Found 13319 items
1 October, 2002 by Gareth Chisham, Mervyn Freeman, Michael Pinnock
[1] We present measurements of the convection electric field in the dayside ionosphere during extended intervals when the interplanetary magnetic field (IMF) has a negative Bz component and a significant…1 October, 2002 by Mark Clilverd
Wave-particle interactions driven by whistler mode waves in the inner Van Allan belt is an important loss process for the energetic electrons found in this region. In this paper we…1 October, 2002 by Eric Wolff, Robert Mulvaney
A detailed record of non-sea-salt calcium, a proxy for dust, and sea-salt sodium, a proxy for sea salt, covering the last 45 kyr is presented. It shows that in the…1 October, 2002 by Anna Jones, Eric Wolff
Experimental observations have shown photochemical production in the upper layers of firn. We use a modeling approach for Antarctica in summer, calculating the actinic flux in snowpack, and estimating NOX…1 July, 2002 by Martin Collins
The systematics of the deep-sea cirrate octopod genus Opisthoteuthis Verrill in the Atlantic Ocean is reviewed. Comparisons, based on examination of all extant type material and new, reported and unreported…1 July, 2002 by Martin Collins
Small benthic octopodids of the genus Pareledone are commonly found around the shelf area of the sub-Antarctic island South Georgia but little is known about their biology. During three consecutive…Read more on Distribution of Pareledone spp. (Octopodidae: Eledoninae) around South Georgia
1 June, 2002 by John King
The surface energy budget of coastal polynyas in the southern Weddell Sea has been evaluated for the period 1992–1998 using a combination of satellite observations, meteorological data, and simple physical…Read more on Coastal polynyas in the southern Weddell Sea: variability of the surface energy budget
1 May, 2002
[1] Statistical properties of the interplanetary magnetic field fluctuations can provide an important insight into the solar wind turbulent cascade. Recently, analysis of the Probability Density Functions (PDF) of the…Read more on Finite size scaling in the solar wind magnetic field energy density as seen by WIND
1 January, 2002
The Pacific margin of the Antarctic Peninsula was drilled during Ocean Drilling Program (ODP) Leg 178 to understand the past 10 m.y. of its glacial history and to test a…1 January, 2002 by Mervyn Freeman
[1] We analyze the power spectrum of the line-of-sight ionospheric velocity measured by the SuperDARN CUTLASS Finland radar and of contemporaneous magnetic field perturbations measured by nearby IMAGE magnetometers. The…1 January, 2002 by Paul Rodhouse
A total of 211 juvenile and paralarval squid were collected on five research cruises made in the Scotia Sea region during the austral summer (1996-1999). These included specimens of Alluroteuthis…Read more on Distribution of juvenile squid in the Scotia Sea in relation to regional oceanography
1 January, 2002
Data from a monostatic acoustic radar operating at British Antarctic Survey's Halley station on a coastal Antarctic ice shelf show a band of small target echoes at an altitude of…1 January, 2002 by Michael Pinnock
This study investigates further the relationship between regions of the magnetosphere and the characteristics of HF radar Doppler spectra recorded in the ionospheric projection of those regions. It builds on…Read more on Influence of magnetospheric processes on winter HF radar spectra characteristics
1 January, 2002
Plasma leptin levels were determined in 8 lactating female and 20 pup Antarctic fur seals (Arctocephalus ga:ella) during fasting periods of normal duration. Plasma leptin levels ranged from 1.35-3.19 ng.ml(-1)…1 January, 2002
We used the otoliths from a sample of Dissostichus eleginoides pre-recruits, whose length density was distinctly polymodal, to see whether ages estimated by reading otoliths were congruent with the length…Read more on Length-at-age in juvenile Patagonian toothfish (Dissostichus eleginoides)
1 January, 2002
The overwintering success of Euphausia superba is a key factor that dictates population size, but there is uncertainty over how they cope with the scarcity of pelagic food. Both nonfeeding…1 January, 2002
Oxygen and carbon isotopic ratios were measured on left-coiling Neogloboquadrina pachyderma separated from sediments recovered from Holes 1096B (3152 m water depth) and 1101A (3280 m water depth) during Ocean…1 January, 2002
During Leg 178, multiple advanced piston corer holes were drilled at our sites (1095, 1096, 1098, and 1099). Cores from the holes were correlated on board to produce composite depths…1 January, 2002 by Iain Staniland
The Antarctic fur seal (Arctocephalus gazella) and macaroni penguin (Eudyptes chrysolophus) are sympatric top predators that occur in the Southern Ocean around South Georgia where they are, respectively, the main…Read more on Are penguins and seals in competition for Antarctic krill at South Georgia?
