Found 14112 items
1 January, 2005
The method of collecting and analyzing boluses to characterize the cephalopod diet of albatrosses has been used in many diet studies. However, no study has validated this method. We compared…1 January, 2005 by John King
A non-hydrostatic numerical model, the Regional Atmospheric Modeling System (RAMS), has been used to investigate the development of katabatic jumps in Coats Land, Antarctica. In the control run with a…Read more on Numerical simulations of katabatic jumps in coats land, Antartica
1 January, 2005
The Kyffhäuser Crystalline Complex, Central Germany, forms part of the Mid-German Crystalline Rise, which is assumed to represent the Variscan collision zone between the East Avalonian terrane and the Armorican…1 December, 2004 by Mark Clilverd
In this study we consider the dependence of precipitation fluxes arising from whistler-induced radiation belt losses on the strength of the associated lightning's return stroke current. As a result of…Read more on Radiation belt electron precipitation fluxes associated with lightning
3 November, 2004 by Mark Clilverd
It has been suggested that whistler-induced electron precipitation (WEP) may be the most significant inner radiation belt loss process for some electron energy ranges. One area of uncertainty lies in…Read more on Investigating radiation belt losses though numerical modelling of precipitating fluxes
1 August, 2004 by Howard Roscoe
Following the recommendations drawn after the Commissioning Phase of the ENVISAT satellite in 2002, SCIAMACHY near real time data processors were upgraded to version 5.01 in early 2004. Before public…1 July, 2004 by Martin Collins
Recent trawling in the Southern Ocean has yielded an unusual and relatively large collection of deep-sea octopods, comprising four species in two genera. Several deep-sea genera, which are inadequately characterised,…Read more on Thaumelodone and other deep water octopodids from the Southern Ocean
14 June, 2004
An extensive variety of instruments, including Geotail, DMSP F11, SuperDARN, and IMP-8, were monitoring the dayside magnetosphere and ionosphere between 14:00 and 18:00 UT on 18 January 1999. The location…8 April, 2004 by Mark Clilverd
PMSE or Polar Mesosphere Summer Echoes are a well-known phenomenon in the summer northern polar regions, in which anomalous VHF/UHF radar echoes are returned from heights similar to85 km. Noctilucent…Read more on The impact of PMSE and NLC particles on VLF propagation
2 April, 2004 by Gareth Chisham, Mervyn Freeman
Latitudinal transitions from low to high Doppler spectral width in backscatter measured by the Super Dual Auroral Radar Network (SuperDARN) are now routinely used as proxies for the polar cap…1 April, 2004 by Mark Belchier
During January 2003 the bathymetric distribution of the cephalopod fauna of the South Georgia and Shag Rocks slope (100-900 m) was investigated using a commercial bottom trawl. Forty-four trawl stations…1 April, 2004 by Eric Wolff
High-resolution chemistry analysis and electrical measurements performed on two ice core records (European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok) spanning the last 45 kyr allow…1 January, 2004 by David Vaughan, Richard Hindmarsh, Richard Hindmarsh
Recent unexpected changes in the Antarctic Ice Sheet, including ice sheet thinning, ice shelf collapse and changes in ice velocities, along with the recent realization that as much as one…1 January, 2004
[1] We examine 22 case studies of CRRES satellite observations of substorm-enhanced whistler-mode waves. These observations were made close to the geomagnetic equator and between 0200 and 0600 MLT. The…1 January, 2004 by Vsevolod Afanasyev
The device has a sensor that periodically measures and records the ambient light level. Following retrieval of the device, the light level records are converted into latitudes and longitudes, which…1 January, 2004 by Richard Hindmarsh, Richard Hindmarsh
The late Holocene retreat of the West Antarctic ice sheet is crucial information for assessing its current dynamics. However, data from this period for parts of the ice sheet where…1 January, 2004
The diet of grey-headed albatrosses at Diego Ramirez was analysed and compared to that of the sympatric black-browed albatross. Diet composition was inferred from an analysis of prey hard parts…1 January, 2004 by Fausto Ferraccioli
