Found 13679 items
1 January, 2009 by Carlos Martin Garcia, Hilmar Gudmundsson, Hamish Pritchard
We use numerical modeling with a full-system Stokes solver to elucidate the effects of nonlinear rheology and strain-induced anisotropy on ice flow at ice divides. We find that anisotropic rheology…1 January, 2009 by Carlos Martin Garcia, Richard Hindmarsh, Richard Hindmarsh
Radar layer geometry in divide areas is strongly influenced by the operation of the Raymond effect, which causes upwarping of the layers as a consequence of the nonlinear rheology of…1 January, 2009 by John Turner, Michael Meredith
This paper reviews developments in our understanding of the state of the Antarctic and Southern Ocean climate, and its relation to the global climate system over the last few millennia.…Read more on State of the Antarctic and Southern Ocean climate system
1 January, 2009
We present concurrent data on ingestion, egg production and the loss of maternal biomass in pre-spring bloom female Calanus finmarchicus incubated under conditions representative of those in situ in the…1 January, 2009
The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5(n-3) (EPA) and…1 January, 2009 by Peter Convey
Terrestrial systems in Antarctica are characterized by substantial spatial and temporal variation. However, few studies have addressed the paucity of data on metabolic responses to the unpredictable Antarctic environment, particularly…Read more on Temporal metabolic rate variation in a continental Antarctic springtail
1 January, 2009 by David Vaughan
Bathymetric charts are essential for modeling oceanic processes, yet, in remote areas, direct measurements of seafloor depth are often scarce. It is possible to augment sparse depth soundings with dense…Read more on Amundsen Sea bathymetry: The benefits of using gravity data for bathymetric prediction
1 January, 2009 by Nigel Meredith, Richard Horne, Sarah Glauert
Recent observations show that the decay rate of relativistic electrons measured at low altitudes in the slot region at L = 2 is an order of magnitude shorter than theoretical…Read more on Relativistic electron loss timescales in the slot region
1 January, 2009 by Nigel Meredith, Richard Horne
The origin of the diffuse aurora has been a source of controversy for many years. More recently, the question has taken a new significance in view of the associated changes…Read more on Survey of upper band chorus and ECH waves: implications for the diffuse aurora
1 January, 2009
The physiological condition of larval Antarctic krill was investigated during austral autumn 2004 and winter 2006 in the Lazarev Sea. The condition of larvae was quantified in both seasons by…1 January, 2009
We perform two superposed epoch analyses of the auroral evolution during substorms using the FUV instrument on the Imager for Magnetopause-to-Aurora Global Explorer ( IMAGE) spacecraft. The larger of the…1 January, 2009 by Lloyd Peck, Simon Morley
Mitochondrial volume density (Vv((mt,f))), cristae surface density (Sv((im,mt))), cristae surface area (Sv((im,f))) and citrate synthase (CS) activity were analysed as indicators of thermal acclimation in foot muscle of the limpet,…1 January, 2009 by Mervyn Freeman
Recent observations of magnetospheric dynamics driven by interaction with both high-speed solar wind streams (HSSs) and interplanetary coronal mass ejections (ICMEs) have shown periodic substonns to be common under strong…Read more on Recurrent substorm activity during the passage of a corotating interaction region
1 January, 2009 by Lloyd Peck, Simon Morley
The upper thermal limits for burrowing and survival were compared with micro-habitat temperature for anomalodesmatan clams: Laternula elliptica (Antarctica, 67A degrees S); Laternula recta, (temperate Australia, 38A degrees S) and…1 January, 2009 by Lloyd Peck, Simon Morley
Latitudinal comparisons of the Southern Ocean limpet, Nacella concinna, and clam, Laternula elliptica, acclimated to 0.0 °C, were used to assess differences in thermal response to two regimes, 0.0, 5.1…Read more on Geographical variation in thermal tolerance within Southern Ocean marine ectotherms
1 January, 2009 by Eric Wolff
We introduce an algorithm (called REDFITmc2) for spectrum estimation in the presence of timescale errors. It is based on the Lomb-Scargle periodogram for unevenly spaced time series, in combination with…Read more on Climate spectrum estimation in the presence of timescale errors
1 January, 2009 by Eric Wolff
Continental margin drill core and seismic data indicate that between 3.0 and 2.5 Ma, high-latitude climate cooling drove both the West and East Antarctic Ice Sheets towards their present expanded…1 January, 2009
