Found 14035 items
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
1 January, 2003 by David Barnes
In just 4 decades, marine litter has become abundant in northern oceans and seas and is increasing on even remote Southern Ocean island shores. The Southern Ocean was thought to…Read more on Rafting by five phyla on man-made flotsam in the Southern Ocean
1 January, 2003 by David Barnes
On polar shores, as at lower latitude, intense battles for space ensue on boulders but the high wind, wave and ice disturbance make the colonisation race a short one in…Read more on High polar spatial competition: extreme hierarchies at extreme latitude
1 January, 2003 by Eric Wolff
[1] Interpretation of the chemical layers measured in ice cores requires knowledge of processes occurring after their deposition on the ice sheet. We present evidence for the diffusion of soluble…Read more on Evolution of chemical peak shapes in the Dome C, Antarctica, ice core
1 January, 2003
Ridges have been observed at the bonds between sintering snow grains. Images collected using the scanning electron microscope (SEM) and x-ray analysis of Antarctic snow are presented. These indicate the…1 January, 2003 by Eric Wolff
Determining the microphysical location of impurities in natural ice from the polar regions is necessary for understanding the physical properties of ice and for assuring the integrity of ice core…Read more on SEM studies of the morphology and chemistry of polar ice
1 January, 2003 by Hilmar Gudmundsson
Results from 15 years of work on glacier-bed mapping by radio-echo soundings on Finsteraar-, Lauteraar- and Unteraargletscher, Switzerland, are summarized, and a new and greatly improved map of the ice-thickness…Read more on The ice-thickness distribution of Unteraargletscher, Switzerland
1 January, 2003 by David Barnes
Extensive sponge assemblages are found in a number of habitats at Lough Hyne Marine Nature Reserve. These habitats are unusual in experiencing a range of environmental conditions, even though they…Read more on Effect of disturbance on assemblages: an example using Porifera
1 January, 2003
Halley the 50-year-old Antarctic survey station where the hole in the ozone layer was discovered, is by necessity in one of the most inhospitable parts of the earth. Its resident…1 January, 2003 by William Block
The ecophysiology of cold tolerance in many terrestrial invertebrate animals is based on water and its activity at low temperatures, affecting cell, tissue and whole organism functions. The normal body…Read more on Water or ice? – the challenge for invertebrate cold survival
1 January, 2003 by William Block
Encapsulation and dehydration techniques using alginate beads are used increasingly for the pre-treatment of various plant materials for cryopreservation to improve survival post-cryogenic storage. This study reports the effects of…1 January, 2003 by William Block
Ceratophysella sigillata (Collembola, Hypogastruridae) has a life cycle which may extend for >2 years in a temperate climate. It exists in two main morphs, a winter-active morph and a summer-dormant…1 January, 2003
Mineralogical and isotopic composition (Sr and Nd) of six dust samples, obtained from six widely spread ice-coring sites in Greenland, were analyzed in order to investigate the regional geographic variability…Read more on Regional variability of ice core dust composition and provenance in Greenland
1 January, 2003 by Eugene Murphy
We investigate systematically the effect of small-scale biological and physical processes on the generation of plankton patchiness, and on the biological production averaged over scales much larger than those of…Read more on Plankton patchiness and its effect on larger-scale productivity
1 January, 2003
The autonomous underwater vehicle (AUV) Autosub-2 was deployed on eight missions ahead of RRS James Clark Ross in the northern Weddell Sea and in the Bransfield Strait, Southern Ocean, to…1 January, 2003 by Andrew Clarke
In teleosts, the proliferation of myogenic progenitor cells is required for muscle growth and nuclear turnover. We measured the cell cycle and S-phase duration of myogenic cells in the fast…1 January, 2003 by Gareth Chisham, Mervyn Freeman
Accurately measuring the location and motion of the polar cap boundary (PCB) in the high-latitude ionosphere can be crucial for studies concerned with the dynamics of the polar cap, e.g.…1 January, 2003 by Andrew Clarke
Temperature affects everything that an organism does. Although we have an increasingly sophisticated understanding of evolutionary adaptation to temperature at the molecular level for some cellular processes, we still know…Read more on Costs and consequences of evolutionary temperature adaptation
1 January, 2003 by Andrew Clarke
This review of polar marine ecosystems covers both the Arctic and Antarctic, identifying the major threats and, where possible, predicting their possible state(s) in 2025. Although the two polar regions…Read more on Polar marine ecosystems: major threats and future change
1 January, 2003 by Mervyn Freeman
We discuss how the ideal formalism of computational mechanics can be adapted to apply to a noninfinite series of corrupted and correlated data, that is typical of most observed natural…1 January, 2003 by Mark Clilverd, Michael Rose
[1] Two independent ground-based experiments and two satellite-borne experiments are used to interpret the changes in plasmaspheric composition at the same point in space during moderate geomagnetic activity on 22…Read more on In situ and ground-based intercalibration measurements of plasma density at L = 2.5
1 January, 2003 by Mark Clilverd
[1] The longest data sets available for estimating thermospheric temperature trends are those from ground-based ionosondes, which often begin during the International Geophysical Year of 1957, close to a solar…Read more on Residual solar cycle influence on trends in ionospheric F2-layer peak height
1 January, 2003 by Mark Clilverd
We consider the likely levels of solar activity in 2100 by analysing the previous history of long-term solar and geomagnetic activity indices. We make use of superposed periods of similar…