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1

Biosurfactant Production by Halotolerant Rhodococcus fascians from Casey Station, Wilkes Land, Antarctica  

Microsoft Academic Search

Isolate A-3 from Antarctic soil in Casey Station, Wilkes Land, was characterized for growth on hydrocarbons. Use of glucose\\u000a or kerosene as a sole carbon source in the culture medium favoured biosynthesis of surfactant which, by thin-layer chromatography,\\u000a indicated the formation of a rhamnose-containing glycolipid. This compound lowered the surface tension at the air\\/water interface\\u000a to 27 mN\\/m as well as

Victoria Gesheva; Erko Stackebrandt; Evgenia Vasileva-Tonkova

2010-01-01

2

Biosurfactant production by halotolerant Rhodococcus fascians from Casey Station, Wilkes Land, Antarctica.  

PubMed

Isolate A-3 from Antarctic soil in Casey Station, Wilkes Land, was characterized for growth on hydrocarbons. Use of glucose or kerosene as a sole carbon source in the culture medium favoured biosynthesis of surfactant which, by thin-layer chromatography, indicated the formation of a rhamnose-containing glycolipid. This compound lowered the surface tension at the air/water interface to 27 mN/m as well as inhibited the growth of B. subtilis ATCC 6633 and exhibited hemolytic activity. A highly hydrophobic surface of the cells suggests that uptake occurs via a direct cell-hydrocarbon substrate contact. Strain A-3 is Gram-positive, halotolerant, catalase positive, urease negative and has rod-coccus shape. Its cell walls contained meso-diaminopimelic acid. Phylogenetic analysis based on comparative analysis of 16S rRNA gene sequences revealed that strain A-3 is closely related to Rhodococcus fascians with which it shares 100% sequence similarity. This is the first report on rhamnose-containing biosurfactant production by Rhodococcus fascians isolated from Antarctic soil. PMID:20135319

Gesheva, Victoria; Stackebrandt, Erko; Vasileva-Tonkova, Evgenia

2010-08-01

3

Cost-efficient methods for marine pollution monitoring at Casey Station, East Antarctica: the choice of sieve mesh-size and taxonomic resolution.  

PubMed

Contaminants from sewage discharge and abandoned waste tips enter the marine environment adjacent to Australia's Casey Station, East Antarctica. To establish cost-efficient methods for benthic pollution monitoring the effects of sieve mesh-size (0.5 and 1.0 mm) and taxonomic aggregation (family, order and class) on the description of infaunal assemblages were determined. The abundance and taxonomy of fauna retained on a 0.5 mm sieve after passing through a 1.0 mm sieve were examined in this study. The 1.0 mm sieve fraction [Human impacts and assemblages in marine soft-sediments at Casey Station, Antarctica, Ph.D. thesis, University of New England, 2001] contained 70% of individuals and 94% of taxa when compared to combined abundances on the 1.0 and 0.5 mm sieves. Furthermore, the addition of 0.5 mm data did not increase sampling precision or the statistical power to detect differences between locations. Differences between locations were detected when species were aggregated to the family level however, further aggregation to order and class levels altered the perceived pattern of differences. Marine pollution monitoring of the soft-bottom benthos at Casey Station is most cost-effective when using a 1.0 mm sieve and identifying fauna to the family level. This is the first reported comparison of sampling techniques using Antarctic benthos. PMID:12586119

Thompson, Belinda W; Riddle, Martin J; Stark, Jonathan S

2003-02-01

4

Benthic diatom communities as indicators of anthropogenic metal contamination at Casey Station, Antarctica  

Microsoft Academic Search

Prior to environmental legislation in the 1980s, anthropogenic waste in Antarctica was often deposited into landfill sites or into the sea. This resulted in metal contamination in terrestrial and near-shore marine environments. In this study, we assess the feasibility of using both past and present diatom assemblages to reconstruct and monitor past and future metal contamination. Our dataset included the

Laura Cunningham; Ben Raymond; Ian Snape; Martin J. Riddle

2005-01-01

5

Biological monitoring of heavy-metal contamination in coastal waters off Casey Station, Windmill Islands, East Antarctica  

Microsoft Academic Search

Heavy-metal concentrations were determined in tissues of different species of benthic invertebrates collected in the Casey region (Australian Antarctic Territory) where an old waste-disposal tip site is a source of contamination. The species studied included the bivalve Laternula elliptica, starfish Notasterias armata, heart urchins Abatus nimrodi and A. ingens and gammaridean amphipod Paramoera walkeri. The specimens were collected at both

S. Duquesne; M. Riddle

2002-01-01

6

Ionospheric convection at Casey, a southern polar cap station  

NASA Astrophysics Data System (ADS)

A digital ionosonde (Digisonde Portable Sounder 4) located at Casey, Antarctica (66.3°S, 110.5°E, -80.8° corrected geomagnetic latitude) has been operational since early 1993 and has accumulated 3 years of plasma drift measurements, providing an excellent data set for studying the characteristics of ionospheric convection flow at a southern polar cap station. The purpose of this study is to investigate the influence of the IMF on the F region ionospheric convection over Casey and to compare it to the Heppner-Maynard satellite-derived electric field models. We find clear dependencies in the drift on the sign and strength of the IMF By and Bz components and with Kp. Antisunward flow dominates during Bz south conditions, turning to have a sunward component around noon when Bz is northward. The By component causes the entire convection system to rotate and distorts the dayside flow in the proximity of the throat, with a dawnward (duskward) component for By negative (positive). Comparison with the Bz south Heppner-Maynard BC, DE, and A patterns is favorable at most times, although we predict a rounder, more dominant dusk (dawn) cell and a smaller crescent-shaped dawn (dusk) cell for By<0 (By>0). There is a dependence on Kp when Bz is south in both the model and the drifts, flow directions becoming more antisunward and velocities becoming higher on the dayside as Kp increases. This implies the polar cap is expanding under conditions of enhanced reconnection. When Bz is north, the F region drift agreement with the BCP(P) and DEP(P) models is excellent on the dawn (dusk) side for By<0 (By>0) but diverges on the opposite side as the pattern flow lines twist sunward. Separation of the drifts into Bz weakly (<3nT) and strongly (>3nT) northward cases did not reveal any appreciable difference in the observed drift velocities.

Smith, P. R.; Dyson, P. L.; Monselesan, D. P.; Morris, R. J.

1998-02-01

7

Polyhydroxyalkanoate production by antarctic soil bacteria isolated from Casey Station and Signy Island  

Microsoft Academic Search

Polyhydroxyalkanoate (PHA) is a family of biopolymers produced by some bacteria and is accumulated intracellularly as carbon and energy storage material. Fifteen PHA-producing bacterial strains were identified from bacteria isolated from Antarctic soils collected around Casey Station (66°17?S, 110°32?E) and Signy Island (60°45?S, 45°36?W). Screening for PHA production was carried out by incubating the isolates in PHA production medium supplemented

Yuh Shan Goh; Irene Kit Ping Tan

8

Human impacts in Antartic marine soft-sediment assemblages: correlations between multivariate biological patterns and environmental variables at Casey Station  

NASA Astrophysics Data System (ADS)

Correlations between the spatial distribution of soft-sediment assemblages and environmental variables were evaluated at a number of control and potentially impacted locations (waste dumps, a sewage outfall and a wharf) at Casey Station, East Antarctica. Patterns of assemblage composition were compared with patterns of environmental variables using univariate and multivariate techniques. The utility of these methods, however, is uncertain in areas of significant habitat heterogeneity (at scales <10 m), such as at Casey Station. A number of environmental variables were measured to determine their potential influence on assemblage structure including sediment heavy metal concentrations, total organic carbon (TOC), grain size and depth. Soft-sediment assemblages clustered strongly into two groups and this pattern was found to be most highly correlated with concentrations of heavy metals of anthropogenic origin: cadmium, copper, lead, tin and zinc. The relationship, however, is complex and is likely to be further influenced by variables affecting the bioavailability of metals such as grain size, TOC and sediment anoxia. Impacted locations were characterised by fewer taxa, lower diversity and lower species richness. One of the control locations was found to have naturally high levels of cadmium, nickel and zinc and had assemblages very similar to those at the potentially impacted, polluted locations. One of the potentially impacted locations had coarse sediments and low levels of heavy metals but had assemblages very similar to other impacted locations. Problems of sampling design for human impacts detection in real world situations are discussed in relation to this study. This study provides evidence that these multivariate statistical methods are useful in heterogeneous environments and across pollution gradients where pollutants have the potential to act as a primary cause of spatial variation in assemblage structure.

Stark, Jonathan S.; Riddle, Martin J.; Snape, Ian; Scouller, Rebecca C.

2003-03-01

9

Polyhydroxyalkanoate production by antarctic soil bacteria isolated from Casey Station and Signy Island.  

PubMed

Polyhydroxyalkanoate (PHA) is a family of biopolymers produced by some bacteria and is accumulated intracellularly as carbon and energy storage material. Fifteen PHA-producing bacterial strains were identified from bacteria isolated from Antarctic soils collected around Casey Station (66°17'S, 110°32'E) and Signy Island (60°45'S, 45°36'W). Screening for PHA production was carried out by incubating the isolates in PHA production medium supplemented with 0.5% (w/v) sodium octanoate or glucose. 16S rRNA gene sequence analysis revealed that the isolated PHA-producing strains were mainly Pseudomonas spp. and a few were Janthinobacterium spp. All the isolated Pseudomonas strains were able to produce medium-chain-length (mcl) PHA using fatty acids as carbon source, while some could also produce mcl-PHA by using glucose. The Janthinobacterium strains could only utilize glucose to produce polyhydroxybutyrate (PHB). A Pseudomonas isolate, UMAB-40, accumulated PHA up to 48% cell dry mass when utilizing fatty acids as carbon source. This high accumulation occurred at between 5°C and 20°C, then decreased with increasing temperatures. Highly unsaturated mcl-PHA was produced by UMAB-40 from glucose. Such characteristics may be associated with the ability of UMAB-40 to survive in the cold. PMID:21945102

Goh, Yuh Shan; Tan, Irene Kit Ping

2012-04-20

10

Ozone profiles above Palmer Station, Antarctica  

NASA Technical Reports Server (NTRS)

NASA's Goddard Space Flight Center/Wallops Flight Facility conducted a series of 52 balloon-borne measurements of vertical ozone profiles over the National Science Foundation (NSF) research facility at Palmer Station, Antarctica (64 deg 46 S, 64 deg 3 W) between August 9 and October 24, 1987. High resolution measurements were made from ground level to an average of 10 mb. While much variation was seen in the profile amounts of ozone, it is clear that a progressive depletion of ozone occurred during the measurement period, with maximum depletion taking place in the 17 to 19 km altitude region. Ozone partial pressures dropped by about 95 percent in this region. Shown here are plotted time dependences of ozone amounts observed at 17 km and at arbitrarily selected altitudes below (13 km) and above (24 km) the region of maximum depletion. Ozone partial pressure at 17 km is about 150nb in early August, and has decreased to less than 10nb in the minimums in October. The loss rate is of the order of 1.5 percent/day. In summary, a progressive depletion in stratospheric ozone over Palmer Station was observed from August to October, 1987. Maximum depletion occurred in the 17 to 19 km range, and amounted to 95 percent. Total ozone overburden decreased by up to 50 percent during the same period.

Torres, Arnold L.; Brothers, George

1988-01-01

11

Asteroseismology at the Concordia station in Antarctica  

NASA Astrophysics Data System (ADS)

SIAMOIS is a project devoted to ground-based asteroseismology, involving an instrument to be installed at the Dome C Concordia station in Antarctica. SIAMOIS provides an asteroseismic programme that can follow the way currently opened by the space project CoRoT, with unique information on G and K type bright stars on the main sequence. In addition, spectrometric observations with SIAMOIS will be able to detect oscillation modes that cannot be analyzed in photometry: the Doppler data, less affected by the stellar activity noise, yield a more precise mode structure inversion. The SIAMOIS concept is based on Fourier Transform interferometry. Such a principle leads to a small instrument designed and developed for the harsh conditions in Antarctic. The instrument will be fully automatic, with no moving parts, and a very simple initial set up in Antarctic. The dedicated scientific programme will avoid the complications related to a versatile instrument. Data reduction will be performed in real time, and the transfer of the asteroseismic data to Europe will require only a modest bandwidth. SIAMOIS will observe with a dedicated small 40-cm telescope. Dome C appears to be the ideal place for ground-based asteroseismic observations. The unequalled weather conditions yield a duty cycle as high as 90% over 3 months, as was observed during the 2005 wintering. This high duty cycle, a crucial point for asteroseismology, is comparable to the best space-based observations. Long time series (up to 3 months) will be possible, thanks to the long duration of the polar night. SIAMOIS can be seen as one of the very first observational projects in astronomy at Dome C. Its scientific programme will take full advantage of the unique quality of this site, and will constitute a necessary first step in preparation of future more ambitious programmes requiring more sophisticated instrumentation and larger collectors

Mosser, B.; Siamois Team

2007-07-01

12

Status of DORIS stations in Antarctica for precise geodesy  

NASA Technical Reports Server (NTRS)

In Antarctica, besides the quite numerous GPS stations, four DORIS stations are permanently operating. In addition to the permanent DORIS stations, episodic campaigns took place at DomeC/Conccordia and on Sorsdal and Lambert glaciers. In this paper, we first collect general information concerning the stations and the campaigns (location, start of measurements, etc). We then present the results of observations of the permanent stations keeping in mind that we are primarily interested here in the vertical component, which is the most uncertain component.

Willis, P.; Amalvict, M.; Shibuya, K.

2005-01-01

13

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

14

Joint US/New Zealand GGOS Station in Antarctica?  

NASA Astrophysics Data System (ADS)

An idea of establishment of a GGOS station in Antarctica to be operated jointly from McMurdo Station (US) and the neighbouring New Zealand's Scott Base is re-examined. Minimal, optimal and maximal scenarios are considered; construction, operation and maintenance costs for different scenarios are discussed. The science case is outlined which includes valuable contribution into study of the Earth orientation parameters, tectonic plate motion, establishment of the Antarctic Vertical Datum, and climate change research.

Gulyaev, S.

2013-12-01

15

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

16

Meteorological surface conditions at Kohnen Station, Antarctica  

NASA Astrophysics Data System (ADS)

Only a few detailed meteorological experiments have been performed in the higher regions of the Antarctic ice sheet. This contribution will describe part of such an experiment and its outcome, performed at Kohnen Station (75.00 S, 0.07 E, 2892 m asl.) in the Antarctic summer of 2001-'02. Results from this experiment are to benefit the interpretation of the ice core presently being drilled at this location. Surface conditions in the 40 day period of measurements varied from typically stable to extraordinarily warm and windy. First we focus on the surface energy balance during this summer period. A model with only a few input parameters is used to combine measured net radiation with calculated heat fluxes to iteratively search for a surface temperature for which all components balance out. Calculated components are compared with measurements. In time this model will be functional for weather stations at different locations. Despite the high albedo (0.82 - 0.92) the net shortwave radiation is the largest component at the surface, contributing a maximum of 100 W/m2. Surprisingly small is the latent heat flux, in fair weather no more than a few W/m2. In general the calculations agree well with the measurements. A shallow convective layer developed in the daytime by the sensible heat flux is confirmed by balloon measurements. Linking the surface conditions to measurements outside of the surface layer we find little correlation, as to be expected.

van As, D.; van den Broeke, M. R.

2003-04-01

17

Rates of soluble carbohydrate utilization in soils from the Windmill Islands Oasis, Wilkes Land, continental Antarctica  

Microsoft Academic Search

A time course study of the fate of glucose, sucrose, and arabitol added to surface soils collected from vegetated and bare sites near Casey Station, Wilkes Land, Antarctica, was performed using gas-liquid chromatography. For both soils, hydrolysis of added sucrose was observed after 24 hours. Following 168 hours incubation at both 5°C and 15°C, hydrolysis of sucrose to glucose and

D. R. Melick; M. Bölter; R. Möller

1994-01-01

18

Halley Research Station, Antarctica: calving risks and monitoring strategies  

NASA Astrophysics Data System (ADS)

The British Antarctic Survey's Halley Research Station is located on the Brunt Ice Shelf, Antarctica, where it is potentially vulnerable to calving events. Existing historical records show that the Brunt Ice Shelf is currently extended further into the Weddell Sea than it was before its last large calving event, so a new calving event may be overdue. We describe three different possible future scenarios for a large-scale calving event on Brunt Ice Shelf. We conclude that currently the most threatening scenario for the Halley Research Station is a calving event on the neighbouring Stancomb-Wills Glacier Tongue, with subsequent detrimental consequences for the stability of the Brunt Ice Shelf. Based on available data, we suggest an increasing likelihood of this scenario occurring after 2020. We furthermore describe ongoing monitoring efforts aimed at giving advanced warning of an imminent calving event.

Anderson, R.; Jones, D. H.; Gudmundsson, G. H.

2014-04-01

19

Halley Research Station, Antarctica: calving risks and monitoring strategies  

NASA Astrophysics Data System (ADS)

The British Antarctic Survey's Halley Research Station is located on the Brunt Ice Shelf, Antarctica, where it is potentially vulnerable to calving events. Existing historical records show that the Brunt Ice Shelf is currently extended further into the Weddell Sea than it was before its last large calving event, so a new calving event may be overdue. We describe three different possible future scenarios for a large-scale calving event on Brunt Ice Shelf, and conclude that the currently most threatening scenario for the Halley Research Station is a calving event on the neighbouring Stancomb-Wills Glacier Tongue, with subsequent detrimental consequences for the stability of the Brunt Ice Shelf. Based on available data, we suggest an increasing likelihood of this scenario occurring after 2020. We furthermore describe ongoing monitoring efforts aimed at giving advanced warning of an imminent calving event.

Anderson, R.; Jones, D. H.; Gudmundsson, G. H.

2013-11-01

20

Chemical composition of fresh snowfalls at Palmer Station, Antarctica  

NASA Astrophysics Data System (ADS)

A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64°46'S, 64°05'W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium, sulfate, magnesium, calcium, potassium, fluoride, ammonium, and nitrate, excluding hydrogen and hydroxide. The pH of these samples ranged between 4.0-6.2. The relatively low nitrate and relatively high sulfate concentrations found in our samples are consistent with the results of other studies for this region of Antarctica. The ions and pH do not appear to favor a particular wind direction during this period. The total deposition of sulfate and flouride via snowfall between 10 January and 10 February is conservatively estimated to be 4.78 and 1.3 kg km -2, respectively.

DeFelice, T. P.

21

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

22

Surface Flux Measurements at King Sejong Station in West Antarctica  

NASA Astrophysics Data System (ADS)

The Antarctic Peninsula is important in terms of global warming research due to pronounced increase of air temperature over the last century. The first eddy covariance system was established and turbulent fluxes of heat, water vapor, CO2 and momentum have been measured at King Sejong Station (62 \\deg 13øØS, 58 \\deg 47øØW) located in the northern edge of the Antarctic Peninsula since December in 2002. Our objectives are to better understand the interactions between the Antarctic land surface and the atmosphere and to test the feasibility of the long-term operation of eddy covariance system under extreme weather conditions. Various lichens cover the study area and the dominant species is Usnea fasciata-Himantormia. Based on the analyses on turbulent statistics such as integral turbulence characteristics of vertical velocity (w) and heat (T), stationarity test and investigation of correlation coefficient, they follow the Monin-Obukhov similarity and eddy covariance flux data were reliable. About 50 % of total retrieved sensible heat flux data could be used for further analysis. We will report on seasonal variations of energy and mass fluxes and environmental variables. In addition, factors controlling these fluxes will be presented. Acknowledgement: This study was supported by ¡rEnvironmental Monitoring on Human Impacts at the King Sejong Station, Antarctica¡_ (Project PP04102 of Korea Polar Research Institute) and ¡rEco-technopia 21 project¡_ (Ministry of Environment of Korea).

Choi, T.; Lee, B.; Lee, H.; Shim, J.

2004-12-01

23

Antarctica  

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

24

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

25

Spectroscopic measurements of tropospheric iodine oxide at Neumayer Station, Antarctica  

NASA Astrophysics Data System (ADS)

First measurements of iodine oxide (IO) in the Antarctic troposphere are reported. Since March 1999, a newly developed dual channel spectrograph has been continuously performing Differential Optical Absorption Spectroscopy (DOAS) measurements of zenith scattered sunlight at Neumayer-Station, Antarctica (70°39?S, 8°15?W). The spectral signature of IO was clearly detected by observing five vibrational absorption bands located in the wavelength region between 415 and 461 nm. The observed diurnal variation of IO is characterized by a rapid decrease in the differential slant column density (DSCD) with increasing solar zenith angle (SZA) during twilight. This observation points to a fast conversion of reactive iodine into its nighttime reservoir species. It also strongly indicates that the detected IO is located in the troposphere. The decrease of the IO DSCD of up to 1 · 1014 molec/cm² between 80° and 95° SZA is unexpectedly large. Under the assumption that IO is located in the marine boundary layer (MBL) (below 2 km), IO mixing ratios may reach up to ?10 ppt. The seasonal variation shows higher IO amounts during summer than during winter. This finding is possibly caused by the smaller distance to the open sea, where the iodocarbons are emitted, and by the more efficient photodissociation of the organic iodine precursors.

Frieß, U.; Wagner, T.; Pundt, I.; Pfeilsticker, K.; Platt, U.

26

Deployment of Autonomous GPS Stations in Marie Byrd Land, Antarctica  

NASA Technical Reports Server (NTRS)

During the 1998-1999 Antarctic field season, we installed three autonomous GPS stations in Marie Byrd Land, West Antarctica to measure glacio-isostatic rebound and rates of spreading across the West Antarctic Rift System. The systems collect data throughout the entire year and therefore must function during the warm, relatively mild summer, and cold, harsh winters. They are powered by gel cell batteries that are charged by wind and solar power. The system includes dual data logging capability. We log data at 5 minute intervals within the receiver and at 30 second intervals to a serial data logger. We do not require 365 days of continuous data for well determined crustal velocities, but rather long periods (greater than 24 hours) of continuous data distributed throughout the year. Therefore, for simplicity, we designed the system to accept occasional data interruptions. The batteries, in addition to supplying power, act as a thermal capacitive heat storage device to help regulate the temperatures within the system. This storage system absorbs the majority of the 10-15 watts of power from the receiver and 5 watts from the data logger which helps to maintain temperature for long periods of time. Power is switched off when the temperature within the system enclosure reaches 50'C and is reconnected at 20 C. If battery voltage drops too low the batteries will freeze. Therefore, we cut the power off when the batteries drop to a low voltage of 12.45V. Power is restored at 13.2V. The temperature and power hysteresis allows for a minimum of several days of data to be collected before system shutdowns. A check of all three stations in late January 1999 indicated that the thermal and power control systems are performing as expected. We plan to implement satellite telemetry to the systems during the 2000-2001 season following a year of development.

Donnellan, Andrea; Luyendyk, Bruce; Rebold, Thomas; Awaya, Henry; Nesbit, William; Dace, Gregory

1999-01-01

27

Ionospheric GPS-TEC during the 2004 major storm events at Scott Base station Antarctica  

Microsoft Academic Search

In this work, we investigate the characteristics of the 2004 major storm events based on GPS-TEC measurement at Scott Base station Antarctica (77.9degS, 166.8degE). The F2 layer critical frequencies and peak height during the storm from the ionosonde measurement at the station are also investigated. Our main emphasis was on the characteristics and response during major storms events. Our results

Sumazly Sulaiman; Mohd Alauddin Mohd Ali; Baharudin Yatim

2007-01-01

28

Temporal and spatial patterns of anthropogenic disturbance at McMurdo Station, Antarctica  

NASA Astrophysics Data System (ADS)

Human visitations to Antarctica have increased in recent decades, raising concerns about preserving the continent's environmental quality. To understand the spatial and temporal patterns of anthropogenic disturbances at the largest scientific station in Antarctica, McMurdo Station, a long-term monitoring program has been implemented. Results from the first nine years (1999-2007) of monitoring are reported. Most physical disturbance of land surfaces occurred prior to 1970 during initial establishment of the station. Hydrocarbons from fuel and anthropogenic metals occur in patches of tens to hundreds of square meters in areas of fuel usage and storage. Most soil contaminant concentrations are not expected to elicit biological responses. Past disposal practices have contaminated marine sediments with polychlorinated biphenyls (PCBs), petroleum hydrocarbons, and metals in close proximity to the station that often exceed concentrations expected to elicit biological responses. Chemical contamination and organic enrichment reduced marine benthic ecological integrity within a few hundred meters offshore of the station. Contaminants were detected in marine benthic organisms confirming bioavailability and uptake. PCBs in sediments are similar to suspected source materials, indicating minimal microbial degradation decades after release. Anthropogenic disturbance of the marine environment is likely to persist for decades. A number of monitoring design elements, indicators and methodologies used in temperate climates were effective and provide guidance for monitoring programs elsewhere in Antarctica.

Kennicutt, Mahlon C., II; Klein, Andrew; Montagna, Paul; Sweet, Stephen; Wade, Terry; Palmer, Terence; Sericano, Jose; Denoux, Guy

2010-07-01

29

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.

30

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

31

Black carbon aerosol at McMurdo Station, Antarctica.  

PubMed

Aerosol light absorption as black carbon (BC) was measured from November 19, 1995, to February 6, 1996, at a location 0.65 km downwind of the center of McMurdo Station on the Antarctic coast. The results show a bimodal frequency distribution of BC concentrations. Approximately 65% of the measurements were found in a mode at a low range of concentrations centered at approximately 20 ng/m3. These concentrations are higher than those found at other remote Antarctic locations and probably represent contamination from the station. The remaining measurements were in a high-concentration mode (BC approximately 300 ng/m3), indicating direct impact of local emissions from combustion activities at the station. High values of BC were associated with winds from the direction of the station, and the BC flux showed a clear directionality. Maximum BC concentrations occurred between 7:00 and 11:00 a.m. The "polluted" mode accounted for more than 80% of the BC frequency-weighted impact at this location. PMID:11321916

Hansen, A D; Lowenthal, D H; Chow, J C; Watson, J G

2001-04-01

32

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

33

Lidar measurement of stratospheric aerosol at Syowa Station, Antarctica  

NASA Technical Reports Server (NTRS)

Lidar measurement on Antarctic aerosols were made during the Antarctic Middle Atmosphere (AMA) period, 1983 to 1985, at Syowa Station. Topics measured are winter enhancement aerosol layer and volcanic effect of El Chichon on the Antarctic stratosphere aerosols. The large depolarization ratio (maximum value was about 0.8) seems to support sublimation growth of ice crystals. The lidar measurements showed a meaningful time lag between aerosol content increase and depolarization ratio increase. Considering the balloon observations made in early winter, it was speculated that an increase in large particle number concentration also contributed to the winter enhancement. The El Chichon cloud spread to the Antarctic region by the beginning of 1983. The temporal change of integrated backscatter coefficient shows a clear decay pattern, although strong winter enhancement superposes.

Iwasaka, Y.; Hirasawa, T.; Fukunishi, H.; Ono, T.; Nomura, A.

1986-01-01

34

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

35

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

36

Antarctica  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on icebergs and water salinity, as well as the environment of the continent of Antarctica. Students research this area and do an experiment demonstrating the relationship between water salinity and ice floating or sinking in the ocean. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

Cahill, Mary

37

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

38

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

39

Effects on skylight at South Pole Station, Antarctica, by ice crystal precipitation in the atmosphere.  

