Showing 11923 items
1 January, 2000
The ionosphere provides an excellent window on magnetospheric and solar wind processes. Often discrete magnetospheric boundaries are imaged in the ionosphere. These boundaries can be detected by a variety of…Read more on Ground-based imaging of magnetospheric boundaries
1 January, 2000
Fifty years ago the processes responsible for the formation of the ionospheric layers were well established, Appleton, Bartels and Chapman having been in the vanguard of the exploration phase of…Read more on Ionospheric research 50 years ago, today and tomorrow
1 January, 2000 by Michael Pinnock
Reconnection at the dayside magnetopause is the principal method by which energy is transferred from the solar wind into the magnetosphere-ionosphere system. There is still considerable uncertainty as to whether…Read more on Some comments on transient and steady-state reconnection at the dayside magnetopause
1 January, 2000 by Mark Clilverd
Magnetospheric line radiation (MLR) events are relatively narrowband VLF signals (∼30 Hz) that sometimes drift in frequency and that have been observed in both ground-based and satellite data sets. We…1 January, 2000 by Mark Clilverd
Magnetospheric line radiation (MLR) events are relatively narrowband VLF signals that sometimes drift in frequency and have been observed in both ground-based and satellite data sets. We present the results…Read more on Temporal properties of magnetospheric line radiation
1 January, 2000 by David Maxfield, Mark Clilverd, Michael Rose
In January 1998 an imaging riometer system was deployed at Halley, Antarctica (76°S, 27°W), involving the construction of an array of 64 crossed-dipole antennas and a ground plane. Weather conditions…Read more on The effect of snow accumulation on imaging riometer performance
1 January, 2000 by Eric Wolff, Robert Mulvaney
In order to estimate past changes in atmospheric NOx concentration, nitrate, an oxidation product of NOx, has often been measured in polar ice cores. In the frame of the European…Read more on Factors controlling nitrate in ice cores: Evidence from the Dome C deep ice core
1 January, 2000 by Lloyd Peck
Phagocytosis was studied in vitro using coelomic fluid of the Antarctic starfish Odontaster validus at 0°C. The number of coelomocytes present was determined and the phagocytic activity of the phagocytic…1 January, 2000
Dynamic provenance variations are deduced from sand-grain detrital modes in samples obtained from the CRP-2/2A drillcore. Below an important unconformity at 307 metres below sea floor (mbsf), sand grains in…1 January, 2000
An account is given of the unpublished work of Ivan Mackenzie Lamb, who spent almost 35 years working on the taxonomy and ecology of Antarctic lichens. Much of his meticulous…Read more on I.M. Lamb’s unpublished contribution to Antarctic lichenology
1 January, 2000 by Robert Mulvaney
For the first time, annually resolved accumulation rates have been determined in central Antarctica by means of counting seasonal signals of ammonium, calcium, and sodium. All records, obtained from three…1 January, 2000 by Robert Mulvaney
The ammonium, calcium, and sodium concentrations from three intermediate depth ice cores drilled in the area of Dronning Maud Land, East Antarctica, have been investigated. Since all measurements were performed…1 January, 2000
Examination of fracture surfaces near the fusion crust of the martian meteorite Allan Hills (ALH) 84001 have been conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and…Read more on Investigations into an unknown organism on the martian meteorite Allan Hills 84001
1 January, 2000 by Robert Mulvaney
We detected a compound previously unreported in the atmosphere, trifluoromethyl sulfur pentafluoride (SF5CF3). Measurements of its infrared absorption cross section show SF5CF3 to have a radiative forcing of 0.57 watt…Read more on A potent greenhouse gas identified in the atmosphere: SF5CF3
1 January, 2000
Recent suggestion and experimental indications that the magnetotail dynamics exhibit self-organized critical behavior have re-motivated interest in sandpile (avalanche) models. Some examples of specific interest for geomagnetic activity have the…1 January, 2000
CRP-2/2A hole, drilled at 77.006oS and 163.719oE, about 14 km east of Cape Roberts, in the Ross Sea, reached 624 metres below sea floor and recovered a thick Miocene-Oligocene succession…Read more on Macrofossils from CRP-2/2A, Victoria Land Basin, Antarctica
1 January, 2000 by Mark Clilverd
Observations of field strengths of signals from a number of VLF transmitters, after propagation over long paths in the Earth–ionosphere waveguide, have been used to examine changes in the daytime…Read more on Solar cycle changes in daytime VLF subionospheric attenuation
