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Sample records for casey station antarctica

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

    PubMed

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

    2014-12-01

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

  2. A permeable reactive barrier (PRB) media sequence for the remediation of heavy metal and hydrocarbon contaminated water: A field assessment at Casey Station, Antarctica.

    PubMed

    Statham, Tom M; Stark, Scott C; Snape, Ian; Stevens, Geoffrey W; Mumford, Kathryn A

    2016-03-01

    A field trial was conducted at Casey Station, Antarctica to assess the suitability of a permeable reactive barrier (PRB) media sequence for the remediation of sites containing both hydrocarbon and heavy metal contamination. An existing PRB was modified to assess a sequence consisting of three sections: (i) Nutrient release/hydrocarbon sorption using ZeoPro™ and granular activated carbon; (ii) Phosphorus and heavy metal capture by granular iron and sand; (iii) Nutrient and excess iron capture by zeolite. The media sequence achieved a greater phosphorus removal capacity than previous Antarctic PRB configurations installed on site. Phosphorus concentrations were reduced during flow through the iron/sand section and iron concentrations were reduced within the zeolite section. However, non-ideal flow was detected during a tracer test and supported by analysis of media and liquid samples from the second summer of operation. Results indicate that the PRB media sequence trialled might be appropriate for other locations, especially less environmentally challenging contaminated sites. PMID:26774301

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

    PubMed

    Goh, Yuh Shan; Tan, Irene Kit Ping

    2012-04-20

    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

  4. Continental Dynamics Between India and Antarctica by Global Network Solution Using Maitri, Indian GPS Station at Antarctica

    NASA Astrophysics Data System (ADS)

    N., R.; Malaimani, E.

    2003-12-01

    The GPS-Geodesy program initiated in 1995 by establishing a Permanent IGS GPS Tracking station at NGRI has resulted in the estimation of Indian plate motion to be 37 +/-2.0 mmy-1 towards NNE direction. To understand the tectonic activity and crustal deformation in the south of Indian peninsula, the driving mechanisms and the response of the Indian Ocean Lithosphere and holistically compound the Indian Plate kinematics, NGRI has extended the GPS-Geodesy programme by establishing a permanent GPS station at Maitri, at Antarctica in 1997 in Schirmacher oasis between SANAE and SYOWA. The data from the IGS stations in the islands surrounding Indian plate is included in the global network solution. Very long baselines from Kerguelen, as it is relatively a stable site, to Maitri and other IGS Stations in different plates Casey, Davis, Seychelles, Coco, Hartebeesthoek, Yaragadee, and Tidbinbilla have been estimated. The GPS derived velocity vectors of these sites throw a significant insight into the plausible causes of northward movement of Indian plate. These results also elucidate the strain accumulation processes in the Indian Ocean and the effects of these forces on the Indian Plate.

  5. Ozone profiles above Palmer Station, Antarctica

    NASA Technical Reports Server (NTRS)

    Torres, Arnold L.; Brothers, George

    1988-01-01

    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.

  6. A mesoscale vortex over Halley Station, Antarctica

    SciTech Connect

    Turner, J.; Lachlan-Cope, T.A.; Warren, D.E. ); Duncan, C.N. )

    1993-05-01

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

  7. Observations of Pc2 waves by Cluster and ground stations in Antarctica

    NASA Astrophysics Data System (ADS)

    Liu, Y.

    2013-12-01

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

  8. Status of DORIS stations in Antarctica for precise geodesy

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

  9. Seasonal features of black carbon measured at Syowa Station, Antarctica

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Black carbon (BC) is one of important aerosol constituents because the strong light absorption ability. Low concentrations of aerosols and BC let BC make insignificant contribution to aerosol radiative forcing in the Antarctica at the moment. Because of less or negligible source strength of BC in the Antarctic circle, BC can be used as a tracer of transport from the mid-latitudes. This study aims to understand seasonal feature, transport pathway, and origins of black carbon in the Antarctic coats. Black carbon measurement has been made using 7-wavelength aethalometer at Syowa Station, Antarctica since February, 2005. Mass BC concentrations were estimated from light attenuation by Weingartner's correction procedure (Weingartner et al., 2003) in this study. Detection limit was 0.2 - 0.4 ng/m3 in our measurement conditions (2-hour resolution and flow rate of ca. 10LPM). BC concentrations ranged from near detection limit to 55.7 ng/m3 at Syowa Station, Antarctica during the measurements. No trend has been observed since February, 2005. High BC concentrations were coincident with poleward flow from the mid-latitudes under the storm conditions by cyclone approach, whereas low BC concentrations were found in transport from coastal regions and the Antarctic continent. Considering that outflow from South America and Southern Africa affect remarkably air quality in the Southern Ocean of Atlantic and Indian Ocean sectors, BC at Syowa Station might be originated from biomass burning and human activity on South America and Southern Africa. Seasonal features of BC at Syowa Station shows maximum in September - October and lower in December - April. Spring maximum in September - October was obtained at the other Antarctic stations (Neumayer, Halley, South pole, and Ferraz). Although second maximum was found in January at the other stations, the maximum was not observed at Syowa Station.

  10. JARE Syowa Station 11-m Antenna, Antarctica

    NASA Technical Reports Server (NTRS)

    Aoyama, Yuichi; Doi, Koichiro; Shibuya, Kazuo

    2013-01-01

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

  11. Identification of small open reading frames in the Glaciozyma antarctica genome

    NASA Astrophysics Data System (ADS)

    Mat-Sharani, Shuhaila; Bharudin, Izwan; Zainuddin, Nursyafiqi; Abdul-Murad, Abdul-Munir; Abu-Bakar, Farah-Diba; Najimuddin, Nazalan; Mahadi, Nor-Muhammad; Firdaus-Raih, Mohd

    2015-09-01

    Glaciozyma antarctica is an obligate psychrophilic yeast that was isolated from Casey Research Station, Antarctica. The objective of this study was to identify small Open Reading Frames (sORFs) in the G. antarctica genome. Small ORFs have been found in other organisms including Saccharomyces cerevisiae and human and they have been known to partake in a diverse variety of functions. In this study, ORFs were searched from the existing G. antarctica genome annotations and this resulted 294 sORFs (of at most 100 amino acids) which represented 4% of the 7857 annotated ORFs. Several of these sORFs were validated by mapping to EST and transcriptome of G. antarctica.

  12. Outdoor Education, Camp Casey.

    ERIC Educational Resources Information Center

    Stansberry, Steve; And Others

    A curriculum guide for the Camp Casey Outdoor Education program is contained in this document. Designed for fifth grade students and teachers in Northshore School District, Bothell, Washington, it emphasizes learning activities for use in the outdoors. General understandings relevant to the objectives of the program form the frame into which the…

  13. Hexabromocyclododecane flame retardant in Antarctica: Research stations as sources.

    PubMed

    Chen, Da; Hale, Robert C; La Guardia, Mark J; Luellen, Drew; Kim, Stacy; Geisz, Heidi N

    2015-11-01

    Historical persistent organic pollutants (POPs) are banned from Antarctica under international treaty; but contemporary-use POPs can enter as additives within polymer and textile products. Over their useful lives these products may release additives in-situ. Indeed, we observed 226 and 109 ng/g dry weight (dw) of the total concentrations of α-, β- and γ-hexabromocyclododecane (HBCD) in indoor dust from McMurdo Station (U.S.) and Scott Station (New Zealand), respectively. Sewage sludge collected from wastewater treatment facilities at these stations exhibited ∑HBCD of 45 and 69 ng/g dw, respectively. Contaminants originally within the bases may exit to the local outdoor environment via wastewaters. Near McMurdo, maximum ∑HBCD levels in surficial marine sediments and aquatic biota (invertebrates and fish) were 2350 ng/g (total organic carbon basis) and 554 ng/g lipid weight, respectively. Levels declined with distance from McMurdo. Our results illustrate that Antarctic research stations serve as local HBCD sources to the pristine Antarctic environment. PMID:26312743

  14. Mini Neutron Monitors at Concordia Research Station, Central Antarctica

    NASA Astrophysics Data System (ADS)

    Poluianov, Stepan; Usoskin, Ilya; Mishev, Alexander; Moraal, Harm; Kruger, Helena; Casasanta, Giampietro; Traversi, Rita; Udisti, Roberto

    2015-12-01

    Two mini neutron monitors are installed at Concordia research station (Dome C, Central Antarctica, 75° 06' S, 123° 23' E, 3,233 m.a.s.l.). The site has unique properties ideal for cosmic ray measurements, especially for the detection of solar energetic particles: very low cutoff rigidity < 0.01 GV, high elevation and poleward asymptotic acceptance cones pointing to geographical latitudes > 75° S. The instruments consist of a standard neutron monitor and a "bare" (lead-free) neutron monitor. The instrument operation started in mid-January 2015. The barometric correction coefficients were computed for the period from 1 February to 31 July 2015. Several interesting events, including two notable Forbush decreases on 17 March 2015 and 22 June 2015, and a solar particle event of 29 October 2015 were registered. The data sets are available at cosmicrays.oulu.fi and nmdb.eu.

  15. Biodiversity of air-borne microorganisms at Halley Station, Antarctica.

    PubMed

    Pearce, David A; Hughes, K A; Lachlan-Cope, T; Harangozo, S A; Jones, A E

    2010-03-01

    A study of air-borne microbial biodiversity over an isolated scientific research station on an ice-shelf in continental Antarctica was undertaken to establish the potential source of microbial colonists. The study aimed to assess: (1) whether microorganisms were likely to have a local (research station) or distant (marine or terrestrial) origin, (2) the effect of changes in sea ice extent on microbial biodiversity and (3) the potential human impact on the environment. Air samples were taken above Halley Research Station during the austral summer and austral winter over a 2-week period. Overall, a low microbial biodiversity was detected, which included many sequence replicates. No significant patterns were detected in the aerial biodiversity between the austral summer and the austral winter. In common with other environmental studies, particularly in the polar regions, many of the sequences obtained were from as yet uncultivated organisms. Very few marine sequences were detected irrespective of the distance to open water, and around one-third of sequences detected were similar to those identified in human studies, though both of these might reflect prevailing wind conditions. The detected aerial microorganisms were markedly different from those obtained in earlier studies over the Antarctic Peninsula in the maritime Antarctic. PMID:20091326

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

    SciTech Connect

    Johnson, B.J.; Deshler, T.

    1994-12-31

    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.

  17. Seasonality of reactive nitrogen oxides (NOy) at Neumayer Station, Antarctica

    NASA Astrophysics Data System (ADS)

    Weller, R.; Jones, A. E.; Wille, A.; Jacobi, H.-W.; McIntyre, H. P.; Sturges, W. T.; Huke, M.; Wagenbach, D.

    2002-12-01

    NO, NOy (total reactive nitrogen oxides), gaseous HNO3, and particulate nitrate (p-NO3-) were measured at Neumayer Station from February 1999 to January 2000. In addition, during February 1999, the NOy component species peroxyacetyl nitrate (PAN) and methyl, ethyl, i-propyl, and n-propyl nitrates were determined. We found a mean NOy mixing ratio of 46 ± 29 pptv, with significantly higher values between February and end of May (58 ± 35 pptv). Between February and November, the (HNO3 + p-NO3-)/NOy ratio was extremely low (around 0.22) and in contrast to NOy the seasonality of p-NO3- and HNO3 showed a distinct maximum in November and December, leading to a (HNO3 + p-NO3-)/NOy ratio of 0.66. Trajectory analyses and radioisotope measurements (7Be, 10Be, 210Pb, and 222Rn) indicated that the upper troposphere or stratosphere was the main source region of the observed NOy with a negligible contribution of ground-level sources at northward continents. Frequent maxima of NOy mixing ratios up to 100 pptv are generally associated with air mass transport from the free troposphere of continental Antarctica, while air masses with the lowest NOy mixing ratios were typically advected from the marine boundary layer.

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Chubachi, S.

    1985-01-01

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

  20. Antarctica

    Atmospheric Science Data Center

    2013-04-16

    ... Twilight in Antarctica, February 24, 2000 . Nearly 15 times every 24 hours, the Terra spacecraft, traveling southward, crosses from ... D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. The MISR data were obtained from the NASA Langley ...

  1. Designing a new post-hole seismological station on Antarctica inlandsis (Concordia station)

    NASA Astrophysics Data System (ADS)

    Bès de Berc, M.; Maggi, A.; Leveque, J. J.; Thore, J. Y.

    2015-12-01

    Concordia (75°S 123°E) is a scientific base operated by French and Italian polar institutes IPEV (Institut Paul-Emile Victor) and PNRA (Programma Nazionale di Ricerche in Antartide, and is located on the inlandsis of the East Antarctica plateau. It hosts a seismological station CCD which has provided observatory quality data since the year 2000, has been integrated into the Geoscope network since 2008 and whose data are now available in real-time from IRIS. The current seismic vault is located 800m from Concordia base, as far away as is deemed logistically possible by IPEV, at a depth of 12m. The vault is thermally very stable, but given the close distance to the base, suffers from increased diurnal noise (up to 40 dB) at frequencies above 1Hz, especially in the summer season. Anthropic noise is trapped in the firn (snow) layer, which forms an 100-110m thick waveguide, and is picked up very easily in the seismic vault. The vault is made from steel containers buried vertically in the snow. The hydrostatic pressure of the snow is deforming them: we see container cracking events on the seismograms, and also visual evidence of container deformation inside the vault. In the near future, this deformation will create a security problem.We have decided to progressively abandon our current vault, and construct a new post-hole seismological installation nearby. We plan to drill to 130m depth, which would place us below the firn layer waveguide and also below the ice pinch-out depth. To be able to run the station for several years and change or service the instrumentation if required, we need to keep the hole open, to avoid any hydrostatic movement, and to maintain good coupling between the sensor and the surrounding hard ice. To achieve these goals, we shall install a casing in the fin layer and then drill a few meters more without casing in hard ice. After installing the instrument, we shall then fill the whole hole with a drilling fluid whose density is similar to that

  2. Visible spectroscopy at McMurdo Station, Antarctica

    SciTech Connect

    Solomon, S.

    1987-09-01

    Ground-based observations and satellite data confirm that total ozone abundance over Antarctica during the austral spring has decreased by 50 percent during the last 10 years. As participants in the 1986-1987 National Ozone Expedition, the author measured as many stratospheric chemical constituents as possible to obtain a better understanding of chemical and dynamic processes that may contribute to this decline. Data from last austral spring indicate that abundances of ozone-destroying chlorine compounds were about 29 to 50 times greater than anticipated and vary diurnally. Although these data, as well as lower than expected abundances of nitrogen dioxide, are consistent with the theory that enhanced chlorine chemistry is causing the ozone depletion, these findings do not prove that this model is correct. To augment his data base, during austral spring 1987, the author will continue to use ground-based visible absorption spectroscopy to measure the stratospheric column abundances of ozone, nitrogen compounds, and chlorine compounds. This method provides simultaneous measurements of ozone change and the abundances of reactive nitrogen and reactive chlorine species. Possible correlations between simultaneous measurements of these three constituents are valuable for distinguishing between proposed mechanisms of ozone depletion. The author will take measurements using direct light from the Sun and Moon or by measuring the scattered light from the zenith sky.

  3. Snowpack Chemistry of Reactive Gases at Station Concordia, Antarctica

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  4. Dworkin and Casey on abortion.

    PubMed

    Stroud, Sarah

    1996-01-01

    This article responds to two important recent treatments of abortion rights. I will mainly discuss Ronald Dworkin's recent writings concerning abortion: his article "Unenumerated rights: whether and how Roe should be overruled," and his book Life's Dominion. In these writings Dworkin presents a novel view of what the constitutional and moral argument surronding abortion is really about. Both debates actually turn, he argues, on the question of how to interpret the widely shared idea that human life is sacred. At the heart of the abortion debate is the essentially religious notion that human life has value which transcends its value to any particular person; abortion is therefore at bottom a religious issue. Dworkin hopes to use this analysis to show that the religion clauses of the First Amendment provide a "textual home" for a woman's right to choose abortion. I wish to scrutinize this suggestion here; I want to probe the precise consequences for abortion rights of such an understanding of their basis. I will argue that the consequences are more radical than Dworkin seems to realize. The other work I will examine here is the important 1992 Supreme Court decision on abortion, Planned Parenthood v. Casey. The controlling opinion in that case, written jointly by Justices Kennedy, O'Connor, and Souter, strongly reaffirmed Roe v. Wade, but also upheld most of the provisions of a Pennsylvania statute that had mandated various restrictions on abortion. The justices' basis for upholding these restictions was their introduction of a new constitutional standard for abortion regulations, an apparently weaker standard than those that had governed previous Supreme Court abortion decisions. I think there is a flaw in Casey's new constitutional test for abortion regulations, and I will explain, when we turn to Casey, what it is and why it bears a close relation to Dworkin's reluctance to carry his argument as far as it seems to go. PMID:11660187

  5. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-01-01

    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.

  6. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-05-01

    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.

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

    NASA Technical Reports Server (NTRS)

    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

    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.

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

    PubMed

    Prus, Wojciech; Fabiańska, Monika J; Łabno, Radosław

    2015-06-15

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

  9. Monitoring atmospheric nitrous oxide background concentrations at Zhongshan Station, east Antarctica.

    PubMed

    Ye, Wenjuan; Bian, Lingen; Wang, Can; Zhu, Renbin; Zheng, Xiangdong; Ding, Minghu

    2016-09-01

    At present, continuous observation data for atmospheric nitrous oxide (N2O) concentrations are still lacking, especially in east Antarctica. In this paper, nitrous oxide background concentrations were measured at Zhongshan Station (69°22'25″S, 76°22'14″E), east Antarctica during the period of 2008-2012, and their interannual and seasonal characteristics were analyzed and discussed. The mean N2O concentration was 321.9nL/L with the range of 320.5-324.8nL/L during the five years, and it has been increasing at a rate of 0.29% year(-1). Atmospheric N2O concentrations showed a strong seasonal fluctuation during these five years. The concentrations appeared to follow a downtrend from spring to autumn, and then increased in winter. Generally the highest concentrations occurred in spring. This trend was very similar to that observed at other global observation sites. The overall N2O concentration at the selected global sites showed an increasing annual trend, and the mean N2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere. Our result could be representative of atmospheric N2O background levels at the global scale. This study provided valuable data for atmospheric N2O concentrations in east Antarctica, which is important to study on the relationships between N2O emissions and climate change. PMID:27593286

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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

  11. Seasonal fluctuation of DNA photodamage in marine plankton assemblages at Palmer Station, Antarctica.

    PubMed

    Meador, Jarah; Jeffrey, Wade H; Kase, Jason P; Pakulski, J Dean; Chiarello, Stephanie; Mitchell, David L

    2002-03-01

    Ultraviolet radiation-induced DNA damage frequencies were measured in DNA dosimeters and natural plankton communities during the austral spring at Palmer Station, Antarctica, during the 1999-2000 field season. We found that the fluence of solar ultraviolet-B radiation (UV-B) at the earth's surface correlated with stratospheric ozone concentrations, with significant ozone depletion observed because of "ozone hole" conditions. To verify the interdependence of ozone depletion and DNA damage in natural microbial communities, seawater was collected daily or weekly from Arthur Harbor at Palmer Station, Antarctica, throughout "ozone season," exposed to ambient sunlight between 0600 and 1800 h and fractionated using membrane filtration to separate phytoplankton and bacterioplankton populations. DNA from these fractions was isolated and DNA damage measured using radioimmunoassay. Under low-ozone conditions cyclobutane dimer concentrations in bacterioplankton and phytoplankton communities were maximal. DNA damage measured in dosimeters correlated closely with ozone concentrations and UV-B fluence. Our studies offer further support to the theory that stratospheric deozonation is detrimental to marine planktonic organisms in the Southern Ocean. PMID:11950092

  12. The 1994 to 2008 concentration variations of atmospheric CO2 observed at Jubany Station (Antarctica)

    NASA Astrophysics Data System (ADS)

    Gallo, Veronica; de Simone, Sara; Ciattaglia, Luigi; Rafanelli, Claudio; Diego, Piero

    2010-05-01

    Since 1994 the Italian PNRA (National Research Program in Antarctica) and the Argentina DNA (Direction National de Antartico) have been collecting continuous atmospheric carbon dioxide measurements at Jubany. The Antarctic station at Jubany (62° 14'S, 58° 40'W) is located in King George Island, in the South Shetland archipelago, north of the Antarctic Peninsula. The laboratory is situated at an elevation of 15 m.s.l. on the SE slope of Potter Bay. The measurements are taken by using a Siemens U5 analyzer based on NDIR (Non Dispersive InfraRed) absorption method. Details are given on the station environment, meteorological conditions, instrumentation, and data selection strategy. The paper presents the first 14 years (1994-2008) of continuous atmospheric CO2 measurements; the interannual and seasonal variations of CO2 data are described

  13. Ralph Casey ... Journalist, Educator, Social Scientist.

    ERIC Educational Resources Information Center

    Lindley, William R.

    1978-01-01

    Tells how Ralph Casey, one of the pioneers in journalism education, developed journalism education at the University of Minnesota along a social science rather than a literary pathway, and influenced other departments to do the same. (RL)

  14. FY 1994 ambient air monitoring report for McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1994-12-01

    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.

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

    SciTech Connect

    Deshler, T.; Hofmann, D.J.; Hereford, J.V.; Sutter, C.B. )

    1990-02-01

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

  16. Seasonal and diurnal variation of the atmospheric NO2 at Syowa Station, Antarctica

    NASA Technical Reports Server (NTRS)

    Shibasaki, K.

    1985-01-01

    Extensive attention has been directed to nitrogen dioxide (NO2) since its important role in the atmospheric chemistry relating to the stratospheric ozone (e.g., WMO, 1982) has been pointed out. However, the behavior of NO2 in the atmosphere has still not been fully confirmed, although ground-based, balloon and satellite measurements of NO2 have been reported by many scientists. Especially, only a few measurements made at high latitude in the Southern Hemisphere have been reported. The total atmospheric NO2 by ground-based visible absorption spectroscopy at Syowa Station (69 deg S, 39.6 deg E), Antarctica. The observation continued from March 1983, to January 1984. The principles of measurement, instrumentation and the method of data analysis are described in detail.

  17. Ozone profiles at McMurdo Station, Antarctica, the austral spring of 1990

    SciTech Connect

    Deshler, T. ); Hofmann, D.J. )

    1991-04-01

    Vertical profiles of ozone and temperature were measured on 40 occasions during the austral spring of 1990 at McMurdo Station, Antarctica, and once again near record levels of ozone depletion were observed. Total ozone decreased from 260 DU in late August to its minimum value of 145 DU on 9 October, when the ozonesonde was at it's lower detection limit from 15 to 16.5 km. Ozone reductions were observed almost exclusively between 12 and 20 km, with a half life of 20 days. This is similar to previous years. Although McMurdo was within the polar vortex for most of the period, there were several occasions when the edge of the vortex was over McMurdo. During these periods, ozone above 20 km approximately doubled, but below 20 km remained relatively unchanged.

  18. Cloning and expression of phosphoglycerate mutase from the psychrophilic yeast, Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Jaafar, Nardiah Rizwana; Bakar, Farah Diba Abu; Murad, Abdul Munir Abdul; Mahadi, Nor Muhammad

    2015-09-01

    The conversion of 3-phosphoglycerate to 2-phosphoglycerate during glycolysis and gluconeogenesis is catalyzed by phosphoglycerate mutase (PGM). Better understanding of metabolic reactions performed by this enzyme has been studied extensively in prokaryotes and eukaryotes. Here, we report a phosphoglycerate mutase from the psychrophilic yeast, Glaciozyma antarctica. cDNA encoding for PGM from G. antarctica PI12, a psychrophilic yeast isolated from sea ice at Casey Station, Antarctica was amplified. The gene was then cloned into a cloning vector and sequenced, which verified its identity as the gene putatively encoding for PGM. The recombinant protein was expressed in Escherichia coli BL21 (DE3) as inclusion bodies and this was confirmed by SDS-PAGE and Western blot.

  19. Column ozone measurements from Palmer Station, Antarctica: Variations during the Austral Springs of 1988 and 1989

    SciTech Connect

    Lubin, D. ); Frederick, J.E. )

    1990-08-20

    The National Science Foundation scanning spectroradiometer at Palmer Station, Antarctica (64{degree}-46{prime}S, 64{degree}04{prime}W), provides hourly ground-based measurements of solar ultraviolet (UV) irradiance. In addition to defining the UV radiation environment of the region, these measurements allow the derivation of the column density of atmospheric ozone above the station nearly every daylight hour. This hourly time resolution, not generally available from other methods of monitoring Antarctic ozone abundances, enables the detection of large and rapid changes in total column ozone and UV surface irradiance associated with the dynamics of the polar vortex. Column ozone abundance is derived from a ratio of measured irradiances at 300 and 313.5 nanometers (nm) by means of theoretical calculation of this ratio as a function of total ozone amount. Noontime ozone abundances over Palmer Station obtained from this method agree with those obtained by the Total Ozone Mapping Spectrometer (TOMS) instrument aboard Nimbus 7 to within about 10% throughout the austral spring of 1988. Ozone recovery at Palmer Station, associated with the breakup of the polar vortex as indicated by TOMS satellite ozone observations, occurred rapidly within a 24-hour period beginning in midafternoon on November 15. Over the Antarctic Peninsula, the 1989 ozone depletion was slightly greater than in 1988, the minimum noontime ozone abundances over Palmer Station as measured by the spectroradiometer being 194 and 166 Dobson units for October 14, 1988, and October 14, 1989, respectively. The 1989 ozone depletion however ended by November 5 over the Antarctic Peninsula, 10 days earlier than the 1988 event.

  20. Teleseismic SKS splitting beneath East Antarctica using broad-band stations around Soya Coast

    NASA Astrophysics Data System (ADS)

    Usui, Y.; Kanao, M.

    2006-12-01

    We observed shear wave splitting of SKS waves from digital seismographs that are recorded at 5 stations around Soya Coast in the Lutzow-Holm Bay, East Antarctica. Their recording systems are composed of a three-component broadband seismometer (CMG-40T), a digital recording unit and a solar power battery supply. The events used were selected from 1999 to 2004 and phase arrival times were calculated using the IASPEI91 earth model (Kennet, 1995). In general, we chose the data from earthquakes with m>6.0 and a distance range 85° < Δ < 130° for the most prominent SKS waves We used the methods of Silver and Chan (1991) for the inversion of anisotropy parameters and estimated the splitting parameters φ (fast polarization direction) and δt (delay time between split waves) assuming a single layer of hexagonal symmetry with a horizontal symmetry axis. The weighted averages of all splitting parameters (φ, δt) for each station are AKR (30±4, 1.30±0.2), LNG (58±6, 1.27±0.2), SKL (67±10, 0.94±0.2), SKV (40±6, 1.28±0.3) and TOT (52±8, 1.26±0.3), where the weights are inversely proportional to the standard deviations for each solution. As compared to typical delay times of SKS waves which show 1.2s (Silver and Chan 1991; Vinnik et al., 1992), the result shows generally the same value. In previous study, Kubo and Hiramatsu (1998) estimate the splitting parameter for Syowa station (SYO), where is located near our using stations in East Antarctica, and the results are (49±3, 0.70±0.1). Although it is consistent with our results for fast polarization direction, δt for our results are large relatively to those of SYO. The difference may be due to either different incident angle or more complex anisotropic structure. We found that fast polarization direction is systematically parallel to coast line in the Lutzow-Holm Bay, East Antarctica, which is consistent with NE-SW paleo compressional stress. The absolute plate motion based on the HS2-NUVEL1 (Gripp and Gordon

  1. Streaky noise in seismic normal mode band observed at Syowa Station, Antarctica

    NASA Astrophysics Data System (ADS)

    Hayakawa, H.; Shibuya, K.; Doi, K.; Aoyama, Y.

    2010-12-01

    Background free oscillations are known as continuous and global signals on noise level in seismic normal mode band. These were found from record of superconducting gravimeter (SG) at Syowa Station, Antarctica in 1998 [Nawa et al. 1998], and then were confirmed at various sites. Other unknown slightly broad spectrum peaks were also found as streak on spectrogram of Syowa SG data in seismic normal mode band. But the feature is not found in gravimeter and seismometer records from any other sites, including IDA gravimeter record at SPA station, Antarctica. New SG (SG058), that is the third generation at Syowa Station, has started to observe since January 2010. The second generation SG (CT43, 2004-2009) had strong drift. The auxiliary barometer was less resolution (0.1 hPa) and its pressure record had a lot of steps and spikes occurring frequently by housing problem. To study in seismic normal mode band, high quality pressure data is needed to remove atmospheric pressure effect to gravity from SG data because a nominal admittance factor for its effect is -3 nm/s^2/hPa. The new barometer of SG058 system has a resolution of 0.001 hPa, and the housing problem has been fixed. In this study, we investigated the unknown streaky noise in seismic normal mode band using spectrograms of the new SG and other data observed at Syowa Station. The slightly broad spectrum peaks are clearly found at 2.5, 3.5, 7.6, 8.2 13.2, 16.7 mHz from the SG data during January - May 2010. Strength of these peaks shows time variation and it is not necessarily for phase to agree with each others. These unknown peaks are not intrinsic noise of the first generation SG (TT70, 1993 - 2003) but are local or regional signal (noise) around Syowa Station. The atmospheric pressure doesn’t have this steaky feature. The sea level variation causes noise level of Syowa SG data to be high by the effect of attraction and loading [Nawa et al. 2003]. Because the noise spectral peaks less than 3 mHz are removed by

  2. Distribution of ice thickness and subglacial topography of the "Chinese Wall" around Kunlun Station, East Antarctica

    NASA Astrophysics Data System (ADS)

    Cui, Xiang-Bin; Sun, Bo; Su, Xiao-Gang; Guo, Jing-Xue

    2016-03-01

    As fundamental parameters of the Antarctic Ice Sheet, ice thickness and subglacial topography are critical factors for studying the basal conditions and mass balance in Antarctica. During CHINARE 24 (the 24th Chinese National Antarctic Research Expedition, 2007/08), the research team used a deep ice-penetrating radar system to measure the ice thickness and subglacial topography of the "Chinese Wall" around Kunlun Station, East Antarctica. Preliminary results show that the ice thickness varies mostly from 1600 m to 2800 m along the "Chinese Wall", with the thickest ice being 3444 m, and the thinnest ice 1255 m. The average bedrock elevation is 1722 m, while the minimum is just 604 m. Compared with the northern side of the ice divide, the ice thickness is a little greater and the subglacial topography lower on the southern side, which is also characterized by four deep valleys. We found no basal freeze-on ice in the Gamburtsev Subglacial Mountains area, subglacial lakes, or water bodies along the "Chinese Wall". Ice thickness and subglacial topography data extracted from the Bedmap 2 database along the "Chinese Wall" are consistent with our results, but their resolution and accuracy are very limited in areas where the bedrock fluctuates intensely. The distribution of ice thickness and subglacial topography detected by ice-penetrating radar clarifies the features of the ice sheet in this "inaccessible" region. These results will help to advance the study of ice sheet dynamics and the determination of future locations of the GSM's geological and deep ice core drilling sites in the Dome A region.

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

    SciTech Connect

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

    1997-01-01

    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.

  4. AIRS Observations of DomeC in Antarctica and Comparison with Automated Weather Stations (AWS)

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, Dave; Broberg, Steve

    2006-01-01

    We compare the surface temperatures at Dome Concordia (DomeC) deduced from AIRS data and two Automatic Weather Stations at Concordia Station: AWS8989 , which has been in operation since December 1996, and AWS.it, for which data are available between January and November 2005. The AWS8989 readings are on average 3 K warmer than the AWS.it readings, with a warmer bias in the Antarctic summer than in the winter season. Although AIRS measures the skin brightness temperature, while the AWS reports the temperature of the air at 3 meter above the surface, the AIRS measurements agree well with the AWS.it readings for all data and separately for the summer and winter seasons, if data taken in the presence of strong surface inversions are filtered out. This can be done by deducing the vertical temperature gradient above the surface directly from the AIRS temperature sounding channels or indirectly by noting that extreme vertical gradients near the surface are unlikely if the wind speed is more than a few meters per second. Since the AIRS measurements are very well calibrated, the agreement with AWS.it is very encouraging. The warmer readings of AWS8989 are likely due to thermal contamination of the AWS8989 site by the increasing activity at Concordia Station. Data from an AWS.it quality station could be used for the evaluation of radiometric accuracy and stability of polar orbiting sounders at low temperatures. Unfortunately, data from AWS.it was available only for a limited time. The thermal contamination of the AWS8989 data makes long-term trends deduced from AWS8989 and possibly results about the rapid Antarctic warming deduced from other research stations on Antarctica suspect. AIRS is the first hyperspectral infrared sounder designed in support of weather forecasting and climate research. It was launched in May 2002 on the EOS Aqua spacecraft into a 704 km altitude polar sun-synchronous orbit. The lifetime of AIRS, estimated before launch to be at least 5 years is

  5. Application of a quantitative histological health index for Antarctic rock cod (Trematomus bernacchii) from Davis Station, East Antarctica.

    PubMed

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

    2015-08-01

    A quantitative Histological Health Index (HHI) was applied to Antarctic rock cod (Trematomus bernacchii) using gill, liver, spleen, kidney and gonad to assess the impact of wastewater effluent from Davis Station, East Antarctica. A total of 120 fish were collected from 6 sites in the Prydz Bay region of East Antarctica at varying distances from the wastewater outfall. The HHI revealed a greater severity of alteration in fish at the wastewater outfall, which decreased stepwise with distance. Gill and liver displayed the greatest severity of alteration in fish occurring in close proximity to the wastewater outfall, showing severe and pronounced alteration respectively. Findings of the HHI add to a growing weight of evidence indicating that the current level of wastewater treatment at Davis Station is insufficient to prevent impact to the surrounding environment. The HHI for T. bernacchii developed in this study is recommended as a useful risk assessment tool for assessing in situ, sub-lethal impacts from station-derived contamination in coastal regions throughout Antarctica. PMID:26070020

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2001-10-01

    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

  8. Stratospheric ClO profiles from McMurdo Station, Antarctica, spring 1992

    NASA Technical Reports Server (NTRS)

    Emmons, L. K.; Shindell, D. T.; Reeves, J. M.; De Zafra, R. L.

    1995-01-01

    We 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 NO2. 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.

  9. Stratospheric ClO profiles from McMurdo Station, Antarctica, spring 1992

    SciTech Connect

    Emmons, L.K.; Shindell, D.T.; Reeves, J.M.

    1995-02-20

    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.

  10. Results of TSP metals monitoring at McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1994-04-01

    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.

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

    SciTech Connect

    Johnson, B.J.; Deshler, T.; Rozier, W.R. )

    1994-02-15

    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.

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

    NASA Technical Reports Server (NTRS)

    Deshler, Terry; Hofmann, David J.

    1994-01-01

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

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

    SciTech Connect

    Barry, J.P.

    1995-09-01

    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.

  14. Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica.

    PubMed

    Corbett, Patricia A; King, Catherine K; Stark, Jonathan S; Mondon, Julie A

    2014-10-15

    During the 2009/2010 summer, a comprehensive environmental impact assessment (EIA) of the wastewater discharge at Davis Station, East Antarctica was completed. As part of this, histological alteration of gill and liver tissue in Antarctic Rock-cod (Trematomus bernacchii) from four sites along a spatial gradient from the wastewater outfall were assessed. All fish within 800 m of the outfall exhibited significant histological changes in both tissues. Common pathologies observed in fish closest to the outfall include proliferation of epithelial cells with associated secondary lamellar fusion in the gills and multifocal granulomata with inflammation and necrosis as well as cysts in the liver. Fish from sites >800 m from the outfall also exhibited alterations but to a lesser degree, with prevalence and severity decreasing with increasing distance from the outfall. This study highlights the value of histopathological investigations as part of EIAs and provides the first evidence of sub-lethal alteration associated with wastewater discharge in East Antarctica. PMID:25173596

  15. Impact of human activities on the geomagnetic field of Antarctica: a high resolution aeromagnetic survey over Mario Zucchelli Station.

    PubMed

    Armadillo, E; Bozzo, E; Gambetta, M; Rizzello, D

    2012-10-15

    Environmental protection of Antarctica is a fundamental principle of the Antarctic Treaty. Impact assessment and significance evaluation are due for every human activity on the remote continent. While chemical and biological contaminations are widely studied, very little is known about the electromagnetic pollution levels. In this frame, we have evaluated the significance of the impact of Mario Zucchelli Antarctic Station (Northern Victoria Land) on the local geomagnetic field. We have flown a high resolution aeromagnetic survey in drape mode at 320m over the Station, covering an area of 2km(2). The regional and the local field have been separated by a third order polynomial fitting. After the identification of the anthropic magnetic anomaly due to the Station, we have estimated the magnetic field at the ground level by downward continuation with an original inversion scheme regularized by a minimum gradient support functional to avoid high frequency noise effects. The resulting anthropic static magnetic field at ground extends up to 650m far from the Station and reaches a maximum peak to peak value of about 2800nT. This anthropic magnetic anomaly may interact with biological systems, raising the necessity to evaluate the significance of the static magnetic impact of human installations in order to protect the electromagnetic environment and the biota of Antarctica. PMID:22706521

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

    NASA Astrophysics Data System (ADS)

    Ogawa, T.

    1996-12-01

    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-->

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

    SciTech Connect

    Kondo, Y.; Matthews, W.A.; Solomon, S.; Koike, M.; Hayashi, M.; Yamazaki, K.; Nakajima, H.; Tsukui, K. |||

    1994-07-01

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

  18. Meteorological profiles comparison from global models and experimental radiosoundings at the Antarctica station of Belgrano

    NASA Astrophysics Data System (ADS)

    Adame, J. A.; Yela, M.; Parrondo, M. C.; Ochoa, H.; Gil, M.

    2012-04-01

    Ozonesoundings are launched from Antarctic Belgrano station (77.87S, 34.62W) since 1999 in the framework of an extensive stratospheric trace-gas measurement program. In the frame of VIOLIN (Extended Vertical Investigation of the Ozone Layer In ANtarctica) project and as a previous step in the application of meteorological models, a comparison-validation exercise has been carried out using simulations and experimental profiles. The aim is to assess the reliability of the meteorological files obtained from global models which could be used as input data in models of higher spatial resolution. Meteorological profiles (potential temperature, relative humidity, wind speed and direction) have been obtained from ECMWF and NCEP-GDAS models with a spatial resolution of 1°x1° and 14 vertical levels from 950 to 500 mb. The simulated profiles have been compared with in situ soundings at Belgrano. A total of 83 soundings covering the period from 2009 to 2010 have been used. Data have been grouped in three period's: diurnal, nocturnal and transition diurnal-nocturnal or vice versa. The comparison has been performed with the statistical root mean square deviation (RMSD) and BIAS for the four meteorological variables. Results show that potential temperature using both models and wind speed with NCEP-GDAS are underestimated while the rest of parameters are overestimated. The RMSD of the potential temperature ranges between 1.7 and 3.2 °C with a BIAS of -0.18 to -0.74 °C. No differences were found according to the time of the year. The relative humidity analysis shows a RMSD between 21.4 and 30.2 % while the BIAS was ranging from 9.9 to 14.8 %. Best results have been obtained in the transition period. For the wind speed the RMSD oscillate between 2.9 and 4.9 m/s with a BIAS from -0.35 to 0.31 m/s. The wind direction is the parameter with the highest differences, RMSD between 68 and 104°, with a BIAS from 34 to 62°. The highest differences have been found for the diurnal period

  19. Twenty Years of Ozone Profile Measurements Above McMurdo Station, Antarctica During Austral Spring

    NASA Astrophysics Data System (ADS)

    Mercer, J. L.; Deshler, T.; Kroger, C.; Nardi, B.; Johnson, B. J.

    2005-12-01

    Balloon-borne ozonesonde measurements from 0 to ~35 km above McMurdo Station, Antarctica (78°S) have provided vertical profiles of the development of the ozone hole between late August and late October each year since 1986. Here, we present the twenty-year history of these measurements and discuss long-term trends occurring in the periods prior to the onset of major ozone loss and during major depletion. In late August, prior to significant ozone loss, column ozone averaged ~250 DU from 1986 to 1998, dropped below 230 DU from 1999-2001, and has stayed above 250 DU since 2002. During the same period, column ozone minima as well as ozone between 12-20 km, the region of maximum loss, show a similar trend. During the period of major depletion above McMurdo (15 Sept-15 Oct), maximums, minimums and averages of total and 12-20 km column ozone show a steady decline from 1986 until the mid-1990s. Record minimums were observed in 1993, two years after the eruption of Pinatubo, and again in 2001. In the 12-20 km region, minima reached zero in the mid 1990s. The thickness of the region of complete ozone destruction grew from 4 km, in 1995-1997, to over 6 km, in 1998-2001, and persisted for over a week, suggesting a vortex-wide feature. These observations are consistent with predictions and observations of peaking halogen abundance in the lower stratosphere around 2000. Similarly large ozone depletion was thus expected for another five years with a slow decline thereafter. Ozonesonde measurements in 2003 and 2004, however, do not support this. Averages of total and 12-20 km column ozone in late August and between 15 September-15 October show less depletion than in the late 1990s, and are approaching values observed in the early 1990s. The cause of this lessening in ozone loss during the last few years is puzzling. Is it a result of extended anomalous stratospheric dynamics, or indicative of a larger scale trend? These observations, including the 2005 measurements (currently in

  20. 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

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

    SciTech Connect

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

    2014-09-01

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

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

    SciTech Connect

    Barry, J.P.

    1994-08-01

    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.

  3. Climatology of clouds and precipitation over East Antarctica using ground-based remote sensing at the Princess Elizabeth station

    NASA Astrophysics Data System (ADS)

    Souverijns, Niels; Gossart, Alexandra; Gorodetskaya, Irina; Lhermitte, Stef; Van Tricht, Kristof; Mangold, Alexander; Laffineur, Quentin; Van Lipzig, Nicole

    2016-04-01

    The surface mass balance of the Antarctic ice sheet is highly dependent on the interaction between clouds and precipitation. Our understanding of these processes is challenged by the limited availability of observations over the area and problems in Antarctic climate simulations by state-of-the-art climate models. Improvements are needed in this field, as the Antarctic ice sheet is expected to become a dominant contributor to sea level rise in the 21st century. In 2010, an observational site was established at the Princess Elisabeth (PE) Antarctic station. PE is located in the escarpment area of Dronning Maud Land, East Antarctica (72°S, 23°E). The instruments consist of several ground-based remote sensing instruments: a ceilometer (measuring cloud-base height and vertical structure), a 24-GHz Micro Rain Radar (MRR; providing vertical profiles of radar effective reflectivity and Doppler velocity), and a pyrometer (measuring effective cloud base temperature). An automatic weather station provides info on boundary-layer meteorology (temperature, wind speed and direction, humidity, pressure), as well as broadband radiative fluxes and snow height changes. This set of instruments can be used to infer the role of clouds in the Antarctic climate system, their interaction with radiation and their impact on precipitation. Cloud and precipitation characteristics are derived from 5-year-long measurement series, which is unprecedented for the Antarctic region. Here, we present an overview of the cloud and precipitation climatology. Statistics on cloud occurrence are calculated on annual / seasonal basis and a distinction between liquid / mixed phase and ice clouds is made. One can discriminate between liquid-bearing and ice-only clouds by investigating the ceilometer attenuated backscatter, since liquid phase clouds have a much higher signal. Furthermore, by using pyrometer measurements, we are able to identify the range of temperatures at which liquid / ice clouds are

  4. Spatial and temporal variability of marine-origin matter along a transect from Zhongshan Station to Dome A, Eastern Antarctica.

    PubMed

    Li, Chuanjin; Xiao, Cunde; Shi, Guitao; Ding, Minghu; Qin, Dahe; Ren, Jiawen

    2016-08-01

    The spatiotemporal distribution pattern of marine-origin matter on the Antarctica ice sheet was used to study variations in the source regions, transport mechanisms and post-depositional influences. We present data on sea salt ions, sulfur components and stable isotopes from surface and snow pit samples collected along the transect route from Zhongshan Station to Dome A during the austral summer in 2012-2013. A general decreasing trend in the accumulation, sea salt ions and sulfur components occurred with increasing distance from the coast and increasing elevation. However, different sources of the marine components, transport pathways and post-depositional influences were responsible for their different spatial distribution patterns. The marine ions in the coastal snow pit varied seasonally, with higher sea salt ion concentrations in the winter and lower concentrations in the summer; the opposite pattern was found for the sulfur compounds. The sea ice area surrounding Antarctica was the main source region for the deposited sea salt and the open sea water for the sulfur compounds. No significant trends in the marine-origin components were detected during the past 3 decades. Several periods of elevated deposition of sea salt ions were associated with lower temperatures (based on δD and δ(18)O) or intensified wind fields. In comparison to the sea salt ions, the sulfur concentrations exhibited the opposite distribution patterns and were associated with changes in the surrounding sea ice extent. PMID:27521951

  5. Simulation of Ophthalmic Alterations at the Arctic, Antarctica and the International Space Station for Long-Duration Spaceflight

    NASA Astrophysics Data System (ADS)

    De Morais Mendonca Teles, Antonio; Gonçalves, Cristiane

    2016-07-01

    Well, we propose a series of long-period medical simulations in scientific bases at the Arctic, at Antarctica and aboard the International Space Station (ISS), involving natural ophthalmic diseases such as radiation, solar and trauma retinopathy, keratoconus, cataract, glaucoma, etc., and ophthalmic alterations by accidental injuries. These natural diseases, without a previous diagnosis, specially those specific retinopathy, appear after 1 month to 1.5 year, in average. Such studies will be valuable for the human deep-space exploration because during long-duration spaceflight, such as staying at the ISS, a Moon base and a manned trip to planet Mars, requires several months within such environments, and during such periods ophthalmic diseases and accidents might eventually occur, which could seriously affect the 'round-the-clock' work schedule of the astronauts and the long-duration spaceflight manned program.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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).

