Found 14035 items
1 January, 2006 by Melody Clark
Background Comparative approaches using protostome and deuterostome data have greatly contributed to understanding gene function and organismal complexity. The family 2 G-protein coupled receptors (GPCRs) are one of the largest…Read more on Evolution of secretin family GPCR members in the metazoa
1 January, 2006
The third primary production algorithm round robin (PPARR3) compares output from 24 models that estimate depth-integrated primary production from satellite measurements of ocean color, as well as seven general circulation…Read more on A comparison of global estimates of marine primary production from ocean color
1 January, 2006 by Jaume Forcada, Richard Phillips
With rare exceptions, avian offspring are continuously attended by one parent for at least the first few days after hatching. The duration of this phase of the nesting cycle is…1 January, 2006 by Richard Phillips
Studies attempting to document reproductive or other pre-lethal senescence effects in wild birds typically face an array of problems, including flaws in statistical analyses, non-adaptive philopatry to deteriorating environments, confounding…1 January, 2006 by Richard Phillips
Although there is increasing evidence that climatic variations during the non-breeding season shape population dynamics of seabirds, most aspects of their winter distribution and ecology remain essentially unknown. We used…1 January, 2006
Lidar observations of polar mesospheric clouds (PMC) were made at Rothera, Antarctica, from December 2002 to March 2005. Overall, 128 hours of PMC were detected among the 459 hours of…1 January, 2006
The diumal variations in the parameters of Pc3 (20–60 mHz) and Pc4 (10–19 mHz) pulsations at latitudes of the dayside cusp and polar cap have been studied using data of…1 January, 2006
Introduction In our studies [Chugunova et al., 2002,03,04] we found the occurrence of ULF waves in the nominal Рс3-4 band in the polar cap. About 15% of this ULF activity…1 January, 2006 by Andrew Clarke
The EASIZ (Ecology of the Antarctic Sea Ice Zone) programme ran from 1994 to 2004, and involved over 150 scientists from more than 17 countries. The main scientific aim was…1 January, 2006 by Andrew Clarke
In recent years, a number of species–energy hypotheses have been developed to explain global patterns in plant and animal diversity. These hypotheses frequently fail to distinguish between fundamentally different forms…1 January, 2006 by Mark Clilverd
During the sudden decrease of geosynchronous electron flux (>2 MeV) of 17:10–17:20 UT, January 21, 2005 large-scale precipitation into the atmosphere was observed. Estimates from ground-based radio propagation experiments at…1 January, 2006 by Mark Clilverd
At Ny Ålesund, Svalbard (78°54′N, 11°53′E, L ∼ 18), a narrowband VLF receiver was used to monitor the behavior of the amplitude of several high-power transmitters located in the Northern…Read more on Modeling polar ionospheric effects during the October-November 2003 solar proton events
1 January, 2006 by Mark Clilverd
We use a model for sunspot number using low-frequency solar oscillations, with periods 22, 53, 88, 106, 213, and 420 years modulating the 11-year Schwabe cycle, to predict the peak…1 January, 2006
The colonization of the underside of rocks normally requires that the material is sufficiently translucent to allow the penetration of photosynthetically active radiation. We examined the underside of 950 opaque…Read more on Hypolithic colonization of opaque rocks in the Arctic and Antarctic polar desert
1 January, 2006 by Martin Collins, Paul Rodhouse
The Southern Ocean cephalopod fauna is distinctive, with high levels of endemism in the squid and particularly in the octopodids. Loliginid squid, sepiids and sepiolids are absent from the Southern…1 January, 2006 by Martin Collins
The cirrate octopods are deep-sea, cold-adapted cephalopod molluscs that are found throughout the world's oceans, usually at depths in excess of 300 m, but shallower in cold water at high…Read more on Taxonomy, ecology and behaviour of the cirrate octopods
1 January, 2006 by Peter Convey
