Found 14089 items
1 January, 2000 by Richard Horne
We investigate the propagation, growth, and decay of fast magnetosonic waves in the Earth's magnetosphere which are believed to contribute to proton heating up to energies of a few hundred…Read more on Proton and electron heating by radially propagating fast magnetosonic waves
1 January, 2000
We present a new type of equation to describe the growth patterns of procellariiform seabirds and other species whose chicks characteristically lose mass towards the end of the rearing period.…Read more on Chick growth in albatrosses: curve fitting with a twist
1 January, 2000
We compared the parental division of labour and the pattern and rate of parental provisioning by two sympatric species of albatross of similar mass and breeding timetable but differing in…1 January, 2000 by Anna Jones
Because investigations of PAN at higher southern latitudes are very scarce, we measured surface PAN concentrations for the first time in Antarctica. During the Photochemical Experiment at Neumayer (PEAN'99) campaign…1 January, 2000 by Anna Jones, Eric Wolff
Measurements were made of NO and NO2, in controlled experiments to investigate their production from snow. Throughout a diurnal cycle, measurements were made of ambient air and air from inside…Read more on Speciation and rate of photochemical NO and NO2 production in Antarctic snow
1 January, 2000
The Dynasonde is a digital ionosonde which measures the amplitude and phase of radio echoes reflected from the ionosphere. In addition to the frequency and virtual range of each echo,…Read more on Dynasonde observations of electron concentration gradients above Tromsø
1 January, 2000 by Dominic Hodgson
Lake-sediment cores from Heywood and Sombre Lakes on Signy Island (South Orkney Islands), Antarctica, have yielded a conformable radiocarbon chronology for the Holocene and a high-resolution record of environmental change.…1 January, 2000
Boreholes in the large, extinct Antarctic Neogene pectinid Zygochlamys anderssoni suggest that this scallop was preyed upon by a large predatory muricid gastropod impossibly a Trophon species). The holes occur…1 January, 2000 by Michael Pinnock
This paper deals with an evolution of the electric field in the dayside auroral and equatorial ionosphere during asubstorm on July 16, 1995. A southward turning of the IMF detected…1 January, 2000 by Ed King
The Weddell Sea embayment is central to reconstructions of the West Antarctic region of Gondwana. Some reconstructions represent this area as a pre-break-up component, the Filchner block, defined by the…1 January, 2000 by Anna Jones, John Turner, Thomas Lachlan-Cope
During 1994/95 a UK Overseas Development Administration (now Department for International Development - DFID) funded project was undertaken to predict ozone amount over Punta Arenas in southern Chile. A low-cost…Read more on A pilot study for predicting ozone amounts for the general public in southern Chile
1 January, 2000 by Howard Roscoe, Jonathan Shanklin
Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe TOMS, and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network…1 January, 2000
Strontium isotope stratigraphy was used to date 16 discrete horizons within the CRP-2/2A drillhole. Reworked Quaternary (1 January, 2000
The growth rates of heterotrophic nanoflagellates (HNAN), mixotrophic cryptophytes, dinoflagellates and ciliates in field assemblages from Ace Lake in the Vestfold Hills (eastern Antarctica) and Lakes Fryxell and Hoare (McMurdo…1 January, 2000 by Richard Hindmarsh, Richard Hindmarsh
When predicting the deformation of the Earth under surface loads, most models follow the same methodology, consisting of producing a unit response that is then con-volved with the appropriate surface…1 January, 2000 by Philip Leat
Segment E2 is situated in the back-arc East Scotia Ridge. The segment is unusual in that it has an axial topographic high underlain by a seismically imaged melt lens. The…Read more on Magma supply in back-arc spreading segment E2, East Scotia Ridge
1 January, 2000 by Philip Leat, Teal Riley
