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1

An extreme wind event at Casey Station, Antarctica  

NASA Astrophysics Data System (ADS)

Model output, satellite data, and in situ observations are used to investigate the conditions that gave rise to an extreme wind event at the Australian Casey Station (66.27°S, 110.53°E) on the coast of East Antarctica. The event took place over the period March 20-22, 1992, and resulted in Casey Station's highest ever wind gust for March (66.9 m s-1, 130 knots) and 10 m mean winds of near 50 m s-1. The event occurred when a deep low was located just north of the coast and there was high surface pressure inland. The rapid deepening of the low took place within a strong baroclinic zone lying north-south between a cold trough and a ridge bringing very warm air southward. A conceptual model is proposed for the very strong winds experienced at Casey Station. Key elements of the model are (1) a synoptic-scale high-low pressure couplet, providing a strengthening pressure gradient; (2) entrainment of radiatively cooled air by the supercritical synoptic gradient, leading to downslope flow; (3) the acceleration of the wind down the lee slope of Law Dome, occurring primarily in response to a topographically induced, long-period, vertically propagating gravity wave; and (4) sources of negative buoyancy, including prestorm radiatively cooled air and, later in the storm, maritime air cooled by heat flux to the ice surface. The topographically induced gravity wave increases the horizontal temperature difference, thus increasing the negative buoyancy of the surface airflow.

Turner, John; Lachlan-Cope, Tom A.; Marshall, Gareth J.; Pendlebury, Stephen; Adams, Neil

2001-04-01

2

Water treatment design for site remediation at Casey Station, Antarctica: site characterisation and particle separation  

Microsoft Academic Search

Antarctica is commonly regarded as a pristine environment, but more than a century of human activity has left an extensive legacy of abandoned waste. The Australian Antarctic Division (AAD) has identified the Thala Valley Tip near Casey Station as a high priority site for remediation. However, there are difficulties with regards to contaminant dispersal by melt-water during extraction of wastes

Kathy A. Northcott; Ian Snape; Michael A. Connor; Geoffrey W. Stevens

2003-01-01

3

Hydraulic performance of a permeable reactive barrier at Casey Station, Antarctica.  

PubMed

A permeable bio-reactive barrier (PRB) was installed at Casey Station, Antarctica in 2005/06 to intercept, capture and degrade petroleum hydrocarbons from a decade old fuel spill. A funnel and gate configuration was selected and implemented. The reactive gate was split into five separate cells to enable the testing of five different treatment combinations. Although different treatment materials were used in each cell, each treatment combination contained the following reactive zones: a zone for the controlled release of nutrients to enhance degradation, a zone for hydrocarbon capture and enhanced degradation, and a zone to capture excess nutrients. The materials selected for each of these zones had other requirements, these included; not having any adverse impact on the environment, being permeable enough to capture the entire catchment flow, and having sufficient residence time to fully capture migrating hydrocarbons. Over a five year period the performance of the PRB was extensively monitored and evaluated for nutrient concentration, fuel retention and permeability. At the end of the five year test period the material located within the reactive gate was excavated, total petroleum hydrocarbon concentrations present on the material determined and particle size analysis conducted. This work found that although maintaining media reactivity is obviously important, the most critical aspect of PRB performance is preserving the permeability of the barrier itself, in this case by maintaining appropriate particle size distribution. This is particularly important when PRBs are installed in regions that are subject to freeze thaw processes that may result in particle disintegration over time. PMID:25078614

Mumford, K A; Rayner, J L; Snape, I; Stevens, G W

2014-12-01

4

Blowing snow at Mizuho station, Antarctica.  

PubMed

Blowing snow observations were carried out at Mizuho station, Antarctica, from October to November 2000. A blowing snow observation system including snow particle counters, which can sense not only the number of snow particles, but also their diameters, was situated on a 30 m tower. All instruments worked correctly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. Measurements were compared with a blowing snow model that accounted for most physical processes including aerodynamic entrainment, grain/bed collisions, wind modification, particle size distribution and turbulent fluctuations on the particle trajectories. Simulated and measured results showed close agreement, and the validity of the model was demonstrated. Vertical profiles of horizontal mass flux from saltation to suspension, as well as the particle size distributions were expressed precisely, which could not be achieved using the previous models. PMID:16011937

Nishimura, Kouichi; Nemoto, Masaki

2005-07-15

5

Measurement of moss growth in continental Antarctica  

Microsoft Academic Search

Using steel pins inserted into growing moss colonies near Casey Station, Wilkes Land, continental Antarctica, we have measured\\u000a the growth rate of three moss species: Bryum pseudotriquetrum and Schistidium antarctici over 20 years and Ceratodon purpureus over 10 years. This has provided the first long-term growth measurements for plants in Antarctica, confirming that moss shoots\\u000a grow extremely slowly in Antarctica, elongating between

P. M. Selkirk; M. L. Skotnicki

2007-01-01

6

A mesoscale vortex over Halley Station, Antarctica  

SciTech Connect

A detailed analysis of the evolution and structure of a mesoscale vortex and associated cloud comma that developed at the eastern edge of the Weddell Sea, Antarctica, during the early part of January 1986 is presented. The system remained quasi-stationary for over three days close to the British research station Halley (75[degrees]36'S, 26'42[degrees]W) and gave severe weather with gale-force winds and prolonged snow. The formation and development of the system were investigated using conventional surface and upper-air meteorological observations taken at Halley, analyses from the U.K. Meteorological Office 15-level model, and satellite imagery and sounder data from the TIROS-N-NOAA series of polar orbiting satellites. The thermal structure of the vortex was examined using atmospheric profiles derived from radiance measurements from the TIROS Operational Vertical Sounder. Details of the wind field were examined using cloud motion vectors derived from a sequence of Advanced Very High Resolution Radiometer images. The vortex developed inland of the Brunt Ice Shelf in a strong baroclinic zone separating warm air, which had been advected polewards down the eastern Weddell Sea, and cold air descending from the Antarctic Plateau. The system intensified when cold, continental air associated with an upper-level short-wave trough was advected into the vortex. A frontal cloud band developed when slantwise ascent of warm air took place at the leading edge of the cold-air outbreak. Most of the precipitation associated with the low occurred on this cloud band. The small sea surface-atmospheric temperature differences gave only limited heat fluxes and there was no indication of deep convection associated with the system. The vortex was driven by baroclinic forcing and had some features in common with the baroclinic type of polar lows that occur in the Northern Hemisphere. 25 refs., 14 figs.

Turner, J.; Lachlan-Cope, T.A.; Warren, D.E. (British Antarctic Survey, Cambridge (United Kingdom)); Duncan, C.N. (Univ. of Edinburgh (United Kingdom))

1993-05-01

7

Antarctica: A Southern Hemisphere Windpower Station?  

E-print Network

The International Polar Year commences in 2007. We offer a macroproject plan to generate a large amount of electricity on the continent of Antarctica by using sail-like wind dams incorporating air turbines. Electricity can be used to make exploration and exploitation efforts on Antarctica easier. We offer the technical specifications for the Fabric Aerial Dam and indicate some of the geographical facts underpinning our macro-engineering proposal.

Alexander A. Bolonkin; Richard B. Cathcart

2007-01-04

8

Observations of Pc2 waves by Cluster and ground stations in Antarctica  

NASA Astrophysics Data System (ADS)

We analyzed a Pc2 wave event above the He+ cyclotron frequency detected by the four Cluster satellites and multiple ground stations in Antarctica. During the wave event, Cluster satellites were located sunward from L~13 in the outer magnetosphere to the magnetopause, over 13o - 20o magnetic latitude, north of the equator near local magnetic noon. The Poynting flux results show that the wave packet energy propagated dominantly along the geomagnetic field direction and in alternating directions rather than uni-directionally from the equator, implying the wave source was located in a high latitude region away from the equator, where a minimum in the B field is located. The footprint of Cluster was closest to the Zhong Shan and Davis (ZHS/DAV) stations (L~14) in Antarctica. Consequently, the frequency range and the burst-pattern of the dynamic spectra from ZHS and DAV are highly consistent with those seen by Cluster. Although wave packets on Cluster occurred from 0800 UT to 1430 UT, lasting for 6.5 hours, the wave bursts on ZHS and DAV stations were concentrated earlier at 0800-1040 UT. This suggests the azimuthal extent of the wave source may be estimated at 2.6 hours and the wave packets were guided by the field lines from Cluster to ZHS/DAV. The waves at Mawson (L~9) and Casey (L~38.8) are rather weak and the wave burst-patterns appear obviously different from those at ZHS/DAV and Cluster, suggesting the wave energy propagated toward both high and low latitudes via the inonospheric waveguide.

Liu, Y.

2013-12-01

9

Measurements of enhanced springtime ultraviolet radiation at Palmer Station, Antarctica  

Microsoft Academic Search

Measurements of ultraviolet solar spectra from Palmer Station, Antarctica have defined the surface radiation environment of the region during the Austral spring of 1988. At wavelengths where absorption by ozone is negligible, 335-345 nm, the noontime irradiances show the expected gradual increase from the first day of measurements, September 19 through December 21. Large variations related to cloudiness are imposed

Dan Lubin; John E. Frederick; C. Rocky Booth; Timothy Lucas; David Neuschuler

1989-01-01

10

Biodiversity of air-borne microorganisms at Halley station, Antarctica  

Microsoft Academic Search

A study of air-borne microbial biodiversity over an isolated scientific research station on an ice-shelf in continental Antarctica\\u000a was undertaken to establish the potential source of microbial colonists. The study aimed to assess: (1) whether microorganisms\\u000a were likely to have a local (research station) or distant (marine or terrestrial) origin, (2) the effect of changes in sea\\u000a ice extent on

David A. PearceK; K. A. Hughes; T. Lachlan-Cope; S. A. Harangozo; A. E. Jones

2010-01-01

11

Concordia CCD - A Geoscope station in continental Antarctica  

NASA Astrophysics Data System (ADS)

Concordia (Dome C, Antarctica) has had a permanent seismic station since 2005. It is run by EOST and INGV in collaboration with the French and Italian polar institutes (IPEV and PNRA). It is installed in an ice-vault, at 12m depth, distant 1km from the permanent scientific base at Concordia. The temperature in the vault is a constant -55°C. The data quality at the station has improved continuously since its installation. In 2007, the station was declared at ISC as an open station with station code CCD (ConCorDia), with data available upon request. It is only the second permanent station in the Antarctic continent, after South Pole. In 2010, CCD was included in the Geoscope network. Data from CCD starting in 2007 are now freely available from the Geoscope Data Center and IRIS. We present an analysis of the data quality at CCD, and describe the technical difficulties of operating an observatory-quality seismic station in the extreme environmental conditons present in continental Antarctica.

Maggi, A.; Lévêque, J.; Thoré, J.; Bes de Berc, M.; Bernard, A.; Danesi, S.; Morelli, A.; Delladio, A.; Sorrentino, D.; Stutzmann, E.; Geoscope Team

2010-12-01

12

VLF wave injection into the magnetosphere from Siple Station, Antarctica  

Microsoft Academic Search

Radio signals in the 1.5- to 16-kHz range transmitted from Siple Station, Antarctica (L = 4), are used to control wave-particle interactions in the magnetosphere. Observations at the conjugate point show signal growth and triggered emissions including risers, failers, and hooks. Growth rates of the order of 100 dB\\/s and total gains up to 30 dB are observed. Triggered emissions

R. A. Helliwell; J. P. Katsufrakis

1974-01-01

13

JARE Syowa Station 11-m Antenna, Antarctica  

NASA Technical Reports Server (NTRS)

In 2012, the 52nd and the 53rd Japanese Antarctic Research Expeditions (hereinafter, referred to as JARE-52 and JARE-53, respectively) participated in five OHIG sessions - OHIG76, 78, 79, 80, and 81. These data were recorded on hard disks through the K5 terminal. Only the hard disks for the OHIG76 session have been brought back from Syowa Station to Japan, in April 2012, by the icebreaker, Shirase, while those of the other four sessions are scheduled to arrive in April 2013. The data obtained from the OHIG73, 74, 75, and 76 sessions by JARE-52 and JARE-53 have been transferred to the Bonn Correlator via the servers of National Institute of Information and Communications Technology (NICT). At Syowa Station, JARE-53 and JARE-54 will participate in six OHIG sessions in 2013.

Aoyama, Yuichi; Doi, Koichiro; Shibuya, Kazuo

2013-01-01

14

The New Very Broadband Seismic Station TROLL, Antarctica  

NASA Astrophysics Data System (ADS)

Troll is the name of the Norwegian permanent research station in Dronning Maud Land, Antarctica. The research base is located inside the continent, at an elevation of about 1300 m and at a distance of about 230 km from the shelf ice border. In the first week of February 2012, a new very broadband seismic station was installed at TROLL. Contrary to many other seismic stations inside the Antarctic continent, the new seismic sensor could be installed on bedrock (migmatite), on a hill at about 300 m distance from the main buildings of the Troll research base. A bedrock installation has the advantage that seismic signals are not disturbed by multiples due to the thick Antarctic ice sheet. The equipment consists of a Streckeisen STS-2.5 broadband sensor and a Quanterra Q330HR 26 bit digitizer. All data are transferred in real time via a satellite link to NORSAR for analysis and further distribution. During the first year, the new seismic station and corresponding data transmission has been running very stably. Initial analysis of the station's event detection capability shows that the performance is comparable to, and sometimes better than, the best performing three-component stations of the International Monitoring System (IMS). We will present examples of diurnal and seasonal variations in the background noise level of the station, the observed global, regional and local seismicity, and the very exciting monitoring capabilities of icebergs drifting along the coast of Dronning Maud Land.

Kvaerna, Tormod; Schweitzer, Johannes; Pirli, Myrto; Roth, Michael

2013-04-01

15

Measurements of enhanced springtime ultraviolet radiation at Palmer Station, Antarctica  

NASA Astrophysics Data System (ADS)

Measurements of ultraviolet solar spectra from Palmer Station, Antarctica have defined the surface radiation environment of the region during the Austral spring of 1988. At wavelengths where absorption by ozone is negligible, 335-345 nm, the noontime irradiances show the expected gradual increase from the first day of measurements, September 19 through December 21. Large variations related to cloudiness are imposed on this background. At wavelengths less than 310 nm the influence of the 1988 ozone 'hole' is apparent. The noontime irradiance observed in the wavelength band 295-305 nm October 19, two months prior to summer solstice, exceeded any value measured through December 21.

Lubin, Dan; Frederick, John E.; Booth, C. Rocky; Lucas, Timothy; Neuschuler, David

1989-08-01

16

Record low ozone measured at McMurdo Station, Antarctica, during the austral spring of 1993  

SciTech Connect

The annual springtime ozone hole over Antarctica has been studied extensively since it was first reported. The University of Wyoming has participated in monitoring the development of the ozone hole over Antarctica since 1986 using balloonborne instruments to measure vertical profiles of ozone and particles at McMurdo Station, Antarctica. During austral spring 1993, record minimums in total column ozone were observed along with a record low within the main ozone layer at 12-20 kilometers (km). 6 refs., 2 figs.

Johnson, B.J.; Deshler, T. [Univ. of Wyoming, Laramie, WY (United States)

1994-12-31

17

Antarctica  

Atmospheric Science Data Center

article title:  Twilight in Antarctica     View larger JPEG image  (51 kb) Twilight in Antarctica, February 24, 2000 . Nearly 15 times every 24 hours, the Terra ... - The Ross Ice Shelf and the Transantarctic Mountains of Antarctica at twilight. project:  MISR category:  ...

2013-04-16

18

Monitoring the remediation of a near shore waste disposal site in Antarctica using the amphipod Paramoera walkeri and diffusive gradients in thin films (DGTs)  

Microsoft Academic Search

The water quality of a marine embayment (Brown Bay) was monitored during the remediation of an abandoned waste disposal site at Casey Station, East Antarctica, using a combination of biomonitoring and chemical methods. The Antarctic amphipod Paramoera walkeri, in field mesocosms suspended in the water column, was deployed adjacent to the site and at two reference sites for periods of

Jonathan S. Stark; Glenn J. Johnstone; Anne S. Palmer; Ian Snape; Bronwyn L. Larner; Martin J. Riddle

2006-01-01

19

Antarctica  

NSDL National Science Digital Library

A variety of classroom activities and lessons on Antarctica from the Gulf of Maine Aquarium, including: Coping with the Cold, Blubber Glove, Salt Concentration, Penguin Adaptation, Chick Die-Off, Changes in Antarctic Ice, and Creating Plankton. Discover how penguins are the "litmus paper of the sea," see satellite imagery of the changing ice formations around Antarctica, and learn how animals can survive in sub-freezing water. Links to other Aquarium modules.

20

A special ozone observation at Syowa Station, Antarctica from February 1982 to January 1983  

NASA Technical Reports Server (NTRS)

The behavior of stratospheric ozone at high latitudes is especially interesting, since the stratospheric ozone at high latitudes is thought to be transported from low latitudes through dynamical processes. However, only limited information has so far been obtained, because ozone observations at high latitudes are sparse. There are only two ozone observation stations operating in Antarctica: Syowa Station and Amundsen-Scott, where the total ozone has been observed in sunlit months only. To make up for this deficiency, extensive observations were carried out at Syowa Station as part of MAP. Some preliminary results of these observations are described.

Chubachi, S.

1985-01-01

21

A special ozone observation at Syowa Station, Antarctica from February 1982 to January 1983  

NASA Astrophysics Data System (ADS)

The behavior of stratospheric ozone at high latitudes is especially interesting, since the stratospheric ozone at high latitudes is thought to be transported from low latitudes through dynamical processes. However, only limited information has so far been obtained, because ozone observations at high latitudes are sparse. There are only two ozone observation stations operating in Antarctica: Syowa Station and Amundsen-Scott, where the total ozone has been observed in sunlit months only. To make up for this deficiency, extensive observations were carried out at Syowa Station as part of MAP. Some preliminary results of these observations are described.

Chubachi, S.

1985-12-01

22

Absolute-gravity stations in Western Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

Absolute-gravity stations are an important part of the geodetic infrastructure of the Antarctic. They provide accurate starting values for gravity surveys performed e.g. for the determination of the geoid, for geological studies and for geophysical investigations. The time variation in gravity determined from repeated absolute-gravity measurements provides insights into the Glacial Isostatic Adjustment (GIA) and into solid Earth deformation due to variation in contemporary ice load. Given sufficient joint coverage with International Terrestrial Reference Frame (ITRF) sites, gravity rates in high latitudes could in principle provide an independent check of the geocentricity of the z-dot (velocities in the direction of the rotation axis of the Earth) of the ITRF. We review the absolute gravity stations in Western and Central Dronning Maud Land. The oldest station is at the Finnish base Aboa, with 5 measurements by the Finnish Geodetic Institute (FGI) starting with the FINNARP 1993 expedition. Measurements at Maitri (India) and Novolazarevskaya (Russia) were first performed in 2004 by the National Geophysical Research Institute (NGRI) of India, and by the FGI, respectively. In the season 2010/11 a new station was constructed at Troll (Norway). In the season 2011/12 the aforementioned four sites were occupied by the FG5-221 absolute gravimeter of the FGI. At Sanae IV (South Africa) there are previous occupations by the FG5-221, in 2003/4 and 2005/6. All these bases have continuous GNSS stations. Numerous supporting measurements have been made at the sites: microgravity networks, levelling and GNSS ties to excentres etc., for controlling the stability of the stations. At some sites, nearby glacier elevations were surveyed to monitor the attraction of the variable close-field snow and ice masses. We give a description of the sites and the measurements performed at them. The work has benefited from the co-operation in the COST Action ES0701 "Improved Constraints on Models of GIA".

Mäkinen, Jaakko; Rasindra, Ravik; Chand, Uttam; Tiwari, Virendra; Lukin, Valery; Anisimov, Michail; Melvaer, Yngve; Melland, Gudmund; Koivula, Hannu; Näränen, Jyri; Poutanen, Markku

2013-04-01

23

Snowpack Chemistry of Reactive Gases at Station Concordia, Antarctica  

NASA Astrophysics Data System (ADS)

During December 2012 a new experiment for the study of snow photochemical processes and surface gas exchange was installed at Dome Concordia, Antarctica. The experiment consists of two sampling manifolds ('snow tower') which facilitate the withdrawal of interstitial firn air from four depths in the snowpack and from above the surface. One of these snow towers can be shaded for investigation of the dependency of snow chemistry on solar radiation. A nearby 12 m meteorological tower facilitates above surface turbulence and trace gas gradient measurements. Temperature profiles and UV and IR light penetration are monitored in the snowpack. Air samples are directed through sampling lines to a nearby underground laboratory that houses the experiment control system and gas monitors. The system is fully automated, sampling gases from the array of inlet ports sequentially, and is intended to be operated continuously for a full annual cycle. The computerized control system can be accessed remotely for data retrieval and quality control and for configuring experimental details. Continuous gas measurements include ozone, nitrogen oxides, methane, carbon monoxide, and gaseous elemental mercury. Whole air samples were sampled on four occasions for volatile organic compound analysis. The objective of this research is the study of the year-round snowpack gas chemistry and its dependency on snowpack and above surface physical and environmental conditions. A particular emphasis will be the investigation of the effects of increased UV radiation during the occurrence of the stratospheric ozone hole. We will present the conceptual design of the experiment and data examples from the first three months of the experiment.

Helmig, Detlev; Mass, Alex; Hueber, Jacques; Fain, Xavier; Dommergue, Aurelien; Barbero, Albane; Savarino, Joel

2013-04-01

24

Application of ground-penetrating radar at McMurdo Station, Antarctica  

SciTech Connect

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

Stefano, J.E.

1992-01-01

25

Application of ground-penetrating radar at McMurdo Station, Antarctica  

SciTech Connect

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

Stefano, J.E.

1992-05-01

26

Immune System Dysregulation and Latent Herpesvirus Reactivation During Winterover at Concordia Station, Dome C, Antarctica  

NASA Technical Reports Server (NTRS)

Immune system dysregulation occurs during spaceflight and consists of altered peripheral leukocyte distribution, reductions in immunocyte function and altered cytokine production profiles. Causes may include stress, confinement, isolation, and disrupted circadian rhythms. All of these factors may be replicated to some degree in terrestrial environments. NASA is currently evaluating the potential for a ground-based analog for immune dysregulation, which would have utility for mechanistic investigations and countermeasures evaluation. For ground-based space physiology research, the choice of terrestrial analog must carefully match the system of interest. Antarctica winter-over, consisting of prolonged durations in an extreme/dangerous environment, station-based habitation, isolation and disrupted circadian rhythms, is potentially a good ground-analog for spaceflight-associated immune dysregulation. Of all Antarctica bases, the French-Italian Concordia Station, may be the most appropriate to replicate spaceflight/exploration conditions. Concordia is an interior base located in harsh environmental conditions, and has been constructed to house small, international crews in a station-environment similar to what should be experienced by deep space astronauts. The ESA-NASA CHOICE study assessed innate and adaptive immunity, viral reactivation and stress factors during Concordia winterover deployment. The study was conducted over two winterover missions in 2009 and 2010. Final study data from NASA participation in these missions will be presented.

Crucian, B. E.; Feuerecker, M.; Salam, A. P.; Rybka, A.; Stowe, R. P.; Morrels, M.; Meta, S. K.; Quiriarte, H.; Quintens, Roel; Thieme, U.; Kaufmann, I.; Baatout, D. S.; Pierson, D. L.; Sams, C. F.; Chouker, A.

2011-01-01

27

Gravity measurements with a portable absolute gravimeter A10 in Syowa Station and Langhovde, East Antarctica  

NASA Astrophysics Data System (ADS)

Absolute gravity values were measured with a portable absolute gravimeter A10 in East Antarctica, for the first time by the Japanese Antarctic Research Expedition. This study aims to investigate regional spatiotemporal variations of ice mass distributions and associated crustal deformations around Syowa Station by means of repeated absolute gravity measurements, and we obtained the first absolute gravity value in Southern Langhovde on the Antarctic Continent. The average absolute gravity value at the newly installed benchmark AGS01 in Langhovde (obtained on 3 February 2012) was 982535584.2 ± 0.7 ?gal (1 [?gal] = 1 × 10-8 [m/s2]), which was in agreement with the gravity values obtained by the past relative gravity measurements within 1 mgal. In addition, the average absolute gravity value obtained at AGSaux in Syowa Station was consistent with both previous absolute gravity values and those obtained by simultaneous measurements using an FG5 gravimeter, owing to adequate data corrections associated with tidal effects and time variations in atomic clock frequencies. In order to detect the gravity changes associated with the ice mass changes and other tectonic phenomena, we plan to conduct absolute gravity measurements at AGS01 again and at other campaign sites around Syowa Station as well in the near future, with careful attention paid to the impacts of severe environmental conditions in Antarctica on gravity data collection.

Kazama, Takahito; Hayakawa, Hideaki; Higashi, Toshihiro; Ohsono, Shingo; Iwanami, Shunsuke; Hanyu, Tomoko; Ohta, Harumi; Doi, Koichiro; Aoyama, Yuichi; Fukuda, Yoichi; Nishijima, Jun; Shibuya, Kazuo

2013-09-01

28

Geochemical markers of soil anthropogenic contaminants in polar scientific stations nearby (Antarctica, King George Island).  

PubMed

The organic contamination of Antarctic soils and terrestrial sediments from nearby of five polar scientific stations on King George Island (Antarctica) was investigated. Gas chromatography-mass spectrometry (GC-MS) was applied to find composition of dichloromethane extracts of soil and terrestrial sediments. The presence of geochemical markers, such as n-alkanes, steranes, pentacyclic triterpenoids, and alkyl PAHs, their distribution types, and values of their ratios indicates the predominating source of organic fossil fuels and products of their refining rather than from the natural Antarctic environment. Fossil fuel-originated compounds well survived in conditions of Antarctic climate over long times thus enabling to characterize geochemical features of source fossil fuel identified as petroleum expelled from kerogen II of algal/bacterial origins deposited in sub-oxic conditions and being in the middle of catagenesis. Both microbial activity and water leaching play an important role in degradation of terrestrial oil spills in the Antarctica climate, and petroleum alteration occurs lowly over long periods of time. Synthetic anthropogenic compounds found in terrestrial Antarctica sediments included diisopropylnaphthalenes, products of their sulfonates degradation in paper combustion, and organophosporus compounds used as retardants and plasticizers. PMID:25770449

Prus, Wojciech; Fabia?ska, Monika J; ?abno, Rados?aw

2015-06-15

29

Halogen oxides from MAXDOAS observations at Belgrano station (Antarctica, 78ºS) in 2013  

NASA Astrophysics Data System (ADS)

BrO and IO play an important role in the tropospheric distribution of ozone. Tropospheric distribution of both radicals in Antarctica is still an open issue since there are some uncertainties over both its geographical and vertical distribution. Accurate MAXDOAS measurements of both components are important to set the their vertical distribution and to understand the halogen chemistry in the troposphere in Antarctica, where BrO and IO ground based measurements are very sparse and satellite observations have some limitations. In February 2011 a Multiaxis Differential Optical Absorption Spectroscopy (MAX- DOAS) instrument was installed at Belgrano II station (Antarctica) to have a better understanding of BrO distribution in this site and to improve the Antarctic program INTA has been performing from 1994 for stratospheric ozone monitoring and research. In this same framework in February 2013, a second MAXDOAS spectrometer started to measure IO continuosly. Both instruments have been entirely developed at INTA including the detector read-out electronics and have been been robustly designed for continuous operation in rough environment like Antarctica. Belgrano station is a candidate to be a NDACC site for continuous monitoring of atmospheric composition. Within the framework of NORS project NDACC expertise is being exported to MAXDOAS observations carried out in this station. In this work IO and BrO MAXDOAS DSCD between 2º and 90º elevation angles are presented from February to early April and from September to October 2013. Tropospheric IO is detected almost every day of measurement above the detection limit and the seasonal evolution show a good agreement with previous works as Saiz-Lopez et al., 2007, with higher columns towards the end of February, early March. The observed behaviour during the spring is, however, highly variable. Tropospheric BrO is as well detected during the whole period of measurements above detection limit with columns increasing towards the end of the period. During spring the column is, as in the case of IO, highly variable with some strong and sudden enhancements episodes during the month of September and October.

Puentedura, Olga; Yela, Margarita; Gil, Manuel; Perez-Camacho, Manuel; Navarro-Comas, Monica; Ochoa, Hector

2014-05-01

30

Ground-based measurements of column amounts of NO{sub 2} over Syowa Station, Antarctica  

SciTech Connect

The authors interpret column measurements of NO{sub 2} made from Syowa Station, Antarctica since March, 1990. It is lowest in midwinter, and peaks in midsummer. The fall rate of decrease is considerably greater than the spring increase rate. Temperature trends indicate that late winter polar stratospheric clouds could form, providing an explanation for low NO{sub 2} abundances. They have used a box model to simulate the observed density variations. Increasing amounts of aerosols from the eruption of Pinatubo probably account for lower NO{sub 2} densities in late spring of 1991. Effects due to the atmospheric aerosol loading are seen to extend into 1992, and also during 1992 the vortex boundary was located differently with respect to the observation station.

Kondo, Y.; Hayashi, M.; Nakajima, H.; Tsukui, K. [Nagoya Univ., Toyokawa (Japan)] [Nagoya Univ., Toyokawa (Japan); Matthews, W.A. [National Institute of Water and Atmospheric Research, Lauder (New Zealand)] [National Institute of Water and Atmospheric Research, Lauder (New Zealand); Solomon, S. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)] [National Oceanic and Atmospheric Administration, Boulder, CO (United States); Yamazaki, K. [Meteorological Research Institute, Tsukuba (Japan)] [Meteorological Research Institute, Tsukuba (Japan)

1994-07-20

31

Geodetic and Seismological Research at the new Princess Elisabeth Station, Queen Maud Land, East Antarctica  

NASA Astrophysics Data System (ADS)

On February 15th 2009, Belgium together with the International Polar Foundation inaugurated a new Antarctic base named Princess Elisabeth in honour of the granddaughter of King Albert II of Belgium. The base, located in the Queen Maud Land, East Antarctica (lat = 71°57’S, long = 23°20’E) was built to fully operate with renewable energies, conditions motivated by present climatic issues. Among the wide range of ambitious scientific projects already initiated, a solid earth GIANT-LISSA project will be conducted by the Royal Observatory of Belgium to better understand the ongoing geodynamics affecting East Antarctica such as ice mass change and to shed light onto the past and present tectonics by investigating lithospheric structure and local and regional intra-plate seismicity. Here we present these scientific goals focussing particularly on the seismology experiment. We describe the technical aspects of the instrumentation to be shipped and installed during the coming BELARE 2009-2010 expedition: one surface and one borehole broadband seismometers in addition to two GPS stations. Absolute and relative gravity measurements will be undertaken the following year in collaboration with Luxembourg University. In regard of the excellent site conditions provided by the elongated nunatak outcrop hosting the Princess Elisabeth base, the scientific expectations are high allowing to envision further initiatives and collaborations.

Lombardi, D.; Camelbeeck, T.; Rapagnani, G.; van Camp, M. J.; Bergeot, N.; Bruyninx, C.; Francis, O.; van Dam, T. M.

2009-12-01

32

Ozone and temperature profiles over McMurdo Station Antarctica in the Spring of 1989  

SciTech Connect

Ozone and temperature were measured in 39 balloon soundings at McMurdo station Antarctica (78{degree}S) in the spring of 1989. Compared to 1986 and 1988 the stratosphere was colder and ozone depletion worse. Compared to 1987 the stratosphere warmed earlier but ozone depletion was similar, both in the magnitude and rate of depletion. Within regions of the atmosphere in 1989 ozone depletion was between 80 and 98% complete. This was again similar to 1987 and suggests that conditions observed in 1987 exceeded the minimum required for rapid and complete ozone depletion. As in previous years ozone was destroyed primarily between 12 and 20 km and there were several short periods, < 5 days, when rapid depletion was observed.

Deshler, T.; Hofmann, D.J.; Hereford, J.V.; Sutter, C.B. (Univ. of Wyoming (USA))

1990-02-01

33

FY 1994 ambient air monitoring report for McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring performed during the 1994 fiscal year (FY 1994) in the vicinity of McMurdo Station, Antarctica. Routine monitoring was performed during the 1993-1994 austral summer at three locations for airborne particulate matter less than 10 micrometers (PM-10) and at two locations for carbon monoxide (CO), sulfur dioxide (SO{sub 2}), and nitrogen oxides (NO, NO{sub 2}, and NO{sub x}). Selected PM-10 filters were analyzed for arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel. Additional air samples were collected at three McMurdo area locations and at Black Island for determination of the airborne concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks.

Lugar, R.M.

1994-12-01

34

Mesospheric nitric oxide (NO) enhancements above Troll Station, Antarctica during March-May 2008  

NASA Astrophysics Data System (ADS)

Nitric oxide (NO) vertical volume mixing ratio profiles, measured using a ground-based passive sub-millimetre (250 GHz) radiometer at Troll Station, Antarctica (72.0 ° S, 2.5 ° E, invariant latitude 62.5° ), are reported for a 50-day period during March-May 2008. Enhanced levels of mesospheric NO are observed in the 75 km-90 km altitude range following a series of small geomagnetic storms (peak Ap index daily mean of 36) close to the minimum of solar cycle 23. Detailed analysis of the period 26 March to 3 April (2008 days 86-94) with 3-hour temporal resolution indicates significant differences in night-time and day-time production of odd nitrogen (NOx ). The characteristics of the energetic particle flux and energy spectrum and its impact on atmospheric chemistry have been investigated using the Sodankylü Ion-Neutral Chemistry a (SIC) model.

Newnham, David; Espy, Patrick; Clilverd, Mark; Rodger, C. J.; Seppala, Annika; Maxfield, David; Hartogh, Paul

35

Tracing biomass burning aerosol from South America to Troll Research Station, Antarctica  

NASA Astrophysics Data System (ADS)

The atmospheric observatory at the Norwegian Research Station Troll in Queen Maud Land, Antarctica, holds, since February 2007, the first all-year Antarctic atmospheric aerosol particle number size distribution measurements. These are colocated with measurements of the aerosol absorption and spectral scattering coefficients. In June 2007, this instrument set observed an aerosol whose properties were indicative of a biomass burning aerosol. These properties included two log-normal size distribution modes with median particle diameters of 0.105 ?m and 0.36 ?m, sharply falling off to smaller and larger sizes, and peaks in scattering and absorption coefficient. With backward plume calculations of the Lagrangian transport model FLEXPART and the MODIS fire activity product, a source-receptor relationship was established between biomass burning events in Central Brazil and the aerosol seen at Troll. This is the first direct evidence that the Antarctic continent is susceptible to emissions from as far north as Southern tropical latitudes.

Fiebig, M.; Lunder, C. R.; Stohl, A.

2009-07-01

36

Bursts of cloud condensation nuclei (CCN) by dissipating clouds at Palmer Station, Antarctica  

SciTech Connect

The authors present here a case study of cloud-mediated production of cloud condensation nuclei (CCN) recorded at Palmer Station (64{degrees}46`S, 64{degrees}05`W), Antarctica on 20 Jan 1994. Four instances of CCN bursts occured on January 17, 19, 20 and February 7, 1994 when cloud base descended to the surface and dissipated under prevailing meteorlogical conditions. The most spectacular event ocurred on January 20 when the CCN concentration was enhanced by a factor of four at 0.025% supersaturation (with respect to water) compared to the prevent concentration. At 1.25% supersaturation, the corresponding enhancement was by a factor of seven. This indicated a larger production of aerosol particles in smaller size ranges. The elevated CCN concentrations were measured for over fifteen hours. The CCN activity spectrum during the event resembled the ones that are typical of previous measurements in the urban plumes of St. Louis and Denver. 30 refs., 3 figs.

Saxena, V.K. [North Carolina State Univ., Raleigh, NC (United States)] [North Carolina State Univ., Raleigh, NC (United States)

1996-01-01

37

Results of monitoring for PCDDs and PCDFs in ambient air at McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 austral summer in the vicinity of McMurdo Station, Antarctica. Fifteen air samples were collected from four different locations for determination of the presence and concentration of PCDD/PCDF compounds. General Metal Works Inc. PS-1 air samplers equipped with polyurethane foam (PUF) with a sample flow rate of approximately 0.27 m{sup 3}/min. were used to collect air samples. Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with U.S. Environmental Protection Agency guidance for local ambient air quality networks. PCDD/PCDF compounds were not detected at the predominantly upwind location and at a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 meters downwind of the station. The most frequent, most varied, and highest levels of PCDDs/PCDFs were measured at a {open_quotes}downtown{close_quotes} location, where concentrations of total PCDDs ranged from 0.27 to 1.80 pg/m{sup 3} and total PCDFs from less than 0.1 to 2.77 pg/m{sup 3}. Results from the remote Black Island site indicate that the background Antarctic air is still {open_quotes}free{close_quotes} of PCDD/PCDF compounds (not detectable at current method detection limits). The initial baseline effort demonstrated that site selection and sampling equipment performance were satisfactory, provided useful data for assessing the impact of McMurdo operations on the local ambient air quality, and provided baseline data for assessing the Antarctica continental air quality.

Lugar, R.M.

1993-09-01

38

Monthly scale surface ozone depletion during polar sunrise in 2006 observed at Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

Surface ozone concentration is monitored at Syowa Station, Antarctica since 1988. The ozone concentration shows clear seasonal cycle with the maximum value in June - July and the minimum value in January reflecting both the seasonal varied intrusion of stratospheric air and the transport of air from sub-polar or middle latitude through lower troposphere in addition to the photochemical destruction. Surface ozone depletion (SOD) prolonged for about a month was observed in July 2006. The SOD during polar sunrise was sometimes observed in polar region; however, its duration was almost a several days. Monthly scale SOD was rarely observed. The atmospheric temperature was considerably low in July 2006 and the monthly averaged value of -24.1°C recorded lowest value in history at Syowa Station. Inspection of potential height at 500 hPa suggests Syowa Station was situated in polar vortex that intensified in July relative to anteroposterior months. Backward trajectory shows no intrusion of lower troposphere air from sub-polar region or mid latitude. Variation of greenhouse gases observed simultaneously at Syowa Station shows no local contamination occurred. Ozone concentration is known to decrease by dry deposition and photochemical destruction with halogen species. Its reaction and also release of halogen species from sea surface is active under low temperature. Another factor leading monthly scale SOD was considered to be bromine that accumulated into snow layer. Blizzard was rarely observed in previous month (June 2006) at the station, but observed a few times in July 2006. This phenomenon implies the possibility that the bromine accumulated into snow during June was released into atmosphere in July and activated the photochemical reaction under polar sunrise. These evidence suggests that the monthly scale SOD observed at Syowa Station in July 2006 is probably caused by 1) holding of extremely low temperature around Syowa Station caused by intense and continued polar vortex, 2) formation of inversion layer over the ground surface caused by extremely low temperature, 3) increase of Br- and BrO release, which excites catalytic cycle of ozone destruction, from sea surface and its activated reaction at record low temperature, 4) diffusion of Br- particle stored in snow to lower troposphere by turbulences occurred in July 2006.

Watai, T.; Hashida, G.; Yamanouchi, T.

2008-12-01

39

The behaviour of residual contaminants at a former station site, Antarctica.  

PubMed

In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latte may, however, be a visible consequence of the minor contamination occurring at this site. PMID:12628197

Webster, Jenny; Webster, Kerry; Nelson, Peter; Waterhouse, Emma

2003-01-01

40

Recent Progress of Geodetic Research around Syowa Station, Antarctica, in Relation to IPY2007-2008  

NASA Astrophysics Data System (ADS)

Several precise geodetic observations with VLBI, GPS, absolute gravimeter (AG), superconducting gravimeter (SG), etc. have been carried out at Syowa Station from early 1990s. The VLBI result (1999-2003) supports the hypothesis of one rigid Antarctic plate, however, longer observations may clear discrepancy from the NNR-NUVEL-1A model. Crustal uplift rates by VLBI, GPS and DORIS are within the range from 2.3 mm/yr to 4.6 mm/yr. Absolute gravity observations done three times during 1994-2004 at the Syowa IAGBN(A)#0417 point gave the change rate of -0.3+- 0.4 microGal/yr, and require more time span to estimate the relation between dg/dt and dh/dt. The 10-years' SG data were archived and the tidal gravimetric factors to an accuracy of 0.1percent were obtained for the periods from 0.5 to 32 days. Two ocean bottom pressure gauges (OBPs) installed to the north of Syowa Station (about 250 km) recorded the tsunami induced by the Sumatera Earthquake of December 26, 2004. We have an archive of 20,000 SAR scenes from JERS-1, ERS-1, and ERS-2 over East Antarctica, and studying to delineate the grounding zone to update the ADD coastlines for the regions from 25W to 40E. Several planned activities of the above related themes and other observations will be presented.

Shibuya, K.; Doi, K.; Nogi, Y.; Kanao, M.

2005-12-01

41

Draft Genome Sequence of Arthrobacter gangotriensis Strain Lz1yT, Isolated from a Penguin Rookery Soil Sample Collected in Antarctica, near the Indian Station Dakshin Gangotri  

PubMed Central

We report here the 4.3-Mb genome of Arthrobacter gangotriensis strain Lz1yT, isolated from a penguin rookery soil sample collected in Antarctica, near the Indian station Dakshin Gangotri. PMID:23766407

Ara, Sreenivas; Bandi, Sunil; Singh, Aditya; Kumar Pinnaka, Anil

2013-01-01

42

Comprehensive characterization report on Winter Quarters Bay, McMurdo Station, Antarctica  

SciTech Connect

Winter Quarters Bay is a small embayment located adjacent to the United States largest base in Antarctica, McMurdo Station. McMurdo Station, which is managed by the National Science Foundation`s Office of Polar Programs, was constructed in 1955, has been in constant use since that time, and has a population of about 1,000 persons during the summer and about 250 people for the winter. The bay offers shelter for ships and an ice dock is used during January and February to off load fuel and cargo. During earlier times, trash from the McMurdo Station was piled on the steep shoreline of the bay, doused with several thousand gallons of fuel and ignited. That practice has ceased and the site has been regraded to cover the waste. The bottom of the bay is littered with drums, equipment, tanks, tires, all sorts of metal objects, cables, etc., especially the southeastern side where dumping took place. The sediments are gravel in some places yet fine and fluid at other sites with coarse particles intermixed. The original benthic community is not well recorded but significant ecological changes have occurred. Sediments are contaminated with PCBs, metals, and hydrocarbon fuels. This report summarizes available information on Winter Quarters Bay and was originally intended to be used by workshop participants to become familiar with the bay prior to becoming updated with unpublished data by various Antarctic investigators. The proposed workshop was to assist the National Science Foundation in determining whether and how the bay should be remediated and to develop an integrated research plan if additional data were needed. However, plans changed, the workshop was never conducted, but the briefing report was prepared. Most of this report reviews and summarizes other published data. The only new data are those from the Idaho National Engineering and Environmental Laboratory`s investigation into the distribution of organic contaminants in the bay and sediment toxicity testing.

Crockett, A.B.; White, G.J.

1997-01-01

43

Ozone profiles over McMurdo Station, Antarctica, during August, September, and October of 1986 - 1991  

NASA Technical Reports Server (NTRS)

Vertical profiles of ozone and temperature have been measured at McMurdo Station, Antarctica, during the springs of 1986 to 1991, roughly every two days from 25 August to 31 October. Comparisons of temporal histories and average vertical structure for these years reveals some striking consistency in the ozone depletion process. Ozone depletion generally begins in early September, and with a half-life of 20-30 days, reaches its maximum in mid-October. The depletion occurs almost exclusively between 12 and 20 km. At the time of maximum depletion total ozone has been decreased roughly 40 percent while ozone between 12 and 20 km has been reduced 80 percent. Recovery generally begins in late October with the influx, above 20 km, of ozone rich air from the lower latitudes. From this record the worst years for ozone depletion were 1987, 1989, and 1990. A new region of ozone depletion, below 12 km, was observed in 1991, coinciding with the entrainment of a volcanic cloud into the polar vortex.

Deshler, Terry; Hofmann, David J.

1994-01-01

44

Ozone profiles at McMurdo Station, Antarctica during the austral spring of 1992  

SciTech Connect

Thirty-seven vertical profiles of ozone and temperature were measured at McMurdo Station, Antarctica (78[degrees]S) from 23 August to 31 October 1992. Total column ozone dropped from an initial 223 Dobson Units (DU) on 24 August to 158 DU on 27 September. The 12-20 km column reached a record low of 17 DU on 9 October, an 84% loss compared to the initial value of 106 DU. The most severely depleted layer was between 12 and 15 km which coincided with the volcanic aerosol layer (11-16 km) observed by aerosol counter flights and the Italian Lidar at McMurdo. By the end of September the polar vortex elongated and shifted away from McMurdo. Subsequent profiles, above 20 km altitude, were typically 15-20[degrees]C warmer and ozone concentrations were 50-100% higher for the remainder of the measurement period. The 12-16 km layer, however, remained 80 to 97% depleted compared to the initial profile. 9 refs., 5 figs.

Johnson, B.J.; Deshler, T.; Rozier, W.R. (Univ. of Wyoming, Laramie, WY (United States))

1994-02-15

45

Stratospheric ClO profiles from McMurdo Station, Antarctica, spring 1992  

SciTech Connect

The authors describe ground-based measurements of ClO made at McMurdo Station, Antarctica, during September and October 1992. Vertical profiles were retrieved from molecular rotational emission spectra at 278 GHz. Peak mixing ratios of 1.6{+-}0.3 ppbv were seen in mid-September at approximately 18 km altitude, suggestive of somewhat larger quantities than were measured at the same site and season in 1987. As the core of the polar vortex moved away from McMurdo by early October, the ClO mixing ratio at this altitude dropped to less than 0.2 ppbv, coincident with increasing temperature, ozone, and NO{sub 2}. The diurnal variation of ClO was also observed. The lower stratospheric layer from 15 to 27 km was found to reach approximately midday abundance by 2-3 hours after sunrise. The column abundance in this layer began to decrease by the period 4-2 hours before sunset and had declined to approximately one quarter of its midday value by 2-0 hours before sunset. In contrast, the ClO column in the upper stratosphere, from 28 to 50 km, built up slowly until midday and remained large while sunlight persisted. 20 refs., 7 figs., 2 tabs.

Emmons, L.K.; Shindell, D.T.; Reeves, J.M. [State Univ. of New York, Stony Brook, NY (United States)] [and others] [State Univ. of New York, Stony Brook, NY (United States); and others

1995-02-20

46

Solar Cycle Variation of Upper Thermospheric Temperature Over King Sejong Station, Antarctica  

NASA Astrophysics Data System (ADS)

A ground Fabry-Perot interferometer has been used to measure atomic oxygen nightglow (OI 630.0 nm) from the thermosphere (about 250 km) at King Sejong station (KSS, geographic: 62.22oS, 301.25oE; geomagnetic: 50.65oS, 7.51oE), Antarctica. While numerous studies of the thermosphere have been performed on high latitude using ground-based Fabry-Perot interferometers, the thermospheric measurements in the Southern Hemisphere are relatively new and sparse. Therefore, the nightglow measurements at KSS play an important role in extending the thermospheric studies to the Southern Hemisphere. In this study, we investigated the effects of the geomagnetic and solar activities on the thermospheric neutral temperatures that have been observed at KSS in 1989 and 1997. The measured average temperatures are 1400 K in 1989 and 800 K in 1997, reflecting the influence of the solar activity. The measurements were compared with empirical models, MSIS-86 and semi-empirical model, VSH.

Chung, Jong-Kyun; Won, Young-In; Kim, Yong-Ha; Lee, Bang-Yong; Kim, Jhoon

2000-12-01

47

Mesospheric CO above Troll station, Antarctica observed by a ground based microwave radiometer  

NASA Astrophysics Data System (ADS)

This paper presents mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72° S, 2.5° E, 1270 m a.s.l.). The dataset covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles are only presented during the Antarctic winter. CO is measured for approximately 2 h each day and profiles are retrieved approximately every half hour. The retrieved profiles, covering the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km), are compared to measurements from Microwave Limb Sounder on the Aura satellite (Aura/MLS) and Whole Atmosphere Community Climate Model with Specified Dynamics (SD-WACCM). This intercomparison reveals a low bias of 0.5 to 1 ppmv at 0.1 hPa (approximately 64 km) and 2.5 to 3.5 ppmv at 0.01 hPa (approximately 80 km) of the BAS microwave radiometer compared to both reference datasets. One explanation for this low bias could be the known high bias of MLS which is on the same order of magnitude. The ground based radiometer shows high and significant correlation (coefficients higher than 0.9/0.7 compared to MLS/SD-WACCM) at all altitudes compared with both reference datasets. The dataset can be accessed under http://dx.doi.org/10/mhq.

Straub, C.; Espy, P. J.; Hibbins, R. E.; Newnham, D. A.

2013-06-01

48

Mesospheric CO above Troll station, Antarctica observed by a ground based microwave radiometer  

NASA Astrophysics Data System (ADS)

This paper presents mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72° S, 2.5° E, 1270 a.m.s.l.). The data set covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles can only be retrieved during Antarctic winter. CO is measured for approximately 2 h each day and profiles are retrieved approximately every half hour. The retrieved profiles, covering the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km), are compared to measurements from Aura/MLS and SD-WACCM. This intercomparison reveals a low bias of 0.5 to 1 ppmv at 0.1 hPa (approximately 64 km) and 2.5 to 3.5 ppmv at 0.01 hPa (approximately 80 km) of the BAS microwave radiometer compared to both reference datasets. One explanation for this low bias could be the known high bias of MLS which is in the same order of magnitude. The ground based radiometer shows high and significant correlation (coefficients higher than 0.9/0.65 compared to MLS/SD-WACCM) at all altitudes compared with both reference datasets. doi:10.5285/DE3E2092-406D-47A9-9205-3971A8DFB4A9

Straub, C.; Espy, P. J.; Hibbins, R. E.; Newnham, D. A.

2013-01-01

49

Culturable bacterial diversity at the Princess Elisabeth Station (Utsteinen, Sør Rondane Mountains, East Antarctica) harbours many new taxa.  