A Geomagnetic Depth Sounding profile was performed across the glaciated Rennick Graben and the adjacent fault-bounded terranes of northern Victoria Land in East Antarctica. Induction arrows analysis and a 2D…1 January, 2004 by Andrew Clarke
Zooplankton growth rates are hard to measure directly, and proxy measurements are desirable to encompass the variety of species and scales of interest. The growth rate hypothesis of stoichiometric theory…1 January, 2004
Antarctic krill ( Euphausia superba) and salps ( mainly Salpa thompsoni) are major grazers in the Southern Ocean(1-4), and krill support commercial fisheries(5). Their density distributions(1,3,4,6) have been described in…Read more on Long-term decline in krill stock and increase in salps within the Southern Ocean
1 January, 2004 by Eric Wolff, Robert Mulvaney
The Antarctic Vostok ice core provided compelling evidence of the nature of climate, and of climate feedbacks, over the past 420,000 years. Marine records suggest that the amplitude of climate…Read more on Eight glacial cycles from an Antarctic ice core
1 January, 2004
The International Geophysical Year (1957–1958) was inspired by the realization that much better and more complete information was needed about the Earth and geospace to understandand manage the complete terrestrial…Read more on Moving beyond the IGY: the electronic Geophysical Year (eGY) concept
1 January, 2004 by David Barnes
Variability in interference competition was studied in benthic marine communities of the arctic and subarctic Atlantic intertidal and shallow subtidal zones. We sampled multiple square-metre quadrats at distances of 10(1).…1 January, 2004 by David Barnes
Over long periods of geological time the island rich NE Indian Ocean region has developed to be a region of high marine species richness but in the last few decades…Read more on Natural and plastic flotsam strading in the Indian Ocean
1 January, 2004 by David Barnes
Finding evidence for climate change in the sea has been less easy than on land. As ice-loading of nearshore waters (through ice sheet collapses) seems a most likely signal of…Read more on Scale-dependent variation in competitive ability among encrusting Arctic species
1 January, 2004 by David Barnes
There is much concern about the potential for invasive species to enter the only marine region left with no known exotics - the Southern Ocean. Attention has focused on planktonic…1 January, 2004 by Eric Wolff
Understanding the microstructure of ice underpins the interpretation of ice-core measurements and many ice-sheet properties. A detailed study of polar snow and ice using scanning electron microscope (SEM) and X-ray…Read more on Distribution of soluble impurities in cold glacial ice
1 January, 2004 by Philip Trathan, Sally Thorpe
In January and February 2000, four ships conducted an extensive hydrographic survey of the Scotia Sea as part of the CCAMLR 2000 Survey. There were 169 CTD stations to at…1 January, 2004 by Roger Worland
A species of the fungus Neozygites (Zygomycetes: Entomophthorales) is recorded from the Antarctic mite Alaskozetes antarcticus (Acarina: Oribatidales) collected off the west coast of the Antarctic peninsula. The features of…Read more on First report of an entomophthoralean fungus on an arthropod host in Antarctica
1 January, 2004
We surveyed Antarctic krill (Euphausia superba) under sea ice using the autonomous underwater vehicle Autosub-2. Krill were concentrated within a band under ice between 1 and 13 kilometers south of…1 January, 2004 by David Barnes, Lloyd Peck
Ice is a major structuring force in marine and freshwater environments at high latitudes. Although recovery from scouring has been quantified in time, the frequency of scouring in the Antarctic…1 January, 2004
Global rates and patterns of fecundity in marine epipelagic copepods were studied as a function of temperature, body weight of the female and concentration of chlorophyll a. We divided data…1 January, 2004
A recent taxonomic revision of wandering albatross elevated each of the four subspecies to species. We used mitochondrial DNA and nine microsatellite markers to study the phylogenetic relationships of three…Read more on Global population structure and taxonomy of the wandering albatross species complex
