Found 14049 items
1 January, 2003
[1] Between 1996 and 1998, a concerted effort was made to study the deep open ocean convection in the Labrador Sea. Both in situ observations and numerical models were employed…Read more on The Labrador Sea Deep Convection Experiment data collection
1 January, 2003
Planetary wave activity at quasi 16-, 10- and 5-day periods has been compared at various altitudes through the middle and upper atmosphere over Halley (76degreesS, 27degreesW), Antarctica, during the austral…Read more on Simultaneous observations of planetary waves from 30 to 220 km
1 January, 2003 by Dominic Hodgson
Ultraviolet radiation (UVR) damages most biota, yet little evidence exists for its long-term effects on natural ecosystems. We used paleoecological techniques at three low-elevation lakes to show that algal abundance…Read more on Climatic control of ultraviolet radiation effects on lakes
1 January, 2003
Paleolimnology provides information on the past chemical, physical and biological nature of water bodies. In polar regions, where global climatic changes can be exacerbated compared with lower latitudes, the science…Read more on Paleolimnology in the High Arctic – implications for the exploration of Mars
1 January, 2003
Photosynthetic activity of the moss Sanionia uncinata (Hedw.) Loeske was investigated on Léonie Island (67°35'S, 68°20'W, Antarctic Peninsula) in response to short-term changes of UV-B radiation. The UV-environment of natural…1 January, 2003
In 2000 the UK started a Patagonian toothfish (Dissostichus eleginoides) tagging program to investigate the spatial and temporal movement of fish and to validate otolith-based growth estimates. Approximately 2 260…1 January, 2003
Five populations of habitat-specific, morphologically distinct Algophagus mites (Astigmata: Algophagidae) were found to occur on the sub-Antarctic Prince Edward islands. Although these mites did not differ among themselves with respect…1 January, 2003 by Gareth Marshall
Several papers have described a significant trend toward the positive phase of the Southern Hemisphere annular mode (SAM) in recent decades. The SAM is the dominant mode of atmospheric variability…Read more on Trends in the Southern Annular Mode from observations and reanalyses
1 January, 2003 by Sandra McInnes, Sandra McInnes
Lecophagus antarcticus, described as a new species of predaceous Hyphomycete of rotifers and tardigrades, was collected from cyanobacterial mats and sediments at shallow lake margins on Signy Island, South Orkney…1 January, 2003 by Andrew Wood, Eugene Murphy, Jonathan Watkins, Sally Thorpe
Data from a variety of sources reveal a warm-core anticyclonic circulation above the Northwest Georgia Rise (NWGR), an similar to2000-m high bathymetric feature north of South Georgia. The sense of…Read more on An anticyclonic circulation above the Northwest Georgia Rise, Southern Ocean
1 January, 2003 by Eugene Murphy, Jonathan Watkins, Michael Meredith, Peter Ward, Sally Thorpe
[1] In December 2000 we conducted high-resolution hydrographic and towed undulator transects across the South Georgia shelf and into the deep waters of the Georgia Basin. The Southern Antarctic Circumpolar…1 January, 2003 by Richard Horne
[1] We perform a survey of the plasma wave and particle data from the CRRES satellite during 26 geomagnetically disturbed periods to investigate the viability of a local stochastic electron…1 January, 2003 by Richard Horne
Electromagnetic ion cyclotron (EMIC) waves which propagate at frequencies below the proton gyrofrequency can undergo cyclotron resonant interactions with relativistic electrons in the outer radiation belt and cause pitch-angle scattering…1 January, 2003
The physiological condition and feeding activity of the dominant larval stages of Euphausia superba (calyptopis stage III, furcilia stages I and II) were investigated from February to March 2000 at…Read more on Feeding and energy budgets of larval Antarctic krill Euphausia superba in summer
1 January, 2003 by David Vaughan
Mapping surface air temperature in the Antarctic Peninsula region is made unusually difficult by: the scarcity of meteorological stations, strong climatic gradients and recent rapid regional warming. We have compiled…1 January, 2003
Data obtained from the MF radars situated at Davis, Syowa and Rothera in Antarctica are used to detect a nonmigrating component of the semidiurnal tide in the mesosphere and lower…Read more on Observations of a nonmigrating component of the semidiurnal tide over Antarctica
1 January, 2003 by David Vaughan
[1] Crevasses form in response to tensile stresses in glaciers and ice sheets. It has been widely assumed that crevasses initiate at, or near, the surface of the ice, from…Read more on Subsurface crevasse formation in glaciers and ice sheets
1 January, 2003 by Kevin Newsham
Changes to the radiative environment arising from stratospheric ozone (O3) depletion and subsequent associations between these changes and the pigmentation of the moss Andreaea regularis were measured in late austral…1 January, 2003 by Kevin Newsham