Antarctic terrestrial biota are generally limited by the inexorably linked environmental factors of low summer temperature and lack of available water. However, in parts of the Antarctic, both these factors…Read more on Responses of terrestrial Antarctic ecosystems to climate change
1 January, 2006 by Peter Convey
Question: How does geothermal activity influence terrestrial plant colonization, species composition and community development in the Antarctic? Location: South Sandwich Islands, maritime Antarctic. Methods: Bryophytes were documented during a biological…Read more on Geothermal bryophyte habitats in the South Sandwich Islands, maritime Antarctic
1 January, 2006 by Peter Convey
The consequences of climate change are exciting considerable concern worldwide. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. This paper…Read more on Antarctic terrestrial ecosystems: responses to environmental change
1 January, 2006 by Katrin Linse
The isolated Southern Ocean has given rise to specially adapted, endemic species. The uniformity of physical conditions within the Southern Ocean south of the Polar Front is thought to limit…1 January, 2006 by Adrian Jenkins, Hugh Corr, Keith Nicholls
This paper describes the novel technique of using a phase-sensitive radio-echo system to determine the basal melt rate along a short profile near Halley Station on the Brunt Ice Shelf.…Read more on Direct measurements of ice-shelf bottom melting rates by phase sensitive radar
1 January, 2006 by Geraint Tarling
We measured vertical migration of zooplankton in an arctic fjord at 79uN between June and September 2002 and transcending a period of continuous illumination to one of true day and…1 January, 2006 by Alistair Crame
The extensive Cretaceous sedimentary sequence exposed within the James Ross Basin, Antarctica, is critical for regional stratigraphic correlations in the Southern Hemisphere, and also for our understanding of the radiation…Read more on Mid-Cretaceous stratigraphy of the James Ross Basin, Antarctica
1 January, 2006 by Dominic Hodgson
Aim There is no previous direct evidence for the occurrence of lacustrine refuges for invertebrate fauna in Antarctica spanning the Last Glacial Maximum (LGM). In the absence of verified LGM…1 January, 2006
Despite the loss of CryoSat, ESA’s first Earth opportunity mission, during its launch sequence in Oct 2005 ESA have been fortunate enough to have acquired, processed to Level 1b and…1 January, 2006 by Janet Silk, Vsevolod Afanasyev
In temperate regions, winter presents animals with a number of challenges including depressed food abundance, increased daily energy requirements, higher frequency of extreme weather events and shortened day length. Overcoming…1 January, 2006
At Rothera Research Station (67.3°S, 68.1°W), Antarctica, 296 h of day and nighttime Fe-Boltzmann temperature lidar data were accumulated in 2003. During this time, sporadic iron layers (FeS) were observed…Read more on Statistics of sporadic iron and relation to atmospheric dynamics
1 January, 2006 by Hugh Corr
The polarisation behaviour of radar waves transmitted through Brunt Ice Shelf at a site near Halley has been investigated using a step-frequency radar with a centre frequency of 300 MHz…Read more on Polarisation of radio waves transmitted through Brunt Ice Shelf
1 January, 2006 by Adrian Jenkins, Hugh Corr, Keith Nicholls
We have collected ice penetrating polarimetric radar data on Brunt, George VI and Ronne ice shelves using a vector network analyser as a continuous wave (CW) step-frequency radar. Being a…Read more on Interpretation of polarimetric ice penetrating radar data over Antarctic ice shelves
1 January, 2006
After isostatic correction for their sedimentary fill, the depths of two small oceanic basins in the southern Scotia Sea suggest that both started to open in mid to late Eocene…Read more on Small basins in the Scotia Sea: the Eocene Drake Passage gateway
1 January, 2006 by Vsevolod Afanasyev
By attaching 9-g loggers (recording dusk and dawn times to a memory chip) to the coded leg rings of Barnacle Geese Branta leucopsis caught in a breeding colony at Tobseda…1 January, 2006
We analyze ground-based Fabry-Perot interferometer observations of upper thermospheric (∼250 km) horizontal neutral winds derived from Doppler shifts in the 630.0 nm (red line) nightglow. The winds were measured over…1 January, 2006