  7. Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica. 6. Observations of BrO

    SciTech Connect

    Carroll, M.A.; Solomon, S.; Schmeltekopf, A.L. ); Sanders, R.W. )

    1989-11-30

    Observations of the evening twilight BrO abundance over McMurdo Station, Antarctica during austral spring, 1987, are described. The observed variation of the slant column abundance with increasing solar zenith angles suggests that most of the BrO is located near 15 km. The total vertical column abundance observed during 1 week of measurements yielded an average value of 2.5 {times} 10{sup 13} cm{sup {minus}2}, assuming the room temperature absorption cross sections measured by Cox et al. (1982). These values are consistent with BrO mixing ratios of about 5-15 parts per trillion by volume distributed from 150 to 20 mbar. If the differential absorption cross section of BrO increases by 30% at temperatures characteristic of the Antarctic lower stratosphere, as indicated by Sander and Watson (1981), then the BrO measurements reported in this paper should be decreased by 30%.

  8. Ozone over McMurdo Station, Antarctica, austral spring 1986 - Altitude profiles for the middle and upper stratosphere

    NASA Technical Reports Server (NTRS)

    Connor, Brian J.; Barrett, J. W.; Parrish, A.; Solomon, P. M.; De Zafra, R. L.

    1987-01-01

    In the austral spring of 1986, a program of measurements of the ozone altitude profile (for the z values between 25 and 55 km), relevant to an understanding of the ozone hole, was conducted at McMurdo Station, Antarctica. The measurements were performed using ground-based millimeter-wave spectrometry. It was found that the ozone mixing ratio peaked at altitudes ranging from 28 to 34 km, with peak values between 5 and 9 ppm by volume. During the period between September 12 and October 29, the ozone mixing ratio decreased, with great variability, by about 15 percent at 25 km, with no significant decrease at higher altitudes. The observation of the depletion occurring only below 25 km is consistent with ozone-sonde observations during previous years.

  9. 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)

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

    1994-01-01

    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).

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

    SciTech Connect

    1995-05-01

    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.

  11. Aerosol and CCN properties at Princess Elisabeth station, East Antarctica: seasonality, new particle formation events and properties around precipitation events

    NASA Astrophysics Data System (ADS)

    Mangold, Alexander; Laffineur, Quentin; De Backer, Hugo; Herenz, Paul; Wex, Heike; Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina; Van Lipzig, Nicole

    2016-04-01

    Since 2010, several complementary ground-based instruments for measuring the aerosol composition of the Antarctic atmosphere have been operated at the Belgian Antarctic research station Princess Elisabeth, in Dronning Maud Land, East Antarctica (71.95° S, 23.35° E, 1390 m asl.). In addition, three ground-based remote sensing instruments for cloud and precipitation observations have been installed for continuous operation, including a ceilometer (cloud base height, type, vertical extent), a 24 Ghz micro-rain radar (vertical profiles of radar effective reflectivity and Doppler velocity), and a pyrometer (cloud base temperature). The station is inhabited from November to end of February and operates under remote control during the other months. In this contribution, the general aerosol and cloud condensation nuclei (CCN) properties will be described with a special focus on new particle formation events and around precipitation events. New particle formation events are important for the atmospheric aerosol budget and they also show that aerosols are not only transported to Antarctica but are also produced there, also inland. Aerosols are essential for cloud formation and therefore also for precipitation, which is the only source for mass gain of the Antarctic ice sheet. Measured aerosol properties comprise size distribution, total number, total mass concentration, mass concentration of light-absorbing aerosol and absorption coefficient and total scattering coefficient. In addition, a CCN counter has been operated during austral summers 2013/14, 2014/15 and 2015/16. The baseline total number concentration N-total was around some hundreds of particles/cm3. During new particle formation events N-total increased to some thousands of particles/cm3. Simultaneous measurements of N-total, size distribution and CCN number revealed that mostly the number of particles smaller than 100 nm increased and that the concentration of cloud condensation nuclei increased only very

  12. Sounding rockets in Antarctica

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

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

    SciTech Connect

    Lugar, R.M.; Harles, R.L.

    1996-02-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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

  15. An analysis of strong wind events simulated in a GCM near Casey in the Antarctic

    SciTech Connect

    Murphy, B.F.; Simmonds, I. )

    1993-02-01

    Strong wind events occurring near Casey (Antarctica) in a long July GCM simulation have been studied to determine the relative roles played by the synoptic situation and the katabatic flow in producing these episodes. It has been found that the events are associated with strong katabatic and strong gradient flow operating together. Both components are found to increase threefold on average for these strong winds, and although the geostrophic flow is the stronger, it rarely produces strong winds without katabatic flow becoming stronger than it is in the mean. The two wind components do not flow in the same direction; indeed, there is some cancellation between them, since katabatic flow acts in a predominant downslope direction, while the geostrophic wind acts across slope. The stronger geostrophic flow is associated with higher-than-average pressures over the continent and the approach of a strong cyclonic system toward the coast and a blocking system downstream. The anomalous synoptic patterns leading up to the occasions display a strong wavenumber 4 structure. The very strong katabatic flow appears to be related to the production of a supply of cold air inland from Casey by the stronger-than-average surface temperature inversions inland a few days before the strong winds occur. The acceleration of this negatively buoyant air mass down the steep, ice-sheet escarpment results in strong katabatic flow near the coast. 24 refs., 11 figs.

  16. Physico-chemical characterization of total suspended particulate matter over two coastal stations of Antarctica and adjoining ocean

    NASA Astrophysics Data System (ADS)

    Ali, Kaushar; Trivedi, D. K.; Sahu, Saroj

    2015-12-01

    Physical and chemical characteristics of the total suspended particulate matter (TSPM) measured during 11 January-21 March, 2009 and 09 December 2009-09 January, 2010 over two stations of Antarctica (Larsemann Hills and Maitri) and adjoining ocean are investigated. It is found that the concentration of TSPM is low over all the observational locations. Day-to-day variation in the concentration of TSPM is mainly controlled by variation in the weather systems and associated meteorological parameters. Average concentration of TSPM over Larsemann Hills is 7.6 μg/m3 during Jan-Mar 2009 and 2.4 μg/m3 during Dec. 2009-Jan 2010. It is 9.0 μg/m3 over Maitri during Jan-Mar 2009. On excluding the TSPM data of the disturbed weather days during Jan-Mar 2009, the concentration of TSPM is found to be 4.2 μg/m3 over Larsemann Hills and 4.3 μg/m3 over Maitri. The TSPM at all the observational locations is acidic in nature with a maximum pH value of 5.56 at Larsemann Hills. The pH value of TSPM over Maitri is found to be 5.28. The acidic nature of TSPM indicates the absence of sufficient neutralizing alkaline minerals. Among the measured chemical anions Cl- dominates at all the locations except at Maitri where SO42- ion shows maximum concentration. The dominant cation is Na+ at all the observational stations. Sizeable fraction of SO42-/SUP is found at all the observational locations. Abundance of SO42 in the atmosphere of Antarctica and its surrounding region is mainly due to emission of dimethylsulfide (DMS) phytoplankton and its oxidation finally to SO42- particles by gas-to-particle conversion. The highest concentration of SO42- over Maitri is attributed to the contribution from anthropogenic activity at Maitri, in addition to the biogenic SO42-. NH4+ plays dominant role in neutralizing the acidic components of the aerosols.

  17. A methodology study to define pathways and heights to calculate backtrajectories at near coastal Continental Antarctica station (Belgrano)

    NASA Astrophysics Data System (ADS)

    Adame, J. A.; Yela, M.; Navarro, M.; Parrondo, M. C.; Gil, M.

    2012-04-01

    Within the framework of the VIOLIN (Extended Vertical Investigation of the Ozone Layer In ANtarctica) project, different atmospheric components are measured in the Antarctica station of Belgrano (77.87S, 34.62W) such as surface ozone. In order to investigate the origin of the observed chemical species, a study to identify the features and variability of air masses impacting the area has been carried out. The pathways of the air masses are determined through back trajectories calculated with the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model. As a first step of this study it is necessary to define duration and heights for which the back trajectories will be obtained. The NCEP-GDAS meteorological data with a 1°x1° spatial resolution and 14 vertical levels from surface to 500 mb have been used as input. The years 2009 and 2010 have been used to perform this study which will be expanded in the future. To determinate the optimal duration of the back trajectories daily back trajectories starting at 12:00 UTC for starting altitudes of 500 and 1500 m, with durations of 120, 168, 240 and 360 hours. A cluster methodology has been used to group the back trajectories. An optimal cluster number between 4 and 6 has been obtained. The back trajectories corresponding to 120 and 168 hours show pathways covering half of the Antarctic continent while the ones obtained with 240 and 360 hours travel across all continent. The back trajectories lasting168 hours have been selected as optimal. To study optimum heights and using duration of 168 hours we calculated daily back trajectories starting at 100, 500, 1000, 1500, 2000, 2500, 3000, 3500, and 4000 m. The typologies and path of air masses increase with height. The results obtained in this work identify five groups that represent the lowest 4000 m which are the back trajectories of 100, 500, 1000-1500, 2000-2500 and 3500-4000 m. As conclusion, to perform a study of air masses origin in Belgrano which will help

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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, α- and γ-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).

  19. Dispersal and dilution of wastewater from an ocean outfall at Davis Station, Antarctica, and resulting environmental contamination.

    PubMed

    Stark, Jonathan S; Bridgen, Phil; Dunshea, Glenn; Galton-Fenzi, Ben; Hunter, John; Johnstone, Glenn; King, Catherine; Leeming, Rhys; Palmer, Anne; Smith, James; Snape, Ian; Stark, Scott; Riddle, Martin

    2016-06-01

    The Antarctic Treaty permits the discharge of wastewater into Antarctic marine waters providing that conditions exist for initial dilution and rapid dispersal. We investigated the dilution and dispersal of macerated wastewater around Australia's Davis Station in East Antarctica and examined sediments for evidence of contaminants. Methods used to examine hydrodynamic conditions included current meters, dye release experiments and measurement of sewage-associated microbial markers and surfactants in the water column. We measured marine sediments for metals, nutrients, PBDEs, hydrocarbons and faecal sterols. We propose that if there is adequate dilution and dispersal there would be no significant difference in contaminant concentrations in sediments around the outfall compared to distant control sites. Currents were strongly correlated with prevailing wind conditions. Modelling indicated that diffusivity of wastewater had the greatest effect on dilution factors and that neither discharge rates nor local currents had as much effect. During summer conditions of open water, wastewater is likely to be constrained in a narrow plume close to the coast. Concentrations of sewage bacteria were high around the outfall and detected up to 1.5 km away, along with dye. There were significant differences in sediment concentrations of metals, PBDEs, hydrocarbons, nutrients and faecal sterols between sites within 2 km of the outfall and control sites. We conclude that dilution and dispersal conditions at the Davis outfall are insufficient to prevent the accumulation of contaminants in local sediments and that microbial hazards posed by wastewater are an environmental risk to local wildlife. PMID:26966813

  20. Calibration and Validation of Airborne LiDAR at McMurdo Station, Antarctica for Operation IceBridge

    NASA Astrophysics Data System (ADS)

    Sonntag, J. G.

    2014-12-01

    Airborne LiDAR flight operations based at McMurdo Station, Antarctica, present unusual challenges for calibrating and validating the sensor measurements at the level of a few centimeters. NASA's Airborne Topographic Mapper (ATM) team prefers to perform regular, near-daily calibrations of range and angular biases of our sensor for the lengthy field deployments typical for Operation IceBridge (OIB). For the fall 2013 OIB deployment to McMurdo, we had to adapt our usual technique of regular overflights of an independently-surveyed airport parking ramp to deal with the fact that the McMurdo airfield was located on tidally-influenced sea ice, and that very few nearby durable surfaces were free of variable-depth snow during the OIB deployment. We detail our approach for dealing with these challenges, which included multiple GPS/vehicle surveys of the sea ice runway to quantify surface changes due to grooming operations, combined with GPS tide-gauge measurements of the runway's tidal motion. We also conducted a remote GPS/vehicle survey of a mostly snow-free road on Black Island, and included both sites during near-daily overflights with the ATM. We discuss the quantitative results of these surveys and the associated ATM overflights, and present conclusions for future deployments. Finally we discuss a related validation effort in which we compare ATM results from overflights of snow-free areas in the Dry Valleys with ATM surveys of the same area from a 2001 effort there.

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

    SciTech Connect

    Johnson, B.J.; Deshler, T.; Zhao, R.

    1995-02-01

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

  2. Influence of cloud fraction and snow cover to the variation of surface UV radiation at King Sejong station, Antarctica

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Koo, Ja-Ho; Kim, Jhoon

    2015-10-01

    This study investigated how cloud fraction and snow cover affect the variation of surface ultraviolet (UV) radiation by using surface Erythemal UV (EUV) and Near UV (NUV) observed at the King Sejong Station, Antarctica. First the Radiative Amplification Factor (RAF), the relative change of surface EUV according to the total-column ozone amount, is compared for different cloud fractions and solar zenith angles (SZAs). Generally, all cloudy conditions show that the increase of RAF as SZA becomes larger, showing the larger effects of vertical columnar ozone. For given SZA cases, the EUV transmission through mean cloud layer gradually decreases as cloud fraction increases, but sometimes the maximum of surface EUV appears under partly cloudy conditions. The high surface EUV transmittance under broken cloud conditions seems due to the re-radiation of scattered EUV by cloud particles. NUV transmission through mean cloud layer also decreases as cloud amount increases but the sensitivity to the cloud fraction is larger than EUV. Both EUV and NUV radiations at the surface are also enhanced by the snow cover, and their enhancement becomes higher as SZA increases implying the diurnal variation of surface albedo. This effect of snow cover seems large under the overcast sky because of the stronger interaction between snow surface and cloudy sky.

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

    NASA Astrophysics Data System (ADS)

    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

    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

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

    PubMed

    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

    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

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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

    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

  7. Balloon-borne observations of lower stratospheric water vapor at Syowa Station, Antarctica in 2013

    NASA Astrophysics Data System (ADS)

    Tomikawa, Yoshihiro; Sato, Kaoru; Hirasawa, Naohiko; Tsutsumi, Masaki; Nakamura, Takuji

    2015-12-01

    Balloon-borne observations of lower stratospheric water vapor were conducted with the Cryogenic Frostpoint Hygrometer (CFH) in July, September, and November 2013 at Syowa Station (69.0oS, 39.6oE) in the Antarctic. High-precision and high vertical resolution data of water vapor concentration up to an altitude of about 28 km were obtained successfully except for a contamination in the observation of July 2013. A comparison between the CFH and coincident satellite (i.e., Aura/MLS) observations showed a good agreement within their uncertainty. A position of Syowa Station relative to the stratospheric polar vortex edge varied depending on both the observation date and altitude. Temperature and pressure histories of the observed air parcels were examined by 10-day backward trajectories. These analyses clearly demonstrated that most air parcels observed in the lower stratosphere above Syowa Station experienced final dehydration inside the polar vortex. On the other hand, a clear signature of rehydration or incomplete dehydration was also observed around a 25 hPa pressure level in the observation of July 2013.

  8. The ultraviolet radiation environment of Antarctica - McMurdo Station during September-October 1987

    NASA Technical Reports Server (NTRS)

    Lubin, Dan; Frederick, John E.; Krueger, Arlin J.

    1989-01-01

    Daily data from the Nimbus-7 TOMS were combined with a model of atmospheric radiative transfer to compute the time evolution of ultraviolet irradiance, at wavelengths from 290 to 350 nm, incident on McMurdo Station during September-October 1987. Large changes in column ozone occur as the polar vortex moves over the site. This is accompanied by correspondingly large variations in UV radiation at the earth's surface. At a wavelength near 305 nm, the irradiance in early October exceeds values appropriate to an unperturbed ozone layer by a factor of 5-6. As December 21 approaches, the noontime UV irradiance increases, irrespective of changes in ozone.

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

    NASA Astrophysics Data System (ADS)

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

    1998-08-01

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

  10. Characteristics of immersion freezing nuclei at the South Pole station in Antarctica

    NASA Astrophysics Data System (ADS)

    Ardon-Dryer, K.; Levin, Z.; Lawson, R. P.

    2011-04-01

    The effectiveness of aerosols as immersion freezing nuclei at the South Pole station was investigated during January and February 2009 using the FRIDGE-TAU. The analysis consisted of testing the freezing temperature of about 100-130 drops per sample containing aerosols collected at ground level and on a balloon lifted to different heights. All the drops froze between -18 °C and -27 °C. The temperature in which 50 % of the drops froze occurred at -24 °C, while nuclei concentration of 1 L-1 at -23 °C was calculated. Meteorological conditions such as wind speed, ice precipitation as well as the trajectories of the air masses affected the ice nuclei concentrations. Higher concentrations were observed on days when the winds were stronger or when the air mass originated from the sea.

  11. Characteristics of immersion freezing nuclei at the south pole station in Antarctica

    NASA Astrophysics Data System (ADS)

    Ardon-Dryer, K.; Levin, Z.; Lawson, R. P.

    2011-01-01

    The effectiveness of aerosols as immersion freezing nuclei at the South Pole station was investigated during January and February 2009 using the FRIDGE-TAU. The analysis consisted of testing the freezing temperature of about 100-130 drops per sample containing aerosols collected at ground level and on a balloon lifted to different heights. All the drops froze between -18 °C and -27 °C. The temperature in which 50% of the drops froze occurred at -24 °C, while nuclei concentration of 1 L-1 at -22 °C was calculated. Meteorological conditions such as wind speed, ice precipitation as well as the trajectories of the air masses affected the ice nuclei concentrations. Higher concentrations were observed on days when the winds were stronger or when the air mass originated from the sea.

  12. Results of SO{sub 2}, NO{sub x}, and CO monitoring at McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1993-05-01

    This report presents the results of ambient air monitoring of carbon monoxide (CO), sulfur dioxide (SO{sub 2}), nitric oxide (NO), nitrogen dioxide (NO{sub 2}), and total oxides of nitrogen (NO{sub x}) performed during the final weeks of the 1992-1993 austral summer in the vicinity of McMurdo Station, Antarctica. Commercially available, high sensitivity ambient air gas analyzers were used to continuously measure gas concentrations at two locations over a two and a three week time period respectively. Sampling site selection, sampling procedures and quality assurance procedures used for this effort were consistent with U.S. Environmental Protection Agency guidelines for local ambient air quality networks. CO, SO{sub 2}, and NO{sub 2} concentrations measured were below the associated U.S. National Ambient Air Quality Standards. Carbon monoxide levels measured at both locations were near or below the instrument detection limit of 0.1 part per million (ppm). Hourly average SO{sub 2} concentrations ranged from below the detection limit of 1 part per billion (ppb) to a single maximum hourly average value of 60 ppb. Hourly average NO{sub 2} concentrations ranged from below the detection limit of 1 ppb to a single maximum hourly average value of 26 ppb. The impact on local air quality of ships docked at an ice pier was observed and quantified. The initial baseline effort demonstrated that site selection and sampling equipment performance were satisfactory, and provided useful data for assessing the impact of McMurdo operations on the local ambient air quality.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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).

  14. Nitrogen Dioxide Total Column Over Terra Nova Bay Station - Antarctica - During 2001

    NASA Astrophysics Data System (ADS)

    Bortoli, D.; Ravegnani, F.; Giovanelli, G.; Petritoli, A.; Kostadinov, I.

    GASCOD (Gas Analyzer Spectrometer Correlating Optical Differences), installed at the Italian Antarctic Station of Terra Nova Bay (TNB) - 74.69S, 164.12E - since 1995, carried out a full dataset of zenith scattered light measurements for the year 2001. The application of DOAS methodology to the collected data gave as final results, the slant column values for nitrogen dioxide. The seasonal variation shows a maxi- mum in the summer and it is in good agreement with the results obtained by other authors. The data analysis is performed by using different parameters like the po- tential vorticity (PV) at 500 K and the atmospheric temperatures at the same level. After the verification of the linear dependency between the NO2 slant column values and the temperature of NO2 cross section utilized in the DOAS algorithm, the actual stratospheric temperatures (from ECMWF) over TNB are applied to the results. The sensible changes in the nitrogen dioxide slant column values allow to highlight the good matching between the NO2 AM/PM ratio and the potential vorticity at 500 K. The NO2 slant column values follow the variations of the stratospheric temperature mainly during the spring season, when the lowest temperatures are observed and the ozone-hole phenomena mainly occur. ACKNOWLEDGMENTS: The author Daniele Bortoli was financially supported by the "Subprograma Ciência e Tecnologia do Ter- ceiro Quadro Comunitário de Apoio". The National Program for Antarctic Research (PNRA) supported this research.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

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

    SciTech Connect

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

    1989-11-30

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  19. Ice thickness, internal layers, and surface and subglacial topography in the vicinity of Chinese Antarctic Taishan station in Princess Elizabeth Land, East Antarctica

    NASA Astrophysics Data System (ADS)

    Tang, Xue-Yuan; Guo, Jing-Xue; Sun, Bo; Wang, Tian-Tian; Cui, Xiang-Bin

    2016-03-01

    We present the results of two ground-based radio-echo-sounding (RES) and GPS surveys performed in the vicinity of new Chinese Taishan station, Princess Elizabeth Land, East Antarctica, obtained in two austral summers during CHINARE 21 (2004/2005) and CHINARE 29 (2012/2013). The radar surveys measured ice thickness and internal layers using 60- and 150-MHz radar systems, and GPS measurements showed smooth surface slopes around the station with altitudes of 2607-2636 m above sea level (a.s.l.). Radar profiles indicate an average ice thickness of 1900 m, with a maximum of 1949 m and a minimum of 1856 m, within a square area measuring approximately 2 km × 2 km in the vicinity of the station. The ice thickness beneath the station site is 1870 m. The subglacial landscape beneath the station is quiet sharp and ranges from 662 to 770 m a.s.l., revealing part of a mountainous topography. The ice volume in the grid is estimated to be 7.6 km3. Along a 60-MHz radar profile with a length of 17.6 km at the region covering the station site, some disturbed internal layers are identified and traced; the geometry of internal layers within the englacial stratigraphy may imply a complex depositional process in the area.

  20. Autonomous Long-Path DOAS Measurements of Tropospheric Trace Gases at Neumayer Station III, Antarctica: First Results

    NASA Astrophysics Data System (ADS)

    Nasse, Jan-Marcus; Frieß, Udo; Pöhler, Denis; Weller, Rolf; Platt, Ulrich

    2016-04-01

    Reactive Halogen Species (RHS, like IO, BrO, ClO, etc.) have an important impact on atmospheric chemistry. In Polar Regions, the role of halogen radical chemistry has been subject of intensive research for more than two decades. Among the most prominent effects of RHS on the Polar atmosphere are the change of the oxidative capacity of the troposphere including wide-spread and frequently virtually complete destruction of tropospheric ozone, in particular during springtime, as well as the oxidation and subsequent deposition of gaseous elemental mercury. The number of field observations and the understanding of the underlying processes varies greatly between bromine, iodine and chlorine compounds. While elevated BrO concentrations resulting from autocatalytic processes (the so-called bromine explosion mechanism) are frequently observed, the abundance and influence of iodine is still subject to discussions and available observations give no consistent picture. With only a few direct observations of chlorine compounds, such as ClO and OClO, the role of tropospheric chlorine chemistry remains poorly understood to date, despite strong evidence for its relevance. The lack of observations of chlorine radicals is mainly due to the challenging detection, particularly in the case of ClO. Scattered sunlight DOAS measurements, which are available from a number of Polar locations, are not sensitive for ClO, due to insufficient radiation intensity in the UV spectral region (<308nm) where this molecule is absorbing. Here we present the overall design and first results of a novel Long Path DOAS (Differential Optical Absorption Spectroscopy) instrument with an active light source suitable for the detection of ClO. It has been set up at the German Research Station Neumayer III in coastal Antarctica during the summer season 2015/16 and is planned to operate autonomously for at least one year. The instrument is able to detect - in addition to ClO - many trace gases absorbing in the UV

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

    NASA Technical Reports Server (NTRS)

    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

    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.)

  2. Thermotolerance and molecular chaperone function of an SGT1-like protein from the psychrophilic yeast, Glaciozyma antarctica.

    PubMed

    Yusof, Nur Athirah; Hashim, Noor Haza Fazlin; Beddoe, Travis; Mahadi, Nor Muhammad; Illias, Rosli Md; Bakar, Farah Diba Abu; Murad, Abdul Munir Abdul

    2016-07-01

    The ability of eukaryotes to adapt to an extreme range of temperatures is critically important for survival. Although adaptation to extreme high temperatures is well understood, reflecting the action of molecular chaperones, it is unclear whether these molecules play a role in survival at extremely low temperatures. The recent genome sequencing of the yeast Glaciozyma antarctica, isolated from Antarctic sea ice near Casey Station, provides an opportunity to investigate the role of molecular chaperones in adaptation to cold temperatures. We isolated a G. antarctica homologue of small heat shock protein 20 (HSP20), GaSGT1, and observed that the GaSGT1 mRNA expression in G. antarctica was markedly increased following culture exposure at low temperatures. Additionally, we demonstrated that GaSGT1 overexpression in Escherichia coli protected these bacteria from exposure to both high and low temperatures, which are lethal for growth. The recombinant GaSGT1 retained up to 60 % of its native luciferase activity after exposure to luciferase-denaturing temperatures. These results suggest that GaSGT1 promotes cell thermotolerance and employs molecular chaperone-like activity toward temperature assaults. PMID:27154490

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

    SciTech Connect

    Johnson, B.J.; Deshler, T. )

    1993-01-01

    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.

  4. Incorporating Yoga Therapy into Primary Care: The Casey Health Institute.

    PubMed

    Ross, Alyson; Williams, Laurie; Pappas-Sandonas, Mary; Touchton-Leonard, Katharine; Fogel, David

    2015-01-01

    Individuals seek complementary and alternative medicine (CAM) for a variety of health conditions, and yoga is a popular CAM modality. Over the past few decades, yoga has become incorporated into hundreds of healthcare facilities, most commonly in large university medical centers. While research has shown yoga to be effective in reducing symptoms and improving outcomes in chronic health conditions, most patients seek yoga therapy on their own, as few primary care practitioners have incorporated yoga therapy into their practices. The purpose of this article is to describe the efforts of the Casey Health Institute to incorporate yoga therapy into their primary care integrative medicine center. At Casey Health, a full-time Clinical Yoga Specialist works alongside the physicians, nurses, and CAM providers in delivering care to a wide variety of patients. The majority of referrals to yoga therapy have been for pain-related musculoskeletal conditions, as well as hypertension, headaches, anxiety, depression, and sleep disturbances. Most patients attend weekly 60-minute individual sessions, and the Clinical Yoga Specialist stays in touch with the patient between appointments via telephone and email. T h e Clinical Yoga Specialist has become an integral part of Casey Health, participating in collaborative medical appointments in which two CAM practitioners provide simultaneous treatments to a patient. She also participates in the clinic's ongoing weight loss program. The Clinical Yoga Specialist spends one morning each week "floating" in the clinic, when she is on-call to the practitioners to assist in treatment and/or to introduce a yoga therapy experience to the patients. These brief interventions introduce the patients to the therapeutic benefits of yoga, while simultaneously demonstrating yoga's effectiveness to the healthcare providers. Casey Health has developed a unique teacher training program whose faculty includes senior Iyengar yoga teachers as well as physicians

  5. Triggering of whistler mode emissions by the band-limited impulse (BLI) Associated with amplified Vlf signals from Siple Station, Antarctica

    NASA Astrophysics Data System (ADS)

    Helliwell, Robert A.

    2000-05-01

    At termination of an amplified and saturated (Bsat) Vlf pulse from Siple Station, Antarctica, a band-limited (50-500 Hz range) impulse (BLI) is generated which in turn triggers a narrowband emission, of about the same amplitude, that starts at about 50-150 Hz above the frequency of Bsat, called the positive frequency offset (PFO). The BLI creates the PFO by reducing the parallel velocities of existing phase-bunched cyclotron resonant electrons that form the source currents (J⊥) of the stimulated radiation. The PFO is proportional to the magnetic field intensity BBLI of the BLI. Since BBLI ≈ Bsat the PFO then becomes a measure of the saturated field Bsat. An example for L = 4 and a pitch angle of 60°, gives Bsat ≅ 5pT, in good agreement with previous estimates of Bsat.

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

    SciTech Connect

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

    1994-07-01

    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.

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

    SciTech Connect

    Sanders, R.W.; Solomon, S.; Mount, G.H. ); Smith, J.P.; Perliski, L.; Miller, H.L. ); Keys, J.G. ); Schmeltekopf, A.L. )

    1993-04-20

    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.

  8. 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)

    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

    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

  9. The state of permafrost surrounding "Gabriel de Castilla" Spanish Antarctic Station (Deception Island, Antarctica): Studying the possible degradation due to the infrastructures heating effect.

    NASA Astrophysics Data System (ADS)

    Recio, Cayetana; Ángel de Pablo, MIguel; Ramos, MIguel; Molina, Antonio

    2015-04-01

    Permafrost degradation is one of the effects of the global warming. Many studies reveal the increase of active layer and reduction on permafrost table thickness, also in Antarctica. However, these trends on permafrost can be accelerated by the human activities, as the heating produced by the Antarctic stations infrastructures when they are not properly isolated from the ground. In Deception island, South Shetland Archipelago, we started 3 years ago a monitoring program at the 26 years old "Gabriel de Castilla" Spanish Antarctic Station (SAS), It is focused on charactering the state of permafrost, since in the coastal scarps at tens of meters from the station an increase on erosion had been detected. Although the main cause of the erosion of this coastal volcanoclastic materials is the 2 meters thick icefield which forms during the winter in the inner sea of this volcanic island, we want to detect any possible contribution to the coastal erosion caused by the permafrost degradation related to the SAS presence. We present our preliminary analysis based on three years of continuous ground temperature data, monitored at a shallow borehole (70 cm deep) in the SAS edge, together with the active layer thickness measured around the station and their vicinities in two thawing seasons. We complete this study with the analysis of the continuous temperature data taken inside the SAS and the air and ground temperatures below the station, acquired during the last Antarctic Campaign (December 2014-February 2015). These preliminary results are fundamental 1) to discard any contribution from the SAS presence, and to help to improve its thermal isolation, 2) to help improve our knowledge about the thermal state of permafrost in the area, and 3) to help to understand the causes of the coastal erosion in the volcanic Deception Island.

  10. Five years' gravity observation with the superconducting gravimeter OSG#058 at Syowa Station, East Antarctica: gravitational effects of accumulated snow mass

    NASA Astrophysics Data System (ADS)

    Aoyama, Yuichi; Doi, Koichiro; Ikeda, Hiroshi; Hayakawa, Hideaki; Shibuya, Kazuo

    2016-05-01

    Continuous gravimetric observations have been made with three successive generations of superconducting gravimeter over 20 yr at Syowa Station (39.6°E, 69.0°S), East Antarctica. The third-generation instrument, OSG#058, was installed in January 2010 and was calibrated by an absolute gravimeter during January and February, 2010. The estimated scale factor was -73.823 ± 0.053 μGal V-1 (1 μGal = 10-8 m s-2). The first 5 yr of OSG#058 data from 2010 January 7 to 2015 January 10 were decomposed into tidal waves (M3 to Ssa) and other non-tidal components by applying the Bayesian tidal analysis program BAYTAP. Long-term non-tidal gravity residuals, which were obtained by subtracting annual and 18.6 year tidal waves and the predicted gravity response to the Earth's variable rotation, showed significant correlation with the accumulated snow depth measured at Syowa Station. The greatest correlation occurred when the gravity variations lagged the accumulated snow depth by 21 d. To estimate the gravitational effect of the accumulated snow mass, we inferred a conversion factor of 3.13 ± 0.08 μGal m-1 from this relation. The accumulated snow depth at Syowa Station was found to represent an extensive terrestrial water storage (the snow accumulation) around Syowa Station, which was estimated from the Gravity Recovery and Climate Experiment satellite gravity data. The snow accumulation around Syowa Station was detectable by the superconducting gravimeter.

  11. Five years' gravity observation with the superconducting gravimeter OSG#058 at Syowa Station, East Antarctica: Gravitational effects of accumulated snow mass

    NASA Astrophysics Data System (ADS)

    Aoyama, Yuichi; Doi, Koichiro; Ikeda, Hiroshi; Hayakawa, Hideaki; Shibuya, Kazuo

    2016-02-01

    Continuous gravimetric observations have been made with three successive generations of superconducting gravimeter over 20 years at Syowa Station (39.6°E, 69.0°S), East Antarctica. The third-generation instrument, OSG#058, was installed in January 2010 and was calibrated by an absolute gravimeter during January and February, 2010. The estimated scale factor was -73.823 ± 0.053 μGal/V (1 μGal = 10-8 m/s2). The first five years of OSG#058 data from January 7, 2010 to January 10, 2015 were decomposed into tidal waves (M3 to Ssa) and other non-tidal components by applying the Bayesian tidal analysis program BAYTAP. Long-term non-tidal gravity residuals, which were obtained by subtracting annual and 18.6 year tidal waves and the predicted gravity response to the Earth's variable rotation, showed significant correlation with the accumulated snow depth measured at Syowa Station. The greatest correlation occurred when the gravity variations lagged the accumulated snow depth by 21 days. To estimate the gravitational effect of the accumulated snow mass, we inferred a conversion factor of 3.13 ± 0.08 μGal/m from this relation. The accumulated snow depth at Syowa Station was found to represent an extensive terrestrial water storage (the snow accumulation) around Syowa Station, which was estimated from the Gravity Recovery and Climate Experiment (GRACE) satellite gravity data. The snow accumulation around Syowa Station was detectable by the superconducting gravimeter.

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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

  13. Tracking spatial distribution of human-derived wastewater from Davis Station, East Antarctica, using δ15N and δ13C stable isotopes.

    PubMed

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

    2015-01-15

    Stable isotope ratios, δ15N and δ13C were effectively used to determine the geographical dispersion of human derived sewage from Davis Station, East Antarctica, using Antarctic rock cod (Trematomus bernacchii). Fish within 0-4 km downstream of the outfall exhibited higher δ15N and δ13C values relative to reference sites. Nitrogen in particular showed a stepped decrease in δ15N with increasing distance from the discharge point by 1-2‰. Stable isotopes were better able to detect the extent of wastewater contamination than other techniques including faecal coliform and sterol measures. Uptake and assimilation of δ15N and δ13C up to 4 km from the outfall adds to growing evidence indicating the current level of wastewater treatment at Davis Station is not sufficient to avoid impact to the surrounding environment. Isotopic assimilation in T. bernacchii is a viable biomarker for investigation of initial sewage exposure and longer term monitoring in the future. PMID:25487089

  14. 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)

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

    2013-12-01

    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.

  15. 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

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

    2004-01-01

    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.

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

    PubMed

    Lisle, John T; Smith, James J; Edwards, Diane D; McFeters, Gordon A

    2004-12-01

    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. PMID:15574926

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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

  18. Two-day period fluctuation of PMC occurrence over Syowa Station, Antarctica observed by a ground-based lidar and AIM satellite.

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Suzuki, H.; Tsutsumi, M.; Ejiri, M. K.; Tomikawa, Y.; Abo, M.; Kawahara, T.; Tsuda, T. T.; Nishiyama, T.

    2014-12-01

    A Rayleigh/Raman lidar system has been operated by the Japanese Antarctic Research Expedition (JARE) since February, 2011 (JARE 52nd) in Syowa Station Antarctica (69.0S, 39.5E). The lidar system consists of a pulsed Nd:YAG laser (355nm) as a transmitter and two telescopes with four photo multiplier tubes which are to detect Rayleigh scattered light from low and high atmosphere at 355 nm and N2 Raman emission at 387nm. Polar Mesospheric Cloud (PMC) was detected by the lidar at 22:30UT (+3hr for LT) on Feb 4th, 2011, the first day of a routine operation. This event was the first time to detect PMC over Syowa Station by a lidar [Suzuki et al., Ann. Geophys., 2013]. However, signal to noise ratio (SNR) of the PMC event was not so good due to large shot noises from daytime background signals. Moreover, a receiver system was designed mainly for nighttime observations. In this way, observation of PMC during the midnight sun, which also corresponds to most frequent PMC season, was difficult. Thus, to improve SNR of the PMC observation with the lidar during daytime, a narrow band-pass Fabry-Perot etalon unit has been developed and installed in the receiver system on Dec 2013 by JARE 55th. By using this new system, clear PMC signals were successfully detected under daylight condition during the period of summer operation of JARE55th. During this period of 53 days (from 17 Dec. 2013 to 7 Feb. 2014), only 11 days were with a clear sky and suitable for PMC observation. Thus, it was difficult to study temporal variations on a PMC activity only by using the lidar data. Fortunately, NASA's AIM satellite had passed near Syowa Station and provided with complimentary PMC data during observation gap of the lidar. By combining our lidar data with the AIM/CIPS data, nearly continuous monitoring of PMC variability over Syowa Station was achieved for period between 13th and 18th in January 2014. PMC occurrence with an interval of two days over Syowa Station during the period was clearly

  19. 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

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

    2005-05-01

    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.

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

    SciTech Connect

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

    2005-05-01

    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.

  1. 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)

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

    1989-01-01

    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.

  2. 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

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

    2014-04-01

    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

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

    SciTech Connect

    Stamnes, K.; Slusser, J.; Bowen, M. ); Booth, C.; Lucas, T.

    1990-11-01

    Spectral measurements of solar ultraviolet (UV) radiation taken at McMurdo Station, Antarctica are used to determine biologically effective UV dose, ozone column content, and effective cloud optical depth. The seasonal variation in these parameters from September 15, 1988 through April 15, 1989 is presented and discussed. Although no days from September 15 through October experienced UV dose exceeding that occurring at summer solstice, the temporal variation in the level of UV radiation is markedly asymmetric with respect to summer solstice. A general enhancement by about 20% in biologically effective UV dose in October, 1988 compared to March, 1989 is clearly evident. The main cause of this asymmetry appears to be the coincident deficiency in ozone abundance appears to be the coincident deficiency in ozone abundance by about 8% in spring compared to fall. The percent increase in UV dose per percent decrease in ozone abundance is about 2.5 in agreement with theoretical predictions. The total ozone amount is generally depleted (to about 250 DU) during October 1988, but there are large day-to-day fluctuations. Presumably these fluctuations are caused primarily by the motion of the polar vortex. After summer solstice UV radiation levels and ozone amounts exhibit much less pronounced day-to-day fluctuations. No spring/fall asymmetry in cloudiness, as it affects the surface ultraviolet radiation budget, is discernible from the measurements if the surface albedo is assumed to vary symmetrically around solstice.

  4. Effect of stratospheric ozone depletion and enhanced ultraviolet radiation on marine bacteria at Palmer Station, Antarctica in the early austral spring.

    PubMed

    Pakulski, J Dean; Kase, Jason P; Meador, Jarah A; Jeffrey, Wade H

    2008-01-01

    We investigated the interactions between ozone-depleted air masses and subsequent changes in UVB on marine bacterial abundance and production at Palmer Station, Antarctica from September to November 1999. During periods of low total column ozone (TCO), bacterial cell concentrations declined by 57%. Photoinhibition of bacterial [(3)H]-leucine (Leu) and [(3)H]-thymidine (TdR) incorporation due to UVB was greatest during periods of low TCO in September and early October. During diel ( approximately 28 h) exposure experiments, light treatment samples exhibited >75-100% inhibition of TdR incorporation by mid-afternoon. Leu incorporation exhibited maximum inhibition (50-100%) at sunset and early evening hours. Leu and TdR incorporation in light treatment samples did not exhibit recovery during subsequent periods of darkness. Bacterial Leu and TdR incorporation rates were inversely related to Setlow Dose during a period of recovery from low TCO. These data further suggested a threshold exposure below which bacterial Leu and TdR incorporation recovered rapidly. Recovery of bacterial production after acute Setlow Dose exposures lagged recovery of TCO and was linearly related to TCO measured 2 days previously. This lag in recovery may have resulted from the energetically expensive repair of UVR-induced DNA damage acquired during periods of low TCO. PMID:18173723

  5. Tephra layers in the Byrd Station ice core and the Dome C ice core, Antarctica and their climatic importance

    NASA Astrophysics Data System (ADS)

    Kyle, Philip R.; Jezek, Peter A.; Mosley-Thompson, Ellen; Thompson, Lonnie G.

    1981-08-01

    Volcanic glass shards from tephra layers in the Byrd Station ice core were chemically analyzed by electron microprobe. Tephra in seven layers have similar peralkaline trachyte compositions. The tephra are believed to originate from Mt. Takahe, on the basis of their chemical similarity to analyzed rocks from Mt. Takahe and because dated rock samples from the volcano are younger than 250,000 years old. Glass shards from 726 m deep in the Dome C ice core, which is 2400 km from Byrd Station, are composed of peralkaline trachyte and may have also been derived from Mt. Takahe. The tephra could have resulted from eruptions which were triggered by increased ice loading during the late Wisconsin glaciation. Preliminary grain size data suggest the eruptions were only minor and they were unlikely to have instantaneously altered global climate as have explosive eruptions in the tropics. Nevertheless, the effect of this localized volcanic activity upon the Antarctic energy budget warrants further investigation.

  6. Snowdrift events detection: a comparison of satellite imagery with ground-based remote sensing observations at Princess Elisabeth Station, East Antarctica.

    NASA Astrophysics Data System (ADS)

    Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina; Lhermitte, Stef; Lenaerts, Jan; Mangold, Alexander; Laffineur, Quentin; Palm, Stephen; van Lipzig, Nicole M. P.

    2016-04-01

    Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS) mass balance and its contribution to sea level rise. Constraining AIS SMB remains problematic due to the scarcity of observational data and challenges climate modeling, which in turn limits our current understanding of the processes contributing to AIS SMB. Particularly, a large uncertainty exists regarding the impact of drifting snow on local SMB measurements. This issue is investigated using long-term observations available at the Princess Elisabeth (PE) station. PE station is located in the escarpment area of Dronning Maud Land, East Antarctica (72°S, 23°E). Several instruments analyze atmospheric conditions, cloud and precipitation properties, as well as drifting snow. The ground-based remote sensing instruments include a ceilometer providing 910 nm attenuated backscatter profiles at 15-sec temporal resolution. These profiles can not only be used for estimating cloud base heights, but also the top height of the drifting snow layer during cloud-free conditions. Contribution of drifting snow to the local SMB can be estimated using automatic weather station (AWS) measurements, which include boundary-layer meteorology (temperature, wind speed and direction, humidity, pressure), as well as broadband radiative fluxes and snow height changes. This poster uses the ground-based long-term observations available at PE to evaluate the blowing snow events detection by satellite imagery. The near-surface blowing snow layers are apparent in lidar backscatter profiles (532 nm attenuated backscatter) and enable snowdrift events detection (spatial and temporal frequency, height and optical depth). These data are available for three full-years (2007-2009) and is processed from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), at a high resolution (1x1 km digital elevation model extending from 40 km altitude to below sea level). However, the

  7. Ground-based monitoring of nitric oxide (NO) in the mesosphere and the lower thermosphere from Syowa Station in Antarctica

    NASA Astrophysics Data System (ADS)

    Mizuno, Akira; Nakamura, Takuji; Miyoshi, Yoshizumi; Fujiwara, Hitoshi; Tsutsumi, Masaki; Ejiri, Mitsumu K.; Nagahama, Tomoo; Isono, Yasuko; Kataoka, Ryuho; Hiroyuki, Maezawa; Uemura, Miku

    Ion-molecule chemistry triggered by energetic particle precipitation (EPP) due to large solar proton events or geomagnetic storms influences the atmospheric minor constituents such as HOx, NOx and ozone from the upper stratosphere to the lower thermosphere. To understand the effect of the EPP on the middle atmosphere in the polar region, we installed a new spectroscopic radiometer at Syowa Station (69.00S, 39.85E) in the 52nd Japanese Antarctic Research Expedition. We have carried out ground-based continuous observations of spectral line of nitric oxide (NO) at 250.796 GHz since January 2012. We obtained 197 and 172 daily averaged NO spectra in 2012 and 2013 (until 30 September; DOY 273), respectively. The NO spectra are characterized by narrow line width of about 0.5MHz at FWHM, suggesting that the NO emitting region is between 75 and 100 km based on the relationship between the pressure broadening line width and the altitude. We derived partial column density of NO from the spectral intensity. We found two temporal variation patterns of the NO column density, i.e., long-term and short-term variations. The long-term variation is a seasonal one with a maximum in the winter and a minimum in the summer. The column density of NO during the winter was about 4 times larger than that during the summer. This seasonal variation is considered to be related to the atmospheric transport and the photo-dissociation of NO by solar radiation. The other short-term variation is associated with EPP events such as solar proton events and geomagnetic storms. Typical duration of the short-term variation is 5-10 days. At Syowa Station, we have found that the short-term variations were caused mainly by the precipitation of electrons rather than protons based on the comparison with the precipitating fluxes of protons and electrons obtained by the POES and METOP-02 satellites. We studied more detailed behavior of NO within a day by using high time resolution (˜ 3-hour) data for one of the

  8. Investigating the Crust and Upper Mantle of Antarctica based on S-Wave Receiver Functions Deployed in Ice Stations

    NASA Astrophysics Data System (ADS)

    Ramirez, C.; Nyblade, A.; Hansen, S. E.; Heeszel, D.; Wiens, D. A.; Anandakrishnan, S.; Aster, R. C.; Huerta, A. D.; Shore, P.; Wilson, T. J.

    2014-12-01

    The thick ice sheets that cover over 97% of the Antarctic continent make it difficult to study its geology. Seismic and other geophysical methods are the most effective ways to obtain information in this remote location. Using the classic receiver function technique, the P-to-S (Ps) conversion from the crust-mantle boundary is often masked by the ice multiples. Although removing these multiples by computational methods has been done, S-wave receiver functions (SRF) are a viable alternative and complementary method to estimate the crustal structure using S-to-P (Sp) conversions, which do not interfere with the ice multiples. In this project, we analyzed the data from the TAMSEIS, GAMSEIS and POLENET/ANET temporary seismic deployments. Sp arrival times are observed at ~5-6s in the Transantarctic Mountains and Wilkes Basin region, ~6-8s in the Gamburtsev Mountains and Vostok Higlands, and ~3-4s in the West Antarctic Rift System (WARS) and Marie Byrd Land Dome area. We used a grid search approach, combining the Sp time with Rayleigh wave phase velocities for 18 to 30 seconds, to estimate the Moho depth at each of the ice stations in the networks. The Moho depths obtained using these Sp times ranged from 28-45km, 37-59km and 16-35km respectively for the three general areas. We stacked the SRFs for several stations regionally in an attempt to obtain a qualitative view of the upper mantle structure. Most of the regional stacks do not show clear signs of seismic velocity discontinuities in the upper mantle.

