Showing 11862 items
1 January, 2007
During high-speed solar wind streams, substorms occur repetitively and relativistic electron fluxes enhance significantly. It has recently been proposed that enhanced dawnside chorus waves lead to the energization of the…1 January, 2007
A two day workshop on Southern Ocean cephalopods was held in Hobart, Tasmania, Australia prior to the triennial 2006 Cephalopod International Advisory Council (CIAC) symposium. The workshop provided a second…1 January, 2007 by Adrian Jenkins
[1] Contrary to popular belief, the melting of floating ice (in the form of ice shelves, icebergs and sea ice) may have a non-zero impact on sea level. This is…1 January, 2007 by Adrian Jenkins
Introduction George VI Ice Shelf, sandwiched between the western coast of Palmer Land and the eastern coast of Alexander Island, is the largest and most studied of the west Antarctic…Read more on Circulation and melting beneath George VI Ice Shelf, Antarctica
1 January, 2007 by Joanne Johnson
We report chemical compositions of authigenic alteration minerals in subglacially erupted hyaloclastite breccias from James Ross Island, Antarctica, which provide a geochemical proxy for paleoenvironment. Analyses of zeolites (phillipsite and…Read more on Zeolite compositions as proxies for eruptive paleoenvironment
1 January, 2007 by Anna Jones
Chemical processes in the troposphere are driven by a combination of factors. Emissions from the Earth’s surface, either natural or anthropogenic, are the primary source of trace gases in the…1 January, 2007 by Eric Wolff
A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage…Read more on Orbital and millennial Antarctic climate variability over the past 800,000 years
1 January, 2007 by Roger Worland
Antioxidant enzymes (CAT, catalase; GPx, selenium nondependent glutathione peroxidase; GST, glutathione-S-transferase; GR, glutathione reductase; DHAR, dehydroascorbate reductase) were determined in the mitochondria of diapausing and non-diapausing larvae and pupae of…1 January, 2007 by David Barnes
How animals are distributed in the world's largest surface environment, the deep sea, is poorly understood. The ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) III cruise…1 January, 2007
We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids,…1 January, 2007
The Milankovitch theory of climate change proposes that glacial–interglacial cycles are driven by changes in summer insolation at high northern latitudes. The timing of climate change in the Southern Hemisphere…1 January, 2007 by Alistair Crame
The Cenomanian-Santonian biostratigraphy of the James Ross Basin, north-eastern Antarctic Peninsula is in need of comprehensive revision. This is being achieved by the systematic re-investigation of a series of key…Read more on Coniacian ammonites from James Ross Island, Antarctica
1 January, 2007 by Fausto Ferraccioli
The Antarctic magnetic anomaly map compiled marine and airborne surveys collected south of 60 degrees S through 1999 and used Magsat data to help fill in the regional gaps between…1 January, 2007
The 2 most common experimental methods used to estimate rates of juvenile growth in marine copepods are the molt rate (MR) method, and the artificial cohort (AC) method. Recently, we…1 January, 2007 by Ed King
We conducted a seismic experiment on polar firn on Adelaide Island, Antarctica. We measured the speed of compressional and shear waves at different depths in the firn by sampling waves…Read more on Use of shear waves to measure Poisson’s ratio in polar firn
1 January, 2007 by Andy Smith, Ed King
We present seismic and radar data from the onset region of Rutford Ice Stream, West Antarctica, which show the form and internal structure of a variety of bed forms beneath…1 January, 2007 by Richard Hindmarsh, Richard Hindmarsh
The largest channels on Mars are the Northwestern Slope Valleys (NSVs) of Tharsis, which have previously been interpreted as the probable erosional trace of catastrophic flooding. It is argued here…Read more on Did ice streams shape the largest channels on Mars?