1 January, 2000
In terms of the convention governing the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), management advice for the Antarctic krill (Euphausia superba) fishery should take the needs…Read more on Modeling the consequences of Antarctic krill harvesting on Antarctic fur seals
1 January, 2000 by Eugene Murphy, Philip Trathan, Sally Thorpe
The Antarctic Circumpolar Current (ACC) crosses rugged topography to the north of South Georgia. In this region the subsurface expression of the Polar Front (PF) is generally thought to occur…1 January, 2000 by John Turner
The First International Symposium on Operational Weather Forecasting in Antarctica was held in Hobart, Australia, from 31 August to 3 September 1998. There were 40 attendees at the meeting from…1 January, 2000 by Andrew Clarke
Early embryos, blastulae, prisms and 4-arm plutei of the Antarctic shallow-water echinoid Sterechinus neumayeri were subjected to a temperature/pressure regime from -1.2 to +2.5°C and from 1 to 250 atm.…1 January, 2000 by Eric Wolff, Robert Mulvaney
The comparison between electric (electric-conductivity measurement (ECM) and dielectric profiling (DEP)) and chemical (sulphate and chloride) depth profiles along the first 400 m of the EPICA-Dome C ice core revealed…Read more on Holocene electrical and chemical measurements from the EPICA–Dome C ice core
1 January, 2000
Under the typical high-latitude conditions of temperature, productivity and settlement of chlorophyll and phaeophytin to the sediment, many benthic organisms in the Antarctic show strong seasonal variation. Although meiofauna comprise…1 January, 2000
A major ductile fault zone, the eastern Palmer Land shear zone, has been identified east of the spine of the southern Antarctic Peninsula. This shear zone separates newly identified geological…1 January, 2000 by Vsevolod Afanasyev
We review the general search problem of how to find randomly located objects that can only be detected in the limited vicinity of a forager, and discuss its quantitative description…1 January, 2000 by Michael Pinnock
We have found observational evidence for a rapid communication of interplanetary magnetic field (IMF) changes to the global ionosphere and evidence for the state of the magnetosphere in the previous…1 January, 2000
The provisioning strategies of two closely related species of albatross breeding sympatrically were studied at Campbell Island, New Zealand. Black-browed Albatrosses (Diomedea melanophrys) had a higher provisioning rate of chicks…1 January, 2000
We examined the provisioning strategy of a long-lived seabird to test the prediction from life-history theory that adults should preferentially allocate resources towards their own needs rather than towards their…1 January, 2000
The effects of growth temperature on soluble carbohydrate and lipid content of Humicola marvinii, Geomyces pannorum and Mortierella elongata isolated from the Antarctic (Signy Island; 60° 43′S, 45°38′W) were investigated.…1 January, 2000 by Roger Worland
Panagrolaimus davidi is a freeze-tolerant Antarctic nematode which survives extensive intracellular freezing. This paper describes the development of culture techniques which provide clean samples, with a high degree of freeze…1 January, 2000
The eight dominant culturable members of an Antarctic fellfield soil bacterial community were four Arthrobacter species, Sanguibacter suarezii, Aureobacterium testaceum, a Bacillus sp., and a Pseudomonas sp.. All of the…1 January, 2000
Chlorophyll a and nutrient concentrations along with temperature and salinity values were measured at 22 CTD stations along a 735-km transect running to the northwest of the island of South…1 January, 2000 by David Pearce
Water samples from a range of fresh-water Antarctic lakes on Signy Island (South Orkney Islands: 60°45′S, 45 °38′W) were examined for the presence of virus-like particles (VLPs) during the 1998/1999 field…1 January, 2000 by Andrew Wood
We develop a new approach to quantifying habitat use within the foraging ranges of satellite-tracked seabirds. We applied kernel estimation techniques to 167 days (3738 locations) of data from Black-browed…1 January, 2000
Gravel-free, high-resolution (1-metre spacing, 32 channel) particle size data from the CRP-2/2A drill core indicate that many of the diamictites were likely deposited from floating ice. Textural dislocations occur at…1 January, 2000 by Roger Worland, William Block
Heleomyza borealis Boh. (Diptera, Heleomyzidae) overwinters as larvae in Arctic habitats, where they may experience winter temperatures below − 15°C. The larvae freeze at c.− 7°C but in acclimation experiments 80% survived…Read more on Survival of Heleomyza borealis (Diptera, Heleomyzidae) larvae down to -60oC