An ultramafic lamprophyre dyke is described from the otherwise tholeiitic Ferrar magmatic province of Antarctica. We report an Ar-Ar age of 183 ± 2.2 Ma for the dyke, indistinguishable from…1 January, 2000 by Howard Roscoe
A three‐dimensional chemical‐transport model of the stratosphere has been used to study the 1996 austral winter and spring. Both the model and ozonesonde measurements show that ozone depletion associated with…Read more on Model and measurements show Antarctic ozone loss follows edge of polar night
1 January, 2000
New bathymetric and magnetic anomaly data from the Phoenix Ridge, Antarctica, show that extinction of all three remaining segments occurred at the time of magnetic chron C2A (3.3 ± 0.2…Read more on Autopsy on a dead spreading center: The Phoenix Ridge, Drake Passage, Antarctica
1 January, 2000
Aerobic endospore-forming bacteria were isolated from soils taken from active fumaroles on Mount Rittmann and Mount Melbourne in northern Victoria Land, Antarctica, and from active and inactive fumaroles on Candlemas…1 January, 2000
New swath bathymetric, multichannel seismic and magnetic data reveal the complexity of the intersection between the extinct West Scotia Ridge (WSR) and the Shackleton Fracture Zone (SFZ), a first-order NW-SE…Read more on Tectonics of an extinct ridge-transform intersection, Drake Passage (Antarctica)
1 January, 2000
Measurements of blowing snow particle concentration from the second Stable Antarctic Boundary Layer Experiment (STABLE 2) are presented. The measurements, made at Halley Station (75.6 degreesS, 26.7 degreesW) throughout the…Read more on Profile measurements of blowing snow at Halley, Antarctica
1 January, 2000
Oribatid mites are typically terrestrial, though many species of Ameronothroidea are marine intertidal. Marine ameronothroids are cosmopolitan with genera being endemic to the Holarctic, sub-Antarctic, or equatorial Indo-Pacific and tropical…1 January, 2000 by Gareth Marshall
In this study numerical weather prediction model data are utilized to examine the precipitation regime at Thurston Island (TI) (∼72°S, 99°W) in West Antarctica. This region was chosen because the…1 January, 2000 by Gareth Marshall
Fifty years of monthly mean sea level pressure (MSLP) data from the NCEP/NCAR reanalysis (hereinafter NNR) are validated against station observations in the extratropical South Pacific and West Antarctica. The…1 January, 2000
Satellite-derived maps of surface UV irradiance are currently limited by their poorly assessed accuracy. Here we use an extensive data set of ground-based spectral measurements from two Alpine sites to…Read more on Uncertainties in satellite-derived estimates of surface UV doses
1 January, 2000
Cyanobacteria and eukaryotic algae, together with bacteria and fungi, are known to be primary colonizers of mineral soils throughout Antarctica. Their species diversity and soil coverage were studied in 18…1 January, 2000 by Alistair Crame
New 87Sr/86Sr analyses of macrofossils from 13 key marker horizons on James Ross and Vega Islands, Antarctica, allow the integration of the Antarctic Late Cretaceous succession into the standard biostratigraphic…1 January, 2000 by Nigel Meredith, 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 GEOS-1 and GEOS-2…1 January, 2000
The current status of birds at Rothera, Adelaide Land, Antarctica is presented. Of the 23 species recorded, Snow Petrel Pagodroma nivea, Wilson’s Storm Petrel Oceanites oceanicus, Antarctic Shag or Cormorant…Read more on The birds of Rothera, Adelaide Island, Antarctic Peninsula
1 January, 2000
The Bouvet triple junction has been proposed to have evolved as a ridge-fault-fault (RFF) type between 20 and 10 Ma, connecting the southernmost Mid-Atlantic Ridge (SMAR) with the Bouvet and…1 January, 2000
Data are presented here on low molecular weight carbohydrates contents (assessed from samples collected in situ) of selected, representative terrestrial species from the maritime Antarctic. Significant seasonal variation for most…Read more on Soluble carbohydrates (trehalose in particular) and cryoprotection in polar biota
1 January, 2000 by Eric Wolff, Robert Mulvaney
