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Sample records for active south pole

  1. Bacterial Activity in South Pole Snow

    PubMed Central

    Carpenter, Edward J.; Lin, Senjie; Capone, Douglas G.

    2000-01-01

    Large populations (200 to 5,000 cells ml−1 in snowmelt) of bacteria were present in surface snow and firn from the south pole sampled in January 1999 and 2000. DNA isolated from this snow yielded ribosomal DNA sequences similar to those of several psychrophilic bacteria and a bacterium which aligns closely with members of the genus Deinococcus, an ionizing-radiation- and desiccation-resistant genus. We also obtained evidence of low rates of bacterial DNA and protein synthesis which indicates that the organisms were metabolizing at ambient subzero temperatures (−12 to −17°C). PMID:11010907

  2. Cassini Observes the Active South Pole of Enceladus

    NASA Technical Reports Server (NTRS)

    Porco, C. C.; Helfenstein P.; Thomas, P. C.; Ingersoll, A. P.; Wisdom, J.; West, R.; Neukum, G.; Denk, T.; Wagner, R.; Roatsch, T.; Kieffer, S.; Turtle, E.; McEwen, A.; Johnson, T. V.; Rathbun, J.; Veverka, J.; Wilson, D.; Perry, J.; Spitale, J.; Brahic, A.; Burns, J. A.; DelGenio, A. D.; Dones, L.; Murray, C. D.; Squyres, S.

    2007-01-01

    Cassini has identified a geologically active province a the south pole of Saturn's moon Enceladus. The shape of Enceladus suggests a possible intense heating epoch in the past by capture into a 1:4 secondary spin/orbit resonance.

  3. Lunar South Pole Illumination

    NASA Video Gallery

    Simulated illumination conditions over the lunar South Pole region, from ~80°S to the pole. The movie runs for 28 days, centered on the LCROSS impact date on October 9th, 2009. The illumination ca...

  4. Neptune's 'Hot' South Pole

    NASA Technical Reports Server (NTRS)

    2007-01-01

    These thermal images show a 'hot' south pole on the planet Neptune. These warmer temperatures provide an avenue for methane to escape out of the deep atmosphere.

    The images were obtained with the Very Large Telescope in Chile, using an imager/spectrometer for mid-infrared wavelengths on Sept. 1 and 2, 2006. The telescope is operated by the European Organization for Astronomical Research in the Southern Hemisphere (known as ESO).

    Scientists say Neptune's south pole is 'hotter' than anywhere else on the planet by about 10 degrees Celsius (50 degrees Fahrenheit). The average temperature on Neptune is about minus 200 degrees Celsius (minus 392 degrees Fahrenheit).

    The upper left image samples temperatures near the top of Neptune's troposphere (near 100 millibar pressure, which is one-tenth the Earth atmospheric pressure at sea level). The hottest temperatures are indicated at the lower part of the image, at Neptune's south pole (see the graphic at the upper right). The lower two images, taken 6.3 hours apart, sample temperatures at higher altitudes in Neptune's stratosphere. They do show generally warmer temperatures near, but not at, the south pole. They also show a distinct warm area which can be seen in the lower left image and rotated completely around the back of the planet and returned to the earth-facing hemisphere in the lower right image.

  5. The South Pole Telescope

    SciTech Connect

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  6. South Pole Lorentz Invariance Test

    NASA Astrophysics Data System (ADS)

    Hedges, Morgan; Smiciklas, Marc; Romalis, Michael

    2014-05-01

    Atomic spin co-magnetometers are among the most sensitive instruments to test for violations of CPT and Lorentz symmetry. Our rotating co-magnetometer has, in recent years, set the most stringent limits for such violations in fermions with measurements conducted in Princeton. In order to eliminate the gyroscopic pickup of Earth's rotation as a major limiting background, we now operate a Rb-21Ne co-magnetometer at the Amundsen-Scott South Pole Station. We discuss the current status of our ongoing South Pole experiment along with the latest results. This research is funded by NSF grant #PLR-1142032.

  7. South Pole Lorentz Invariance Test

    NASA Astrophysics Data System (ADS)

    Hedges, Morgan; Smiciklas, Marc; Romalis, Michael

    2015-04-01

    Tests of Lorentz and CPT symmetries are important because they form a cornerstone of quantum field theory and general relativity. To test one of the consequences of local Lorentz invariance we have performed a precision test of spatial isotropy at the Amundsen-Scott station near the geographic South Pole. This location provides the most isotropic environment available on Earth. We use an atomic spin co-magnetometer to compare energy levels in 21 Ne and Rubidium atoms as the apparatus rotates with respect to the cosmos. Our experimental sensitivity is more than an order of magnitude greater than in previous such measurements, known as Hughes-Drever experiments. By operating at the South Pole we eliminate background signals due to the gyroscopic interactions of spins with Earth's rotation as well as diurnal environmental effects. The experiment has finished a 2-year data collection period and we expect to present the final results at the meeting. This is the first precision atomic physics experiment performed at the Pole and we will discuss the potential for future such measurements.

  8. South Pole Lorentz Invariance Test

    NASA Astrophysics Data System (ADS)

    Hedges, Morgan; Smiciklas, Marc; Romalis, Michael

    2015-05-01

    Searches for Lorentz and CPT violation play an important role in testing current theories of space-time. To test one of the consequences of local Lorentz invariance we have performed a precision test of spatial isotropy at the Amundsen-Scott station near the geographic South Pole. This location provides the most isotropic environment available on Earth. The experiment is a rotating atomic-spin co-magnetometer which compares energy levels of 21Ne and Rubidium atoms as a function of direction. The experimental sensitivity obtained is more than an order of magnitude better than in previous such measurements, known as Hughes-Drever experiments. By operating the experiment at the Pole we are able to eliminate background signals due to the gyroscopic interactions of spins with Earth's rotation as well as diurnal environmental effects. Here we will present final results from the experiment's 2-year data collection period. This is the first precision atomic physics experiment performed at the Pole, and we will discuss the potential for future such measurements.

  9. Polarimetric submillimeter observations from the South Pole

    NASA Technical Reports Server (NTRS)

    Novak, Giles; Platt, Stephen R.; Dragovan, Mark

    1995-01-01

    We discuss proposed observations of the polarization of submillimeter continuum emission from the extended Galactic Center region. The observations will be made from the South Pole, using the VIPER 2-meter telescope.

  10. Dynamics of Enceladus South Pole Ejecta

    NASA Astrophysics Data System (ADS)

    Makuch, Martin; Schmidt, J.; Spahn, F.

    2007-10-01

    The Saturnian moon Enceladus was recently found to be a potent source of gas and dust particles. There was an active region observed on the south pole of Enceladus with jets spraying material in the space. The ejected dust particles are considered to be the main source of the faint E ring. In our work we investigate the long-term dynamics of icy particles ejected from the south pole of Enceladus. The motion of the ejected grains, being subject to many perturbation forces, strongly depends on particle properties (e.g. size, charge etc.). We study the resulting spatial distribution of particles in the E ring. Primarily we focus on the structure of the ring in the vicinity of Enceladus. In our study we also concentrated on processes limiting particle lifetime. These are mainly collisions with Enceladus and other Saturnian satellites or main ring, as well as the sputtering of particles by plasma ions bombardment. Modeling the equilibrium between particle sources and sinks we found the size distribution which is expected to be observed in the E ring.

  11. Dynamics of Enceladus south pole ejecta

    NASA Astrophysics Data System (ADS)

    Makuch, M.; Schmidt, J.; Spahn, F.

    2007-08-01

    The Saturnian moon Enceladus was recently found to be a potent source of gas and dust particles. There was an active region observed on the south pole of Enceladus with jets spraying material in the space. The ejected dust particles are considered to be the main source of the faint E ring. In our work we investigate the long-term dynamics of icy particles ejected from the south pole of Enceladus. The motion of the ejected grains, being subject to many perturbation forces, strongly depends on particle properties (e.g. size, charge etc.).We study the resulting spatial distribution of particles in the E ring. Primarily we focus on the structure of the ring in the vicinity of Enceladus. In our study we also concentrated on processes limiting particle lifetime. These are mainly collisions with Enceladus and other Saturnian satellites or main ring, as well as the sputtering of particles by plasma ions bombardment. Modeling the equilibrium between particle sources and sinks we found the size distribution which is expected to be observed in the E ring.

  12. Gravity increase at the south pole

    USGS Publications Warehouse

    Behrendt, John C.

    1967-01-01

    Abstract. Measurements made between December 1957 and January 1966 of the gravity difference between the McMurdo Sound pendulum station, which is on bedrock, and the South Pole station, which is on the Antarctic ice sheet, show a gravity increase at the South Pole of 0.11 milligals per year. The most likely hypothesis for the increase is that it was caused by ice flowing downslope across a gravity gradient and by the sinking of the South Pole station as a result of accumulation of ice. An alternate hypothesis that the gravity increase was caused by a decrease in ice thickness, of about 40 centimeters per year, is theoretically possible but is not supported by direct evidence.

  13. Detectors for the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Chang, C. L.; Ade, P.; Aird, K.; Austermann, J.; Beall, J.; Becker, D.; Benson, B.; Bleem, L.; Britton, J.; Carlstrom, J.; Cho, H.; de Haan, T.; Crawford, T.; Crites, A.; Datesman, A.; Dobbs, M.; Everett, W.; Ewall-Wice, A.; George, E.; Halverson, N.; Harrington, N.; Henning, J.; Hilton, G.; Holzapfel, W.; Hoover, S.; Hubmayr, J.; Irwin, K.; Keisler, R.; Kennedy, J.; Lee, A.; Leitch, E.; Li, D.; Lueker, M.; Marrone, D. P.; Mcmahon, J.; Mehl, J.; Meyer, S.; Montgomery, J.; Montroy, T.; Natoli, T.; Nibarger, J.; Niemack, M.; Novosad, V.; Padin, S.; Plagge, T.; Pryke, C.; Reichardt, C.; Ruhl, J.; Saliwanchik, B.; Sayre, J.; Schafer, K.; Shirokoff, E.; Story, K.; Vanderlinde, K.; Vieira, J.; Wang, G.; Williamson, R.; Yefremenko, V.; Yoon, K. W.; Young, E.

    The South Pole Telescope (SPT) is a 10-m mm/sub-mm telescope at the Amundsen-Scott South Pole Station. It's primary science goals consist of a galaxy cluster survey for understanding Dark Energy and probing the physics of Inflation through the CMB polarization. Both science goals require exceptional sensitivity necessitating focal planes with many optical elements. The focal planes of the SPT utilize Transition Edge Sensor (TES) bolometers to build arrays of nearly 1000 detectors. In this talk, I will present the TES bolometer technology for both the first SPT focal plane and its upcoming upgrade to a polarization sensitive array.

  14. The 10 Meter South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Carlstrom, J. E.; Ade, P. A. R.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Busetti, S.; Chang, C. L.; Chauvin, E.; Cho, H.-M.; Crawford, T. M.; Crites, A. T.; Dobbs, M. A.; Halverson, N. W.; Heimsath, S.; Holzapfel, W. L.; Hrubes, J. D.; Joy, M.; Keisler, R.; Lanting, T. M.; Lee, A. T.; Leitch, E. M.; Leong, J.; Lu, W.; Lueker, M.; Luong-Van, D.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Padin, S.; Plagge, T.; Pryke, C.; Ruhl, J. E.; Schaffer, K. K.; Schwan, D.; Shirokoff, E.; Spieler, H. G.; Staniszewski, Z.; Stark, A. A.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2011-05-01

    The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with a 966 pixel, multicolor, millimeter-wave, bolometer camera. It is located at the Amundsen-Scott South Pole station in Antarctica. The design of the SPT emphasizes careful control of spillover and scattering, to minimize noise and false signals due to ground pickup. The key initial project is a large-area survey at wavelengths of 3, 2, and 1.3 mm, to detect clusters of galaxies via the Sunyaev-Zel’dovich effect and to measure the small-scale angular power spectrum of the cosmic microwave background (CMB). The data will be used to characterize the primordial matter power spectrum and to place constraints on the equation of state of dark energy. A second-generation camera will measure the polarization of the CMB, potentially leading to constraints on the neutrino mass and the energy scale of inflation.

  15. The South Pole and the Ross Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  16. The Gattini South Pole UV experiment

    NASA Astrophysics Data System (ADS)

    Moore, Anna M.; Ahmed, Sara; Ashley, Michael C. B.; Croner, Ernest; Delacroix, Alex; Ebihara, Yusuke; Fucik, Jason; Martin, D. Christopher; Velur, Viswa; Weatherwax, Allan

    2012-09-01

    The Gattini South Pole UV experiment (Gattini SPUV) was deployed to the South Pole dark sector in February 2010 and has recently completed a highly successful first season of winter time observations. The experiment has, for the first time ever, measured and categorized the optical night sky brightness at the very blue wavelengths. The experiment consists of a remotely operated 6” aperture custom designed telescope. The telescope feeds a blue sensitive imager with 4 degree field of view that contains a bank of 3 filters: SDSS g’, Bessel U and a custom “super U” filter specifically designed to probe the sky emission at wavelengths approaching the atmospheric cut-off. The filters are continually cycled with exposure times ranging from 30 to 300 seconds throughout the winter period. The telescope, in addition, feeds a 2 degree long slit VPH grating spectrograph with R~1000. The bandwidth is 350-450nm. The spectra are recorded simultaneously with the imager exposures. The experiment is designed for low temperature Antarctic operation and resides on the roof of the MAPO building in the South Pole Antarctic sector. The primary science goals are to categorize the Antarctic winter-time sky background at the very bluest of wavelengths as a pathfinder for the Antarctic Cosmic Web Imager. We present a technical overview of the experiment and results from the first winter season.

  17. Collecting Micrometeorites from the South Pole Water Well

    DTIC Science & Technology

    1997-05-01

    Amundsen – Scott South Pole Station . Because of the large volume of ice melted, the well is the larg- est source of micrometeorites yet discovered. The...Susan Taylor, James H. Lever, Ralph P. Harvey, and May 1997 John Govoni C R R EL R EP O R T 9 7 -1 Collecting Micrometeorites from the South Pole ...Water Well Abstract: A collector was designed and built to retrieve micrometeorites from the floor of the South Pole Water Well. The large volume of

  18. Helioseismology from the South Pole: 1987 campaign

    SciTech Connect

    Jefferies, S.; Pomerantz, M.A. ); Duvall, T.L. Jr. ); Harvey, J.W.; Jaksha, D. )

    1988-01-01

    Helioseismology is the study of the Sun's interior by means of observations of its global oscillations. The Sun constantly oscillates, at periods of about 5 minutes, in millions of different modes which probe different depth and latitude ranges. Helioseismological observations have been made from the Amundsen-Scott South Pole Station nearly every year since 1980. This site offers the unique advantage of uninterrupted sunlight during the austral summer (except for clouds, of course) and otherwise generally good atmospheric conditions for astronomical observations. Thus, it is possible to measure oscillations without long nighttime gaps which confuse measurements made at low-latitude observatories. Measurements from the South Pole and elsewhere have shown that the solar interior is roughly similar to the predictions of the theory of stellar structure and evolution. This theory is one of the key foundations of our present picture of the universe. It is, therefore, disturbing that there are small, but highly significant, discrepancies between theory and observations and that these discrepancies have not been resolved by reasonable adjustments of theoretical parameters and physics. Currently, the source of these discrepancies is not at all clear. Helioseismology, however, not only revealed the problem but offers excellent prospects for solving it.

  19. South Pole-Aitken Basin Mission (SPAM)

    NASA Astrophysics Data System (ADS)

    Weitz, C. M.; Yingst, R. A.; Minitti, M.; Head, J. W., III; Prockter, L.; Dahl, J. M.; Cooper, C. D.; Crumpler, L.; Gershman, R.; Welch, R.; Jet Propulsion LABORATORY Team

    1997-03-01

    Recent Clementine data of the farside of the moon has shown high resolution details of the South Pole-Aitken basin. The basin is over 2500 km in diameter, making it the largest impact basin thus far identified in our solar system. Estimates for the excavation depth from the basin suggest that the lower crust/upper mantle may have been reached. Clementine UVVIS data show noritic compositions and high FeO wt pct compositions, supporting that at least the lower crust may have been excavated. Because the geology of the area offers a unique opportunity to study the stratigraphy of the lunar crust at depth as well as the composition of rocks from the lunar farside, we have selected a site in the South Pole-Aitken basin for a sample return mission. Although the mission described below is currently unsuitable as a Discovery class mission, other scenarios are still possible that will reduce the mass and make the mission more feasible.

  20. South Pole Region of the Moon as Seen by Clementine

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Lunar mosaic of 1500 Clementine images of the south polar region of the moon. The projection is orthographic, centered on the south pole. The Schrodinger Basin (320 km in diameter) is located in the lower right of the mosaic. Amundsen-Ganswindt is the more subdued circular basin between Schrodinger and the pole. The polar regions of the moon are of special interest because of the postulated occurrence of ice in permanently shadowed areas. The south pole is of greater interest because the area that remains in shadow is much larger than that at the north pole.

  1. Heavy Cratering near Callisto's South Pole

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Images from NASA's Galileo spacecraft provide new insights into this region near Callisto's south pole. This two frame mosaic shows a heavily cratered surface with smooth plains in the areas between craters. North is to the top of the image. The smoothness of the plains appears to increase toward the south pole, approximately 480 kilometers (293 miles) south of the bottom of the image. This smoothness of Callisto's surface was not evident in images taken during the 1979 flyby of NASA's Voyager spacecraft because the resolution was insufficient to show the effect. This smooth surface, and the process(es) that cause it, are among the most intriguing aspects of Callisto. Although not fully understood, the process(es) responsible for this smoothing could include erosion by tiny meteorites and energetic ions. Some craters, such as Keelut, the 47 kilometer (29 mile) crater in the lower right corner, have sharp, well defined rims. Keelut contains an inner ring surrounding a central depression about 17 kilometers (11 miles) in diameter. Keelut, and the more irregularly shaped, degraded Reginleif, the 32 kilometer (19.5 mile) crater in the top center of the image, are very shallow and have flat floors. Crater forms can be seen down to less than 2 kilometers (1.2 miles) in diameter in the image. Each picture element (pixel) in this image is approximately 0.68 kilometers (0.41 miles) across.

    This image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter, on May 6th, 1997. The center of the image is located at 71.3 degrees south latitude, 97.6 degrees west longitude, and was taken when the spacecraft was approximately 35,470 kilometers (21,637 miles) from Callisto.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at

  2. Effect of plasticity on the dynamics of Enceladus's south pole

    NASA Astrophysics Data System (ADS)

    Behounkova, M.; Cadek, O.; Tobie, G.; Choblet, G.

    2012-09-01

    The intense activity at the south pole of Enceladus hints at an internal water reservoir. However, there is no direct evidence of liquid water at present and its long-term stability in the interior remains problematic. By modeling heat production and transfer in the ice shell in a spherical geometry, in a previous study Behounková et al. [1], we have shown that tidal heating naturally leads to a concentration of convective hot upwellings in the south polar region, favoring the preservation of liquid water at depth. We show that large volumes of water are produced within the ice shell at the south pole during periods of elevated orbital eccentricity (3-5 times the present-day value). Strong lateral variations in the melt production and crystallization rates result in stress concentration in the south polar region, thus providing an explanation for the tectonic activity observed today. We predict that an internal ocean may be sustained over the long term as the consequence of repeated periods with elevated orbital eccentricity, leading to episodic melting and resurfacing events. In order to model the resurfacing event following a tidally-induced melting episode, we are currently incorporating plasticity effects. We also improve the modeling of tidal deformation by incorporating the Andrade model, which is expected to better reproduce the viscoelastic properties of water ice Castillo-Rogez et al. [2].

  3. DISCOVERY OF FOG AT THE SOUTH POLE OF TITAN

    SciTech Connect

    Brown, M. E.; Smith, A. L.; Chen, C.; Adamkovics, M.

    2009-11-20

    While Saturn's moon Titan appears to support an active methane hydrological cycle, no direct evidence for surface-atmosphere exchange has yet appeared. The indirect evidence, while compelling, could be misleading. It is possible, for example, that the identified lake features could be filled with ethane, an involatile long-term residue of atmospheric photolysis; the apparent stream and channel features could be ancient remnants of a previous climate; and the tropospheric methane clouds, while frequent, could cause no rain to reach the surface. We report here the detection of fog at the south pole of Titan during late summer using observations from the VIMS instrument on board the Cassini spacecraft. While terrestrial fog can form from a variety of causes, most of these processes are inoperable on Titan. Fog on Titan can only be caused by evaporation of nearly pure liquid methane; the detection of fog provides the first direct link between surface and atmospheric methane. Based on the detections presented here, liquid methane appears widespread at the south pole of Titan in late southern summer, and the hydrological cycle on Titan is currently active.

  4. The impact of human activities in africa,the north and south pole regions on global climate change

    NASA Astrophysics Data System (ADS)

    Abubakar, Babagana

    As a result of the rapid increase in the petroleum exploration, Industrial, deforestation and other human activities going on within or around the Arctic and Antarctica ice caps near or in the temperate region countries like Canada, Greenland, Russia, U.S.A (Alaska), Iceland, Finland, Argentina, Tasmania and New Zealand among many others plus the increase in deforestation activities in Tropical world countries like the Amazon of Brazil, The Tropical Rain forest of Nigeria, Zaire (Democratic Republic of Congo), Cotedvoire, Indonesia etc. in addition to the Sahara and the Kalahari deserts encouragement as a result of human factors plus the uncontrolled disposals of broken Refrigerators, Air conditioners and propellants containing chlorofluorocarbon substances capable of destroying the Ozone layer in African refuse dumps (B.Abubkar,2006) are collectively becoming a threat to the world climate. This explains why the volume of the Ocean keeps on rising, global temperature keeps ascending and the global climate is becoming abnormal since the beginning of the above mentioned activities in the above mentioned locations. It was in view of the above that this research was conducted and came up with the under listed suggestions/recommendations: 1. The temperature region countries like Canada, Russia, U.S.A, Argentina etc. should come up with polices restricting certain industries with the possibilities of causing environmental hazards from operating near the Ice Caps of the Arctic or Antarctica even in areas which the Ice was frozen thousands of years ago as the case with Greenland. 2. The research and exploration activities going on around or on the Arctic and the Antarctica regions should be carried out with utmost care and concern to the global climate. 3. The deforestation activities going on without control in most of the Tropical World Countries should be monitored by the United Nation's Specialized Agencies on forest and other related international organization in such

  5. The Impact of Human Activities in Africa, the North and South Pole Regions on Global Climate Change.

    NASA Astrophysics Data System (ADS)

    Abubakar, B.

    2007-05-01

    As a result of the rapid increase in the petroleum exploration, Industrial, deforestation and other human activities going on within or around the Arctic and Antarctica ice caps near or in the temperate region countries like Canada, Greenland, Russia, U.S.A (Alaska), Iceland, Finland, Argentina, Tasmania and New Zealand among many others plus the increase in deforestation activities in Tropical world countries like the Amazon of Brazil, The Tropical Rain forest of Nigeria, Zaire (Democratic Republic of Congo), Cotedvoire, Indonesia etc. in addition to the Sahara and the Kalahari deserts encouragement as a result of human factors plus the uncontrolled disposals of broken Refrigerators, Air conditioners and propellants containing chlorofluorocarbon substances capable of destroying the Ozone layer in African refuse dumps (B.Abubkar,2006) are collectively becoming a threat to the world climate. This explains why the volume of the Ocean keeps on rising, global temperature keeps ascending and the global climate is becoming abnormal since the beginning of the above mentioned activities in the above mentioned locations. It was in view of the above that this research was conducted and came up with the under listed suggestions/recommendations: 1. The temperature region countries like Canada, Russia, U.S.A, Argentina etc. should come up with polices restricting certain industries with the possibilities of causing environmental hazards from operating near the Ice Caps of the Arctic or Antarctica even in areas which the Ice was frozen thousands of years ago as the case with Greenland. 2. The research and exploration activities going on around or on the Arctic and the Antarctica regions should be carried out with utmost care and concern to the global climate. 3. The deforestation activities going on without control in most of the Tropical World Countries should be monitored by the United Nation's Specialized Agencies on forest and other related international organization in such

  6. Design and performance of the South Pole Acoustic Test Setup

    NASA Astrophysics Data System (ADS)

    Abdou, Y.; Becker, K.-H.; Berdermann, J.; Bissok, M.; Bohm, C.; Böser, S.; Bothe, M.; Carson, M.; Descamps, F.; Fischer-Wolfarth, J.-H.; Gustafsson, L.; Hallgren, A.; Heinen, D.; Helbing, K.; Heller, R.; Hundertmark, S.; Karg, T.; Krieger, K.; Laihem, K.; Meures, T.; Nahnhauer, R.; Naumann, U.; Oberson, F.; Paul, L.; Pohl, M.; Price, B.; Ribordy, M.; Ryckbosch, D.; Schunck, M.; Semburg, B.; Stegmaier, J.; Sulanke, K.-H.; Tosi, D.; Vandenbroucke, J.; Wiebusch, C.

    2012-08-01

    The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic characteristics of the South Pole ice in the 10-100 kHz frequency range, for the purpose of assessing the feasibility of an acoustic neutrino detection array at the South Pole. The SPATS hardware consists of four vertical strings deployed in the upper 500 m of the South Pole ice cap. The strings form a trapezoidal array with a maximum baseline of 543 m. Each string has seven stages equipped with one transmitter and one sensor module (glaciophone). Sound is detected or generated by piezoelectric ceramic elements inside the modules. Analogue signals are sent to the surface on electric cables where they are digitized by a PC-based data acquisition system. The data from all strings are collected on a central computer in the IceCube Laboratory from where they are sent to a central data storage facility via a satellite link or stored locally on tape. A technical overview of SPATS and its performance is presented.