  9. Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica. 7. OClO diurnal photochemistry and implications for ozone destruction

    SciTech Connect

    Solomon, S.; Sanders, R.W. ); Miller, H.L. Jr. )

    1990-08-20

    Observations of the ratio between the change in slant column abundance of OClO and that of ozone as a function of solar zenith are used to deduce the diurnal cycle of the daytime OClO column abundance above Antarctica during September 1987. This approach effectively normalizes other factors such as air mass factor changes and allows study of the photochemical variations of OClO during twilight. The data exhibits a marked increase in OClO at large solar zenith angles in the evening twilight (near 90{degree}-93{degree}), in agreement with model predictions. The increase is likely caused primarily by the attenuation of the OClO photolysis rate in the twilight. Knowledge of both the full diurnal and daily variations of OClO deduced from the data can be used to evaluate the destruction of the ozone column due to coupled chlorine-bromine chemistry. The inferred ozone loss above McMurdo Station assuming presently accepted photochemistry is 19.5 {plus minus} 10 Dobson units over the entire month of September, or about 20 {plus minus} 10% of the observed total column decline. This value is in general agreement with inferences drawn from in-situ measurements of ClO and BrO. In mid-September, available OClO and HOCl column measurement suggest that the chlorine-bromine and chlorine-hydrogen cycles respectively contribute about 22-28% and 3-4% of the observed rate of column ozone decrease at that time of the month. Model calculations constrained by ClO, BrO, and OClO measurements suggest that these mechanisms combined with photolysis of the ClO dimer can account for much, and possibly all, of the total ozone destruction rate observed in mid-September 1987.

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

    USGS Publications Warehouse

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

    2007-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

  12. 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)

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

    2012-12-01

    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

  13. Spatiotemporal variations of monocarboxylic acids in snow layers along a transect from Zhongshan Station to Dome A, eastern Antarctica

    NASA Astrophysics Data System (ADS)

    Li, Chuanjin; Xiao, Cunde; Shi, Guitao; Ding, Minghu; Kang, Shichang; Zhang, Lulu; Hou, Shugui; Sun, Bo; Qin, Dahe; Ren, Jiawen

    2015-05-01

    The spatiotemporal distributions of formate and acetate in snow layers along a transect from Zhongshan Station to Dome A are presented here. The mean concentrations of mono-carboxylic acids in summer surface snow layers were 2.93 ± 1.72 ng g- 1 and 10.07 ± 5.87 ng g- 1 for formate and acetate, respectively. In the snow pit samples, the concentrations varied between 0.47 ± 0.14 ng g- 1 and 3.12 ± 4.24 ng g- 1 for formate and between 5.31 ± 1.55 ng g- 1 and 13.29 ± 4.64 ng g- 1 for acetate. Spatially, the concentrations of both acids featured negative trends with increasing elevation and distance inland for the initial 600 km of the transect, which implies that marine sources from the coastal oceans dominate the acid supply. Different distribution styles of the acids in the interior section (600-1248 km) suggest that different source region and transporting mechanism may be responsible for the acid deposition in the interior regions. Seasonal variations in the amounts of acid in a coastal snow pit (29-A) indicate higher values in the summer and lower amounts in the winter. An enlarged source region and intensified production and transport mechanisms were primarily responsible for the higher values in summer. Longer records from the interior snow pits (29-L and 29-M) indicate elevated values in the 1970s and lower values in the 1980s and early 1990s. The increases in the mono-carboxylic acids since 1999 in snow pit 29-L and since 2005 in snow pit 29-M were temporally coincident with Chinese expedition activities in the area, suggesting that human activities were responsible for the increases in the acid load during recent decades.

  14. The seismic noise environment of Antarctica

    DOE PAGESBeta

    Anthony, Robert E.; Aster, Richard C.; Wiens, Douglas; Nyblade, Andrew; Anandakrishnan, Sridhar; Huerta, Audrey; Winberry, J. Paul; Wilson, Terry; Rowe, Charlotte

    2014-11-26

    Seismographic coverage of Antarctica prior to 2007 consisted overwhelmingly of a handful of long running and sporadically deployed transient stations, many of which were principally collocated with scientific research stations. Thus, despite very cold temperatures, sunless winters, challenging logistics, and extreme storms, recent developments in polar instrumentation driven by new scientific objectives have opened up the entirety of Antarctica to year–round and continuous seismological observation (e.g., Nyblade et al., 2012).

  15. Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica

    NASA Astrophysics Data System (ADS)

    Ritter, François; Steen-Larsen, Hans Christian; Werner, Martin; Masson-Delmotte, Valérie; Orsi, Anais; Behrens, Melanie; Birnbaum, Gerit; Freitag, Johannes; Risi, Camille; Kipfstuhl, Sepp

    2016-07-01

    Quantifying the magnitude of post-depositional processes affecting the isotopic composition of surface snow is essential for a more accurate interpretation of ice core data. To achieve this, high temporal resolution measurements of both lower atmospheric water vapor and surface snow isotopic composition are required. This study presents continuous measurements of water vapor isotopes performed in East Antarctica (Kohnen station) from December 2013 to January 2014 using a laser spectrometer. Observations have been compared with the outputs of two atmospheric general circulation models (AGCMs) equipped with water vapor isotopes: ECHAM5-wiso and LMDZ5Aiso. During our monitoring period, the signals in the 2 m air temperature T, humidity mixing ratio q and both water vapor isotopes δD and δ18O are dominated by the presence of diurnal cycles. Both AGCMs simulate similar diurnal cycles with a mean amplitude 30 to 70 % lower than observed, possibly due to an incorrect simulation of the surface energy balance and the boundary layer dynamics. In parallel, snow surface samples were collected each hour over 35 h, with a sampling depth of 2-5 mm. A diurnal cycle in the isotopic composition of the snow surface is observed in phase with the water vapor, reaching a peak-to-peak amplitude of 3 ‰ for δD over 24 h (compared to 36 ‰ for δD in the water vapor). A simple box model treated as a closed system has been developed to study the exchange of water molecules between an air and a snow reservoir. In the vapor, the box model simulations show too much isotopic depletion compared to the observations. Mixing with other sources (advection, free troposphere) has to be included in order to fit the observations. At the snow surface, the simulated isotopic values are close to the observations with a snow reservoir of ˜ 5 mm depth (range of the snow sample depth). Our analysis suggests that fractionation occurs during sublimation and that vapor-snow exchanges can no longer

  16. Landsat Image Mosaic of Antarctica

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    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.

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

    ERIC Educational Resources Information Center

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

    2000-01-01

    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…

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

    ERIC Educational Resources Information Center

    Giloth, Robert; Phillips, William

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

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

    ERIC Educational Resources Information Center

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

    2007-01-01

    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.…

  20. Measuring Foster Parent Potential: Casey Foster Applicant Inventory-Worker Version (CFAI-W)

    ERIC Educational Resources Information Center

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

    2007-01-01

    Objective: This article examines the psychometric properties of the Casey Foster Applicant Inventory-Worker Version (CFAI-W), a questionnaire designed to assess the potential of foster family care applicants to provide foster care. Method: Retrospective data were collected from 208 foster care workers who completed two copies of the CFAI-W, one…

  1. Retaining Low-Income Residents in the Workforce: Lessons from the Annie E. Casey Jobs Initiative.

    ERIC Educational Resources Information Center

    Giloth, Bob; Gewirtz, Susan

    Annie E. Casey Jobs Initiative sites recognize the challenge that long-term retention poses in today's labor market for low-income residents. They have developed key elements of an operational definition of retention, including the following: no limitation to one job, but only very limited gaps between jobs; and jobs in construction or other…

  2. CO2 and O3 vertical distributions over the Showa Station, Antarctica before and during the ozone hole formation in 2014, measured by balloon-borne CO2 and O3 instruments

    NASA Astrophysics Data System (ADS)

    Miyaji, K.; Matsumi, Y.; Nakayama, T.; Ouchi, M.; Imasu, R.; Kawasaki, M.

    2015-12-01

    The vertical and horizontal distributions of CO2 mixing ratio in the troposphere and stratosphere are considered to include the information on the source and sink of CO2, as well as transport of air masses in the atmosphere. However, only a limited number of vertical profiles for CO2 mixing ratio, which were typically obtained based on aircraft-based observations, are available. We have originally developed a new balloon-born instrument (CO2 sonde) to measure CO2 vertical profile from surface up to about 10 km in altitude. The ozone hole formation is typically observed in the early spring over Antarctica. To our knowledge, no study focusing on the change in the CO2 vertical profile before and after the ozone hole formation has been reported. In the present study, we launched four CO2 sondes at Syowa Station, Antarctica between June and October in 2014 to obtain CO2 vertical distributions before and during the ozone hole formation. Observations of ozone vertical distributions using traditional ozone sondes were also conducted on the same days. In the presentation, we will report the relationships between the vertical distributions of CO2 and ozone.

  3. Redescription of Stenolophus thoracicus Casey (Coleoptera, Carabidae, Harpalini), a valid species

    PubMed Central

    Bousquet, Yves; Messer, Peter W.

    2010-01-01

    Abstract Stenolophus thoracicus Casey is revalidated. The species is redescribed based on a study of the syntypes and of several conspecific specimens from eastern North America. The species differs from the other eastern species of the subgenus Agonoleptus in having the metasternum shorter and the wings reduced to tiny stubs. The dorsal habitus and median lobe of the aedeagus, along with the structures of the internal sac, are illustrated. PMID:21594130

  4. 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)

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

    2013-07-01

    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

  5. My IGY in Antarctica

    NASA Technical Reports Server (NTRS)

    Bentley, Charles

    2012-01-01

    Dr Charles Bentley is the A.P. Crary Professor Emeritus of Geophysics, Department of Geology and Geophysics, University of Wisconsin-Madison. Dr. Bentley joined the Arctic Institute of North America in 1956 to participate in International Geophysical Year (IGY)-related activities in the Antarctic. He wintered over consecutively in 1957 and 1958 at Byrd Station, a station in the interior of West Antarctica that housed 24 men each winter - 12 Navy support people and 12 civilian scientists/technicians. During the austral summers, he also participated in over-snow traverses, first as co-leader, then leader (the other coleader went home after the first year). These traverses consisted of six men and three vehicles, and lasted several months. These traverses covered more than 1609 kilometers (1000 miles) of largely unmapped and unphotographed terrain. During these traverses, connections to Byrd Station were by radio (daily, when the transmission conditions were good enough) and roughly every 2 weeks by resupply flight.

  6. Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica 8. Observations of nighttime NO[sub 2] and NO[sub 3] from April to October 1991

    SciTech Connect

    Solomon, S.; Sanders, R.W.; Mount, G.H. ); Smith, J.P.; Perliski, L.; Miller, H.L. ); Keys, J.G. ); Schmeltekopf, A.L.

    1993-01-20

    Lunar absorption spectra have been used to determine the vertical column abundances of NO[sub 2] and NO[sub 3] above McMurdo Station, Antarctica (77.8[degrees]S), during the fall, winter, and spring seasons in 1991. The observed nighttime NO[sub 2] and NO[sub 3] amounts during the fall and spring were broadly consistent with model predictions and with daytime measurements. During winter, local photochemistry would imply a long polar night, with associated gradual removal of NO[sub 2] and buildup of NO[sub 3] and N[sub 2]O[sub 5]. The winter observations of both species differ from such simple predictions by factors greater than 10, with the measured NO[sub 2] being far larger than predicted while the measured NO[sub 3] is much smaller than predicted. The concurrent measurement of both NO[sub 2] and NO[sub 3] strongly constrain possible solutions for these discrepancies and suggest that air parcel excursions to sunlit, lower latitudes likely take place quite regularly throughout the winter (approximately every 3-7 days). Thus the concept of an extended period of polar night as often applied in modeling studies of polar photochemistry appears inconsistent with these observations. 34 refs., 9 figs.

  7. Abortion on the Supreme Court agenda: Planned Parenthood v. Casey and its possible consequences.

    PubMed

    Koslov, T I

    1992-01-01

    On June 29, 1992, the US Supreme Court released its Planned Parenthood of Southeastern Pennsylvania v. Casey opinion. A majority of the Court reaffirmed the essential holding of the landmark Roe v. Wade case, including a recognition of a woman's guaranteed constitutional right to choose an abortion before viability. At the same time, the Court eliminated Roe's trimester framework, established a new, less stringent undue burden standard for reviewing governmental limitations upon woman's right to choose, and applied this standard in upholding the constitutionality of most of Pennsylvania's abortion restrictions. Currently, 15 states have informed consent laws, and 13 states have laws requiring waiting periods between counseling and the abortion; many states also require parental notification or consent, some with the option of judicial bypass. Now that the Court has upheld the constitutionality of restrictions such as these, it is expected that states will enforce existing provisions and impose new limitations as well. In Illinois, the proposed Abortion Informed Consent Act would require the dissemination of particular information and then impose a 72-hour waiting period between counseling and abortion. In North Dakota, a state with only 1 abortion clinic, the State Attorney General announced that he expected to begin enforcing a 24-hour waiting period. And in Tennessee, as in other states, Casey may encourage courts to lift injunctions that have prevented enforcement of waiting periods or other restrictions. Casey explicitly implicates patient autonomy, the doctor patient relationship, and the First Amendment rights of health professionals. As the Court's new interpretation of Roe suggests, the right to privacy will never be immune from redefinition. PMID:1434769

  8. Stratospheric ozone and nitrogen dioxide amount obtained with GASCOD-type DOAS spectrometer at Terra Nova Bay Station (Antarctica) during December 2000 - January 2001

    NASA Astrophysics Data System (ADS)

    Bortoli, Daniele; Ravegnani, Fabrizio; Kostadinov, Ivan K.; Giovanelli, Giorgio; Petritoli, Andrea

    2002-01-01

    GASCODs are UV-Visible ground-based spectrometers developed at the ISAO Institute and used to detect stratospheric trace gases involved in the ozone cycle such as NO2, OClO, BrO, by application of Differential Optical Absorption Spectroscopy (DOAS) methodology to the zenith scattered light collected data. After several tests both in laboratory and in Antarctic region, one of the spectrometers was modified for unattended and continuous measurement in extreme high-latitude environment. The instrument was installed in December 1995 in the Italian Station at Terra Nova Bay (74 degree(s)26'S, 164 degree(s)03E', Ross Sea). The GASCOD is still working and causing very interesting data for the study of the denitrification processes during the formation of the so-called ozone hole over the Antarctic region. When the station is unmanned, to allow for the continuous NO2 monitoring for whole the year without mechanical problems, the fixed [407 - 460] nm spectral region is investigated. The results for Nitrogen Dioxide, obtained by application of DOAS algorithms to the data recorded during the year 2000, are presented. During a leg (December 2000 - January 2001) of the 16th Italian Antarctic Expedition, after the usual instrument check, many measurements were carried out in other spectral regions, with the aim to obtain information about the stratospheric tracers contents. The results obtained for Ozone, Nitrogen dioxide and Formaldehyde at different Solar Zenith Angle are presented.

  9. Seasonal variation of wave activities near the mesopause region observed at King Sejong Station (62.22°S, 58.78°W), Antarctica

    NASA Astrophysics Data System (ADS)

    Lee, Changsup; Kim, Yong Ha; Kim, Jeong-Han; Jee, Geonhwa; Won, Young-In; Wu, Dong L.

    2013-12-01

    We analyzed the neutral wind data at altitudes of 80-100 km obtained from a VHF meteor radar at King Sejong Station (KSS, 62.22°S, 58.78°W), a key location to study wave activities above the stratospheric vortex near the Antarctic Peninsula. The seasonal behavior of the semidiurnal tides is generally consistent with the prediction of Global Scale Wave Model (GSWM02) except in the altitude region above ~96 km. Gravity wave (GW) activities inferred from the neutral wind variances show a seasonal variation very similar to the semidiurnal tide amplitudes, suggesting a strong interaction between gravity waves and the tide. Despite the consistent seasonal variations of the GW wind variances observed at the adjacent Rothera station, the magnitudes of the wind variance obtained at KSS are much larger than those at Rothera, especially during May-September. The enhanced GW activity at KSS is also observed by Aura Microwave Limb Sounder (MLS) from space in its temperature variance. The observed large wind variances at KSS imply that the Antarctic vortex in the stratosphere may act as an effective filter and source for the GWs in the upper atmosphere.

  10. Tsunami Observations on Hydrophones and Island Seismic Stations

    NASA Astrophysics Data System (ADS)

    Hanson, J. A.; Bowman, J. R.; Reasoner, C. L.; Shields, G.

    2007-12-01

    The tsunami generated by the great Indonesian earthquake of 26 December 2004 was recorded across a myriad of technologies, many of which had not been designed, nor expected, to record tsunami signals. We reported on the tsunami signals from this event observed at hydrophones, intended for nuclear test monitoring, and broadband seismometers that are part of the global seismic network (GSN). Our observations led us to examine more recently reported tsunamis and other historic tsunamis. The great Sumatra-Andaman earthquake (Mw 9.1) produced high-frequency (greater than 5 mHz) dispersed tsunami signals, in addition to the destructive wave, recorded by hydrophone stations offshore from Diego Garcia and Cape Leeuwin, Australia, and by many seismic stations in the Indian Ocean and on the coast of Antarctica. Dispersed energy was observed to 60 mHz. The details within the dispersed signal provided source information to which tide gauge data are insensitive. The source of high-frequency signals could be determined using event- to-station distances estimated from the dispersion. Fine structure in the tsunami signal indicated a possible secondary high-frequency source. The dispersion observations and modeling also identified individual reflector sources over basin-wide distances. Two other recent tsunamis were observed in the Indian Ocean. The 28 March 2005 earthquake (Mw 8.6) produced high-frequency tsunami waves (to 20 mHz) observed at the Diego Garcia hydrophone station and the AIS seismic station. In addition, the lower frequency, non-dispersed tsunami waves were seen at four other seismic stations. The Mw 7.7 earthquake on 17 July 2006 south of Java also generated high frequency tsunami waves (to 10 mHz). Clear, dispersed signals were observed on hydrophone stations and seismic stations at the Cocos-Keeling Islands, and Casey, Antarctica. The first arriving energy is consistent with a source located at the earthquake epicenter. However, the strongest signals at Cocos

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  12. Estimation of mesospheric vertical winds from a VHF meteor radar at King Sejong Station, Antarctica (62.2S, 58.8W)

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Lee, C.; Kim, J.; Jee, G.

    2013-12-01

    For the first time, vertical winds near the mesopause region were estimated from radial velocities of meteor echoes detected by a VHF meteor radar at King Sejong Station (KSS) in 2011 and 2012. Since the radar usually detects more than a hundred echoes every hour in an altitude bin of 88 - 92 km, much larger than other radars, we were able to fit measured radial velocities of these echoes with a 6 component model that consists of horizontal winds, spatial gradients of horizontal winds and vertical wind. The conventional method of deriving horizontal winds from meteor echoes utilizes a 2 component model, assuming that vertical winds and spatial gradients of horizontal winds are negligible. We analyzed the radar data obtained for 8400 hours in 2012 and 8100 hours in 2011. We found that daily mean values of vertical winds are mostly within +/- 1 m/s, whereas those of zonal winds are a few tens m/s mostly eastward. The daily mean vertical winds sometimes stay positive or negative for more than 20 days, implying that the atmosphere near the mesopause experiences episodically a large scale low and high pressure environments, respectively, like the tropospheric weather system. By conducting Lomb-normalized periodogram analysis, we also found that the vertical winds have diurnal, semidiurnal and terdiurnal tidal components with about equal significance, in contrast to horizontal winds that show a dominant semidiurnal one. We will discuss about uncertainties of the estimated vertical wind and possible reasons of its tidal and daily variations.

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

    ERIC Educational Resources Information Center

    Iversen, Roberta Rehner

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

  14. Coccinellidae (Coleoptera) of South Dakota: New State Record for Anatis lecontei Casey and Erratum to Delete Hyperaspis fimbriolata Melsheimer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we provide collection information to add Anatis lecontei Casey to the list of South Dakota Coccinellidae based on its collection for the first time in the state. We also include an erratum to delete Hyperaspis fimbriolata Melsheimer from the list based on its mistaken inclusion in an...

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

    ERIC Educational Resources Information Center

    Annie E. Casey Foundation, 2006

    2006-01-01

    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…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Antarctica Research in the Polar Research Center of China

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  18. Bringing Antarctica Home

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

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

    PubMed

    Omonzejele, Peter F

    2011-01-01

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

  20. Mineral resources of Antarctica

    SciTech Connect

    Rowley, P.D.; Williams, P.L.; Pride, D.E.

    1983-01-01

    Metallic and nonmetallic mineral occurrences are abundant in Antarctica. The most significant known deposits are of iron, copper, and coal. In the Precambrian shield of East Antarctica, for example, iron is present as banded iron-formation and as magnetite in veins, pods, and schist. The largest deposits of iron are in the Prince Charles Mountains, where bodies of banded iron-formation at least as thick as 400 m extend, mostly under the ice for at least 120 km. Widely scattered morainal boulders and outcrops of iron-rich rock suggest that undiscovered iron deposits are also distributed over many other parts of East Antarctica. Gondwana reconstructions suggest that many more mineral deposits occur in Antarctica. However, ice covers nearly 98 percent of the continent, and few of the bedrock areas have even been prospected or geologically, geophysically, or geochemically mapped in detail.

  1. Antarctica: up for grabs

    SciTech Connect

    Shapley, D.

    1982-11-01

    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)

  2. 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.

  3. Live from Antarctica: the Coldest, Windiest Place on Earth

    NASA Technical Reports Server (NTRS)

    1994-01-01

    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.

  4. Living and Working in Antarctica.

    ERIC Educational Resources Information Center

    Kemp, Noel

    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…

  5. Antarctica - Lessons for a Mars exploration program

    NASA Technical Reports Server (NTRS)

    Mckay, C. P.

    1985-01-01

    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.

  6. Geographic names of Antarctica

    USGS Publications Warehouse

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

    1956-01-01

    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.

  7. Antarctica, why so Blue?

    NASA Astrophysics Data System (ADS)

    Reif, C.; Williams, Q.; Manners, U.

    2006-12-01

    Are all fast seismic anomalies at the core-mantle boundary (CMB) created alike? Much attention has been paid to the relative variations of seismic wave speeds in slow regions of the lowermost mantle, but there is a wealth of information in the fast anomalies as well. Here we systematically characterize fast regions at the CMB in terms of their shear, compressional, and bulk wave speed anomalies and Poisson's ratio using the largest long-period catalog to date of S, ScS, Sdiff, P, and Pdiff arrival times. The fastest regions at the CMB occur beneath Antarctica, Central America, and eastern Asia. The latter two have been active subduction zones for more than 200 Ma. However, Antarctica is an exception in that subduction has not occurred there in the last 100 Ma. And, during the final stages of subduction, young oceanic lithosphere may be positively buoyant compared to the mantle and not be likely to sink all the way to the CMB. Therefore, the youngest (and thus coldest) material beneath Antarctica near the CMB is around 130 Ma in age. It is puzzling why the region beneath Antarctica would have one of the fastest seismic signals since plate reconstructions indicate that for the last 200 Ma, the greatest volume of material has been subducted under the northern Pacific. However, outside of Antarctica, the strongest fast anomalies at the CMB are geographically coincident with the current pattern of subduction, not that of the distant past. It has been noted that the seismic anomalies at the CMB do not fit those predicted by past plate reconstructions, and this mismatch has been explained in terms of the presence of the thermal boundary layer. Here, we examine thermal and compositional effects that could be produced by the interaction of subducted material with a basal thermal boundary layer, and probe how strong fast anomalies can be produced in both unexpected (Antarctica) and expected regions (eastern Asia), while fast anomalies anticipated elsewhere (northern Pacific

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

    ERIC Educational Resources Information Center

    Belanger, Dian Olson

    2004-01-01

    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…

  9. Practical analysis of tide gauges records from Antarctica

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2015-04-01

    We have collected and analyzed in a basic way the currently available time series from tide gauges deployed along the coasts of Antarctica. The database of the Permanent Service for Mean Sea Level (PSMSL) holds relative sea level information for 17 stations, which are mostly concentrated in the Antarctic Peninsula (8 out of 17). For 7 of the PSMSL stations, Revised Local Reference (RLR) monthly and yearly observations are available, spanning from year 1957.79 (Almirante Brown) to 2013.95 (Argentine Islands). For the remaining 11 stations, only metric monthly data can be obtained during the time window 1957-2013. The record length of the available time series is not generally exceeding 20 years. Remarkable exceptions are the RLR station of Argentine Island, located in the Antarctic Peninsula (AP) (time span: 1958-2013, record length: 54 years, completeness=98%), and the metric station of Syowa in East Antarctica (1975-2012, 37 years, 92%). The general quality (geographical coverage and length of record) of the time series hinders a coherent geophysical interpretation of the relative sea-level data along the coasts of Antarctica. However, in an attempt to characterize the relative sea level signals available, we have stacked (i.e., averaged) the RLR time series for the AP and for the whole Antarctica. The so obtained time series have been analyzed using simple regression in order to estimate a trend and a possible sea-level acceleration. For the AP, the the trend is 1.8 ± 0.2 mm/yr and for the whole Antarctica it is 2.1 ± 0.1 mm/yr (both during 1957-2013). The modeled values of Glacial Isostatic Adjustment (GIA) obtained with ICE-5G(VM2) using program SELEN, range between -0.7 and -1.6 mm/yr, showing that the sea-level trend recorded by tide gauges is strongly influenced by GIA. Subtracting the average GIA contribution (-1.1 mm/yr) to observed sea-level trend from the two stacks, we obtain 3.2 and 2.9 mm/yr for Antarctica and AP respectively, which are interpreted

  10. Geohydrology and distribution of volatile organic compounds in ground water in the Casey Village area, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.; Conger, Randall W.; Grazul, Kevin E.

    1998-01-01

    Casey Village and the adjoining part of the U.S. Naval Air Warfare Center (NAWC) are underlain by the Late Triassic-age Stockton Formation, which consists of a dipping series of siltstones and sandstones. The direction of vertical ground-water gradients in the Stockton Formation varies among well locations and sometimes with time. Vertical gradients can be substantial; the difference in water levels at one well pair (two wells screened at different depths) was 7.1 ft (feet) over a 32-ft vertical section of the aquifer. Potentiometric-surface maps show a groundwater divide that bisects the Casey Village area. For wells screened between 18 and 64 ft below land surface (bls), the general ground-water gradient is to the east and northeast on the east side of the divide and to the south and southwest on the west side of the divide. For wells screened between 48 and 106 ft bls, the general ground-water gradient is to the northeast on the east side of the divide and to the southwest and northwest on the west side of the divide. An aquifer test at one well in Casey Village caused drawdown in wells on the opposite side of the ground-water divide on the NAWC and shifted the ground-water divide in the deeper potentiometric surface to the west. Drawdowns formed an elliptical pattern, which indicates anisotropy; however, anisotropy is not aligned with strike or dip. Hydraulic stress caused by pumping crosses stratigraphic boundaries. Between 1993 and 1996, the trichloroethylene (TCE) concentration in water samples collected from wells in Casey Village decreased. The highest concentration of TCE measured in water from one well decreased from 1,200 mg/L (micrograms per liter) in 1993 when domestic wells were pumped in Casey Village to 140 mg/L in 1996, 3 years after the installation of public water and the cessation of domestic pumping. This suggests that pumping of domestic wells may have contributed to TCE migration. Between 1993 and 1996, the tetrachloroethylene (PCE

  11. Antarctica: Discovery & Exploration.

    ERIC Educational Resources Information Center

    Gascoigne, Toss; Collett, Peter

    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)…

  12. Getting Antarctica down Cold!

    ERIC Educational Resources Information Center

    Sandmeier, Kay; Greeson, Linda

    1990-01-01

    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…

  13. Married to Antarctica.

    ERIC Educational Resources Information Center

    Monastersky, Richard

    1991-01-01

    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)

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

    USGS Publications Warehouse

    Sloto, Ronald A.; Grazul, Kevin E.

    1995-01-01

    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.

  15. Boundary layer halogens in coastal Antarctica.

    PubMed

    Saiz-Lopez, Alfonso; Mahajan, Anoop S; Salmon, Rhian A; Bauguitte, Stephane J-B; Jones, Anna E; Roscoe, Howard K; Plane, John M C

    2007-07-20

    Halogens influence the oxidizing capacity of Earth's troposphere, and iodine oxides form ultrafine aerosols, which may have an impact on climate. We report year-round measurements of boundary layer iodine oxide and bromine oxide at the near-coastal site of Halley Station, Antarctica. Surprisingly, both species are present throughout the sunlit period and exhibit similar seasonal cycles and concentrations. The springtime peak of iodine oxide (20 parts per trillion) is the highest concentration recorded anywhere in the atmosphere. These levels of halogens cause substantial ozone depletion, as well as the rapid oxidation of dimethyl sulfide and mercury in the Antarctic boundary layer. PMID:17641195

  16. Ozone Hole Over Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  17. Earth - Antarctica Mosaic

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This color picture of the limb of the Earth, looking north past Antarctica, is a mosaic of 11 images taken during a ten-minute period near 5:45 p.m. PST Dec. 8, 1990, by Galileo's imaging system. Red, green and violet filters were used. The picture spans about 1,600 miles across the south polar latitudes of our planet. The morning day/night terminator is toward the right. The South Pole is out of sight below the picture; the visible areas of Antarctica are those lying generally south of South America. The violet-blue envelope of Earth's atmosphere is prominent along the limb to the left. At lower left, the dark blue Amundsen Sea lies to the left of the Walgreen and Bakutis Coasts. Beyond it, Peter Island reacts with the winds to produce a striking pattern of atmospheric waves.

  18. Princess Astrid Coast, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  19. Preparing Young People to Succeed in College and Beyond. The Connection Strategy: Stories and Results from the Annie E. Casey Foundation's Education Investments

    ERIC Educational Resources Information Center

    Jehl, Jeanne

    2007-01-01

    For many young people, the "pipeline" to educational and economic success is truly broken. This report describes how some of the Annie E. Casey Foundation's education grantees in Atlanta are working to mend the pipeline for young people in their communities by connecting standards and expectations for learning from early childhood to college entry…

  20. Informal STEM Education in Antarctica

    NASA Astrophysics Data System (ADS)

    Chell, K.

    2010-12-01

    Tourism in Antarctica has increased dramatically with tens of thousands of tourists visiting the White Continent each year. Tourism cruises to Antarctica offer a unique educational experience for lay people through informal science-technology-engineering-mathematics (STEM) education. Passengers attend numerous scientific lectures that cover topics such as the geology of Antarctica, plate tectonics, glaciology, and climate change. Furthermore, tourists experience the geology and glaciology first hand during shore excursions. Currently, the grand challenges facing our global society are closely connected to the Earth sciences. Issues such as energy, climate change, water security, and natural hazards, are consistently on the legislative docket of policymakers around the world. However, the majority of the world’s population is uninformed about the role Earth sciences play in their everyday lives. Tourism in Antarctica provides opportunities for informal STEM learning and, as a result, tourists leave with a better understanding and greater appreciation for both Antarctica and Earth sciences.

  1. Deployment of Autonomous GPS Stations in Marie Byrd Land, Antartica

    NASA Technical Reports Server (NTRS)

    Donnellan, A.; Luyendyk, B.; Smith, M.; Dace, G.

    1999-01-01

    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 Antartic Rift System.

  2. How isolated is Antarctica?

    PubMed

    Clarke, Andrew; Barnes, David K A; Hodgson, Dominic A

    2005-01-01

    The traditional view of Antarctica and the surrounding Southern Ocean as an isolated system is now being challenged by the recent discovery at the Antarctic Peninsula of adult spider crabs Hyas areneus from the North Atlantic and of larvae of subpolar marine invertebrates. These observations question whether the well described biogeographical similarities between the benthic fauna of the Antarctic Peninsula and the Magellan region of South America result from history (the two regions were once contiguous), or from a previously unrecognized low level of faunal exchange. Such exchange might be influenced by regional climate change, and also exacerbated by changes in human impact. PMID:16701330

  3. Hovercraft experience in Antarctica

    NASA Astrophysics Data System (ADS)

    Cook, Harvey C.

    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.

  4. Antarctica Day: An International Celebration

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    For more than half a century, the 1959 Antarctic Treaty continues to shine as a rare beacon of international cooperation. To celebrate this milestone of peace in our civilization with hope and inspiration for future generations, Antarctica Day is celebrated each year on December 1st , the anniversary of the Antarctic Treaty signing. As an annual event - initiated by the Foundation for the Good Governance of International Spaces (www.internationalspaces.org/) in collaboration with the Association of Polar Early Carer Scientists (www.apecs.is) - Antarctica Day encourages participation from around the world. The Antarctic Treaty set aside 10% of the earth, 'forever to be used exclusively for peaceful purposes in the interest of mankind.' It was the first nuclear arms agreement and the first institution to govern all human activities in an international region beyond sovereign jurisdictions. In this spirit, Antarctica Day aims to: - Demonstrate how diverse nations can work together peacefully, using science as a global language of cooperation for decision making beyond national boundaries, - Provide strategies for students learning about Antarctica through art, science and history at all school levels, - Increase collaboration and communication between classrooms, communities, researchers and government officials around the world, and - Provide a focus for polar educators to build on each year. Through close collaboration with a number of partners. Antarctica Day activities have included: a Polar Film Festival convened by The Explorers Club; live sessions connecting classrooms with scientists in Antarctica thanks to PolarTREC and ARCUS; an international activity that involved children from 13 countries who created over 600 flags which exemplify Antarctica Day (these were actually flown in Antarctica with signed certificates then returned to the classes); a map where Antarctica Day participants all over the world could share what they were doing; an Antarctic bird count

  5. The crustal thickness of West Antarctica

    NASA Astrophysics Data System (ADS)

    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

    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.

  6. Total ozone by lunar Dobson observation at Syowa, Antarctica

    NASA Technical Reports Server (NTRS)

    Chubachi, Shigeru; Kajiwara, Ryoichi; Kondoh, Kouji

    1988-01-01

    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.

  7. Petroleum geology of western Antarctica

    SciTech Connect

    Kingston, J. )

    1990-05-01

    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.

  8. An emission inventory of sulfur from anthropogenic sources in Antarctica

    NASA Astrophysics Data System (ADS)

    Shirsat, S. V.; Graf, H. F.

    2009-05-01

    This paper presents first results of a comprehensive emission inventory of chemical species from anthropogenic activities (power generation, vehicles, ships and aircraft) in Antarctica, covering the 2004-2005 period. The inventory is based on estimated emission rates of fuel consumption provided by some of the Antarctic research stations. Since the emission sources have different modes of operation and use a variety of fuel, the emission flux rate of chemical species is calculated by multiplying the fuel consumption value with the density of fuel and appropriate emission factors. A separate inventory is prepared for each anthropogenic emission source in Antarctica. Depending on the type of operation, emission rates of SO2, and BC (Black Carbon, from shipping only) have been calculated using the above technique. However, only results of SO2 emissions from each source are presented here. Emission inventory maps of SO2 depicting the track/path taken by each mobile source are shown. The total annual SO2 is 158 Mg from power generation and vehicle operations, 3873 Mg from ships and 56 Mg from aircraft for 2004-2005 and these values undergo strong seasonality following the human activity in Antarctica. Though these figures are small when compared to the emissions at most other regions of the world, they are an indication that human presence in Antarctica leads to at least local pollution. The sources are mainly line and point sources and thus the local pollution potentially is relatively strong.

  9. An emission inventory of sulfur from anthropogenic sources in Antarctica

    NASA Astrophysics Data System (ADS)

    Shirsat, S. V.; Graf, H. F.

    2009-01-01

    This paper presents first results of a comprehensive emission inventory of chemical species from anthropogenic activities (power generation, vehicles, ships and aircraft) in Antarctica, covering the 2004-2005 period. The inventory is based on estimated emission rates of fuel consumption provided by some of the Antarctic research stations. Since the emission sources have different modes of operation and use a variety of fuel, the emission flux rate of chemical species is calculated by multiplying the fuel consumption value with the density of fuel and appropriate emission factors. A separate inventory is prepared for each anthropogenic emission source in Antarctica. Depending on the type of operation, emission rates of SO2, and BC (Black Carbon, from shipping only) have been calculated using the above technique. However, only results of SO2 emissions from each source are presented here. Emission inventory maps of SO2 depicting the track/path taken by each mobile source are shown. The total annual SO2 is 158 Mg from power generation and vehicle operations, 3873 Mg from ships and 56 Mg from aircraft for 2004-2005 and these values undergo strong seasonality following the human activity in Antarctica. Though these figures are small when compared to the emissions at most other regions of the world, they are an indication that human presence in Antarctica leads to at least local pollution. The sources are mainly line and point sources and thus the local pollution potentially is relatively strong.

  10. Volcanic earthquake swarms at Mt. Erebus, Antarctica

    NASA Astrophysics Data System (ADS)

    Kaminuma, Katsutada; Ueki, Sadato; Juergen, Kienle

    1985-04-01

    Mount Erebus is an active volcano in Antarctica located on Ross Island. A convecting lava lake occupies the summit crater of Mt. Erebus. Since December 1980 the seismic activity of Mt. Erebus has been continuously monitored using a radio-telemetered network of six seismic stations. The seismic activity observed by the Ross Island network during the 1982-1983 field season shows that: (1)Strombolian eruptions occur frequently at the Erebus summit lava lake at rates of 2-5 per day; (2)centrally located earthquakes map out a nearly vertical, narrow conduit system beneath the lava lake; (3)there are other source regions of seismicity on Ross Island, well removed from Mt. Erebus proper. An intense earthquake swarm recorded in October 1982 near Abbott Peak, 10 km northwest of the summit of Mt. Erebus, and volcanic tremor accompanying the swarm, may have been associated with new dike emplacement at depth.

  11. Automatic Weather Station (AWS) Lidar

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  12. Human Activity and Pollution in Antarctica

    NASA Astrophysics Data System (ADS)

    Graf, H.-F.; Shirsat, S. V.; Podzun, R.

    2009-04-01

    A regional climate chemistry model is used to determine the level of pollution of the Antarctic continent due to anthropogenic and natural emission of sulphur species. Based on an emission inventory for the year 2004/2005 including emissions from energy use and ground traffic at and between Antarctic research stations, flight activity, tourist and scientific ship operations, and emissions from the Mt. Erebus volcano, atmospheric concentration and deposition rates of sulphur species and black carbon were simulated at 0.5 degree resolution for the whole Antarctic continent. The biggest anthropogenic source of pollution is ship operations. These concentrate near the Antarctic Peninsula and close to the big scientific stations at Queen Maud Land and in the Ross sea area. The prevailing winds guarantee that most of the anthropogenic emissions from sources near the coast will be blown to lower latitudes and do not affect the continent. While atmospheric concentrations over vast areas remain extremely low, in some places locally concentrations and deposition rates are reached that may be detectable by in-situ measurements and give rise to concern. Especially at the Peninsula atmospheric concentrations and surface deposition of sulphur and soot are dominated by ship emissions. The largest part of shipping activity in this region is from tourist ships, a strongly increasing business. The by far biggest source of sulphur species in Antarctica is the Mt. Erebus volcano. It is also the only source that remains equally strong in polar winter. However, due to its high altitude and the long life time of SO2, especially in winter resulting in long range transport and dilution, Erebus emissions contribute relatively little to deposition of sulphur in the most anthropogenic polluted areas while they dominate the sulphur deposition in central Antarctica.

  13. Particle-size distribution in soils of West Antarctica

    NASA Astrophysics Data System (ADS)

    Abakumov, E. V.

    2010-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  15. GOCE and Antarctica

    NASA Astrophysics Data System (ADS)

    Forsberg, Rene

    2015-03-01

    GOCE has mapped the gravity field of the planet with unprecedented accuracy, and will leave a legacy gravity field measurement unmatched for many years to come. GOCE data in Antarctica demonstrate the mapping of significant crustal anomalies and deep subglacial valleys, and give for the first time a unified overlook of the gravitation field north of 83.3°S, and the accuracy and high resolution of GOCE is confirmed by comparison to recent airborne gravity data. A “beauty spot” of the global GOCE gravity field map is, however, the lack of data at the polar gaps, beyond 83.5 latitude. Although GRACE fills the polar gaps at medium to long wavelengths, the crucial wavelength band around harmonic degrees 120-240 will remain unmapped, unless terrestrial data are used. The gravity data coverage of the Arctic is pretty much done, thanks to major US, European and Russian airborne and surface surveys carried out since the early 1990’s. In the Antarctic, however, the situation is the opposite: virtually no surface or airborne data exist in the polar gap; therefore an international effort to fill in this gap by airborne gravity would be timely now, to make the final GOCE legacy gravity field models truly global. It is possible to fill this gap at a sufficient accuracy level in one field season, and plans for doing exactly that in a European-US cooperation 2015/16 are outlined.

  16. Solar Eclipses Observed from Antarctica

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.

    2013-01-01

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

  17. Application of SAR interferometry in Grove Mountains, east Antarctica

    NASA Astrophysics Data System (ADS)

    E, Dongchen; Zhou, Chunxia; Liao, Mingsheng

    2004-02-01

    Synthetic aperture radar interferometry has been proposed as a potential technique for digital elevation model (DEM) generation, topographic mapping, and surface motion detection especially in the inaccessible areas. Grove Mountains Area locates to the southwest of Princess Elizabeth Land, inland areas of east Antarctica. The topographical map of the core area (11 x 10 KM2) was printed after the field surveying with GPS and total station was finished under the atrocious weather conditions during the 16th CHINARE (Chinese National Antarctic Research Expedition) 1999/2000. This paper will present an experimental investigation of the ERS-1/2 SAR tandem data in 1996 on DEM generation of the Grove Mountains Core Area, analyze the data processing, and compare the DEM with the actual topographic form. It is confirmed that InSAR is a very useful technique to be utilized in Antarctica, and can be used to produce more products instead of dagnerous field surveying.

  18. Lithospheric Structure of East Antarctica: Results From the First Year of the SSCUA Broadband Seismic Deployment

    NASA Astrophysics Data System (ADS)

    Reading, A. M.

    2004-12-01

    Recent geological and geochronological work has changed our concept of the former Gondwana continents surrounding a central Archaean craton, East Antarctica. The revised tectonic framework shows mobile belts and tectonic province boundaries which correlate well with East Antarctica's former neighbours in the supercontinent and trend perpendicular to the present day Antarctic coastline. Constraints are however restricted to those areas where the rock is exposed above the ice. Indirect, geophysical methods are required to map the extent of tectonic provinces in the continental interior and provide information on the deep structure. Following a pilot deployment in 2001/02, a set of 6 remote broadband earthquake recording stations were deployed in the Lambert Glacier region, East Antarctica, from the coast at 65°S deep into the interior to a latitude of 75°S. The aim was to determine the Seismic Structure of the Continent Under Antarctica (SSCUA) using a variety of seismological techniques. The stations were solar-powered and hence shut down during the Antarctic winter to re-commence recording after the return of daylight in the austral spring. After one year, 3 stations were relocated to further test contemporary terrane models of the lithosphere in this region. At the present time (December 2004) recording continues across the deployment with most stations due to be uplifted at the end of the 2004/05 summer season. Results of receiver function inversions for seismic structure beneath the recording stations of the first main deployment are presented. To the west of the Lambert Glacier, the Rayner province extends from Mawson Station to Beaver Lake with a fairly deep Moho at 42 km. To the east, seismic velocity profiles have a different character, showing slower crustal velocities. A province boundary exists between the Reinbolt Hills and the northern Mawson Escarpment where the crust is shallower at 34 km. These results are the first determinations of the seismic

  19. Antarctica as a Martian model.

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  20. Surface winds over West Antarctica

    NASA Technical Reports Server (NTRS)

    Bromwich, David

    1993-01-01

    Five winter months (April-August 1988) of thermal infrared satellite images were examined to investigate the occurrence of dark (warm) signatures across the Ross Ice Shelf in the Antarctic continent. These features are inferred to be generated by katabatic winds that descend from southern Marie Byrd Land and then blow horizontally across the ice shelf. Significant mass is added to this airstream by katabatic winds blowing from the major glaciers that flow through the Transantarctic Mountains from East Antarctica. These negatively buoyant katabatic winds can reach the northwestern edge of the shelf - a horizontal propagation distance of up to 1,000 km - 14 percent of the time. Where the airstream crosses from the ice shelf to the ice-covered Ross Sea, a prominent coastal polynya is formed. Because the downslope buoyancy force is near zero over the Ross Ice Shelf, the northwestward propagation of the katabatic air mass requires pressure gradient support. The study shows that the extended horizontal propagation of this atmospheric density current occurred in conjunction with the passage of synoptic cyclones over the southern Amundsen Sea. These cyclones can strengthen the pressure gradient in the interior of West Antarctica and make the pressure field favorable for northwestward movement of the katabatic winds from West Antarctica across the ice shelf in a geostrophic direction. The glacier winds from East Antarctica are further accelerated by the synoptic pressure gradient, usually undergo abrupt adjustment beyond the exit to the glacier valley, and merge into the mountain-parallel katabatic air mass.

  1. Tectonic development of West Antarctica and its relation to East Antarctica

    SciTech Connect

    Dalziel, I.W.D. )

    1987-09-01

    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.

  2. Pine Island Glacier, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This pair of MISR images of the Pine Island Glacier in western Antarctica was acquired on December 12, 2000 during Terra orbit 5246. At left is a conventional, true-color image from the downward-looking (nadir) camera. The false-color image at right is a composite of red band data taken by the MISR forward 60-degree, nadir, and aftward 60-degree cameras, displayed in red, green, and blue colors, respectively. Color variations in the left (true-color) image highlight spectral differences. In the multi-angle composite, on the other hand, color variations act as a proxy for differences in the angular reflectance properties of the scene. In this representation, clouds show up as light purple. Blue to orange gradations on the surface indicate a transition in ice texture from smooth to rough. For example, the bright orange 'carrot-like' features are rough crevasses on the glacier's tongue. In the conventional nadir view, the blue ice labeled 'rough crevasses' and 'smooth blue ice' exhibit similar coloration, but the multi-angle composite reveals their different textures, with the smoother ice appearing dark purple instead of orange. This could be an indicator of different mechanisms by which this ice is exposed. The multi-angle view also reveals subtle roughness variations on the frozen sea ice between the glacier and the open water in Pine Island Bay.

