Showing 9286 items
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
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
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 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 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
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 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 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…1 January, 2004
In most seabird species incubation shifts shorten when hatching approaches, a behavioural response allowing the chick to be fed soon after hatching. Three mechanisms have been proposed to explain these…1 January, 2004
Northern giant petrels (Macronectes halli) are among the largest and most sexually size dimorphic species of seabirds, with females being only 80% the mass of males. Both sexes scavenge on…Read more on Sexual size dimorphism in northern giant petrels: ecological correlates and scaling
1 January, 2004 by Lloyd Peck
Spermatogenesis, oogenesis and fecundity are described and the gonad index calculated for 10 individuals from each month using histological and image analysis techniques for the Antarctic brittle star Ophionotus victoriae…1 January, 2004
The metabolic rate of moulting macaroni penguins Eudyptes chrysolophus was investigated using three techniques in order to test two hypotheses concerning the energetic cost of the moult fast in penguins.…Read more on Energetics of the moult fast in female macaroni penguins Eudyptes chrysolophus
1 January, 2004
We tested the hypothesis that implanted data loggers have no effect on the survival, breeding success and behaviour of macaroni penguins Eudyptes chrysolophus . Seventy penguins were implanted with heart…Read more on Effects of long-term implanted data loggers on macaroni penguins Eudyptes chrysolophus
1 January, 2004
Shortening of telomeres, specific nucleotide repeats that cap eukaryotic chromosomes, is thought to play an important role in cellular and organismal senescence. We examined telomere dynamics in two long-lived seabirds,…Read more on Telomere loss in relation to age and early environment in long-lived birds
1 January, 2004 by Alistair Crame
Fragments of large, bilamellar aspidostomatid bryozoan colonies occur in Early Miocene glaciomarine sedimentary sequences of the Cape Melville Formation, King George Island, South Shetland Islands, West Antarctica. Investigation of the…1 January, 2004
15 years of weekly Antarctic ice extent and 10 m winds from numerical meteorological reanalyses have been used to test the hypothesis that the Antarctic final winter ice extent (FWE)…1 January, 2004
During some El Nino events Rossby wave trains (RWT) are observed to strongly modulate the seasonal atmospheric circulation of the South Pacific extratropics in the austral winter and spring. Here…1 January, 2004 by Roger Worland, Peter Convey
Population densities of the Collembola Cryptopygus antarcticus and Friesea grisea were compared in two maritime Antarctic habitats with different moisture availability. C. antarcticus was absent from the drier rock platform…1 January, 2004
The relative role of the atmosphere, oceans and cryosphere in contributing towards middle Pliocene warmth (ca 3 Ma BP) is investigated using the HadCM3 coupled ocean-atmosphere general circulation model. The…Read more on Modelling Pliocene warmth: contribution of atmosphere, oceans and cryosphere
1 January, 2004
This paper describes the results from a new palaeoclimate modelling exercise for the Early Cretaceous (Barremian) focussed on the Weald (SE England), using a Limited Area Numerical Climate Model (LAM).…Read more on Cretaceous (Wealden) climates: a modelling perspective
1 January, 2004 by Robert Larter
The analysis of the morphology and stratigraphy of the Antarctic Peninsula Pacific margin offshore from Adelaide Island shows 3 main evolutionary intervals, from the Late Miocene to the recent which…1 January, 2004 by Robert Larter
A Fossil Mounded Sedimentary Body (MB) has been identified in the Miocene sedimentary record on the central continental rise west of Adelaide Island, Antarctic Peninsula, using multichannel seismic reflection profiles.…1 January, 2004 by Jonathan Watkins, Philip Trathan
Following an assessment of Antarctic krill (Euphausia superba) in the Scotia Sea, CCAMLR established a precautionary catch limit of 4 million tonnes and further adopted 15 small-scale management units (SSMUs).…1 January, 2004 by Jonathan Watkins, Philip Trathan
In January and February 2000, a collaborative survey designed to assess the biomass of Antarctic krill across the Scotia Sea was conducted aboard research vessels from Japan, Russia, the UK…1 January, 2004 by Richard Hindmarsh, Richard Hindmarsh
A computational analysis of the accuracy of different approximations to the Stokes equations for momentum balance used in ice sheet modeling is performed by solving a particular tractable form of…1 January, 2004 by Richard Hindmarsh, Richard Hindmarsh
The shallow-ice approximation is used to analyse the normal-mode stability of long-wavelength, thermally coupled, free-surface flows of glaciers and ice sheets along infinite flow sections. The viscosity of the ice…1 January, 2004 by Dominic Hodgson
To compile reference data for palaeolimnological studies using fossil pigments, we examined the extent to which environmental variables, gross morphology and species composition influence the modern pigment content of in…1 January, 2004
Recent genetic studies of natural populations have shown that heterozygosity and other genetic estimates of parental relatedness correlate with a wide variety of fitness traits, from juvenile survival and parasite…1 January, 2004 by Eugene Murphy
Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC)…Read more on Advection, krill, and Antarctic marine ecosystems
1 January, 2004 by Robert Mulvaney
This paper presents an overview of firn accumulation in Dronning Maud Land (DML), Antarctica, over the past 1000 years. It is based on a chronology established with dated volcanogenic horizons…1 January, 2004
Chlorophyll-a (Chl-a) concentrations in surface waters were measured at 137 hydrographic stations occupied by four research vessels participating in the CCAMLR 2000 Survey and the values were compared to estimates…1 January, 2004
During January and February 2000 four research vessels, from Russia, the UK, Japan, and the United States, conducted an oceanographic survey with 137 hydrographic stations within the Scotia Sea and…1 January, 2004
Zoroaster fulgens is a slope-dwelling seastar species that is distributed throughout the Atlantic Ocean. Studies into the population structure and systematics of marine animals have increasingly found that species with…