Showing 11862 items
1 January, 2009
Methane (CH4) is the second most important anthropogenic greenhouse gas in the atmosphere. Rapid variations of the CH4 concentration, as frequently registered, for example during the last ice age, have…1 January, 2009 by Victoria Peck
The evolution and dynamics of the last British-Irish Ice Sheet (BIIS) have hitherto largely been reconstructed from onshore and shallow marine glacial geological and geomorphological data. This reconstruction has been…1 January, 2009 by Gareth Marshall, Howard Roscoe
The role of eddies in modulating the Southern Ocean response to the southern annular mode (SAM) is examined, using an ocean model run at multiple resolutions from coarse to eddy…1 January, 2009 by Geraint Tarling, Michael Thorne, Melody Clark
A change in photoperiod has been implicated in triggering a transition from an active to a quiescent state in Antarctic krill. We examined this process at the molecular level, to…1 January, 2009 by Mark Clilverd
Here we use the ERA-40 and ECMWF operational surface level air temperature data sets from 1957 to 2006 to examine polar temperature variations during years with different levels of geomagnetic…Read more on Geomagnetic activity and polar surface air temperature variability
1 January, 2009 by Geraint Tarling, Martin Collins, Nadine Johnston, Peter Ward
The diets of 9 species of myctophid fishes, Electrona carlsbergi, E. antarctica, Gymnoscopelus fraseri, G. nicholsi, G. braueri, Protomyctophum bolini, P. choriodon, Krefftichthys anderssoni and Nannobrachium achirus, were investigated during…Read more on Feeding ecology of myctophid fishes in the northern Scotia Sea
1 January, 2009 by Emily Shuckburgh
The Lyapunov diffusivity is used to investigate local isentropic mixing events in the upper troposphere lower stratosphere (UTLS) region. The diagnostic highlights the seasonal cycle of the longitudinally varying mixing…1 January, 2009 by Emily Shuckburgh
The robustness of Nakamura's effective diffusivity diagnostic for quantifying eddy diffusivities of tracers within a streamwise-average framework is carefully examined in an oceanographic context, and the limits of its applicability…Read more on Robustness of an effective diffusivity diagnostic in oceanic flows
1 January, 2009 by Emily Shuckburgh
A diagnostic framework is presented, based on the Nakamura effective diffusivity, to investigate the regional variation in eddy diffusivity. Comparison of three different diffusivity calculations enables the effects of locally…1 January, 2009 by Eric Wolff, Louise Sime
table isotope ratios of oxygen and hydrogen in the Antarctic ice core record have revolutionized our understanding of Pleistocene climate variations and have allowed reconstructions of Antarctic temperature over the…Read more on Evidence for warmer interglacials in East Antarctic ice cores
1 January, 2009 by Gareth Marshall, Liz Thomas, Louise Sime, Robert Mulvaney
Analysis of ERA40 temperature and accumulation data suggests that annual mean isotopic fluctuations due to temperature change will be geographically very variable across the Peninsula: isotopic variations of 0.4 parts…1 January, 2009 by Pierre Dutrieux
Ocean eddies and fronts affect surface stress via two mechanisms: (1) ocean surface currents altering the relative motion between air and sea and, hence, the stress fields and (2) ocean…1 January, 2009 by Claus-Dieter Hillenbrand
In this paper, we examine the nature of the Pliocene Antarctic Peninsula Ice Sheet by comparing the terrestrial and marine geological records of the Antarctic Peninsula and surrounding sea floor…1 January, 2009 by Andy Smith
A grid of seismic reflection lines has been used to image basal topography and infer basal conditions and flow processes beneath similar to 140 km(2) of Rutford Ice Stream, West…1 January, 2009 by Claus-Dieter Hillenbrand, James Smith
Subglacial meltwater plays a significant yet poorly understood role in the dynamics of the Antarctic ice sheets. Here we present new swath bathymetry from the western Amundsen Sea Embayment, West…1 January, 2009 by Dominic Hodgson, Kevin Newsham, Peter Convey
We quantified the metabolic cost to the Antarctic leafy liverwort Cephaloziella varians of responding to an abrupt increase in ultraviolet B (UVB) radiation exposure in the natural environment at Rothera…1 January, 2009
The products of andesite and dacite glaciovolcanism at Kerlingarfjoll are unlike others previously described in the literature. Three sequences of lithofacies are described and interpreted here. The andesitic deposits at…1 January, 2009 by Gabriele Stowasser, Martin Collins
Fatty acid biomarkers were used to investigate the feeding ecology of 17 mesopelagic fish species occurring in the Southern Ocean. Fatty acid signatures of species where little or no dietary…1 January, 2009