PubMed

Measurements of the radiance and polarization of the skylight at South Pole Station, Antarctica, were made for clear cloud-free skies and cloudless skies with ice crystal precipitation. The measurements were made at six narrowband wavelengths from 321 to 872 nm in the principal plane. The data show that scattering by ice crystals increases the radiance in the backscatter plane, decreases it in the solar plane, and shifts the radiance minimum to a point closer to the sun. The crystals decrease the maximum value of linear polarization and shift the position of the maximum away from the sun. The influence of ice crystal scattering is greatest at the longer wavelengths. PMID:18195749

Fitch, B W; Coulson, K L

1983-01-01

40

Effects on skylight at South Pole Station, Antarctica, by ice crystal precipitation in the atmosphere  

NASA Technical Reports Server (NTRS)

Measurements of the radiance and polarization of the skylight at South Pole Station, Antarctica, were made for clear cloud-free skies and cloudless skies with ice crystal precipitation. The measurements were made at six narrowband wavelengths from 321 to 872 nm in the principal plane. The data show that scattering by ice crystals increases the radiance in the backscatter plane, decreases it in the solar plane, and shifts the radiance minimum to a point closer to the sun. The crystals decrease the maximum value of linear polarization and shift the position of the maximum away from the sun. The influence of ice crystal scattering is greatest at the longer wavelengths.

Fitch, B. W.; Coulson, K. L.

1983-01-01

41

Work plan for the preliminary site investigation for McMurdo Station, Ross Island, Antarctica  

SciTech Connect

This document presents the final work plan for the preliminary site investigation to be conducted at McMurdo Station, Ross Island, Antarctica. A draft version of this report was presented to the National Science Foundation (NSF) in January 1991. This work plan includes a brief site description and background, a discussion of the environmental setting, a sampling and analytical program for data collection, and a brief description of sampling and data management procedures. A description of the geologic and geophysical investigation to be conducted is also included. 18 refs., 4 figs., 4 tabs.

Stefano, J.E.; Patton, T.L.; McGinnis, L.D.; Bebrich, C.A.; Knudson, D.A.; Picel, K.C.

1991-05-01

42

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

43

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

44

Haze episodes at Syowa Station, coastal Antarctica: Where did they come from?  

NASA Astrophysics Data System (ADS)

During our aerosol measurement program at Syowa Station, Antarctica, in 2004-2007, some low-visibility (haze) phenomena were observed during winter-spring under conditions with low winds and without drifting snow and fog. During "Antarctic haze" phenomena, the number concentration of aerosol particles and black carbon concentration increased by 1 to 2 orders higher relative to background conditions at Syowa Station, whereas surface O3 concentration dropped simultaneously, especially after polar sunrise. Chemical analysis showed that major aerosol constituents in the haze phenomena were sea salt (e.g., Na+, Cl-). Trajectory analysis and the Navy Aerosol Analysis and Prediction System model showed that plumes from biomass burning in South America and southern Africa were transported to Syowa Station, on the Antarctic coast, because of the eastward (occasionally westward) approach of cyclones in the Southern Ocean and subsequent poleward flow. This poleward flow from midlatitudes of the plume and injection of sea-salt particles during the transport might engender Antarctic haze phenomena at Syowa Station. Differences of O3 concentration between the background and the haze conditions tended to be larger in spring (after polar sunrise) than in winter. Enhancement of sea-salt particles in the haze events can serve important roles in providing additional sources of reactive halogen species.

Hara, K.; Osada, K.; Yabuki, M.; Hashida, G.; Yamanouchi, T.; Hayashi, M.; Shiobara, M.; Nishita, C.; Wada, M.

2010-07-01

45

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

National Technical Information Service (NTIS)

This report describes the analysis and investigation of wind energys potential to reduce the quantity of diesel fuel consumed to provide power and heat to the two U.S. Antarctica facilities at McMurdo and the Amundsen-Scott South Pole Station. Staff from ...

I. Baring-Gould R. Robichaud K. McLain

2005-01-01

46

Influence of Solar Energetic Phenomena on GPS PWV During the Major Storm of 2003 at Scott Base Station, Antarctica  

Microsoft Academic Search

The influence of solar energetic phenomena, solar flare index and extreme ultraviolet (EUV) on precipitable water vapor (PWV) are investigated during the intense 2003 geomagnetic storms at Scott Base station Antarctica for the period between 22 October and 7 November 2003. The PWV parameter is obtained from the GPS signals and surface meteorological data (pressure, temperature and humidity) measured at

Z. A. Abdul Rashid; W. Suparta; M. A. Mohammed Ali; B. Yatim

2006-01-01

47

11-year Solar Cycle and Long Term Trend in OH airglow Temperature Observations at the South Pole Station, Antarctica  

Microsoft Academic Search

We have examined Michelson Interferometer OH airglow temperature data to investigate solar cycle and long-term variations of mesospheric temperatures at the South Pole Station, Antarctica (90o S). The aforementioned MI has been making observations of temperature and airglow emissions since 1992 during austral winter night. These continuous measurements during the six months of each polar winter allow us to investigate

I. Azeem; G. G. Sivjee; Y. Won; C. Mutiso

2005-01-01

48

Upper-Bound Radiation Dose Assessment for Military Personnel at McMurdo Station, Antarctica, between 1962 and 1979.  

National Technical Information Service (NTIS)

U.S. veterans who were assigned at McMurdo Station, Antarctica, from 1962 to 1979, have expressed concern that their health may have been affected by radiological releases from an onsite nuclear power plant. This report presents the results of the Departm...

G. R. Fairchild J. D. Dunavant M. Chehata P. K. Blake W. J. Morris

2013-01-01

49

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

50

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

51

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

52

A study of the structure of low-level katabatic winds at Mizuho Station, East Antarctica  

NASA Astrophysics Data System (ADS)

Low-level katabatic wind profiles, which have shapes similar to those of the low-level jet (LLJ) wind profiles, are often observed during strong winds in the summer period at Mizuho Station, which is located at 70°42' S, 44°20' E in East Antarctica. The profiles may be classified according to the height of the maximum wind speed, z m , found below 30 m height. The behavior of z m and of conditions in the layer above z mare explained well by the normalized frequency, f N = Nz/U at 30 m, whose value can be used to predict the existence of a LLJ wind profile. Subsidence and inertial oscillations above z m are related closely to the height and time variations of z m. Thus, not only effects emanating upward from surface but also momentum and heat transported downward from above are significant for the evolution of z m.

Chiba, Osamu; Kobayashi, Shun'ichi

1986-12-01

53

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

54

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

55

Extracting fair-weather data from atmospheric electric-field observations at Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

At Syowa Station (69.0°S, 39.6°E), located on East Ongul Island near the continent of Antarctica, atmospheric electric-field observations started in 1968 and had been carried out intermittently. An improved electric-field mill at Syowa Station had and obtained better-quality atmospheric electric-field data from February 2005 to January 2006. After a 1-year interruption, the observations resumed in January 2007. The atmospheric electric-field data from Syowa Station are often contaminated due to local disturbances caused by near-ground meteorological phenomena. We examined correlations between the atmospheric electric field and near-ground weather from February 2005 to January 2006 and from February 2007 to January 2008, and proposed a criterion to extract “fair-weather” electric-field data based on wind speed and cloud coverage data. The diurnal variation of fair-weather data in January followed the shape of the so-called Carnegie curve. Fair-weather data obtained during a substorm showed some correspondence between the atmospheric electric field and variations in the geomagnetic field. This newly developed extraction method may enable the use of atmospheric electric-field data for studying the solar terrestrial environment.

Minamoto, Yasuhiro; Kadokura, Akira

2011-09-01

56

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

57

Sulphate profile in EPICA-DML ice core (Kohnen Station East Antarctica) by Fast Ion Chromatography.  

NASA Astrophysics Data System (ADS)

Kohnen Station (Dronning Maud Land - Atlantic sector of Antarctica) is one of the two drilling sites, the other being located at Dome C, chosen in the framework of EPICA project. Unlike Dome C ice core (EDC), where the low accumulation rate allowed recovering climatic and environmental data covering more than 800.000 years, the Kohnen Station ice core (EDML) is expected to provide paleo-data related to the last two glacial/interglacial cycles, due to the higher accumulation rate. On the other hand, the thicker annual accumulation rate grants a stratigraphy with higher temporal detail, providing more accurate information about fast climatic variations super-imposed to the major cycles. Moreover, EDML is expected to be influenced by Atlantic Ocean, then potentially able to give information about variations in the North Atlantic Deep Water and its relationship with global climate change. In order to temporally set the EDML paleo-records and allow a reliable synchronization with paleo-data memorised in Greenland and Antarctica ice cores, an accurate dating of the ice core is fundamental. The high accumulation rate and relative closeness to the sea drives toward the use of marine biogenic substances, irreversibly fixed in the snow layers as seasonal markers. Non-sea-salt sulphate coming from atmospheric oxidation of dimethylsulphide emitted by phytoplanktonic activity seems to be useful to this purpose. Since at Kohnen Station nss-sulphate is the dominant contribute to the sulphate budget, high-resolution sulphate profile could be used for a stratigraphic dating (summer maxima). An improvement of the FIC method, successfully used for in field measurement on EDC ice core, was performed. The method was applied to ice core processing at Bremerhaven (D) in June 2002 (113 to 449 m depth), giving a continuous sulphate record at 1.0 cm ice resolution, with a melting rate of 4.0 cm/min. The measured standard deviation is lower than 5.0 % and the detection limit is 4.0 ug/l. The data elaboration is in progress but preliminary results related to selected ice core sections seem to confirm a seasonal trend able to allow a reliable annual layer counting. Abrupt sulphate peaks, related to volcanic eruptions, superimposed to the seasonal trend, provide depth horizons for an absolute dating by knowing the event date or by comparing the same volcanic signatures recorded in already dated ice cores.

Severi, M.; Becagli, S.; Benassai, S.; Castellano, E.; Migliori, A.; Udisti, R.

2003-04-01

58

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

59

Simultaneous aerosol measurements of unusual aerosol enhancement in troposphere over Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

Unusual aerosol enhancement is often observed at Syowa Station, Antarctica during winter through spring. Simultaneous aerosol measurements near the surface and in the upper atmosphere were conducted twice using a ground-based optical particle counter, a balloon-borne optical particle counter, and micro-pulse LIDAR (MPL) in August and September 2012. During 13-15 August, aerosol enhancement occurred immediately after a storm condition. A high backscatter ratio and aerosol concentrations were observed from the surface to ca. 2.5 km over Syowa Station. Clouds appeared occasionally at the top of aerosol-enhanced layer during the episode. Aerosol enhancement was terminated on 15 August by strong winds caused by a cyclone's approach. In the second case on 5-7 September, aerosol number concentrations in Dp > 0.3 ?m near the surface reached > 104 L-1 at about 15:00 UT on 5 September in spite of calm wind conditions, whereas MPL measurement exhibited aerosols were enhanced at about 04:00 UT at 1000-1500 m above Syowa Station. The aerosol enhancement occurred near the surface-ca. 4 km. In both cases, air masses with high aerosol enhancement below 2.5-3 km were transported mostly from the boundary layer over the sea-ice area. In addition, air masses at 3-4 km in the second case came from the boundary layer over the open-sea area. This air mass history strongly suggests that dispersion of sea-salt particles from the sea-ice surface contributes considerably to the aerosol enhancement in the lower free troposphere (about 3 km) and that the release of sea-salt particles from the ocean surface engenders high aerosol concentrations in the free troposphere (3-4 km).

Hara, K.; Hayashi, M.; Yabuki, M.; Shiobara, M.; Nishita-Hara, C.

2013-10-01

60

Measurement of black carbon at Syowa station, Antarctica: seasonal variation, transport processes and pathways  

NASA Astrophysics Data System (ADS)

Measurement of black carbon (BC) was carried out at Syowa station Antarctica (69° S, 39° E) from February 2004 until January 2007. The BC concentration at Syowa ranged from below detection to 176 ng m-3 during the measurements. Higher BC concentrations were observed mostly under strong wind (blizzard) conditions due to the approach of a cyclone and blocking event. The BC-rich air masses traveled from the lower troposphere of the Atlantic and Indian Oceans to Syowa (Antarctic coast). During the summer (November-February), the BC concentration showed a diurnal variation together with surface wind speed and increased in the katabatic wind from the Antarctic continent. Considering the low BC source strength in the Antarctic continent, the higher BC concentration in the continental air (katabatic wind) might be caused by long range transport of BC via the free troposphere from mid- and low- latitudes. The seasonal variation of BC at Syowa had a maximum in August, while at the other coastal stations (Halley, Neumayer, and Ferraz) and the continental station (Amundsen-Scott), the maximum occurred in October. This difference may result from different transport pathways and scavenging of BC by precipitation during the transport from the source regions. During the austral summer, long-range transport of BC via the free troposphere is likely to make an important contribution to the ambient BC concentration. The BC transport flux indicated that BC injection into the Antarctic region strongly depended on the frequency of storm (blizzard) conditions. The seasonal variation of BC transport flux increased by 290 mg m-2 month-1 in winter-spring when blizzards frequently occurred, whereas the flux decreased to lower than 50 mg m-2 month-1 in the summer with infrequent blizzards.

Hara, K.; Osada, K.; Yabuki, M.; Hayashi, M.; Yamanouchi, T.; Shiobara, M.; Wada, M.

2008-05-01

61

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

62

Simultaneous aerosol measurements of unusual aerosol enhancement in the troposphere over Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

Unusual aerosol enhancement is often observed at Syowa Station, Antarctica, during winter and spring. Simultaneous aerosol measurements near the surface and in the upper atmosphere were conducted twice using a ground-based optical particle counter, a balloon-borne optical particle counter, and micropulse lidar (MPL) in August and September 2012. During 13-15 August, aerosol enhancement occurred immediately after a storm condition. A high backscatter ratio and high aerosol concentrations were observed from the surface to ca. 2.5 km over Syowa Station. Clouds appeared occasionally at the top of the aerosol-enhanced layer during the episode. Aerosol enhancement was terminated on 15 August by strong winds from a cyclone's approach. In the second case, on 5-7 September, aerosol number concentrations in Dp > 0.3 ?m near the surface reached > 104 L-1 at about 15:00 UT (Universal Time) on 5 September despite calm wind conditions, whereas MPL measurement exhibited aerosols were enhanced at about 04:00 UT at 1000-1500 m above Syowa Station. The aerosol enhancement occurred near the surface to ca. 4 km. In both cases, air masses with high aerosol enhancement below 2.5-3 km were transported mostly from the boundary layer over the sea-ice area. In addition, air masses at 3-4 km in the second case came from the boundary layer over the open-sea area. This air mass history strongly suggests that dispersion of sea-salt particles from the sea-ice surface contributes considerably to aerosol enhancement in the lower free troposphere (about 3 km) and that the release of sea-salt particles from the ocean surface engenders high aerosol concentrations in the free troposphere (3-4 km). Continuous MPL measurements indicate that high aerosol enhancement occurred mostly in surface-lower free troposphere (3 km) during the period July-September.

Hara, K.; Hayashi, M.; Yabuki, M.; Shiobara, M.; Nishita-Hara, C.

2014-04-01

63

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.

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

2014-01-01

64

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

65

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

66

Results of TSP metals monitoring at McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring of metals in total suspended particulate (TSP) matter performed during the 1992--1993 austral summer at McMurdo Station, Antarctica. Seven samples of TSP were collected from three different locations and analyzed for arsenic, beryllium, cadmium, chromium, lead, nickel, and mercury. Critical-flow high-volume air samplers with a sample flow rate of approximately 1.1 m{sup 3}/minute were used to collect the particulate matter on quartz fiber filters for subsequent laboratory analysis. Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks. The data indicate that McMurdo operations have a measurable impact on the qualitative toxic metals composition of suspended particulate matter in the ambient air; however a definitive quantitative impact could not be concluded. The levels measured are well below the US National Ambient Air Quality Standards and American Conference of Governmental Industrial Hygienists worker exposure levels. Lead was the most prevalent of the seven toxic metals and was detected in all samples at concentrations ranging from 1.4 ng/m{sup 3} to 38 ng/m{sup 3}. Data on the concentration of eleven other metal species are presented. Most notable was the relatively high abundance of titanium and copper, which were detectable at levels up to 2,100 ng/m{sup 3} and 230 ng/m{sup 3}, respectively.

Lugar, R.M.

1994-04-01

67

Sources of PM10 and sulfate aerosol at McMurdo Station, Antarctica.  

PubMed

Source contributions to PM10 and sulfate aerosol at McMurdo Station, Antarctica during the austral summers of 1995-1996 and 1996-1997 were estimated using Chemical Mass Balance (CMB) receptor modeling. The average PM10 (particles with aerodynamic diameters less than 10 microm) concentration at Hut Point, located less than 1 km downwind of downtown McMurdo, was 3.4 microg/m3. Emissions profiles were determined for potentially important aerosol source types in McMurdo: exposed soil, power generation, space heating, and surface vehicles. Soil dust, sea salt, combustion emissions, sulfates, marine biogenic emissions as methanesulfonate, and nitrates contributed 57%, 15%, 14%, 10%, 3%, and 1%, respectively, of average estimated PM10 at Hut Point (3.2 microg/m3). Soil dust, sea salt, and combustion sources contributed 12%, 8%, and 20%, respectively, of the average PM10 sulfate concentration of 0.46 microg/m3. Marine biogenic sources contributed 0.17 microg/m3 (37%). The remaining sulfate is thought to have come from emissions from Mt. Erebus or hemispheric pollution sources. PMID:11592425

Mazzera, D M; Lowenthal, D H; Chow, J C; Watson, J G

2001-10-01

68

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

69

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

70

Weather in Antarctica  

NSDL National Science Digital Library

This homepage includes information about the weather in Antarctica and links to pages on the climate, wind chill, clouds, snow and ice, and pressure and storms of Antarctica. The current weather conditions updated automatically at various stations are also provided.

Hutchings, Thomas

1998-01-01

71

Investigation of crystal anisotropy using seismic data from Kohnen Station, Antarctica  

NASA Astrophysics Data System (ADS)

The flow behavior of glaciers and ice sheets is influenced by a preferred orientation of the anisotropic ice crystals. Knowledge about crystal anisotropy is mainly provided by crystal orientation fabric (COF) data from ice cores. To gain a broader understanding about the distribution of crystal anisotropy in ice sheets and glaciers we use seismic measurements. Two effects are important: (i) sudden changes in crystal orientation fabric (COF) lead to englacial reflections and (ii) the anisotropic fabric induces an angle dependency on the seismic velocities and, thus, also recorded traveltimes. For comparisons of ice core data and seismic results we connect COF data with the elasticity tensor and, thus, determine seismic velocities and reflection coefficients for cone and girdle fabrics from ice-core data. In the Antarctic field season 2012 we carried out a vertical seismic profiling (VSP) survey within the borehole of the EDML ice core and a seismic wideangle survey close to Kohnen Station, Antarctica. From the VSP survey we derive interval velocities and compare these velocities to the theoretically calculated velocities from COF ice-core data. The overall velocity trend derived from the ice-core data is well reflected in the VSP velocities. It shows, that the choice of the monocrystal elasticity tensor for the calculation of velocities from ice-core data is important for a good fit with the VSP velocities. For comparison of seismic data with radar and ice-core data we use stacked traces of the wideangle survey. Thus, we are able to identify COF induced reflections in both the seismic and radar data sets.

Diez, Anja; Eisen, Olaf; Weikusat, Ilka; Lambrecht, Astrid; Mayer, Christoph; Hofstede, Coen; Bohlen, Thomas; Miller, Heinrich

2014-05-01

72

Radar observations of ionospheric irregularities at Syowa Station, Antarctica: a brief overview  

NASA Astrophysics Data System (ADS)

We briefly overview the radar observations that have been made for 30 years at Syowa Station, Antarctica for studying small-scale electron-density irregularities in the southern high-latitude E- and F-region ionosphere. Some observational results (i.e., long-term variations of radio aurora, Doppler spectra with narrow spectral widths and low Doppler velocities, and simultaneous observations of radar and optical auroras) from VHF radars capable of detecting 1.3- to 3-m scale irregularities are presented. A new 50-MHz radar system equipped with phased-antenna arrays began operation in February 1995 to observe two-dimensional behaviours of E-region irregularities. An HF radar experiment also began in February 1995 to explore decameter-scale E- and F-region irregularities in the auroral zone and polar cap. These two radars will contribute to a better understanding of the ionospheric irregularities and ionospheric physics at southern high latitudes. Acknowledgements. This work has been supported by the UK Particle-Physics and Astronomy Research Council. The assistance of the director and staff of the EISCAT Scientific Association, the staff of the Norsk Polarinstitutt and the director and staff of the Swedish Institute of Space Physics is gratefully acknowledged. In addition the authors would like to thank Professor Evgeny Tereshchenko of the Polar Geophysical Institute in Mumansk, Russia and Dr Tuomo Nygrén of the University of Oulu, Finland for provision of data from EISCAT special program time during the November 1995 campaign. Topical Editor D. Alcaydé thanks E. J. Fremouw and another referee for their help in evaluating this paper.--> Correspondence to: I. K. Walker-->

Ogawa, T.

1996-12-01

73

IMF-associated cloudiness above near-pole station Vostok: Impact on wind regime in winter Antarctica  

NASA Astrophysics Data System (ADS)

Changes in the cloudiness above the Antarctic station Vostok during the winter season were examined in relation to strong disturbances in the interplanetary magnetic field (IMF). A reliable relationship between cloud formation and IMF has been found: cloudiness increased under the influence of a strong southward IMF and decreased under the northward IMF. The surface temperature at Vostok station, which is derivative of the constant radiation cooling of air situated at the ice sheet and adiabatic warming of the air masses, incoming into the central Antarctica from the middle and upper troposphere, is enhanced or reduced. Quite opposite regularity in the temperature changes is typical of altitudes higher than the suggested cloud layer position (5-8 km). The processes occurring on the Antarctic ridge leads to anomalous winds at the ice dome and decay of the circumpolar vortex at the periphery of the Antarctic continent. As a result, the surface easterlies at the coast stations are replaced by southerlies, and the cold air masses flow from Antarctica out over the Southern Ocean.

Troshichev, O.; Vovk, V.; Egorova, L.

2008-07-01

74

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.

75

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

76

[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

77

CROCKETT BARN AND BLOCKHOUSE FROM SOUTH FORT CASEY ROAD, LOOKING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CROCKETT BARN AND BLOCKHOUSE FROM SOUTH FORT CASEY ROAD, LOOKING SOUTHEAST. The Crockett blockhouse was moved from its original location to a tract of land along South Fort Casey Road in 1938, making it more accessible to tourists. During the same year it was given to the Daughters of the Pioneers of Washington and restored by Works Progress Administration crews. - Crockett Farm, 1056 Fort Casey Road, Coupeville, Island County, WA

78

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

79

Biologically effective ultraviolet radiation, total ozone abundance, and cloud optical depth at McMurdo Station, Antarctica - September 15 1988 through April 15 1989  

Microsoft Academic Search

Measured UV irradiation data is used in conjunction with a radiative transfer model to determine the seasonal variation in effective biological UV dose, total ozone abundance, and cloud optical depth at McMurdo Station, Antarctica from September 15, 1988 through April 15, 1989. It is noted that comparison of UV radiation levels in Austral spring 1988 and Austral fall 1989 reveals

Knut Stamnes; James Slusser; Melissa Bowen; Charles Booth; Timothy Lucas

1990-01-01

80

GPS water vapour project associated with global solar radiation at Scott Base station Antarctica  

Microsoft Academic Search

The project conducted is due to the contribution of Malaysian scientist to the Antarctic research. Using ground-based GPS and surface meteorological measurements, the atmospheric precipitable water vapour (PWV) circulation from Scott Base Antarctica (77.85°S, 166.76°E) are observed. As the Sun plays a significant role in the hydrological cycle and precipitation, the association between water vapour and solar radiation has been

Wayan Suparta; Selangor Darul Ehsan

2009-01-01

81

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

82

Analysis of Background Seismic Noise Recorded at the Amundsen-Scott South Pole Station, Antarctica  

Microsoft Academic Search

A small array of high frequency seismometers was recently placed around the Amundsen-Scott South Pole Station in order to characterize seismic noise generated by the station during operations. This week long experiment, titled, \\

K. R. Anderson; R. Aster; B. C. Beaudoin; R. Butler

2006-01-01

83

Measurement of atmospheric opacity at 278 GHz at McMurdo Station, Antarctica in austral spring seasons, 1986 and 1987  

NASA Technical Reports Server (NTRS)

A quasi-continuous record is presented of atmospheric opacity measured at 278 GHz (1.1 mm wavelength) from the McMurdo Station (Antarctica) during austral spring seasons of 1986 (August 30 - October 30) and 1987 (September 4 - October 13) with measurements taken every 20 minutes (except during storms or other periods of high opacity). All data are reduced to represent opacity in the zenith direction. It was found that, during much of September, the two successive years differed considerably in tropospheric opacity. In 1986, water vapor and attendant opacity were generally lower, due to low tropospheric temperatures. Measured opacities were found to be higher than would be expected from the empirical relationships representing opacity as a function of water vapor column density at mm-wavelengths, as proposed by Rice and Ade (1979), Zammit and Ade (1981), and Liebe (1985).

De Zafra, R. L.; Jaramillo, M.; Barrett, J.; Emmons, L. K.; Parrish, A.

1990-01-01

84

Simultaneous PMC and PMSE observations with a ground-basedlidar and SuperDARN HF radar over Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

A Rayleigh-Raman lidar system had been installed by the 52nd JapaneseAntarctic Research Expedition on February, 2011 at Syowa Station Antarctica(69.0°S, 39.5°E). Polar Mesospheric Cloud (PMC) was detected by the lidar at22:30UT (+3hr for LT) on Feb 4th, 2011, the first day of a routineoperation. This event is the first time to detect PMC over Syowa Station bya lidar. In the same night, SuperDARN HF radar with oblique incidence beamsalso detected Polar Mesosphere Summer Echoes (PMSEs) during 21:30UT to23:00UT. Although these signals were detected at different times andlocations, PMC motion estimated using horizontal wind velocities obtained bya collocated MF radar strongly suggests that they have a common origin (i.e.ice particle). We consider that this event occurred in the end of PMCactivity period at Syowa Station in the austral summer season (2010-2011),since the lidar did not detected any PMC signals on other days in February,2011. This is consistent with satellite-born PMC observations by AIM/CIPSand atmospheric temperature observations by AURA/MLS instruments.

Suzuki, Hidehiko; Nakamura, Takuji; Tsutsumi, Masaki; Kawahara, Takuya D.; Ogawa, Tadahiko; Tomikawa, Yoshihiro; Ejiri, Mitsumu K.; Sessai Yukimatu, Akira; Abo, Makoto

2012-07-01

85

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

86

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

87

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

88

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

89

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

90

Sounding rockets in Antarctica  

NASA Technical Reports Server (NTRS)

Sounding rockets are versatile tools for scientists studying the atmospheric region which is located above balloon altitudes but below orbital satellite altitudes. Three NASA Nike-Tomahawk sounding rockets were launched from Siple Station in Antarctica in an upper atmosphere physics experiment in the austral summer of 1980-81. The 110 kg payloads were carried to 200 km apogee altitudes in a coordinated project with Arcas rocket payloads and instrumented balloons. This Siple Station Expedition demonstrated the feasibility of launching large, near 1,000 kg, rocket systems from research stations in Antarctica. The remoteness of research stations in Antarctica and the severe environment are major considerations in planning rocket launching expeditions.

