Found 13319 items
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
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