1 January, 2002
In marine ecosystems, characterisation of the foraging areas and habitats of predators is a key factor in interpreting their ecological role, We studied the foraging areas of the macaroni penguin…1 January, 2002
Understanding how parental expenditure reflects food availability and influences reproductive output is a key part of studies of breeding performance. Provisioning behaviour is an important aspect of parental expenditure. We…Read more on Provisioning behaviour of macaroni penguins Eudyptes chrysolophus
1 January, 2002 by David Barnes
Bryozoans seem fairly typical amongst Antarctic benthos, in both timing and magnitude of growth. Growth varies interspecifically from nearly comparable to much slower than warm water equivalent species. Factors including…Read more on Modelling multivariate determinants of growth in Antarctic bryozoans
1 January, 2002 by David Barnes
Two clades of marine bryozoans, cyclostomes and cheilostomes, exemplify the benefits of applying a multidisciplinary approach to the interpretation of long-term evolutionary patterns. The cyclostome bryozoans were dominant in the…1 January, 2002 by David Barnes
There is a complex and dynamic interrelationhip between hermit crabs, humans and the coastal environment. Hermit crab homes (shells) are often hard to come by, but humans are helping out…1 January, 2002 by David Barnes
Colonization by alien species poses one of the greatest threats to global biodiversity1. Here I investigate the colonization by marine organisms of drift debris deposited on the shores of 30…1 January, 2002 by David Barnes
Many organisms overlap in their use of resources in space and time. Where and when resources are restricted, species must compete for them. Living space, often a critical resource controlling…Read more on Polarization of competition increases with latitude
1 January, 2002 by David Barnes
1. Resources vary critically in space and time so the ability of animals to utilize them necessarily does so in sympathy. For hermit crabs in coastal SW Madagascar, a critical…1 January, 2002 by David Barnes
Populations of the echinoid Paracentrotus lividus have undergone spectacular population fluctuations over the last 40 yr at Lough Hyne, SW Ireland, Censuses in 2000 and 2001, reported here, show no…1 January, 2002 by Eric Wolff, Robert Mulvaney
The microstructure and location of impurities in polar ice are of great relevance to ice core studies. We describe a reliable method to examine ice in the scanning electron microscope…Read more on A technique for the examination of polar ice using the scanning electron microscope
1 January, 2002 by Eric Wolff, Robert Mulvaney
[1] Electrical conductivity measurements made using the dielectric profiling technique (DEP) are compared to chemical data from the top 350 m of the Dome C ice core in Antarctica. The…Read more on Effect of density on electrical conductivity of chemically laden polar ice
1 January, 2002 by Eric Wolff, Robert Mulvaney
Samples taken from the Dome C ice core, Antarctica, and the GRIP ice core, Greenland, are examined using the scanning electron microscope to determine their microstructure. In both cores, samples…1 January, 2002
We studied the mercury contamination of 13 species of seabirds breeding on Bird Island, South Georgia, in 1998. Total mercury concentrations in body feather samples of birds caught at their…1 January, 2002 by David Barnes
A series of measurements were taken from 50 random examples of the arborescent sponges Raspailia rainosa and Stelligera stuposa at a number of sites and depths at Lough Hyne, Co.…1 January, 2002
1. The food consumption of an animal. both at the individual and the population level, is an essential component for assessing the impact of that animal on its ecosystem. As…Read more on The energetics of gentoo penguins, Pygoscelis papua, during the breeding season
1 January, 2002 by Alistair Crame
Brachiopods are reported for the first time from the Lower Miocene Cape Melville Formation of King George Island, South Shetland Islands, West Antarctica. Two genera, Liothyrella Thomson and Paraldingia Richardson…Read more on Brachiopods from the Lower Miocene of King George Island, West Antarctica
1 January, 2002 by William Block