  7. SOUTH ELEVATION OF BATTERY COMMAND CENTER WITH GRADUATED MEASURING POLE. ...

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

    SOUTH ELEVATION OF BATTERY COMMAND CENTER WITH GRADUATED MEASURING POLE. THE ENTRY STAIRWAY IS IN THE FOREGROUND. THE ABOVE-GROUND SECTION OF THE STRUCTURE IS ON THE RIGHT, UNDERGROUND PORTION ON THE LEFT. VIEW FACING NORTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  8. Late 20th Century increase in South Pole snow accumulation

    USGS Publications Warehouse

    Mosley-Thompson, E.; Paskievitch, J.F.; Gow, A.J.; Thompson, L.G.

    1999-01-01

    A compilation of the 37-year history of net accumulation at the South Pole [Mosley-Thompson et al., 1995] suggests an increase in net annual accumulation since 1965. This record is sporadic and its quality is compromised by spatially restricted observations and nonsystematic measurement procedures. Results from a new, spatially extensive network of 236 accumulation poles document that the current 5-year (1992-1997) average annual net accumulation at the South Pole is 84.5??8.9 mm water equivalent (w.e.). This accumulation rate reflects a 30% increase since the 1960s when the best, although not optimal, records indicate that it was 65 mm w.e. Identification of two prominent beta radioactivity horizons (1954/1955 and 1964/1965) in six firn cores confirms an increase in accumulation since 1965. Viewed from a longer perspective of accumulation provided by ice cores and a snow mine study, the net accumulation of the 30-year period, 1965-1994, is the highest 30-year average of this millennium. Limited data suggest this recent accumulation increase extends beyond the South Pole region and may be characteristic of the high East Antarctic Plateau. Enhanced accumulation over the polar ice sheets has been identified as a potential early indicator of warmer sea surface temperatures and may offset a portion of the current rise in global sea level. Copyright 1999 by the American Geophysical Union.

  9. Titan's Gas Behavior During the South Pole Fall

    NASA Astrophysics Data System (ADS)

    Cottini, Valeria; Nixon, Conor A.; Achterberg, Richard K.; Jennings, Donald E.; Gorius, Nicolas; Irwin, Patrick G. J.

    2015-11-01

    Titan’s southern middle atmosphere has been showing several changes since the start of fall season in 2009. In 2012 a large cloud appeared [1], [2], [3], temperatures became very low and condensation and gas concentration at the South Pole increased [3], [4].In this work we will show the results of gas abundances retrievals in the South Pole and their latitudinal variation changes as the cold season evolved with time.We analyzed several Cassini Composite InfraRed Spectrometer (CIRS [5]) mid-infrared observations of the South Pole acquired during 2013-2014. The data coordinates were converted in order to be centered on the atmospheric pole and refer to the 1 mbar level and not to the surface. We first determine stratospheric temperatures from the same data and latitudes from the n4 band of methane centered around 1300 cm-1. We retrieve the temperature profiles applying a radiative transfer forward model combined with a non-linear optimal estimation inversion method [6]. We then retrieve the main gases abundances and track their variation with latitude using the same method.Latitudinal changes of the main Titan’s gases - HC3N, C4H2, C6H6, C2H2, C2H4, C3H8 and HCN - show different trends in the Southern polar regions over 2014, when winter was getting closer. We observe a ring-shape in some of the gas abundance distributions, with a local maximum peak around -75 deg of latitude. We also observe an increase of abundance of most of the gases toward the south pole, as seen previously in the North during the winter. The observed increase of benzene over the South Pole is definitely evident and strong. References: [1] West, R. A. et al. (2013) BAAS, 45, 305.03. [2] Jennings, D. E. et al. (2012) ApJ, 754, L3. [3] de Kok, R. et al. (2014), Nature, 514, 7520, 65-67. [4] Vinatier S. et al. (2015) Icarus, Volume 250, p. 95-115. [5] Flasar et al. (2004) Space Sci. Rev., 115, 169-297. [6] Irwin, P.G.J. et al. (2008) J. Quant. Spectrosc. Radiat. Trans., 109, 1136-1150.

  10. The South Pole Telescope: Unraveling the Mystery of Dark Energy

    NASA Astrophysics Data System (ADS)

    Reichardt, Christian L.; de Haan, Tijmen; Bleem, Lindsey E.

    2016-07-01

    The South Pole Telescope (SPT) is a 10-meter telescope designed to survey the millimeter-wave sky, taking advantage of the exceptional observing conditions at the Amundsen-Scott South Pole Station. The telescope and its ground-breaking 960-element bolometric camera finished surveying 2500 square degrees at 95. 150, and 220 GHz in November 2011. We have discovered hundreds of galaxy clusters in the SPT-SZ survey through the Sunyaev-Zel’dovich (SZ) effect. The formation of galaxy clusters the largest bound objects in the universe is highly sensitive to dark energy and the history of structure formation. I will discuss the cosmological constraints from the SPT-SZ galaxy cluster sample as well as future prospects with the soon to-be-installed SPT-3G camera.

  11. The South Pole Imaging Fabry Perot Interferometer (SPIFI)

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Bradford, C. M.; Swain, M. R.; Jackson, J. M.; Bolato, A. D.; Davidson, J. A.; Savage, M.

    1996-01-01

    The design and construction of the South Pole imaging Fabry-Perot interferometer (SPIFI) is reported. The SPIFI is a direct detection imaging spectrometer for use in the far infrared and submillimeter bands accessible to the 1.7 m telescope at the South Pole, and in the submillimeter bands accessible to the 15 m James Clerk Maxwell Telescope (JCMT), HI. It employs a 5 x 5 silicon bolometer array and three cryogenic Fabry Perot interferometers in series in order to achieve velocity resolutions of between 300 km/s and 30 km/s over the entire field of view with a resolution of up to 1 km/s at the center pixel. The scientific justification for the instrument is discussed, considering the spectral lines available to SPIFI. The optical path, the cryogenic Fabry-Perot, the adiabatic demagnetization refrigerator and the detector array are described. The instrument's sensitivity is presented and compared with coherent systems.

  12. Lunar Prospecting: Searching for Volatiles at the South Pole

    NASA Technical Reports Server (NTRS)

    Trimble, Jay; Carvalho, Robert

    2016-01-01

    The Resource Prospector is an in-situ resource utilization (ISRU) technology demonstration mission, planned for a 2021 launch to search for and analyze volatiles at the Lunar South Pole. The mission poses unique operational challenges. Operating at the Lunar South Pole requires navigating a surface with lighting, shadow and regolith characteristics unlike those of previous missions. The short round trip communications time enables reactive surface operations for science and engineering. Navigation of permanently shadowed regions with a solar powered rover creates risks, including power and thermal management, and requires constant real time decision making for safe entry, path selection and egress. The mission plan requires a faster rover egress from the lander than any previous NASA rover mission.

  13. Atmospheric ozone at South Pole, Antarctica, in 1986

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Oltmans, S. J.; Grass, R. D.

    1988-01-01

    Results of NOAA's measurements of the ozone vertical distributions at the South Pole and of the annual course of total ozone, conducted in 1986 with balloon-borne electrochemical concentration cell (ECC) ozonesondes and a Dobson spectrophotometer, are described. The major finding was that the stratospheric ozone decreases abruptly between September 20 and October 15, with the bulk decrease occurring between 12 and 21 km. In this period, the column ozone and ozone volume mixing ratio at 16 km (the altitude of the normal ozone maximum at South Pole) decreased by 78 percent, and column ozone between 12 and 21 km decreased by 50 percent. The results of these measurements are compared with data obtained in 1971, and the changes observed in the ozone vertical distributions and in the temporal variations of atmospheric ozone are discussed.

  14. Direct detection of variable tropospheric clouds near Titan's south pole.

    PubMed

    Brown, Michael E; Bouchez, Antonin H; Griffith, Caitlin A

    Atmospheric conditions on Saturn's largest satellite, Titan, allow the possibility that it could possess a methane condensation and precipitation cycle with many similarities to Earth's hydrological cycle. Detailed imaging studies of Titan have hitherto shown no direct evidence for tropospheric condensation clouds, although there has been indirect spectroscopic evidence for transient clouds. Here we report images and spectra of Titan that show clearly transient clouds, concentrated near the south pole, which is currently near the point of maximum solar heating. The discovery of these clouds demonstrates the existence of condensation and localized moist convection in Titan's atmosphere. Their location suggests that methane cloud formation is controlled seasonally by small variations in surface temperature, and that the clouds will move from the south to the north pole on a 15-year timescale.

  15. Seasonal Evolution of Titan's South Pole 220 cm-1 Cloud

    NASA Astrophysics Data System (ADS)

    Jennings, Donald

    2016-06-01

    A cloud of ices that had been seen only in Titan's north during winter began to emerge at the south pole in 2012. Discovered by Voyager IRIS as an emission feature at 220 cm-1, the cloud has been studied extensively in both the north and south by Cassini CIRS. The spectral feature acts as a tracer of the seasonal changes at Titan's poles, relating to evolving composition, temperature structure and dynamics. Although candidates have been proposed, the chemical makeup of the cloud has never been identified. The cloud is composed of condensates derived from gases created at high altitude and transported to the cold, shadowed pole. In the north the cloud has diminished gradually over the Cassini mission as Titan has transitioned from winter to spring. The southern cloud, on the other hand, grew rapidly after 2012. By late 2014 it had developed a complex ring structure that was confined to latitudes poleward of 70°S within the deep temperature well that had formed at the south pole [1]. The location of the cloud coincides in latitude with the HCN cloud reported by ISS and VIMS [2,3]. CIRS also saw enhanced gas emissions at those latitudes [4]. When it first formed, the cloud was abundant at altitudes as high as 250 km, while later it was found mostly at 100-150 km, suggesting that the material that had been deposited from above had gathered at the lower altitudes. Radiance from the southern cloud increased until mid-2015 and since then has decreased. The cloud may be transitioning to the more uniform hood morphology familiar in the north. Taking the north and south together, by the end of the Cassini mission in 2017 we will have observed almost an entire seasonal cycle of the ice cloud.

  16. Background Studies for Acoustic Neutrino Detection at the South Pole

    NASA Technical Reports Server (NTRS)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K. H.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Stamatikos, M.

    2012-01-01

    The detection of acoustic signals from ultra-high energy neutrino interactions is a promising method. to measure the flux of cosmogenic neutrinos expected on Earth. The energy threshold for this process depends strongly on the absolute noise level in the target material. The South Pole Acoustic Test Setup (SPATS). deployed in the upper part of four boreholes of the IceCube Neutrino Observatory, has monitored the noise in Antarctic ice at the geographic South Pole for more than two years down to 500 m depth. The noise is very stable and Gaussian distributed, Lacking an in situ calibration up to now, laboratory measurements have been used to estimate the absolute noise level in the 10-50 kHz frequency range to be smaller than 20 mPa. Using a threshold trigger. sensors of the South Pole Acoustic Test Setup registered acoustic events in the IceCube detector volume and its vicinity. Acoustic signals from refreezing IceCube holes and from anthropogenic sources have been used to test the localization of acoustic events. An upper limit on the neutrino flux at energies E(sub v) > 10(exp 11) GeV is derived from acoustic data taken over eight months.

  17. Transient water vapor at Europa's south pole.

    PubMed

    Roth, Lorenz; Saur, Joachim; Retherford, Kurt D; Strobel, Darrell F; Feldman, Paul D; McGrath, Melissa A; Nimmo, Francis

    2014-01-10

    In November and December 2012, the Hubble Space Telescope (HST) imaged Europa's ultraviolet emissions in the search for vapor plume activity. We report statistically significant coincident surpluses of hydrogen Lyman-α and oxygen OI 130.4-nanometer emissions above the southern hemisphere in December 2012. These emissions were persistently found in the same area over the 7 hours of the observation, suggesting atmospheric inhomogeneity; they are consistent with two 200-km-high plumes of water vapor with line-of-sight column densities of about 10(20) per square meter. Nondetection in November 2012 and in previous HST images from 1999 suggests varying plume activity that might depend on changing surface stresses based on Europa's orbital phases. The plume was present when Europa was near apocenter and was not detected close to its pericenter, in agreement with tidal modeling predictions.

  18. Recent increase in Ba concentrations as recorded in a South Pole ice core

    NASA Astrophysics Data System (ADS)

    Korotkikh, Elena V.; Mayewski, Paul A.; Dixon, Daniel; Kurbatov, Andrei V.; Handley, Michael J.

    2014-06-01

    Here we present high-resolution (∼9.4 samples/year) records of Ba concentrations for the period from 1541 to 1999 A.D. obtained from an ice core recovered at the South Pole (US ITASE-02-6) site. We note a significant increase in Ba concentration (by a factor of ∼23) since 1980 A.D. The Ba crustal enrichment factor (EFc) values rise from ∼3 before 1980 A.D. to ∼32 after 1980 A.D. None of the other measured major and trace elements reveal such significant increases in concentrations and EFc values. Comparison with previously reported Antarctic Ba records suggests that significant increases in Ba concentrations at South Pole since 1980 A.D. are most likely caused by local source pollution. The core was collected in close proximity to Amundsen-Scott South Pole Station; therefore activities at the station, such as diesel fuel burning and intense aircraft activity, most likely caused the observed increase in Ba concentrations and its EFc values in the South Pole ice core record.

  19. Lunar South Pole Illumination: Review, Reassessment, and Power System Implications

    NASA Technical Reports Server (NTRS)

    Fincannon, James

    2007-01-01

    This paper reviews past analyses and research related to lunar south pole illumination and presents results of independent illumination analyses using an analytical tool and a radar digital elevation model. The analysis tool enables assessment at most locations near the lunar poles for any time and any year. Average illumination fraction, energy storage duration, solar/horizon terrain elevation profiles and illumination fraction profiles are presented for various highly illuminated sites which have been identified for manned or unmanned operations. The format of the data can be used by power system designers to develop mass optimized solar and energy storage systems. Data are presented for the worse case lunar day (a critical power planning bottleneck) as well as three lunar days during lunar south pole winter. The main site under consideration by present lunar mission planners (on the Crater Shackleton rim) is shown to have, for the worse case lunar day, a 0.71 average illumination fraction and 73 to 117 hours required for energy storage (depending on power system type). Linking other sites and including towers at either site are shown to not completely eliminate the need for energy storage.

  20. Autumn at Titan's South Pole: The 220 cm-1 Cloud

    NASA Astrophysics Data System (ADS)

    Jennings, D. E.; Cottini, V.; Achterberg, R. K.; Anderson, C. M.; Flasar, F. M.; de Kok, R. J.; Teanby, N. A.; Coustenis, A.; Vinatier, S.

    2015-10-01

    Beginning in 2012 an atmospheric cloud known by its far-infrared emission has formed rapidly at Tit an's South Pole [1, 2]. The build-up of this condensate is a result of deepening temperatures and a gathering of gases as Winter approaches. Emission from the cloud in the south has been doubling each year since 2012, in contrast to the north where it has halved every 3.8 years since 2004. The morphology of the cloud in the south is quite different from that in the north. In the north, the cloud has extended over the whole polar region beyond 55 N, whereas in the south the cloud has been confined to within about 10 degrees of the pole. The cloud in the north has had the form of a uniform hood, whereas the southern cloud has been much more complex. A map from December 2014,recorded by the Composite Infrared Spectrometer (CIRS) on Cassini, showed the 220 cm-1 emission coming from a distinct ring with a maximum at about 80 S. In contrast, emissions from the gases HC3N, C4H2 and C6H6 peaked near the pole and had a ring at 70 S. The 220 cm-1 ring at 80 S coincided with the minimum in the gas emission pattern. The80 S condensate ring encompassed the vortex cloud seen by the Cassini Imaging Science Subsystem (ISS) and Visible and Infrared Mapping Spectrometer (VIMS)[3, 4]. Both the 220 cm-1 ring and the gas "bull's-eye" pattern were centered on a point that was shifted from the geographic South Pole by 4 degrees in the direction of the Sun. This corresponds to the overall tilt of Titan's atmosphere discovered from temperature maps early in the Cassini mission by Achterberg et al. [5]. The tilt may be reinforced by the presumably twice-yearly (north and south) spin-up of the atmosphere at the autumnal pole. The bull's-eye pattern of the gas emissions can be explained by the retrieved abundance distributions, which are maximum near the pole and decrease sharply toward lower latitudes, together with temperatures that are minimum at the pole and increase toward lower latitudes

  1. South Pole Queen Maud Land Traverses, 1964-68 (Invited)

    NASA Astrophysics Data System (ADS)

    Bentley, C. R.

    2009-12-01

    Between early December, 1964, and late January, 1968, the three-part "South Pole Queen Maud Land Traverse" (SPQMLT), supported by the U.S. Antarctic Research Program (USARP), explored the previously unexamined interior of Queen Maud Land, making measurements of surface height and slope, surface mass balance, bore-hole temperatures, ice thickness, seismic wave velocities in and below the ice, gravity, and magnetics. The traverse followed a zigzag, space-filling route between Pole Station, the abandoned Pole of Relative Inaccessibility station, and Plateau Station on the east and roughly the Greenwich Meridian on the west. The traverse equipment featured two large Model 843 Tucker Sno-Cats, designed and built especially for work on the high East Antarctic plateau. Unfortunately, for programmatic reasons a planned 4th season to drive the Sno-Cats back to Pole Station could not be supported, so they were permanently abandoned at the end of the third traverse, at 78° 42.2'S, 6° 52'W. The SPQMLT was remarkable not only for working in a previously unexplored area, but also for the introduction of several new techniques to Antarctic traverse studies, two of which, radar sounding and determination of accumulation rates using a dated radioactive fallout horizon, were major advances that will be discussed by other authors in this session. In this presentation I will discuss the seismic, gravity, and magnetic observations and what they suggest about the character of the underlying terrain. Because of the pronounced differences in route pattern between the SPQMLT and the recent Troll-Pole-Troll traverses the data will be strongly complementary. From SPQMLT only the positions and surface heights are not up to modern standards of accuracy, but the former are adequate for regional studies and the latter have all been superseded by satellite radar and laser altimetry anyway.

  2. Two Years of Ozone Observations from the South Pole Brewer

    NASA Astrophysics Data System (ADS)

    McElroy, Tom; Savastiouk, Volodya; Evans, Robert; Oltmans, Samuel; Booth, John; Cox, Amy

    2010-05-01

    A Mark III, double-monochromator Brewer Ozone Spectrophotometer has now been operating at the Amundsen-Scott Antarctic Base for more than two years. The instrument was installed under an agreement with the US National Oceanic and Atmospheric Administration (NOAA) by Environment Canada in February of 2008. It has now collected more than two years of observations. Both direct sun data and moon measurements have been made and the results compared with the station Dobson Spectrophotometer observations. The Brewer has operated well under the harsh conditions at the South Pole, enduring outside temperatures below -70C. Some the results of the analysis of these data will be presented and discussed.

  3. Multi-Body Orbit Architectures for Lunar South Pole Coverage

    NASA Technical Reports Server (NTRS)

    Grebow, D. J.; Ozimek, M. T.; Howell, K. C.; Folta, D. C.

    2006-01-01

    A potential ground station at the lunar south pole has prompted studies of orbit architectures that ensure adequate coverage. Constant communications can be achieved with two spacecraft in different combinations of Earth-Moon libration point orbits. Halo and vertical families, as well as other orbits near L1 and L2 are considered. The investigation includes detailed results using nine different orbits with periods ranging from 7 to 16 days. Natural solutions are generated in a full ephemeris model, including solar perturbations. A preliminary station-keeping analysis is also completed.

  4. Sampling South Pole-Aitken Basin: The Moonrise Approach

    NASA Technical Reports Server (NTRS)

    Jolliff, B. L.; Shearer, C. K.; Cohen, B. A.

    2012-01-01

    The South Pole-Aitken basin (SPA) is the largest of the giant impact basins in the inner Solar System, and its location on Earth s Moon makes it the most accessible. Exploration of SPA through direct collection and analysis of representative materials addresses issues as fundamental as the characteristics of the chemical reservoir from which the Moon originated, early differentiation and production of crust and development of global asymmetry, relationships between magmatic activity and internal thermal evolution, and effects of giant impact events on the terrestrial planets. Owing to its great size and superposition relationships with other lunar impact basins, SPA is the oldest and as such anchors the lunar chronology. Moreover, numerous large impact craters and basins are contained within it such that materials (rocks) of the SPA basin contain a record of the early impact chronology, one less likely to have been affected by the large, late nearside basins (e.g., Imbrium). Understanding the early basin chronology is key to deciphering the sequence and effects of early giant impact bombardment of the inner Solar System. That record exists on the Moon, and materials of the SPA basin will allow us to read that record. Knowledge of the early bombardment history will test - and may reshape - a key paradigm relating to early Solar System evolution. Did the planets form with the alignment of today, or was there a major reorientation of the giant planets that led to destabilization of asteroid orbits, and a cataclysmic bombardment of the inner Solar System hundreds of millions of years after accretion of the planets? Implications include understanding environments for early life-supporting habitats on Earth and Mars, and relationships to new observations of extra-solar planetary systems.

  5. Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30)

    NASA Technical Reports Server (NTRS)

    Mest, S. C.; Berman, D. C.; Petro, N. E.

    2010-01-01

    In this study we use recent image, spectral and topographic data to map the geology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-7]. The overall objective of this research is to constrain the geologic evolution of LQ-30 (60 -90 S, 0 - 180 ) with specific emphasis on evaluation of a) the regional effects of impact basin formation, and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Determining the geologic history of LQ-30 and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of potential resources (e.g., H, Fe, Th) and their relationships with surface materials.

  6. The Seasonal and Diurnal Variations of Lower and Middle Atmosphere Temperatures at the South Pole

    NASA Astrophysics Data System (ADS)

    Chu, X.; Pan, W.; Gardner, C. S.

    2001-05-01

    An Fe Boltzmann Temperature Lidar was operated at the Amundsen-Scott South Pole Station from 1999-2001. Temperature profiles were obtained by combining the lidar data from 30-75 km and the balloon data from ground to around 35 km. We summarize the seasonal variations of the troposphere up to mesosphere temperatures at the South Pole. Furthermore, more than 24 hours continuous lidar observations at the South Pole allow us to study the diurnal variations of the stratosphere temperatures. We also present the seasonal and diurnal variations of the mesospheric Fe densities, which indicate the effects of Fe chemistry and the persistent oscillations at the South Pole.

  7. What is the South Pole-Aitken basin hiding?

    NASA Astrophysics Data System (ADS)

    Garrick-Bethell, I.; Nimmo, F.; Wieczorek, M. A.

    2010-12-01

    The South Pole-Aitken (SP-A) basin is remarkable because of its great age, size, elliptical structure, and asymmetrical depth of excavation. Recent studies have elucidated its general shape (e.g. [1]), but questions still remain about what processes influenced the distribution of topography and crustal thickness inside the basin. There are emerging indications that SP-A may have impacted into a unique terrain, and that there is a remaining signature of that terrain imbedded in the details of the SP-A topography and crustal thickness. A recent study of the lunar farside highlands north of the basin [2] demonstrated that their crustal structure and shape can be described by a degree-2 harmonic that extends over about a quarter of the lunar surface. The process that generated this terrain would have likely once extended into the southern half of the farside and its characteristic degree-2 shape would have been obscured by the South Pole-Aitken impact. If so, the low topography in the southern central part of the basin, which is the lowest on the Moon, would be partially the result of the superposition of the SP-A excavation cavity over a preexisting degree-2 terrain that decreases in elevation and crustal thickness towards the south pole. We tested this hypothesis in several ways, including fitting degree-2 harmonics to the farside highlands and extrapolating them across the basin, “removing” the expected degree-2 signal from SP-A, and measuring the degree-2 character of the interior basin topography and crustal thickness. In all cases, there is evidence that the preexisting terrain was degree-2 in character, and that it controlled portions of the basin topography and crustal structure we see now. There are three implications of these results. The first is that the north-south asymmetry in the depth of SP-A [1] is not likely due to some asymmetry in the impact process that develops at very large scales. The second is that knowledge of the preexisting crustal

  8. Aerosol measurements at the south pole during 1987. Data report

    SciTech Connect

    Bodhaine, B.A.; Harris, J.M.

    1992-11-01

    The Climate Monitoring and Diagnostics Laboratory (CMDL) of the National Oceanic and Atmospheric Administration (NOAA) operates an atmospheric monitoring observatory at Amundsen-Scott Station, South Pole. The aerosol measurement program consists of the continuous measurement of condensation nuclei (CN) concentration and aerosol scattering extinction coefficient. During 1987, a special aerosol experiment was conducted that included filter samples for subsequent analysis by the proton induced x-ray emission technique, diffusion battery measurements for size information in the sub-0.1 micrometer size range, and aerosol absorption measurements using an aethalometer. Surface and upper air meteorological data were also available. The purpose of the report is to present all of the aerosol data obtained during 1987.

  9. South Pole submillimeter isotropy measurements of the cosmic microwave background

    SciTech Connect

    Dragovan, M. ); Platt, S.R.; Pernic, R.J. ); Stark, A.A. )

    1990-01-15

    Observations were made from the United States Amundsen-Scott South Pole Station during the austral summer of 1988--89 to search for spatial anisotropy in the submillimeter Cosmic Microwave Background. Three 30{prime}{times}30{prime} regions of the sky were observed at 350 {mu}m, 450 {mu}m, and 600 {mu}m with the University of Chicago 32-Channel Submillimeter Photometer and a 1.2-meter off-axis parabolic telescope, designed and constructed at AT T Bell Laboratories. Reimaging optics gave each of the 32 bolometers in the array a 5-arc minute field of view. The search is sensitive to fluctuations on all angular scales between 5- and 30-arc minutes.