Alford, G. C.; Cooper, G. W.; Peterson, N. E.

1982-01-01

91

Analysis of Background Seismic Noise Recorded at the Amundsen-Scott South Pole Station, Antarctica  

NASA Astrophysics Data System (ADS)

A small array of high frequency seismometers was recently placed around the Amundsen-Scott South Pole Station in order to characterize seismic noise generated by the station during operations. This week long experiment, titled, "South Pole Analysis of Machines" or SPAM was conducted in January of 2006 using equipment provided by IRIS PASSCAL to sample the high frequency noise sources generated at the NSF's research base. These data will be correlated to those observed at the ultra quiet GSN seismic station (QSPA) located 5 miles from the base. The purpose of the experiment is to show that although the QSPA sensors are 5 miles away and nearly 1000 feet deep in the ice, there is still a risk of contamination of the signals by cultural noise from the South Pole research base. A Quiet Sector was established around the QSPA station in order to minimize vibrational noise sources, but there is interest in moving some experiments out into the Quiet Sector. Characterizing the noise sources will help us determine the potential reduction in data quality expected at the QSPA station as experiments move closer to the site. Sensors were placed next to the power generators, aircraft taxiway, large antenna towers, as well as at the base of the new station itself. Sensors were also placed between the research base and the QSPA station to get an idea of the propagation of the noise toward the QSPA station. Several high frequency noise sources are clearly seen on all array elements with a number of very clear spectral lines above 1 Hz. These are primarily associated with snow moving tractors and power generators. Smaller signals are seen that may be related to wind loading on the new South Pole elevated station along with harmonics that appear to be correlated with large air handling equipment in the station. Also evident are air operations with landings, takeoffs, taxi and idling C-130's evident. Although greatly attenuated, almost all of these signals are observed at the QSPA station. Therefore, encroachment of any of these noise sources into the Quiet Sector will adversely affect the signal-to-noise ratio in the frequencies above 1 Hz for seismograms recorded at QSPA. At this point, QSPA is by far the quietest seismic station in the world at these high frequencies. We hope that we can preserve these low background noise levels and keep the QSPA one of the quietest places on Earth.

Anderson, K. R.; Aster, R.; Beaudoin, B. C.; Butler, R.

2006-12-01

92

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.

93

Geomagnetic and geoelectric pulsations recorded at the station Commandante Ferraz, Antarctica  

NASA Astrophysics Data System (ADS)

Geomagnetic and geoelectric pulsations in the range from 10 to 500 seconds are recorded at the Brazilian station Commandante Ferraz in the Antarctic Peninsula. The characteristics of the PC3 and PC4 micropulsations are studied and discussed in terms of hydromagnetic waves generated at the sunward side of the Earth's magnetosphere. Besides, the same measurements are utilized to obtain a local conductivity profile of the Earth's crust and upper mantle at the station region using principles of electromagnetic induction.

Trivedi, N. B.; Padilha, A. L.; Dacosta, J. M.

1987-07-01

94

Glacio-meteorological conditions in the vicinity of the Belgian Princess Elisabeth Station, Antarctica  

NASA Astrophysics Data System (ADS)

During two consecutive reconnaissance surveys in 2004 and 2005 and a revisit in 2008, the glaciological and meteorological conditions of the vicinity of the new Belgian Princess Elisabeth Station (71°57'S; 23°20'E) on Utsteinen Ridge were investigated. We set up an automatic weather station, measured the ice thickness around the Utsteinen Ridge, and established a stake network. Results of these baseline investigations show that Utsteinen Ridge is a sheltered spot from the main katabatic winds and that also during the winter months, air temperatures are rather mild and witness the coreless winter. Mass balance is generally low (near zero) with accumulation to the east and relatively small ablation to the west of Utsteinen Ridge. Ice flow in the vicinity of the station is also minimal, since the Sor Rondane Mountains upstream of the station block most of the ice flow, a feature that is most apparent in the area where the station is situated. Measurements of the surface topography separated by four years show that the construction of the station seems to have a limited effect on the redistribution of snow around it.

Pattyn, F.; Matsuoka, K.; Berte, J.

2009-04-01

95

A new French-Italian geomagnetic observatory in Dome C, Antarctica  

NASA Astrophysics Data System (ADS)

Concordia is a scientific station located in the inner part of Antarctica (latitude 75° 06' S, longitude 123° 23' E, at about 3,200 m above sea level), about 950 km away from the coast. Near by the station a permanent Base is under construction and is expected to open in the year 2004. All this is the result of a join French Italian Antarctic Programs (IFRTP and PNRA respectively) effort to provide support to a growing number of scientific researches. The station is located 1.200 from Terra Nova Bay (Italy), 560 km away from Vostok Station (Russia), 1.100 Km from Dumont D'Urville (France) and Casey (Australia). During the 1998-1999 and 1999-2000 expeditions in Antarctica, some preliminary tests were carried out in order to evaluate the suitability of Dome C site for a permanent geomagnetic observatory. Two parallel data acquisition systems, each equipped with overhauser and flux-gate magnetometers were installed in two shelters at about 300 m from the Base camp. After some tests and checks, the site was considered a good site for geomagnetic investigations. The instrumentation is now in France and in Italy to prepare the instruments and the acquisition systems for the final installation that will take place during the 2004-2005 expedition.

Cafarella, L.; Zirizzotti, A.; di Mauro, D.; Schott, J. J.; Pèrès, A.; Cantin, J. M.

2003-04-01

96

First observations of ionospheric irregularities and flows over the south geomagnetic pole from the SuperDARN HF radar at McMurdo Station, Antarctica  

Microsoft Academic Search

In February 2010 a new SuperDARN radar began operation at McMurdo Station, Antarctica. The radar's orientation places the south geomagnetic pole near the center of the field of view at about 1200 km range. The radar is the highest latitude radar of the SuperDARN network, both geographically and geomagnetically, and the observations have a different character than those of the

W. A. Bristow; R. T. Parris; J. Spaleta

2010-01-01

97

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

98

The connectivity of crystallite agglomerates in low-density firn at Kohnen station, Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

In this study, the three-dimensional (3-D) microstructure of polar firn is investigated by means of X-ray microfocus computer tomography (?CT). Basic topological properties including the Euler and coordination numbers are derived from the reconstructed 3-D volume images. It is shown that sample volumes of about 4 cm3 are representative for polar firn in terms of their connectivity. The connectivity function defined as the change of Euler number with structure size is calculated via image-processing routines. It is used to split the ice phase at small bridges into single crystallite agglomerates. The bond-size distributions and the mean size of the agglomerates are estimated. All ?CT measurements were carried out on the uppermost 9 m of a shallow firn core (B35) drilled during the 2005/06 field campaign at Kohnen station, Dronning Maud Land (DML), Antarctica. The results are compared with estimates from classical two-dimensional (2-D) surface section observations. The 3-D approach confirms the linear relationship between coordination number and density which hitherto has only been derived from 2-D observations. Layers of buried snow dunes show a stronger connectivity than layers of moderate crystal size and density. The formation of agglomerates made of crystallites is a common feature of polar firn in DML. It is proposed that the growth of agglomerates leads to reduced critical densities for the transition between the densification regime of grain boundary sliding and plastic deformation.

Freitag, J.; Kipfstuhl, S.; Faria, S. H.

99

Seasonal variations in the horizontal wind structure from 0 100 km above Rothera station, Antarctica (67° S, 68° W)  

NASA Astrophysics Data System (ADS)

A medium frequency spaced-antenna radar has been operating at Rothera station, Antarctica (67° S, 68° W) for two periods, between 1997-1998 and since 2002, measuring winds in the mesosphere and lower thermosphere. In this paper monthly mean winds are derived and presented along with three years of radiosonde balloon data for comparison with the HWM-93 model atmosphere and other high latitude southern hemisphere sites. The observed meridional winds are slightly more northwards than those predicted by the model above 80 km in the winter months and below 80 km in summer. In addition, the altitude of the summer time zero crossing of the zonal winds above the westward jet is overestimated by the model by up to 8 km. These data are then merged with the wind climatology obtained from falling sphere measurements made during the PORTA campaign at Rothera in early 1998 and the HWM-93 model atmosphere to generate a complete zonal wind climatology between 0 and 100 km as a benchmark for future studies at Rothera. A westwards (eastwards) maximum of 44 ms-1 at 67 km altitude occurs in mid December (62 ms-1 at 37 km in mid July). The 0 ms-1 wind contour reaches a maximum altitude of 90 km in mid November and a minimum altitude of 18 km in January extending into mid March at 75 km and early October at 76 km.

Hibbins, R. E.; Shanklin, J. D.; Espy, P. J.; Jarvis, M. J.; Riggin, D. M.; Fritts, D. C.; Lübken, F.-J.

2005-07-01

100

Seasonal variations in the horizontal wind structure from 0-100 km above Rothera station, Antarctica (67° S, 68° W)  

NASA Astrophysics Data System (ADS)

A medium frequency spaced-antenna radar has been operating at Rothera station, Antarctica (67° S, 68° W) for two periods, between 1997-1998 and since 2002, measuring winds in the mesosphere and lower thermosphere. In this paper monthly mean winds are derived and presented along with three years of radiosonde balloon data for comparison with the HWM-93 model atmosphere and other high latitude southern hemisphere sites. The observed meridional winds are slightly more northwards than those predicted by the model above 80 km in the winter months and below 80 km in summer. In addition, the altitude of the summer time zero crossing of the zonal winds above the westward jet is overestimated by the model by up to 8 km. These data are then merged with the wind climatology obtained from falling sphere measurements made during the PORTA campaign at Rothera in early 1998 and the HWM-93 model atmosphere to generate a complete zonal wind climatology between 0 and 100 km as a benchmark for future studies at Rothera. A westwards (eastwards) maximum of 44 ms-1 at 67 km altitude occurs in mid December (62 ms-1 at 37 km in mid July). The 0 ms-1 wind contour reaches a maximum altitude of 90 km in mid November and a minimum altitude of 18 km in January extending into mid March at 75 km and early October at 76 km.

Hibbins, R. E.; Shanklin, J. D.; Espy, P. J.; Jarvis, M. J.; Riggin, D. M.; Fritts, D. C.; Lübken, F.-J.

2005-11-01

101

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

102

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

103

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

104

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

105

Observed temperature structure of the atmosphere above Syowa Station, Antarctica (69°S, 39°E)  

Microsoft Academic Search

By combining balloonsonde and Na\\/Rayleigh temperature lidar observations made at Syowa Station (69°S, 39°E) during 2000 and 2001 (a total of 176 observations, 5.9 observations per week), the winter temperature structure from 0 to 110 km is characterized from March to October. The data are also compared with the temperature model of South Pole from Pan and Gardner [2003] which

Taku D. Kawahara; Chester S. Gardner; Akio Nomura

2004-01-01

106

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

107

Geological structures deduced from airborne geophysical surveys around Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

The area around Syowa Station, the Japanese Antarctic station in Lutzow-Holm Bay, is widely considered to be a junction of the Africa, India, Madagascar, and Antarctic continents, according to the reconstruction model of Gondwana. This area is key to investigating the formation of Gondwana. Joint Japanese-German airborne geophysical surveys were conducted around Syowa Station in January 2006 to reveal the tectonic evolution contributing to the formation of Gondwana in this area. Ice radar, magnetic, and gravity data were obtained from onshore areas. Several characteristic features that may be related to the tectonic evolution of Gondwana were inferred primarily from magnetic anomalies and from gravity anomalies and bedrock topography. The boundaries of the Lutzow-Holm Complex, the Yamato-Belgica Complex, and the Western Rayner Complex are defined, but the inland extension of the boundary between the Lutzow-Holm and the Yamato-Belgica Complexes is unknown south of 71S. The main geological structural trends of the Lutzow-Holm Complex derived from magnetic anomalies are NW-SE and are concordant with the geological results in the coastal region. However, nearly NE-SW-trending magnetic anomalies cut across the NW-SW magnetic anomaly trends, and the NE-SW right lateral strike-slip faults are deduced from the magnetic and the gravity anomaly data in the Lutzow-Holm Complex. The Lutzow-Holm Complex is divided into four blocks based on the estimated strike-slip faults. The strike-slip faults were possibly generated during a younger stage of Pan-African orogeny, after the formation of NW-SE-striking geological structures. These results provide new constraints for the formation of Gondwana.

Nogi, Y.; Jokat, W.; Kitada, K.; Steinhage, D.

2012-12-01

108

Ground-based Observations for the Upper Atmosphere at King Sejong Station, Antarctica  

NASA Astrophysics Data System (ADS)

Since the operation of the King Sejong Station (KSS) started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI) and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI) was installed to observe the temperature in the mesosphere and lower thermosphere (MLT) region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere

Jee, Geonhwa; Kim, Jeong-Han; Lee, Changsup; Kim, Yong Ha

2014-06-01

109

Case study of a mesospheric wall event over Ferraz station, Antarctica (62° S)  

NASA Astrophysics Data System (ADS)

On 16-17 July 2007 during an observational campaign at Comandante Ferraz Antarctic Station (62° S, 58° W), a mesospheric wall was observed with an airglow all-sky imager. The wave appeared like an extensive dark region in the all-sky airglow images, with a large depletion in the OH emission. Simultaneous mesospheric winds measured with a MF radar at Rothera station and temperature profiles from SABER instrument, on board of TIMED satellite, were used to obtain the propagation condition of the wave. Wind measurements during four days, around the time of observation of the wave, are presented in order to discuss the type and consistence of the duct in which this wave was propagating. By using wavelet analysis and tidal amplitude components we found that 12 and 8 h components were the most important periodicities around the time interval of the wave observation. A collocated imaging spectrometer, for mesospheric temperature measurements, has been operated simultaneously with the all-sky imager. Direct effects of the mesospheric front have been seen in the spectrometric measurements, showing an abrupt decrease in both OH intensity and rotational temperature when the wave front passes overhead. The main contribution of the present work is the investigation of the type of duct in which the wall event was propagating. We found evidences for a thermal duct structure to support the mesospheric wall propagation. This result was obtained by two types of analysis: (a) the tidal components analysis and winds filtering (harmonic analysis), and (b) comparison between the terms of the m2 dispersion relation.

Bageston, J. V.; Wrasse, C. M.; Hibbins, R. E.; Batista, P. P.; Gobbi, D.; Takahashi, H.; Andrioli, V. F.; Fechine, J.; Denardini, C. M.

2011-01-01

110

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

111

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

Microsoft Academic Search

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987—1991 by means of a network of nine AWS (auto- matic weather stations). Spatial configurations of temper- ature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell

E. Cogliani; G. Abbate; S. Racalbuto

1996-01-01

112

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

Microsoft Academic Search

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987–1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues,

E. Cogliani; G. Abbate; S. Racalbuto

1997-01-01

113

Semi-annual to decadal oscillations as recorded at Neumayer research station, Antarctica  

NASA Astrophysics Data System (ADS)

Monthly time series of temperature, wind speed and sea level pressure recorded at Neumayer polar research station (70°39'S, 8°15'W) during the last 30 years are analysed in order to identify the climate oscillations and associated teleconnection patterns at time scales from half-year to decades. Oscillations with periods of six months (semi-annual) and one year (annual) were identified in all records. Both annual and semi-annual oscillations are non-stationary in time. The dominant pattern of interannual to decadal variability, which captures the out of phase variations of temperature and wind speed with sea level pressure, shows a persistent 2-3 years oscillation. This oscillation is related with a wave-train atmospheric circulation pattern similar to the Pacific South American (PSA) modes. This suggests a tropical origin of this oscillation. The second pattern of interannual to decadal variability, which captures in-phase variations of these variables, shows enhanced variability at 5-6 year time scales. This oscillation is induced by the Antarctic Oscillation (AAO) which shows enhanced variability at these time scales. Analysis of the variability of high resolution stable isotope time series from four ice cores from Neumayer region reveals similar oscillations. This suggests that ice core data from the region could be used to reconstruct the phase and amplitude of atmospheric circulation patterns associated to these oscillations during past periods.

Rimbu, Norel; Lohmann, Gerrit; Koenig-Langloo, Gert; Ionita, Monica

2013-04-01

114

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

115

Stratosphere aerosol and cloud measurements at McMurdo Station Antarctica during the spring of 1987  

NASA Technical Reports Server (NTRS)

Measurements of stratospheric aerosols with balloonborne optical particle counters on 6 occasions at McMurdo Station (78 deg S) in the spring of 1986 indicated subsidence of the stratospheric sulfate layer during the time that the ozone hole was forming (Hofmann et al., 1988). Since dynamic models of ozone depletion involving upwelling in the spring polar vortex would suggest the opposite, we repeated the measurements with an increased frequency (about one sounding per week) in 1987. During 3 of the aerosol soundings in 1986, temperatures in the 15 to 20 km range were low enough (less than 80 C) for HNO3 to co-condense with water according to several theories of polar stratospheric cloud formation. However, particles were not observed with the characteristic size suggested by theory (approx. 0.5 microns). For this reason, it was proposed that polar stratospheric clouds may predominantly consist of large (approx. 5 to 50 microns) ice crystals at very low (approx. 10 sup 4- 10 sup 3 cm cubed) concentrations (Rosen et al., 1988). The particle counter employed would be relatively insensitive to these low concentrations. With the increased frequency of soundings in 1987, and adding additional size discrimination in the 1 to 2 micron region, this hypothesis could be verified if suitably low temperatures were encountered.

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

1988-01-01

116

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

117

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

118

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

119

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

120

Concentration of 10Be in an ice core from the Dome Fuji station, Eastern Antarctica: Preliminary results from 1500 to 1810 yr AD  

NASA Astrophysics Data System (ADS)

We present preliminary data of our 10Be analysis of an ice core retrieved from Dome Fuji station, Eastern Antarctica for 1500-1810 yr AD. The concentration of 10Be from 1500-1810 yr AD ranged between 7.0 × 10 4 and 13.0 × 10 4 atoms g -1 and a prominent peak was observed in the period 1645-1715 yr AD (i.e., the Maunder Minimum period). An increase in the concentration was also observed in the periods before 1540 yr AD and near to 1800 yr AD. A comparison of our 10Be record with the South Pole 10Be record shows a clear similarity in their temporal fluctuations. On the other hand, our record shows ˜2.5 times higher concentration of 10Be than in the South Pole record attributable to the difference in local snow accumulation rates. These observations suggest a direct (uncomplicated) fallout of atmospheric 10Be onto inland Antarctica, which in turn, leads to a detailed 10Be stratigraphy throughout this region. We believe that the 10Be profiles of the ice cores from the Dome Fuji station are therefore likely to be a good proxy indicator of changes in solar activity.

Horiuchi, Kazuho; Ohta, Aoi; Uchida, Tomoko; Matsuzaki, Hiroyuki; Shibata, Yasuyuki; Motoyama, Hideaki

2007-06-01

121

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

122

Simultaneous PMC and PMSE observations with a ground-based lidar and SuperDARN HF radar at Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

A Rayleigh-Raman lidar system was installed in January 2011 at Syowa Station, Antarctica (69.0° S, 39.6° E). Polar mesospheric clouds (PMCs) were detected by lidar at around 22:30 UTC (LT -3 h) on 4 February 2011, which was the first day of observation. This was the first detection of PMCs over Syowa Station by lidar. On the same day, a Super Dual Auroral Radar Network (SuperDARN) HF radar with oblique-incidence beams detected polar mesospheric summer echoes (PMSE) between 21:30 and 23:00 UTC. This event is regarded as the last PMC activity around Syowa Station during the austral summer season (2010-2011), since no other PMC signals were detected by lidar in February 2011. This is consistent with results of PMC and mesopause temperature observations by satellite-born instruments of AIM (Aeronomy of Ice in the Mesosphere)/CIPS (Cloud Imaging and Particle Size) and AURA/MLS (Microwave Limb Sounder) and horizontal wind measurements taken by a separate MF radar. Doppler velocity of PMSE observed by the HF radar showed motion toward Syowa Station (westward). This westward motion is consistent with the wind velocities obtained by the MF radar. However, the PMSE region showed horizontal motion from a north-to-south direction during the PMC event. This event indicates that the apparent horizontal motion of the PMSE region can deviate from neutral wind directions and observed Doppler velocities.

Suzuki, H.; Nakamura, T.; Ejiri, M. K.; Ogawa, T.; Tsutsumi, M.; Abo, M.; Kawahara, T. D.; Tomikawa, Y.; Yukimatu, A. S.; Sato, N.

2013-10-01

123

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

124

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

125

First observations of ionospheric irregularities and flows over the south geomagnetic pole from the SuperDARN HF radar at McMurdo Station, Antarctica  

NASA Astrophysics Data System (ADS)

In February 2010 a new SuperDARN radar began operation at McMurdo Station, Antarctica. The radar’s orientation places the south geomagnetic pole near the center of the field of view at about 1200 km range. The radar is the highest latitude radar of the SuperDARN network, both geographically and geomagnetically, and the observations have a different character than those of the auroral zone radars. One particular feature of note is the high incidence of observed backscatter. When ionospheric altitudes are above the solar shadow height the incidence of observation is greater than 80% for a large portion of the radar field of view. This is indicative of the near constant presence of field-aligned density irregularities in the polar cap. This paper presents statistics of the observations along with estimates of the convection velocity maps. Prevailing IMF and solar wind velocity were taken from the Omni database and compared to the observed flows.

Bristow, W. A.; Parris, R. T.; Spaleta, J.

2010-12-01

126

Detection of Seismic Sources Associated with Ice Movement in Antarctica using POLENET Seismic Array, AGAP Seismic Array, and GSN Seismic Stations  

NASA Astrophysics Data System (ADS)

Antarctica has the fewest reported seismic events of all the continents. In 2009 and 2010 only four Antarctic events were located by the ISC bulletin. The lack of seismicity is partly due to limited station coverage (only 9 permanent stations). Over 40 temporary stations have been installed beginning in 2007 as part of the IPY POLENET and AGAP projects. These stations greatly increase coverage, especially in the Antarctic interior, and allow us to locate events too small to be recorded at coastal stations. Recent interest in long period glacial sources (due to calving or ice movement) has led to the development and implementation of new detection algorithms. Traditional detections rely on high frequency impulsive signals typical of fast slipping earthquakes. These detectors miss 'slow' events (often associated with ice motion such as calving or slip events such as the tidally controlled periodic slip of the Whillans Ice Stream) that do not generate high frequency P phases and thus are absent from global catalogs. This study analyzes seismic data from 2009-2011 filtered in both long period (33-75s) and short period (0.1-2s) bands from over 50 stations. We detect, associate, and locate events in short period bands by identifying first arriving P and S phases using both automated STA/LTA detection and visual inspection. We also use a modified time reversal to identify 'slow' events. Long period envelopes are shifted by Rayleigh wave propagation times and stacked at equidistantly spaced source locations. The source is the location displaying the greatest amplitude stack. We find the Vanderford glacier region is highly seismic in both bands (one high frequency event being large enough to be included in the ISC bulletin). The David and Mullock glacier regions of the Transantarctic Mountains frequently produce magnitude 3-4 events (detected in the high frequency band) associated with ice movements. Several tectonic earthquakes have been detected in the interior of the continent near the center of East Antarctica (depths between 20-40 km). We have also detected a new type of cryospheric source characterized by ~ 1 s Rayleigh waves traveling in the ice layer (1.5-1.7 km/s propagation velocity) over distances of up to 1000 km. These sources are located within the upper part of the ice sheet and are distributed around the interior of East Antarctica, and may correspond to large crevassing or snow collapse events. We continue to analyze both long and short period bands of data collected starting in IPY. When completed the catalog will give great insight into both the tectonic and glacial processes capable of producing seismic waves (such as calving or sudden ice stream motion) active in unobserved regions of the the Antarctic continent.

Lough, A. C.; Barcheck, C. G.; Wiens, D. A.; Barklage, M. E.; Nyblade, A.; Aster, R. C.; Anandakrishnan, S.; Huerta, A. D.; Wilson, T. J.

2011-12-01

127

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.

128

PRELIMINARY RESULTS OF THE PERFORMANCE OF AUTOMATIC WEATHER STATION IN THE PERPETUAL FROST CLIMATE OF EAST ANTARCTICA  

Microsoft Academic Search

In the year 2006-07, India Meteorological Department (IMD) expanded and upgraded its network of Automatic Weather Stations (AWS) by induction of 125 satellite linked AWS. A central receiving earth station in complete redundancy mode is also established at INSAT AWS Laboratory, IMD, Pune for reception of data through KALPANA1 (74 °E) satellite in near real time. IMD has planned to

Manish Ranalkar; B. Amudha; N. T. Niyas; R. D. Vashistha

129

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

130

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

131

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

132

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

Microsoft Academic Search

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

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

2005-01-01

133

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

Microsoft Academic Search

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

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

2005-01-01

134

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

135

Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica  

USGS Publications Warehouse

McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered.

Lisle, J. T.; Smith, J. J.; Edwards, D. D.; McFeters, G. A.

2004-01-01

136

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

137

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

138

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

139

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

140

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

141

Sodium layer in the thermosphere (110-130 km) observed at Syowa Station (69.0S, 39.6E) in Antarctica  

NASA Astrophysics Data System (ADS)

The neutral metallic atom layers (such as sodium, iron, potassium layers) are normally distributed at a height range of 80-110 km (in the upper mesosphere and lower thermosphere). Resonance scattering lidar observations of these metallic layers have been used as an important tool for investigation of the upper mesosphere and lower thermosphere. On the other hand, ground-based observations of the neutral atmosphere at higher altitude (above 110 km) are quite limited. Recently, observations of metallic layers above 110 km up to 155 km have been reported from some stations. Such high-altitude metallic layers (so-called thermospheric metallic layers) is currently well-unknown phenomenon, and has possibility to greatly improve our understanding of the lower thermosphere. Intensive sodium temperature lidar observations were carried out at Syowa Station (69.0S, 39.6E) in Antarctica between 2000 and 2002 as a part of JARE observations. From the observational data, we investigate thermospheric sodium layer (above 110 km). In this presentation, we will report a thermospheric sodium layer event (up to 130 km) observed on 23 September 2000. In this event, the lidar detected significant signals not only from 80-110 km but also from 110-130 km. More detailed analysis has provided the temperature and the sodium-density measurements at this height range up to 130 km. The estimated sodium density reached about tens of cm-3 at around 120 km. The temperature profile in the thermospheric sodium layer was fairly comparable to that from the NRLMSISE-00 model. We will show these results and discuss similarity and difference between the observed thermospheric sodium layer event and previously reported thermospheric metal layer events.

Tsuda, T. T.; Chu, X.; Nakamura, T.; Ejiri, M. K.; Kawahara, T.

2012-12-01

142

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

143

Tardigrades of the Australian Antarctic Territories: the Windmill Islands, East Antarctica  

Microsoft Academic Search

Six species of tardigrades,Pseudechiniscus suillus, Macrobiotussp.,Hypsibius antarcticus, Ramajendas frigidus, Diphascon chilenenseandDiphascon pinguewere extracted from mosses and lichens from the ice-free regions of the Windmill Islands near Casey Base, East Antarctica. Significant positive associations were found between the three common species (Pseudechiniscus suillus, Hypsibius antarcticus, Diphascon chilenense) and bryophytes, whereas strong negative associations were found between these species and algae and

W. R. MILLER; J. D. MILLER; H. HEATWOLE

1996-01-01

144

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

145

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

146

Chemical composition of size-segregated aerosol collected all year-round at Concordia Station (Dome C, Antarctica). Transport processes and climatic implications.  