1 January, 2004 by Geraint Tarling
Net and acoustic studies of diel vertical migration (DVM) in krill often show a degree of dispersion around the mean population depth, which becomes greater during night-time. Trade-off models can…1 January, 2004 by Melody Clark
Two principal groups of receptors orthologous with human PAC(1)R and VPAC(1)R and were identified and characterised at the genomic level in the teleost fish Fugu rubripes. An additional group orthologous…1 January, 2004 by Richard Phillips
A Gray-headed Albatross (Thalassarche chrysostoma) was recorded traveling, in the course of a foraging trip, at a minimum average ground speed of >110 km h(-1) for similar to9 h with…1 January, 2004 by Janet Silk, Richard Phillips
We identified a range of foraging strategies adopted by grey-headed albatrosses Thalassarche chrysostoma rearing chicks at Bird Island, South Georgia, by simultaneously using satellite telemetry, wet/dry activity recorders and stomach…1 January, 2004 by Lloyd Peck
Oxygen availability limits the maximum potential size attainable in benthic gammaridean amphipods from the suborder to the generic level, while also influencing size within species. In this paper we investigate…1 January, 2004
Plasma transport and energy dissipation in the driven dynamic magnetosphere are intermittent (bursty), and occur on a range of spatiotemporal scales. System observables such as geomagnetic indices, and auroral images,…Read more on Robustness and scaling: key observables in the complex dynamic magnetosphere
1 January, 2004 by Gareth Chisham, Mervyn Freeman
The boundary between quasi-dipolar (closed) geomagnetic field lines and those connected to the interplanetary magnetic field (open) is a key diagnostic for the magnetospheric system. This study presents an HF…1 January, 2004 by Gareth Chisham, Mervyn Freeman, Michael Pinnock
This study presents, for the first time, detailed spatiotemporal measurements of the reconnection electric field in the Northern Hemisphere ionosphere during an extended interval of northward interplanetary magnetic field. Global…1 January, 2004 by Mark Clilverd
Polar mesospheric clouds (PMC) were observed by an Fe Boltzmann temperature lidar at Rothera (67.5degreesS, 68.0degreesW), Antarctica in the austral summer of 2002-2003.The Rothera PMC are much weaker, less frequent,…1 January, 2004
The trans-Antarctic search-coil magnetometer network has been used to study a possible coupling between the nighttime substorm activity and the behavior of ULF pulsations in the dayside cusp and nightside…Read more on Coupling between substorms and ULF disturbances at polar latitudes
1 January, 2004 by Andrew Clarke, Lloyd Peck, Melody Clark, Peter Convey
With the development of genomic science and its battery of technologies, polar biology stands on the threshold of a revolution, one that will enable the investigation of important questions of…1 January, 2004 by Andrew Clarke
In a challenging and provocative paper Gillooly et al. (2001) have proposed that the metabolism of all organisms can be described by a single equation, * Q = b0M3/4e−E/kT, where…Read more on Is there a Universal Temperature Dependence of metabolism?
1 January, 2004 by Andrew Clarke, Alistair Crame
The modern benthic fauna of the Antarctic continental shelf is characterized by the lack of active, skeleton-breaking (durophagous) predators such as crabs, lobsters and many fish, and the dominance in…Read more on Evolution and diversity of the benthic fauna of the Southern Ocean continental shelf
1 January, 2004 by Andrew Clarke
Annual shell growth was determined by mark and recapture in the limpet Nacella concinna (Strebel 1908) at two contrasting sites in Antarctica. At Signy Island, 60degreesS, growth was moderately fast,…Read more on Growth in the limpet Nacella concinna from contrasting sites in Antarctica
1 January, 2004
Impact-shocked gneiss shocked to greater than 10 GPa in the Haughton impact structure in the Canadian High Arctic has an approximately 25-times greater pore surface area than unshocked rocks. These…1 January, 2004