  10. Lunar South Pole space water extraction and trucking system

    SciTech Connect

    Zuppero, A. |; Zupp, G.; Schnitzler, B.; Larson, T.K.; Rice, J.W.

    1998-03-01

    This concept proposes to use thermal processes alone to extract water from the lunar South Pole and launch payloads to low lunar orbit. Thermal steam rockets would use water propellant for space transportation. The estimated mass of a space water tanker powered by a nuclear heated steam rocket suggests it can be designed for launch in the Space Shuttle bay. The performance depends on the feasibility of a nuclear reactor rocket engine producing steam at 1,100 degrees Kelvin, with a power density of 150 Megawatts per ton of rocket, and operating for thousands of 20 minute cycles. An example uses reject heat from a small nuclear electric power supply to melt 17,800 tons per year of lunar ice. A nuclear heated steam rocket would use the propellant water to launch and deliver 3,800 tons of water per year to a 100 km low lunar orbit.

  11. A New Source of Micrometeorites: The South Pole Water Well

    NASA Astrophysics Data System (ADS)

    Taylor, S.; Lever, J.; Harvey, R.

    1996-03-01

    In 1995 we built, tested and deployed a collector to suction particulates from the bottom of the South Pole drinking water well (SPWW) in the hope of finding large numbers of micrometeorites. The SPWW, because it melts huge amounts of firn and ice, provides an efficient way of concentrating micrometeorites, which occur ubiquitously but in low concentrations in terrestrial environments. We made 5 separate collections, traversing an area of about 30 m^2 and collecting approximately 200 g of material. Microscopic examination of the 250-425 micrometer size fraction from 2 of the 5 collections suggests that 1 of every 1000 particles in this size fraction is a melted micrometeorite. There are also translucent and transparent spherules, similar to those described by Maurette et al., which are thought to be extraterrestrial and particles which appear to be unmelted micrometeorites. Dating of the ice brackets the depositional age of any micrometeorites collected between 1000-1500 AD.

  12. Lack of exposed ice inside lunar south pole Shackleton Crater.

    PubMed

    Haruyama, Junichi; Ohtake, Makiko; Matsunaga, Tsuneo; Morota, Tomokatsu; Honda, Chikatoshi; Yokota, Yasuhiro; Pieters, Carle M; Hara, Seiichi; Hioki, Kazuyuki; Saiki, Kazuto; Miyamoto, Hideaki; Iwasaki, Akira; Abe, Masanao; Ogawa, Yoshiko; Takeda, Hiroshi; Shirao, Motomaro; Yamaji, Atsushi; Josset, Jean-Luc

    2008-11-07

    The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all.

  13. Persistent parainfluenza virus shedding during isolation at the South Pole.

    PubMed

    Muchmore, H G; Parkinson, A J; Humphries, J E; Scott, E N; McIntosh, D A; Scott, L V; Cooney, M K; Miles, J A

    1981-01-15

    Persistent parainfluenza virus shedding in healthy young adults occurred throughout the 8 1/2-month winter isolation period at Amundsen-Scott South Pole Station during 1978. Two episodes of respiratory illness were observed after 10 and 29 weeks of complete social isolation. Throat swabs collected both routinely, and during each outbreak of respiratory illness, were directly inoculated into cell cultures. Parainfluenza virus types 1 and 3 were recovered from both symptomatic and asymptomatic subjects throughout the winter. No other viruses were obtained by these efforts. The presence of parainfluenza virus in these subjects long after the accepted incubation period for viral upper respiratory illness, and when the introduction of new virus to this community was impossible, suggests its persistence in man.

  14. Coordinated ground and space measurements of auroral surge over South Pole. Technical report

    SciTech Connect

    Rosenberg, T.J.; Detrick, D.L.; Mizera, P.F.; Gorney, D.J.; Berkey, F.T.

    1988-02-01

    Coincident ground-based and satellite observations are presented of a premidnight auroral surge over Amundsen-Scott South Pole station. The set of near-simultaneous measurements provides an excellent opportunity to gain a more-quantitative understanding of the nature of premidnight substorm activity at high geomagnetic latitudes. The surge produced a rapid onset of cosmic radio noise absorption at the station. On the polar-orbiting DMSP-F6 spacecraft, intense x-ray emissions with E > 2-keV energy were imaged 1 to 2 deg magnetically equatorward of the South Pole approximately 1 min prior to the peak of the absorption event. The precipitating electron spectrum determined from the x-ray measurements could be characterized by an e-folding energy of approx. 11 keV and is found to be adequate to account for the cosmic noise absorption and maximum auroral luminosity recorded at South Pole. Photometer, all-sky camera, riometer, and magnetometer data are used to estimate the velocity of motion and spatial extent of the auroral precipitation and the ionospheric currents associated with the surge.

  15. Coordinated ground and space measurements of an auroral surge over South Pole

    SciTech Connect

    Rosenberg, T.J.; Detrick, D.L.; Mizera, P.F.; Gorney, D.J.; Berkey, F.T.; Eather, R.H.; Lanzerotti, L.J.

    1987-10-01

    Coincident ground-based and satellite observations are presented of a premidnight auroral surge over Amundsen-Scott South Pole station. The set of near-simultaneous measurements provides an excellent opportunity to gain a more quantitative understanding of the nature of premidnight substorm activity at high geomagnetic latitudes. The surge produced a rapid onset of cosmic radio noise absorption at the station. On the polar-orbiting DMSP F6 spacecraft, intense X ray emissions with E>2 keV energy were imaged 1/sup 0/ to 2/sup 0/ magnetically equatorward of South Pole approximately 1 min prior to the peak of the absorption event. The spectrum of precipitating electrons determined from the X ray measurements could be characterized by an e-folding energy of approx.11 keV and is found to be adequate to account for the cosmic noise absorption and maximum auroral luminosity recorded at South Pole. Photometer, all-sky camera, riometer, and magnetometer data are used to estimate the velocity of motion and spatial extent of the auroral precipitation and the ionospheric currents associated with the surge. The electron precipitation region is deduced to have a latitudinal scale size of <100 km and to move poleward with a speed of approx.1--2 km/s coincident with the movement of a westward electrojet.

  16. Radio-frequency probes of Antarctic ice at South Pole

    NASA Astrophysics Data System (ADS)

    Besson, D.; Kravchenko, I.

    2013-05-01

    Using hardware developed for the ARA (Askaryan Radio Array) particle astrophysics experiment, we herein report on the amplitude and temporal characteristics of polarized surface radar echo data collected in South Polar ice using radio sounding equipment with 0.5-ns echo-time sampling. We observe strong echoes at 6, 9.6, 13.9, 17, and 19 μs following vertical pulse emission from the surface, corresponding to reflectors in the upper half of the ice sheet. The synchronicity of those echoes for all broadcast azimuthal polarizations affirms the lack of observable birefringence over the upper half of the ice sheet. Of the five strongest echoes, three exhibit an evident amplitude correlation with the local surface ice flow direction, qualitatively consistent with measurements in East Antarctica. Combined with other radio echo sounding data, we conclude that observed birefringent asymmetries at South Pole are generated entirely in the lower half of the ice sheet. By contrast, birefringent asymmetries are observed at shallow depths in East Antarctica.

  17. A Century of Science at the South Pole: From Struggling to Survive to Exploring New and Unseen Frontiers

    NASA Astrophysics Data System (ADS)

    Hynes, Shelly; Bacque, L.; Landsberg, R.

    2012-01-01

    In December of 1911, Norwegian Roald Amundsen and his team became the first to reach the geographic South Pole. Briton Robert F. Scott also reached the South Pole a month later on the 17th of January, 1912. Their successful treks to the South Pole were part of an international rivalry equivalent in its time to the "Space Race” of the 1960's. 100 years later, the National Science Foundation's Amundsen-Scott South Pole Station is home to two massive cutting-edge instruments that are yielding new insights into the Universe at both the smallest and largest scales. The 280-ton, 10-meter South Pole Telescope is probing anisotropies in the cosmic microwave background to understand the nature of Dark Energy and the infant Universe. The IceCube Neutrino Observatory, a cubic kilometer of instrumented ice, searches for evidence of high energy neutrinos that may originate in violent astrophysical events such as supernovae, gamma ray bursts, and active galactic nuclei, as well as help us understand dark matter. The session will highlight education and outreach initiatives associated with both projects.

  18. Effect of complex rheology on the dynamics of Enceladus' south pole

    NASA Astrophysics Data System (ADS)

    Behounkova, M.; Cadek, O.; Tobie, G.; Choblet, G.

    2012-12-01

    The intense activity at the south pole of Enceladus hints at an internal water reservoir. However, there is no direct evidence of liquid water at present and its long-term stability in the interior remains problematic. By modeling heat production and transfer in the ice shell in a spherical geometry, in a previous study (Behounkova et al. Icarus, 2012), we have shown that tidal heating naturally leads to a concentration of convective hot upwellings in the south polar region, favoring the preservation of liquid water at depth. We show that large volumes of water are produced within the ice shell at the south pole during periods of elevated orbital eccentricity (3-5 times the present-day value). Strong lateral variations in the melt production and crystallization rates result in stress concentration in the south polar region, thus providing an explanation for the tectonic activity observed today. We predict that an internal ocean may be sustained over the long term as the consequence of repeated periods with elevated orbital eccentricity, leading to episodic melting and resurfacing events. In order to model the resurfacing events following tidally-induced melting episodes, we are currently incorporating plasticity effects. We also improve the modeling of tidal deformation by incorporating the Andrade model, which is expected to better reproduce the viscoelastic properties of water ice (Castillo-Rogez et al. 2011). New 3D simulations will be presented and discussed.

  19. Evolution of the Far-Infrared Cloud at Titan's South Pole

    NASA Technical Reports Server (NTRS)

    Jennings, Donald E.; Achterberg, R. K.; Cottini, V.; Anderson, C. M.; Flasar, F. M.; Nixon, C. A.; Bjoraker, G. L.; Kunde, V. G.; Carlson, R. C.; Guandique, E.; Kaelberer, M. S.; Tingley, J. S.; Albright, S. A.; Segura, M. E.; de Kok, R.; Coustenis, A.; Vinatier, S.; Bampasidis, G.; Teanby, N. A.; Calcutt, S.

    2015-01-01

    A condensate cloud on Titan identified by its 220 cm (sup -1) far-infrared signature continues to undergo seasonal changes at both the north and south poles. In the north the cloud, which extends from 55 North to the pole, has been gradually decreasing in emission intensity since the beginning of the Cassini mission with a half-life of 3.8 years. The cloud in the south did not appear until 2012 but its intensity has increased rapidly, doubling every year. The shape of the cloud at the South Pole is very different from that in the north. Mapping in December 2013 showed that the condensate emission was confined to a ring with a maximum at 80 South. The ring was centered 4 degrees from Titan's pole. The pattern of emission from stratospheric trace gases like nitriles and complex hydrocarbons (mapped in January 2014) was also offset by 4 degrees, but had a central peak at the pole and a secondary maximum in a ring at about 70 South with a minimum at 80 South. The shape of the gas emissions distribution can be explained by abundances that are high at the atmospheric pole and diminish toward the equator, combined with correspondingly increasing temperatures. We discuss possible causes for the condensate ring. The present rapid build up of the condensate cloud at the South Pole is likely to transition to a gradual decline during 2015-16.

  20. Mesospheric Winds and Magnetic Fields from the South Pole

    NASA Astrophysics Data System (ADS)

    Martin, C. L.; Burrows, S. M.; Brown, M. J.; Roberts, E. A.

    2007-12-01

    We show how carbon monoxide (CO) can be used as a tracer of mesospheric neutral wind speeds, by measuring small Doppler shifts in its rotational emission spectrum. Since the altitude range we are most sensitive to is generally inaccessible to many other measurement techniques, this fills a significant experimental gap. Using this method, high-resolution ground-based measurements of mesospheric CO taken from the AST/RO sub-millimeter telescope, located at Amundsen-Scott South Pole Station have been used to calculate wind speeds and column densities over the Antarctic from 2002 to 2005. For more information see Burrows et al. JGR-Atmospheres doi:10.1029/2006JD007993. In addition, the 2→ 1 rotational transition of O18O has been measured and used as a tracer of the mesospheric magnetic field over the Antarctic. We demonstrate how the Zeeman splitting of this molecule was used to measure the Earth's magnetic field during the geomagnetic storm of January 2003.

  1. Accretion rate of cosmic spherules measured at the South Pole

    NASA Astrophysics Data System (ADS)

    Taylor, Susan; Lever, James H.; Harvey, Ralph P.

    1998-04-01

    Micrometeorites are terrestrially collected, extraterrestrial particles smaller than about 1mm, which account for most of the mass being accreted to the Earth,. Compared with meteorites, micrometeorites more completely represent the Earth-crossing meteoroid complex, and should include fragments of asteroids, comets, Mars and our Moon, as well as pre-solar and interstellar grains,. Previous measurements of the flux of micrometeoroids that survive to the Earth's surface have large uncertainties owing to the destruction of particles by weathering, inefficiencies in magnetic collection or separation techniques, low particle counts,, poor age constraint,, or highly variable concentrating processes,. Here we describe an attempt to circumvent these problems through the collection of thousands of well preserved and dated micrometeorites from the bottom of the South Pole water well, which supplies drinking water for the Scott-Amundsen station. Using this collection, we have determined precise estimates of the flux and mass distribution for 50-700-µm cosmic spherules (melted micrometeorites). Allowing for the expected abundance of unmelted micrometeorites in the samples, our results indicate that about 90% of the incoming mass of submillimetre particles evaporates during atmospheric entry. Our data indicate the loss of glass-rich and small stony spherules from deep-sea deposits,, and they provide constraints for models describing the survival probability of micrometeoroids,.

  2. Regionalized Lunar South Pole Surface Navigation System Analysis

    NASA Technical Reports Server (NTRS)

    Welch, Bryan W.

    2008-01-01

    Apollo missions utilized Earth-based assets for navigation because the landings took place at lunar locations in constant view from the Earth. The new exploration campaign to the lunar south pole region will have limited Earth visibility, but the extent to which a navigation system comprised solely of Earth-based tracking stations will provide adequate navigation solutions in this region is unknown. This report presents a dilution-of-precision (DoP)-based, stationary surface navigation analysis of the performance of multiple lunar satellite constellations, Earth-based deep space network assets, and combinations thereof. Results show that kinematic and integrated solutions cannot be provided by the Earth-based deep space network stations. Also, the stationary surface navigation system needs to be operated either as a two-way navigation system or as a one-way navigation system with local terrain information, while the position solution is integrated over a short duration of time with navigation signals being provided by a lunar satellite constellation.

  3. Numerical Modeling of the South Pole-Aitkin Impact

    NASA Technical Reports Server (NTRS)

    Collins, G. S.; Melosh, H. J.

    2004-01-01

    The South Pole-Aitkin (SPA) basin, on the far side of the Moon, is the largest and oldest impact structure still preserved in the solar system. The crater is about 2500 km in diameter and formed in the Pre-Nectarian era of lunar history, over 4 Gyr ago. At this time, the thermal state of the Moon was much hotter than it is today. Accretional energy from the rapidly forming Moon melted the outermost few hundred kilometers of the Moon. As this magma ocean differentiated and cooled a 60 100-km thick low-density crust formed at the surface; below this the residual melt, with a higher density, cooled to form the lunar mantle. The giant SPA impact event punctured the Moon some time during the cooling of the magma ocean and thus provides a unique window for studying the lunar interior and the early formative processes of the Moon. The impact excavated otherwise inaccessible samples of the deep crust and (possibly) upper mantle, which has inspired proposed sample return missions. Furthermore, the thermal and rheologic state of the early Moon played a role in shaping the final structure of the basin. To aid in site selection for future sample return missions to the SPA basin, and to investigate the effect of thermal state on final crater structure, we performed some numerical simulations of the SPA impact event.

  4. Total ozone, ozone vertical distributions, and stratospheric temperatures at South Pole, Antarctica, in 1986 and 1987

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Grass, R. D.; Reitelbach, P. J.; Franchois, P. R.; Kuester, S. E.

    1988-01-01

    Seventy-six electrochemical cell (ECC) ozonesondes were flown at South Pole, Antarctica, during 1987 in a continuing program to document year-round changes in Antarctica ozone that are dynamically and photochemically induced. Dobson spectrophotometer total ozone observations were also made. For the twilight months of March and September when Dobson instrument observations cannot be made at South Pole, total ozone amounts were deduced from the ECC ozonesonde soundings. ECC sonde total ozone data obtained during the polar night (April to August), supplemented the sparse total ozone data obtained from Dobson instrument moon observations. Similar ozone profile and total ozone observations were made at South Pole in 1986.

  5. Orographic Condensation at the South Pole of Titan

    NASA Astrophysics Data System (ADS)

    Corlies, Paul; Hayes, Alexander; Adamkovics, Mate

    2016-10-01

    Although many clouds have been observed on Titan over the past two decades (Griffith et al. 1998, Rodriquez et al 2009, Brown et al. 2010), only a handful of clouds have been analyzed in detail (Griffith et al 2005, Brown et al 2009, Adamkovics et al 2010). In light of new data and better radiative transfer (RT) modelling, we present here a reexamination of one of these cloud systems observed in March 2007, formerly identified as ground fog (Brown et al 2009), using the Cassini VIMS instrument. Combining our analysis with RADAR observations we attempt to understand the connection and correlation between this low altitude atmospheric phenomenon and the local topography, suggesting instead, a topographically driven (orographic) cloud formation mechanism. This analysis would present the first links between cloud formation and topography on Titan, and has valuable implications in understanding additional cloud formation mechanisms, allowing for a better understanding of Titan's atmospheric dynamics.We will also present an update on an ongoing ground based observation campaign looking for clouds on Titan. This campaign, begun back in April 2014, has been (nearly) continuously monitoring Titan for ongoing cloud activity. Although a variety of telescope and instruments have been used in an effort to best capture the onset of cloud activity expected at Titan's North Pole, no cloud outbursts have yet been observed from the ground (though frequent observations have been made with Cassini ISS/VIMS). This is interesting because it further suggests a developing dichotomy between Titan's seasons, since clouds were observable from the ground during southern summer. Thus, monitoring the onset of large scale cloud activity at Titan's North Pole will be crucial to understanding Titan's hydrologic cycle on seasonal timescales.

  6. Ulysses(*) reaches the South Pole of the Sun

    NASA Astrophysics Data System (ADS)

    1994-08-01

    One of the many investigations being carried out is a search for the Sun's south magnetic pole. As in the case of the Earth, the magnetic pole is offset from the rotation axis, and at some time in September it should sweep directly into line with Ulysses. Just as the polar regions of the Earth were the last to be explored, so it is with the Sun. For more than thirty years spacecraft have investigated the stream of electric particles know as the solar wind. Ulysses, developed by ESA, built by European Industry and flown in collaboration with NASA, is the first to fly through the solar wind coming from the poles. As Ulysses reaches its highest solar latitude of 80.2 degrees on 13 September, European and American researchers will gather at the ESA/ESTEC, the European Space Research and Technology Centre in Noordwijk, the Netherlands, for a scientific workshop at which they will assess the results from the nine experiments carried by the spacecraft. For the week of the workshop, the ESA/ESTEC conference centre will be transformed into a busy scientific laboratory. The large meeting rooms will be divided into 24 working areas, where the Ulysses experiment teams will take up temporary residence. Bringing a variety of computing equipment with them, the scientists will be able to retrieve the latest data from the spacecraft and perform detailed analyses. The emphasis will be on informality, with exchange of scientific ideas - and data - the key ingredient, leading ultimately to a better understanding of the fascinating information being gathered by Ulysses on its unique exploratory journey. Presentations to the media at ESA/ESTEC will start at 10h00 on 16 September. Media representatives wishing to attend are kindly requested to fill out the attached form and return it - preferably by fax (+33.1.42.73.76.90) - to : ESA Public Relations Division, 8/10, rue Mario Nikis - 75015-PARIS. Note to Television Editors : A video index, containing extensive background material on the

  7. J SERIES MAGAZINE. J 107 SOUTH ELEVATION W/POLE. Naval ...

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

    J SERIES MAGAZINE. J 107 SOUTH ELEVATION W/POLE. - Naval Magazine Lualualei, Headquarters Branch, Inert Storehouse Type, Twelfth Street between Kwajulein & New Mexico Streets, Pearl City, Honolulu County, HI

  8. Interpreting Radar View near Mars' South Pole, Orbit 1334

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A radargram from the Shallow Subsurface Radar instrument (SHARAD) on NASA's Mars Reconnaissance Orbiter is shown in the upper-right panel and reveals detailed structure in the polar layered deposits of the south pole of Mars.

    The sounding radar collected the data presented here during orbit 1334 of the mission, on Nov. 8, 2006.

    The horizontal scale in the radargram is distance along the ground track. It can be referenced to the ground track map shown in the lower right. The radar traversed from about 75 to 85 degrees south latitude, or about 590 kilometers (370 miles). The ground track map shows elevation measured by the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor orbiter. Green indicates low elevation; reddish-white indicates higher elevation. The traverse proceeds up onto a plateau formed by the layers.

    The vertical scale on the radargram is time delay of the radar signals reflected back to Mars Reconnaissance Orbiter from the surface and subsurface. For reference, using an assumed velocity of the radar waves in the subsurface, time is converted to depth below the surface at one place: about 1,500 meters (5,000 feet) to one of the deeper subsurface reflectors. The color scale varies from black for weak reflections to white for strong reflections.

    The middle panel shows mapping of the major subsurface reflectors, some of which can be traced for a distance of 100 kilometers (60 miles) or more. The layers are not all horizontal and the reflectors are not always parallel to one another. Some of this is due to variations in surface elevation, which produce differing velocity path lengths for different reflector depths. However, some of this behavior is due to spatial variations in the deposition and removal of material in the layered deposits, a result of the recent climate history of Mars.

    The Shallow Subsurface Radar was provided by the Italian Space Agency (ASI). Its operations are led by the University of Rome and its

  9. Interpreting Radar View near Mars' South Pole, Orbit 1360

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A radargram from the Shallow Subsurface Radar instrument (SHARAD) on NASA's Mars Reconnaissance Orbiter is shown in the upper-right panel and reveals detailed structure in the polar layered deposits of the south pole of Mars.

    The sounding radar collected the data presented here during orbit 1360 of the mission, on Nov. 10, 2006.

    The horizontal scale in the radargram is distance along the ground track. It can be referenced to the ground track map shown in the lower right. The radar traversed from about 74 degrees to 85 degrees south latitude, or about 650 kilometers (400 miles). The ground track map shows elevation measured by the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor orbiter. Green indicates low elevation; reddish-white indicates higher elevation. The traverse proceeds up onto a plateau formed by the layers.

    The vertical scale on the radargram is time delay of the radar signals reflected back to Mars Reconnaissance Orbiter from the surface and subsurface. For reference, using an assumed velocity of the radar waves in the subsurface, time is converted to depth below the surface at one place: about 800 meters (2,600 feet) to one of the strongest subsurface reflectors. This reflector marks the base of the polar layered deposits. The color scale varies from black for weak reflections to white for strong reflections.

    The middle panel shows mapping of the major subsurface reflectors, some of which can be traced for a distance of 100 kilometers (60 miles) or more. The layering manifests the recent climate history of Mars, recorded by the deposition and removal of ice and dust.

    The Shallow Subsurface Radar was provided by the Italian Space Agency (ASI). Its operations are led by the University of Rome and its data are analyzed by a joint U.S.-Italian science team. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science

  10. South Pole ice stream temporal and spatial evolution in the last glacial cycle

    NASA Astrophysics Data System (ADS)

    Blankenship, D. D.; Cavitte, M. G.; Young, D. A.; Carter, S. P.; Gutowski, G.; Bingham, R. G.; Siegert, M. J.

    2012-12-01

    While considered to be the most stable part of the Antarctic continent, recent studies show East Antarctic ice sheet has a high potential for rapid change and significant sea level contribution. Airborne radar sounding has shown that major ice stream tributaries have disrupted ice at the South Pole, portraying a complex evolution for the East Antarctic ice sheet. We confirm the temporal and spatial extent of these flow regime changes through the analysis of dated internal layers observed using airborne sounding data. Layering is time-registered to the local dust record from ICE CUBE boreholes and the SPRESSO core, which constrains ice stream transient penetration between 50 ka and about 10 ka, corresponding to the last glacial maximum. The ice stream margin position has migrated through time, initially at 10 km grid north of the South Pole, and migrated to the grid south by 40km before shutting off. The active portion of the ice sheet has undergone significant melting, bringing ice from the MIS 5e interglacial very close to the bedrock with respect to the inactive portion to the grid north. Shear heating from the ice stream margin migration is consistent with subglacial lakes previously observed in the area (Peters et al, 2008). This ice stream is further evidence for a substantial, rapid sea level contribution from the deep interior of the East Antarctic Ice Sheet.

  11. EVOLUTION OF THE FAR-INFRARED CLOUD AT TITAN’S SOUTH POLE

    SciTech Connect

    Jennings, Donald E.; Achterberg, R. K.; Cottini, V.; Anderson, C. M.; Flasar, F. M.; Nixon, C. A.; Bjoraker, G. L.; Kunde, V. G.; Carlson, R. C.; Guandique, E.; Kaelberer, M. S.; Tingley, J. S.; Albright, S. A.; Segura, M. E.; Kok, R. de; Coustenis, A.; Vinatier, S.; Bampasidis, G.; Teanby, N. A.; Calcutt, S.