PubMed

We studied the culturable heterotrophic bacterial diversity present at the site of the new Princess Elisabeth Station at Utsteinen (Dronning Maud Land, East Antarctica) before construction. About 800 isolates were picked from two terrestrial microbial mat samples after incubation on several growth media at different temperatures. They were grouped using rep-PCR fingerprinting and partial 16S rRNA gene sequencing. Phylogenetic analysis of the complete 16S rRNA gene sequences of 93 representatives showed that the isolates belonged to five major phyla: Actinobacteria, Bacteroidetes, Proteobacteria, Firmicutes and Deinococcus-Thermus. Isolates related to the genus Arthrobacter were the most prevalent whereas the genera Hymenobacter, Deinococcus, Cryobacterium and Sphingomonas were also recovered in high numbers in both samples. A total of 35 different genera were found, the majority of which has previously been reported from Antarctica. For the genera Aeromicrobium, Aurantimonas, Rothia, Subtercola, Tessaracoccus and Xylophilus, this is the first report in Antarctica. In addition, numerous potential new species and new genera were recovered; many of them currently restricted to Antarctica, particularly in the phyla Bacteroidetes and Deinococcus-Thermus. PMID:21501941

Peeters, Karolien; Ertz, Damien; Willems, Anne

2011-07-01

50

Ocean current observations near McMurdo Station, Antarctica, 1993 to 1994: Relation to wastewater discharge dispersal  

SciTech Connect

This report presents analyses of current measurements from McMurdo Sound, Antarctica during December, 1993 to November, 1994, in relation to dispersal of the McMurdo Station wastewater plume. Data collected from 1991 to 1993 are also discussed here. Six current meters were deployed near McMurdo Station, Antarctica, from December 1993 to November 1994. Five functioned properly throughout the observation period, and one failed. Analyses of 5 data series include: (1) summaries of current speed and direction, (2) directional analyses of flow, (3) time series current vectors averaged over 1, 3, 6, 12, and 24 h, (4) principal axes of flow, (5) maps of mean seasonal flow, (6) progressive vector plots, (7) spectral analyses, and (8) low-pass filtered (30h) time series of currents at McMurdo Station. Observations of flow near McMurdo Station during 1994 were generally similar to 1993. Short term variation in flow was related principally to diurnal tidal motions. Longer period oscillations in flow such as seasonal shifts, and non-periodic changes in current speed and direction were likely related to changes in ice cover and wind stress in the vicinity of McMurdo Station or over much larger scales or both. Three distinct oceanographic {open_quote}seasons{close_quote} were apparent in time series from 1992 to 1994, from stations furthest offshore, where the effects of local topography are minimal. The spring-summer (Oct.-Jan.) period of both years was dominated by regional southward flow, which generates a counter-clockwise eddy (McMurdo Gyre) adjacent to McMurdo Station. With regard to dispersal of the wastewater plume from McMurdo Station, observations of currents during 1994 generally corroborate those from 1993, and the recommendation that the outfall pipe should be repositioned offshore of the McMurdo Gyre is supported.

Barry, J.P. [J.P. Barry Consulting, Monterey, CA (United States)

1995-09-01

51

Ground-based measurements of column amounts of NO2 over Syowa Station, Antarctica  

SciTech Connect

The column amounts of NO2 have been measured using visible spectroscopy at Syowa Station, Antarctica (69 deg S), from March 1990. The NO2 slant column amount at a solar zenith angle of 90 deg exhibits a large seasonal variation reaching the minimum value of 1 x 10(exp 16)/sq cm or less in midwinter, and it increases to the maximum value of 17 x 10(exp 16)/sq cm in midsummer. The recovery of NO2 in spring is 2-3 times slower than the fall decay. The observed temperature indicates that polar stratospheric clouds (PSCs) are expected to form from midwinter to early spring. A decrease in ozone was observed from early August and continued to the end of September, which is consistent with the observed depletion in NO2 during the same period. A chemical box model has been used to interpret quantitatively these observed results. The observed NO2 values in fall are in agreement with the box model including only gas phase chemistry or with heterogeneous chemistry on background sulfuric acid aerosols. In addition, the very low NO2 amounts and slow rate of increase observed from midwinter to early spring agree well with the model results assuming heterogeneous chemistry on PSCs. From the late spring of 1991 the NO2 amounts are lower by more than 30%, presumably due to the increased rate of conversion of NO(x) into HNO3 via N2O5 on the enhanced amount of sulfuric acid aerosols resulting from the Pinatubo eruption.

Kondo, Y.; Matthews, W.A.; Solomon, S.; Koike, M.; Hayashi, M.; Yamazaki, K.; Nakajima, H.; Tsukui, K. [Nagoya Univ., Toyokawa (Japan)]|[National Institute of Water and Atmospheric Research, Lauder (New Zealand)]|[NOAA, Boulder, CO (United States)]|[Meteorological Research Institute, Tsukuba (Japan)

1994-07-01

52

Anthropogenic Disturbance and Biodiversity of Marine Benthic Communities in Antarctica: A Regional Comparison  

PubMed Central

The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are some generalizations regarding responses which will aid future management of stations. PMID:24919053

Stark, Jonathan S.; Kim, Stacy L.; Oliver, John S.

2014-01-01

53

Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica: a regional comparison.  

PubMed

The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are some generalizations regarding responses which will aid future management of stations. PMID:24919053

Stark, Jonathan S; Kim, Stacy L; Oliver, John S

2014-01-01

54

Casey Doyle: Artist at Play  

ERIC Educational Resources Information Center

The article discusses the work of Casey Doyle, and the narrative metaphors and personal explorations that inform his sculptures and how, for his undergraduate thesis, he selected a body of work whose central theme explores his identity as a gay man, informing his relationships with family, friends and society. (Contains 5 figures.)

Sanders, James H., III; Doyle, Casey

2008-01-01

55

Benthic changes at McMurdo Station, Antarctica following local sewage treatment and regional iceberg-mediated productivity decline.  

PubMed

McMurdo Station, the largest research station in Antarctica, ceased on-site garbage dumping in 1988 and initiated sewage treatment in 2003. In 2003-2004 its sea-ice regime was altered by the massive B-15A and C-19 iceberg groundings in the Ross Sea, approximately 100km distant. Here we follow macrofaunal response to these changes relative to a baseline sampled since 1988. In the submarine garbage dump, surface contaminants levels have declined but associated macrofaunal recolonization is not yet evident. Although sewage-associated macrofauna were still abundant around the outfall nearly 2yr after initiation of treatment, small changes downcurrent as far as 434m from the outfall suggest some community recovery. Widespread community changes in 2003-2004, not seen in the decade previously, suggests that the benthos collectively responded to major changes in sea-ice regime and phytoplankton production caused by the iceberg groundings. PMID:19945127

Conlan, K E; Kim, S L; Thurber, A R; Hendrycks, E

2010-03-01

56

Electric Vehicle Performance at McMurdo Station (Antarctica) and Comparison with McMurdo Station Conventional Vehicles  

SciTech Connect

This report examines the performance of two electric vehicles (EVs) at McMurdo, Antarctica (McMurdo). The study examined the performance of two e-ride Industries EVs initially delivered to McMurdo on February 16, 2011, and compared their performance and fuel use with that of conventional vehicles that have a duty cycle similar to that of the EVs used at McMurdo.

Sears, T.; Lammert, M.; Colby, K.; Walter, R.

2014-09-01

57

Ocean current observations near McMurdo Station, Antarctica from 1991 to 1993: Relation to wastewater discharge dispersal  

SciTech Connect

Analyses of ocean currents in the vicinity of McMurdo Station, Antarctica, are relevant to the transport and dispersal of wastewater from the McMurdo Station sewage outfall pipe. Observations of ocean currents during the initial phases of this study have been presented by Howington and McFeters. These studies, using coliform bacterial counts as an indicator of dispersion of the wastewater plume and current meters to measure flow patterns, indicated that dispersal of the plume by local currents does not effectively remove the plume from the vicinity of McMurdo Sound, under the present outfall pipe location. Moreover, these studies suggest that, although the flow pattern is generally consistent with transport of the plume away from McMurdo Station, episodes of current reversal are sufficient to transport the wastewater plume along the shore toward the southeast, eventually overlapping the seawater intake area near the McMurdo jetty. Several concerns included (a) impacts of wastewater inputs to nearshore benthic and pelagic habitats adjacent to McMurdo Station, (b) effects of wastewater input to the McMurdo Station fresh water intake source, and (c) reduction in human impacts on the McMurdo Sound ecosystem. These concerns motivated studies to characterize nearshore currents more extensively in relation to dispersal of the wastewater plume. This report discusses analysis results of current observations from November 1992 to November 1993.

Barry, J.P. [J. P. Consulting, Monterey, CA (United States)

1994-08-01

58

[Polycyclic aromatic hydrocarbons content in Antarctica soils as exemplified by the Russian polar stations].  

PubMed

The comprehensive study of the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in soils of Antarctica (reference landscapes--mountains Hudson, Haswell Archipelago contaminated soil--Mirny, Druznaya-4, Bellingshausen--and imported soils) was performed with the use of HPLC in a gradient mode. A characteristic feature of the studied PAHs content of soils is the predominance of low-molecular polyarenes in them. Due to anthropogenic pollution the quantitative accumulation of both light and heavy PAHs occurs under the qualitative increase in the proportion of heavy polyarenes. Polyarenes pool in the studied soils is represented mainly by light PAHs: naphthalene, phenanthrene, fluoranthene, pyrene, etc. The content of benzo(a)pyrene does not exceed the MCL (adopted in the Russian Federation) for this ecotoxicant. Performed primary factual and statistical analysis of data permitted to reveal that heavy PAH pollution of Antarctica soils is in the most initial stage, there is no sustained and statistically significant accumulation of PAHs in soils of maritime as well as continental Antarctica. There are established the levels of the actual content of various PAHs in soils of different regions of the Antarctica, which is the basic data for further comparative analysis of data of geochemical studies. PMID:24749277

Abakumov, E V; Lodygin, E D; Gabov, D A; Krylenkov, V A

2014-01-01

59

Observed trends for CF 3-containing compounds in background air at Cape Meares, Oregon, Point Barrow, Alaska, and Palmer Station, Antarctica  

Microsoft Academic Search

The concentrations of CF3-containing compounds in archived air samples collected at Cape Meares, Oregon, from 1978 to 1997, at Point Barrow, Alaska, from 1995 to 1998, and at Palmer Station, Antarctica, from 1991 to 1997, were determined by high resolution gas chromatography and high resolution mass spectrometry. The CF3-containing compounds measured by this method and discussed here are: the perfluorinated

J. A Culbertson; J. M Prins; E. P Grimsrud; R. A Rasmussen; M. A. K Khalil; M. J Shearer

2004-01-01

60

Balloon-borne measurements of aerosol, condensation nuclei, and cloud particles in the stratosphere at McMurdo Station, Antarctica, during the spring of 1987  

Microsoft Academic Search

Measurements of the vertical profile of particles with condensation nuclei counters and eight channel aerosol detectors at McMurdo Station, Antarctica, in 1987 verified observations made in 1986 concerning the absence of upwelling in the polar vortex and the presence of a condensation nuclei layer in conjunction with the ozone hole region. New observations of a bimodal aerosol size distribution, consisting

D. J. Hofmann; J. M. Rosen; J. W. Harder; J. V. Hereford

1989-01-01

61

Health and safety plan for the preliminary site investigation for McMurdo Station, Ross Island, Antarctica  

SciTech Connect

The primary purpose of this health and safety plan is to provide the Argonne National Laboratory (ANL) field team with important procedures, regulations, and requirements necessary for performing work at McMurdo Station, Antarctica, with a minimum hazard to its health and safety. Field workers will be required to conduct their operations in a safe environment through specific safety and occupational health procedures. The plan assigns responsibilities and provides for contingencies that may arise at the site. The health and safety plan will also demonstrate to the National Science Foundation (NSF), the US Department of Energy (DOE), the US Environmental Protection Agency (EPA), the US Occupational Safety and Health Administration (OSHA), environmental interest groups, and other countries represented in Antarctica that the health and safety of ANL personnel have been given the utmost consideration in planning the work operations, applicable rules and regulations of the area have been met, and the health and safety of the public and the environment have been given significant consideration during field sampling activities. This document represents the final health and safety plan for the preliminary site investigation. A draft version of this report was presented to NSF in January 1991. 16 refs., 3 figs., 8 tabs.

Wozny, M.C.

1991-05-01

62

Why Antarctica?  

NASA Astrophysics Data System (ADS)

The dry, cold, tenuous and stable air above the Antarctic Plateau provides superb conditions for the conduct of many classes of astronomical observations. We review in particular the rationale for undertaking near- IR, mm and particle astronomy in Antarctica, disciplines where telescopes are now operating at the US Amundsen-Scott South Pole Station.

Burton, M. G.

1996-01-01

63

The controlled ecological life support system Antarctic analog project: Analysis of wastewater from the South Pole Station, Antarctica, volume 1  

NASA Technical Reports Server (NTRS)

The Controlled Ecological Life Support system (CELSS) Antarctic Analog Project (CAAP) is a joint National Science Foundation (NSF) and NASA project for the development, deployment and operation of CELSS technologies at the Amundsen-Scott South Pole Station. NASA goals are operational testing of CELSS technologies and the conduct of scientific studies to facilitate technology selection and system design. The NSF goals are that the food production, water purification, and waste treatment capabilities which will be provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, and minimize environmental impacts associated with human presence on the polar plateau. This report presents an analysis of wastewater samples taken from the Amundsen-Scott South Pole Station, Antarctica. The purpose of the work is to develop a quantitative understanding of the characteristics of domestic sewage streams at the South Pole Station. This information will contribute to the design of a proposed plant growth/waste treatment system which is part of the CELSS Antarctic Analog Project (CAAP).

Flynn, Michael T.; Bubenheim, David L.; Straight, Christian L.; Belisle, Warren

1994-01-01

64

Atmospheric ozone above Troll station, Antarctica observed by a ground based microwave radiometer  

NASA Astrophysics Data System (ADS)

This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT), Antarctica (72°01' S, 02°32' E, 62° Mlat). The instrument operated at Troll from February 2008 through January 2010, and hourly averaged spectra were used to retrieve approximately 20 ozone profiles per day. The ozone profiles cover the pressure range from 3 hPa to 0.02 hPa (approximately 38 to 72 km) which includes the topside of the stratospheric ozone layer and the peak of the tertiary maximum. Comparing the retrieved ozone volume mixing ratio (vmr) values to Aura/MLS and SD-WACCM shows no significant bias to within the instrumental uncertainties. The long-term variations (>20 days) between MLS and SD-WACCM agree well with BAS-MRT at all altitudes with significant correlation coefficients of at least 0.9 (0.7 with SD-WACCM) in the upper stratosphere and middle mesosphere. A weaker correlation is found for the long-term variations in summer when most of the vmr values are below the random noise level of Aura/MLS. The correlation of short-term variations (<20 days) between MLS and BAS-MRT agree well at all altitudes with significant correlation coefficients of at least 0.7 in the upper stratosphere and middle mesosphere. The ozone profiles retrieved at Troll, Antarctica extend the sparse data coverage of middle atmospheric ozone above Antarctica, where, due to the dynamic nature of the ozone concentrations, systematic observations with a high temporal resolution are desirable. The O3 profiles presented here are stored at the UK's Polar Data Centre (http://doi.org/nc3) and are available for public scientific use.

Daae, M.; Straub, C.; Espy, P. J.; Newnham, D. A.

2014-03-01

65

Atmospheric ozone above Troll station, Antarctica observed by a ground based microwave radiometer  

NASA Astrophysics Data System (ADS)

This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT), Antarctica (72°01' S, 02°32' E, 62° Mlat). The instrument operated at Troll from February 2008 through January 2010, and hourly averaged spectra were used to retrieve approximately 22 ozone profiles per day. The ozone profiles cover the pressure range from 3 to 0.02 hPa (approximately 38 to 72 km) which includes the topside of the stratospheric ozone layer and the peak of the tertiary maximum. Comparing the retrieved ozone volume mixing ratio (vmr) values to Aura/MLS and SD-WACCM shows no significant bias to within the instrumental uncertainties. The long-term variations (> 20 days) between MLS and SD-WACCM agree well with BAS-MRT at all altitudes with significant correlation coefficients of at least 0.9 (0.7 with SD-WACCM) in the upper stratosphere and middle mesosphere. A weaker correlation is found for the long-term variations in summer when most of the vmr values are below the random noise level of Aura/MLS. The correlation of short-term variations (< 20 days) between MLS and BAS-MRT agree well at all altitudes with significant correlation coefficients of at least 0.7 in the upper stratosphere and middle mesosphere. The ozone profiles retrieved at Troll, Antarctica extend the sparse data coverage of middle atmospheric ozone above Antarctica, where, due to the dynamic nature of the ozone concentrations, systematic observations with a high temporal resolution are desirable. The O3 profiles presented here are stored at the UK's Polar Data Centre (http://doi.org/nc3) and are available for public scientific use.

Daae, M.; Straub, C.; Espy, P. J.; Newnham, D. A.

2013-09-01

66

WBUR Journeys to Antarctica  

NSDL National Science Digital Library

This is the record of an environmental reporter's expedition to Antarctica. During his time in Antarctica, the author wrote reports and captured photos, video and audio of the animals, the environment and the people who live there. Topics include wildlife and how it has been affected by climate change, equipment needed for working in Antarctica, and life at Palmer Station. A series of journal entries by the author give an account of what it was like to travel, work, and live in Antarctica. An extensive collection of multimedia materials includes photos, videos, and an interactive tour of Palmer Station.

67

Results of monitoring for polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air at McMurdo station, Antarctica  

SciTech Connect

This paper presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 and 1993-1994 austral summers in the vicinity of McMurdo Station, Antarctica. Twenty-eight air samples were collected from four different locations to determine the identity and concentration of PCDD/PCDF compounds. PCDD/PCDF compounds were not detected at either the predominantly upwind location or a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 m downwind of the station. The most frequent, most varied, and highest levels of PCDDs/PCDFs were measured at a `downtown` location, where concentrations of total PCDDs ranged from 0.12 to 1.80 pg/m{sup 3} and total PCDDs ranged from less than 0.02 to 2.77 pg/m{sup 3}. The data indicate that there are combustion sources at McMurdo other than the solid waste incinerator (power plants, vehicles, heating furnaces, etc.) that contribute PCDD/PCDF compounds to the ambient air. The greatest variety and highest concentration of PCDD/PCDF congeners measured in 1992-1993 during incineration of selected solid wastes implicates the interim incinerator as the likely source of the increased presence of these compounds in air. 18 refs., 2 figs., 3 tabs.

Lugar, R.M. [ERM-Program Management Co., Idaho Falls, ID (United States)] [ERM-Program Management Co., Idaho Falls, ID (United States); Harles, R.L. [EPA/AREAL, Research Triangle Park, NC (United States)] [EPA/AREAL, Research Triangle Park, NC (United States); Dupuy, A.E.; McDaniel, D.D. [EPA/OPPTS/OPP/BEAD/ACB, Stennis Space Center, MS (United States)] [EPA/OPPTS/OPP/BEAD/ACB, Stennis Space Center, MS (United States)

1996-02-01

68

Trip Report: McMurdo Station, Antarctica 30 November 21 December 2006  

E-print Network

arrived at the United States Antarctic Program's (USAP) McMurdo Station on a C-17 via Christchurch, New Zealand on 30 November 2006. My research work was done at the McMurdo weather office ("MacWeather"), whichPa geopotential height plot if necessary, to the infrared (IR) imagery in a similar geographic orientation

Howat, Ian M.

69

Ozone profile measurements of McMurdo Station, Antarctica, during the spring of 1987  

Microsoft Academic Search

Ozone and temperature profiles were measured in 50 balloon flights at McMurdo Station (78 deg S) during the spring of 1987. Compared to similar data obtained in 1986, stratospheric temperatures were lower and the spring time Antarctic ozone reduction was greater in magnitude, extended to higher altitude, and proceeded at a higher rate in 1987. Ozone partial pressures reached values

D. J. Hofmann; J. W. Harder; J. M. Rosen; J. V. Hereford; J. R. Carpenter

1989-01-01

70

Ozone profiles at McMurdo Station, Antarctica during he spring of 1993; record low ozone season  

SciTech Connect

Record low ozone was measured by balloon-borne ozonesondes (40 flights) at McMurdo Station, Antarctica (78 deg S) during the 1993 austral spring. Total column ozone declined by 55% from an initial 275 Dobson Units (DU) on 30 August to a minimum of 130 +/- 7 DU on 2 October. Ozone within the 12-20 km showed a 95% decrease from an initial 138 DU in August to a record low 7 DU on 19 October. Probable cause of the 1993 record low ozone, based on balloon-borne observations at McMurdo include: the presence of the Pinatubo volcanic aerosol layer between 11 and 16 km (though decreased from the 1992 season); a colder than normal stratosphere over McMurdo (183 K minimum); and a relatively stable polar vortex which delayed the intrusion of high levels of ozone from outside the polar vortex wall until after 22 October. These conditions provided an optimum environment for the formation of polar stratospheric clouds (PSCs), essential to the heterogeneous chemistry that subsequently leads to the catalytic destruction of ozone by reactive chlorine.

Johnson, B.J.; Deshler, T.; Zhao, R. [Univ. of Wyoming, Laramie, WY (United States)] [Univ. of Wyoming, Laramie, WY (United States)

1995-02-01

71

Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, ?- and ?-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007-2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar to observations for Arctic samples, HCB is the predominant POP compound, with levels of around 22 pg m-3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART).

Kallenborn, R.; Breivik, K.; Eckhardt, S.; Lunder, C. R.; Manø, S.; Schlabach, M.; Stohl, A.

2013-07-01

72

Observations of Earth space by self-powered stations in Antarctica.  

PubMed

Coupling of the solar wind to the Earth magnetosphere/ionosphere is primarily through the high latitude regions, and there are distinct advantages in making remote sensing observations of these regions with a network of ground-based observatories over other techniques. The Antarctic continent is ideally situated for such a network, especially for optical studies, because the larger offset between geographic and geomagnetic poles in the south enables optical observations at a larger range of magnetic latitudes during the winter darkness. The greatest challenge for such ground-based observations is the generation of power and heat for a sizable ground station that can accommodate an optical imaging instrument. Under the sponsorship of the National Science Foundation, we have developed suitable automatic observing platforms, the Automatic Geophysical Observatories (AGOs) for a network of six autonomous stations on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength intensified all-sky camera that records the auroral activity, an imaging riometer, fluxgate and search-coil magnetometers, and ELF/VLF and LM/MF/HF receivers. Originally these stations were powered by propane fuelled thermoelectric generators with the fuel delivered to the site each Antarctic summer. A by-product of this power generation was a large amount of useful heat, which was applied to maintain the operating temperature of the electronics in the stations. Although a reasonable degree of reliability was achieved with these stations, the high cost of the fuel air lift and some remaining technical issues necessitated the development of a different type of power unit. In the second phase of the project we have developed a power generation system using renewable energy that can operate automatically in the Antarctic winter. The most reliable power system consists of a type of wind turbine using a simple permanent magnet rotor and a new type of power control system with variable resistor shunts to regulate the power and dissipate the excess energy and at the same time provide heat for a temperature controlled environment for the instrument electronics and data system. We deployed such systems and demonstrated a high degree of reliability in several years of operation in spite of the relative unpredictability of the Antarctic environment. Sample data are shown to demonstrate that the AGOs provide key measurements, which would be impossible without the special technology developed for this type of observing platform. PMID:20059157

Mende, S B; Rachelson, W; Sterling, R; Frey, H U; Harris, S E; McBride, S; Rosenberg, T J; Detrick, D; Doolittle, J L; Engebretson, M; Inan, U; Labelle, J W; Lanzerotti, L J; Weatherwax, A T

2009-12-01

73

Observations of Earth space by self-powered stations in Antarctica  

NASA Astrophysics Data System (ADS)

Coupling of the solar wind to the Earth magnetosphere/ionosphere is primarily through the high latitude regions, and there are distinct advantages in making remote sensing observations of these regions with a network of ground-based observatories over other techniques. The Antarctic continent is ideally situated for such a network, especially for optical studies, because the larger offset between geographic and geomagnetic poles in the south enables optical observations at a larger range of magnetic latitudes during the winter darkness. The greatest challenge for such ground-based observations is the generation of power and heat for a sizable ground station that can accommodate an optical imaging instrument. Under the sponsorship of the National Science Foundation, we have developed suitable automatic observing platforms, the Automatic Geophysical Observatories (AGOs) for a network of six autonomous stations on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength intensified all-sky camera that records the auroral activity, an imaging riometer, fluxgate and search-coil magnetometers, and ELF/VLF and LM/MF/HF receivers. Originally these stations were powered by propane fuelled thermoelectric generators with the fuel delivered to the site each Antarctic summer. A by-product of this power generation was a large amount of useful heat, which was applied to maintain the operating temperature of the electronics in the stations. Although a reasonable degree of reliability was achieved with these stations, the high cost of the fuel air lift and some remaining technical issues necessitated the development of a different type of power unit. In the second phase of the project we have developed a power generation system using renewable energy that can operate automatically in the Antarctic winter. The most reliable power system consists of a type of wind turbine using a simple permanent magnet rotor and a new type of power control system with variable resistor shunts to regulate the power and dissipate the excess energy and at the same time provide heat for a temperature controlled environment for the instrument electronics and data system. We deployed such systems and demonstrated a high degree of reliability in several years of operation in spite of the relative unpredictability of the Antarctic environment. Sample data are shown to demonstrate that the AGOs provide key measurements, which would be impossible without the special technology developed for this type of observing platform.

Mende, S. B.; Rachelson, W.; Sterling, R.; Frey, H. U.; Harris, S. E.; McBride, S.; Rosenberg, T. J.; Detrick, D.; Doolittle, J. L.; Engebretson, M.; Inan, U.; Labelle, J. W.; Lanzerotti, L. J.; Weatherwax, A. T.

2009-12-01

74

Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian Research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, a- and g-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007-2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar as observed for Arctic samples, HCB is the predominant POP compound with levels of around 22 pg m-3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART). The POP levels determined in Troll air were compared with 1 concentrations found in earlier measurement campaigns at other Antarctic research stations from the past 18 yr. Except for HCB for which similar concentration distributions were observed in all sampling campaigns, concentrations in the recent Troll samples were lower than in samples collected during the early 1990s. These concentration reductions are obviously a direct consequence of international regulations restricting the usage of POP-like chemicals on a worldwide scale.

Kallenborn, R.; Breivik, K.; Eckhardt, S.; Lunder, C. R.; Manø, S.; Schlabach, M.; Stohl, A.

2013-03-01

75

GARS O'Higgins as a core station for geodesy in Antarctica  

NASA Astrophysics Data System (ADS)

The German Antarctic Receiving Station GARS O'Higgins at the northern tip of the Antarctic Peninsula is a dual purpose facility for Earth observation since more than 20 years. It serves as a satellite ground station for payload data downlink and telecommanding of remote sensing satellites as well as a geodetic observatory for global reference frames and global change. Both applications use the same 9m diameter radio telescope. For space geodesy and astrometry the radio telescope significantly improves the coverage on the southern hemisphere and plays an essential role within the global Very Long Baseline Interferometry (VLBI) network. In particular the determination of the Earth Orientation Parameters (EOP) and the sky coverage of the International Celectial Reference Frame (ICRF) benefit from the location at high southern latitude. Further geodetic instrumentation includes different permanent GNSS receivers (since 1995), two SAR corner reflectors (since 2013) and in the past a PRARE system (1996 - 2004). In addition absolute gravity measurements were performed in 1997 and 2011. All geodetic reference points are tied together by a local survey network. The various geodetic instrumentation and the long time series at O'Higgins allow a reliable determination of crustal motions. VLBI station velocities, continuous GNSS time series and absolute gravity measurements consistently document an uplift rate of about 5 mm/a. A pressure gauge and a radar tide gauge being refererenced to space by a GNSS antenna on top allow the measurement of sea level changes independently from crustal motions, and the determination of the ellipsoidal height of the sea surface, which is, the geoid height plus the mean dynamic topography. The outstanding location on the Antarctic continent makes GARS O'Higgins also in future attractive for polar orbiting satellite missions and an essential station for the global VLBI network. Future plans envisage a development towards an observatory for environmentally relevant research.

Klügel, Thomas; Diedrich, Erhard; Falk, Reinhard; Hessels, Uwe; Höppner, Kathrin; Kühmstedt, Elke; Metzig, Robert; Plötz, Christian; Reinhold, Andreas; Schüler, Torben; Wojdziak, Reiner

2014-05-01

76

Nitrogen dioxide monitoring with an automatic DOAS station at Terra Nova Bay, Antarctica  

NASA Astrophysics Data System (ADS)

During the last few years UV-Vis spectrometers were developed at the FISBAT Institute and are used for application of differential optical absorption spectroscopy method to detect many atmospheric trace gases playing important roles in the stratospheric chemistry. After several test both in laboratory and in Antarctic region, one of the spectrometers, called GASCOD2/2, was modified in collaboration with ENEA for unattended and automatic measurement in extreme high-latitude environment. The instrument was installed in December 1995 in the Italian Station at Terra Nova Bay. The aim of this research is to study the dentrification processes during the formation of the so-called ozone hole over the Antarctic region. The preliminary results for the first year of nitrogen dioxide measurement are presented and discussed.

Ravegnani, Fabrizio; Kostadinov, Ivan K.; Giovanelli, Giorgio

1998-08-01

77

A sediment mesocosm experiment to determine if the remediation of a shoreline waste disposal site in Antarctica caused further environmental impacts.  

PubMed

A shoreline waste disposal site at Casey Station, Antarctica was removed because it was causing impacts in the adjacent marine environment (Brown Bay). We conducted a field experiment to determine whether the excavation created further impacts. Trays of clean, defaunated sediment were deployed at two locations within Brown Bay and two control locations, two years prior to remediation. Trays were sampled one year before, 1month before, 1month after and two years after the excavation. An increase in metals was found at Brown Bay two years after the remediation. However there was little evidence of impacts on sediment assemblages. Communities at each location were different, but differences from before to after the remediation were comparable, indicating there were unlikely to have been further impacts. We demonstrate that abandoned waste disposal sites in hydrologically active places in Antarctica can be removed without creating greater adverse impacts to ecosystems downstream. PMID:25306301

Stark, Jonathan S; Johnstone, Glenn J; Riddle, Martin J

2014-12-15

78

Spatial-temporal dynamics of chemical composition of surface snow in East Antarctica along the Progress station-Vostok station transect  

NASA Astrophysics Data System (ADS)

In January of 2008, during the 53rd Russian Antarctic Expedition, surface snow samples were taken from 13 shallow (0.7 to 1.5 m depth) snow pits along the first tractor traverse from Progress to Vostok stations, East Antarctica. Sub-surface snow/firn layers are dated from 2.1 to 18 yr. The total length of the coast to inland traverse is more than 1280 km. Here we analysed spatial variability of concentrations of sulphate ions and elements and their fluxes in the snow deposited within the 2006-2008 time interval. Anions were analysed by high-performance liquid chromatography (HPLC), and the determination of selected metals, including Na, K, Mg, Ca and Al, was carried out by mass spectroscopy with atomization by induced coupled plasma (ICP-MS). Surface snow concentration records were examined for trends versus distance inland, elevation, accumulation rate and slope gradient. Na shows a significant positive correlation with accumulation rate, which decreases as distance from the sea and altitude increase. K, Ca and Mg concentrations do not show any significant relationship either with distance inland or with elevation. Maximal concentrations of these elements with a prominent Al peak are revealed in the middle part of the traverse (500-600 km from the coast). Analysis of element correlations and atmospheric circulation patterns allow us to suggest their terrestrial origin (e.g. aluminosilicates carried as a continental dust) from the Antarctic nunatak areas. Sulphate concentrations show no significant relationship with distance inland, elevation, slope gradient and accumulation rate. Non-sea salt secondary sulphate is the most important contribution to the total sulphate budget along the traverse. Sulphate of volcanic origin attributed to the Pinatubo eruption (1991) was revealed in the snow pit at 1276 km (depth 120-130 cm).

Khodzher, T. V.; Golobokova, L. P.; Osipov, E. Yu.; Shibaev, Yu. A.; Lipenkov, V. Ya.; Osipova, O. P.; Petit, J. R.

2014-05-01

79

A Comparison of Ozonesonde Measurements and Slimcat Model Calculations For Mcmurdo Station, Antarctica, Spanning Nine Austral Springs  

NASA Astrophysics Data System (ADS)

In situ ozone measurements from McMurdo Station, Antarctica (78 S, 166 E), have been compared to SLIMCAT model calculations for the austral springs of 1991 - 2000. The in situ measurements were performed by the University of Wyoming us- ing balloon-borne electrochemical cell ozonesondes. The resolution of the measured profile is approximately 25 m. SLIMCAT is an off-line 3D chemical transport model with a detailed stratospheric chemistry scheme. The model was integrated from 1999- 2000 using a horizontal resolution of 7.5 x 7.5 degrees and was forced with UKMO analyses. The model output is one profile per day with a height resolution of 18 levels between~250 hPa and~0.3 hPa. For this study total ozone and ozone mixing ratios at the 468 K and 565 K isentropic surfaces as a function of time are compared. Individual daily profiles are also compared. Total ozone measurements and model agree very well in most years, whith slight over- estimation of measurements in 1993, 1998, 1999, and 2000. These years exhibited strongest ozone depletion amongst all years considered with rapid ozone loss and nearly ozone-free layers. Ozone mixing ratios at the 468 K isentropic surface show that the model captures well the rapid ozone loss at this altitude. Generally though, the measurements are below model calculations, and minima approaching 0 ppmv ozone in the most severe ozone loss years were not resolved by the model. Discrep- ancies at the 565 K level are larger between measurements and model than at 468 K. For the one year, 1994, when there were measurements throughout the winter and into spring, the SLIMCAT model shows very precise agreement with the observations for the onset of ozone loss, as well as the rate of ozone loss.

Kroger, C.; Chipperfield, M.; Deshler, T.

80

Extremely low N2O concentrations in the springtime stratosphere at McMurdo Station, Antarctica  

NASA Technical Reports Server (NTRS)

Measurements have been made of stratospheric N2O using the Stony Brook millimeter-wave remote sensing spectrometer at McMurdo Station, and NO2 mixing ratios are found that are less than 1.5 at 20 km and less than 1.10 at 25 km compared to values measured during the Antarctic summer. The observed mixing ratios are also much less than those predicted by global-scale models of stratospheric chemistry and dynamics. As the NO2 signal remained very weak when McMurdo was at the edges of the ozone hole and showed no signs of recovering during October, it is concluded that the geographical and temporal extent of the region of low NO2 is comparable to or greater than that of the ozone hole. These results argue against theories that require springtime upwelling to explain the Antarctic ozone hole. It is suggested that the air in the Antarctic lower stratosphere during late winter and early spring has been subjected to considerable downward transport.

Parrish, A.; De Zafra, R. L.; Jaramillo, M.; Connor, B.; Solomon, P. M.

1988-01-01

81

Observation of atmospheric minor constituents by FTIR at Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

As a part of the Antarctic MAP activity, a ground-based spectroscopic observation of atmospheric infrared transmission was started at Syowa station (69 deg 00'S, 39 deg 35'E) in March 24, 1983. Observations of sunlight as a radiation source were made with a Fourier transform infrared spectrometer having a maximum path difference of 80 mm and an apodized FWHM resolution of approx. 0.12/cm. In routine operation through the year, the resolution of approx. 0.8/cm was applied for economy of data-processing time. The 408 spectra for 72 days were obtained in about 10 months until January 23, 1984. From the absorption features revealed in the spectra over the wave number range of 500 to 7500/cm, a preliminary estimate of N202 gamma sub 1 band absorption was attempted. An apparent transmittance was defined at the wave number 2576/cm, where the absorption by N20 molecules affected the observed intensity strongly. A ray-tracing technique and a line-by-line calculation with a model atmosphere and the AFGL atmospheric absorption line parameters compilation were applied to the calculation of the synthetic spectra.

Makino, Y.; Muramatsu, H.; Kawaguchi, S.; Yamanouchi, T.; Tanaka, M.; Ogawa, T.

1985-12-01

82

Observation of atmospheric minor constituents by FTIR at Syowa Station, Antarctica  

NASA Technical Reports Server (NTRS)

As a part of the Antarctic MAP activity, a ground-based spectroscopic observation of atmospheric infrared transmission was started at Syowa station (69 deg 00'S, 39 deg 35'E) in March 24, 1983. Observations of sunlight as a radiation source were made with a Fourier transform infrared spectrometer having a maximum path difference of 80 mm and an apodized FWHM resolution of approx. 0.12/cm. In routine operation through the year, the resolution of approx. 0.8/cm was applied for economy of data-processing time. The 408 spectra for 72 days were obtained in about 10 months until January 23, 1984. From the absorption features revealed in the spectra over the wave number range of 500 to 7500/cm, a preliminary estimate of N202 gamma sub 1 band absorption was attempted. An apparent transmittance was defined at the wave number 2576/cm, where the absorption by N20 molecules affected the observed intensity strongly. A ray-tracing technique and a line-by-line calculation with a model atmosphere and the AFGL atmospheric absorption line parameters compilation were applied to the calculation of the synthetic spectra.

Makino, Y.; Muramatsu, H.; Kawaguchi, S.; Yamanouchi, T.; Tanaka, M.; Ogawa, T.

1985-01-01

83

Ozone profile measurements of McMurdo Station, Antarctica, during the spring of 1987  

NASA Technical Reports Server (NTRS)

Ozone and temperature profiles were measured in 50 balloon flights at McMurdo Station (78 deg S) during the spring of 1987. Compared to similar data obtained in 1986, stratospheric temperatures were lower and the spring time Antarctic ozone reduction was greater in magnitude, extended to higher altitude, and proceeded at a higher rate in 1987. Ozone partial pressures reached values as low as 3 nbar (as compared to about 10 nbar in 1986) in the 16- to 18-km region in early and late October, down from about 150 nbar in late August. These low values suggest essentially complete removal of ozone in this region. The upper boundary of the depletion region was observed to be 2-3 km higher than in 1986, extending to altitudes as high as 24 km in mid-September. When averaged over September, the ozone mixing ratio at 18 km decayed with a half-life of only 12.4 days, as compared to about 28 days in 1986. Adiabatic vertical motions over 1- to 2-km intervals between 12 and 20 km with consequent ozone reductions were observed in association with the formation of nacreous clouds, indicating these to be rare events on a local scale probably associated with mountain lee waves.

Hofmann, D. J.; Harder, J. W.; Rosen, J. M.; Hereford, J. V.; Carpenter, J. R.

1989-01-01

84

Ozone profile measurements at McMurdo Station Antarctica during the spring of 1987  

NASA Technical Reports Server (NTRS)

During the Antarctic spring of 1986, 33 ozone soundings were conducted from McMurdo Station. These data indicated that the springtime decrease in ozone occurred rapidly between the altitudes of 12 and 20 km. During 1987, these measurements were repeated with 50 soundings between 29 August and 9 November. Digital conversions of standard electrochemical cell ozonesondes were again employed. The ozonesonde pumps were individually calibrated for flow rate as the high altitude performance of these pumps have been in question. While these uncertainties are not large in the region of the ozone hole, they are significant at high altitude and apparently resulted in an underestimate of total ozone of about 7 percent (average) as compared to the Total Ozone Mapping Spectrometer (TOMS) in 1986, when the flow rate recommended by the manufacturer was used. At the upper altitudes (approx. 30 km) the flow rate may be overestimated by as much as 15 percent using recommended values (see Harder et al., The UW Digital Ozonesonde: Characteristics and Flow Rate Calibration, poster paper, this workshop). These upper level values are used in the extrapolation, at constant mixing ratio, required to complete the sounding for total ozone. The first sounding was on 29 August, prior to major ozone depletion, when 274 DU total ozone (25 DU extrapolated) was observed. By early October total ozone had decreased to the 150 DU range; it then increased during mid-October owing to motion of the vortex and returned to a value of 148 DU (29 DU extrapolated) on 27 October.

Hofmann, D. J.; Harder, J. W.; Rosen, J. M.; Hereford, J.; Carpenter, J. R.

1988-01-01

85

Ozone profile measurements at McMurdo Station, Antarctica, during the spring of 1987  

SciTech Connect

Ozone and temperature profiles were measured in 50 balloon flights at McMurdo Station (78{degree}S) during the spring of 1987. Compared to similar data obtained in 1986, stratospheric temperatures were lower and the springtime Antarctic ozone reduction was greater in magnitude, extended to higher altitude, and proceeded at a higher rate in 1987. Ozone partial pressures reached values as low as 3 nbar (as compared to about 10 nbar in 1986) in the 16- to 18-km region in early and late October, down from about 150 nbar in late August. These low values suggest essentially complete removal of ozone in this region. The upper boundary of the depletion region was observed to be 2-3 km higher than in 1986, extending to altitudes as high as 24 km in mid-September. When averaged over September, the ozone mixing ratio at 18 km decayed with a half-life of only 12.4 days, as compared to about 28 days in 1986. Adiabatic vertical motions over 1- to 2-km intervals between 12 and 20 km with consequent ozone reductions were observed in association with the formation of nacreous clouds, indicating these to be rare events on a local scale probably associated with mountain lee waves.

Hofmann, D.J.; Harder, J.W.; Rosen, J.M.; Hereford, J.V.; Carpenter, J.R. (Univ. of Wyoming, Laramie (United States))

1989-11-30

86

Soil formation in coastal continental Antarctica (Wilkes Land)  

Microsoft Academic Search

Recent antarctic soil studies suggest that in terrestrial ecosystems of coastal regions soil formation and chemical weathering occur to a greater extent than predicted by former models. This paper summarizes pedogenic findings from the Casey area on the coast of East Antarctica and presents a proposal of soil formation sequences on a large-scale data base. Soil organic matter accumulation and

Lothar Beyer; Kristina Pingpank; Gunther Wriedt; Manfred Bölter

2000-01-01

87

The ESA-NASA 'CHOICE' Study: Winterover at Concordia Station, Interior Antarctica, as an Analog for Spaceflight-Associated Immune Dysregu1ation  

NASA Technical Reports Server (NTRS)

For ground-based space physiological research, the choice of analog must carefully match the system of interest. Antarctica winter-over at the European Concordia Station is potentially a ground-analog for spaceflight-associated immune dysregulation (SAID). Concordia missions consist of prolonged durations in an extreme/dangerous environment, station-based habitation, isolation, disrupted circadian rhythms and international crews. The ESA-NASA CHOICE study assess innate and adaptive immunity, viral reactivataion and stress factors during Concordia winter-over deployment. To date, not all samples have been analyzed. Here, only data will be preliminary presented for those parameters where sample/data analysis is completed (i.e., Leukocyte subsets, T cell function, and intracellular/secreted cytokine profiles.)

Crucian, Brian E,; Feuerecker, M.; Salam, A. P.; Rybka, A.; Stowe, R. P.; Morrels, M.; Mehta, S. K.; Quiriarte, H.; Quintens, Roel; Thieme, U.; Kaufmann, I.; Baatout, D. S.; Pierson, D. L.; Sams, C. F.; Chouker, A.

2011-01-01

88

Tracking spatial distribution of human-derived wastewater from Davis Station, East Antarctica, using ?15N and ?13C stable isotopes.  

PubMed

Stable isotope ratios, ?15N and ?13C were effectively used to determine the geographical dispersion of human derived sewage from Davis Station, East Antarctica, using Antarctic rock cod (Trematomus bernacchii). Fish within 0-4 km downstream of the outfall exhibited higher ?15N and ?13C values relative to reference sites. Nitrogen in particular showed a stepped decrease in ?15N with increasing distance from the discharge point by 1-2‰. Stable isotopes were better able to detect the extent of wastewater contamination than other techniques including faecal coliform and sterol measures. Uptake and assimilation of ?15N and ?13C up to 4 km from the outfall adds to growing evidence indicating the current level of wastewater treatment at Davis Station is not sufficient to avoid impact to the surrounding environment. Isotopic assimilation in T. bernacchii is a viable biomarker for investigation of initial sewage exposure and longer term monitoring in the future. PMID:25487089

Corbett, Patricia A; King, Catherine K; Mondon, Julie A

2015-01-15

89

Balloonborne measurements of ozone and aerosol profiles at McMurdo Station, Antarctica, during the austral spring of 1992  

SciTech Connect

This paper reports some of the findings of an overall study of the ozone hole over Antarctica. Vertical profiles of ozone and aerosols were measured, and the inclusion of aerosols from the June 1991 eruption of Mount Pinatubo was of particular interest. 4 refs., 2 figs.

Johnson, B.J.; Deshler, T. (Univ. of Wyoming, Laramie, WY (United States))

1993-01-01

90

Polycyclic aromatic hydrocarbons in soil and surface marine sediment near Jubany Station (Antarctica). Role of permafrost as a low-permeability barrier.  

PubMed

Although Antarctica is still considered as one of the most pristine areas of the world, the growing tourist and fisheries activities as well as scientific operations and their related logistic support are responsible for an increasing level of pollutants in this fragile environment. Soils and coastal sediments are significantly affected near scientific stations particularly by polycyclic aromatic hydrocarbons (PAHs). In this work sediment and soil were sampled in two consecutive summer Antarctic expeditions at Potter Cove and peninsula, in the vicinity of Jubany Station (South Shetland Islands). Two- and 3-ring PAHs (methylnaphthalene, fluorene, phenanthrene and anthracene) were the main compounds found in most sites, although total PAH concentrations showed relatively low levels compared with other human-impacted areas in Antarctica. Pattern distribution of PAHs observed in samples suggested that low-temperature combustion processes such as diesel motor combustion and open-field garbage burning are the main sources of these compounds. An increase in PAH concentrations was observed from surface to depth into the active soil layer except for a unique sampling site where a fuel spill had been recently reported and where an inverted PAH concentration gradient was observed. The highest level was detected in the upper layer of permafrost followed by a sharp decrease in depth, showing this layer is acting as a barrier for downward PAH migration. When PAH levels in soil from both sampling programs were compared a significant decrease (p<0.01) was observed in summer 2005 (range at 75-cm depth: 12+/-1-153+/-22 ng/g) compared to summer 2004 (range at 75-cm depth: 162+/-15-1182+/-113 ng/g) whereas concentrations in surface sediment collected nearby the station PAHs increased drastically in 2005 (range: 36+/-3-1908+/-114 ng/g) compared to 2004 (range: 28+/-3-312+/-24 ng/g). Precipitation regime and water run off suggest that an important wash out of soil-PAHs occurred during the interval time between samplings. Results showed that the present PAH contamination level of Jubany Station is relatively low compared to other reported cases in Antarctica but also suggests that an increase in rain and in thawing processes caused by the global warming could result in an important soil-associated PAH mobilization with unpredictable consequences for the biota of Potter Cove. PMID:17570467

Curtosi, Antonio; Pelletier, Emilien; Vodopivez, Cristian L; Mac Cormack, Walter P

2007-09-20

91

Casey Journalism Center on Children and Families  

NSDL National Science Digital Library

Based at the University of Maryland, College Park, the Casey Journalism Center on Children and Families (CJC) is a nonprofit program administered by the Philip Merrill College of Journalism. The CJC is funded by the Annie E. Casey Foundation, the Freddie Mac Foundation, and a number of individual donors. The CJC provides numerous fellowship and training opportunities for new and experienced journalists, and visitors with an interest in such programs can look over their offerings in the "Fellowships/Training" section. The CJC also gives out an annual award for meritorious journalism, and visitors can read each year's winning investigative pieces on the site as well. As might be expected, the site contains a "Resources" section for working journalists who write on topics like child neglect, violence, and public support systems. Visitors to these respective areas will find links to statistical sites, brief summaries of relevant data, and links for locating experts and external resources.

92

Welcome to Antarctica!  

NSDL National Science Digital Library

This site provides a virtual tour of Antarctica and the Amundsen-Scott research station at the South Pole. The tour begins in New Zealand and goes to the station at McMurdo on the coast of Antarctica and finally to the center of the continent and the South Pole. Photos accompanied by brief captions are provided of scenes along the tour route. Users can also go directly to McMurdo or the South Pole, use a site map for the tour, or use a search engine.

93

Nitrate analysis of snow and ice core samples collected in the vicinity of a waste detonation event, McMurdo Station, Antarctica  

SciTech Connect

On December 30, 1991, a small quantity of hazardous materials was detonated at a site near McMurdo Station, Antarctica. The materials involved in the detonation represented highly reactive or explosive wastes that could not be transported safely for disposal in the United States. Detonation was therefore considered the safest and most effective means for disposing these hazardous materials. One concern regarding the detonation of these substances was that the process could generate or distribute measurable quantities of contaminants to the area surrounding the detonation site. Nitrate was selected as a tracer to document the distribution of contaminants from the detonation. Snow and ice cores were collected about 4 months after the event. These cores were analyzed for nitrate concentrations in May 1993, and a map was generated to show the extent of nitrate contamination. This report describes the collection of these samples and summarizes the analytical results.

White, G.J.; Lugar, R.M.; Crockett, A.B.

1994-07-01

94

Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica 9. Observations of OClO from April to October 1991  

SciTech Connect

This paper presents results from a series of measurements of atmospheric OClO covering the period April to October 1991, made at McMurdo Station, Antarctica. These measurements were made to extend the knowledge of the general role of atmospheric chlorine dioxide in the general problem of ozone depletion. It is now recognized that atmospheric depletion of ozone occurs in regions other than near the poles, and is mediated by processes beyond polar stratospheric clouds and accompanying photochemistry. This paper reports on a seasonal study of chlorine dioxide abundances using visible and near-ultraviolet absorption spectroscopy. Scattered light is the light source used for many of the observations. The observed abundances are combined with other measurements of NO[sub 2] and NO[sub 3], and a simple box type circulation model to infer that these species can be transported to lower latitudes, and exposed to sunlight, resulting in atmospheric ozone depletion.

