Found 14065 items
1 January, 2004 by Dominic Hodgson
Bacteriophaeophytin a with geranylgeraniol as the C-17(3) esterifying alcohol has been identified in a sediment from Progress Lake, east Antarctica by using atmospheric pressure chemical ionisation liquid chromatography-mass spectrometry. This…1 January, 2004 by Dominic Hodgson
High performance liquid chromatography-mass spectrometry has permitted the identification of a homologous series of novel alkylsulfide derivatives of chlorophyll a containing between one and five carbon atoms, in sediment from…1 January, 2004 by Dominic Hodgson
High performance liquid chromatography-mass spectrometry has been used to identify the cyanophyta-derived ultraviolet screening pigment scytonemin and its reduced counterpart in an Antarctic lake sediment. The formation of an artefact…1 January, 2004 by Roger Worland
Many insects in temperate regions overwinter in diapause, during which they are cold hardy. In these insects, one of the metabolic adaptations to the unfavorable environmental conditions is the synthesis…1 January, 2004 by Iain Staniland
Using Antarctic fur seals (Arctocephalus gazella (Peters, 1875)) in a feeding trial, we investigated the use of milk fatty acids to determine diet. In a regime designed to replicate an…1 January, 2004 by Iain Staniland
We investigated intra-specific and geographic variation in the behaviour of female Antarctic fur seals Arctocephalus gazella by serially sampling 11 individuals throughout their breeding season using satellite tracking, time-depth recorders…1 January, 2004
Seven previously undescribed palynomorphs, Brazilea sp. B, ?Carbaneuletes sp. A, ?Reduviasporonites sp. and Algal palynomorph spp. 1 to 4, some of which are closely similar to the spores and filaments…1 January, 2004 by Hilmar Gudmundsson
Short-term variations in horizontal and vertical surface motion were studied with high temporal resolution during the ablation season in Lauteraargletscher, Bernese Alps, Switzerland. Horizontal surface flow speed oscillated diurnally, showing…1 January, 2004 by Richard Horne
Understanding the behavior of relativistic electrons in the Earth's outer radiation belt during substorms and storms is a current challenge in magnetospheric physics. In this paper, we model energetic electron…1 January, 2004 by Kevin Hughes
Biofilms present complex assemblies of micro-organisms attached to surfaces. They are dynamic structures in which various metabolic activities and interactions between the component cells occur. When phage come in contact…1 January, 2004 by Philip Trathan
Inferring feeding activities from undulations in diving depth profiles is widespread in studies of foraging marine predators. This idea, however, has rarely been tested because of practical difficulties in obtaining…1 January, 2004 by Michael Dunn, Philip Trathan
Marine birds and mammals spend most of their lives in the open ocean far from human observation, which makes obtaining information about their foraging behaviour difficult. Here, we show, by…Read more on Penguin-mounted cameras glimpse underwater group behaviour
1 January, 2004 by Philip Trathan
Knowledge of the spatial and temporal dynamics of foraging penguins is important to our understanding of the Southern Ocean marine ecosystem. We use satellite tracking to provide the first data…Read more on Winter distribution and behaviour of gentoo penguins Pygoscelis papua at South Georgia
1 January, 2004 by Geraint Tarling, Peter Ward
A modelling approach was developed to identify the most likely composition of life-cycle phenotypes and mortality rates for Calanoides acutus found within the Scotia Sea. A stage- and age-structured model…1 January, 2004
Global estimates of sea-surface temperature (SST) distributions represent an important prescribed boundary condition for atmosphere-only general circulation models (AGCMs) which aim to Simulate the behaviour of the past climate system.…1 January, 2004 by Sally Thorpe
A particle tracking scheme that uses velocity output from an interannually varying forced run of a global ocean circulation model (Parallel Ocean Climate Model; POCM_4C) allows variability in the transport…1 January, 2004 by Jaume Forcada
Exposure to organochlorines induces retinoid deficiency in mammals; hence, retinoids are potential biomarkers of the impact of these pollutants. Appropriate target tissues to monitor retinoids in cetaceans have not been…Read more on Tissue distribution of retinoids in common dolphins Delphinus delphis
