key process in ice-sheets dynamics
25 June, 2010
We study the dynamics of dimethylsulphide (DMS) and dimethylsulphoniopropionate (DMSP) using the global ocean biogeochemistry model PlankTOM5, which includes three phytoplankton and two zooplankton functional types (PFTs). We present a…Read more on Simulating dimethylsulphide seasonality with the Dynamic Green Ocean Model PlankTOM5
2 June, 2010 by Andy Smith, Ed King, Hugh Corr
Subglacial Lake Ellsworth has been proposed as a candidate for direct measurement and sampling, to identify microbial life and extract sedimentary climate records. We present a detailed characterization of the…1 June, 2010 by Gareth Chisham, Mervyn Freeman
We present, for the first time, the probability density function (PDF) of ionospheric vorticity measurements made by the SuperDARN HF radars. We show that the PDF is typically heavy-tailed and…Read more on On the non-Gaussian nature of ionospheric vorticity
1 June, 2010 by Teal Riley
The results of lithological mapping using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for the Wright Peninsula region of Adelaide Island, Antarctic Peninsula are compared with existing geological…1 June, 2010 by Eric Wolff
It is generally accepted that variations in the precession and eccentricity of Earth's orbit, and Earth's axial tilt, influence long-term climate fluctuations; the combined variations are referred to as Milankovitch…1 May, 2010 by Andrew Clarke
1. We present a statistical analysis of the scaling of resting (basal) metabolic rate, BMR, with body mass, Bm and body temperature, Tb, in mammals. 2. Whilst the majority of…Read more on Scaling of basal metabolic rate with body mass and temperature in mammals
1 May, 2010 by Adrian Jenkins, Paul Holland
In the vicinity of the Antarctic Peninsula observations show diminishing sea ice and a rapid warming of atmosphere and ocean. These changes have led to the collapse of ice shelves…Read more on Ice and ocean processes in the Bellingshausen Sea, Antarctica
23 April, 2010 by Kevin Hughes
The Antarctic Treaty and associated agreements have little to say specifically on bioprospecting activities within the Treaty area. Consequently, Antarctic bioprospecting has elicited much debate within the Antarctic community, particularly…13 April, 2010 by Michael Meredith
The Antarctic Circumpolar Current (ACC), the world’s largest oceanic flow (∼135 million cubic meters per second), is an important component of the ocean climate, as it connects the three major…1 April, 2010
Rafting is one of the important deformation mechanisms of sea ice. This process is widespread in the north Caspian Sea, where multiple rafting produces thick sea ice features, which are…Read more on A model for the consolidation of rafted sea ice
1 April, 2010 by Mai Mai Lam, Nigel Meredith, Richard Horne, Sarah Glauert, Tracy Moffat-Griffin
Energetic electrons are deposited into the atmosphere from Earth's inner magnetosphere, resulting in the production of odd nitrogen (NOx). During polar night, NOx can be transported to low altitudes, where…Read more on Origin of energetic electron precipitation >30 keV into the atmosphere
1 April, 2010 by Mark Clilverd, Mai Mai Lam
The coupling of the Van Allen radiation belts to the Earth's atmosphere through precipitating particles is an area of intense scientific interest. Currently, there are significant uncertainties surrounding the precipitating…26 March, 2010
In 2008 the temporal focus of the Palaeoclimate Modelling Intercomparison Project was expanded to include a model intercomparison for the mid-Pliocene warm period (3.29–2.97 million years ago). This project is…16 March, 2010 by Philip Trathan
Diving animals have to counter both drag and buoyancy when moving through the water column. The magnitude of these forces depends upon an animal's swim speed and current depth. Feet,…Read more on Optimal stroke frequency during diving activity in seabirds
11 March, 2010
While Antarctica is often described as a pristine environment, there is an increasing awareness of the potential threats from local pollution sources including tourist ships and emissions associated with scientific…2 February, 2010 by David Vaughan
In recent decades, seven out of twelve ice shelves around the Antarctic Peninsula (AP) have either retreated significantly or have been almost entirely lost. At least some of these retreats…1 February, 2010 by Mark Clilverd
A type of electromagnetic phenomenon has been found in the electric VLF data measured by the low Earth orbit DEMETER satellite, which was nonidentified earlier as a different class of…Read more on An unusual VLF signature structure recorded by the DEMETER satellite
1 February, 2010 by Hugh Venables