Sanders, R.W.; Solomon, S.; Mount, G.H. (National Oceanic and Atmospheric Administration, Boulder, CO (United States)); Smith, J.P.; Perliski, L.; Miller, H.L. (Univ. of Colorado, Boulder (United States)); Keys, J.G. (Department of Scientific and Industrial Research, Lauder, Central Otago (New Zealand)); Schmeltekopf, A.L. (A.L. Schmeltekopf, Marshall, NC (United States))

1993-04-20

95

Applied Research Staff: Casey DiCocco  

Cancer.gov

Casey DiCocco, MPH is a Presidential Management Fellow designated to the National Cancer Institute. He received his Master of Public Health from Columbia University's Mailman School of Public Health in May 2013. During his graduate education, his focus was on health promotion and social science research. He received his BA from Boston University in 2009. Since joining NCI's PMF program in July 2013, Mr.

96

Welcome New Staff: Casey DiCocco  

Cancer.gov

Casey DiCocco, MPH is a Presidential Management Fellow designated to the National Cancer Institute. He received his Master of Public Health from Columbia University's Mailman School of Public Health in May 2013. During his graduate education, his focus was on health promotion and social science research. He received his BA from Boston University in 2009. Since joining NCI's PMF program in July 2013, Mr.

97

The ESA-NASA CHOICE Study: Winterover at Concordia Station, Interior Antarctica, A Potential Analog for Spaceflight-Associated Immune Dysregulation  

NASA Technical Reports Server (NTRS)

For ground-based space physiological research, the choice of terrestrial analog must carefully match the system of interest. Antarctica winter-over at the European Concordia Station is potentially a superior ground-analog for spaceflight-associated immune dysregulation (SAID). Concordia missions consist of prolonged durations in an extreme/dangerous environment, station-based habitation, isolation, disrupted circadian rhythms and international crews. The ESA-NASA CHOICE study assesses innate and adaptive immunity, viral reactivation and stress factors during Concordia winterover deployment. Initial data obtained from the first study deployment (2009 mission; 'n' of 6) will be presented, and logistical challenges regarding analog usage for biological studies will also be discussed. The total WBC increased, and alterations in some peripheral leukocyte populations were observed during winterover at Concordia Station. Percentages of lymphocytes and monocytes increased, and levels of senescent CD8+ T cells were increased during deployment. Transient increases in constitutively activated T cell subsets were observed, at mission time points associated with endemic disease outbreaks. T cell function (early blastogenesis response) was increased near the entry/exit deployment phases, and production of most measured cytokines increased during deployment. Salivary cortisol demonstrated high variability during winterover, but was generally increased. A 2-point circadian rhythm of cortisol measurement (morning/evening) was unaltered during winterover. Perceived stress was mildly elevated during winterover. Other measures, including in-vitro DTH assessment, viral specific T cell number/function and latent herpesvirus reactivation have not yet been completed for the 2009 winterover subjects. Based on the preliminary data, alterations in immune cell distribution and function appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Based on the initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune changes.

Crucian, B. E.; Stowe, R. P.; Mehta, S. K.; Quiriarte, H.; Pierson, D L.; Sams, C. F.

2010-01-01

98

Denaturing gradient gel electrophoresis fingerprinting of soil bacteria in the vicinity of the Chinese Great Wall Station, King George Island, Antarctica.  

PubMed

Bacterial diversity was investigated in soil samples collected from 13 sites around the Great Wall Station, Fildes Peninsula, King George Island, Antarctica, using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes. The classes alpha-, beta-, and gamma-Proteobacteria, as well as the phylum Actinobacteria, were found to be the dominant bacteria in the soils around the Great Wall Station. Although the selected samples were not contaminated by oil, a relationship between soil parameters, microbial biodiversity, and human impact was still seen. Sample sites in human impacted areas showed lower bacterial biodiversity (average H' = 2.65) when compared to non-impacted sites (average H' = 3.05). There was no statistically significant correlation between soil bacterial diversity and total organic carbon (TOC), total nitrogen, or total phosphorus contents of the soil. Canonical correlation analysis showed that TOC content was the most important factor determining bacterial community profiles among the measured soil parameters. In conclusion, microbial biodiversity and community characteristics within relatively small scales (1.5 km) were determined as a function of local environment parameters and anthropogenic impact. PMID:24520704

Pan, Qi; Wang, Feng; Zhang, Yang; Cai, Minghong; He, Jianfeng; Yang, Haizhen

2013-08-01

99

Micromorphological features of the fine earth and skeletal fractions of soils of West Antarctica in the areas of Russian Antarctic stations  

NASA Astrophysics Data System (ADS)

Micromorphological features of the fine earth and skeletal fractions of soils of West Antarctica forming under different conditions of pedogenesis have been studied in the areas of Russian Antarctic stations. The processes of mineral weathering and alteration of rock fragments are more pronounced in the Subantarctic soils with better developed humification and immobilization of iron compounds under conditions of surface overmoistening. The biogenic accumulative processes in the soils of King George Island result in the appearance of initial forms of humic plasma that have not been detected in the Antarctic soils in the areas of the Russkaya and Leningradskaya stations. Humus films on mineral grains are present in the soils of King George Island, and organic plasmic material is present in the ornithogenic soils under penguin guano on Lindsey Island. High-latitude Antarctic soils may contain surface concentrations of organic matter; rock fragments are covered by iron oxides and soluble salts. The formation of amorphous organic plasma takes place in the ornithogenic soils of Lindsey Island. The microprobe analysis indicates the presence of local concentrations of organic matter and pedogenic compounds not only on the surface of rock fragments but also in the fissures inside them. This analysis has also proved the translocation of guano-derived organic substances inside rock fragments through a system of fissures in the soils of Lindsey Island and the development of a network of pores inside rock fragments in the soils of King George Island.

Abakumov, E. V.; Gagarina, E. I.; Sapega, V. F.; Vlasov, D. Yu.

2013-12-01

100

General sound classification and similarity in MICHAEL CASEY  

E-print Network

General sound classification and similarity in MPEG-7 MICHAEL CASEY MERL Cambridge Research Laboratory, Cambridge, USA E-mail: casey@merl.com We introduce a system for generalised sound classification of environmental sounds, musical instruments, music genre and human speakers. In addition to classification

Casey, Michael

101

Linking the Annual Variation of Snow Radar-derived Accumulation in West Antarctica to Long-term Automatic Weather Station Measurements  

NASA Astrophysics Data System (ADS)

Understanding the snow accumulation rate on polar ice sheets is important in assessing mass balance and ice sheet contribution to sea level rise. Measuring annual accumulation on a regional scale and extending back in time several decades has been accomplished using the Center for Remote Sensing of Ice Sheets (CReSIS) Snow Radar on the NASA DC-8 that is part of NASA's Ice-Bridge project. The Snow Radar detects and maps near-surface internal layers in polar firn, operating from 2- 6 GHz and providing a depth resolution of ~4 cm. During November 2011, Snow Radar data were obtained for large areas of West Antarctica, including a flight segment that passed within ~70 km of Byrd Station (80°S, 119°W). Byrd Station has a very long automatic weather station (AWS) record, extending from present to 1980, with 3 relatively brief gaps in the record. The AWS data for Byrd Station were obtained from the Antarctic Meteorological Research Center (AMRC) at the University of Wisconsin. The L1B Snow Radar data products, available from the National Snow and Ice Data Center (NSIDC), were analyzed using layer picking software to obtain the depth of reflectors in the firn that are detected by the radar. These reflectors correspond to annual markers in the firn, and allow annual accumulation to be determined. Using the distance between the reflectors and available density profiles from ice cores, water equivalent accumulation for each annual layer back to 1980 is obtained. We are analyzing spatial variations of accumulation along flight lines, as well as variations in the time series of annual accumulation. We are also analyzing links between annual accumulation and surface weather observations from the Byrd Station AWS. Our analyses of surface weather observations have focused on annual temperature, atmospheric pressure and wind extremes (e.g. 5th and 95th percentiles) and links to annual snow accumulation. We are also examining satellite-derived sea ice extent records for the Bellingshausen and Amundsen seas sector (60°W-120°W) over the same 31-year time period and comparing results to annual snow accumulation. Results from this work will be presented at the meeting.

Feng, B.; Braaten, D. A.; Gogineni, P.; Paden, J. D.; Leuschen, C.; Purdon, K.

2013-12-01

102

Analysis of the Use of Wind Energy to Supplement the Power Needs at McMurdo Station and Amundsen-Scott South Pole Station, Antarctica (Poster)  

SciTech Connect

This poster summarizes the analysis of the inclusion of wind-driven power generation technology into the existing diesel power plants at two U.S. Antarctic research stations, McMurdo and Amundsen-Scott South Pole Station. Staff at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) conducted the analysis. Available data were obtained on the wind resources, power plant conditions, load, and component cost. We then used NREL's Hybrid2 power system modeling software to analyze the potential and cost of using wind turbine generators at the two aforementioned facilities.

Baring-Gould, E. I.; Robichaud, R.; McLain, K.

2005-05-01

103

Analysis of the Use of Wind Energy to Supplement the Power Needs at McMurdo Station and Amundsen-Scott South Pole Station, Antarctica  

SciTech Connect

This report summarizes an analysis of the inclusion of wind-driven power generation technology into the existing diesel power plants at two U.S. Antarctic research stations, McMurdo and Amundsen-Scott South Pole Station. Staff at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) conducted the analysis. Raytheon Polar Services, which currently holds the private sector support contract for the two research stations, was a major contributor to this report. To conduct the analysis, available data were obtained on the wind resources, power plant conditions, load, and component cost. Whenever possible, we validated the information. We then used NREL's Hybrid2 power system modeling software to analyze the potential and cost of using wind turbine generators at the two aforementioned facilities. Unfortunately, the power systems and energy allocations at McMurdo and South Pole Station are being redeveloped, so it is not possible to validate future fuel use. This report is an initial assessment of the potential use of wind energy and should be followed by further, more detailed analysis if this option is to be considered further.

Baring-Gould, I.; Robichaud, R.; McLain, K.

2005-05-01

104

Astronomy in Antarctica  

E-print Network

Antarctica provides a unique environment for astronomy. The cold, dry and stable air found above the high plateau, as well as the pure ice below, offers new opportunities across the photon & particle spectrum. The summits of the plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway at four plateau sites: the Amundsen-Scott South Pole Station, Concordia Station at Dome C, Kunlun Station at Dome A and Fuji Station at Dome F, in addition to long duration ballooning from the coastal station of McMurdo. Astronomy conducted includes optical, IR, THz & sub-mm, measurements of the CMBR, solar, as well as high energy astrophysics involving measurement of cosmic rays, gamma rays and neutrinos. Antarctica is also the richest source of meteorites on our planet. An extensive range of site testing measurements have been made over the high plateau. We summarise the facets of Antarctica that are dri...

Burton, Michael G

2010-01-01

105

Proposed Casey`s Pond Improvement Project, Fermi National Accelerator Laboratory  

SciTech Connect

The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA), evaluating the impacts associated with the proposed Casey`s Pond Improvement Project at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. The improvement project would maximize the efficiency of the Fermilab Industrial Cooling Water (ICW) distribution system, which removes (via evaporation) the thermal load from experimental and other support equipment supporting the high energy physics program at Fermilab. The project would eliminate the risk of overheating during fixed target experiments, ensure that the Illinois Water Quality Standards are consistently achieved and provide needed additional water storage for fire protection. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required.

NONE

1995-05-01

106

Accuracy assessment of land surface temperature retrievals from Landsat 7 ETM + in the Dry Valleys of Antarctica using iButton temperature loggers and weather station data.  

PubMed

The McMurdo Dry Valleys of Antarctica are the largest snow/ice-free regions on this vast continent, comprising 1% of the land mass. Due to harsh environmental conditions, the valleys are bereft of any vegetation. Land surface temperature is a key determinate of microclimate and a driver for sensible and latent heat fluxes of the surface. The Dry Valleys have been the focus of ecological studies as they arguably provide the simplest trophic structure suitable for modelling. In this paper, we employ a validation method for land surface temperatures obtained from Landsat 7 ETM + imagery and compared with in situ land surface temperature data collected from four transects totalling 45 iButtons. A single meteorological station was used to obtain a better understanding of daily and seasonal cycles in land surface temperatures. Results show a good agreement between the iButton and the Landsat 7 ETM + product for clear sky cases. We conclude that Landsat 7 ETM + derived land surface temperatures can be used at broad spatial scales for ecological and meteorological research. PMID:24366817

Brabyn, Lars; Zawar-Reza, Peyman; Stichbury, Glen; Cary, Craig; Storey, Bryan; Laughlin, Daniel C; Katurji, Marwan

2014-04-01

107

Balloon-borne measurements of aerosol, condensation nuclei, and cloud particles in the stratosphere at McMurdo Station, Antarctica, during the spring of 1987  

NASA Technical Reports Server (NTRS)

Measurements of the vertical profile of particles with condensation nuclei counters and eight channel aerosol detectors at McMurdo Station, Antarctica, in 1987 verified observations made in 1986 concerning the absence of upwelling in the polar vortex and the presence of a condensation nuclei layer in conjunction with the ozone hole region. New observations of a bimodal aerosol size distribution, consisting of a large-particle mode mixed in with the small-particle sulfate mode, at temperatures below -79 C are consistent with the presence of nitric acid-water particles at low concentrations. Higher concentrations of large particles were observed in association with nacreous clouds. An unusual particle layer which contained enhanced concentrations of both the small-particle (sulfate) mode and the large-particle (nitric acid) mode was detected at temperatures below -85 C, suggesting simultaneous nucleation and growth phenomena. The vortex condensation nuclei layer was observed to form at the same time as the ozone hole, indicating that formation of the layer is triggered by photochemical processes and may be important in controlling ozone depletion above 22 km.

Hofmann, D. J.; Rosen, J. M.; Harder, J. W.; Hereford, J. V.

1989-01-01

108

Classroom Antarctica  

NSDL National Science Digital Library

As part of the Australian Antarctic Division, Classroom Antarctica gives dozens of downloadable Adobe Acrobat files that allow students to discover this unique continent. Subjects include the history of the scientific research undertaken on Antarctica, surviving its climate, its biological ecosystem, the land's physical characteristics and affects on climate, and much more.

1969-12-31

109

SIAMOIS: Asteroseismology in Antarctica Beno^it MOSSER1  

E-print Network

SIAMOIS: Asteroseismology in Antarctica Beno^it MOSSER1 & the SIAMOIS team2 1 LESIA, Observatoire-based asteroseismology project, to pursue velocity measurements from the Dome C Concordia station in Antarctica. Dome C conditions in Antarctica. The instrument will be fully automatic, with no moving parts, and it will require

Demoulin, Pascal

110

Characteristics of highprecipitation events in Dronning Maud Land, Antarctica  

E-print Network

, Antarctica E. Schlosser,1 K. W. Manning,2 J. G. Powers,2 M. G. Duda,2 G. Birnbaum,3 and K. Fujita4 Received events at the deep ice core drilling site Kohnen Station, Dronning Maud Land, Antarctica, during precipitation events in Dronning Maud Land, Antarctica, J. Geophys. Res., 115, D14107, doi:10.1029/2009JD013410

Schlosser, Elisabeth

111

Observed trends for CF3-containing compounds in background air at Cape Meares, Oregon, Point Barrow, Alaska, and Palmer Station, Antarctica.  

PubMed

The concentrations of CF(3)-containing compounds in archived air samples collected at Cape Meares, Oregon, from 1978 to 1997, at Point Barrow, Alaska, from 1995 to 1998, and at Palmer Station, Antarctica, from 1991 to 1997, were determined by high resolution gas chromatography and high resolution mass spectrometry. The CF(3)-containing compounds measured by this method and discussed here are: the perfluorinated compound, C(3)F(8) (FC 218); four perhalogenated compounds, CF(3)Cl (CFC 13), CF(3)CF(2)Cl (CFC 115), CF(3)CFCl(2) (CFC 114a), and CF(3)Br (Halon 1301); and three hydrofluorocompounds, CF(3)H (HFC 23), CF(3)CH(3) (HFC 143a), and CF(3)CH(2)F (HFC 134a). For four of these compounds, very few measurements have been previously reported. The atmospheric concentrations of all of the CF(3)-containing compounds continuously increased in time over the sample collection periods. From these data, the annual rates of emission into the atmosphere have been estimated. The emission rates fall into one of three distinct categories. The annual emission rates of C(3)F(8), CF(3)H, CF(3)CH(3), and CF(3)CH(2)F have continuously increased over the last two decades. That of CF(3)CFCl(2) has decreased continuously. Emission rates for CF(3)Cl, CF(3)CF(2)Cl, and CF(3)Br reached maximum levels in the late 1980s, and have been decreasing in the 1990s. The emission rates of C(3)F(8), CF(3)CH(3) and CF(3)CH(2)F were nearly zero 20 years ago but have increased rapidly during the last decade. PMID:15050808

Culbertson, J A; Prins, J M; Grimsrud, E P; Rasmussen, R A; Khalil, M A K; Shearer, M J

2004-05-01

112

The CELSS Antarctic Analog Project: an advanced life support testbed at the Amundsen-Scott South Pole Station, Antarctica.  

PubMed

The Controlled Ecological Life Support System (CELSS) Antarctic Analog Project (CAAP) is a joint endeavor between the National Science Foundation, Office of Polar Programs (NSF-OPP) and the National Aeronautics and Space Administration (NASA). Its fundamental objective is to develop, deploy and operate a testbed of NASA CELSS technologies and life support approaches at the Amundsen-Scott South Pole Station, located at latitude 90 degrees S, longitude 0 degrees. The goal of NASA's CELSS Program is to develop technologies and systems that will allow spacefaring scientists and explorers to carry out long duration extraterrestrial missions, leading ultimately to permanent habitation of the Solar System, without total dependence on a costly resupply system. A CELSS would do this by providing regenerated life support materials (air, food and water) and by processing "waste" materials into useful resources. This will be accomplished using biological and physical/chemical techniques in a nearly closed environmental habitation system. CELSS technologies also have great implications for application to terrestrial systems with intrinsic transferability to society at large. The CELSS Program intends to provide opportunities for the transfer of these systems and technologies outside the US Space Program, to applications within the American economy as space technology spin-offs. PMID:11538582

Straight, C L; Bubenheim, D L; Bates, M E; Flynn, M T

1994-01-01

113

Geoenvironments from the vicinity of Arctowski Station, Admiralty Bay, King George Island, Antarctica: vulnerability and valuation assessment  

USGS Publications Warehouse

The use of a geographic information system (GIS) allows the mapping and quantification of biotic and physical features of importance to the environmental planning of Antarctic areas. In this paper we examined the main aspects of the geoenvironments of Arctowski Station vicinity (Admiralty bay, Maritime Antartica), by means of a photointerpretation of an orthomosaic at 1:6000 scale, produced by non-conventional aerial photographs obtained by the Brazilian Cryosols project. We carried out a preliminary environmental valuation and vulnerability assessment of the area. Hence, geoenvironments were classified and ranked according with their biological valuation and vulnerability (fragility), mapping 20 units covering approximately 150 ha. The most fragile geoenvironmental units were former and present penguin rookeries with different vegetation covers, all very prone to degradation by over-trampling and human perturbations. The relationships between each geoenvironment were also explored, emphasizing the ecological aspects and their valuation. In quantitative terms, the most vulnerable and fragile units (classes 4 and 5) occupy nearly 22 % of the total area, being highly concentrated near the coastal areas. There, ornithogenic input is an important factor favoring the vegetation development.

Schaefer, Carlos Ernesto G.R.; Santana, Rogério Mercandelle; Simas, Felipe Nogueira Bello; Francelino, Márcio R.; Filho, Elpídio Inácio Fernandes; Albuquerque, Miriam Abreu; Calijuri, Maria Lúcia

2007-01-01

114

Five-year analysis of background carbon dioxide and ozone variations during summer seasons at the Mario Zucchelli station (Antarctica)  

NASA Astrophysics Data System (ADS)

The work focuses on the analysis of CO2 and O3 surface variations observed during five summer experimental campaigns carried out at the ‘Icaro Camp’ clean air facility (74.7°S, 164.1°E, 41 m a.s.l.) of the ‘Mario Zucchelli’ Italian coastal research station. This experimental activity allowed the definition of summer average background O3 values that ranged from 18.3 ± 4.7 ppbv (summer 2005-2006) to 21.3 ± 4.0 ppbv (summer 2003-2004). Background CO2 concentrations showed an average growth rate of 2.10 ppmv yr-1, with the highest CO2 increase between the summer campaigns 2002-2003 and 2001-2002 (+2.85 ppmv yr-1), probably reflecting the influence of the 2002/2003 ENSO event. A comparison with other Antarctic coastal sites suggested that the summer background CO2 and O3 at MZS-IC are well representative of the average conditions of the Ross Sea coastal regions. As shown by the analysis of local wind direction and by 3-D back-trajectory calculations, the highest CO2 and O3 values were recorded in correspondence to air masses flowing from the interior of the Antarctic continent. These results suggest that air mass transport from the interior of the continent exerts an important influence on air mass composition in Antarctic coastal areas.

Cristofanelli, P.; Calzolari, F.; Bonafè, U.; Lanconelli, C.; Lupi, A.; Busetto, M.; Vitale, V.; Colombo, T.; Bonasoni, P.

2011-11-01

115

Variation of NO in lower thermosphere associated with a magnetic storm on April 2012 detected at Syowa station in Antarctica  

NASA Astrophysics Data System (ADS)

In the polar regions, it is known that energetic particle precipitation (EPP) induces ion-molecule chemistry and changes abundances of some minor molecules in the upper- and sometimes in the middle-atmosphere. Energetic solar protons directly enter the middle atmosphere, causing increase of HOx and NOx radicals and decrease of ozone (e.g., Jackman et al. 2001). Energetic electrons also increase NOx in the thermosphere, and the NOx-rich air is transported downward in the polar vortex during the polar winter (e.g., Seppälä et al. 2007). To understand the relationship between the EPP induced NOx variation and the solar activities in more detail, we newly installed a millimeter-wave spectroscopic radiometer at Syowa Station (69.00S, 39.85E) in the 52nd Japanese Antarctic Research Expedition. We have been carried out ground-based continuous monitoring of millimeter-wave ozone (235.709 GHz) and NO (250.796 GHz) spectral lines with a 70 kHz resolution and a 1 GHz bandwidth since March 2011. Based on the NO spectra integrated over 24 hours (UT 0-24), we found enhancement of the NO emission in 25-29 April, 2012. During this period, there was no significant solar proton increase. The peak intensity of the NO emission increased up to 4.1 K on 28th, while an average of the NO intensities from 18 to 23 April was estimated to be 1.4 K. After the enhancement, the intensity decreased below 2.5 K on 30th. In this period, a large magnetic storm occurred and its main phase was on April 23. The minimum value of Dst index reached -100 nT on April 24, and the electron flux with an energy less than 30 keV became a maximum of ~104 cm-2 s-1 str-1 on April 25 observed by POES. These results suggest that the remarkable enhancement of NO emission is associated with the energetic electron precipitation from radiation belts, although there is a 5-day delay between at the peak of the NO intensity and the main phase of the magnetic storm. In addition, from the NO data integrated every 12 hours (MLT 0-12 and 12-24), we clearly found that the NO intensity observed in MLT 0-12 is about 50 % stronger than that in MLT 12-24 on average during a period from 26 to 29 April. This suggests that the NO intensity is modulated in connection with the dawn-dusk asymmetry of the electron distribution in the magnetopause. In this presentation, we will discuss a possible mechanism for the two different kind of NO intensity variations, i.e. persistent enhancement for a few days and daily variation, observed related with EPP at Syowa Station.

Isono, Y.; Mizuno, A.; Nagahama, T.; Ejiri, M. K.; Kataoka, R.; Kuwahara, T.; Maezawa, H.; Miyoshi, Y.; Nakamura, T.; Tsutsumi, M.

2012-12-01

116

Antarctica Ice  

NSDL National Science Digital Library

This short video examines the recent melting ice shelves in the Antarctica Peninsula; the potential collapse of West Antarctic ice shelf; and how global sea levels, coastal cities, and beaches would be affected.

National Geographic

117

Cool Antarctica  

NSDL National Science Digital Library

Paul Ward, the designer of this site, spent over two years in Antarctica as a marine biologist with the British Antarctic Survey. Currently a teacher at a community college in Britain, Ward decided to develop this site to provide information about Antarctica's history, wildlife, and the various explorers who have traveled across the continent. The section featuring Ward's photographs is quite compelling, featuring hundreds of pictures of wildlife, the area's mountains, and icebergs. The historical pages are quite detailed, particularly those about the legendary Ernest Shackleton and his amazing Trans-Antarctica Expedition of 1914 to 1917. Persons looking for material about visiting Antarctica will find a section dedicated to helping people prepare for a visit to the area, including information about various cruise operators and what type of clothing is most suitable.

118

Devotion to Jesus and Historical Investigation. A Grateful, Clarifying and Critical Response to Professor Casey   

E-print Network

It is obviously very gratifying to have my recent book (Lord Jesus Christ: Devotion to Jesus in Earliest Christianity, hereafter referred to as LJC) given the attention represented in Professor Casey’s commissioned review ...

Hurtado, Larry W

2004-01-01

119

SPRILIB Antarctica  

NSDL National Science Digital Library

The Scott Polar Research Institute at the University of Cambridge has recently made available online the database, SPRILIB Antarctica. SPRILIB Antarctica, a subset of SPRILIB, a polar and glaciological bibliographic database, contains 33,000 records from 1602 to 1996. The database offers comprehensive coverage of Antarctic literature on all subjects in all available languages for the period before 1962. However, it only includes some periodical articles and conference papers for the period after 1962. This database is intended to complement the Antarctic Bibliography at the Cold Regions Bibliography page of the Library of Congress site, and for the period after 1962, the Antarctic Bibliography contains comprehensive coverage of Antarctic literature. The SPRILIB Antarctica database is searchable by keyword, author, time period, place, expedition, or date of publication.

120

Classroom Antarctica  

NSDL National Science Digital Library

This website is a collection of units designed to teach students about the global importance of Antarctica. Topics covered in these units includes ice, the ocean, geology, weather, topography, auroras, the history of Antarctic exploration, living in Antarctica, animals, plants, the Antarctic Treaty, and the environment. Each unit has a selection of activities that are adaptable to the range of abilities in a class and the particular interests of the students. There are hundreds of useful web links throughout and a wealth of support material listed under Classroom Resources.

Elizabeth Haywood

121

Aviation Opens Antarctica  

NSDL National Science Digital Library

The history of aviation and the history of Antarctic exploration and science are inextricably entwined. In 1929, naval aviation pioneer Richard E. Byrd, became the first person to fly over the South Pole, dropping a flag to mark his achievement and breaking the isolation of the skies over the Pole for the first time since the age of the dinosaurs. Today, more than 100 such flights annually cross the 900 miles between McMurdo Station (NSF's logistics hub in Antarctica) and the South Pole.

122

Antarctica Geology  

NSDL National Science Digital Library

This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

123

Undermining Antarctica  

SciTech Connect

Antarctica is not a global footnote. Its seas contain one of the world's richest concentrations of marine life. And the continent and adjacent shelf may harbor quantities of oil, gas, and other minerals. Many nations want to cash in on these resources. So in 1980 the member countries of the Antarctic Treaty - the agreement that sets the continent aside as a peaceful scientific reserve - signed a pact to regulate the harvesting of fish and other Antarctic life. Now the group, consisting today of 37 nations, is trying to finish a legal framework for exploiting minerals in the region. Antarctica plays a vital role in global atmospheric and oceanic systems. Its vast frozen crust, which accounts for more than 90 percent of the world's ice, greatly affects weather and sea levels and contains an invaluable record of the earth's climatic history. The continent provides precious information on increases in atmospheric carbon dioxide and global pollutants such as DDT. In other words, what happens to Antarctica is of vital importance to us all. It is essential, then, that the minerals pact now being devised heed the concerns of the many nations that don't have a say in Antarctica today, and that it does not endanger this precious continent.

Mitchell, B.

1988-02-01

124

Antarctic temperatures since the late 1950s: SAM cooling,1 background warming, and West Antarctica heating up2  

E-print Network

Antarctic temperatures since the late 1950s: SAM cooling,1 background warming, and West Antarctica to take advantage of a recently revised key temperature record from West7 Antarctica (Byrd Station.42±0.21 C decade-1 ), West Antarctica (0.21±0.10 C decade-1 ), and Antarctica as a14 whole (0.12±0.08 C

Howat, Ian M.

125

A survey of natural electromagnetic noise in the frequency range f = 1-10 kHz at Halley station, Antarctica: 1. Radio atmospherics from lightning  

Microsoft Academic Search

This paper presents results from the first systematic survey of VLF wave activity at Halley, Antarctica (76°S, 27°W, L = 4.3). Beginning in 1971, the peak, average and minimum (P, A, M) signal levels observed in four frequency bands centred on 0.75 kHz, 1.25 kHz, 3.2 kHz and 9.6 kHz have been recorded every 5 min. At these frequencies the

A. J. Smith; P. J. Jenkins

1998-01-01

126

A survey of natural electromagnetic noise in the frequency range f = 1–10 kHz at Halley station, Antarctica: 1. Radio atmospherics from lightning  

Microsoft Academic Search

This paper presents results from the first systematic survey of VLF wave activity at Halley, Antarctica (76 °S, 27 °W, L = 4.3). Beginning in 1971, the peak, average and minimum (P, A, M) signal levels observed in four frequency bands centred on 0.75 kHz, 1.25 kHz, 3.2 kHz and 9.6 kHz have been recorded every 5 min. At these

A. J. Smith; P. J. Jenkins

1998-01-01

127

Discover Antarctica  

NSDL National Science Digital Library

Antarctica is arguably the continent that most people know the least about, so it is nice to find out that the Royal Geographical Society (in partnership with the British Antarctic Survey) has created this website which explores all aspects of life on this landmass. The "Imagining Antarctica" area is a fine place to start, and visitors can watch a short video clip about the continent, test their existing knowledge with a short quiz, and then participate in a "being there" activity. Other engaging sections include "A Changing Climate", "Living There Today" and "What Future?" The site also lists all of the resources by format, including audio files, video clips, Word documents, and images. Finally, the site also includes a "Teachers' Area", which offers a number of learning activities for students and teacher notes that are correlated to each of the main sections of the site.

128

SIAMOIS : AN ASTEROSEISMIC NETWORK WITH 1 SITE... IN ANTARCTICA Mosser Beno^it1  

E-print Network

SIAMOIS : AN ASTEROSEISMIC NETWORK WITH 1 SITE... IN ANTARCTICA Mosser Beno^it1 and the SIAMOIS- seismology, involving an instrument to be installed at the Dome C Concordia station in Antarctica. Dome C ap with a dedicated small 40-cm telescope. Key words: Instrumentation, Antarctica, Stars: oscilla- tions. 1

Demoulin, Pascal

129

Life after Casey: the view from Rehnquist's Potemkin Village.  

PubMed

The U.S. Supreme Court's most recent pronouncement on abortion rights [Planned Parenthood of Southeastern Pennsylvania v. Casey] resembles the dieter's dilemma: one knows exactly how to get where one is going but lacks the willpower to follow through. In an opinion filled with exceptionally progressive, equality-based arguments for reproductive freedom, the Court nonetheless manages to back away from its own ineluctably drawn conclusions. In the end it not only ignores its own best arguments but eviscerates its previous analyses of fundamental rights and judicial protection of personal liberties from the excesses of the polity. PMID:11652123

Charo, R Alta

1993-01-01

130

Gateway to Antarctica  

NSDL National Science Digital Library

The International Centre for Antarctic Information and Research is produces the Gateway Antarctica. This Web server has been set up to provide the international community with information about Antarctica.

1969-12-31

131

Bouvet Island near Antarctica  

Atmospheric Science Data Center

... Lozier. Bouvet was convinced it was the northernmost tip of Antarctica but could not circumnavigate or land upon the island due to severe ... Bouvet Island location:  Antarctica Atlantic Ocean thumbnail:  ...

2013-04-16

132

The IRAIT Project Infrared Astronomy from Antarctica  

Microsoft Academic Search

The Concordia Station (Candidi 2003), on the Antarctica Plateau, will soon become one of the best observatories to perform infrared observations in the 2 20 mum atmospheric windows and beyond, thanks to its low sky background, low temperature and high atmospheric transparency. The possibility of passively cooling the telescope is a further advantage. We describe here the first permanent Antarctic

M. Busso; G. Tosti; F. Roncella; M. Bagaglia; G. Nucciarelli; R. Fastellini; O. Straniero; M. Dolci; M. Ragni; I. di Varano; L. Corcione; C. Abia; I. Dominguez; F. Rossi; A. Nicolini

2005-01-01

133

ANTARCTICA. By  

E-print Network

Four studies are presented using various petrologic, gaseous and aqueous geochemical methods to investigate volcanic and hydrothermal systems in different geologic settings. Each study contributes to aspects of geothermal exploration: from the theoretical in investigating the occurrence of water-rock interaction at Erebus volcano (Antarctica), to the practical in locating the depths of acidic feed zones in the Krafla (Iceland) production wells as well as testing new low-temperature geothermal exploration methods in Socorro, New Mexico.. The Socorro Geothermal Area in New Mexico represents a low-temperature, geothermal system demonstrated by several hot springs and an exploration slim hole drilled at the base of Socorro Peak. Low temperature reservoirs typically lack surface manifestations and equilibrated sample fluids necessary to assess the extent and economic potential of the resource. Extensive past work performed on Socorro Peak, including temperature gradient drilling and heat flow model (Barroll and Reiter, 1991; Mailloux et al., 1999), allows us to test alternative methods for exploring similar blind, low temperature resources. Two methods tested here included soil mapping by selective extraction and a multi-isotope fluid chemistry survey. Selective extraction soil mapping, a method common in mineral exploration, applies two distinct biosynthetic leaches,

Lara Bevan Owens

134

Vertical profiles of atmospheric temperature between upper troposphere and mesosphere obtained from Rayleigh/Raman lidar installed at Syowa station in Antarctica  

NASA Astrophysics Data System (ADS)

Atmospheric gravity waves (AGWs) propagating upward from lower atmospheric sources play a dominant role in transporting and depositing energy and momentum from upper troposphere (UT) to lower mesosphere (LM). Particularly, in polar region, these effects of AGWs are well-known to strongly decelerate the polar night jet and drive large scale meridional circulation from the summer pole towards the winter pole. In addition, polar stratospheric clouds (PSCs) described in relation to ozone depletion are effectively induced by orographic AGWs. Therefore, investigation of the activity of AGWs between UT and LM based on continuous observational studies can be regarded as one of important subjects in the middle atmosphere dynamics. The National Institute of Polar Research (NIPR) is leading a six year prioritized project of the Antarctic research observations since 2010. One of the sub-projects is entitled 'the global environmental change revealed through the Antarctic middle and upper atmosphere'. As a part of the sub-project, a Rayleigh/Raman lidar (RR lidar) was installed at Syowa, Antarctica (69S, 39E) in January, 2011. The operation has been conducted since February 2011 and the RR lidar has kept measuring temperature profiles continuously between approximately 10 and 80 km for almost 3 years. The RR lidar system in Syowa can obtain photon count data for 4 channels simultaneously, and each data is recorded separately in binnary format. We used the data from 3 channels, i.e., Raman (10-30km), Rayleigh-Low (20-65km), Rayleigh-High (30-80km), for estimations of temperature profiles from UT to LM. In order to estimate height continuous profiles of atmospheric temperature based on the 3 different channels, we are examining the following analysis methods. (1) The temperature for Rayleigh-High and Rayleigh-Low channels estimated by solving the lidar equation can be assigned to temperature at an initial height for the lidar equation in Rayleigh-Low and Raman channels, respectively. (2) The initial heights for the lidar equation can be determined automatically taking into account time and height dependent shot noises due to background luminosity. (3) The error propagations from the initial height to lower heights are evaluated by assigning artificial temperature offset ranging from -50 to 50 K. The height continuous temperature profiles between UT and LM obtained from improved analysis methods would allows us to investigate important scientific issues such as temporal and height variabilities of potential energy per unit mass of AGWs and the relationship between occurrence of PSCs and background atmospheric temperature.

Nishiyama, Takanori; Nakamura, Takuji; Tsutsumi, Masaki; Kawahara, Takuya D.; Tomikawa, Yoshihiro; Suzuki, Hidehiko; Ejiri, Mitsumu K.; Abo, Makoto; Tsuda, Takuo T.

135

Recent surface mass balance from Syowa Station to Dome F, East Antarctica: comparison of field observations, atmospheric reanalyses, and a regional atmospheric climate model  

NASA Astrophysics Data System (ADS)

Stake measurements at 2 km intervals are used to determine the spatial and temporal surface mass balance (SMB) in recent decades along the Japanese Antarctic Research Expedition traverse route from Syowa Station to Dome F. To determine SMB variability at regional scales, this traverse route is divided into four regions, i.e., coastal, lower katabatic, upper katabatic and inland plateau. We also perform a regional evaluation of large scale SMB simulated by the regional atmospheric climate model versions 2.1 and 2.3 (RACMO2.1 and RACMO2.3), and the four more recent global reanalyses. Large-scale spatial variability in the multi-year averaged SMB reveals robust relationships with continentality and surface elevation. In the katabatic regions, SMB variability is also highly associated with surface slope, which in turn is affected by bedrock topography. Stake observation records show large inter-annual variability in SMB, but did not indicate any significant trends over both the last 40 years for the coastal and lower katabatic regions, and the last 20 years record for the upper katabatic and inland plateau regions. The four reanalyses and the regional climate model reproduce the macro-scale spatial pattern well for the multi-year averaged SMB, but fail to capture the mesoscale SMB increase at the distance interval ~300 to ~400 km from Syowa station. Thanks to the updated scheme in the cloud microphysics, RACMO2.3 shows the best spatial agreement with stake measurements over the inland plateau region. ERA-interim, JRA-55 and MERRA exhibit high agreement with the inter-annual variability of observed SMB in the coastal, upper katabatic and inland plateau regions, and moderate agreement in the lower katabatic region, while NCEP2 and RACMO2.1 inter-annual variability shows no significant correlation with the observations for the inland plateau region.

Wang, Yetang; Hou, Shugui; Sun, Weijun; Lenaerts, Jan T. M.; van den Broeke, Michiel R.; van Wessem, J. M.

2015-02-01

136

Discovery and exploration of Antarctica  

SciTech Connect

The continent of Antarctica, some 5000 mi/sup 2/ in area, lies almost wholly within the Antarctic Circle. Some ancient philosophers and cartographers postulated the existence of a southern landmass, but the concept remained untested for centuries. In 1772-1775, Captain James Cook circumnavigated the continent and crossed the Antarctic Circle, but he sighted no land and concluded that the existence of a continent was unlikely. The first definite sightings of land by American, British, and Russian ships occurred in the Antarctic Peninsula region near 1820. In 1840, parts of the coast were mapped and landings were made by American, British, and French expeditions led, respectively, by Wilkes, Ross, and d'Urville. The first systematic geological field work was conducted by the Borchgrevink expedition in 1899-1900 near Cape Adare, south of New Zealand. During the first years of the present century, major expeditions were led by such men as Nordenskiold, Scott, Shackleton, Amundsen, and Mawson, culminating in the journeys to the South Pole by Amundsen and Scott during the 1911-1912 field season. The US has sent a number of expeditions to Antarctica during the last 60 years, beginning with the Byrd Expeditions of 1928-1930 and 1933-1935 when aircraft were used extensively and a flight was made to the South Pole. These expeditions were followed by the US Antarctic Service Expedition in 1939-1941. After World War II, US activities resumed with Operation Highjump in 1946-1947, followed the next year by Operation Windmill and the Ronne Antarctic Research Expedition. As late as 1955, most of Antarctica remained poorly known geologically. The International Geophysical Year (IGY) in 1957-1958 led to the building of 48 new stations in Antarctica by 12 nations and marked the beginning of the current period of sustained research.

Craddock, C.

1987-05-01

137

Spatial distribution of 17O-excess in surface snow along a traverse from Zhongshan station to Dome A, East Antarctica  

NASA Astrophysics Data System (ADS)

The influence of temperature on the triple isotopic composition of oxygen in water is still an open question and limits the interpretation of water isotopic profiles in Antarctic ice cores. The main limitation arises from the lack of 17O-excess measurements in surface snow and especially for remote regions characterized by low temperature and accumulation rate. In this study, we present new 17O-excess measurements of surface snow along an East Antarctic traverse, from the coastal Zhongshan station to the highest point of the Antarctic ice sheet at Dome A. The 17O-excess data significantly decrease inland, with a latitudinal gradient of - 1.33 ± 0.41 per meg/degree, an altitudinal gradient of - 0.48 ± 0.17 permeg / 100 m, and a temperature gradient of 0.35 ± 0.11 permeg /°C. Theoretical calculations performed using a Rayleigh model attribute this inland decrease to kinetic isotopic fractionation occurring during condensation from vapor to ice under supersaturation conditions at low temperatures. However, large heterogeneity of 17O-excess in Antarctic precipitation cannot only be explained by temperature at condensation and/or influences of relative humidity in the moisture source region.

Pang, Hongxi; Hou, Shugui; Landais, Amaelle; Masson-Delmotte, Valérie; Prie, Frederic; Steen-Larsen, Hans Christian; Risi, Camille; Li, Yuansheng; Jouzel, Jean; Wang, Yetang; He, Jing; Minster, Bénédicte; Falourd, Sonia

2015-03-01

138

Antarctica Part Two  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet across, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 2 finds Jonathan continuing his exploration of Antarctica including an encounter with a Leopard seal. This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Jonathan Bird Productions

2011-06-06

139

Antarctica Research in the Polar Research Center of China  

NASA Astrophysics Data System (ADS)

The Polar Research Center of China (PRCC) was established in the early 1990s (formerly Polar Research Institute of China) to serve as the leading national organization for Antarctica-related research in China. Current research areas of center staff scientists include glaciology and paleoclimatology, upper atmospheric physics, polar and marine biology, and oceanagrphy. In addition to its own active research, PRCC on behalf of the China Antarctic and Arctic Administration coordinates and provides logistical support to Antarctica research activities by all Chinese scientists. The center organizes and manages the annual Chinese Research Expedition to Antarctica with participation from many other national and academic institutions. In its first decade of existence, PRCC has accumulated valuable experience in conducting and facilitating research in Antarctica, particularly in the areas of logistic support for field programs, staffing and managing the two permanent stations in Antarctica (Great Wall and Zhongshan). The successful operation of the Chinese Antarctica research program has benefitted from generous assistance from several more established national (for example, Australia, Japan and the United States) Antarctica programs and from frequent contact with international colleagues working on Antarctica research. Among the many issues and problems frequently encountered in the last decade are: (1) The scale of research activities is often seriously constrained by logistic capabilities and funding; (2) Limited computer network and library resources hamper speedy and timely access to relevant international scientific literature; (3) Acquisition of high quality scientific (field and laboratory) equipment and special supplies can be limited by funding and access to suppliers.

Zhang, Z.; Li, Y.; Liu, S.; Cole-Dai, J.

2003-12-01

140

Bringing Antarctica Home  

ERIC Educational Resources Information Center

When one thinks of the amazing creatures of Antarctica, an insect probably does not come to mind. But this unlikely animal, and a scientific expedition to Antarctica, was the foundation for a learning event that created a community of learners spanning kindergarten through sixth grade and extended beyond the classroom. Miami University's Antarctic…

Constible, Juanita; Williams, Lauren; Faure, Jaime; Lee, Richard E., Jr.

2012-01-01

141

Some Background on Antarctica  

NSDL National Science Digital Library

This online article provides an overview of Antarctica and the reasons so many scientists are drawn to the continent. It includes a compilation of facts, an overview of the kinds of questions that can be answered in Antarctica, and insight into the scientific importance of the research conducted there.

142

Antarctica Part One  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet wide, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 1 finds Jonathan diving in Ushuaia, Patagonia in Argentina before boarding the ship to Antarctica, then he finally gets to Antarctica and meets some penguins! This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Jonathan Bird Productions

2011-05-04

143

Antarctica: little paying perspectives  

SciTech Connect

The continent of Antarctica has a surface of 14,200,000 sq km. It rests upon one of the deeper epicontinental platforms of the world, which descends steeply to the oceanic depths. The 200-m isobath is almost in its totality inside of the main ice zone. More than 95% of the continent itself is found under a layer of terrestrial ice composed of ca. 3,000,000 cu km of ice, with an average thickness of 2000 m. The ice and sea impede the access to the continent, and cyclonic storms surround the Antarctica in an endless sequence that moves from west to east. Almost all Antarctica geology is under ice, and only the highest places of mountains outcrop. The geologic structure is composed of 6 tectonic units. Antarctica has mineral resources, but the obstacles encountered in personnel and material movement make the Antarctica petroleum perspective very poor, since the recovery cost goes beyond the present selling price.

Ivanhoe, L.F.

1981-07-01

144

Autophagy in Antarctica  

PubMed Central

The midge Belgica antarctica is the only insect endemic to Antarctica and has the southernmost range of any insect. In its natural environment, B. antarctica frequently faces desiccating conditions, as environmental water is frozen for up to 9 months annually. The molecular mechanisms by which B. antarctica tolerates extreme dehydration are poorly understood, but recent work from our laboratory reports genome-wide expression changes in response to extreme dehydration (~40% water loss), the first genome-scale transcriptome reported for an Antarctic animal. Among transcripts differentially regulated during dehydration, there is coordinated upregulation of numerous genes involved in autophagy, including genes responsible for autophagosome synthesis and autophagy-associated transcription factors. Also, several genes and pathways that interact with and regulate autophagy, e.g., sestrins and proteasomal genes, are concurrently upregulated. This suggests that autophagy and related processes are key elements regulating stress tolerance in this extreme environment. PMID:23380735

Teets, Nicholas M.; Denlinger, David L.

2013-01-01

145

Antarctica: up for grabs  

SciTech Connect

Antarctica is viewed as a special area, requiring meticulous diplomacy to develop international agreements for exploiting its resources. Little exploration has been accomplished, but oil, gas, and marine krill resources are protected by a 14-nation treaty dating from 1961. The treaty fixed national claims on specific territories and launched scientific activities that reflect national interests. Studies of meteorology, climatology, oceanography, upper-atmospheric physics, and territorial biology have revealed Antarctica's resource potential for krill, minerals, and even ice. 4 figures. (DCK)

Shapley, D.

1982-11-01

146

Live from Antarctica: The coldest, windiest place on Earth  

NASA Astrophysics Data System (ADS)

In this first part of a four part 'Passport to Knowledge Special', hosted by Camille Jennings from Maryland Public Television, children from Maryland and Texas schools had the opportunity to directly interact with and ask questions of scientists and researchers in Antarctica live. The physical characteristics of Antarctica are featured, along with their effects on the human and microbiological organisms living in the region. The reasons behind the clothing worn in the Antarctic and the importance of the meteorological station are featured. Interviews with Professor Ian Dolziel (U of Texas) and Lt. commander John Joseph, NSFA (the head of the Navy Meteorology Center) occur with the school children, along with actual video footage of the surrounding geological features and geography. The 'Weatherops' is located at McMurdo Station, Antarctica.

147

Live from Antarctica: the Coldest, Windiest Place on Earth  

NASA Technical Reports Server (NTRS)

In this first part of a four part 'Passport to Knowledge Special', hosted by Camille Jennings from Maryland Public Television, children from Maryland and Texas schools had the opportunity to directly interact with and ask questions of scientists and researchers in Antarctica live. The physical characteristics of Antarctica are featured, along with their effects on the human and microbiological organisms living in the region. The reasons behind the clothing worn in the Antarctic and the importance of the meteorological station are featured. Interviews with Professor Ian Dolziel (U of Texas) and Lt. commander John Joseph, NSFA (the head of the Navy Meteorology Center) occur with the school children, along with actual video footage of the surrounding geological features and geography. The 'Weatherops' is located at McMurdo Station, Antarctica.

1994-01-01

148

An Evaluation of Yellow Perch Perca flavescens Mortality in South Dakota Casey Walter Schoenebeck  

E-print Network

An Evaluation of Yellow Perch Perca flavescens Mortality in South Dakota By Casey Walter Aid Project F-15-R, Study 1504). #12;iv Abstract An Evaluation of Yellow Perch Perca flavescens, and mortality) of common yellow perch Perca flavescens population types have been previously investigated

149

Extending Ladders: Findings from the Annie E. Casey Foundation's Jobs Initiative.  

ERIC Educational Resources Information Center

In 1995, the Anne E. Casey Foundation launched the Jobs Initiative (JI) in six cities to change labor market prospects for low-income young people in order to help them get jobs that could move their families out of poverty. The JI attempts to change the way employers recruit and supervise workers and how work is structured; to prepare workers and…

Fleischer, Wendy

150

Getting Results: Outcomes Management and the Annie E. Casey Foundations Jobs Initiative.  

ERIC Educational Resources Information Center

The Anne E. Casey Foundation (AECF) funded replications of effective jobs projects to achieve better job placement and retention for low-income, young adults. The six projects funded, collectively called the Jobs Initiative (JI), in Denver, Milwaukee, New Orleans, Philadelphia, Seattle, and St. Louis, used an outcomes framework developed by The…

Giloth, Robert; Phillips, William

151

AdvoCasey: Documenting Programs That Work for Kids and Families, 2000.  

ERIC Educational Resources Information Center

This publication includes five articles on health care and health promotion within impoverished communities. "The Health of Families and Communities" (Douglas W. Nelson) introduces the issue, discussing the work of the Annie E. Casey Foundation in communities. "Inconspicuous Consumption: Treating Latent TB Infection in Seattle" (Bill Rust) reports…

Nelson, Douglas W.; Rust, Bill; Hinds, Michael DeCourcy

2000-01-01

152

Measuring Foster Parent Potential: Casey Foster Parent Inventory-Applicant Version  

ERIC Educational Resources Information Center

Objective: The Casey Foster Applicant Inventory-Applicant Version (CFAI-A) is a new standardized self-report measure designed to assess the potential to foster parent successfully. The CFAI-A is described, and results concerning its psychometric properties are presented. Method: Data from a sample of 304 foster mothers from 35 states are analyzed.…

Orme, John G.; Cuddeback, Gary S.; Buehler, Cheryl; Cox, Mary Ellen; Le Prohn, Nicole S.