Recent studies suggested that, during the transition out of the last glacial period, one near‐coastal site in Antarctica showed a response similar to that of Greenland, and unlike that of…Read more on The transition from the Last Glacial Period in inland and near‐coastal Antarctica
1 January, 2000 by Andy Smith
Bakaninbreen, southern Svalbard, began a prolonged surge during 1985. In 1986, an internal reflecting horizon on radio echo sounding data was interpreted to show that the position of the surge…Read more on Glacier surge propagation by thermal evolution at the bed
1 January, 2000 by Robert Larter
We present multi-channel seismic (MCS) reflection profiles and bathymetry data acquired across a remote and poorly surveyed part of the Antarctic continental margin in the Bellingshausen and Amundsen Seas. This…1 January, 2000 by Alistair Crame
New palaeontological collections made from Upper Cretaceous strata exposed within the James RossBasin, Antarctica, include ten echinoid species. Five species are described for the first time from Antarctica, while four…Read more on Upper Cretaceous echinoids from James Ross Basin, Antarctica
1 January, 2000
The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study the occurrence of salmonella serotypes in…1 January, 2000 by Teal Riley
New SHRIMP U–Pb zircon, Rb–Sr whole-rock, and 40Ar–39Ar data are presented for the Jurassic silicic volcanic rocks and related granitoids of Patagonia and the Antarctic Peninsula. U–Pb is the only…1 January, 2000 by Robert Mulvaney
We investigate the seasonal relationship of the sulphur-bearing anions methane sulphonate (MSA−) and non-sea-salt sulphate (nssSO42−) in sections of firn and ice cores from the Antarctic Peninsula and Weddell Sea…Read more on Migration of methane sulphonate in Antarctic firn and ice
1 January, 2000 by David Pearce
A method to study bacterioplankton community structure in Antarctic freshwater lake samples is described. Small samples (between 300 and 1000 ml) taken in remote field locations were used for crude DNA…Read more on A method to study bacterioplankton community structure in Antarctic lakes
1 January, 2000 by Philip Leat
Petrographic and geochemical studies of peridotites from the South Sandwich forearc region provide new evidence for the evolution of the South Sandwich arc–basin system and for the nature of interactions…1 January, 2000 by Lloyd Peck
Shell growth in Yoldia eightsi was measured over an austral summer and winter in 1992. In specimens < 12 mm length, growth was not significantly different between summer and winter periods,…1 January, 2000 by Alistair Crame, Lloyd Peck
Antarctic marine ectotherms are often described as only being capable of living in a restricted temperature range, i.e. they are stenothermal. However, few data exist demonstrating that for a given…1 January, 2000
In 1986, the Bird Biology Subcommittee of the Scientific Committee on Antarctic Research (SCAR) Working Group on Biology recommended that a list of recent publications on Antarctic and sub-Antarctic seabirds…Read more on Publications and theses on Antarctic and sub-Antarctic birds, 1995
1 January, 2000
In 1986, the Bird Biology Subcommittee of the Scientific Committee on Antarctic Research (SCAR) Working Group on Biology recommended that a list of recent publications on Antarctic and sub-Antarctic seabirds…Read more on Publications and theses on Antarctic and sub-Antarctic birds, 1996
1 January, 2000
In 1986, the Bird Biology Subcommittee of the Scientific Committee on Antarctic Research (SCAR) Working Group on Biology recommended that a list of recent publications on Antarctic and sub-Antarctic seabirds…Read more on Publications and theses on Antarctic and sub-Antarctic birds, 1997
1 January, 2000
Fossil wood is subject to different taphonomic, sampling and recognition biases in the palaeobotanical record when compared with leaves and palynomorphs. Wood therefore provides a systematically independent source of information…1 January, 2000
Fossil angiosperm wood from Upper Cretaceous sediments of Livingston Island and James Ross Island in the northern Antarctic Peninsula region is identified as having the combination of anatomical characters most…Read more on The fossil record of Cunoniaceae: new evidence from Late Cretaceous wood of Antarctica?