The composition of saprotrophic fungal communities on sessile oak (Quercus petraea) and sycamore (Acer pseudoplatanus) leaf litters from a woodland at Cefnpennar in South Wales, UK, were analysed in late…1 January, 2003 by Adrian Jenkins, Keith Nicholls
We use new data from the southern Weddell Sea continental shelf to describe water mass conversion processes in a formation region for cold and dense precursors of Antarctic Bottom Water.…Read more on Water mass modification over the continental shelf north of Ronne Ice Shelf, Antarctica
1 January, 2003
A record of Holocene hydrological changes has been produced from variations in oxygen-isotope composition (delta(18)O) preserved in freshwater lake sediments from maritime Antarctica. Small amounts (1 January, 2003
Schistidium is the richest moss genus in the Antarctic consisting of twelve species, one of which, S. deceptionense Ochyra, Bednarek-Ochyra, & Lewis Smith, is here described as new to science…1 January, 2003
Rb-Sr and Sm-Nd whole-rock data for granitoids and orthogneisses from the western part of the Sierras Septentrionales of the southern Buenos Aires province yield an errorchron of 2009 +/- 71…1 January, 2003
Small outcrops of the basement of the Deseado Massif, consisting of weathered, altered granitoids and their metasedimentary host rocks, were dated by the U-Pb zircon method using thermal ionization mass…Read more on Chronological study of the pre-Permian basement rocks of southern Patagonia
1 January, 2003 by David Pearce
The bacterioplankton community structure in Moss Lake, a maritime Antarctic oligotrophic lake, was determined with vertical depth in the water column, during the ice-free period on Signy Island in the…1 January, 2003 by David Pearce
The biodiversity of the pelagic bacterioplankton community of a maritime Antarctic freshwater lake was examined by cultivation-dependent and cultivation-independent techniques to determine predominant bacterioplankton populations present. The culture-dependent techniques used…1 January, 2003 by David Pearce
This review seeks to highlight the potential importance of viruses in Antarctic ecosystems and describe the limited scope of Antarctic virus studies to date, including studies of marine, terrestrial and…1 January, 2003 by Lloyd Peck
The trend towards large size in marine animals with latitude, and the existence of giant marine species in polar regions have long been recognized, but remained enigmatic until a recent…Read more on Reduced oxygen at high altitude limits maximum size
1 January, 2003 by John Turner
Increasingly, output from numerical weather prediction (NWP) models is being used for real-time weather forecasts for the Antarctic and for Antarctic-related climate diagnostics studies. Evidence is presented that indicates that…Read more on Numerical weather prediction model performance over high southern latitudes
1 January, 2003 by Mervyn Freeman, Richard Horne
Vlasov simulations of the current-driven ion-acoustic instability produced in Maxwellian and non-Maxwellian (Lorentzian, kappa = 2) electron-ion plasma with number density 7 x 10(6) cm(-3), reduced mass ratio m(i)/m(e) =…Read more on Anomalous resistivity in non-Maxwellian plasmas
1 January, 2003 by Richard Phillips
The relative importance of genetic vs. environmental factors in determining the pattern of avian post-embryonic development is much debated. Previous cross-fostering of albatrosses suggested that although inter-specific variation in growth…Read more on Chick metabolic rate and growth in three species of albatross: a comparative study
1 January, 2003 by Richard Phillips
Recent studies have been equivocal in determining whether long-lived seabirds are able to respond to chick nutritional status and regulate provisioning rates accordingly. With some exceptions, albatrosses and petrels that…1 January, 2003 by Richard Phillips
Effects of deployment of miniaturized transmitters and loggers have been well studied in penguins, but much less so in flying seabirds. We examined the effects of satellite tag (platform terminal…Read more on Effects of satellite transmitters on albatrosses and petrels
1 January, 2003 by Eric Wolff
A record of the concentrations of Pb and Ba and the isotopic composition of Pb has been established for a remote, low accumulation site in the Atlantic sector of Antarctica…Read more on One hundred fifty-year record of lead isotopes in Antarctic snow from Coats Land
1 January, 2003 by Eugene Murphy
We develop and analyse a simple, two-compartment (chlorophyll and nitrate) model of the surface mixed layer of the ocean. The mixed-layer depth is modulated intermittently to simulate the effects of…Read more on Phytoplankton biomass and residual nitrate in the pelagic ecosystem
1 January, 2003
Cool temperate rainforests growing on the flanks of the Andes and along the Coastal Range in Valdivia (Chile) today provide the closest analogue for the fossil floras of Antarctica during…1 January, 2003