2007-01-01

153

Recent changes in solar irradiance in Antarctica  

SciTech Connect

A significant decrease in the annual sums of global irradiance reaching the surface in Antarctica, averaging -0.28 W m{sup -2} yr{sup -1}, was derived from an analysis of all complete years of measurement available from 12 pyranometer stations, 10 of which were on the coast. The decrease was greater than could be attributed to the nonhomogeneous nature of the database, the estimated errors of measurement, or changes in the amount of cloud cover. The smaller database of radiation balance measurements available showed no statistically significant change. Possible causes of these results are discussed, as is the implication that the recent surface warming in Antarctica is not due to radiative forcing. 49 refs., 3 figs., 5 tabs.

Stanhill, G.; Cohen, S. [Institute of Soils and Water, Bet Dagan (Israel)] [Institute of Soils and Water, Bet Dagan (Israel)

1997-08-01

154

The International Geophysical Year in Antarctica: Uncommon Collaborations, Unprecedented Results  

ERIC Educational Resources Information Center

When 1 July 1957 ''dawned'' in the dark of the south polar night, Americans at seven scientific stations scattered across Antarctica officially began systematic, synoptic observations of the air above and ice below. Joining scientists from 11 other countries on the polar continent, they were part of the International Geophysical Year, an 18-month…

Belanger, Dian Olson

2004-01-01

155

Annual Review 2008 Gateway Antarctica  

E-print Network

Annual Review 2008 Gateway Antarctica Centre for Antarctic Studies and Research #12;1 Table of Contents From the Board 2 Directors Comment 3 Gateway Antarctica 5 Research 7 PhD Candidates 27 Teaching 41 the Board As GatewayAntarctica heads into its second decade, we can reflect on 2008 as both a milestone year

Hickman, Mark

156

Living and Working in Antarctica.  

ERIC Educational Resources Information Center

This source book, designed for 11- to 14-year-old students, seeks to describe what life is like in Antarctica. In spite of extreme weather conditions, people go to Antarctica to work every summer. Some of them stay there during the winter as well. This book seeks to supply answers to such questions as: How do people get to Antarctica? Why do they…

Kemp, Noel

157

Geographic names of Antarctica  

USGS Publications Warehouse

The geographic nomenclature of Antarctica was long in need of an overall systematic treatment, objective in approach and based upon thorough examination of all the evidence. The results of such treatment over a period of about three years were presented in Geographical Names of Antarctica, Special Publication No. 86 of the Board on Geographical Names, in May 1947, two supplements to which were issued in 1949 and 1951. The continuing program since that publication has now covered most of the geographic naming in Antarctica. As research has filled in many of the previous gaps in knowledge, a number of names have been modified and minor amendments have been made in the policies. This revised publication brings together the greatly enlarged body of names officially standardized for use by the United States Government, together with new pertinent background information.

U.S. Board on Geographic Names; Department of the Interior; Burrill, Meredith F.; Bertrand, Kenneth J.; Alberts, Fred G.

1956-01-01

158

How to Use Bee Houses for Cavity-Nesting Bees Christine Casey, Haagen-Dazs Honey Bee Haven  

E-print Network

-Dazs Honey Bee Haven UC Davis Department of Entomology and Nematology October 2014How to Use Bee Houses for Cavity-Nesting Bees Christine Casey, Haagen Thirty percent of California's native bee fauna are solitary bees that nest above

Ishida, Yuko

159

Antarctica's Dry Valleys  

NSDL National Science Digital Library

In this video segment produced by ThinkTV with the Byrd Polar Research Center, a young scientist describes her journey to the remote Dry Valleys of Antarctica and her search for life under some of the most extreme conditions on Earth.

ThinkTV

2010-11-30

160

Antarctica: Discovery & Exploration.  

ERIC Educational Resources Information Center

An examination of Antarctica, from the first sightings to the heroic explorations of the late 18th and early 19th centuries to modern-day research, is presented in this book. Twelve chapters are as follows: (1) The search begins; (2) Whalers and sealers: bites and nibbles; (3) The new continent: first sight; (4) Wintering: the first party; (5)…

Gascoigne, Toss; Collett, Peter

161

Antarctica: Sea Ice  

NSDL National Science Digital Library

This video segment, adapted from a NOVA broadcast, shows how sea ice forms in the Southern Ocean around Antarctica and how its seasonal fluctuation dramatically changes the continent. The segment, two minutes thirty-five seconds in length, includes rare footage of the destruction of the British ship 'Endurance', trapped and crushed by sea ice in 1914.

162

POP Goes Antarctica?  

NSDL National Science Digital Library

As students explore this Web site, they will learn how scientists work together to answer questions. This site follows several scientists to Antarctica where they are doing research on Persistent Organic Pollutants. A daily journal, glossary, and learning activities will help incorporate this into classroom lesson plans.

Susan Cowles

2002-01-01

163

Getting Antarctica down Cold!  

ERIC Educational Resources Information Center

Outlines learning activities for applying geography's five fundamental themes to studying Antarctica and points out the learning potential, for studying the economic, historical, and political geography of the continent. Groups activities for grades K-5, 6-8, and 8-12. Stresses cooperative learning in general, and includes a role play activity for…

Sandmeier, Kay; Greeson, Linda

1990-01-01

164

Married to Antarctica.  

ERIC Educational Resources Information Center

A novel theory about Earth's ancient history is presented. It is proposed that North America and Antarctica once lay side by side for perhaps as long as a billion years. The importance of these continental connections to geology and other disciplines is discussed. (KR)

Monastersky, Richard

1991-01-01

165

British Antarctic Survey: About Antarctica  

NSDL National Science Digital Library

This brief overview of Antarctica covers its wildlife (penguins and other birds, seals, whales, fish, plants) and its geography (ice features, geologic features, weather, the ozone hole). There is also a series of short articles on protecting Antarctica's environment, including waste disposal and cleanup, protecting wildlife and plants, and protecting special areas and historic sites. The teacher resources page features a link to 'Discovering Antarctica', a resource that is intended to enthuse young people in Antarctic research and to give teachers access to an authoritative resource from the UK's national Antarctic operator. Other topics include tourism in Antarctica and geopolitical issues (the Antarctic Treaty, place names, the British Antarctic Territory).

166

Learning About Antarctica's Past  

NSDL National Science Digital Library

Learning about Antarctica's past can give K-Grade 5 teachers and students lessons in geology, climate, and ecology along with literacy experiences in sequencing and time lines. The author identifies online resources for both adults and younger learners. A three-section unit plan begins with sequencing events and follows with earth's history over billions of years and the records found in rocks and fossils. The article appears in the free, online magazine Beyond Penguins and Polar Bears.

Carol Landis

2011-01-01

167

Princess Astrid Coast, Antarctica  

NASA Technical Reports Server (NTRS)

The continent of Antarctica is almost completely covered by a thick blanket of ice, punctuated only by steep mountain peaks and a handful of dry valleys. Antarctica is also ringed by a permanent ice shelf, and that is surrounded by seasonal sea ice. The image above, acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS) on September 26, 2001, shows many of the types of ice found in Antarctica. At the bottom of the image is the ice of the continental glacier, which is up to 4,000 meters thick in the interior. These thick glaciers are held in place by coastal mountain ranges. Some ice does flow through the mountains, spilling onto the relatively flat land of the Princess Astrid Coast. Cold air also spills over the mountains, creating very strong and persistent 'katabatic' winds. These scour the snow off the tops of the glaciers, leaving pale blue patches of bare ice. Above the coastline is the ice shelf, which is much smoother. There, glacial ice actually floats on the sea surface. Beyond that is the chaotic surface of the sea ice, which has been solidifying all winter long. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

168

Hydrology of Antarctica  

SciTech Connect

The hydrology of the Southern Ocean floor, the ice sheet covering Antarctica, and the bedrock underlying it is a matter of great interest. This article attempts to shed some light on the problem of the hydrology of this part of the world in the form of prognoses, because the available direct information on the subsurface waters of this vast region is completely inadequate. From the standpoint of their practical utilization, the fresh waters at the base of the Antarctic ice sheet and the waters below the permafrost of the larger islands of Antarctica are the most promising. The large artesian basins of Antarctica with a thick mantle of sedimentary rocks are of interest for their oil and gas potential. One can be certain also of obtaining thermal waters from some of the artesian structures of this continent. Special attention should be paid to the fumaroles and solfataras in areas of present-day volcanism, and to the rift zones, where thermal waters may also be obtained. 16 references.

Kiryukhin, V.A.; Tolstikhin, N.I.

1988-01-01

169

Bird imagery and motif in Sean O'Casey's Dublin trilogy  

E-print Network

" the child can shake a fist at the savage sparrow, and admire the bull, strong enough to toll the bell, listen to the solemn rook who read the burial service from his little book, and sorrow with the dove who became the chief mourner. 17 Although O..., Thro' ravish'd hours--- Then sorrow, woe and pain lose all their powers, For each is dead, and life is only ours. (p. 80) O'Casey has already told us in the stage directions that Davoren is dedicated to the philosophy of "the redemption of all...

O'Valle, Violet May Owen

1978-01-01

170

Automatic Weather Station (AWS) Lidar  

NASA Technical Reports Server (NTRS)

An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.

Rall, Jonathan A.R.; Abshire, James B.; Spinhirne, James D.; Smith, David E. (Technical Monitor)

2000-01-01

171

Antarctica Day: An International Celebration  

NASA Astrophysics Data System (ADS)

For more than half a century, the 1959 Antarctic Treaty continues to shine as a rare beacon of international cooperation. To celebrate this milestone of peace in our civilization with hope and inspiration for future generations, Antarctica Day is celebrated each year on December 1st , the anniversary of the Antarctic Treaty signing. As an annual event - initiated by the Foundation for the Good Governance of International Spaces (www.internationalspaces.org/) in collaboration with the Association of Polar Early Carer Scientists (www.apecs.is) - Antarctica Day encourages participation from around the world. The Antarctic Treaty set aside 10% of the earth, 'forever to be used exclusively for peaceful purposes in the interest of mankind.' It was the first nuclear arms agreement and the first institution to govern all human activities in an international region beyond sovereign jurisdictions. In this spirit, Antarctica Day aims to: - Demonstrate how diverse nations can work together peacefully, using science as a global language of cooperation for decision making beyond national boundaries, - Provide strategies for students learning about Antarctica through art, science and history at all school levels, - Increase collaboration and communication between classrooms, communities, researchers and government officials around the world, and - Provide a focus for polar educators to build on each year. Through close collaboration with a number of partners. Antarctica Day activities have included: a Polar Film Festival convened by The Explorers Club; live sessions connecting classrooms with scientists in Antarctica thanks to PolarTREC and ARCUS; an international activity that involved children from 13 countries who created over 600 flags which exemplify Antarctica Day (these were actually flown in Antarctica with signed certificates then returned to the classes); a map where Antarctica Day participants all over the world could share what they were doing; an Antarctic bird count involving the International Association of Antarctic Tour Operators; and public lectures and online videos (including a notable submission from Polar Educators International). Antarctica Day was initiated as a legacy of the 2009 Antarctic Treaty Summit (www.atsumit50.aq), which was convened at the Smithsonian Institution with 40 sponsoring institutions from around the world as part of the International Polar Year. Antarctic Day involved participants from 14 nations in 2010. 28 nations in 2011, and 26 nations in 2012 with representatives from all 7 continents. Antarctica Day 2013 will have recently taken place before the AGU Fall Meeting 2013, and we will present updates at that time. Our aim is to continue expanding Antarctica Day as a globally-accessible platform to share, interpret and cherish the values associated with Antarctica for the benefit of present and future generations. We look forward to the discussion and sharing that this session will provide.

Pope, A.; Hambrook Berkman, J.; Berkman, P. A.

2013-12-01

172

Direct gravimetric determination of aerosol mass concentration in central antarctica.  

PubMed

In Antarctica, experimental difficulties due to extreme conditions have meant that aerosol mass has rarely been measured directly by gravimetry, and only in coastal areas where concentrations were in the range of 1-7 ?g m(-3). The present work reports on a careful differential weighing methodology carried out for the first time on the plateau of central Antarctica (Dome C, East Antarctica). To solve problems of accurate aerosol mass measurements, a climatic room was used for conditioning and weighing filters. Measurements were carried out in long stages of several hours of readings with automatic recording of temperature/humidity and mass. This experimental scheme allowed us to sample from all the measurements (up to 2000) carried out before and after exposure, those which were recorded under the most stable humidity conditions and, even more importantly, as close to each other as possible. The automatic reading of the mass allowed us in any case to obtain hundreds of measurements from which to calculate average values with uncertainties sufficiently low to meet the requirements of the differential weighing procedure (±0.2 mg in filter weighing, between ±7% and ±16% both in aerosol mass and concentration measurements). The results show that the average summer aerosol mass concentration (aerodynamic size ?10 ?m) in central Antarctica is about 0.1 ?g m(-3), i.e., about 1/10 of that of coastal Antarctic areas. The concentration increases by about 4-5 times at a site very close to the station. PMID:21141836

Annibaldi, Anna; Truzzi, Cristina; Illuminati, Silvia; Scarponi, Giuseppe

2011-01-01

173

Petroleum geology of western Antarctica  

SciTech Connect

Antarctica's geology is mostly obscured by thick, moving ice that covers 95% of the land and continental shelf. Reconnaissance investigations of outcrops, shallow boreholes, and geophysical surveys are limited and peripheral owing to ice coverage. However, it is possible to outline substantial elements of the regional geology. Further insight is gained by comparison to analogous sedimentary provinces, especially provinces once adjoined within the framework of the Gondwana supercontinent until middle Cretaceous. The petroleum potential of Antarctica, as in the case of the other related high-standing Gondwana continental fragments, is in Early Cretaceous rifts associated with the Gondwana breakup and with the Pacific convergence in the west Antarctica back arc. The Pacific-facing western Antarctica includes two structural provinces: (1) the Cretaceous and younger interior rift system on the east side of the Weddell and Ross Sea embayment, which contain aulacogens that form the boundary with East Antarctica and (2) the back-arc and fore-arc basins adjoining the Antarctica Peninsula and extending into Marie Byrd Land and the Bellingshausen Sea which are associated with the eastward convergence of the Pacific plate. The petroleum potential of the rifts may be assessed by analogies with related rifts of Australia, India, and South Africa; assessment of the convergent basins of western Antarctica depends upon analogy with similar basins of South America, New Zealand, and Indonesia. An estimate of the petroleum potential of western Antarctica generally is comparable with oil and gas occurrences (both in overall quantity and in field sizes) in the other Gondwana continental fragments. However, in view of the thict moving ice cover, the remote locale, and severe climate, petroleum production is largely beyond technology at this time and probably is economically unfeasible.

Kingston, J. (Geological Survey, Santa Barbara, CA (USA))

1990-05-01

174

Cryopreservation of Phaeocystis antarctica.  

PubMed

A large number of clonal isolates of the prymnesiophyte Phaeocystis antarctica have been established at the Alfred Wegener Institute in Bremerhaven, Germany, to address questions on the genetic diversity and ecological response patterns to climate change. However, at present the wider scientific community cannot access these strains and their long-term conservation, (currently by serial transfer), cannot be assured. Cryopreservation could provide the solution to these issues, as it would guarantee the long-term security of this genetically and ecological invaluable collection. This study outlines the successful application of conventional approaches and the use of novel, combined non-penetrating and penetrating cryoprotective strategies that have been successfully applied to the different life-stages of this alga. PMID:24441367

Gabler-Schwarz, S; Rad-Menendez, C; Achilles-Day, Uem; Campbell, C N; Day, J G

2013-01-01

175

Particle-size distribution in soils of West Antarctica  

NASA Astrophysics Data System (ADS)

The particle-size distribution in soils sampled near Russian polar stations in West Antarctica has been studied. It is shown that the soils of the Subantarctic zone (the Bellingshausen Station on King George Island) are characterized by a higher content of silt and clay in the fine earth fraction and by a higher content of the fine earth fraction in comparison with the soils of the proper Antarctic tundra barrens near the Lenin-gradskaya Station and the Antarctic cold desert near the Russkaya Station. In the latter soils, the content of rock fragments is higher than that in the soils of the Antarctic tundra barrens. In the soils of the tundra barrens, a considerable accumulation of fine earth may take place in large cavities (hollows) on the stony bedrock surface. Desert pavements are formed in both types of Antarctic landscapes.

Abakumov, E. V.

2010-03-01

176

Free Parking Available for Famous Idaho Potato Bowl Media Contact: Casey Jones, Executive Director, Transportation & Parking Services  

E-print Network

Free Parking Available for Famous Idaho Potato Bowl Media Contact: Casey Jones, Executive Director, Transportation & Parking Services (208) 426-4306 caseyjones3@boisestate.edu Fans attending the Famous Idaho of non-perishable food and toiletry items. Boise State is teaming up on the food drive with the Idaho

Barrash, Warren

177

Good Wheel Hunting: UMass Lowell's Scavenger Hunt Robot System Robert Casey, Andrew Chanler, Munjal Desai, Brenden Keyes,  

E-print Network

Good Wheel Hunting: UMass Lowell's Scavenger Hunt Robot System Robert Casey, Andrew Chanler, Munjal into the Scavenger Hunt Competition at the AAAI-2005 Robot Competition and Exhibition. The scavenger hunt entry, all used to locate the objects in the scavenger hunt. INTRODUCTION The AAAI-2005 Scavenger Hunt

Yanco, Holly A.

178

The Annie E. Casey Foundation 2006 Kids Count Pocket Guide. State Profiles of Child Well-Being Series  

ERIC Educational Resources Information Center

Kids Count, a project of the Annie E. Casey Foundation, is a national and state by- state effort to track the status of children in the United States. By providing policymakers and citizens with benchmarks of child well-being, Kids Count seeks to enrich local, state, and national discussions concerning ways to secure better futures for all…

Annie E. Casey Foundation, 2006

2006-01-01

179

Forest transitions and ecosystem services in Zimbabwe Supervisors: Dr Casey Ryan (UoE), Dr Isla Grundy (University of Zimbabwe)  

E-print Network

Forest transitions and ecosystem services in Zimbabwe Supervisors: Dr Casey Ryan (UoE), Dr Isla and a variety of other ecosystem services. However the expansion of agricultural land and the curing of tobacco is accelerating deforestation and forest degradation rates. These structural changes to the ecosystem threaten

180

A review of the species of Geraeus Pascoe and Linogeraeus Casey found in the continental United States (Coleoptera: Curculionidae: Baridinae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The baridine weevils with a smooth inner mandibular face and unmodified antenna are reviewed for the continental U.S. Toxeres Germar 1829, a new synonym of Geraeus Pascoe 1889, is suppressed as nomen oblitum and Geraeus is conserved as nomen protectum. Pycnogeraeus Casey 1920 is a new synonym of G...

181

Moving Up Is a Steep Climb: Parents' Work and Children's Welfare in the Annie E. Casey Foundation's Jobs Initiative.  

ERIC Educational Resources Information Center

This monograph presents findings from ethnographic research about parents' work and children's welfare in the Annie E. Casey Foundation's Job Initiative. The Initiative was designed to improve the futures of poor, inner city people who were disadvantaged in their previous work efforts because of inadequate education, immigrant/refugee status,…

Iversen, Roberta Rehner

182

High-field magnetic force microscopy as susceptibility imaging Casey Israel, Weida Wu, and Alex de Lozannea  

E-print Network

High-field magnetic force microscopy as susceptibility imaging Casey Israel, Weida Wu, and Alex de into a superconducting mag- net in a liquid He dewar.17 The tip on the MFM cantilever was sputter coated with Co85Cr15

Wu, Weida

183

The cryptoendolithic microbial environment in the Ross Desert of Antarctica: Satellite-transmitted continuous nanoclimate data, 1984 to 1986  

Microsoft Academic Search

A satellite mediated station for monitoring nanoclimate (climate in the millimeter range) data, suitable for use in polar regions is described. The station, located in the Ross desert of Antarctica, has been in operation for more than 3 years, measuring rock temperatures, air temperature, light, snow, wind, and moisture. The data indicate that biological activity in the cryptoendolithic microbial ecosystem

E. Imre Friedmann; Christopher P. McKay; James A. Nienow

1987-01-01

184

Variability in AIRS-retrieved cloud amount and thermodynamic phase over west versus east Antarctica influenced by the SAM  

NASA Astrophysics Data System (ADS)

In a sample of summertime cloud retrievals from the NASA Atmospheric Infrared Sounder (AIRS), a positive Southern Annular Mode (SAM) index polarity is associated with greater cloud frequency and larger effective cloud fraction over West Antarctica compared with a negative SAM index polarity. The opposite result appears over the high East Antarctic Plateau. Comparing AIRS-retrieved cloud fraction with Antarctic Automatic Weather Station 2 m air temperature data, a positive and significant correlation is found over most of West Antarctica, signifying a longwave heating effect of clouds. Over East Antarctica correlations between Sun elevation and 2 m air temperature are strongest, consistent with lower cloud amount.

Lubin, Dan; Kahn, Brian H.; Lazzara, Matthew A.; Rowe, Penny; Walden, Von P.

2015-02-01

185

GPS ionospheric TEC measurement during the 23rd November 2003 total solar eclipse at Scott Base Antarctica  

Microsoft Academic Search

The total solar eclipse of 23rd November 2003 over Antarctica presents a unique oportunity to investigate the influence of the sun on the earth upper ionosphere. At Scott Base station, Antarctica (GEO: ?77.85°, 166.76°; CGM: ?79.94°, 327.23°), the partial solar eclipse was observed with the magnitude of 0.769. This solar eclipse event was a rare event due to its mixed

Zainol Abidin Abdul Rashid; Mohammad Awad Momani; Sumazly Sulaiman; Mohamad Alauddin Mohd Ali; Baharudin Yatim; Grahame Fraser; Natsuo Sato

2006-01-01

186

Let's Talk with Carol Finn about Using GPS (Global Positioning System) to Study Ice and Geology in Antarctica  

NSDL National Science Digital Library

In this interview, a geophysicist working in Antarctica describes her work reading the magnetic data of Antarctic rocks that lie below the ice's surface. She discusses her area of study, the Transantarctic Mountains near Byrd station, her study methods, and why her work is important. There is also a brief summary of personal information, and some advice for students about studying and conservation in Antarctica.

187

Investigating West Antarctica, Then and Now  

NSDL National Science Digital Library

This article profiles Charles Bentley, a geophysicist who has worked in Antarctica over a period of seven decades. The article provides an overview of his research as well as changes in the way scientists live and work in Antarctica.

Carol Landis

188

The ethics of commercial surrogate mothering: a response to Casey Humbyrd.  

PubMed

This article critically examines the argument advanced by Casey Humbyrd in support of international commercial surrogate mothering. It finds her arguments unconvincing especially at the point of implementation. This is because the author was unable to demonstrate how regulation and her notion offair compensation would not lead to undue inducement and exploitation in resource-poor settings where urgent needs often exist. In fact, the argument advanced in this article is that commercial surrogate mothering cannot but be exploitative in so far as urgent and compelling needs exist. To logically drive home this point, the elements of exploitation were discussed in order to show that regulation and fair compensation cannot prevent exploitative transaction in commercial surrogate mothering arrangements. This may happen in the same way as regulation and compensation framework have not been successful in preventing the allegations of exploitation in the research context especially where studies are conducted in resource-poor countries. PMID:23350220

Omonzejele, Peter F

2011-01-01

189

Research on the Web: Snapshots of Antarctica  

NSDL National Science Digital Library

This Web research activity gives students a broad overview of Antarctica. They are asked to work as scientists, making predictions and observations and recording their findings. All directions are included in a printable handout. Students begin by gathering background information on Antarctica and polar research. They then view images of Antarctica taken from space and ones that compare its size to the United States. They end by answering questions about Antarctica's size, physical conditions, and why scientists conduct research there.

190

Precipitation regime of Dronning Maud Land, Antarctica, derived from Antarctic Mesoscale Prediction System (AMPS) archive data  

Microsoft Academic Search

The precipitation regime of Dronning Maud Land (DML), Antarctica, was studied using Antarctic Mesoscale Prediction System (AMPS) archive data. Precipitation is the most important component of the mass balance of the Antarctic ice sheet. Precipitation studies of DML are particularly important because two deep ice core drilling sites, Kohnen Station and Dome Fuji, are located in this region. For the

E. Schlosser; M. G. Duda; J. G. Powers; K. W. Manning

2008-01-01

191

Solar Eclipses Observed from Antarctica  

NASA Astrophysics Data System (ADS)

Aspects of the solar corona are still best observed during totality of solar eclipses, and other high-resolution observations of coronal active regions can be observed with radio telescopes by differentiation of occultation observations, as we did with the Jansky Very Large Array for the annular solar eclipse of 2012 May 20 in the US. Totality crossing Antarctica included the eclipse of 2003 November 23, and will next occur on 2021 December 4; annularity crossing Antarctica included the eclipse of 2008 February 7, and will next occur on 2014 April 29. Partial phases as high as 87% coverage were visible and were imaged in Antarctica on 2011 November 25, and in addition to partial phases of the total and annular eclipses listed above, partial phases were visible in Antarctica on 2001 July 2011, 2002 December 4, 2004 April 19, 2006 September 22, 2007 September 11, and 2009 January 26, and will be visible on 2015 September 13, 2016 September 1, 2017 February 26, 2018 February 15, and 2020 December 14. On behalf of the Working Group on Solar Eclipses of the IAU, the poster showed the solar eclipses visible from Antarctica and this article shows a subset (see www.eclipses.info for the full set). A variety of investigations of the Sun and of the response of the terrestrial atmosphere and ionosphere to the abrupt solar cutoff can be carried out at the future eclipses, making the Antarctic observations scientifically useful.

Pasachoff, Jay M.

2013-01-01

192

An Automatic Video Meteor Observation Using UFO Capture at the Showa Station  

NASA Astrophysics Data System (ADS)

The goal of our study is to clarify meteor activities in the southern hemi-sphere by continuous optical observations with video cameras with automatic meteor detection and recording at Syowa station, Antarctica.

Fujiwara, Y.; Nakamura, T.; Ejiri, M.; Suzuki, H.

2012-05-01

193

Antarctica as a Martian model.  

NASA Technical Reports Server (NTRS)

Results of a survey of a variety of environments in the dry valleys of Antarctica, ranging from mountain crests to valley floors. The main purpose of the investigation was the determination of active microbial multiplication in the soil. A series of techniques was employed which permitted the detection of bacterial growth in situ. All evidence points to an active growth of micro-organisms in the Antarctic soil in all locations examined. The measurements were supported by electron micrographs of soil films which showed colonial growth covering soil particles. These findings suggest that Antarctica does not serve as a useful model for the Martian environment in evaluating quarantine standards.

Vishniac, W. V.; Mainzer, S. E.

1973-01-01

194

Tectonic development of West Antarctica and its relation to East Antarctica  

SciTech Connect

Over several years, the author has compiled data and conducted field research to gain an understanding of the relationship between East and West Antarctica through geologic time. The investigations have focused on the Scotia Arc and the region at the base of the Antarctic Peninsula extending to the Ellsworth, Thiel, and Whitmore mountains. During the 1983-1984 austral summer, US and British geologists began an intensive investigation in the Ellsworth Mountains and Martin Hills, at Mount Smart, and near Siple Station. Field work includes geology, paleomagnetism, geochronology, and geophysics, with radio-echo sounding and aeromagnetic surveys conducted by British geophysicists. This investigation attempts to define the limits of the crustal blocks and determine the tectonic nature of the ice-covered area between them.

Dalziel, I.W.D. (Univ. of Texas, Austin (USA))

1987-09-01

195

Deployment of a broadband seismic network in west Antarctica  

NASA Astrophysics Data System (ADS)

A network of six broadband seismic stations was deployed in West Antarctica in November, 1998. A new data recording instrument and power system was developed to operate the stations year round using solar energy in the summer and wind energy in the winter. The data logging technology, designed to record geophysical parameters (broadband seismic and geodetic GPS—Global Positioning System), is also appropriate for other remote Antarctic and Arctic data recording applications with similar data band-widths. The seismicity of Antarctica is hypothesized to be low, but that could be an artifact of the poor distribution and small number of seismic stations on the continent. One goal of the experiment is to record data in the West Antarctic (the region most likely to exhibit seismic activity) for sufficient lengths of time in order to address this hypothesis fully. In addition, the data are useful for determining crust and mantle structure and properties. The network has been active for about half the time since installation, which is sufficient to draw statistically significant conclusions on regional seismicity. The experiment will continue for the next two years, with system modifications that should improve the performance of the network.

Anandakrishnan, S.; Voigt, D. E.; Burkett, P. G.; Long, B.; Henry, R.

2000-07-01

196

Remote Sensing and Skywave Digital Communication from Antarctica  

PubMed Central

This paper presents an overview of the research activities undertaken by La Salle and the Ebro Observatory in the field of remote sensing. On 2003 we started a research project with two main objectives: implement a long-haul oblique ionospheric sounder and transmit the data from remote sensors located at the Spanish Antarctic station Juan Carlos I to Spain. The paper focuses on a study of feasibility of two possible physical layer candidates for the skywave link between both points. A DS-SS based solution and an OFDM based solution are considered to achieve a reliable low-power low-rate communication system between Antarctica and Spain. PMID:22303166

Bergadà, Pau; Deumal, Marc; Vilella, Carles; Regué, Joan R.; Altadill, David; Marsal, Santi

2009-01-01

197

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica  

NASA Technical Reports Server (NTRS)

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, the first year-round observations available for any site in Taylor Valley are reported. The mean annual solar flux at Lake Hoare was 92 W/sq m during 1986, the mean air temperature -17.3 C, and the mean 3-m wind speed 3.3 m/s. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year.

Clow, Gary D.; Mckay, Christopher P.; Simmons, George M., Jr.; Wharton, Robert A., Jr.

1988-01-01

198

Research on the Web: Living and Working in Antarctica  

NSDL National Science Digital Library

This Web research activity has students examine travel information prepared by the Antarctic Support Services. All directions are included in a printable handout. Students begin by reviewing the U.S. Antarctic Program Participant Guide, which contains information to help researchers and staff prepare for life in this extreme environment. They then view images of the living and working spaces at the Palmer Station. They end by answering a series of questions, which helps them draw conclusions about the technologies humans have adopted in order to live and work in Antarctica.

199

What Organisms Live in Antarctica?  

NSDL National Science Digital Library

In these activities students will discover the characteristics that enable Antarctica's many life forms to live in this continent of extreme cold, wind, and extended periods of light and darkness. In this weeklong unit, students research how flora and fauna have adapted to thrive in Antarctica, and use their knowledge to create imaginary polar organisms. Throughout this module, students collect their findings in a portfolio. The comprehensive curriculum materials contain a Web activity in which students investigate the living conditions in Antarctica and some of the adaptations its organisms have made, a classroom activity in which students apply what they have learned to create models of imaginary polar creatures, several readings that provide a broad perspective, including excerpts from early explorers' journals, and question and answer interviews with scientists working in Antarctica. Teacher tools include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, a student handout with guidance for putting together their portfolios and examples of creative final projects, and additional readings.

200

Antarctica: geology and hydrocarbon potential  

SciTech Connect

The first impression of the hydrocarbon potential of Antarctica is generally negative. The environment is hostile and only 2% of the continent is seen through the ice. Careful study of the surprisingly ample volume of published data available on the geology and geophysics and Antarctica, coupled with the application of the principles and mechanics of plate tectonics relative to the oceans and adjacent land masses, gives a different and very positive attitude toward the hydrocarbon potential of this vast unexplored frontier area. On the basis of limited data, 21 sedimentary basins are identified for Antarctica and immediately adjacent areas. These include six onshore subglacial basins and 15 offshore basins. Excluding 11 basins considered to have little or no potential, the other 10 basins contain an estimated 16.9 million km/sup 3/ (4.05 million mi/sup 3/) of sediment having a potential hydrocarbon yield of 203 billion bbl oil equivalent. The problems associated with hydrocarbon exploration in Antarctica are formidable. Technology is adequate for seismic surveys and exploratory drilling of the Antarctic continental shelf, as concluded from current operations in the Arctic and from operating requirements of drilling rigs under construction. However, a working relationship among involved nations must first be evolved and production, storage, and transportation problems solved.

St. John, B.

1984-09-01

201

Research on the Web: Antarctic Weather Stations  

NSDL National Science Digital Library

This Web research activity helps students see the link between wind speeds and geographical features. All directions are included in a printable handout. Students begin by gathering wind-speed measurements for 10 weather stations in Antarctica, converting the data, as needed, to allow comparisons. Next, they record wind data for five consecutive days and calculate the average wind speed for each station. They then examine elevation data for the 10 weather stations. They end by developing a hypothesis for the different patterns they've observed.

202

Let's Talk with David Nold about Safety and Wintering Over in Antarctica  

NSDL National Science Digital Library

At this site students discover that Antarctica's winter runs from mid-February through late August and if one decides to stay, one is there for the duration since all aircraft traffic is stopped. They will also learn how research crews prepare to go it alone. This in-depth profile of a safety and health engineer offers a look at what it takes to keep an Antarctic research station running year-round. In the question and answer profile the engineer answers more than 15 questions, including why kids should know about deep sea Antarctica, what the big deal is about wintering over, and if things change drastically when the summer crew arrives. He also describes a typical workday in the winter there and explains what he misses about Antarctica when he is not there.

203

Relationship between total ozone amounts and stratospheric temperature at Syowa, Antarctica  

SciTech Connect

Using statistical methods, the relationship has been studied between total ozone and 100-mbar temperatures at Syowa Station, Antarctica (69[degrees]S, 40[degrees]E), based on data obtained in 1961-1981 and 1982-1988, the time of ozone depletion in Antarctica. Results indicate a strong, positive correlation between total ozone and 100-mbar stratospheric temperatures during September-March for all years, but lower ozone values at 100-mbar stratospheric temperatures colder than about [minus]60[degrees]C during the 1982-1988 period. Ozone destruction by heterogeneous photochemical processes is the main cause of ozone depletion over Syowa during the 1980's, with a lesser contribution from a change in air dynamics (heat, ozone, and momentum transport to Antarctica during the austral spring) that increased polar vortex stability, thereby promoting photochemical ozone depression within the vortex. 27 refs., 9 figs., 2 tabs.

Shigeru Chubachi (Meteorological Research Inst., Ibaraki (Japan))

1993-02-20

204

Fecal Coliforms in Antarctica  

NSDL National Science Digital Library

In this interrupted case study, students explore the environmental consequences of Antarctic research as they design experiments to assess the impact of disposing untreated sewage from a research station into the ocean. Students review experimental methods to measure coliform bacteria, examine data, and decide what actions, if any, should be taken. The can be used in either a non-majors course in science literacy or a general microbiology class studying bacterial detection methods. For non-majors, the instructor would emphasize the mechanics of data collection and analysis and may touch on the environmental implications of finding fecal coliforms in Antarctic waters. For microbiology students, the instructor would highlight the bacteriology and pair the case with a lab.

Stephen C. Nold

2002-01-01

205

Terrestrial Spaceflight Analogs: Antarctica  

NASA Technical Reports Server (NTRS)

Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

Crucian, Brian

2013-01-01

206

Changes in sleep patterns during prolonged stays in Antarctica  

NASA Astrophysics Data System (ADS)

Various countries have permanent research bases in Antarctica that are manned year-round by a few members of an expedition team, facing extremes of temperature with the associated hardships. Acclimatisation to such an environment is associated with pyschophysiological changes along with alterations in sleep patterns. The present study was undertaken to explore the changes in sleep patterns of six members of the Indian expedition team during their winter stay at Maitri, the permanent research station of India in Antarctica. The mean (± SEM) age, height and weight of the subjects were 35.7 ± 2.32 years, 168.3 ± 2.37 cm and 71.0 ± 1.88 kg, respectively. Polysomnographic sleep recordings were obtained as baseline data in November 2004 in Delhi (altitude 260 m, latitude 29° N, longitude 77° E); data on the same parameters were collected at Maitri, Antarctica (altitude 120 m, latitude 70° 45' 39? S, longitude 11° 44' 49? E) from January to December 2005. A one-way analysis of variance with repeated measures showed a significant variation with time (month effect) in most of the sleep parameters recorded. Total sleep time decreased from Delhi baseline values in all months, sleep efficiency decreased significantly during winter months, duration of waking period after sleep onset increased significantly in winter, sleep latency increased immediately after exposure in January, stages 3 and 4 (slow wave sleep) reduced during dark winter months, whereas stages 1 and 2 and rapid eye movement sleep increased during dark winter months. This study observed a prevailing general trend of sleep disturbances amongst overwintering members in a modern Antarctic station.

Bhattacharyya, Moushum; Pal, Madhu Sudan; Sharma, Yogendra Kumar; Majumdar, Dhurjati

2008-11-01

207

Antarctica: Challenging Forecasts for a Challenging Environment  

NSDL National Science Digital Library

Antarctica: Challenging Forecasts for a Challenging Environment features two educational pieces. The first is the overview giving the general audience a broad look at Antarctica including some history, interesting facts, real-life experiences, climate, and the challenges inherent to this frozen continent. The second is the main presentation where experts in Antarctic research and forecasting, share their knowledge of the continent. They discuss forecasting challenges as well as present and future research topics while providing elaborations on the uniqueness in Antarctica’s location, topography, and forecasting techniques as compared to other parts of the globe.

COMET

2007-08-14

208

The mantle transition zone beneath West Antarctica: Seismic evidence for hydration and thermal upwellings  

NASA Astrophysics Data System (ADS)

prior work suggests that a mantle plume is associated with Cenozoic rifting and volcanism in West Antarctica, the existence of a plume remains conjectural. Here we use P wave receiver functions (PRFs) from the Antarctic POLENET array to estimate mantle transition zone thickness, which is sensitive to temperature perturbations, throughout previously unstudied parts of West Antarctica. We obtain over 8000 high-quality PRFs using an iterative, time domain deconvolution method filtered with a Gaussian width of 0.5 and 1.0, corresponding to frequencies less than ˜0.24 and ˜0.48 Hz, respectively. Single-station and common conversion point stacks, migrated to depth using the AK135 velocity model, indicate that mantle transition zone thickness throughout most of West Antarctica does not differ significantly from the global average, except in two locations; one small region exhibits a vertically thinned (210 ± 15 km) transition zone beneath the Ruppert Coast of Marie Byrd Land and another laterally broader region shows slight, vertical thinning (225 ± 25 km) beneath the Bentley Subglacial Trench. We also observe the 520 discontinuity and a prominent negative peak above the mantle transition zone throughout much of West Antarctica. These results suggest that the mantle transition zone may be hotter than average in two places, possibly due to upwelling from the lower mantle, but not broadly across West Antarctica. Furthermore, we propose that the transition zone may be hydrated due to >100 million years of subduction beneath the region during the early Mesozoic.

Emry, E. L.; Nyblade, A. A.; Julià, J.; Anandakrishnan, S.; Aster, R. C.; Wiens, D. A.; Huerta, A. D.; Wilson, T. J.

2015-01-01

209

Antarctica as an Educational Resource  

NSDL National Science Digital Library

"As an educational resource, Antarctica is extremely broad in scope with the potential to contribute to a number of study areas," from the sciences to history, sociology, and politics. Authored by molecular biologist Clive Evans at the University of Auckland, this Web site provides a convenient resource for introducing Antarctica into the classroom and could be adapted for a range of grade levels. Luckily for life science educators, the site focuses primarily on Antarctic biology, adaptation, human impact, and the environment. Web pages contain detailed background information, as well as questions and suggested activities to stimulate discussion and help students explore the material. A more in-depth exploration of the material requires additional resources; references and Web links are provided.

210

Variation in the ribosomal ITS-sequence of the lichens Buellia frigida and Xanthoria elegans from the Vestfold Hills, eastern Antarctica  

Microsoft Academic Search

Abstract:Thalli of the lichens Buellia frigida and Xanthoria elegans were collected from five different locations each 5–15km apart in the Vestfold Hills, Princess Elizabeth Land, eastern Antarctica. A further collection was made from Mawson Station, Mac Robertson Land, eastern Antarctica, 660km away. DNA was extracted from whole thalli and the ribosomal ITS region amplified by PCR using fungal specific primers.

P. S. Dyer; G. J. Murtagh

2001-01-01

211

Seasonal and diurnal dependence of Pc 3-5 magnetic pulsation power at geomagnetically conjugate stations in the auroral zones  

Microsoft Academic Search

Seasonal and diurnal variations of Pc 3-5 magnetic pulsation powers have been examined using 2 years of magnetic data from geomagnetically conjugate stations, Syowa in Antarctica and Husafell and Tjornes in Iceland. The magnetic pulsation powers are found to be relatively higher at the winter hemisphere station than at the summer station. The pulsations observed during equinox show a diurnal

Hiroaki Saito; Takeo Yoshino; Natsuo Sato; Yutaka Tonegawa; Thorsteinn Saemundsson

1989-01-01

212

GPS determination of the velocity and strain-rate fields on Schirmacher Glacier, central Dronning Maud Land, Antarctica  

Microsoft Academic Search

Global positioning system (GPS) campaigns were conducted during the 2003 and 2004 austral summer seasons to obtain insight into the velocity and strain-rate distribution on Schirmacher Glacier, central Dronning Maud Land, East Antarctica. GPS data were collected at 21 sites and analyzed to estimate the site coordinates, baselines and velocities. The short-term precision of the base station, MAIT, is estimated

P. S. Sunil; C. D. Reddy; M. Ponraj; Ajay Dhar; D. Jayapaul

2007-01-01

213

Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica  

Microsoft Academic Search

The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Interglacial periods differed in temporal evolution and duration. Atmospheric

J. R. Petit; J. Jouzel; D. Raynaud; N. I. Barkov; J.-M. Barnola; I. Basile; M. Bender; J. Chappellaz; M. Davis; G. Delaygue; M. Delmotte; V. M. Kotlyakov; M. Legrand; V. Y. Lipenkov; C. Lorius; L. Pépin; C. Ritz; E. Saltzman; M. Stievenard

1999-01-01

214

Gateway Antarctica's Christchurch City Council Antarctic Scholarship  

E-print Network

Gateway Antarctica's Christchurch City Council Antarctic Scholarship The Christchurch City Council postgraduate study at Masters or PhD level in Antarctic Research with one season of logistical support provided by Antarctica New Zealand. 1. The Scholarship will be known as the Christchurch City Council Antarctic

Hickman, Mark

215

Crust and Upper Mantle Structure of Antarctica from Rayleigh Wave Tomography  

NASA Astrophysics Data System (ADS)

We combine data from three temporary arrays of seismometers (AGAP/GAMSEIS 2007-2010, ANET/POLENET 2007-2012, TAMSEIS 2001-2003) deployed across Antarctica, along with permanent stations in the region, to produce a large scale shear velocity model of the continent extending from the Gamburtsev Subglacial Mountains (GSM) in East Antarctica, across the Transantarctic Mountains (TAM) and West Antarctic Rift System (WARS) to Marie Byrd Land (MBL) in West Antarctica. Our combined dataset consists of Rayleigh wave phase and amplitude measurements from 112 stations across the study region. We first invert for 2-D Rayleigh wave phase velocities using the two-plane wave method. These results are then inverted for shear velocity structure using crustal thicknesses derived from ambient noise tomography and teleseismic receiver functions. We refine our shear velocity model by performing a Monte Carlo simulation that explores the tradeoff between crustal thickness and upper mantle seismic velocities. The resulting model is higher resolution than previous studies (~150 km resolution length) and highlights significant differences in crustal and uppermost mantle structure between East and West Antarctica in greater detail than previously possible. East Antarctica is underlain by thick crust (reaching ~55 km beneath the GSM) and fast, cratonic lithosphere. West Antarctica is defined by thinner crust and slow upper mantle velocities indicative of its more recent tectonic activity. The observed boundary in crustal thickness closely follows the TAM front. MBL is underlain by a thicker lithosphere than that observed beneath the WARS, but slow mantle velocities persist to depths greater than 200 km, indicating a 'deep seated' (i.e. deeper than the deepest resolvable features of our model) thermal source for volcanism in the region. The slowest seismic velocities at shallow depths are observed in the Terror Rift region of the Ross Sea along an arc following the TAM front, where the most recent extension has occurred, and in another region of active volcanism. The Ellsworth-Whitmore Mountains are underlain by relatively thick crust and an intermediate thickness lithosphere, consistent with its hypothesized origin as a remnant Precambrian crustal block. We also produce upper mantle viscosity models for the study region using a temperature-dependent rheology, assuming that mantle seismic anomalies are dominated by temperature variations. Initial results closely correlate with the velocity model, with viscosities beneath West Antarctica inferred to be orders of magnitude lower than beneath East Antarctica. These viscosity results have important implications for our understanding of glacial isostatic adjustment, which is of particular interest in producing models of past and future changes in the Antarctic Ice Sheets.

Wiens, D. A.; Heeszel, D. S.; Sun, X.; Chaput, J. A.; Aster, R. C.; Nyblade, A.; Anandakrishnan, S.; Wilson, T. J.; Huerta, A. D.

2012-12-01

216

Antarctic meteorology: a study with automatic weather stations  

Microsoft Academic Search

This thesis chiefly addresses a) the use of Automatic Weather Stations (AWS) in determining the near-surface climate and heat budget of Antarctica and, specifically, Dronning Maud Land (DML), and b) the determination of source regions of Antarctic moisture with the aid of a trajectory model and an atmospheric model. The primary motivation behind this interest is the drilling of two

C. Reijmer

2001-01-01

217

Sterols and fecal indicator microorganisms in sediments from Admiralty Bay, Antarctica  

Microsoft Academic Search

A B S T R A C T Sediments from the proximity of Ferraz station outfall, located in Admiralty Bay, Antarctica, were analyzed for fecal indicator microorganisms and sterols during the austral summer of 1999\\/2000 in order to assess human sewage input. Concentrations of total sterols and coprostanol ranged from 0.09 to 19.6 µg.g -1 and < 0.01 and 14.0

César de Castro Martins; Rosalinda Carmela Montone; Rosa Carvalho Gamba; Vivian Helena Pellizari

2005-01-01

218

MORPHOLOGY OF THE AQUATIC MOSSES COLLECTED IN LAKE YUKIDORI, LANGHOVDE, ANTARCTICA  

Microsoft Academic Search

National Institute of Polar Research, 9-10, Kaga 1-chome, Ztabashi-ku, Tokyo 173 Abstract: Participating in the 29th Japanese Antarctic Research Expedition (JARE-29, 1987-1989), the authors collected aquatic mosses growing in Lake Yukidori, Langhovde near Syowa Station, East Antarctica. The moss specimens examined are mostly submerged forms of Bryum pseudotriquetrum (HEDw.) GAERTN., MEYER et SCHERB. which is usually characterized by elongate stems,

Hiroshi KANDA; Shuji OHTANI

219

Potential methane reservoirs beneath Antarctica.  

PubMed

Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14?kilometres thick and an estimated 21,000 petagrams (1?Pg equals 10(15)?g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300?metres in West Antarctica and 700?metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387

Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

2012-08-30

220

A Novel Adenovirus in Chinstrap Penguins (Pygoscelis antarctica) in Antarctica  

PubMed Central

Adenoviruses (family Adenoviridae) infect various organ systems and cause diseases in a wide range of host species. In this study, we examined multiple tissues from Chinstrap penguins (Pygoscelis antarctica), collected in Antarctica during 2009 and 2010, for the presence of novel adenoviruses by PCR. Analysis of a 855-bp region of the hexon gene of a newly identified adenovirus, designated Chinstrap penguin adenovirus 1 (CSPAdV-1), showed nucleotide (amino acid) sequence identity of 71.8% (65.5%) with South Polar skua 1 (SPSAdV-1), 71% (70%) with raptor adenovirus 1 (RAdV-1), 71.4% (67.6%) with turkey adenovirus 3 (TAdV-3) and 61% (61.6%) with frog adenovirus 1 (FrAdV-1). Based on the genetic and phylogenetic analyses, CSPAdV-1 was classified as a member of the genus, Siadenovirus. Virus isolation attempts from kidney homogenates in the MDTC-RP19 (ATCC® CRL-8135™) cell line were unsuccessful. In conclusion, this study provides the first evidence of new adenovirus species in Antarctic penguins. PMID:24811321

Lee, Sook-Young; Kim, Jeong-Hoon; Park, Yon Mi; Shin, Ok Sarah; Kim, Hankyeom; Choi, Han-Gu; Song, Jin-Won

2014-01-01

221

Dry Valleys of Antarctica: Limnoir  

NSDL National Science Digital Library

This journal account describes the work of the limnology team on the lakes in the dry valleys of Antarctica in the form of a short story. It describes the long-term monitoring of lake water and organisms in order to create a picture of the ecology of the lakes. The account points out that galcial meltwater is essentially the only source of water and nutrients to the lakes and describes some of the specialized equipment used for sampling and testing. It also describes some of the organisms (extremophiles) which have adapted to the harsh conditions in the lakes.

Karen Cozzetto

222

Station Models  

NSDL National Science Digital Library

This project will allow users to become acquainted with station models that are found on weather maps. Students will study the various atmospheric variables that are depicted on a station model and then practice on an interactive station model program. Part 1 - Being able to read and interpret weather maps is a very important skill in meteorology. One of the most basic skills of predicting the weather is being able to interpret a station model of a given location. A station model is a bundle of information that ...