Ice cores provide a record of changes in dust flux to Antarctica, which is thought to reflect changes in atmospheric circulation and environmental conditions in dust source areas(1-9). Isotopic tracers…1 January, 2009 by Lloyd Peck
We identified 100 scientific questions that, if answered, would have the greatest impact on conservation practice and policy. Representatives from 21 international organizations, regional sections and working groups of the…Read more on One hundred questions of importance to the conservation of global biological diversity
1 January, 2009 by Eugene Murphy, Geraint Tarling, Jonathan Watkins, Sophie Fielding
Swarming is a fundamental part of the life of Euphausia superba, yet we still know very little about what drives the considerable variability in swarm shape, size and biomass. We…Read more on Variability and predictability of Antarctic krill swarm structure
1 January, 2009 by Geraint Tarling
The process of egg release is a complex and crucial step in the life cycle of euphausiids, especially with regards mortality and recruitment success. We examined this process in Antarctic…1 January, 2009 by Peter Convey
Research in extremely delicate environments must be sensitive to the need to minimize impacts caused simply through the presence of research personnel. This study investigates the effectiveness of current advice…1 January, 2009 by Liz Thomas, Thomas Bracegirdle
Back trajectory analysis, provided by the British Atmospheric Data Centre using meteorological parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis ERA-40 (1980-2001) and operational analysis (2002-2006), is…Read more on Improving ice core interpretation using in situ and reanalysis data
1 January, 2009 by Angelika Renner, Sally Thorpe
An array of 40 surface drifters, drogued at 15-m depth, was deployed in February 2007 to the east of the tip of the Antarctic Peninsula as part of the Antarctic…Read more on Surface circulation at the tip of the Antarctic Peninsula from drifters
1 January, 2009 by Kevin Hughes, Peter Convey
We review the scientific literature, especially from the past decade, on the impacts of human activities on the Antarctic environment. A range of impacts has been identified at a variety…Read more on Impacts of local human activities on the Antarctic environment
1 January, 2009 by Louise Sime
Stable water isotopes have been added to the full hydrological cycle of the Hadley Centre Climate model (HadCM3) coupled atmosphere-ocean GCM. Simulations of delta O-18 in precipitation and at the…1 January, 2009 by Philip Trathan
The Southern Ocean is ofren portrayed as rhe last great wilderness. However, the marine living resources of the sub-Antarctic islands haw been harvested for over two centuries. ExploitaLion began with…1 January, 2009 by Martin Collins
The sensitivity hypothesis seeks to explain the correlation between the wavelength of visual pigment absorption maxima (lambda(max)) and habitat type in fish and other marine animals in terms of the…1 January, 2009 by Andrew Orr, Gareth Marshall, John Turner, Tony Phillips
We use quality controlled in situ meteorological observations collected at Antarctic research stations over the last 60 years to carry out the first continent-wide investigation into the occurrence, variability, and…1 January, 2009 by John Turner
The two polar regions have experienced remarkably different climatic changes in recent decades. The Arctic has seen a marked reduction in sea-ice extent throughout the year, with a peak during…Read more on Contrasting climate change in the two polar regions
1 January, 2009 by Mark Clilverd
Energetic particle precipitation couples the solar wind to the Earth's atmosphere and indirectly to Earth's climate. Ionisation and dissociation increases, due to particle precipitation, create odd nitrogen (NOx) and odd…1 January, 2009 by David Pearce, Kevin Newsham
Although dark septate fungal endophytes (DSE) occur widely in association with plant roots in cold-stressed habitats, little is known of the taxonomic status of DSE in Antarctica. Here we investigate…1 January, 2009 by Kevin Newsham
Fungi with dematiaceous septate hyphae, termed dark septate endophytes (DSE), are common in plant roots, particularly in cold-stressed habitats, but their effects on their host plants remain obscure. Here, we…1 January, 2009 by Richard Horne
The physical processes affecting the dynamics of the Earth's particle radiation environment are reviewed along with scientific and engineering models developed for its description. The emphasis is on models that…Read more on Dynamics of the Earth’s particle radiation environment
1 January, 2009 by Geraint Tarling