    2015-05-10

    A condensate cloud on Titan identified by its 220 cm{sup −1} far-infrared signature continues to undergo seasonal changes at both the north and south poles. In the north, the cloud, which extends from 55 N to the pole, has been gradually decreasing in emission intensity since the beginning of the Cassini mission with a half-life of 3.8 years. The cloud in the south did not appear until 2012 but its intensity has increased rapidly, doubling every year. The shape of the cloud at the south pole is very different from that in the north. Mapping in 2013 December showed that the condensate emission was confined to a ring with a maximum at 80 S. The ring was centered 4° from Titan's pole. The pattern of emission from stratospheric trace gases like nitriles and complex hydrocarbons (mapped in 2014 January) was also offset by 4°, but had a central peak at the pole and a secondary maximum in a ring at about 70 S with a minimum at 80 S. The shape of the gas emission distribution can be explained by abundances that are high at the atmospheric pole and diminish toward the equator, combined with correspondingly increasing temperatures. We discuss possible causes for the condensate ring. The present rapid build up of the condensate cloud at the south pole is likely to transition to a gradual decline from 2015 to 2016.

  12. Observations of a 12 H wave in the mesopause region at the South Pole

    SciTech Connect

    Collins, R.L.; Senft, D.C.; Gardner, C.S. )

    1992-01-03

    In December 1989 a Na lidar was installed at the Amundsen-Scott South Pole Station and was used to measure aerosol, stratospheric temperature and mesospheric Na profiles through October 1990. The mesospheric Na data are used to characterize the gravity wave field in the mesopause region, These first lidar observations of Na layer dynamics at the South Pole show strong wave activity during the Antarctic winter. Data for 25 June and 19 August 1990 UT are presented here. The total wave induced variances in atmospheric density are respectively 29 and 35(%){sup 2}. The Na layer centroid height is very low during both observation periods. On 25 June a strong 12 h oscillation is observed in the bottomside of the Na layer which extends to altitudes as low as 74 km. The vertical displacement and temperature amplitudes associated with the 12 h oscillation are respectively 1.9 km and 19 K. The characteristics of the 12 h wave are similar to the pseudotide observed at Svalbard by Walterscheid et al.

  13. Dawn-sector energetic electron precipitation above the south geographic pole

    SciTech Connect

    Theall, J.R.; Benbrook, J.R.; Bering, E.A. III ); Matthews, D.L.; Rosenberg, T.J. )

    1988-01-01

    During the 1985-1986 austral summer, the University of Houston and the University of Maryland conducted the first balloon campaign from South Pole Station which measured the ionospheric electric field and bremsstrahlung X-rays. Presented here are some of the X-ray data from dawn-sector time period of 0700 to 1000 universal time on 19 December 1985 (local magnetic noon is 1530 universal time). The measurements were made during a geomagnetically active period. Syowa Station magnetograms provided by Yamagishi et al. (1987) show a sudden commencement of a large magnetic storm occurring at approximately 0120 universal time, followed by a series of several substorms. The strongest of these substorms was observed to begin at Syowa at {approximately}0740 universal time and reached maximum intensity just after 0800 universal time. Four additional substorm expansions were seen at South Pole Station during the next 2 hours that were not seen at Syowa. The Berger and Seltzer model was applied to these events. An interesting feature of the three events is the dispersion in electron energy, with more energetic electrons arriving first, followed by greater numbers of lower energy particles.

  14. Abundances and variability of tropospheric volatile organic compounds at the South Pole and other Antarctic locations

    NASA Astrophysics Data System (ADS)

    Beyersdorf, Andreas J.; Blake, Donald R.; Swanson, Aaron; Meinardi, Simone; Rowland, F. S.; Davis, Douglas

    2010-11-01

    Multiyear (2000-2006) seasonal measurements of carbon monoxide, hydrocarbons, halogenated species, dimethyl sulfide, carbonyl sulfide and C 1-C 4 alkyl nitrates at the South Pole are presented for the first time. At the South Pole, short-lived species (such as the alkenes) typically were not observed above their limits of detection because of long transit times from source regions. Peak mixing ratios of the longer lived species with anthropogenic sources were measured in late winter (August and September) with decreasing mixing ratios throughout the spring. In comparison, compounds with a strong oceanic source, such as bromoform and methyl iodide, had peak mixing ratios earlier in the winter (June and July) because of decreased oceanic production during the winter months. Dimethyl sulfide (DMS), which is also oceanically emitted but has a short lifetime, was rarely measured above 5 pptv. This is in contrast to high DMS mixing ratios at coastal locations and shows the importance of photochemical removal during transport to the pole. Alkyl nitrate mixing ratios peaked during April and then decreased throughout the winter. The dominant source of the alkyl nitrates in the region is believed to be oceanic emissions rather than photochemical production due to low alkane levels. Sampling of other tropospheric environments via a Twin Otter aircraft included the west coast of the Ross Sea and large stretches of the Antarctic Plateau. In the coastal atmosphere, a vertical gradient was found with the highest mixing ratios of marine emitted compounds at low altitudes. Conversely, for anthropogenically produced species the highest mixing ratios were measured at the highest altitudes, suggesting long-range transport to the continent. Flights flown through the plume of Mount Erebus, an active volcano, revealed that both carbon monoxide and carbonyl sulfide are emitted with an OCS/CO molar ratio of 3.3 × 10 -3 consistent with direct observations by other investigators within the

  15. Sample Return Mission to the South Pole Aitken Basin

    NASA Astrophysics Data System (ADS)

    Duke, M. B.; Clark, B. C.; Gamber, T.; Lucey, P. G.; Ryder, G.; Taylor, G. J.

    1999-01-01

    The South Pole Aitken Basin (SPA) is the largest and oldest observed feature on the Moon. Compositional and topographic data from Galileo, Clementine, and Lunar Prospector have demonstrated that SPA represents a distinctive major lunar terrane, which has not been sampled either by sample return missions (Apollo, Luna) or by lunar meteorites. The floor of SPA is characterized by mafic compositions enriched in Fe, Ti, and Th in comparison to its surroundings. This composition may represent melt rocks from the SPA event, which would be mixtures of the preexisting crust and mantle rocks. However, the Fe content is higher than expected, and the large Apollo basin, within SPA, exposes deeper material with lower iron content. Some of the Fe enrichment may represent mare and cryptomare deposits. No model adequately accounts for all of the characteristics of the SPA and disagreements are fundamental. Is mantle material exposed or contained as fragments in melt rock and breccias? If impact melt is present, did the vast sheet differentiate? Was the initial mantle and crust compositionally different from other regions of the Moon? Was the impact event somehow peculiar, (e.g., a low-velocity impact)? The precise time of formation of the SPA is unknown, being limited only by the initial differentiation of the Moon and the age of the Imbrium event, believed to be 3.9 b.y. The questions raised by the SPA can be addressed only with detailed sample analysis. Analysis of the melt rocks, fragments in breccias, and basalts of SPA can address several highly significant problems for the Moon and the history of the solar system. The time of formation of SPA, based on analysis of melt rocks formed in the event. would put limits on the period of intense bombardment of the Moon, which has been inferred by some to include a "terminal cataclysm." If close to 3.9 Ga, the presumed age of the Imbrium Basin, the SPA date would confirm the lunar cataclysm. This episode, if it occurred, would have

  16. Comparison of the Jovian north and south pole aurorae using the IUE observatory

    NASA Technical Reports Server (NTRS)

    Skinner, T. E.; Moos, H. W.

    1984-01-01

    New results on the spatial and temporal variability of the auroral emissions from Jupiter have been obtained from three IUE observations of the south pole made during the period July 1983 to March 1984. The current observations, together with previous IUE studies of the north pole aurora, provide convincing evidence for persistent longitudinal asymmetries in the Jovian auroral emissions. The strongest emissions appear to originate from regions centered near lambda-III of about 0 deg at the south pole and lambda-III of about 185 deg at the north pole. Differences in surface magnetic field strength seem inadequate to explain the extent to which particles precipitating along field lines into a given longitude sector in one hemisphere are inhibited from precipitating along the same field lines into the opposite hemisphere. Thus, the IUE auroral results present a challenge to existing models of auroral production.

  17. The 1500m South Pole Ice Core: Recovering a 40 Ka Environmental Record

    NASA Technical Reports Server (NTRS)

    Casey, Kimberly Ann; Neumann, Thomas Allen; Fudge, T. J.; Neumann, T. A.; Steig, E. J.; Cavitte, M. G. P.; Blankenship, D. D.

    2014-01-01

    Supported by the US National Science Foundation, a new 1500 m, approximately 40 ka old ice core will be recovered from South Pole during the 2014/15 and 2015/16 austral summer seasons using the new US Intermediate Depth Drill. The combination of low temperatures, relatively high accumulation rates and low impurity concentrations at South Pole will yield detailed records of ice chemistry and trace atmospheric gases. The South Pole ice core will provide a climate history record of a unique area of the East Antarctic plateau that is partly influenced by weather systems that cross the West Antarctic ice sheet. The ice at South Pole flows at approximately 10m a(exp-1) and the South Pole ice-core site is a significant distance from an ice divide. Therefore, ice recovered at depth originated progressively farther upstream of the coring site. New ground-penetrating radar collected over the drill site location shows no anthropogenic influence over the past approximately 50 years or upper 15 m. Depth-age scale modeling results show consistent and plausible annual-layer thicknesses and accumulation rate histories, indicating that no significant stratigraphic disturbances exist in the upper 1500m near the ice-core drill site.

  18. Large scale dynamical structure measured over the South Pole, 2001-2003

    NASA Astrophysics Data System (ADS)

    Palo, S. E.; Iimura, H.; South Pole Team

    In January 2001 the University of Colorado in conjunction with the Institute for Experimental Meteorology in Obninsk Russia installed a new 46.3MHz all-sky meteor radar system at the Amundsen-Scott South Pole Station. This system utilizes a single transmitter and receiver with multiple data acquisitions systems. These data acquisition systems are adapted from the Colorado Obninsk Radar system (COBRA) and the Meteor Echo Detection and Collection system (MEDAC). Because of its unique location at the rotational pole of the Earth this system has the ability to measure the meridional winds at four distinct longitudes around the pole. Utilizing these measurements the spatial structure including zonal wavenumber and direction of propagation can be determined for disturbances in the vicinity of the pole. Results for the large-scale dynamical features observed over the pole including the migrating diurnal and nonmigrating semidiurnal tides will be presented. With observations spanning multiple years it is now possible to investigate the interannual variability of these features over the pole. These results will be compared with previous meteor radar measurements made at the South Pole in 1996 and 1997.

  19. Seasonal Variations of Atmospheric Electricity Measured at Amundsen-Scott South Pole Station

    NASA Astrophysics Data System (ADS)

    Reddell, B. D.; Benbrook, J. R.; Bering, E. A.; Cleary, E. N.; Few, A. A.

    2004-12-01

    This paper investigates seasonal variations of the vertical electric field and current density as measured at the South Pole between 1991 and 1993. After initial data reduction, a model approach was used to decouple the magnetospheric and atmospheric components of the measurements. This approach calculated and subtracted the polar-cap ionospheric potential from the measured data to obtain a signal of global tropospheric origin, in principle. The diurnal variations of the resulting data were averaged as a function of UT. These averages were calculated for the data as a whole and for the date sorted and binned by season and by magnetic activity level. The seasonally-binned average results are consistent with recent papers indicating that the electric field measurement show global convective-electrical activity to be a minimum during the northern hemisphere winter, in contradiction to the original 1929 Carnegie data. Because the electric field was a maximum during the northern hemisphere summer season, the mid-latitude regions must contribute more strongly than the tropics to global atmospheric electricity. This analysis supports the link of electrical activity to global temperature. The magnetic activity binned results suggest that the polar cap potential model used under estimates the cross polar cap potential when there is a high Kp index. This result can be explained if the model did not have equal weighting across the Kp range or if the limitation on the spherical harmonic coefficients did not give the potential at the South Pole. A complete high-latitude model is needed in order to estimate saturation of the cross-cap potential, as some theories predict.

  20. The first ozone observations with the Brewer spectrophotometer at the South Pole

    NASA Astrophysics Data System (ADS)

    Savastiouk, V.; McElroy, C. T.; Evans, R. D.

    2009-05-01

    In February of 2008, Environment Canada in cooperation with National Oceanic and Atmospheric Administration installed the Brewer ozone spectrophotometer, serial number #085, at the Amundsen-Scott South Pole Station, Antarctica. The Brewer spectrophotometer (the Brewer) is a fully automated instrument, which allows continuous 24-hour a day direct-sun observations at the South Pole from September to March and periodic moon observations for the remainder of the year. Brewer #085 has been independently calibrated before its deployment at the South Pole and the internal tests from the instrument show that the instrument has been stable for the past year. Brewer #085 has now collected more than a year worth of data. Both the direct-sun and moon observations have been processed and analyzed. The results of this analysis are presented and discussed.

  1. Localized bending and heating at Enceladus' south pole

    NASA Astrophysics Data System (ADS)

    Beuthe, M.

    2015-10-01

    Since the discovery in 2005 of geysers at the southpole of Enceladus, this midsize moon of Saturn has become famous as the most active icy world in the solar system and as a potential harbor for microbial life. All data gathered during flybys by the Cassini probe point to the existence of a subsurface ocean maintained by tidal heating in the icy crust. This explanation, however, is in conflict with geophysical models which only account for a tenth of the heat output. Such models are based on an approach designed for larger satellites, for which elastic effects are weaker and lateral inhomogeneities are less prominent. By contrast, lateral variations of interior structure are probably the key to understand Enceladus' geological activity. We will test the hypothesis that tidal dissipation is greatly enhanced by local bending of a thinner crust in the south polar region. More generally, we plan to develop a new and faster method to compute tidal dis-sipation in small bodies with lateral heterogeneities,consisting in modeling the crust as a two-dimensional spherical shell with variable thickness or rigidity and with depth-dependent rheology.

  2. Submillimeter Atmospheric Transparency at Maunakea, at the South Pole, and at Chajnantor

    NASA Astrophysics Data System (ADS)

    Radford, Simon J. E.; Peterson, Jeffery B.

    2016-07-01

    For a systematic assessment of submillimeter observing conditions at different sites, we constructed tipping radiometers to measure the broad band atmospheric transparency in the window around 350 μm wavelength. The tippers were deployed on Maunakea, Hawaii, at the South Pole, and in the vicinity of Cerro Chajnantor in northern Chile. Identical instruments permit direct comparison of these sites. Observing conditions at the South Pole and in the Chajnantor area are better than on Maunakea. Simultaneous measurements with two tippers demonstrate conditions at the summit of Cerro Chajnantor are significantly better than on the Chajnantor plateau.

  3. Evolution of the Far-Infrared Cloud at Titan's South Pole

    NASA Technical Reports Server (NTRS)

    Jennings, Donald E.; Achterberg, R. K.; Cottini, V.; Anderson, C. M.; Flasar, F. M.; Nixon, C. A.; Bjoraker, G. L.; Kunde, V. G.; Carlson, R. C.; Guandique, E.; Kaelberer, M. S.; Tingley, J. S.; Albright, S. A.; Segura, M. E.; de Kok, R.; Coustenis, A.; Vinatier, S.; Bampasidis, G.; Teanby, N. A.; Calcutt, S.

    2015-01-01

    A condensate cloud on Titan identified by its 220 cm-1 far-infrared signature continues to undergo seasonal changes at both the north and south poles. In the north, the cloud, which extends from 55 N to the pole, has been gradually decreasing in emission intensity since the beginning of the Cassini mission with a half-life of 3.8 years. The cloud in the south did not appear until 2012 but its intensity has increased rapidly, doubling every year. The shape of the cloud at the south pole is very different from that in the north. Mapping in 2013 December showed that the condensate emission was confined to a ring with a maximum at 80 S. The ring was centered 4deg from Titan's pole. The pattern of emission from stratospheric trace gases like nitriles and complex hydrocarbons (mapped in 2014 January) was also offset by 4deg, but had a central peak at the pole and a secondary maximum in a ring at about 70 S with a minimum at 80 S. The shape of the gas emission distribution can be explained by abundances that are high at the atmospheric pole and diminish toward the equator, combined with correspondingly increasing temperatures. We discuss possible causes for the condensate ring. The present rapid build up of the condensate cloud at the south pole is likely to transition to a gradual decline from 2015 to 2016. Key words: molecular processes - planets and satellites: atmospheres - planets and satellites: composition - planets and satellites: individual (Titan) - radiation mechanisms: thermal

  4. Solid tidal friction above a liquid water reservoir as the origin of the south pole hotspot on Enceladus

    NASA Astrophysics Data System (ADS)

    Tobie, G.; Čadek, O.; Sotin, C.

    2008-08-01

    Earth, Jupiter's moon Io and Saturn's tiny moon Enceladus are the only solid objects in the Solar System to be sufficiently geologically active for their internal heat to be detected by remote sensing. Interestingly, the endogenic activity on Enceladus is only located on a specific region at the south pole, from which jets of water vapor and ice particles have been observed [Spencer, J.R., and 9 colleagues, 2006. Science 311, 1401-1405; Porco, C.C., and 24 colleagues, 2006. Science 311, 1393-1401]. The current polar location of the thermal anomaly can possibly be explained by diapir-induced reorientation of the satellite [Nimmo, F., Pappalardo, R.T., 2006. Nature 441, 614-616], but the thermal anomaly triggering and the heat power required to sustain it over geological timescales remain problematic. Using a three-dimensional viscoelastic numerical model simulating the response of Enceladus to tidal forcing, we explore the effect of a low-viscosity anomaly in the ice shell, localized to the south polar region, on the tidal dissipation patterns. We demonstrate that only interior models with a liquid water layer at depth can explain the observed magnitude of dissipation rate and its particular location at the south pole. Moreover, we show that tidally-induced heat must be generated over a relatively broad region in the southern hemisphere, and it is then transferred toward the south pole where it is episodically released during relatively short resurfacing events. As large tidal dissipation and internal melting cannot be induced in the south polar region in the absence of a pre-existing liquid decoupling layer, we propose that liquid water must have been present in the interior for a very long period of time, and possibly since the satellite formation. Owing to the orbital equilibrium requirement [Meyer, J., Wisdom, J., 2007. Icarus 188, 535-539], sustaining some liquid water at depth is impossible if heat is continuously emitted at a rate of 4-8 GW at the south pole

  5. South-polar features on Venus similar to those near the north pole.

    PubMed

    Piccioni, G; Drossart, P; Sanchez-Lavega, A; Hueso, R; Taylor, F W; Wilson, C F; Grassi, D; Zasova, L; Moriconi, M; Adriani, A; Lebonnois, S; Coradini, A; Bézard, B; Angrilli, F; Arnold, G; Baines, K H; Bellucci, G; Benkhoff, J; Bibring, J P; Blanco, A; Blecka, M I; Carlson, R W; Di Lellis, A; Encrenaz, T; Erard, S; Fonti, S; Formisano, V; Fouchet, T; Garcia, R; Haus, R; Helbert, J; Ignatiev, N I; Irwin, P G J; Langevin, Y; Lopez-Valverde, M A; Luz, D; Marinangeli, L; Orofino, V; Rodin, A V; Roos-Serote, M C; Saggin, B; Stam, D M; Titov, D; Visconti, G; Zambelli, M; Ammannito, Eleonora; Barbis, Alessandra; Berlin, Rainer; Bettanini, Carlo; Boccaccini, Angelo; Bonnello, Guillaume; Bouye, Marc; Capaccioni, Fabrizio; Moinelo, Alejandro Cardesin; Carraro, Francesco; Cherubini, Giovanni; Cosi, Massimo; Dami, Michele; De Nino, Maurizio; Del Vento, Davide; Di Giampietro, Marco; Donati, Alessandro; Dupuis, Olivier; Espinasse, Sylvie; Fabbri, Anna; Fave, Agnes; Veltroni, Iacopo Ficai; Filacchione, Gianrico; Garceran, Katia; Ghomchi, Yamina; Giustini, Maurizio; Gondet, Brigitte; Hello, Yann; Henry, Florence; Hofer, Stefan; Huntzinger, Gerard; Kachlicki, Juergen; Knoll, René; Driss, Kouach; Mazzoni, Alessandro; Melchiorri, Riccardo; Mondello, Giuseppe; Monti, Francesco; Neumann, Christian; Nuccilli, Fabrizio; Parisot, Jerome; Pasqui, Claudio; Perferi, Stefano; Peter, Gisbert; Piacentino, Alain; Pompei, Carlo; Reess, Jean-Michel; Rivet, Jean-Pierre; Romano, Antonio; Russ, Natalie; Santoni, Massimo; Scarpelli, Adelmo; Semery, Alain; Soufflot, Alain; Stefanovitch, Douchane; Suetta, Enrico; Tarchi, Fabio; Tonetti, Nazzareno; Tosi, Federico; Ulmer, Bernd

    2007-11-29

    Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole. The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.

  6. Plans for a 10-m submillimeter-wave telescope at the South Pole

    NASA Astrophysics Data System (ADS)

    Stark, Antony A.; Carlstrom, John E.; Israel, Frank P.; Menten, Karl M.; Peterson, Jeffrey B.; Phillips, Thomas G.; Sironi, Giorgio; Walker, Christopher K.

    1998-07-01

    A 10 meter diameter submillimeter-wave telescope has been proposed for installation and scientific use at the NSF Amundsen-Scott South Pole Station. Current evidence indicates that the South Pole is the best submillimeter-wave telescope site among all existing or proposed ground-based observatories. Proposed scientific programs place stringent requirements on the optical quality of the telescope design. In particular, reduction of the thermal background and offsets requires an off-axis, unblocked aperture, and the large field of view needed for survey observations requires shaped optics. This mix of design elements is well-suited for large-scale (square degree) mapping of line and continuum radiation from submillimeter-wave sources at moderate spatial resolutions (4 to 60 arcsecond beam size) and high sensitivity (milliJansky flux density levels). The telescope will make arcminute angular scale, high frequency Cosmic Microwave Background measurements from the best possible ground-based site, using an aperture which is larger than is currently possible on orbital or airborne platforms. The telescope design is homologous. Gravitational changes in pointing and focal length will be accommodated by active repositioning of the secondary mirror. The secondary support, consisting of a large, enclosed beam, permits mounting of either a standard set of Gregorian optics, or prime focus instrumentation packages for CMBR studies. A tertiary chopper is located at the exit pupil of the instrument. An optical design with a hyperboloidal primary mirror and a concave secondary mirror provides a flat focal surface. The relatively large classical aberrations present in such an optical arrangement can be small compared to diffraction at submillimeter wavelengths. Effective use of this telescope will require development of large (1000 element) arrays of submillimeter detectors which are background-limited when illuminated by antenna temperatures near 50 K.

  7. Balloon observations of ultra-low-frequency waves in the electric field above the South Pole

    SciTech Connect

    Liao, B.; Benbrrook, J.R.; Bering E.A. III; Byrne, G.J.; Theall, J.R. )

    1988-01-01

    The physics of ultra-low-frequency waves in the magnetosphere, near the cusp and in the polar cap, is important because this region is one where ultra-low-frequency wave energy from the magnetopause can most easily enter the magnetosphere. During the 1985-1986 South Pole balloon campaign, eight stratospheric balloon payloads were launched from Amundsen-Scott Station, South Geographic Pole, Antarctica, to record data on ultra-low-frequency waves. The payloads were instrumented with three-axis double-probe electric field detectors and X-ray scintillation counters. This paper concentrates on the third flight of this series, which was launched at 2205 universal time on 21 December 1985. Good data were received from the payload until the transmitter failed at 0342 universal time on 22 December. During most of the four hours that the balloon was afloat, an intense ultra-low-frequency wave event was in progress. The electric-field data from this period have been examined in detail and compared with magnetic field data, obtained with ground-based fluxgate and induction magnetometers to determine the characteristics of the waves. After float was reached, the electric-field data in figure 1 show large-amplitude, quasi-periodic fluctuations suggesting the presence of intense ultra-low-frequency wave activity. In conclusion, the electric-field signature observed from flight 3 appears to have been essentially an electrostatic event or possibly a short-wavelength hydromagnetic wave with a varying and interesting polarization character. The authors are continuing the analysis of the data to determine the source of the observed ultra-low-frequency waves.

  8. Continuous Lidar Monitoring of Polar Stratospheric Clouds at the South Pole

    NASA Technical Reports Server (NTRS)

    Campbell, James R.; Welton, Ellsworth J.; Spinhirne, James D

    2009-01-01

    Polar stratospheric clouds (PSC) play a primary role in the formation of annual ozone holes over Antarctica during the austral sunrise. Meridional temperature gradients in the lower stratosphere and upper troposphere, caused by strong radiative cooling, induce a broad dynamic vortex centered near the South Pole that decouples and insulates the winter polar airmass. PSC nucleate and grow as vortex temperatures gradually fall below equilibrium saturation and frost points for ambient sulfate, nitrate, and water vapor concentrations (generally below 197 K). Cloud surfaces promote heterogeneous reactions that convert stable chlorine and bromine-based molecules into photochemically active ones. As spring nears, and the sun reappears and rises, photolysis decomposes these partitioned compounds into individual halogen atoms that react with and catalytically destroy thousands of ozone molecules before they are stochastically neutralized. Despite a generic understanding of the ozone hole paradigm, many key components of the system, such as cloud occurrence, phase, and composition; particle growth mechanisms; and denitrification of the lower stratosphere have yet to be fully resolved. Satellite-based observations have dramatically improved the ability to detect PSC and quantify seasonal polar chemical partitioning. However, coverage directly over the Antarctic plateau is limited by polar-orbiting tracks that rarely exceed 80 degrees S. In December 1999, a NASA Micropulse Lidar Network instrument (MPLNET) was first deployed to the NOAA Earth Systems Research Laboratory (ESRL) Atmospheric Research Observatory at the Amundsen-Scott South Pole Station for continuous cloud and aerosol profiling. MPLNET instruments are eye-safe, capable of full-time autonomous operation, and suitably rugged and compact to withstand long-term remote deployment. With only brief interruptions during the winters of 2001 and 2002, a nearly continuous data archive exists to the present.