The increasing robotic exploration of Mars and eventual human exploration and settlement of that planet threatens to have a significant environmental impact on scientifically important sites and sites of natural…1 January, 2004
Over the last forty years, the circle of organisms thought worthy of inclusion within an ethical framework has expanded markedly, in large part in response to Aldo Leopold's 'land ethic'.…1 January, 2004
In this paper I explore potential relationships between humans and Martian polar ices. Martian ices contain within them multimillion year histories of atmospheric, geological and maybe even biological processes. Polar…1 January, 2004
During the spring, when ozone depletion at the polar regions is at its maximum and consequently the environmental UV exposure is potentially high, many terrestrial communities are covered in snow…1 January, 2004
Ultraviolet radiation is more damaging on the surface of Mars than on Earth because of the lack of an ozone shield. We investigated micro-habitats in which UV radiation could be…Read more on Zones of photosynthetic potential on Mars and the early Earth
1 January, 2004
High-latitude polar deserts are among the most extreme environments on Earth. Here we describe a large and previously unappreciated habitat for photosynthetic life under opaque rocks in the Arctic and…1 January, 2004 by Martin Collins
A new species and genus of cirrate octopod, Cryptoteuthis brevibracchiata, is described from a single specimen captured at 2274-2300 m in the Porcupine Seabight, northeastern Atlantic. The species possesses characteristics…1 January, 2004
The standard way in which the sea-ice dynamics equation is used in models assumes that the wind stress and ocean drag do not depend on the sea-ice concentration. It is…Read more on On the consistent scaling of terms in the sea-ice dynamics equation
1 January, 2004 by Alistair Crame
This 436-page book was developed in association with the International Biogeography Society and concentrates explicitly on the fundamental change in historical biogeography, island biogeography and marine biogeography that occurred between…Read more on Pattern and process in marine biogeography: a view from the poles
1 January, 2004 by Alistair Crame
Application of a strontium isotope stratigaphy to the Late Cretaceous sedimentary succession of Antarctica has provided the impetus for a comprehensive strati-graphical revision of the terminal Maastrichtian Stage. Both the…1 January, 2004
The marine resources of the Antarctic region are of global significance. In managing Southern Ocean marine resources, especially fisheries, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR)…Read more on Management of Southern Ocean fisheries: global forces and future sustainability
1 January, 2004
High-resolution surface fluxes over the global ocean are needed to evaluate coupled atmosphere–ocean models and weather forecasting models, provide surface forcing for ocean models, understand the regional and temporal variations…1 January, 2004
During end-Neoproterozoic to early Paleozoic time, the southern margin of Gondwana was affected by widespread subduction-related orogenesis. In East Antarctica this event is known as the Ross orogeny, whose manifestation…1 January, 2004 by Geraint Tarling
Adaptive strategies of two fjord populations of Northern krill (Meganyctiphanes norvegica Sars) were studied and compared with other populations from different climatic and oceanic conditions. The Gullmarsfjord (West Sweden) and…1 January, 2004
It is unknown how pelagic marine protists undergo diversification and speciation. Superficially, the open ocean appears homogeneous, with few clear barriers to gene flow, allowing extensive, even global, dispersal. Yet,…1 January, 2004 by David Barnes
The link between movement and migration of organisms to patterns of biodiversity may be an important mechanism of biodiversity maintenance at local scales. but is regularly underestimated in marine studies.…1 January, 2004 by David Barnes
Small-scale patterns of low-, mid- and high-shore intertidal species density, richness and abundance were systematically examined to assess the potential influence of 'mobility' on spatial community dynamics and diversity. Mobile…Read more on Quantifying spatial patterns of intertidal biodiversity: is movement important?