    To the left of the 'icebergs' label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of the label. These small icebergs are associated with dark streaks. Analysis of the illumination geometry suggests that these streaks are surface features, not shadows. Wind-driven motion and thinning of the sea ice in the vicinity of the icebergs is one possible explanation.

    Recently, Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center discovered in Landsat 7 imagery a newly-formed crack traversing the Pine Island Glacier. This crack

  3. IPY: Engaging Antarctica: Bringing Antarctic Geoscience to the Public Through a NOVA Documentary and an Innovative Flexible Exhibit for Informal Science Education Venues

    NASA Astrophysics Data System (ADS)

    Rack, F.; Diamond, J.; Levy, R.; Berg, M.; Dahlman, L.; Jackson, J.

    2006-12-01

    IPY: Engaging Antarctica is an informal science education project designed to increase the general public's understanding of scientific research conducted in Antarctica. The project focuses specifically on the multi- national, NSF-funded Antarctic Drilling Project (ANDRILL). The ANDRILL project is the newest geological drilling program in an ongoing effort to recover stratigraphic records from Antarctica. ANDRILL's primary objectives are to investigate Antarctica's role in global environmental change over the past 65 million years and to better understand its future response to global changes. Additionally, through ANDRILL's Research Immersion for Science Educators program (ARISE), 12 science educators from four countries will work on science research teams in Antarctica and produce educational materials that feature Antarctic geoscience. The Engaging Antarctica project will produce both a NOVA television documentary and an innovative informal learning exhibit. The documentary, Antarctica's Icy Secrets, will provide a geological perspective on how Antarctica continues to play a major role in affecting global climate by altering ocean currents and sea levels. The learning exhibit, one that blends standards- and inquiry-based learning with the latest information technologies, is coined the Flexhibit. The Engaging Antarctica Flexhibit will provide a digital package of high resolution images for banners as well as learning activities and ideas for exhibit stations that can be implemented by youth groups. Flexhibit images will feature ANDRILL scientists at work, and audio files, available as podcasts, will tell scientists' stories in their own words, speaking directly to the public about the joys and challenges of Antarctic geological research.

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

    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.

  5. Remote Sensing and Skywave Digital Communication from Antarctica

    PubMed Central

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

    2009-01-01

    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

  6. Remote sensing and skywave digital communication from antarctica.

    PubMed

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

    2009-01-01

    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

  7. Direct gravimetric determination of aerosol mass concentration in central antarctica.

    PubMed

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

    2011-01-01

    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 μg 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 μm) in central Antarctica is about 0.1 μg 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

  8. Transiting planet candidates with ASTEP 400 at Dome C, Antarctica

    NASA Astrophysics Data System (ADS)

    Mékarnia, D.; Guillot, T.; Rivet, J.-P.; Schmider, F.-X.; Abe, L.; Gonçalves, I.; Agabi, A.; Crouzet, N.; Fruth, T.; Barbieri, M.; Bayliss, D. D. R.; Zhou, G.; Aristidi, E.; Szulagyi, J.; Daban, J.-B.; Fanteï-Caujolle, Y.; Gouvret, C.; Erikson, A.; Rauer, H.; Bouchy, F.; Gerakis, J.; Bouchez, G.

    2016-08-01

    ASTEP 400, the main instrument of the ASTEP (Antarctica Search for Transiting ExoPlanets) programme, is a 40-cm telescope, designed to withstand the harsh conditions in Antarctica, achieving a photometric accuracy of a fraction of milli-magnitude on hourly timescales for planet-hosting southern bright (R˜12 mag) stars. We review the performances of this instrument, describe its operating conditions, and present results from the analysis of observations obtained during its first three years (2010-2012) of operation, before its repatriation in 2014. During this time, we observed a total of 22 stellar fields (1° × 1° FoV). Each field, in which we measured stars up to magnitude R=18 mag, was observed continuously during ˜7 to ˜30 days. More than 200 000 frames were recorded and 310 000 stars processed, using an implementation of the optimal image subtraction (OIS) photometry algorithm. We found 43 planetary transit candidates. Twenty of these candidates were observed using spectroscopic follow-ups including four targets classified as good planet candidates. Our results demonstrate that accurate near-continuous photometric observations are achievable from the Concordia station at Dome C in Antarctica, even if we were not able to reach the nominal photometric precision of the instrument. We conducted a correlation analysis between the RMS noise and a large number of external parameters and found that source of the ˜1 mmag correlated noise is not obvious and does not depend on a single parameter. However, our analysis provided some hints and guidance to increase the photometric accuracy of the instrument. These improvements should equip any future telescope operating in Antarctica.

  9. Terrestrial Spaceflight Analogs: Antarctica

    NASA Technical Reports Server (NTRS)

    Crucian, Brian

    2013-01-01

    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.

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

    SciTech Connect

    Shigeru Chubachi )

    1993-02-20

    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.

  11. Temperature trend estimates in the troposphere over Antarctica by use of analysis of the GPS radio occultation data

    NASA Astrophysics Data System (ADS)

    Zhang, Kefei; Fu, Erjiang; Wang, Chuan-Sheng; Liou, Yuei-An; Pavelyev, Alexander; Kuleshov, Yuriy

    2010-05-01

    characteristics. Latest research results have demonstrated the great potential of the new technique to global climate monitoring and numerical weather prediction. With the newly launched six FORMOSAT-3 LEO satellites in 2006, thousands of high-quality, globally-distributed daily vertical profiles of refractivity, temperature and moisture have been obtained [Liou et al. 2007]. It is anticipated that GPS RO technique will play an important role in meteorological studies because of the significantly increased amount of atmospheric observations and improved data processing methodology. In this study, we use GPS RO data and collocated radiosonde data from three Australian weather observation stations (Casey, Davis and Mawson) to evaluate impacts of different collocation criteria (specifically, 100, 200 and 300 km spatial buffers and 1, 2 and 3 hour temporal buffers). Spatial and temporal variations in troposhperic temperatures over Antarctica are also investigated using the GPS RO data. Detailed analysis of refractivity and temperature profiles is presented and seasonal temperature variations in the troposphere are discussed. References Johanson, C. M., and Q. Fu, 2007: Antarctic atmospheric temperature trend patterns from satellite observations. Geophys. Res. Lett. 34, L12703, doi:10.1029/2006GL029108. Liou, Y.-A., A. G. Pavelyev, S. F. Liu, A. A. Pavelyev, N. Yen, C. Y. Huang, and C. J. Fong, 2007: FORMOSAT-3 GPS radio occultation mission: preliminary results. IEEE Trans. Geosci. Remote Sensing, 45(10), doi:10.1109/TGRS.2007.903365. Steig, E. J., D. P. Schneider, S.D. Rutherford, M. M. Mann, J. C. Comiso, and D. T. Shindell, 2009: Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature 457, 22 January 2009, doi: 10.1038/nature07669. Turner, J., S.R. Colwell, G.J. Marshall, T.A. Lachlan-Cope, A.M. Carleton, P.D. Jones, V. Lagun, P.A. Reid, and S. Iagovkina, 2005: Antarctic climate change during the last 50 years. Int. J. Climatol. 25, 279

  12. A review of Canadian and Alaskan species of the genera Clusiota Casey and Atheta Thomson, subgenus Microdota Mulsant & Rey (Coleoptera, Staphylinidae, Aleocharinae)

    PubMed Central

    Klimaszewski, Jan; Webster, Reginald P.; Sikes, Derek; Bourdon, Caroline; Labrecque, Myriam

    2015-01-01

    Abstract This paper treats 13 species of the subgenus Microdota Mulsant & Rey of Atheta Thomson and 3 species of the genus Clusiota Casey in Canada and Alaska. We report here 4 species new to science, and 3 new provincial records. The following species are new to science: Atheta (Microdota) curtipenis Klimaszewski & Webster, sp. n., Atheta (Microdota) formicaensis Klimaszewski & Webster, sp. n., Atheta (Microdota) macesi Klimaszewski & Webster, sp. n., and Clusiota grandipenis Klimaszewski & Webster, sp. n. The new provincial records are: Atheta (Microdota) pseudosubtilis Klimaszewski & Langor, new to AB, and Atheta (Microdota) subtilis (Scriba), an adventive Palaearctic species new to North America, first reported in LB and NB. The two Clusiota Casey species are reviewed, and their distribution is revised. A female Clusiota impressicollis was discovered in Ontario and is illustrated here for the first time. A key to all Canadian species of the subgenus Microdota and genus Clusiota are provided. Atheta (Microdota) holmbergi Bernhauer and Atheta (Microdota) alesi Klimaszewski & Brunke are transferred here to the subgenus Dimetrota Mulsant & Rey. PMID:26478708

  13. Site-testing in Antarctica

    NASA Astrophysics Data System (ADS)

    Storey, J. W. V.; Lawrence, J. S.; Ashley, M. C. B.

    2007-10-01

    Sites on the Antarctic Plateau such as Dome A, Dome C and South Pole, offer unique and exceptionally favourable conditions for astronomy. Site testing over the past decade has revealed extremely low infrared backgrounds, low water vapour, excellent infrared transmission and very low levels of atmospheric turbulence. Although several large facilities have already been built in Antarctica and plans for many more are well underway, there is still much to learn about this unique and beautiful place.

  14. Nitrous Acid at Concordia (Inland Site) and Dumont d'Urville (Costal Site), East Antarctica

    NASA Astrophysics Data System (ADS)

    Kerbrat, M.; Legrand, M.; Preunkert, S.; Gallée, H.; Kleffman, J.

    2012-04-01

    One of the most recent important finding made in Antarctica after the discovery of the appearance of the Antarctic ozone hole in the early 80's was the discovery of a very oxidizing canopy over the South Pole region in relation with unexpected high levels of NO. There is a strong need however to extend investigations of the oxidation capacity of the lower atmosphere at the scale of the whole Antarctic continent, and in particular, over East Antarctica. That motivated the OPALE (Oxidant Production over Antarctic Land and its Export) project. Indeed the limited data gained by using aircraft sampling during ANTCI 2003 suggest that over the East Antarctic plateau even higher NO emissions persist. Among several not yet resolved questions related to the high level of oxidants over Antarctica is the role of nitrous acid (HONO). During the austral summer 2010/2011 the levels of nitrous acid (HONO) were for the first time investigated at Concordia (75°06'S, 123°33'E) and Dumont D'Urville (66°40'S, 140°01'E), two stations located in East Antarctica. Also for the first time in Antarctica, HONO was measured by deploying a long path absorption photometer (LOPAP). At Concordia, from the end of December 2010 to mid January 2011 HONO mixing ratios at 1 m above the snow surface ranged between 5 and 60 pptv. Diurnal cycles were observed with levels peaking in the morning (06:30 to 07:30) and the evening (19:00 to 20:00). At Dumont d'Urville, background mixing ratios close to 2 pptv were observed in February 2011. No clear diurnal cycles were observed at that site but several events of air masses export from inland Antarctica were encountered with enhanced HONO levels reaching 10 pptv at night. These first HONO data gained in East Antarctica are discussed in terms of sources and sinks along with synoptic weather conditions.

  15. Changes in sleep patterns during prolonged stays in Antarctica

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

    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.

  16. Icebergs in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Two large icebergs, designated B-15A and C-16, are captured in this MISR nadir camera view of the Ross Ice Shelf and Ross Sea in Antarctica. The image was acquired on December 10, 2000 during Terra orbit 5220.

    Iceberg C-16 calved off the ice shelf in late September and is nearly 50 kilometers in length. It is seen here having migrated to the vicinity of Cape Bird on Ross Island. The initial letter designation in an iceberg's name denotes the longitudinal quadrant in which it is first seen, and new icebergs sighted in that quadrant are sequentially numbered. B-15 divided from the ice shelf last March, and initially was nearly as large as the state of Connecticut. It has since broken up into several pieces, hence the final letter designation in the berg shown in this image.

    Ross Island lies between 77 and 78 degrees south latitude, and consists of several volcanic peaks, of which the still active Mt. Erebus is the tallest (3794 meters). It overlooks McMurdo Station, a U.S. research facility located near the tip of the island's Hut Point Peninsula.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  17. Social, occupational and cultural adaptation in Antarctica

    NASA Astrophysics Data System (ADS)

    Nicolas, Michel; Bishop, Sheryl; Weiss, Karine; Gaudino, Marvin

    2016-07-01

    Life in isolated and confined environments (ICEs, e.g., polar stations, submarine or space missions), is subject to important constraints which can generate psychosociological impaired outcomes. This study investigated psychological, social, occupational and cultural variables which are among the most important determinants in adaptation to a one-year wintering in Antarctica with 13 international participants. Our findings confirm and give further insight into the role of social (Cohesiveness, Social Support) and occupational (Implementation / Preparedness, Counterproductive Activity, Decision Latitude and Psychological Job Demands) dimensions of adaptation to ICE environments. Relationships between various social and occupational dimensions studies reflected detrimental effects ranging from decrements in cohesiveness, social support and work performance which differed across professional status and multicultural factors. These psychosocial issues have important implications for pre-mission selection and training, monitoring and support of crews during the mission and post-mission readaptation. Operational recommendations are suggested to improve adaptation, success and well-being for long-term ICE missions, e.g., to Mars and beyond.

  18. Seismic Tomography of Erebus Volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Zandomeneghi, Daria; Kyle, Philip; Miller, Pnina; Snelson, Catherine; Aster, Richard

    2010-02-01

    Mount Erebus (77°32'S, 167°10'E elevation 3794 meters) is the most active volcano in Antarctica and is well known for its persistent lava lake. The lake constitutes an “open window” into the conduit and underlying feeding system and offers a rare opportunity to observe a shallow convecting magmatic system. Imaging and modeling of the internal structure of Erebus volcano are best done through compiling information from arrays of seismometers positioned strategically around the volcano. From these data, the three-dimensional (3-D) structure of the conduit can be pieced together. Building this 3-D model of Erebus was a main goal of the seismic tomographic experiment Tomo Erebus (TE). During the 2007-2008 austral field season, 23 intermediate-period seismometers were installed to contribute data, through the winter, for the passive-source aspect of the experiment. One year later, 100 three-component short-period stations were deployed to record 16 chemical blasts (see Figure 1).

  19. Soils of Marie Byrd Land, West Antarctica

    NASA Astrophysics Data System (ADS)

    Lupachev, A. V.; Abakumov, E. V.

    2013-10-01

    Soils of Marie Byrd Land-one of the remotest and difficultly accessible regions of Antarctica-were investigated in the area of the mothballed Russkaya station located to the south of 74° S. Despite the extremely severe wind regime (the average wind velocity is 13 m/s, and the maximum wind velocity is up to 60 m/s), the projective cover of vegetation in the area of the station averages 25-40% and reaches 60-80% in some places. The phenomena of physical weathering of the bedrock-exfoliation, stone pavements, residual rocks exposed by wind (hoodoos), and others-are clearly manifested. In most of the described soils, normal organic and organomineral horizons are absent. The soil profiles represent the mixture of the residues of mosses and lichens and the gravelly eluvium. The fine earth material is blown out of the surface horizons by strong winds; its residual accumulation takes place in the middle and lower parts of the profiles. The classification position of these soils is open to argument; they are close to Petrozems and Lithozems. Most of the profiles are underlain by the massive or slightly disintegrated bedrock with dry permafrost at a depth of 20 to 50 cm. Soils with dry permafrost comprise about 75% of the surveyed area. In separate loci in the depressions of the local mesorelief and on gentle slopes, the soils with clearly expressed cryoturbation features are developed; their profiles are underlain by the ice-rich permafrost and compose about 15% of the surveyed area. Anthropogenically disturbed soils and soils polluted with petroleum hydrocarbons, heavy metals, and other pollutants occupy about 10% of the surveyed area.

  20. Landsat Image Mosaic of Antarctica (LIMA)

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    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.

  1. Potential methane reservoirs beneath Antarctica.

    PubMed

    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

    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

  2. Crust and Upper Mantle Structure of Antarctica from Rayleigh Wave Tomography

    NASA Astrophysics Data System (ADS)

    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

    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

  3. 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

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

    2011-01-01

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

  4. HalleyVI - a station for science

    NASA Astrophysics Data System (ADS)

    Rose, Mike; Tuplin, Karl

    2013-04-01

    There has been a research station at Halley in Antarctica (75°35'S, 26°34'W) since 1956. Halley has a long and successful scientific record, notably the discovery of the Ozone Hole and significant contributions to areas as diverse as Geology and Space physics. Halley is located on a floating and flowing iceshelf with constant surface accumulation. These conditions have resulted in the necessary regular rebuilding of the station and HalleyVI has just been completed. Halley VI has been fully scientifically operational since Feb 2012. The station supports a chemical and turbulence clean area, an electromagnetic quiet zone, an area for radars, and flexible facilities on the station to support a wide variety of science activities. This presentation outlines the major features of the new station, its current scientific activities, and the facilities that allow the hosting of a wide variety of scientific experiments.

  5. Infrasound array observations in the Lützow-Holm Bay region, East Antarctica

    NASA Astrophysics Data System (ADS)

    Murayama, Takahiko; Kanao, Masaki; Yamamoto, Masa-Yuki; Ishihara, Yoshiaki; Matsushima, Takeshi; Kakinami, Yoshihiro

    2015-03-01

    The characteristic features of infrasound waves observed in Antarctica reveal a physical interaction involving surface environmental variations in the continent and the surrounding Southern Ocean. A single infrasound sensor has been making continuous recordings since 2008 at Syowa Station (SYO; 69.0S, 39.6E) in the Lützow-Holm Bay (LHB) of East Antarctica. The continuously recorded data clearly show the contamination of background oceanic signals (microbaroms) throughout all seasons. In austral summer 2013, several field stations with infrasound sensors were established along the coast of the LHB. Two infrasound arrays of different diameters were set up: one at SYO (with a 100-m spacing triangle) and one in the S16 area on the continental ice sheet (with a 1000-m spacing triangle). In addition to these arrays, isolated single stations were deployed at two outcrops in the LHB. These newly established arrays clearly detected the propagation direction and frequency content of microbaroms from the Southern Ocean. Microbarom measurements are a useful tool for characterizing ocean wave climates, complementing other oceanographic and geophysical data from the Antarctic. In addition to the microbaroms, several other remarkable infrasound signals were detected, including regional earthquakes, and airburst shock waves emanating from a meteoroid entering the atmosphere over the Russian Republic on 15 February 2013. Detailed and continuous measurements of infrasound waves in Antarctica could prove to be a new proxy for monitoring regional environmental change as well as temporal climate variations in high southern latitudes.

  6. Understanding the Dynamic Neotectonic System in Antarctica

    NASA Astrophysics Data System (ADS)

    Wilson, T. J.

    2004-05-01

    Feedbacks and interactions between components of the earth system are fundamental to polar geodynamic processes. The Antarctic Neotectonics (ANTEC) group has developed a vision for a major interdisciplinary program to investigate linkages between neotectonic processes in Antarctica, focused on understanding 1) how the stress/strain regimes of the lithosphere respond to changing ice mass loads; 2) how glacial isostatic adjustment and the tectono-thermal structure of the lithosphere influence modern ice sheet dynamics; 3) how tectonic motions and magmatism are linked with fluctuations of the Antarctic ice sheets through the Cenozoic; and 4) how evolving continental-scale paleogeography, volcanism, and erosion/sedimentation influence climate change. A primary focus to address these science goals is achieving continental-scale deployments of remote geodetic and geophysical observatories across the continental interior. Developing technologies are beginning to allow observatory operation through the polar night, due to advances in power sources and data storage capacity. Continued development in these areas, as well as in communications technologies to allow data transfer from remote stations, is required. Ground-based experiments must be integrated with campaigns by spaceborne instruments, to discriminate cryosphere mass flux signals from neotectonic activity. Coordination of ground-based observatory deployments with ongoing efforts to develop airborne geophysical platforms and new drilling systems will facilitate mapping and sampling unknown subglacial terrain and the earth's deep interior. Promising new areas of investigation to understand how surface processes are linked with tectonism in polar environments lie in application of new mapping technologies (LIDAR, ice-penetrating radar), new chronological tools, and assimilation of new surface information into modeling. If we can meet the logistical and funding challenges of instrumenting the Antarctic interior on a

  7. Multi-instrument MLT study in Antarctica

    NASA Astrophysics Data System (ADS)

    Tsutsumi, M.; Syowa Mlt Team

    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.

  8. Tectonic structure of East Antarctica

    NASA Astrophysics Data System (ADS)

    Leychenkov, German; Grikurov, Garrik; Golynsky, Alexander

    2013-04-01

    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

  9. Geoethical approach to mineral activities in Antarctica

    NASA Astrophysics Data System (ADS)

    Talalay, Pavel

    2013-04-01

    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

  10. Wind profiler installed in Antarctica

    NASA Astrophysics Data System (ADS)

    Balsley, B. B.; Carey, J.; Woodman, R. F.; Sarango, M.; Urbina, J.; Rodriguez, R.; Ragaini, E.

    A VHF (50 MHz) wind profiler was installed in Antarctica at the Peruvian Base “Machu Picchu” on King George Island from January 21 to 26. The wind profiler will provide a first look at atmospheric dynamics over the region.The profiler—the first of its kind in Antarctica—is a National Science Foundationsponsored cooperative project of the University of Colorado, the Geophysical Institute of Peru, the University of Piura (Peru), and the Peruvian Navy. This venture was also greatly facilitated by Peru's Comision Nacional de Asuntos Antartidos and Consejo Nacional de Ciencias y Tecnologia, with additional logis tics support provided by the Argentinean Navy and the Uruguayan Air Force.

  11. Lithospheric Structure of Antarctica and Implications for Geological and Cryospheric Evolution

    NASA Astrophysics Data System (ADS)

    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

    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

  12. Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

    PubMed

    Yao, Yao; Meng, Xiang-Zhou; Wu, Chen-Chou; Bao, Lian-Jun; Wang, Feng; Wu, Feng-Chang; Zeng, Eddy Y

    2016-06-01

    Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe. The composition profiles of PAHs indicated that PAHs in the inland lakes were derived mainly from local oil spills, which was corroborated by a large number of fuel spillage reports from ship and plane crash incidents in Antarctica during recent years. Clearly, local human activities, rather than long-range transport, are the dominant sources of PAH contamination to the inland lakes. Finally, the present study demonstrates the efficacy of PE-based passive samplers for investigating PAHs in the aquatic environment of Antarctica under complex field conditions. PMID:26946176

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

    SciTech Connect

    White, G.J.

    1996-08-01

    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.

  14. Concentration and isotope ratio of sulfur species in snow along the route to Dome Fuji, Antarctica

    NASA Astrophysics Data System (ADS)

    Hirabayashi, M.; Motoyama, H.

    2014-12-01

    Snow ice sample in Antarctica contains particulate matter. Particulates originate from continent, volcano, sea, space, and organism. Methanesulfonate ion and sulfate ion are major sulfur compounds packed in snow ice in Antarctica. The isotopic ratio of an element reflects the origin and the history of the particle matter. Since the isotopic ratio of sulfur species depends on the source, the information about the source contribution of particulate matter can be estimated by analyzing the isotopic ratios of sulfur species. In this research, concentrations of sulfur species and isotopic ratios of sulfur species in snow collected on the route form coastal area to Dome Fuji station in Antarctica 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. Quantitative analyses of sulfur species were performed using ion chromatograph and quadrupole type mass spectrometer. The isotopic ratios of isolated sulfur species were measured using elemental analyzer and the magnetic field type mass spectrometer. Average concentrations and maximum concentration of methanesulfonate ion in the snow samples were 17 ng/ml and 123 ng/ml, respectively. Average concentrations and maximum concentration of sulfate ion were ng/ml 63 and 419 ng/ml, respectively. Further results and discussion about the behavior and origin of sulfur species in the snow will be presented.

  15. Antarctica natural laboratory and space analogue for psychological research.

    PubMed

    Suedfeld, P; Weiss, K

    2000-01-01

    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

  16. Yukimarimo at Dome C, Antarctica

    NASA Astrophysics Data System (ADS)

    Petenko, Igor

    2015-04-01

    Natural frostballs called "yukimarimo" were observed at at Dome C, Antarctica, during the winter of 2014. Frostballs have spheroidal or lightly oblate form. Four cases of the yukimarimo were observed in the period April - August. The characteristics concerning their sizes, density, distribution over the surface varied for different cases. The diameters ranged from several millimetres to 120 mm, the density ranged from 15 to 60 kg/m3 . The heaviest one weighted 14 g and had a diameter of ≈90 mm. The initial "material" from which they formed resembles candy floss or fluff. In one case, only the initial stage of the small-yukimarimo formation was observed; the further development was interrupted. The meteorological conditions observed diuring the yukimarimo were not particular. The near-surface temperature varied between -70° and -60°C. Winds favouring to the yukimarimo formation were low, but not less than 2 m/s^1. A two-step mechanism of their formation and development is assumed: 1) at the initial stage, an electrostatic attraction favours the clumping of ice crystals to form some ice mass resembling floss structured in spherical pieces; 2) some pieces of ice floss are rolled by the wind and collect more ice crystals and increase in size like to a tumbleweed. Special comprehensive studies of electrical properties of the frost during the initial stage are necessary. Videos of moving yukimarimo at different stages of their formation are available.

  17. Terra Nova Bay Polynya, Antarctica

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

  18. Space analogue studies in Antarctica

    NASA Astrophysics Data System (ADS)

    Lugg, D.; Shepanek, M.

    1999-09-01

    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.

  19. Space analogue studies in Antarctica

    NASA Technical Reports Server (NTRS)

    Lugg, D.; Shepanek, M.

    1999-01-01

    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.

  20. Antarctica: Scientific Journeys from McMurdo to the Pole.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    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…

  1. Space station

    NASA Technical Reports Server (NTRS)

    Stewart, Donald F.; Hayes, Judith

    1989-01-01

    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.

  2. Reasons for medical consultation among members of the Indian Scientific Expeditions to Antarctica

    PubMed Central

    Bhatia, Abhijeet; Malhotra, Pradip; Agarwal, Ashok Kumar

    2013-01-01

    The article attempts to analyze the disease burden in a healthy, pre-screened population subjected to prolonged residence in the hostile environment of Antarctica. This retrospective epidemiological study was conducted utilizing data from medical consultation room on board the Indian Antarctic expedition vessels and at Indian Antarctic station, Maitri from seven Indian Scientific Expeditions to Antarctica (ISEA). The study group (n=327) consisted of 325 men and two women. The total number of medical room consultations was 1989. Maximum consultations were for injuries (27.25%); 14.68% were musculoskeletal and 10.31% were bruises and lacerations. Disturbances of gastrointestinal tract (19.66%) were the second most common disorders. Psychological disturbances accounted for 2.66% consultations. Cold injuries constituted 2.01% consultations and photophthalmia accounted for 1.06% consultations. PMID:23423959

  3. Reasons for medical consultation among members of the Indian Scientific Expeditions to Antarctica.

    PubMed

    Bhatia, Abhijeet; Malhotra, Pradip; Agarwal, Ashok Kumar

    2013-01-01

    The article attempts to analyze the disease burden in a healthy, pre-screened population subjected to prolonged residence in the hostile environment of Antarctica. This retrospective epidemiological study was conducted utilizing data from medical consultation room on board the Indian Antarctic expedition vessels and at Indian Antarctic station, Maitri from seven Indian Scientific Expeditions to Antarctica (ISEA). The study group (n=327) consisted of 325 men and two women. The total number of medical room consultations was 1989. Maximum consultations were for injuries (27.25%); 14.68% were musculoskeletal and 10.31% were bruises and lacerations. Disturbances of gastrointestinal tract (19.66%) were the second most common disorders. Psychological disturbances accounted for 2.66% consultations. Cold injuries constituted 2.01% consultations and photophthalmia accounted for 1.06% consultations. PMID:23423959

  4. Space Station

    NASA Technical Reports Server (NTRS)

    Anderton, D. A.

    1985-01-01

    The official start of a bold new space program, essential to maintain the United States' leadership in space was signaled by a Presidential directive to move aggressively again into space by proceeding with the development of a space station. Development concepts for a permanently manned space station are discussed. Reasons for establishing an inhabited space station are given. Cost estimates and timetables are also cited.

  5. Annually-resolved temperature reconstructions of the past 2000 years from Dome-Fuji, East Antarctica

    NASA Astrophysics Data System (ADS)

    Motizuki, Yuko; Takahashi, Kazuya; Nakai, Yoichi; Motoyama, Hideaki

    2016-04-01

    We present annually-resolved temperature and SST reconstructions of the past 2000 years based on water (oxygen and deuterium) isotope measurement on a shallow ice core drilled in 2010 at Dome Fuji station, East Antarctica. These time series records will be an essential contribution to the PAGES 2k project from sparse data area in Antarctica. Dome Fuji station is located on a summit of Dronning Maud Land at an altitude of 3810 m a.s.l. (above sea level) (77o19'01'' S, 39o42'12'' E) in East Antarctica. The 10 m depth mean snow temperature at Dome Fuji is ‑57.3oC1). The inland area around Dome Fuji has been recognized to be especially unique: The snow and ice there contain much stratospheric information. The direct evidence for this comes from tritium contents originated from the nuclear bomb tests in the 1960s; the tritium fallout at the Dome Fuji site is outstandingly high among 16 snow pit samples widely collected over Antarctica2). To date the concerned Dome Fuji ice core, we applied volcanic signature matching to transfer the West Antarctic Ice Sheet (WAIS) Divide ice core chronology constructed by annual layer counting as used in the study by Sigl et al. (2014)3). In our presentation, we confine ourselves to discuss the oscillation periodicity that we observed in the oxygen isotope record in our data: The periods of approximately 10, 20, and 200 years were found. We will present the time series analyses for this in detail, and will discuss the origin of this periodicity. References: 1) Kameda, T., Motoyama, H., Fujita, S., and Takahashi, S.: "Past temporal and spatial variability of surface mass balance at Dome Fuji", East Antarctica, by the stake method from 1995 to 2006, J. Glaciol., 54, 107-116, 2008. 2) Fourre, E., Jean-Baptiste, P., Dapoigny, A., Baumier, D., Petit, J.-R., and Jouzel, J.: "Past and recent tritium levels in Arctic and Antarctic polar caps", Earth Planet. Sc. Lett., 245, 56-64, 2006. 3) Sigl, M., J. McConnell, M. Toohey, M. Curran, S. Das

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

    ERIC Educational Resources Information Center

    Campbell, Brian; Bindschadler, Robert

    2009-01-01

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

  7. Validation of EOS Aqua AMSR Sea Ice Products for East Antarctica

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  8. Frictionless Telescopes in Antarctica: Why and How?

    NASA Astrophysics Data System (ADS)

    Quattri, M.

    Seeing quality in Antarctica is in the hundredth arcseconds range out of the boundary layer. To take advantage of this quality telescopes should be in thermal equilibrium with the outside environment and should minimize the non linearity's like limit cycles which will deteriorate tracking. At the ESO Very Large Telescope (VLT) 8m telescopes this is realized using oil bearings and direct drives on the axes to avoid slip stick effects on the motion. In Antarctica this could be realized using magnetic bearings, possibly combined with motors, on the axes, with also advantages concerning power consumptions and maintenance of the system.

  9. 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.

  10. Live from Antarctica: Then and Now

    NASA Technical Reports Server (NTRS)

    1994-01-01

    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.

  11. Acting Antarctica: science on stage

    NASA Astrophysics Data System (ADS)

    Ciceri, Piera; Tizzoni, Paola; Pierro, Luigia

    2016-04-01

    Key-words: Polar science, Earth science, Theatre, Hands on activities The legendary Antarctic Expedition of sir E. Shackleton and his crew of 27 aboard the Endurance (1914/16) trapped in the Antarctic ice has become the starting point to learn about Polar Science and Climate Change. While the students were involved into this incredible adventure by the astonishing images of the Australian photographer Frank Hurley (who joined the crew), they discovered the world in which this story happened. Students were then involved in hands-on activities and role plays and have become the writers of the play "Uomini a scienza ai confini del mondo". They act the story of Shackelton's expedition and they tell at the same time to the audience about ice pack, ice cores and their role in understanding the past of the climate, physical and geographical characteristic of polar regions, thermal phenomena related to adaptations of polar animals, solar radiation at different latitude, day/night duration. The theater was the place to "stage" some scientific experiments and to explain the current research carried out in polar regions and their importance in climate change studies and to stress some similarities between Antarctica and space. The project was carried out from teachers of science, letters and geography and was born in collaboration with the "Piccolo Teatro di Milano" and the association "Science Under 18" with the support of a professional actor and director and was played for other schools at "EXPO 2015" in Milano (Italy). In our opinion drama activities improve reading comprehension, and both verbal and non-verbal communication skills. To be able to write and to act, students need a deep understanding of contents. Arts, including theatre, are a good key to involve emotionally students. To have an audience different from their own teachers and classmates offers a real task and the opportunity to play and let grow real skills.

  12. Sleep and Mood During A Winter in Antarctica

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  13. The Bess-Polar II Long Duration Flight Above Antarctica

    NASA Technical Reports Server (NTRS)

    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

    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

  14. Antarctica--the Ultimate Summer Institute.

    ERIC Educational Resources Information Center

    Van Wey, Nate J.

    1995-01-01

    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…

  15. Antarctica: What Shall We Do with It?

    ERIC Educational Resources Information Center

    Branson, Margaret S.; Long, Cathryn J.

    1977-01-01

    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)

  16. CyberHunt: Head Off to Antarctica.

    ERIC Educational Resources Information Center

    Kloza, Brad

    2001-01-01

    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)

  17. Read--and Walk--to Antarctica

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

  18. Lystrosaurus zone (triassic) fauna from antarctica.

    PubMed

    Kitching, J W; Collinson, J W; Elliot, D H; Colbert, E H

    1972-02-01

    Tetrapod skeletons recently found in the Fremouw Formation in the Shackleton Glacier area, Transantarctic Mountains, include several forms that closely compare to South African species. Faunal similarities that confirm a close connection between Antarctica and Africa during the Triassic Period lend further support to the concept of Gondwanaland and continental drift. PMID:17755654

  19. Antarctica: Is It More Than Just Ice?

    ERIC Educational Resources Information Center

    Johnson, Cheryl; Gutierrez, Melida

    2009-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  1. Application of a Terrestrial LIDAR System for Elevation Mapping in Terra Nova Bay, Antarctica.

    PubMed

    Cho, Hyoungsig; Hong, Seunghwan; Kim, Sangmin; Park, Hyokeun; Park, Ilsuk; Sohn, Hong-Gyoo

    2015-01-01

    A terrestrial Light Detection and Ranging (LIDAR) system has high productivity and accuracy for topographic mapping, but the harsh conditions of Antarctica make LIDAR operation difficult. Low temperatures cause malfunctioning of the LIDAR system, and unpredictable strong winds can deteriorate data quality by irregularly shaking co-registration targets. For stable and efficient LIDAR operation in Antarctica, this study proposes and demonstrates the following practical solutions: (1) a lagging cover with a heating pack to maintain the temperature of the terrestrial LIDAR system; (2) co-registration using square planar targets and two-step point-merging methods based on extracted feature points and the Iterative Closest Point (ICP) algorithm; and (3) a georeferencing module consisting of an artificial target and a Global Navigation Satellite System (GNSS) receiver. The solutions were used to produce a topographic map for construction of the Jang Bogo Research Station in Terra Nova Bay, Antarctica. Co-registration and georeferencing precision reached 5 and 45 mm, respectively, and the accuracy of the Digital Elevation Model (DEM) generated from the LIDAR scanning data was ±27.7 cm. PMID:26389918

  2. Application of a Terrestrial LIDAR System for Elevation Mapping in Terra Nova Bay, Antarctica

    PubMed Central

    Cho, Hyoungsig; Hong, Seunghwan; Kim, Sangmin; Park, Hyokeun; Park, Ilsuk; Sohn, Hong-Gyoo

    2015-01-01

    A terrestrial Light Detection and Ranging (LIDAR) system has high productivity and accuracy for topographic mapping, but the harsh conditions of Antarctica make LIDAR operation difficult. Low temperatures cause malfunctioning of the LIDAR system, and unpredictable strong winds can deteriorate data quality by irregularly shaking co-registration targets. For stable and efficient LIDAR operation in Antarctica, this study proposes and demonstrates the following practical solutions: (1) a lagging cover with a heating pack to maintain the temperature of the terrestrial LIDAR system; (2) co-registration using square planar targets and two-step point-merging methods based on extracted feature points and the Iterative Closest Point (ICP) algorithm; and (3) a georeferencing module consisting of an artificial target and a Global Navigation Satellite System (GNSS) receiver. The solutions were used to produce a topographic map for construction of the Jang Bogo Research Station in Terra Nova Bay, Antarctica. Co-registration and georeferencing precision reached 5 and 45 mm, respectively, and the accuracy of the Digital Elevation Model (DEM) generated from the LIDAR scanning data was ±27.7 cm. PMID:26389918

  3. Receiver functions from west Antarctica; crust and mantle properties from POLENET

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    We use receiver functions to extract crustal thickness and mantle transition zone depths across a wide extent of West Antarctica and the Transantarctic mountains using POLENET data, including recently recovered data from a 14-station West Antarctic Rift Zone transect. An adaptive approach for generating and analyzing P-receiver functions over ice sheets and sedimentary basins (similar to Winberry and Anandakrishnan, 2004) is applied using an extended time multitaper deconvolution algorithm and forward modeling synthetic seismogram fitting. We model P-S receiver functions via a layer stripping methodology (beginning with the ice sheet, if present), and fit increasingly longer sections of synthetic receiver functions to model the multiples observed in the data derived receiver functions. We additionally calculate S-P receiver functions, which provide complementary structural constraints, to generate consistent common conversion point stacks to image crustal and upper mantle discontinuities under West Antarctica. Crust throughout West Antarctica is generally thin (23-29 km; comparable to the U.S. Basin and Range) with relative thickening under the Marie Byrd Land volcanic province (to 32 km) and the Transantarctic Mountains. All constrained west Antarctic crust is substantially thicker than that in the vicinity of Ross Island, where crust as thin as 17 km is inferred in the Terror Rift region.

  4. Trace element contamination and availability in the Fildes Peninsula, King George Island, Antarctica.

    PubMed

    Padeiro, Ana; Amaro, Eduardo; Dos Santos, Margarida M C; Araújo, Maria F; Gomes, Susana S; Leppe, Marcelo; Verkulich, Sergey; Hughes, Kevin A; Peter, Hans-Ulrich; Canário, João

    2016-06-15

    The Ardley Cove area (located on the Maxwell Bay shoreline, Fildes Peninsula, King George Island, Antarctica) is characterized not only by its high biodiversity, but also by a high density of scientific stations, making it potentially one of the most impacted areas of Antarctica. In order to assess the source, contamination levels, distribution and availability of several trace elements (Cr, Ni, Cu, Zn, As, Pb, Cd and Hg) in and around Maxwell Bay, soil and seawater samples were collected. Soil samples were also collected in the study reference site near the Bellingshausen Dome area, as it lies far from centers of human activity and associated infrastructure. Enrichment factors (EFs) and sequential extractions were also used to assess the degree of contamination and availability of the trace elements under investigation. The results obtained in this study pointed to the existence of several contamination hotspots, mainly related to high levels of Zn, Pb, Cd, Cr and Ni. Comparison of the contaminant distribution patterns with data from earlier studies allowed the identification of anthropogenic sources. Use of the EF approach and sequential extractions confirmed these findings. In particular, higher extraction proportions were obtained for Zn and Pb (68 and 71%, respectively), which were also the same elements where the highest EFs were determined. The results obtained in this study clearly point to human impact on the natural environment in this region of Antarctica and we recommend the implementation of appropriate contamination control and remediation methods. PMID:27224418

  5. Lithospheric Structure and Seismotectonics of Central East Antarctica

    NASA Astrophysics Data System (ADS)

    Reading, A. M.

    2006-12-01

    The lithosphere of central East Antarctica, the sector of the continent between 30°E - 120°E, is investigated using seismic methods including receiver function and shear-wave splitting analysis. Data from the broadband stations of the temporary SSCUA deployment (in the continental interior) are used together with records from the permanent GSN stations (on the coast) to carry out the first studies of crustal depth and structure, and patterns of seismic anisotropy across this region. The depth of the Moho is found to be 42 km (+/- 2 km) beneath Mawson station with similar structures extending southward across the Rayner province as far south as Beaver Lake. The Fisher Terrane is characterised by a crustal shear wavespeed profile showing few discontinuties with the Moho at a similar depth to the Rayner. South of Fisher, the crust becomes much shallower, with the Moho at 32 km depth. This shallow crust extends across the Lambert glacier to the Prydz coast and the Lambert Terrane. The characteristic crustal wavespeed profiles provide baseline structure for mapping the extent of the terrance beneath the Antarctic Ice Sheet in future deployments. Observations of seismic anisotropy are less well- defined but, at a reconnaissance level, show fast directions parallel to the present day coastline. This may be controlled by rift-related influences on the lithosphere associated with the breakup of East Gondwana. The seismicity is confirmed to be extremely low. The only seismogenic forces on the Antarctic plate in this region are acting at the boundary between the continental and oceanic lithosphere west of 50°E and east of 100°E and represent a superposition of tectonic and glaciogenic controls. The Lambert Glacier region shows little or no seismotectonic activity in the continental interior or on the oceanic margin.

  6. Multiple meteoroid impact in Antarctica

    NASA Astrophysics Data System (ADS)

    Weihoupt, J. W.; Rice, A.; van der Hoeven, F.

    2006-12-01

    In the late 1950's, geophysical field parties undertaking gravity surveys across Antarctica observed over a large area of Wilkes Land (> 240km across) an exceptionally pronounced negative free air anomaly ((to -158.3 mgal). This area was later interpreted as a possible meteor impact site because the gravity profiles were similar to those of known impact sites (apparent rim structures, circular basins, central peaks or rings), they possessed appropriate aspect ratios (e.g., crater diameter vs crater depth), anomalously steep negative free air gravity anomaly gradients (to 4.71 mgal/km) were characteristic of impact craters and uncharacteristic of solely mantle-related or geologic crustal variations, etc. The condition of the ice covering the anomaly (heavily crevassed), the apparent lack of isostatic compensation with surrounding environs, etc suggested the impact was geologically recent and that perhaps a tektite strewn field was associated with it. The distance from the postulated impact to the Australian strewn field was appropriate as are the ages of the tektites there. This early work has been augmented with the detection of a dominant cluster of negative free air gravity anomalies crossing the continental-oceanic boundary, and the East and West Antarctic structural boundary (i.e., Transantarctic Mountains). These anomalies are coincident with complex subglacial craterform topographic features inferred from radiosounding (to -500m below MSL). The major interior positive free air gravity anomalies are associated with subglacial topographic highs. The elliptical distribution of the negative gravity anomalies resemble known multiple impact distributions (scatter ellipses with the larger anomalies forward and the lesser ones aft). This more recent information favors expanding the original proposal to that of a multiple meteoroid impact. The multiple impact hypotheses would explain aeromagnetic surveys revealing ring-shaped structures in the subglacial rock surface

  7. Molecular composition of atmospheric aerosols from Halley Bay, Antarctica, using ultra-high resolution mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kourtchev, Ivan; Brough, Neil; Rincon, Angela; Jones, Anna; Kalberer, Markus

    2016-04-01

    Antarctica is one of the few pristine places to study natural processes of atmospheric aerosols and anthropogenic impacts on the clean remote atmosphere. Although stratospheric aerosol in Antarctica has now been explored in some detail because of the ozone depletion phenomenon, tropospheric aerosol particles in Antarctica remain very little studied. The main goal of this work is to identify in detail the organic chemical composition of aerosol from Halley Bay station, which is located on the Brunt Ice Shelf floating on the Weddell Sea in Antarctica. In this study we characterise the molecular composition of aerosols from three seasons (summer, autumn and winter in 2012) using ultra-high resolution mass spectrometry (UHRMS). The technique provides high accuracy and high mass resolving power that allows determining unambiguous number of organic compounds present in complex organic mixtures (Noziere et al., 2015). The molecular composition interpretation was facilitated using visualisation methods (e.g. double bond equivalent, Van Krevelen diagrams, Kendrick mass analysis, and carbon oxidation state), which allowed to identify patterns, such as differences between sampling times and atmospheric processes. The majority of the identified compounds were attributed to nitrogen and sulphur containing species which exhibited very strong seasonal trends. Relatively large fraction (up to 30% of the total number of molecules) of these species contained very low hydrogen to carbon ratios (below 1) indicating that the site is impacted by anthropogenic emissions. Influences of the meteorological parameters and air mass trajectories on the molecular composition are discussed. Nozière et al., The Molecular Identification of Organic Compounds in the Atmosphere: State of the Art and Challenges, Chem. Rev., 115, 3920-3983, 2015.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  9. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  10. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  11. Planetary geomorphology field studies: Iceland and Antarctica

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1984-01-01

    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.

  12. Intercomparison of ozone measurements over Antarctica

    NASA Technical Reports Server (NTRS)

    Margitan, J. J.; Farmer, C. B.; Toon, G. C.; Brothers, G. A.; Browell, E. V.; Gregory, G. L.; Hypes, W.; Larsen, J. C.; Mccormick, M. P.; Krueger, A. J.

    1989-01-01

    Measurements of the abundances of ozone over Antarctica 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 ozone sondes from four sites in Antarctica. 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 percent, 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.

  13. The Landsat Image Mosaic of Antarctica

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  14. Life on ice, Antarctica and Mars

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  15. Observation Station

    ERIC Educational Resources Information Center

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  16. The Ice: A Journey to Antarctica

    NASA Astrophysics Data System (ADS)

    Ford, Arthur B.