1 January, 2004 by Jaume Forcada
We determined retinoid concentrations in various body positions of the blubber of 25 common dolphins (Delphinus delphis) to study topographical variation in concentrations. Specimens were obtained from incidental catches and…1 January, 2004 by Philip Trathan
Penguin populations are potentially sensitive indicators of ecological change in Antarctic and sub-Antarctic marine ecosystems. Aerial photographic surveys provide the most robust method for estimating breeding population size, particularly for…Read more on Image analysis of color aerial photography to estimate penguin population size
1 January, 2004 by Philip Trathan
There is a unique diversity and density of land-based marine predators breeding at Bird Island, South Georgia, operating at a wide variety of spatial and temporal scales. These provide exceptional…Read more on Marine predators at South Georgia: an overview of recent bio-logging studies
1 January, 2004
A new snow-soil-vegetation-atmosphere transfer (Snow-SVAT) scheme, which simulates the accumulation and ablation of the snow cover beneath a forest canopy, is presented. The model was formulated by coupling a canopy…1 January, 2004
Observations of the atmospheric, near-surface vertical electric field component E-z have been carried out at the Russian-Antarctic station, Vostok, since 1998 under the framework of a cooperative Russian-Australian project. Only…1 January, 2004 by Roger Worland
Eretmocerus eremicus is a parasitoid wasp that is not native to Britain. It is a biological control agent of glasshouse whitefly and has recently been released under licence in Britain…1 January, 2004 by John Turner
This paper reviews our understanding of how the effects of the El Nino-southern oscillation (ENSO) might be transmitted from the tropical Pacific Ocean to the Antarctic, and examines the evidence…Read more on The El Niño-Southern Oscillation and Antarctica
1 January, 2004 by Gareth Marshall, John Turner, Steve Colwell, Thomas Lachlan-Cope
A new dataset of monthly and annual mean near-surface climate data ( temperature, surface and mean sea level pressure, and wind speed) for the Antarctic region has been created using…1 January, 2004
Organic-rich deposits, uncovered during overburden removal from mantled gypsum karst at Knocknacran opencast gypsum mine, Co. Monaghan, are the best candidate to date for a last interglacial record in Ireland.…1 January, 2004 by David Vaughan, John King
It has been an underlying assumption in many studies that near-surface layers imaged by ground-penetrating radar (GPR) can be interpreted as depositional markers or isochrones. It has been shown that…1 January, 2004 by Dominic Hodgson
Reconstructions of historical primary production, and of the algal groups and habitats that contribute to it, are fundamental in studies of climate and environmental change in both marine and freshwater…1 January, 2004 by Dominic Hodgson
Information on East Antarctic coastal environments during the Holocene is relatively sparse. This is surprising as sedimentary records from the interface between land and sea can provide chronologies of climatic…1 January, 2004 by Dominic Hodgson
The Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that…1 January, 2004 by David Barnes
The so-called 'covering behaviour' of echinoids is known to vary with habitat according to the types of covering items available, but the full extent of the role played by habitat…1 January, 2004 by Norman Ratcliffe, Richard Phillips
1. Skuas are top predators in marine ecosystems and may have detrimental effects on seabird communities they prey upon. However, predation rates are poorly understood and poorly quantified. Using a…Read more on Predation by great skuas at a large Shetland seabird colony
1 January, 2004 by Richard Phillips
It is clear that discards from commercial fisheries are a key food resource for many seabird species around the world(1-8). But predicting the response of seabird communities to changes in…Read more on Changes in fisheries discard rates and seabird communities
1 January, 2004 by Claire Waluda, Paul Rodhouse, Philip Trathan
Squid are short lived, with highly labile populations that respond rapidly to changes in environmental conditions. This makes them a good model for studying the response of recruitment processes to…1 January, 2004 by Claire Waluda, Paul Rodhouse