1 January, 2007
The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is bound by its Article II, 3 to follow an ecosystem approach to management. This approach has been extended…Read more on Fisheries in the Southern Ocean: an ecosystem approach
1 January, 2007 by Mai Mai Lam, Nigel Meredith, Richard Horne, Sarah Glauert
We simulate the behaviour of relativistic (976 keV) electrons in the outer radiation belt (3 ≤ L ≤ 7) during the first half of the CRRES mission. We use a…1 January, 2007 by David Vaughan
For the Filchner-Ronne Ice Shelf we have compiled measurements of meteoric ice thickness from many institutions, and several different techniques (e.g. radar and seismic sounding) to produce an improved digital…1 January, 2007 by Claus-Dieter Hillenbrand, James Smith, Joanne Johnson, Robert Larter
The potential for rapid deglaciation, or collapse, of the 2–million–square–kilometer West Antarctic Ice Sheet (WAIS) in response to climate change is one of the most serious environmental threats facing mankind.…Read more on West Antarctic Ice Sheet change since the last glacial period
1 January, 2007 by David Pearce
Antarctic lakes are characterised by simplified, truncated food webs. The lakes range from freshwater to hypersaline with a continuum of physical and chemical conditions that offer a natural laboratory in…Read more on The biodiversity and ecology of Antarctic lakes: models for evolution
1 January, 2007 by Nigel Meredith
In the first part of this study of the substorm of March 12, 1991, the space-time structure of substrorm disturbance and dynamics of auroral ions were considered. This second part…1 January, 2007 by Nigel Meredith
The substorm on March 12, 1991 is studied using the data of ground-based network of magnetometers, all-sky cameras and TV recordings of aurora, and measurements of particle fluxes and magnetic…1 January, 2007
Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams…Read more on Saturation of the Southern Ocean CO2 sink due to recent climate change
1 January, 2007 by Philip Leat, Robert Larter
Protector Shoal, the northernmost and most silicic volcano of the South Sandwich arc, erupted dacite–rhyolite pumice in 1962. We report geochemical data for a new suite of samples dredged from…1 January, 2007 by Richard Hindmarsh, Richard Hindmarsh
Variations in the depth of radar-detectable englacial layers (isochrones) are commonly used to assess past variability in accumulation rates, but little is known about the effect of internal and basal…Read more on Three-dimensional flow influences on radar layer stratigraphy
1 January, 2007 by Katrin Linse
The assemblages inhabiting the continental shelf around Antarctica are known to be very patchy, in large part due to deep iceberg impacts. The present study shows that richness and abundance…1 January, 2007 by Chester Sands, Katrin Linse
The bivalve Lissarca notorcadensis is one of the most abundant species in Antarctic waters and has colonised the entire Antarctic shelf and Scotia Sea Islands. Its brooding reproduction, low dispersal…1 January, 2007
Rapid identification of yeast isolates from clinical samples is particularly important given their innately variable antifungal susceptibility profiles. We present here an analysis of the utility of PCR amplification and…1 January, 2007 by Claus-Dieter Hillenbrand, Michael Meredith
Drake Passage opening has often been viewed as a single, discrete event, possibly associated with abrupt changes in global circulation and climate at or near the Eocene-Oligocene boundary. A new…Read more on Drake Passage and Cenozoic climate: An open and shut case?