We analyze upper thermospheric (∼250 km) nighttime horizontal neutral wind patterns, during geomagnetically quiet (Kp < 3) conditions, over the following locations: South Pole (90°S), Halley (76°S, 27°W), Millstone Hill…1 January, 2006
Nitric oxide, which reacts catalytically to destroy ozone, can be produced in great abundance in the middle atmosphere during energetic particle precipitation triggered by solar storms. During the Antarctic winter,…1 January, 2006 by Eugene Murphy
A time-dependent, size-structured, physiologically based krill growth model was used in conjunction with a circulation model to test the hypothesis that Antarctic krill (Euphausia superba) populations at South Georgia are…1 January, 2006 by Adrian Jenkins, Keith Nicholls
The field work during ”Polarstern” cruise ANT XVI/2 aimed to measure circulation and water mass properties in the Atlantic sector of the Southern Ocean, to investigate the contribution of the…1 January, 2006
Sea ice is a two-phase, two-component, reactive porous medium: an example of what is known in other contexts as a mushy layer. The fundamental conservation laws underlying the mathematical description…1 January, 2006 by Fausto Ferraccioli, Philip Leat
New airborne geophysical data reveal subglacial imprints of crustal growth of the Antarctic Peninsula by Mesozoic arc magmatism and terrane accretion along the paleo-Pacific margin of Gondwana. Potential field signatures…Read more on New aerogeophysical view of the Antarctic Peninsula: more pieces, less puzzle
1 January, 2006
Zircons gneisses and migmatites collected from the Antarctic Peninsula have different core–rim hafnium isotope ratio relationships depending on whether evidence for zircon dissolution is present or absent. Two samples contain…1 January, 2006 by Eugene Murphy, Jaume Forcada, Philip Trathan
Climate warming and associated sea ice reductions in Antarctica have modified habitat conditions for some species. These include the congeneric Adélie, chinstrap and gentoo penguins, which now demonstrate remarkable population…1 January, 2006 by Jaume Forcada
Winter dispersal in leopard seals is poorly understood because of its low density in most of its range. By combining photo-identification and tagging data from Bird Island, South Georgia, in…1 January, 2006 by Andrew Clarke
We suggest that the epibenthic communities of passive suspension feeders that dominate some high-Antarctic seafloors present unique archaic features that are the result of long isolation, together with the effects…1 January, 2006 by Fausto Ferraccioli
For a number of years the multi-national ADMAP working group has been compiling near surface and satellite magnetic data in the region south of 60° S. By the end of…Read more on ADMAP – a digital magnetic anomaly map of the Antarctic
1 January, 2006 by Mark Preston, Philip Trathan
The use of automated systems to record the identity of individual penguins and their movements in and out of a colony can provide an effective means of studying penguin biology…1 January, 2006 by Hilmar Gudmundsson
Most of the ice lost from the Antarctic ice sheet passes through a few fast-flowing and highly dynamic ice streams(1). Quantifying temporal variations in flow in these ice streams, and…Read more on Fortnightly variations in the flow velocity of Rutford Ice Stream, West Antarctica
1 January, 2006
We present a multiple regression analysis of time series of the leading modes of variability in high latitudes, the Northern and Southern Annular Modes (NAM and SAM). The potential forcing…1 January, 2006 by Alistair Crame
Considerable controversy exists concerning the stability of the Antarctic Ice Sheet during the Neogene Period. The northern Antarctic Peninsula is in a critical position in this debate as it represents…1 January, 2006
Increasing evidence exists that the strong warming of the West Antarctic Peninsula (WAP) region since the 1950s is related to reduced sea ice that is likely to be due to…1 January, 2006
The contribution of the atmospheric circulation to a record minimum extent of open water in the polar Ross Sea (RS) region in the 2003 austral summer is examined. Two major…1 January, 2006 by Roger Worland
1. Cold tolerance is a fundamental adaptation of insects to high latitudes. Flexibility in the cold hardening process, in turn, provides a useful indicator of the extent to which polar…1 January, 2006 by Roger Worland, Peter Convey