1 January, 2002 by William Block
Four case studies are used to examine the relationships of water, ice nucleators and desiccation in the cold survival of invertebrates and the viability of frozen plant material: the freeze…Read more on Interactions of water, ice nucleators and desiccation in invertebrate cold survival
1 January, 2002
1. Estimating food consumption is central to defining the ecological role of marine predators. This study developed an algorithm for synthesizing information about physiology, metabolism, growth, diet, life history and…1 January, 2002
1. The oceanography of the South Georgia region is principally that of the Southern Ocean rather than the South Atlantic. A combination of factors, including advection, local bathymetry and high…1 January, 2002 by Iain Staniland
The study examined the distribution of critical habitat for foraging by female Antarctic fur seals breeding at the island of South Georgia. Bathymetric features of the continental shelf around the…Read more on Distribution of foraging by female Antarctic fur seals
1 January, 2002 by Jonathan Watkins, Jeremy Robst, Mark Belchier, Vsevolod Afanasyev
Three separate acoustic surveys of Antarctic krill (Euphausia superba) were conducted around South Georgia in the 2000/01 season: in October 2000 (early-season); during late December/early January 2000/01 (mid-season), and in…1 January, 2002 by Lloyd Peck
Oxygen consumption and ammonia excretion of the Antarctic fish Notothenia corikeps (18.4 cm L-F) increased respectively two and fourfold above fasting levels 24 h after feeding with a single meal…1 January, 2002 by Philip Leat, Teal Riley
Silicic volcanic rocks are associated with most, if not all, continental flood basalt provinces and volcanic rifted margins, where they can form substantial parts of the eruptive stratigraphy and have…1 January, 2002 by Alistair Crame
Cretaceous radiation of angiosperms from low to high palaeolatitudes, coupled with the break-up of Gondwana, played a major role in establishing and maintaining biogeographic patterns across the southern hemisphere. Uncertainties…Read more on Cretaceous patterns of floristic change in the Antarctic Peninsula
1 January, 2002
Recent work has suggested that in highly correlated systems, such as sandpiles, turbulent fluids, ignited trees in forest fires and magnetization in a ferromagnet close to a critical point, the…Read more on Extremum statistics: a framework for data analysis
1 January, 2002 by Gareth Chisham, Michael Pinnock
The HF radar Doppler spectral width boundary (SWB) in the cusp represents a very good proxy for the equatorward edge of cusp ion precipitation in the dayside ionosphere. For intervals…1 January, 2002 by Andrew Clarke
The 2002 Annual Symposium of the British Ecological Society on Macroecology: reconciling divergent perspectives on large-scale ecological patterns was held at the University of Birmingham, UK from 17 to 19…1 January, 2002 by Mark Clilverd
The aa index provides the longest geomagnetic data set that can be used in the analysis of magnetospheric and ionospheric phenomena. All phases of the solar cycle show increases in…1 January, 2002 by Mark Clilverd
[1] We analyze Trimpi signatures during 23 and 24 April 1994 at four sites on or near the Antarctic Peninsula (Palmer, Faraday, Rothera, and Halley) on subionospheric VLF signals received…Read more on Determining the size of lightning-induced electron precipitation patches
1 January, 2002
During the past decade new questions in science have emerged that require broad inter-disciplinary approaches. 'Do asteroids and comets cause extinctions?' and 'Was there, or is there, life on Mars?'…Read more on Astrobiology – a new opportunity for interdisciplinary thinking
1 January, 2002
Some believe that the planet Mars holds promise as a new home for humankind and that it could become the focus of a large scale colonisation effort at some undefined…1 January, 2002
We used ultraviolet radiation dosimeters to investigate human exposure at two polar latitudes with a 24-h photoperiod: at Rothera Station (UK) (67degreesS) and at a field camp in the Haughton…1 January, 2002