The distribution and abundance of the fleet targeting Jumbo flying squid (Dosidicus gigas) in the Eastern Pacific is examined during the 1999 fishery season. The commercial fishery consists of a…1 January, 2004 by Huw Griffiths, Peter Ward
An analysis of mesozooplankton community structure in the Scotia Sea was carried out, based on 123 RMT1 double oblique hauls (0-200m) taken during the CCAMLR 2000 Survey. Standardized sample data…1 January, 2004 by Jonathan Watkins
The CCAMLR 2000 Survey is the first large-scale multinational, multi-ship survey in the Southern Ocean since 1979/80. Conducted using strict method protocols and within a 32-day time frame it provides…1 January, 2004 by David Barnes
Deployment of artificial substrata is a common method of investigating early community development and recruitment, but rarely are such experiments of long enough duration to include even year time scales.…1 January, 2004 by David Barnes
Artificial substrata are an often-used tool in assessing community development; here we quantify the changing presence of functional groups of benthos with replicate, depth, site, and time in order to…Read more on Quantifying assemblage distinctness with time: an example using temperate epibenthos
1 January, 2004
The thermal histories of two subglacial rhyolite glasses from Torfajokull complex of south central Iceland have been determined from changes in the relaxation of enthalpy in the calorimetric glass transition…1 January, 2004
A monospecific population of cypridinid ostracods (Myodocopida) has been recovered from an ammonoid-bearing concretion of Namurian (Kindescoutian, R1a-b) age in the Bowland Shale Formation of Central England. These deposits represent…Read more on A Carboniferous necrophagous myodocopid ostracod from Derbyshire, England
1 January, 2004 by Dominic Hodgson
Bacteriochlorophylls c and d, recovered from two sedimentary sequences, were converted to bacteriophaeophorbide methyl esters by methanolysis and analysed by atmospheric pressure chemical ionisation liquid chromatography-multi-stage mass spectrometry (APCI LC-MSn).…1 January, 2004
Geographical information Systems (GIS) provide tools for manipulating and analysing the large thematic datasets associated with Gondwana research. We have used a customised version of Environmental Systems Research Institute's ArcGIS,…1 January, 2004 by Eric Wolff
In the clamour of predictions about future climate changes, it can be difficult to get hold of facts. However, by drilling ice cores from polar ice sheets and analysing them,…1 January, 2004 by Eric Wolff
One of our major aims as Earth systems scientists is to predict how the Earth will behave in the future, particularly in the face of changes imposed upon it as…Read more on The EPICA challenge to the Earth system modeling community
1 January, 2004
The alpine cockroach Celatoblatta quinquemaculata is common at altitudes of around 1500 m on the Rock and Pillar range of Central Otago, New Zealand where it experiences freezing conditions in…1 January, 2004 by Paul Rodhouse, Philip Trathan
Knowledge about the areas used by the foraging wandering albatross, Diomedea exulans, its prey and overlap with longline fisheries is important information not only for the conservation of this species…1 January, 2004
Two-dimensional (2-D) statistical distributions of spectral power and coherence of polar geomagnetic variations with quasi-periods about 10 min are analyzed using data from magnetometer arrays in Antarctica. Examination of the…Read more on Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica
1 January, 2004
Metapelitic rock samples from the NE Shackleton Range, Antarctica, include garnet with contrasting zonation patterns and two age spectra. Garnet porphyroblasts in K-rich kyanite-sillimanite- staurolite-garnet-muscovite-biotite schists from Lord Nunatak show…1 January, 2004 by John King, Thomas Lachlan-Cope
A regional atmospheric model, with a horizontal grid spacing (Deltax) of 14 km, is used to study the surface mass balance components ( precipitation, sublimation, and snow drift) in the…1 January, 2004 by John Turner, Steve Colwell
A 14 year integration with a regional atmospheric model has been used to determine the near-Surface climatological wind field over the Antarctic ice sheet at a horizontal grid spacing of…Read more on The near-surface wind field over the Antarctic continent
1 January, 2004