1 January, 2000 by Roger Worland, Peter Convey
This study examined the rate of cold hardening of a field population of Antarctic springtails and the effect of eating food with particular levels of ice nucleating activity on the…1 January, 2000 by Roger Worland
The effect of consuming terrestrial algae on the cold tolerance of two Antarctic micro-arthropods was examined. From the results of preferential feeding experiments, seven species of Antarctic terrestrial micro-algae were…1 January, 2000 by Richard Horne
SPEAR is a new polar cap HF radar facility which is to be deployed on Svalbard. The principal capabilities of SPEAR will include the generation of artificial plasma irregularities, operation…1 January, 2000
Commercial sealing in the 18th and 19th centuries had a major impact on the Antarctic and subantarctic fur seal populations (Arctocephalus gazella and A. tropicalis) in the Southern Ocean. The…1 January, 2000
Surface habitats in Antarctic deserts are near the limits of life on Earth and resemble those hypothesized for early Mars. Cyanobacteria dominate the transient riverbeds, stromatolitic sediments in ice-covered lakes,…Read more on Antarctic ecosystems as models for extraterrestrial surface habitats
1 January, 2000
Fourier-transform laser Raman spectroscopy in the near infrared (1064 nm) has been used to characterize a variety of key pigments and biomolecules produced by cyanobacteria and other stress-tolerant microbes in…1 January, 2000 by Martin Collins
The commensal relationship between a snailfish, tentatively identified as Careproctus sp. (Osteichthyes: Liparidae), and the lithodid crab Paralomis formosa (Crustacea: Lithodidae) was photographed in situ using a baited camera vehicle,…1 January, 2000
The validity of a radiative transfer model can be checked either by comparing its results with measurements or with solutions for artificial cases. Unfortunately, neither type of comparison can guarantee…Read more on From model intercomparison toward benchmark UV spectra for six real atmospheric cases
1 January, 2000
Samples were collected from the top 200 m of the water column at 50 stations during two cruises in different, near equinoctial seasons on an Atlantic transect near the 20°W…Read more on Bacterial growth and grazing loss in contrasting areas of North and South Atlantic
1 December, 1999
While some people involved in the acoustic remote sensing field are aware of the possibility of receiving dot echoes from nonatmospheric targets, most of the papers available in the scientific…Read more on Quantitative analysis and interpretation of dot echoes observed with a Doppler sodar
1 December, 1999 by Gareth Marshall, John Turner
The quality of the Antarctic operational analyses that were distributed over the Global Telecommunications System during the First Regional Observing Study of the Troposphere project special observing period of July…Read more on An assessment of operational Antarctic analyses based on data from the FROST Project
1 September, 1999 by Anna Jones, Eric Wolff
The occurence of a diurnal variability in measured total oxidised nitrogen (NOy) was observed at Neumayer, Antarctica, (70 degrees 39'8, 8 degrees 15'W) during a recent summer measurement campaign. Minima…Read more on Investigating possible causes of the observed diurnal variability in Antarctic NOy
1 August, 1999 by John Turner
Extensive oceanographic and atmospheric observations obtained during three independent experiments in the Atlantic Ocean are used to demonstrate the relationship between wind speed and the temperature deviation ΔT, which is…Read more on Implications of the oceanic thermal skin temperature deviation at high wind speed
1 June, 1999
A simple one-dimensional sandpile model is constructed which possesses exact analytical solvability while displaying both scale-free behavior and fractal properties. The sandpile grows by avalanching on all scales, yet its…Read more on Exactly solvable sandpile with fractal avalanching
1 June, 1999 by Richard Horne
Electron pitch angle distributions sharply peaked at 90 degrees pitch angle were first recorded in the energy range 50 eV < E < 500 eV by the GEOS1 and GEOS2…Read more on ‘Pancake’ electron distributions in the outer radiation belts
1 March, 1999 by David Barnes, Rod Arnold
Aim Encrusting faunal communities on rocks were examined from Southern Ocean intertidal and subtidal (6 m) zones to investigate potential change with latitude. Location The site locations were South Georgia…1 January, 1999 by Paul Rodhouse
Ommastrephid squid of the genus Illex form an important trophic component of large areas of the Atlantic ocean, both as prey for fish, seabirds, whales and other cephalopods, and as…1 January, 1999 by Paul Rodhouse