Detailed sedimentological and microtextural analyses of newly-discovered late Neogene diamictites and other coarse-grained facies, mostly sandwiched between hyaloclastite of the James Ross Island Volcanic Group and Cretaceous sandstone and mudstone,…1 January, 2009 by Kevin Newsham
We review the distributions and functions of mycorrhizas and dark septate root endophytes in polar regions. Arbuscular mycorrhizas (AM) are present in the Arctic and Antarctic to 82 ºN and…Read more on Mycorrhizas and dark septate root endophytes in polar regions
1 January, 2009 by Kevin Newsham
We report a meta-analysis of data from 34 field studies into the effects of ultraviolet B (UVB) radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses…Read more on Responses of plants in polar regions to UVB exposure: a meta-analysis
1 January, 2009 by Keith Makinson, Keith Nicholls
Interactions between the Southern Ocean and the Weddell Sea ice shelves are important both to the Antarctic Ice Sheet and to the production of globally significant water masses. Here we…1 January, 2009
We present a first detailed climatological study of individual quasi-monochromatic mesospheric, shortperiod gravity-wave events observed over Antarctica. The measurements were made using an all-sky airglow imager located at Halley Station…1 January, 2009 by Emily Shuckburgh
It has been proposed that plants are capable of producing methane by a novel and unidentified biochemical pathway. Emission of methane with an apparently biological origin was recorded from both…1 January, 2009 by Robert Larter
Swath bathymetric and sub-bottom profiler data reveal a variety of submarine landforms such as gullies, slide scars, subtle shelf edge-parallel ridges and elongated depressions, and small debris flows along the…1 January, 2009 by Eric Wolff, Howard Roscoe
Frost flowers play a role in air-ice exchange in polar regions, contribute to tropospheric halogen chemistry, and affect ice core interpretation. Frost flowers were observed and collected on the Hudson…Read more on Frost flower surface area and chemistry as a function of salinity and temperature
1 January, 2009
The oceanic southern margin of Gondwana, from southern South America through South Africa, West Antarctica, New Zealand (in its pre break-up position), and Victoria Land to Eastern Australia is one…Read more on The tectonic context of the Early Palaeozoic southern margin of Gondwana
1 January, 2009 by Peter Convey
Changes in the higher plant populations of the Argentine Islands over the last four to five decades have been central to developing an understanding of the likely biological responses to…Read more on Current status of the Antarctic herb tundra formation in the central Argentine Islands
1 January, 2009 by David Pearce
To date, wherever life has been sought on Earth, it has almost always been found—from high in the stratosphere (Imshenetskii et al., 1975, 1978, 1986; Wainwright et al., 2003) to…Read more on Antarctic subglacial lake exploration: a new frontier in microbial ecology
1 January, 2009 by David Pearce, Kevin Hughes
Antarctic microbial biodiversity is the result of a balance between evolution, extinction and colonization, and so it is not possible to gain a full understanding of the microbial biodiversity of…Read more on Microorganisms in the atmosphere over Antarctica
1 January, 2009 by Ali Massey, Lloyd Peck, Melody Clark, Simon Morley
1. Climate change is affecting species distributions and will increasingly do so. However, current understanding of which individuals and species are most likely to survive and why is poor. Knowledge…1 January, 2009 by Ali Massey, Lloyd Peck, Michael Thorne, Melody Clark
Acclimation is possibly the most important criterion deciding an animal's ability to survive change. Species with poor abilities to acclimate to small environmental change are likely to be the most…Read more on Lack of acclimation in Ophionotus victoriae: brittle stars are not fish
1 January, 2009 by Richard Phillips
Information on predator and prey distributions is integral to our understanding of migratory connectivity, food web dynamics and ecosystem structure. In marine systems, although large animals that return to land…1 January, 2009 by Richard Phillips
Many pelagic seabirds are thought to regulate reproductive effort by adopting a dual foraging strategy, alternating or mixing short foraging trips over local shelf waters (maximising provisioning rates) with longer…1 January, 2009 by Hugh Venables, Sophie Fielding
The addition of iron to high- nutrient, low- chlorophyll regions induces phytoplankton blooms that take up carbon(1-3). Carbon export from the surface layer and, in particular, the ability of the…Read more on Southern Ocean deep-water carbon export enhanced by natural iron fertilization