Mr. Ertl

2007-11-03

223

Glacial isostatic crustal uplift in southern Victoria Land, Antarctica, from geologic and geodetic records  

NASA Astrophysics Data System (ADS)

Geologic records and geodetic measurements of glacial isostatic crustal motions are presented from the southern Victoria Land region of Antarctica. In much of the world, key records used for mapping and modeling glacial isostatic crustal motions come from raised paleoshorelines and beaches of ice-marginal lakes and seas. While such records are scarce in Antarctica, preserved paleoshorelines are present in the southern Victoria Land region of Antarctica. Light detection and ranging (LiDAR) data coverages of these features were acquired during the 2001-2002 austral summer field season by NASA's Airborne Topographic Mapper (ATM) system, resulting in 2 meter horizontal resolution digital elevation models (DEMs). This study utilizes these DEM data to derive crustal tilt values from observed changes in elevation along the length of the shorelines. Radiocarbon age data are correlated with the associated degree of shoreline tilt to derive a rate of crustal deformation since deglaciation. Modern rates of glacial isostatic crustal motion are derived from GPS stations in the same region. Campaign station occupation began in 1996-1997 under the TAMDEF (Transantarctic Mountain DEFormation Network) project, and continuous GPS data collected began in 1999 and continues under the ANET/POLENET (Antarctica Polar Earth Observing Network) project, enabling analysis of decadal scale time series. Integrated gradient curves from paleoshoreline records and GPS crustal velocities show exponential form and indicate tilting down to the east. Eastward tilt may be the result of substantial loss of East Antarctic ice, a collapsing forebulge linked to ice centers in the Ross Sea region or in interior West Antarctica, or differences in earth response due to laterally varying earth structure. Modeling of these new data, along with comparison of tilt directions to centers of ice mass loss, provide tests of these scenarios and yield new insights into earth models and ice history.

Konfal, S.; Wilson, T.; Bevis, M. G.; Kendrick, E. C.; Hall, B. L.

2011-12-01

224

What Hazards Do Humans Encounter in Antarctica?  

NSDL National Science Digital Library

Students investigate the challenges of living and working in Antarctica and the technologies that help researchers meet those challenges. This resource includes: teacher tools (downloadable readings, breakdowns of tasks, teacher strategies, grading sheet and rubric), an online activity (students review the preparation materials given to researchers traveling to Antarctica), classroom activities (testing the properties of fabrics for use in Antarctica and a Jeopardy-style question and answer game), outside readings (including excerpts from Sir Edmund Hillary's journal), and a handout for students (guidance for assembling portfolios, examples of projects).

2002-01-01

225

Semantic Awareness in Product Lifecycle Management Systems Casey James Baker, Douglas Eddy, Dr. Sundar Krishnamurty, Dr. Ian Grosse, Dr. Jack Wileden  

E-print Network

Semantic Awareness in Product Lifecycle Management Systems Casey James Baker, Douglas Eddy, Dr time to market. Semantic awareness has the potential to enrich PLM systems, yet semantic functionality for adopting semantic functionality. A case study was performed with a widely used PLM system (PTC's Windchill

Mountziaris, T. J.

226

Initiation of Irrigation Effects on Temporal Nitrate Leaching F. X. M. Casey,* N. Derby, R. E. Knighton, D. D. Steele, and E. C. Stegman  

E-print Network

Initiation of Irrigation Effects on Temporal Nitrate Leaching F. X. M. Casey,* N. Derby, R. E that was converted from dryland to center- 1980). Albus and Knighton (1998) found that the initia- pivot irrigation in 1989. The vadose zone was monitored with four tion of irrigation caused a flush of NO3­N to the shallow

Steele, Dean D.

227

Lithospheric Structure of Antarctica and Implications for Geological and Cryospheric Evolution  

NASA Astrophysics Data System (ADS)

Recent broadband seismic deployments, including the AGAP/GAMSEIS array of 24 broadband seismographs over the Gamburtsev Subglacial Mountains (GSM) in East Antarctica and the POLENET/ANET deployment of 33 seismographs across much of West Antarctica, reveal the detailed crust and upper mantle structure of Antarctica for the first time. The seismographs operate year-around even in the coldest parts of Antarctica, due to novel insulated boxes, power systems, and modified instrumentation developed in collaboration with the IRIS PASSCAL Instrument Center. We analyze the data using several different techniques to develop high-resolution models of Antarctic seismic structure. We use Rayleigh wave phase velocities at periods of 20-180 s determined using a modified two-plane wave decomposition of teleseismic Rayleigh waves to invert for the three dimensional shear velocity structure. In addition, Rayleigh wave group and phase velocities obtained by ambient seismic noise correlation methods provide constraints at shorter periods and shallower depths. Receiver functions provide precise estimates of crustal structure beneath the stations, and P and S wave tomography provides models of upper mantle structure down to ~ 500 km depth along transects of greater seismic station density. The new seismic results show that the high elevations of the GSM are supported by thick crust (~ 55 km), and are underlain by thick Precambrian continental lithosphere that initially formed during Archean to mid-Proterozoic times. The absence of lithospheric thermal anomalies suggests that the mountains were formed by a compressional orogeny during the Paleozoic, thus providing a locus for ice sheet nucleation throughout a long period of geological time. Within West Antarctica, the crust and lithosphere are extremely thin near the Transantarctic Mountain Front and topographic lows such as the Bentley Trench and Byrd Basin, which represent currently inactive Cenozoic rift systems. Slow seismic velocities beneath Marie Byrd Land at asthenospheric depths suggest a major thermal anomaly, possibly due to a mantle plume. Volcanic earthquakes detected in this region indicate the presence of currently active magma systems. The results suggest large lateral changes in parameters needed for glaciological models, including lithospheric thickness, mantle viscosity, and heat flow. Extremely high heat flow is predicted for much of West Antarctica, consistent with recent results from the WAIS ice drilling. Using the seismic results to estimate mantle viscosity, we find several orders of magnitude difference in viscosity between East and West Antarctica, with lowest viscosities found beneath Marie Byrd Land and the West Antarctic Rift System. Realistic glacial isostatic adjustment models must take these large lateral variations into account.

Wiens, Douglas; Heeszel, David; Sun, Xinlei; Lloyd, Andrew; Nyblade, Andrew; Anandakrishnan, Sridhar; Aster, Richard; Chaput, Julien; Huerta, Audrey; Hansen, Samantha; Wilson, Terry

2013-04-01

228

Tectonic structure of East Antarctica  

NASA Astrophysics Data System (ADS)

First overviews of tectonic structure of the Southern Continent were made by the pioneers of Antarctic earth science investigations almost 100 years ago. Despite rapidly advancing international geological studies under the Antarctic Treaty, the presentations of Antarctic tectonic structure remained largely speculative until the end of the past century when implementation of modern analytical and remote-sensing research technologies enabled compilation of more credible tectonic models of Antarctica. The East Antarctic bedrock consists mainly of the Precambrian crystalline complexes and the Paleozoic-Early Mesozoic platform units. Crystalline Shield is locally complicated by Neoproterozoic aulacogenes and Late Paleozoic to Mesozoic rifts. Shield assemblages reliably recognized in coastal outcrops indicate the predominant occurrence of Archean cratonic nuclei and Mesoproterozoic mobile belts. The undisturbed platform cover strata are exposed in East Antarctica mainly along its boundary with West Antarctica. Tectonic structure of ice-covered regions (more that 99% of the East Antarctic territory) is interpreted using mostly magnetic and bedrock topography data, but other geophysical and geological information (satellite, airborne and over-ice gravity; seismology; active seismics; erratics; detrital zircons dates; etc.) is also important. Archean cratons are geologically documented in western Dronning Maud Land, Enderby Land, Princess Elizabeth Land and in the southern Prince Charles Mts. Their distribution under the ice is marked by a specific magnetic pattern including low-amplitude mosaic and/or high-amplitude long-wavelength anomalies. The most extensive ancient craton being 1000 km across is believed to extend from the southern Prince Charles Mts. to the Gamburtsev Mts. Mesoproterozoic mobile belts are distinguished by elongated high-amplitude magnetic anomalies and are mapped along the costal area as the zone of 250-600 km wide. The Gamburtsev Mts. area is also interpreted to be a part of Mesoproterozoic mobile belt. Precambrian aulacogens and Paleozoic to Mesozoic rifts are more difficult to recognize with confidence from geophysical data, except the largest Lambert-Amery rift which is well expressed in potential fields and bedrock topography. Many other linear bedrock depressions are believed to result from ice erosion which probably amplified structural features such as faults, sutures, boundaries of tectonic provinces. Extensive platform cover is assumed to occur mainly in vast subglacial lowlands of East Antarctic interior. Geophysical data, as well as erratics found in costal moraines and offshore sediments, suggest that Beacon and/or Ferrar Supergroups or their stratigraphic/structural equivalents can be expected to continue under the ice beyond the limits of the Ross Orogen where they may rest on the older platform complexes and/or directly on the crystalline basement.

Leychenkov, German; Grikurov, Garrik; Golynsky, Alexander

2013-04-01

229

Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?  

SciTech Connect

Many of the ecological systems found in continental Antarctica are comprised entirely of microbial species. Concerns have arisen that these microbial systems might be at risk either directly through the actions of humans or indirectly through increased competition from introduced species. Although protection of native biota is covered by the Protocol on Environmental Protection to the Antarctic Treaty, strict measures for preventing the introduction on non-native species or for protecting microbial habitats may be impractical. This report summarizes the research conducted to date on microbial ecosystems in continental Antarctica and discusses the need for protecting these ecosystems. The focus is on communities inhabiting soil and rock surfaces in non-coastal areas of continental Antarctica. Although current polices regarding waste management and other operations in Antarctic research stations serve to reduce the introduction on non- native microbial species, importation cannot be eliminated entirely. Increased awareness of microbial habitats by field personnel and protection of certain unique habitats from physical destruction by humans may be necessary. At present, small-scale impacts from human activities are occurring in certain areas both in terms of introduced species and destruction of habitat. On a large scale, however, it is questionable whether the introduction of non-native microbial species to terrestrial Antarctica merits concern.

White, G.J.

1996-08-01

230

Long-Term Variability of Stratospheric Temperature Above Central Antarctica  

NASA Astrophysics Data System (ADS)

Long-term variations of atmospheric temperature at different isobaric surfaces above central Antarctica and their possible coupling with correspondent changes in the near-Earth space were studied. Data of atmospheric balloon sounding at two Antarctic intercontinental stations Vostok and Amundsen-Scott (South Pole) taken for the last 40 years were used in this study. A central part of the Antarctica continent with its minimum of man-made pollution, uniformity of severe thermal and circulation regimes is an ideal place for study of the real climatic changes. It was found that stratospheric temperature at both stations averaged seasonally or annually does not demonstrate any meaningful correlation with correspondent sunspot number variations. On the other hand there is a notable correlation (r > 0,6) between stratospheric temperature at both stations and annually averaged values of the solar wind dynamic pressure. The latter parameter whose long-term time series were originally calculated by the authors is proportional to energy transferred to the Earth system " ma g n e t o s p here -ionosphere -atmosphere " from the outer space. A concept of the global electric circuit with a Electro-Motive Force generator located at the dayside magnetopause and driven by the solar wind energy is one of the possible realistic physical mechanisms capable to explain interaction between solar wind and middle atmosphere. Electrically conducting layers of ionosphere, ionic region in stratosphere and the Earth surface are the passive elements of this scheme. Mutual coupling between stratosphere thermal regimes at two stations (Vostok and South Pole) demonstrates obvious seasonal dependence: there is a good correlation between them in summer while it disappears in winter and equinoxes. It was found also that stratospheric temperature above South Pole Station varies in the same manner as correspondent parameter above North Pole as reported previously by Labitzke and Naujokat (2000). At both geographic poles stratospheric temperature had obvious tendency to warming in 1972-1995. On the other hand , the correspondent Vostok data demonstrate clear tendency to cooling in this period. Possible explanations of these results are given.

Shirochkov, A.; Makarova, L.

231

Weddell Seal Research at Erebus Bay, Antarctica  

USGS Multimedia Gallery

Technician recording seals' tag information in field notebook and portable computer.  Cold! Photo by USGS scientist William A Link at Erebus Bay, Antarctica.  Images were obtained under NMFS Permit No: 1032-1917.  ...

232

Petroleum and mineral resources of Antarctica  

SciTech Connect

Following the introduction, this publication contains the following papers: (1) Are there petroleum resources in Antarctica. by John C. Behrendt; (2) Mineral occurrences of Antarctica by Peter D. Rowley, Paul L. Williams, and Douglas E. Pride; and (3) Dufek intrusion of Antarctica and a survey of minor metals and possible resources by Arthur B. Ford. The first report summarizes the information relevant to petroleum resources. Although uneconomic at present, petroleum is generally considered more likely to be exploited (if supergiant fields were ever found) in the next few decades than hard minerals. The second report reviews the reported occurrences of minerals in Antarctica and discusses their significance. The final report discusses the Dufek layered mafic intrusion, second only to the Bushveld Complex in size in the world; the Dufek intrusion might be considered as a potential target for mineral exploration. 370 references, 28 figures, 4 tables.

Behrendt, J.C. (ed.)

1983-01-01

233

Why Is Antarctica the Windiest Place on Earth?  

NSDL National Science Digital Library

This weeklong unit has students examine weather reports to learn for themselves how windy Antarctica can get, and what the contributing factors are. Throughout, they collect their findings in a portfolio. The comprehensive curriculum materials contain teacher tools, which include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, and additional readings. There are three activities in which students develop questions for further study, examine weather data collected at several Antarctic weather stations, and investigate the behavior of cold air. Question and answer interviews with two Antarctic researchers, a polar climatologist and a glacial geologist, who study different aspects of katabatic winds, provide more information, and a student handout that offers guidance for putting together portfolios and examples of creative final projects completes the package.

234

THE BIRDS OF SEYMOUR ISLAND, ANTARCTICA  

Microsoft Academic Search

During January-February 2000, we obtained information on the abundance and distribution of seabirds in Seymour Island, Antarctica. Six species breed in this area: Adélie Penguin (Pygoscelis adeliae; 28,255 pairs), Wilson's Storm-petrel (Oceanites oceanicus; 22), Brown Skua (Catharacta antarctica; 30), South Polar Skua (C. maccormicki; 33), Kelp Gull (Larus dominicanus; 296) and Antarctic Tern (Sterna vittata; 107). In addition, five non-breeding

Diego Montalti; Guillermo E. Soave

235

Antarctica: Soils, weathering processes and environment  

SciTech Connect

Antarctica is currently the subject of world-wide interest, both because of its supposed potential for minerals, and because of its very high aesthetic and environmental values. It is therefore timely to review the current state of soil science in Antarctica, for, as is found elsewhere in the world, land management needs to be in accordance with soil attributes. The authors therefore provide background information to allow the Antarctic environment as it is related to soil formation to be understood.

Campbell, I.B.; Claridge, G.G.C.

1987-01-01

236

Putting Antarctica on the Map  

NSDL National Science Digital Library

In this six-day unit, students examine historical maps of Antarctica and research early explorers to gain perspective on how cartography and our understanding of the globe have changed. Throughout the unit, students collect their findings in a portfolio. Teacher tools for this unit include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, and additional readings. Student activities include a Web activity in which students examine and compare historical maps and their modern-day equivalents, focusing on how map-making techniques have changed, a classroom activity in which students examine the history of Antarctic exploration and conduct research on a topic of interest, and several readings that provide a broad perspective. A student handout with guidance for putting together their portfolios and examples of creative final projects is also included.

237

Ralf Siebenmorgen IR instrument from Antarctica (thermal) IR instruments from Antarctica  

E-print Network

Ralf Siebenmorgen IR instrument from Antarctica (thermal) IR instruments from Antarctica: what can be gained Ralf Siebenmorgen Why? pwv, T, aerosols IR projects: DomeC and elsewhere Science cases Conclusion: my favoured modes (thermal) IR := 2-24µm = K,L,M,N,Q #12;Ralf Siebenmorgen IR instrument from

Siebenmorgen, Ralf

238

Pine Island Glacier, Antarctica, MISR Multi-angle Composite  

Atmospheric Science Data Center

article title:  Pine Island Glacier, Antarctica, MISR Multi-angle Composite     ... iceberg has finally separated from the calving front of Antarctica's Pine Island Glacier. Scientists first detected a rift in the ...

2013-12-17

239

Heavy metal and sulphur emissions to the atmosphere from human activities in Antarctica  

NASA Astrophysics Data System (ADS)

Investigators have used the temporal record of heavy metal and sulphur concentrations in Antarctic snow to assess the extent of global atmospheric pollution in the Southern Hemisphere. These studies would be compromised by any significant local pollution from within Antarctica itself. Here, we present a comprehensive inventory of heavy metal and S emissions from human activities south of 60°S. These emissions are found to be due mainly to the use of gasoline, diesel fuel and kerosene on stations and in field operations, and to waste burning. We find that for S, Cd, Cu and Zn, emissions from within Antarctica are probably important only in local areas. However, for Pb, these emissions (about 1800 kg Pb a -1), particularly from leaded gasoline and aviation gasoline, could account for a very significant part of the fallout flux to snow over the continent.

Boutron, Claude F.; Wolff, Eric W.

240

Accumulation Rate Variability along Norway-US Traverse Route, East Antarctica  

NASA Astrophysics Data System (ADS)

A ~2000 km-long transect of 400 MHz ground-penetrating radar (GPR) data was collected during the 2008-2009 Norway-US scientific traverse between South Pole and Troll Station on the Indian Ocean side of East Antarctica. The GPR profiles extend into the firn-ice transition. Density contrasts give rise to many highly reflective stratigraphic horizons in the firn, which can be traced continuously for several hundreds of kilometers, both near the surface and at depth. Here, the structure of these reflecting horizons is used to examine the depositional environment of the ice sheet. We also assign ages to the GPR horizons using intersecting ice cores, which allow us to quantify spatial and temporal variability in snow accumulation rates in a little known portion of East Antarctica.

Hall, M. L.; Hamilton, G. S.; Arcone, S. A.

2009-12-01

241

Concentration of trace inorganic species in surface snow along the route to Dome Fuji, Antarctica  

NASA Astrophysics Data System (ADS)

In the southern hemisphere, especially Antarctica, it is considered that ocean and stratosphere are major sources of halogen species. However, there is little data about halogen species contained in snow and ice in Antarctica. In this research, trace inorganic species (Br, Cl, F, I) in Antarctica snow were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°01'S, 40°03'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The snow samples were also collected from a pit dug at Dome Fuji station. Those samples were collected in the 2009/2010 austral summer. The samples were transported to Japan without thawing. The quantitative analyses of elements were performed using an ion chromatograph mass spectrometer (IC-MS) and a quadrupole type inductively-coupled plasma mass spectrometer (ICP-MS). The IC-MS system consists of a single quadrupole type mass spectrometer (Agilent Technologies 6150) connected to an ion chromatograph (Dionex ICS-2000). 14 anion species including halogen species (Br-, BrO3-, CH3COO-, CH3SO3-, Cl-, C2O42-, F-, HCOO-, I-, IO3-, NO2-, NO3-, PO43-, SO42-) were analyzed by this system. The maximum concentration of Br- and I- was observed around 71°S and near 74°S on the traverse route. Average concentrations and maximum concentration of Br- were 0.2 ng/ml and 0.4 ng/ml, respectively. Average concentrations and maximum concentration of I- were 0.05 ng/ml and 0.3 ng/ml, respectively. Further results and discussion about the behavior and origin of halogen ion species in snow will be presented.

Hirabayashi, M.; Motoyama, H.

2013-12-01

242

TROPOSPHERIC CLOUDS IN ANTARCTICA David H. Bromwich,1,2  

E-print Network

TROPOSPHERIC CLOUDS IN ANTARCTICA David H. Bromwich,1,2 Julien P. Nicolas,1,2 Keith M. Hines,1 regions, little is known about clouds in Antarctica. This arises in part from the challenging deployment, and aerosol concentrations found in Antarctica create unique conditions for cloud for- mation that greatly

Howat, Ian M.

243

Surface temperature and salinity variations between Tasmania and Antarctica, 19931999  

E-print Network

Surface temperature and salinity variations between Tasmania and Antarctica, 1993­1999 Alexis ship between Tasmania and Dumont D'Urville, Antarctica, as part of the SURVOSTRAL program (Surveillance: Chaigneau, A., and R. Morrow, Surface temperature and salinity variations between Tasmania and Antarctica

244

Gateway Antarctica's Ministry of Foreign Affairs and Trade Scholarship  

E-print Network

Gateway Antarctica's Ministry of Foreign Affairs and Trade Scholarship in Antarctic and Southern in support of research and teaching in Antarctic Studies in recognition of Antarctica as a continent devoted to the understanding of Antarctica or the Southern Ocean. At least one of the scholar's supervisors of studies

Hickman, Mark

245

Post Graduate Research Opportunities Aquatic Ecosystem Research at Gateway Antarctica  

E-print Network

Post Graduate Research Opportunities Aquatic Ecosystem Research at Gateway Antarctica In existence moved to Gateway Antarctica at the University of Canterbury. The programme comes with a legacy of multidisciplinary research into all types of aquatic ecosystems in Antarctica, a network of international

Hickman, Mark

246

A BARREL of fun in AntARcticA  

E-print Network

A BARREL of fun in AntARcticA National Aeronautics and Space Administration www.nasa.gov Volume 10 balloon scientists, are having a BARREL of fun in Antarctica. The Balloon Array for Radiation belt--to launch over Antarctica. The balloon-borne instruments will gather data on magnetic systems and send

Christian, Eric

247

HYDROLOGIC PROCESSES INFLUENCING STREAMFLOW VARIATION IN FRYXELL BASIN, ANTARCTICA  

E-print Network

HYDROLOGIC PROCESSES INFLUENCING STREAMFLOW VARIATION IN FRYXELL BASIN, ANTARCTICA Peter of southern Victoria Land, Antarctica is a large polar desert located along the west coast of the Ross Sea Union 93 #12;ECOSYSTEM DYNAMICS IN A POLAR DESERT: THE MCMURDO DRY VALLEYS, ANTARCTICA94 alluvium

MacDonald, Lee

248

Antarctica: Scientific Journeys from McMurdo to the Pole.  

ERIC Educational Resources Information Center

This issue of Exploratorium Magazine focuses on Antarctica. Antarctica has one of the most extreme climates in the world with an untouched environment inviting researchers with great opportunities for study. This issue describes the journey of four Exploratorium staff members to frozen Antarctica. Chapters include: (1) "Life at the Bottom of the…

Brand, Judith, Ed.

2002-01-01

249

Belgische wetenschappers ontdekken 18 kilo zware meteoriet op Antarctica  

E-print Network

Belgische wetenschappers ontdekken 18 kilo zware meteoriet op Antarctica donderdag 28 februari 2013 Antarctica', zegt ULB-geoloog en teamleider Vincent Debaille. `Dit is de grootste meteoriet die in 25 jaar gevonden is in oostelijk Antarctica.' De chondriet is momenteel in Japan voor onderzoek, waar hij aan een

Claeys, Philippe

250

Space analogue studies in Antarctica  

NASA Astrophysics Data System (ADS)

Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mltogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

Lugg, D.; Shepanek, M.

1999-09-01

251

Terra Nova Bay Polynya, Antarctica  

NASA Technical Reports Server (NTRS)

In Terra Nova Bay, off the Scott Coast of Victoria Land, Antarctica, a large pocket of open water persists throughout most of the Southern Hemisphere winter, even while most of the rest of the Antarctic coastline is firmly embraced by the frozen Southern Ocean. This pocket of open water--a polynya--results from exceptionally strong winds that blow downslope from the Trans-Antarctic Mountains. These fierce katabatic winds drive the sea ice eastward. Since the dominant ice drift pattern in the area is northward, the Drygalski Ice Tongue prevents the bay from being re-populated with sea ice. This image of the Terra Nova Bay polynya was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite on October 16, 2007. Sea ice sits over the Ross Sea like a cracked and crumbling windshield. Blue-tinged glaciers flow down from the Trans-Antarctic Mountains. Although glaciers can appear blue because of melt water, they can also get that tint when the wind scours and polishes the ice surface. Given the strength of the katabatic winds along this part of the Antarctic coast, it is likely that the blue color of these glaciers is a result of their having been swept clean of snow. The large image has a spatial resolution (level of detail) of 250 meters per pixel.

2007-01-01

252

Space analogue studies in Antarctica  

NASA Technical Reports Server (NTRS)

Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

Lugg, D.; Shepanek, M.

1999-01-01

253

The Landsat Image Mosaic of Antarctica (LIMA): A Cutting-Edge Way for Students and Teachers to Learn about Antarctica  

ERIC Educational Resources Information Center

By studying Antarctica via satellite and through ground-truthing research, we can learn where the ice is melting and why. The Landsat Image Mosaic of Antarctica (LIMA), a new and cutting-edge way for scientists, researchers, educators, students, and the public to look at Antarctica, supports this research and allows for unprecedented views of our…

Campbell, Brian; Bindschadler, Robert

2009-01-01

254

Sensible and latent heat flux estimates in Antarctica  

NASA Technical Reports Server (NTRS)

The assumption has been made that the net annual contribution of water by the processes of deposition and sublimation to the Antarctic Ice Sheet is zero. The U.S. Antarctic Program started installing reliable automatic weather stations on the Antarctic Continent in 1980. The initial units were equipped to measure wind speed, wind direction, air pressure, and air temperature. During the 1983-1984 field season in Antarctica, three units were installed that measured a vertical air temperature difference between the nominal heights of 0.5 m and 3.0 m and relative humidity at a nominal height of 3 m. The measurements of the vertical air temperature difference and the relative humidity are the minimum required to estimate the sensible and latent heat fluxes to the air, while not exceeding the available energy requirements for the weather stations. The estimates of the net annual sublimation and deposition on the Ross Ice Shelf amount to 20 to 80 percent of the annual accumulation. We conclude that the assumption that annual sublimation and deposition are zero is not valid under Antarctic conditions.

Stearns, Charles R.; Weidner, George A.

1993-01-01

255

Sleep and Mood During A Winter in Antarctica  

NASA Technical Reports Server (NTRS)

Seasonal variations in sleep characteristics and their association with changes in mood were examined in 91 American men and women also who spent the 1991 austral winter at three different research stations in Antarctica. Measures of total hours of sleep over a 24-hr period, duration of longest (i.e.,"nighttime") sleep event, number of sleep events, time of sleep onset, and quality of sleep remained unchanged over the course of the austral winter (March through October). However, exposure to total darkness based on station latitude was significantly associated with total hours of sleep, duration of are longest sleep event, time of sleep onset, and quality of sleep. Reported vigor the previous month was a significant independent predictor of changes in all five sleep measures; previous month's measures of all six POMS subscales were significant independent predictors of sleep quality. Sleep characteristics were significant independent predictors of vigor and confusion the following month; total sleep, longest sleep event, sleep onset and sleep quality were significant independent predictors of tension-anxiety and depression. Changes in mood during the austral winter are preceded by changes in sleep characteristics, but prolonged exposure to the photoperiodicity characteristic of the high latitudes appears to be associated with improved sleep. In turn, mood changes appear to affect certain sleep characteristics, especially sleep quality.

Palinkas, Lawrence A.; Houseal, Matt; Miller, Christopher

2000-01-01

256

Mapping Sediment Contamination and Toxicity in Winter Quarters Bay, Antarctica  

SciTech Connect

Winter Quarters Bay (WQB) is a small embayment located adjacent to McMurdo Station, the largest researchbase in Antarctica. The bay is approximately 250 m wide andlong, with a maximum depth of 33 m. Historically, trashfrom the McMurdo Station was piled on the steep shoreline ofWQB, doused with fuel and ignited. That practice hasceased, and the adjacent land area has been regraded tocover the residual waste. The bottom of WQB remainslittered with drums, equipment, tanks, tires, cables, andother objects, especially the southeastern side of the baywhere dumping took place. Sediments are contaminated withPCBs, metals, and hydrocarbon fuels. The objectives of this study were to map the distributionof organic contaminants in WQB, assess the toxicity of WQB sediments using a simple microbial test, anddetermine correlations between toxicity and contaminantlevels. The study suggests that adverse ecological effectshave occurred from one or more of the contaminants found inWQB but the source of the toxic impacts to bay sedimentsremains unknown. Whole sediment toxicity was onlycorrelated with oil-equivalent while solvent extracts ofsediments were correlated with PAHs and oil-equivalent. Theauthors recommend that an integrated research plan bedeveloped that focuses on determining what additionalinformation is needed to make informed decisions on possibleremediation of WQB.

White, Gregory J; Crockett, Alan Bronson

2003-07-01

257

Geology of the Continental Margin of Enderby and Mac. Robertson Lands, East Antarctica: Insights from a Regional Data Set  

Microsoft Academic Search

In 2001 and 2002, Australia acquired an integrated geophysical data set over the deep-water continental margin of East Antarctica from west of Enderby Land to offshore from Prydz Bay. The data include approximately 7700 km of high-quality, deep-seismic data with coincident gravity, magnetic and bathymetry data, and 37 non-reversed refraction stations using expendable sonobuoys. Integration of these data with similar

H. M. J. Stagg; J. B. Colwel; N. G. Direen; P. E. O’Brien; G. Bernardel; I. Borissova; B. J. Brown; T. Ishirara

2004-01-01

258

Live from Antarctica: Then and now  

NASA Astrophysics Data System (ADS)

This real-time educational video series, featuring Camille Jennings from Maryland Public Television, includes information from Antarctic scientists and interactive discussion between the scientists and school children from both Maryland and Hawaii. This is part of a 'Passport to Knowledge Special' series. In this part of the four part Antarctic series, the history of Antarctica from its founding to the present, its mammals, plants, and other life forms are shown and discussed. The importance of Antarctica as a research facility is explained, along with different experiments and research that the facilities there perform.

259

Live from Antarctica: Then and Now  

NASA Technical Reports Server (NTRS)

This real-time educational video series, featuring Camille Jennings from Maryland Public Television, includes information from Antarctic scientists and interactive discussion between the scientists and school children from both Maryland and Hawaii. This is part of a 'Passport to Knowledge Special' series. In this part of the four part Antarctic series, the history of Antarctica from its founding to the present, its mammals, plants, and other life forms are shown and discussed. The importance of Antarctica as a research facility is explained, along with different experiments and research that the facilities there perform.

1994-01-01

260

Crustal structure across the Filchner Ronne Shelf, Antarctica  

NASA Astrophysics Data System (ADS)

Crustal structure across the Filchner Ronne Shelf, Antarctica U. Herter, W. Jokat One large gap in understanding the tectonic evolution of Antarctica beside the few rock outcrops on the continent is the missing information on crustal thickness along its margins but also in its interior. E.g., the few marine deep seismic lines are located mainly along the Antarctic Peninsula/Pacific margin, but for most of the East Antarctic margins such information is not available. In this contribution we concentrate on one of the most remote areas in Antarctica, the Filchner Ronne Shelf (FRS). The area is underlain by approximately 12 km of sediments, but its crustal fabric is questionable. Thus, some existing deep seismic sounding data were modeled and reinterpreted. Especially, data gathered in 1995 have been analyzed, and a more detailed 2D P-wave velocity model has been calculated. For the profiles in total 12 RefTek stations each with nine geophone chains were placed on the ice shelf and 3175 airgun shots along a 480 km transect were fired by two 32 l BOLT-Airguns each 60 s. Signals were recorded up to distances of 180 km. Due to the ice coverage it was not possible to acquire the data without gaps or along straight lines, which caused some difficulties in the modeling process. Furthermore, in the new model all data from older experiments of the AWI and Soviet Antarctic expeditions acquired with dynamite sources were incorporated. The model shows a sedimentary basin with a thickness up to 12 km and a large velocity inversion in a deeper sediment unit. The crustal thickness varies from 40 km beneath the Antarctic Peninsula, and 14 km of basement in the center part of the profile. Towards Berkner Island the crust thickens again, but the top of the basement is still 11 km deep. The lower crustal velocities range between 6.8 and 7.2 km/s. We interpret the crustal structure as clear evidence for the presence of a failed rift. The initial stretching of the continental crust documented by the high lower crustal velocity might have already starting during Jurassic times and terminated most likely with the opening of the Weddell Sea more in the north. Yet, it is not clear if in the central part of FRS already thick oceanic crust is found, or if the data still represent highly extended and intruded continental crust. Here, our P-wave model differs from previously published models. Based on the seismic velocities a density model was derived and fitted to the existing ship- and airborne gravity data. Finally, the seismic and gravity data were combined with aeromagnetic data.

Herter, U.; Jokat, W.

2012-04-01

261

The Bess-Polar II Long Duration Flight Above Antarctica  

NASA Technical Reports Server (NTRS)

The Balloon-borne Experiment with a Superconducting Spectrometer, BESS, has been developed to study elementary particle phenomena in the early universe through measurements of low energy antiprotons to investigate their origin and through a search for antihelium. The BESS collaboration carried out nine northern latitude flights between 1993 and 2002. BESS-Polar is an advanced program of the BESS collaboration to study these topics with much greater precision using long duration flights above Antarctica. The BESS-Polar spectrometer was successfully developed to accumulate much larger numbers of events during long duration flights around the South Pole. Approximately a factor of four reductions in the amount of material in the particle beam enables measurement of much lower energy antiprotons down to 100 MeV (at top of atmosphere). The first BESS-Polar flight (BESS-Polar I) of 8.5 days was carried out above Antarctica in December 2004. recording 900 million cosmic-ray events. The second BESS-Polar flight (BESS-Polar 11) was successfully carried out in the austral summer season of 2007-2008. Based on experience with BESS-Polar I, the spectrometer was improved in performance and achieved long term stability during the flight. A newly constructed magnet with a larger liquid He capacity and improved thermal insulation and an upgraded data storage system with larger capacity of hard disk drives (HDDs) enabled longer observation time. BESS-Polar II was launched on December 22, 2007 from Williams Field, McMurdo Station, in Antarctica. The spectrometer worked properly and observed cosmic rays for about 24.5 days at float altitude, recording 4.6 billion events on the HDDs until the limit of the magnet operation was reached on January 16, 2008. The flight was terminated and the spectrometer was safely landed on the West Antarctic ice sheet (1000 km from the South Pole) on January 21, 2008. Here, the BESS-Polar instrument is discussed, highlighting improvements made for BESS-Polar II, and overviews of the flight and performance are reported.

Sasaki, Makoto; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka, Ken-ichi; Suzuki, Junichi; Nishimura, Jun; Sakai, Ken-ichi; Shinoda, Ryoko; Orito, Reio; Matsukawa, Yosuke; Kusumoto, Akira; Yoshida, Tetsuya; Fuke, Hideyuki; Mitchell, John W.; Streitmatter, Robert E.; Hams, Thomas; Sasaki, Makoto; Seo, Eun-suk; Lee, Moo-hyon; Kim, Ki-chun; Thakur, Needharika

2008-01-01

262

Geodesy in Antarctica: A pilot study based on the TAMDEF GPS network, Victoria Land, Antarctica  

NASA Astrophysics Data System (ADS)

The objective of the research presented in this dissertation is a combination of practical and theoretical problems to investigate unique aspects of GPS (Global Positioning System) geodesy in Antarctica. This is derived from a complete analysis of a GPS network called TAMDEF (Trans Antarctic Mountains Deformation), located in Victoria Land, Antarctica. In order to permit access to the International Terrestrial Reference Frame (ITRF), the McMurdo (MCM4) IGS (The International GNSS Service for Geodynamics, formerly the International GPS Service) site was adopted as part of the TAMDEF network. The following scientific achievements obtained from the cited analysis will be discussed as follows: (1) The GPS data processing for the TAMDEF network relied on the PAGES (Program for Adjustment of GPS Ephemerides) software that uses the double-differenced iono-free linear combination, which helps removing a big partial of bias (mm level) in the final positioning. (2) To validate the use of different antenna types in TAMDEF, an antenna testing experiment was conducted using the National Geodetic Survey (NGS) antenna calibration data, appropriate for each antenna type. Sub-daily and daily results from the antenna testing are at the sub-millimeter level, based on the fact that 24-hour solutions were used to average any possible bias. (3) A potential contributor that might have an impact on the TAMDEF stations positioning is the pseudorange multipath effect; thus, the root mean squared variations were estimated and analyzed in order to identify the most and least affected sites. MCM4 was found to be the site with highest multipath, and this is not good at all, since MCM4 is the primary ITRF access point for this part of Antarctica. Additionally, results from the pseudorange multipath can be used for further data cleaning to improve positioning results. (4) The Ocean Tide Modeling relied on the use of two models: CATS02.01 (Circum Antarctic Tidal Simulation) and TPXO6.2 (TOPEX/Poseidon) to investigate which model suits the Antarctic conditions best and its effect on the vertical coordinate component at the TAMDEF sites. (5) The scatter for the time-series results of the coordinate components for the TAMDEF sites are smaller when processed with respect to the Antarctic tectonic plate (Case I), in comparison with the other tectonic plates outside Antarctica (Case II-IV). Also, the seasonal effect due to the time-series seen in the TAMDEF sites with longer data span are site dependent; thus, data processing is not the reason for these effects. (6) Furthermore, the results coming from a homogeneous global network with coordinates referred and transformed to the ITRF2000 at epoch 2005.5 reflect the quality of the solution, obtained when processing TAMDEF network data with respect to the Antarctic tectonic plate. (7) An optimal data reduction strategy was developed, based on three different troposphere models and mapping functions, tested and used to estimate the total wet zenith delay (TWZD) which later was transformed to precipitable water vapor (PWV). PWV was estimated from GPS measurements and validated with a numerical weather model, AMPS (Antarctic Mesoscale Prediction System) and radiosonde PWV. Additionally, to validate the TWZD estimates at the MCM4 site before their conversion into the GPS PWV, these estimates were directly compared to TWZD computed by the CDDIS (Crustal Dynamics Data Information System) analysis center. (8) The results from the Least-Squares adjustment with Stochastic Constraints (SCLESS) as performed with PAGES are very comparable (mm-level) to those obtained from the alternative adjustment approaches: MINOLESS (Minimum-Norm Least-Squares adjustment); Partial-MINOLESS (Partial Minimum-Norm Least-Squares adjustment), and BLIMPBE (Best Linear Minimum Partial-Bias Estimation). Based on the applied network adjustment models within the Antarctic tectonic plate (Case I), it can be demonstrated that the GPS data used are clean of bias after proper care has been taken of ionosphere, troposphere, multipath, and some other s

Vazquez Becerra, Guadalupe Esteban

263

Summer biomass of a population of Phyllophora antarctica (Phyllophoraceae, Rhodophyta) from Antarctica  

Microsoft Academic Search

Results of a study on summer biomass in aninfralittoral population of Phyllophora antarctica A.et E. S. Gepp from Terra Nova\\u000a Bay (Ross Sea,Antarctica) are reported. The population studied grewat depths of 5 to 12 m. The highest value of biomass(1548\\u000a wet g m?2) was found at the end of January at6 m depth. Data showed that biomass depended mainly onthe

Mario Cormaci; Giovanni Furnari; Blasco Scammacca; Giuseppina Alongi; Marcello Catra

1997-01-01

264

Science Nation: Climate Change Likely to Devastate Emperor Penguin Populations in Antarctica  

NSDL National Science Digital Library

A new study indicates melting sea ice, caused by climate change, may soon wreak havoc on one colony of emperor penguins--and that could spell doom for a large swath of the entire species. French scientists have been monitoring the emperor penguin colony around the French research station in Terre Adelie in Antarctica since the 1960s. A study funded in part by the National Science Foundation (NSF) is modeling how the Terre Adelie emperor penguin population will likely respond to melting sea ice associated with climate change.

265

Antarctica: general aspects and Brazilian research activities  

Microsoft Academic Search

The continent of Antarctica consists of 14 million km2, roughly equivalent to the whole of South America, and is of immense interest to humanity, in particular to the countries of the Antarctic Treaty. The Antarctic continent is the continent of superlatives: it is almost isolated from the rest of the continents, and is severely cold, windy, and dry. In winter,

L. A. Schuch; V. K. Garg; E. Kuzmann; R. Garg; A. C. de Oliveira

2001-01-01

266

Antarctica: Is It More Than Just Ice?  

ERIC Educational Resources Information Center

The authors introduced polar science in a fourth-grade classroom by means of 3 hands-on activities that addressed (1) the melting of glaciers and ice, (2) the differences between the North and the South Pole, and (3) the geography and landforms of Antarctica. An assessment 4 months after the original activity showed that students remembered the…

Johnson, Cheryl; Gutierrez, Melida

2009-01-01

267

Read--and Walk--to Antarctica  

ERIC Educational Resources Information Center

The students at Crestwood Primary School proved that they have what it takes to exercise their bodies and their minds. In an effort to support their teacher's scientific expedition to Antarctica, students from kindergarten to second grade pledged to read books and do physical activity that equated to the 12,900 km (8,000-mile) journey to the…

Harr, Natalie; Doneyko, Kathleen; Lee, Richard E., Jr.

2012-01-01

268

Hydrogen emissions from Erebus volcano, Antarctica  

E-print Network

Hydrogen emissions from Erebus volcano, Antarctica Yves Moussallam1 , Clive Oppenheimer1, 2, 3 of molecular hydrogen (H2) emissions from passively degassing volcanoes has recently been made possible using with SO2, H2O and CO2, in the gas and aerosol plume emitted from the phonolite lava lake at Erebus volcano

Paris-Sud XI, Université de

269

Antarctica: What Shall We Do with It?  

ERIC Educational Resources Information Center

Describes a role playing exercise in which students act as delegates to a meeting at which they will revise the Antarctic Treaty. Background information is presented about Antarctica, the Antarctic Treaty, and positions of 19 nations with regard to the Treaty. (Author/DB)

Branson, Margaret S.; Long, Cathryn J.

1977-01-01

270

Fossils in Antarctica: British Antarctic Survey  

NSDL National Science Digital Library

Although marching penguins add to Antarctica's allure, The British Antarctic Survey (BAS) has found fossil evidence that dinosaurs, marsupials, and forests inhabited the area long before penguins charmed the world with their trademark waddle. Since 1940, when the fossil collection of the BAS was started, it has grown to 40,000 specimens. The "Fossils" section of the BAS website can be found on the left side of the homepage in the "About Antarctica" area, and is divided into two explanatory sections: "Fossils from the Antarctic" and "Fossil Locations in Antarctica". There are also links in each section, near the top right hand corner of the page, to "Type and Figured Fossil Collection" and "Fossils Picture Gallery". In the "Fossils from the Antarctic" section, the types of fossils found are explained and include: molluscs, arthropods, echinoderms and plants. The "Fossil Locations in Antarctica" section has a map of the three islands where a large amount of fossils have been found, along with descriptions of each island and what general types of fossils have been found on them.

271

CyberHunt: Head Off to Antarctica.  

ERIC Educational Resources Information Center

Explains how to take an elementary class on a cyber visit to the continent of Antarctica, the highest, driest, and coldest continent on earth. A student reproducible page presents eight web sites to visit in this quest as well as questions to answer about each site. Answers to the questions are included. (SM)

Kloza, Brad

2001-01-01

272

Groenlandaspis in Antarctica, Australia and Europe  

Microsoft Academic Search

Groenlandaspis is a member of the Arthrodira, a group of Devonian armoured fishes. In the past Groenlandaspis has been found only in eastern Greenland but now Alexander Ritchie has recognised at least six species from sites in Greenland, Europe, Australia and Antarctica. His account demonstrates that these arthrodires enjoyed a very wide geographical distribution during the Upper Devonian and that

Alexander Ritchie

1975-01-01

273

Antarctica--the Ultimate Summer Institute.  

ERIC Educational Resources Information Center

Describes personal experiences of a participant in the National Science Foundation program, Teachers Experiencing Antarctica. Uses the study of the temperature history of Taylor Dome to provide teachers with the experience of research and help other teachers recognize that there are opportunities outside the classroom for personal and professional…

Van Wey, Nate J.

1995-01-01

274

Medical memorials in Antarctica: a gazetteer of medical place-names.  

PubMed

In Antarctica an astonishing more than 300 'medical' place-names record the lives of surgeons and physicians who have served as leaders, clinicians and scientists in the field of polar medicine and other doctors memorialized for their service to medicine. These enduring medical memorials are to be found in the names of glaciers, mountains, capes and islands of the vast frozen Southern Continent. This Antarctic Medical Gazetteer features, inter alii, doctor-expedition leaders, including Jean-Baptiste Charcot (1867-1936) of France and Desmond Lugg (b. 1938) of Australia. The Medical Gazetteer lists 43 geographical features on Brabant Island that were named after famous doctors. This Gazetteer also includes a collection of medical place-names on the Loubet Coast honouring Dr John Cardell (1896-1966) and nine other pioneers who worked on the prevention of snow blindness and four islands of the Lyall Islands Group, including Surgeon Island, named after United States Antarctic Medical Officers. Eleven geographic features (mountains, islands, nunataks, lakes and more) are named after Australian doctors who have served with the Australian National Antarctic Research Expeditions based at Davis Station. Biographic memorials in Antarctica comprise a collective witness of esteem, honouring in particular those doctors who have served in Antarctica where death and injury remains a constant threat. PMID:23143322

Sullivan, Peter; Pearn, John

2012-11-01

275

Geodetic GNSS measurements as a basis for geodynamic and glaciological research in Antarctica  

NASA Astrophysics Data System (ADS)

For about twenty years our institute has been carrying out geodetic GNSS measurements and has been actively working in international collaboration for Antarctic research. Episodic GPS (and later GNSS) measurements of all contributing nations enter the "Database of the SCAR Epoch Crustal Movement Campaigns" which is being maintained at the institute in the framework of SCAR-GIANT. GNSS measurements form a basis for the realization of the International Terrestrial Reference Frame (ITRF) and its densification in Antarctica. Linked to respective products of an ongoing activity to re-process GNSS data of globally distributed stations a consistent and precise TRF realization can be reached. We will give an overview on the latest developments and the subsequent applications for geodynamic and glaciological investigations in Antarctica. Complementary to continuous GNSS observations episodic GNSS measurements have the potential to provide independent data on vertical deformations, which can be used to investigate the present-day ice-mass balance and to refine models of the glacial-isostatic adjustment. Repeated and properly referenced GNSS measurements at the ice surface yield ice-flow velocities and local ice-surface height changes. We will present latest results, e.g. for the Amundsen Sea sector, the subglacial Lake Vostok region and near-coastal regions of Dronning Maud Land or Enderby Land. Thus, it will be discussed how geodetic GNSS measurements form an important and indispensable basis for geodetic Earth system research with the focus on Antarctica.

Scheinert, Mirko; Dietrich, Reinhard; Knöfel, Christoph; Fritsche, Mathias; Rülke, Axel; Schröder, Ludwig; Richter, Andreas; Eberlein, Lutz

2013-04-01

276

Three dimensional crust and upper mantle velocity structure of Antarctica from seismic noise correlation (Invited)  

NASA Astrophysics Data System (ADS)

The successful deployment and year-around operation of the AGAP/GAMSEIS and POLENET/ANET arrays in Antarctica, which include more than 50 broadband seismic stations, provides an unprecedented opportunity to study the detailed structure beneath the continent. Using about four years of continuous data from these arrays (from late 2007 through end of 2011), together with data from the previous TAMSEIS array and permanent stations around Antarctica, we acquire empirical Green's functions between all possible pairs of seismographs by cross-correlating seismic ambient noise. We then extract Rayleigh wave group and phase velocities from 8 to 60 s, and velocity maps for each period are determined by tomographic inversion. Finally, shear velocities in the crust and upper mantle, together with Moho depths are determined from the Rayleigh wave dispersion curves at each location. Our results show the crust and upper mantle structure with higher resolution than obtained in previous studies. The general features are: 1) At shallow depths (several to tens of km), fast velocities are seen beneath the Gamburtsev Mountains (GSM), Transantarctic Mountains (TAM), Marie Byrd Land and Ellsworth Mountains, while slow velocities are seen underneath the West Antarctic rift system (WARS) and Ross Embayment. We interpret this result as indicating thick sedimentary deposits in the WARS and Ross Sea. 2) We also find slow velocities in East Antarctica and fast velocities in West Antarctica at about 20-40 km, which is consistent with the thick/thin crust thickness in these two regions. The transition between the fast and slow velocity is along the Transantarctic Mountains front. 3) Beneath the Gamburtsev Mountains in East Antarctica, low crustal velocities extend to about 55 km, suggesting the mountains are supported by thickened crust. 4) There are pronounced slow upper mantle anomalies within the WARS, indicating a mantle thermal anomaly resulting from Cenozoic extension. 5) Clear fast anomalies occur beneath the Ronne Ice Shelf at intermediate depths (20-50 km), indicating thin crust in this region. 6) Marie Byrd Land has a relatively thin crust of around 30 km, thus its high topography may supported by a low density upper mantle related to a mantle plume.

Sun, X.; Wiens, D. A.; Nyblade, A.; Anandakrishnan, S.; Aster, R. C.; Chaput, J. A.; Huerta, A. D.; Wilson, T. J.

2013-12-01

277

Seismic monitoring at Deception Island volcano (Antarctica): Recent advances  

NASA Astrophysics Data System (ADS)

Deception Island (South Shetland Island, Antarctica) is an active volcano with recent eruptions (e.g. 1967, 1969 and 1970). It is also among the Antarctic sites most visited by tourists. Besides, there are currently two scientific bases operating during the austral summers, usually from late November to early March. For these reasons it is necessary to deploy a volcano monitoring system as complete as possible, designed specifically to endure the extreme conditions of the volcanic environment and the Antarctic climate. The Instituto Andaluz de Geofísica of University of Granada, Spain (IAG-UGR) performs seismic monitoring on Deception Island since 1994 during austral summer surveys. The seismicity basically includes volcano-tectonic earthquakes, long-period events and volcanic tremor, among other signals. The level of seismicity is moderate, except for a seismo-volcanic crisis in 1999. The seismic monitoring system has evolved during these years, following the trends of the technological developments and software improvements. Recent advances have been mainly focused on: (1) the improvement of the seismic network introducing broadband stations and 24-bit data acquisition systems; (2) the development of a short-period seismic array, with a 12-channel, 24-bit data acquisition system; (3) the implementation of wireless data transmission from the network stations and also from the seismic array to a recording center, allowing for real-time monitoring; (4) the efficiency of the power supply systems and the monitoring of the battery levels and power consumption; (5) the optimization of data analysis procedures, including database management, automated event recognition tools for the identification and classification of seismo-volcanic signals, and apparent slowness vector estimates using seismic array data; (6) the deployment of permanent seismic stations and the transmission of data during the winter using a satellite connection. A single permanent station is operating at Deception Island since 2008. In the current survey we collaborate with the Spanish Army to add another permanent station that will be able to send to the IAG-UGR seismic information about the activity of the volcano during the winter, using a communications satellite (SPAINSAT). These advances simplify the field work and the data acquisition procedures, and allow us to obtain high-quality seismic data in real-time. These improvements have a very important significance for a better and faster interpretation of the seismo-volcanic activity and assessment of the volcanic hazards at Deception Island volcano.