Levels of genetic diversity and population differentiation were examined in temporally (1990 to 1997) and geographically separated samples of the argentine short-finned squid Illex argentines using 7 microsatellite loci. Number…1 January, 1999 by Michael Pinnock
The SuperDARN radars are proving to be a very powerful experimental tool for exploring solar wind-magnetosphere-ionosphere interactions. They measure the autocorrelation function (ACF) of the transmitted signal backscattered from the…Read more on On the SuperDARN autocorrelation function observed in the ionospheric cusp
1 January, 1999 by Peter Ward
Euphausia superba (hereafter 'krill') and copepods are major zooplankton taxa in the Southern Ocean, but there is little information on how they interact. This paper investigates their coincidence across a…1 January, 1999 by Roger Worland, William Block
On the sub-Antarctic island of South Georgia the field distributions of two herbivorous perimyloid beetles Hydromedion sparsutum and Perimylops antarcticus overlap with the latter occurring at higher altitudes. An introduced…1 January, 1999
The ionospheric signature of a flux transfer event (FTE) seen in EISCAT radar data has been used as the basis for a modelling study using a new numerical model of…Read more on Localized structure in the cusp and high-latitude ionosphere: a modelling study
1 January, 1999
Physical and chemical characteristics and solution geochemistry of major and trace elements were investigated in an area of volcanic soil colonized by mosses at Edmonson Point (central Victoria Land) during…1 January, 1999
Marine geophysical data from the western Falkland Plateau show strongly lineated magnetic anomalies and a coincident linear gravity high that identify the southeastern margin of a Falkland Islands block as…1 January, 1999
The climate record of glacially transported sediments in prograded wedges around the Antarctic outer continental shelf, and their derivatives in continental rise drifts, may be combined to produce an Antarctic…Read more on Antarctic glacial history from numerical models and continental margin sediments
1 January, 1999 by David Barnes
Erect bryozoans are extremely abundant and diverse in polar waters and individual species may span a wide range in latitude and bathymetry. A number of aspects of lifestyle, including polypide…1 January, 1999 by David Barnes
Polar benthic communities are subject to a range of disturbance levels from a variety of sources, principal amongst which is ice. This occurs in four main forms: the ice-foot, ice…Read more on The influence of ice on polar nearshore benthos
1 January, 1999
Summary 1. The plankton dynamics of Ace Lake, a saline, meromictic basin in the Vestfold Hills, eastern Antarctica was studied between December 1995 and February 1997. 2. The lake supported two distinct…Read more on Annual plankton dynamics in an Antarctic saline lake
1 January, 1999
We investigated the relationship between body mass and the rate and pattern of feather growth of the four outermost primaries of Wandering Albatross (Diomedea exulans) chicks. Maximum growth rates were…Read more on Wing and primary growth of the Wandering Albatross
1 January, 1999
The diet of breeding white-chinned petrels was studied during the summers of 1996 and 1998 at South Georgia. Krill abundance/availability was high throughout 1996 but apparently low at the beginning…1 January, 1999
The influence of two sampling protocols on diet determination of two marine predators, the gentoo penguin (Pygoscelis papua) and Antarctic fur seal (Arctocephalus gazella), was investigated. The collection of diet…1 January, 1999
Rhynchonellid brachiopods are reported for the first time from the Oberek Cliff Member of the Oligocene Polonez Cove Formation of King George Island, South Shetland Islands, West Antarctica. Rhynchonellids are…Read more on Rhynchonellid brachiopods from the Oligocene of King George Island, West Antarctica
1 January, 1999
The nitrogenous excretion rates (total ammonia nitrogen, urea, and primary amines) of plunderfish Harpagifer antarcticus were related significantly to length and to wet mass (mass exponents of 0·94, 1·01, 1·07…Read more on Nitrogenous excretion in the Antarctic plunderfish
1 January, 1999
This study examined three competing hypotheses to explain how lactating Antarctic fur seals (Arctocephalus gazella) respond to changes in the level of resource availability. Antarctic fur seals have episodic bouts…1 January, 1999
Archival data loggers were used to collect information about depth, swimming speed, and heart rate in 23 free-ranging antarctic fur seals. Deployments averaged 9.6 ± 5.6 days (SD) and totaled…Read more on Heart rate and behaviour of fur seals: implications for measurement of field energetics