NASA Astrophysics Data System (ADS)

Ice-core stratigraphies of chemical components of atmospheric gases and aerosols trapped in the snow layers by scavenging processes are a powerful tool in understanding past climatic and environmental changes. The deep ice core drilled at Dome C in the framework of the EPICA project allowed reconstructing the last 8 glacial-interglacial cycles and highlightened the complex relationships between climatic forcings and environmental feedback processes. In interpreting ice core records as a function of past climatic variations, some difficulties arise from uncertainties in considering selected chemical species as reliable markers of climatic and environmental processes and in attributing the different load and composition of aerosols over Antarctica to changes in source intensity (such as aridity, wind strength, emersion of continental platform by sea-level lowering etc..) and/or to variations in atmospheric processes (such as meridional and zonal atmospheric circulation, polar vortex intensity, scavenging efficiency, transport pathways etc..). Besides, two new aspects are actually under discussions: the possible use of Na as sea-ice cover marker (via frost flower formation on the sea-ice surface during the pack-ice formation) and the identification of continental source areas for mineral dust reaching internal regions of Antarctica during glacial and interglacial periods. In order to better address such controversial issues, since 2005 a continuous, high temporal resolution size-segregated aerosol and surface snow sampling has been performed at Dome C (central East Antarctic Plateau, 75° 06' S, 123° 23' E), in the framework of "Station Concordia" Project (a Italian PNRA- French IPEV joint program). The chemical analysis of size-segregated aerosol and daily superficial snow samples, collected all year-round for more than 4 years, can contribute to clarify some of the above mentioned topics. In particular: the possible seasonal pattern of sea spray aerosol could be related to sea-ice formation timing and/or to changes in zonal wind intensity and atmospheric pathway; the mineralogical analysis of insoluble dust particles can allow the identification of continental sources, by comparison with soils collected in the potential source areas (PSAs); finally, the seasonal pattern of biogenic markers (such as methanesulphonic acid and non-sea-salt sulphate) can be linked to sea surface temperature, sea-ice cover and southern-hemisphere circulation modes (e.g., SOI, AAO or SAM and ACW). As regard as depositional and post-depositional processes, the analysis of chemical markers in aerosol, superficial snow and hoar crystals, sampled contemporaneously, will allow understanding the key factors (e.g., snow acidity, solar irradiation) affecting the preservation of components reversibly fixed in the snow layers (such as, for instance, methanesulphonic acid, nitrate and chloride). A summary of the major results from the chemical analysis of aerosol and snow collected at Dome C is here presented.

Udisti, Roberto; Becagli, Silvia; Frosini, Daniele; Galli, Gaia; Ghedini, Costanza; Rugi, Francesco; Severi, Mirko; Traversi, Rita

2010-05-01

147

The Geography of Antarctica.  

National Technical Information Service (NTIS)

Contents: Development of geographic theories on Antarctica; The theory of a southern continent; Temperate and high latitudes in the Southern Hemisphere; Morphometric parameters of Antarctica; Rock surface of Antarctica; Ice Antarctica (climate and glaciat...

K. K. Markov V. I. Bardin V. L. Lebedev A. I. Orlov I. A. Suetova

1970-01-01

148

The Geology of Antarctica.  

National Technical Information Service (NTIS)

Contents: Tectonic setting of Antarctica; Basic tectonic divisions of Antarctica; The bedrock topography of Antarctica; The crystalline basement rock surface; Crustal structure in Antarctica; Seismic refraction studies of the upper crust; Crustal structur...

G. P. Woollard

1970-01-01

149

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.

150

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.

Geographic, National

151

Virtual Antarctica  

NSDL National Science Digital Library

Provided by Terraquest.com, the Virtual Antarctica Web site presents a ship's expedition to the continent and describes what is found along the way. The science portion describes such things as the geology, geography, and climate of the area, as well as various biological features of the land and water. Other sections of the site contain information on Antarctica's history and ecology, as well as other resources such as a glossary and map.

1995-01-01

152

Landsat Image Mosaic of Antarctica  

USGS Publications Warehouse

Description Fact sheet introduces the Landsat Image Mosaic of Antarctica (LIMA) with images from a section of the mosaic over McMurdo Station, descriptions of the four versions of LIMA, where to access and download LIMA, and a brief explanation of the Antarctic Web portal.

U.S. Geological Survey

2007-01-01

153

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.

154

Thermospheric winds near Antarctica Peninsular  

NASA Astrophysics Data System (ADS)

Recently a new Fabry-Perot interferometer was installed at Palmer station, Antarctica (64S, 64W). The instrument is capable of measuring thermospheric winds by observing Doppler shifts in the nightglow emission. The goal of this instrument is to understand the thermospheric wind effect on the ionosphere in the region. The wind results will be compared with ionosonde measurements nearby. And observational results will be compared with NCAR TIEGCM model simulation results. Antarctica Peninsular region is known to have ionosphere observations that are quite different from model simulation results. Thermospheric wind observation hopefully can help resolve some of the differences.

Wu, Qian

2012-07-01

155

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.

156

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

157

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.

158

Antarctica: Cooling or Warming?  

NASA Astrophysics Data System (ADS)

We consider the 14 longest instrumental monthly mean temperature records from the Antarctica and analyse their correlation properties by wavelet and detrended fluctuation analysis. We show that the stations in the western and the eastern part of the Antarctica show significant long-term memory governed by Hurst exponents close to 0.8 and 0.65, respectively. In contrast, the temperature records at the inner part of the continent (South Pole and Vostok), resemble white noise. We use linear regression to estimate the respective temperature differences in the records per decade (i) for the annual data, (ii) for the summer and (iii) for the winter season. Using a recent approach by Lennartz and Bunde [1] we estimate the respective probabilities that these temperature differences can be exceeded naturally without inferring an external (anthropogenic) trend. We find that the warming in the western part of the continent and the cooling at the South Pole is due to a gradually changes in the cold extremes. For the winter months, both cooling and warming are well outside the 95 percent confidence interval, pointing to an anthropogenic origin. In the eastern Antarctica, the temperature increases and decreases are modest and well within the 95 percent confidence interval. [1] S. Lennartz and A. Bunde, Phys. Rev. E 84, 021129 (2011)

Bunde, Armin; Ludescher, Josef; Franzke, Christian

2013-04-01

159

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

NASA Astrophysics Data System (ADS)

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987-1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues, throughout the year. A second warm island is present to the north along the coast, between Aviator and Mariner ice tongues, for most of the year. From February to March a rapid drop in temperature is observed at all stations. A strong thermal gradient develops during February, March, April and October, November, December, between the coastal region and inner highlands. The baric configuration follows the elevation of the area. Annual average pressure and temperature as functions of stations altitude show linear trends. Severe katabatic wind episodes are recorded at all stations, with wind speed exceeding 25 m s-1 and direction following the orographic features of the inner areas. Co-occurrences of these episodes were observed for stations located along stream lines of cold air drainage. The autocorrelation function of maximum wind speed time series shows wind persistence of 2-3 days and wind periodicity of about one week. Acknowledgements. We gratefully appreciate the on-line DMSP database facility at APL (Newell et al., 1991) from which this study has benefited greatly. We wish to thank E. Friis-Christensen for his encouragement and useful discussions. A. Y. would like to thank the Danish Meteorological Institute, where this work was done, for its hospitality during his stay there and the Nordic Baltic Scholarship Scheme for its financial support of this stay. Topical Editor K.-H. Glassmeier thanks M. J. Engebretson and H. Lühr for their help in evaluating this paper.--> Correspondence to: A. Yahnin-->

Cogliani, E.; Abbate, G.; Racalbuto, S.

1996-10-01

160

Astronomy in Antarctica  

NASA Astrophysics Data System (ADS)

Antarctica provides a unique environment for astronomers to practice their trade. The cold, dry and stable air found above the high Antarctic plateau, as well as the pure ice below, offers new opportunities for the conduct of observational astronomy across both the photon and the particle spectrum. The summits of the Antarctic 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, at stations run by the USA, France/Italy, China, Japan and the USA, respectively. The astronomy conducted from Antarctica includes optical, infrared, terahertz and sub-millimetre astronomy, measurements of cosmic microwave background anisotropies, solar astronomy, as well as high energy astrophysics involving the 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 sites. In this article, we summarise the facets of Antarctica that are driving developments in astronomy there, and review the results of the site testing experiments undertaken to quantify those characteristics of the Antarctic plateau relevant for astronomical observation. We also outline the historical development of the astronomy on the continent, and then review the principal scientific results to have emerged over the past three decades of activity in the discipline. These range from determination of the dominant frequencies of the 5 min solar oscillation in 1979 to the highest angular scale measurements yet made of the power spectrum of the CMBR anisotropies in 2010. They span through infrared views of the galactic ecology in star formation complexes in 1999, the first clear demonstration that the Universe was flat in 2000, the first detection of polarization in the CMBR in 2002, the mapping of the warm molecular gas across the ~ 300 pc extent of the Central Molecular Zone of our Galaxy in 2003, the measurement of cosmic neutrinos in 2005, and imaging of the thermal Sunyaev Zel’dovich effect in galaxy clusters in 2008. This review also discusses how science is conducted in Antarctica, and in particular the difficulties, as well as the advantages, faced by astronomers seeking to bring their experiments there. It also reviews some of the political issues that will be encountered, both at national and international level. Finally, the review discusses where Antarctic astronomy may be heading in the coming decade, in particular plans for infrared and terahertz astronomy, including the new facilities being considered for these wavebands at the high plateau stations.

Burton, Michael G.

2010-10-01

161

Antarctica. Commission Reports 1962.  

National Technical Information Service (NTIS)

Contents: Geological structure of the central Queen Maud Land mountains in east Antarctica; Morphometric parameters of Antarctica; Blank areas on maps of the Antarctic; The geomorphological map of Antarctica; Physiographic zoning map of the Antarctic; Pal...

V. A. Bugaev

1969-01-01

162

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

163

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

164

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

165

Connecting Schools, Families & Communities: Stories and Results from the Annie E. Casey Foundation's Education Investments  

ERIC Educational Resources Information Center

Partnerships among schools, families, and community organizations can reconnect urban schools to their communities and improve results for young people and their families. This report provides an overview of Casey's investment philosophy and strategies, and its approach to defining and documenting grantmaking results. The report highlights the…

Jehl, Jeanne

2007-01-01

166

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.

167

Apiosordaria antarctica and Thielavia antarctica, two new ascomycetes from Antarctica.  

PubMed

Two new species of ascomycetes, Apiosordaria antarctica, isolated from soil, and Thielavia antarctica, isolated from a sample of the lichen Usnea cf. aurantio-atra, both collected on King George Island (Antarctica), are described and illustrated. Apiosordaria antarctica is characterized by ostiolate ascomata with agglutinated hairs, eight-spored, uniseriate and cylindrical asci, and two-celled, irregularly navicular ascospores, with an upper cell ornamented with very small warts and with an apical germ pore. Thielavia antarctica is characterized by nonostiolate ascomata, with a thick peridium, eight-spored, cylindrical asci, uniseriate, oblate, ovoid ascospores, a slightly protruding apical germ pore, and a phialidic anamorph. PMID:21149023

Stchigel, Alberto M; Guarro, Josep; Mac Cormack, Walter

2003-01-01

168

The role of synoptic-scale features and advection in prolonged warming and generation of different forms of precipitation at Dome Fuji station, Antarctica, following a prominent blocking event  

NASA Astrophysics Data System (ADS)

A blocking event over the East Antarctic ice sheet during June 1997 generated the highest surface air temperature (which increased from around -70°C to around -30°C) and pressure of that year at the Dome Fuji station (77.5°S, 40°E). Following the blocking event, the anomalously high air temperature (around -50°C to -60°C) and pressure were maintained at the surface for about 1 week. This study investigates how these warm conditions were maintained and documents the sequential occurrence of two forms of synoptic-scale high-pressure systems with conditions that produced precipitation by different processes in each case. In the first half of the warm period, a solitary high-pressure system (the Solitary High) formed over the Dome Fuji station and traveled west over East Antarctica after being cut off from the tip of the preceding blocking ridge. During this phase, tropospheric temperatures were higher, and surface-based temperature inversions were more intense than during the following period. While a dry-out developed in the troposphere below about 300 hPa, the precipitation of ice crystals in the surface-based temperature inversion layer was generated by deposition of moisture that had become trapped in the boundary layer after being transported onto the continent by the previous blocking ridge. This mechanism has not been previously reported elsewhere. During the second half of the warm period, a ridge of high pressure (the Transcontinental Ridge) traversed East Antarctica almost completely, and its western section was amplified by the merging of the Solitary High with a preceding quasi-stationary Rossby wave train propagating along the Southern Ocean. This ridge allowed an intrusion of warm, moist air from the Weddell Sea toward the station, which generated precipitation throughout the whole troposphere by orographic uplift once again, and ended the dry-out. This represents the typical mechanism of both moisture transportation and the generation of precipitation, and this mechanism was the same as that associated with the preceding blocking ridge.

Hirasawa, Naohiko; Nakamura, Hisashi; Motoyama, Hideaki; Hayashi, Masahiko; Yamanouchi, Takashi

2013-07-01

169

The genus Pseudolathra Casey in China: new species and new records (Coleoptera, Staphylinidae, Paederinae)  

PubMed Central

Abstract Two new species of the genus Pseudolathra Casey from mainland China are described and attributed to their respective species groups, P. cylindrata sp. n. from Hubei and Sichuan, and P. superficiaria sp. n. from Yunnan. Pseudolathra pulchella (Kraatz, 1859), P. transversiceps Assing, 2013 and P. bipectinata Assing, 2013 from Yunnan are reported from China for the first time. The history of the exploration of the Chinese fauna of Pseudolathra is summarized.

Li, Xiao-Yan; Solodovnikov, Alexey; Zhou, Hong-Zhang

2013-01-01

170

Bouvet Island near Antarctica  

... 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

171

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

172

Decrease of auroral intensity associated with reversal of plasma convection in response to an interplanetary shock as observed over Zhongshan station in Antarctica  

NASA Astrophysics Data System (ADS)

We examined temporal variations of a dayside aurora and corresponding ionospheric plasma convection observed by an all-sky camera (ASC) and the Super Dual Auroral Radar Network (SuperDARN) over Zhongshan (ZHS), located at -74.5° in magnetic latitude (MLAT) in Antarctica, during a geomagnetic sudden commencement (SC) event that occurred on 27 May 2001. Simultaneous ASC observations at South Pole (SP, -74.3° MLAT) were also analyzed. During the SC time, ZHS and SP were located in the postnoon (1610 MLT) and prenoon (1100 MLT) sectors, respectively. Before the SC onset (1458UT), the ASC at ZHS observed an auroral arc with moderate intensity in the poleward direction of the field of view (FOV), and the SuperDARN radar detected sunward ionospheric plasma flow over ZHS. Just after the SC onset, the auroral intensity over ZHS decreased rapidly and the direction of the plasma flow was reversed to antisunward. Decrease of auroral intensity and reversal of the associated plasma convection in response to a sudden increase of the solar wind dynamic pressure at the early stage of a SC event has never been reported before. We suggest that these observational results were generated by a downward field-aligned current (FAC) and are consistent with a physical model of SC. The model predicts the appearance of a pair of FACs flowing downward (upward) in the postnoon (prenoon) sector at the very beginning of the SC, which is also supported by our observations. Consistence of the detailed observations with the model will be discussed in the paper, and we argue that here we present the first optical observational evidence supporting the validity of the model.

Liu, J. J.; Hu, H. Q.; Han, D. S.; Araki, T.; Hu, Z. J.; Zhang, Q. H.; Yang, H. G.; Sato, N.; Yukimatu, A. S.; Ebihara, Y.

2011-03-01

173

Antarctica and Continental Drift.  

National Technical Information Service (NTIS)

Continental drift reconstructions by computerized matching of the 1,000 fm isobaths are presented for Africa/Antarctica, Australia/Antarctica and India/Antarctica. Sufficiently good congruency is obtained for the first two to suggest that they are probabl...

R. S. Dietz J. C. Holden W. P. Sproll

1972-01-01

174

First observations of ionospheric irregularities and flows over the south geomagnetic pole from the Super Dual Auroral Radar Network (SuperDARN) HF radar at McMurdo Station, Antarctica  

NASA Astrophysics Data System (ADS)

Observations from the first 100 days of operation of the Super Dual Auroral Radar Network (SuperDARN) radar at McMurdo Station, Antarctica are presented. The observations are examined for incidence of ionospheric scatter, which is higher than has been found at the auroral zone radars of the SuperDARN network. During some hours of each day, the probability of observing ionospheric scatter exceeded 90%. In the later portion of the period examined, there was a period of time each day during which the scatter incidence dropped significantly. Incidence was as examined versus solar illumination of the ionosphere, and it was found that the decreases coincided with periods when the ionosphere was in darkness. From this, it is concluded that propagation effects were the reason for the decreases. Plasma velocity observations from the period are also presented and compared with the prevailing interplanetary magnetic field (IMF). The observations were averaged over the central polar cap (? > 85°) and were selected for intervals when the radar line of sight was nearly parallel to the Earth-Sun (E-S) line or perpendicular (E-S-perp) to it. A linear relationship was found between the IMF z component and the E-S velocity and similar relationship between the E-S-perp velocity and the IMF y component. There was a significant spread of velocities about the best fit lines. The IMF and average velocity time series were cross-correlated for a number of intervals, and it was found that the average correlation was about 50%, though during some intervals, the correlation exceeds 80%. No explanation is given for the variance of the correlation.

Bristow, W. A.; Spaleta, J.; Parris, R. T.

2011-12-01

175

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

176

Robert Casey  

Cancer.gov

Skip to Main Content CCR Home | About CCR | CCR Intranet Main Navigation Home Profiles Research Newsworthy References Special Interest Groups Training Main Links Psycho-Oncology Home Profiles Research Publications Newsworthy/Resources References Special

177

Long-term variability of stratospheric temperature above central Antarctica  

Microsoft Academic Search

Long-term variations of atmospheric temperature at different isobaric surfaces above central Antarctica were studied. Data of atmospheric balloon soundings at two Antarctic intercontinental stations Vostok and Amundsen-Scott (South Pole) taken for the last 40 years were used in this study. It was found that stratospheric temperature at both stations averaged seasonally or annually does not demonstrate any meaningful correlation with

L. N Makarova; A. V Shirochkov

2002-01-01

178

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.

Productions, Jonathan B.

2011-06-06

179

Research on the Web: Antarctic Weather Stations  

NSDL National Science Digital Library

This activity will help students see the link between wind speeds and geographical features. 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 stations and end by developing an hypothesis for the different patterns they have observed. In Antarctica, scientists often have trouble measuring katabatic winds, which are so strong they can knock down the instruments. Students discover for themselves why Antarctica is the windiest place on Earth.

180

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

181

Benchmarking the Performance of Employment and Training Programs: A Pilot Effort of the Annie E. Casey Foundation's Jobs Initiative.  

ERIC Educational Resources Information Center

As part of its Jobs Initiative (JI) program in six metropolitan areas Denver, Milwaukee, New Orleans, Philadelphia, St. Louis, and Seattle the Annie E. Casey Foundation sought to develop and test a method for establishing benchmarks for workforce development agencies. Data collected from 10 projects in the JI from April through March, 2000,…

Welch, Doug

182

Magnetotelluric measurements in Antarctica  

NASA Astrophysics Data System (ADS)

During austral summer 1984-1985 magnetotelluric measurements were carried out in North Victoria Land, Antarctica. The magnetic field was measured by a three-component fluxgate magnetometer. Copper screens (50 cm × 50 cm) were used as electrodes for recording the electric field, connected to a two channel electrograph with an input impedance of 10 12 ?. Analogue data are digitized with 12 bit resolution by a data acquisition system. 1 Mb of solid state CMOS-RAM memory was used to store the data in the field until it could be played back onto 3.5 inch floppy discs during station control. All equipment is designed for low power consumption. In the field it is supplied by a battery, which is charged by solar panels. Time series of measured data are presented. The influence of the polar electrojet (PEJ) on the source fields is clearly seen by comparing 24-h time series with the position of the auroral oval at different times of the day. Despite the clear effect of the PEJ in the data, the calculated apparent resistivity and phase curves seem to be rather uninfluenced. Initial interpretations have led to a typical continental resistivity distribution, showing decreasing resistivity with increasing depth.

Beblo, M.; Liebig, V.

183

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

184

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.

185

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

186

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.

Productions, Jonathan B.

2011-05-04

187

Surveying Antarctica: from dogsled to satellite  

USGS Publications Warehouse

Base maps of Antarctica are needed at scales of 1:250,000 to plot scientific data, yet after 20 years of a major mapping effort, only about 20 percent of the continent has been accurately mapped using aerial photographs and ground surveys. Encompassing nearly 14.3 million square kilometers (5.5 million square miles), Antarctica still presents a formidable mapping task. Except for the area around the geographic South Pole, Landsat could, in just a few years, provide the images to planimetrically map Antarctica at such scales as 1:250,000. Just 11 Landsat images would encompass the same area mapped to date at a 1:250,000 scale. Navigation satellite data from ground stations can provide the necessary horizontal and vertical ground control in many areas. Other polar orbiting satellites could be used to establish elevation profiles of the ice surfaces on Antarctica. If this presently available space technology is fully utilized, the scientific exploration of the huge Antarctic continent will be greatly accelerated, fulfilling one of the goals Commander Byrd began to work toward 50 years ago.

Williams, Richard S., Jr.

1979-01-01

188

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

189

Weather and mass balance in the ablation zone of the Taylor Glacier, Antarctica  

Microsoft Academic Search

A simple model that predicts ablation from weather station measurements on the Taylor Glacier, Antarctica is presented along with ablation measurements at about 250 ablation stakes. The model output matches the ablation measurements at the weather station locations. Via extrapolation of the weather station measurements to the rest of the glacier, the model also makes predictions for the rest of

A. K. Bliss; K. M. Cuffey; J. Kavanaugh; D. Morse

2005-01-01

190

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.

191

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

192

Antarctica - Lessons for a Mars exploration program  

NASA Technical Reports Server (NTRS)

The history of exploration and the international system of control of Antarctica has often been cited as a paradigm for the exploration of space. The small isolated research stations have been used to model the psychological stresses of future space missions. In addition, the programmatic structure of the U.S. Antarctic Research Program provides several possible analogs to future Mars Programs presently under discussion. These are: (1) Continued presence; (2) Civilian, military and private sector involvement; (3) Scientific activities; (4) Risk assessment and logistical support; (5) Accessibility for non-specialists; (6) Political and strategic motivations; (7) International cooperation/competition. Survival in Antarctica is contingent on advanced technology and the active transport of supplies. The scientific exploration of this remote and barren expanse without, of course, the aid and guidance of indigenous people certainly provides one of the closest analogs available to future science activities on the Martian surface.

Mckay, C. P.

1985-01-01

193

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

194

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

195

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

196

Stable isotopes in daily precipitation at Dome Fuji, East Antarctica  

Microsoft Academic Search

Daily precipitation samples for stable isotope analysis were collected throughout 2003 at Dome Fuji Station, inland East Antarctica. Stable isotopes show significantly depleted values with a large seasonal variability, which have never been obtained. Temporal changes in ?-T relation and d-excess are consistent with those found in geographical distribution. Precipitation was obtained almost everyday, though the amounts were quite small

Koji Fujita; Osamu Abe

2006-01-01

197

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; with a Foreward by Burrill, Meredith F.; and a List of Expeditions by Bertrand, Kenneth J.; Alberts, Fred G.

1956-01-01

198

Comparison of an ionosonde drift model at a single station with polar convention patterns  

NASA Astrophysics Data System (ADS)

A study of convection at a single point in the polar cap is made by comparing vertical incidence ionosonde Doppler drift data with the Weimer 96 (W96) convection model. Four years of data are used to construct a local convention model at Casey, Antarctica (geographic 66.3°S, 110.5°W, geomagnetic 80.8°S). The Casey 97 (C97) model is capable of producing a drift velocity for any time and interplanetary magnetic field (IMF) vector in the By-Bz plane for either summer or winter seasons. The direct comparison of vectors predicted by C97 and W96 shows there is generally very good agreement between them at all IMF angles. Because of this, our findings consequently support the existence of multiple convection cells for IMF angles within 30° of northward (+Z). For all other angles there is a distortion of the two-cell pattern that becomes a minimum when the IMF is strongly southward with slightly a positive By component. Drawing on an earlier study with the Heppner-Maynard model [Smith et al., 1998], but now using the C97 model for comparison, we also find their patterns only begin to match the Casey results when |By|>>Bz. A significant seasonal dependence also exists within the C97 and W96 models, although the agreement with each other in winter is not as good. The presence of additional summer lobe cells embedded within the merging cells is supported, particularly for a rounder, expanded dusk cell.

Smith, Paul R.; Dyson, Peter L.; Morris, Ray J.

199

Altitude and configuration of the potentiometric surface, Casey Village, Warminster and Upper Southampton townships, Bucks County, Pennsylvania, August 3, 1995  

USGS Publications Warehouse

A map showing the potentiometric surface in Casey Village, Warminster and Upper Southampton Townships, Bucks County, was constructed from water levels measured on August 3, 1995. The potentiometric surface, measured in 17 wells screened between 18 and 64 feet below land surface, ranged from 321.99 to 344.80 feet above sea level. The potentiometric surface, measured in 12 wells screened between 48 and 108 feet below land surface, ranged from 321.95 to 337.50 feet above sea level.

Sloto, Ronald A.; Grazul, Kevin E.

1995-01-01

200

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

201

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

202

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

203

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

204

Why Is It Always Cold in Antarctica?  

NSDL National Science Digital Library

In this week-long unit, students examine weather reports from all over the world in order to understand global temperature patterns. Throughout the unit, students collect their findings in a portfolio. The comprehensive curriculum materials contain teacher tools, a Web activity in which students examine 12 months of weather data for several U.S. cities, comparing their findings with the same 12 months at Antarctica weather stations, two hands-on experiments, two Q&A interviews and a student handout with guidance for putting together their portfolios and examples of creative final projects.