The taxonomic listing given in Lichens of Antarctica and South Georgia (Øvstedal & Lewis Smith 2001) has been updated. 17 additional taxa of lichenised fungi are described, including several nomenclatural…Read more on Additions and corrections to the lichens of Antarctica and South Georgia
1 January, 2004 by David Vaughan
In an earlier study, melt/freeze rates beneath most of the Filchner–Ronne Ice Shelf, Antarctica, were estimated using an assumption of a steady-state ice shelf applied to a velocity field derived…1 January, 2004
An interdisciplinary biostratigraphical study of Tournaisian–early Viséan sedimentary rocks from six sections in central Scotland has established the ranges of important palynomorph and ostracod taxa that can be used to…1 October, 2003
The novel use of imaging riometers to observe mesospheric gravity waves is described. Imaging riometers respond to changes in the absorption of cosmic radio noise in the ionospheric D-region which…Read more on Utilizing riometry to observe gravity waves in the sunlit mesosphere
1 August, 2003 by Richard Horne
[1] Pitch angle and energy diffusion rates for scattering by whistler-mode chorus waves are proportional to the wave magnetic field intensity and are strongly dependent on the frequency distribution of…31 July, 2003 by Gareth Chisham, Mervyn Freeman, Michael Pinnock
Using ionospheric data from the SuperDARN radar network and a DMSP satellite we obtain a comprehensive description of the spatial and temporal pattern of dayside reconnection. During a period of…1 July, 2003
There has been some debate over the years concerning the accuracy of mesospheric wind observations made using the imaging Doppler interferometer (IDI) technique. The high potential and increasing use of…Read more on Validation of imaging Doppler interferometer winds using meteor radar
1 June, 2003 by Mark Clilverd
Cold plasma mass density profiles in the plasmasphere have been determined for the geomagnetically quiet day of 19th August 2000 using the cross-phase technique applied to ground-based magnetometer data from…31 May, 2003
The temporal and spatial behaviour of the ionospheric parameters foF2 and h'F during isolated substorms are examined using data from ionospheric stations distributed across Europe and western Asia. The main…31 May, 2003 by Mai Mai Lam
We test the proposal that the Sun’s magnetic activity, communicated via the solar wind, provides a link between solar variability and the Earth’s climate in the Antarctic troposphere. The strength…1 May, 2003
Graneledone verrucosa (Verrill 1881), the type species of the genus Graneledone, is redescribed based on historical material and previously unreported specimens that have resulted from an increase in deep-sea fishing…Read more on A redescription of Graneledone verrucosa (Verrill, 1881) (Octopoda: Octopodidae)
1 May, 2003 by Richard Horne, Sarah Glauert
We present the first relativistic electron pitch-angle and momentum diffusion rates for scattering by whistler-mode waves in the low density regieme. Diffusion rates are strongly dependent on the ratio between…Read more on Resonant diffusion of radiation belt electrons by whistler-mode chorus
1 May, 2003 by Richard Horne
Resonant interactions with whistler-mode chorus waves provide an important process for electron loss and acceleration during storm times. We demonstrate that wave propagation significantly affects the electron scattering rates. We…1 May, 2003 by Martin Collins
Phylogenetic relationships among the cirrate octopods (Mollusca: Cephalopoda) were investigated using partial sequences of the 16S rRNA mitochondrial gene. The derived phylogeny supports the traditional separation of cirrate families based…30 April, 2003 by Michael Pinnock
A -190-nT negative bay in the geomagnetic X component measured at Macquarie Island (-65degreesA) showed that an ionospheric substorm occurred during 09:58 to 11:10 UT on 27 February 2000. Signatures…1 April, 2003 by Jonathan Watkins, Peter Ward
[1] The pelagic ecosystem around the island of South Georgia is subject to significant interannual variability, and changes in zooplankton community composition can be used as natural ecosystem experiments to…1 March, 2003
Mesospheric temperatures derived from spectroscopic measurements of the hydroxyl (OH) nightglow have been observed from Rothera (67.6°S, 68.1°W) and Halley (75.6°S, 26.6°W) stations in Antarctica during the 2002 austral winter…1 March, 2003