Carmona, E.; Almendros, J.; Martín, R.; Cortés, G.; Alguacil, G.; Moreno, J.; Martín, B.; Martos, A.; Serrano, I.; Stich, D.; Ibáñez, J. M.

2012-04-01

278

Language Learning Stations.  

ERIC Educational Resources Information Center

Describes use of learning stations at elementary and secondary levels. Explains vocabulary, grammar, conversation, listening, reading and culture stations; materials and equipment for stations; management concerns. (BK)

Strauber, Sandra K.

1981-01-01

279

Validation of EOS Aqua AMSR Sea Ice Products for East Antarctica  

NASA Technical Reports Server (NTRS)

This paper presents results from AMSR-E validation activities during a collaborative international cruise onboard the RV Aurora Australis to the East Antarctic sea ice zone (64-65 deg.S, 110-120 deg.E) in the early Austral spring of 2003. The validation strategy entailed an IS-day survey of the statistical characteristics of sea ice and snowcover over a Lagrangian grid 100 x 50 km in size (demarcated by 9 drifting ice beacons) i.e. at a scale representative of Ah4SR pixels. Ice conditions ranged h m consolidated first-year ice to a large polynya offshore from Casey Base. Data sets collected include: snow depth and snow-ice interface temperatures on 24 (?) randomly-selected floes in grid cells within a 10 x 50 km area (using helicopters); detailed snow and ice measurements at 13 dedicated ice stations, one of which lasted for 4 days; time-series measurements of snow temperature and thickness at selected sites; 8 aerial photography and thermal-IR radiometer flights; other satellite products (SAR, AVHRR, MODIS, MISR, ASTER and Envisat MERIS); ice drift data; and ancillary meteorological (ship-based, meteorological buoys, twice-daily radiosondes). These data are applied to a validation of standard AMSR-E ice concentration, snowcover thickness and ice-temperature products. In addition, a validation is carried out of ice-surface skin temperature products h m the NOAA AVHRR and EOS MODIS datasets.

Massom, Rob; Lytle, Vicky; Allison, Ian; Worby, Tony; Markus, Thorsten; Scambos, Ted; Haran, Terry; Enomoto, Hiro; Tateyama, Kazu; Pfaffling, Andi

2004-01-01

280

PERSPECTIVE How committed are we to monitoring human impacts in Antarctica?  

NASA Astrophysics Data System (ADS)

Under the Antarctic Treaty System, environmental monitoring is a legal obligation for signatory nations and an essential tool for managers attempting to minimize local human impacts, but is it given the importance it merits? Antarctica is a vast frozen continent with an area around 1.5 times that of Europe (14 000 000 km2), but the majority of its terrestrial life is found on multiple outcrops or 'islands' of ice-free coastal ground, with a combined area of ~6000 km2, equivalent to four times that of Greater London (Tin et al 2009). The biological communities of these ice-free terrestrial habitats are dominated by a small number of biological groups, primarily mosses, lichens, microinvertebrates and microorganisms. They include many endemic species, while birds and marine mammals use coastal areas as breeding sites (Chown and Convey 2007). Figure 1 Figure 1. Map of the Antarctic Treaty area (south of latitude 60°S) showing the locations of year-round and seasonal stations built on rock or permanent ice (i.e. ice sheets or ice shelves). Data on station locations were taken from the Council of Managers of National Antarctic Programs website (COMNAP 2010). There is evidence to suggest that although these stations are registered on the COMNAP list, a number of stations are not regularly occupied or in use (see United Kingdom et al 2006, p 9). Since the influx of national scientific research programmes and infrastructure that accompanied the International Geophysical Year (1957-1958), Antarctica's habitats have been encroached upon increasingly by human activities. Over 120 research stations have been built (~75 currently operational) with the great majority located on ice-free coastal ground to allow ease of access by ship. (Headland 2009, COMNAP 2010). Construction of cargo and personnel landing and handling facilities, station buildings, airport infrastructure, roads and fuel storage areas have, to varying degrees, destroyed native vegetation and terrestrial fauna and displaced bird and marine mammals from breeding sites in their immediate environment. An early history of poor environmental management and waste disposal practices around many stations has left a legacy of fuel-contaminated ground and abandoned waste sites in adjacent marine and terrestrial environments (Tin et al 2009). Construction of research stations and other infrastructure fulfils two national objectives: (1) supporting geopolitical aspirations of claimant nations and (2) demonstrating a significant commitment to undertaking science in Antarctica, which is a prerequisite for attaining consultative status at the Antarctic Treaty Consultative Meeting. However, these objectives may not be supported equally, with little or no science performed routinely at some stations (United Kingdom et al 2006). In addition, co-ordination of science activities between nations—another aspiration under the Antarctic Treaty—is often lacking, leading to duplication of research between national programmes, and even that undertaken at nearby stations. In some cases, components of national research programmes lack any international, open or objective assessment of quality. Nevertheless, new nations continue to become involved in Antarctic affairs, and almost inevitably seek to establish their own infrastructure, while some established Treaty Parties continue to further expand their existing logistic and infrastructure footprints. Despite calls for nations to share existing infrastructure or reuse abandoned stations (ATCM 2006), new stations continue to be constructed on pristine sites, with the Antarctic terrestrial environment in particular coming under increased pressure. The Protocol on Environmental Protection to the Antarctic Treaty (commonly known as the Environmental Protocol), which came into force in 1998, sets out common minimum standards for environmental management by all Antarctic Treaty Parties. Under the Protocol, it is mandatory to regularly monitor the environmental impacts caused by any new infrastructure that requires the completion of a Comprehensive E

Hughes, Kevin A.

2010-12-01

281

Norwegian-United States IPY Science Traverse in East Antarctica: Route Planning and Firn Temperature Investigation  

NASA Astrophysics Data System (ADS)

In austral summers of 2007-2008 and 2008-2009, Norway and the United States will conduct a collaborative traverse in Dronning Maud Land, East Antarctica. The objective of the traverse is to obtain field measurements (ice cores, snow pits, AWS's, firn temperatures, GPR profiling) that will aid us in advancing our understanding of climate variability of a vast yet under-explored sector of Antarctica and its roll in the global climate system. University of Colorado will assist the traverse route planning using remote sensing and conduct a study of multi-decadal scale climate change using firn temperature measurements. In the first season, the traverse will leave from Norwegian Troll Station (72° S, 2.5° E), and end at Amundsen-Scott Station at the South Pole, visiting Plateau (72.3° S, 40.5° E) and Pole of Inaccessibility (83.8° S, 65.8° E), sites of now abandoned stations. The first-season traverse will connect these four locations, the distance totaling to about 2500 km. Second-season traverse, from South Pole to Troll, will take a different route near the western edge of the Dronning Maud Land. The duration of both traverses is around 80 days including stops for ice coring and setting up AWS's etc. Details of routes and sites of scientific tasks are decided upon examinations of MOA (Mosaic of Antarctica) and RAMP (Radarsat Antarctic Mapping Project) images. Megadune fields and blue ice areas are identified in images that are of interest for studies of snow accumulation variations and interaction of local topography with the atmosphere. The firn temperature investigation aims at obtaining reliable surface temperature trend in multi-decadal to century scale in the interior of Antarctica. Our approach is to monitor temperature changes at several discrete depths in the firn over an extended period of time. This provides a time-series of the borehole temperature profile. Simulations by simple heat transfer model with artificial surface temperature history show that the trend of several tens of degrees (~0.5° C) per century is detectable with well-calibrated PRT's (Platinum Resistance Thermometers) placed at the depth of around 50 ~ 60 m and monitored over 1 ~ 2 years. Further, careful monitoring of intermediate depths (10 ~ 30 m) will help to discriminate between inter-annual to decadal scale variations and longer-term trends. We will set up at least four automated firn temperature recording systems with 10 to 12 PRT's distributed over the upper 50 to 60 m in the firn, together with standard AWS data at sites. Data will be transmitted multiple times per day by a satellite system (ARGOS).

Muto, A.; Scambos, T.

2006-12-01

282

Effects of salinity and temperature on Deschampsia antarctica  

Microsoft Academic Search

Deschampsia antarctica is one of two species of vascular plants native to Antarctica. Populations of D. antarctica have become established on recently exposed glacial forelands on the Antarctic Peninsula and these plants may rely upon nutrient\\u000a inputs from hauled out mammals, seabirds and sea spray. However, not much is known about the ability of these plants to tolerate\\u000a salinity stress.

Christopher T. Ruhland; Matthew A. Krna

2010-01-01

283

Sky Station  

NSDL National Science Digital Library

While satellites are the current backbone of telecommunications and wireless infrastructure, the company that maintains this Web site envisions a completely new technology. The Stratospheric Telecommunications Service (STS) relies on "lighter-than-air platforms which are held in a geo-stationary position in the stratosphere (approximately 21Km) over a major metropolitan area." The Sky Station company documents much of the STS theory online, as well as maintaining news and information articles about the progress of the system's development. US and international organizations have already reserved some of the radio frequency spectrum for stratospheric platforms, and it seems to have considerable support from important agencies.

284

Antarctica: Signs of the Great Thaw  

NSDL National Science Digital Library

Over the past few years, organizations like National Geographic and the National Academy of Sciences have been offering up interactive features on their websites. Many print newspapers have entered this arena as of late, including the New York Times and the Chicago Tribune. Recently, the Tribune offered up this tremendously interesting and visually engaging portrait of the effects of global warming on and around Antarctica. Visitors can start their travels through the continent by looking at the ways in which the thawing sea ice is taking its toll on the Adelie penguins, and then continue to learn about how scientists are attempting to reconstruct the history of various global climate changes. After that, they can take a 360 degree look around the South Pole and also listen to the voices of people who live and work on Antarctica. Free registration required.

285

Planetary geomorphology field studies: Iceland and Antarctica  

NASA Technical Reports Server (NTRS)

Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. These studies, conducted in Iceland and in Antarctica, investigated physical and chemical weathering mechanisms and rates, eolitan processes, mudflow phenomena, drainage development, and catastrophic fluvial and volcanic phenomena. Continuing investigations in Iceland fall in three main catagories: (1) catastrophic floods of the Jokulsa a Fjollum, (2) lahars associated with explosive volcanic eruptions of Askja caldera, and (3) rates of eolian abrasion in cold, volcanic deserts. The ice-free valleys of Antarctica, in particular those in South Victoria Land, have much is common with the surface of Mars. In addition to providing independent support for the application of the Iceland findings to consideration of the martian erosional system, the Antarctic observations also provide analogies to other martian phenomena. For example, a family of sand dunes in Victoria Valley are stabilized by the incorporation of snow as beds.

Malin, M. C.

1984-01-01

286

Life on ice, Antarctica and Mars  

NASA Technical Reports Server (NTRS)

The study of the origin of life and the prospects for human exploration of Mars are two themes developed in a new 57-minute film, Life on Ice, Antarctica, and Mars, produced by the InnerSpace Foundation and WHRO Television for broadcast by the Public Broadcasting System (PBS). A brief explanation of the film and how it relates to the future human exploration of space is presented.

Anderson, D. T.; Mckay, C. P.; Wharton, Robert A., Jr.; Sagan, C.; Squyres, S. W.; Simmons, G. M.

1991-01-01

287

The Landsat Image Mosaic of Antarctica  

NASA Astrophysics Data System (ADS)

The first-ever true-color, high-resolution digital mosaic of Antarctica has been produced from nearly 1100 Landsat-7 ETM+ images collected between 1999 and 2003. The Landsat Image Mosaic of Antarctica (LIMA) project was an early benchmark data set of the International Polar Year and represents a close and successful collaboration between NASA, USGS, the British Antarctic Survey and the National Science Foundation. The mosaic was successfully merged with lower resolution MODIS data south of Landsat coverage to produce a complete true-color data set of the entire continent. LIMA is being used as a platform for a variety of education and outreach activities. Central to this effort is the NASA website 'Faces of Antarctica' that offers the web visitor the opportunity to explore the data set and to learn how these data are used to support scientific research. Content is delivered through a set of mysteries designed to pique the user's interest and to motivate them to delve deeper into the website where there are various videos and scientific articles for downloading. Detailed lesson plans written by teachers are provided for classroom use and Java applets let the user track the motion of ice in sequential Landsat images. Web links take the user to other sites where they can roam over the imagery using standard pan and zoom functions, or search for any named feature in the Antarctic Geographic Names data base that returns to the user a centered true-color view of any named feature. LIMA also has appeared is a host of external presentations from museum exhibits, to postcards and large posters. It has attracted various value-added providers that increase LIMA's accessibility by allowing users to specify subsets of the very large data set for individual downloads. The ultimate goal of LIMA in the public and educational sector is to enable everyone to become more familiar with Antarctica.

Bindschadler, R.; Vornberger, P.; Fleming, A.; Fox, A.; Morin, P.

2008-12-01

288

Can increasing CO2 cool Antarctica?  

NASA Astrophysics Data System (ADS)

CO2 is the strongest anthropogenic forcing agent for climate change since pre-industrial times. Like other greenhouse gases, CO2 absorbs terrestrial surface radiation and causes emission from the atmosphere to space. As the surface is generally warmer than the atmosphere, the total long-wave emission to space is commonly less than the surface emission. However, this does not hold true for the high elevated areas of central Antarctica. Our investigations show, that for the high elevated areas of Antarctica the greenhouse effect (GHE) of CO2 is commonly around zero or even negative. This is based on the quantification of GHE as the difference between long-wave surface emission and top of atmosphere emission. We demonstrate this behaviour with the help of three models: a simple two-layer model, line-by-line calculations, and an ECMWF experiment. Additionally, in this region an increase in CO2 concentration leads to an instantaneous increased long-wave energy loss to space, which is a cooling effect on the earth-atmosphere system. However, short-wave warming by the weak absorption of solar radiation by CO2 are not taken into account here. The reason for this counter-intuitive behaviour is the fact that in the interior of Antarctica the surface is often colder than the stratosphere above. Radiation from the surface in the atmospheric window emitted to space is then relatively lower compared to radiation in the main CO2 band around 15 microns, which originates mostly from the stratosphere. Increasing CO2 concentration leads to increasing emission from the atmosphere to space, while blocking additional portions of surface emission. If the surface is colder than the stratosphere, this leads to additional long-wave energy loss to space for increasing CO2. Our findings for central Antarctica are in strong contrast to the generally known effect that increasing CO2 has on the long-wave emission to space, and hence on the Antarctic climate.

Schmithuesen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter

2014-05-01

289

Tohoku Tsunami Created Icebergs In Antarctica  

NSDL National Science Digital Library

This website, from NASA, offers an article, images, and a video about the connection between the 2011 tsunami off the coast of Japan and a large ice calving event in Antarctica. Scientists observed ice calving soon after the Japan event and attributed it to the swell caused by the tsunami; this finding marks the first direct observation of such a connection between tsunamis and icebergs.

Patrick Lynch

290

Springtime stratospheric NO2 in Antarctica  

Microsoft Academic Search

We present springtime measurements of column amounts of stratospheric nitrogen dioxide measured by ground based absorption spectroscopy from Scott Base, Antarctica (77.8°S, 166.7°E). There is a rapid build up from <1 × 1015 molecules cm?2 at the end of August to about 5 × 1015 molecules cm?2 by mid October. The period covered is the transition time between winter night,

R. L. McKenzie; P. V. Johnston

1984-01-01

291

Analysis of continuous GPS measurements from southern Victoria Land, Antarctica  

USGS Publications Warehouse

Several years of continuous data have been collected at remote bedrock Global Positioning System (GPS) sites in southern Victoria Land, Antarctica. Annual to sub-annual variations are observed in the position time-series. An atmospheric pressure loading (APL) effect is calculated from pressure field anomalies supplied by the European Centre for Medium-Range Weather Forecasts (ECMWF) model loading an elastic Earth model. The predicted APL signal has a moderate correlation with the vertical position time-series at McMurdo, Ross Island (International Global Navigation Satellite System Service (IGS) station MCM4), produced using a global solution. In contrast, a local solution in which MCM4 is the fiducial site generates a vertical time series for a remote site in Victoria Land (Cape Roberts, ROB4) which exhibits a low, inverse correlation with the predicted atmospheric pressure loading signal. If, in the future, known and well modeled geophysical loads can be separated from the time-series, then local hydrological loading, of interest for glaciological and climate applications, can potentially be extracted from the GPS time-series.

Willis, Michael J.

2007-01-01

292

Meteorological data for the astronomical site at Dome A, Antarctica  

E-print Network

We present an analysis of the meteorological data collected at Dome A, Antarctica by the Kunlun Automated Weather Station, including temperatures and wind speeds at eight elevations above the snow surface between 0m and 14.5m. The average temperatures at 2m and 14.5m are $-54^{\\circ}$C and $-46^{\\circ}$C, respectively. We find that a strong temperature inversion existed at all heights for more than 70% of the time, and the temperature inversion typically lasts longer than 25 hours, indicating an extremely stable atmosphere. The temperature gradient is larger at lower elevations than higher elevations. The average wind speed was 1.5m/s at 4m elevation. We find that the temperature inversion is stronger when the wind speed is lower and the temperature gradient decreases sharply at a specific wind speed for each elevation. The strong temperature inversion and low wind speed results in a shallow and stable boundary layer with weak atmospheric turbulence above it, suggesting that Dome A should be an excellent site...

Hu, Yi; Ashley, Michael C B; Bonner, Collin S; Hu, Keliang; Liu, Qiang; Li, Yuansheng; Ma, Bin; Wang, Lifan; Wen, Haikun

2014-01-01

293

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica.  

USGS Publications Warehouse

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, we report on the first year-round observations available for any site in Taylor Valley. This dataset augments the year-round data obtained at Lake Vanda (Wright Valley) by winter-over crews during the late 1960s and early 1970s. The mean annual solar flux at Lake Hoare was 92 W m-2 during 1986, the mean air temperature -17.3 degrees C, and the mean 3-m wind speed 3.3 m s-1. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year. Temperature increases of 20 degrees-30 degrees C are frequently observed during the winter due to strong fo??hn winds descending from the Polar Plateau. A model incorporating nonsteady molecular diffusion into Kolmogorov-scale eddies in the interfacial layer and similarity-theory flux-profiles in the surface sublayer, is used to determine the rate of ice sublimation from the acquired meteorological data. Despite the frequent occurrence of strong winter fo??hns, the bulk of the annual ablation occurs during the summer due to elevated temperatures and persistent moderate winds. The annual ablation from Lake Hoare is estimated to have been 35.0 +/- 6.3 cm for 1986.

Clow, G.D.; McKay, C.P.; Simmons, G.M., Jr.; Wharton, R.A., Jr.

1988-01-01

294

Present and Future Observations of the Earthshine from Antarctica  

NASA Astrophysics Data System (ADS)

It is likely that images of Earth-like planets will be obtained in the next years. The first images will actually come down to single dots, in which biomarkers can be searched. Taking the Earth as a example of planet providing life, Earthshine observations showed that the spectral signature of photosynthetic pigments and atmospheric biogenic molecules was detectable, suggesting that, in principle, life on other planets could be detected on a global scale, if it is widely spread and distinguishable from known abiotic spectral signatures. As for the Earth, we already showed that the Vegetation Red Edge which is related to chlorophyll absorption features was larger when continents, versus oceans, were facing the Moon. It proved that an elementary mapping of a planet was even possible. In the frame of the LUCAS (LUmière Cendrée en Antarctique par Spectroscopie) project, the Earthshine has been measured in the Concordia Research Station (Dome C, Antarctica) long enough to observe variations corresponding to different parts of the Earth facing the Moon. An extension of this project, called LUCAS II, would allow long-term observations to detect seasonal variations in the vegetation signal. These data, together with precise measurements of the Earth's albedo, will help to validate a model of global and spectral albedo of our planet.

Briot, Danielle; Arnold, Luc; Jacquemoud, Stéphane

2013-01-01

295

Site testing for submillimetre astronomy at Dome C, Antarctica  

E-print Network

Over the past few years a major effort has been put into the exploration of potential sites for the deployment of submillimetre astronomical facilities. Amongst the most important sites are Dome C and Dome A on the Antarctic Plateau, and the Chajnantor area in Chile. In this context, we report on measurements of the sky opacity at 200 um over a period of three years at the French-Italian station, Concordia, at Dome C, Antarctica. We also present some solutions to the challenges of operating in the harsh polar environ- ment. Dome C offers exceptional conditions in terms of absolute atmospheric transmission and stability for submillimetre astron- omy. Over the austral winter the PWV exhibits long periods during which it is stable and at a very low level (0.1 to 0.3 mm). Higher values (0.2 to 0.8 mm) of PWV are observed during the short summer period. Based on observations over three years, a transmission of around 50% at 350 um is achieved for 75% of the time. The 200-um window opens with a typical transmission...

Tremblin, P; Schneider, N; Durand, G Al; Ashley, M C B; Lawrence, J S; Luong-Van, D M; Storey, J W V; Durand, G An; Reinert, Y; Veyssiere, C; Walter, C; Ade, P; Calisse, P G; Challita, Z; Fossat, E; Sabbatini, L; Pellegrini, A; Ricaud, P; Urban, J

2011-01-01

296

A 40-cm infrared telescope in Antarctica  

NASA Astrophysics Data System (ADS)

In Antarctica the cold and dry air is expected to provide the best observing conditions on the Earth for astronomical observations from infra-red to sub-millimeter. To enjoy the advantages in Antarctica, we have a plan to make astronomical observations at Dome Fuji, which is located at inland Antarctica. However, the harsh environment is very problematic. For example, the temperature comes down to as low as-80 degree Celsius in winter, where instruments designed for temperate environment would not work. In this context, we have developed a 40 cm infra-red telescope, which is dedicated for the use even in winter at Dome Fuji. In designing the telescope, we took account of the difference of the thermal expansion rate among materials, which were used for the telescope. Movable parts like motors were lubricated with grease which would be effective at -80 degrees. Most parts of the telescope are made of aluminum to make the telescope as light as possible, so that it makes the transportation from seacoast to inland and assembling at Dome Fuji easier. We also report the experiment that we have done at Rikubetsu (the coldest city in Japan) in February 2008.

Murata, Chihiro; Ichikawa, Takashi; Lundock, Ramsey Guy; Taniguchi, Yuichiro; Okita, Hirohumi

2008-07-01

297

Monitoring of nitrogen dioxide, ozone and halogens radicals in Antarctica  

NASA Astrophysics Data System (ADS)

Monitoring of atmospheric compounds at high latitudes is a key factor for a better understanding of the processes driving the chemical cycles of ozone and related chemical species. In this frame, the GASCOD (Gas Analizer Spectrometer Correlating Optical Differences) equipment is installed at the Mario Zucchelli Station (MZS - 74.69S, 164.12E) since December 1995, carrying out observations of nitrogen dioxide (NO2) and ozone (O3). The recent advances in sensor technologies and processor capabilities, suggested the setup of a new equipment, based on the same optical layout of the 'old' GASCOD , with enhanced performances and improved capabilities for the measurements of solar radiation in the UV-visible spectral range (300-700nm). The efforts accomplished, allowed for the increase of the investigated tracers. Actually, mainly due to the enlargement of the covered spectral range and to the adoption of a CCD sensor, in addition to the NO2 and O3 compounds, others species can be monitored with the new instrumental setup such as bromine, chlorine and iodine oxides (BrO, OClO and IO). The innovative equipment called GASCODNG (GASCOD New Generation) was installed at MZS during the 2012/2013 Italian Antarctic expedition, in the framework of the research projects SAMOA (Automatic Station Monitoring Antarctic Ozonosphere) and MATAGRO (Monitoring Atmospheric Tracers in Antarctica with Ground Based Observations) funded by the Italian and Portuguese Antarctic programs respectively. In this paper a brief description of the new equipment is provided, highlighting the main improvements with regard to the 'old' one. Furthermore the full dataset (1996 - 2012) of NO2 total columns, obtained with the GASCOD installed at MZS, is compared with the data obtained with satellite borne equipments (GOME, SCIAMACHY, OMI and GOME2) and the main statistical parameters are analyzed and discussed in detail.

Bortoli, Daniele; Ravegnani, Fabrizio; Costa, Maria J.; Genco, Silvia; Kulkarni, Pavan K.; Mendes, Rui; Domingues, Ana Filipa; Anton, Manuel; Giovanelli, Giorgio; Silva, Ana Maria

2013-10-01

298

Anthropogenic and natural disturbances to marine benthic communities in Antarctica  

SciTech Connect

Sampling and field experiments were conducted from 1975 to 1990 to test how the structure of marine benthic communities around McMurdo Station, Antarctica varied with levels of anthropogenic contaminants in marine sediments. The structure of communities (e.g., infauna density, species composition, and life history characteristics) in contaminated and uncontaminated areas were compared with the structure of communities influenced by two large-scale natural disturbances, anchor ice formation and uplift or iceberg scour. Benthic communities changed radically along a steep spatial gradient of anthropogenic hydrocarbon, metal, and PCB contamination around McMurdo Station. The heavily contaminated end of the gradient, Winter Quarters Bay, was low in infaunal and epifaunal abundance and was dominated by a few opportunistic species of polychaete worms. The edge of the heavily contaminated bay, the transition area, contained several motile polychaete species with less opportunistic life histories. Uncontaminated sedimentary habitats harbored dense tube mats of infaunal animals numerically dominated by populations of polychaete worms, crustaceans, and a large suspension feeding bivalve. These species are generally large and relatively sessile, except for several crustacean species living among the tubes. Although the community patterns around anthropogenic and natural disturbances were similar, particularly motile and opportunistic species at heavily disturbed and marginal areas, the natural disturbances cover much greater areas of the sea floor about the entire Antarctic continent. On the other hand, recovery from chemical contamination is likely to take many more decades than recovery from natural disturbances as contaminant degradation is a slow process. 77 refs., 6 figs., 5 tabs.

Lenihan, H.; Oliver, J.S. [Moss Landing Marine Labs., CA (United States)

1995-05-01

299

A comparison between Pc5 geomagnetic field variations at different high latitude stations  

NASA Astrophysics Data System (ADS)

In this work we present a statistical analysis of geomagnetic field fluctuations in the Pc5 frequency band at Terra Nova Bay (Antarctica) and Cambridge Bay (Canada). The location of the two stations is particularly interesting in that they have exactly the same magnetic local time (MLT=UT-8hr) and almost opposite corrected geomagnetic latitude (-80.0^o and 77.4^o, respectively). The analysis is extended also to the stations Scott Base and Dumont D& acute; Urville (Antarctica), located at the same geomagnetic latitude as Terra Nova Bay but at different magnetic local time (MLT=UT-7hr and MLT=UT-13hr). In particular, the study is focused on the coherence between the signals observed at the different stations and on its local time and seasonal dependence.

Santarelli, L.; Lepidi, S.; Cafarella, L.; Palangio, P.

2003-04-01

300

Occurrence and turnover of DMSP and DMS in deep waters of the Ross Sea, Antarctica  

NASA Astrophysics Data System (ADS)

High concentrations of the phytoplankton metabolite dimethylsulfoniopropionate (DMSP) and its degradation product dimethylsulfide (DMS) are associated with blooms of Phaeocystis antarctica in the Ross Sea, Antarctica. Episodic and rapid vertical export of Phaeocystis biomass to deep water has been reported for the Ross Sea, therefore we examined the distribution and microbial consumption rates of DMSP and DMS throughout the sub-euphotic water column. Total DMSP (dissolved+particulate; DMSPt) was present at 0.5-22 nM at depths between 70 and 690 m during both the early bloom (November) and the late bloom (January). Sub-euphotic peaks of DMSP were sometimes associated with mid-water temperature maxima, and elevated DMSP below 70 m was found mainly in water masses characterized as Modified Circumpolar Deep Water or Antarctic Shelf Water. Overall, 50-94% of the integrated water-column DMSPt was found below the euphotic zone. At one station during the early bloom, local maxima of DMSPt (14 nM) and DMS (20 nM) were observed between 113 and 240 m and these maxima corresponded with high chlorophyll a concentrations, P. antarctica cell numbers, and Fv/Fm (the quantum yield of photosystem II). During the late bloom, a sub-euphotic maximum of DMSPt (15.8 nM) at 250 m cooccurred with peaks of chlorophyll a concentration, DMSP lyase activity, bacterial production and dissolved DMSP consumption rates. DMSP turnover contributed ˜12% of the bacterial carbon demand between 200 and 400 m. DMS concentrations peaked at 286 m but the maximum concentration (0.42 nM) was far lower than observed during the early bloom, probably because of relatively rapid biological consumption of DMS (1-3 turnovers per day) which, in turn, contributed to elevated dissolved dimethylsulfoxide (DMSO) concentrations. Relatively stable DMSPt distributions at some sites suggest that rapid sinking of Phaeocystis biomass is probably not the major mechanism responsible for mesopelagic DMSP accumulations. Rather, subduction of near-surface water masses, lateral advective transport or trapping of slowly sinking P. antarctica biomass in intermediate water masses are more likely mechanisms. We found that a culture of P. antarctica maintained cellular integrity during 34 days of darkness, therefore the presence of intact cells (and DMSP) at depth can be explained even under a slow sinking/advection scenario. Whatever the mechanism, the large pools of DMSP and DMS below the euphotic zone suggest that export exerts a control on potential DMS emission from the surface waters of the Ross Sea.

Rellinger, Alison N.; Kiene, Ronald P.; del Valle, Daniela A.; Kieber, David J.; Slezak, Doris; Harada, Hyakubun; Bisgrove, John; Brinkley, Jordan

2009-05-01

301

The French-Italian Concordia Station  

NASA Astrophysics Data System (ADS)

Concordia is a French-Italian permanent station located at Dome C, Antarctica. The station provides accommodation for up to 16 people over winter and more than 70 scientists and technicians during the austral summer. The scientific projects implemented at Concordia are strictly dependent on the characteristics of the site: a) the presence of a 3 300 m thick ice cap that allows access to the planet's climate archives and the reconstruction of glacial-interglacial cycles over more than 800 000 years; b) a particularly stable pure and dry atmosphere ideal for astronomy observations and for research on the chemical composition of the atmosphere; c) a distant location from coastal perturbations favourable to magnetic and seismological observatories to complement a poor world data network in the southern hemisphere; and d) a small totally isolated group of people confined to the station over a long winter, offering an opportunity for a range of medical and psychological studies useful to prepare long duration deep space missions. We will address the main characteristics of this station and its interest for science.

Mekarnia, Djamel; Frenot, Yves

2013-01-01

302

Lutzow-Holm Bay and the Shirase Glacier, Antarctica  

NASA Technical Reports Server (NTRS)

These views from the Multi-angle Imaging SpectroRadiometer (MISR) portray the Lutzow-Holm Bay region of Queen Maud Land, East Antarctica, on September 5,2002. Although Queen Maud Land remains one of the least studied regions of Antarctica, Lutzow-Holm Bay is an exception. Syowa (pronounced 'Showa') Station is the Japanese Antarctic Research Expedition base situated on Ongul Island, just off the eastern coast of the Bay (in the top right-hand portion of these views). Scientists there have studied changes in the ice sheet and sea level for several decades. Large outlet glaciers, such as the fast-flowing Shirase Glacier in the lower right-hand corner of these images, are the primary drainage systems for the Antarctic ice sheet.

These two views provide information on both the spectral and angular reflectance properties of the region and can be used to understand the geophysical environment. The top panel shows the region from MISR's downward-looking (nadir) camera and is a false-color view in which the near-infrared, green and blue spectral bands have been displayed as red, green and blue. Because of the tendency of water to absorb near-infrared wavelengths, some ice types exhibit an especially bright blue hue in this display.

The lower panel is a multi-angular composite from three MISR cameras in which changes in reflection at different view angles, as well as in the near-infrared spectral region, assist with the identification of rough and smooth ice surfaces. In this display, red band data from MISR's 60-degree forward and backward-viewing cameras are displayed as red and blue, respectively, and near-infrared data from the nadir camera are displayed as green. Using this technique, surfaces that predominantly exhibit backward scattering (generally rough surfaces) appear red/orange, and surfaces that predominantly exhibit forward scattering (generally smooth surfaces) appear in blue hues. Clouds (and other surfaces that exhibit both forward and backward scattering) appear purple.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuouslyand every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 16454. The panels cover an area of about 335 kilometers x 257 kilometers, and utilize data from blocks 145 to 147 within World Reference System-2 path 151.

2003-01-01

303

STRESS PROTEINS OF THE ANTARCTIC MIDGE, BELGICA ANTARCTICA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Antarctica presents one of the earth’s most inhospitable environments. Though an abundance of animals have adapted to life associated with the sea in this part of the world, few animals have adapted to the rigors of a terrestrial existence. One exception is the flightless midge Belgica antarctica ...

304

Functional ingredients produced by culture of Koliella antarctica  

Microsoft Academic Search

Unicellular algae represent an interesting source of bioactive food ingredients. In this study, fatty acids and carotenoids of Koliella antarctica, a psychrophylic Antarctic unicellular alga, were investigated. K. antarctica was cultivated at different temperatures and harvested at the early exponential growth phase and at the late exponential growth phase. After 240h, at the end of the late exponential growth phase,

Vincenzo Fogliano; Carlo Andreoli; Anna Martello; Marianna Caiazzo; Ornella Lobosco; Fabio Formisano; Pier Antimo Carlino; Giuseppe Meca; Giulia Graziani; Vittoria Di Martino Rigano; Vincenza Vona; Simona Carfagna; Carmelo Rigano

2010-01-01

305

Birth of a Large Iceberg in Pine Island Bay, Antarctica  

NSDL National Science Digital Library

This lithograph shows the break-off of a large iceberg from the Pine Island Glacier in West Antarctica. This event occurred between November 4th and 12th, 2001, and provides powerful evidence of rapid changes underway in this area of Antarctica. The images were acquired by the MISR instrument onboard NASA's Terra spacecraft.

2012-12-06

306

PUTATIVE STRESS REGULATED GENES OF THE ANTARCTIC MIDGE, BELGICA ANTARCTICA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Antarctica presents one of the earth’s most inhospitable environments. Though an abundance of animals have adapted to life associated with the sea in this part of the world, few animals have adapted to the rigors of a terrestrial existence. One exception is the flightless midge Belgica antarctica ...

307

Antarctica: King of Cold: Grades 2-3: Illustrated Book  

NSDL National Science Digital Library

This informational text explains that while both the Arctic and Antarctica are cold, Antarctica is much colder and drier - a polar desert. The text is written at a grade two through grade three reading level. This version is a full-color PDF that can be printed, cut and folded to form a book. Each book contains color photographs and illustrations.

Jessica Fries-Gaither

308

Basic training module for vitreoretinal surgery and the Casey Eye Institute Vitrectomy Indices Tool for Skills Assessment  

PubMed Central

Background The purpose of this study was to design and implement a vitreoretinal training module that would be useful for ophthalmology residents and fellows to learn the basic maneuvers required in vitreoretinal surgery. Methods A prospective pilot study evaluating the training module was undertaken in 13 ophthalmology trainees (residents and vitreoretinal fellows) with varying levels of vitreoretinal training experience. A vitreoretinal training module was designed and consisted of a three-port vitrectomy setup (sclerotomy wound construction, infusion placement), intraocular tasks (core vitrectomy, driving the operating microscope, membrane peel, air–fluid exchange), and wound closure. Standard vitrectomy instrumentation, the VitRet eye (Phillips Studio, Bristol, UK) and vitreous-like fluid using dairy creamer and balanced saline were utilized. A five-point Likert scale, ie, the Casey Eye Institute Vitrectomy Indices Tool for Skills Assessment (CEIVITS), was devised to evaluate each component of the module. Vitreoretinal surgical maneuvers were digitally recorded and graded by an attending vitreoretinal surgeon. Linear regression and correlation were performed to evaluate the relationship between prior vitreoretinal experience and CEIVITS performance. The main outcome measures were correlation of vitreoretinal surgical experience and CEIVITS performance on simulated tasks using a basic vitreoretinal training module. Results Thirteen participants from postgraduate year 2 to postgraduate year 6 levels were evaluated. Nine participants were male and four were female. The median age of participants was 32 (range 30–36) years and surgical experience was 0–410 prior vitreoretinal surgical procedures. A positive correlation (P < 0.05) was observed between vitreoretinal surgical experience and CEIVITS performance on the following tasks: total score (P = 0.021), sclerotomy wound construction (P = 0.047), infusion line placement (P = 0.012), air–fluid exchange (P = 0.004), and wound closure (P = 0.032). Post module surveys showed that the majority of trainees felt that the vitreoretinal training module improved their understanding of vitreoretinal surgery. The nonbiohazardous nature of the setup was advantageous from sanitation and cost perspectives. Conclusion The implementation of our training module for residency and vitreoretinal fellowship was feasible and the CEIVITS adequately assessed basic vitrectomy maneuvers. Given that ophthalmologic and subspecialty instruction migrates from an apprenticeship to a competency-based model, the face and content validity makes the CEIVITS module a promising one in vitreoretinal surgical instruction. PMID:21966195

Yeh, Steven; Chan-Kai, Brian T; Lauer, Andreas K

2011-01-01

309

GPS Measurement of Glacial Isostatic Adjustment in Antarctica: Current Results and Future Prospects  

NASA Astrophysics Data System (ADS)

Global Positioning System (GPS) measurements at bedrock sites in Antarctica hold the potential for partially testing chronological models for the mid-to-late Holocene (8-0 Ka) collapse of the West Antarctic Ice Sheet. A network of permanent GPS sites exists in Antarctica mainly at coastal sites, but sites in the interior of Antarctica, near present and paleo ice accumulation centers, are key to shedding light on the history of the Antarctic ice sheet. Considerable effort has been expended by several groups of investigators during the last decade to acquire these data. These efforts have resulted in several new data points with which to test current models of postglacial rebound. We have collected GPS data quasi-continuously between November 1996 and January 2001 at two autonomous GPS stations in the northern Transantarctic Mountains, only one of which produced a high-quality vertical rate time series. The vertical rate at Mt. Coates in the Dry Valleys indicates uplift of 4.5 ± 2.3 mm/yr, most likely due to glacial isostatic motion. Uplift at Mt. Coates deviates significantly from uplift predictions based on deglaciation models ICE-3G and ICE-4G, but is consistent with the D91-1.5 model of variable and continued ice sheet ablation to 2 kyr and a viscosity of 1021 Pa s in the upper mantle and 1022 Pa s in the lower mantle beneath the region. The lack of spatial coverage at reasonable wavelength results in a predicted uplift rate that is largely insensitive to lithospheric thickness. The range of upper mantle viscosities indicated by the deglaciation model that includes persistent drawdown to 2 kyr suggests a subcratonic upper mantle. However, the large error estimates on this uplift rate allow upper mantle viscosities ranging from about 2 x 1020 Pa s to nearly 1022 Pa s. High-quality uplift data from the interior of the continent are key to providing stronger constraints on both deglaciation history and Earth rheology. Longer and more continuous time series from a network of stations that sample the spatial gradients in uplift are needed to advance better models of glacial isostatic adjustment and complement GRACE estimates of present-day ice mass change in Antarctica.

Raymond, C. A.; Ivins, E. R.; James, T. S.

2004-12-01

310

Glacial/interglacial ice-stream stability in the Weddell1 Sea embayment, Antarctica2  

E-print Network

1 Glacial/interglacial ice-stream stability in the Weddell1 Sea embayment, Antarctica2 3 Andrew S-level rise from Antarctica; it helps explain observed anomalies34 in glacio-isostatic adjustment; above all they drain the bulk of ice from Antarctica. Most ice streams in Antarctica46 lead into floating ice

311

Space Station propulsion system  

NASA Technical Reports Server (NTRS)

Viewgraphs on space station propulsion systems are presented. Topics covered include: space station propulsion system requirements; space station propulsion system design; space station propulsion system drivers; hydrazine technology development; waste fluid disposal system; space station propulsion system evolution; propellant selection trade study; technology needs to water electrolysis/oxygen-hydrogen propulsion system; and technology needs for bipropellant systems.

Henderson, J.

1990-01-01

312

The global historical climatology network: Long-term monthly temperature, precipitation, sea level pressure, and station pressure data  

SciTech Connect

This NDP contains monthly temperature, precipitation, sea level pressure, and station pressure data for thousands of meteorological stations worldwide. The database was compiled from pre-existing national, regional, and global collections of data as a part of the Global Historical Climatology Network (CHCN) project. It contains data from roughly 6000 temperature stations, 7500 precipitation stations, 1800 sea level pressure stations, and 1800 station pressure stations. Each station has at least 10 years of data, and about 40% have more than 50 years of data. Spatial coverage is good over most of the globe, particularly for the United States and Europe. Data gaps are evident over the Amazon rainforest, the Sahara desert, Greenland, and Antarctica.

Vose, R.S.; Schmoyer, R.L. [Oak Ridge National Lab., TN (United States); Steurer, P.M.; Peterson, T.C. [National Climatic Data Center, Asheville, NC (United States)] [and others

1992-12-31

313

Exhumation of the Shackleton Range, Antarctica  

NASA Astrophysics Data System (ADS)

The Shackleton Range is situated between 80° - 81°S and 19° - 31°W, where it forms the continuation of the Transantarctic Mountains in the Weddell Sea sector of Antarctica. There, Precambrian igneous and metamorphic basement is overlain by (meta-) sedimentary rocks of an Early Paleozoic nappe stack and post-orogenic red beds. Nappe stacking resulted from the collision of East and West Gondwana due to the closure of the Mozambique Ocean in pan-African times. The uplift and exhumation history of the Shackleton Range has been analysed earlier based on a series of vertical fission track profiles (Schäfer, 1998; Lisker et al., 1999). Zircon ages range from ~160 to 210 Ma while apatite ages between ~95 and ~170 Ma comprise a break in slope of the altitude regression at ~110 Ma, and are accompanied by mean track lengths of 12.7 - 14.1 µm (standard deviation 1.0 - 1.4 µm). These data have been interpreted qualitatively in terms of two cooling/ exhumation stages during Jurassic and mid-Cretaceous times. However, the recognition of Jurassic volcaniclastic rocks associated with the ~180 Ma Ferrar event in the vicinity of the sample locations (Buggisch et al., 1994) challenges this exhumation concept. Moreover, new fission track proxy data (Dpar) and apatite (U-Th-Sm)/He ages between 88 and 171 Ma allow thermal history modelling of the combined thermochronological data. First tentative thermal history models suggest early Mesozoic cooling followed by (post-) Jurassic heating and final cooling since the Late Cretaceous. This scenario requires burial of the Shackleton Range region, and therefore the existence of a sedimentary basin at least during the Jurassic-Early Cretaceous, and subsequent basin inversion. The thickness of the now vanished sedimentary strata did unlikely exceed 2 - 3 km. Future work including additional apatite fission track analyses will help to quantifying geometry, depth and timing of this depocentre and evaluating potential links with the coeval basin (system) along the Transantarctic Mountains and/ or similar settings in Dronning Maud Land (e.g., the Heimefrontfjella). References: Buggisch, W., Kleinschmidt, G., Höhndorf, A. and Pohl, J., 1994, Stratigraphy and Facies of Sediments and Low-Grade Metasediments in the Shackleton Range, Antarctica. Polarforschung, 63: 9-32. Lisker, F., Schäfer, T. and Olesch, M., 1999, The Uplift/Denudation History of the Shackleton Range (Antarctica) Based on Fission-Track Analyses. Terra Antarctica, 6: 345-352. Schäfer, T., 1998, Thermo-tektonische Entwicklung von Oates Land und der Shackleton Range (Antarktis) basierend auf Spaltspur-Analysen. Berichte zur Polarforschung, 263: 107 p.

Lucka, Nicole; Lisker, Frank; Läufer, Andreas; Spiegel, Cornelia

2013-04-01

314

Antarctica: measuring glacier velocity from satellite images  

SciTech Connect

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

Lucchitta, B.K.; Ferguson, H.M.

1986-11-28

315

Antarctica: Measuring glacier velocity from satellite images  

USGS Publications Warehouse

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

Lucchitta, B.K.; Ferguson, H.M.

1986-01-01

316

Autonomous Observations in Antarctica with AMICA  

E-print Network

The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2-28 micron infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.

Di Rico, Gianluca; Dolci, Mauro; Straniero, Oscar; Valentini, Angelo; Valentini, Gaetano; Di Cianno, Amico; Giuliani, Croce; Magrin, Demetrio; Bonoli, Carlotta; Bortoletto, Favio; D'Alessandro, Maurizio; Corcione, Leonardo; Riva, Alberto

2010-01-01

317

Intelligent Virtual Station (IVS)  

NASA Technical Reports Server (NTRS)

The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

2002-01-01

318

Cenozoic motion between East and West Antarctica  

PubMed

The West Antarctic rift system is the result of late Mesozoic and Cenozoic extension between East and West Antarctica, and represents one of the largest active continental rift systems on Earth. But the timing and magnitude of the plate motions leading to the development of this rift system remain poorly known, because of a lack of magnetic anomaly and fracture zone constraints on seafloor spreading. Here we report on magnetic data, gravity data and swath bathymetry collected in several areas of the south Tasman Sea and northern Ross Sea. These results enable us to calculate mid-Cenozoic rotation parameters for East and West Antarctica. These rotations show that there was roughly 180 km of separation in the western Ross Sea embayment in Eocene and Oligocene time. This episode of extension provides a tectonic setting for several significant Cenozoic tectonic events in the Ross Sea embayment including the uplift of the Transantarctic Mountains and the deposition of large thicknesses of Oligocene sediments. Inclusion of this East-West Antarctic motion in the plate circuit linking the Australia, Antarctic and Pacific plates removes a puzzling gap between the Lord Howe rise and Campbell plateau found in previous early Tertiary reconstructions of the New Zealand region. Determination of this East-West Antarctic motion also resolves a long standing controversy regarding the contribution of deformation in this region to the global plate circuit linking the Pacific to the rest of the world. PMID:10724159

Cande; Stock; Muller; Ishihara

2000-03-01

319

Snowfall increases future ice discharge from Antarctica  

NASA Astrophysics Data System (ADS)

Future sea level rise is one of the major impacts of anthropogenic climate change. While enhanced snowfall over Antarctica as projected in regional as well as global climate models constitutes a comparably certain negative future contribution to global sea level, the largest uncertainty arises from the dynamic ice discharge from Antarctica. Here we show that these two processes are not independent, but that future ice discharge is enhanced up to three times due to additional snowfall under global warming. The effect exceeds that of surface warming as well as that of basal ice-shelf melting and is due to the difference in surface elevation change caused by snowfall on grounded and floating ice. As a result of their dynamic similarity, the ratio between basal-melt-induced- and snowfall-induced ice loss is relatively independent of the specific representation of the transition zone. In an ensemble of simulations, capturing ice-physics uncertainty, the additional dynamic ice loss along the coastline compensates between 30 and 65% of the ice gain due to enhanced snowfall over the entire continent. The reported effect thus strongly counters a potential negative contribution to global sea level by the Antarctic Ice Sheet.

Winkelmann, R.; Levermann, A.; Martin, M. A.; Frieler, K.

2012-12-01

320

Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica  

NASA Astrophysics Data System (ADS)

The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Interglacial periods differed in temporal evolution and duration. Atmospheric concentrations of carbon dioxide and methane correlate well with Antarctic air-temperature throughout the record. Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.

Petit, J. R.; Jouzel, J.; Raynaud, D.; Barkov, N. I.; Barnola, J.-M.; Basile, I.; Bender, M.; Chappellaz, J.; Davis, M.; Delaygue, G.; Delmotte, M.; Kotlyakov, V. M.; Legrand, M.; Lipenkov, V. Y.; Lorius, C.; Pépin, L.; Ritz, C.; Saltzman, E.; Stievenard, M.

1999-06-01

321

Measurements in polar stratospheric clouds over Antarctica in September 1989  

NASA Technical Reports Server (NTRS)

The results of six balloon flights at McMurdo Station, Antarctica, under varying temperature conditions, are used in a study of polar stratospheric clouds during Sept. 1989. A particle counter, with size resolution in the 0.5 micron radius region, indicates that cloud size distributions are always bimodal. Mode radii ranging from 0.05 to 0.10 microns were observed for the small particle mode, representing the sulfate layer or condensational growth enhancements of it. The data are not inconsistent with the expected increase in size with decreasing temperature of the small particle mode in the sulfate layer owing to deliquescence although this phenomenon is often masked by nitric acid trihydrate (NAT) condensation when temperatures are sufficiently low. Mode radii generally ranged from 1.5 to 3.5 micron for the large particle mode at concentrations 3 to 4 orders of magnitude lower than the small particle mode. The large particle mode, which normally comprises most of the mass, is presumably caused by NAT condensation on larger particles of the sulfate layer and indicates HNO3 mixing ratios of 1 to 5 ppbv for most of the cloud layers observed, suggesting substantial denitrification. On several occasions, distributions were observed with mode radii as high as 7 microns, and correspondingly large inferred mass, indicating water ice clouds in the 12 to 15 km region. On other occasions, absence of such clouds at very low temperatures indicated water vapor mixing ratios of less than 3 ppmv suggesting dehydration. Generally, the inferred HNO3 mixing ratios were higher in the lower stratosphere, suggesting redistribution through particle sedimentation.