205

Use of 1.0% or 0.5% KI-buffered Cathode Solution in ECC Ozonesondes: An Analysis of Dual-Ozonesonde Flights Over McMurdo Station, Antarctica Through Comparison With Remote Measurements and a Transfer Function to Convert Between Solution  

NASA Astrophysics Data System (ADS)

Balloon-borne electrochemical concentration cell ozonesondes have been used to measure vertical profiles of ozone concentration from 0 to ~ 35km above McMurdo Station, Antarctica since 1986. These instruments have precisions of ~ 5%. The accuracy partially depends on the concentration of potassium- iodide (KI) cathode solution used in the electrochemical concentration cell. The use of 1.0% KI sensing solution has been maintained at McMurdo, even though in 1996 the manufacturer recommended reducing the concentration to 0.5%. Since then, laboratory studies (Smit et al., 2006) and field comparisons (Deshler et al., 2006) have indicated that the use of 1.0% KI cathode sensing solution can lead to an overestimation of ozone of up to 5% below 20 km, and up to 10% above 20 km. However, these overestimations are thought to be dependent on the amount of ozone entering the chamber, and thus could be less for measurements taken during times of polar ozone depletion. Here, we present the results of dual ozonesonde flights over McMurdo Station, Antarctica (78° S) using 1.0% and 0.5% buffered KI solution. Comparison between vertical ozone profiles from dual flights shows that 0.5% buffered solution consistently gives lower values of ozone than the 1.0% buffered solution when ozone partial pressure is > 5mPa. Total column ozone values are calculated from balloon flight measurements and compared with total column ozone measured by the Total Ozone Mapping Spectrometer (TOMS) on NASA's Earth Probe satellite and by a Dobson spectrophotometer operated approximately 1 km from McMurdo station. When total column ozone is > 250DU, the 0.5% solution compares better with the TOMS and Dobson spectrophotometer data. However, in most cases where total ozone is < 250DU, measurements with 1.0% solution compare better with both TOMS and Dobson spectrophotometer measurements. Recent analysis of dual-ozonesonde flights in mid- and polar latitudes has led to the development of a simple linear transfer function where the Ratio (1.0KI/0.5KI) = 1.106 - 0.027 × log10(Pressure). This transfer function has been suggested for homogenizing long-term data sets where both 1.0% and 0.5% KI-sensing solutions have been used, and thus its application is investigated here.

Mercer, J. L.; Deshler, T.; Wood, S. W.; Nichol, S.

2006-12-01

206

Deep-water sedimentary environments of the northwestern Weddell Sea and South Sandwich Islands, Antarctica  

Microsoft Academic Search

Two transects have been sampled using short cores (multi and box), seabed photography, video sequences, and sediment profile images across the northwestern Weddell Sea and South Sandwich Forearc, Antarctica. A total of 12 core stations were examined for sediment structure, texture and composition to determine their depositional history. Four of the core stations from the Weddell Continental Slope, Abyssal Plain

John A. Howe; Tracy M. Shimmield; Robert Diaz

2004-01-01

207

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).

208

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.

Landis, Carol

2011-01-01

209

Antarctica in Images  

NSDL National Science Digital Library

This classroom activity introduces students to Antarctica's organisms, landscapes, and seascapes. After examining the images in the photo gallery, students work in small groups to discuss their conclusions about the living conditions on this continent. The printable three-page handout includes a series of questions to help students structure their thoughts while viewing the gallery images and a group worksheet that guides students through a discussion of their evolving hypotheses and conclusions.

210

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

211

Persistence, Partnership and Public Will: The Annie E. Casey Foundation's Investments in Kentucky School Reform. Principles for Effective Education Grantmaking. Case Study Number 2  

ERIC Educational Resources Information Center

This case study explores the sustained role the Annie E. Casey Foundation played for more than a decade to help create an environment in which an ambitious and comprehensive effort to improve public education for all children in Kentucky would have the time, resources and attention needed to prove its worth. As the case describes, the sweeping…

Sherwood, Kay E.

2006-01-01

212

Transforming Neighborhoods into Family-Supporting Environments: Evaluation Issues and Challenges. Report of the Annie E. Casey Foundation's Research and Evaluation Conference (Baltimore, Maryland, March 1999).  

ERIC Educational Resources Information Center

The Annie E. Casey Foundation's fourth conference occurred as the Foundation launched a new neighborhood transformation and family development strategy centered on strengthening families. This conference summary presents discussions of the major themes from the conference. Section 1, "Understanding the Connection between Families and Communities,"…

Annie E. Casey Foundation, Baltimore, MD.

213

Ties That Bind: The Practice of Social Networks. Number Two in a Series of Reports on Social Networks from The Annie E. Casey Foundation  

ERIC Educational Resources Information Center

This report documents the Annie E. Casey Foundation's effort to learn from families, communities and organizations around the country about their experiences with social network strategies and approaches. Using the voices and experiences of the families and organizations visited, the report summarizes findings from these visits and helps lay the…

Bailey, Terri J.

2006-01-01

214

Persistence, Partnership and Public Will: The Annie E. Casey Foundation's Investments in Kentucky School Reform. Principles for Effective Education Grantmaking. Case in Brief Number 2  

ERIC Educational Resources Information Center

"Persistence, Partnership and Public Will" explores the sustained role the Annie E. Casey Foundation played in Kentucky for more than a decade to help create an environment in which the state's ambitious and comprehensive effort to improve education for all of its students would have the time, resources and attention needed to prove its worth. The…

Grantmakers for Education, 2012

2012-01-01

215

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

216

Intermediate-focus earthquakes under South Shetland Islands (Antarctica)  

Microsoft Academic Search

This study is based on data from five field surveys (1992-1996) of seismic monitoring on Deception Island (South Shetland Islands, Antarctica). In the 1994-95 and 1995-96 surveys earthquakes were recorded by a seismic array. In previous surveys data were collected by a high-dynamic range, short-period station. The analysis of the events shows evidence of intermediate-focus seismicity [50

J. M. Ibáñez; J. Morales; G. Alguacil; J. Almendros; R. Ortiz; E. Del Pezzo

1997-01-01

217

Intermediate-focus earthquakes under South Shetland Islands (Antarctica)  

Microsoft Academic Search

This study is based on data from five field surveys (1992–1996) of seismic monitoring on Deception Island (South Shetland Islands, Antarctica). In the 1994–95 and 1995–96 surveys earthquakes were recorded by a seismic array. In previous surveys data were collected by a high-dynamic range, short-period station. The analysis of the events shows evidence of intermediate-focus seismicity [50 < H< 100

J. M. Ibáñez; J. Morales; G. Alguacil; J. Almendros; R. Oritz; E. Del Pezzo

1997-01-01

218

Hovercraft experience in Antarctica  

NASA Astrophysics Data System (ADS)

The Model 1500 TD air-cushion vehicle (ACV) has been modified for the extreme conditions encountered in Antarctic operations; these operations began in the 1988-1989 austral summer. Performance evaluations covering 300 hours of engine operations have been obtained which demonstrate the basic soundness of this ACV's design and construction, and its applicability to Antarctic operations, where it was able to reduce travel time and fuel consumption in excess of 40 percent. In addition, passenger comfort was increased manyfold over wheeled and tracked vehicles for comparable missions. The ACV is judged capable of solving many of the transportation problems experienced in Antarctica.

Cook, Harvey C.

219

Total solar eclipse over Antarctica on 23 November 2003 and its effects on the atmosphere and snow near the ice sheet surface at Dome Fuji  

Microsoft Academic Search

The Moon cast a long shadow over Antarctica on 23 November 2003 in a total solar eclipse. The eclipse was observed at Dome Fuji Station, located at the highest point of East Dronning Maud Land, Antarctica, and lasted 1 h 41 min 37 s in a cloudless condition, during which the Sun was completely obscured for 1 min 43 s.

Takao Kameda; Koji Fujita; Okimasa Sugita; Naohiko Hirasawa; Shuhei Takahashi

2009-01-01

220

Surface wave tomography of South America and Antarctica  

NASA Astrophysics Data System (ADS)

We present the results of a study of the dispersion characteristics of broadband fundamental mode seismic surface waves propagating across South America, Antarctica and the surrounding oceans. We analyzed data from 765 earthquakes recorded at 48 seismic stations for South America and from 576 earthquakes recorded at 44 stations for Antarctica, which produced 11,700 dispersion curves for Rayleigh Waves and 8,200 dispersion curves for Love waves. The main results of this study are represented in the form of group velocity maps for Rayleigh (20 s--175 s) and Love (20 s--125 s) waves. The South American maps reveal a number of sedimentary basins across the continent (such as Maturin-Llanos, Maranon-Ucayali-Madre de Dios, Chaco-Tarija, Parana Basins), the Caribbean, and western Gulf of Mexico; the thickened crust beneath the Andes, the Altiplano, and the Brazilian Highlands; sub-continental roots and the Galapagos Ridge and the Galapagos hot spot. The Antarctic maps demonstrate such features as the thick crust in East Antarctica and beneath the Transantarctic Mountains, mid-ocean ridges, the East Antarctic craton, and a number of hot spots. The average lateral resolution is on the order of 500--550 km on the Antarctic continent and 650--750 km on the South American continent, which is a significant improvement over that reported in global scale studies. The difference between these two results is likely due to different algorithms used to assess the resolution on the both continents. We produced azimuthal anisotropy maps for the 2psi component of group velocity across Antarctica and the surrounding oceans; these maps correlate fairly well with those of the global study (Trampert and Woodhouse, 1996). The estimated group velocity maps can be inverted to produce new shear velocity models across the studied regions, which may improve knowledge of the crust and the uppermost mantle beneath South America and Antarctica.

Vdovin, Oleg Yurevich

221

The crustal thickness of West Antarctica  

NASA Astrophysics Data System (ADS)

P-to-S receiver functions (PRFs) from the Polar Earth Observing Network (POLENET) GPS and seismic leg of POLENET spanning West Antarctica and the Transantarctic Mountains deployment of seismographic stations provide new estimates of crustal thickness across West Antarctica, including the West Antarctic Rift System (WARS), Marie Byrd Land (MBL) dome, and the Transantarctic Mountains (TAM) margin. We show that complications arising from ice sheet multiples can be effectively managed and further information concerning low-velocity subglacial sediment thickness may be determined, via top-down utilization of synthetic receiver function models. We combine shallow structure constraints with the response of deeper layers using a regularized Markov chain Monte Carlo methodology to constrain bulk crustal properties. Crustal thickness estimates range from 17.0±4 km at Fishtail Point in the western WARS to 45±5 km at Lonewolf Nunataks in the TAM. Symmetric regions of crustal thinning observed in a transect deployment across the West Antarctic Ice Sheet correlate with deep subice basins, consistent with pure shear crustal necking under past localized extension. Subglacial sediment deposit thicknesses generally correlate with trough/dome expectations, with the thickest inferred subice low-velocity sediment estimated as ˜0.4 km within the Bentley Subglacial Trench. Inverted PRFs from this study and other published crustal estimates are combined with ambient noise surface wave constraints to generate a crustal thickness map for West Antarctica south of 75°S. Observations are consistent with isostatic crustal compensation across the central WARS but indicate significant mantle compensation across the TAM, Ellsworth Block, MBL dome, and eastern and western sectors of thinnest WARS crust, consistent with low density and likely dynamic, low-viscosity high-temperature mantle.

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

2014-01-01

222

Total ozone by lunar Dobson observation at Syowa, Antarctica  

NASA Technical Reports Server (NTRS)

The lunar Dobson observation is almost the only way to get the total ozone in or around the polar night season at high latitudes where the total ozone observation by solar Dobson is not available. The total ozone observations by lunar Dobson were carried out at Syowa Station (69 S, 40 E), Antarctica in 1969, and 1982 to 1986, in the months from March to October. The method, the accuracy and the results of the lunar Dobson observation carried out at Syowa Station from 1982 to 1986 are described.

Chubachi, Shigeru; Kajiwara, Ryoichi; Kondoh, Kouji

1988-01-01

223

Crustal Thickness across West Antarctica from Polenet  

NASA Astrophysics Data System (ADS)

Recent data and methodological advances in deep seismic imaging have yielded invaluable information about the crust and mantle of continental and regional scales. Receiver function analysis, pioneered nearly 40 years ago, continues to be widely used to study abrupt velocity transitions at depth and to recover key information such as crustal thickness and Poisson's ratio, mantle transition zone thicknesses, and Moho topography. We examine P-to-S receiver functions, S-to-P receiver functions, and surface wave kernels to study crustal thicknesses and mantle transition zone depths across a wide extent of West Antarctica and the Transantarctic Mountains (TAM) as part of the POLENET project. The presence of thick ice sheets and, in some areas, underlying sedimentary basins, create complications in identifying key (e.g., Moho) conversions that are normally readily visible in continental settings. We have successfully applied several approaches to the entirety of available POLENET and other Antarctic stations to optimally circumvent these issues, including deconvolution, forward modeling, FK-filtering, and regularized Markov Chain Monte Carlo inversion methods. We report on the most recently obtained crustal thickness and other results in the context of Antarctic tectonics and the crustal structure of the WAIS, TAM and Marie Byrd Land (MBL) regions. Moho depths for West Antarctica vary from ~23-30 km towards MBL, with thinning on the coast of MBL.

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

2012-12-01

224

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

225

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

226

The United States in Antarctica -- Report of the U.S. Antarctic Program External Panel  

NSF Publications Database

... 3.0 Antarctica -- The Environment 3.0 Antarctica -- The Environment (continued) 4.0 Antarctica -- ... Antarctica -- Past and Present (continued) 5.0 Antarctica -- Significance Today 5.0 Antarctica -- ...

227

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

228

Cold colonies: Antarctic spatialities at Mawson and McMurdo stations  

Microsoft Academic Search

In 1954, a small team of Australian men landed at Horseshoe Harbor and began constructing Mawson Station: the permanent colonization of Antarctica was initiated. Two years later, Americans began the construction of their major Antarctic base, McMurdo. Although Antarctica is routinely represented as an empty wilderness, over the last 50 years tens of thousands of humans have occupied the continent,

Christy Collis; Quentin Stevens

2007-01-01

229

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.

230

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.

Landis, Carol

231

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.

232

Geodetic GPS-based analysis of recent crustal motions in Victoria Land (Antarctica)  

Microsoft Academic Search

GPS measurements were collected within the framework of the VLNDEF (Victoria Land Network for DEFormation control) project, which was started in 1999 with the aim of detecting crustal deformation in Northern Victoria Land (Antarctica). The network was established in 1999 and is composed of one permanent station (TNB1), which has been observing since 1998, and 28 periodically surveyed control points.

Antonio Zanutta; Luca Vittuari; Stefano Gandolfi

2008-01-01

233

An analysis of temperatures and wind speeds above Dome C, Antarctica  

Microsoft Academic Search

A good astronomical site must fulfill several criteria including low atmospheric turbulence and low wind speeds. It is therefore important to have a detailed knowledge of the temperature and wind conditions of a location considered for future astronomical research. Antarctica has unique atmospheric conditions that have already been exploited at the South Pole station. Dome C, a site located on

E. Aristidi; K. Agabi; M. Azouit; E. Fossat; J. Vernin; T. Travouillon; C. Meyer; J. W. V. Storey; B. Halter; W. L. Roth; V. Walden

2005-01-01

234

Annual cycle of landfast sea ice in Prydz Bay, east Antarctica  

Microsoft Academic Search

Under the Chinese National Antarctic Research Expedition program in 2006, the annual thermal mass balance of landfast ice in the vicinity of Zhongshan Station, Prydz Bay, east Antarctica, was investigated. Sea ice formed from mid-February onward, and maximum ice thickness occurred in late November. Snow cover remained thin, and blowing snow caused frequent redistribution of the snow. The vertical ice

Ruibo Lei; Zhijun Li; Bin Cheng; Zhanhai Zhang; Petra Heil

2010-01-01

235

Numerical simulation of VLF risers, fallers, and hooks observed in Antarctica  

Microsoft Academic Search

The VLF database from Halley station, Antarctica, has been searched, and prominent examples of discrete emissions are presented. Risers, fallers, quasi-constant tones, and upward and downward hooks are all common. Also observed are risers and fallers triggered from the tops of hiss bands. A one-dimensional Vlasov VHS code has been used to simulate the main types of events observed. Using

A. J. Smith; D. Nunn

1998-01-01

236

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

237

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

238

Snow chemistry across Antarctica  

NASA Astrophysics Data System (ADS)

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO3, SO4) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of Antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http://www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized.

Bertler, N.; Mayewski, P. A.; Aristarain, A.; Barrett, P.; Becagli, S.; Bernardo, R.; Bo, S.; Xiao, C.; Curran, M.; Qin, D.; Dixon, D.; Ferron, F.; Fischer, H.; Frey, M.; Frezzotti, M.; Fundel, F.; Genthon, C.; Gragnani, R.; Hamilton, G.; Handley, M.; Hong, S.; Isaksson, E.; Kang, J.; Ren, J.; Kamiyama, K.; Kanamori, S.; Kärkäs, E.; Karlöf, L.; Kaspari, S.; Kreutz, K.; Kurbatov, A.; Meyerson, E.; Ming, Y.; Zhang, M.; Motoyama, H.; Mulvaney, R.; Oerter, H.; Osterberg, E.; Proposito, M.; Pyne, A.; Ruth, U.; Simões, J.; Smith, B.; Sneed, S.; Teinilä, K.; Traufetter, F.; Udisti, R.; Virkkula, A.; Watanabe, O.; Williamson, B.; Winther, J.-G.; Li, Y.; Wolff, E.; Li, Z.; Zielinski, A.

239

Carbonaceous micrometeorites from Antarctica.  

PubMed

Over 100 000 large interplanetary dust particles in the 50-500 micrometers size range have been recovered in clean conditions from approximately 600 tons of Antarctic melt ice water as both unmelted and partially melted/dehydrated micrometeorites and cosmic spherules. Flux measurements in both the Greenland and Antarctica ice sheets indicate that the micrometeorites deliver to the Earth's surface approximately 2000x more extraterrestrial material than brought by meteorites. Mineralogical and chemical studies of Antarctic micrometeorites indicate that they are only related to the relatively rare CM and CR carbonaceous chondrite groups, being mostly chondritic carbonaceous objects composed of highly unequilibrated assemblages of anhydrous and hydrous minerals. However, there are also marked differences between these two families of solar system objects, including higher C/O ratios and a very marked depletion of chondrules in micrometeorite matter; hence, they are "chondrites-without-chondrules." Thus, the parent meteoroids of micrometeorites represent a dominant and new population of solar system objects, probably formed in the outer solar system and delivered to the inner solar system by the most appropriate vehicles, comets. One of the major purposes of this paper is to discuss applications of micrometeorite studies that have been previously presented to exobiologists but deal with the synthesis of prebiotic molecules on the early Earth, and more recently, with the early history of the solar system. PMID:11543069

Engrand, C; Maurette, M

1998-07-01

240

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

241

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

242

Antarctica: A Cold Desert Ecosystem  

NSDL National Science Digital Library

This Antarctica lesson has students locate the continent on a globe and on a map, describe and illustrate major Antarctic ecosystems, and explain relationships between those ecosystems. They will also construct a rough map of Antarctic ecosystems and explore relationships among the creatures that populate them. This lesson can be adapted to focus on other regions, including the one in which students live.

243

Antarctica — Before and after Gondwana  

Microsoft Academic Search

The origin of the Antarctic continent can be traced to a relatively small late Archaean cratonic nucleus centred on the Terre Adélie regions of East Antarctica and the Gawler Craton region of South Australia. From the late Archaean to the present, the evolution of the proto-Antarctic continent was remarkably dynamic with quasi-continuous growth driven by accretionary or collisional events, episodically

Steven D. Boger

2011-01-01

244

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.

245

Relationship between the increase temperature and variation of ozone level over the Antarctica and Tibetan plateau in spring  

Microsoft Academic Search

on the ozone and aerological sounding data at Syowa Station (69? 00’S, 39?35’E), Antarctica during 1966—1979 and Lhasa Station\\u000a (39?40’N, 91?08’E), Tibetan Plateau during 1979—1983, the processes of temperature increase in spring over the Tibetan Plateau\\u000a and the Antarctica are compared in this paper, and the relationship between the increase of air temperature and variation\\u000a of total ozone and ozone

Dengyi Gao; Sadao Kawagochi

1986-01-01

246

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.

Bergada, Pau; Deumal, Marc; Vilella, Carles; Regue, Joan R.; Altadill, David; Marsal, Santi

2009-01-01

247

Remote sensing and skywave digital communication from antarctica.  

PubMed

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

248

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.

249

Assessment and Review of GIA Models for Antarctica and Greenland  

NASA Astrophysics Data System (ADS)

One of the major obstacles to reducing the uncertainty of GRACE-based ice mass balance estimates for the ice sheets during 2002-2011 is our poor control on the ongoing glacial isostatic adjustment of bedrock (GIA). The later adjustments cause vertical motions of rock at the crustal surface and at great depths within the mantle. These are sources of positive mass trend when measured in space gravimtery data. The poorly understood signal in Antarctica may be large enough to manifest uncertainties that approach 190 Gt/yr (Velicogna and Wahr, 2006), dominating the background error in trend for Antarctica, and potentially corrupting solutions for mass balance for ice drainage basins in the north and central parts of Greenland. This source of error is independent of method, and corrupts the interpretable trend in both spherical harmonic field or mascon releases. Two of the most recent GRACE mass balance assessments for GIA in Antarctica employ combinations of ICE5G and IJ05 models, both of which are now more than half a decade old. In part, because of the urgency to report to the IPCC on the mass balance of Antarctica with greater certainty, GIA modeling has been the focus of intense research in the past 6-7 years. Significant progress lies in three areas of research: i.) Constraint on paleo-ice sheet reconstruction coming from dated sedimentary coring ('bathtub rings') and moraine and nunatuk rock nuclide exposures ('dip sticks of the past'). This data is now rich enough that, in fact, for some areas of Antarctica we now know much more about ice mass evolution since Last Glacial Maximum (21 thousand years ago), that we do for the great Laurentide ice sheet of North America; ii.) Integration of simple ice dynamics models that are specifically constrained by these data (Whitehouse et al., 2011, ISAES XI Edinburgh); iii.) A more robust GPS data set for vertical motion trends of longer legacy (almost two decades in some cases) approaching 50 individual station records on bedrock (Thomas et al., 2011, ISAES XI Edinburgh). One upshot of these more recent Antarctic studies is that they reveal relatively older exposure and sediment dates. A great deal of ice (roughly half) had been lost to the ocean by 11.5 ka, (relatively more than in the IJ05 and ICE5G models). Furthermore, more precise lower elevation limits for ice fee nunataks and mountain outcrops throughout Last Glacial Maximum (e.g., Bentley et al., 2011) are retrieved. These reveal that the ice sheet was likely to be considerably less thick than in the ice domes of ICE5G in west Antarctica, and less thick in the western Weddell Sea, southernmost Antarctic Peninsula and coastal east Antarctica than in the IJ05 model. These two new features must be integrated into new predictions of the GRACE GIA correction for ice mass balance. The most immediate implications are that the past corrections for Antarctica are simply too large and that GRACE-based inference of mass loss are too large by substantial amounts. ICE5G corrections are likely too large by more than 50-60% and IJ05 too large by 20%, or more. New models for both Greenland and Antarctica are discussed.

Ivins, E. R.

2011-12-01

250

Crust and Upper Mantle Shear Wave Structure of Antarctica From Seismic Ambient Noise  

NASA Astrophysics Data System (ADS)

We determine the 3D shear velocity structure of the crust and upper mantle in East and West Antarctica using Green’s functions obtained from seismic ambient noise cross-correlation. The data we used are from the newly installed seismic stations from Antarctic's Gamburtsev Province (AGAP) project, including the Gamburtsev Antarctic Mountains Seismic Experiment (GAMSEIS), the Polar Earth Observing Network (POLENET), station EAGLE along the CHINARE traverse, and permanent stations around Antarctica from various other networks. Based on the availability of the data from these ongoing deployments, we report here on only 12 months of recordings from 2008. We obtain good resolution in regions extending from the Gamburtsev Mountains to the South Pole in East Antarctica, and to the Ross Sea area of West Antarctica. Resolution will improve after we recover the data from an additional 16 stations installed during the 2008-2009 season in January of 2010, and from subsequent recording years. We first acquire cross-correlation seismogram between all possible station pairs. We then extract the Rayleigh wave group and phase dispersion curves from the interstation correlograms from 8 to 60s. After that, the group and phase velocity maps for each period are determined by tomographic inversion. Finally, shear wave velocities at each node are inverted to construct a 3D crust and upper mantle model of the whole region. During the shear velocity inversion, we also use the BEDMAP ice thicknesses as the top layer to incorporate the effect of icecap on the surface wave velocities. Our preliminary results clearly show: 1) At shallow depth (< 20 km), slow velocities correlate well with sedimentary basins (e.g., the Ross Embayment), and high velocities correlate with mountain area ( the Gamburtsev and Transarctic Mountains). 2) At intermediate depth (20-40 km), East Antarctica shows low velocity while West Antarctica shows fast velocity, which is consistent with the thick/thin crust in these two regions. The sharp transition of the fast/slow velocity is across the Transantarctic Mountains, as has been indicated by previous TAMSEIS work in the McMurdo/Dry Valleys region. 3) Beneath the Gamburtsev Mountains, low crustal velocities extend to deeper depths (~60 km) than in the surrounding regions, suggesting the mountains are supported by thickened crust. 4) Velocities are relatively fast though out East Antarctica at greater depths, consistent with thick cold cratonic lithosphere. 5) Low velocities in the Ross Embayment to at least 100 km depth suggest a broad warm anomaly in the upper mantle.

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

2009-12-01

251

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

252

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.

253

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

254

Addition to the Greenhouse at McMurdo Station, Antarctica  

NSF Publications Database

... fossil fuels. III. Alternatives Alternative A. In this alternative, no action would be taken to ... proposed action; Reasonable alternatives including the alternative of no action; Anticipated ...

255

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.

256

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

257

Lidar observation of the mesospheric sodium layer in Antarctica  

NASA Technical Reports Server (NTRS)

The mesospheric sodium layer has been observed at Syowa Station in Antarctica during the wintering period of the 26th Japanese Antarctic Research Expedition. A lidar observation of the polar middle atmosphere at the station has been performed as a part of the Middle Atmosphere Program since 1983. At first stratospheric aerosols have been observed by the system based on a ruby laser. In 1985 a new transmitting system consisting of a tunable dye laser was added to that system to observe the sodium layer, too. The characteristics of the lidar system are given. The results of the mesospheric sodium layer observed on 42 nights during the period from March to October, 1985 are also given.

Nomura, A.; Iwasaka, Y.; Fukunishi, H.; Hirasawa, T.; Kawaguchi, S.; Kano, T.

1986-01-01

258

Scott v. Casey.  

PubMed

Claims by federal prison inmates that alleged psychological injuries sustained after they volunteered in the late 1950s to participate in medical experiments on the effects of lysergic acid diethylmide (LSD) were barred by the U.S. District Court, Northern District of Georgia, because they were not filed within two years of the inmates' having learned of their injuries. The evidence showed that by the early 1960s the prisoners possessed the critical facts both that they had suffered injuries from ingestion of the drug and that federal prison authorities had cooperated. Although the complicity of the CIA had only later become known, the statute of limitations ran from the time of first knowledge. PMID:11648210

1983-04-29

259

Seismic anisotropy of the Victoria Land region, Antarctica  

NASA Astrophysics Data System (ADS)

We present shear wave splitting results obtained from the analysis of core-refracted teleseismic phases recorded by permanent and temporary seismographic stations located in the Victoria Land region (Antarctica). We use an eigenvalue technique to isolate the rotated and shifted shear wave particle motion, to determine the best splitting parameters. Average values show clearly that dominant fast axis direction is NE-SW oriented, in accordance with previous measurements obtained around this zone. Only two stations, OHG and STAR, show different orientations, with N-S and NNW-SSE main directions. On the basis of the periodicity of single shear wave splitting measurements with respect to backazimuths of events under study, we infer the presence of lateral and vertical changes in the deep anisotropy direction. To test this hypothesis we model waveforms using a cross-convolution technique for the cases of one and two anisotropic layers. We obtain a significant improvement on the misfit in the double layer case for the two stations. For stations where a multilayer structure does not fit, we investigate lateral anisotropy changes at depth through Fresnel zone computation. We find that anisotropy beneath the Transantarctic Mountains (TAM) is considerably different from that beneath the Ross Sea. This feature influences the measurement distribution for the two permanent stations TNV and VNDA. Our results show a dominant NE-SW direction over the entire region, however other anisotropy directions are present and maybe interpreted in the context of regional tectonics.