1 January, 2007 by Katrin Linse
Epimeria schiaparelli sp. nov. from the Ross Sea, Antarctica, is described in detail. The new species occurs on the shelf in 130–350 m depth. Epimeria schiaparelli can be distinguished from…1 January, 2007 by Hua Lu, Richard Horne
The relative effects of solar irradiance and geomagnetic activity on the atmospheric temperature anomalies (Ta) are examined from the monthly to interdecadal timescales. Geomagnetic Ap (Ap) signals are found primarily…Read more on Atmospheric temperature responses to solar irradiance and geomagnetic activity
1 January, 2007
Evidence suggests that C4 grasses, adapted to conditions of low CO2, high temperatures, and water-stressed environments, expanded relatively quickly, and in several geographically distinct regions, during the Late Miocene (approximately…Read more on Modelling Late Oligocene C4 grasses and climate
1 January, 2007
Three juvenile narwhals captured during August 1998 in the northeast of Svalbard, Norway, were equipped with satellite-relayed data loggers (SRDLs) that transmitted diving and swim-speed data, in addition to location,…1 January, 2007 by Povl Abrahamsen, Keith Makinson, Keith Nicholls
Introduction Over the Antarctic continental shelves, the focus of attention has been on the export of cold dense shelf waters to the world’s deep ocean and their contribution to Antarctic…Read more on Oceanographic processes near the Filchner Sill – plans for fieldwork in 2007
1 January, 2007 by Gareth Marshall
In this short communication we examine the relationship between the Southern Hemisphere Annular Mode (SAM) and Antarctic near-surface temperatures using data from Antarctic stations for 1957-2004. This near half-century period…1 January, 2007
Centennial climate variability over the last ice age exhibits clear bipolar behavior. High-resolution analyses of marine sediment cores from the Iberian margin trace a number of associated changes simultaneously. Proxies…1 January, 2007 by Sandra McInnes, Sandra McInnes
The major increase in distribution records of limno-terrestrial tardigrades over the last ten years has enabled us to reassess the global biogeography of the Tardigrada using cluster analysis, principal components…Read more on An attempt to revisit the global biogeography of limno-terrestrial Tardigrada
1 January, 2007 by Kevin Newsham
We examined the influence of elevated UV-B radiation on the extractability of carbohydrates from leaf litter of Quercus robur. Saplings were exposed to a 30% elevation above the ambient level…1 January, 2007 by Nigel Meredith, Richard Horne, Sarah Glauert
Energetic electrons (E > 100 keV) in the Earth's radiation belts undergo Doppler-shifted cyclotron resonant interactions with a variety of whistler mode waves leading to pitch angle scattering and subsequent…1 January, 2007
Decadal hindcast simulations of Arctic Ocean sea ice thickness made by a modern dynamic-thermodynamic sea ice model and forced independently by both the ERA-40 and NCEP/NCAR reanalysis data sets are…1 January, 2007 by Lloyd Peck, Simon Morley
Low temperature limits the rate of biochemical reactions and aerobic scopes of cold water ectotherms. To compensate for this limiting effect, animals living in cold environments often possess physiological or…1 January, 2007 by Mervyn Freeman
We compare the probability distributions of substorm magnetic bay magnitudes from observations and a minimal substorm model. The observed distribution was derived previously and independently using the IL index from…1 January, 2007 by Lloyd Peck, Simon Morley
Seasonal dormancy is a widespread mechanism for reducing energy expenditure during periods of low energy availability. Seasonal variation in activity and the cost of pumping water through the siphons were…1 January, 2007 by Andrew Clarke, Andrew Fleming, Eugene Murphy, Geraint Tarling, Iain Staniland, Jaume Forcada, Jonathan Watkins, Martin Collins, Michael Meredith, Nadine Johnston, Peter Enderlein, Paul Rodhouse, Philip Trathan, Peter Ward, Sally Thorpe, Simeon Hill
The Scotia Sea ecosystem is a major component of the circumpolar Southern Ocean system, where productivity and predator demand for prey are high. The eastward-flowing Antarctic Circumpolar Current (ACC) and…1 January, 2007 by Eugene Murphy, Jaume Forcada, Jonathan Watkins, Michael Meredith, Nadine Johnston, Philip Trathan, Sally Thorpe