    The title is misleading for a non—“OAE” (Old Antarctic Explorer, to whom “The Ice” is Antarctica) because The Ice is about far more than just ice. It does indeed cover just about all you'd want to know (or more) about Antarctic ice, from the vast south polar sheets and glaciers to the great tabular bergs, bergy bits, brash ice, pancake ice, frazil ice, and the pack of the polar seas; but it also explores nearly every aspect of this “Last of Lands” in an unusually comprehensive coverage. From the “Heroic Ages” of early 20th-century explorers Robert Scott, Ernest Shackleton, and Roald Amundsen to the present “Cruise Ship Age,”Antarctica has produced a wealth of literature in the “Journey to…” style — which Pyne's is not. Instead, his product from one short (3-month) visit under a National Endowment for the Humanities fellowship takes all readers o n a webwork journey through time, space, ice, and rocks for an appreciation of “ The Ice” in a way found in no other book. This, his fifth book (another one is Fire in America, Princeton University Press, Princeton, N.J., 1982), is a significant contribution to the literature of Antarctica. Pyne's prose cannot be paraphrased for a review, as the reader will be able to appreciate from the excerpts to follow.

  17. Indicator Species Population Monitoring in Antarctica with Uav

    NASA Astrophysics Data System (ADS)

    Zmarz, A.; Korczak-Abshire, M.; Storvold, R.; Rodzewicz, M.; Kędzierska, I.

    2015-08-01

    A program to monitor bird and pinniped species in the vicinity of Arctowski Station, King George Island, South Shetlands, Antarctica, has been conducted over the past 38 years. Annual monitoring of these indicator species includes estimations of breeding population sizes of three Pygoscelis penguin species: Adélie, gentoo and chinstrap. Six penguin colonies situated on the western shores of two bays: Admiralty and King George are investigated. To study changes in penguin populations Unmanned Aerial Vehicles were used for the first time in the 2014/15 austral summer season. During photogrammetric flights the high-resolution images of eight penguin breeding colonies were taken. Obtained high resolution images were used for estimation of breeding population size and compared with the results of measurements taken at the same time from the ground. During this Antarctic expedition eight successful photogrammetry missions (total distance 1500 km) were performed. Images were taken with digital SLR Canon 700D, Nikon D5300, Nikon D5100 with a 35mm objective lens. Flights altitude at 350 - 400 AGL, allowed images to be taken with a resolution GSD (ground sample distance) less than 5 cm. The Image J software analysis method was tested to provide automatic population estimates from obtained images. The use of UAV for monitoring of indicator species, enabled data acquisition from areas inaccessible by ground methods.

  18. Thermalizing a telescope in Antarctica - analysis of ASTEP observations

    NASA Astrophysics Data System (ADS)

    Guillot, T.; Abe, L.; Agabi, A.; Rivet, J.-P.; Daban, J.-B.; Mékarnia, D.; Aristidi, E.; Schmider, F.-X.; Crouzet, N.; Gonçalves, I.; Gouvret, C.; Ottogalli, S.; Faradji, H.; Blanc, P.-E.; Bondoux, E.; Valbousquet, F.

    2015-09-01

    The installation and operation of a telescope in Antarctica represent particular challenges, in particular the requirement to operate at extremely cold temperatures, to cope with rapid temperature fluctuations and to prevent frosting. Heating of electronic subsystems is a necessity, but solutions must be found to avoid the turbulence induced by temperature fluctuations on the optical paths. ASTEP 400 is a 40 cm Newton telescope installed at the Concordia station, Dome C since 2010 for photometric observations of fields of stars and their exoplanets. While the telescope is designed to spread star light on several pixels to maximize photometric stability, we show that it is nonetheless sensitive to the extreme variations of the seeing at the ground level (between about 0.1 arcsec and 5 arcsec) and to temperature fluctuations between -30 oC and -80 oC. We analyze both day-time and night-time observations and obtain the magnitude of the seeing caused by the mirrors, dome and camera. The most important effect arises from the heating of the primary mirror which gives rise to a mirror seeing of 0.23 arcsec K-1. We propose solutions to mitigate these effects.

  19. SIAMOIS: An Asteroseismic Network with 1 Site in Antarctica

    NASA Astrophysics Data System (ADS)

    Mosser, B.; Siamois Group

    2006-11-01

    SIAMOIS is a project devoted to ground-based asteroseismology, involving an instrument to be installed at the Dome C Concordia station in Antarctica. 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. As a consequence, S IAMOIS is the only asteroseismic programme that can follow the way opened by the space project C O ROT: it will provide unique information on G and K type bright stars on the main sequence. In addition, spectrometric observations with S IAMOIS will be able to detect oscillation modes that cannot be analysed in photometry, and will be less affected by stellar activity noise, increasing the complementarity with space-based photometric observations.

  20. Analysis of continuous GPS measurements from southern Victoria Land, Antarctica

    USGS Publications Warehouse

    Willis, Michael J.

    2007-01-01

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

  1. Present and Future Observations of the Earthshine from Antarctica

    NASA Astrophysics Data System (ADS)

    Briot, Danielle; Arnold, Luc; Jacquemoud, Stéphane

    2013-01-01

    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.

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

    USGS Publications Warehouse

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

    1988-01-01

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

  3. Volcano Monitoring with Coda Wave Interferometry at Mount Erebus, Antarctica

    NASA Astrophysics Data System (ADS)

    Gret, A.; Snieder, R.; Aster, R.

    2003-12-01

    Multiply-scattered waves dominate the late seismic coda. Small changes in the medium that would have no detectable influence on the first arrivals can be highly amplified by multiple scattering and readily observed in the coda. We apply coda wave interferometry to monitor subsurface temporal changes at Mount Erebus Volcano, Ross Island, Antarctica. Erebus is one of the few volcanoes known to have an open conduit system hosting a persistent convecting lava lake. Strombolian eruptions, caused by the explosive decompression of large bubbles of exsolved volatiles disrupt the lake itself, which subsequently refills within a few minutes. Because of the recoverability of this system, these eruptions provide a repeatable seismic source of seismic waves for sampling the strongly scattering volcano. Repeating eruption seismograms have been recorded at fixed station sites over several years, and the coda is seen to be highly reproducible over extended periods of time. We find waveform correlation coefficients as high as 0.98 for short-period seismograms recorded up to several days apart. However, in comparing seismograms separated by approximately a month, we note a small decrease in correlation. Furthermore, we see a much larger decorrelation of the waveforms spanning a time period of one or even two years. Coda energy is thus providing information on systematic source and/or subsurface changes.

  4. Multi-sensor observation of precipitation in a coastal region of Antarctica

    NASA Astrophysics Data System (ADS)

    Berne, Alexis; Grazioli, Jacopo; Genthon, Christophe; DelGuasta, Massimo

    2016-04-01

    In the framework of a Italian-French-Swiss collaboration, a suite of instruments dedicated to the observation of solid precipitation was deployed at the French Antarctic station Dumont d'Urville on the coast of Adélie Land in Antarctica during (southern) summer 2015-2016. On the remote sensing side, a depolarization lidar (531 nm), a 24-GHz vertical Doppler profiler (MRR from Metek) and a scanning X-band polarimetric radar (called MXPol) were nearly collocated. For measurement at the ground level, a weather station (for local meteorological conditions), a weighing gauge (Pluvio2 from OTT, with wind shield), an optical disdrometer (Biral) and a multi-angle snowflake camera (MASC) were complementing the remote sensing instruments. In addition, daily radiosounding records collected by MeteoFrance were available. This experimental set up was built in order to investigate the added value of remote sensing for the monitoring and understanding of Antarctic precipitation (variability, microphysics), as well as to collect reference data for the evaluation of satellite precipitation products derived from CloudSat and simulated from numerical prediction weather models. Moreover, the potential of radar measurement to distinguish blowing snow from precipitation, an acute problem in the windy coastal regions of Antarctica, was also investigated. This contribution presents the motivation, the set-up and a first analysis of this unprecedented data set about Antarctic precipitation.

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

    NASA Astrophysics Data System (ADS)

    Dibbern, J. S.

    1987-02-01

    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.

  6. Bioaccumulation of heavy metals in marine organisms and sediments from Admiralty Bay, King George Island, Antarctica.

    PubMed

    Trevizani, Tailisi Hoppe; Figueira, Rubens Cesar Lopes; Ribeiro, Andreza Portella; Theophilo, Carolina Yume Sawamura; Majer, Alessandra Pereira; Petti, Monica Angélica Varella; Corbisier, Thais Navajas; Montone, Rosalinda Carmela

    2016-05-15

    The Antarctic continent is considered a low-impact environment; however, there is a tendency to increase the contaminants' levels due to human activities in the research stations. In this study, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn levels in sediment and biota were determined in the environmental samples from Admiralty Bay (King George Island, Antarctica) collected in 2003. The results demonstrated high concentrations of Cu and Zn in the sediments. There was bioaccumulation of As in the biota from Admiralty Bay and bioaccumulation of Zn specifically in the biota from Martel Inlet. In addition, the results were useful in order to understand the heavy metal levels for the pre-accident condition of Comandante Ferraz Antarctic Station, where an accident occurred in 2012, and also for the comparison with current conditions within the monitoring work developed by INCT-APA (National Institute of Science and Technology for Environmental Research Antarctic). PMID:26936119

  7. Monitoring of nitrogen dioxide, ozone and halogens radicals in Antarctica

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  8. Macromolecular compositions of phytoplankton in the Amundsen Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Kim, Bo Kyung; Lee, Jang Han; Joo, HuiTae; Song, Ho Jung; Yang, Eun Jin; Lee, Sang Hoon; Lee, Sang H.

    2016-01-01

    The biochemical compositions (proteins, carbohydrates, and lipids) of phytoplankton provide useful information for their environmental growth conditions and nutritional status as a basic food source for upper trophic consumers. Concentrations of these compositions were assessed at 100, 30, and 1% light penetration depths within the euphotic zone in the Amundsen Sea, Antarctica, using colorimetric techniques. The major inorganic nutrients were generally abundant throughout the study area. The average chlorophyll a (chl-a) concentration was 49.2 mg m-2 (S.D.=±27.6 mg m-2) and large phytoplankton (>20 μm) accounted for 64.1% of the total chl-a concentration. The biochemical compositions of the phytoplankton were not significantly different among different light depths or productivity stations. The overall compositions of proteins, carbohydrates, and lipids from all stations averaged 65.9% (S.D.=±12.5%), 22.4% (S.D.=±10.9%), and 11.7% (S.D.=±6.5%), respectively. Regardless of dominant phytoplankton species, nitrogen-abundant conditions sustained high protein compositions of phytoplankton in the Amundsen Sea during the cruise period. Based on the macromolecular compositions, the average food material (FM) concentration was 219.4 μg L-1 (S.D.=±151.1 μg L-1) and correlated positively with the primary productivity in the Amundsen Sea. High protein/carbohydrate ratios (>1) and large proportions of proteins suggest that phytoplankton provide nitrogen-sufficient foods to higher trophic consumers through a higher efficiency of protein carbon incorporated into herbivores.

  9. Anthropogenic and natural disturbances to marine benthic communities in Antarctica

    SciTech Connect

    Lenihan, H.; Oliver, J.S.

    1995-05-01

    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.

  10. PUTATIVE STRESS REGULATED GENES OF THE ANTARCTIC MIDGE, BELGICA ANTARCTICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. STRESS PROTEINS OF THE ANTARCTIC MIDGE, BELGICA ANTARCTICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Understanding the ECMWF winter surface temperature biases over Antarctica

    NASA Astrophysics Data System (ADS)

    Dutra, Emanuel; Sandu, Irina; Balsamo, Gianpaolo; Beljaars, Anton; Freville, Helene; Vignon, Etienne; Brun, Eric

    2016-04-01

    Atmospheric reanalysis provide long-term estimates of the state of the atmosphere and surface. However, the reanalysis quality is dependent on the quality and quantity of observations used by the data assimilation systems and by the performance of the forecast model. Recent studies have found that the ECMWF ERA-Interim reanalysis has a warm bias of surface temperature over Antarctica. We evaluate several factors that could explain this bias of surface temperature, and to some extent 2-meters temperature, in the ECMWF model and ERA-Interim reanalysis over Antarctica during winter. We focused on the Polar night where the solar radiation and latent heat fluxes can be neglected. Four main changes, derived from the surface energy balance, were tested including (i) reduction of the snow thermal inertia, (ii) full decoupling of the skin layer from the surface; (iii) reduced roughness lengths and (iv) different stability functions for the transfer coefficients calculations in the surface layer. Different configurations were tested within the ECMWF Integrated Forecasts System (IFS) in short-range forecasts and in stand-alone surface-only simulations at South Pole station. It was found that the model underestimates strong radiative cooling events and this can be mainly associated with a too strong land-atmosphere coupling over glaciers. The reduction of the snow thermally active depth had a positive effect allowing the model to better represent those radiative cooling effects. The reduction of the roughness lengths and the different stability functions also result in further cooling in stand-alone mode, but their impact was not so pronounced in the coupled forecasts. In general, averaged over the Antarctic continent, the reduction of the snow thermal active depth leads to a cooling of 1 K. The reduction of the roughness lengths resulted in an additional cooling of about 1 K. Our results indicate that the representation of a fast time scale to the thermal exchanges between

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

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

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

  14. Antarctica: measuring glacier velocity from satellite images

    SciTech Connect

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

    1986-11-28

    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.

  15. Antarctica: Measuring glacier velocity from satellite images

    USGS Publications Warehouse

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

    1986-01-01

    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.

  16. Low deuterium content of Lake Vanda, Antarctica

    USGS Publications Warehouse

    Ragotzkie, R.A.; Friedman, I.

    1965-01-01

    Lake Vanda in Victoria Land, Antarctica, is permanently ice-covered and permanently stratified, with warm, salty water near the bottom. Deuterium analyses of lake water from several levels indicate that the lake has a low deuterium content, and that it is stratified with respect to this isotope. This low deuterium content supports the evidence from the lake's ionic content that the saline layer is not of marine origin, and it indicates that evaporation from the ice surface has taken place. The stratification of the lake with respect to deuterium suggests that the upper and lower layers of water were formed at different times from different sources of glacial melt water.

  17. Exhumation of the Shackleton Range, Antarctica

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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

  18. U.S. Geological Survey Scientific Activities in the Exploration of Antarctica: Introduction to Antarctica (Including USGS Field Personnel: 1946-59)

    USGS Publications Warehouse

    Tony K. Meunier Edited by Williams, Richard S., Jr.; Ferrigno, Jane G.

    2007-01-01

    international) programs in biology, geology, geophysics, hydrology, and mapping. Therefore, the USGS was the obvious choice for these tasks, because it already had a professional staff of experienced mapmakers, scientists, and program managers with the foresight, dedication, and understanding of the need for accurate maps to support the science programs in Antarctica when asked to do so by the U.S. National Academy of Sciences. Public Laws 85-743 and 87-626, signed in August 1958, and in September 1962, respectively, authorized the Secretary, U.S. Department of the Interior, through the USGS, to support mapping and scientific work in Antarctica (Meunier, 1979 [2007], appendix A). Open-File Report 2006-1116 includes scanned facsimiles of postal cachets. It has become an international practice to create postal cachets to commemorate special events and projects in Antarctica. A cachet is defined as a seal or commemorative design printed or stamped on an envelope to mark a philatelic or special event. The inked impression illustrates to the scientist, historian, stamp collector, and general public the multidisciplinary science projects staffed by USGS and collaborating scientists during the field season. Since 1960, philatelic cachets have been created by team members for each USGS field season and, in most cases, these cachets depict the specific geographic areas and field season program objectives. The cachets become a convenient documentation of the people, projects, and geographic places of interest for that year. Because the cachets are representative of USGS activities, each year's cachet is included as a digital facsimile in that year's Open-File Report. In the 1980s, multiple USGS cachets were prepared each year, one for use by the winter team at Amundsen-Scott South Pole Station and the other for the project work areas of the austral summer field season programs.

  19. Applications of Subspace Seismicity Detection in Antarctica

    NASA Astrophysics Data System (ADS)

    Myers, E. K.; Aster, R. C.; Benz, H.; McMahon, N. D.; McNamara, D. E.; Lough, A. C.; Wiens, D. A.; Wilson, T. J.

    2014-12-01

    Subspace detection can improve event recognition by enhancing the completeness of earthquake catalogs and by improving the characterization and interpretation of seismic events, particularly in regions of clustered seismicity. Recent deployments of dense networks of seismometers enable subspace detection methods to be more broadly applied to intraplate Antarctica, where historically very limited and sporadic network coverage has inhibited understanding of dynamic glacial, volcanic, and tectonic processes. In particular, recent broad seismographic networks such as POLENET/A-Net and AGAP provide significant new opportunities for characterizing and understanding the low seismicity rates of this continent. Our methodology incorporates three-component correlation to detect events in a statistical and adaptive framework. Detection thresholds are statistically assessed using phase-randomized template correlation levels. As new events are detected and the set of subspace basis vectors is updated, the algorithm can also be directed to scan back in a search for weaker prior events that have significant correlations with the updated basis vectors. This method has the resolving power to identify previously undetected areas of seismic activity under very low signal-to-noise conditions, and thus holds promise for revealing new seismogenic phenomena within and around Antarctica. In this study we investigate two intriguing seismogenic regions and demonstrate the methodology, reporting on a subspace detection-based study of recently identified clusters of deep long-period magmatic earthquakes in Marie Byrd Land, and on shallow icequakes that are dynamically triggered by teleseismic surface waves.

  20. Cenozoic motion between East and West Antarctica

    PubMed

    Cande; Stock; Muller; Ishihara

    2000-03-01

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

  1. The Landsat Image Mosaic of Antarctica

    USGS Publications Warehouse

    Bindschadler, R.; Vornberger, P.; Fleming, A.; Fox, A.; Mullins, J.; Binnie, D.; Paulsen, S.J.; Granneman, B.; Gorodetzky, D.

    2008-01-01

    The Landsat Image Mosaic of Antarctica (LIMA) is the first true-color, high-spatial-resolution image of the seventh continent. It is constructed from nearly 1100 individually selected Landsat-7 ETM+ scenes. Each image was orthorectified and adjusted for geometric, sensor and illumination variations to a standardized, almost seamless surface reflectance product. Mosaicing to avoid clouds produced a high quality, nearly cloud-free benchmark data set of Antarctica for the International Polar Year from images collected primarily during 1999-2003. Multiple color composites and enhancements were generated to illustrate additional characteristics of the multispectral data including: the true appearance of the surface; discrimination between snow and bare ice; reflectance variations within bright snow; recovered reflectance values in regions of sensor saturation; and subtle topographic variations associated with ice flow. LIMA is viewable and individual scenes or user defined portions of the mosaic are downloadable at http://lima.usgs.gov. Educational materials associated with LIMA are available at http://lima.nasa.gov.

  2. Trace metals in Antarctica related to climate change and increasing human impact.

    PubMed

    Bargagli, R

    2000-01-01

    Metals are natural constituents of the abiotic and biotic components of all ecosystems, and under natural conditions they are cycled within and between the geochemical spheres--the atmosphere, lithosphere, hydrosphere, and biosphere--at quite steady fluxes. In the second half of the twentieth century, the huge increase in energy and mineral consumption determined anthropogenic emissions of several metals exceeding those from natural sources, e.g., volcanoes and windborne soil particles. In the Northern Hemisphere, the biogeochemical cycles of Pb, Cd, Zn, Cu, and other metals were significantly altered, even in Arctic regions. On the contrary, available data on trace metal concentrations in abiotic matrices from continental Antarctica, summarized in this review, suggest that the biogeochemical cycle of Pb is probably the only one that has been significantly altered by anthropogenic emissions in Antarctica and elsewhere in the Southern Hemisphere, especially in the period 1950-1975. Environmental contamination by other metals from anthropogenic sources in Antarctica itself can generally only be detected in snow samples taken within a range of a few kilometers or several hundred meters from scientific stations. Local metal pollution from human activities in Antarctica may compromise studies aimed at assessing the biogeochemical cycle of trace elements and the effects of global climate change. Thus, this review focuses on concentrations of metals in atmospheric particulate, snow, surface soils, and freshwater from the Antarctic continent and surface sediments and seawater from the Southern Ocean, which can plausibly be regarded as global background values of trace elements. These baselines are also necessary in view of the construction of new stations, the expansion of existing facilities to support research, and the growth of tourism and fisheries. Despite difficulties in making comparisons with data from other remote areas of the world, concentrations of trace metals

  3. The French-Italian Concordia Station

    NASA Astrophysics Data System (ADS)

    Mekarnia, Djamel; Frenot, Yves

    2013-01-01

    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.

  4. Measurements in polar stratospheric clouds over Antarctica in September 1989

    NASA Technical Reports Server (NTRS)

    Deshler, Terry

    1991-01-01

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

  5. Seismicity in the vicinity of Ross Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Rowe, C. A.; Kienle, J.

    1986-12-01

    Earthquakes in the Ross Sea, Antarctica, are of two types: volcanic, and those which appear to be of tectonic origin. Volcanic events in the vicinity of Ross Island are associated exclusively with Mount Erebus, Ross Island; this volcano erupts regularly, generating several earthquakes per day whose characteristics are quite distinct from non-volcanic events. These nonvolcanic earthquakes are recognizable by their distinct P- and S-wave arrivals, and a lack of the high frequency, often monochromatic character typical of Erebus events. One hundred fifty-seven tectonic microearthquakes (M < 2.0) were recorded in 1983 and 1984 by the ten station network on Ross Island; these events were located using the least-squares routine, HYPOELLIPSE. Of these events, 106 have RMS residual traveltime errors of less than or equal to 0.6 seconds; they are clustered in the vicinity of Ross Island, but are not restricted to it. There is a linear trend of epicenters cutting across the island and continuing northward. Most activity seems to center beneath Mount Terra Nova, between Mount Erebus and Mount Terror. Mean depth for events is 8.2 km; however, depths are rather evenly distributed over a range of 0 to 25 km. Modelling based on Bouger gravity anomalies and seismic refraction studies indicates a depth to the Moho of about 40 km beneath the continent, shallowing to 27 km beneath the Ross Sea. This 27 km depth is approximately equal to the lower limit of the tectonic seismicity detected by the Erebus network; hence, events are of crustal origin. These data suggest, with the rift-type geochemistry of Erebus' magma, that the Ross Sea is a site of active crustal extension and rifting.

  6. OH and RO2 radicals at Dome C (East Antarctica): first observations and assessment of photochemical budget

    NASA Astrophysics Data System (ADS)

    Kukui, Alexandre; Loisil, Rodrigue; Kerbrat, Michael; Frey, Markus; Gil Roca, Jaime; Jourdain, Bruno; Ancellet, Gérard; Bekki, Slimane; Legrand, Michel; Preunkert, Susanne

    2013-04-01

    Measurements of OH and total peroxy RO2 (HO2 + organic peroxy) radicals were performed in December 2011/January 2012 at the Dome C Concordia station (East Antarctica, 75.1° S / 123.3° E) in the frame of the Oxidant Production over Antarctic Land and its Export (OPALE) project. The goal of these first on the East Antarctica plateau radical measurements was to estimate the oxidative capacity and assess the role of snow emissions on the radical budget in this part of Antarctica. The OH concentration levels were found to be in general similar to those observed at South Pole. However, based on the analysis of the OH sources and sinks derived from the available measurements of NOx, HONO, HCHO, H2O2 and others, it has been concluded that, in contrast to South Pole, the photolysis of HONO is the major OH source at Dome C site. The role of HONO as the major source of OH is also supported by an excellent correlation of OH with the production rate of OH from the HONO photolysis. The observed diurnal profiles of OH and RO2 are discussed in relation with boundary dynamics and the variability of photolysis and snow emissions rates.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  9. Three-dimensional Shear Wave Velocity Structure of The Upper Mantle Below Antarctica

    NASA Astrophysics Data System (ADS)

    Danesi, S.; Morelli, A.

    We measure fundamental-mode Rayleigh and Love surface wave group dispersion curves from seismograms recorded by stations in the Antarctic continent and neigh- boring lands at latitude below -30. Our growing regional dataset is merged with the global dataset of phase velocity measurements by Ekström et al. (1997, JGR 102, 8137-8157). Our inversion procedure is divided in two steps. The first is a linear to- mographic inversion of the dispersion measurements to model laterally heterogeneous group velocity at different periods. Wave slowness is parameterized by spline interpo- lation on a geographical grid, with knots equally spaced by 250 km in an orthographic projection. For each point in these maps we then compute the vertical profile of shear wave velocity vs. depth by iterative nonlinear inversion. Crustal properties are as- sumed to be known and follow the CRUST2.0 model (Bassin et al., 2000, EOS Trans AGU, 81 F897). The resulting vS model shows intense negative anomalies under oceanic ridges, at least down to 150 km. The strongest values are related to young oceanic crust near rapidly opening ridges. Shallow low velocity anomalies characterize volcanic provinces and hot-spots in Marie Byrd Land, Ross Sea, Kerguelen, Balleny and South Sandwich archipelagoes. Only few slow anomalies reach depths below 150km (West Antarctica, Ross Sea and the triple junction among Southeast Pacific-South Pacific- Indian Ridges). The East Antarctica archean craton has deep, fast (cold) continental roots reaching at least 200km in depth.

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

    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 (κ) and crustal thickness (H) have been obtained from receiver functions analysed using the H-κ 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.

  11. Proposal to protect marine areas around Antarctica

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-05-01

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

  12. Ice-shelf melting around Antarctica.

    PubMed

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

    2013-07-19

    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

  13. Ice-Shelf Melting Around Antarctica

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  14. Iceberg B-15, Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Iceberg B-15 broke from the Ross Ice Shelf in Antarctica in late March. Among the largest ever observed, the new iceberg is approximately 170 miles long x 25 miles wide. Its 4,250 square-mile area is nearly as large as the state of Connecticut. The iceberg was formed from glacial ice moving off the Antarctic continent and calved along pre-existing cracks in the Ross Ice Shelf near Roosevelt Island. The calving of the iceberg essentially moves the northern boundary of the ice shelf about 25 miles to the south, a loss that would normally take the ice shelf as long as 50-100 years to replace. This infrared image was acquired by the DMSP (Defense Meteorological Satellite Program) F-13 satellite on April 13, 2000. For more images see Antarctic Meteorological Research Center Image courtesy of the University of Wisconsin - Madison, Space Science and Engineering Center, Antarctic Meteorological Research Center

  15. Occurrence and diversity of marine yeasts in Antarctica environments

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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 β-galactosidase and killer toxins.

  16. Oxygen isotope studies and compilation of isotopic dates from Antarctica

    SciTech Connect

    Grootes, P.M.; Stuiver, M.

    1986-01-01

    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.

  17. Ice-shelf melting around Antarctica

    NASA Astrophysics Data System (ADS)

    Rignot, E.; Jacobs, S.

    2008-12-01

    The traditional view on the mass balance of Antarctic ice shelves is that they loose mass principally from iceberg calving with bottom melting a much lower contributing factor. Because ice shelves are now known to play a fundamental role in ice sheet evolution, it is important to re-evaluate their wastage processes from a circumpolar perspective using a combination of remote sensing techniques. We present area average rates deduced from grounding line discharge, snow accumulation, firn depth correction and ice shelf topography. We find that ice shelf melting accounts for roughly half of ice-shelf ablation, with a total melt water production of 1027 Gt/yr. The attrition fraction due to in-situ melting varies from 9 to 90 percent around Antarctica. High melt producers include the Ronne, Ross, Getz, Totten, Amery, George VI, Pine Island, Abbot, Dotson/Crosson, Shackleton, Thwaites and Moscow University Ice Shelves. Low producers include the Larsen C, Princess Astrid and Ragnhild coast, Fimbul, Brunt and Filchner. Correlation between melt water production and grounding line discharge is low (R2 = 0.65). Correlation with thermal ocean forcing from the ocean are highest in the northern parts of West Antarctica where regressions yield R2 of 0.93-0.97. Melt rates in the Amundsen Sea exhibit a quadratic sensitivity to thermal ocean forcing. We conclude that ice shelf melting plays a dominant role in ice shelf mass balance, with a potential to change rapidly in response to altered ocean heat transport onto the Antarctic continental shelf.

  18. 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...

  19. 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...

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

    SciTech Connect

    Vose, R.S.; Schmoyer, R.L.; Steurer, P.M.; Peterson, T.C.

    1992-12-31

    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.

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

    PubMed

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

    2016-05-01

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

  2. Ground-based infrared measurements of tropospheric source gases over Antarctica during the 1986 austral spring

    NASA Technical Reports Server (NTRS)

    Toon, G. C.; Farmer, C. B.; Schaper, P. W.; Blavier, J.-F.; Lowes, L. L.

    1989-01-01

    Simultaneous measurements of the atmospheric burdens of CH4, N2O, CO2, CF2Cl2, and CO above McMurdo Station, Antarctica, have been derived from solar absorption spectra obtained by the Jet Propulsion Laboratory high-resolution Fourier transform spectrometer. In all cases the burdens are smaller than midlatitude values. Furthermore, retrievals of N2O and CH4 indicate that the tropospheric mixing ratios were normal and that the depletion of the burdens can best be accounted for by a downward shift of the volume mixing ratio profiles by some 6-8 km. This rules out the possibility of large-scale upwelling of ozone-poor tropospheric air into the stratosphere being the cause of the Antarctic springtime ozone depletion.

  3. Numerical simulation of whistler-triggered VLF emissions observed in Antarctica

    NASA Astrophysics Data System (ADS)

    Nunn, D.; Smith, A. J.

    1996-03-01

    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 WTE events were the triggering of long steep risers from the lower whistler arm. A VHS/VLF Vlasov hybrid simulation code was run and successfully simulated the main categories of WTE: risers and fallers off the upper arm and risers from the lower arm. Agreement with observations was generally very good, although in the case of triggered fallers and risers from the lower arm, very high frequency sweep rates were not obtained. The Vlasov code is highly efficient and well suited to this problem.

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

    SciTech Connect

    Keskin, S.S.; Olmez, I.; Langway, C.C. Jr.

    1994-12-31

    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.

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

    NASA Technical Reports Server (NTRS)

    Morley, Bruce M.

    1988-01-01

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

  6. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  7. Photosynthesis-irradiance responses in the Ross Sea, Antarctica: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Smith, W. O., Jr.; Donaldson, K.

    2015-06-01

    A meta-analysis of photosynthesis-irradiance measurements was completed using data from the Ross Sea, Antarctica, using a total of 417 independent measurements. PmB, the maximum, chlorophyll-specific, irradiance-saturated rate of photosynthesis, averaged 1.1 ± 0.06 μg C (μg Chl)-1 h-1. Light-limited, chlorophyll-specific photosynthetic rates (αB) averaged 0.030 ± 0.023 μg C (μg Chl)-1 h-1 (μmol quanta m-2 s-1)-1. Significant variations in PmB and αB were found as a function of season, with spring maximum photosynthetic rates being 60% greater than those in summer. Similarly, α values were 48% greater in spring. There was no detectable effect of sampling location on the photo-synthetic parameters, and temperature and macronutrient (NO3) concentrations also did not have an influence. However, irradiance and carbon dioxide concentrations, when altered under controlled conditions, exerted significant influences on photosynthetic parameters. Specifically, reduced irradiance resulted in significantly decreased PmB and increased αB values, and increased CO2 concentrations resulted in significantly increased PmB and αB values. Comparison of photosynthetic parameters derived at stations where iron concentrations were above and below 0.1 nM indicated that reduced iron levels were associated with significantly increased PmB values, confirming the importance of iron within the photosynthetic process. No significant difference was detected between stations dominated by diatoms and those dominated by the haptophyte Phaeocystis antarctica. The meta-analysis confirms the photosynthetic rates predicted from global analyses that are based solely on temperature and irradiance availability, but suggests that, for more accurate predictions of productivity in polar systems, a more detailed model that includes temporal effects of photosynthetic parameters will be required.

  8. Significant warming of continental West Antarctica in the last 50 years

    NASA Astrophysics Data System (ADS)

    Steig, E. J.; Schneider, D. P.

    2008-12-01

    We use statistical climate field reconstruction techniques to determine monthly temperature anomalies for the near-surface of the Antarctic ice sheet since 1957. Two independent data sets are used to provide estimates of the spatial covariance patterns of temperature: automatic weather stations and thermal infrared satellite observations. Quality-controlled data from occupied instrumental weather stations are used to determine the amplitude of changes in those covariance patterns through time. We use a modified principal component analyses technique (Steig et al., in review, Nature) to optimize the combination of spatial and temporal information. Verification statistics obtained from subsets of the data demonstrate the resulting reconstructions represent improvements relative to climatological mean values. We find that significant warming has occurred over most of continental West Antarctica. This is an area much larger than previously reported; most studies have concluded that warming is limited to the Antarctic Peninsula. An updated version of the recent temperature reconstruction of Monaghan et al. (2008, JGR) independently confirms our results. Warming in continental West Antarctica in the last 50 years exceeds 0.1 °C/decade, and is strongest in Spring. A possible explanation is an increase in storms in the Amundsen-Bellinghausen sea, resulting in enhanced warm air fluxes to the continent. Increased storminess in this sector is associated with the positive phase of the zonal wave-3 pattern, which independent observations suggest has increased since the 1970s (Raphael, GRL, 2004). The substantial negative sea ice anomalies in the Amundsen-Bellinghausen sea may also play a role. Our results suggest that changes in the wave-3 pattern dominates over (possibly anthropogenic) changes in the Southern Annular Mode in explaining recent Antarctic temperature variability.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    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.

  10. Spurious barometric pressure acceleration in Antarctica and propagation into GRACE Antarctic mass change estimates

    NASA Astrophysics Data System (ADS)

    Kim, Byeong-Hoon; Eom, Jooyoung; Seo, Ki-Weon; Wilson, Clark R.

    2016-06-01

    Apparent acceleration in GRACE Antarctic ice mass time series may reflect both ice discharge and surface mass balance contributions. However, a recent study suggests there is also contamination from errors in atmospheric pressure de-aliasing fields (ECMWF operational products) used during GRACE data processing. To further examine this question, we compare GRACE atmospheric pressure de-aliasing (GAA) fields with in-situ surface pressure data from coastal and inland stations. Differences between the two are likely due to GAA errors, and provide a measure of error in GRACE solutions. Time series of differences at individual weather stations are fit to four presumed error components: annual sinusoids, a linear trend, an acceleration term, and jumps at times of known ECMWF model changes. Using data from inland stations, we estimate that atmospheric pressure error causes an acceleration error of about +7.0 Gt/yr2, which is large relative to prior GRACE estimates of Antarctic ice mass acceleration in the range of -12 to -14 Gt/yr2. We also estimate apparent acceleration rates from other barometric pressure (reanalysis) fields, including ERA-Interim, MERRA and NCEP/DOE. When integrated over East Antarctica, the four mass acceleration estimates (from GAA and the three reanalysis fields) vary considerably (by ˜2-16 Gt/yr2). This shows the need for further effort to improve atmospheric mass estimates in this region of sparse in situ observations, in order to use GRACE observations to measure ice mass acceleration and related sea level change.

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

    NASA Astrophysics Data System (ADS)

    Blake, James A.; Narayanaswamy, Bhavani E.

    2004-07-01

    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

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

    NASA Astrophysics Data System (ADS)

    Gorodetskaya, I. V.; Kneifel, S.; Maahn, M.; Thiery, W.; Schween, J. H.; Mangold, A.; Crewell, S.; Van Lipzig, N. P. M.

    2015-02-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  14. Deregulation and Station Trafficking.

    ERIC Educational Resources Information Center

    Bates, Benjamin J.

    To test whether the revocation of the Federal Communications Commission's "Anti-Trafficking" rule (requiring television station owners to keep a station for three years before transferring its license to another party) impacted station owner behavior, a study compared the behavior of television station "traffickers" (owners seeking quick turnovers…

  15. Hydrogen emissions from Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    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.

  16. Odd cloud in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  17. Sedimentary basins in Ross Sea, Antarctica

    SciTech Connect

    Cooper, A.K.; Davey, F.J.

    1986-07-01

    The Ross Sea lies in the Pacific sector of the Antarctic continental margin. Three major sedimentary basins (from east to west, the Eastern, Central, and Victoria Land basins) lie beneath the broad, deep continental shelf of the Ross Sea. These north-south-trending basins occur in the extensionally deformed region between East and West Antarctica. Multichannel seismic reflection (MCS) surveys have been conducted over these basins since 1980 by West German, French, Japanese, and US expeditions. The MCS and previous geophysical surveys have shown that the three basins contain 5-6 km of sedimentary rock, possibly Late Cretaceous and younger. An additional 6-8 km of sedimentary and volcanic rock lies within the deeper parts of the Victoria Land basin. The basins are separated by uplifted and eroded basement ridges covered by thin sedimentary sections. Each basin has distinct characteristics, commonly related to its extensional origin. Petroleum hydrocarbons are unknown from the Ross Sea region, with the possible exception of ethane gas recovered by the Deep Sea Drilling Project. Previous model studies, based on estimated sediment thickness, assumed temperature gradients, and postulated seismostratigraphy, indicate that hydrocarbons could be generated at depths of 3.5-6km within the sedimentary section. However, this hypothesis cannot be verified without further geologic and geophysical data from the Ross Sea region.

  18. Fabric and texture at Siple Dome, Antarctica

    USGS Publications Warehouse

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

    2005-01-01

    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.

  19. A magnetospheric substorm observed at Sanae, Antarctica

    SciTech Connect

    Gledhill, J.A.; Dore, I.S.; Haggard, R. ); Goertz, C.K. ); Hughes, W.J. ); Scourfield, M.W.J.; Wakerley, P.A.; Walker, A.D.M. ); Smits, D.P.; Sutcliffe, P.R. ); Stoker, P.H. )

    1987-03-01

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

  20. Intercomparison of ozone measurements over Antarctica

    SciTech Connect

    Margitan, J.J.; Farmer, C.B.; Toon, G.C. ); Brothers, G.A. ); Browell, E.V.; Gregory, G.L.; Hypes, W.; Larsen, J.C.; McCormick, M.P. ); Cariolle, D. ); Coffey, M.T.; Mankin, W. ); Farman, J.C. ); Harder, J.W.; Mount, G.H.; Ravishankara, A.R.; Schemeltekopf, A.L.; Tuck, A.F. ); Hofmann, D.J. ); Ismail, S.; Kooi, S. ); Jakoubek, R.O.; Proffitt, M.H.; Wahner, A.; Watterson, I. Univ. of Colorado, Boulder ); Komhyr, W. (NOAA Air Resources La

    1989-11-30

    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.

  1. The Center for Astrophysics in Antarctica

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  2. Mass casualty incident response and aeromedical evacuation in antarctica.

    PubMed

    Mills, Christopher N; Mills, Gregory H

    2011-02-01

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

  3. Space Station Spartan study

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  4. Tectonic evolution of west Antarctica and its relation to east Antarctica

    SciTech Connect

    Dalziel, I.W.D.

    1987-05-01

    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.

  5. Site testing for submillimetre astronomy at Dome C, Antarctica

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

    Aims: Over the past few years a major effort has been put into the exploration of potential sites for the deployment of submillimetre astronomical facilities. Amongst the most important sites are Dome C and Dome A on the Antarctic Plateau, and the Chajnantor area in Chile. In this context, we report on measurements of the sky opacity at 200 μm over a period of three years at the French-Italian station, Concordia, at Dome C, Antarctica. We also present some solutions to the challenges of operating in the harsh polar environment. Methods: The 200-μm atmospheric opacity was measured with a tipper. The forward atmospheric model MOLIERE (Microwave Observation LIne Estimation and REtrieval) was used to calculate the atmospheric transmission and to evaluate the precipitable water vapour content (PWV) from the observed sky opacity. These results have been compared with satellite measurements from the Infrared Atmospheric Sounding Interferometer (IASI) on Metop-A, with balloon humidity sondes and with results obtained by a ground-based microwave radiometer (HAMSTRAD). In addition, a series of experiments has been designed to study frost formation on surfaces, and the temporal and spatial evolution of thermal gradients in the low atmosphere. Results: Dome C offers exceptional conditions in terms of absolute atmospheric transmission and stability for submillimetre astronomy. Over the austral winter the PWV exhibits long periods during which it is stable and at a very low level (0.1 to 0.3 mm). Higher values (0.2 to 0.8 mm) of PWV are observed during the short summer period. Based on observations over three years, a transmission of around 50% at 350 μm is achieved for 75% of the time. The 200-μm window opens with a typical transmission of 10% to 15% for 25% of the time. Conclusions: Dome C is one of the best accessible sites on Earth for submillimetre astronomy. Observations at 350 or 450 μm are possible all year round, and the 200-μm window opens long enough and with a

  6. Continuous on-line water vapor isotope measurements in Antarctica

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    In the context of a globally warming climate it is crucial to study the climate variability in the past and to understand the underlying mechanisms (1). Precipitation deposited on the polar ice caps provides a means to retrieve information on temperature changes (through the paleo-temperature dependence of the isotopic composition of the ice) and atmospheric composition (of gas stored in bubbles in the ice) on time scales from one to almost one million years, with sub-annual resolution in the most recent centuries. However, it is now widely recognized that the calibration of the paleo-thermometer is highly problematic. For this reason attempts to model the global water cycle, including the isotope signals, are ongoing with the aim of providing a more physical basis of the isotope - temperature relation. Currently, there is a large divergence in the results obtained by different modeling strategies. The missing link in these model studies is their forcing by experimental data on the pre-deposition isotopic composition of the vapor phase compartment of the hydrological cycle. We propose to measure the isotopic composition of moisture carried towards and deposited on Antarctica, in order to constrain the numerical models. In this context we are developing a modified, more sensitive and precise, version of a laser water vapor isotope spectrometer, originally designed for stratospheric studies (2, 3). This instrument, which will first be operated at the Norwegian station of Troll in Queen Maud Land, will enable the continuous, online measurement of all three stable isotope ratios of atmospheric water vapor. So far, such data is non-existent. Our data should improve the validity of the models and improve the understanding of the physical mechanisms at the basis of the isotope thermometer. This in turn will lead to an increased confidence in the predictions of (general circulation) models concerning climate variability. (1) International Panel on Climate Change (IPCC), 4

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

    NASA Technical Reports Server (NTRS)

    Flynn, Michael

    2005-01-01

    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.

  8. Annual cycle of distribution of three ice-associated copepods along the coast near Dumont d'Urville, Terre Adélie (Antarctica)

    NASA Astrophysics Data System (ADS)

    Loots, Christophe; Swadling, Kerrie M.; Koubbi, Philippe

    2009-11-01

    In polar regions sea ice is a site of enhanced primary production during winter and provides important habitat for small grazers, such as copepods. We sampled zooplankton from the sea ice and water column throughout 2005, near Dumont d'Urville station (Terre Adélie, Antarctica). Three species of ice-associated copepods were found: two calanoid copepods Paralabidocera antarctica and Stephos longipes and the harpacticoid copepod Drescheriella glacialis. P. antarctica was the most abundant of the three and was closely associated with the sea ice during most of the year. This species had a one year life cycle with a probable over-wintering period in the sea ice as nauplii and a short copepodite phase in spring. Reproduction and spawning occurred in early summer. A comparison with two other populations (near Syowa and Davis stations) along the east coast of Antarctica showed that there was a temporal shift in the life cycles of the three populations, which was linked to variability in sea ice conditions. D. glacialis was the second most abundant copepod and was more common during the winter than during summer, indicating its preference for the sea ice habitat. In autumn, the presence of D. glacialis in the deeper part of the water column suggested that this species colonised the sea ice from the benthos. S. longipes was found only in the water column near Dumont d'Urville and was not very abundant. In Terre Adélie particular environmental conditions, such as the absence of a permanent sea ice zone throughout the year, a longer time of open water, strong katabatic winds and the presence of polynyas, have influenced both the abundance and distribution of the three common ice-associated copepods.

  9. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

    PubMed Central

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

    2014-01-01

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

  10. Ongoing deformation of Antarctica following recent Great Earthquakes

    NASA Astrophysics Data System (ADS)

    King, Matt A.; Santamaría-Gómez, Alvaro

    2016-03-01

    Antarctica's secular motion is thought to be almost everywhere governed by horizontal rigid plate rotation plus three-dimensional deformations due to past and present changes in ice ocean loading, known as glacial isostatic adjustment (GIA). We use geodetic data to investigate deformation following the 1998 M ~8.2 Antarctic intraplate Earthquake and show sustained three-dimensional deformation along East Antarctica's coastline, 600 km from the rupture location. Using a model of viscoelastic deformation, we are able to match observed northward velocity changes, and either east or height, but not all three directions simultaneously, apparently partly due to lateral variations in mantle rheology. Our modeling predicts that much of Antarctica may still be deforming, with further deformation possible from the 2004 M 8 Macquarie Ridge Earthquake. This previously unconsidered mode of Antarctic deformation affects geodetic estimates of plate motion and GIA; its viscous nature raises the prospect of further present-day deformation due to earlier Great Earthquakes.

  11. Cryoconite and Ice-bubble Microbial Ecosystems in Antarctica

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  12. Where does CO2 in Antarctica cool the atmosphere ?

    NASA Astrophysics Data System (ADS)

    Schmithüsen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter; Jung, Thomas

    2016-04-01

    In a recent study we have shown that for the high altitude plateau in Antarctica CO2 causes a surplus in infrared emission to space compared to what is emitted from the surface. This corresponds to a negative greenhouse effect, and is due to the fact that for this region the surface is typically colder than the atmosphere above, opposite to the rest of the world. As a consequence, for this region an increase in CO2 leads to an increase in the energy loss to space, leading to an increase in the negative greenhouse effect. We now studied in more detail the radiative effect of CO2 and compared the results with available measurements from Antarctica. H. Schmithüsen, J. Notholt, G. Köngig-Langlo, T, Jung. How increasing CO2 leads to an increased negative greenhouse effect in Antarctica. Geophysical Research Letters, in press, 2015. doi: 10.1002/2015GL066749.

  13. Provenance of dust to Antarctica: A lead isotopic perspective

    NASA Astrophysics Data System (ADS)

    Gili, Stefania; Gaiero, Diego M.; Goldstein, Steven L.; Chemale, Farid, Jr.; Koester, Edinei; Jweda, Jason; Vallelonga, Paul; Kaplan, Michael R.