1 January, 2000
Fossil wood of the Winteraceae from the Upper Cretaceous sediments of James Ross Island, Antarctic Peninsula, is described here for the first time. The specimen is characterized by the absence…Read more on The first record of fossil wood of Winteraceae from the Upper Cretaceous of Antarctica
1 January, 2000
The Late Cretaceous and early Tertiary sediments from the northern Peninsula region of Antarctica yield a rich assemblage of fossil wood with well preserved anatomy. Wood specimens of a previously…1 January, 2000
Sassafrasoxylon gottwaldii sp. nov. is a new taxon for fossil wood with a suite of features diagnostic of Sassafras Nees & Eberm. of the Lauraceae. The fossil wood described is…1 January, 2000
The continental rise west of the Antarctic Peninsula includes a number of large sediment mounds interpreted as contourite drifts. Cores from six sediment drifts spanning some 650 km of the…1 January, 2000 by Peter Convey
The Scotia Arc comprises South Georgia, South Sandwich, South Orkney and South Shetland Islands together with the Antarctic Peninsula. Free-living Acari of the Scotia Arc contain immigrant and endemic elements.…1 January, 2000
The motion field of the northern Larsen Ice Shelf, Antarctic Peninsula, was analyzed using radar interferometry in combination with field measurements and finite-element model calculations. The ice shelf between Jason…1 January, 2000
A paleomagnetic study of the late Middle to possibly early Late Cambrian Liberty Hills Formation in the Ellsworth Mountains, Antarctica, reveals a stable magnetization with positive fold and reversal tests.…Read more on A new Late Middle Cambrian paleomagnetic pole for the Ellsworth Mountains, Antarctica
1 January, 2000 by Eric Wolff, Victoria Auld
Frost flowers collected from the surface of new sea ice near the Brunt Ice Shelf, Antarctica, show depletion in sulphate and sodium relative to other sea water ions. This is…Read more on Frost flowers as a source of fractionated sea salt aerosol in the polar regions
1 January, 2000 by Eric Wolff
Snow samples taken at various distances from the emperor penguin (Aptenodytes forsteri) colony near Halley station were analysed by ion chromatography. Extremely high ammonium concentrations were encountered at the colony…Read more on Ammonium and potassium in snow around an emperor penguin colony
1 January, 2000 by John King
Internal gravity waves are frequently observed in stably stratified regions of the atmospheric boundary layer. In order to determine the statistical influence of such waves on the dynamics of the…1 January, 2000
The distribution of whales and krill in two survey boxes north of South Georgia was examined by comparing sightings and underway acoustic data collected as part of a multi-disciplinary research…1 January, 2000
Chicks of albatrosses, like other Procellariiformes, become independent at a mass similar to their parents but during growth attain a peak mass some 30% or more greater, before losing mass…1 January, 2000 by John King
A simple model of the convective (thermal) internal boundary layer has been developed for climatological studies of air-sea-ice interaction, where in situ observations are scarce and first-order estimates of surface…1 January, 2000
1. Lake Fryxell, situated in the McMurdo Dry Valleys, Antarctica, offers the opportunity to study microbial loop processes in the absence of crustacean zooplankton and other higher organisms. This is the…Read more on Stratification and dynamics of microbial loop communities in Lake Fryxell, Antarctica
1 January, 2000 by Richard Horne
Results are reported from an experiment in which the HF high power facility at Tromsø was utilised to inject artificial ULF waves into the magnetosphere by means of modulated heating…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 William Block
Field studies and sampling of terrestrial invertebrates for ecophysiological experiments were undertaken in the summer of 1994 and 1995 in different geographic regions of the Asian Transect (Krasnoyarsk to Karaul)…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 Howard Roscoe
We present an overview of exisiting problems in air-mass factor calculations for NO2 vertical column measurements by UV-visible ground-based spectrometry, Sensitivity studies made using different radiative transfer models allow us…Read more on Improved air-mass factors for ground-based total NO2 measurements: a sensitivity study
1 January, 2000
The British Antarctic Survey (BAS) maintains a research and support station on Rothera Point (67 degrees 34'S, 68 degrees 08'W), located on the southeastern side of Adelaide Island, about 15…Read more on Performance of rip-rap shore protection (1992-1998) Rothera Station, Antarctica
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 by Mervyn Freeman
We carried out a superposed epoch analysis, using a database of substorm chorus events observed at Halley, Antarctica, within an hour of magnetic midnight, to define a set of 123…1 January, 2000
An account is given of phanerogams and cryptogams(bryophytes and lichens) growing in extreme habitats in Antarctica. These include high altitude and far southern sites, geothermal sites in volcanic areas, and…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
It has been suggested that the dynamics of the magnetotail may exhibit forced and/or self-organized critical behaviour. Recent analysis of experimental data seem to be in concert with this idea.…Read more on Renormalization-group study of a sandpile (FSOC)analog for magnetospheric activity