The notion that ultraviolet (UV) fluxes, and thus biologically weighted irradiances, were higher on Archaean Earth than on present-day Earth has been a pervasive influence on thinking concerning the nature…Read more on Photobiological uncertainties in the Archaean and post-Archaean world
1 January, 2002
Of Martian expeditionary accomplishments, the Trans-Mars Expedition is the most audacious in terms of the logistical challenges imposed upon it and diversity of scientific foci it could encompass. The similar…Read more on The Trans-Mars Expedition – a long-distance, long-duration, scientific EVA
1 January, 2002
Exactly 130 years passed between the discovery by Isaac Newton that white light was composed of colors [1] and the discovery of ultraviolet radiation by Johann Wilhelm Ritter, a German…Read more on The ultraviolet radiation environment of Earth and Mars: past and present
1 January, 2002
Some molecules, particularly aromatics, have high molar extinction coefficients at wavelengths in the damaging ultraviolet radiation region of the spectrum between 200 and 400 nm. Thus, under a UV radiation…Read more on On the plausibility of a UV transparent biochemistry
1 January, 2002
Because of the ubiquity of subsurface microbial life on Earth, examination of the subsurface of Mars could provide an answer to the question of whether microorganisms exist or ever existed…Read more on Impact excavation and the search for subsurface life on Mars
1 January, 2002
Impact craters contain ecosystems that are often very different from the ecosystems that surround them. On Earth over 150 impact craters have been identified in a wide diversity of biomes.…1 January, 2002
Asteroid and comet impacts on Earth are commonly viewed as agents of ecosystem destruction, be it on local or global scales. However, for some microbial communities, impacts may represent an…1 January, 2002
Bacillus subtilis spore biological dosimeters and electronic dosimeters were used to investigate the exposure of terrestrial microbial communities in micro-habitats covered by snow and ice in Antarctica. The melting of…1 January, 2002 by Martin Collins
Three species of cirrate octopod are reported from deep-sea collections around the coasts of Greenland and Iceland in the North Atlantic. Twenty-one specimens of Stauroteuthis syrtensis were caught from east…Read more on Cirrate octopods from Greenland and Iceland waters
1 January, 2002 by Martin Collins
During January 2000 a baited video camera system was deployed fifteen times at depths of 719-1518 m around the Subantarctic island of South Georgia. Four species of lithodid (Anomura: Lithodidae)…1 January, 2002 by Martin Collins
Cephalopods (n = 515) were identified from a series of plankton and fine meshed mid-water trawls, taken between 1977 and 1999, around the British Isles. The collections were not directed…Read more on Distribution of cephalopods from plankton surveys around the British Isles
1 January, 2002 by David Barnes, Peter Convey
The oceanic islands in the Southern Ocean can be considered amongst the remotest shores as, not only are they uninhabited (except for small research stations) and geographically isolated, but they…Read more on Debris accumulation on oceanic island shores of the Scotia Arc, Antarctica
1 January, 2002 by Peter Convey
The terrestrial biota of the Antarctic Peninsula region are experiencing marked changes in climate, especially rising temperatures, precipitation, and UV-B radiation-a combination unique worldwide. These changes, combined with the inherent…Read more on Response of Antarctic terrestrial microarthropods to long-term climate manipulations
1 January, 2002 by Peter Convey
There is increasing evidence supporting rapid trajectories of environmental change in the Antarctic. This study describes preliminary data on soil faunal responses to artificial environmental amelioration obtained using a 'greenhouse'…Read more on Antarctic soil nematode response to artificial climate amelioration
1 January, 2002 by Adrian Jenkins, Hugh Corr, Keith Nicholls
[1] We describe a novel technique for measuring the basal melt rate at a point on an ice shelf. The method uses a phase-sensitive radar to observe the change in…1 January, 2002 by Alistair Crame