Determining how climate fluctuations affect ocean ecosystems requires an understanding of how biological and physical processes interact across a wide range of scales. Here we examine the role of physical…Read more on Climatically driven fluctuations in Southern Ocean ecosystems
1 January, 2007 by Andy Smith
For over 2-years we have collected GPS data similar to 40 km upstream of the grounding line on Rutford Ice Stream, West Antarctica. Here we examine deviations from mean downstream…1 January, 2007 by Anje-Margriet Neutel
Understanding how complex food webs assemble through time is fundamental both for ecological theory and for the development of sustainable strategies of ecosystem conservation and restoration. The build-up of complexity…Read more on Reconciling complexity with stability in naturally assembling food webs
1 January, 2007 by Kevin Newsham
1. Predicting the effects of warming and species loss on ecosystems are two significant challenges currently facing ecologists. However, little is known of the interactive effects of these two factors.…Read more on Interactive effects of warming and species loss on model Antarctic microbial food webs
1 January, 2007 by Eugene Murphy, Philip Trathan
A recent review by Ainley et al. has suggested that recent investigations of the ecological structure and processes of the Southern Ocean have “almost exclusively taken a bottom-up, forcing-by-physical-processes approach…1 January, 2007 by Robert Larter
The Amundsen Sea continental shelf is one of the most remote areas of coastal Antarctica and was relatively unexplored until the late 1980s. Over the last two decades, increased oceanographic…1 January, 2007 by Robert Larter
[1] Marine geophysical data from the Antarctic continental shelf indicate the former presence of ice streams that drained through bathymetric troughs during the last glacial cycle. Streaming flow is recorded…Read more on Till characteristics, genesis and transport beneath Antarctic paleo-ice streams
1 January, 2007
We investigated the shielding against solar ultraviolet radiation and inducible damage, as well as the short-term response of whole animal metabolic rate in two Antarctic shallow water amphipod species. Light…1 January, 2007 by Andrew Wood, Richard Phillips
A total of 547 sightings of 291 banded wandering albatrosses Diomedea exulans and 21 sightings of 14 banded giant petrels Macronectes spp. were made from toothfish longliners operating on the…1 January, 2007 by Richard Hindmarsh, Richard Hindmarsh
The relationship between velocity field and isochrone geometry along a steady flowline of an ice sheet is examined. The method is analytical and based upon the stream function and its…1 January, 2007
The mass balance of polythermal ice masses is critically dependent on the proportion of surface-generated meltwater that subsequently refreezes in the snowpack and firn. In order to quantify this effect…1 January, 2007 by Adrian Jenkins, Paul Holland
A two-dimensional numerical model is used to simulate the dynamics of buoyant, meltwater-rich plumes flowing beneath the ice shelf occupying much of Pine Island Bay, West Antarctica. Recent studies have…Read more on Numerical modeling of ocean-ice interactions under Pine Island Bay’s ice shelf.
1 January, 2007 by David Pearce
As a result of the recent application of DNA based technology to the investigation of maritime Antarctic freshwater lakes, patterns have begun to emerge in the bacterioplankton communities that dominate…Read more on First evidence for a bipolar distribution of dominant freshwater lake bacterioplankton
1 January, 2007 by Andrew Clarke, Helen Peat, Peter Convey
Aim To establish how well the terrestrial flora of the Antarctic has been sampled, how well the flora is known, and to determine the major patterns in diversity and biogeography.…Read more on Diversity and biogeography of the Antarctic flora
1 January, 2007 by Lloyd Peck
Embryos of the large infaunal clam Laternula elliptica and the scallop Adamussium colbecki, from Antarctica, were cultured over an 18-month period. Their development rates were extremely slow, taking 240 and…1 January, 2007 by Lloyd Peck, Melody Clark, Simon Morley
Animal responses to changing environments are most commonly studied in relation to temperature change. The current paradigm for marine ectotherms is that temperature limits are set through oxygen limitation. Oxygen…1 January, 2007 by Andy Smith
A major meltwater body exists beneath a tributary of Bindschadler Ice Stream, West Antarctica, in a region where subglacial lakes have not been mapped but near where rapid vertical motion…1 January, 2007