Salimbeni, S.; Pondrelli, S.; Danesi, S.; Morelli, A.

2010-07-01

260

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

261

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

262

Byrd Station Snow Tunnels - Maintenance Equipment and Techniques.  

National Technical Information Service (NTIS)

To prevent excessive snow-tunnel closure, equipment and techniques were developed to score and trim the snow-tunnel walls at Byrd Station Antarctica. The equipment includes a chain saw and guide for scoring the snow to a controlled depth, hand tools for c...

G. E. Sherwood S. E. Gifford

1965-01-01

263

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

264

Field Measurements of the Total and Spectral Albedo of Snow and Ice in Dronning Maud Land, Antarctica  

Microsoft Academic Search

Variabilities in the spectral and total (between 300-3000 nm) albedo of snow were studied in the Dronning Maud Land region of Antarctica during the austral summers of 1999\\/2000 and 2000\\/2001. The measurement area consisted of a traverse going inland from the coast via the Finnish Antarctic research station Aboa, and the vicinity of the South African Antarctic station SANAE 4.

Kai Rasmus

265

Landsat Image Mosaic of Antarctica (LIMA)  

USGS Publications Warehouse

For most of us, Antarctica was at best a distant acquaintance. Now, with the Landsat Image Mosaic of Antarctica (LIMA), we are on intimate terms. In stunning, up-close and personal detail, LIMA brings Antarctica to life. Explore this virtually cloudless, seamless, most geometrically accurate, and highest resolution satellite mosaic of Antarctica. A team of scientists from the U.S. Geological Survey, the British Antarctic Survey, and the National Aeronautics and Space Administration, with funding from the National Science Foundation, created LIMA in support of the International Polar Year (IPY; 2007?08). As the first major scientific outcome of the IPY, LIMA truly fulfills the IPY goals. LIMA is an international effort, supports current scientific polar research, encourages new projects, and helps the general public visualize Antarctica and changes happening in this southernmost environment. Researchers and the general public can download LIMA and all component Landsat scenes at no charge.

Geological Survey (U.S.)

2007-01-01

266

The Status of Antarctica in the Light of International Law.  

National Technical Information Service (NTIS)

Contents: Antarctica as an object of international law; The legal status of the land areas of Antarctica; The legal status of the maritime areas of Antarctica; The legal status of the Antarctic air space; The legal status of Antarctica in the light of the...

J. Machowski

1977-01-01

267

The effects of petroleum hydrocarbon and heavy metal contamination of marine sediments on recruitment of Antarctic soft-sediment assemblages: a field experimental investigation  

Microsoft Academic Search

A manipulative field experiment was conducted at Casey Station, Antarctica, to determine the effect of contamination of marine sediments on the recruitment and development of soft-sediment assemblages. Uncontaminated marine sediments were defaunated and then contaminated by adding hydrocarbons (diesel fuel and lubrication oil) or heavy metals (extracted from contaminated soil) prior to deployment on the seabed for a period of

Jonathan S Stark; Ian Snape; Martin J Riddle

2003-01-01

268

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

269

Cutaneous and diphtheritic avian poxvirus infection in a nestling Southern Giant Petrel ( Macronectes giganteus ) from Antarctica  

Microsoft Academic Search

The Southern giant petrel (Macronectes giganteus) is declining over much of its range and currently is listed as vulnerable to extinction by the International Union for the\\u000a Conservation of Nature (IUCN). Island-specific breeding colonies near Palmer Station, Antarctica, have been monitored for\\u000a over 30 years, and because this population continues to increase, it is critically important to conservation. In austral summer

Valerie Shearn-Bochsler; D. Earl Green; Kathryn A. Converse; Douglas E. Docherty; Teresa Thiel; Heidi N. Geisz; William R. Fraser; Donna L. Patterson-Fraser

2008-01-01

270

In situ radioglaciological measurements near Taylor Dome, Antarctica and implications for UHE neutrino astronomy  

Microsoft Academic Search

Radiowave detection of the Cherenkov radiation produced by neutrino-ice\\u000acollisions requires an understanding of the radiofrequency (RF) response of\\u000acold polar ice. We herein report on a series of radioglaciological measurements\\u000aperformed approximately 10 km north of Taylor Dome Station, Antarctica from\\u000aDec. 6, 2006 - Dec. 16, 2006. Using RF signals broadcast from: a) an englacial\\u000adiscone, submerged to

D. Z. Besson; J. Jenkins; S. Matsuno; J. Nam; M. Smith; S. W. Barwick; J. J. Beatty; W. R. Binns; C. Chen; P. Chen; J. M. Clem; A. Connolly; P. F. Dowkontt; M. A. DuVernois; R. C. Field; D. Goldstein; P. W. Gorham; A. Goodhue; C. Hast; C. L. Hebert; S. Hoover; M. H. Israel; J. Kowalski; J. G. Learned; K. M. Liewer; J. T. Link; E. Lusczek; B. Mercurio; C. Miki; P. Miocinovic; C. J. Naudet; J. Ng; R. Nichol; K. Palladino; K. Reil; A. Romero-Wolf; M. Rosen; L. Ruckman; D. Saltzberg; D. Seckel; G. S. Varner; D. Walz; F. Wu

2007-01-01

271

Climate sensitivity of the ice cap of King George Island, South Shetland Islands, Antarctica  

Microsoft Academic Search

A two-dimensional vertically integrated ice-flow model has been\\u000aused to simulate the current state of the ice cap of King George Island, South Shetland\\u000aIslands, Antarctica, as well as the sensitivity of this state to climate change. The model\\u000awas forced by an energy-balance model that generates the specific mass balance from\\u000aclimatological input data of two research stations. It

Wouter H. Knap; Johannes Oerlemans; Martin Cadee

1996-01-01

272

Numerical simulation of whistler-triggered VLF emissions observed in Antarctica  

Microsoft Academic Search

The British Antarctic Survey VLF database from Halley (L=4.3) and Faraday (L=2.3) stations, Antarctica, has been searched for clear examples of whistler-triggered emissions (WTEs). Dominant events were the triggering of risers or quasi-constant frequency emissions from the upper arm of a whistler. A fairly frequent occurrence was the triggering of steep fallers from the whistler upper arm. At Faraday most

D. Nunn; A. J. Smith

1996-01-01

273

Real-Time Mesoscale Modeling Over Antarctica: The Antarctic Mesoscale Prediction System  

Microsoft Academic Search

*Byrd Polar Research Center Contribution Number 1276In support of the United States Antarctic Program (USAP), the National Center for Atmospheric Research and the Byrd Polar Research Center of The Ohio State University have created the Antarctic Mesoscale Prediction System (AMPS): an experimental, real-time mesoscale modeling system covering Antarctica. AMPS has been designed to serve flight forecasters at McMurdo Station, to

Jordan G. Powers; Andrew J. Monaghan; Arthur M. Cayette; David H. Bromwich; Ying-Hwa Kuo; Kevin W. Manning

2003-01-01

274

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

PubMed

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

275

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.

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

2014-01-01

276

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.

Cozzetto, Karen

277

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.

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

2011-01-01

278

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

279

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

280

Analysis of the Mantle Transition Zone beneath West Antarctica using P-wave receiver functions  

NASA Astrophysics Data System (ADS)

Several exposed, sub-glacial, and submarine volcanoes exist throughout West Antarctica in the vicinity of the West Antarctic Rift System; prior work has suggested that a mantle plume beneath the region influences the observed rifting and volcanism. However the existence of a mantle plume has not been verified, because models from recent seismic tomography results are not well resolved at mantle transition zone depths. We use P-wave receiver functions (PRFs) from all Antarctic seismic stations installed at sites above less than 1 km of ice, including recent 2007-2012 Antarctic POLENET, permanent GSN, and the 2000-2003 TAMSEIS seismographs to explore the depth to and the thickness of the mantle transition zone beneath West Antarctica. We calculate PRFs for all earthquakes occurring at 30-90° with Mb>5.5 using a time-domain iterative deconvolution method filtered using a Gaussian-width factor of 0.5, corresponding to frequencies less than ~0.24 Hz. Using this method, we check stability of the deconvolution by convolving the vertical component with the final radial receiver function, rejecting all receiver functions that did not recover at least 80% of the original trace. Maps showing Ps pierce-points cover most of West Antarctica and the Transantarctic Mountains, with particularly good coverage beneath Marie Byrd Land and the region around Ross Island. Preliminary results for P receiver functions stacked by station and migrated to depth using the ak135 1-d velocity model indicate a depressed 410' discontinuity beneath West Antarctica; beneath the Transantarctic and East Antarctic sites, the 410' is not depressed. However, no clear depth patterns are observed for the 660' discontinuity throughout West Antarctica; at several West Antarctic sites, the 660' may even be depressed slightly. Additional work using common conversion point (CCP) stacking will enable us to more clearly map the depth of the 410' and 660' and to identify spatial variations in mantle transition zone thickness.

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

2013-12-01

281

Solar wind influence on atmospheric processes in winter Antarctica  

NASA Astrophysics Data System (ADS)

The experimental results demonstrate influence of the great southward interplanetary magnetic field (IMF) and the corresponding geoeffective interplanetary electric field on atmospheric pro-cesses in the central Antarctica, where the large-scale system of vertical circulation takes place during the winter seasons. The interplanetary electric field influence is realized through ac-celeration of the air masses, descending into the lower atmosphere from the troposphere, and formation of cloudiness above the Antarctic Ridge, where the descending air masses enter the surface layer. The cloudiness results in the sudden warmings in the surface atmosphere, because the cloud layer efficiently backscatters the long wavelength radiation going from ice sheet, but does not affect the process of adiabatic warming of the descending air masses. Influence of the interplanetary electric field on cloudiness has been revealed for epochs of the solar activity minimum, when Forbush decreases effect is absent. The altitudinal profiles of temperature, varying in the opposite manner under influence of the southward and northward IMF, indicate that the cloud layer formation occurs at h = 8 -10 km. The acceleration of the descending air masses is followed by a sharp increase of the atmospheric pressure in the near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. As a result, the circumpolar vortex around the periphery of the Antarctic continent decays and the surface easterlies, typical of the coast stations during the winter season, are replaced by southerlies. It is suggested that the resulting invasion of the cold air masses into the Southern ocean leads to destruction the regular relationships between the sea level pressure fluctuations in the South-east Pacific high and the North Australian-Indonesian low, since development the El-Niño event n strongly follows anomalous atmospheric processes in the winter Antarctica.

Troshichev, Oleg; Egorova, Larisa; Vovk, Valery; Janzhura, Alexander

282

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. 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; 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, over the course of three days, students examine the history of Antarctic exploration and conduct research on a topic of interest; several readings that provide a broad perspective, including excerpts from early explorers' journals and a Q&A interview with a marine biologist who studies the history of Antarctica and a student handout with guidance for putting together their portfolios and examples of creative final projects.

283

Space station  

NASA Technical Reports Server (NTRS)

The history of American space flight indicates that a space station is the next logical step in the scientific pursuit of greater knowledge of the universe. The Space Station and its complement of space vehicles, developed by NASA, will add new dimensions to an already extensive space program in the United States. The Space Station offers extraordinary benefits for a comparatively modest investment (currently estimated at one-ninth the cost of the Apollo Program). The station will provide a permanent multipurpose facility in orbit necessary for the expansion of space science and technology. It will enable significant advancements in life sciences research, satellite communications, astronomy, and materials processing. Eventually, the station will function in support of the commercialization and industrialization of space. Also, as a prerequisite to manned interplanetary exploration, the long-duration space flights typical of Space Station missions will provide the essential life sciences research to allow progressively longer human staytime in space.

Stewart, Donald F.; Hayes, Judith

1989-01-01

284

Multi-instrument MLT study in Antarctica  

NASA Astrophysics Data System (ADS)

The study of polar MLT region dynamics at Syowa station using various radio and optical instruments is overviewed. An MF radar (since 1999), applied to night time meteor wind measurement in addition to a conventional correlation measurement technique, provides wind information over a broad height range from 60 to nearly 120km. A sodium lidar (2000-2002) observed night time mesopause region temperature. The observed winter time mean temperature showed a significant difference from that at Arctic sites, suggesting a difference in the general circulation pattern and also wave activity between Arctic and Antarctic [Kawahara et al., 2002]. Wave analysis, especially tidal components, using both the MF radar and lidar is also being made. Other optical instrument observations including an all-sky monochromatic imager and a Fabry-Perot imager started recently. Behavior of small scale atmospheric waves is being studied using sodium airglow images, which are less affected by aurora activity compared with other emissions, together with background wind information observed by the MF radar. Recently SuperDARN HF radars, originally designed for polar F region plasma study, get much attention for their great potential for MLT study such as meteor wind and PMSE measurements. Using the two SuperDARN radars located at Syowa we developed a meteor measurement technique, of which quality is nearly comparable to that of a dedicated meteor radar [Yukimatu and Tsutsumi, 2002]. The new technique is planned to be applied to the almost twenty SuperDARN radars surrounding Arctic and Antarctica, and is expected to provide information on the longitudinal structure of background wind and planetary scale waves.

Tsutsumi, M.; Syowa Mlt Team

285

Antarctica?s hypsometry and crustal thickness: Implications for the origin of anomalous topography in East Antarctica  

NASA Astrophysics Data System (ADS)

The hypsometry of Antarctica revealed by BEDMAP2 data is characterised by deglaciated modal elevations of ˜-450 m and ˜650 m for West and East Antarctica, respectively, and an East Antarctic plateau that is topographically anomalous by ˜400-600 m with respect to global continental modal elevation estimates. Superimposed on the East Antarctic plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ˜400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model was derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness estimates. The average crustal thickness of East Antarctica is ˜40 km (for West Antarctica ˜24 km), a value typical of continental shields, and while crustal thicknesses of >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, crustal thicknesses elsewhere across East Antarctica offer no suggestion of crustal-level continental-scale support for the broader plateau. Enderby Land, for example, resides on the plateau and is characterised by a modal elevation of ˜750 m and crust ˜40 km thick, whereas off the plateau in East Antarctica, the Aurora and Wilkes Subglacial Basins have modal elevations of ˜-50 m and ˜50 m, respectively, yet similarly thick crust. The lack of crustal support for the elevated broader East Antarctic plateau, coupled with seismic images showing fast upper mantle velocities beneath the plateau, suggest a mid-to-lower mantle source for East Antarctica's anomalous topography.

O'Donnell, J. P.; Nyblade, A. A.

2014-02-01

286

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

287

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

288

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

289

Evidence for plant viruses in the region of Argentina Islands, Antarctica.  

PubMed

This work focused on the assessment of plant virus occurrence among primitive and higher plants in the Antarctic region. Sampling occurred during two seasons (2004/5 and 2005/6) at the Ukrainian Antarctic Station 'Academician Vernadskiy' positioned on Argentina Islands. Collected plant samples of four moss genera (Polytrichum, Plagiatecium, Sanionia and Barbilophozia) and one higher monocot plant species, Deschampsia antarctica, were further subjected to enzyme-linked immunosorbent assay to test for the presence of common plant viruses. Surprisingly, samples of Barbilophozia and Polytrichum mosses were found to contain antigens of viruses from the genus Tobamovirus, Tobacco mosaic virus and Cucumber green mottle mosaic virus, which normally parasitize angiosperms. By contrast, samples of the monocot Deschampsia antarctica were positive for viruses typically infecting dicots: Cucumber green mottle mosaic virus, Cucumber mosaic virus and Tomato spotted wilt virus. Serological data for Deschampsia antarctica were supported in part by transmission electron microscopy observations and bioassay results. The results demonstrate comparatively high diversity of plant viruses detected in Antarctica; the results also raise questions of virus specificity and host susceptibility, as the detected viruses normally infect dicotyledonous plants. However, the means of plant virus emergence in the region remain elusive and are discussed. PMID:17328120

Polischuk, Valery; Budzanivska, Irena; Shevchenko, Tetyana; Oliynik, Svitlana

2007-02-01

290

Protecting United States Interests in Antarctica.  

National Technical Information Service (NTIS)

This thesis begins by presenting a geographic overview of the physical features and resources in Antarctica and the Southern Ocean. Next, it details the history of claims and interests over Antarctic territory, with particular emphasis on United States ac...

R. W. Scott

1988-01-01

291

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

292

Geoethical approach to mineral activities in Antarctica  

NASA Astrophysics Data System (ADS)

Antarctica is the outermost from civilization space continent. From 14.0 million km2 of surface area about 98% of Antarctica is covered by ice that averages at least 1.6 km in thickness. Geologically, the continent is the least explored in the world, and it is almost absolutely unknown what mineral resources Antarctica has as they are buried in rock that is covered by a thick ice sheet. It is thought to have large and valuable mineral deposits under the ice. This is because of what has been found in samples taken from the small areas of rock that are exposed, and also from what has been found in South Africa and South America. Up until 180 million years ago, Antarctica was a part of the Gondwanaland super continent, attached to South America, the Southern part of Africa, India and Australia, these continents then drifted apart until they reached their current positions. This leads to a possibility that Antarctica may also share some of the mineral wealth of these continents. Right now on the ice-free areas of Antarctica iron ore, chromium, copper, gold, nickel, platinum, coal and hydrocarbons have been found. The Protocol on Environmental Protection to the Antarctic Treaty, also known as the Madrid Protocol, was signed in 1991 by the signatories to the Antarctic Treaty and became law in January 1998. The Protocol provides for comprehensive protection of the Antarctic environment and associated ecosystems and includes a ban on all commercial mining for at least fifty years (this is up for review in 2041). Current climate change and melting ice in Polar Regions is opening up new opportunities to exploit mineral and oil resources. Even Antarctica's weather, ice and distance from any industrialized areas mean that mineral extraction would be extremely expensive and also extremely dangerous, the depletion of mineral recourses on the Earth can reverse banning of mining in Antarctica in future. There is no question that any resource exploitation in Antarctica will cause severe not only permanent, local impact on the environment, but also will have implications for other Earth's systems as a whole. Mineral prospecting and exploration in Antarctica need to be reflected and respected in any concept of environmental sustainability. Anyway, first stage of the geological surveying should be carried purely scientific and not designed to explore for and identify mineral deposits. It's obvious that although various countries claim sovereignty in certain regions of Antarctica, the continent should be continued to be politically neutral. Efforts of scientists and politicians should respect their own responsibility for the protection of the fragile Antarctic environment and of our planet in the whole taking care for future generations.

Talalay, Pavel

2013-04-01

293

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

294

A Multi-Aperture Scintillation Sensor for Dome A, Antarctica  

NASA Astrophysics Data System (ADS)

Site-testing measurements by the Australian group has already shown that Dome C on the Antarctic plateau is one of the best ground-based astronomical sites. Furthermore, Dome A, the Antarctic Kunlun Station, as the highest point on Antarctic inland plateau, where a Chinese Antarctic scientific expedition team first reached in 2005, is widely predicted to be an even better astronomical site by the international astronomical community. Preliminary site-testing carried out by the Center for Antarctic Astronomy (CAS) also confirms Dome A as a potential astronomical site. Multi-aperture scintillation sensors (MASS) can measure the seeing and isoplantic angle, the turbulence profile, etc., which are very important site-testing parameters that we urgently need. The MASS site testing at Dome A is presented here, and includes the method of processing data and the hardware for the extreme conditions of Dome A, Antarctica.

Chen, Hualin; Pei, Chong; Yuan, Xiangyan

2013-01-01

295

Why Is Antarctica the Windiest Place on Earth?  

NSDL National Science Digital Library

Students investigate the causes of Antarctica's strong, persistent winds in this weeklong unit. They also learn the causes of these ferocious katabatic winds. This site contains teacher tools, which include 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 also three activities in which students examine the overview information and develop questions for further study, examine weather data collected at several Antarctic weather stations, and investigate the behavior of cold air. In addition there are interviews with Antarctic researchers, a polar climatologist and a glacial geologist. There is also a handout to give students guidance for putting together their portfolios and examples of creative final projects.

296

Antarctica natural laboratory and space analogue for psychological research.  

PubMed

This introduction to the special issue traces the history of psychosocial concerns related to Antarctic exploration, from the heroic age of early explorers through the International Geophysical Year (IGY) of 1957 to 1958 to recent and current systematic research projects. The introduction discusses the organization and topics of international psychological investigations in polar stations and summarizes the articles that follow. Living in Antarctica imposes some unusual restrictions as well as opportunities, and it requires psychological adaptation to extreme environmental circumstances. The thrust of previous scientific and popular literature has been to focus on the negative effects of the situation and ignore the positive ones; however, ongoing studies are bringing about a more balanced view. Having an accurate understanding is important not only intrinsically and for appropriate application in the Antarctic itself but also in analogous extreme and unusual environments. These include extended space flight and space habitation, such as the projected voyage to Mars. PMID:11542946

Suedfeld, P; Weiss, K

2000-01-01

297

Ice-forming nuclei in Antarctica: New and past measurements  

NASA Astrophysics Data System (ADS)

The paper provides a review of past and a few new measurements of Ice-forming Nuclei (IN) in Antarctica. The few available published data were mostly obtained adopting different devices and methods and for a limited period of time. Consequently, data are scattered and give an incomplete picture of the Antarctic situation. It should be pointed out, however, that ice nucleation is an intricate process, depending on many parameters (supersaturation relative to ice and water, aerosol physical-chemical properties, possible conditioning and preactivation of particles, different modes of nucleation). Therefore, the uncertainty does not concern the Antarctic continent alone, but all measurements performed world-wide. A comparison of the published data can be made between Saxena and Weintraub (1988) at Palmer Station, and Ardon-Dryer et al. (2011) at the South Pole, as both studies measured IN in the immersion mode, even if at different temperature. Saxena and Weintraub (1988) obtained in three filters IN concentrations of about 104 m- 3 at T = - 6 °C, - 11 °C and - 13 °C, and 103 m- 3 at T = - 17 °C, in an additional filter (February-December 1983). At the South Pole Ardon-Dryer et al. (2011) obtained a concentration of about 5 × 102 m- 3 at T = - 19 °C, and the IN concentration increased until about 40 × 103 m- 3 at the activation temperature of - 26 °C. Such values are higher than those measured by Bigg (1973) near Antarctica, using a thermal diffusion chamber (deposition or deposition-condensation modes). IN concentrations measured at Terra Nova Bay are lower than those reported above, and are comparable to values reported for the Scott Base, Byrd Station and cruises at latitude 60°-70° S.

Belosi, F.; Santachiara, G.; Prodi, F.

2014-08-01

298

Pine Island Glacier, Antarctica, MISR Multi-angle Composite  

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

299

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

300

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

301

Core structure re-examined using new teleseismic data recorded in Antarctica: evidence for, at most, weak cylindrical seismic anisotropy in the inner core  

Microsoft Academic Search

We present a significant addition to the data set of traveltimes of seismic PKP waves that sample the Earth's lowermost mantle and core along the Earth's rotation axis. Recorded at permanent Global Seismic Network (GSN) and temporary SSCUA deployment broad-band seismographic stations in Antarctica, the new data improve the previously poor and biased coverage that underlies the seismic constraints on

Daniel Leykam; Hrvoje Tkalcic; Anya M. Reading

2010-01-01

302

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

303

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

304

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

305

Atmospheric trace gas studies in Antarctica  

SciTech Connect

This paper overviews trace gas studies that were carried out in Antarctica, with an emphasis on those by the Washingon State University Laboratory for Atmospheric Research. The results of trend analysis revealed that, although the atmospheric concentrations of F-11, F-12, CH3CCl3, and other halocarbons are still increasing, their rate of increase has slowed from the increasing rates observed in the 1970s. Vertical concentration profiles in Antarctica are shown to be dependent upon the seasonal variations in circulation patterns associated with the final warming and breakup of the polar vortex. It is shown that the stratospheric-tropospheric air exchange over Antarctica is influenced primarily by the following factors: (1) general circulation patterns with subsidence over the polar regions, (2) stratospheric air injection in the vicinity of jet streams and injection from tropopause folding upstream of troughs, and (3) mountain waves of sufficient magnitude to displace air parcels across the tropopause. 120 references.

Cronn, D.R.; Schilling, K.J.

1988-08-01

306

What Organisms Live in Antarctica Today?  

NSDL National Science Digital Library

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 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; 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've learned to create models of imaginary polar creatures; several readings that provide a broad perspective, including excerpts from early explorers' journals and Q&A interviews with scientists working in Antarctica and a student handout with guidance for putting together their portfolios and examples of creative final projects.

307

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

308

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

309

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.

310

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

311

Solar cycle signature and secular long-term trend in OH airglow temperature observations at South Pole, Antarctica  

Microsoft Academic Search

We have examined Michelson Interferometer OH airglow temperature data to investigate solar cycle and long-term variations of mesospheric temperatures at South Pole Station (SPS), Antarctica (90°S). The data set used here is continuous (24 hours a day) and taken during 1994-2004 austral winters. We have used a Multiple Linear Regression (MLR) technique to elucidate solar cycle and the trend term

S. M. I. Azeem; G. G. Sivjee; Y.-I. Won; Charles Mutiso

2007-01-01

312

Solar cycle signature and secular long-term trend in OH airglow temperature observations at South Pole, Antarctica  

Microsoft Academic Search

We have examined Michelson Interferometer OH airglow temperature data to investigate solar cycle and long-term variations of mesospheric temperatures at South Pole Station (SPS), Antarctica (90°S). The data set used here is continuous (24 hours a day) and taken during 1994–2004 austral winters. We have used a Multiple Linear Regression (MLR) technique to elucidate solar cycle and the trend term

S. M. I. Azeem; G. G. Sivjee; Y.-I. Won; Charles Mutiso

2007-01-01

313

A quantitative analysis of sources for summertime phytoplankton variability over 18 years in the South Shetland Islands (Antarctica) region  

Microsoft Academic Search

Eighteen years of summertime hydrographic and chlorophyll-a (Chl-a) data (?2700 stations) from the South Shetland Islands (Antarctica) region show that a “bell-shaped” (unimodal) distribution of phytoplankton biomass results annually when plotted against the inshore to offshore gradient in surface salinity. The maximum for this unimodal Chl-a distribution corresponds with a shallow upper mixed layer (UML) in iron-rich waters that occurs

C. D. Hewes; C. S. Reiss; O. Holm-Hansen

2009-01-01

314

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

315

Magnetotelluric survey across the Vestfold Hills, East Antarctica  

NASA Astrophysics Data System (ADS)

Reconstruction of Gondwana depends significantly on geophysical information from Antarctica. In 2009, a magnetotelluric survey was collected across a suggested neoproterozoic suture zone near Davis Station in East Antarctica with the aim of delineating the boundary between the high grade metamorphic Rauer Group and the younger Vestfold Hills. A total of 32 broadband MT measurements were collected covering over 100km extending from the Vestfold Hills south to the Larsmann Hills, including the Rauer Group. Because the survey was collected near the geomagnetic south pole, robust time-frequency analysis was used to estimate times when the non-planar assumption of MT was violated. Interestingly, robust time-frequency analysis locates the best window to estimate the MT transfer function to be 0600-1400 UT, when geomagnetic source field power in the MT dead band is at a maximum. Little effects from source field effects are found for periods smaller than 100 seconds. Presented are the first models of the 3D resistivity structure underlying the Rauer Group, Vestfold Hills and extending to the Larsmann Hills. Ice thickness is characterized well finding a conductive layer just below the ice interpreted as a thin water layer. Conductivity anomalies estimated from 3D inversion of the data correlate well with magnetic data collected by the ADMAP project. The 3D model locates a conductive body underlying the Rauer Group extending to the Larsmann Hills that could be the source of metamorphism, while the lithology under the Vestfold Hills is resistive. This contrast indicates a boundary in the resistivity structure that could be interpreted as a neoproterozoic suture zone, but constraining this interpretation is difficult due to lack of geophysical information of the region. A three-dimensional resistivity block model compared to a 2D slice illustrating the magnetic intensity from the ADMAP project and the phase tensor response of the MT data at a period of 10s. Magnetic highs correlate with the enhanced conductivity structure in the middle crust.