Over the past 70 years, three counts have been conducted on the Rockhopper Penguin (Eudyptes chrysocome) population on the Falkland Islands during the 1932/33, 1995/96 and 2000/01 breeding seasons. The…Read more on Re-evaluation of historical rockhopper penguin population data in the Falkland Islands
1 January, 2003 by Helen Peat, Lloyd Peck, Peter Convey
Polar lakes act as key early detectors of global change effects. Duration and thickness of snow and ice cover determines albedo, underwater light availability, thermal and chemical regimes and mixing…Read more on Ecological responses of maritime Antarctic lakes to regional climate change
1 January, 2003 by Eric Wolff
Size-segregated aerosol samples were collected with a cascade impactor at 2 week intervals for a year at the research station Halley, situated near the coast in the Weddell Sea region…Read more on A year-long record of size-segregated aerosol composition at Halley, Antarctica
1 January, 2003
U-Pb sensitive high-resolution ion microprobe data together with geochemical and Nd isotope analyses obtained in the basement complex of the Sierra de la Ventana Fold Belt indicate that the Early…1 January, 2003
The semidiurnal tide (SDT) is investigated through comparative analysis of horizontal winds measured at Poker Flat (65degreesN, 147degreesW), Andenes (69degreesN, 16degreesE), Davis (69degreesS, 78degreesE), and Rothera (68degreesS, 69degreesW). At the…1 January, 2003 by Philip Leat, Teal Riley
Rare basaltic volcanic rocks from the northern Antarctic Peninsula (Jason Peninsula) are established as marginally predating a silicic large igneous province, which developed along the proto-Pacific margin of Gondwana. Ar-40-Ar-39…1 January, 2003 by Philip Leat, Teal Riley
Ultramafic lamprophyre (UML) dykes from the Ferrar Province (Pensacola Mountains) of Antarctica preserve trace element and isotope signatures similar to Bouvet volcanic rocks, which are considered to reflect the palaeo…1 January, 2003 by David Vaughan, Hugh Corr
An airborne radio-echo sounding campaign carried out in the upper reaches of Bailey Ice Stream and Slessor Glacier, in Coats Land, East Antarctica, has revealed that tributaries of enhanced flow…Read more on Basal topography and ice flow in the Bailey/Slessor region of East Antarctica
1 January, 2003 by Gareth Chisham, Mervyn Freeman, Michael Pinnock
Reconnection at the dayside magnetopause is of fundamental importance in determining the dynamics and composition of the magnetosphere and the high latitude ionosphere. There are two competing hypotheses for such…1 January, 2003 by Mark Clilverd
The behavior of high-energy electrons trapped in the Earth's Van Allen radiation belts has been extensively studied, through both experimental and theoretical techniques. While the evidence for whistler induced electron…1 January, 2003
The UV radiation environment on planetary surfaces and within atmospheres is of importance in a wide range of scientific disciplines. Solar UV radiation is a driving force of chemical and…Read more on Solar UV irradiation conditions on the surface of Mars
1 January, 2003 by Howard Roscoe, Jonathan Shanklin, Steve Colwell
Water vapour is a potent greenhouse gas, and the observed increases in water vapour in the stratosphere act to cool it. Possible changes in stratospheric temperatures are important for future…1 January, 2003 by Eric Wolff, Robert Mulvaney
Chloride (Cl-) and sodium (Na+) in ice cores originate mainly from sea salt, and one would thus expect the Cl-/Na+ ratio to reflect the seawater ratio. However, at Dome C,…1 January, 2003 by Dominic Hodgson
A floristic and taxonomic survey was made of the diatom communities of sediments and microbial mats in 66 freshwater and saline lakes and pools in the Larsemann Hills, Rauer Islands…1 January, 2003
The use of stable isotopes to study food webs has increased rapidly, but there are still some uncertainties in their application. We examined the delta(15)N and delta(13)C values of Antarctic…1 January, 2003
[1] The photolysis frequency of NO2, j(NO2), was determined by various instrumental techniques and calculated using a number of radiative transfer models for 4 days in June 1998 at the…1 January, 2003 by Richard Hindmarsh, Richard Hindmarsh
Internal isochronous ice sheet layers, recorded by airborne ice-penetrating radar, were measured along an ice flowline across a large (> I km high) subglacial hill in the foreground of the…1 January, 2003
Our understanding of Lake Vostok, the huge subglacial lake beneath the East Antarctic Ice Sheet, has improved recently through the identification of key physical and chemical interactions between the ice…1 January, 2003 by Dominic Hodgson
Novel transformation products of chlorophyll a incorporating a methyl sulfide group in the substituent at the C-3 position have been identified in Recent sediments from an Antarctic lake.1 January, 2003 by Iain Staniland
This study investigated how female Antarctic fur seals adapt their foraging behavior, over time scales of days, to spatial unpredictability in the distribution of their food. Lactating Antarctic fur seals…1 January, 2003 by Iain Staniland