Modality in the supercooling points of cold tolerant but freezing intolerant terrestrial arthropods has proved a pragmatically reliable means of distinguishing between summer and winter cold hardiness in such species.…Read more on Ecologically realistic modalities in arthropod supercooling point distributions
1 January, 2006
We present data from the European Space Agency's Airborne SAR/Interferometric Radar Altimeter System (ASIRAS), flown during the CryoVex 2004 field calibration/validation campaign, and new, high-resolution depth profiles of snow density…Read more on ASIRAS airborne radar resolves internal annual layers in the dry-snow zone of Greenland
1 January, 2006
We have made side-by-side measurements in several boreholes at Summit, Greenland, using borehole optical stratigraphy (BOS) and neutron-scattering density logging techniques. The BOS logs show strong positive correlation at shallow…1 January, 2006 by Alistair Crame
The fossilized remains of Cretaceous angiosperm leaves are preserved within sandstones and siltstones of the Coniacian Hidden Lake Formation (Gustav Group) and the Santonian-early Campanian Santa Marta Formation (Marambio Group)…1 January, 2006
In this study we employ the TRIFFID (Top-down Representation of Interactive Flora and Foliage Including Dynamics) Dynamic Global Vegetation Model (DGVM) and the Hadley Centre Atmospheric General Circulation Model version…1 January, 2006 by Peter Convey
Antarctic ecosystems represent one extreme of the continuum of environmental conditions across the planet. To our eyes, the environment appears harsh but, even though terrestrial biological diversity is restricted, a…Read more on Physiological traits of organisms in a changing environment
1 January, 2006 by Robert Larter
A Fossil Mounded Sedimentary Body (MB) has been identified in the sedimentary record on the central continental rise west of Adelaide Island, on the Antarctic Peninsula Pacific margin. The growth…1 January, 2006
An imaging Doppler interferometer (IDI) at Halley, Antarctica (76°S, 26°W) has been used to record near continuous mean winds in the mesosphere/lower thermosphere since December 1996. Monthly mean winds are…Read more on Mean winds and tides in the mesosphere and lower thermosphere above Halley, Antarctica
1 January, 2006 by Eugene Murphy, Philip Trathan, Simeon Hill
The ecosystem approach to fisheries recognises the interdependence between harvested species and other ecosystem components. It aims to account for the propagation of the effects of harvesting through the food-web.…Read more on Modelling Southern Ocean ecosystems: krill, the food-web, and the impacts of harvesting
1 January, 2006 by Claus-Dieter Hillenbrand
Oceanic stratification represents an effective mechanism to reduce vertical mixing of the water column, thereby locking up carbon dioxide (CO2) in the deep sea and preventing air–sea exchange of CO2.…Read more on Polar stratification: A critical view from the Southern Ocean
1 January, 2006 by Richard Hindmarsh, Richard Hindmarsh
Membrane stresses act along thin bodies which are relatively well lubricated on both surfaces. They operate in ice sheets because the bottom is either sliding, or is much less viscous…1 January, 2006 by Hilmar Gudmundsson, Richard Hindmarsh, Richard Hindmarsh
Internal isochronic layers in ice sheets sensed by radar show two characteristic relationships to the basal topography: Either they override it, with layers above the crests of rises lying essentially…1 January, 2006 by Richard Hindmarsh, Richard Hindmarsh
Calculations of thermomechanically coupled ice sheet evolution using the shallow ice approximation exhibit the development of fingering instabilities in velocity, temperature, and thickness, which have been argued to resemble and…Read more on Stress gradient damping of thermoviscous ice flow instabilities
1 January, 2006
Using a global data set on egg hatch times in zooplanktonic and nektonic ectotherms from marine waters, the combined effects of body size, temperature and life-history attributes on development times…1 January, 2006 by Dominic Hodgson