Most of the Southern Ocean is a high-nutrient, low-chlorophyll (HNLC) area. There are exceptions to this situation downstream of some of the islands, where iron from the islands or surrounding…28 January, 2010 by Peter Ward
During the austral summer of 2008, we carried out a high resolution survey of the microplankton communities along a south to north transect covering a range of environments across the…1 January, 2010 by Richard Phillips
We investigated the concentrations of 22 essential and non-essential elements among a community of Procellariiformes (and their prey) to identify the extent to which trophic position and foraging range governed…1 January, 2010 by Amelie Kirchgaessner
This paper presents results of a combined analysis of cloud observations made at the Antarctic base Faraday/Vernadsky between 1960 and 2005 and sea ice concentration from the HadISST1 data set.…Read more on An analysis of cloud observations from Vernadsky, Antarctica
1 January, 2010 by Emily Shuckburgh
Meridional cross sections of effective diffusivity in the Southern Ocean are presented and discussed. The effective diffusivity, K-eff, characterizes the rate at which mesoscale eddies stir properties on interior isopycnal…Read more on Enhancement of mesoscale eddy stirring at steering levels in the Southern Ocean
1 January, 2010 by Claire Allen, Dominic Hodgson
Analyses of a 12 m marine sediment core from Neny Fjord, Marguerite Bay, Antarctic Peninsula (68.2571°S, 66.9617°W), yield a high-resolution record of Holocene climate variability. The sediments preserve signals of…1 January, 2010
The MarQUEST (Marine Biogeochemistry and Ecosystem Modelling Initiative in QUEST) project was established to develop improved descriptions of marine biogeochemistry, suited for the next generation of Earth system models. We…Read more on Marine ecosystem models for earth systems applications: The MarQUEST experience
1 January, 2010 by Andrew Clarke
Phytoplankton assemblages from seasonally sea-ice covered Ryder Bay (Adelaide Island, Antarctica) were studied over three austral summers (2004–2007), to link sea-ice variability and environmental conditions with algal speciation. Typical of…Read more on Seasonal progression of diatom assemblages in surface waters of Ryder Bay, Antarctica
1 January, 2010 by Hilmar Gudmundsson, Robert Arthern
As simulations of 21st-century climate start to include components with longer timescales, such as ice sheets, the initial conditions for those components will become critical to the forecast. This paper…Read more on Initialization of ice-sheet forecasts viewed as an inverse Robin problem
1 January, 2010 by Pierre Dutrieux
A complex pattern of zonal currents below the thermocline has been observed in the equatorial Pacific and Atlantic Oceans. The currents have typical speeds from 10 to 15 cm s−1…Read more on Deep equatorial ocean circulation induced by a forced- dissipated Yanai beam
1 January, 2010 by Vsevolod Afanasyev
Since 1899 ringing (or banding) remained the most important source of information about migration routes, stopover sites and wintering grounds for birds that are too small to carry satellite-based tracking…Read more on Year-round tracking of small trans-Saharan migrants using light-level geolocators
1 January, 2010 by Philip Trathan
Long-distance migration enables many organisms to take advantage of lucrative breeding and feeding opportunities during summer at high latitudes and then to move to lower, more temperate latitudes for the…1 January, 2010 by Eric Wolff
The papers in this issue originate from a symposium held in Venice in November 2008 to celebrate the official end of the European Project for Ice Coring in Antarctica (EPICA).…Read more on Climate of the last million years: new insights from EPICA and other records
1 January, 2010
Glacial terminations during the late Pleistocene epoch are associated with changes in insolation. They are also punctuated by millennial-scale climate shifts, characterized by a weakening and subsequent strengthening of the…Read more on Extreme deepening of the Atlantic overturning circulation during deglaciation
1 January, 2010 by David Barnes, Claus-Dieter Hillenbrand
Collapse of the West Antarctic Ice Sheet (WAIS) would raise global sea level by similar to 3.3-5 m. Ice-sheet models and geological data suggest at least one collapse has happened…Read more on Faunal evidence for a late quaternary trans-Antarctic Seaway
1 January, 2010 by David Barnes
Aim At the height of glaciations such as the Last Glacial Maximum (LGM), benthic life on polar continental shelves was bulldozed off nearly all of the Antarctic shelf by grounded…1 January, 2010 by David Barnes, Lloyd Peck, Simon Morley