    2016-03-01

    Antarctic ice preserves an ~800 kyr record of dust activity in the Southern Hemisphere. Major efforts have been dedicated to elucidate the origin of this material in order to gain greater insight into the atmospheric dust cycle. On the basis of Pb isotopes in Antarctic dust samples and potential sources, this contribution demonstrates for the first time that Patagonia is the main contributor of dust to Antarctica during interglacial periods as well as glacials, although the potential importance of Tierra del Fuego remains unclear because of its geochemical similarities to Patagonia. An important new finding is that the Puna-Altiplano sector of the continent is a second important dust source to eastern Antarctica during both glacials and interglacials, being more prominent during interglacials. The data indicate South America is the primary dust source to Antarctica during both glacials and interglacials.

  14. Life beneath the surface of the central Texan Balcones Escarpment: genus Anillinus Casey, 1918 (Coleoptera, Carabidae, Bembidiini): new species, a key to the Texas species, and notes about their way of life and evolution

    PubMed Central

    Sokolov, Igor M.; Reddell, James R.; Kavanaugh, David H.

    2014-01-01

    Abstract The Texas fauna of the genus Anillinus Casey, 1918 includes three previously described species (A. affabilis (Brues), 1902, A. depressus (Jeannel), 1963 and A. sinuatus (Jeannel), 1963) and four new species here described: A. acutipennis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. comalensis Sokolov & Kavanaugh, sp. n. (type locality: 7 miles W of New Braunfels, Comal County, Texas); A. forthoodensis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. wisemanensis Sokolov & Kavanaugh, sp. n. (type locality: Wiseman Sink, Hays County, Texas). A key for identification of adults of these species is provided. The fauna includes both soil- and cave-inhabiting species restricted to the Balcones Fault Zone and Lampasas Cut Plain and adjacent areas underlain by the Edwards-Trinity Aquifer. Based on morphological and distributional data, we hypothesize that four lineages of endogean Anillinus species extended their geographical ranges from a source area in the Ouachita-Ozark Mountains to the Balconian region in central Texas. There the cavernous Edwards-Trinity aquifer system provided an excellent refugium as the regional climate in the late Tertiary and early Quaternary became increasingly drier, rendering life at the surface nearly impossible for small, litter-inhabiting arthropods. Isolated within the Edwards-Trinity aquifer system, these anilline lineages subsequently differentiated, accounting for the currently known diversity. The paucity of specimens and difficulty in collecting them suggest that additional undiscovered species remain to be found in the region. PMID:25061356

  15. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic.

    PubMed

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Samatadze, Tatiana E; Twardovska, Maryana O; Zoshchuk, Svyatoslav A; Andreev, Igor O; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  16. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic

    PubMed Central

    Amosova, Alexandra V.; Bolsheva, Nadezhda L.; Samatadze, Tatiana E.; Twardovska, Maryana O.; Zoshchuk, Svyatoslav A.; Andreev, Igor O.; Badaeva, Ekaterina D.; Kunakh, Viktor A.; Muravenko, Olga V.

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

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

    NASA Astrophysics Data System (ADS)

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

    2004-11-01

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

  18. Declassified Intelligence Satellite Photography (DISP) Coverage of Antarctica

    NASA Technical Reports Server (NTRS)

    Bindschadler, Robert; Seider, Wendy

    1998-01-01

    This report summarizes the results of a nine-week summer project examining all Declassified Intelligence Satellite Photography (DISP) of Antarctica. It was discovered that the data were collected in three separate missions during 1962 and 1963. The first two missions covered only the coastal areas, while the third mission covered the entire continent. Many of the 1782 frames collected were cloudy. This is especially true of West Antarctica. An optimal set of photographs covering the entire Antarctic coastline is identified along with some examples that show changes in the coastline which have occurred since the early 1960s.

  19. Avian cholera in Southern Great Petrel (Macronectes giganteus) from Antarctica

    USGS Publications Warehouse

    Leotta, G.A.; Rivas, M.; Chinen, I.; Vigo, G.B.; Moredo, F.A.; Coria, N.; Wolcott, M.J.

    2003-01-01

    A southern giant petrel (Macronectes giganteus) was found dead at Potter Peninsula, King George Island, South Shetland, Antarctica. The adult male was discovered approximately 48 hr after death. Macroscopic and microscopic lesions were compatible with avian cholera and the bacterium Pasteurella multocida subsp. gallicida, serotype A1 was isolated from lung, heart, liver, pericardial sac, and air sacs. In addition, Escherichia coli was isolated from pericardial sac and air sacs. This is the first known report of avian cholera in a southern giant petrel in Antarctica.

  20. The Prospects of Integral-Field Spectroscopy for Antarctica

    NASA Astrophysics Data System (ADS)

    Kelz, A.

    The first suite of instruments and associated science cases for a larger facility at Dome C are mainly targeted towards imaging and surveys. While the potential advantages for astronomical observations from Antarctica are applicable to both imaging and spectroscopy, spectrographs are more complex to build and harder to use in a fully automatic and remote operation. However, the innovative technique of 3D-Spectroscopy (3DS) offers imaging and spectroscopic capabilities simultaneously with applications to a wide range of astronomical programmes. Furthermore, 3DS provides several operational benefits, that are well suited for a location such as Antarctica.

  1. Distribution of narrow-width magnetic anomalies in Antarctica

    USGS Publications Warehouse

    Behrendt, John C.

    1964-01-01

    Data for aeromagnetic profiles obtained in Antarctica during the 1963-64 austral summer were used together with earlier results to construct a map showing the areal distribution of narrow-width magnetic anomalies. Numerous anomalies are associated with known volcanic mountains in western Antarctica. A large area of few anomalies is probably a result of an extension of the thick metasedimentary section observed in the Ellsworth Mountains. Portions of the Trans-Antarctic Mountains have associated anomalies which are probably caused by late Cenozoic volcanic rocks.

  2. The GRAD high-altitude balloon flight over Antarctica

    NASA Technical Reports Server (NTRS)

    Eichhorn, G.; Coldwell, R. L.; Dunnam, F. E.; Rester, A. C.; Trombka, J. I.; Starr, R.

    1989-01-01

    The Gamma Ray Advanced Detector (GRAD) consists of a n-type germanium detector inside an active bismuth-germanate Compton and charged particle shield with additional active plastic shielding across the aperture. It will be flown on a high-altitude balloon at 36 km altitude at a latitude of 78 deg S over Antarctica for observations of gamma radiation emitted by the radioactive decay of Co-56 in the supernova SN1987A, for assessment of the performance of bismuth-germanate scintillation material in the radiation environment of near space, for gathering information on the gamma-ray background over Antarctica, and for testing fault-tolerant software.

  3. Ice megadunes on Mars: analogy with Antarctica

    NASA Astrophysics Data System (ADS)

    Herny, Clémence; Massé, Marion; Bourgeois, Olivier; Carpy, Sabrina; Le Mouélic, Stéphane; Appéré, Thomas; Smith, Isaac; Spiga, Aymeric; Rodriguez, Sébastien

    2014-05-01

    Mass and energy balance of ice sheets are driven by complex interactions between the atmosphere and the cryosphere. Feedbacks between katabatic winds and the cryosphere may lead to the formation of sedimentation waves, so-called megadunes, at the surface of ice sheets. These have been first described in Antarctica. Here we use topographic data, optical images, and spectroscopic data acquired by Mars orbiters. We show that the surface of the Martian North Polar Cap displays two superimposed sets of sedimentation waves with differing wavelengths. These sedimentation waves have similarities with Antarctic ice megadunes regarding their surface morphology, texture, grain size, and internal stratigraphic architecture. Their shallow-dipping upwind sides, their tops and the intervening troughs are covered by young ice and occasional sastrugi fields, indicative of net accumulation. On the other hand, their steep-dipping downwind sides either expose exhumed layers of dusty old ice or correspond to smooth surfaces of coarse-grained ice, indicative of net ablation or reduced net accumulation associated with sublimation and metamorphism. These surface characteristics and the internal stratigraphic architecture revealed by radar sounding are consistent with the interpretation that both sets of Martian sedimentation waves grow and migrate upwind in response to the development of periodic accumulation/ablation patterns controlled by katabatic winds. The smaller waves, characterized by reduced net accumulation on their downwind sides, are probably analogous to the Antarctic megadunes that have been described so far. On the other hand, a terrestrial equivalent remains to be discovered for the larger ones, characterized by net ablation on their downwind sides. The recognition of these sedimentation waves provides the basis for the development of a common model of ice/wind interaction at the surface of Martian and terrestrial ice sheets and for future investigations on the respective

  4. Electric field measurements from Halley, Antarctica

    NASA Astrophysics Data System (ADS)

    Nicoll, Keri; Harrison, R. Giles

    2016-04-01

    Antarctica is a unique location for the study of atmospheric electricity. Not only is it one of the most pollutant free places on Earth, but its proximity to the south magnetic pole means that it is an ideal location to study the effects of solar variability on the atmospheric electric field. This is due to the reduced shielding effect of the geomagnetic field at the poles which leads to a greater flux of incoming Galactic Cosmic Rays (GCRs) as well as an increased probability of energetic particle precipitation from SEPs and relativistic electrons. To investigate such effects, two electric field mills of different design were installed at the British Antarctic Survey Halley base in February 2015 (75. 58 degrees south, 26.66 degrees west). Halley is situated on the Brunt Ice Shelf in the south east of the Weddell Sea and has snow cover all year round. Preliminary analysis has focused on selection of fair weather criteria using wind speed and visibility measurements which are vital to assess the effects of falling snow, blowing snow and freezing fog on the electric field measurements. When the effects of such adverse weather conditions are removed clear evidence of the characteristic Carnegie Curve diurnal cycle exists in the Halley electric field measurements (with a mean value of 50V/m and showing a 40% peak to peak variation in comparison to the 34% variation in the Carnegie data). Since the Carnegie Curve represents the variation in thunderstorm activity across the Earth, its presence in the Halley data confirms the presence of the global atmospheric electric circuit signal at Halley. The work presented here will discuss the details of the Halley electric field dataset, including the variability in the fair weather measurements, with a particular focus on magnetic field fluctuations.

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

    NASA Astrophysics Data System (ADS)

    Hughes, Kevin A.

    2010-12-01

    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

  6. Space Radar Image of Weddell Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths

  7. Space Station Power System

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.

    1984-01-01

    The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

  8. Space Station power system

    SciTech Connect

    Baraona, C.R.

    1984-04-01

    The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

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

    SciTech Connect

    Allison, I. ); Wendler, G. ); Radok, U. )

    1993-05-20

    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.

  10. Ambient Seismic Noise Correlation on Iceberg C16, Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Okal, E. A.; MacAyeal, D. R.

    2014-12-01

    This study focuses on the ambient noise transmission between 4 seismometer stations distributed on iceberg C16, Ross Sea, Antarctica. These stations were deployed for a 60-day period in 2003/4. The noise source was associated with constant collisions between C16 and a neighboring iceberg, B15A, which was continually being driven into the northeast edge of C16 by ocean tides. The most significant modes of ambient noise transmission were found to be (1) hydroacoustic modes that bounce off the seabed below the iceberg, and (2) flexural-gravity waves that involve the flexural rigidity of the ice layer. The technique used in the study (and in similar studies of the Amery Ice Shelf reported by Zhan and others) provides a new method for studying floating ice with high sensitivity to factors that control hydroacoustic propagation over long distances. It is possible that secular changes in the sub ice ocean layer (such as changes caused by decreasing ice thickness over time) can be observed using ambient noise correlation similar to that performed here. This suggests a way in which seismic observations can constrain variables that characterize how floating ice, and in particular floating ice shelves, buttress glaciers and ice streams that discharge into the ocean.

  11. Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling

    NASA Astrophysics Data System (ADS)

    Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2012-05-01

    Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ∑ indicator PCBs and ∑14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

  12. Balloon-borne observations of stratospheric aerosol in Antarctica from 1972 to 1984

    NASA Technical Reports Server (NTRS)

    Hofmann, D. J.

    1985-01-01

    Stratospheric levels of particles with r or = 0.15 microns were monitored with optical particle counters in approximately monthly balloon soundings at Laramie, Wyoming (41 deg N) since 1971. These measurements were used to characterize the background stratospheric aerosol layer and the disturbed layer following major volcanic eruptions. Levels of particles with r or = 0.01 microns have also been measured with balloon-borne counters since 1973. The latter are collectively called condensation nuclei (CN) as they are characteristic of aerosol in the early stages of growth. While they dominate the size distribution in the tropsophere, they are a trace species in the undisturbed stratosphere. From 1972 until 1980, annual balloon soundings from McMurdo Station (78 deg S) and/or Amundsen-Scott Station (90 deg S), in Antarctica, have also been conducted to crudely monitor Southern Hemisphere aerosol levels. These measurements were continued in 1983 and 1984. Profiles of r 0.15 microns aerosol concentrations as measured during January at the south pole from 1972 to 1975 and in 1980 are given. The former are typical of undisturbed conditions and indicate the small degree of variability under these conditions. The latter indicates the effect of minor volcanic activity, visible in the 10 to 15 km region.

  13. Towards temporal monitoring using coda correlations of icequakes on Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Chaput, J. A.; Campillo, M.; Roux, P.; Knox, H. A.; Aster, R. C.

    2014-12-01

    Recent theoretical advances pertaining to the properties of multiply scattered wavefields have yielded a plethora of numerical and controlled source studies aiming to better understand what information may be derived from these otherwise chaotic signals. Where temporal monitoring is concerned, recent advances in data mining have allowed the recovery of remarkably time-coherent correlation functions from ambient noise, and have furthermore permitted the direct mapping of velocity changes due to large earthquakes. Though not directly representative of the Green's function between stations, these time-coherent correlation functions have even been used to predict eruptive sequences on the Piton de la Fournaise volcano by detecting injection events. However, the exact nature of the correlation function in this case, particularly its coda, is unclear.Here, we seek to expand the concept of temporal monitoring to a more deterministic case, where we do in fact have a practical understanding of the correlation functions. In this study, we use a large network of short period and broadband instruments on Erebus volcano, Antarctica, to reconstruct inter-station correlation functions that converge towards a high degree of symmetry. We subsequently use a Markov Chain Monte Carlo algorithm to iteratively resample the time windows on which are built the correlation functions for maximum symmetry and coherence in time. These resampled correlation functions are then scanned for changes in decoherence, and these changes are then mapped in time and space to the volcanic edifice. We compare these changes to other evidence of temporal variation on Erebus volcano.

  14. Precipitation measurements by using of a disdrometer at Syowa station

    NASA Astrophysics Data System (ADS)

    Hirasawa, Naohiko; Yamanouchi, Takashi; Konishi, Hiroyuki

    2016-04-01

    The Laser Precipitation Monitor (LPM, manufactured by Thies) has been installed as a disdrometer at Syowa station, East Antarctica, since February 2015. We firstly explore the character of the data because, basically, our experiences in precipitation measurement in the Antarctic region have been very few and also because disdrometer is in a test phase toward the operational use in the world. Indeed, SPICE (Solid Precipitation InterComparison Experiment) project conducted by WMO at various sites around the world (including two sites in Japan) has tested several disdrometers, including LPM. LPM measures precipitation particle size and fall velocity for an individual particle, and compiles the precipitation microphysical parameters together with estimated precipitation intensity per minute. From our domestic experiences related to SPICE, we have confirmed that LPM measurements are affected by wind such as the higher intensity of precipitation under the higher wind speed. At the poster, we will discuss the precipitation intensity obtained at Syowa station, being compared with other meteorological parameters.

  15. FY 1993 environmental sampling and analysis report for wastewater discharge at McMurdo Station, Antarctica

    SciTech Connect

    Crockett, A.B.

    1994-04-01

    Wastewater impact assessment at McMurdo has been or is being conducted by four organizations: Antarctic Support Associates (ASA), which conducts the effluent monitoring; Moss Landing Marine Laboratories, which conducts all of the benthic monitoring and most of the biological monitoring; Montana State University, which conducted water quality and water current measurements; and EG&G Idaho, which conducted water quality and sea ice monitoring. All four programs are interrelated and were needed to determine the impact of the wastewater discharge on the marine environment. This report summarizes the relevant monitoring work being conducted by Antarctic Support Associates, Moss Landing, and Montana State personnel, and specifically documents the results of EG&G Idaho`s efforts.

  16. Low-power magnetometer observation with satellite data transmission at unmanned site in Antarctica

    NASA Astrophysics Data System (ADS)

    Yamagishi, H.; Kadokura, A.

    2012-12-01

    We will report technical experiences from 6 years of unmanned low power magnetometer observation in Antarctica with daily data transmission via Iridium satellite telephone link. One of the difficulties of unmanned observation in Antarctica is dark winter months in which power supply from solar panel can not be expected. One solution for this difficulty is to minimize the power consumption (as small as ~1 W) to manage the observation in winter months with limited amount of batteries (~400Ah). Another difficulty is to collect data from the observation site. It is quite expensive and laborious to send a party to the observation site to obtain the data in Antarctica. Although cost for satellite communication is expensive, it is much more economical to collect data via satellite data link by installing a telephone terminal into the observation system. It seems that power consumption of a satellite phone (~10 W) does not fit to the low power system. However, as long as the observed data is not too large (<1 Mbyte per day), turn on period of the satellite phone is short (<1 hour per day) and the daily average of total power consumption lies within the available power of ~1 W. We have developed low-power magnetometer system with Iridium satellite phone data link. Basic design of the low-power system is similar to that developed by British Antarctic Survey (intermittent operation of magnetometer and GPS). However, we have made some improvements; reduced power consumption (0.2 W) at high sampling rate (1Hz) and increased sensitivity (0.2nT), so that geomagnetic pulsation study can be possible. In our observation system, satellite data transfer is only made in sunlit season with the total power consumption of 1 W (0.8W for Iridium phone and 0.2W for others). During dark winter months, observed data are stored in CF memory with diminished power consumption of 0.2W. When the sun comes in spring, the stored data are transmitted along with the daily observed data. It takes nearly

  17. Photosynthesis-irradiance responses in the Ross Sea, Antarctica: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Smith, W. O., Jr.; Donaldson, K. A.

    2014-12-01

    A meta-analysis of photosynthesis/irradiance measurements was completed using data from the Ross Sea, Antarctica. A total of 544 independent measurements were included. PsB, the maximum, chlorophyll-specific, irradiance-saturated rate of photosynthesis, averaged 1.07 ± 0.060 μg C (μg chl)-1 h-1. Light-limited photosynthetic rates (α) averaged 0.03 ± 0.023 μg C (μg chl)-1 h-1 μmol photons m-2 s-1)-1. Significant variations in PsB and α were found as a function of season, with spring maximum photosynthetic rates being 59% greater than those in summer. Similarly, α values were 48% greater in spring. There was no detectable effect of space on the photosynthetic parameters, and temperature and macronutrient (NO3) concentrations also did not exert a strong influence. However, irradiance, dissolved iron concentrations, and carbon dioxide concentrations when altered under controlled conditions exerted significant influences on photosynthetic parameters. Specifically, reduced irradiance resulted in decreased PsB and α values, whereas reduced iron concentrations were associated with increased PsB and α values. Increased CO2 concentrations also resulted in significantly increased PsB and α values. No significant difference was detected between stations dominated by diatoms and those dominated by the haptophyte Phaeocystis antarctica. The meta-analysis generally confirms the photosynthetic rates predicted from global analyses that are based solely on temperature and irradiance availability, but suggests that for more accurate predictions of the productivity of polar systems a more detailed model that includes temporal effects of photosynthetic parameters will be required.

  18. Application of a regional model to astronomical site testing in western Antarctica

    NASA Astrophysics Data System (ADS)

    Falvey, Mark; Rojo, Patricio M.

    2016-08-01

    The quality of ground-based astronomical observations is significantly affected by local atmospheric conditions, and the search for the best sites has led to the construction of observatories at increasingly remote locations, including recent initiatives on the high plateaus of East Antarctica where the calm, dry, and cloud-free conditions during winter are recognized as amongst the best in the world. Site selection is an important phase of any observatory development project, and candidate sites must be tested in the field with specialized equipment, a process both time consuming and costly. A potential means of screening site locations before embarking on field testing is through the use of regional climate models (RCMs). In this study, we describe the application of the Polar version of the Weather Research and Forecasting (WRF) model to the preliminary site suitability assessment of a hitherto unstudied region in West Antarctica. Numerical simulations with WRF were carried out for the winter (MJJA) of 2011 at 3- and 1-km spatial resolution over a region centered on the Ellsworth mountain range. Comparison with observations of surface wind speed and direction, temperature, and specific humidity at nine automatic weather stations indicates that the model performed well in capturing the mean values and time variability of these variables. Credible features revealed by the model includes zones of high winds over the southernmost part of the Ellsworth Mountains, a deep thermal inversion over the Ronne-Fincher Ice Shelf, and strong west to east moisture gradient across the entire study area. Comparison of simulated cloud fraction with a CALIPSO spacebourne Lidar climatology indicates that the model may underestimate cloud occurrence, a problem that has been noted in previous studies. A simple scoring system was applied to reveal the most promising locations. The results of this study indicate that the WRF model is capable of providing useful guidance during the

  19. Precipitable Water Vapor from GPS in Antarctica: Opportunities from the TAMDEF GPS Network, Victoria Land.

    NASA Astrophysics Data System (ADS)

    Vazquez, G. E.; Grejner, D. A.

    2005-12-01

    An experiment was carried out in order to estimate Precipitable Water Vapor (PWV) using the Global Positioning System (GPS) data collected by the Trans Antarctic Mountain Deformation Network, Victoria Land in Antarctica. TAMDEF is the OSU and US Geological Survey joint project sponsored by National Science Foundation (NSF). Estimation of PWV from the GPS data could play a crucial role in weather and climate study for Antarctica, by increasing the spatial and temporal resolutions of PWV estimates that can be used together with traditional meteorological data (such as ground meteorological stations and radiosonde) in the numerical weather prediction models. The basic observation used in this experiment is the ion-free, double-difference phase observations. Data collected by the TAMDEF network were processed using the PAGES software (Program for the Adjustment of GPS Ephemerides) with a 30-s sampling rate and 15-degree cutoff angle, using precise GPS orbits disseminated by the IGS (International GPS Service). PAGES is a production and research tool employed for a variety of NGS products (Mader et al. 1995). Optimal data reduction strategy was developed based on three different models tested. The Niell Mapping Functions and CfA 2.2 mapping functions with the Saastamoinen model, and the Marini model were used to estimate the wet delay (step Piece-Wise Linear strategy), which later was transformed to PWV via Bevis et al. (1992). The GPS PWV estimates are currently being compared to the radiosonde data in order to assess the quality of the GPS PWV solutions. The preliminary results are very promising, indicating a good match between the two methods. In summary, introducing GPS-derived PWV to weather/climate models will improve the model's predictive capability, and will allow a better understanding of the Antarctic weather conditions (and climate). Furthermore, more exact forecast of storm systems will recover surface, coastal, and air travel safety across the Antarctic

  20. Application of a regional model to astronomical site testing in western Antarctica

    NASA Astrophysics Data System (ADS)

    Falvey, Mark; Rojo, Patricio M.

    2016-04-01

    The quality of ground-based astronomical observations is significantly affected by local atmospheric conditions, and the search for the best sites has led to the construction of observatories at increasingly remote locations, including recent initiatives on the high plateaus of East Antarctica where the calm, dry, and cloud-free conditions during winter are recognized as amongst the best in the world. Site selection is an important phase of any observatory development project, and candidate sites must be tested in the field with specialized equipment, a process both time consuming and costly. A potential means of screening site locations before embarking on field testing is through the use of regional climate models (RCMs). In this study, we describe the application of the Polar version of the Weather Research and Forecasting (WRF) model to the preliminary site suitability assessment of a hitherto unstudied region in West Antarctica. Numerical simulations with WRF were carried out for the winter (MJJA) of 2011 at 3- and 1-km spatial resolution over a region centered on the Ellsworth mountain range. Comparison with observations of surface wind speed and direction, temperature, and specific humidity at nine automatic weather stations indicates that the model performed well in capturing the mean values and time variability of these variables. Credible features revealed by the model includes zones of high winds over the southernmost part of the Ellsworth Mountains, a deep thermal inversion over the Ronne-Fincher Ice Shelf, and strong west to east moisture gradient across the entire study area. Comparison of simulated cloud fraction with a CALIPSO spacebourne Lidar climatology indicates that the model may underestimate cloud occurrence, a problem that has been noted in previous studies. A simple scoring system was applied to reveal the most promising locations. The results of this study indicate that the WRF model is capable of providing useful guidance during the

  1. Anthropogenic and biogenic hydrocarbons in soils and vegetation from the South Shetland Islands (Antarctica).

    PubMed

    Cabrerizo, Ana; Tejedo, Pablo; Dachs, Jordi; Benayas, Javier

    2016-11-01

    Two Antarctic expeditions (in 2009 and 2011) were carried out to assess the local and remote anthropogenic sources of aliphatic and aromatic hydrocarbons, as well as potential biogenic hydrocarbons. Polycyclic aromatic hydrocarbons (PAHs), n-alkanes, biomarkers such as phytane (Ph) and pristane (Pr), and the aliphatic unresolved complex mixture (UCM), were analysed in soil and vegetation samples collected at Deception, Livingston, Barrientos and Penguin Islands (South Shetland Islands, Antarctica). Overall, the patterns of n-alkanes in lichens, mosses and grass were dominated by odd-over-even carbon number alkanes. Mosses and vascular plants showed high abundances of n-C21 to n-C35, while lichens also showed high abundances of n-C17 and n-C19. The lipid content was an important factor controlling the concentrations of n-alkanes in Antarctic vegetation (r(2)=0.28-0.53, p-level<0.05). n-C12 to n-C35 n-alkanes were analysed in soils with a predominance of odd C number n-alkanes (n-C25, n-C27, n-C29, and n-C31), especially in the background soils not influenced by anthropogenic sources. The large values for the carbon predominance index (CPI) and the correlations between odd alkanes and some PAHs suggest the potential biogenic sources of these hydrocarbons in Antarctica. Unresolved complex mixture and CPI values ~1 detected at soils collected at intertidal areas and within the perimeter of Juan Carlos research station, further supported the evidence that even a small settlement (20 persons during the austral summer) can affect the loading of aliphatic and aromatic hydrocarbons in nearby soils. Nevertheless, the assessment of Pr/n-C17 and Ph/n-C18 ratios showed that hydrocarbon degradation is occurring in these soils. PMID:27450242

  2. Leifsonia psychrotolerans sp. nov., a psychrotolerant species of the family Microbacteriaceae from Livingston Island, Antarctica.

    PubMed

    Ganzert, Lars; Bajerski, Felizitas; Mangelsdorf, Kai; Lipski, André; Wagner, Dirk

    2011-08-01

    A cold-tolerant, yellow-pigmented, Gram-positive, motile, facultatively anaerobic bacterial strain, LI1(T), was isolated from a moss-covered soil from Livingston Island, Antarctica, near the Bulgarian station St. Kliment Ohridski. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a clade with the species Leifsonia kafniensis KFC-22(T), Leifsonia pindariensis PON10(T) and Leifsonia antarctica SPC-20(T), with which it showed sequence similarities of 99.0, 97.9 and 97.9 %, respectively. DNA-DNA hybridization revealed a reassociation value of 2.7 % with L. kafniensis LMG 24362(T). The DNA G+C content of strain LI1(T) was 64.5 mol%. The growth temperature range was -6 to 28 °C, with optimum growth at 16 °C. Growth occurred in 0-5 % NaCl and at pH 4.5-9.5, with optimum growth in 1-2 % NaCl and at pH 5.5-6.5. The predominant fatty acids were anteiso-C(15 : 0), C(18 : 0) and iso-C(15 : 0). The polar lipids were phosphatidylglycerol and diphosphatidylglycerol. Physiological and biochemical tests clearly differentiated strain LI1(T) from L. kafniensis. Therefore, a novel cold-tolerant species within the genus Leifsonia is proposed: Leifsonia psychrotolerans sp. nov. (type strain LI1(T) = DSM 22824(T) = NCCB 100313(T)). PMID:20833887

  3. Evaluation of four global reanalysis products using in situ observations in the Amundsen Sea Embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; Renfrew, I. A.; Orr, A.; Webber, B. G. M.; Holland, D. M.; Lazzara, M. A.

    2016-06-01

    The glaciers within the Amundsen Sea Embayment (ASE), West Antarctica, are amongst the most rapidly retreating in Antarctica. Meteorological reanalysis products are widely used to help understand and simulate the processes causing this retreat. Here we provide an evaluation against observations of four of the latest global reanalysis products within the ASE region—the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-I), Japanese 55-year Reanalysis (JRA-55), Climate Forecast System Reanalysis (CFSR), and Modern Era Retrospective-Analysis for Research and Applications (MERRA). The observations comprise data from four automatic weather stations (AWSs), three research vessel cruises, and a new set of 38 radiosondes all within the period 2009-2014. All four reanalyses produce 2 m temperature fields that are colder than AWS observations, with the biases varying from approximately -1.8°C (ERA-I) to -6.8°C (MERRA). Over the Amundsen Sea, spatially averaged summertime biases are between -0.4°C (JRA-55) and -2.1°C (MERRA) with notably larger cold biases close to the continent (up to -6°C) in all reanalyses. All four reanalyses underestimate near-surface wind speed at high wind speeds (>15 m s-1) and exhibit dry biases and relatively large root-mean-square errors (RMSE) in specific humidity. A comparison to the radiosonde soundings shows that the cold, dry bias at the surface extends into the lower troposphere; here ERA-I and CFSR reanalyses provide the most accurate profiles. The reanalyses generally contain larger temperature and humidity biases, (and RMSE) when a temperature inversion is observed, and contain larger wind speed biases (~2 to 3 m s-1), when a low-level jet is observed.

  4. Space station automation II

    SciTech Connect

    Chiou, W.C.

    1986-01-01

    This book contains the proceedings of a conference on space station automation. Topics include the following: distributed artificial intelligence for space station energy management systems and computer architecture for tolerobots in earth orbit.

  5. Station Tour: Russian Segment

    NASA Video Gallery

    Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

  6. Space station power system

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  7. The use of epilithic Antarctic lichens (Usnea aurantiacoatra and U. antartica) to determine deposition patterns of heavy metals in the Shetland Islands, Antarctica.

    PubMed

    Poblet, A; Andrade, S; Scagliola, M; Vodopivez, C; Curtosi, A; Pucci, A; Marcovecchio, J

    1997-11-27

    Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. PMID:9447747

  8. The Space Station program

    NASA Technical Reports Server (NTRS)

    Hinners, N. W.

    1986-01-01

    Cost constraints to a large degree control the functionality and form of the IOC of the Space Station. Planning of Station missions must be delayed to retain flexibility, a goal also served by modular development of the Station and by multi-use laboratory modules. Early emphasis on servicing other spacecraft is recommended, as is using available Shuttle flight time for R&D on Space Station technologies and operations.

  9. Canadian Space Station program

    NASA Technical Reports Server (NTRS)

    Doetsch, K. H.

    1991-01-01

    Information on the Canadian Space Station Program is given in viewgraph form. Topics covered include the Mobile Servicing Center (MSC), Space Station Freedom assembly milestones, the MB-3 launch configuration, a new workstation configuration, strategic technology development, the User Development Program, the Space Station Program budget, and Canada's future space activities.

  10. An evolutionary insight into Newcastle disease viruses isolated in Antarctica.

    PubMed

    Soñora, Martin; Moreno, Pilar; Echeverría, Natalia; Fischer, Sabrina; Comas, Victoria; Fajardo, Alvaro; Cristina, Juan

    2015-08-01

    The disease caused by Newcastle disease virus (NDV) is a severe threat to the poultry industry worldwide. Recently, NDV has been isolated in the Antarctic region. Detailed studies on the mode of evolution of NDV strains isolated worldwide are relevant for our understanding of the evolutionary history of NDV. For this reason, we have performed Bayesian coalescent analysis of NDV strains isolated in Antarctica to study evolutionary rates, population dynamics, and patterns of evolution. Analysis of F protein cleavage-site sequences of NDV isolates from Antarctica suggested that these strains are lentogenic. Strains isolated in Antarctica and genotype I reference strain Ulster/67 diverged from ancestors that existed around 1958. The time of the most recent common ancestor (MRCA) was established to be around 1883 for all class II viruses. A mean rate of evolution of 1.78 × 10(-3) substitutions per site per year (s/s/y) was obtained for the F gene sequences of NDV strains examined in this study. A Bayesian skyline plot indicated a decline in NDV population size in the last 25 years. The results are discussed in terms of the possible role of Antarctica in emerging or re-emerging viruses and the evolution of NDV populations worldwide. PMID:26014920

  11. Mass Casualty Incident Response and Aeromedical Evacuation in Antarctica

    PubMed Central

    Mills, Christopher N.; Mills, Gregory H.

    2011-01-01

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

  12. Airborne geophysical study in the pensacola mountains of antarctica

    USGS Publications Warehouse

    Behrendt, John C.; Meister, L.; Henderson, J.R.

    1966-01-01

    A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to -80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explain the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 ?? associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anomaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement.

  13. Antarctica: Arena for South American Cooperation or Conflict.

    ERIC Educational Resources Information Center

    Child, Jack

    A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

  14. Epilithic lichens in the Beacon sandstone formation, Victoria Land, Antarctica

    NASA Technical Reports Server (NTRS)

    Hale, M. E.; Friedmann, E. I. (Principal Investigator)

    1987-01-01

    The epilithic lichen flora on the Beacon sandstone formation in Victoria Land consists of seven species: Acarospora gwynnii Dodge & Rudolph, Buellia grisea Dodge & Baker, B. pallida Dodge & Baker, Carbonea capsulata (Dodge & Baker) Hale comb. nov., Lecanora fuscobrunnea Dodge & Baker, Lecidea cancriformis Dodge & Baker, and L. siplei Dodge & Baker. The typification of the species is given along with descriptions and distribution in Antarctica.

  15. Changes in annual precipitation over the Earth's land mass excluding Antarctica from the 18th century to 2013

    NASA Astrophysics Data System (ADS)

    van Wijngaarden, W. A.; Syed, A.

    2015-12-01

    Precipitation measurements made at nearly 1000 stations located in 114 countries were studied. Each station had at least 100 years of observations resulting in a dataset comprising over 1½ million monthly precipitation amounts. Data for some stations extend back to the 1700s although most of the data exist for the period after 1850. The total annual precipitation was found if all monthly data in a given year were present. The percentage annual precipitation change relative to 1961-90 was plotted for 6 continents; as well as for stations at different latitudes and those experiencing low, moderate and high annual precipitation totals. The trends for precipitation change together with their 95% confidence intervals were found for various periods of time. Most trends exhibited no clear precipitation change. The global changes in precipitation over the Earth's land mass excluding Antarctica relative to 1961-90 were estimated to be: -1.2 ± 1.7, 2.6 ± 2.5 and -5.4 ± 8.1% per century for the periods 1850-2000, 1900-2000 and 1950-2000, respectively. A change of 1% per century corresponds to a precipitation change of 0.09 mm/year.

  16. Microbial Energetics Beneath the Taylor Glacier, Antarctica

    NASA Astrophysics Data System (ADS)

    Mikucki, J. A.; Turchyn, A. V.; Farquhar, J.; Priscu, J. C.; Schrag, D. P.; Pearson, A.

    2007-12-01

    Subglacial microbiology is controlled by glacier hydrology, bedrock lithology, and the preglacial ecosystem. These factors can all affect metabolic function by influencing electron acceptor and donor availability in the subglacial setting leaving biogeochemical signatures that can be used to determine ecosystem processes. Blood Falls, an iron-rich, episodic subglacial outflow from the Taylor Glacier in the McMurdo Dry Valleys Antarctica provides an example of how microbial community structure and function can provide insight into subglacial hydrology. This subglacial outflow contains cryoconcentrated, Pliocene-age seawater salts that pooled in the upper Taylor Valley and was subsequently covered by the advance of the Taylor Glacier. Biogeochemical measurements, culture-based techniques, and genomic analysis were used to characterize microbes and chemistry associated with the subglacial outflow. The isotopic composition of important geochemical substrates (i.e., δ34Ssulfate, Δ33Ssulfate, δ18Osulfate, δ18Owater, Δ14SDIC) were also measured to provide more detail on subglacial microbial energetics. Typically, subglacial systems, when driven to anoxia by the hydrolysis of organic matter, will follow a continuum of redox chemistries utilizing electron acceptors with decreasing reduction potential (e.g., Fe (III), sulfate, CO2). Our data provide no evidence for sulfate reduction below the Taylor Glacier despite high dissolved organic carbon (450 μM C) and measurable metabolic activity. We contend that, in the case of the Taylor Glacier, the in situ bioenergetic reduction potential has been 'short-circuited' at Fe(III)-reduction and excludes sulfate reduction and methanogenesis. Given the length of time that this marine system has been isolated from phototrophic production (~2 Mya) the ability to degrade and consume increasingly recalcitrant organic carbon is likely an important component to the observed redox chemistry. Our work indicates that glacier hydrology

  17. The influence of ultraviolet-B radiation on growth, hydroxycinnamic acids and flavonoids of Deschampsia antarctica during Springtime ozone depletion in Antarctica.

    PubMed

    Ruhland, Christopher T; Xiong, Fusheng S; Clark, W Dennis; Day, Thomas A

    2005-01-01

    We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the growth, biomass production and phenylpropanoid concentrations of Deschampsia antarctica during the springtime ozone depletion season at Palmer Station, along the Antarctic Peninsula. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B either by 83% (reduced UV-B) or by 12% (near-ambient UV-B) over the 63 day experiment (7 November 1998-8 January 1999) when ozone depletion averaged 17%. Plants growing under near-ambient UV-B had 41% and 40% lower relative growth rates and net assimilation rates, respectively, than those under reduced UV-B. The former plants produced 50% less total biomass as a result of having 47% less aboveground biomass. The reduction in aboveground biomass was a result of a 29% lower leaf elongation rate resulting in shorter leaves and 59% less total leaf area in plants grown under reduced UV-B. p-Coumaric, caffeic and ferulic acids were the major hydroxycinnamic acids, and luteolin derivatives were the major flavonoids in both insoluble and soluble leaf extracts. Concentrations of insoluble p-coumaric and caffeic acid and soluble ferulic acids were 38%, 48% and 60% higher, respectively, under near-ambient UV-B than under reduced UV-B. There were no UV-B effects on concentrations of insoluble or soluble flavonoids. PMID:15689180

  18. Geodetic Tying of Antarctica and India With 10 Years of Continuous GPS Measurements for Geodynamical and Strain Accumulation Studies in the South of Indian Peninsula

    NASA Astrophysics Data System (ADS)

    Ec, M.; N, R.

    2008-12-01

    To holistically understand the geodynamical and crustal deformation processes between India and Antarctica, two global networks (IND and ANT) have been chosen. The objective is to geodetically connect the two continents. The IGS Station at Diego Garcia (DGAR) is the common station between the two networks. 10 years of data from 1997 to 2007 were used. By these global networks' analyses, the stations HYDE in India and MAIT at Antarctica are geodetically tied through the station DGAR. Very long baselines have been estimated from HYDE and also from Kerguelen (KERG) to other chosen IGS stations in and around India and Antarctica. Our analysis and results using ANT network show an increase in the baseline lengths between Kerguelen in Antarctic plate and other stations such as SEY1, DGAR and COCO and shortening of baseline lengths between HYDE in Indian plate and all these above stations using IND network. The analysis using ANT network also shows lengthening of baselines from Kerguelen to the sites Yaragadee (YAR1) and Tidbinbilla (TID2) in Australian plate; and Seychelles (SEY1) in Male plate, COCO in the diffuse plate boundary between India and Australia and DGAR in Capricorn plate at the rates of 5.3cm/yr, 3.8cm/yr, 5.6mm/yr, 3.03 cm/yr and 5.5 cm/yr respectively. The high rate of movement of COCO Island in comparison to Seychelles could be the result of excessive strain accumulation due to the Indo-Australia diffuse plate boundary forces acting upon this region. The estimated elastic strain accumulation shows an increasing trend of 1.27x 10-8 yr-1 in the south of Indian peninsula. Our results show the precision of approximately 3-4mm (North), 5-6 mm (East), and 10-12mm (vertical) for the estimation of site coordinates. These results provide new information on the direction and rate of Indian plate motion, the driving mechanisms of Indian plate and intraplate seismicity of the Indian Ocean on the whole.

  19. 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...

  20. Reconstruction of the East Africa and Antarctica continental margins

    NASA Astrophysics Data System (ADS)

    Nguyen, L. C.; Hall, S. A.; Ball, P.; Bird, D. E.

    2015-12-01

    The Early Jurassic separation of Antarctica from Africa plays an important role in our understanding of the dispersal of Gondwana. Previously proposed reconstruction models often contain overlaps and gaps in the restored margins that reflect difficulties in accurately delineating the continent-ocean boundary (COB) and determining the amount and distribution of extended continental crust. This study focuses on the evolution of the African margin adjacent to the Mozambique Basin and the conjugate margin of Antarctica near the Riiser Larsen Sea. New satellite-derived gravity data have been used to trace the orientations and landward limits of fracture zones in the study area. A 3-D gravity inversion has produced a crustal thickness model that reliably quantifies the extent and amount of stretched crust. Information on crustal thickness along with the identification of fracture zones reveal the COBs that are located significantly closer to the coasts of Africa and Antarctica than previously recognized. Correlation of both fracture zone azimuths and the identified COBs over the conjugate margins suggest Antarctica began drifting away from Africa at approximately 171 Ma in a roughly SSE direction. Of several scenarios examined, the Beira High is most likely oceanic and may be a conjugate feature of the southern Astrid Ridge. An areal-balancing method that involves restoring the crust to a uniform pre-rift thickness has been used to perform the non-rigid reconstruction for both non-volcanic and volcanic margin with magmatic underplating. Based on the results, Africa underwent extension of 65-105 km while Antarctic crust was stretched by 90-190 km. Both margins reveal a trend of increasing extension from east to west. Various models tested to determine the direction of extension during rifting suggest that Antarctica underwent a counter-clockwise rotation with respect to Africa between 186-171 Ma prior to the onset of seafloor spreading.

  1. Pituitary-gonadal hormones during prolonged residency in Antarctica

    NASA Astrophysics Data System (ADS)

    Sawhney, R. C.; Malhotra, A. S.; Prasad, Rajendra; Pal, Karan; Kumar, Rajesh; Bajaj, A. C.

    Plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and testosterone levels were measured in nine eugonadal men in New Delhi and during the 1st week of different months of their stay at Dakshin Gangotri in Antarctica. During their 12-month stay in Antarctica, they were exposed to a severely cold climate, long polar nights and polar days, high wind velocity, increased amounts of solar and ultraviolet radiation and geomagnetism, as well as physical and social isolation. Plasma testosterone tended to increase in March, but a significant increase (P<0.05) was not seen until April. The mean testosterone levels in May, June, September and November were also significantly higher than the March or New Delhi values. The absolute values of LH, FSH and PRL did not show any month-to-month changes in Antarctica. However, when the hormone levels were expressed as a percentage of the individual annual Antarctic mean, significant differences as a percentage of the individual annual Antarctic mean, significant differences were observed. The testosterone peak in April, May and June was associated with an increase in LH. The nadirs of testosterone, LH, FSH and PRL were seen in either July or August. FSH showed the highest values in March, whereas the highest PRL values were seen in November. These observations suggest the presence of circannual variations in gonadotropin, PRL and LH in Antarctica which are independent of polar days and polar nights. It appears that factors other than the duration of daylight might be involved in regulating these changes. The significance of maintenance of testosterone levels in the supra-physiological range in Antarctica remains unknown but may be important in acclimatization/habituation to the extreme polar cold by increasing basal metabolic rate, protein synthesis and erythropoiesis.

  2. Pituitary-gonadal hormones during prolonged residency in Antarctica.

    PubMed

    Sawhney, R C; Malhotra, A S; Prasad, R; Pal, K; Kumar, R; Bajaj, A C

    1998-08-01

    Plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and testosterone levels were measured in nine eugonadal men in New Delhi and during the 1st week of different months of their stay at Dakshin Gangotri in Antarctica. During their 12-month stay in Antarctica, they were exposed to a severely cold climate, long polar nights and polar days, high wind velocity, increased amounts of solar and ultraviolet radiation and geomagnetism, as well as physical and social isolation. Plasma testosterone tended to increase in March, but a significant increase (P < 0.05) was not seen until April. The mean testosterone levels in May, June, September and November were also significantly higher than the March or New Delhi values. The absolute values of LH, FSH and PRL did not show any month-to-month changes in Antarctica. However, when the hormone levels were expressed as a percentage of the individual annual Antarctic mean, significant differences as a percentage of the individual annual Antarctic mean, significant differences were observed. The testosterone peak in April, May and June was associated with an increase in LH. The nadirs of testosterone, LH, FSH and PRL were seen in either July or August. FSH showed the highest values in March, whereas the highest PRL values were seen in November. These observations suggest the presence of circannual variations in gonadotropin, PRL and LH in Antarctica which are independent of polar days and polar nights. It appears that factors other than the duration of daylight might be involved in regulating these changes. The significance of maintenance of testosterone levels in the supra-physiological range in Antarctica remains unknown but may be important in acclimatization/habituation to the extreme polar cold by increasing basal metabolic rate, protein synthesis and erythropoiesis. PMID:9780846

  3. Upper Mantle Seismic Anisotropy Beneath West Antarctica from Shear Wave Splitting Analysis of POLENET/ANET Data

    NASA Astrophysics Data System (ADS)

    Accardo, N.; Wiens, D. A.; Hernandez, S.; Aster, R. C.; Nyblade, A.; Anandakrishnan, S.; Huerta, A. D.; Wilson, T. J.