Particle acceleration consequences from fluctuating electric ields superposed on an X-type magnetic field in collisionless solar plasma are studied. Such a system is chosen to mimic generic features of dynamic…Read more on Particle acceleration by fluctuating electric fields at a magnetic field null point
1 January, 2007
Ciliate diversity was investigated in situ in freshwater ecosystems of the maritime (South Shetland Islands, mainly Livingston Island, 63°S) and continental Antarctic (Victoria Land, 75°S), and the High Arctic (Svalbard,…1 January, 2007 by Janet Silk, Richard Phillips, Vsevolod Afanasyev
We integrated information from satellite transmitters, GPS loggers and wet/dry activity loggers to compare the at-sea behaviour of 4 sympatric albatross species by night and day: wandering Diomedea exulans, grey-headed…Read more on Foraging behaviour of four albatross species by night and day
1 January, 2007 by Janet Silk, Richard Phillips, Vsevolod Afanasyev
In the first published study of the wintering ranges and activity patterns of skuas from any colony, we combined tracking (geolocator) and stable isotope analysis in a comparison of migration…1 January, 2007 by Peter Ward, Sophie Fielding
Phytoplankton community composition has important implications for upper-ocean biogeochemistry and export production. The species composition of the phytoplankton community (diatoms, Phaeocystis antarctica) was examined around the Crozet Plateau (Southern Ocean)…1 January, 2007 by David Vaughan, Hamish Pritchard
Over the last half century, the Antarctic Peninsula (AP) has been among the most rapidly warming regions on Earth. This has led to increased summer snowmelt, loss of ice shelves,…Read more on Widespread acceleration of tidewater glaciers on the Antarctic Peninsula
1 January, 2007 by Lloyd Peck
A cause and effect understanding of thermal limitation and adaptation at various levels of biological organization is crucial in the elaboration of how the Antarctic climate has shaped the functional…Read more on Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view
1 January, 2007
CO2 emissions from fossil-fuel burning and industrial processes have been accelerating at a global scale, with their growth rate increasing from 1.1% y(-1) for 1990-1999 to >3% y(-1) for 2000-2004.…Read more on Global and regional drivers of accelerating CO2 emissions
1 January, 2007 by Anna Jones
Measurements of C2–C8 non-methane hydrocarbons (NMHCs) have been made in situ at Halley Base, Antarctica (75°35'S, 26°19'W) from February 2004 to February 2005 as part of the Chemistry of the…1 January, 2007
Management of human impacts in the Antarctic requires an effective system of monitoring to provide information about the process being managed and the effectiveness of management actions. Human impacts arise…Read more on Monitoring and management in the Antarctic – making the link between science and policy
1 January, 2007 by Mark Belchier
Larval release, hatching rhythms and moult patterns were examined in a captive population of the subantarctic lithodid, Paralomis spinosissima from the South Georgia and Shag Rocks region. Larvae hatched throughout…1 January, 2007 by Martin Collins, Mark Belchier
Chaenocephalus aceratus (Family Channicthyidae) is one of the dominant species of demersal fish living on the South Georgia shelf where it is caught in low numbers as by-catch in the…1 January, 2007 by Philip Trathan
We used Argos satellite transmitters to monitor the movement and oceanographic habitats used by rockhopper penguins Eudyptes chrysocome chrysocome during their winter dispersal from Staten Island, Argentina, for 2002 (n…1 January, 2007 by Philip Trathan
Understanding the relationship between reproductive performance and food availability requires knowledge about many different variables, including such factors as the length of incubation shifts, provisioning rates and patterns, as well…1 January, 2007 by Mark Clilverd
In this study we report on ground-based observations of short bursts of relativistic electron precipitation (REP), detected by a subionospheric propagation sensor in Sodankyla, Finland during 2005. In two similar…1 January, 2007 by Mark Clilverd
Lightning-generated whistlers lead to coupling between the troposphere, the Van Allen radiation belts and the lower-ionosphere through Whistler-induced electron precipitation (WEP). Lightning produced whistlers interact with cyclotron resonant radiation belt…1 January, 2007 by Mark Clilverd, Nigel Meredith