We reconstruct terrestrial and freshwater environments of the last two Quaternary interglacials in coastal east Antarctica by examining multi-proxy evidence in a lake sediment core. The record, from Progress Lake…1 January, 2006 by Dominic Hodgson, James Smith, Stephen Roberts
Temperatures on the Antarctic Peninsula are increasing at a rate of 3.4°C per century, more than five times the global mean. At the same time, the region's ice shelves have…Read more on Examining Holocene stability of Antarctic Peninsula ice shelves
1 January, 2006 by Dominic Hodgson
Research in East Antarctica has shown several recent environmental changes that may be linked to human impacts on climate. In order to detect the influence and context of these changes…Read more on Recent rapid salinity rise in three East Antarctic lakes
1 January, 2006 by Jaume Forcada
Published studies of wild vertebrate populations have almost universally reported positive associations between genetic variation measured at microsatellite loci and fitness, creating the impression of ubiquity both in terms of…1 January, 2006 by Philip Trathan
Genetic tagging, the identification of individuals using their genotypes, provides a powerful tool for studying animals that are difficult to observe or identify using conventional techniques. However, despite being widely…1 January, 2006 by Kevin Newsham, Peter Convey
Antarctic terrestrial ecosystems are noted for their relative simplicity and limited trophic structure. In this context, knowledge of biotic interactions in structuring terrestrial soil communities would seem beneficial from a…Read more on Biotic interactions in Antarctic terrestrial ecosystems: are they a factor?
1 January, 2006 by Paul Holland
A model of the dynamics and thermodynamics of a plume of meltwater at the base of an ice shelf is presented. Such ice shelf water plumes may become supercooled and…Read more on The effects of rotation and ice shelf topography on frazil-laden ice shelf water plumes
1 January, 2006 by David Vaughan, Hugh Corr
Airborne radar sounding over the Thwaites Glacier (TG) catchment and its surroundings provides the first comprehensive view of subglacial topography in this dynamic part of the West Antarctic Ice Sheet…1 January, 2006 by Richard Horne, Sarah Glauert
During the declining phase of the solar cycle fast solar wind streams produce corotating interaction regions (CIRs) that drive moderate geomagnetic storms. These storms often have an unusually long recovery…Read more on Mechanisms for the acceleration of radiation belt electrons
1 January, 2006 by Kevin Hughes
This study shows that increased UV-B arising from stratospheric ozone depletion over Antarctica reduced cell viability and the maximum quantum yield of photochemistry (F v/F m) in a unicellular terrestrial…1 January, 2006 by Kevin Hughes, Peter Convey
In the Arctic, seasonal ozone depletion is resulting in periods of enhanced UV-B radiation at ground level while regional climate change is associated with increasing temperatures. These changes are likely…1 January, 2006 by David Barnes
Fatty acid analyses are emerging as a powerful technique to probe trophic interactions between organisms. In this paper, the application of both this procedure and gonad index (GI) determination on…1 January, 2006 by Kevin Hughes, Peter Convey
1 January, 2006 by Kevin Hughes
Fuel oil has been extensively relied upon as an energy source since the earliest discovery and exploration of Antarctica. During this time oil spills have occurred, particularly around established research…Read more on Oil pollution in the Antarctic terrestrial environment
1 January, 2006
Dating Jurassic terrestrial floras in the Antarctic Peninsula has proved problematic and controversial. Here U–Pb series dating on detrital zircons from a conglomerate interbedded with fossil plant material provide a…1 January, 2006
Recent detailed mapping, section logging and an improved understanding of the geological evolution of the Antarctic Peninsula provide a robust framework for an improved lithostratigraphic subdivision of the Latady Basin,…1 January, 2006 by Teal Riley
The Jurassic Mount Poster Formation of eastern Ellsworth Land, southern Antarctic Peninsula, comprises silicic ignimbrites related to intracontinental rifting of Gondwana. The identification of less voluminous basaltic and sedimentary facies…