Thiel, S.; Peacock, J.; Selway, K.; Collins, A. S.; Heinson, G. S.

2012-12-01

316

Solar wind influence on atmosphere processes in winter Antarctica  

NASA Astrophysics Data System (ADS)

. Galactic cosmic rays altered by the solar wind are traditionally regarded as the most plausible agent of the solar activity influence on the Earth's atmosphere. Meanwhile, it is well known that severe reductions in the galactic cosmic rays flux, known as Forbush decrease (FD), are caused by the solar wind of high speed and density, which sweeps the galactic cosmic rays on its way. Since the FD beginnings are registered at the Earth's orbit simultaneously with dramatic disturbances in the solar wind, the atmospheric effects, assigned to Forbush decreases, can be, in reality, result of the solar wind influence on the atmospheric processes. The paper presents the summary of the experimental results demonstrating the strong influence of the interplanetary electric field on atmospheric processes in the central Antarctica, where the large-scale system of vertical circulation is formed during the winter seasons. The influence is realized through acceleration of the air masses, descending into the lower atmosphere from troposphere, and formation of cloudiness above the Antarctic Ridge, where the descending air masses income into the surface layer. The acceleration is followed by sharp increase of the atmospheric pressure in the near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. The cloudiness formation is resulted in the sudden warmings in the surface atmosphere, since the cloud layer efficiently backscatters the long wavelength radiation going from the ice sheet, but does not affect the adiabatic warming process of the descending tropospheric air masses. When drainage flow strong strengthening the circumpolar vortex about the periphery of the Antarctic continent decays, the surface easterlies typical of the coast stations during the winter season are replaced by southerlies and the cold Antarctic air masses rush in the Southern ocean.

Troshichev, Oleg

317

Solar wind influence on atmospheric processes in winter Antarctica  

NASA Astrophysics Data System (ADS)

Galactic cosmic rays (GCRs) altered by solar wind are traditionally regarded as the most plausible agent of solar activity influence on the Earth's atmosphere. However, it is well known that severe reductions in the GCRs flux, known as Forbush decreases (FDs), are caused by solar wind of high speed and density, which sweeps away the GCRs on its way. Since the FD beginnings are registered at the Earth's orbit simultaneously with dramatic disturbances in the solar wind, the atmospheric effects, assigned to FDs, can be, in reality, the results of the solar wind influence on the atmospheric processes. This paper presents a summary of the experimental results demonstrating the strong influence of the interplanetary electric field on atmospheric processes in central Antarctica, where the large-scale system of vertical circulation is formed during winter seasons. The influence is realized through acceleration of the air masses, descending into the lower atmosphere from the troposphere, and the formation of cloudiness above the Antarctic Ridge, where the descending air masses enter the surface layer. The acceleration is followed by a sharp increase of the atmospheric pressure near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. The cloudiness formation results in the sudden warmings in the surface atmosphere, since the cloud layer efficiently backscatters the long wavelength radiation from the ice sheet, but does not affect the adiabatic warming process of the descending tropospheric air masses. When the drainage flow strengthening the circumpolar vortex around the periphery of the Antarctic continent decays, the surface easterlies typical of the coast stations during the winter season are replaced by southerlies and the cold Antarctic air masses flow out to the Southern ocean.

Troshichev, O.

2008-12-01

318

Scientific Experiences Using Argentinean Sounding Rockets in Antarctica  

NASA Astrophysics Data System (ADS)

Argentina in the sixties and seventies, had experience for developing and for using sounding rockets and payloads to perform scientific space experiments. Besides they have several bases in Antarctica with adequate premises and installations, also duly equipped aircrafts and trained crews to flight to the white continent. In February 1965, scientists and technical people from the "Instituto de Investigacion Aeronáutica y Espacial" (I.I.A.E.) with the cooperation of the Air Force and the Tucuman University, conducted the "Matienzo Operation" to measure X radiation and temperature in the upper atmosphere, using the Gamma Centauro rocket and also using big balloons. The people involved in the experience, the launcher, other material and equipment flew from the south tip of Argentina to the Matienzo base in Antarctica, in a C-47 aircraft equipped with skies an additional jet engine Marbore 2-C. Other experience was performed in 1975 in the "Marambio" Antartic Base, using the two stages solid propellent sounding rocket Castor, developed in Argentina. The payload was developed in cooperation with the Max Planck Institute of Germany. It consist of a special mixture including a shape charge to form a ionized cloud producing a jet of electrons travelling from Marambio base to the conjugate point in the Northern hemisphere. The cloud was observed by several ground stations in Argentina and also by a NASA aircraft with TV cameras, flying at East of New York. The objective of this experience was to study the electric and magnetic fields in altitude, the neutral points, the temperature and electrons profile. The objectives of both experiments were accomplished satisfactorily.

Sánchez-Peña, Miguel

2000-07-01

319

Video podcasts as a long-distance outreach tool: Polar science from Byrd Camp, West Antarctica  

NASA Astrophysics Data System (ADS)

Video Podcasts offer a unique opportunity to actively engage the public in ongoing research projects by revealing faces and stories from field, lab and engineering efforts that often happen behind the scenes. Podcasts thus allow the science community to not only present their accomplishments, but also the where, how and why. Publishing these videos in real time while stationed at remote field camps brings particular challenges to the process. This was the case during the POLNET (Polar Earth Observing Network) field seasons at Byrd Camp, West Antarctica. With no internet connection and limited flights in and out of camp, the team worked to produce a series of Video Podcast field updates that were flown to McMurdo Station and uploaded to a web server off the continent. These videos provided glimpses of living and working on a remote ice sheet while installing GPS and seismic stations. At a time when climate science is under extreme scrutiny, this project offered a tangible and human view of efforts to model how ice masses are changing. In any science education effort, the risk of diluting the science until it is no longer meaningful poses certain challenges. At the same time, going into great depth about the methods and theories using technical vocabulary can immediately turn away an audience that is already inundated with information. These videos represent an attempt to creatively and accurately present scientific concepts in short, digestible segments that bring elements of fun from the unique field setting and personalities of Byrd Camp, West Antarctica.

Berg, M.; Science; Engineering Team Of Polenet Field Seasons 2009-10; 2010-11

2011-12-01

320

The Center for Astrophysical Research in Antarctica  

Microsoft Academic Search

The Antarctic Plateau is the coldest, driest place on earth. Instruments deployed there enjoy unique advantages for observations requiring (1) the lowest possible thermal background emission, (2) the high transparency and extreme stablity of the Antarctic atmosphere at wavelengths sensitive to water vapor absorption, or (3) continuous access to the polar sky. The Center for Astrophysical Research in Antarctica (CARA)

D. A. Harper

1998-01-01

321

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

322

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

323

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

324

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

325

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

326

Optical sky brightness at Dome C, Antarctica  

Microsoft Academic Search

Dome C, Antarctica is a prime site for astronomical observations in terms of climate, wind speeds, turbulence, and infrared and terahertz sky backgrounds (for example, see Aristidi et al. 2005; Storey et al. 2005). However, at present little is known about the optical sky brightness and atmospheric extinction. Using a variety of modelling techniques, together with data from the South

Suzanne L. Kenyon; John W. V. Storey

2007-01-01

327

Planetary geomorphology field studies: Iceland and Antarctica  

Microsoft Academic Search

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

M. C. Malin

1984-01-01

328

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.

329

Which Map's the Best Map for Antarctica?  

NSDL National Science Digital Library

This classroom activity helps students understand the benefits and drawback of globes, Mercator maps, and polar map projections. After closely examining all three, students discuss how we represent a spherical object like the Earth on flat surface. The printable five-page handout includes a series of inquiry-based questions related to the representation of Antarctica on the three types of maps.

330

Nearshore krill distribution around Livingston Island, Antarctica  

Microsoft Academic Search

The near-shore regions of Livingston Island, Antarctica were studied during the austral summers of 2002 and 2004 to measure the Antarctic krill population and factors which control their distribution. These waters serve as the main feeding grounds for the seasonally resident fur seal and penguin populations of Cape Shirreff. Shallow and highly variable bathymetry in this area precludes surveying from

Joseph D. Warren; David A. Demer

2001-01-01

331

Cenozoic motion between East and West Antarctica  

Microsoft Academic Search

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

Joann M. Stock; R. Dietmar Müller; Takemi Ishihara; Steven C. Cande

2000-01-01

332

Charting the bathymetry of Weddell Sea, Antarctica  

Microsoft Academic Search

The Federal Republic of Germany has carried out several marine research expeditions including multibeam surveys by the research vessel Polarstern in the southern Atlantic Ocean. Since the bathymetry of the Weddell Sea, Antarctica, is insufficiently known, the Alfred Wegener Institute for Polar and Marine Research (AWI) is preparing bathymetric maps for this region.One project is the production of the series

Heinrich Hinze

1994-01-01

333

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.

334

Structure and thermal regime beneath the South Pole region, East Antarctica, from magnetotelluric measurements  

NASA Astrophysics Data System (ADS)

Ten tensor magnetotelluric (MT) soundings have been acquired in a 54 km long profile across the South Pole area, East Antarctica. The MT transect was offset from the South Pole station ~5 km and oriented 210 grid north, approximately normal to the Trans-Antarctic Mountains. Surveying around South Pole station was pursued for four main reasons. First, we sought to illuminate first-order structure and physico-chemical state (temperatures, fluids, melts) of the crust and upper mantle of this part of East Antarctica. Secondly, conditions around the South Pole differ from those of previous MT experience at central West Antarctica, so that the project would help to define MT surveying feasibility over the entire continent. Thirdly, the results would provide a crustal response baseline for possible long-term MT monitoring to deep upper mantle depths at the South Pole. Fourthly, because Antarctic logistics are difficult, support facilities at the South Pole enable relatively efficient survey procedures. In making the MT measurements, the high electrical contact impedance at the electrode-firn interface was overcome using a custom-design electrode pre-amplifier at the electrode with low output impedance to the remainder of the recording electronics. Non-plane-wave effects in the data were suppressed using a robust jackknife procedure that emphasized outlier removal from the vertical magnetic field records. Good quality data were obtained, but the rate of collection was hampered by low geomagnetic activity and wind-generated, electrostatic noise induced in the ice. Profile data were inverted using a 2-D algorithm that damps model departures from an a priori structure, in this case a smooth 1-D profile obtained from inversion of an integral of the TM mode impedance along the profile. Inverse models show clear evidence for a pronounced (~1 km thickness), conductive section below the ice tentatively correlated with porous sediments of the Beacon Supergroup. Substantial variations in sedimentary conductance are inferred, which may translate into commensurate variations in sediment thickness. Low resistivities below ~30 km suggest thermal activity in the lower crust and upper mantle, and mantle support for this region of elevated East Antarctica. This contrasts with resistivity structure imaged previously in central West Antarctica, where resistivity remains high into the upper mantle consistent with a fossil state of extensional activity there.

Wannamaker, Philip E.; Stodt, John A.; Pellerin, Louise; Olsen, Steven L.; Hall, Darrell B.

2004-04-01

335

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

336

Climatology of Pc 1-2 Waves Observed at High Latitudes in Antarctica: A Progress Report  

NASA Astrophysics Data System (ADS)

An increased occurrence of electromagnetic ion cyclotron (EMIC) waves in Earth's magnetosphere has long been noted during the aftermath of magnetic storms. Such waves, classified as Pc 1-2 waves (0.2 - 5 Hz), have been suggested in many theoretical and some observational studies as a significant loss mechanism for both ring current ions and, via parasitic interactions, radiation belt electrons. We have applied the automated wave analysis technique developed by Bortnik et al. [JGR A04204, 2007] to a large, multi-year suite of data from search coil magnetometers deployed at selected stations in Antarctica. These stations include Halley (L = 4.5), AGO A80 (L = 6.3), AGO A81 (L = 7.7), AGO P2 (L = 8.4), AGO P3 (L = 10.2), and South Pole Station (L = 13.6). Data from South Pole Station were recorded nearly continuously for over a solar cycle. Data from U. S. and British Automated Geophysical Observatories span over one solar cycle, but are not continuous at any given station throughout this period. Beginning with 2006 and 2007 data from Halley, we have at each station noted the mean frequency, amplitude, time, and duration of events. We have also parameterized the occurrence of these events according to UT, Kp, Dst, month, phase of magnetic storms, and phase of the solar cycle.

Murphy, M. T.; Engebretson, M. J.; Posch, J. L.; Lessard, M. R.

2008-05-01

337

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2010 CFR

...Restrictions on collection of meteorites in Antarctica. 674.4 Section 674.4 Public...Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research...

2010-10-01

338

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2010 CFR

...Restrictions on collection of meteorites in Antarctica. 674.4 Section 674.4 Public...Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research...

2009-10-01

339

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2013 CFR

...Restrictions on collection of meteorites in Antarctica. 674.4 Section 674.4 Public...Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research...

2013-10-01

340

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2011 CFR

...Restrictions on collection of meteorites in Antarctica. 674.4 Section 674.4 Public...Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research...

2011-10-01

341

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2012 CFR

...Restrictions on collection of meteorites in Antarctica. 674.4 Section 674.4 Public...Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research...

2012-10-01

342

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.

1997-01-01

343

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

344

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

345

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

346

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

347

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.

Lynch, Patrick; Nasa

348

Tides In The Subglacial Lake Vostok, Antarctica  

Microsoft Academic Search

Subglacial lakes belong to the most interesting glaciological features in Antarctica, where the 240-km-long Lake Vostok is the most prominent one. For the understanding of the dynamics of the Lake Vostok system different compo- nents such as ice thickness and ice motion, lake bathymetry, geothermal heat flow, water circulation and melting-refreezing have to be investigated and modelled in a complex

R. Dietrich; K. Shibuya; A. Pötzsch; T. Ozawa

2002-01-01

349

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

350

Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica  

NASA Astrophysics Data System (ADS)

This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

Dibbern, J. S.

1987-02-01

351

An analysis of temperatures and wind speeds above Dome C, Antarctica  

NASA Astrophysics Data System (ADS)

A good astronomical site must fulfill several criteria including low atmospheric turbulence and low wind speeds. It is therefore important to have a detailed knowledge of the temperature and wind conditions of a location considered for future astronomical research. Antarctica has unique atmospheric conditions that have already been exploited at the South Pole station. Dome C, a site located on a local maximum of the Antarctic plateau, is likely to have even better conditions. In this paper we present the analysis of two decades of wind speed measurements taken at Dome C by an automated weather station (AWS). We also present temperature and wind speed profiles taken over four Antarctic summers using balloon-borne weather sondes. We will show that as well as having one of the lowest average wind speed ever recorded at an existing or potential observatory, Dome C also has an extremely stable upper atmosphere and a very low inversion layer.

Aristidi, E.; Agabi, K.; Azouit, M.; Fossat, E.; Vernin, J.; Travouillon, T.; Lawrence, J. S.; Meyer, C.; Storey, J. W. V.; Halter, B.; Roth, W. L.; Walden, V.

2005-02-01

352

Snow accumulation and its moisture origin over Dome Argus, Antarctica  

NASA Astrophysics Data System (ADS)

The spatial and temporal variability of snow accumulation near Dome Argus, Antarctica, is assessed using new snow pit and stake measurement data together with existing snow pit, ice core and automatic weather station records. Snow accumulation rate shows large inter-annual variations, but stable multi-decadal levels over the last seven centuries. Spatial variations in snow accumulation within the space of 50 km of Dome Argus are relatively small, probably thanks to the smooth topography. A comparison of theses accumulation observations with ECMWF reanalyses (ERA-40 and ERA-Interim) suggests ECMWF reanalysis captures the seasonal variations, but underestimates the overall snow accumulation at Dome Argus by ~50 %. The moisture sources for precipitation over Dome Argus are examined by means of a Lagrangian moisture source diagnostic, based on the tracing of specific humidity changes along air parcel trajectories, for the period 2000-2004 using operational ECMWF analysis data. Dome Argus mainly receives moisture from the mid-latitude (46 ± 4°S) South Indian Ocean, with a seasonal latitudinal shift of about 6°. Compared to other central East Antarctic deep ice core sites such as Dome F, Dome C, Vostok, and EPICA Dronning Maud Land, Dome Argus has a more southerly moisture origin, probably due to topographic influences on the moisture transport paths. These results have important implications for the interpretation of future ice cores at Dome Argus.

Wang, Yetang; Sodemann, Harald; Hou, Shugui; Masson-Delmotte, Valérie; Jouzel, Jean; Pang, Hongxi

2013-02-01

353

LiDAR in extreme environment: surveying in Antarctica  

NASA Astrophysics Data System (ADS)

This study was performed under the patronage of the Italian National Research Programme in Antarctica (PNRA) with the aim to realize a high resolution Digital Elevation Model (DEM) of the moraine named "Boulder Clay" which insists approximately 7 km far from the Italian Research Base "Mario Zucchelli Station" in the Terra Nova Bay area. The DEM will be included in the project for the construction of two runways to be used as support facilities for the scientific research campaigns which take place on regular basis each year. Although the research efforts to realize a detailed cartography of the area is on-going, for the specific aim and urgency of this project it was decided to perform a laser scanning survey in this extreme environment in order to obtain contour lines describing the terrain elevation each 50 cm and volume analysis. The final result will be super imposed on a photogrammetric DEM with contour lines each 2.5 m and satellite images. This paper focus both on the final scientific data and on all the challenges have to be faced in such extreme and particular environment during the laser scanning survey.

Abate, D.; Pierattini, S.; Bianchi Fasani, G.

2013-10-01

354

Radiocarbon analyses along the EDML ice core in Antarctica  

NASA Astrophysics Data System (ADS)

Samples, 17 in total, from the EDML core drilled at Kohnen station Antarctica are analysed for 14CO and 14CO2 with a dry-extraction technique in combination with accelerator mass spectrometry. Results of the in situ produced 14CO fraction show a very low concentration of in situ produced 14CO. Despite these low levels in carbon monoxide, a significant in situ production is observed in the carbon dioxide fraction. For the first time we found background values for the ice samples which are equal to line blanks. The data set is used to test a model for the production of 14C in the ice matrix, in combination with a degassing as 14CO2 and possibly as 14CO into the air bubbles. Application of the model, for which no independent validation is yet possible, offers the opportunity to use radiocarbon analysis as dating technique for the air bubbles in the ice. Assigning an arbitrary error of 25% to the calculation of the in situ production leads to age estimates, after correction for the in situ production, which are in agreement with age estimates based on a volcanic layer match of EDML to the Dome C timescale in combination with a correction for firn diffusion.

van de Wal, R. S. W.; Meijer, H. A. J.; de Rooij, M.; van der Veen, C.

2007-02-01

355

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

356

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

357

Habitat and leaf cytogenetic characteristics of Deschampsia antarctica Desv. in the Maritime Antarctica  

NASA Astrophysics Data System (ADS)

Antarctic hairgrass ( Deschampsia antarctica Desv.) was studied in the Maritime Antarctica with respect to general ecological characteristics, soil conditions, viral contamination, cell nucleus area, and relative DNA content. Material was gathered in six localities that were highly diverse in terms of the nature of soil-like substrata, presence of viral antigen determinants, and the average nucleus area and relative DNA content in leaf epidermis and parenchyma cells. Our results show that Antarctic hairgrass lives upon soils that are variable with respect to trace elements, pH, and other soil characteristics. The hairgrass is susceptible to a number of viruses, and shows substantial variation in DNA content and nucleus size.

Parnikoza, I. Yu.; Miryuta, N. Yu.; Maidanyuk, D. N.; Loparev, S. A.; Korsun, S. G.; Budzanivska, I. G.; Shevchenko, T. P.; Polischuk, V. P.; Kunakh, V. A.; Kozeretska, I. A.

358

Unprecedented upper-air dropsonde observations over Antarctica from the 2010 Concordiasi Experiment: Validation of satellite-retrieved temperature profiles  

NASA Astrophysics Data System (ADS)

The 2010 Concordiasi field experiment took place over Antarctica from September to December 2010. During Concordiasi, for the first time, 13 National Center for Atmospheric Research Driftsonde systems were launched from McMurdo station, ascended to the stratosphere, and then drifted with the winds. The Driftsonde provides a unique platform to release dropsondes that measure the atmosphere from the lower stratosphere to the surface in otherwise difficult to reach parts of the globe. A total of 639 soundings were obtained and provided unprecedented high quality profiles over Antarctica. The sounding temperature profiles are compared with matched profiles from ten satellite products. All satellite products except The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) are consistent colder than the sounding data, with larger discrepancies over the Antarctic continent than the coast and ocean. The COSMIC data are in agreement with the sounding data and display no degradation over the continent.

Wang, Junhong; Hock, Terry; Cohn, Stephen A.; Martin, Charlie; Potts, Nick; Reale, Tony; Sun, Bomin; Tilley, Frank

2013-03-01

359

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

360

Aerospace crew station design  

NASA Technical Reports Server (NTRS)

Consideration is given to spacecraft cockpits and work stations, commercial aircraft cockpits and crew stations, high performance aircraft cockpits and crew stations, and space stations and habitat crew stations. Particular attention is given to an historical review of NASA manned spacecraft crew stations, ESA spacelab crew stations, the evolution of commercial aircraft flight station design, Boeing 757/767 flight deck, a historical review of Concorde flight deck design, trends in the cockpit design of new European fighters, and state-of-the-art applications for Space Station crew interface design.

Carr, Gerald P. (editor); Montemerlo, Melvin D. (editor)

1984-01-01

361

Isolation and identification of Pseudomonas spp. from Schirmacher Oasis, Antarctica.  

PubMed Central

Ten cultures of Pseudomonas spp. were established from soil samples collected in and around a lake in Antarctica. Based on their morphology, biochemical and physiological characteristics, and moles percent G + C of their DNA, they were identified as P. fluorescens, P. putida, and P. syringae. This is the first report on the identification of Pseudomonas spp. from continental Antarctica.

Shivaji, S; Rao, N S; Saisree, L; Sheth, V; Reddy, G S; Bhargava, P M

1989-01-01

362

The larval alimentary canal of the Antarctic insect, Belgica antarctica  

Microsoft Academic Search

On the Antarctica continent the wingless midge, Belgica antarctica (Diptera, Chironomidae) occurs further south than any other insect. The digestive tract of the larval stage of Belgica that inhabits this extreme environment and feeds in detritus of penguin rookeries has been described for the first time. Ingested food passes through a foregut lumen and into a stomodeal valve representing an

James B. Nardi; Lou Ann Miller; Charles Mark Bee; Richard E. Lee Jr.; David L. Denlinger

2009-01-01

363

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.

Fries-Gaither, Jessica

364

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.

365

Iron Meteorites from Antarctica: More Specimens, Still 40% Ungrouped.  

National Technical Information Service (NTIS)

Clarke was the first to recognize that ungrouped irons are more common in Antarctica than in the regions where most irons have been collected; his conclusion was based on the first 21 irons collected in Antarctica. Wasson et al. reported compositional dat...

J. T. Wasson

1999-01-01

366

Modelling flow and accreted ice in subglacial Lake Concordia, Antarctica  

Microsoft Academic Search

More than 150 subglacial lakes have been discovered in Antarctica so far. Due to obvious challenges with exploration, numerical modelling remains one of the major tools to acquire information about those hard-to-access objects. Until now only the huge Lake Vostok has been investigated in detail. This paper focuses on Lake Concordia — the second largest subglacial lake in Antarctica over

Malte Thoma; Klaus Grosfeld; Irina Filina; Christoph Mayer

2009-01-01

367

Seismic stratigraphy of the Adare Trough area, Antarctica  

Microsoft Academic Search

The Adare Trough, located 100 km NE of Cape Adare, Antarctica, is the extinct third arm of a Tertiary spreading ridge that separated East from West Antarctica. We use seismic reflection data, tied to DSDP Site 274, to link our seismic stratigraphic interpretation to changes in ocean-bottom currents, Ross Sea ice cover, and regional tectonics through time. Two extended unconformities are

R. Dietmar Müller

2006-01-01

368

Magnetic study in the conjugate corridors of India and Antarctica  

Microsoft Academic Search

Conjugate corridors of India and Antarctica are defined using several plate reconstruction models. Magnetic data in two conjugate corridors of the Bay of Bengal (Eastern continental margin of India) and Enderby Basin (East Antarctica) was compared under the constraints of bathymetry and satellite derived free-air gravity data. An excellent correlation in the magnetic anomaly pattern is observed along two pairs

M. A. Desa; M. V. Ramana; T. Ramprasad; B. J. P. Kumar

2009-01-01

369

Rock glaciers in the South Shetland Islands, Western Antarctica  

Microsoft Academic Search

Rock glaciers are found in the peripheral regions of Antarctica particularly in the Antarctic Peninsula region. Study of these features is relevant for the palaeoenvironmental reconstruction of maritime Antarctica because they are indicators of permafrost and periglacial conditions. This paper reports and analyzes the results of an inventory of rock glaciers and protalus lobes in the South Shetland Islands. Nine

Enrique Serrano; Jerónimo López-Mart??nez

2000-01-01

370

Space Station propulsion system  

NASA Astrophysics Data System (ADS)

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.

371

Space Station Spartan Study.  

National Technical Information Service (NTIS)

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 wil...

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

1985-01-01

372

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

373

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

374

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

375

The meteorite collection sites of Antarctica  

NASA Astrophysics Data System (ADS)

The characteristics of the six major regions associated with meteorite stranding surfaces in Antarctica are described, which include the MacKay Glacier/David Glacier region (containing Allan Hills); (2) North Victoria Land; (3) the Lewis Cliff area; (4) the Thiel Mountains, Pecora Escarpment, and Patuxent Range; (5) the Yamato Mountains meteorite stranding surface; and (6) the Sor Rondane Mountains. Five models for the production of meteorite stranding surfaces are reviewed. These are: (1) simple deflation of the ice sheet, (2) passive receiver of falling meteorites, (3) stagnant ice against an absolute barrier, (4) slow-moving ice impeded by a subice barrier, and (5) ice masses in collision.

Cassidy, William; Harvey, Ralph; Schutt, John; Delisle, Georg; Yanai, Keizo

1992-12-01

376

Optical sky brightness at Dome C, Antarctica  

NASA Astrophysics Data System (ADS)

Dome C, Antarctica is a prime site for astronomical observations in terms of climate, wind speeds, turbulence, and infrared and terahertz sky backgrounds (for example, see Aristidi et al. 2005; Storey et al. 2005). However, at present little is known about the optical sky brightness and atmospheric extinction. Using a variety of modelling techniques, together with data from the South Pole, the brightness of the night sky at Dome C is estimated in Kenyon & Storey (2006) including the contributions from scattered sunlight, moonlight,aurorae, airglow, zodiacal light, integrated starlight, diffuse Galactic light and artificial sources. The results are compared to Mauna Kea, Hawaii. We summarise the main conclusions.