Newly acquired aeromagnetic data indicate the presence of a dike swarm that may have acted as a magma transport and feeder system from the plume impact site up to 3,500…1 March, 2003
By combining reconstruction of airmass back-trajectories from dust deposition sites in Europe and measurements of the (Nd) isotopic composition of deposited dust particles, potential sources of different Saharan dust events…Read more on Case study of a Chinese dust plume reaching the French Alps
1 January, 2003 by Peter Convey
The Antarctic Peninsula region represents our best natural laboratory to investigate how earth's major climate systems interact and how such systems respond to rapid regional warming. The scale of environmental…Read more on Antarctic Peninsula climate variability: historical and paleoenvironmental perspectives
1 January, 2003 by Hilmar Gudmundsson
A non-linear regression model describing the mass-balance distribution of the whole Vatnajokull ice cap, Iceland, for the years 1992-2000 is presented. All available data from some 40 locations over this…1 January, 2003 by Paul Rodhouse
The syntypes of the endemic Southern Ocean octopodid Pareledone polymorpha (Robson, 1930) were re-examined and measurements, counts and indices are presented. The two forms described by Robson, namely oblonga and…Read more on Adelieledone, a new genus of octopodid from the Southern Ocean
1 January, 2003
Co-located high resolution profiles of acoustic backscatter, wind vector and potential temperature are presented, measured within the stable atmospheric boundary layer over an Antarctic ice shelf. Acoustic profiles from a…1 January, 2003
The diet of black-browed albatrosses was studied at Gonzalo Island, Diego Ramirez, Chile, during the early chick-rearing periods of 2000, 2001, and 2002. Diet composition was determined by sampling chick-stomach…Read more on The diet of black-browed albatrosses at the Diego Ramirez Islands, Chile
1 January, 2003 by Kevin Hughes, Peter Convey, Rod Arnold
Over 15 months between January 1990 and March 1991, a range of physical, chemical and biological parameters was monitored regularly in fellfield soils of frost-sorted polygons at four sites on…1 January, 2003 by Robert Arthern
We describe a new approach for estimating changes in ice sheet mass. Two methods are in common use: the ice budget and geodetic methods. The first makes use of separate…Read more on Optimal estimation of changes in the mass of ice sheets
1 January, 2003
The response of rhizosphere microbial communities associated with natural populations of Deschampsia antarctica growing on Leonie Island (67degrees36'S, 68degrees21'W, Antarctic Peninsula) to UV radiation was investigated. UV radiation was controlled…1 January, 2003 by Martin Collins
The few existing measurements of deep-sea fish physiology consistently indicate reduced basal metabolism and metabolic power. A possible explanation for this is the reduction in selective pressure for burst activity…1 January, 2003 by Lloyd Peck
In vivo P-31-nuclear magnetic resonance (NMR) spectroscopy was used to measure the levels of ATP, phospho-L-arginine (PLA), and inorganic phosphate in the adductor muscle of the Antarctic scallop Adamussium colbecki…1 January, 2003
[1] The International Photolysis Frequency Measurement and Model Intercomparison (IPMMI) took place in Boulder, Colorado, from 15 to 19 June 1998, aiming to investigate the level of accuracy of photolysis…1 January, 2003 by David Barnes
Many mobile animals migrate because of the different benefits provided by different localities in time and space. For hermit crabs, such benefits include resource (shell, water, food) acquisition and gamete…Read more on Ecology of subtropical hermit crabs in SW Madagascar: short-range migrations
1 January, 2003 by David Barnes
Most organisms experience competition for resources, probably most of the time. As the structure and requirements of closely related species are generally liable to be more similar than in distantly…1 January, 2003 by David Barnes
To see the 'big pictures', it seems increasingly clear that experimental design, data collection and analyses of ecological investigation need to be at multiple scales. This causes problems with data…1 January, 2003 by David Barnes
The waters surrounding Antarctica are amongst the most isolated large areas of continental shelf, cut off for about 15 to 30 million yr by both deep water and the oceanographic…Read more on Zoobenthic biodiversity, biomass and abundance at Adelaide Island, Antarctica