The relevance of laboratory experiments in predicting effects of climate change has been questioned, especially in Antarctica where sea temperatures are remarkably stable. Laboratory studies of Southern Ocean marine animal…1 January, 2010 by David Barnes
More so than at any previous time, there is a heightened awareness of the amount of plastic in the environment, it's spread to even remote localities and the multiple influences…1 January, 2010 by Andrew Fleming, Eugene Murphy, Jaume Forcada
There is a need to characterise the physical environment associated with Antarctic minke whale density in order to understand long-term changes in minke whale distribution and density in open waters…1 January, 2010
This paper reviews the ways in which the palaeo record of Antarctic Ice Sheet change can be used to improve understanding of contemporary ice sheet behaviour, and thus enhance predictions…1 January, 2010 by Eric Wolff
Along the EPICA Dome C ice core, we measured concentrations of different water-soluble aerosol constituents and deduced total depositional flux records. Here we present high-resolution sodium, calcium, ammonium and nitrate…1 January, 2010 by Andy Smith, Ed King, Hamish Pritchard
This review presents a perspective on recent trends in glacial geomorphological research, which has seen an increasing engagement with investigating glaciation over larger and longer timescales facilitated by advances in…Read more on Glacial geomorphology: towards a convergence of glaciology and geomorphology
1 January, 2010 by Eric Wolff, Robert Mulvaney
The Sr and Nd isotopic composition of dust extracted from recent snow layers at the top of Berkner Island ice sheet (located within the Filchner–Ronne Ice Shelf at the southern…1 January, 2010 by Thomas Bracegirdle
Marine cold air outbreaks (MCAOs) are events where cold air flows over a relatively warm sea surface. Such outbreaks are associated with severe mesoscale weather systems that are not generally…Read more on Climatology and variability of Southern Hemisphere marine cold-air outbreaks
1 January, 2010
A survey was undertaken to determine the extent of Leratiomyces ceres (syn. Stropharia aurantiaca sensu auct.) in soil surrounding apparently isolated occurrences of fungal fruit bodies on woodchip mulch. A…1 January, 2010
[1] Microzooplankton ingest a significant fraction of primary production in the ocean and thus remineralize nutrients and stimulate regenerated primary production. We synthesized observations on microzooplankton carbon-specific grazing rate, partitioning…1 January, 2010 by Guy Hillyard, Michael Thorne, Roger Worland, Melody Clark, Peter Convey
The ability of the Antarctic microarthropod Cryptopygus antarcticus (Collembola, Isotomidae) to survive low temperatures has been well studied at the physiological level, with recent investigations indicating the importance of the…1 January, 2010
There has never been a greater need for delivering timely and policy-relevant information on the magnitude and evolution of the human-disturbed carbon cycle. In this paper, we present the main…1 January, 2010 by Peter Convey
Quantitative scaling relationships among body mass, temperature and metabolic rate of organisms are still controversial, while resolution may be further complicated through the use of different and possibly inappropriate approaches…1 January, 2010 by Iain Staniland
Predictable sources of food underpin lifetime reproductive output in long lived animals. The most important foraging areas of top marine predators are therefore likely to be related to environmental features…Read more on The influence of diet on foraging habitat models: a case study using nursing fur seals
1 January, 2010 by Richard Phillips
In birds, the period spent brooding or guarding young chicks is highly variable, but such variation has seldom been studied. Previous single-year studies of Antarctic petrels Thalassoica antarctica and grey-headed…1 January, 2010 by Andrew Clarke, Michael Meredith
Dissolved iodine speciation in surface seawater at a coastal Antarctic site has been studied over a period spanning three austral summers. The sampling site is biologically productive, with a summertime…1 January, 2010 by David Pearce, Peter Convey
In a previous study, soil bacterial diversity at environmentally distinct locations on Signy Island was examined using denaturing gradient gel electrophoresis (DGGE) profiling, and a range of chemical variables in…1 January, 2010 by Lloyd Peck, Michael Thorne, Melody Clark
Background: The Antarctic clam, Laternula elliptica, is an infaunal stenothermal bivalve mollusc with a circumpolar distribution. It plays a significant role in bentho-pelagic coupling and hence has been proposed as…1 January, 2010