Timing of reproduction in a seasonal cycle is a life history trait with important fitness consequences. Capital breeders produce offspring from stored resources and, by decoupling feeding and reproduction, may…Read more on The adaptive value of energy storage and capital breeding in seasonal environments
1 January, 2009
Among the many octopods collected during recent Antarctic trawling surveys were 93 specimens of an undescribed octopod with biserial suckers. Although most similar in appearance to the sub-Antarctic Benthoctopus levis…1 January, 2009 by Hugh Venables, Michael Meredith
A large phytoplankton bloom occurs downstream of South Georgia, an island on the northern edge of the Scotia Sea, Atlantic sector of the Southern Ocean. This is due to natural…1 January, 2009 by Dominic Hodgson
To date, little is known about the relative importance of dispersal related versus local factors in shaping microbial metacommunities. A common criticism regarding existing datasets is that the level of…1 January, 2009 by Richard Phillips
Colonial seabirds are relatively easy to observe, count, measure and manipulate, and consequently have long been used as models for testing ecological hypotheses. A combination of animal tracking and satellite…1 January, 2009 by Gareth Marshall, Philip Trathan, Richard Phillips
By extracting energy from the highly dynamic wind and wave fields that typify pelagic habitats, albatrosses are able to proceed almost exclusively by gliding flight. Although energetic costs of gliding…Read more on Wind field and sex constrain the flight speeds of central-place foraging albatrosses
1 January, 2009 by Povl Abrahamsen, Keith Nicholls
The intricate near-circumpolar system of fronts and currents surrounding Antarctica isolates much of Earth's freshwater from the saline oceans immediately north. The Antarctic Slope Front sustains bathymetrically steered flow at…1 January, 2009
Lévy flights and fractional Brownian motion have become exemplars of the heavy-tailed jumps and longranged memory widely seen in physics. Natural time series frequently combine both effects, and linear fractional…1 January, 2009 by Lloyd Peck
Anthropogenic emissions of carbon dioxide (CO2) from fossil fuel combustion and deforestation are rapidly increasing the atmospheric concentration of CO2 and reducing the pH of the oceans. This study shows…1 January, 2009 by David Barnes
Pockmarks are one of the most obvious and abundant structural features of the North Sea seabed, yet their influence on fauna is virtually unknown. We report the distribution of benthic…Read more on Pockmarks: refuges for marine benthic biodiversity
1 January, 2009 by David Barnes
Despite pockmarks being one of the most widespread small-scale topographic features of the seabed, almost nothing is known of their influence on fauna. Here we present the first ecological study…Read more on Benthic ecology of pockmarks in the Inner Oslofjord, Norway
1 January, 2009 by Robert Larter
Multichannel seismic reflection profiles provide a record of the glacial development in the western Amundsen Sea Embayment during the Neogene. We identified a northwest-dipping reflector series of more than 1…1 January, 2009 by Peter Ward, Sophie Fielding
The extent to which Antarctic phytoplankton stocks are controlled by 'bottom-up' and/or 'top-down' factors is highly variable. Here we consider data collected at South Georgia during 3 summer surveys that…1 January, 2009 by Rowan Whittle
The first lobopodian known from the Ordovician is described from the Soom Shale Lagerstatte, South Africa. The organism shows features homologous to Palaeozoic marine lobopodians described from the Middle Cambrian…Read more on An Ordovician lobopodian from the Soom Shale Lagerstatte, South Africa
1 January, 2009
The plume of Ice Shelf Water (ISW) flowing into the Weddell Sea over the Filchner sill contributes to the formation of Antarctic Bottom Water. The Filchner overflow is simulated using…1 January, 2009
A comprehensive set of new geochronological data from different parts of the Shackleton Range in East Antarctica, comprising U–Pb single zircon and Th–U–Pb single and multi-grain monazite data, combined with…1 January, 2009 by Eric Wolff
The change from a glacial to an interglacial climate is paced by variations in Earth’s orbit. However, the detailed sequence of events that leads to a glacial termination remains controversial.…Read more on Glacial terminations as southern warmings without northern control
1 January, 2009 by Ed King
We present 1 and 100 MHz ground-based radar data from the onset region of Rutford Ice Stream, West Antarctica, which indicate the form and internal structure of isochrones. In the…1 January, 2009