Large geomagnetic storms are associated with electron population changes in the outer radiation belt and the slot region, often leading to significant increases in the relativistic electron population. The increased…1 January, 2007 by Andrew Clarke, Eugene Murphy, Nadine Johnston
The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life…1 January, 2007
The Antarctic biota is highly endemic, and the diversity and abundance of taxonomic groups differ from elsewhere in the world. Such characteristics have resulted from evolution in isolation in an…Read more on Evolution and biodiversity of Antarctic organisms: a molecular perspective
1 January, 2007 by Howard Roscoe
We present results of multiple regressions of the leading mode of atmospheric variability at southern high latitudes: the Southern Annular Mode (SAM). It is regressed against indices with large interannual…Read more on Influences of ozone depletion, the solar cycle and the QBO on the Southern Annular Mode
1 January, 2007 by Robert Mulvaney
As a result of intensive field activities carried out by several nations over the past 15 years, a set of accumulation measurements for western Dronning Maud Land, Antarctica, was collected,…1 January, 2007 by Martin Miller
Geochemical—and perhaps biochemical—processes may yield tell-tale proxies in rocks and minerals on the Earth or other planetary bodies, in the form of distinctive slopes of linear fractionation arrays on the…1 January, 2007 by Andrew Wood, Richard Phillips
Although Grey-headed Albatrosses Thalassarche chrysostoma are usually regarded as biennial breeders, taking a year off following a successful breeding attempt, a small proportion of successful birds attempt to breed annually.…Read more on Breeding frequency in Grey-headed Albatrosses Thalassarche chrysostoma
1 January, 2007 by Anna Jones, Howard Roscoe
Halogens influence the oxidizing capacity of Earth's troposphere, and iodine oxides form ultrafine aerosols, which may have an impact on climate. We report year-round measurements of boundary layer iodine oxide…1 January, 2007 by Philip Trathan
It is obvious, at least qualitatively, that small animals move their locomotory apparatus faster than large animals: small insects move their wings invisibly fast, while large birds flap their wings…1 January, 2007 by Dominic Hodgson
1. Many coastal lagoons in eastern Australia have changed as a result of recent human activities. However, it is often difficult to determine the extent of change and the ecological…1 January, 2007 by Eugene Murphy, Jonathan Watkins, Peter Enderlein
Upward-looking acoustic Doppler current profilers (300 kHz) and echo sounders (125 kHz) were deployed on moorings on- and off-shelf to the northwest of South Georgia between 14 October 2002 and…1 January, 2007
1] The impact of extreme sea ice initial conditions on modelled climate is analysed for a fully coupled atmosphere ocean sea ice general circulation model, the Hadley Centre climate model…Read more on Impact of instantaneous sea ice removal in a coupled general circulation model
1 January, 2007 by Katrin Linse
The abyssal depths of the polar oceans are thought to be low in diversity compared with the shallower polar shelves and temperate and tropical deep-sea basins. Our recent study on…1 January, 2007 by Claire Waluda
Cephalopod movement occurs during all phases of the life history, with the abundance and location of cephalopod populations strongly influenced by the prevalence and scale of their movements. Environmental parameters,…Read more on Approaches to resolving cephalopod movement and migration patterns
1 January, 2007 by Mark Clilverd
In this study we combine odd nitrogen (NOx) observations from the GOMOS and POAM III instruments with a radio wave ionization index to provide a detailed description of the generation…1 January, 2007
Interferometric synthetic aperture radar data show that Devon Ice Cap (DIC), northern Canada, is drained through a network of 11 glacier systems. More than half of all ice discharge is…1 January, 2007 by Adrian Jenkins, Deb Shoosmith
Introduction This report provides an overview of a 2006 cruise to the Amundsen Sea, the oceanographic data collected, and how we intend to use these data to further our understanding…Read more on Oceanographic fieldwork in the Amundsen Sea: an overview of cruise JR141