  9. Observation of 18.6-year modulation tide at the South Pole

    NASA Astrophysics Data System (ADS)

    Rydelek, P. A.; Knopoff, L.; Zürn, W.

    1982-07-01

    We have observed long-period variations in the amplitudes of the diurnal and semidiurnal gravity tides at the South Pole which we attribute to the tidal effects of the 18.6-year regression of the nodes of the lunar orbit. The observations are in agreement with theoretical values of the 18.6-year amplitude modulation of these tides.

  10. Photoelectric Photometry of Faint M-Type Stars in the Direction of the South Galactic Pole

    NASA Astrophysics Data System (ADS)

    Pesch, P.

    1982-04-01

    Photoelectric V (Johnson-Morgan UBV system) and (V I) (Kron-Mayall PVI system) photometry is presented for 54 faint M-type stars from Pesch and Sanduleak's catalog of probable dwarf stars of type M3 and later in the direction of the south galactic pole. The observations were made in November 1978 with the 1.5-m CTIO reflector.

  11. Comparison of UV irradiance measurements at Summit, Greenland; Barrow, Alaska; and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Bernhard, G.; Booth, C. R.; Ehramjian, J. C.

    2008-08-01

    An SUV-150B spectroradiometer for measuring solar ultraviolet (UV) irradiance was installed at Summit, Greenland, in August 2004. Here we compare the initial data from this new location with similar measurements from Barrow, Alaska, and South Pole. Measurements of irradiance at 345 nm performed at equivalent solar zenith angles (SZAs) are almost identical at Summit and South Pole. The good agreement can be explained with the similar location of the two sites on high-altitude ice caps with high surface albedo. Clouds attenuate irradiance at 345 nm at both sites by less than 6% on average, but can reduce irradiance at Barrow by more than 75%. Clear-sky measurements at Barrow are smaller than at Summit by 14% in spring and 36% in summer, mostly due to differences in surface albedo and altitude. Comparisons with model calculations indicate that aerosols can reduce clear-sky irradiance at Summit by 4 6%; aerosol influence is largest in April. Differences in total ozone at the three sites have a large influence on the UV Index. At South Pole, the UV Index is on average 20 80% larger during the ozone hole period than between January and March. At Summit, total ozone peaks in April and UV Indices in spring are on average 10 25% smaller than in the summer. Maximum UV Indices ever observed at Summit, Barrow, and South Pole are 6.7, 5.0, and 4.0, respectively. The larger value at Summit is due to the site's lower latitude. For comparable SZAs, average UV Indices measured during October and November at South Pole are 1.9 2.4 times larger than measurements during March and April at Summit. Average UV Indices at Summit are over 50% greater than at Barrow because of the larger cloud influence at Barrow.

  12. Comparison of UV climates at Summit, Greenland; Barrow, Alaska and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Bernhard, G.; Booth, C. R.; Ehramjian, J. C.

    2008-03-01

    An SUV-150B spectroradiometer for measuring solar ultraviolet (UV) irradiance was installed at Summit, Greenland, in August 2004. Here we compare the initial data from this new location with similar measurements from Barrow, Alaska and South Pole. Measurements of irradiance at 345 nm performed at equivalent solar zenith angles (SZAs) are almost identical at Summit and South Pole. The good agreement can be explained with the similar location of the two sites on high-altitude ice caps with high surface albedo. Clouds have little impact at both sites, but can reduce irradiance at Barrow by more than 75%. Clear-sky measurements at Barrow are smaller than at Summit by 14% in spring and 36% in summer, mostly due to differences in surface albedo and altitude. Comparisons with model calculations indicate that aerosols can reduce clear-sky irradiance at 345 nm by 4-6%; aerosol influence is largest in April. Differences in total ozone at the three sites have a large influence on the UV Index. At South Pole, the UV Index is on average 20-80% larger during the ozone hole period than between January and March. At Summit, total ozone peaks in April and UV Indices in spring are on average 10-25% smaller than in the summer. Maximum UV Indices ever observed at Summit and South Pole are 6.7 and 4.0, respectively. The larger value at Summit is due to the site's lower latitude. For comparable SZAs, average UV Indices measured during October and November at South Pole are 1.9-2.4 times larger than measurements during March and April at Summit. Average UV Indices at Summit are over 50% greater than at Barrow because of the larger cloud influence at Barrow.

  13. Dynamics of the lower thermosphere over South Pole from meteor radar wind measurements

    NASA Astrophysics Data System (ADS)

    Forbes, J. M.; Portnyagin, Yu. I.; Makarov, N. A.; Palo, S. E.; Merzlyakov, E. G.; Zhang, X.

    1999-07-01

    A meteor radar was operated at Amundsen-Scott Station, South Pole, from January 19, 1995 through January 26, 1996 and from November 21, 1996 through January 27, 1997. Hourly wind measurements were obtained nearly continuously over these time periods, at an approximate altitude of 95 km and at about 2° latitude from South Pole along the longitude meridians 0°, 90°E, 90°W, and 180°. The scientific advances achieved to date through analyses of these data are presented, including updates to several of our previously published works. The findings addressed herein include the following: (1) Strong divergences of zonal-mean meridional winds occasionally occur over South Pole, implying extreme vertical winds; (2) The monthly mean zonally asymmetric (zonal wavenumber s = 1) wind component varies during the year in a manner consistent with migration of the center of the polar vortex with respect to the geographic (rotational) pole; (3) Strong (>15 m/s) westward-propagating migrating diurnal ( s = 1) and non-migrating semidiurnal ( s = 1) oscillations exist except during winter months; (4) Long-period (˜2-10 days) waves exist during winter months which are primarily eastward-propagating; (5) Intradiurnal (periods ˜6-11.5 hours) westward-propagating oscillations exist, which are thought to be gravitational normal modes, or "Lamb" waves.

  14. Science, the South Pole, and the Japanese expedition of 1910-1912.

    PubMed

    Stevenson, William R

    2011-12-01

    In November 1910, Shirase Nobu (1861-1946) sailed from Tokyo Bay aboard the Kainan Maru as part of an international race for the South Pole. The Japanese had no history of polar exploration and looked to British precedence to compensate for their lack of experience. Following the British example required that they include a scientific dimension to their venture. It is clear, however, that Shirase and his men had little scientific understanding. Nevertheless, on failing to reach the Pole, science became the central aim of the expedition and the primary means to declaring their efforts a success.

  15. AMIE/SMART-1 Moon North and South Poles First Results

    NASA Astrophysics Data System (ADS)

    Josset, J. L.; Beauvivre, S.; Amie Science Team

    The Advanced Moon micro-Imager Experiment AMIE on board ESA SMART-1 the first European mission to the Moon launched on 27th September 2003 is an imaging system with scientific technical and public outreach oriented objectives The SMART-1 polar orbit around the Moon with an apolune at about 2500 km and a perilune at about 500 km allows to image the poles areas with different illumination conditions We present here the first results obtained by AMIE Camera System at North and South poles

  16. The south pole region of the moon as seen by Clementine

    USGS Publications Warehouse

    Shoemaker, E.M.; Robinson, M.S.; Eliason, E.M.

    1994-01-01

    The Clementine mission has provided the first comprehensive set of high-resolution images of the south pole region of the moon. Within 5?? of latitude of the pole, an area of an estimated 30,000 square kilometers remained in shadow during a full lunar rotation and is a promising target for future exploration for ice deposits. The Schrodinger Basin (320 kilometers in diameter), centered at 75??S, is one of the two youngest, least modified, great multiring impact basins on the moon. A large maar-type volcano localized along a graben within the Schrodinger Basin probably erupted between 1 and 2 billion years ago.

  17. North Pole, South Pole: the quest to understand the mystery of Earth's magnetism

    NASA Astrophysics Data System (ADS)

    Turner, G. M.

    2010-12-01

    The story of the quest to understand Earth’s magnetic field is one of the longest and richest in the history of science. It weaves together Greek philosophy, Chinese mysticism, the development of the compass and navigation, the physics of electromagnetism and the jig-saw like piecing together of the internal structure of the planet beneath our feet. The story begins with Magnes, an old shepherd, trudging up the mountainside after a violent thunder storm, astonished at how the iron studs in his boots stick to the rocks. It was Alexander von Humboldt who, three millennia on, pointed to lightning as the source of such magnetization. The first compass was made 2000 years ago in China - to divine the ways of feng shui - a guide to planting crops, planning streets, orienting buildings and more. It reached Europe as a navigational tool in the 12th century - no-one is quite sure how, but en route it changed from south-pointing to the north-pointing compasses of today. The earliest truly scientific experiments and writings concerned magnets and geomagnetism: Petrus Peregrinus’ Epistola of 1269, and William Gilbert’s De Magnete of1600, in which he declared Magnus magnes globus terrestris ipse est - the Earth itself is a great magnet. By then it was recognized that the compass didn’t point exactly north, and the discrepancy varied from place to place and changed over time - something of a problem for Gilbert’s idea of a geocentric axial dipole. However declination and secular variation were problems well known to Edmund Halley, who, in 1700, charted the angle of declination over the Atlantic Ocean, and in the process introduced the Halleyan line - the contour. Many of the world’s greatest scientists have turned their minds to the problem of magnetism and geomagnetism in particular - Coulomb, Gauss, Faraday, Maxwell - yet in 1905, Einstein described geomagnetism as “one of the great unsolved problems of physics”. In the mid-late nineteenth century new areas of

  18. Integration of Lunar Polar Remote-Sensing Data Sets: Evidence for Ice at the Lunar South Pole

    NASA Technical Reports Server (NTRS)

    Nozette, Stewart; Spudis, Paul D.; Robinson, Mark S.; Bussey, D. B. J.; Lichtenberg, Chris; Bonner, Robert

    2001-01-01

    In order to investigate the feasibility of ice deposits at the lunar south pole, we have integrated all relevant lunar polar data sets. These include illumination data, Arecibo ground-based monostatic radar data, newly processed Clementine bistatic radar data, and Lunar Prospector neutron spectrometer measurements. The possibility that the lunar poles harbor ice deposits has important implications not only as a natural resource for future human lunar activity but also as a record of inner solar system volatiles (e.g., comets and asteroids) over the past billion years or more. We find that the epithermal neutron flux anomalies, measured by Lunar Prospector, are coincident with permanently shadowed regions at the lunar south pole, particularly those associated with Shackleton crater. Furthermore, these areas also correlate with the beta=0 circular polarization ratio (CPR) enhancements revealed by new processing of Clementine bistatic radar echoes, which in turn are colocated with areas of anomalous high CPR observed by Arecibo Observatory on the lower, Sun-shadowed wall of Shackleton crater. Estimates of the extent of high CPR from Arecibo Observatory and Clementine bistatic radar data independently suggest that approximately 10 square kilometers of ice may be present on the inner Earth-facing wall of Shackleton crater. None of the experiments that obtained the data presented here were ideally suited for definitively identifying ice in lunar polar regions. By assessing the relative merits of all available data, we find that it is plausible that ice does occur in cold traps at the lunar south pole and that future missions with instruments specifically designed to investigate these anomalies are worthy.

  19. A New Quiet GSN Site at the South Pole: Comparison of Seismic Data Between SPA and QSPA.

    NASA Astrophysics Data System (ADS)

    Anderson, K. R.; Aster, R. C.; Butler, R.; Hutt, C.; Storm, T.; Anderson, D.; Vineyard, J. J.; Albert, D. G.

    2003-12-01

    Due to increasing noise from Amundsen-Scott South Pole Station (ASSPS), a new Global Seismic Network (GSN) station, QSPA, was constructed in the 2002-2003 field season to supplant the previous GSN station, SPA, in operation since c. 1985. QSPA is the first experiment established at the South Pole Remote Earth Science and Seismological Observatory (SPRESSO). The new instruments reside in the newly-designated seismic Quiet Sector, 8 km southeast of ASSPS. SPRESSO provides a much lower noise environment, yet is close enough to the south pole to be effectively co-sited with Earth's rotational axis for long-period seismological purposes. The SPRESSO site was selected after examining tractor surface noise propagation, balanced against power and communication considerations. Numerical modeling showed that ASSPS noise should be fairly well trapped in near-surface, lower-velocity firn zone and indicated that a burial depth of 300 m would very substantially reduce noise. QSPA consists of a Geotech Instruments KS-54000 at 275 m and Guralp CMG-3Tb at 255 m depth, separated horizontally by 10 m. These depths are approximately 160 m below the local firn/ice transition. QSPA also includes a near-surface vault ( ˜5 m depth) housing Streckeisen STS-1V and STS-2 sensors. SPA has been left in operation for a period of ˜1 yr to allow for a thorough comparison with QSPA. Although 8 km from the South Pole station activities, the QSPA site borehole instruments still sense South Pole noise. However, these noise levels are significantly diminished at frequencies >1 Hz and at periods >20 s. From 1 to 15 Hz, the improved noise environment is especially dramatic. For example, background noise at 2 Hz is 15 db below SPA, ˜20-25 dB at 3 Hz, ˜30-35 dB at 4Hz, and ˜35-40 dB above 5Hz. Between 2 and 10 Hz the QSPA Guralp borehole sensor shows data intervals with noise levels below the Peterson (1993) Low Noise Model (PLNM) (with minimum noise at ˜3Hz ˜12dB below PLNM), making the site among

  20. Long-term air quality monitoring at the South Pole by the NOAA program Geophysical Monitoring for Climatic Change

    SciTech Connect

    Robinson, E.; Rodhaine, B.A.; Komhyr, W.D.; Oltmans, S.J.; Steele, L.P.

    1988-02-01

    The objectives of the NOAA program of Geophysical Monitoring for Climatic Change (GMCC) for the South Pole include measurements of atmospheric changes which can potentially impact climate. This paper discusses the long-term GMCC South Pole air chemistry data for carbon dioxide, total ozone, surface ozone, methane, halocarbons, nitrous oxide, and aerosol concentrations, comparing the findings with GMCC data for other regions. Special consideration is given to the results of recent GMCC ozonesonde operations and to an asessment of Dobson ozone spectrophotometer data taken at South Pole by NOAA since 1964. Data are discussed in the framework of Antarctic ozone hole phenomenon. 49 references.

  1. The Meteorology and Chemistry of High Nitric-Acid Episodes at the South Pole

    NASA Astrophysics Data System (ADS)

    Neff, William; Davis, Douglas

    2016-04-01

    Between 1998 and 2007, a series of field experiments carried out at the South Pole and with aircraft over a wider area revealed a very chemically active boundary layer overlying the east Antarctic ice sheet during the Austral summer. An early discovery was unexpectedly high concentrations of nitric acid (NO) at the South Pole. These were argued to be a result of the UV pholoysis of reactive nitrogen in surface and/or near-surface snow followed by subsequent confinement and non-linear HOx/NOx chemistry within a thin stable atmospheric boundary layer. The concentrations of NO also demonstrated daily, intraseasonal, as well as interannual variability as seen in the four field programs. This paper seeks to elucidate the interplay of large-to-small scale meteorology and chemistry at the South Pole that leads to highly variable NO concentrations and to examine boundary layer depth effects on NO in years when no direct measurements were available, in particular during the latest field program in 2006-2007. The importance of the South Pole is that it, unlike other high-latitude sites, has no diurnal cycle to disturb the evolution of the mostly stable boundary layer and its physics and chemistry. In the spring, as the solar elevation angle increases, nitrate photolysis rates increase. At the same time, the stratospheric vortex warms and with its breakup, the total column ozone increases leading to decreased photolysis rates. In addition, following the formation of the thermal tropopause in early spring, the tropospheric circulation over Antarctica changes dramatically, affecting the transport and dominant source regions for warm air and clouds arriving at the South Pole. The timing of the final warming ranged from early-November to mid-December for the four field experiment years. During the 30 days prior to the final increase in column ozone, as the thermal tropopause forms (~100 hPa), the winds at 300 hPa become bimodal, either along the eastern side of the Weddell Sea

  2. Decadal change in the troposphere and atmospheric boundary layer over the South Pole

    SciTech Connect

    Neff, W.D.

    1994-12-31

    During the austral winter of 1993, the Environmental Technology Laboratory carried out a detailed field study of the atmospheric boundary layer at Amundsen-Scott South Pole Station to determine the effect of transitory synoptic disturbances on the surface-energy budget. This study used newly developed 915-megahertz radar wind-profiling technology for the first time in the Antarctic in combination with conventional boundary layer instrumentation that included a short tower, sonic anemometer, microbarograph array, and doppler sodar. Recent discussions, however, of interdecadal variability in the circumpolar circulation around Antarctica and of decadal changes in summer cloudiness at the South Pole, motivated our study of the long-term variability in boundary layer characteristics, cloudiness, and tropospheric flow behavior to provide a climatological context for our single year`s observations. 7 refs., 3 figs.

  3. Seasonal and Interannual Variability of Short Period Lamb Waves Observed over South Pole

    NASA Astrophysics Data System (ADS)

    Palo, S.; Gerhardt, D.

    2009-12-01

    A meteor radar system was installed at Amundsen-Scott South Pole station in 2001 and became fully operational in 2002. This radar has operated nearly continuously since and is providing horizontal wind measurements in four separate azimuth directions. This feature provides the ability to determine the zonal wavenumber and direction of propagation for the observed perturbations. With multiple years of observations we have the opportunity to investigate the coherent seasonal structure of the large scale observations over South Pole. These include the migrating diurnal and semidiurnal oscillations which are large during the summer months as well as both eastward and westward propagating planetary waves. Throughout the year short period (8-14) hour oscillations are present and have been associated with Lamb Waves. In this paper we present a spatial and temporal analysis of these planetary waves.

  4. Millimeter Source Counts and Spectral Indices Measured with the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Vieira, Joaquin

    2009-01-01

    We present millimeter-wave (mm) number counts and spectral indices from a new survey taken with the 10 m South Pole Telescope located at the Amundsen-Scott South Pole Station in Antarctica. Extragalactic mm sources are expected to be the dominant contaminant in the current generation of fine-scale cosmic microwave background and Sunyaev-Zel'dovich effect experiments. Here we characterize the spectral and flux distributions of mm sources down to a few mJy at 150 and 225 GHz from an 80 square degree field with uniform coverage. Two distinct populations of mm sources are observed, characterized by their spectral indices: (1) a population of bright sources with falling or flat spectra and cm-wave counterparts and (2) a population of sources with positive spectral indices with number counts consistent with previous observations of submillimeter galaxies.

  5. Operation and First Data of DM-Ice17 at the South Pole

    NASA Astrophysics Data System (ADS)

    Kauer, Matthew

    2013-04-01

    DM-Ice17 is a set of two NaI(Tl) detectors with a combined mass of 17 kg located at a depth of 2450 m in the Antarctic ice at the South Pole. In this experiment the signature for WIMP dark matter is an annual modulation in the nuclear recoil signal events. DM-Ice17 is a prototype detector for a first direct search for dark matter in the Southern Hemisphere. Seasonal effects have a reversed phase relative to the Northern Hemisphere and together provide a complimentary understanding of those systematics. Furthermore, the South Pole ice provides an extremely stable environment year around. In this talk we present data from the operation of the DM-Ice17 experiment since January 2011 and discuss the stability, performance, and expected WIMP sensitivity.

  6. A Project for Photometry of Early-type Binaries at the South Pole

    NASA Astrophysics Data System (ADS)

    Chen, K.-Y.; Martins, D. H.

    1993-12-01

    Five O-type close binary systems, HD 93206, HD 101205, HD 152218, HD 152248, and HD 152249 are selected to be observed photometrically at the South Pole. An automated 40-cm optical telescope was designed specially for the harsh environment. The telescope was built and funded in China; and it is now being tested mechanically. A CCD camera will be mounted at the Nasmyth focus. Complete UBVRI light curves of these stars and their solutions are to be obtained. The results will provide basic information for constructing evolutional models of O-type stars and their interactions in binary system. Standard stars are to be observed also. These photometric data will be used to determine the atmospheric extinctions at the South Pole as well as the transformation equations of the instrumental system to the standard system. This research is a joint project of the University of Florida, Beijing Astronomical Obsevatory, Yunnan Observatory, and the University of Alaska, Anchorage.

  7. Simultaneous observations of auroras from the South Pole Station and of precipitating electrons by Isis 1.

    NASA Technical Reports Server (NTRS)

    Winningham, J. D.; Heikkila, W. J.; Akasofu, S.-I.; Yasuhara, F.

    1973-01-01

    On the basis of the simultaneous observations of auroras from the South Pole and of precipitating electrons by the Isis 1 satellite it is shown that (1) a midday auroral arc (photographed on black and white film) occurs within the cleft (cusp) region projected to the appropriate auroral height along the geomagnetic field; (2) in the evening sector an aurora, observed by Isis 1 and the South Pole all-sky camera, extended for at least 5 hours of local geomagnetic time in the expected position of the auroral oval; and (3) during a period of extreme magnetic quiet, cleftlike electrons were observed just poleward of a narrow region of intense precipitation in the midnight sector. An earth-sun oriented arc was seen at the projected location of the intense electron flux.

  8. A Southern Hemisphere atmospheric history of carbon monoxide from South Pole firn air

    NASA Astrophysics Data System (ADS)

    Verhulst, K. R.; Aydin, M.; Novelli, P. C.; Holmes, C. D.; Prather, M. J.; Saltzman, E. S.

    2013-12-01

    Carbon monoxide (CO) is a reactive trace gas and is important to tropospheric photochemistry as a major sink of hydroxyl radicals (OH). Major sources of CO are fossil fuel combustion, linked mostly to automotive emissions, biomass burning, and oxidation of atmospheric methane. Understanding changes in carbon monoxide over the past century will improve our understanding of man's influence on the reactivity of the atmosphere. Little observational information is available about CO levels and emissions prior to the 1990s, particularly for the Southern Hemisphere. The NOAA global flask network provides the most complete instrumental record of CO, extending back to 1988. Annually averaged surface flask measurements suggest atmospheric CO levels at South Pole were relatively stable from 2004-2009 at about 51 nmol mol-1 [Novelli and Masarie, 2013]. In this study, a 20th century atmospheric history of CO is reconstructed from South Pole firn air measurements, using a 1-D firn air diffusion model. Firn air samples were collected in glass flasks from two adjacent holes drilled from the surface to 118 m at South Pole, Antarctica during the 2008/2009 field season and CO analysis was carried out by NOAA/CCG. Carbon monoxide levels increase from about 45 nmol mol-1 in the deepest firn sample at 116 m to 52 nmol mol-1 at 107 m, and remain constant at about 51-52 nmol mol-1 at shallower depths. Atmospheric histories based on the firn air reconstructions suggest that CO levels over Antarctica increased by roughly 40% (from about 36 to 50 nmol mol-1) between 1930-1990, at a rate of about 0.18 nmol mol-1 yr-1. Firn air and surface air results suggest the rate of CO increase at South Pole slowed considerably after 1990. The firn air-based atmospheric history is used to infer changes in Southern Hemisphere CO emissions over the 20th century.

  9. Performance of PV panels for solar energy conversion at the South Pole

    NASA Astrophysics Data System (ADS)

    Peeran, Syed M.

    Expanding research facilities at the Amundson-Scott South pole station require increased electric power generation. Presently, electric power generation is by diesel generators using the JP8 fuel. As the station is accessible only for a short supply period during the austral summer, there are limitations upon the supply of fuel for power generation. This makes it necessary to seriously consider the use of the renewable energy sources. Although there is no sunlight for six months in the year, abundant solar energy is available during the remaining 6 months because of the clear skies, the clarity of air and the low humidity at the south pole. As the buildings at the south pole are built either without windows or with only porthole type windows, large areas on the walls and the roof are available for mounting the photovoltaic (PV) panels. In addition there is unlimited space around the station for constructing a PV panel 'farm'. In this paper four types of PV panels are evaluated; the 2-axis tracking panels, vertical 1-axis tracking panels, fixed vertical panels on the walls of buildings and mounted outdoors, and fixed horizontal panels on the roofs of the buildings. Equations are developed for the power output in KW/sq. ft and annual energy in kWh/sq. ft for each type of panel. The equations include the effects of the inclination of the sun above the horizon, the movement of the sun around the horizon, the direct, reflected and diffused components of the solar radiation, the characteristics of the solar cells and the types of dc/ac inverters used to interface the output of the cells with the existing ac power. A conceptual design of a 150-kW PV generation system suitable for the south pole is also discussed in this paper.

  10. Tidal analysis of meridional winds at the South Pole using a VHF interferometric meteor radar

    NASA Astrophysics Data System (ADS)

    Lau, Elías M.; Avery, Susan K.; Avery, James P.; Palo, Scott E.; Makarov, Nikolai A.

    2006-08-01

    Atmospheric tides are perturbations driven by the periodic absorption of solar radiation. They manifest themselves everywhere in the atmosphere, and an understanding of their sources, propagation, and interaction with other waves is vital to comprehend the global atmosphere. In order to measure the horizontal wind field in the mesosphere-lower thermosphere (MLT) over the geographical South Pole and use these measurements to understand the large-scale dynamics of this region, a VHF meteor radar was installed at the Amundsen-Scott station at the South Pole in 2001. The radar operated for a few months in 2001 and with minor interruptions in 2002 and 2003. However, toward the end of 2003, receiver problems caused a drop in our meteor echo rates, preventing us from getting tidal results after October 2003. We report on the temporal behavior of the diurnal and semidiurnal tides observed in the meridional wind field at mesospheric and lower thermospheric heights in the vicinity of the geographic South Pole. With the interferometric capabilities of this radar, we also document for the first time the vertical structure of these tides. The zonal wave number one component of the diurnal tide shows consistency for all years that we analyze. On the other hand, the zonal wave number one component of the semidiurnal tide shows significantly more year-to-year variability. Our results are compared to previous observations and model predictions. A significant decrease in the amplitude of this oscillation from December 2002 to February 2003 is also observed and discussed.