This study assesses the relation between the year-to-year variability of the semidiurnal tides (SDT) observed at high latitudes of both hemispheres and the global stratospheric stationary planetary wave (SPW) with…Read more on Asymmetry in the interhemispheric planetary wave-tide link between the two hemispheres
1 January, 2009
Antarctic ecosystems are fascinating in their limited trophic complexity, with decomposition and nutrient cycling functions being dominated by microbial activities. Not only are Antarctic habitats exposed to extreme environmental conditions,…Read more on Environmental microarray analyses of Antarctic soil microbial communities
1 January, 2009 by Michael Pinnock
Ground-based dual-frequency GPS observations can be used to create images of electron density. This is well established for the Arctic ionosphere; here one of the first results is presented for…Read more on Imaging of the Antarctic ionosphere: Experimental results
23 December, 2008 by Richard Phillips
Trawl activity on the continental shelf break off South Africa provides large quantities of food in the form of discards for a range of species, including non-breeding black-browed albatrosses Thalassarche…9 December, 2008 by Eric Wolff, Louise Sime
The many different proxy records from the European Project for Ice Coring in Antarctica (EPICA) Dome C ice core allow for the first time a comparison of nine glacial terminations…Read more on The Southern Hemisphere at glacial terminations: insights from the Dome C ice core
5 December, 2008 by Hilmar Gudmundsson
An optimal estimation method for simultaneously determining both basal slipperiness and basal topography from variations in surface flow velocity and topography along a flow line on ice streams and ice…1 December, 2008 by Martin Collins
Understanding how environmental forcing has generated and maintained large-scale patterns of biodiversity is a key goal of evolutionary research and critical to predicting the impacts of global climate change. We…1 December, 2008 by Adrian Jenkins, Povl Abrahamsen, Keith Nicholls
Limitations of access have long restricted exploration and investigation of the cavities beneath ice shelves to a small number of drillholes. Studies of sea-ice underwater morphology are limited largely to…28 November, 2008
We quantify the relative roles of natural and anthropogenic influences on the growth rate of atmospheric CO2 and the CO2 airborne fraction, considering both interdecadal trends and interannual variability. A…28 October, 2008 by Liz Thomas
One hundred early career researchers working in a range of disciplines met in Russia on 7 July for a career development workshop targeting polar researchers. The workshop was hosted by…Read more on Professional development training for early career polar researchers
21 October, 2008 by Richard Horne
Various types of plasma waves have profound effects on acceleration and scattering of radiation belt particles. For the purposes of radiation belt modeling it is necessary to know statistical distributions…1 October, 2008 by Martin Collins, Mark Belchier
Recruitment variability in juvenile Patagonian toothfish (Dissostichus eleginoides), a commercially important, deepwater nototheniid fish, was examined at the sub-Antarctic island of South Georgia, South Atlantic. Data from 13 demersal trawl…24 September, 2008 by Anna Jones, Eric Wolff
Nitrate is frequently measured in ice cores, but its interpretation remains immature. Using daily snow surface concentrations of nitrate at Halley (Antarctica) for 2004–2005, we show that sharp spikes (>factor…1 September, 2008 by Adrian Jenkins
Results are presented from an isopycnic coordinate model of ocean circulation in the Amundsen Sea, focusing on the delivery of Circumpolar Deep Water (CDW) to the inner continental shelf around…26 August, 2008 by Carlos Martin Garcia, Hilmar Gudmundsson, Richard Hindmarsh, Richard Hindmarsh
We present the results of the first ice sheet model intercomparison project for higher-order and full-Stokes ice sheet models. These models are compared and verified in a series of six…Read more on Benchmark experiments for higher-order and full-Stokes ice sheet models (ISMIP-HOM)
1 August, 2008 by Richard Phillips
Parasitism can be a major constraint on host condition and an important selective force. Theoretical and empirical evidence shows that maternal condition affects relative investment in sons and daughters; however,…Read more on Parasite treatment affects maternal investment in sons
29 July, 2008 by Anna Jones, Eric Wolff
Gas phase formaldehyde concentrations were measured during the 2004-2005 CHABLIS campaign at Halley research station, Antarctica. Data coverage span from May 2004 through to January 2005, thus capturing the majority…17 July, 2008 by Anna Jones, Eric Wolff, Howard Roscoe