Female Antarctic fur seals returning ashore after foraging trips were restrained, and fecal material was obtained by introducing approximately one litre of warm water into the animal's colon via the…Read more on An enema method for obtaining fecal material from known individual seals on land
1 January, 2003
The timing and synchronisation of Greenland and Antarctic climate events that occurred during the last glacial period are still under debate, as is the magnitude of temperature change associated with…1 January, 2003 by Hilmar Gudmundsson
During a period of diurnal fluctuations in glacial flow speed, vertical strain was measured with sub-daily temporal resolution on Unteraargletscher, Switzerland. Mean vertical strain in boreholes up to 300-m deep…Read more on Diurnal variations in vertical strain observed in a temperate valley glacier
1 January, 2003 by Hilmar Gudmundsson
The effects of spatial and temporal variations in basal lubrication on the englacial strain rate and surface velocity distribution are investigated with a numerical ice-flow model. General aspects of the…1 January, 2003
This study presents the first direct evidence, based on biochemical analysis of fresh material, that certain benthic foraminifera feed selectively on specific components of seasonally deposited phytodetritus in their natural…1 January, 2003 by Michael Dunn, Philip Trathan
Chinstrap penguins Pygoscelis antarctica are one of the major consumers of Antarctic krill Euphausia superba in the Southern Ocean. To examine their foraging strategy, we studied foraging trip patterns and…1 January, 2003
The land–sea interface, or Coastal Transition Zone (CTZ), is the area that links terrestrial and marine habitats. We use here the definition of [Schaefer, 1972]: “the sea and the land…1 January, 2003 by Geraint Tarling
The diel vertical migration (DVM) and population dynamics of northern krill were investigated in the Clyde Sea over several years using depth-discrete net-sampling and a moored 300 kHz acoustic Doppler…1 January, 2003 by Geraint Tarling
The molting, spawning, and recruitment of northern krill (Meganyctiphanes norvegica) were analyzed over an annual cycle (1999-2000) in the Clyde Sea (west coast of Scotland). Results supported the hypothesis of…1 January, 2003
Earthquake data from the Scotia Arc to early 2002 are reviewed in the light of satellite gravity and other data in order to derive a model for the motion of…1 January, 2003 by Eugene Murphy, Jonathan Watkins, Philip Trathan
Oceanographic data collected to the north of South Georgia were examined for three consecutive summers (1996/97, 1997/98, 1998/99). The results show the existence of a shelf break front during each…1 January, 2003 by Eugene Murphy, Philip Trathan
The data set of Reynolds and Smith [1994] is used to describe temporal variability in sea surface temperature (SST) at South Georgia. Time series analysis indicates that high levels of…1 January, 2003 by Gareth Marshall, John King, John Turner, Thomas Lachlan-Cope
The exceptional sea-ice retreat and advance that occurred in the Bellingshausen Sea, Antarctica during August 1993 was the largest such winter event in this sector of the Antarctic during the…Read more on An exceptional winter sea-ice retreat/advance in the Bellingshausen Sea, Antarctica
1 January, 2003 by Andrew Clarke, Lloyd Peck
Quasi-monthly samples of the Antarctic pectinid bivalve Adamussium colbecki were examined to determine the gametogenic pattern and periodicity. Both female and male gametogenic patterns show a very distinct seasonal development,…1 January, 2003
A conceptual model is proposed where bulk transtension, or local transtension during bulk simple shear (resulting from mantle anisotropy- or lithosphere rheology contrasts), of heterogeneously enriched lithospheric mantle, trigger localised…1 January, 2003
A major new synthesis of ophiolite geochronology and map of global Phanerozoic distribution indicates that previously noted pulses of ophiolite obduction can be linked to superplume-related tectonism. A marked cyclicity…Read more on Ophiolite obduction pulses as a proxy indicator of superplume events?
1 January, 2003 by Dominic Hodgson, David Vaughan, Gareth Marshall, John King, John Turner, Robert Mulvaney
The Intergovernmental Panel on Climate Change (IPCC) confirmed that mean global warming was 0.6 +/- 0.2degreesC during the 20th century and cited anthropogenic increases in greenhouse gases as the likely…Read more on Recent rapid regional climate warming on the Antarctic Peninsula
1 January, 2003 by Andy Smith, David Vaughan
The acoustic impedance of the subglacial material beneath 7.2 km profiles on four ice streams in Antarctica has been measured using a seismic technique. The ice streams span a wide…Read more on Acoustic impedance and basal shear stress beneath four Antarctic ice streams
1 January, 2003 by Dominic Hodgson
The water chemistry of lake systems on the edge of the Antarctic continent responds quickly to changes in the moisture balance. This is expressed as increasing salinity and decreasing lake…