We still have much to learn about the evolution of taxonomic diversity gradients through geologic time. For example, have latitudinal gradients always been as steep as they are now, or…1 January, 2002 by Alistair Crame
The steepest latitudinal and longitudinal gradients in taxonomic diversity at the present day are those associated with tropical high diversity foci. Although there has been a tendency in the past…Read more on Cenozoic palaeogeography and the rise of modern biodiversity patterns
1 January, 2002 by Eugene Murphy, Philip Trathan
Recent changes in Antarctic seabird populations may reflect direct and indirect responses to regional climate change. The best long-term data for high-latitude Antarctic seabirds (Adelie and Emperor penguins and snow…Read more on Environmental change and Antarctic seabird populations
1 January, 2002 by Andrew Wood
1. The rich zooplankton, fish and squid resources on the Patagonian Shelf sustain substantial populations of largely resident seabirds and marine mammals, These habitats are also visited seasonally by similar…1 January, 2002
The Falkland Trough is a west-east bathymetric deep that separates the Falkland Plateau from the North Scotia Ridge in the western South Atlantic. It lies in the path of Circumpolar…Read more on Contourite sedimentation in the Falkland Trough, western South Atlantic
1 January, 2002 by Robert Larter
Interpretations of multichannel seismic (MCS) reflection and potential field data suggest that some prominent gravity anomalies in the Bellingshausen Sea are associated with plate boundaries that were active during the…1 January, 2002
The Patuxent Range forms the most southerly third of the Pensacola Mountains, East Antarctica. Largely unstudied since the original geological survey work of the 1960s, the Patuxent Range was thought…1 January, 2002
Observations made by the DMSP 1710 satellite during the recovery phase from geomagnetic disturbances in June 1991 show regions of He+ dominance around 830 km altitude at 09:00 MLT. These…1 January, 2002 by Adrian Jenkins, Hugh Corr
The polarization behaviour of radar waves transmitted through two Antarctic ice shelves has been investigated using a step frequency radar with a centre frequency of 300 MHz and a bandwidth…Read more on Polarization of radio waves transmitted through Antarctic ice shelves
1 January, 2002 by Adrian Jenkins, Hugh Corr, Keith Nicholls
[1] Accurate position data show that Brunt Ice Shelf has an irregular three-dimensional motion driven by the ocean tide. A 30-day GPS record from Halley station shows not only the…Read more on Tide-induced lateral movement of Brunt Ice Shelf, Antarctica
1 January, 2002
The opening of Powell Basin was part of the regional response to N55°W relative plate motion of South America away from Antarctica, which led to the formation of Drake Passage…Read more on Opening history of Powell Basin, Antarctic Peninsula
1 January, 2002
We propose a new type of robotic mission for the exploration of Mars. This mission is called Vanguard and represents the fruits of a collaboration that is both international and…Read more on Vanguard – a proposed European astrobiology experiment on Mars
1 January, 2002
One of the linchpins of the UK’s contribution to the burgeoning field of astrobiology is the Beagle 2 mission, due to fly to Mars in 2003 on the Mars Express…Read more on Vanguard: a new development in experimental astrobiology
1 January, 2002
Previous models of the equilibrium temperature and existence regions of mesospheric aerosols have shown significant radiative heating of the aerosols and, consequently, a substantially reduced existence region. We have developed…Read more on Equilibrium temperature of water-ice aerosols in the high-latitude summer mesosphere
1 January, 2002
Using ground-based measurements of the hydroxyl (OH) Meinel (3,1) band nightglow near 1500 nm, nightly means of mesospheric temperature and OH radiance from 1991 to 1998 have been derived over…Read more on Trends and variability of mesospheric temperature at high-latitudes
1 January, 2002
Recent disintegration of a number of Antarctic Peninsula ice shelves has given us a unique opportunity to investigate sub-ice-shelf sediments. We characterize three sediment facies associations of two Antarctic Peninsula…