  11. The vertical structure and temporal variability of the atmospheric tides over South Pole

    NASA Astrophysics Data System (ADS)

    Lau, E.; Palo, S.; Avery, S.; Avery, J.; Iimura, H.; Makarov, N.

    Studies of the mesosphere and lower thermosphere MLT over the South Pole during the 1990s revealed the existence of an unexpected westward propagating semidiurnal tidal component with zonal wavenumber one This tidal component was first observed in the austral winter using optical instruments Observations made later with a meteor radar in the mid 1990s showed that this nonmigrating component of the semidiurnal tide had a much larger amplitude during the austral summer sim 20 m s and practically disappeared during the winter A similar behavior was observed for the migrating diurnal tide but with smaller amplitudes Initial comparisons of the nonmigrating component of the semidiurnal tide with models like the Global Scale Wave Model GSWM showed that the observed amplitudes were significantly larger than the model predictions However the GSWM only includes nonmigrating tidal components generated via latent heating and it is believed that the nonmigrating semidiurnal tide observed at South Pole is the result of a nonlinear interaction between the migrating semidiurnal tide and the wave one stationary planetary wave Recently the Middle Atmosphere Circulation Model at Kyushu University MACMKU was able to reproduce some of the main temporal variations of the observations as nonlinear effects are included in this general circulation model However the MACMKU maximum amplitudes were larger than the observations A new meteor radar was installed at the Amundsen-Scott station at the South Pole in 2001 to further the understanding of the dynamics

  12. Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves

    SciTech Connect

    IceCube Collaboration; Klein, Spencer

    2009-06-04

    We have measured the speed of both pressure waves and shear waves as a function of depth between 80 and 500 m depth in South Pole ice with better than 1% precision. The measurements were made using the South Pole Acoustic Test Setup (SPATS), an array of transmitters and sensors deployed in the ice at the South Pole in order to measure the acoustic properties relevant to acoustic detection of astrophysical neutrinos. The transmitters and sensors use piezoceramics operating at {approx}5-25 kHz. Between 200 m and 500 m depth, the measured profile is consistent with zero variation of the sound speed with depth, resulting in zero refraction, for both pressure and shear waves. We also performed a complementary study featuring an explosive signal propagating vertically from 50 to 2250 m depth, from which we determined a value for the pressure wave speed consistent with that determined for shallower depths, higher frequencies, and horizontal propagation with the SPATS sensors. The sound speed profile presented here can be used to achieve good acoustic source position and emission time reconstruction in general, and neutrino direction and energy reconstruction in particular. The reconstructed quantities could also help separate neutrino signals from background.

  13. Infrared measurements of increased CF(2)Cl(2) (CFC- 12) absorption above the South Pole.

    PubMed

    Rinsland, C P; Goldman, A; Murcray, F J; Murcray, F H; Murcray, D G; Levine, J S

    1988-02-01

    High-resolution ground-based solar spectra recorded at the Amundsen-Scott South Pole station in Dec. 1980 and Nov. 1986 have been analyzed in the region of the CF(2)Cl(2) (chlorofluorocarbon 12) nu(8) band Q branches at 1161 cm(-1). An increase in the CF(2)Cl(2) total vertical column above the South Pole of 1.24 +/- 0.15 over the 6-yr period, corresponding to an average rate of increase of 3.6 +/- 2.1%, is derived. This rate of increase is lower than indicated by in situ measurements at the South Pole over the same time period, but there is agreement when the rather error bars of the spectral measurement results are considered. Spectroscopic parameters that can successfully model CF(2)C1(2) absorption at low temperatures are needed to improve retrieval accuracies and could be applied to a number of pre-1980 atmospheric spectral data sets in the literature to obtain an improved record of early CF(2)Cl(2) concentration trends for comparison with estimates of historical release rates.

  14. High-Resolution Local Crustal Magnetic Field Modeling of the Martian South Pole

    NASA Astrophysics Data System (ADS)

    Plattner, A.; Simons, F. J.

    2014-12-01

    The Mars Global Surveyor (MGS) satellite mission has brought us a wealth of information about the Martian magnetic field. Besides determining that Mars currently does not possess an active core field, MGS revealed that Mars contains an unexpectedly wide crustal magnetic field intensity range. In its orbit insertion, MGS performed a series of low altitude passes down to around 100 km above surface. During this mission phase the magnetic field measurements were active. In particular the nighttime low-altitude data are of high interest because they contain minimal noise from solar wind. Since these data only cover a small portion of the planet's surface, to date all Martian crustal magnetic field models blend the highest-quality data with lower quality measurements collected either at higher satellite altitudes or during daytime. In this contribution we present a locally inverted crustal magnetic field model for the Martian South Polar region calculated from only the highest-quality MGS data using locally constructed altitude vector Slepian functions. The South Polar region of Mars contains the southern part of the strongly magnetized Terra Sirenum and the area south of the Tharsis volcanic highland. Besides parts of planetary scale features our area of data coverage also contains local features such as the presumably volcanic Australe Montes and the Prometheus impact crater. These ingredients compose a highly heterogeneous crustal magnetic field. We show that even for our dense low-altitude low-noise data set the inversion for the crustal magnetic field of a weakly magnetized region adjacent to a region containing a strong magnetic field leads to artifacts in the weak region. With our local method we can avoid these artifacts by selecting subregions of roughly homogeneous field intensity and individually invert for crustal magnetic fields from data within only these subregions. This regional and subregional modeling allows us to reveal previously obscured crustal

  15. Magnetic Signature of the Lunar South Pole-Aitken Basin: Character, Origin, and Age

    NASA Technical Reports Server (NTRS)

    Purucker, Michael E.; Head, James W., III; Wilson, Lionel

    2012-01-01

    A new magnetic map of the Moon, based on Lunar Prospector (LP) magnetometer observations, sheds light on the origin of the South Pole-Aitken Basin (SPA), the largest and oldest of the recognized lunar basins. A set of WNW-trending linear to arcuate magnetic features, evident in both the radial and scalar observations, covers much of a 1000 km wide region centered on the NW portion of SPA. The source bodies are not at the surface because the magnetic features show no first-order correspondence to any surface topographic or structural feature. Patchy mare basalts of possible late Imbrianage are emplaced within SPA and are inferred to have been emplaced through dikes, directly from mantle sources. We infer that the magnetic features represent dike swarms that served as feeders for these mare basalts, as evident from the location of the Thomson/ Mare Ingenii, Van de Graaff, and Leeuwenhoek mare basalts on the two largest magnetic features in the region. Modeling suggests that the dike zone is between 25 and 50 km wide at the surface, and dike magnetization contrasts are in the range of 0.2 A/m. We theorize that the basaltic dikes were emplaced in the lunar crust when a long-lived dynamo was active. Based on pressure, temperature, and stress conditions prevalent in the lunar crust, dikes are expected to be a dominantly subsurface phenomenon, consistent with the observations reported here.

  16. Magnetic signature of the lunar South Pole-Aitken basin: Character, origin, and age

    NASA Astrophysics Data System (ADS)

    Purucker, Michael E.; Head, James W., III; Wilson, Lionel

    2012-05-01

    A new magnetic map of the Moon, based on Lunar Prospector magnetometer observations, sheds light on the origin of the South Pole-Aitken basin (SPA), the largest and oldest of the recognized lunar basins. A set of WNW-trending linear to arcuate magnetic features, evident in both the radial and scalar observations, covers much of a 1000 km wide region centered on the NW portion of SPA. The source bodies are not at the surface because the magnetic features show no first-order correspondence to any surface topographic or structural feature. Patchy mare basalts of possible late Imbrian-age are emplaced within SPA and are inferred to have been emplaced through dikes, directly from mantle sources. We infer that the magnetic features represent dike swarms that served as feeders for these mare basalts, as evident from the location of the Thomson/Mare Ingenii, Van de Graaff, and Leeuwenhoek mare basalts on the two largest magnetic features in the region. Modeling suggests that the dike zone is between 25 and 50 km wide at the surface, and dike magnetization contrasts are in the range of 0.2 A/m. We theorize that the basaltic dikes were emplaced in the lunar crust when a long-lived dynamo was active. Based on pressure, temperature, and stress conditions prevalent in the lunar crust, dikes are expected to be a dominantly subsurface phenomenon, consistent with the observations reported here.

  17. Technical comment on "Hydrogen mapping of the lunar South Pole using the LRO neutron detector experiment LEND".

    PubMed

    Lawrence, David J; Eke, Vincent R; Elphic, Richard C; Feldman, William C; Funsten, Herbert O; Prettyman, Thomas H; Teodoro, Luis F A

    2011-11-25

    Based on a study of high-energy epithermal (HEE) neutrons in data from the Lunar Exploration Neutron Detector (LEND) on NASA's Lunar Reconnaissance Orbiter (LRO), the background from HEE neutrons is larger than initially estimated. Claims by Mitrofanov et al. (Reports, 22 October 2010, p. 483) of enhanced hydrogen abundance in sunlit portions of the lunar south pole and quantitative hydrogen concentration values in south pole permanently shaded regions are therefore insufficiently supported.

  18. Seasonal variations of atmospheric electricity measured at Amundsen-Scott South Pole Station

    NASA Astrophysics Data System (ADS)

    Reddell, B. D.; Benbrook, J. R.; Bering, E. A.; Cleary, E. N.; Few, A. A.

    2004-09-01

    Recent studies have shown that the general understanding of the Earth's global circuit is not entirely complete. Electric current originates from thunderstorm cloud tops and travels to the ionosphere, where it then leaks back down to the Earth's surface. Superimposed on this current is the dynamo generated from the interaction of the solar wind with Earth's magnetosphere. This paper investigates seasonal variations of the vertical electric field and current density as measured at the South Pole between 1991 and 1993. After initial data reduction, a model approach was used to decouple the magnetospheric and atmospheric components of the measurements. This approach calculated and subtracted the polar cap ionospheric potential from the measured data to obtain a signal of global tropospheric origin, in principle. The diurnal variations of the resulting data were averaged as a function of UT. These averages were calculated for the data as a whole and for the date sorted and binned by season and by magnetic activity level. The seasonally binned average results are consistent with recent papers indicating that the electric field measurement show global convective electrical activity to be a minimum during the Northern Hemisphere winter, in contradiction to the original 1929 Carnegie data. Because the electric field was a maximum during the Northern Hemisphere summer season, the midlatitude regions must contribute more strongly than the tropics to global atmospheric electricity. This analysis supports the link of electrical activity to global temperature. The magnetic activity binned results suggest that the polar cap potential model used underestimates the cross polar cap potential when there is a high Kp index.

  19. BICEP2/SPUD: Searching for Inflation with Degree Scale Polarimetry from the South Pole

    NASA Technical Reports Server (NTRS)

    Nguyen, Hien Trong; Kovac, John; Adec, Peter; Aikin, Randol; Benton, Steve; Bock, Jamie; Brevik, Justus; Carlstrom, John; Dowell, Darren; Duband, Lionel; Golwala, Sunil; Halpern, Mark; Hasselfield, Matthew; Irwin, Kent; Jones, William; Kaufman, Jonathan; Keating, Brian; Kuo, Chao-Lin; Lange, Andrew; Matsumura, Tomotake; Netterfield, Barth; Pryke, Clem; Ruhl, John; Sheehy, Chris; Sudiwala, Rashmi

    2008-01-01

    BICEP2/SPUD is the new powerful upgrade of the existing BICEP1 experiment, a bolometric receiver to study the polarization of the cosmic microwave background radiation, which has been in operation at the South Pole since January 2006. BICEP2 will provide an improvement up to 10 times mapping speed at 150 GHz compared to BICEP1, using the same BICEP telescope mount. SPUD, a series of compact, mechanically-cooled receivers deployed on the DASI mount at the Pole, will provide similar mapping speed in to BICEP2 in three bands, 100, 150, and 220 GHz. The new system will use large TES focal plane arrays to provide unprecedented sensitivity and excellent control of foreground contamination.

  20. Tectonic implications of paleomagnetic poles from Lower Tertiary Volcanic Rocks, south central Alaska

    NASA Astrophysics Data System (ADS)

    Hillhouse, John W.; Grommé, C. Sherman; Csejtey, Bela, Jr.

    1985-12-01

    We have determined the paleolatitude of lower Tertiary volcanic rocks in southern Alaska to measure possible poleward translation of the Wrangellia and the Peninsular terranes after 50 m.y. ago. Previous paleomagnetic studies have shown that in Triassic and Jurassic time these terranes were located near the equator and have moved at least 3000 km poleward relative to the North American craton. Our sample localities are in the northern Talkeetna Mountains in mildly deformed andesite and dacite flows (50.4, 51.3, 53.9, and 56.3 m.y. by K-Ar) that overlap Lower Cretaceous flysch, Lower Permian volcanic rocks of Wrangellia, and Upper Triassic pillow basalt of the Susitna terrane. Results from 26 cooling units (23 of reversed polarity and 3 of normal polarity) give a mean paleomagnetic pole at 69.5°N, 179.6°E, α95 = 12.2°. Stratigraphic sections from opposite limbs of a syncline yield directional paths that pass the fold test, satisfying a necessary condition for primary origin of the magnetization. The corresponding mean paleolatitude (76°N) of the northern Talkeetna Mountains is 8°±10° higher than the latitude predicted from the Eocene reference pole for North America. Therefore, northward drift of the Talkeetna superterrane, which is the amalgamation of the Wrangellia and Peninsular terranes during and after Middle Jurassic time, was probably complete by 50 m.y. ago. Our results are consistent with paleomagnetic poles from uppermost Cretaceous and Paleocene volcanic sequences in Denali National Park, the Lake Clark region, northern Bristol Bay region, and near McGrath. These poles generally lie south of the cratonic poles, suggesting that the region between the Kaltag, Bruin Bay, and Castle Mountain faults has rotated counterclockwise relative to North America since the early Eocene.

  1. Searching for the Remnants of Southern Seas: Cassini Observations of the South Pole of Titan

    NASA Astrophysics Data System (ADS)

    Stofan, Ellen R.; Aharonson, O.; Hayes, A. G.; Kirk, R.; Lopes, R.; Lorenz, R. D.; Lucas, A.; Lunine, J. I.; Malaska, M.; Radebaugh, J.; Stiles, B. W.; Turtle, E. P.; Wall, S. D.; Wood, C. A.; Cassini Radar Team

    2012-10-01

    The north polar region of Titan is home to three large seas along with hundreds of smaller lakes, while the south pole apparently has only two partially filled basins of liquid hydrocarbons. Aharonson et al. [2009] has suggested that cycles analogous to Croll-Milankovich cycles on Earth cause long-term cyclic transfer of hydrocarbons from pole to pole, with the north pole now containing the bulk of the liquids. Less than 50,000 years ago, the cycle would have been reversed, suggesting that the south polar region should contain remnants of southern seas. To identify such seas, we search for features enclosed by an apparent remnant shoreline, with an interior region of smooth (radar-dark) plains. Two such features can be readily identified, each with areal extents of over 100,000 km2, along with several other possible candidate remnant seas or large lakes. One of the possible seas now contains Ontario Lacus. Analysis of the morphologic and topographic characteristics of the two candidate remnant seas can help constrain the possible depth and basin characteristics of the northern seas, as well as possible rates of surface modification in the time since the seas have (largely) dried up. In addition, analysis of the radar characteristics of the remnant sea basins may help us to determine if such processes also acted at equatorial regions where evidence of rainfall [Turtle et al., 2011] and a possible lake has recently been presented [Griffith et al., 2012], and at the more homogeneous mid-latitudes on Titan. References: Aharonson, O. et al., Nature Geoscience 2, 851-854; Griffith, C. et al., Nature 486, 237-239; Turtle, E.P. et al., Science 331, 1414-1417.

  2. A Study of Parallels Between Antarctica South Pole Traverse Equipment and Lunar/Mars Surface Systems

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Hoffman, Stephen, J.; Thur, Paul

    2010-01-01

    The parallels between an actual Antarctica South Pole re-supply traverse conducted by the National Science Foundation (NSF) Office of Polar Programs in 2009 have been studied with respect to the latest mission architecture concepts being generated by the United States National Aeronautics and Space Administration (NASA) for lunar and Mars surface systems scenarios. The challenges faced by both endeavors are similar since they must both deliver equipment and supplies to support operations in an extreme environment with little margin for error in order to be successful. By carefully and closely monitoring the manifesting and operational support equipment lists which will enable this South Pole traverse, functional areas have been identified. The equipment required to support these functions will be listed with relevant properties such as mass, volume, spare parts and maintenance schedules. This equipment will be compared to space systems currently in use and projected to be required to support equivalent and parallel functions in Lunar and Mars missions in order to provide a level of realistic benchmarking. Space operations have historically required significant amounts of support equipment and tools to operate and maintain the space systems that are the primary focus of the mission. By gaining insight and expertise in Antarctic South Pole traverses, space missions can use the experience gained over the last half century of Antarctic operations in order to design for operations, maintenance, dual use, robustness and safety which will result in a more cost effective, user friendly, and lower risk surface system on the Moon and Mars. It is anticipated that the U.S Antarctic Program (USAP) will also realize benefits for this interaction with NASA in at least two areas: an understanding of how NASA plans and carries out its missions and possible improved efficiency through factors such as weight savings, alternative technologies, or modifications in training and

  3. Collection and Analysis of Firn Air from the South Pole, 2001

    NASA Astrophysics Data System (ADS)

    Butler, J. H.; Montzka, S. A.; Battle, M.; Clarke, A. D.; Mondeel, D. J.; Lind, J. A.; Hall, B. D.; Elkins, J. W.

    2001-12-01

    In January 2001, we collected an archive of 20th century air from the firn (snowpack) at the South Pole. Samples were collected into separate pairs of 3L glass flasks for measurements of O2/N2 (Bowdoin/Princeton) and carbon cycle gases (CMDL); individual 3L stainless steel and glass flasks for measurements of halocarbons, N2O, SF6, and COS; large (33L) stainless steel canisters for maintaining an archive of air for future analyses; and a few canisters each for measurement of 14CH4 (NIWA/CSIRO) and very low-level analyses of SF6 (SIO). Although it was hoped to obtain air dating back to the turn of the century, the analyses suggest that the earliest date was 1925 for CO2 and the mid- to late teens for heavier gases such as methyl bromide or methyl chloride. This talk will compare the analyses of halocarbons in these recently collected samples to those of air in flasks sampled at the South Pole in 1995. We also will present some results for compounds not measured in the 1995 South Pole samples owing to a paucity of air. Measurements made of the same gases in the firn air at both ends of this six-year interval, along with real-time atmospheric measurements of the same gases, are useful in evaluating assumptions about diffusion in the firn and may allow for the direct calculation of diffusion coefficients at low temperatures. This, in turn, would improve age estimates for firn air samples. New measurements will add to our existing histories established for the 20th century from analyses of firn air samples collected in both Greenland and Antarctica.

  4. Selecting and Certifying a Landing Site for Moonrise in South Pole-Aitken Basin

    NASA Technical Reports Server (NTRS)

    Jolliff, B.; Watkins, R.; Petro, N.; Moriarty, D.; Lawrence, S.; Head, J.; Pieters, C.; Hagerty, J.; Fergason, R.; Hare, T.; Gaddis, L.; Hayne, P.

    2017-01-01

    MoonRise is a New Frontiers mission concept to land in the South Pole-Aitken (SPA) basin, collect samples, and return the samples to Earth for detailed mineral, chemical, petrologic, geochronologic, and physical properties analyses to address science questions relevant to the early evolution of the Solar System and the Moon. Science associated with this mission concept is described elsewhere; here we discuss selection of sites within SPA to address science objectives using recent scientific studies (orbital spectroscopy, gravity, topography), and the use of new data (LRO) to certify safe landing sites for a robotic sample return mission such as MoonRise.

  5. Test of Lorentz Invariance with a RB-21NE Comagnetometer at the South Pole

    NASA Astrophysics Data System (ADS)

    Smiciklas, M. A.; Romalis, M. V.

    2014-01-01

    Atomic spin comagnetometers are among the most sensitive devices for testing Lorentz symmetry of fermions. In Princeton, we have used our rotating comagnetometer to set the most stringent limits on CPT-odd and CPT-even Lorentz violating effects in neutrons. However, gyroscopic pickup of the Earth's rotation represents a significant systematic effect limiting sensitivity. To suppress this systematic, we have installed a Rb-21Ne comagnetometer at the Amundsen-Scott South Pole Station with data collection being performed over the course of the austral winter.

  6. 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

  7. Testing a Prototype for a New Cosmic Ray Particle Detector at the South Pole

    NASA Astrophysics Data System (ADS)

    Howell, R.; Rimsa, E.; Tharp, T.; Andeen, K.

    2017-01-01

    Cosmic ray research has grown rapidly in the past century, often using vacuum photomultiplier tubes (PMTs) to analyze the light produced by high-energy particles passing through scintillating material. Silicon photomultipliers (SiPMs) are now being recognized as a more efficient alternative to PMTs. Different types of photon events have been characterized using a SensL brand SiPM in combination with a QuarkNet Data Acquisition board. The goal of this study is to test the viability of the SiPM for a new generation surface detector at the South Pole.

  8. Surveying the South Pole-Aitken basin magnetic anomaly for remnant impactor metallic iron

    USGS Publications Warehouse

    Cahill, Joshua T.S.; Hagerty, Justin J.; Lawrence, David M.; Klima, Rachel L.; Blewett, David T.

    2014-01-01

    The Moon has areas of magnetized crust ("magnetic anomalies"), the origins of which are poorly constrained. A magnetic anomaly near the northern rim of South Pole-Aitken (SPA) basin was recently postulated to originate from remnant metallic iron emplaced by the SPA basin-forming impactor. Here, we remotely examine the regolith of this SPA magnetic anomaly with a combination of Clementine and Lunar Prospector derived iron maps for any evidence of enhanced metallic iron content. We find that these data sets do not definitively detect the hypothesized remnant metallic iron within the upper tens of centimeters of the lunar regolith.

  9. Optimization of transition edge sensor arrays for cosmic microwave background observations with the south pole telescope

    SciTech Connect

    Ding, Junjia; Ade, P. A. R.; Anderson, A. J.; Avva, J.; Ahmed, Z.; Arnold, K.; Austermann, J. E.; Bender, A. N.; Benson, B. A.; Bleem, L. E.; Byrum, K.; Carlstrom, J. E.; Carter, F. W.; Chang, C. L.; Cho, H. M.; Cliche, J. F.; Cukierman, A.; Czaplewski, D.; Divan, R.; de Haan, T.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Gilbert, A.; Gannon, R.; Guyser, R.; Halverson, N. W.; Harrington, N. L.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Hubmayr, J.; Huang, N.; Irwin, K. D.; Jeong, O.; Khaire, T.; Kubik, D.; Kuo, C. L.; Lee, A. T.; Leitch, E. M.; Meyer, S. S.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Shariff, J. A.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J.; Stan, L.; Stark, A. A.; Story, K.; Suzuki, A.; Tang, Q. Y.; Thakur, R. B.; Thompson, K. L.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Wu, W. L. K.; Yefremenko, V.; Yoon, K. W.

    2016-12-15

    In this study, we describe the optimization of transition-edge-sensor (TES) detector arrays for the thirdgeneration camera for the South PoleTelescope.The camera,which contains ~16 000 detectors, will make high-angular-resolution maps of the temperature and polarization of the cosmic microwave background. Our key results are scatter in the transition temperature of Ti/Au TESs is reduced by fabricating the TESs on a thin Ti(5 nm)/Au(5 nm) buffer layer and the thermal conductivity of the legs that support our detector islands is dominated by the SiOx dielectric in the microstrip transmission lines that run along

  10. Mach-Zehnder Modulator Performance on the NIF South Pole Bang Time Diagnostic

    SciTech Connect

    Beeman, B.; MacPhee, A. G.; Kimbrough, J. R.; Chow, R.; Carpenter, A.; Bond, E.; Zayas-Rivera, Z.; Bell, P.; Celeste, J.; Clancy, T.; Miller, E. K.; Edgell, D.; Donaldson, W. R.

    2013-09-01

    We present performance data for Mach-Zehnder optical modulators fielded on the National Ignition Facility (NIF) as a potential signal path upgrade for the South Pole Bang Time diagnostic. A single channel demonstration system has been deployed utilizing two modulators operating in a 90-degree In phase and Quadrature (I/Q) configuration. X-ray target emission signals are split and fed into two recording systems: a reference CRT based oscilloscope, Greenfield FTD10000, and the dual Mach-Zehnder system. Results of X-ray implosion time (bang time) determination from these two recording systems are compared and presented.

  11. Record low ozone at the south pole in the Spring of 1993

    SciTech Connect

    Hofmann, D.J.; Oltmans, S.J.; Lathrop, J.A.; Harris, J.M.; Voemel, H. )

    1994-03-15

    On October 12, 1993, a balloon-borne ozone detector recorded a total ozone value of 91[+-]5 Dobson Units (DU) at the US Amundsen-Scott Station at the south pole. This is the lowest value of total ozone ever recorded anywhere, 13% below the previous low of 105 DU at the south pole in October of 1992. A region with a thickness of 5 km, from 14 to 19 km, was totally devoid of ozone as compared to only about half this thickness for the ozone void in 1992. Sub-100 DU total ozone values were observed on several soundings during 1993 whereas the 105 DU value was observed on only one occasion in 1992. The vertical profile of ozone indicates that the main reason for the record low ozone values in 1993 was an approximately 1 km upward extension of the ozone hole caused by unusual ozone loss in the 18-23 km region. Temperatures in this region were unusually low in September and October. Thus, the extension of the ozone hole may have been the result of the prolonged presence of polar stratospheric clouds at 18-23 km combined with the continued presence of sulfate aerosol from the Pinatubo eruption and, finally, increased chlorine levels. This scenario resulted in elevated ozone loss in a region where the ozone loss process is normally not saturated. 8 refs., 4 figs.