Kenyon, Suzanne L.; Storey, John W. V.

2007-08-01

377

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

378

Palmer Automatic Weather Station  

NSF Publications Database

Title : Palmer Automatic Weather Station Type : Antarctic EAM NSF Org: OD / OPP Date : December 06 ... Environmental Action Memorandum (Palmer Automatic Weather Station) To: Files (S.7 - Environment ...

379

Weather, ice, and snow conditions at Deception Island, Antarctica: long time-series photographic monitoring  

NASA Astrophysics Data System (ADS)

An autonomous weather station (Terrestrial station) was developed and deployed at Deception Island, Antarctica, an active volcanic island, to monitor the daily weather conditions as part of a long time-series marine ecosystem study of the sunken caldera, Port Foster. The principal components of the Terrestrial station were a time-lapse digital camera, ultrasonic wind sensor, controller, wind turbine generators, and batteries. The Terrestrial station was installed on a ridge at 200 m altitude overlooking Port Foster and the surrounding terrain from 9 March 1999 until 20 November 2000. Ice cover on Port Foster began in late July 2000 and was intermittently visible through early November. Daily averaged wind speeds ranged from 0.2 m s -1 in October to 47.4 m s -1 in June, with the prevailing direction from the southwest and less frequently from the northeast. Daily averaged air temperatures fluctuated from a low of -12.6°C in August 2000 to 2.7°C in March 1999. Weather conditions measured at Deception Island were generally consistent with those concurrently measured in the region of the South Shetland Islands. Ice cover in Port Foster was less pronounced in 1999 and 2000 than reported in previous years, suggesting regional warming.

Smith, K. L.; Baldwin, R. J.; Glatts, R. C.; Chereskin, T. K.; Ruhl, H.; Lagun, V.

2003-06-01

380

Use of a characteristic time scale of microwave emission to determine accumulation variability in Antarctica  

NASA Astrophysics Data System (ADS)

Relationship of the Passive Microwave Characteristic Time Scale of Emission to Accumulation Rate in Antarctica Authors: Lora S. Koenig1, Eric J. Steig1, Dale P. Winebrenner2 1) Department of Earth and Space Sciences, University of Washington 2) Applied Physics Laboratory, University of Washington Passive microwave sensors offer a potential tool for retrieving accumulation rates over the Greenland and Antarctic ice sheets. However, no retrieval method developed to date is reliable in both temporal and spatial domains. A new retrieval method is presented that shows considerable promise. The characteristic timescale of emission (? 0) is the ratio of the microwave extinction length in the firn, squared, to the firn thermal diffusivity. This characteristic time scale arises in a convolution expression that relates physical temperature to microwave brightness temperature, replacing the "emissivity" term in the traditional Rayleigh-Jeans approximation. ? 0 can be estimated for the entire Antarctic continent by comparing thermal infrared observations of physical surface temperature from the AVHRR satellite with passive microwave brightness temperatures at the 37 GHz vertically polarized channel measured by the Scanning Multichannel Microwave Radiometer (SMMR) and Special Senor Microwave Imager (SSM/I). Comparison between ? 0 and independent estimates of accumulation rate from radar-echo-sounding observations near Byrd Station Antarctica shows a strong linear relationship for accumulation rates over a broad range -- from 10 to 50 cm/year ice equivalent. Averaged over the 18 years of available data, ? 0 varies over this area from a few days to more than three months. Estimates of ? 0 over short time intervals of three years show patterns reminiscent of expected accumulation rate variability, and are of the correct magnitude to plausibly relate to temporal accumulation rate changes. Additional radar accumulation measurements from West Antarctica, which provide temporal as well as spatial estimates of accumulation over broad areas, are currently being compared with calculations of ? 0 to further examine the extent to which the observed spatial relationship holds in the temporal domain.

Koenig, L. S.; Steig, E. J.; Winebrenner, D. P.

2004-12-01

381

Development of an Automatic Blowing Snow station  

NASA Astrophysics Data System (ADS)

On the Antarctic ice sheet, strong katabatic winds blow throughout the year and a large but unknown fraction of the snow which falls on it is removed continuously. This constitutes a significant factor in mass and energy balance and is all the more important when predicting the likely effects of global climate change. Further, recent experimental work has indicated that the snowdrift sublimation can lead to significant mass losses during strong winds and can be also an important factor in the surface mass balance of the Antarctic ice sheets. Nishimura and Nemoto (2005) carried out the blowing snow observations at Mizuho station, Antarctica in 2000 with the snow particle counters (SPC) that can sense not only the number of snow particles but also their diameters. SPC worked properly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. However, the SPC requires rather high power supply and the data is stored in PC; it is not always suitable for the unmanned observations under the severe Antarctic conditions. Thus, we have developed a simpler device by measuring the attenuation of the light intensity, which strongly depends on the blowing snow flux. A small wind turbine and a cold-proof buttery were utilized as a power source. Firstly, its performance was tested with comparing the SPC in a cold wind tunnel system and it proved adequately fit for practical use by combining the output of the anemometer. In 2009/2010 winter, three systems have been set at Ishikari, Col du Lac blanc in France, and S17 near Syowa station in Antarctica, and the tests are still continuing.

Nishimura, K.

2010-12-01

382

Sources of Sea Salts to Coastal Antarctica  

NASA Astrophysics Data System (ADS)

Coastal Antarctic sea salt aerosols are partitioned into two main sources, namely ocean sea spray and surface sea ice. The sea spray source is related to windiness over the surface ocean and the action of bubbles bursting. The sea ice source is due to frost flowers which form on the surface of sea ice, which are concentrated in sea salts and are lofted by wind action over the sea ice zone. At high accumulation coastal sites, with seasonal resolution, it is possible to estimate the sources of both using deviations of the sodium to sulphate ratio from that found in seawater. To date, from ice core records in east Antarctica (including iceberg B09B near the Mertz Glacier, Law Dome, Wilkes Land and Wilhelm II land), we have found that the source strength from surface sea ice to the Antarctic ice sheet diminishes with elevation and distance inland. We present new data from coastal ice core sites including Mill Island off the coast of east Antarctica and the upper and lower Totten glacier to the east of Law Dome. Using this combined dataset we estimate the source strengths of sea salt aerosols, their partitioning and quantify the relationship with elevation and distance inland.

Curran, M. A.; van Ommen, T. D.; Moy, A. D.; Vance, T.; Wong, G. J.; Goodwin, I. D.; Domensino, B.

2010-12-01

383

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

NASA Astrophysics Data System (ADS)

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 quality data recorded by Japan in 1999 allows a new regional interpretation of this sector of the Antarctic margin.

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

2004-09-01

384

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

385

Crustal Vp-Vs ratios and thickness for Ross Island and the Transantarctic Mountain front, Antarctica  

NASA Astrophysics Data System (ADS)

We investigate crustal Vp-Vs ratios and thickness along the Transantarctic Mountain (TAM) front and on Ross Island, Antarctica to determine if the TAM crust has been modified by the Neogene magmatism associated with Ross Island. A seismic low velocity zone (LVZ) in the upper mantle beneath Ross Island extends laterally ˜80 km under the TAM front, and mantle temperatures within the LVZ may be sufficiently elevated for partial melting to have occurred and modified the crust. Data for the study come from 16 temporary seismic stations that were part of the TAM Seismic Experiment and three permanent stations. Estimates of Vp/Vs (?) and crustal thickness (H) have been obtained from receiver functions analysed using the H-? stacking method for 10 of the stations, and for the remaining stations, crustal thickness has been calculated by using the Moho Ps arrival time with an assumed Vp/Vs value. A Vp/Vs value of 1.88 is obtained for Ross Island, consistent with the mafic composition of the volcanic rocks from Mt. Erebus. Vp/Vs values for stations in the TAM situated away from the LVZ range from 1.63 to 1.78, with a mean of 1.73, while values for stations in the TAM lying above the LVZ range from 1.67 to 1.78, with a mean of 1.72. This result indicates that there is little difference in bulk crustal composition for areas above and away from the LVZ, and together with a Vp/Vs value (1.73) that is typical for felsic to intermediate composition crust, suggests that the crust along the TAM front has not been altered significantly by mafic magmatism. Crustal thickness estimates along the coast are quite variable, ranging from 18 to 33 km, and increase to 39 km inland beneath the crest of the TAM. On Ross Island, crustal thickness estimates range between 19 and 27 km.

Finotello, Marco; Nyblade, Andrew; Julia, Jordi; Wiens, Douglas; Anandakrishnan, Sridhar

2011-04-01

386

Long-term changes in the upper stratospheric ozone at Syowa, Antarctica  

NASA Astrophysics Data System (ADS)

Analyses of stratospheric ozone data determined from Dobson-Umkehr measurements since 1977 at the Syowa (69.0° S, 39.6° E), Antarctica, station show a significant decrease in ozone at altitudes higher than that of the 4 hPa pressure level during the 1980s and 1990s. Ozone values over Syowa have remained low since 2001. The time series of upper stratospheric ozone from the homogenized NOAA SBUV (Solar Backscatter Ultraviolet Instrument)(/2) 8.6 overpass data (±4°, 24 h) are in qualitative agreement with those from the Syowa station data. Ozone recovery during the austral spring over the Syowa station appears to be slower than predicted by the equivalent effective stratospheric chlorine (EESC) curve. The long-term changes in the station's equivalent latitude (indicative of vortex size/position in winter and spring) are derived from MERRA (Modern Era Retrospective-analysis for Research and Applications) reanalyses at ~ 2 and ~ 50 hPa. These data are used to attribute some of the upper and middle stratospheric ozone changes to the changes in vortex position relative to the station's location. In addition, high correlation of the Southern Hemisphere annular mode (SAM) with polar upper stratospheric ozone during years of maximum solar activity points toward a strong relationship between the strength of the Brewer-Dobson circulation and the polar stratospheric ozone recovery. In the lower stratosphere, ozone recovery attributable to CFCs (chlorofluorocarbons) is still not definitive, whereas the recovery of the upper stratosphere is slower than predicted. Further research indicates that dynamical and other chemical changes in the atmosphere are delaying detection of recovery over this station.

Miyagawa, K.; Petropavlovskikh, I.; Evans, R. D.; Long, C.; Wild, J.; Manney, G. L.; Daffer, W. H.

2014-04-01

387

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

388

Preliminary data analysis from the IPY autonomous surface ozone monitoring network in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

In sharp contrast with stratospheric ozone, the detailed climatology of tropospheric ozone over Antarctica is relatively understudied, partly due the difficulty in establishing long-term measurements in this remote part of our World. The scarcity of year-round surface ozone data is closely tied to that of manned research stations, often confined to coastal Antarctica, with the exception of the South Pole and more recent Concordia continental stations on the East Antarctic Plateau. Current long-term datasets (eg South Pole, Neumayer, Sanae, Halley) reveal similar annual seasonal behaviour: ~30 ppbv winter maximum, and 10-15 ppbv summer minimum. Coastal stations also show well-recognised Ozone Depletion Events (ODE), phenomena which have been observed both in Arctic and Antarctic regions, when near-zero ozone concentrations are measured during the springtime polar sunrise; this ozone loss process is believed to involve rapid photo-catalytic chemistry of Bromine/Iodine species on aerosols and/or frost flowers over open sea-ice leads. The ozone monitoring network presented in this study was proposed as part of the International Polar Year (IPY) to fill in the gap in our knowledge of the regional and climatological extent of ODE, and to probe the snow pack photochemistry impact on the overlying boundary layer oxidative capacity over the Antarctic Plateau. Between December 2007 and January 2009, a network of ten low-powered autonomous surface ozone monitors was deployed along the Weddell Sea coast and up the Dronning Maud Land (DML) plateau. The study region covers ~800km of the South-eastern Weddell Sea coastline. Four sites were located on ice shelves to study the effect of long fetched ODE. Other sites were deployed on a transect between the ice shelf bound coastal zone and up to 2400 m altitude on the DML Plateau, towards the Kohnen station operated by the Alfred Wegener Institute. This North-to-South transect roughly follows the Stancombe-Wills ice stream, an area of katabatic flow funnelling. It should allow us to gauge the effect of Antarctic Eastern Plateau outflow and the impact of (eg NOx) emissions from the continental snow pack on in-situ surface ozone production, in an area removed from ozone depleting oceanic halogen precursors. We present preliminary data from the network, and put it in the context of existing long term surface ozone measurements carried out from manned monitoring stations in the DML region.

Bauguitte, S. J.-B.; Jones, A. E.; Hutterli, M. A.; Anderson, P. S.; Maxfield, D. J.; Roscoe, H. K.; Wolff, E. W.; Virkkula, A.; Kirkwood, S.; Weller, R.

2009-04-01

389

IT?S GOOD TO BE BIG?PHAEOCYSTIS ANTARCTICA COLONY SIZE UNDER THE INFLUENCE OF ZOOPLANKTON GRAZERS  

EPA Science Inventory

The haptophyte Phaeocystis antarctica forms extremely dense accumulations in the Ross Sea, Antarctica, and accounts for over 60% of the seasonal primary production. Similar to the Phaeocystis species in the northern hemisphere, P. antarctica exists as solitary cells and mucilagin...

390

It?s good to be big--- Phaeocystis antarctica colony size under the influence of zooplankton grazers  

EPA Science Inventory

The haptophyte Phaeocystis antarctica forms extremely dense accumulations in the Ross Sea, Antarctica, and accounts for over 60% of the seasonal primary production. Similar to the Phaeocystis species in the northern hemisphere, P. antarctica exists as solitary cells and mucilagin...

391

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

392

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

393

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

394

Extraordinary blowing snow transport events in East Antarctica  

Microsoft Academic Search

In the convergence slope\\/coastal areas of Antarctica, a large fraction of snow is continuously eroded and exported by wind\\u000a to the atmosphere and into the ocean. Snow transport observations from instruments and satellite images were acquired at the\\u000a wind convergence zone of Terra Nova Bay (East Antarctica) throughout 2006 and 2007. Snow transport features are well-distinguished\\u000a in satellite images and

Claudio Scarchilli; Massimo Frezzotti; Paolo Grigioni; Lorenzo De Silvestri; Lucia Agnoletto; Stefano Dolci

2010-01-01

395

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.

Fries-Gather, Jessica

396

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 three images presented were acquired by the vertical-viewing (nadir) camera of the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra spacecraft.

2004-10-02

397

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.

398

Ice-shelf melting around Antarctica.  

PubMed

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. PMID:23765278

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

2013-07-19

399

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

400

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

401

Six-hour zonally symmetric tidal oscillations of the winter mesopause over the South Pole Station  

Microsoft Academic Search

Four complete cycles of a 6-h quasi-monochromatic variation in OH Meinel (3,1) and (4,2) band airglow brightness (I) and rotational distribution temperature (T) were observed with a near infrared (1.0-1.7 microns) Michelson Interferometer operating at the South Pole Station in Antarctica. The simultaneous occurrence of a quasi-periodic variation in I and T suggests the presence of a coherent wave phenomenon

G. G. Sivjee; R. L. Walterscheid

1994-01-01

402

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

403

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.

Mills, Christopher N.; Mills, Gregory H.

2011-01-01

404

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

405

IESID: Automatic system for monitoring ground deformation on the Deception Island volcano (Antarctica)  

NASA Astrophysics Data System (ADS)

When establishing the relative distance between two GNSS-GPS stations with sub-centimeter accuracy, it is necessary to have auxiliary data, some of which can only be collected some time after the moment of measurement. However, for monitoring highly-active geodynamic areas, such as volcanoes and landslides, data precision is not as essential as rapid availability, processing of data in real-time, and fast interpretation of the results. This paper describes the development of an integrated automatic system for monitoring volcanic deformation in quasi real-time, applied to the Deception volcano (Antarctica). This experimental system integrates two independent modules that enable researchers to monitor and control the status of the GNSS-GPS stations, and to determine a surface deformation parameter. It comprises three permanent stations, one of which serves as the reference for assessing the relative distance in relation to the other two. The availability of GNSS-GPS data in quasi real-time is achieved by means of a WiFi infrastructure and automated data processing. This system provides, in quasi real-time, a time series of varying distances that tells us the extent to which any ground deformation is taking place.

Peci, Luis Miguel; Berrocoso, Manuel; Páez, Raúl; Fernández-Ros, Alberto; de Gil, Amós

2012-11-01

406

Pondering a Climate Conundrum in Antarctica  

NSF Publications Database

... 1MB) The U.S. Antarctic Program field camp at Lake Hoare in the McMurdo Dry Valleys, with the ... weather station record from the shore of Lake Hoare reveals that seasonally averaged surface air ...

407

Benthic infaunal communities across the Weddell Sea Basin and South Sandwich Slope, Antarctica  

NASA Astrophysics Data System (ADS)

The present study represents the first quantitative investigation of deep-sea benthic infauna in Antarctica. Box cores and multicores were used to collect sediment from 12 stations across the slope and abyssal basin of the Weddell Sea and the slope off the South Sandwich Islands, including sites in the South Sandwich Trench (6300 m). The multicore was a more efficient sampler than the box core. Nine phyla of invertebrates were found, dominated by annelids (67%), crustaceans (20%); other phyla (13%). A total of 117 taxa were identified to the species level: 72 were polychaetes; 45 were crustaceans. Many taxa are new to science. Highest densities were at the 1000 m depth on the western slope of the Weddell Sea (260 individuals per 0.1 m -2) and at ca. 2200 m on the South Sandwich Slope (132 individuals per 0.1 m -2); lowest densities were in the central Weddell Sea Basin (39 individuals per 0.1 m -2). Species richness and rarefaction analysis suggest that the fauna is undersampled. The 117 species identified in this study were represented by only 237 specimens, indicating that species were being added at a rate of one species for every two specimens collected. Rarefaction curves do not begin to reach an asymptote supporting high estimates of diversity. Some species appear to be limited to distinct zones in upper and middle slope depths, other species extend from the slope to the abyssal basin, and at least two species appear to be restricted to the abyssal basin. In general, the densities of infauna on the slopes surrounding the Weddell Sea Basin have lower densities than well-studied areas off North America. However, abyssal populations in Antarctica appear to have denser infaunal populations than those from off New England and the North Pacific Gyre. Productive surface waters of the Weddell Sea and subsequent sinking of phytoplankton to the seabed are probable reasons for the higher benthic productivity in Antarctic abyssal sediments. Similarity analyses were not informative because so few species were collected. Two stations in the Weddell Abyssal Basin were the only ones to exhibit a high level of similarity due to two shared polychaetes. Data on reproductive status of some polychaetes suggest that species limited to abyssal depths are reproducing there. Other species with broader depth ranges may be receiving recruits from slope depths. The results suggest that the deep-water infauna in Antarctica is largely endemic, but has some components that occur along other continental margins and adjacent abyssal basins.

Blake, James A.; Narayanaswamy, Bhavani E.

2004-07-01

408

Space station power system  

NASA Technical Reports Server (NTRS)

It is pointed out that space station planning at NASA began when NASA was created in 1958. However, the initiation of the program for a lunar landing delayed the implementation of plans for a space station. The utility of a space station was finally demonstrated with Skylab, which was launched in 1972. In May 1982, the Space Station Task Force was established to provide focus and direction for space station planning activities. The present paper provides a description of the planning activities, giving particular attention to the power system. The initial space station will be required to supply 75 kW of continuous electrical power, 60 kW for the customer and 15 kW for space station needs. Possible alternative energy sources for the space station include solar planar or concentrator arrays of either silicon or gallium arsenide.

Forestieri, A. F.; Baraona, C. R.

1984-01-01

409

Fire Station Location Package.  

National Technical Information Service (NTIS)

Using the PTI Fire Station Package, local administrators and fire officials evaluate adequacy of station locations - present and planned - on response time rather than arbitrary distance requirements to get the most protection for the least investment. A ...

1975-01-01

410

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.

411

Rheological Implications of the Internal Structure and Crystal Fabrics of the West Antarctic Ice Sheet as Revealed by Deep Core Drilling at Byrd Station.  

National Technical Information Service (NTIS)

Crystalline textures and fabrics of ice cores from the 2164-m-thick ice sheet at Byrd Station, Antarctica, reveal the existence of an anisotropic ice sheet. A gradual but persistent increase in the c-axis preferred orientation of the ice crystals was obse...

A. J. Gow T. Williamson

1976-01-01

412

Space Station - early  

NASA Technical Reports Server (NTRS)

James Hansen wrote: 'Langley engineers check out the interior of the inflatable 24-foot space station in January 1962.'... 'The first idea for an inflatable station was the Erectable Torus Manned Space Laboratory. A Langley space station team led by Paul Hill and Emanuel 'Manny' Schnitzer developed the concept with the help of the Goodyear Aircraft Corporation.'

1962-01-01

413

33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.  

Code of Federal Regulations, 2010 CFR

...false Operating requirements: Discharge of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable...79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10...

2010-07-01

414

33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.  

Code of Federal Regulations, 2013 CFR

...false Operating requirements: Discharge of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable...79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10...

2013-07-01

415

33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.  

Code of Federal Regulations, 2010 CFR

...false Operating requirements: Discharge of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable...79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10...

2009-07-01

416

33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.  

Code of Federal Regulations, 2012 CFR

...false Operating requirements: Discharge of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable...79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10...

2012-07-01

417

33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.  

Code of Federal Regulations, 2011 CFR

...false Operating requirements: Discharge of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable...79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10...

2011-07-01

418

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

419

Space Station Live: Station Communications Upgrade  

NASA Video Gallery

NASA Public Affairs Officer Nicole Cloutier-Lemasters recently spoke with Penny Roberts, one of the leads for the International Space Station Avionics and Software group, about the upgrade of the K...

420

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

421

Origin of the inland Acari of Continental Antarctica, with particular reference to Dronning Maud Land  

Microsoft Academic Search

The extant Acari occurring on the inland mountain ranges and nunataks of Continental Antarctica comprise only pre-Pleistocene endemic Prostigmata and Cryptostigmata of which the Prostigmata are the probable earlier colonists. The inland acarofauna of Continental Antarctica has a different origin from that of Maritime Antarctica, though both are the relict descendants of a Mesozoic acarofauna, which has been radically depleted

PHILIP J. A. PUGH

1996-01-01

422

Basal Mass Balance of Antarctica and Greenland  

NASA Astrophysics Data System (ADS)

Basal melting represents a poorly constrained component of the total ice sheet mass balance that may have a significant impact on the contribution of polar ice sheets to sea level changes. The thermal budget in the basal environment depends on coarsely known parameters such as geothermal heat flux, velocity, and basal stress. By utilizing recent data sets, an improved estimate of the current basal mass balance of Antarctica and Greenland can be made, resulting in an increase of basal melt from previous calculations. This translates into a significant fraction of the land ice’s total mass budget. The components of the basal melt are calculated from the vertical conductive loss of heat, the influx of heat from the geothermal heat flux, and shearing. The basal temperature is estimated using a semi-implicit finite difference numerical scheme to solve the 2-D thermodynamic equation, simplified by neglecting horizontal diffusion of heat. Two geothermal heat flux data sets are used in the current investigation, yielding similar annual melt rates and thus basal mass loss. Basal stress is approximated as the driving stress, which, together with balance velocities, are used to approximate the shear heating contribution to the basal heat budget. Other assumptions made in this study neglect unphysical driving stresses and basal temperature solutions. Future work on this project will extend calculations of the basal mass balance through the last glacial maximum by using ice thickness reconstructions.

Hossainzadeh, S.; Tulaczyk, S. M.

2010-12-01

423

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

424

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

425

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

426

Intercomparison of ozone measurements over Antarctica  

SciTech Connect

Measurements of the abundances of ozone over Antarctic in August and September 1987 obtained during the Airborne Antarctic Ozone Experiment are intercompared. These measurements of ozone concentrations and total column abundance were obtained by three satellite instruments, two IR and one UV column-measuring instruments aboard the DC-8, one in situ DC-8, and two in situ ER-2 instruments, an upward looking lidar aboard the DC-8, and ozonesondes from four sites in Antarctica. Given the natural variability of ozone in the Antarctic and the fact that the data were not truly coincident spatially and temporally, this intercomparison is suitable only for identifying gross disparities among the techniques, rather than confirming the accuracies as rigorously as is normally done in an intercomparison. This paper presents a summary of the ozone data, using the data and accuracies given by the individual investigators in the individual papers in this issue, without any attempt to critically review or evaluate the data. In general, very good agreement (within about 10-20%, limited by natural variability) among the various techniques was found, with no systematic biases detected. These observations confirm the low ozone amounts reported in the Antarctic stratosphere.

Margitan, J.J.; Farmer, C.B.; Toon, G.C. (California Inst. of Tech., Pasadena (United States)); Brothers, G.A. (Chemal, Inc., Wallops Island, VA (United States)); Browell, E.V.; Gregory, G.L.; Hypes, W.; Larsen, J.C.; McCormick, M.P. (NASA Langley Research Center, Hampton, VA (United States)); Cariolle, D. (Centre National de la Recherches Meteorologiques, Toulouse (France)); Coffey, M.T.; Mankin, W. (National Center for Atmospheric Research, Boulder, CO (United States)); Farman, J.C. (British Antarctic Survey, Cambridge (United Kingdom)); Harder, J.W.; Mount, G.H.; Ravishankara, A.R.; Schemeltekopf, A.L.; Tuck, A.F. (NOAA Aeronomy Lab., Boulder, CO (United States)); Hofmann, D.J. (Univ. of Wyoming, Laramie (United States)); Ismail, S.; Kooi, S. (ST Systems, Inc., Hampton, VA (United States)); Jakoubek, R.O.; Proffitt, M.H.; Wahner, A.; Watterson, I. (NOAA Aeronomy Lab., Boulder, CO (United States) Univ. of Colorado, Boulder (United States)); Komhyr, W. (NOAA Air Resources La

1989-11-30

427

Tectonic evolution of west Antarctica and its relation to east Antarctica  

SciTech Connect

West Antarctica consists of five major blocks of continental crust separated by deep sub-ice basins. Marie Byrd Land appears to have been rifted off the adjacent margin of the East Antarctic craton along the line of the Transantarctic Mountains during the Mesozoic. Ellsworth-Whitmore mountains and Haag Nunataks blocks were also rifted from the margin of the craton. They appear to have moved together with the Antarctic Peninsula and Thurston Island blocks, segments of a Pacific margin Mesozoic-Cenozoic magmatic arc, during the Mesozoic opening of the Weddell Sea basin. Paleomagnetic data suggest that all four of these blocks remained attached to western Gondwanaland (South America-Africa) until approximately 125 m.y. ago, and that the present geographic configuration of the Antarctic continent was essentially complete by the mid-Cretaceous, although important Cenozoic rifting has also occurred. Fragmentation of the Gondwanaland supercontinent was preceded in the Middle to Late Jurassic by an important and widespread thermal event of uncertain origin that resulted in the emplacement of an extensive bimodal igneous suite in South America, Africa, Antarctica, and Australia. This was associated with the development of the composite back-arc basin along the western margin of South America. Inversion of this basin in the mid-Cretaceous initiated Andean orogenesis. The presentation will include new data from the joint US-UK West Antarctic Tectonics Project.

Dalziel, I.W.D.

1987-05-01

428

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 compos