1 January, 2004 by Simon Morley
The diet of the seven star flying squid, Martiala hyadesi, from the South Georgia sector of the Scotia Sea was described front stomach contents collected in winter (June) 2001. Diet…1 January, 2004
Continental-slope and shelf-edge morphology off Marguerite Bay, western Antarctic Peninsula, is investigated using swath-bathymetric data and parametric sub-bottom profiler records, together with sediment cores. Marguerite Bay has a well-defined cross-shelf…1 January, 2004
Fast-flowing ice streams and outlet glaciers currently account for as much as 90% of the discharge from the Antarctic and Greenland Ice Sheets. Although the deformation of subglacial material has…Read more on Thickness and extent of the subglacial till layer beneath an Antarctic paleo-ice stream
1 January, 2004
An unprecedented major stratospheric warming occurred in the Antarctic winter of 2002. We present measurements of winds in the mesosphere-lower thermosphere (MLT) made with MF radars located at Davis (69degreesS,…1 January, 2004 by Robert Larter
An animated reconstruction shows South Pacific plate kinematics between 90 and 45 Ma, using the satellite-derived gravity anomaly field, interpolated isochrons and plate rotation parameters from both published and new…1 January, 2004 by Robert Larter
The onset of independent Bellingshausen plate movement in the South Pacific is estimated at just after chron C33o. This event closely follows a change in the offset sense on the…1 January, 2004
The role of Antarctic epilithic lichens in the primary colonization of rocks and in the formation of soils is receiving attention because of the production of the stress-protective biochemicals needed…1 January, 2004
FT-Raman spectra were obtained for two Antarctic extremophiles, the epilithic lichens Xanthoria elegans and Caloplaca sublobulata from the maritime ecological long-term research site on Leonie Island. Twelve specimens from cloches…1 January, 2004
Detailed FT-Raman spectra of Antarctic cryptoendolithic colonies in Beacon sandstone have revealed some novel information about the biogeological modification process involving iron(III) mobilization by the organism. The previously unreported but…Read more on Biological modification of haematite in Antarctic cryptoendolithic communities
1 January, 2004
The FT-Raman spectra are described of green and red snow algae, Chlamydomona, involved in the colonization of exposed surfaces of the McLeod Glacier, Jane Col, Signy Island, situated at the…1 January, 2004
The Cassini RADAR instrument is a multimode 13.8 GHz multiple-beam sensor that can operate as a synthetic-aperture radar (SAR) imager, altimeter, scatterometer, and radiometer. The principal objective of the RADAR…1 January, 2004
We describe how the exploration of the Martian environment would be considerably enhanced through the use of Raman spectroscopy. Furthermore, Raman spectroscopy is particularly suited for both mineralogical analysis of…Read more on The role of Raman spectroscopy as an astrobiological tool in the exploration of Mars
1 January, 2004
We have analyzed ELF-VLF receiver and search coil magnetometer data from five Antarctic stations from 1998 and 1999 to study quasiperiodic emissions (QPs) and periodic emissions (PEs), which occur as…1 January, 2004
Airglow imager and dynasonde/imaging Doppler interferometer (IDI) radar wind measurements at Halley Station, Antarctica (75.6degreesS, 26.6degreesW) have been used to estimate the seasonal variation of the vertical fluxes of horizontal…1 January, 2004
Airglow imager and dynasonde/IDI radar wind measurements at Halley Station, Antarctica (76degreesS, 27degreesW) have been used to estimate the diurnal variation of the vertical fluxes of horizontal momentum carried by…Read more on Tidal modulation of the gravity-wave momentum flux in the Antarctic mesosphere
1 January, 2004 by Andrew Fleming
We compared both SeaWiFS (Sea-viewing Wide Field-of-View Sensor) and MODIS (Moderate-resolution Imaging Spectroradiometer) chlorophyll-a (chl-a) measurements with simultaneous ship based data obtained during a 2003 British Antarctic Survey (BAS) research…1 January, 2004 by Jaume Forcada
Line-transect estimators were developed to assess abundance of coastal dolphins Tursiops truncatus and Stenella coeruleoalba encountered in low densities during aerial sighting surveys. The analysis improved on conventional approaches by…1 January, 2004 by Andrew Clarke, Lloyd Peck
Seasonal changes in protein and nitrogen metabolism have not previously been reported in any Antarctic suspension-feeding species that ceases feeding for extended periods in winter. To provide comparison with data…1 January, 2004 by Gareth Chisham, Mervyn Freeman
The Doppler spectral width of backscatter from the SuperDARN HF radars has been routinely used to identify the ionospheric cusp. The probability distribution of spectral width values has been described…1 January, 2004 by Mervyn Freeman, Simon Morley
A minimal model for the evolution of the global dynamical state of the magnetotail during the substorm has been developed, involving only three simple rules and one free parameter D-the…1 January, 2004 by Richard Phillips
We have developed a new GPS data logger consisting of a receiver, timer, memory, and battery. It is principally designed for long period tracking of migratory birds. It can fix…1 January, 2004 by Claus-Dieter Hillenbrand
Two sediment cores from the deep-sea Murray Canyons area, south of Kangaroo Island, Australia were investigated for quantity and composition of terrigenous material. Spanning the last 175 ka, terrigenous matter…