1 January, 2009 by David Vaughan, Hamish Pritchard, Robert Arthern
Many glaciers along the margins of the Greenland and Antarctic ice sheets are accelerating and, for this reason, contribute increasingly to global sea-level rise(1-7). Globally, ice losses contribute similar to…Read more on Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets
1 January, 2009 by Claus-Dieter Hillenbrand
Sediments in the belt under the Antarctic Circumpolar Current (ACC) contain high quantities of siliceous microfossils (mainly diatoms) and very little to zero carbonate. This prevents establishment of the age…1 January, 2009 by Richard Phillips
In some seabirds sexually dimorphic in size, males and females segregate at sea or diverge in other aspects of foraging behavior. We examined factors influencing foraging strategies of Cory's Shearwater…Read more on Flight morphology and foraging behaviour of male and female Cory’s shearwaters
1 January, 2009 by Hilmar Gudmundsson
We propose a new approach to indirectly estimate basal properties of ice streams, i.e. bedrock topography and basal slipperiness, from observations of surface topography and surface velocities. We demonstrate how…1 January, 2009 by Michael Meredith, Zhaomin Wang
The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This…1 January, 2009 by Claus-Dieter Hillenbrand
Marine sediment cores from the former Larsen A Ice Shelf area reveal three lithological units deposited during ice sheet advance and retreat from the continental shelf. The uppermost Unit 1…1 January, 2009 by Angelika Renner, Sally Thorpe
We present a validation of three global z-level eddy-permitting/resolving ocean general circulation models against hydrographic observations and remote sensing sea ice data from the Weddell Sea. The Weddell Sea is…Read more on Validation of three global ocean models in the Weddell Sea
1 January, 2009 by Philip Leat, Teal Riley
Jurassic dykes of western Dronning Maud Land (Antarctica) form a minor component of the Karoo large igneous province. An extensive local dyke swarm intrudes Neoproterozoic gneisses and Jurassic syenite plutons…1 January, 2009 by Kevin Newsham
Populations of the two native Antarctic vascular plant species (Deschampsia antarctica and Colobanthus quitensis) have expanded rapidly in recent decades, yet little is known about the effects of these expansions…1 January, 2009 by Dominic Hodgson, James Smith, Stephen Roberts
Field data constraining the rate and spatial pattern of deglaciation and relative sea-level (RSL) change on the Antarctic Peninsula (AP) are relatively sparse, but are needed to improve regional ice…1 January, 2009 by Vsevolod Afanasyev
Aim To identify the wintering grounds of the threatened western European Lesser Kestrels to focus conservation efforts in those areas. Location Huelva Province, southern Spain, as breeding range, and western…Read more on Geolocators map the wintering grounds of threatened Lesser Kestrels in Africa
1 January, 2009 by Vsevolod Afanasyev
Light level geolocators, also known as GLS loggers, are electronic devices intended for tracking the location of wide-ranging animals using ambient light to estimate latitude and longitude. Miniaturized geolocators that…Read more on Effects of geolocator attachments on breeding parameters of Lesser Kestrels
1 January, 2009
The winter-spring transition is a dynamic time within the glacier system, because it marks a period of instability as the glacier undergoes a change in state from winter to summer.…1 January, 2009 by Dominic Hodgson
This study is the first published survey of diatom-environment relationships Oil sub-Antarctic Macquarie Island. Fifty-eight sites in 50 coastal and inland lakes were sampled for benthic diatoms and water chemistry.…1 January, 2009
We demonstrate that global satellite products can be used to evaluate climate model soil moisture predictions but conclusions should be drawn with care. The quality of a limited area climate…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 Andy Smith, David Vaughan, Hilmar Gudmundsson, Hamish Pritchard
Pine Island Glacier, Antarctica, has been undergoing several related changes for at least two decades; these include acceleration, thinning and grounding line retreat. During the first major ground-based study between…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 Howard Roscoe
A new climatology of stratospheric BrO profiles based on a parameterization using dynamical and chemical indicators has been developed, with the aim to apply it to the retrieval of tropospheric…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…