    2011-12-01

    We constrain azimuthal anisotropy in the Antarctic upper mantle using shear wave splitting parameters obtained from teleseismic SKS, SKKS, and PKS phases recorded at 30 broad-band seismometers deployed in West Antarctica, and the Transantarctic Mountains as a part of POLENET/ANET. The first seismometers were deployed in late 2007 and additional seismometers were deployed in 2008 and 2009. The seismometers generally operate year-round using solar power, insulated boxes, and either rechargeable AGM or primary lithium batteries. We used an eigenvalue technique to linearize the rotated and shifted shear wave particle motions and determine the best splitting parameters. Robust windows around the individual phases were chosen using the Teanby cluster-analysis algorithm. We visually inspected all results and assigned a quality rating based on factors including signal-to-noise ratios, particle motions, and error contours. The best results for each station were then stacked to get an average splitting direction and delay time. The delay times range from 0.33 to 1.33 s, but generally average about 1 s. We conclude that the splitting results from anisotropy in the upper mantle, since the large splitting times cannot be accumulated in the relatively thin crust (20-30 km) of the region. Overall, fast directions in West Antarctica are at large angles to the direction of Antarctic absolute plate motion in either hotspot or no-net rotation frameworks, showing that the anisotropic fabric does not result from shear associated with the motion of Antarctica over the mantle. The West Antarctic fast directions are also much different than those found in East Antarctica by previous studies. We suggest that the East Antarctic splitting results from anisotropy frozen into the cold cratonic continental lithosphere, whereas West Antarctic splitting is related to Cenozoic tectonism. Stations within the West Antarctic Rift System (WARS), a region of Cenozoic extension, show fast directions

  4. A Raman scattering and FT-IR spectroscopic study on the effect of the solar radiation in Antarctica on bovine cornea

    NASA Astrophysics Data System (ADS)

    Yamamoto, Tatsuyuki; Murakami, Naoki; Yoshikiyo, Keisuke; Takahashi, Tetsuya; Yamamoto, Naoyuki

    2010-01-01

    The Raman scattering and FT-IR spectra of the corneas, transported to the Syowa station in Antarctica and exposed to the solar radiation of the mid-summer for four weeks, were studied to reveal that type IV collagen involved in corneas were fragmented. The amide I and III Raman bands were observed at 1660 and 1245 cm -1, respectively, and the amide I and II infrared bands were observed at 1655 and 1545 cm -1, respectively, for original corneas before exposure. The background of Raman signals prominently increased and the ratio of amide II infrared band versus amide I decreased by the solar radiation in Antarctica. The control experiment using an artificial UV lamp was also performed in laboratory. The decline rate of the amide II/amide I was utilized for estimating the degree of fragmentation of collagen, to reveal that the addition of vitamin C suppressed the reaction while the addition of sugars promoted it. The effect of the solar radiation in Antarctica on the corneas was estimated as the same as the artificial UV lamp of four weeks (Raman) or one week (FT-IR) exposure.

  5. Spurious barometric pressure acceleration in Antarctica and propagation into GRACE Antarctic mass change estimates

    NASA Astrophysics Data System (ADS)

    Kim, Byeong-Hoon; Eom, Jooyoung; Seo, Ki-Weon; Wilson, Clark R.

    2016-08-01

    Apparent acceleration in Gravity Recovery and Climate Experiment (GRACE) Antarctic ice mass time-series may reflect both ice discharge and surface mass balance contributions. However, a recent study suggests there is also contamination from errors in atmospheric pressure de-aliasing fields [European Center for Medium-Range Weather Forecast (ECMWF) operational products] used during GRACE data processing. To further examine this question, we compare GRACE atmospheric pressure de-aliasing (GAA) fields with in situ surface pressure data from coastal and inland stations. Differences between the two are likely due to GAA errors, and provide a measure of error in GRACE solutions. Time-series of differences at individual weather stations are fit to four presumed error components: annual sinusoids, a linear trend, an acceleration term and jumps at times of known ECMWF model changes. Using data from inland stations, we estimate that atmospheric pressure error causes an acceleration error of about +7.0 Gt yr-2, which is large relative to prior GRACE estimates of Antarctic ice mass acceleration in the range of -12 to -14 Gt yr-2. We also estimate apparent acceleration rates from other barometric pressure (reanalysis) fields, including ERA-Interim, MERRA and NCEP/DOE. When integrated over East Antarctica, the four mass acceleration estimates (from GAA and the three reanalysis fields) vary considerably (by ˜2-16 Gt yr-2). This shows the need for further effort to improve atmospheric mass estimates in this region of sparse in situ observations, in order to use GRACE observations to measure ice mass acceleration and related sea level change.

  6. CryoSat-2 validation in East Antarctica: ASIRAS, ALS and in situ data analysis over Law Dome and Totten Glacier

    NASA Astrophysics Data System (ADS)

    Watson, C.; Burgette, R. J.; Helm, V.; Roberts, J. L.; Young, N. W.; Beardsley, J.; Tregoning, P.; Coleman, R.; Steinhage, D.; Fricker, H. A.; Young, D. A.; Blankenship, D. D.

    2012-12-01

    The joint TOT-Cal / CryoVExANT2011 project contributes to the validation of the CryoSat-2 altimetry mission through investigations of a key portion of the East Antarctic ice sheet near Australia's Casey Station. Spanning parts of Law Dome and the Totten Glacier, the study site includes a diverse range of along and across track surface slopes (ranging from 0° to over 2°), significant spatial variability in accumulation rate, as well as significant regions with known surface lowering (at rates greater than 1 m/yr). These characteristics combine to provide valuable validation targets for the CryoSat-2 mission. Two field campaigns at the study site have been completed during the 2010/11 and 2011/12 austral summer field seasons. In 2010/11, the primary in situ data collected included skidoo based kinematic GPS transects and airborne nadir pointing laser observations of the surface elevation (from ICECAP flights of Operation ICEBridge). In 2011/12, the AWI Polar-6 aircraft successfully completed aerial surveys across the region equipped with the scanning LiDAR and the ESA Airborne SAR / Interferometric Altimeter System (ASIRAS). These datasets combine with in-situ GPS observations (fixed stations and skidoo-based kinematic sampling), corner cube reflector placements and snow pit surveys. Together, these data provide a number of near contemporaneous observations of surface elevation and firn characteristics along CryoSat-2 ground tracks. Through repeated airborne observation, an insight into temporal changes over the most dynamic parts of the Totten Glacier where focused surface lowering and mass loss is known to be occurring can be achieved. In this contribution, we present early results investigating spatial variability present in the 2011/12 ASIRAS data, as well as temporal changes observed between successive acquisitions of airborne laser data (2010/11 and 2011/12). Comparison with CryoSat-2 SAR-In data is also presented.

  7. Massive Ice Layer Formed by Refreezing of Ice-shelf Surface Melt Ponds: Larsen C Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Kuipers Munneke, P.; Hubbard, B. P.; Luckman, A. J.; Ashmore, D.; Bevan, S. L.; Kulessa, B.; Jansen, D.; O'Leary, M.

    2015-12-01

    Surface melt ponds now form frequently on ice shelves across the northern sector of the Antarctic Peninsula in response to regional warming and local föhn winds. Analysis of a new, 1-year set of observations from an Automatic Weather Station on Larsen C Ice Shelf, Antarctica, reveals that föhn winds are able to cause intense melt in summer, and even into the late austral autumn. A potentially important, but hitherto unknown, consequence of this intense surface melting and ponding is the formation of high-density near-surface ice from the refreezing of that water. We report the discovery of a massive subsurface ice layer located in an area of intense melting and intermittent ponding on Larsen C Ice Shelf, Antarctica. We combine borehole optical televiewer logging and ground-based radar measurements with remote sensing and firn modelling to investigate the formation and spatial extent of this layer, found to be tens of kilometres across and tens of metres deep. The presence of this ice layer has the effect of raising local ice shelf density by ~190 kg m-3 and temperature by 5 - 10 °C above values found in areas unaffected by ponding and hitherto used in models of ice-shelf fracture and flow.

  8. Changes in the character of Polar stratospheric clouds over Antarctica in 1992 due to the Pinatubo volcanic aerosol

    SciTech Connect

    Deshler, T.; Johnson, B.J.; Rozier, W.R. )

    1994-02-15

    Vertical profiles of aerosol concentration were measured on 8 occasions from McMurdo Station, Antarctica (78[degrees]S), between late August and early October 1992. Polar stratospheric clouds (PSCs) were observed on 6 of these soundings. The characteristics of PSCs, and ozone, were quite different above and below about 16 km. Above 16 km PSCs were variable in time, with particles > 1.0 [mu]m radius contributing significantly to the surface area, generally < 8 [mu]m[sup 2] cm[sup [minus]3]. Below 16 km PSCs were much more stable and were dominated by high concentrations of smaller particles, < 1.0 [mu]m, with surface areas of 20-30 [mu]m[sup 2] cm[sup [minus]3]. This lower layer coincided with the altitude of the primary Pinatubo volcanic aerosol as measured in mid September and October, and with the 4 km region of the atmosphere where ozone was virtually completed destroyed over Antarctica in 1992. 12 refs., 4 figs.

  9. Breakup of the Larsen Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Recent Moderate-resolution Imaging Spectroradiometer (MODIS) satellite imagery analyzed at the University of Colorado's National Snow and Ice Data Center revealed that the northern section of the Larsen B ice shelf, a large floating ice mass on the eastern side of the Antarctic Peninsula, has shattered and separated from the continent. This particular image was taken on March 5, 2002. The shattered ice formed a plume of thousands of icebergs adrift in the Weddell Sea. A total of about 3,250 square kilometers of shelf area disintegrated in a 35-day period beginning on January 31, 2002. Over the last five years, the shelf has lost a total of 5,700 square kilometers and is now about 40 percent the size of its previous minimum stable extent. Ice shelves are thick plates of ice, fed by glaciers, that float on the ocean around much of Antarctica. The Larsen B shelf was about 220 meters thick. Based on studies of ice flow and sediment thickness beneath the ice shelf, scientists believe that it existed for at least 400 years prior to this event and likely existed since the end of the last major glaciation 12,000 years ago. For reference, the area lost in this most recent event dwarfs Rhode Island (2,717 square kilometers) in size. In terms of volume, the amount of ice released in this short time is 720 billion tons--enough ice for about 12 trillion 10-kilogram bags. This is the largest single event in a series of retreats by ice shelves along the peninsula over the last 30 years. The retreats are attributed to a strong climate warming in the region. The rate of warming is approximately 0.5 degrees Celsius per decade, and the trend has been present since at least the late 1940s. Overall in the peninsula, the extent of seven ice shelves has declined by a total of about 13,500 square kilometers since 1974. This value excludes areas that would be expected to calve under stable conditions. Ted Scambos, a researcher with the National Snow and Ice Data Center (NSIDC) at

  10. Space Station Freedom Utilization Conference

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary.

  11. Temporal changes in the skin Malassezia microbiota of members of the Japanese Antarctic Research Expedition (JARE): A case study in Antarctica as a pseudo-space environment.

    PubMed

    Sugita, Takashi; Yamazaki, Takashi; Yamada, Shin; Takeoka, Hajime; Cho, Otomi; Tanaka, Takafumi; Ohno, Giichiro; Watanabe, Kentaro; Makimura, Koichi; Ohshima, Hiroshi; Ishioka, Noriaki; Mukai, Chiaki

    2015-09-01

    The International Space Station (ISS) is located approximately 400 km above the Earth. Astronauts staying at the ISS are under microgravity and are thus unable to bathe or shower; instead, they wash their bodies using wet tissues. For astronauts, skin hygiene management is important to maintain the quality of life during long-term stays on the ISS. In Antarctica, members of a Japanese geological investigation team negotiate their way over land using snowmobiles. During their 3-month stay, they are subject to a "pseudo-space" environment similar to that experienced by ISS astronauts, including the inability to bathe or shower. In this study, temporal changes in the colonization levels of skin lipophilic fungi, Malassezia were investigated in 16 team members. Compared to the levels before their trip to Antarctica, the fold changes in Malassezia colonization levels during the researchers' stay in Antarctica were in the range of 3.0 ± 1.9 to 5.3 ± 7.5 in cheek samples, 8.9 ± 10.6 to 22.2 ± 40.0 in anterior chest samples, 6.2 ± 5.4 to 16.9 ± 25.5 in behind-the-ear samples, and 1.7 ± 0.9 to 17.4 ± 33.4 in sole-of-the-foot samples. On the scalp, the level of Malassezia colonization increased dramatically, by 96.7 ± 113.8 to 916.9 ± 1251.5 fold. During their stay in Antarctica, the team members experienced itchy scalps and produced a large number of scales. The relative proportions of Malassezia globosa and M. restricta shifted to seborrheic dermatitis/dandruff types. These results provide useful information for the development of skin hygiene management plans for astronauts staying at the ISS. PMID:26129888

  12. Ferrar Dolerite Sill Emplacement Styles, Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Kattenhorn, S. A.

    2005-12-01

    The Ferrar Dolerite of the Dry Valleys region of Antarctica, 100 km WNW of McMurdo Station, provides an unparalleled opportunity to examine both the physical and chemical characteristics of a magmatic plumbing system across a crustal depth range of several km. The mid-Jurassic Ferrar system consists of 4 distinct sill levels (100 to >300 m thick) and an extrusive component: the Kirkpatrick Basalt. The upper three sills (Mt. Fleming, Asgard, and Peneplain sills) intruded the Devonian-Triassic sedimentary section (the Beacon Sandstone). The lowermost sill (Basement sill) intruded Ordovician granite at a depth of ~3-4 km and is >330 m in thickness in places. The Basement sill is unique in this system in that: (1) It intruded into igneous rocks, resulting in sill geometries that are distinct from overlying sills that intruded along bedding planes; (2) It contains a laterally restricted, internally layered core of predominantly orthopyroxenite (the "Opx Tongue"); (3) Sill boundaries show evidence of initial brittle emplacement with subsequent thermal reintegration of sill walls in places, particularly adjacent to the Opx Tongue. The Basement sill intruded the granite from several to >100 m below the contact with the overlying sediments, defined by a Devonian erosional peneplain (the Kukri surface). Abutting relationships suggest that the Basement sill event postdated the overlying Peneplain sill. Emplacement features of the sills were examined along the walls of several valleys to characterize the styles of intrusion. At the W end of Wright Valley, the upper sills exhibit numerous vertical steps and jogs indicative of where adjacent sill segments intruded bedding planes at slightly different stratigraphic levels, then linked by fracturing through bridges of intervening host rock which became entrained within the sills. In contrast, a 7-km-long exposure of the Basement sill along the N wall of E Wright Valley maintains a fairly planar geometry. However, numerous vertical

  13. The strain accumulation studies between India and Antarctica in the Southern Indian Peninsula with GPS/GNSS-Geodesy by geodetically tying the two continents

    NASA Astrophysics Data System (ADS)

    Narayana Babu, R. N.; EC, M.

    2011-12-01

    Two global networks (IND and ANT) have been chosen that geodetically connect the two continents to holistically understand the geodynamical and crustal deformation processes in the south of Indian peninsula between India and Antarctica,. Since the baseline length between HYDE, India and MAIT, Antarctica is more than 10,000 km, it is mandatory to form these two different networks to improve the accuracy of the baseline measurements by GPS and so the IGS Station at Diego Garcia (DGAR) is chosen as the common station between the two networks. 13 years of data from 1997 to 2010 were used. By these global networks' analyses, the stations HYDE and MAIT are geodetically tied through DGAR. Very long baselines have been estimated from HYDE and also from Kerguelen (KERG) to other chosen IGS stations in and around India and Antarctica. Our analysis and results using ANT network show an increase in the baseline lengths between Kerguelen in Antarctic plate and other stations such as SEY1, DGAR and COCO and shortening of baseline lengths between HYDE in Indian plate and all these above stations using IND network. The analysis using ANT network also shows lengthening of baselines from Kerguelen to the sites Yaragadee (YAR1) and Tidbinbilla (TID2) in Australian plate; and Seychelles (SEY1) in Male plate, COCO in the diffuse plate boundary between India and Australia and DGAR in Capricorn plate at the rates of 5.3cm/yr, 3.8cm/yr, 5.6mm/yr, 3.03 cm/yr and 5.5 cm/yr respectively. The high rate of movement of COCO Island in comparison to Seychelles could be the result of excessive strain accumulation due to the Indo-Australia diffuse plate boundary forces acting upon this region. The estimated elastic strain accumulation shows an increasing trend of 1.27x 10-8 yr-1 in the south of Indian peninsula. Our results show the precision of approximately 3-4mm (North), 5-6 mm (East), and 10-12mm (vertical) for the estimation of site coordinates. These results provide new information on the

  14. COCHISE: Cosmological Observations from Concordia, Antarctica

    NASA Astrophysics Data System (ADS)

    Sabbatini, L.; Dall'Oglio, G.; Pizzo, L.; Cavaliere, F.; Miriametro, A.

    2011-02-01

    COCHISE is a 2.6 meter millimetric telescope devoted to cosmological observations. It is located near the Concordia Station, on the high Antarctic plateau, probably the best site in the world for (sub)millimetric observations. At present time, COCHISE is the largest telescope installed at Concordia: besides the scientific expectations, it is of great interest as a pathfinder for future Antarctic telescopes. The main characteristics of the telescope will be presented, including the scientific goals and the technical aspects related to the use of such an instrument at the extreme conditions of the Antarctic environment. Key aspects of the atmospheric transmission will be also discussed, by showing the preliminary results of site testing experiments.

  15. Space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.

    1987-01-01

    The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

  16. Rich bacterial assemblages from Maritime Antarctica (Potter Cove, South Shetlands) reveal several kinds of endemic and undescribed phylotypes.

    PubMed

    Landone Vescovo, Ignacio A; Golemba, Marcelo D; Di Lello, Federico A; Culasso, Andrés C A; Levin, Gustavo; Ruberto, Lucas; Mac Cormack, Walter P; López, José L

    2014-01-01

    Bacterial richness in maritime Antarctica has been poorly described to date. Phylogenetic affiliation of seawater free-living microbial assemblages was studied from three locations near the Argentinean Jubany Station during two Antarctic summers. Sixty 16S RNA cloned sequences were phylogenetically affiliated to Alphaproteobacteria (30/60 clones), Gammaproteobacteria(19/60 clones), Betaproteobacteria and Cytophaga-Flavobacteriia-Bacteroides (CFB), which were (2/60) and (3/60) respectively. Furthermore, six out of 60 clones could not be classified. Both, Alphaproteobacteria and Gammaproteobacteria, showed several endemic and previously undescribed sequences. Moreover, the absence of Cyanobacteria sequences in our samples is remarkable. In conclusion, we are reporting a rich sequence assemblage composed of widely divergent isolates among themselves and distant from the most closely related sequences currently deposited in data banks. PMID:25444131

  17. Station Crew Celebrates Christmas

    NASA Video Gallery

    Aboard the orbiting International Space Station, Expedition 34 Commander Kevin Ford, Russian Flight Engineers Oleg Novitskiy, Evgeny Tarelkin and Roman Romanenko, NASA Flight Engineer Tom Marshburn...

  18. Space Station fluid resupply

    NASA Technical Reports Server (NTRS)

    Winters, AL

    1990-01-01

    Viewgraphs on space station fluid resupply are presented. Space Station Freedom is resupplied with supercritical O2 and N2 for the ECLSS and USL on a 180 day resupply cycle. Resupply fluids are stored in the subcarriers on station between resupply cycles and transferred to the users as required. ECLSS contingency fluids (O2 and N2) are supplied and stored on station in a gaseous state. Efficiency and flexibility are major design considerations. Subcarrier approach allows multiple manifest combinations. Growth is achieved by adding modular subcarriers.

  19. Space Station operations

    NASA Technical Reports Server (NTRS)

    Gray, R. H.

    1985-01-01

    An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

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

    SciTech Connect

    Saito, Hiroaki National Institute of Polar Research, Tokyo ); Sato, Natsuo ); Tonegawa, Yutaka ); Yoshino, Takeo ); Saemundsson, T. )

    1989-06-01

    Seasonal and diurnal variations of Pc 3-5 magnetic pulsation powers have been examined using 2 years of magnetic data from geomagnetically conjugate stations, Syowa in Antarctica and Husafell and Tjoernes in Iceland. The magnetic pulsation powers are found to be relatively higher at the winter hemisphere station than at the summer station. The pulsations observed during equinox show a diurnal dependence, i.e., that the power density is higher in the geomagnetic morning at the stations in Iceland than at Syowa, and this relationship is reversed in the afternoon. The power density ratio of Pc 3 pulsations between the conjugate stations, which is associated with the seasons and with local time, is higher than that of Pc 5. These characteristics can be attributed to the effects of sunlight in the ionosphere, i.e., Pc 3-5 pulsations are shielded when the waves propagate from the magnetosphere to the ground through the sunlit ionosphere.

  1. The European Project for Ice Coring in Antarctica - An Overview

    NASA Astrophysics Data System (ADS)

    Miller, H.

    2003-04-01

    The European Project for Ice Coring in Antarctica (EPICA), which is a joint project between 10 European nations, currently is drilling two icecores at different locations in Antarctica with the major aims of retrieving the oldest continuous ice core record and a high resolution one covering at least the last climate cycle. Both drilling projects are well on their way. The record of Dome C according to preliminary data extends back substantially further than 500.000 years and the drilling in Dronning Maud Land, which was started in the 2001/2002 season will have recovered ice from well within the last glacial by the end of the ongoing field season. As introduction to the following talks in this session an overview will be given on the overall scientific rationale of the project and its implementation as well as its major milestones in logistic and scientific development.

  2. Airborne laser scanning for high-resolution mapping of Antarctica

    NASA Astrophysics Data System (ADS)

    Csatho, Bea; Schenk, Toni; Krabill, William; Wilson, Terry; Lyons, William; McKenzie, Garry; Hallam, Cheryl; Manizade, Serdar; Paulsen, Timothy

    In order to evaluate the potential of airborne laser scanning for topographic mapping in Antarctica and to establish calibration/validation sites for NASA's Ice, Cloud and land Elevation Satellite (ICESat) altimeter mission, NASA, the U.S. National Science Foundation (NSF), and the U.S. Geological Survey (USGS) joined forces to collect high-resolution airborne laser scanning data.In a two-week campaign during the 2001-2002 austral summer, NASA's Airborne Topographic Mapper (ATM) system was used to collect data over several sites in the McMurdo Sound area of Antarctica (Figure 1a). From the recorded signals, NASA computed laser points and The Ohio State University (OSU) completed the elaborate computation/verification of high-resolution Digital Elevation Models (DEMs) in 2003. This article reports about the DEM generation and some exemplary results from scientists using the geomorphologic information from the DEMs during the 2003-2004 field season.

  3. Synchronous climate changes in Antarctica and the North Atlantic

    USGS Publications Warehouse

    Steig, E.J.; Brook, E.J.; White, J.W.C.; Sucher, C.M.; Bender, M.L.; Lehman, S.J.; Morse, D.L.; Waddington, E.D.; Clow, G.D.

    1998-01-01

    Central Greenland ice cores provide evidence of abrupt changes in climate over the past 100,000 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic, confirming the link between millennial-scale climate variability and ocean thermohaline circulation. It is shown here that two of the most prominent North Atlantic events - the rapid warming that makes the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation - are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica. This result contrasts with evidence from ice cores in other regions of Antarctica, which show an asynchronous response between the Northern and Southern Hemispheres.

  4. The subglacial geology of Wilkes Land, East Antarctica

    NASA Astrophysics Data System (ADS)

    Aitken, A. R. A.; Young, D. A.; Ferraccioli, F.; Betts, P. G.; Greenbaum, J. S.; Richter, T. G.; Roberts, J. L.; Blankenship, D. D.; Siegert, M. J.

    2014-04-01

    Wilkes Land is a key region for studying the configuration of Gondwana and for appreciating the role of tectonic boundary conditions on East Antarctic Ice Sheet (EAIS) behavior. Despite this importance, it remains one of the largest regions on Earth where we lack a basic knowledge of geology. New magnetic, gravity, and subglacial topography data allow the region's first comprehensive geological interpretation. We map lithospheric domains and their bounding faults, including the suture between Indo-Antarctica and Australo-Antarctica. Furthermore, we image subglacial sedimentary basins, including the Aurora and Knox Subglacial Basins and the previously unknown Sabrina Subglacial Basin. Commonality of structure in magnetic, gravity, and topography data suggest that pre-EAIS tectonic features are a primary control on subglacial topography. The preservation of this relationship after glaciation suggests that these tectonic features provide topographic and basal boundary conditions that have strongly influenced the structure and evolution of the EAIS.

  5. The significance of Antarctica for studies of global geodynamics

    USGS Publications Warehouse

    Sutherland, R.

    2007-01-01

    Antarctica has geometric significance for global plate kinematic studies, because it links seafloor spreading systems of the African hemisphere (Indian and Atlantic Oceans) with those of the Pacific. Inferences of plate motions back to 44 Ma, around the onset of rapid spreading south of Australia and formation of a new boundary through New Zealand, are consistent with Antarctic rifting and formation of the Adare Basin during 44-26 Ma (i.e., no additional plate motions are required in the South Pacific). The time period 52-44 Ma represents a profound global and South Pacific tectonic change, and significant details remain unresolved. For 74 Ma a significant nonclosure of the South Pacific plate-motion circuit is identified if Antarctic motion is not included. Alternate inferences of motion through Antarctica during the interval 74-44 Ma imply significantly different subduction volumes and directions around the Pacific, and imply different relative motions between hotspots

  6. Synchronous climate changes in antarctica and the north atlantic

    PubMed

    Steig; Brook; White; Sucher; Bender; Lehman; Morse; Waddington; Clow

    1998-10-01

    Central Greenland ice cores provide evidence of abrupt changes in climate over the past 100,000 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic, confirming the link between millennial-scale climate variability and ocean thermohaline circulation. It is shown here that two of the most prominent North Atlantic events-the rapid warming that marks the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation-are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica. This result contrasts with evidence from ice cores in other regions of Antarctica, which show an asynchronous response between the Northern and Southern Hemispheres. PMID:9756484

  7. The search for postglacial rebound near the Lambert Glacier, Antarctica

    NASA Astrophysics Data System (ADS)

    Tregoning, Paul; Welsh, Andrew; McQueen, Herbert; Lambeck, Kurt

    2000-11-01

    A GPS network has been installed to monitor vertical crustal movement in the Lambert Glacier region, East Antarctica. The program commenced in January 1998 with a solar-powered GPS system installed at Beaver Lake. Solar-powered observations were also made late in the Antarctic summer of 1999. In January 2000, two new solar-powered sites will be installed to expand the monitoring network. In addition, we will be installing a hydrogen fuel cell power system at Beaver Lake to enable the equipment to operate throughout the winter months when solar power is not available. In this paper we outline the equipment which has been developed in order to operate remote GPS equipment in Antarctica, provide predictions of the expected rate of rebound and comment on preliminary results from the data collected to date.

  8. Topographic and hydrological controls on Subglacial Lake Ellsworth, West Antarctica

    NASA Astrophysics Data System (ADS)

    Vaughan, David G.; Rivera, Andrés; Woodward, John; Corr, Hugh F. J.; Wendt, Jens; Zamora, Rodrigo

    2007-09-01

    Subglacial Lake Ellsworth (SLE) was identified using reconnaissance data collected in the 1970s, here we present more detailed surveys. SLE lies beneath 3.2 km of ice in a subglacial valley in West Antarctica. It has an area of only ~18 km2, is dissimilar to the large tectonically-controlled lakes beneath East Antarctica and is a strong candidate for in situ exploration. Our analysis indicates that the ice above SLE is floating on a fluid whose density is 950-1013 kg m-3. This could indicate freshwater, but certainly precludes seawater, or high salt, acid, or clathrate content. The water in the lake is unlikely to be produced solely by local melt; it is more likely delivered via subglacial drainage. Our surveys show no identifiable hydrological barrier to outflow, meaning SLE is effectively full; new water entering the lake is likely balanced by outflow, which would drain into another lake that we have also identified.

  9. Ozone hits low levels over Antarctica, U. S

    SciTech Connect

    Zurer, P.

    1993-10-04

    This year's Antarctic ozone hole is as deep as any ever observed and is approaching the record geographical extent of 1992, according to preliminary satellite data. In addition, both groundbased and satellite observations indicate that ozone concentrations over the U.S. hit record lows earlier this year. For more than a decade, almost all the ozone at certain altitudes over Antarctica has been destroyed as the Sun returns to the polar region in September. This dramatic photochemical depletion, catalyzed by chlorine and bromine from man-made compounds, reaches its nadir in early October. Ozone levels return to near normal later in the season, when the circular pattern of winds that isolates air over Antarctica breaks down, and ozone-rich air pours in from the north.

  10. In silico analysis of glucoamylase from a psychrophilic yeast, Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Yusuf, Siti Nur Hasanah Mohd; Bakar, Farah Diba Abu; Mahadi, Nor Muhammad; Murad, Abdul Munir Abdul

    2015-09-01

    Glaciozyma antarctica has a total of 7857 putative genes and its whole genome sequence is available online in Malaysia Genome Institute. In this study, we screened for potential glycoside hydrolase family 15 genes from the G. antarctica. From G. antarctica database, two sequences have been identified as a putative genes encoded glycoside hydrolase family 15 based on its sequence similarity and present of glycoside hydrolase family 15 conserved domains. Based on the bioinformatic analysis conducted on the genome database of G. antarctica, there are two putative genes predicted to encode glycoside hydrolase family 15 protein. These genes have been represented as LAN_ 14_077 and LAN_10_097 in the database.

  11. Another bipolar deep-sea anemone: new species of Iosactis (Actiniaria, Endomyaria) from Antarctica

    NASA Astrophysics Data System (ADS)

    Rodríguez, Estefanía

    2012-06-01

    A new species of deep-sea burrowing sea anemone is described and illustrated from Antarctica. Iosactis antarctica sp. nov. is characterised by easily deciduous tentacles with sphincters in the base, smooth column, endodermal marginal sphincter, same mesenteries proximally and distally, 24 perfect mesenteries regularly arranged, diffuse retractor musculature and basilar muscles well developed. Iosactis antarctica sp. nov. is the second species of the deep-sea abyssal genus Iosactis; it differs from I. vagabunda in internal anatomy, cnidae and geographic distribution. The description of I. antarctica sp. nov. provides the opportunity to revaluate the morphology of the proximal end of this genus.

  12. ECC (Electrochemical Concentration Cell) ozonesonde observations at Mirny, Antarctica, during 1988

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Lathrop, J. A.; Arbuzova, V. N.; Khattatov, V. U.; Nureyev, P. G.; Rudakov, V. V.; Zamyshlayev, I. V.

    1989-01-01

    Atmospheric ozone vertical distributions, air temperatures, and wind speed and direction data are presented for 40 balloon electrochemical concentration cell ozone soundings made at Mirny, Antarctica, in 1988.

  13. Mapping Antarctica using Landsat-8 - the preliminary results

    NASA Astrophysics Data System (ADS)

    Cheng, X.; Hui, F.; Qi, X.

    2014-12-01

    The first Landsat Image Mosaic of Antarctica (LIMA) was released in 2009, which was created by USGS, BAS, and NASA from more than 1,000 Landsat ETM+ scenes. As the first major scientific outcome of the IPY, LIMA supports current scientific polar research, encourages new projects, and helps the general public visualize Antarctica and changes happening to this southernmost environment. As the latest satellite of Landsat mission, the Landsat-8 images the entire Earth every 16 days in an 8-day offset from Landsat-7. Data collected by the instruments onboard the satellite are available to download at no charge within 24 hours of reception. The standard Landsat 8 products provided by the USGS EROS Center consist of quantized and calibrated scaled Digital Numbers (DN) in 16-bit unsigned integer format and can be rescaled to the Top Of Atmosphere (TOA) reflectance and/or radiance. With the support of USGS portal, we searched and downloaded more than 1600 scenes of Level 1 T- Terrain Corrected Landsat 8 image products covering Antarctica from late 2013 to early 2014. These data were converted to planetary radiance for further processing. Since the distribution of clouds in these images are random and much complicated, statistics on the distribution of clouds were performed and then help to decide masking those thicker cloud to keep more useful information left and avoid observation holes. A preliminary result of the Landsat-8 mosaic of Antarctica under the joint efforts of Beijing Normal University, NSIDC and University of Maryland will be released on this AGU fall meeting. Comparison between Landsat 7 and 8 mosaic products will also be done to find the difference or advantage of the two products.

  14. Sedimentary Rocks of the Buckeye Range, Horlick Mountains, Antarctica.

    PubMed

    Long, W E

    1962-04-27

    In the Buckeye Range of the Horlick Mountains, 4000 feet of sedimentary rocks nonconformably overlie a granitic basement and underlie a thick diabasic sill. The sedimentary section consists of Devonian sandstone and shale (Horlick formation), Carboniferous (?) tillite (Buckeye formation), Permian (?) platy and carbonaceous shale (Discovery Ridge formation), and Permian arkose, shale, and numerous coal beds (Mount Glossopteris formation). This apparently is the first report of a Paleozoic tillite in Antarctica. PMID:17745908

  15. Victoria Land, Ross Sea, and Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On December 19, 2001, MODIS acquired data that produced this image of Antarctica's Victoria Land, Ross Ice Shelf, and the Ross Sea. The coastline that runs up and down along the left side of the image denotes where Victoria Land (left) meets the Ross Ice Shelf (right). The Ross Ice Shelf is the world's largest floating body of ice, approximately the same size as France. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  16. Spatial-temporal dynamics of chemical composition of surface snow in East Antarctic along the transect Station Progress-Station Vostok

    NASA Astrophysics Data System (ADS)

    Khodzher, T. V.; Golobokova, L. P.; Shibaev, Y. A.; Lipenkov, V. Y.; Petit, J. R.

    2013-05-01

    This paper presents data on chemical composition of the Antarctic snow sampled during the 53rd Russian Antarctic Expedition (RAE, 2008) along the first tractor traverse (TT) from Station Progress to Station Vostok (East Antarctica). Snow samples were obtained from the cores drilled at 55.3, 253, 337, 369, 403, 441, 480, 519, 560, 618, 819, and 1276 km from Station Progress. Data on horizontal and deep distribution of chemical components in the snow provide evidence of spatial and temporal variations of conditions for the snow cover formation along the transect under study. Sea salt was the main source for chemical composition of snow cover near the ice edge. Concentrations of marine-derived components decreased further inland. A hypothesis was put forward that some ions in the snow cover of the central part of East Antarctica were likely to be of continental origin. Elevated concentrations of sulphate ions of continental origin were recorded in some profiles of the transect at a depth of 130-150 cm which was attributed to buried signals of the Pinatubo volcano eruption (1991).

  17. Isolation and characterization of halotolerant Streptomyces radiopugnans from Antarctica soil.

    PubMed

    Bhave, S V; Shanbhag, P V; Sonawane, S K; Parab, R R; Mahajan, G B

    2013-05-01

    An actinomycete wild strain PM0626271 (= MTCC 5447), producing novel antibacterial compounds, was isolated from soil collected from Antarctica. The taxonomic status of the isolate was established by polyphasic approach. Scanning electron microscopy observations and the presence of LL-Diaminopimelic acid in the cell wall hydrolysate confirmed the genus Streptomyces. Analysis of 16S rRNA gene sequence showed highest sequence similarity to Streptomyces radiopugnans (99%). The phylogenetic tree constructed using near complete 16S rRNA gene sequences of the isolate and closely related strains revealed that although the isolate fell within the S. radiopugnans gene subclade, it was allocated a different branch in the phylogenetic tree, separating it from the majority of the radiopugnans strains. Similar to type strain, S. radiopugnans R97(T) , the Antarctica isolate displayed thermo tolerance as well as resistance to (60) Co gamma radiation, up to the dose of 15 kGy. However, media and salt tolerance studies revealed that, unlike the type strain, this isolate needed higher salinity for its growth. This is the first report of S. radiopugnans isolated from the Antarctica region. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of Streptomyces radiopugnans MTCC 5447 is JQ723477. PMID:23384241

  18. Permafrost warming and vegetation changes in continental Antarctica

    NASA Astrophysics Data System (ADS)

    Guglielmin, Mauro; Dalle Fratte, Michele; Cannone, Nicoletta

    2014-04-01

    Continental Antarctica represents the last pristine environment on Earth and is one of the most suitable contexts to analyze the relations between climate, active layer and vegetation. In 2000 we started long-term monitoring of the climate, permafrost, active layer and vegetation in Victoria Land, continental Antarctica. Our data confirm the stability of mean annual and summer air temperature, of snow cover, and an increasing trend of summer incoming short wave radiation. The active layer thickness is increasing at a rate of 0.3 cm y-1. The active layer is characterized by large annual and spatial differences. The latter are due to scarce vegetation, a patchy and very thin organic layer and large spatial differences in snow accumulation. The active layer thickening, probably due to the increase of incoming short wave radiation, produced a general decrease of the ground water content due to the better drainage of the ground. The resultant drying may be responsible for the decline of mosses in xeric sites, while it provided better conditions for mosses in hydric sites, following the species-specific water requirements. An increase of lichen vegetation was observed where the climate drying occurred. This evidence emphasizes that the Antarctic continent is experiencing changes that are in total contrast to the changes reported from maritime Antarctica.

  19. Soil formation in Seymour Island, Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Souza, Katia Karoline Delpupo; Schaefer, Carlos Ernesto G. R.; Simas, Felipe Nogueira Bello; Spinola, Diogo Noses; de Paula, Mayara Daher

    2014-11-01

    The Antarctic Peninsula marks the climatic transition between Maritime and Continental Antarctica. Ice-free areas at the western side of the Peninsula (Maritime Antarctica) have been increasingly studied in the last 10 years whereas soils on the eastern coast have been relatively less studied. The objective of the present study is to analyze the properties of soils developed on Seymour Island, in the Weddell sea sector, eastern coast of the Antarctic Peninsula, in order to identify the main factors and processes involved in soil formation under semi-polar desert conditions in this part of Antarctica. Twenty-one pedons were described, sampled and analyzed for their physical, chemical and mineralogical attributes. Most of the soils were classified as Gelisols and Cryosols by the Soil Taxonomy and WRB/FAO, respectively. Three soil groups were found: immature alkaline soils on sandstones and siltstones, acid sulfate and ornithogenic soils. Soils have little cryoturbation and are all affected by salinization with natric and salic characters. Acid sulfate soils are the most weathered soils in Seymour Island. Due to the dry climate, phosphatization is still incipient with P-rich ornithogenic layers with little interaction with the mineral substrate. The Soil Taxonomy and WRB/FAO systems lack adequate classification criteria to classify all soils developed in transitional areas that are affected by a combination of salinization, sulfurization and phosphatization.

  20. Ice crystal precipitation at Dome C site (East Antarctica)

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    For the first time, falling ice crystals were collected on glass slides covered with a thin layer of 2% formvar in chloroform at the Dome Concordia site (Dome C), Antarctica. Samplings were performed in the framework of the 27th Italian Antarctica expedition of the Italian National Program for Research in Antarctica in the period 21 February-6 August 2012. Events of clear-sky precipitations and precipitations from clouds were considered and the replicas obtained were examined under Scanning Electron Microscope (SEM). Several shapes of ice crystals were identified, including "diamond dust" (plates, pyramids, hollow and solid columns), and crystal aggregates varying in complexity. Single events often contained both small (10 μm to 50 μm) and large (hundreds of microns) crystals, suggesting that crystals can form simultaneously near the ground (height of a few hundred metres) and at higher layers (height of thousands of metres). Images of sampled crystal replicas showed that single bullets are not produced separately, but by the disintegration of combinations of bullets. Rimed ice crystals were absent in the Dome C samples, i.e. the only mode of crystal growth was water vapour diffusion. On considering the aerosol in the sampled crystals, we reached the conclusion that inertial impaction, interception and Brownian motion were insufficient to explain the scavenged aerosol. We therefore presume that phoretic forces play a role in scavenging during the crystal growth process.

  1. Enhanced LANDSAT images of Antarctica and planetary exploration

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.; Bowell, J. A.; Edwards, K.; Eliason, E. M.; Ferguson, H. M.

    1987-01-01

    Since early in the LANDSAT program, black-and-white paper prints of band 7 (near infrared) of the LANDSAT multispectral scanner have been used extensively to prepare semicontrolled maps of Antarctica. Image-processing techniques are now employed to enhance fine detail and to make controlled image-mosaic maps in color. LANDSAT multispectral images of Antarctica help to expand our knowledge of extraterrestrial bodies by showing bare-ice areas as bright blue patches; on such patches meteorites tend to be concentrated and are collected. Many subtle flow features in Antarctic ice streams resemble features at the mouths of Martian outflow channels, which suggests that the channels also contained ice. Furthermore, flow lines in Antarctic ice sheets that merge with ice shelves resemble Martian flow features associated with dissected terrain along the Martian northern highland margin, and support the concept that ice was involved in the transport of material from the southern highlands to the northern lowland plains. In Antarctica, as on Mars, the virtual absence of fluvial activity over millions of years has permitted the growth of glacial and eolian features to unusually large sizes.

  2. A combined observational and modeling approach to study modern dust transport from the Patagonia desert to East Antarctica

    NASA Astrophysics Data System (ADS)

    Gassó, S.; Stein, A.; Marino, F.; Castellano, E.; Udisti, R.; Ceratto, J.

    2010-09-01

    The understanding of present atmospheric transport processes from Southern Hemisphere (SH) landmasses to Antarctica can improve the interpretation of stratigraphic data in Antarctic ice cores. In addition, long range transport can deliver key nutrients normally not available to marine ecosystems in the Southern Ocean and may trigger or enhance primary productivity. However, there is a dearth of observational based studies of dust transport in the SH. This work aims to improve current understanding of dust transport in the SH by showing a characterization of two dust events originating in the Patagonia desert (south end of South America). The approach is based on a combined and complementary use of satellite retrievals (detectors MISR, MODIS, GLAS, POLDER, OMI), transport model simulation (HYSPLIT) and surface observations near the sources and aerosol measurements in Antarctica (Neumayer and Concordia sites). Satellite imagery and visibility observations confirm dust emission in a stretch of dry lakes along the coast of the Tierra del Fuego (TdF) island (~54° S) and from the shores of the Colihue Huapi lake in Central Patagonia (~46° S) in February 2005. Model simulations initialized by these observations reproduce the timing of an observed increase in dust concentration at the Concordia Station and some of the observed increases in atmospheric aerosol absorption (here used as a dust proxy) in the Neumayer station. The TdF sources were the largest contributors of dust at both sites. The transit times from TdF to the Neumayer and Concordia sites are 6-7 and 9-10 days respectively. Lidar observations and model outputs coincide in placing most of the dust cloud in the boundary layer and suggest significant deposition over the ocean immediately downwind. Boundary layer dust was detected as far as 1800 km from the source and ~800 km north of the South Georgia Island over the central sub-Antarctic Atlantic Ocean. Although the analysis suggests the presence of dust at

  3. A Combined Observational and Modeling Approach to Study Modern Dust Transport from the Patagonia Desert to East Antarctica

    NASA Technical Reports Server (NTRS)

    Gasso, S.; Stein, A.; Marino, F.; Castellano, E.; Udisti, R.; Ceratto, J.

    2010-01-01

    The understanding of present atmospheric transport processes from Southern Hemisphere (SH) landmasses to Antarctica can improve the interpretation of stratigraphic data in Antarctic ice cores. In addition, long range transport can deliver key nutrients normally not available to marine ecosystems in the Southern Ocean and may trigger or enhance primary productivity. However, there is a dearth of observational based studies of dust transport in the SH. This work aims to improve current understanding of dust transport in the SH by showing a characterization of two dust events originating in the Patagonia desert (south end of South America). The approach is based on a combined and complementary use of satellite retrievals (detectors MISR, MODIS, GLAS ,POLDER, OMI,), transport model simulation (HYSPLIT) and surface observations near the sources and aerosol measurements in Antarctica (Neumayer and Concordia sites). Satellite imagery and visibility observations confirm dust emission in a stretch of dry lakes along the coast of the Tierra del Fuego (TdF) island (approx.54deg S) and from the shores of the Colihue Huapi lake in Central Patagonia (approx.46deg S) in February 2005. Model simulations initialized by these observations reproduce the timing of an observed increase in dust concentration at the Concordia Station and some of the observed increases in atmospheric aerosol absorption (here used as a dust proxy) in the Neumayer station. The TdF sources were the largest contributors of dust at both sites. The transit times from TdF to the Neumayer and Concordia sites are 6-7 and 9-10 days respectively. Lidar observations and model outputs coincide in placing most of the dust cloud in the boundary layer and suggest significant de- position over the ocean immediately downwind. Boundary layer dust was detected as far as 1800 km from the source and approx.800 km north of the South Georgia Island over the central sub-Antarctic Atlantic Ocean. Although the analysis suggests the

  4. Space station executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An executive summary of the modular space station study is presented. The subjects discussed are: (1) design characteristics, (2) experiment program, (3) operations, (4) program description, and (5) research implications. The modular space station is considered a candidate payload for the low cost shuttle transportation system.

  5. "Inventive" Learning Stations

    ERIC Educational Resources Information Center

    Jarrett, Olga

    2010-01-01

    Learning stations can be used for myriad purposes--to teach concepts, integrate subject matter, build interest, and allow for inquiry--the possibilities are limited only by the imagination of the teacher and the supplies available. In this article, the author shares suggestions and a checklist for setting up successful learning stations. In…

  6. Space station dynamics

    NASA Technical Reports Server (NTRS)

    Berka, Reg

    1990-01-01

    Structural dynamic characteristics and responses of the Space Station due to the natural and induced environment are discussed. Problems that are peculiar to the Space Station are also discussed. These factors lead to an overall acceleration environment that users may expect. This acceleration environment can be considered as a loading, as well as a disturbance environment.

  7. The Station System

    ERIC Educational Resources Information Center

    Brooks, David W.

    1970-01-01

    Describes an introductory college chemistry course utilizing laboratory stations and laboratory instruction by video taped presentations. Author discusses the general operation of the laboratory, the method used in evaluating students' progress, the teaching effectiveness and economy of the station system. Results of a student questionnaire reveal…

  8. Characteristic Surface Processes Between Atmosphere, Cryosphere and Oceanic Environment Inferred from Infrasound Array Observations in Lützow-Holm Bay, East Antarctica

    NASA Astrophysics Data System (ADS)

    Ishihara, Y.; Kanao, M.; Yamamoto, M. Y.; Kakinami, Y.; Murayama, T.; Okada, K.; Toda, S.; Matsushima, T.