  12. SPT-3G: The third generation camera and survey for the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Henning, Jason; SPT-3G Collaboration

    2015-01-01

    We discuss the design and status of the third generation camera, SPT-3G, for the South Pole Telescope (SPT), and the scientific goals of the resultant SPT-3G survey. The SPT is a 10-m telescope located at the NSF Amundsen-Scott South Pole station optimized for low-noise and high-resolution imaging of the cosmic microwave background (CMB). The camera will consist of 16,200 polarization-sensitive transition-edge sensors (TES), contained within 2,700 multichroic pixels with observing bands centered at 95, 150, and 220 GHz. The SPT-3G survey will observe for four years starting in 2016. It will map 2500 square degrees to a depth of approximately 2 μK·arcmin in temperature: an order of magnitude lower noise than current state-of-the-art arcminute-scale surveys over comparable areas. This unprecedented map depth will enable high signal-to-noise imaging of B-modes due to gravitational lensing of the CMB. These measurements will place constraints on the sum of the neutrino masses and the shape and amplitude of an inflationary B-mode signal at larger angular scales. The SPT-3G survey will also detect several thousand clusters, in particular significantly expanding the number of known high-redshift massive clusters, enabling new constraints on gravity and cosmology.

  13. Hydrology-based understanding of Ontario Lacus in Titan's south pole

    NASA Astrophysics Data System (ADS)

    Dhingra, Rajani D.; Barnes, Jason W.; Yanites, Brian J.; Kirk, Randolph L.

    2015-11-01

    Ontario Lacus is the largest presently filled lake at the south pole of Titan. Many other large basins in south pole exist at lower elevations than Ontario Lacus but are currently empty. To find out what sets Ontario apart from those empty basins, we have carried a detailed hydrological assessment of Ontario Lacus. Topography of the region, as derived from Cassini RADAR altimetry was used to determine the catchment area of Ontario Lacus. We could map the areal extent of catchments as far as southern mid-latitudes. Clouds in southern mid and high latitudes have been observed by Cassini VIMS which indicate possible precipitation in those regions. Precipitation in southern mid-latitudes coupled with the large catchment areas of Ontario Lacus could be the reason behind it being filled. Our mass conservation calculations indicate that if runoff was the only contributor to the lake volume, then the lake might be filled within one Titan year (29.5 Earth years) in entirety. We also observe a non-linear relationship between the longest identifiable stream and the catchment area (Hack's Law) which is consistent with terrestrial hydrological systems and may help in further interpretation of the hydrology of Ontario Lacus.

  14. Baseline acidity of precipitation at the South Pole during the last two millennia

    NASA Astrophysics Data System (ADS)

    Cragin, J. H.; Giovinetto, M. B.; Gow, A. J.

    Measurements of meltwater pH from annual layers of South Pole firn and ice samples ranging in age from 40 to 2000 years B.P. show that precipitation at this remote site has a higher natural acidity than that expected from atmospheric equilibrium with CO2. The average pH of deaerated (CO2-free) samples was 5.64 ± 0.08, while air-equilibrated samples averaged 5.37 ± 0.08, a pH that is about a factor of two more acidic than the expected background pH of 5.65. The observed “excess” acidity can be accounted for by SO42- and NO3- levels in the samples originating from non-anthropogenic H2SO4 and HNO3. Because of the presence of these naturally occurring acids in South Pole precipitation, a pH of 5.4 is considered a more representative baseline reference pH for acid precipitation studies.

  15. A test field for Gaia. Radial velocity catalogue of stars in the South Ecliptic Pole

    NASA Astrophysics Data System (ADS)

    Frémat, Y.; Altmann, M.; Pancino, E.; Soubiran, C.; Jofré, P.; Damerdji, Y.; Heiter, U.; Royer, F.; Seabroke, G.; Sordo, R.; Blanco-Cuaresma, S.; Jasniewicz, G.; Martayan, C.; Thévenin, F.; Vallenari, A.; Blomme, R.; David, M.; Gosset, E.; Katz, D.; Viala, Y.; Boudreault, S.; Cantat-Gaudin, T.; Lobel, A.; Meisenheimer, K.; Nordlander, T.; Raskin, G.; Royer, P.; Zorec, J.

    2017-01-01

    Context. Gaia is a space mission that is currently measuring the five astrometric parameters, as well as spectrophotometry of at least 1 billion stars to G = 20.7 mag with unprecedented precision. The sixth parameter in phase space (i.e., radial velocity) is also measured thanks to medium-resolution spectroscopy that is being obtained for the 150 million brightest stars. During the commissioning phase, two fields, one around each ecliptic pole, have been repeatedly observed to assess and to improve the overall satellite performances, as well as the associated reduction and analysis software. A ground-based photometric and spectroscopic survey was therefore initiated in 2007, and is still running to gather as much information as possible about the stars in these fields. This work is of particular interest to the validation of the radial velocity spectrometer outputs. Aims: The paper presents the radial velocity measurements performed for the Southern targets in the 12-17 R magnitude range on high- to mid-resolution spectra obtained with the GIRAFFE and UVES spectrographs. Methods: Comparison of the South Ecliptic Pole (SEP) GIRAFFE data to spectroscopic templates observed with the HERMES (Mercator in La Palma, Spain) spectrograph enabled a first coarse characterisation of the 747 SEP targets. Radial velocities were then obtained by comparing the results of three different methods. Results: In this paper, we present an initial overview of the targets to be found in the 1 sq. deg SEP region that was observed repeatedly by Gaia ever since its commissioning. In our representative sample, we identified one galaxy, six LMC S-stars, nine candidate chromospherically active stars, and confirmed the status of 18 LMC Carbon stars. A careful study of the 3471 epoch radial velocity measurements led us to identify 145 RV constant stars with radial velocities varying by less than 1 km s-1. Seventy-eight stars show significant RV scatter, while nine stars show a composite spectrum

  16. Nature of the South Pole on Mars Determined by Topographic Forcing of Atmosphere Dynamics

    NASA Technical Reports Server (NTRS)

    Colaprete, A.; Barnes, Jeffrey R.; Haberle, Robert M.; Hollingsworth, Jeffery L.; Kieffer, Hugh H.; Titus, Timothy N.

    2005-01-01

    Introduction: The observed Springtime (Ls approx. 200) surface albedo in the Martian southern polar region is shown in Figure 1. In general, the hemisphere west of Hellas is marked by relatively high values of surface albedo. In contrast, the hemisphere east of Hellas contains extensive regions of very low surface albedo. One of the brightest features within the western hemisphere is the South Pole Residual Cap (SPRC). The dark region, which dominates the eastern hemisphere, is the "Cryptic" region[1]. The nature of the SPRC has been the source of considerable debate since its identification as CO2 ice by the Viking spacecraft. Two fundamental questions still exist regarding the SPRC s formation, location and stability. First, why is the SPRC offset from the geographic pole? There are no local topographic features or surface properties that can account for the offset in the SPRC. Second, does the SPRC represent a large or a small reservoir of CO2? If the former, then it could possibly buffer the surface pressure. If the latter, then the SPRC may not survive every year.

  17. Mesosphere and Lower-Thermosphere Wind Observations from a New South Pole Meteor Radar

    NASA Astrophysics Data System (ADS)

    Avery, S. K.; Palo, S. E.; Avery, J. P.; Lu, Y.

    2002-12-01

    A new meteor radar with altitude resolution was installed at the Amundsen-Scott South Pole station as part of the TIMED/CEDAR program. The radar has been operating almost continuously for 8 months. Preliminary results from late January through February 2002 have been obtained using various analysis techniques. During this period of time, the averaged hourly winds were projected onto 8 different longitude meridians in the height range spanning 80-105 km with a 5 km height resolution. Our results show the presence of waves with periods of 12, 24, and 72 hours that propagate westward and are consistent with a zonal wavenumber one longitudinal structure. A zonal wavenumber of 2 is also present at times for the semidiurnal wave period. During this period, a consistent divergent wind pattern where the wind vectors are northward (away from the pole) at all longitudes occurs from 1700-0200 UT while cross polar winds are present at all other times. This paper will present these preliminary features of the wind field and discuss future comparison with TIMED measurements and other Antarctica radar measurements.

  18. South pole bang-time diagnostic on the National Ignition Facility

    SciTech Connect

    MacPhee, A; Edgell, D; Bradley, D K; Bond, E J; Burns, S; Callahan, D A; Celeste, J; Kimbrough, J; Mackinnon, A J; Magoon, J; Eckart, M J; Glebov, V; Hey, D; Lacielle, G; Kilkenny, J; Parker, J; Sangster, T C; Shoup, M J; Stoeckl, C; Thomas, T

    2012-05-01

    The south pole bang-time (SPBT) diagnostic views National Ignition Facility (NIF) implosions through the lower hohlraum laser entrance hole to measure the time of peak x-ray emission (peak compression) in indirect drive implosions. Five chemical-vapor-deposition (CVD) diamond photoconductive detectors (PCD's) with different filtrations and sensitivities record the time-varying x rays emitted by the target. Wavelength-selecting highly oriented pyrolytic graphite (HOPG) crystal mirror monochromators increase the x-ray signal-to-background ratio by filtering for 11-keV emission. Diagnostic timing and the in-situ temporal instrument response function are determined from laser impulse shots on the NIF. After signal deconvolution and background removal, the bang time is determined to 45-ps accuracy. The x-ray 'yield' (mJ/sr/keV at 11 keV) is determined from the total area under the peak.

  19. Absolute measurements of the cosmic microwave background from Amundsen-Scott South Pole Station

    SciTech Connect

    Bersanelli, S.; Bonelli, G.; Sironi, G. ); Levin, S. ); Smoot, G.F.; Bensadoun, M.; De Amici, G.; Limon, M.; Vinje, W. )

    1993-01-01

    Observations of the cosmic microwave background play a central role in modern cosmology. The existence of the CMB as a remanent of the early Universe has constituted a pillar for the Big Bang scenario. The recent cosmic background explorer differential microwave radiometer results have provided further support to the generally accepted standard model by detecting for the first time primordial fluctuations in the CMB field at the limits expected by structure formation theories. An international program of ground-based absoluted measurements of the CMB at the centimeter and multicentimeter wavelengths was initiated in 1982. This paper reports results at the South Pole, one of a few areas of low-background environments. 12 refs., 2 tabs.

  20. The south pole automatic condensation nuclei counter: instrument details and five years of observations

    SciTech Connect

    Murphy, M.E.; Bodhaine, B.A.

    1980-02-01

    An automatic General Electric (G.E.) condensation nuclei counter has been operating continuously at the Amundson-Scott South Pole station since 1974 as part of the Geophysical Monitoring for Climatic Change (GMCC) program. This instrument (calibrated by a Pollak nuclei counter standard), with its high sensitivity and fast response, can provide continuous aerosol climatology and identify periods of contamination from local sources. The annual variation of nuclei concentration is apparent and is repeatably consistent over the five year period. Nuclei concentrations occasionally reach values as low as 7/cu cm during the austral winter (April through September), begin to increase near the time of astronomical sunrise, and reach values as high as about 240/cu cm during summer months. The continuously operating G.E. condensation nuclei counter in conjunction with the Pollak nuclei counter, have produced an excellent data set over the five year period, 1974-1978.

  1. Measurements of OH, H2SO4, and MSA at the South Pole during ISCAT

    NASA Astrophysics Data System (ADS)

    Mauldin, R. L., III; Eisele, F. L.; Tanner, D. J.; Kosciuch, E.; Shetter, R.; Lefer, B.; Hall, S. R.; Nowak, J. B.; Buhr, M.; Chen, G.; Wang, P.; Davis, D.

    The first measurements of OH, H2SO4, and MSA performed at the South Pole as part of the Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) study are presented. OH concentrations were found to be quite elevated for such a dry environment, with average values of 2x106 molecule cm-3. Model simulations suggest that much of the observed OH is a result of unexpectedly high NO concentrations. Concentrations of H2SO4 and MSA were generally low with average values of 2.5x105 and 1x105 molecule cm-3, respectively. Major variations in the concentration levels of the above species were found to have a high correlation with changes in the polar mixing layer as estimated from the measured temperature difference from 22 to 2m above the snow surface. Chemical details are discussed.

  2. The nature and origin of Mafic Mound in the South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Moriarty, Daniel P.; Pieters, Carle M.

    2015-10-01

    "Mafic Mound" is a distinctive and enigmatic feature 75 km across and 1 km high near the center of the vast South Pole-Aitken Basin (SPA). Using several modern data sets, we characterize the composition, morphology, and gravity signature of the structure in order to assess its origin. Mafic Mound is found to exhibit a perched circular depression and a homogeneous high-Ca pyroxene-bearing composition. Several formation hypotheses based on known lunar processes are evaluated, including the possibilities that Mafic Mound represents (1) uplifted mantle, (2) SPA-derived impact melt, (3) a basalt-filled impact crater, or (4) a volcanic construct. Individually, these common processes cannot fully reproduce the properties of Mafic Mound. Instead, we propose a hybrid origin in which Mafic Mound is an edifice formed by magmatic processes induced by the formation and evolution of SPA. This form of nonmare volcanism has not previously been documented on the Moon.

  3. Small satellites with micro-propulsion for communications with the Lunar South Pole Aitkens Basin

    NASA Astrophysics Data System (ADS)

    Haque, Samudra E.; Straub, Jeremy; Whalen, David

    A lunar sample return mission to the Lunar South-Pole Aitkens Basin (LSPAB) has been highlighted as a high priority objective of the most recent (2011) Decadal Survey for Planetary Science, by the National Research Council. This class of mission, however, faces a dramatic communications limitation, due to the lack of a frequent, or continuous, line-of-sight communications path to Earth-based ground stations. Brunner and others have proposed a communications system utilizing Low Lunar Polar Orbits (LLPO) and Lunar Halo orbits for this purpose. Ely and others have outlined proposals for using several communication satellites to form a relay network using LLPO, taking into account the Lunar masscon's that would perturb such orbits. However, any relay network of communication satellites would still have to connect back to a suitable Earth-based ground station (Near Earth Network, or otherwise), or a tracking and data relaying satellite (e.g., TDRS).

  4. Searching for Primordial Gravitational Waves at Degree Scales from the South Pole

    NASA Astrophysics Data System (ADS)

    Brevik, Justus A.

    We report on the preliminary performance of the BICEP2 mm-wave polarimeter, deployed in 2009 to the South Pole and will observe through 2012. BICEP2 is currently imaging the polarization of the cosmic microwave background at 150 GHz using an array of 512 antenna-coupled superconducting bolometers. It has been designed for high sensitivity and low systematics in order to pursue the primordial B-mode polarization signal. The instrument and its characterization are presented in this thesis, with particular attention to the detectors and readout system. The instrument sensitivity, mapping speed are discussed along with the expected constraint on the scalar-to-tensor ratio that should be made from one year of data.

  5. Thorium Anomalies in the NW Quadrant of the South Pole-Aitken Basin

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.; McKinnon, William B.; Benner, Lance A. M.; Jolliff, Bradley L.

    2004-01-01

    The relatively high concentrations of Th near the Imbrium antipode in the South Pole-Aitken (SPA) basin might represent Imbrium ejecta, a consequence of convergence of Th-rich material ejected by the Imbrium impact that occurred in the Th-rich Procellarum KREEP Terrane. Here, we present landing positions for 7500 fragments ejected from Imbrium obtained by three-body (Earth-Moon-fragment) numerical integration for uniformly selected azimuthal launch positions, ejection angles of 45 deg, and velocities from 0.95 to 0.99 lunar escape. This provides an estimate of the density of infalling ejecta fragments to be expected in the vicinity of the Imbrium antipode. Similar calculations for 35 and 50 deg leave large empty regions surrounding the antipode.

  6. The Optical Gravitational Lensing Experiment. Gaia South Ecliptic Pole Field as Seen by OGLE-IV

    NASA Astrophysics Data System (ADS)

    Soszyński, I.; Udalski, A.; Poleski, R.; Kozłowski, S.; Wyrzykowski, Ł.; Pietrukowicz, P.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Ulaczyk, K.; Skowron, J.

    2012-09-01

    We present a comprehensive analysis of the Gaia South Ecliptic Pole (GSEP) field, 5.3 square degrees area around the South Ecliptic Pole on the outskirts of the LMC, based on the data collected during the fourth phase of the Optical Gravitational Lensing Experiment, OGLE-IV. The GSEP field will be observed during the commissioning phase of the ESA Gaia space mission for testing and calibrating the Gaia instruments. We provide the photometric maps of the GSEP region containing the mean VI photometry of all detected stellar objects and their equatorial coordinates. We show the quality and completeness of the OGLE-IV photometry and color-magnitude diagrams of this region. We conducted an extensive search for variable stars in the GSEP field leading to the discovery of 6789 variable stars. In this sample we found 132 classical Cepheids, 686 RR Lyr type stars, 2819 long-period, and 1377 eclipsing variables. Several objects deserving special attention were also selected, including a new classical Cepheid in a binary eclipsing system. To provide empirical data for the Gaia Science Alert system we also conducted a search for optical transients. We discovered two firm type Ia supernovae and nine additional supernova candidates. To facilitate future Gaia supernovae detections we prepared a list of more than 1900 galaxies to redshift about 0.1 located in the GSEP field. Finally, we present the results of astrometric study of the GSEP field. With the 26 months time base of the presented here OGLE-IV data, proper motions of stars could be detected with the accuracy reaching 2 mas/yr. Astrometry allowed to distinguish galactic foreground variable stars detected in the GSEP field from LMC objects and to discover about 50 high proper motion stars (proper motion ≥ 100 mas/yr). Among them three new nearby white dwarfs were found. All data presented in this paper are available to the astronomical community from the OGLE Internet archive.

  7. Further study of flickering auroral roar emission: 1. South Pole observations

    NASA Astrophysics Data System (ADS)

    Ye, S.; Labelle, J.; Weatherwax, A. T.

    2006-07-01

    Hughes and LaBelle (2001) reported a single example of a new geophysical phenomenon: ˜10 Hz modulation of auroral radio emissions near twice the auroral ionospheric electron gyrofrequency. They called this phenomenon flickering auroral roar and suggested that it is related to flickering aurora, which results from ˜10 Hz modulation of the precipitating auroral electrons. Observations at South Pole Station during 2003 using a new high-bandwidth receiving system have yielded 10 examples of flickering roar emissions. Although 10 examples is still a small number for statistics, these observations considerably extend previous knowledge of this phenomenon which was based on a single example. On the basis of the 2003 South Pole data set, flickering auroral roar accounts for only about 1-2% of auroral roar in number of seconds, but ˜20% of auroral roar events have some flickering feature. The observed modulation frequencies range from ˜3 to 30 Hz. The 10- to 20-Hz modulations, which correspond to about 65% of the time when flickering roar occurs, are much more common than the higher-frequency 20- to 30-Hz modulations, which correspond to about 20% of the time when flickering roar occurs. These frequencies compare favorably with optical observations of auroral emissions, rocket observations of electron flux modulations, and modeling results. If these frequencies correspond to the oxygen gyrofrequency where electrons and ion cyclotron waves interact, the 3- to 30-Hz frequency range would imply sources at altitudes of 1500-10,500 km. Six of the ten flickering roar examples occurred during substorm expansion phase as defined from local magnetometer data, in contrast to flickering aurora, which is usually observed after the onset of auroral breakup.

  8. 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).

  9. Crustal architecture of the Transantarctic Mountains between the Scott and Reedy Glacier region and South Pole from aerogeophysical data

    NASA Astrophysics Data System (ADS)

    Studinger, Michael; Bell, Robin E.; Fitzgerald, Paul G.; Buck, W. Roger

    2006-10-01

    Aerogeophysical data collected in transects between the South Pole and West Antarctica, crossing the Transantarctic Mountains at the 150°W meridian, are used to constrain the sub-ice topography, the sub-ice geology and the inland structure of the Transantarctic Mountains. Forward modeling of gravity data suggests slight crustal thickening of 5 km beneath the mountain front indicating partial isostatic compensation by thickened crust. New magnetic data help characterize the sub-ice geology inland of the Transantarctic Mountains with the observed magnetic anomaly field dominated by Granite Harbour Intrusives, similar to the magnetic field in Victoria Land. However, the typical pattern of anomalies caused by Jurassic tholeiitic magmatism elsewhere along the Transantarctic Mountains is not observed, nor is the mesa topography that is often associated with the Ferrar Dolerite. Together, these observations rule out the widespread presence of Ferrar Dolerite sills within the survey area. A pronounced magnetic lineament, herein named the South Pole Lineament, parallel to the 0°/180° longitudinal meridian, beneath the South Pole defines a previously unknown tectonic trend of the East Antarctic craton. The lineament suggests the presence of a lithospheric-scale structure beneath South Pole, projecting into a fault mapped from ice-penetrating radar data and extending to Shackleton Glacier, the site of a major geological boundary across the Transantarctic Mountains. Potentially, the lineament is the expression of the edge of the undeformed craton, an inherited structure created during assembly or breakup of Rodinia and Gondwana supercontinents; or an intracontinental transform.

  10. Albedo of the south pole on Mars determined by topographic forcing of atmosphere dynamics

    USGS Publications Warehouse

    Colaprete, A.; Barnes, J.R.; Haberle, R.M.; Hollingsworth, J.L.; Kieffer, H.H.; Titus, T.N.

    2005-01-01

    The nature of the martian south polar cap has remained enigmatic since the first spacecraft observations. In particular, the presence of a perennial carbon dioxide ice cap, the formation of a vast area of black 'slab ice' known as the Cryptic region and the asymmetric springtime retreat of the cap have eluded explanation. Here we present observations and climate modelling that indicate the south pole of Mars is characterized by two distinct regional climates that are the result of dynamical forcing by the largest southern impact basins, Argyre and Hellas. The style of surface frost deposition is controlled by these regional climates. In the cold and stormy conditions that exist poleward of 60?? S and extend 180?? in longitude west from the Mountains of Mitchel (???30?? W), surface frost accumulation is dominated by precipitation. In the opposite hemisphere, the polar atmosphere is relatively warm and clear and frost accumulation is dominated by direct vapour deposition. It is the differences in these deposition styles that determine the cap albedo.

  11. Albedo of the South Pole on Mars Determined by Topographic Forcing of Atmosphere Dynamics

    NASA Technical Reports Server (NTRS)

    Colaprete, Anthony; Barnes, Jeffrey R.; Haberle, Robert M.; Hollingsworth, Jeffery L.; Kleffer, Hugh H.; Titus, Timothy N.

    2005-01-01

    The nature of the martian south polar cap has remained enigmatic since the first spacecraft observations. In particular, the presence of a perennial carbon dioxide ice cap, the formation of a vast area of black slab ice known as the Cryptic region and the asymmetric springtime retreat of the cap have eluded explanation. Here we present observations and climate modelling that indicate the south pole of Mars is characterized by two distinct regional climates that are the result of dynamical forcing by the largest southern impact basins, Argyre and Hellas. The style of surface frost deposition is controlled by these regional climates. In the cold and stormy conditions that exist poleward of 60 degrees S and extend 180 degrees in longitude west from the Mountains of Mitchel (about 30 degrees W), surface frost accumulation is dominated by precipitation. In the opposite hemisphere, the polar atmosphere is relatively warm and clear and frost accumulation is dominated by direct vapour deposition. It is the differences in these deposition styles that determine the cap albedo.

  12. Hydrogen mapping of the lunar south pole using the LRO neutron detector experiment LEND.

    PubMed

    Mitrofanov, I G; Sanin, A B; Boynton, W V; Chin, G; Garvin, J B; Golovin, D; Evans, L G; Harshman, K; Kozyrev, A S; Litvak, M L; Malakhov, A; Mazarico, E; McClanahan, T; Milikh, G; Mokrousov, M; Nandikotkur, G; Neumann, G A; Nuzhdin, I; Sagdeev, R; Shevchenko, V; Shvetsov, V; Smith, D E; Starr, R; Tretyakov, V I; Trombka, J; Usikov, D; Varenikov, A; Vostrukhin, A; Zuber, M T

    2010-10-22

    Hydrogen has been inferred to occur in enhanced concentrations within permanently shadowed regions and, hence, the coldest areas of the lunar poles. The Lunar Crater Observation and Sensing Satellite (LCROSS) mission was designed to detect hydrogen-bearing volatiles directly. Neutron flux measurements of the Moon's south polar region from the Lunar Exploration Neutron Detector (LEND) on the Lunar Reconnaissance Orbiter (LRO) spacecraft were used to select the optimal impact site for LCROSS. LEND data show several regions where the epithermal neutron flux from the surface is suppressed, which is indicative of enhanced hydrogen content. These regions are not spatially coincident with permanently shadowed regions of the Moon. The LCROSS impact site inside the Cabeus crater demonstrates the highest hydrogen concentration in the lunar south polar region, corresponding to an estimated content of 0.5 to 4.0% water ice by weight, depending on the thickness of any overlying dry regolith layer. The distribution of hydrogen across the region is consistent with buried water ice from cometary impacts, hydrogen implantation from the solar wind, and/or other as yet unknown sources.

