Showing 11332 items
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
An automated gas chromatograph with sample pre-concentration for the measurement of peroxyacetylnitrate (PAN) was constructed with a minimum detection limit below 1 pptv. This instrument was deployed at the British…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 Eric Wolff
The EPICA (European Project for Ice Coring in Antarctica) Dome C drilling in East Antarctica has now been completed to a depth of 3260 m, at only a few meters…Read more on The EDC3 chronology for the EPICA Dome C ice core
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 Eric Wolff
A chronology called EDML1 has been developed for the EPICA ice core from Dronning Maud Land (EDML). EDML1 is closely interlinked with EDC3, the new chronology for the EPICA ice…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 by Eric Wolff
A common time scale for the EPICA ice cores from Dome C (EDC) and Dronning Maud Land (EDML) has been established. Since the EDML core was not drilled on a…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
1 January, 2007 by Andy Smith, Dominic Hodgson, David Pearce, Ed King, Hugh Corr, Keith Makinson, Richard Hindmarsh, Richard Hindmarsh
Antarctic subglacial lakes have, over the past few years, been hypothesised to house unique forms of life and hold detailed sedimentary records of past climate change. Testing this hypothesis requires…1 January, 2007
The timing of West Antarctic Ice Sheet (WAIS) expansion and retreat during the last glacial cycle is crucial to evaluating the processes controlling ice sheet fluctuations. There is currently debate…1 January, 2007 by Eric Wolff, Howard Roscoe
During springtime in the polar regions, unique photochemistry converts inert halide salt ions (e.g. Br-) into reactive halogen species (e.g. Br atoms and BrO) that deplete ozone in the boundary…Read more on Halogens and their role in polar boundary-layer ozone depletion
1 January, 2007
The first measurements of peroxy (HO2+RO2) and hydroxyl (OH) radicals above the arctic snowpack were collected during the summer 2003 campaign at Summit, Greenland. The median measured number densities for…1 January, 2007 by Roger Worland
Collembola are abundant and functionally significant arthropods in sub-Antarctic terrestrial ecosystems, and their importance has increased as a consequence of the many invasive alien species that have been introduced to…1 January, 2007 by David Barnes
The response of scavengers to a feeding cue at Adelaide Island, West Antarctic Peninsula was investigated using a baited video camera system. Fourteen experimental deployments, each lasting 72 h were…1 January, 2007
Ice scouring is one of the 5 most significant natural forces acting on ecosystems, yet very few data exist linking the intensity of ice disturbance with parameters of benthic community…Read more on Ice disturbance intensity structures benthic communities in nearshore Antarctic waters
1 January, 2007 by David Barnes
Ice scour disturbance has a significant effect on the physical and biological characteristics of polar benthos. A series of grids, each consisting of 25 markers, were deployed along depth transects…1 January, 2007 by David Barnes
Ice scouring is a key structuring force acting on high latitude shallow benthic communities. Despite its importance, detailed studies of scoured communities are still rare. Here we report the ecological…1 January, 2007 by Ed King
GPS crustal velocity data from the Scotia and South Sandwich plates, transform azimuths, spreading data, and an updated earthquake slip vector catalog provide the first Scotia and South Sandwich plate…1 January, 2007 by Andy Smith, David Vaughan, Keith Makinson, Keith Nicholls
What happens beneath a glacier affects the way it flows and the landforms left behind when it retreats. Direct observations from beneath glaciers are, however, rare and the subglacial environment…1 January, 2007 by Andy Smith
Recent applications of the normal-incidence seismic reflection technique to studying subglacial conditions are summarized. Some of the important aspects of the technique are discussed, including critical acquisition parameters and particular…Read more on Subglacial bed properties from normal-incidence seismic reflection data
1 January, 2007 by Peter Fretwell
This paper contributes to knowledge of Holocene relative sea level change along the mainland Ayrshire coast and offshore Isle of Bute, SW Scotland, UK, where few such studies have previously…1 January, 2007 by Dominic Hodgson, James Smith
George VI Ice Shelf is the largest ice shelf on the west coast of the Antarctic Peninsula, covering a total area of 25 000 km2. The northern ice front of…1 January, 2007 by Dominic Hodgson, James Smith, Stephen Roberts
We use lake sediment records from an epishelf lake on Alexander Island to provide a detailed picture of the Holocene history of George VI Ice Shelf (GVI-IS). Core analyses included;…1 January, 2007 by Kevin Newsham, Peter Convey
We measured the responses of pigments and chlorophyll a fluorescence parameters of the Antarctic leafy liverwort Cephaloziella varians to snowmelt during austral spring 2005 at Rothera Point on the western…1 January, 2007 by Iain Staniland
We tested the prediction that lactating fur seals (Arctocephalus gazella) at South Georgia will take prey of greater energy density with increasing distance of foraging from the colony. The study…1 January, 2007
Recent molecular studies investigating higher-level phylogenetics of coleoid cephalopods (octopuses, squids and cuttlefishes) have produced conflicting results. A wide range of sequence alignment and analysis methods are used in cephalopod…1 January, 2007
The concept of a Barcode of Life Database (BoLD) for the Class Cephalopoda (Phylum Mollusca) was introduced at the Cephalopod International Advisory Council (CIAC) symposium in Hobart, Australia, February 2006.…Read more on A barcode of life database for the Cephalopoda? Considerations and concerns
1 January, 2007 by Nigel Meredith
Radiation belt electrons can interact with various modes of plasma wave in their drift orbits about the Earth, including whistler-mode chorus outside the plasmasphere, and both whistler-mode hiss and electromagnetic…1 January, 2007 by Nigel Meredith
Outer zone radiation belt electrons can undergo gyroresonant interaction with various magnetospheric wave modes including whistler-mode chorus outside the plasmasphere and both whistler-mode hiss and electromagnetic ion cyclotron (EMIC) waves…1 January, 2007 by Eugene Murphy, Geraint Tarling, Peter Ward, Sally Thorpe
The high concentration of adult Antarctic krill Euphausia superba Dana around South Georgia, Antarctica, is a product of immigration and not local recruitment. We investigated whether reproduction and early larval…1 January, 2007 by Geraint Tarling, Peter Ward
A stage- and age-structured model was constructed to simulate stage-abundance patterns of Rhincalanus gigas in a data set consisting of over 80 yr of net-catch observations in the Scotia Sea.…1 January, 2007 by Andrew Clarke
Stable, hydrogen-burning, M dwarf stars make up about 75% of all stars in the Galaxy. They are extremely long-lived, and because they are much smaller in mass than the Sun…Read more on A reappraisal of the habitability of planets around M dwarf stars
1 January, 2007 by Eric Wolff, Liz Thomas, Robert Mulvaney
We present a collection of high-resolution chemistry and stable isotope records from the plateau of the Greenland ice cap during the cold event 8200 yr ago. Using a composite of…1 January, 2007 by Mark Clilverd
Nighttime ionospheric D region heights and electron densities are determined from an extensive set of VLF radio phase and amplitude observations. The D region parameters are characterized by the traditional…Read more on Nighttime ionospheric D-region parameters from VLF phase and amplitude
1 January, 2007 by Nigel Meredith, Richard Horne
Energetic electrons (≥50 keV) are injected into the slot region (2 < L < 4) between the inner and outer radiation belts during the early recovery phase of geomagnetic storms.…1 January, 2007 by Eugene Murphy, Jaume Forcada, Philip Trathan
The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly…1 January, 2007 by John Turner
The Antarctic is the windiest continent on Earth, with many of the coastal research stations affected by strong katabatic winds. The strength and persistence of the near-surface winds was noted…