    2014-12-01

    Infrasound is sub-audible sound whose frequency range is about 3 mHz to 20 Hz. Because this frequency is common between atmospheric, oceanic and solid earth vibrations, those waves are interacting with each other and interaction itself generates infrasound. At polar region, cryosphere also play an important role for generation and propagation of infrasound. The Japanese Antarctic infrasound observation started at April 2008. A sensor was installed at Syowa Station (SYO) in Lützow-Holm Bay (LHB) of East Antarctica, as a part of the International Polar Year. Characteristic infrasound waves observed at SYO demonstrate physical interaction involving environmental changes in the Antarctic region. Continuous recordings of infrasound clearly indicate existence of the hums generated by ocean-atmosphere interaction (microbaroms) with peaks of 0.1 to 0.25 Hz. Because larger amount of sea-ice extending around the LHB near SYO suppress ocean wave, the microbaroms become weak during austral winter. Following success of pilot observation, in austral summer in 2013, we extended one-sensor observation at SYO to 3-sensor arrayed observations, and installed a few field stations along the coast of the LHB. Newly established SYO array clearly detected the propagating directions and frequency contents of the microbaroms from Southern Ocean. In addition, we found harmonic signals around lowermost human audible band, however, currently unclear how and what generating hamonic signals. Those signals are recorded under windy condition. Since our system has no mechanical resonance at those frequency ranges, we speculate that the characteristic harmonic signals are probably related to local surficial phenomena such as ice sheet vibration generated by katabatic winds. Infrasound measurement at Antarctica could be a new proxy for monitoring a regional environmental change in high southern latitude. In such point of view, we will continue and improve the observations at and around SYO

  9. Targeting space station technologies

    NASA Technical Reports Server (NTRS)

    Olstad, W. B.

    1983-01-01

    NASA's Space Station Technology Steering Committee has undertaken the definition of the level of technology that is desirable for use in the initial design and operation of an evolutionary, long service life space station, as well as the longer term technology required for the improvement of capabilities. The technology should initially become available in 1986, in order to support a space station launch as early as 1990. Toward this end, the committee seeks to assess technology forecasts based on existing research and testing capacity, and then plan and monitor a program which will move current technology to the requisite level of sophistication and reliability. The Space Shuttle is assumed to be the vehicle for space station delivery, assembly, and support on a 90-day initial cycle. Space station tasks will be military, commercial, and scientific, including on-orbit satellite servicing.

  10. Wavelike Structures in the Turbulent Layer During the Morning Development of Convection at Dome C, Antarctica

    NASA Astrophysics Data System (ADS)

    Petenko, Igor; Argentini, Stefania; Casasanta, Giampietro; Kallistratova, Margarita; Sozzi, Roberto; Viola, Angelo

    2016-06-01

    In the period January-February 2014, observations were made at the Concordia station, Dome C, Antarctica to study atmospheric turbulence in the boundary layer using a high-resolution sodar. The turbulence structure was observed beginning from the lowest height of about 2 m, with a vertical resolution of less than 2 m. Typical patterns of the diurnal evolution of the spatio-temporal structure of turbulence detected by the sodar are analyzed. Here, we focus on the wavelike processes observed within the transition period from stable to unstable stratification occurring in the morning hours. Thanks to the high-resolution sodar measurements during the development of the convection near the surface, clear undulations were detected in the overlying turbulent layer for a significant part of the time. The wavelike pattern exhibits a regular braid structure, with undulations associated with internal gravity waves attributed to Kelvin-Helmholtz shear instability. The main spatial and temporal scales of the wavelike structures were determined, with predominant periodicity of the observed wavy patterns estimated to be 40-50 s. The horizontal scales roughly estimated using Taylor's frozen turbulence hypothesis are about 250-350 m.

  11. High-resolution 900 year volcanic and climatic record from the Vostok area, East Antarctica

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Ion chromatography measurements of 1730 snow and firn samples obtained from three short cores and one pit in the Vostok station area, East Antarctica, allowed for the production of the combined volcanic record of the last 900 years (AD 1093-2010). The resolution of the record is 2-3 samples per accumulation year. In total, 24 volcanic events have been identified, including seven well-known low-latitude eruptions (Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Huanaputina 1600, Kuwae 1452, El Chichon 1259) found in most of the polar ice cores. In comparison with three other East Antarctic volcanic records (South Pole, Plateau Remote and Dome C), the Vostok record contains more events within the last 900 years. The differences between the records may be explained by local glaciological conditions, volcanic detection methodology, and, probably, differences in atmospheric circulation patterns. The strongest volcanic signal (both in sulfate concentration and flux) was attributed to the AD 1452 Kuwae eruption, similar to the Plateau Remote and Talos Dome records. The average snow accumulation rate calculated between volcanic stratigraphic horizons for the period AD 1260-2010 is 20.9 mm H2O. Positive (+13%) anomalies of snow accumulation were found for AD 1661-1815 and AD 1992-2010, and negative (-12%) for AD 1260-1601. We hypothesized that the changes in snow accumulation are associated with regional peculiarities in atmospheric transport.

  12. Isotope Fractionation of Modern Air In Dome C (antarctica) Polar Firn.

    NASA Astrophysics Data System (ADS)

    Landais, A.; Leuenberger, M.; Caillon, N.; Schwander, J.; Jouzel, J.

    Air bubbles trapped in ice cores are unique archives of the past atmospheric com- position. Recent paleoclimatic studies have taken advantage of the effects of thermal and gravitational diffusion occurring in the firn to quantify past abrupt temperature changes. In order to better quantify the thermal diffusion, we have analysed modern air samples pumped within the FIRETRACC European Project at different depths along the firn (upper 100 m of the ice cap) of Dome C polar station (Antarctica). Air bottles were then directly analysed for the isotopic composition of N2, O2 and Ar with mass spectrometer either in Saclay (LSCE) or in Bern (Climate Institute). Similar results were obtained in the two laboratories, which is a validation of the analytical method. The strong seasonal temperature gradient in the upper 30 m of the firn leads to a clear thermal diffusion anomaly for each isotope which is superimposed on the gravitational signal. Comparison of the different magnitudes of these thermally driven anomalies for 15N/14N, 18O/16O and 40Ar/36Ar enables us then to estimate the thermal diffu- sion factors for each isotope pair and use it for later studies in paleothermometry.

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

    USGS Publications Warehouse

    Shearn-Bochsler, Valerie; Green, David Earl; Converse, K.A.; Docherty, D.E.; Thiel, T.; Geisz, H.N.; Fraser, William R.; Patterson-Fraser, Donna L.

    2008-01-01

    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 Conservation of Nature (IUCN). Island-specific breeding colonies near Palmer Station, Antarctica, have been monitored for over 30 years, and because this population continues to increase, it is critically important to conservation. In austral summer 2004, six diseased giant petrel chicks were observed in four of these colonies. Diseased chicks were 6a??9 weeks old and had multiple proliferative nodules on their bills and skin. One severely affected chick was found dead on the nest and was salvaged for necropsy. Histopathological examination of nodules from the dead chick revealed epithelial cell hyperplasia and hypertrophy with numerous eosinophilic intracytoplasmic inclusions (B??llinger bodies). A poxvirus was isolated from multiple nodules. Poxviral infection has not been reported in this species, and the reason for its emergence and its potential impact on the population are not yet known.

  14. Albedo of coastal landfast sea ice in Prydz Bay, Antarctica: Observations and parameterization

    NASA Astrophysics Data System (ADS)

    Yang, Qinghua; Liu, Jiping; Leppäranta, Matti; Sun, Qizhen; Li, Rongbin; Zhang, Lin; Jung, Thomas; Lei, Ruibo; Zhang, Zhanhai; Li, Ming; Zhao, Jiechen; Cheng, Jingjing

    2016-05-01

    The snow/sea-ice albedo was measured over coastal landfast sea ice in Prydz Bay, East Antarctica (off Zhongshan Station) during the austral spring and summer of 2010 and 2011. The variation of the observed albedo was a combination of a gradual seasonal transition from spring to summer and abrupt changes resulting from synoptic events, including snowfall, blowing snow, and overcast skies. The measured albedo ranged from 0.94 over thick fresh snow to 0.36 over melting sea ice. It was found that snow thickness was the most important factor influencing the albedo variation, while synoptic events and overcast skies could increase the albedo by about 0.18 and 0.06, respectively. The in-situ measured albedo and related physical parameters (e.g., snow thickness, ice thickness, surface temperature, and air temperature) were then used to evaluate four different snow/ice albedo parameterizations used in a variety of climate models. The parameterized albedos showed substantial discrepancies compared to the observed albedo, particularly during the summer melt period, even though more complex parameterizations yielded more realistic variations than simple ones. A modified parameterization was developed, which further considered synoptic events, cloud cover, and the local landfast sea-ice surface characteristics. The resulting parameterized albedo showed very good agreement with the observed albedo.

  15. Description of Pseudomonas gregormendelii sp. nov., a Novel Psychrotrophic Bacterium from James Ross Island, Antarctica.

    PubMed

    Kosina, Marcel; Švec, Pavel; Černohlávková, Jitka; Barták, Miloš; Snopková, Kateřina; De Vos, Paul; Sedláček, Ivo

    2016-07-01

    During the microbiological research performed within the scope of activities of Czech expeditions based at the Johann Gregor Mendel Station at James Ross Island, Antarctica, two psychrotrophic gram-stain negative non-fluorescent strains CCM 8506T and CCM 8507 from soil were extensively characterized using genotypic and phenotypic methods. Initial characterization using ribotyping with HindIII restriction endonuclease and phenotyping implies that both isolates belong to a single Pseudomonas species. Sequencing of rrs, rpoB, rpoD and glnA genes of strain CCM 8506(T) confirmed affiliation of investigated strains within the genus Pseudomonas. Further investigation using automated ribotyping with EcoRI (RiboPrinter(®) Microbial Characterisation System), whole-cell protein profiling using the Agilent 2100 Bioanalyzer system, extensive biochemical testing and DNA-DNA hybridization experiments confirmed that both investigated strains are members of a single taxon which is clearly separated from all hitherto described Pseudomonas spp. Based on all findings, we describe a novel species Pseudomonas gregormendelii sp. nov. with the type strain CCM 8506(T) (=LMG 28632T). PMID:27032403

  16. A new species of Laonice (Spionidae, Polychaeta, Annelida) from Bellingshausen Sea (West Antarctica)

    NASA Astrophysics Data System (ADS)

    López, Eduardo

    2011-06-01

    During the Antarctic summers of 2002-2003 and of 2005-2006, the Spanish BENTART cruises were conducted to the Bellingshausen Sea (Western Antarctica), aiming to study its benthic communities, from depths ranging from 100 to 2,000 m. To achieve it, 30 stations were selected; each one was surveyed in such a way that the infaunal, epifaunal and suprabenthic components of the communities were sufficiently characterized. As a part of the study, some spionid individuals were identified as belonging to a new species of the genus Laonice Malmgren, 1867. The new species belongs to a group within the genus that is characterized by the presence of more than two rows of very numerous capillary chaetae in both noto- and neuropodial fascicles of anterior part of the body. However, it can be readily distinguished from the rest of species within the group by the posterior position in which neuropodial pouches appear (chaetiger 16 or 17) and by the caruncle reaching posteriorly chaetiger 19. In addition, other remarkable features of the new species are the short and triangular occipital tentacle, the rudimentary eyes, the hooded neuropodial hooks first appearing in chaetigers 34-37 and the sabre neurochaetae first occurring in chaetigers 20-27.

  17. An Uninhabited Aerial Vehicle (UAV) Concept for Low-Altitude Geophysical Exploration in Antarctica

    NASA Astrophysics Data System (ADS)

    Raymond, C. A.; Behar, A. E.

    2004-05-01

    A concept for a small, agile UAV platform for conducting geophysical mapping in the IPY and beyond has been explored. We have developed a framework concept for community input and feedback based on a low-cost, autonomous vehicle with onboard high-precision inertial navigation that performs vertical take-off and landing (VTOL). The vehicle we have focused on is the GoldenEye-100, developed by Aurora Flight Sciences Corp. (www.aurora.aero), which can carry a lightweight payload and achieve a range of 300-500 km (roundtrip). The VTOL capability would potentially allow flights to be launched from the helicopter deck of an icebreaker, and would remove the logistical burden of ensuring a hazard-free runway on the ice. Vehicle operations are controlled using a portable ground station. A payload concept has also been developed, indicating that the vehicle could easily carry a lightweight, compact magnetometer, camera and laser altimeter. Instruments developed for space missions exist that would enable a high performance system to be carried within the ~10 kg payload envelope. A gravity measurement system and radar sounder are also considered. A capable UAV platform for geophysical mapping would complement the existing aerial research platforms in Antarctica and has the potential to accelerate the exploration and monitoring of critical but remote areas in a cost-effective manner.

  18. Long-Term Dosimetry of Solar UV Radiation in Antarctica with Spores of Bacillus subtilis

    PubMed Central

    Puskeppeleit, Monika; Quintern, Lothar E.; el Naggar, Saad; Schott, Jobst-Ulrich; Eschweiler, Ute; Horneck, Gerda; Bücker, Horst

    1992-01-01

    The main objective was to assess the influence of the seasonal stratospheric ozone depletion on the UV climate in Antarctica by using a biological test system. This method is based on the UV sensitivity of a DNA repair-deficient strain of Bacillus subtilis (TKJ 6321). In our field experiment, dried layers of B. subtilis spores on quartz discs were exposed in different seasons in an exposure box open to solar radiation at the German Antarctic Georg von Neumayer Station (70°37′S, 8°22′W). The UV-induced loss of the colony-forming ability was chosen as the biological end point and taken as a measure for the absorbed biologically harmful UV radiation. Inactivation constants were calculated from the resulting dose-response curves. The results of field experiments performed in different seasons indicate a strongly season-dependent trend of the daily UV-B level. Exposures performed at extremely depleted ozone concentrations (October 1990) gave higher biologically harmful UV-B levels than expected from the calculated season-dependent trend, which was determined at normal ozone values. These values were similar to values which were measured during the Antarctic summer, indicating that the depleted ozone column thickness has an extreme influence on the biologically harmful UV climate on ground. PMID:16348742

  19. Preliminary Results of Heat flow Measurements across the Eastern Flank of the Adare Trough, Antarctica

    NASA Astrophysics Data System (ADS)

    Hong, J. K.; Kim, Y. G.; Jin, Y. K.

    2015-12-01

    Marine heat flow measurement on the ridge is a direct and useful approach to know the current state of thermal regime below the lithosphere. Measurements in ridges located in the Antarctica are practically challenged by harsh conditions such as extensive and moving sea ice cover and stiff seafloor composed of diatomaceous sediments. We planned heat flow measurements across the Adare Trough, north of the Ross Sea, during the recent Korean icebreaker R/V Araon's Antarctic expedition (ANA05B; Dec 12th 2014-Feb 25th 2015) to get thermal information which is a missing piece in terms of geophysical data in this region to describe its asymmetric activity in spreading rate. Finally, we collected information only at three stations across the eastern flank of the Adare Trough over 70 km along with NBP9702 seismic line because of various limitations above. It is a preliminary result that observed heat flow seems significantly higher than estimated one from known magnetic anomaly age using a global age-heat flow curve. In order to conclude some suggestion, we need further studies regarding identification of 'real' heat flow from lithosphere, and increase of the number of data. More heat flow measurements will be carried out again on the eastern flank in the next Araon's Antarctic expedition (tentatively ANA06C; March 2016) to supplement the small number of data.

  20. Climate Change at the Poles: Research Immersion Experience at Bellingshausen, Antarctica

    NASA Astrophysics Data System (ADS)

    Alexeev, V. A.; Repina, I. A.; Baeseman, J. L.; Fernandoy, F.; Bart, S.

    2010-12-01

    We brought a party of 15 scientists, graduate students, and educators to King George Island, the largest of the South Shetland Islands, just off the Antarctic Peninsula, for an international workshop on Antarctica and global climate change in January 2010. Participants included professors, young scientists and graduate students from the Obukhov Institute of Atmospheric Physics, the University of Maryland, the University of Wisconsin, and the Michigan Technological University. Lindsay Bartholomew, an education and outreach specialist at the Museum of Science and Industry in Chicago connected the workshop via video and Internet with an audience of museum visitors. Scientists living and working at Bellingshausen, including Hans-Ulrich Peter, an eminent ecologist from Jena University (Germany), and Bulat Movlyudov (Institute of Geography, Moscow), a distinguished glaciologist, participated in the workshop. Field trips led by Peter and Movlyudov and others were made by day and lectures were held by night. Professors and graduate students made cutting-edge presentations on such subjects as permafrost, glaciology, and global climate models. Three workshop teams conducted field research projects at the foot of the Bellingshausen Dome icecap - two on carbon cycling and one on permafrost. Major funding sources for the workshop included the Russian Foundation for Basic Research (Russia), Wilderness Research Foundation (USA), NSF, University of Wisconsin at Stevens Point, Alfred Wegener Institute (Germany) and Museum for Science and Industry (Chicago). INACH, the Chilean Antarctic Institute, and IAU, the Uruguayan Antarctic Institute, provided air charter services. On King George Island, our group was billeted at Russia’s Bellingshausen science station.

  1. In situ inhibition of primary production due to ultraviolet radiation in Antarctica

    SciTech Connect

    Helbling, E.W.; Villafane, V.E.; Holm-Hansen, O.

    1994-12-31

    Inhibition of photosynthesis due to ultra radiation (UVR) in antarctic phytoplankton has been documented by many authors. Most of these studies have used temperature-controlled incubators in which phytoplankton are exposed to either solar radiation or to UV-visible radiation provided by lamps. Although such experiments are invaluable for determining the effects of solar radiation on the metabolic activity of phytoplankton, they suffer from the fact that the cells will not be exposed to the same spectral irradiance that they would experience at various depths in the water column. The use of in situ incubations of natural phytoplankton assemblages provides the most direct and most realistic procedure to determine the effect of solar UVR on rates of primary production. In this paper, preliminary data obtained from such in situ incubations carried out from October through December 1993 at Palmer Station (64.7{degrees}S 64.1{degrees}W) on Anvers Island, Antarctica is reported. 6 refs., 2 figs.

  2. Long-term dosimetry of solar UV radiation in Antarctica with spores of Bacillus subtilis

    SciTech Connect

    Puskeppeleit, M.; Quintern, L.E.; Naggar, S. el; Schott, J.U.; Eschweiler, U.; Horneck, G.; Buecker, H. )

    1992-08-01

    The main objective was to assess the influence of the seasonal stratospheric ozone depletion on the UV climate in Antarctica by using a biological test system. This method is based on the UV sensitivity of a DNA repair-deficient (TKJ 6321). In the field experiment, dried layers of B. subtilis spores on quartz discs were exposed in different seasons in an exposure box open to solar radiation at the German Antarctic Georg von Neumayer Station (70[degree]37[prime]S, 8[degree]22[prime]W). The UV-induced loss of the colony-forming ability was chosen as the biological end point and taken as a measure for the absorbed biologically harmful UV radiation. Inactivation constants were calculated from the resulting dose-response curves. The results of field experiments performed in different seasons indicate a strongly season-dependent trend of the daily UV-B level. Exposures performed at extremely depleted ozone concentrations gave higher biologically harmful UV-B levels than expected from the calculated season-dependent trend, which was determined at normal ozone values. These values were similar to values which were measured during the Antarctic summer, indicating that the depleted ozone column thickness has an extreme influence on the biologically harmful UV climate on ground.

  3. Evaluation of DNA dosimetry to assess ozone-mediated variability of biologically harmful radiation in Antarctica.

    PubMed

    George, Alison L; Peat, Helen J; Buma, Anita G J

    2002-09-01

    In this study we investigated the use of a DNA dosimeter to accurately measure changes in ultraviolet B radiation (UVBR; 280-315 nm) under Antarctic ozone hole conditions. Naked DNA solution in quartz tubes was exposed to ambient solar radiation at Rothera Research Station, Antarctica, between October and December 1998 for 3 h during UVBR peak hours (1200-1500 h). Trends in UVBR-mediated DNA damage (formation of cyclobutane pyrimidine dimers [CPD]) were related to cloud cover, ozone-column depth and spectroradiometric measurements of ambient radiation. Ozone-column depths ranged from 130 to 375 DU during the study period, resulting in highly variable UVBR doses, from 1.6 to 137 kJ m(-2) over the 3 h exposure, as measured by spectroradiometry. There was a strong positive correlation (86%) between dosimeter CPD concentrations and DNA-weighted UVBR doses. Ozone depth was a strong predictor of DNA damage (63%), and there was no significant relationship between CPD formation and cloud cover. Subtle changes in spectral characteristics caused by ozone depletion were detected by the biodosimeter; the highest CPD concentrations were observed in October when ozone-mediated shifts favored shorter wavelengths of UVBR. We conclude that the DNA biodosimeter is an accurate indicator of biologically effective UVBR, even under highly variable ozone conditions. PMID:12403448

  4. Continuous dosimetry of the biologically harmful UV-radiation in Antarctica with the biofilm technique.

    PubMed

    Quintern, L E; Puskeppeleit, M; Rainer, P; Weber, S; el Naggar, S; Eschweiler, U; Horneck, G

    1994-01-01

    For the first time, a continuous biological dosimetry experiment for cytotoxic solar UV-radiation has been performed in Antarctica. The biologically harmful UV-radiation on the ground was measured at the German Antarctic Georg von Neumayer Station (70 degrees 37' S, 80 degrees 22' W) from December 1990 to March 1992 using the biofilm technique. The UV-sensitive targets were dried spores of Bacillus subtilis which were immobilized on the film surface. The UV-induced inhibition of biological activity, determined photometrically from the protein synthesized after incubation and staining, was taken as a measure for the absorbed UV-dose. Films were exposed in horizontal position for time intervals ranging from 4 days during summer up to 51 and 41 days before and after the polar night respectively. The use of different cut-off filters allowed the calculation of the biologically effective UVA, UVB and the complete UV-radiation (UVA + B). The data were compared with the global radiation and the ozone column thickness indicating an increase of biologically harmful UVB radiation during austral spring at reduced ozone concentrations yielding a radiation amplification factor (RAF) of 1.4, whereas for the total UV(A + B) range the RAF amounted to 0.3. PMID:8151457

  5. Long-Term Dosimetry of Solar UV Radiation in Antarctica with Spores of Bacillus subtilis.

    PubMed

    Puskeppeleit, M; Quintern, L E; El Naggar, S; Schott, J U; Eschweiler, U; Horneck, G; Bücker, H

    1992-08-01

    The main objective was to assess the influence of the seasonal stratospheric ozone depletion on the UV climate in Antarctica by using a biological test system. This method is based on the UV sensitivity of a DNA repair-deficient strain of Bacillus subtilis (TKJ 6321). In our field experiment, dried layers of B. subtilis spores on quartz discs were exposed in different seasons in an exposure box open to solar radiation at the German Antarctic Georg von Neumayer Station (70 degrees 37'S, 8 degrees 22'W). The UV-induced loss of the colony-forming ability was chosen as the biological end point and taken as a measure for the absorbed biologically harmful UV radiation. Inactivation constants were calculated from the resulting dose-response curves. The results of field experiments performed in different seasons indicate a strongly season-dependent trend of the daily UV-B level. Exposures performed at extremely depleted ozone concentrations (October 1990) gave higher biologically harmful UV-B levels than expected from the calculated season-dependent trend, which was determined at normal ozone values. These values were similar to values which were measured during the Antarctic summer, indicating that the depleted ozone column thickness has an extreme influence on the biologically harmful UV climate on ground. PMID:16348742

  6. Geodynamical Processes between Antarctica and India as revealed by very long baselines between the continents estimated from continuous and long-term GPS measurements

    NASA Astrophysics Data System (ADS)

    N, R.; Ec, M.; Akilan, A.

    2006-12-01

    To holistically understand the geodynamical and crustal deformation processes in the south of Indian peninsula between India and Antarctica, two global networks have been chosen that geodetically connect the two continents, the IGS Station at Diego Garcia (DGAR) being the common station between the two networks. 8 years of data from 1997 to 2005 were used. Very long baselines have been estimated from HYDE to other chosen IGS stations in and around India including DGAR. Similarly in the other network, very long baselines have been estimated from Kerguelen to other stations in and around Antarctica again including DGAR. Since the baseline length between HYDE, India and MAITRI, Antarctica is more than 10,000 km, it is mandatory to form these two different networks to improve the accuracy of the baseline measurements by GPS. This is to circumvent the limitation in the estimation of maximum base line length by GPS is of 6,900 km only due to the availability of less number of double difference observables in the GPS data analysis. Our analysis and results show increase of baseline lengths between Kerguelen in Antarctic plate and other stations and shortening of baseline lengths between HYDE in Indian plate and other common stations. By this global network analyses, the stations HYDE and MAITRI are geodetically tied through DGAR. With this geodetic tie up, having got the first geodetic signatures of the geodynamical processes between India and Antarctica, continuous monitoring and estimation would help enhancing the understanding the crustal deformation processes between these two continents despite many plates, micro plates and ridges in this study region.These estimations reveal clearly that the stations in the Australian plate are moving away from the Indian plate conforming to the recent Plate tectonic theory that India and Australia lie in two different plates with a diffuse boundary separating them. GPS derived velocity vectors for the Australian Plate also

  7. On the formation of coastal polynyas in the area of Commonwealth Bay, Eastern Antarctica

    NASA Astrophysics Data System (ADS)

    Wendler, Gerd; Gilmore, Dan; Curtis, Jan

    Antarctica's King George V Land and Adélie Land were first explored by Sir Douglas Mawson and his party during their 1911-1913 expedition. They were astounded by the strength of the katabatic wind, which is so dominant in this area. These strong offshore winds can move the sea ice away from shore, forming coastal polynya, not only in summer but even in midwinter. Poor visibility due to darkness and frequently occurring blowing snow make the study of these polynyas from land-based observations difficult. Recently, coverage of this area by synthetic aperture radar (SAR) satellite imagery, which has a high resolution of 40 m (pixel size 12.5 m), gave additional insight into the characteristics of these polynyas. This high resolution is needed because the width of the polynya is small (10 km or so). Furthermore, of special importance is the fact that SAR data can be obtained during darkness and overcast conditions. Following original Russian work, we modified a simple model for wind-driven coastal polynyas, using actual meteorological data from our coastal automatic weather stations as input. Using mean monthly data for the stations, we show that coastal polynyas are to be expected in the windiest area (Cape Denison-Port Martin); while to the west (Dumont d'Urville) and east (Penguin Point), the average conditions do not produce them. Here, they occur only during strong and long-lasting storms. Our observational data of the polynyas as viewed from SAR and advanced very high resolution radiometer (AVHRR) confirm these findings.

  8. Biochemical and microbial features of shallow marine sediments along the Terra Nova Bay (Ross Sea, Antarctica)

    NASA Astrophysics Data System (ADS)

    Baldi, Franco; Marchetto, Davide; Pini, Francesco; Fani, Renato; Michaud, Luigi; Lo Giudice, Angelina; Berto, Daniela; Giani, Michele

    2010-09-01

    Shallow marine sediments were collected from seven stations (three of which located at Gerlache Inlet, two at Tethys Bay, one at Adelie Cove and one just beneath the Italian Research Base) along the Terra Nova Bay coast (Ross Sea, Antarctica). Their chemical, biochemical and microbiological properties were studied in order to provide further insights in the knowledge of this Antarctic benthic ecosystem. Overall, the organic carbon (OC) represented the major fraction of total carbon (TC) and displayed concentrations similar to or slightly lower than those previously measured in Antarctic bottom sediments. The biopolymeric carbon within OC ranged from 4.1% to 19.9% and showed a wide trophic range (65-834 μg g -1 d.w.). Proteins (PRT) represented on average the main biochemical class contributing to labile organic carbon, followed by lipids (LIP) and carbohydrates (CHO). The activity of aminopeptidase, β- D-glucosidase, alkaline phosphatase and esterase was checked, giving the highest values at Tethys Bay and at the deepest water sediments. The principal component analysis, which was computed considering physical, chemical (elemental and biochemical sedimentary composition) and microbiological parameters (including bacterial abundance, ectoenzymatic activities, T-RFs richness and diversity indices), allowed to obtain two main clusters ("Tethys Bay" and "other stations"). Based on data obtained, two representative 16S rRNA clone libraries using samples from Tethys Bay and Gerlache Inlet were constructed. The sequences of 171 clones were compared to those available in public databases to determine their approximate phylogenetic affiliations. Both aerobic and anaerobic bacteria were disclosed, with the majority of them affiliated with the Gamma- and Deltaproteobacteria, Bacteroidetes and Acidobacteria. The occurrence of strictly anaerobic bacteria suggests that sediments might also undergo anoxic conditions that, in turn, could favor the accumulation of PRT in respect

  9. Precipitation regime and stable isotopes at Dome C and Dome Fuji, East Antarctica

    NASA Astrophysics Data System (ADS)

    Schlosser, Elisabeth; Dittmann, Anna; Stenni, Barbara; Masson-Delmotte, Valerie; Powers, Jordan G.; Manning, Kevin W.; Raphael, Marilyn; Fujita, Koji; Werner, Martin; Valt, Mauro; Cagnati, Anselmo

    2016-04-01

    Dome Fuji and Dome C, both deep ice-core drilling sites in East Antarctica, are the only stations, for which direct daily precipitation measurements and stable isotope ratios of the precipitation samples are available. Whereas the Dome F series encompasses only one year of measurements, the Dome C series has been started in 2006 and is ongoing. For Dome C, the type of precipitation (diamond dust, hoar frost, snowfall) was determined based on crystal type analysis. The weather situations causing precipitation at the stations were analysed using data from the Antarctic Mesoscale Prediction System (AMPS). At both sites, major snowfall events were always related to an amplification of Rossby waves in the circumpolar westerlies, which led to an increased meridional transport of moisture and energy. Furthermore, increased amounts of diamond dust were observed after such event-type precipitation. The stable isotope data of the precipitation samples were related to the different weather situations and precipitation types and also simulated using a simple Rayleigh-type model (MCIM) and compared to output from the global isotopic-enhanced model ECHAM5wiso. Possible moisture sources were estimated using the synoptic analysis combined with back-trajectory calculation. MCIM was better in reproducing the annual cycle of deuterium excess, whereas ECHAM5wiso generally showed a smaller bias of the isotope ratios. Hoar frost shows isotope signals very different from diamond dust and snowfall, which hints at a more local cycle of sublimation and deposition for this type of precipitation, whereas both snowfall and diamond dust are related to large-scale moisture transport. Contrary to the literature, a more northern moisture source was found to be not necessarily associated with more depleted snowfall. This is explained by the strong warm air advection accompanying snowfall events, which decreases the temperature difference between source area and deposition site and thus leads to

  10. Observations of the Summertime Boundary Layer over the Ross Ice Shelf, Antarctica Using SUMO UAVs

    NASA Astrophysics Data System (ADS)

    Nigro, M. A.; Cassano, J. J.; Jolly, B.; McDonald, A.

    2014-12-01

    During January 2014 Small Unmanned Meteorological Observer (SUMO) unmanned aerial vehicles (UAVs) were used to observe the boundary layer over the Ross Ice Shelf, Antarctica. A total of 41 SUMO flights were completed during a 9-day period with a maximum of 11 flights during a single day. Flights occurred as frequently as every 1.5 hours so that the time evolution of the boundary layer could be documented. On almost all of the flights the boundary layer was well mixed from the surface to a depth of less than 50 m to over 350 m. The depth of the well-mixed layer was observed to both increase and decrease over the course of an individual day suggesting that processes other than entrainment were altering the boundary layer depth. The well-mixed layer was observed to both warm and cool during the field campaign indicating that advective processes as well as surface fluxes were acting to control the temporal evolution of the boundary layer temperature. Only a small number of weakly stably stratified boundary layers were observed. Strong, shallow inversions, of up to 6 K, were observed above the top of the boundary layer. Observations from a 30 m automatic weather station and two temporary automatic weather stations 10 km south and west of the main field campaign location provide additional data for understanding the boundary layer evolution observed by the SUMO UAVs during this 9-day period. This presentation will discuss the observed evolution of the summertime boundary layer as well as comment on lessons learned operating the SUMO UAVs at a remote Antarctic field camp.

  11. Report on the First International Symposium on Operational Weather Forecasting in Antarctica.

    NASA Astrophysics Data System (ADS)

    Turner, John; Pendlebury, Stephen; Cowled, Lance; Jacka, Kieran; Jones, Marjorie; Targett, Philip

    2000-01-01

    The First International Symposium on Operational Weather Forecasting in Antarctica was held in Hobart, Australia, from 31 August to 3 September 1998. There were 40 attendees at the meeting from Australia, Belgium, Brazil, China, France, Italy, Russia, and the United Kingdom. In recent years there has been considerable growth in the requirement for weather forecasts for the Antarctic because of the increases in complex scientific research activities and the rapid growth of tourism to the continent. At many of the research stations there are now sophisticated forecasting operations that make use of the data available from drifting buoys and automatic weather stations, the output from numerical weather prediction systems, and high resolution satellite imagery. The models have considerable success at predicting the synoptic-scale depressions that occur over the ocean and in the coastal region. However, the many mesoscale systems that occur, which are very important for forecasting local conditions, are not well represented in the model fields and their movement is mainly predicted via the satellite data. In the future it is anticipated that high resolution, limited-area models will be run for selected parts of the continent. The symposium showed that great advances had been made during recent years in forecasting for the Antarctic as a result of our better understanding of atmospheric processes at high latitudes, along with the availability of high resolution satellite imagery and the output of numerical models. Outstanding problems include the difficulty of getting all of the observations to the main analysis centers outside the Antarctic in a timely fashion, the lack of upper air data from the Antarctic Peninsula and the interior of the continent, and the poor representation of the Antarctic orography and high latitude processes in numerical models. An outcome of the symposium will be a weather forecasting handbook dealing with the entire continent.

  12. Origin of dimethylsulfide, non-sea-salt sulfate, and methanesulfonic acid in eastern Antarctica

    NASA Astrophysics Data System (ADS)

    Cosme, E.; Hourdin, F.; Genthon, C.; Martinerie, P.

    2005-02-01

    Ignoring the origin of atmospheric chemicals is often a strong limitation to the full interpretation of their measurement. In this article, this question is addressed in the case of the sulfur species in Antarctica, with an original method of retrotransport of tracers. The retrotransport model is derived from the Laboratoire de Météorologie Dynamique Zoom-Tracers (LMD-ZT) atmospheric general circulation model, optimized for polar climate and expanded to simulate atmospheric sulfur chemistry. For two East Antarctic scientific stations (Dumont d'Urville and Vostok) the effects of transport and chemistry and the influence of oceanic, volcanic, and anthropogenic sources on dimethylsulfide (DMS), non-sea-salt (nss) sulfate, and methanesulfonic acid (MSA) concentrations are evaluated in summer and winter. The oceanic source largely dominates, but other sources can episodically be significant. The meridional origin and the age of DMS, MSA, and biogenic nss sulfate are also estimated. The latitudes of origin of MSA and nss sulfate are similar in summer, but they differ markedly in winter. This is a signature of their different chemical production scheme. Also, the interannual variability of the origin of the sulfur species at Vostok is weak compared to that at Dumont d'Urville. Acknowledging that the DMS concentrations in the ocean have no interannual variability in the model, this result suggests unsurprisingly that inland Antarctic stations may be better observation sites to monitor large-scale DMS bioproductivity variability than coastal sites are. The combination of slower chemistry and more intense atmospheric circulation in winter leads to unexpected results, such as a younger DMS in winter than in summer at Vostok.

  13. Factors affecting phytoplankton distribution and production in the Elephant Island area, Antarctica

    SciTech Connect

    Helbling, E.W.

    1993-01-01

    During the austral summer of four years, 1990 to 1993, studies on phytoplankton were performed in the Elephant Island area as one component of the US Antarctica Marine Living Resources program. In addition to continuous measurements (temperature, salinity, chlorophyll-a, beam attenuation) made on ship's intake water, a profiling CTD-rosette unit was used to obtain water column characteristics (temperature, salinity, chlorophyll-a, attenuation of solar radiation, beam attenuation) from the surface to 750m depth and also water samples from at least 10 depths for chemical and biological analyses. The sampling grid consisted of an average of 70 stations, all of which were occupied two times each year. The Elephant Island area is a transition zone between the rich coastal areas, where phytoplankton can develop dense blooms, and pelagic waters where the phytoplankton biomass is in general very low. A frontal zone was usually found to the north of Elephant Island and over the continental slope, and high phytoplankton biomass was in general associated with this frontal region. Although the location of this frontal system showed seasonal movement in a north-south direction, it seems to be a consistent feature from year to year. There seems to be considerable year-to-year variability in physical (water temperatures and salinity) and phytoplankton characteristics within the study area, in regard to both distributional patterns in surface waters and to profile characteristics in the upper 100m of the water column. With shallow upper mixed layer depths of less than 50 m, phytoplankton can attain relatively high concentrations. Optimum light conditions for growth occurred when the mixed layer was less than 55% of the euphotic zone. As the area around Elephant Island is characterized by relatively strong and frequent winds, the depth of the upper mixed layer at many stations approached the depth of the euphotic zone, with the result that growth of phytoplankton was light limited.

  14. Foehn winds link climate-driven warming to ice shelf evolution in Antarctica

    NASA Astrophysics Data System (ADS)

    Cape, M. R.; Vernet, Maria; Skvarca, Pedro; Marinsek, Sebastián.; Scambos, Ted; Domack, Eugene

    2015-11-01

    Rapid warming of the Antarctic Peninsula over the past several decades has led to extensive surface melting on its eastern side, and the disintegration of the Prince Gustav, Larsen A, and Larsen B ice shelves. The warming trend has been attributed to strengthening of circumpolar westerlies resulting from a positive trend in the Southern Annular Mode (SAM), which is thought to promote more frequent warm, dry, downsloping foehn winds along the lee, or eastern side, of the peninsula. We examined variability in foehn frequency and its relationship to temperature and patterns of synoptic-scale circulation using a multidecadal meteorological record from the Argentine station Matienzo, located between the Larsen A and B embayments. This record was further augmented with a network of six weather stations installed under the U.S. NSF LARsen Ice Shelf System, Antarctica, project. Significant warming was observed in all seasons at Matienzo, with the largest seasonal increase occurring in austral winter (+3.71°C between 1962-1972 and 1999-2010). Frequency and duration of foehn events were found to strongly influence regional temperature variability over hourly to seasonal time scales. Surface temperature and foehn winds were also sensitive to climate variability, with both variables exhibiting strong, positive correlations with the SAM index. Concomitant positive trends in foehn frequency, temperature, and SAM are present during austral summer, with sustained foehn events consistently associated with surface melting across the ice sheet and ice shelves. These observations support the notion that increased foehn frequency played a critical role in precipitating the collapse of the Larsen B ice shelf.

  15. 4. EASTBOUND VIEW. NORTH TRACK WAITING STATION ON LEFT. STATION ...

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

    4. EASTBOUND VIEW. NORTH TRACK WAITING STATION ON LEFT. STATION ON RIGHT. NOTE TUNNEL IN BACKGROUND. - Baltimore & Ohio Railroad, Harpers Ferry Station, Potomac Street, Harpers Ferry, Jefferson County, WV

  16. Space Station Induced Monitoring

    NASA Technical Reports Server (NTRS)

    Spann, James F. (Editor); Torr, Marsha R. (Editor)

    1988-01-01

    This report contains the results of a conference convened May 10-11, 1988, to review plans for monitoring the Space Station induced environment, to recommend primary components of an induced environment monitoring package, and to make recommendations pertaining to suggested modifications of the Space Station External Contamination Control Requirements Document JSC 30426. The contents of this report are divided as Follows: Monitoring Induced Environment - Space Station Work Packages Requirements, Neutral Environment, Photon Emission Environment, Particulate Environment, Surface Deposition/Contamination; and Contamination Control Requirements.

  17. Space station propulsion technology

    NASA Technical Reports Server (NTRS)

    Norman, A. M.; Briley, G. L.; Evans, S. A.

    1987-01-01

    The objectives of this program are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the initial operational capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion system (SSPS) to that required to support and interface with advanced station functions. These objectives were met by analytical studies and by furnishing a propulsion test bed to the Marshall Space Flight Center for testing.

  18. Madrid space station

    NASA Technical Reports Server (NTRS)

    Fahnestock, R. J.; Renzetti, N. A.

    1975-01-01

    The Madrid space station, operated under bilateral agreements between the governments of the United States and Spain, is described in both Spanish and English. The space station utilizes two tracking and data acquisition networks: the Deep Space Network (DSN) of the National Aeronautics and Space Administration and the Spaceflight Tracking and Data Network (STDN) operated under the direction of the Goddard Space Flight Center. The station, which is staffed by Spanish employees, comprises four facilities: Robledo 1, Cebreros, and Fresnedillas-Navalagamella, all with 26-meter-diameter antennas, and Robledo 2, with a 64-meter antenna.

  19. The space station

    NASA Technical Reports Server (NTRS)

    Munoz, Abraham

    1988-01-01

    Conceived since the beginning of time, living in space is no longer a dream but rather a very near reality. The concept of a Space Station is not a new one, but a redefined one. Many investigations on the kinds of experiments and work assignments the Space Station will need to accommodate have been completed, but NASA specialists are constantly talking with potential users of the Station to learn more about the work they, the users, want to do in space. Present configurations are examined along with possible new ones.

  20. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable Waters COAST GUARD... Pollution and Sewage § 151.79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12...

  1. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable Waters COAST GUARD... Pollution and Sewage § 151.79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12...

  2. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable Waters COAST GUARD... Pollution and Sewage § 151.79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12...

  3. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable Waters COAST GUARD... Pollution and Sewage § 151.79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12...

  4. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of sewage within Antarctica. 151.79 Section 151.79 Navigation and Navigable Waters COAST GUARD... Pollution and Sewage § 151.79 Operating requirements: Discharge of sewage within Antarctica. (a) A vessel certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12...

  5. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Restrictions on collection of meteorites in... SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  6. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Restrictions on collection of meteorites in... SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  7. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Restrictions on collection of meteorites in... SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  8. Antibacterial, antifungal and antiprotozoal activities of fungal communities present in different substrates from Antarctica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antarctica is a pristine and extreme environment that represents a unique opportunity for taxonomic, ecological and biotechnological studies of the microorganisms. In the present work, the fungal communities of rhizosphere soil of Deschampsia antarctica, soil, ornithogenic soil, marine and lake sedi...

  9. Colony Size of Phaeocystis Antarctica (Prymnesiophyceae) as Influenced by Zooplankton Grazers

    EPA Science Inventory

    The haptophyte Phaeocystis antarctica is a dominant phytoplankton species in the Ross Sea, Antarctica, and exists as solitary cells and mucilaginous colonies that differ by several orders of magnitude in size. Recent studies with P. globosa suggested that colony formation and enl...

  10. Antarctica: The Continuing Experiment. Foreign Policy Association Headline Series, No. 273.

    ERIC Educational Resources Information Center

    Quigg, Philip W.

    One of a series of booklets on world issues examines the sharpened differences between those nations that have declared sovereignty over parts of Antarctica and those that have not; between those nations that have arbitrarily assumed responsibility for the administration of Antarctica and the smaller, more numerous nations that believe their…

  11. Survival and Recovery of Phaeocystis Antarctica (Prymnesiophyceae) from Prolonged Darkness and Freezing

    EPA Science Inventory

    The colony-forming haptophyte Phaeocystis antarctica is an important primary producer in the Ross Sea, and must survive long periods of darkness and freezing in this extreme environment. We conducted experiments on the responses of P. antarctica-dominated phytoplankton assemblage...

  12. Automatic Weather Station (AWS) Lidar

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    A ground based, autonomous, low power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. We report on the design and anticipated performance of the proposed instrument and show data from two prototype lidar instruments previously deployed to Antarctica.

  13. Station Assembly Animation

    NASA Video Gallery

    This animation depicts the assembly of the International Space Station since Nov. 20, 1998, with the delivery of the Zarya module, through May 16, 2011, with the delivery of the EXPRESS Logistics C...

  14. Multiple Craft Stations.

    ERIC Educational Resources Information Center

    Johns, Mary Sue

    1980-01-01

    Described are three craft stations (claywork, papermaking, and stamp designing) for intermediate grade students, to correlate with their classroom study which focused on Ohio: its history, geography, cities, industries, products and famous natives. (KC)

  15. Space Station Live! Tour

    NASA Video Gallery

    NASA is using the Internet and smartphones to provide the public with a new inside look at what happens aboard the International Space Station and in the Mission Control Center. NASA Public Affairs...

  16. Space Station Software Issues

    NASA Technical Reports Server (NTRS)

    Voigt, S. (Editor); Beskenis, S. (Editor)

    1985-01-01

    Issues in the development of software for the Space Station are discussed. Software acquisition and management, software development environment, standards, information system support for software developers, and a future software advisory board are addressed.

  17. Space Station Food System

    NASA Technical Reports Server (NTRS)

    Thurmond, Beverly A.; Gillan, Douglas J.; Perchonok, Michele G.; Marcus, Beth A.; Bourland, Charles T.

    1986-01-01

    A team of engineers and food scientists from NASA, the aerospace industry, food companies, and academia are defining the Space Station Food System. The team identified the system requirements based on an analysis of past and current space food systems, food systems from isolated environment communities that resemble Space Station, and the projected Space Station parameters. The team is resolving conflicts among requirements through the use of trade-off analyses. The requirements will give rise to a set of specifications which, in turn, will be used to produce concepts. Concept verification will include testing of prototypes, both in 1-g and microgravity. The end-item specification provides an overall guide for assembling a functional food system for Space Station.

  18. Destination Station Atlanta

    NASA Video Gallery

    Destination Station was recently in Atlanta from April 15 through April 21. During the week, NASA visited schools, hospitals, museums, and the city’s well known Atlanta Science Tavern Meet Up gro...

  19. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Display model of space station concept--Manned Orbiting Research Laboratory in Saturn S-IVB Orbit configuration. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  20. Space station propulsion technology

    NASA Technical Reports Server (NTRS)

    Briley, G. L.

    1986-01-01

    The progress on the Space Station Propulsion Technology Program is described. The objectives are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the Initial Operating Capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion to that required to support and interface with advanced station functions. The evaluation of concepts was completed. The accumulator module of the test bed was completed and, with the microprocessor controller, delivered to NASA-MSFC. An oxygen/hydrogen thruster was modified for use with the test bed and successfully tested at mixture ratios from 4:1 to 8:1.