Deshler, Terry

1991-01-01

322

High resolution 900 yr volcanic and climatic record from the Vostok area, East Antarctica  

NASA Astrophysics Data System (ADS)

Detailed volcanic record of the last 900 yr (1093-2010 AD) has been received using high resolution (2-3 samples per accumulation year) sulfate measurements in four snow/firn cores from the Vostok station area, East Antarctica. Totally, 33 volcanic events have been identified in the record, including well-known low latitude eruption signals found in many polar ice cores (e.g., Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Huanaputina 1600, Kuwae 1452), however in comparison with other Antarctic sites the record has more events covering the last 900 yr. The strongest volcanic signals occurred during mid-13th, mid-15th and 18th centuries. The largest volcanic signal of Vostok (both in sulfate concentration and flux) is the 1452 AD Kuwae eruption. Average snow accumulation rate calculated for the period 1093-2010 AD is 21.3 ± 2.3 mm H2O. Accumulation record demonstrates a slight positive trend, however sharply increased accumulation rate during the periods from 1600 to 1815 AD (by 11% from long-term mean) and from 1963 to 2010 AD (by 15%) are typical features of the site. Na+ record shows strong decadal-scale variability probably connected with coupled changes in atmospheric transport patterns over Antarctica (meridional circulation change) and local glaciology. The obtained high resolution climatic records suggest a high sensitivity of the Vostok location to environmental changes in Southern Hemisphere.

Osipov, E. Yu.; Khodzher, T. V.; Golobokova, L. P.; Onischuk, N. A.; Lipenkov, V. Ya.; Ekaykin, A. A.; Osipova, O. P.

2013-05-01

323

The role of atmospheric rivers in anomalous snow accumulation in East Antarctica  

NASA Astrophysics Data System (ADS)

Recent, heavy snow accumulation events over Dronning Maud Land (DML), East Antarctica, contributed significantly to the Antarctic ice sheet surface mass balance (SMB). Here we combine in situ accumulation measurements and radar-derived snowfall rates from Princess Elisabeth station (PE), located in the DML escarpment zone, along with the European Centre for Medium-range Weather Forecasts Interim reanalysis to investigate moisture transport patterns responsible for these events. In particular, two high-accumulation events in May 2009 and February 2011 showed an atmospheric river (AR) signature with enhanced integrated water vapor (IWV), concentrated in narrow long bands stretching from subtropical latitudes to the East Antarctic coast. Adapting IWV-based AR threshold criteria for Antarctica (by accounting for the much colder and drier environment), we find that it was four and five ARs reaching the coastal DML that contributed 74-80% of the outstanding SMB during 2009 and 2011 at PE. Therefore, accounting for ARs is crucial for understanding East Antarctic SMB.

Gorodetskaya, Irina V.; Tsukernik, Maria; Claes, Kim; Ralph, Martin F.; Neff, William D.; Van Lipzig, Nicole P. M.

2014-09-01

324

Antarctica’s Protected Areas Are Inadequate, Unrepresentative, and at Risk  

PubMed Central

Antarctica is widely regarded as one of the planet's last true wildernesses, insulated from threat by its remoteness and declaration as a natural reserve dedicated to peace and science. However, rapidly growing human activity is accelerating threats to biodiversity. We determined how well the existing protected-area system represents terrestrial biodiversity and assessed the risk to protected areas from biological invasions, the region's most significant conservation threat. We found that Antarctica is one of the planet's least protected regions, with only 1.5% of its ice-free area formally designated as specially protected areas. Five of the distinct ice-free ecoregions have no specially designated areas for the protection of biodiversity. Every one of the 55 designated areas that protect Antarctica's biodiversity lies closer to sites of high human activity than expected by chance, and seven lie in high-risk areas for biological invasions. By any measure, including Aichi Target 11 under the Convention on Biological Diversity, Antarctic biodiversity is poorly protected by reserves, and those reserves are threatened. PMID:24936869

Shaw, Justine D.; Terauds, Aleks; Riddle, Martin J.; Possingham, Hugh P.; Chown, Steven L.

2014-01-01

325

A re-consideration of the taxonomic status of Nebria lacustris Casey (Coleoptera, Carabidae, Nebriini) based on multiple datasets - a single species or a species complex?  

PubMed

This study gathered evidence from principal component analysis (PCA) of morphometric data and molecular analyses of nucleotide sequence data for four nuclear genes (28S, TpI, CAD1, and Wg) and two mitochondrial genes (COI and 16S), using parsimony, maximum likelihood, and Bayesian methods. This evidence was combined with morphological and chorological data to re-evaluate the taxonomic status of Nebria lacustris Casey sensu lato. PCA demonstrated that both body size and one conspicuous aspect of pronotal shape vary simultaneously with elevation, latitude, and longitude and served to distinguish populations from the southern Appalachian highlands, south of the French Broad, from all other populations. Molecular analyses revealed surprisingly low overall genetic diversity within Nebria lacustris sensu lato, with only 0.39% of 4605 bp varied in the concatenated dataset. Evaluation of patterns observed in morphological and genetic variation and distribution led to the following taxonomic conclusions: (1) Nebria lacustris Casey and Nebria bellorum Kavanaugh should be considered distinct species, which is a NEW STATUS for Nebria bellorum. (2) No other distinct taxonomic subunits could be distinguished with the evidence at hand, but samples from northeastern Iowa, in part of the region known as the "Driftless Zone", have unique genetic markers for two genes that hint at descent from a local population surviving at least the last glacial advance. (3) No morphometric or molecular evidence supports taxonomic distinction between lowland populations on the shores of Lake Champlain and upland populations in the adjacent Green Mountains of Vermont, despite evident size and pronotal shape differences between many of their members. PMID:22379387

Kavanaugh, David H; Archambeault, Sophie L; Roopnarine, Peter D; Ledford, Joel

2011-01-01

326

A re-consideration of the taxonomic status of Nebria lacustris Casey (Coleoptera, Carabidae, Nebriini) based on multiple datasets – a single species or a species complex?  

PubMed Central

Abstract This study gathered evidence from principal component analysis (PCA) of morphometric data and molecular analyses of nucleotide sequence data for four nuclear genes (28S, TpI, CAD1, and Wg) and two mitochondrial genes (COI and 16S), using parsimony, maximum likelihood, and Bayesian methods. This evidence was combined with morphological and chorological data to re-evaluate the taxonomic status of Nebria lacustris Casey sensu lato. PCA demonstrated that both body size and one conspicuous aspect of pronotal shape vary simultaneously with elevation, latitude, and longitude and served to distinguish populations from the southern Appalachian highlands, south of the French Broad, from all other populations. Molecular analyses revealed surprisingly low overall genetic diversity within Nebria lacustris sensu lato, with only 0.39% of 4605 bp varied in the concatenated dataset. Evaluation of patterns observed in morphological and genetic variation and distribution led to the following taxonomic conclusions: (1) Nebria lacustris Casey and Nebria bellorum Kavanaugh should be considered distinct species, which is a NEW STATUS for Nebria bellorum. (2) No other distinct taxonomic subunits could be distinguished with the evidence at hand, but samples from northeastern Iowa, in part of the region known as the “Driftless Zone”, have unique genetic markers for two genes that hint at descent from a local population surviving at least the last glacial advance. (3) No morphometric or molecular evidence supports taxonomic distinction between lowland populations on the shores of Lake Champlain and upland populations in the adjacent Green Mountains of Vermont, despite evident size and pronotal shape differences between many of their members. PMID:22379387

Kavanaugh, David H.; Archambeault, Sophie L.; Roopnarine, Peter D.; Ledford, Joel

2011-01-01

327

M Station, Austin  

E-print Network

$100 $150 $200 $250 $300 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) 90 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) 9081 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M... Station 9081 108 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M Station 9081 10849 $0.00/sf Planning ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M Station 9081 10849 $0.00/sf...

Mathon, S.

2011-01-01

328

Space Station Spartan study  

NASA Technical Reports Server (NTRS)

The required extension, enhancement, and upgrading of the present Spartan concept are described to conduct operations from the space station using the station's unique facilities and operational features. The space station Spartan (3S), the free flyer will be deployed from and returned to the space station and will conduct scientific missions of much longer duration than possible with the current Spartan. The potential benefits of a space station Spartan are enumerated. The objectives of the study are: (1) to develop a credible concept for a space station Spartan; and (2) to determine the associated requirements and interfaces with the space station to help ensure that the 3S can be properly accommodated.

Lane, J. H.; Schulman, J. R.; Neupert, W. M.

1985-01-01

329

Concentration of trace inorganic species in surface snow near Dome Fuji, Antarctica  

NASA Astrophysics Data System (ADS)

In the southern hemisphere, especially Antarctica, it is considered that ocean and stratosphere are major source of halogen species. However, there is little data about halogen species contained in snow and ice in Antarctica. In this research, trace inorganic species (Br, Cl, F, I) in the snow samples collected in the Antarctica were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°1'S, 40°3'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The samples were transported to Japan without thawing. The quantitative analyses of elements were performed using the ion chromatograph mass spectrometer (IC-MS) and quadrupole type inductively-coupled plasma mass spectrometer (ICP-MS). The IC-MS system consists of a single quadrupole type mass spectrometer (Agilent Technologies 6150) connected to an ionchromatograph (Dionex ICS-2000). IonPac AS11-HC was used as the separation column of the ionchromatograph. 14 anion species (Br-, BrO3-, CH3COO-, CH3SO3-, Cl-, C2O42-, F-, HCOO-, I-, IO3-, NO2-, NO3-, PO43-, SO42-) were analyzed by this system. Average concentration of Cl- was 50 ng/ml. High concentration of Cl- was observed at the coast region compared with the inland region. The concentration was 150 ng/ml at the coast region. On the other hand, the maximum concentration of Br- and I- was observed around 71°S and near 74°S on the traverse route. Average concentration of Br- was 0.2 ng/ml. The maximum concentration of Br- was ca. 0.6 ng/ml. Average concentration of I- was 0.03 ng/ml. The maximum concentration of I- was ca. 0.1 ng/ml. While it is thought that the source of Cl- is mainly ocean, concentration distribution of Br- and I- differs from Cl-. suggesting the contribution of sources other than ocean. Further results and discussion about the behavior and origin of halogen ion species in snow will be presented.

Hirabayashi, M.; Motoyama, H.

2012-12-01

330

Macrofossil Evidence For Pleuromeialean Lycophytes From the Triassic of Antarctica  

E-print Network

Triassic microfloras from Antarctica contain abundant lycophyte spores. However, macrofossils of this group of plants are missing, and thus the precise affinities of the spore producers remain unknown. Macrofossil remains of a pleuro? meialean...

Bomfleur, Benjamin; Krings, Michael; Taylor, Edith L.; Taylor, Thomas N.

2010-01-01

331

Within-day variability of particulate organic carbon and remote-sensing reflectance during a bloom of Phaeocystis antarctica in  

E-print Network

of Phaeocystis antarctica in the Ross Sea, Antarctica Pierre Gernez*, Rick A. Reynolds, and Dariusz Stramski in the Ross Sea, Antarctica, during development of the annual spring phytoplankton bloom. Measurements

Stramski, Dariusz

332

Lidar observations of polar stratospheric clouds at McMurdo, Antarctica, during NOZE-2  

NASA Technical Reports Server (NTRS)

SRI International operated a dual wavelength (1.064 micrometer and .532 micrometer) aerosol lidar at McMurdo Station, Antarctica, as part of the National Ozone Expedition-2 (NOZE-2). The objective of the project was to map the vertical distributions of polar stratospheric clouds (PSCs), which are believed to play an important role in the destruction of ozone in the Antarctic spring. Altitude, thickness, homogeneity, and duration of PSC events as well as information on particle shape, size or number density will be very useful in determining the exact role of PSCs in ozone destructions, and when combined with measurements of other investigators, additional properties of PSCs can be estimated. The results are currently being analyzed in terms of PSC properties which are useful for modeling the stratospheric ozone depletion mechanism.

Morley, Bruce M.

1988-01-01

333

Why Is There One Long Day and One Long Night in Antarctica?  

NSDL National Science Digital Library

This weeklong unit provides an in-depth look at daily and seasonal light changes in Antarctica. Throughout the unit, students collect their findings in a portfolio. Tools for teachers include downloadable readings, daily breakdowns of tasks, strategies for using the activities, a grading sheet, a project rubric sheet, and additional readings. In addition there is an online activity in which students plug in data in order to see daily and seasonal light patterns on a globe or world map, and a hands-on experiment in which students replicate how the Earth simultaneously revolves on its axis and around a light source. In an interview, a safety and health engineer describes what it takes to keep an Antarctic research station running year-round. A student handout with guidance for putting together student portfolios and examples of creative final projects is also provided.

334

Time-series analysis of chemical trends in a dated ice core from Antarctica  

SciTech Connect

Polar ice sheets contain valuable information about past atmospheric conditions. Atmospherically produced or transported substances from natural and anthropogenic sources are preserved stratigraphically within the ice layers as a result of both wet and dry deposition mechanisms. Substances deposited include aerosols and gaseous compounds. The analysis of trace elements contained in dated annual snow layers provides a measure of the elemental chemistry content of the atmosphere during the same time interval. The aerosol content of the atmosphere and ice sheets is one of the most important parameters for cloud/radiation interaction processes. Ice cores were obtained from the Byrd Station, West Antarctica, in November, 1989. This study presents results obtained from instrumental neutron activation analysis and ion chromatography on 30 samples over a 20 year period.

Keskin, S.S.; Olmez, I. [Massachusetts Institute of Technology, Cambridge, MA (United States); Langway, C.C. Jr. [State Univ. of New York, Buffalo, NY (United States)

1994-12-31

335

Measurements of positive ions and air-earth current density at Maitri, Antarctica  

E-print Network

Simultaneous measurements of the small-, intermediate- and large- positive ions and air earth current density made at a coastal station, Maitri at Antarctica during January to February 2005, are reported. Although, small and large positive ion concentrations do not show any systematic diurnal variations, variations in them are almost similar to each other. On the other hand, variations in intermediate positive ion concentrations are independent of variations in the small/large positive ions and exhibit a diurnal variation which is similar to that in atmospheric temperature on fair weather days with a maximum during the day and minimum during the night hours. No such diurnal variation in intermediate positive ion concentration is observed on cloudy days when variations in them are also similar to those insmall/large positive ion concentrations. Magnitude of diurnal variation in intermediate positive ion concentration on fair weather days increases with the lowering of atmospheric temperature in this season. Sc...

Siingh, Devendraa; Kamra, A K; 10.1029/2006JD008101

2009-01-01

336

Complete mitochondrial genome of the South Polar Skua Stercorarius maccormicki (Charadriiformes, Stercorariidae) in Antarctica.  

PubMed

Abstract The South Polar Skua, gull-like seabirds is the most fascinating Antarctic seabirds that lay two eggs at sites free of snow and ice and predominantly hunt pelagic fish and penguins. Blood samples of the South Polar Skua Stercorarius maccormicki was collected during the summer activity near King Sejong station in Antarctica. The complete mitochondrial DNA sequence of S. maccormicki was 16,669?bp, showing conserved genome structure and orientation found in other avian species. The control region of S. maccormicki was 93- and 80?bp shorter compared to those of Chroicocephalus saundersi and Synthliboramphus antiquus respectively. Interestingly, there is a (CAACAAACAA)6 repeat sequence in the control region. Our results of S. maccormicki mt genome including the repeat sequence, may provide useful genetic information for phylogenetic and phylogeographic histories of the southern skua complex. PMID:25268998

Han, Yeong-Deok; Baek, Ye-Seul; Kim, Jeong-Hoon; Choi, Han-Gu; Kim, Sanghee

2014-09-30

337

Occurrence and diversity of marine yeasts in Antarctica environments  

NASA Astrophysics Data System (ADS)

A total of 28 yeast strains were obtained from the sea sediment of Antarctica. According to the results of routine identification and molecular characterization, the strains belonged to species of Yarrowia lipolytica, Debaryomyces hansenii, Rhodotorula slooffiae, Rhodotorula mucilaginosa, Sporidiobolus salmonicolor, Aureobasidium pullulans, Mrakia frigida and Guehomyces pullulans, respectively. The Antarctica yeasts have wide potential applications in biotechnology, for some of them can produce ?-galactosidase and killer toxins.

Zhang, Xue; Hua, Mingxia; Song, Chunli; Chi, Zhenming

2012-03-01

338

Development of long-duration ballooning in Antarctica  

SciTech Connect

Following four successful long-duration test flights from Australia to South America, a new flight support system with global tracking, command, and telemetry capability is being developed to support long-duration balloon flights of relatively sophisticated instruments at both mid-latitudes and in Antarctica. The first test flight for the joint NASA-NSF program to support flights in Antarctica is scheduled from McMurdo in December 1989, with operational capability two years later.

Jones, W.V. (National Aeronautics and Space Administration, Code ES, Space Physics Division, Washington, DC 20546 (USA))

1990-03-20

339

Antarctica: King of Cold: Grades K-1: Electronic Book  

NSDL National Science Digital Library

This informational text explains that while both the Arctic and Antarctica are cold, Antarctica is much colder and drier - a polar desert. The text is written at a kindergarten through grade one reading level. This is an onscreen version that contains recorded narration allowing students to listen to the text as they read along. Highlighted vocabulary words have individually recorded definitions heard by clicking on the links.

Jessica Fries-Gather

340

Oxygen isotope studies and compilation of isotopic dates from Antarctica  

SciTech Connect

The Quaternary Isotope Laboratory, alone or in collaboration with other investigators, is currently involved in a number of oxygen-isotope studies mainly in Antarctica. Studies of a drill core from the South Pole, seasonal oxygen-18 signals preserved in the Dominion Range, isotope dating of the Ross Ice Shelf, oxygen-18 profiles of the Siple Coast, McMurdo Ice Shelf sampling, and a data compilation of radiometric dates from Antarctica are discussed.

Grootes, P.M.; Stuiver, M.

1986-01-01

341

Ice-Shelf Melting Around Antarctica  

NASA Astrophysics Data System (ADS)

We compare the volume flux divergence of Antarctic ice shelves in 2007 and 2008 with 1979 to 2010 surface accumulation and 2003 to 2008 thinning to determine their rates of melting and mass balance. Basal melt of 1325 ± 235 gigatons per year (Gt/year) exceeds a calving flux of 1089 ± 139 Gt/year, making ice-shelf melting the largest ablation process in Antarctica. The giant cold-cavity Ross, Filchner, and Ronne ice shelves covering two-thirds of the total ice-shelf area account for only 15% of net melting. Half of the meltwater comes from 10 small, warm-cavity Southeast Pacific ice shelves occupying 8% of the area. A similar high melt/area ratio is found for six East Antarctic ice shelves, implying undocumented strong ocean thermal forcing on their deep grounding lines.

Rignot, E.; Jacobs, S.; Mouginot, J.; Scheuchl, B.

2013-07-01

342

Proposal to protect marine areas around Antarctica  

NASA Astrophysics Data System (ADS)

Forty percent of Antarctica's Southern Ocean should be protected in a network of marine protected areas (MPAs) and no-take marine reserves, according to a 21 May report by the Antarctic Ocean Alliance, which is composed of about 20 environmental groups. The protected areas should include the 19 Antarctic marine habitats outlined in the report, along with existing MPAs and areas identified through previous conservation and planning analyses, the report notes. Protected areas should include the Antarctic Peninsula, the Weddell and Ross seas, the Indian Ocean Benthic Environment, and Pacific seamounts, according to the report. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which manages living resources for the Southern Ocean, has already agreed to establish an initial network of Antarctic MPAs this year, the report states.

Showstack, Randy

2012-05-01

343

Which Map's the Best Map for Antarctica?  

NSDL National Science Digital Library

With Antarctica as the focus, this week-long unit provides an in-depth look at the advantages and disadvantages of different map types. Throughout the unit, students collect their findings in a portfolio. The comprehensive curriculum materials contain teacher tools, which include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, and additional readings. There is an online activity in which students first review how latitude and longitude are used in map creation and then are introduced to the different types of map projections. There are two hands-on activities in which students examine how globes, Mercator maps, and polar map projections are used, and create their own map projections using soda bottles.

344

Height changes over subglacial Lake Vostok, East Antarctica: Insights from GNSS observations  

NASA Astrophysics Data System (ADS)

Height changes of the ice surface above subglacial Lake Vostok, East Antarctica, reflect the integral effect of different processes within the subglacial environment and the ice sheet. Repeated GNSS (Global Navigation Satellite Systems) observations on 56 surface markers in the Lake Vostok region spanning 11 years and continuous GNSS observations at Vostok station over 5 years are used to determine the vertical firn particle movement. Vertical marker velocities are derived with an accuracy of 1 cm/yr or better. Repeated measurements of surface height profiles around Vostok station using kinematic GNSS observations on a snowmobile allow the quantification of surface height changes at 308 crossover points. The height change rate was determined at 1 ± 5 mm/yr, thus indicating a stable ice surface height over the last decade. It is concluded that both the local mass balance of the ice and the lake level of the entire lake have been stable throughout the observation period. The continuous GNSS observations demonstrate that the particle heights vary linearly with time. Nonlinear height changes do not exceed ±1 cm at Vostok station and constrain the magnitude of spatiotemporal lake-level variations. ICESat laser altimetry data confirm that the amplitude of the surface deformations over the lake is restricted to a few centimeters. Assuming the ice sheet to be in steady state over the entire lake, estimates for the surface accumulation, on basal accretion/melt rates and on flux divergence, are derived.

Richter, Andreas; Popov, Sergey V.; Fritsche, Mathias; Lukin, Valery V.; Matveev, Alexey Yu.; Ekaykin, Alexey A.; Lipenkov, Vladimir Ya.; Fedorov, Denis V.; Eberlein, Lutz; Schröder, Ludwig; Ewert, Heiko; Horwath, Martin; Dietrich, Reinhard

2014-11-01

345

Snow pit studies from the 2008-9 Norway-US Scientific Traverse of East Antarctica  

NASA Astrophysics Data System (ADS)

The Norway-US Scientific Traverse of East Antarctica is an International Polar Year (IPY) collaborative effort to examine the mass balance of the East Antarctic plateau, focusing on the region of Dronning Maud Land. The traverse field campaign spanned two field seasons, with an inland-bound leg and outland-bound leg during the austral summers of 2007-8 and 2008-9, respectively. An international team of researchers conducted extensive field work en route, including shallow firn cores, shallow, deep and intermediate radar profiles, gravity measurements, firn temperature profiles, borehole stratigraphy, and snow pit studies. This report focuses on the results of snow pit studies of the second year's outland-bound leg from South Pole Station (US) to Troll Station (NOR), which consisted of density, stratigraphy, and snow grain geometry profiles. This traverse route crossed over a variety of features of the East Antarctic ice sheet, including a system of subglacial lakes, points crossed by the International Glaciological Year (IGY) Queen Maud Land traverses of 1964-1968, and a variety of depositional features. The area is predominantly a low-accumulation region where little previous field work had been conducted, the IGY Queen Maude Land traverses being the last scientific traverse to cross this region previous. We compare the physical property profiles collected to the snow pit studies of Koerner (1971) at Plateau Station and to satellite radar data of the larger region.

Courville, Z.; Albert, M. R.

2012-12-01

346

Mass Casualty Incident Response and Aeromedical Evacuation in Antarctica  

PubMed Central

Antarctica is one of the most remote regions on Earth. Mass casualty incident (MCI) responses in Antarctica are prone to complications from multiple environmental and operational challenges. This review of the current status of MCI risks and response strategies for Antarctica focuses on aeromedical evacuation, a critical component of many possible MCI scenarios. Extreme cold and weather, a lack of medical resources and a multitude of disparate international bases all exert unique demands on MCI response planning. Increasing cruise ship traffic is also escalating the risk of MCI occurrence. To be successful, MCI response must be well coordinated and undertaken by trained rescuers, especially in the setting of Antarctica. Helicopter rescue or aeromedical evacuation of victims to off-continent facilities may be necessary. Currently, military forces have the greatest capacity for mass air evacuation. Specific risks that are likely to occur include structure collapses, vehicle incapacitations, vehicle crashes and fires. All of these events pose concomitant risks of hypothermia among both victims and rescuers. Antarctica’s unique environment requires flexible yet robust MCI response planning among the many entities in operation on the continent. PMID:21691470

Mills, Christopher N.; Mills, Gregory H.

2011-01-01

347

Applicability of NASA Polar Technologies to British Antarctic Survey Halley VI Research Station  

NASA Technical Reports Server (NTRS)

From 1993 through 1997 NASA and the National Science Foundation (NSF), developed a variety of environmental infrastructure technologies for use at the Amundsen-Scott South Pole Station. The objective of this program was to reduce the cost of operating the South Pole Station, reduce the environmental impact of the Station, and to increase the quality of life for Station inhabitants. The result of this program was the development of a set of sustainability technologies designed specifically for Polar applications. In the intervening eight years many of the technologies developed through this program have been commercialized and tested in extreme environments and are now available for use throughout Antarctica and circumpolar north. The objective of this document is to provide information covering technologies that might also be applicable to the British Antarctic Survey s (BAS) proposed new Halley VI Research Station. All technologies described are commercially available.

Flynn, Michael

2005-01-01

348

GPS water vapour estimation using meteorological data from Chinese Antarctic research stations  

Microsoft Academic Search

This paper mainly discusses the research deducing atmospheric Precipitable Water Vapor (PWV) from tropospheric zenith wet delay using ground-based GPS receivers. China GreatWall and ZhongShan stations in Antarctica were taken as the researching sites. The data from SCAR Antarctic GPS Campaigns Epoch 1998\\/1999\\/2000 are used to construct the GPS analytical networks. A high-accuracy GPS processing software package-GAMIT\\/GLOBK is utilized; Multiple

Xiao Cheng; Yanmei Zhang; E. Dongchen; Yun Shao

2003-01-01

349

Cloud and precipitation properties from ground-based remote sensing instruments in East Antarctica  

NASA Astrophysics Data System (ADS)

A new comprehensive cloud-precipitation-meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land, East Antarctica. The observatory consists of a set of ground-based remote sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar) combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow accumulation. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, mixed-phase and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly occurring in summer/autumn) indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall > 1 mm h-1 water equivalent (w.e.). Three of such intensive snowfall events occurred during 2011 contributing to anomalously large annual snow accumulation. This is the first deployment of a precipitation radar in Antarctica allowing to assess the contribution of the snowfall to the local surface mass balance. It is shown that on the one hand large accumulation events (>10 mm w.e. day-1) during the measurement period of 26 months were always associated with snowfall, but that on the other hand snowfall did not always lead to accumulation. In general, this promising set of robust instrumentation allows for improved insight in cloud and precipitation processes in Antarctica and can be easily deployed at other Antarctic stations.

Gorodetskaya, I. V.; Kneifel, S.; Schween, J. H.; Crewell, S.; Van Lipzig, N. P. M.

2014-07-01

350

The cryptoendolithic microbial environment in the Ross Desert of Antarctica: satellite-transmitted continuous nanoclimate data, 1984 to 1986  

NASA Technical Reports Server (NTRS)

A satellite mediated station for monitoring nanoclimate (climate in the millimeter range) data, suitable for use in polar regions is described. The station, located in the Ross desert of Antarctica, has been in operation for more than 3 years, measuring rock temperatures, air temperature, light, snow, wind, and moisture. The data indicate that biological activity in the cryptoendolithic microbial ecosystem is limited to the period from mid November to mid February. The total number of hours of biological activity, based on assumptions of the minimum light, temperature and moisture requirements of the community, is less than 1000 h/year. The time above 0 degrees C, representing more nearly optimal conditions, is between 50 and 550 h/year, depending on the orientation of the surface.

Friedmann, E. I.; McKay, C. P.; Nienow, J. A.

1987-01-01

351

An Antarctic research station as a source of brominated and perfluorinated persistent organic pollutants to the local environment.  

PubMed

This study investigated the role of a permanently manned Australian Antarctic research station (Casey Station) as a source of contemporary persistent organic pollutants (POPs) to the local environment. Polybrominated diphenyl ethers (PBDEs) and poly- and perfluoroalkylated substances (PFASs) were found in indoor dust and treated wastewater effluent of the station. PBDE (e.g., BDE-209 26-820 ng g(-1) dry weight (dw)) and PFAS levels (e.g., PFOS 3.8-2400 ng g(-1) (dw)) in dust were consistent with those previously reported in homes and offices from Australia, reflecting consumer products and materials of the host nation. The levels of PBDEs and PFASs in wastewater (e.g., BDE-209 71-400 ng L(-1)) were in the upper range of concentrations reported for secondary treatment plants in other parts of the world. The chemical profiles of some PFAS samples were, however, different from domestic profiles. Dispersal of chemicals into the immediate marine and terrestrial environments was investigated by analysis of abiotic and biotic matrices. Analytes showed decreasing concentrations with increasing distance from the station. This study provides the first evidence of PFAS input to Polar regions via local research stations and demonstrates the introduction of POPs recently listed under the Stockholm Convention into the Antarctic environment through local human activities. PMID:25478728

Wild, Seanan; McLagan, David; Schlabach, Martin; Bossi, Rossana; Hawker, Darryl; Cropp, Roger; King, Catherine K; Stark, Jonathan S; Mondon, Julie; Nash, Susan Bengtson

2015-01-01

352

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica  

E-print Network

The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation changes over the Amundsen Sea, ...

Criscitiello, Alison S.

353

BIG IDEAS FOR JOB CREATIOn A PROJECT OF ThE UnIvERSITy OF CALIFORnIA, BERKELEy AnD ThE AnnIE E. CASEy FOUnDATIOn  

E-print Network

BIG IDEAS FOR JOB CREATIOn A PROJECT OF ThE UnIvERSITy OF CALIFORnIA, BERKELEy AnD ThE AnnIE E. CASEy FOUnDATIOn I n the aftermath of jobs speeches and counter proposals over the nation's stagnant unemployment rate, one thing is clear: The need for job creation will remain in the headlines as long as 25

California at Berkeley, University of

354

Climatology of the East Antarctic ice sheet (100[degrees]E to 140[degrees]E) derived from automatic weather stations  

SciTech Connect

The authors present a climate picture of a large share of eastern Antarctica, arrived at from records obtained from automatic weather stations. These stations have permitted sampling of such data over extended periods of time, which have not been possible before. Data from remote sensing units has been sampled by the ARGOS data collection system on the NOAA series satellites since the late 1970's. Data is presented on temperature, pressure, and wind speed and direction.

Allison, I. (Antarctic Cooperative Research Centre, Hobart (Australia)); Wendler, G. (Univ. of Tasmania, Hobart (Australia)); Radok, U. (Univ. of Colorado, Boulder (United States))

1993-05-20

355

The International Space Station  

NSDL National Science Digital Library

Users can access news articles, background information and links about the International Space Station. Materials presented here include crew biographies, expedition press kits, accounts of science experiments, and imagery taken from the station. Other features include a clock/counter that logs the station's and the crew's time in orbit and information for ground-based observers who wish to view the station as it passes overhead at night.

356

Controlling mechanisms of Thwaites Glacier, West Antarctica  

NASA Astrophysics Data System (ADS)

Ice shelves play a major role in the stability of fast flowing ice streams in Antarctica, by exerting buttressing on inland ice and controlling the discharge of ice into the ocean. However, the mechanisms at work remain poorly understood and interactions between floating and grounded ice need to be better characterized in order to estimate the impact of climate change on the ice sheets. Thwaites glacier, in West Antarctica, features a small and heavily fractured ice shelf that provides limited back stress pressure on inland ice but is pinned on the eastern part on a prominent ridge. Thwaites glacier has maintained a consistently high velocity and negative mass balance for at least 20 years. Recent observations show a widening of its fast flowing area as well as a sustained acceleration since 2006 and a rapid retreat of its grounding line in the center of the glacier. The objective of this work is to characterize the dynamic response of Thwaites glacier to changes in its floating tongue on decadal to centennial time scales. To achieve this objective, we rely on high resolution ice flow modeling and grounding line dynamics using the Ice Sheet System Model (ISSM). We will focus on the complex interplay between the main floating tongue of Thwaites Glacier and its eastern, slow moving ice shelf, which is pinned down by an ice rumple. The speed of the eastern ice shelf is strongly affected by the coupling with the main floating ice tongue, which results in significant fluctuations in speed of the eastern ice shelf the formation of ice shelf cracks at the grounding line during acceleration phases. Our results show that ice rigidity at the junction between the eastern and western part of the shelf controls the dynamic regime of the ice shelf and suggest that Thwaites Glacier is likely to undergo substantial changes in the coming decades. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory and the University of California Irvine under a contract with the National Aeronautics and Space Administration, Cryospheric Sciences and Modeling, Analysis and Prediction Programs

Seroussi, H. L.; Morlighem, M.; Rignot, E. J.; Larour, E. Y.; Mouginot, J.; Khazendar, A.

2013-12-01

357

Southwestern Research Station  

NSDL National Science Digital Library

This Web site profiles AMNH's Southwestern Research Station (SWRS), a year-round field station that allows biologists, geologists, and anthropologists to study the diverse environments and biotas of the Chiricahua Mountains in southeastern Arizona. The site includes an overview of the field station and its work, information on courses offered, and information for visitors, researchers, interns and volunteers.

358

World Hydrogen Fueling Stations  

NSDL National Science Digital Library

This document provides information on hydrogen fueling stations in the United States and other countries including Canada, Australia, Germany and Japan. Individual fueling stations are profiled, including the fuel type provided, when it was opened, how the hydrogen is produced and other details. Small photographs of each station are also included. This document may be downloaded in PDF file format.

359

Deep-water occurrence of the moss Bryum pseudotriquetrum in Radok Lake, Amery Oasis, East Antarctica  

Microsoft Academic Search

Mosses form an important component of the flora in terrestrial and lacustrine ecosystems of Antarctica. Here we report the occurrence of mosses in Radok Lake, Amery Oasis, East Antarctica, which has a maximum water depth of c. 360 m and is presumed to be the deepest freshwater lake in Antarctica. Aquatic mosses, determined as Bryum pseudotriquetrum, were found at water depths

Bernd Wagner; Rod Seppelt

2006-01-01

360

CALIPSO observations of wave-induced PSCs with near-unity optical depth over Antarctica in  

E-print Network

CALIPSO observations of wave-induced PSCs with near-unity optical depth over Antarctica in 2006 Antarctica during the 2006 and 2007 austral winters. These clouds are rare (less than 1% of profiles with daily temperature minimas across Antarctica. Lidar and depolarization ratios within these clouds suggest

Boyer, Edmond

361

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica*  

E-print Network

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica 2013) ABSTRACT The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation

Karnauskas, Kristopher

362

Thickness of the Atmospheric Boundary Layer Above Dome A, Antarctica, during 2009  

E-print Network

Thickness of the Atmospheric Boundary Layer Above Dome A, Antarctica, during 2009 C. S. BONNER,1 M s at Dome A, Antarctica between 2009 February 4 and 2009 August 18. The median thickness of the boundary increase. Winds within the boundary layer over Antarctica are usually katabatic in na- ture. This suggests

Ashley, Michael C. B.

363

Energetic consequences of repeated and prolonged dehydration in the Antarctic midge, Belgica antarctica  

E-print Network

antarctica Nicholas M. Teets a, , Yuta Kawarasaki b , Richard E. Lee Jr. b , David L. Denlinger a of the Antarctic midge, Belgica antarctica, routinely face periods of limited water availability in their natural environments on the Antarctic Peninsula. As a result, B. antarctica is one of the most dehydration

Lee Jr., Richard E.

364

The influence of Antarctica on the momentum budget of the southern  

E-print Network

The influence of Antarctica on the momentum budget of the southern extratropics 1234567 89A64BC7DEF.1(21~13):551.555.4:551.588.5(W) The influence of Antarctica on the momentum budget of the southern extratropics By M. N. JUCKES Antarctica reveals a balance between the Eliassen-Palm fluxconvergence and the Coriolistorque exerted

Wirosoetisno, Djoko

365

International Snow Science Workshop Grenoble Chamonix Mont-Blanc -2013 Simulations of blowing Snow over Antarctica  

E-print Network

Snow over Antarctica Hubert Gallée 1 , Alexandre Trouvilliez1,3 , Charles Amory 1 , Cécile Agosta 2 used to simulate transport of snow by the wind in Adélie Land, Antarctica, over a small domain (500 x that may be much larger than previously estimated. KEYWORDS: Climate Modeling, Antarctica, Snow Transport

Paris-Sud XI, Université de

366

Seismic observations of sea swell on the floating Ross Ice Shelf, Antarctica  

E-print Network

Seismic observations of sea swell on the floating Ross Ice Shelf, Antarctica L. M. Cathles IV,1 by several orders of magnitude over the time period that sea ice surrounding Antarctica decreases from its of Alaska. These remote events emphasize how the iceberg calving margin of Antarctica is connected

Boyce, C. Kevin

367

Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica  

E-print Network

1 Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica N.V. Yagova-periods about ten minutes are analyzed using data from magnetometer arrays in Antarctica. Examination of the 2D be monitored with ground-based magnetic observations at polar latitudes in Antarctica and the Arctic. Because

368

S125JULY 2010STATE OFTHE CLIMATE IN 2009 | 6. ANTARCTICA  

E-print Network

S125JULY 2010STATE OFTHE CLIMATE IN 2009 | 6. ANTARCTICA a. Overview--R. L. Fogt The calendar year 2009 was relatively calm, climatologically speaking, for much of Antarctica, especially compared, the tropical El Niño event in late 2009 did influence Antarctica, particularly through ridging in the South

369

Surface mass balance and stable oxygen isotope ratios from shallow firn cores on Fimbulisen, East Antarctica  

E-print Network

Antarctica E. SCHLOSSER,1 H. ANSCHU¨ TZ,2 E. ISAKSSON,3 T. MARTMA,4 D. DIVINE,5 O.-A. NØST3 1 Institute, Tromsø, Norway ABSTRACT. The mass balance of Antarctica is one of the crucial factors for determining sea was carried out on Fimbulisen, an ice shelf in East Antarctica, to investigate its recent surface mass balance

Schlosser, Elisabeth

370

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, Antarctica  

E-print Network

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, AntarcticaMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency (0315, 0325); 3349 Meteorology and Atmospheric Dynamics: Polar meteorology; KEYWORDS: Antarctica, dry

Fountain, Andrew G.

371

Snow grain-size measurements in Antarctica Michel GAY,1,2  

E-print Network

Snow grain-size measurements in Antarctica Michel GAY,1,2 Michel FILY,1 Christophe GENTHON,1-known characteristic of snow at the surface of Antarctica. In the past, grain-size has been reported using various-size distribution from fieldwork in Antarctica. In particular, except at sites affected by a very particular meteor

Paris-Sud XI, Université de

372

100 Years of Humans in Antarctica1 by Lily Whiteman, National Science Foundation2  

E-print Network

100 Years of Humans in Antarctica1 by Lily Whiteman, National Science Foundation2 3 This winter marks the 100th anniversary of the race to the South Pole. After crossing Antarctica -- the coldest on Anvers Island in the Antarctic Peninsula Region. Forbidding though Antarctica is, the Amundsen

South Bohemia, University of

373

A new high-latitude record for the macaroni penguin (Eudyptes chrysolophus) at Avian Island, Antarctica  

E-print Network

Island, Antarctica K. B. Gorman · E. S. Erdmann · B. C. Pickering · P. J. Horne · J. R. Blum · H. M penguins (Eudyptes chrysolophus) on Avian Island, Antarctica, approximately 1° south of the Antarctic of Antarctica. We also report more frequent extra-l

374

ANTARCTICA: BAROMETER OF CLIMATE CHANGE Report to the National Science Foundation from the Antarctic Meteorology Workshop,  

E-print Network

#12;1 ANTARCTICA: BAROMETER OF CLIMATE CHANGE Report to the National Science Foundation from, Laramie, Wyoming 82071. Publication Date: November 1998. Summary Antarctica plays a central role in global, and improving numerical models allow the question of the global relevance of Antarctica to be explored in detail

Howat, Ian M.

375

The biogeochemistry of Si in the McMurdo Dry Valley lakes, Antarctica  

E-print Network

The biogeochemistry of Si in the McMurdo Dry Valley lakes, Antarctica Heather E. Pugh1 *, Kathleen) of Antarctica. Our data and calculations indicate that biological uptake of Si is not a major process as in temperate systems. Accepted 1 October 2002 Key words: Antarctica, lakes, silica, biogeochemistry

Priscu, John C.

376

COMPUTER VISION APPLICATIONS TO THE STUDY OF SEA-ICE MOTION IN ANTARCTICA  

E-print Network

COMPUTER VISION APPLICATIONS TO THE STUDY OF SEA-ICE MOTION IN ANTARCTICA Salvador Guti ­ The motion of sea-ice in Antarctica is stud- ied using QuikSCAT scatterometer imagery using meth- ods from covered or in the dark side of the earth, such as Antarctica. Among available data it is worthy to note

Long, David G.

377

Seismic evidence for deep low-velocity anomalies in the transition zone beneath West Antarctica  

E-print Network

Seismic evidence for deep low-velocity anomalies in the transition zone beneath West Antarctica in Antarctica that were all restricted to the analysis of the fundamental mode. This paper is therefore mostly Byrd Land, West Antarctica and a portion of the Pacific^ Antarctic Ridge close to the Balleny Islands

378

LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing  

E-print Network

LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing to higher snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea Antarctica1,6 and thus in the ultimate fate of the precipitation- deposited ice mass. Here we show

Levermann, Anders

379

Aeolian flux of biotic and abiotic material in Taylor Valley, Antarctica Marie Saback a  

E-print Network

Aeolian flux of biotic and abiotic material in Taylor Valley, Antarctica Marie Sabacká a , John C Keywords: Aeolian Föhn Antarctica Biotic Abiotic Desert We studied patterns and mechanisms controlling wind-driven flux of soils and associated organic matter in Taylor Valley, Antarctica over a 10-year period using

Wall, Diana

380

Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica  

E-print Network

Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica Paul R. Holland,1 Daniel L Filchner- Ronne Ice Shelf, Antarctica and its underlying ocean cavity. Ice Shelf Water (ISW) plumes-Ronne Ice Shelf, Antarctica, J. Geophys. Res., 112, C05044, doi:10.1029/2006JC003915. 1. Introduction [2

Feltham, Daniel

381

Geophysical models for the tectonic framework of the Lake Vostok region, East Antarctica  

E-print Network

Geophysical models for the tectonic framework of the Lake Vostok region, East Antarctica Michael of East Antarctica were used to develop a conceptual tectonic model for the Lake Vostok region. The model a tectonic boundary within East Antarctica. Based on our kinematic and flexural gravity modelling

Levin, Vadim

382

Analysis of deep-penetrating radar surveys of West Antarctica, US-ITASE 2001  

E-print Network

Analysis of deep-penetrating radar surveys of West Antarctica, US-ITASE 2001 Brian C. Welch echo- sounding (RES) data in West Antarctica along the 2001 US leg of the International Trans Related to Geographic Region: Antarctica. Citation: Welch, B. C., and R. W. Jacobel, Analysis of deep

Jacobel, Robert W.

383

Soil Biology & Biochemistry 38 (2006) 30193034 Terrestrial ecosystem processes of Victoria Land, Antarctica  

E-print Network

, Antarctica J.E. Barretta,Ã, R.A. Virginiaa , D.W. Hopkinsb , J. Aislabiec , R. Bargaglid , J.G. Bockheime , I, Antarctica are ideal systems to test hypotheses about the sensitivity of ecosystem processes to climate in Victoria Land, Antarctica are constrained by combinations of extreme conditions includ- ing low

Wall, Diana

2006-01-01

384

Relative humidity over Antarctica from radiosondes, satellites, and a general circulation model  

E-print Network

Relative humidity over Antarctica from radiosondes, satellites, and a general circulation model A to validate measurements of relative humidity (RH) over Antarctica from the Atmospheric Infrared Sounder (AIRS over Antarctica is well reproduced by the satellite. AIRS data are also compared to simulations from

Walden, Von P.

385

A New Species of Nototheniid (Perciformes: Notothenioidei) Fish from McMurdo Sound, Antarctica  

E-print Network

A New Species of Nototheniid (Perciformes: Notothenioidei) Fish from McMurdo Sound, Antarctica PAUL Sea region of Antarctica. The new species closely resembles the only known congener, C. peninsulae routine surveys at a heavily-sampled site in McMurdo Sound, Ross Sea, Antarctica happened upon a fish

Cheng, Chi-Hing Christina

386

Persistent organic pollutants and stable isotopes in pinnipeds from King George Island, Antarctica  

E-print Network

, Antarctica Caio V. Z. Cipro*,1,2 , Paco Bustamante2 , Satie Taniguchi1 & Rosalinda Carmela Montone1 1 leonina (southern elephant seal, n=1) were collected from King George Island, Antarctica, and analysed/or excrete the majority of them. Keywords: Antarctica; Seal; Stable isotopes; Organochlorine; PBDEs; POPs hal

Paris-Sud XI, Université de

387

Optical Flow and Scale-Space Theory applied to Sea-Ice Motion Estimation in Antarctica  

E-print Network

Optical Flow and Scale-Space Theory applied to Sea-Ice Motion Estimation in Antarctica Salvador-- Sea-ice motion in Antarctica is studied applying methods from computer vision and scale-space theory-ice directions and speeds on Antarctica has been previously approached with correlation [1] or wavelet [2], [3

Long, David G.

388

Accelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica  

E-print Network

Accelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica Joseph S. Levy1 , Andrew G been considered to be a minor process in Antarctica. Here, we use ground-based and airborne Li accelerated in Garwood Valley, Antarctica; 2) the rate of thermokarst erosion is presently , 10 times

Marchant, David R.

389

Rayleigh wave phase velocity analysis of the Ross Sea, Transantarctic Mountains, and East Antarctica  

E-print Network

Antarctica from a temporary seismograph array Jesse F. Lawrence,1,2 Douglas A. Wiens,1 Andrew A. Nyblade,3 from the Ross Sea (RS) region of the West Antarctica rift system, the Transantarctic Mountains (TAMs), and part of East Antarctica (EA). The Transantarctic Mountain Seismic Experiment deployed 41 three

390

Modified shelf water on the continental slope north of Mac Robertson Land, East Antarctica  

E-print Network

Modified shelf water on the continental slope north of Mac Robertson Land, East Antarctica Annie P Antarctica. This bottom layer water mass, with potential temperature in the range À1.8°C source of dense waters in East Antarctica. Citation: Wong, A. P. S., and S. C. Riser (2013), Modified

Riser, Stephen C.

391

Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica  

E-print Network

Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica Salvador Guti computer vision and scale-space theory are applied to the study of sea-ice motion in Antarctica. The input into account that there is practically no ground-truth data available for Antarctica in the form of buoy

Long, David G.

392

Mass casualty incident response and aeromedical evacuation in antarctica.  

PubMed

Antarctica is one of the most remote regions on Earth. Mass casualty incident (MCI) responses in Antarctica are prone to complications from multiple environmental and operational challenges. This review of the current status of MCI risks and response strategies for Antarctica focuses on aeromedical evacuation, a critical component of many possible MCI scenarios. Extreme cold and weather, a lack of medical resources and a multitude of disparate international bases all exert unique demands on MCI response planning. Increasing cruise ship traffic is also escalating the risk of MCI occurrence. To be successful, MCI response must be well coordinated and undertaken by trained rescuers, especially in the setting of Antarctica. Helicopter rescue or aeromedical evacuation of victims to off-continent facilities may be necessary. Currently, military forces have the greatest capacity for mass air evacuation. Specific risks that are likely to occur include structure collapses, vehicle incapacitations, vehicle crashes and fires. All of these events pose concomitant risks of hypothermia among both victims and rescuers. Antarctica's unique environment requires flexible yet robust MCI response planning among the many entities in operation on the continent. PMID:21691470

Mills, Christopher N; Mills, Gregory H

2011-02-01

393

Continuous on-line water vapor isotope measurements in Antarctica  

NASA Astrophysics Data System (ADS)

In the context of a globally warming climate it is crucial to study the climate variability in the past and to understand the underlying mechanisms (1). Precipitation deposited on the polar ice caps provides a means to retrieve information on temperature changes (through the paleo-temperature dependence of the isotopic composition of the ice) and atmospheric composition (of gas stored in bubbles in the ice) on time scales from one to almost one million years, with sub-annual resolution in the most recent centuries. However, it is now widely recognized that the calibration of the paleo-thermometer is highly problematic. For this reason attempts to model the global water cycle, including the isotope signals, are ongoing with the aim of providing a more physical basis of the isotope - temperature relation. Currently, there is a large divergence in the results obtained by different modeling strategies. The missing link in these model studies is their forcing by experimental data on the pre-deposition isotopic composition of the vapor phase compartment of the hydrological cycle. We propose to measure the isotopic composition of moisture carried towards and deposited on Antarctica, in order to constrain the numerical models. In this context we are developing a modified, more sensitive and precise, version of a laser water vapor isotope spectrometer, originally designed for stratospheric studies (2, 3). This instrument, which will first be operated at the Norwegian station of Troll in Queen Maud Land, will enable the continuous, online measurement of all three stable isotope ratios of atmospheric water vapor. So far, such data is non-existent. Our data should improve the validity of the models and improve the understanding of the physical mechanisms at the basis of the isotope thermometer. This in turn will lead to an increased confidence in the predictions of (general circulation) models concerning climate variability. (1) International Panel on Climate Change (IPCC), 4th Assessment Report, Chapters 1 and 6 (2007). (2) E.R.T. Kerstel, R.Q. Iannone, M. Chenevier, S. Kassi, H.-J. Jost, and D. Romanini, A water isotope (2H, 17O, and 18O) spectrometer based on optical-feedback cavity enhanced absorption for in-situ airborne applications, Appl. Phys. B 85(2-3), 397-406 (2006). (3) R.Q. Iannone, S. Kassi, H.-J. Jost, M. Chenevier, D. Romanini, H.A.J. Meijer, S. Dhaniyala, M. Snels, and E.R.Th. Kerstel, Development and airborne operation of a compact water isotope ratio spectrometer, Isotop. Environm. Health Studies 45 (JESIUM 2008 special issue), 1-18 iFirst (2009). doi=10.1080/10256010903172715

Landsberg, Janek; Romanini, Daniele; Holmen, Kim; Isaksson, Elisabeth; Meijer, Harro; Kerstel, Erik

2010-05-01

394

A magnetospheric substorm observed at Sanae, Antarctica  

SciTech Connect

A magnetospheric substorm that occurred at Sanae, Antarctica, on July 27, 1979, was observed by a variety of techniques. A synthesis of the observations is presented, and an attempt made to deduce details of the behavior of the magnetosphere-ionosphere system during the event. While there was some evidence of a growth phase, it was inconclusive. At the onset there was a rapid change in the tail field, which assumed a more dipolar form, accompanied by Pi 2 oscillations and the precipitation of 6-keV electrons, with brightening of the auroral arc, auroral-type sporadic E ionization, and riometer absorption. A positive spike was observed in the D magnetic component, instead of the expected negative one. There was no evidence of the usual westward traveling surge at the beginning of the expansion phase during which the precipitation region, auroral arc, and electrojet moved rapidly poleward, though it may have occurred outside the field of view from Sanae. The H{beta} emission increased by a factor of less than 2, whereas the oxygen and nitrogen emissions monitored increased by 3-4. During the recovery phase, phenomena were consistent with a return of the tail field to an elongated form; a very high ratio of 557.7-nm/630-nm emissions, exceeding 10, was observed; and the electrojet lagged noticeably behind the photon emission regions.