1 January, 1999 by William Block
On the sub-Antarctic island of South Georgia two species of predatory beetle, Trechisibus antarcticus and Oopterus soledadinus (Coleoptera, Carabidae), were accidentally introduced. The colonisation process offers unique opportunities for testing…1 January, 1999 by Eugene Murphy, Philip Trathan
The sub-Antarctic island of South Georgia lies in polar waters to the south of the Polar Front and is influenced by the Weddell Scotia Confluence whose waters reach the island’s…Read more on The shelf break front to the east of the sub-Antarctic island of South Georgia
1 January, 1999 by Alistair Crame
Isopods are one of the key marine groups that radiated extensively in the southern high-latitude regions, and it is widely assumed that they did so essentially through the Cenozoic era.…1 January, 1999
The euphausiid Euphausia crystallorophias Holt and Tattersall, 1906 is considered to be a neritic species. It has been found in greatest abundance along the Antarctic continental margins, often in association…1 January, 1999 by Jonathan Watkins
Acoustic estimates of the densities of Antarctic krill, Euphausia superba, in areas around South Georgia (SG) and Elephant Island (EI) were compared for seven austral summers between 1981 and 1997.…1 January, 1999 by Jonathan Watkins
Acoustic estimates of densities of Antarctic krill, Euphausia superba, at South Georgia during 11 austral summers between 1981 and 1998 are presented. Krill density at the island fluctuated widely from…Read more on Acoustic estimates of krill density at South Georgia, 1981 to 1998
1 January, 1999
The Antarctic euphausiids Euphausia superba and E. crystallorophias were sampled using an 8 m2 rectangular midwater trawl inside the caldera of Deception Island. Specimens of the same species were collected on…1 January, 1999
The metamorphic rocks of the La Grange Nunataks, northwestern Shackleton Range, have a complex structural and metamorphic history, involving Mid-Proterozoic and Ross- (Cambro-Ordovician) aged events. The protolith of the Stratton…1 January, 1999
Fatty acid signature analysis (FASA) makes use of specific fatty acids, as well as entire profiles, to study dietary relationships at different trophic levels. Previously, FASA has been used in…1 January, 1999
The abundance, biomass and community structure of phytoplankton, bacterioplankton and protozooplankton in a maritime Antarctic lake were determined at approximately monthly intervals from December 1994 to February 1996 and compared…1 January, 1999
Changes in abundance, diversity and productivity of plankton in a maritime Antarctic lake were studied between December 1994 and February 1996. There were large intra- and inter-annual fluctuations in population…Read more on Temporal plankton dynamics in a maritime Antarctic Lake
1 January, 1999
METHOD: A retrospective study was performed of 10 yr of medical records to determine the type, severity, etiological factors and treatment of cold injury experienced by members of the British…1 January, 1999
A retrospective analysis of all skiing injuries experienced by members of the British Antarctic Survey between 1989 and 1995 was undertaken to test the hypothesis that skiing was responsible for…Read more on The epidemiology of skiing injuries in Antarctica
1 January, 1999
This paper describes the first ever mesospheric wind observations from Halley, Antarctica, over a full year. The recent implementation of an Imaging Doppler Interferometer at Halley is providing a new,…1 January, 1999 by Andrew Clarke, Nadine Johnston
1. We examined published studies relating resting oxygen consumption to body mass and temperature in post-larval teleost fish. The resulting database comprised 138 studies of 69 species (representing 28 families…Read more on Scaling of metabolic rate with body mass and temperature in teleost fish
1 January, 1999 by Mark Clilverd
We examine the possibility of earthquake precursors influencing the subionospheric propagation of VLF transmissions. We consider the long (12 Mm) path from northeastern United States to Faraday, Antarctica (65°S, 64°W),…Read more on Investigating seismoionospheric effects on a long subionospheric path
1 January, 1999 by Mark Clilverd
We present a detailed study of the times of amplitude minima observed on the 12-Mm path from NAA (24 kHz, 1 MW, Cutler, Maine) to Faraday, Antarctica, during the period…Read more on Sunrise effects on VLF signals propagating over a long north-south path
1 January, 1999 by Mark Clilverd
It is shown that the investigation of lightning activity levels, using very low frequency radio emissions near 10 kHz, needs to take into account the significant influences of subionospheric propagation.…Read more on Diurnal and annual variations in 10-kHz radio noise