Found 14035 items
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
1 January, 2009 by Gareth Marshall, Howard Roscoe, John Turner, Steve Colwell, Thomas Lachlan-Cope
Over the last 30 years, Antarctic mid-tropospheric temperatures in winter have increased by 0.5 K per decade, the largest regional tropospheric warming observed. Over this period, amounts of polar stratospheric…1 January, 2009 by Mai Mai Lam, Nigel Meredith, Richard Horne, Sarah Glauert
Coronal holes produce high speed solar wind streams (HSS) that subsequently interact with the slower downstream solar wind forming co-rotating interaction regions (CIRs). The CIR/HSS combination drives geomagnetic storms that…Read more on Radiation belt electron flux variability during three CIR-driven geomagnetic storms
1 January, 2009 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
The flow of ice streams, which account for most discharge from large ice sheets, is controlled by processes operating at the ice stream bed. Data from modern ice stream beds…1 January, 2009
It has long been recognized that biological activity has a large influence on biogeochemical cycles in the ocean. However, the recognition that the ecosystem composition may also be significant is…1 January, 2009 by Philip Leat, Teal Riley
New whole rock Rb-Sr and zircon U-Pb geochronological data and Sm-Nd isotopic data are presented from the central magmatic arc domain of the Antarctic Peninsula in the area of northwest…1 January, 2009
The island of South Georgia is located at the southern extreme of the South Atlantic Ocean, on the edge of the Southern Ocean that surrounds Antarctica. Intensive commercial whaling at…Read more on Molecular species identification of historical whale remains from South Georgia
1 January, 2009 by Hua Lu
This paper provides some insights on the quasi-biennial oscillation (QBO) modulated 11-year solar cycle (11-yr SC) signals in Northern Hemisphere (NH) winter temperature and zonal wind. Daily ERA-40 Reanalysis and…1 January, 2009
The Mid-Pliocene (ca 3 Myr ago) was a relatively warm period, with increased atmospheric CO2 relative to pre-industrial. It has therefore been highlighted as a possible palaeo-analogue for the future.…Read more on The Arctic cryosphere in the Mid-Pliocene and the future
1 January, 2009 by Richard Horne
High geomagnetic activity occurs continuously during high-speed solar wind streams, and fluxes of relativistic electrons observed at geosynchronous orbit enhance significantly. High-speed streams are preceded by solar wind compression regions,…1 January, 2009 by Katrin Linse
The amphipod genus Epimeria is species rich in the Southern Ocean and at present eight of its 19 species are reported with circum-Antarctic distributions. For the first time, specimens of…1 January, 2009 by Martin Collins, Mark Belchier
Ontogenetic, inter-annual and regional variations in diet were investigated for mackerel icefish, Champsocephalus gunnari, in three successive summer seasons around South Georgia. Stomach contents from 2239 C. gunnari (130-560 mm…1 January, 2009
The systematic development of reduced low-dimensional stochastic climate models from observations or comprehensive highdimensional climate models is an important topic for atmospheric low-frequency variability, climate sensitivity, and improved extended range…Read more on Normal forms for reduced stochastic climate models
1 January, 2009 by Gareth Marshall
In this study, we examine the importance of the annual and semi-annual cycles of precipitation (H-1(P) and H-2(P), respectively) across Antarctica utilizing the ERA-40 re-analysis from 1980 to 2001. A…Read more on On the annual and semi-annual cycles of precipitation across Antarctica
1 January, 2009 by Peter Fretwell
More white-chinned petrels (Procellaria aequinoctialis) are accidentally killed in fisheries than probably any other seabird in the world, but the population impact of this mortality is poorly understood, partly because…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 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 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