Gledhill, J.A.; Dore, I.S.; Haggard, R. (Rhodes Univ., Grahamstown (South Africa)); Goertz, C.K. (Univ. of Iowa, Iowa City (United States)); Hughes, W.J. (Boston Univ., MA (United States)); Scourfield, M.W.J.; Wakerley, P.A.; Walker, A.D.M. (Univ. of Natal, Durban (South Africa)); Smits, D.P.; Sutcliffe, P.R. (Magnetic Observatory of the Council for Scientific and Industrial Research, Hermanus (South Africa)); Stoker, P.H. (Potchefstroom Univ. for Christian Higher Education (South Africa))

1987-03-01

395

The Center for Astrophysics in Antarctica  

NASA Technical Reports Server (NTRS)

Nowhere on Earth are the infrared skies clearer, darker, or more stable than on the high Antarctic Plateau. At some wavelengths, Antarctic telescopes may be more than one to two orders of magnitude more efficient than at other sites. However, exploiting these advantages requires first addressing the formidable practical difficulties of working in the remote and frigid polar environment. This was the motivation for the Center for Astrophysical Research in Antarctica (CARA), one of twenty-five National Science Foundation Science and Technology Centers. At its inception, the Center organized its research into four projects. Three - AST/RO, COBRA, and SPIREX - address key problems in star formation, evolution of galaxies, and the distribution of matter in the early universe. They feature surveys which can be conducted effectively with moderate-size telescopes operated in a highly automated mode. They also explore the potential of the Antarctic Plateau for a broad range of astrophysical research over a spectral range extending from the near-infrared to millimeter wavelengths. A fourth, ATP, was created to obtain quantitative data on the qualities of the South Pole site and to plan for future scientific projects. During the next five years, AST/RO, COBRA, and SPIREX will become operational, and the Center will begin to build a second generation of telescopes which can address a broader range of problems and accommodate a larger community of users.

Pernic, Robert J.; Harper, D. AL, Jr.; Bausch, Judith A.

1995-01-01

396

Hydrogen emissions from Erebus volcano, Antarctica  

NASA Astrophysics Data System (ADS)

The continuous measurement of molecular hydrogen (H2) emissions from passively degassing volcanoes has recently been made possible using a new generation of low-cost electrochemical sensors. We have used such sensors to measure H2, along with SO2, H2O and CO2, in the gas and aerosol plume emitted from the phonolite lava lake at Erebus volcano, Antarctica. The measurements were made at the crater rim between December 2010 and January 2011. Combined with measurements of the long-term SO2 emission rate for Erebus, they indicate a characteristic H2 flux of 0.03 kg s-1 (2.8 Mg day-1). The observed H2 content in the plume is consistent with previous estimates of redox conditions in the lava lake inferred from mineral compositions and the observed CO2/CO ratio in the gas plume (˜0.9 log units below the quartz-fayalite-magnetite buffer). These measurements suggest that H2 does not combust at the surface of the lake, and that H2 is kinetically inert in the gas/aerosol plume, retaining the signature of the high-temperature chemical equilibrium reached in the lava lake. We also observe a cyclical variation in the H2/SO2 ratio with a period of ˜10 min. These cycles correspond to oscillatory patterns of surface motion of the lava lake that have been interpreted as signs of a pulsatory magma supply at the top of the magmatic conduit.

Moussallam, Yves; Oppenheimer, Clive; Aiuppa, Alessandro; Giudice, Gaetano; Moussallam, Manuel; Kyle, Philip

2012-11-01

397

Fabric and texture at Siple Dome, Antarctica  

USGS Publications Warehouse

Preferred c-axis orientations are present in the firn at Siple Dome, West Antarctica, and recrystallization begins as shallow as 200 m depth in ice below -20??C, based on digital analysis of c-axis fabrics, grain-sizes and other characteristics of 52 vertical thin sections prepared in the field from the kilometer-long Siple Dome ice core. The shallowest section analyzed, from 22 m, shows clustering of c axes toward the vertical. By 200 m depth, girdle fabric and other features of recrystallized ice are evident in layers (or regions), separated by layers (regions) of typically finer-grained ice lacking evidence of recrystallization. Ice from about 700-780 m depth, which was deposited during the last ice age, is especially fine-grained, with strongly vertical c axes, but deeper ice shows much larger crystals and strong evidence of recrystallization. Azimuthal asymmetry of some c-axis fabrics, trends in grain-size, and other indicators reveal additional information on processes and history of ice flow at Siple Dome.

Diprinzio, C.L.; Wilen, L.A.; Alley, R.B.; Fitzpatrick, J.J.; Spencer, M.K.; Gow, A.J.

2005-01-01

398

Odd cloud in the Ross Sea, Antarctica  

NASA Technical Reports Server (NTRS)

On January 28, 2002, MODIS captured this image of an interesting cloud formation in the boundary waters between Antarctica's Ross Sea and the Southern Ocean. A dragon? A snake? A fish? No, but it is an interesting example of the atmospheric physics of convection. The 'eye' of this dragon-looking cloud is likely a small spot of convection, the process by which hot moist air rises up into the atmosphere, often producing big, fluffy clouds as moisture in the air condenses as rises into the colder parts of the atmosphere. A false color analysis that shows different kinds of clouds in different colors reveals that the eye is composed of ice crystals while the 'body' is a liquid water cloud. This suggests that the eye is higher up in the atmosphere than the body. The most likely explanation for the eye feature is that the warm, rising air mass had enough buoyancy to punch through the liquid water cloud. As a convective parcel of air rises into the atmosphere, it pushes the colder air that is higher up out of its way. That cold air spills down over the sides of the convective air mass, and in this case has cleared away part of the liquid cloud layer below in the process. This spilling over of cold air from higher up in the atmosphere is the reason why thunderstorms are often accompanied by a cool breeze. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

399

Community structure and feeding ecology of mesopelagic fishes in the slope waters of King George Island (South Shetland Islands, Antarctica)  

NASA Astrophysics Data System (ADS)

The role of mesopelagic fishes in the Southern Ocean ecosystem and more particular their trophic effect on the standing stock of mesozooplankton is at present poorly understood. To get a deeper insight in the Antarctic mid-water ecosystem the mesopelagic fish community of the King George Island slope (South Shetland Islands) was sampled with a pelagic trawl in 1996. The community structure was analysed and the feeding ecology was studied of the five most abundant species. A total of 18 mesopelagic fish species in 10 families was identified. Of these, the Myctophidae was the most important family by species number (9 species), individual number (98.5% of all individuals) and fish wet weight (87.3% of the total weight). The assemblage was numerically dominated by four myctophids ( Electrona antarctica, Gymnoscopelus braueri, Gymnoscopelus nicholsi, Protomyctophum bolini) and one gempilyd ( Paradiplospinus gracilis). Multivariate statistical analysis of the mesopelagic fish data reveals two major groups of stations according to the sampled depth: a shallow group of stations (295-450 m depth) and a deeper group of stations (440-825 m depth). The change in relative abundance of mesopelagic fish species at 440-450 m coincides with the presence of warmer and denser Circumpolar Deep Water at and below these depths. Deeper stations were characterized by a higher density and increased diversity of mesopelagic fish species. The community patterns identified correlated well with the vertical depth distribution of the most abundant species. Dietary analysis reveals that myctophids are mostly zooplanktivorous, while the gempilyd P. gracilis is classified as a piscivorous predator. The small P. bolini feed mainly on copepods of the species Metridia gerlachei, while the most important prey item of the larger myctophids E. antarctica, G. braueri, and G. nicholsi were various species of euphausiids. Investigation of feeding chronology showed that G. nicholsi and P. bolini were feeding day and night. Daily ration estimates for myctophid species ranged from 0.28% to 3.3% of dry body weight (0.5-5.94% of wet body weight). Krill ( Euphausia superba) were the most important food of E. antarctica and G. nicholsi, accounting for 53.1% and 58.3% of the total food weight, respectively. The annual removal from the krill stock by both species was estimated to amount to 11.1-26.7% in the South Shetland Islands region. This estimate emphasizes the important role of mesopelagic fish in the Antarctic ecosystem as a prevalent consumer of krill.

Pusch, C.; Hulley, P. A.; Kock, K.-H.

2004-11-01

400

Space Station overview  

NASA Technical Reports Server (NTRS)

This paper presents an overview of the Space Station, including program guidelines, international involvement, current baseline configuration, and utilization for science and application missions. Space Station configuration and capabilities, plus methods of utilizing the Space Station for scientific and engineering investigations, are described. The Space Station is being designed as a multipurpose facility to support a number of functions, such as a laboratory in space, a transportation node, an assembly facility, a staging base, etc. The description includes the baseline configuration, location of the pressurized modules, servicing and assembly facilities, and the work package structure for Space Station management. The Space Station will accommodate a wide variety of user requirements in laboratory modules and as attached payloads. To show the utility of the Space Station, a variety of science and application missions currently being studied for NASA at the Marshall Space Flight Center are discussed.

De Sanctis, Carmine E.; Priest, C. C.; Wood, W. V.

1987-01-01

401

Permafrost and periglacial research in Antarctica: New results and perspectives  

NASA Astrophysics Data System (ADS)

In the last two years the research within the Antarctic Permafrost, Periglacial Environments and Soils (ANTPAS) Expert Group of the Scientific Committee on Antarctic Research (SCAR) and Working Group of the International Permafrost Association (IPA) provided new results on the dynamics of periglacial environments both in Maritime and Continental Antarctica. In continental Antarctica despite the absence of air warming, in the last 15 years an active layer thickening and acceleration of permafrost degradation erosional phenomena were reported, these being mainly related to the increase of solar radiation. On the other hand, in Maritime Antarctica, with a dramatic air warming, permafrost degradation has been observed, but the role of snow cover on the ground energy balance and consequently on permafrost and active layer has been underlined. Moreover, many contributions on the knowledge on the characteristics of the Antarctic soils were carried out in several areas along a wide latitudinal range.

Guglielmin, Mauro; Vieira, Gonçalo

2014-11-01

402

Ecological biogeography of the terrestrial nematodes of victoria land, antarctica.  

PubMed

The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

Adams, Byron J; Wall, Diana H; Virginia, Ross A; Broos, Emma; Knox, Matthew A

2014-01-01

403

Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica  

PubMed Central

Abstract The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

Adams, Byron J.; Wall, Diana H.; Virginia, Ross A.; Broos, Emma; Knox, Matthew A.

2014-01-01

404

Cryoconite and Ice-bubble Microbial Ecosystems in Antarctica  

NASA Technical Reports Server (NTRS)

During the Antarctica 2000 Expedition samples of rocks and ice bubbles entrained in ice were collected from the blue ice fields near the Moulton Escarpment of the Thiel Mountains (85S, 94W) and the Morris Moraine of the Patriot Hills (80S, 8 1 W) Ellsworth Mountains of Antarctica. Investigation of the microbiota of these cryoconite and ice bubble ecosystems are now being conducted to help refine chemical and morphological biomarkers of potential significance to Astrobiology. The Antarctica 2000 Expedition will be discussed and the preliminary results of the studies of the ice bubble and cryoconite microbial ecosystems discussed. Recent ESEM images of the Antarctic microbiota will be presented a the relevance of ice ecosystems to Astrobiology will be discussed.

Hoover, Richard B.; Rose, M. Franklin (Technical Monitor)

2000-01-01

405

Alternative regimes for mineral-resource development in Antarctica  

SciTech Connect

Alternative regimes for Antarctica are evaluated within which nonliving resources of the continent and adjacent offshore areas can be developed and managed. The study estimates: (a) the better options for each of the states active in Antarctica, and (b) the minerals regime which would best serve the interest of the Antarctic Treaty Consultative States. Multi-Attribute Utility Analysis was used to evaluate alternative regimes, including: (1) identification of relevant interests of states in Antarctica, (2) estimation of the relative importance of these interests for all relevant actors, (3) definition of alternative minerals regimes, and (4) evaluation of the probable effect of each alternative on satisfaction of the interests of each state. The data were used to calculate each state's utilities for the twelve options considered. A questionnaire was sent to Antarctic experts in all Consultative countries.

Westermeyer, W.E.

1982-01-01

406

Estimations of the age of the ice beneath Dome A, Antarctica  

NASA Astrophysics Data System (ADS)

The drilling of a deep ice core at the Chinese Kunlun station, Dome A, East Antarctica, is about to start with high expectations on obtaining the oldest possible ice so far. The Alpine type bedrock of the Gamburtsev mountains in combination with a largely undetermined geothermal heat flux distribution raises questions on the basal thermal conditions that via the melting rate have a strong feedback on the vertical flow velocity and in consequence on the age/depth horizons. Additionally, the undetermined ice fabric introducing anisotropic effects in rheology have to be taken into account. By deploying a full Stokes ice sheet model (http://elmerice.elmerfem.org) we investigate the influence of those parameters, namely anisotropy as well as geothermal heat flux values, on the spatial distribution of the age close to the bedrock. Results are compared with dated radar isochrones in the upper one third of the ice sheet. We find that a non-unique combination of parameters is able to closely reproduce those measured values, leading to the conclusion, that without additional information, the basal age beneath Kunlun station remains undetermined. However, our simulations suggest that vast spatial variation of basal melting rates and, in consequence, the age/depth distribution over a relative small domain exists, increasing the motivation for ice coring, obtaining both high resolution as well as possibly oldest ice from the same site.

Zwinger, Thomas; Sun, Bo; Liyun, Liyun; Moore, John C.; Steinhage, Daniel; Martin, Carlos

2014-05-01

407

Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling  

NASA Astrophysics Data System (ADS)

Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ? indicator PCBs and ?14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

2012-05-01

408

Quasi-16-day period oscillations observed in middle atmospheric ozone and temperature in Antarctica  

NASA Astrophysics Data System (ADS)

Nightly averaged mesospheric temperature derived from the hydroxyl nightglow at Rothera station (67°34' S, 68°08' W) and nightly midnight measurements of ozone mixing ratio obtained from Troll station (72°01' S, 2°32' E) in Antarctica have been used to investigate the presence and vertical profile of the quasi-16-day planetary wave in the stratosphere and mesosphere during the Antarctic winter of 2009. The variations caused by planetary waves on the ozone mixing ratio and temperature are discussed, and spectral and cross-correlation analyses are performed to extract the wave amplitudes and to examine the vertical structure of the wave from 34 to 80 km. The results show that while planetary-wave signatures with periods 3-12 days are strong below the stratopause, the oscillations associated with the 16-day wave are the strongest and present in both the mesosphere and stratosphere. The period of the wave is found to increase below 42 km due to the Doppler shifting by the strong eastward zonal wind. The 16-day oscillation in the temperature is found to be correlated and phase coherent with the corresponding oscillation observed in O3 volume mixing ratio at all levels, and the wave is found to have vertical phase fronts consistent with a normal mode structure.

Demissie, T. D.; Kleinknecht, N. H.; Hibbins, R. E.; Espy, P. J.; Straub, C.

2013-07-01

409

Atmospheric CO2 record from continuous measurements at Jubany Station, Antarctica  

E-print Network

) which differ by 20-25 ppm. The accuracy achieved in the calibration phase and in the atmospheric CO2 measurement permits reporting to +0.1 ppm. Trends On the basis of annual averages calculated from monthly, and Relationship with the Origins of Air Masses. In Conference Proceedings of the VII Workshop on the Antarctic

410

FY 1993 environmental sampling and analysis report for wastewater discharge at McMurdo Station, Antarctica  

SciTech Connect

Wastewater impact assessment at McMurdo has been or is being conducted by four organizations: Antarctic Support Associates (ASA), which conducts the effluent monitoring; Moss Landing Marine Laboratories, which conducts all of the benthic monitoring and most of the biological monitoring; Montana State University, which conducted water quality and water current measurements; and EG&G Idaho, which conducted water quality and sea ice monitoring. All four programs are interrelated and were needed to determine the impact of the wastewater discharge on the marine environment. This report summarizes the relevant monitoring work being conducted by Antarctic Support Associates, Moss Landing, and Montana State personnel, and specifically documents the results of EG&G Idaho`s efforts.

Crockett, A.B.

1994-04-01

411

Space Station Freedom Utilization Conference  

NASA Technical Reports Server (NTRS)

The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary.

1992-01-01

412

Declassified Intelligence Satellite Photography (DISP) Coverage of Antarctica  

NASA Technical Reports Server (NTRS)

This report summarizes the results of a nine-week summer project examining all Declassified Intelligence Satellite Photography (DISP) of Antarctica. It was discovered that the data were collected in three separate missions during 1962 and 1963. The first two missions covered only the coastal areas, while the third mission covered the entire continent. Many of the 1782 frames collected were cloudy. This is especially true of West Antarctica. An optimal set of photographs covering the entire Antarctic coastline is identified along with some examples that show changes in the coastline which have occurred since the early 1960s.

Bindschadler, Robert; Seider, Wendy

1998-01-01

413

Fit between Africa and Antarctica: A Continental Drift Reconstruction.  

PubMed

A computerized (smallest average misfit) best fit position is obtained for the juxtaposition of Africa and Antarctica in a continental drift reconstruction. An S-shaped portion of the Weddell and Princess Martha Coast regions of western East Antarctica is fitted into a similar profile along southeastern Africa. The total amount of overlap is 36,300 square kilometers, and the underlap is 23,600 square kilometers; the total mismatch is thus of 59,900 square kilometers. The congruency along the 1000-fathom isobath is remarkably good and suggests that this reconstruction is valid within the overall framework of the Gondwana supercontinent. PMID:17746368

Dietz, R S; Sproll, W P

1970-03-20

414

Climate change during the last deglaciation in Antarctica  

SciTech Connect

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated. 21 refs,. 2 figs.

Mayewski, P.A.; Twickler, M.S.; Whitlow, S.I. [and others

1996-06-14

415

Photosynthesis-irradiance responses in the Ross Sea, Antarctica: a meta-analysis  

NASA Astrophysics Data System (ADS)

A meta-analysis of photosynthesis/irradiance measurements was completed using data from the Ross Sea, Antarctica. A total of 544 independent measurements were included. PsB, the maximum, chlorophyll-specific, irradiance-saturated rate of photosynthesis, averaged 1.07 ± 0.060 ?g C (?g chl)-1 h-1. Light-limited photosynthetic rates (?) averaged 0.03 ± 0.023 ?g C (?g chl)-1 h-1 ?mol photons m-2 s-1)-1. Significant variations in PsB and ? were found as a function of season, with spring maximum photosynthetic rates being 59% greater than those in summer. Similarly, ? values were 48% greater in spring. There was no detectable effect of space on the photosynthetic parameters, and temperature and macronutrient (NO3) concentrations also did not exert a strong influence. However, irradiance, dissolved iron concentrations, and carbon dioxide concentrations when altered under controlled conditions exerted significant influences on photosynthetic parameters. Specifically, reduced irradiance resulted in decreased PsB and ? values, whereas reduced iron concentrations were associated with increased PsB and ? values. Increased CO2 concentrations also resulted in significantly increased PsB and ? values. No significant difference was detected between stations dominated by diatoms and those dominated by the haptophyte Phaeocystis antarctica. The meta-analysis generally confirms the photosynthetic rates predicted from global analyses that are based solely on temperature and irradiance availability, but suggests that for more accurate predictions of the productivity of polar systems a more detailed model that includes temporal effects of photosynthetic parameters will be required.

Smith, W. O., Jr.; Donaldson, K. A.

2014-12-01

416

Sources and elemental composition of summer aerosols in the Larsemann Hills (Antarctica).  

PubMed

Atmospheric aerosols play a major role in the global climate change. A better physical characterization of the chemical composition of atmospheric aerosols, especially in remote atmosphere, is an important step to reduce the current uncertainty in their effect on the radiative forcing of the climate. In the present work, surface aerosols have been studied over the Southern Ocean and over Bharati, Indian Research Station at Larsemann Hills at the Antarctic coast during the summer season of 2009-2010. Aerosol samples were collected using optical particle counter (OPC) and high-volume air sampler. PM10 and PM2.5 aerosol samples were analyzed for various water-soluble and acid-soluble ionic constituents. The Hysplit model was used to compute the history of the air masses for their possible origin. Supplementary measurements of meteorological parameters were also used. The average mass concentration for PM10 over the Southern Ocean was found to be 13.4 ?g m(3). Over coastal Antarctica, the mass of PM10 was 5.13 ?g m(-3), whereas that of PM2.5 was 4.3 ?g m(-3). Contribution of marine components, i.e., Na, Cl and Mg was dominant over the Southern Ocean (79 %) than over the coastal Antarctica where they were dominant in coarse mode (67 %) than in fine mode (53 %) aerosols. The NH4/nss-SO4 ratio of 1.12 in PM2.5 indicates that the NH4 and SO4 ions were in the form of NH4HSO4. Computation of enrichment factors indicate that elements of anthropogenic origin, e.g., Zn, Cu, Pb, etc., were highly enriched with respect to crustal composition. PMID:25167815

Budhavant, Krishnakant; Safai, P D; Rao, P S P

2015-02-01

417

Space Radar Image of Weddell Sea, Antarctica  

NASA Technical Reports Server (NTRS)

This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths. Oceanographers believe this process forms most of the oceans' deep water. Sea ice covering all of the southern oceans, including the Weddell Sea, typically reaches its most northerly extent in about September. As periods of daylight become gradually longer in the Southern Hemisphere, ice formation stops and the ice edge retreats southward. By February, most of the sea ice surrounding Antarctica disappears. Imaging radar is extremely useful for studying the polar regions because of the long periods of darkness and extensive cloud cover. The multiple frequencies of the SIR-C/X-SAR instruments allow further study into ways of improving the separation of the various thickness ranges of sea ice, which are vital to understanding the heat balance in the ice, ocean and atmospheric system. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

1994-01-01

418

Space station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

Baraona, Cosmo R.

1987-01-01

419

Technology for space station  

NASA Astrophysics Data System (ADS)

Some of the most significant advances made in the space station discipline technology program are examined. Technological tasks and advances in the areas of systems/operations, environmental control and life support systems, data management, power, thermal considerations, attitude control and stabilization, auxiliary propulsion, human capabilities, communications, and structures, materials, and mechanisms are discussed. An overview of NASA technology planning to support the initial space station and the evolutionary growth of the space station is given.

Colladay, R. S.; Carlisle, R. F.

1984-10-01

420

Space Station Parametric Models  

NASA Technical Reports Server (NTRS)

The development of two parametric models for a four-panel planar initial space station is described. The derivations of the distributed parameter model are presented in detail with the hope that the same method and procedures can be employed for stations with different configurations or for changes within the same configuration class. The 19-DOF finite-element model is also described. With the availability of the 19-DOF and a lower-DOF space station models, the frequency characteristics of the various dynamical systems in the space station environment are identified.

Hamidi, M.; Wang, S. J.

1985-01-01

421

Weather Station Model  

NSDL National Science Digital Library

This lesson instructs students on how to read station models, the symbols used on weather maps to show data (temperature, wind speed and direction, barometeric pressure, etc.) for a given reporting station. It includes a diagram of a station model, an explanation of the data conveyed by the numbers and symbols, and a table of definitions for the graphic symbols used with models. There is also a set of interactive station models students can use for practice at interpretation, and an interactive exercise in which students use real-time weather data to interpret models.

422

International Space Station: Update  

NSDL National Science Digital Library

In November 1998, Zarya was launched into space, ushering in the era of the International Space Station (featured in the November 25, 1998 Scout Report for Science & Engineering). This month, the docking of the Zvezda Service Module marks the beginning of yet another phase -- in which Zvezda will serve as living quarters to the first ever resident crew (Expedition One), scheduled to arrive at the International Space Station in early November. This site from NASA provides updated information on the International Space Station, including recent news, planned missions, and a virtual tour of the (yet-to-be-completed) station.

423

Pseudonocardia antarctica sp. nov. an Actinomycetes from McMurdo Dry Valleys, Antarctica.  

PubMed

Strain DVS 5a1 was isolated from a moraine sample from the McMurdo Dry Valleys region of Antarctica. The strain is aerobic, Gram-positive, with white aerial mycelia and brown substrate mycelia, sporulating, has meso-diaminopimelic acid, arabinose and galactose in the cell wall, MK-8 (H4) as the major menaquinone and a mol% G+C content of DNA of 71% thus confirming to the description of the genus Pseudonocardia. Phylogenetic analysis based on the 16S rRNA gene sequence analysis further confirms that DVS 5al which forms a robust clade with P. alni, P. compacta, P. autotrophica and P. kongjuensis is closely related to the genus Pseudonocardia and exhibits maximum similarity of 99.7% with Pseudonocardia alni. However, at whole genome level as determined by DNA-DNA hybridisation DVS 5al exhibits a similarity of only 50% with Pseudonocardia alni. Further, DVS 5al differs from Pseudonocardia alni in that it does not produce acid from D-arabinose, meso-erythritol, melizitose, sorbitol, sucrose, D-trehalose; but produces acid from D-mannitol, D-galactose, D-maltose, D-mannose, inulin, D-ribose and D-xylose. Further, compared to Pseudonocardia alni, it has two additional fatty acids namely Me-C(18:0) and Me-C(19:0) and also possesses one additional unidentified lipid. It also shows distinct differences with P. compacta, P. autotrophica and P. kongjuensis and the other species of Pseudonocardia. It is proposed to assign DVS 5a1 the status of a new species for which the name Pseudonocardia antarctica sp. nov. is suggested. PMID:15053323

Prabahar, Vadivel; Dube, Smita; Reddy, G S N; Shivaji, S

2004-02-01

424

Distribution of sewage input in marine sediments around a maritime Antarctic research station indicated by molecular geochemical indicators  

Microsoft Academic Search

Sediments from Admiralty Bay, Antarctica were collected during the austral summers of 2002\\/2003 and 2003\\/2004 in order to assess the distribution and concentration of sewage indicators originating from Comandante Ferraz Brazilian Antarctic Station. Fecal sterols (coprostanol+epicoprostanol) and linear alkylbenzenes (LABs) ranged from <0.01 to 0.95?gg?1 and <1.0 to 23ngg?1 dry weight, respectively. In general, the higher concentrations were found only

Rosalinda C. Montone; César C. Martins; Márcia C. Bícego; Satie Taniguchi; Denis Albuquerque Moreira da Silva; Lúcia S. Campos; Rolf Roland Weber

2010-01-01

425

GLACIAL GEOLOGY OF CAPE BIRD, ROSS ISLAND, ANTARCTICA  

E-print Network

GLACIAL GEOLOGY OF CAPE BIRD, ROSS ISLAND, ANTARCTICA BY TINA M. DOCHAT1, DAVID R. MARCHANT2, University of Maine, Orono, Maine, USA Dochat,TinaM.,Marchant,D.R.andDenton,G.H.,2000:Gla- cialgeologyof CapeBird,shells,andforaminifersindicatethatacomponent of theicewithinthissheetflowedthroughtheTAM,groundedon theRoss Seafloor,andultimatelyadvancedlandwardontothe lowerslopes of MountBird

Marchant, David R.

426

Abandoned penguin rookeries as Holocene paleoclimatic indicators in Antarctica  

Microsoft Academic Search

Penguins are sensitive indicators of the Antarctic climate and of the environmental parameters that limit their presence and distribution. Paleoenvironmental data, obtained from the study of abandoned penguin rookeries (Pygoscelis adeliae) along the Victoria Land coast in Antarctica, indicate 14C date of 11-13 ka for the oldest abandoned rookery and supply new information about the timing of glacier retreat in

Carlo Baroni; Giuseppe Orombelli

1994-01-01

427

Airborne geophysical study in the pensacola mountains of antarctica  

USGS Publications Warehouse

A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to -80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explain the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 ?? associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anomaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement.

Behrendt, John C.; Meister, L.; Henderson, J.R.

1966-01-01

428

Desiccation tolerance of three moss species from continental Antarctica  

Microsoft Academic Search

Tolerance of desiccation was examined in three species of moss, Grimmia antarctici Card., Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., Meyer et Scherb. collected from two sites of contrasting water availability in the Windmill Islands, continental Antarctica. Physiological tolerance to desiccation was measured using chlorophyll fluorescence in plugs of moss during natural drying in the laboratory. Differences in

Sharon A. Robinson; J. Wasley; M. Popp; C. E. Lovelock

2000-01-01

429

Looking for Life in Antarctica ? and on Mars  

NSDL National Science Digital Library

This online article, from Earth: Inside and Out, reports on the search for microscopic organisms on Earth and Mars. It discusses the work of Chris McKay, an astrobiologist with NASA, the planetary similarities between Earth and Mars and current research in the valleys of Antarctica.

430

Cold tolerance in Tardigrada from Dronning Maud Land, Antarctica  

Microsoft Academic Search

Survival at low temperatures was studied in three species of Tardigrada from Müihlig-Hofmannfjella, Dronning Maud Land, Antarctica. Both hydrated and dehydrated specimens of Echiniscus jenningsi, Macrobiotus furciger and Diphascon chilenense had high survival rates following exposure to -22°C for ca. 600 days, and dehydrated specimens following 3040 days at this temperature. In hydrated E. jenningsi, mortality increased with the duration

Lauritz Sømme; Terje Meier

1995-01-01

431

Fossil and Recent Cheilostomata (Bryozoa) from the Ross Sea, Antarctica  

Microsoft Academic Search

Fifty-six species of cheilostome Bryozoa have been identified in samples from the McMurdo Sound area of the Ross Sea, Antarctica. Material collected alive from beneath the permanent ice sheet, at White Island and Cape Bird, is supplemented by fossil material collected from a coastal moraine deposit at Black Island. The moraine is thought to have formed through the ablation of

P. J. Hayward; P. D. Taylor

1984-01-01

432

Sea Ice and Ocean Energy Balance Studies at Mawson, Antarctica  

Microsoft Academic Search

The present program of year-round energy flux and oceanic measurements over sea ice and open water near Mawson, Antarctica, is described. The impor­ tance of various terms in the energy balance at different times of year is investi­ gated, as well as the application of these results to the parameterization of surface energy exchanges in the sea ice region. Particular

IAN ALLISON; GRAEME AKERMAN

433

A late winter hydrographic section from Tasmania to Antarctica  

Microsoft Academic Search

A hydrographic section between Tasmania and Antarctica was occupied in late winter 1991 as part of the World Ocean Circulation Experiment (WOCE). The primary purpose of the WOCE repeat section SR3 is to measure the exchange between the Indian and Pacific Oceans south of Australia. This paper describes the fronts, water masses and transport observed on the first occupation of

Stephen R. Rintoul; John L. Bullister

1999-01-01

434

The extraterrestrial Earth: Antarctica as analogue for space exploration  

Microsoft Academic Search

The polar regions have often been suggested as surrogates for the exploration and colonization of space. In particular, Antarctica's greater isolation makes it a useful analogue. Its features—abiotic, acultural, alien to human habitation—all echo the regions of interest to contemporary exploration, notably the solar system and the deep oceans. But more than a century of Antarctic experience also suggests that

Stephen J. Pyne

2007-01-01

435

Average September Ozone Levels over Antarctica for 1979 to 1998  

NSDL National Science Digital Library

The evolution of the ozone hole over Antarctica as shown through measurements of average ozone for September for the years 1979 through 1998, excluding 1995. These measurements were made by the TOMS instruments on Nimbus-7, Meteor-3 and Earth Probe. Dark blue represent regions of low ozone and red represents regions of high ozone.

Greg Shirah

1998-10-02

436

Antarctica: Arena for South American Cooperation or Conflict.  

ERIC Educational Resources Information Center

A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

Child, Jack

437

Hydrologic cycling over Antarctica during the middle Miocene warming  

NASA Astrophysics Data System (ADS)

From 20 to 15 million years (Myr) ago, a period of global warmth reversed the previous ice growth on Antarctica, leading to the retreat of the West Antarctic Ice Sheet and the contraction of the East Antarctic Ice Sheet. Pollen recovered from the Antarctic shelf indicates the presence of substantial vegetation on the margins of Antarctica 15.7Myr ago. However, the hydrologic regime that supported this vegetation is unclear. Here we combine leaf-wax hydrogen isotopes and pollen assemblages from Ross Sea sediments with model simulations to reconstruct vegetation, precipitation and temperature in Antarctica during the middle Miocene. Average leaf-wax stable hydrogen isotope (?D) values from 20 to 15.5Myr ago translate to average ?D values of -50‰ for precipitation at the margins of Antarctica, higher than modern values. We find that vegetation persisted from 20 to 15.5Myr ago, with peak expansions 16.4 and 15.7Myr ago coinciding with peak global warmth and vegetation growth. Our model experiments are consistent with a local moisture source in the Southern Ocean. Combining proxy measurements with climate simulations, we conclude that summer temperatures were about 11°C warmer than today, and that there was a substantial increase in moisture delivery to the Antarctic coast.

Feakins, Sarah J.; Warny, Sophie; Lee, Jung-Eun

2012-08-01

438

Epilithic lichens in the Beacon sandstone formation, Victoria Land, Antarctica  

NASA Technical Reports Server (NTRS)

The epilithic lichen flora on the Beacon sandstone formation in Victoria Land consists of seven species: Acarospora gwynnii Dodge & Rudolph, Buellia grisea Dodge & Baker, B. pallida Dodge & Baker, Carbonea capsulata (Dodge & Baker) Hale comb. nov., Lecanora fuscobrunnea Dodge & Baker, Lecidea cancriformis Dodge & Baker, and L. siplei Dodge & Baker. The typification of the species is given along with descriptions and distribution in Antarctica.

Hale, M. E.; Friedmann, E. I. (Principal Investigator)

1987-01-01

439

Observational Study of the Atmospheric Boundary Layer over Antarctica  

Microsoft Academic Search

During the austral summer of 1982\\/83, measurements of wind and temperature profiles were made through the atmospheric boundary layer in Adelie Land, East Antarctica, an area known for strong katabatic winds. It was found that a shallow but strong temperature inversion was developed at night, and destroyed during the day, resulting in the development of a well-mixed layer. Wind hodographs

Zbigniew Sorbjan; Yuji Kodama; Gerd Wendler

1986-01-01

440

Vascular plants as bioindicators of regional warming in Antarctica  

Microsoft Academic Search

Monitoring selected populations of the only two native Antarctic vascular plant species (Colobanthus quitensis andDeschampsia antarctica) over a 27-year period has revealed a significant and relatively rapid increase in numbers of individuals and populations at two widely separated localities in the maritime Antarctic. There is strong evidence that this increase is a response to a warming trend in summer air

R. I. Lewis Smith

1994-01-01

441

Accelerated Sea-Level Rise from West Antarctica  

Microsoft Academic Search

Recent aircraft and satellite laser altimeter surveys of the Amundsen Sea sector of West Antarctica show that local glaciers are discharging about 250 cubic kilometers of ice per year to the ocean, almost 60% more than is accumulated within their catchment basins. This discharge is sufficient to raise sea level by more than 0.2 millimeters per year. Glacier thinning rates

R. Thomas; E. Rignot; G. Casassa; P. Kanagaratnam; C. Acuña; T. Akins; H. Brecher; E. Frederick; P. Gogineni; W. Krabill; S. Manizade; H. Ramamoorthy; A. Rivera; R. Russell; J. Sonntag; R. Swift; J. Yungel; J. Zwally

2004-01-01

442

Grounding Zone Heterogeneity in West Antarctica  

NASA Astrophysics Data System (ADS)

Grounding zones of ice sheets are critical to understanding marine ice sheet dynamics as processes here determine the mass flux from grounded to floating ice, and thus eventually to the ocean. Furthermore, ocean-driven basal melt at grounding lines can initiate grounding line retreat and possibly trigger eventual deglaciation through the marine ice-sheet instability. Despite their importance to ice sheet dynamics and potential to influence sea level, direct basal observations of grounding zones remain sparse. Here we present geophysical data (ice-penetrating radar, active-source seismic, laser altimetry, and GPS data) and modeling results from three grounding zones in West Antarctica (two on Whillans Ice Stream (WIS) and one on Thwaites Glacier (TG)). These data show that grounding zones that have significantly different surface expressions (in the form of either differing surface slopes, recent grounding line behavior, or grounding zone width) also have significant differences in basal features and processes which are important to capture in ice flow models. On WIS, we compare the grounding zone of a subglacial embayment (an area where subglacial water from several subglacial lakes is suspected to drain to the ocean) to that of a subglacial promontory (characterized by steep surface slopes). The embayment is characterized by less dramatic surface and basal slopes, and less basal reflectivity contrast across the grounding zone. This suggests that there is less of a barrier to seawater intrusion into, and possibly, upstream, of the low-tide grounding line. In contrast, data collected over the promontory depict steep surface slopes, dramatic ice thinning across the grounding line, and a strong contrast in basal reflectivity. This indicates that the grounding zone in this promontory is likely a strong barrier to seawater intrusion and thus to grounding zone retreat. The grounding zone of TG has significantly steeper surface slopes than those on WIS and high basal reflectivity extends several kilometers inland of the grounding line in some areas. As on WIS, we interpret this as an indicator of possible seawater intrusion upstream of the grounding-line which may cause basal melt. Including this in our modeling gives results that indicate that if the width of the grounding zone, over which we partially extend basal melt, is greater than the width of underlying bedrock or sedimentary stabilizing structures, the grounding line is prone to retreat over these stabilizing features. These results highlight the need to more accurately incorporate grounding-zone processes and detailed subglacial topography into ice-sheet models in order to prognostically simulate future ice sheet behavior.

Jacobel, R. W.; Christianson, K.; Horgan, H.; Parizek, B. R.; Anandakrishnan, S.; Alley, R. B.; Walker, R. T.; Keisling, B.; Snyder, L.; Gobel, R.; Craig, B.; Dalla-Santa, K.

2012-12-01

443

ViewStationTM ViewStation  

E-print Network

system to include an embedded Web server and Web-based integrated presentation system. This unique monitor Auto-PIP system Auto-on, Auto-swap, Auto-off Composite connector RCA phono S-Video Mini-DIN Video of other high-end group systems. ViewStation is one of the first systems to implement the H.263 video

Pfeifer, Holger

444

Variability of 10Be and ?18O in snow pits from Greenland and a surface traverse from Antarctica  

NASA Astrophysics Data System (ADS)

To examine temporal variability of 10Be in glacial ice, we sampled snow to a depth of 160 cm at the NEEM (North Greenland Eemian Ice Drilling) drilling site in Greenland. The samples span three years between the summers of 2006 and 2009. At the same time, spatial variability of 10Be in glacial ice was explored through collection of the upper ?5 cm of surface snow in Antarctica during part of the Swedish-Japanese traverse from Svea to Syowa station during the austral summer in 2007-2008. The results of the Greenlandic 10Be snow suggested variable concentrations that apparently do not clearly reflect the seasonal change as indicated by the ?18O data. The 10Be concentration variability most likely reflects also effects of aerosol loading and deposition pathways, possibly in combination with post-depositional processes. The Antarctic traverse data expose a negative correlation between 10Be and ?18O, while there are weaker but still significant correlations to altitude and distance to the coast (approximated by the distance to the 70th latitude). These relationships indicate that geographical factors, mainly the proximity to the coast, may strongly affect 10Be concentrations in snow in Queen Maud Land, Antarctica.

Berggren, A.-M.; Aldahan, A.; Possnert, G.; Hansson, M.; Steen-Larsen, H. C.; Sturevik Storm, A.; Mörth, C.-M.; Murad, A.

2013-01-01

445

Correlation between mesospheric ozone and Energetic Particle Precipitation over Troll, Antarctica in the years 2008 and 2009  

NASA Astrophysics Data System (ADS)

The British Antarctic Survey radiometer stationed at Troll, Antarctica (72S, 2.5E, L=4.76) measured ozone in the lower mesosphere and upper stratosphere from February 2008 until February 2010. By looking at anomalies in the polar-winter nighttime ozone, we are able to quantify the influence of Energetic Particle Precipitation (EPP) on ozone during these two years. Time-lagged correlations between geomagnetic indices (AE, Kp and Dst) and ozone anomalies as a function of height have been calculated to quantify which of the indices best accounts for the variability in the ozone. In addition, the MEPED instruments aboard the NOAA satellites have been used to quantify the EPP flux precipitating over Troll. Since the solar activity in 2008 undergoes a strong periodicity, which is linked to rotating coronal holes, this periodicity is also manifested in the EPP and the geomagnetic indices. A correlation analysis between the ozone over Troll and the periodic solar activity that is reflected in the EPP is also carried out, resulting in a statistical quantification of the EPP effects on mesospheric ozone as measured over Troll, Antarctica.

Daae, M.; Espy, P. J.; Nesse Tyssøy, H.; Newnham, D. A.

2013-12-01

446

Changes in the character of Polar stratospheric clouds over Antarctica in 1992 due to the Pinatubo volcanic aerosol  

SciTech Connect

Vertical profiles of aerosol concentration were measured on 8 occasions from McMurdo Station, Antarctica (78[degrees]S), between late August and early October 1992. Polar stratospheric clouds (PSCs) were observed on 6 of these soundings. The characteristics of PSCs, and ozone, were quite different above and below about 16 km. Above 16 km PSCs were variable in time, with particles > 1.0 [mu]m radius contributing significantly to the surface area, generally < 8 [mu]m[sup 2] cm[sup [minus]3]. Below 16 km PSCs were much more stable and were dominated by high concentrations of smaller particles, < 1.0 [mu]m, with surface areas of 20-30 [mu]m[sup 2] cm[sup [minus]3]. This lower layer coincided with the altitude of the primary Pinatubo volcanic aerosol as measured in mid September and October, and with the 4 km region of the atmosphere where ozone was virtually completed destroyed over Antarctica in 1992. 12 refs., 4 figs.

Deshler, T.; Johnson, B.J.; Rozier, W.R. (Univ. of Wyoming, Laramie, WY (United States))

1994-02-15

447

Space station dynamics  

NASA Technical Reports Server (NTRS)

Structural dynamic characteristics and responses of the Space Station due to the natural and induced environment are discussed. Problems that are peculiar to the Space Station are also discussed. These factors lead to an overall acceleration environment that users may expect. This acceleration environment can be considered as a loading, as well as a disturbance environment.

Berka, Reg

1990-01-01

448

Weather Stations: Storms  

NSDL National Science Digital Library

In this activity, learners test how cornstarch and glitter in water move when disturbed. Learners compare their observations with videos of Jupiter's and Earth's storm movements. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

Lunar and Planetary Institute

2011-01-01

449

Station 13 revisited  

NASA Astrophysics Data System (ADS)

The article I wrote on the somewhat mysterious tracking station at Babsfontein in Gauteng (MNASSA Vol. 11 nos 3&4, April 2012) resulted in some correspondence, enabling me to get into contact with people who had worked at the station. This made it necessary to update the original article.

Roberts, G.

2012-10-01

450

ROCKY MOUNTAIN Research Station  

E-print Network

ROCKY MOUNTAIN Research Station New Publications July­ September 2003 What's Inside . . . · Hayman Research Station's Web site for regular updates on new publications at: http. write report number in space provided (e.g., INT-GTR-373). Without a card: 3. Cut off postcard and mail

451

ROCKY MOUNTAIN Research Station  

E-print Network

ROCKY MOUNTAIN Research Station New Publications October­ December 2003 What's Inside . . . · RAWS mailing of New Publications? Check the Rocky Mountain Research Station's Web site for regular updates former INT or RM reports, 2. Follow steps 1, 2, and 3 previous. write report number in space provided (e

452

HUNTERSTON POWER STATION  

Microsoft Academic Search

S>The research work necessary to enable new requirements for the ; Hunterston power station to be met is outlined, and a brief general description ; of the station is given. Components and techniques described include reactor ; vessel and core, fuel handling, reactor servicing machine, steam raising units, ; gas circuits, control and instrumentation, fuel elements, and generating plant. ;

Millar

1959-01-01

453

Pituitary-gonadal hormones during prolonged residency in Antarctica  

NASA Astrophysics Data System (ADS)

Plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and testosterone levels were measured in nine eugonadal men in New Delhi and during the 1st week of different months of their stay at Dakshin Gangotri in Antarctica. During their 12-month stay in Antarctica, they were exposed to a severely cold climate, long polar nights and polar days, high wind velocity, increased amounts of solar and ultraviolet radiation and geomagnetism, as well as physical and social isolation. Plasma testosterone tended to increase in March, but a significant increase (P<0.05) was not seen until April. The mean testosterone levels in May, June, September and November were also significantly higher than the March or New Delhi values. The absolute values of LH, FSH and PRL did not show any month-to-month changes in Antarctica. However, when the hormone levels were expressed as a percentage of the individual annual Antarctic mean, significant differences as a percentage of the individual annual Antarctic mean, significant differences were observed. The testosterone peak in April, May and June was associated with an increase in LH. The nadirs of testosterone, LH, FSH and PRL were seen in either July or August. FSH showed the highest values in March, whereas the highest PRL values were seen in November. These observations suggest the presence of circannual variations in gonadotropin, PRL and LH in Antarctica which are independent of polar days and polar nights. It appears that factors other than the duration of daylight might be involved in regulating these changes. The significance of maintenance of testosterone levels in the supra-physiological range in Antarctica remains unknown but may be important in acclimatization/habituation to the extreme polar cold by increasing basal metabolic rate, protein synthesis and erythropoiesis.

Sawhney, R. C.; Malhotra, A. S.; Prasad, Rajendra; Pal, Karan; Kumar, Rajesh; Bajaj, A. C.

454

Episodic occurrence of high precipitation events in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

The precipitation regime of Dronning Maud Land (DML), Antarctica, was studied using Antarctic Mesoscale Prediction System (AMPS) archive data. Precipitation is the most important component of the mass balance of the Antarctic ice sheet. Precipitation studies of DML are particularly interesting because two deep ice core drilling sites, Kohnen Station and Dome Fuji, are located in this region. For the correct interpretation of the ice core properties a thorough understanding of the precipitation regime is necessary. The high-resolution AMPS archive data for the year 2001-2006 were used to study spatial and temporal distribution of precipitation. AMPS has been developed by the Mesoscale and Microscale Division of NCAR (National Center for Atmospheric Research) and the Polar Meteorology Group of Byrd Polar Research Center (BPRC) of The Ohio State University. For the investigated time period AMPS employed the Polar MM5, a version of the Fifth Generation Pennsylvania State University/NCAR Mesoscale Model optimized for use over ice sheets. Whereas diamond dust is the prevailing type of precipitation with regard to time, several episodically occurring, synoptically induced precipitation events per year can bring unusually high amounts of precipitation and thus a large part of the total annual accumulation. This can cause a strong bias in the ice core data. Additionally, increased temperature and wind speeds during these events need to be taken into account for a correct climatic interpretation of ice cores. A better understanding of the frequency and cause of occurence of such intermittent precipitation in the interior of Antarctica in past and future climates is necessary for both paleoclimatological studies and estimates of future sea level change. We investigated the synoptic situtation for 49 „high precipitation events" that occurred during the time period 2001-2006 at Kohnen Station. The majority of the events was caused by an amplifying of Rossby waves with a strong northwesterly to northeasterly flow between a trough above the Weddell Sea and a blocking high above eastern DML. This synoptic pattern seems to be the most efficient one for bringing large amounts of moisture to the continent. Other, less frequently occuring synoptic situations include a flow from the southwest over the Weddell Sea connected to an upper air low above the Filchner-Ronne-Schelfeis. The model data are also used for a quantitative estimate of the ratio of diamond dust to synoptically induced precipitation.

Schlosser, E.; Powers, J. G.; Manning, K. W.; Duda, M. G.

2009-04-01

455

Surface melting on Larsen Ice Shelf, Antarctica  

NASA Astrophysics Data System (ADS)

The disintegration of Larsen A and B ice shelves in 1995 and 2002, respectively, was preceded by intense surface melting during the summer of ice-shelf collapse and previous summers. To understand the transition of the ice-shelf surface from dry to wet conditions, we developed a one-dimensional model, describing the mass, heat and force balances of water and firn within the ice-shelf surface layer. The model is run using atmospheric data from an automatic weather station on Larsen C ice shelf (World Meteorological Organization station 'Larsen Ice Site') located south of Larsen A and B. The model's derived melting rate is greater than melting predicted by the positive degree-day (PDD) approach, common in studies of ablating ice sheets, such as Greenland. The model shows that the years of ice-shelf break-up (1995 and 2002) are distinguished from previous years by local maxima in the number of melting days. When the PDD approach is considered, however, a maximum in the number of positive degree-days appears in the 2002 break-up year, but not in 1995.

Sergienko, Olga; Macayeal, Douglas R.

456

Madrid space station  

NASA Technical Reports Server (NTRS)

The Madrid space station, operated under bilateral agreements between the governments of the United States and Spain, is described in both Spanish and English. The space station utilizes two tracking and data acquisition networks: the Deep Space Network (DSN) of the National Aeronautics and Space Administration and the Spaceflight Tracking and Data Network (STDN) operated under the direction of the Goddard Space Flight Center. The station, which is staffed by Spanish employees, comprises four facilities: Robledo 1, Cebreros, and Fresnedillas-Navalagamella, all with 26-meter-diameter antennas, and Robledo 2, with a 64-meter antenna.

Fahnestock, R. J.; Renzetti, N. A.

1975-01-01

457