CHABLIS (Chemistry of the Antarctic Boundary Layer and the Interface with Snow) was a collaborative UK research project aimed at probing the detailed chemistry of the Antarctic boundary layer and…16 July, 2008 by Hilmar Gudmundsson
New analytical solutions describing the effects of small-amplitude perturbations in boundary data on flow in the shallow-ice-stream approximation are presented. These solutions are valid for a non-linear Weertman-type sliding law…15 July, 2008 by Alexander Tate, Dominic Hodgson, Peter Fretwell, Robert Larter
A grid derived from a new compilation of marine echo-sounding data sets has allowed us to visualize and map the geomorphology of the entire continental shelf around South Georgia at…7 July, 2008
Observations of the unique chemical environment over snow and ice in recent decades, particularly in the polar regions. have stimulated increasing interest in the boundary layer processes that mediate exchanges…1 July, 2008 by Richard Horne
A survey of plasma wave observations at Jupiter obtained by the plasma wave instrument on board the Galileo spacecraft is presented. The observations indicate that chorus emissions are observed commonly…Read more on A survey of Galileo plasma wave instrument observations of Jovian whistler-mode chorus
17 June, 2008 by Eric Wolff
In situ measurements of dimethyl sulphide (DMS) and methane sulphonic acid (MSA) were made at Halley Station, Antarctica (75 degrees 35' S, 26 degrees 19' W) during February 2004-February 2005…1 June, 2008 by Claire Waluda, Geraint Tarling, Martin Collins, Nadine Johnston, Peter Enderlein
The mesopelagic fish community of the northern Scotia Sea was investigated during the austral autumn using multi-frequency acoustics, opening and closing nets and pelagic trawls fished from the surface to…Read more on Patterns in the distribution of myctophid fish in the northern Scotia Sea ecosystem
1 June, 2008 by Martin Collins
Recent trawling in the Southern Ocean has yielded individuals of a number of species of the deep sea octopod genus Thaumeledone. This paper provides the first molecular study of the…1 June, 2008
We examine ship-based observations of atmospheric O-2 and CO2 in the southern Pacific Ocean made during two voyages: in February 2003 and in April 2004. We found, for the Austral…28 May, 2008
In the upper atmosphere, greenhouse gases produce a cooling effect, instead of a warming effect. Increases in greenhouse gas concentrations are expected to induce substantial changes in the mesosphere, thermosphere,…Read more on Emerging pattern of global change in the upper atmosphere and ionosphere
13 May, 2008 by Gareth Chisham
Accurately mapping the location of ionospheric backscatter targets (density irregularities) identified by the Super Dual Auroral Radar Network (SuperDARN) HF radars can be a major problem, particularly at far ranges…1 May, 2008
The Tyrone Central Inlier is a metamorphic terrane of uncertain affinity situated outboard of the main Dalradian outcrop (south of the Fair Head–Clew Bay Line) and could represent sub-arc basement…1 April, 2008 by Andrew Orr, Gareth Marshall, John King
Summer near-surface temperatures over the northeast coast of the Antarctic Peninsula have increased by more than 2°C over the past 40 years, a temperature increase 3 times greater than that…1 April, 2008 by Martin Collins
The reproductive biology of two species of endemic Southern Ocean octopods was investigated around the sub-Antarctic islands of South Georgia and Shag Rocks. The females of both the species produce…1 April, 2008 by Adrian Jenkins
Oceanographic data are presented from the eastern Bellingshausen Sea, representing the first near-contemporaneous sampling of conditions near both the northern and southern ice fronts of George VI Ice Shelf. Circumpolar…Read more on Circulation and melting beneath George VI Ice Shelf, Antarctica
18 March, 2008
The potential impact of seawater acidification on the concentrations of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP), and the activity of the enzyme DMSP-lyase was investigated during a pelagic ecosystem CO2 enrichment…7 March, 2008
Data from a near co-located imaging Doppler interferometer (IDI) and SuperDARN radar recorded since 1996 have been analysed in a consistent manner to compare the derived mean winds and tides…5 March, 2008 by Keith Nicholls
Melt water from the floating ice shelves at the margins of the southeastern Weddell Sea makes a significant contribution to the fresh water budget of the region. In February 2005…1 March, 2008
The longevity and extent of the oceanic southern margin of Gondwana have made it the subject of intense study for more than 70 years. It was one of the cradles…Read more on The West Gondwana margin : Proterozoic to Mesozoic