Early Pliocene cheilostome bryozoans are preserved in a glacigenic diamictite at Cascade Cliffs, James Ross Island, northern Antarctic Peninsula. Several different marine bryozoan genera were incorporated into the diamictite during…Read more on Early Pliocene Weddell Sea seasonality determined by bryozoans
1 January, 2010 by Andrew Clarke, Alistair Crame
Ecologists have long been fascinated by the flora and fauna of extreme environments. Physiological studies have revealed the extent to which lifestyle is constrained by low temperature but there is…1 January, 2010 by Andrew Clarke
Endothermy has evolved at least twice, in the precursors to modern mammals and birds. The most widely accepted explanation for the evolution of endothermy has been selection for enhanced aerobic…Read more on Temperature, metabolic power and the evolution of endothermy
1 January, 2010 by Mark Clilverd
Noise burst events observed at Sodankylä, Finland, in the frequency range 20–25 kHz during January–April 2005 last up to 4 s, occur more often at midnight, are associated with high…1 January, 2010
Despite clear benefits of optimal arrival time on breeding grounds, migration schedules may vary with an individual bird's innate quality, non-breeding habitat or breeding destination. Here, we show that for…Read more on Breeding latitude drives individual schedules in a trans-hemispheric migrant bird
1 January, 2010 by Peter Convey
Although its major components have been known almost since the earliest exploring expeditions, even today the terrestrial biota of Antarctica is surprisingly poorly described in detail. It is clear that…Read more on Terrestrial biodiversity in Antarctica – recent advances and future challenges
1 January, 2010 by Peter Convey
We report the establishment of two representatives of a new ecological functional group on the sub-Antarctic island of South Georgia - pollinating insects - in the form of the hoverfly…1 January, 2010 by David Herbert
Using archival photography and satellite imagery, we have analysed the rates of advance or retreat of 103 coastal glaciers on South Georgia from the 1950s to the present. Ninety-seven percent…Read more on Glacier retreat on South Georgia and implications for the spread of rats
1 January, 2010
South Georgia is a glaciated island in the South Atlantic, which provides a primary nesting site for the albatrosses and petrels of the Southern Ocean. 60% of the island is…Read more on Estimating ice thickness in South Georgia from SRTM elevation data
1 January, 2010 by Philip Trathan, Richard Phillips
Where life-history stages overlap, there is the potential for physiological conflicts that might be important in mediating carryover effects. However, our knowledge of the specific physiological mechanisms underlying carryover effects…1 January, 2010 by Teal Riley
The island of South Georgia exposes remnants of a Late Jurassic to Early Cretaceous Andean magmatic arc and marginal basin system that was compressively deformed during the mid-Cretaceous main Andean…Read more on Andean sinistral transpression and kinematic partitioning in South Georgia
1 January, 2010
The analysis of many natural time series and especially those related to ice core records often suffers from uneven sampling intervals. For fractional Brownian motion, we show that standard estimates…1 January, 2010 by Povl Abrahamsen
This paper examines the role of atmospheric forcing in modifying the pathways of riverine water on the Laptev Sea shelf, using summer-to-winter hydrographic surveys from 2007-2009. Over the two consecutive…1 January, 2010 by Jaume Forcada
Leopard seals are regular winter visitors to Bird Island, South Georgia, where they mostly prey on fur seals and penguins, and to a lesser extent on Antarctic krill and fish.…Read more on First documentation of leopard seal predation of South Georgia pintail duck
1 January, 2010 by Janet Silk, Richard Phillips
The study of long-distance migration provides insights into the habits and performance of organisms at the limit of their physical abilities. The Arctic tern Sterna paradisaea is the epitome of…Read more on Tracking of Arctic terns Sterna paradisaea reveals longest animal migration
1 January, 2010 by Peter Convey
Coal Nunatak is an ice-free inland nunatak located on southern Alexander Island, adjacent to the west coast of the Antarctic Peninsula. Situated close to the Antarctic continent, it is characterized…Read more on Life history strategy of Lepraria borealis at an Antarctic inland site, Coal Nunatak
1 January, 2010 by Simon Morley
Ocean acidification, or the lowering of seawater pH, is caused by sequestration of atmospheric CO2 into the oceans. This study investigated the effects of present-day pH 8.0, predicted ocean surface…