  13. Radar Imaging of Mercury's North and South Poles at 3.5 cm Wavelength

    NASA Technical Reports Server (NTRS)

    Harcke, L. J.; Zebker, H. A.; Jurgens, R. F.

    2001-01-01

    The Goldstone Solar System Radar has been used to image the north and south poles of Mercury during the inferior conjunctions of February 2001 and June 2001. The sub-Earth latitude was -10.7 degrees in February during observations of the southern hemisphere, and +8.4 degrees in June during observations of the northern hemisphere. These excellent viewing angles provided an opportunity to resolve the radar bright material in polar craters at 6 km range resolution. Fine-scale (1.5 km) resolution images of the northern craters have previously been obtained at 13 cm wavelengths during the July 1999 inferior conjunction. However, due to geometric constraints, the Arecibo radar cannot observe the southern polar region of Mercury until 2004. Our new Goldstone 6 km data are a factor of two higher resolution than Arecibo data collected in March 1992 at 15 km range resolution, and will remain the most highly resolved images of the south polar region for the next few years. Additional information is contained in the original extended abstract.

  14. LRO Camera Imaging of Potential Landing Sites in the South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Jolliff, B. L.; Wiseman, S. M.; Gibson, K. E.; Lauber, C.; Robinson, M.; Gaddis, L. R.; Scholten, F.; Oberst, J.; LROC Science; Operations Team

    2010-12-01

    We show results of WAC (Wide Angle Camera) and NAC (Narrow Angle Camera) imaging of candidate landing sites within the South Pole-Aitken (SPA) basin of the Moon obtained by the Lunar Reconnaissance Orbiter during the first full year of operation. These images enable a greatly improved delineation of geologic units, determination of unit thicknesses and stratigraphy, and detailed surface characterization that has not been possible with previous data. WAC imaging encompasses the entire SPA basin, located within an area ranging from ~ 130-250 degrees east longitude and ~15 degrees south latitude to the South Pole, at different incidence angles, with the specific range of incidence dependent on latitude. The WAC images show morphology and surface detail at better than 100 m per pixel, with spatial coverage and quality unmatched by previous data sets. NAC images reveal details at the sub-meter pixel scale that enable new ways to evaluate the origins and stratigraphy of deposits. Key among new results is the capability to discern extents of ancient volcanic deposits that are covered by later crater ejecta (cryptomare) [see Petro et al., this conference] using new, complementary color data from Kaguya and Chandrayaan-1. Digital topographic models derived from WAC and NAC geometric stereo coverage show broad intercrater-plains areas where slopes are acceptably low for high-probability safe landing [see Archinal et al., this conference]. NAC images allow mapping and measurement of small, fresh craters that excavated boulders and thus provide information on surface roughness and depth to bedrock beneath regolith and plains deposits. We use these data to estimate deposit thickness in areas of interest for landing and potential sample collection to better understand the possible provenance of samples. Also, small regions marked by fresh impact craters and their associated boulder fields are readily identified by their bright ejecta patterns and marked as lander keep-out zones

  15. An Early Cretaceous paleomagnetic pole from Ponta Grossa dikes (Brazil): Implications for the South American Mesozoic apparent polar wander path

    NASA Astrophysics Data System (ADS)

    Bartolomeu Raposo, Maria Irene; Ernesto, Marcia

    1995-10-01

    Paleomagnetic results from the Early Cretaceous Ponta Grossa dike swarm are reported. These dikes crosscut sediments and basement rocks associated with the Ponta Grossa Arch, a tectonic feature in the eastern border of the Paleozoic-Mesozoic Paraná Basin. These dikes are vertical or subvertical and trend mainly NW and NE. Samples from 127 dikes were submitted to both alternating field and thermal demagnetizations; 121 of them yielded characteristic directions interpreted as original thermal remanent magnetizations. Both normal and reversed polarities as well as intermediate directions (6 dikes) are recorded. The paleomagnetic pole is located at 30.3°E, 82.4°S (N=115; α95=2.0° k=43.8). This pole along with the available paleomagnetic poles for the Paraná Basin volcanics (Serra Geral Formation), recalculated in this paper in the light of reported 40Ar/39Ar ages describe an apparent polar wander path segment corresponding to a clockwise rotation (~6.9°) of the South American plate. This movement is compatible with the initial phase of the South Atlantic opening with rifting progressing from south to north. However, the calculated plate velocity is higher than the predicted velocities reported so far based on oceanic floor magnetic anomalies. The new data reported in this paper allowed the calculation of a mean Early Cretaceous pole (60.3°E, 83.8°S N=7, α95=2.9°) which can be discriminated from the Middle-Late Jurassic (191.3°E, 86.2°S N=3, α95=7.8°) and Late Cretaceous (346.5°E, 84.1°S N=5, α95=4.9°) mean poles for South America, indicating a more complex movement of the continent than the simple east-west drift generally proposed.

  16. Boundary Layer and Synoptic Effects on NO Concentrations at the South Pole: A Multiyear Perspective

    NASA Astrophysics Data System (ADS)

    Neff, William; Davis, Douglas

    2015-04-01

    A series of experiments have explored the behavior of NO concentrations at the South Pole as part of the ISCAT (1998, 2000) and ANTCI (2003, 2005, 2006-7) field programs [Davis et al., 2008]. The relationship between NO and boundary layer depth (BLD) proposed by [Davis et al., 2004] was verified by [Neff et al., 2008] using direct sodar measurements of BLD during the period November-December 2003. A longer time series of NOx was generated in the ANTCI program from sunrise in 2006 into summer 2007. However, no direct BLD measurements were available. To address this deficiency, we used multiple linear regression on data from 2003 where both directly observed BLD and meteorological variables were recorded. This analysis showed that the three most important variables were wind speed (r2=0.56), Delta T2-22m (r2=0.32), and wind direction (r2=0.10). The strong dependence on wind speed is consistent with the results of [Neff et al., 2008] showing the dependence of BLD on surface stress (representing turbulent mixing of momentum to the surface). The dependence on wind direction may be unique to the South Pole because of the constancy of surface winds from the northeast that are weakly perturbed by synoptic weather systems: winds from grid east tend to be light, colder, and with shallower BLD whereas those from grid north are stronger, warmer, and have greater BLD. To further test these regression results, we used lower resolution sodar data from the austral spring of 1993(e.g., October/ November). From these data we found that applying the 2003 regression analysis results to 1993 data, ~32% of the variance could be accounted for, despite the coarseness of the 1993 observations. The latter result provided the justification for applying the 2003 BLD regression analysis to our estimating BLDs on the 2006-7 NOx data set. As found in the 2003 data set, the general trend in the 2006-7 data showed that predicted shallow BLDs consistently correlated with higher concentrations of

  17. Constraints on the Volatile Distribution Within Shackleton Crater at the Lunar South Pole

    NASA Technical Reports Server (NTRS)

    Zuber, Maria T.; Head, James W.; Smith, David E.; Neumann, Gregory A.; Mazarico, Erwan; Torrence, Mark H.; Aharonson, Oded; Tye, Alexander R.; Fassett, Caleb I.; Rosenburg, Margaret A.; Melosh, H. Jay

    2012-01-01

    Shackleton crater is nearly coincident with the Moon's south pole. Its interior receives almost no direct sunlight and is a perennial cold trap, making Shackleton a promising candidate location in which to seek sequestered volatiles. However, previous orbital and Earth-based radar mapping and orbital optical imaging have yielded conflicting interpretations about the existence of volatiles. Here we present observations from the Lunar Orbiter Laser Altimeter on board the Lunar Reconnaissance Orbiter, revealing Shackleton to be an ancient, unusually well-preserved simple crater whose interior walls are fresher than its floor and rim. Shackleton floor deposits are nearly the same age as the rim, suggesting that little floor deposition has occurred since the crater formed more than three billion years ago. At a wavelength of 1,064 nanometres, the floor of Shackleton is brighter than the surrounding terrain and the interiors of nearby craters, but not as bright as the interior walls. The combined observations are explicable primarily by downslope movement of regolith on the walls exposing fresher underlying material. The relatively brighter crater floor is most simply explained by decreased space weathering due to shadowing, but a one-micrometre-thick layer containing about 20 per cent surficial ice is an alternative possibility.

  18. Fifty-year Amundsen-Scott South Pole station surface climatology

    NASA Astrophysics Data System (ADS)

    Lazzara, Matthew A.; Keller, Linda M.; Markle, Timothy; Gallagher, John

    2012-11-01

    Fifty-four years of Amundsen-Scott South Pole Station meteorological data have been analyzed to develop a comprehensive climatology from the station's meteorological observations. In reaching the goal of a full climatological analysis, a meteorological station history was required and a full quality control review of the data was conducted. Analysis of the general fifty-year climate is presented for temperature, pressure, wind speed and wind direction along with averages (means), extremes and records, daily ranges, trends and discontinuities. Additional investigations include how often the temperature reaches - 100 °F and changes in the flying season as seen via acceptable temperatures. The analysis found slight decreases in the temperature and pressure over the 1957-2010 time period that are not statistically significant. The wind speed, however, does show a significant downward trend of 0.28 m s- 1 decade- 1 over the same period. The seasonal time series of temperature and pressure illustrate how longer term oscillations are superimposed on shorter-term fluctuations. The seasonal mean wind speed over the 54 year period shows a consistent pattern of decreasing speed for all seasons. In contrast to the mean wind speeds, the maximum wind speeds are increasing for the summer and transition seasons, and the increases are statistically significant. Finally, for the period 1983-2010, the average annual snow accumulation is decreasing at a statistically significant downward rate of - 2.9 mm year- 1.

  19. Photometry of the 4686 A emission line of gamma(2) Velorum from the South Pole

    SciTech Connect

    Taylor, M. Florida Univ., Gainesville )

    1990-10-01

    An automated optical telescope located at the Amundsen-Scott South Pole station on Antarctica, has been used to obtain more than 78 h of photometry of the He II emission line (4686 A) of the spectroscopic binary gamma(2) Velorum. These data were obtained on seven different days during the 1987 austral winter; the longest continuous run spans 19 h. Two independent period search techniques have been used to search for periodic behavior in the strength of the He II emission line of this Wolf-Rayet star. They are: (1) power spectrum analysis and (2) a first-order sine function fit to the data using least squares. Various multiplicities of a period on the order of 1.3 h with amplitudes of a few percent are found in most of these data. According to recent theoretical models of Wolf-Rayet stars, fluctuations in the He II emission line may indicate vibrational instability in gamma(2) Vel. These pulsations may, in turn, give rise to shocks which propagate outward and which may provide the necessary conditions for periodic changes in the state of a given region of the atmosphere to occur. 15 refs.

  20. Comparison of Eight Years Total Column Ozone Retrievals form Brewer and Dobson Spectrophotometers in South Pole

    NASA Astrophysics Data System (ADS)

    Feng, K. H.; Moeini, O.; McElroy, C. T.; Evans, R. D.; Petropavlovskikh, I. V.

    2015-12-01

    Total column ozone measured by a Brewer Mark III spectrophotometer (#85) from 2008 to 2015 is compared to the data obtained from three different Dobson spectrophotometers (#80, #82 and #42) that have been operating in parallel with the Brewer at the Amundsen-Scott Station near the South Pole. Measurements are made using either direct sunlight or light from the moon (up to 2 weeks per month). The result of the comparison was used to assess the performance of the two instrument types and determine the stability of the measurement systems. Both instruments suffer from non-linearity due to the presence of instrumental stray light caused by the out-off-band radiations scattered from the optics within the instrument. Stray light results in an underestimated ozone column at large ozone path lengths. Since measurements made at the location of the station (Latitude 89.99o, Longitude -24.80o) have solar zenith angles of 66.5 degrees or greater, the issue of stray light is a particular concern.

  1. Short-period mesospheric gravity waves and their sources at the South Pole

    NASA Astrophysics Data System (ADS)

    Mehta, Dhvanit; Gerrard, Andrew J.; Ebihara, Yusuke; Weatherwax, Allan T.; Lanzerotti, Louis J.

    2017-01-01

    The sourcing locations and mechanisms for short-period, upward-propagating gravity waves at high polar latitudes remain largely unknown. Using all-sky imager data from the Amundsen-Scott South Pole Station, we determine the spatial and temporal characteristics of 94 observed small-scale waves in 3 austral winter months in 2003 and 2004. These data, together with background atmospheres from synoptic and/or climatological empirical models, are used to model gravity wave propagation from the polar mesosphere to each wave's source using a ray-tracing model. Our results provide a compelling case that a significant proportion of the observed waves are launched in several discrete layers in the tropopause and/or stratosphere. Analyses of synoptic geopotentials and temperatures indicate that wave formation is a result of baroclinic instability processes in the stratosphere and the interaction of planetary waves with the background wind fields in the tropopause. These results are significant for defining the influences of the polar vortex on the production of these small-scale, upward-propagating gravity waves at the highest polar latitudes.

  2. BLAST OBSERVATIONS OF THE SOUTH ECLIPTIC POLE FIELD: NUMBER COUNTS AND SOURCE CATALOGS

    SciTech Connect

    Valiante, Elisabetta; Braglia, Filiberto G.; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Pascale, Enzo; Bock, James J.; Devlin, Mark J.; Klein, Jeff; Gundersen, Joshua O.; Hughes, David H.; Netterfield, Calvin B.; Olmi, Luca; Patanchon, Guillaume; Rex, Marie

    2010-12-15

    We present results from a survey carried out by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) on a 9 deg{sup 2} field near the South Ecliptic Pole at 250, 350, and 500 {mu}m. The median 1{sigma} depths of the maps are 36.0, 26.4, and 18.4 mJy, respectively. We apply a statistical method to estimate submillimeter galaxy number counts and find that they are in agreement with other measurements made with the same instrument and with the more recent results from Herschel/SPIRE. Thanks to the large field observed, the new measurements give additional constraints on the bright end of the counts. We identify 132, 89, and 61 sources with S/N {>=}4 at 250, 350, 500 {mu}m, respectively and provide a multi-wavelength combined catalog of 232 sources with a significance {>=}4{sigma} in at least one BLAST band. The new BLAST maps and catalogs are available publicly at http://blastexperiment.info.

  3. Lunar Meteorites Sayh Al Uhaymir 449 and Dhofar 925, 960, and 961: Windows into South Pole

    NASA Technical Reports Server (NTRS)

    Ziegler, Ryan A.; Jolliff, B. L.; Korotev, R. L.

    2013-01-01

    In 2003, three lunar meteorites were collected in close proximity to each other in the Dhofar region of Oman: Dhofar 925 (49 g), Dhofar 960 (35 g), and Dhofar 961 (22 g). In 2006, lunar meteorite Sayh al Uhaymir (SaU) 449 (16.5 g) was found about 100 km to the NE. Despite significant differences in the bulk composition of Dhofar 961 relative to Dhofar 925/960 and SaU 449 (which are identical to each other), these four meteorites are postulated to be paired based on their find locations, bulk composition, and detailed petrographic analysis. Hereafter, they will collectively be referred to as the Dhofar 961 clan. Comparison of meteorite and component bulk compositions to Lunar Prospector 5-degree gamma-ray data suggest the most likely provenance of this meteorite group is within the South Pole-Aitken Basin. As the oldest, largest, and deepest recognizable basin on the Moon, the composition of the material within the SPA basin is of particular importance to lunar science. Here we review and expand upon the geochemistry and petrography of the Dhofar 961 clan and assess the likelihood that these meteorites come from within the SPA basin based on their bulk compositions and the compositions and characteristics of the major lithologic components found within the breccia.

  4. Compositional heterogeneity of central peaks within the South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Moriarty, D. P.; Pieters, C. M.; Isaacson, P. J.

    2013-11-01

    high-spectral and -spatial resolution Moon Mineralogy Mapper data, we investigate compositional variations across the central peak structures of four impact craters within the South Pole-Aitken Basin (SPA). Two distinct causes of spectral diversity are observed. Spectral variations across the central peaks of Bhabha, Finsen, and Lyman are dominated by soil development, including the effects of space weathering and mixing with local materials. For these craters, the central peak structure is homogeneous in composition, although small compositional differences between the craters are observed. This group of craters is located within the estimated transient cavity of SPA, and their central uplifts exhibit similar mafic abundances. Therefore, it is plausible that they have all uplifted material associated with melts of the lower crust or upper mantle produced during the SPA impact. Compositional differences observed between the peaks of these craters reflect heterogeneities in the SPA subsurface, although the origin of this heterogeneity is uncertain. In contrast to these craters, Leeuwenhoek exhibits compositional heterogeneity across its central peak structure. The peak is areally dominated by feldspathic materials, interspersed with several smaller exposures exhibiting a mafic spectral signature. Leeuwenhoek is the largest crater included in the study and is located in a region of complex stratigraphy involving both crustal (feldspathic) and SPA (mafic melt and ejecta) materials. The compositional diversity observed in Leeuwenhoek's central peak indicates that kilometer-scale heterogeneities persist to depths of more than 10 km in this region.

  5. Prospects for a radio air-shower detector at the South Pole

    NASA Astrophysics Data System (ADS)

    Böser, Sebastian; ARA Collaboration, IceCube Collaboration

    2013-05-01

    IceCube is not only the largest neutrino telescope but also one of the world's most competitive instruments for studying cosmic rays in the PeV to EeV regime where the transition from galactic to extra-galactic sources should occur. It records air showers with the ground sampling stations of IceTop and the in-ice optical modules of IceCube. Further augmenting this observatory with an array of sensors in the 10-100MHz regime that observe the radio emission from air showers will yield complementary information on the shower development. Such a triple-technology observatory should significantly improve the understanding of cosmic rays and enhance many aspects of its physics reach. Here we present first results from two exploratory radio setups deployed at the South Pole. Noise measurements from data taken in two consecutive seasons show a very good agreement of the predicted and observed response of the antennas which were designed specifically for this purpose. The radio background is found to be highly dominated by galactic noise with a prominent absence of anthropogenic radio emitters in the frequency band from 25-300MHz. Motivated by the excellent suitability of the location, we present first performance studies of a proposed Radio Air-Shower Test Array (RASTA) using detailed MonteCarlo simulation and discuss the prospects for its installation.

  6. Illumination conditions at the lunar south pole using high resolution Digital Terrain Models from LOLA

    NASA Astrophysics Data System (ADS)

    Gläser, P.; Scholten, F.; De Rosa, D.; Marco Figuera, R.; Oberst, J.; Mazarico, E.; Neumann, G. A.; Robinson, M. S.

    2014-11-01

    The illumination conditions of the lunar south pole are investigated using a geometrically adjusted, 20 m/pixel Digital Terrain Model (DTM) from laser tracks of the Lunar Orbiter Laser Altimeter (LOLA). Several comparisons with Narrow Angle Camera (NAC) images have been made to cross-validate the results. Illumination conditions were first evaluated over a region of 20 × 20 km over a one-year period (October 22, 2018 - October 22, 2019) at surface level and 2 m above ground. Three potential landing sites are investigated in more detail. A 19-year study covering the lunar precessional cycle was carried out at surface level, 2 and 10 m above ground for a site found at "Connecting Ridge", the ridge connecting the Shackleton and de Gerlache crater. This area was found to be an ideal site for future landing missions with respect to illumination conditions. We identified locations receiving sunlight for 92.27% of the time at 2 m above ground and 95.65% of the time at 10 m above ground. At these locations the longest continuous periods in darkness are typically only 3-5 days.

  7. Lunar South Pole ice as heat sink for Lunar cryofuel production system

    SciTech Connect

    Zuppero, A.; Stanley, M.; Modro, S.M.; Whitman, P.

    1995-03-01

    Recent Clementine bistatic radar data suggest that water ice may be present in a {open_quotes}forever shaded{close_quotes} depression or crater at the South Pole of the Moon. The ice is a feedstock for the electrolysis production of cryogenic oxygen and hydrogen rocket fuels for a transportation system on the moon and for leaving and descending on to the moon. The ice also provides a convective heat sink critical to the practical implementation of high throughput electric power generators and refrigerators that liquefy and cool the oxygen and hydrogen into cryogenic rocket fuel. This brief analysis shows that about a hundred tonnes of hardware delivered to the lunar surface can produce tens of thousands of tonnes of rocket fuel per year, on the moon. And it makes the point that if convective cooling is used instead of radiative cooling, then power and processing systems can be used that exist and have been tested already. This shortens the time by an order of magnitude to develop lunar operations. Quick deployment of a chemical cryofuel energy source is a key factor in the economics of lunar development.

  8. Geomorphic Terrains and Evidence for Ancient Volcanism within Northeastern South Pole-Aitken Basin

    NASA Technical Reports Server (NTRS)

    Petro, Noah; Mest, Scott C.; Teich, Yaron

    2010-01-01

    The interior of the enigmatic South Pole-Aitken Basin has long been recognized as being compositionally distinct from its exterior. However, the source of the compositional anomaly has been subject to some debate. Is the source of the iron-enhancement due to lower-crustal/upper-mantle material being exposed at the surface, or was there some volume of ancient volcanism that covered portions of the basin interior? While several obvious mare basalt units are found within the basin and regions that appear to represent the original basin interior, there are several regions that appear to have an uncertain origin. Using a combination of Clementine and Lunar Orbiter images, several morphologic units are defined based on albedo, crater density, and surface roughness. An extensive unit of ancient mare basalt (cryptomare) is defined and, based on the number of superimposed craters, potentially represents the oldest volcanic materials within the basin. Thus, the overall iron-rich interior of the basin is not solely due to deeply derived crustal material, but is, in part due to the presence of ancient volcanic units.

  9. Core processing and first analysis of ice cores from Siple and South Pole stations

    SciTech Connect

    Stauffer, B.; Schwander, J.

    1984-01-01

    Analysis of ice cores from the Antarctic allows the authors to study the history of climatic parameters such as temperature, annual accumulation, and atmospheric composition. The main goal of their laboratory analysis of these of these ice cores is to investigate the preindustrial atmospheric carbon dioxide concentration and its natural variations and to measure the carbon-13/carbon-12 ratio in the preindustrial carbon dioxide and in other atmospheric trace gases such as methane. The cores drilled during 1983-1984 field season at the South Pole will be analyzed during the coming year. Several analyses have been made, however, on such cores drilled in the previous field seasons: the analysis of the carbon dioxide concentration of air extracted from ice cores indicates that the preindustrial atmospheric carbon dioxide concentration was about 280 parts per million by volume as compared to present levels of about 340 parts per million. There is some evidence that this value is more accurate than the lower value reported earlier by a laboratory in Grenoble and by their laboratory. They also measured the carbon-13/carbon-12 ratios of carbon dioxide and of the methane concentration. These results are still preliminary and will be reported later.

  10. Prospects for Dating the South Pole-Aitken Basin through Impact-Melt Rock Samples

    NASA Technical Reports Server (NTRS)

    Cohen, B. A.; Coker, R. F.; Petro, N. E.

    2016-01-01

    Much of the present debate about the ages of the nearside basins arises because of the difficulty in understanding the relationship of recovered samples to their parent basin. The Apollo breccias are from basin ejecta formations, which are ballistically-emplaced distal deposits that have mixed provenances. The Nectaris, Imbrium, and Serenitatis basins all have mare-basalt fill obscuring their original melt sheets, so geochemical ties are indirect. Though the geological processes acting to vertically and laterally mix materials into regolith are the same as at the Apollo sites, the SPA interior is a fundamentally different geologic setting than the Apollo sites. The South Pole-Aitken basin was likely filled by a large impact melt sheet, possibly differentiated into cumulate horizons. It is on this distinctive melt sheet that the regolith has formed, somewhat diluting but not erasing the prominent geochemical signature seen from orbital assets. By analogy to the Apollo 16 site, a zeroth-order expectation is that bulk samples taken from regolith within SPA will contain abundant samples gardened from the SPA melt sheet. However, questions persist as to whether the SPA melt sheet has been so extensively contaminated with foreign ejecta that a simple robotic scoop sample of such regolith would be unlikely to yield the age of the basin.

  11. Regolith in the South Pole-Aitken Basin is Mainly Indigenous Material

    NASA Technical Reports Server (NTRS)

    Haskin, L. A.; Gillis, J. J.; Jolliff, B. L.; Korotev, R. L.

    2003-01-01

    This abstract is concerned with the probability that a mission to a site within the South Pole-Aitken basin (SPA) would yield a meaningful sample of typical SPA floor material. The probability seems favorable, barring a highly atypical landing site, because the chemical composition of the SPA interior, as determined remotely from orbit, is different from that of the surrounding lunar surface. How representative would the sample be? To what extent have lateral transport or later events compromised the original chemical and mineralogical composition of the floor material? Where or in what kind of deposit should the mission land to provide the best example? We address these questions from the point of view of modeling of impact ejecta deposits. SPA is the largest lunar impact basin. Shallow for its diameter, it has a subdued gravity signature, a lower albedo, and a more Th- and Ferich interior than the surrounding highlands (the Feldspathic Highlands Terrane, FHT). Its floor may represent noritic or perhaps (but less abundant) gabbroic lower crust of the FHT, the upper crust stripped away by the basin-forming impact, possibly an oblique one.

  12. Rock types of South Pole-Aitken basin and extent of basaltic volcanism

    USGS Publications Warehouse

    Pieters, C.M.; Head, J. W.; Gaddis, L.; Jolliff, B.; Duke, M.

    2001-01-01

    The enormous pre-Nectarian South Pole-Aitken (SPA) basin represents a geophysically and compositionally unique region on the Moon. We present and analyze the mineralogical diversity across this basin and discuss the implications for basin evolution. Rock types are derived from Clementine multispectral data based on diagnostic characteristics of ferrous absorptions in fresh materials. Individual areas are characterized as noritic (dominated by low-Ca pyroxene), gabbroic/basaltic (dominated by high-Ca pyroxene), feldspathic (<3-6% FeO), and olivine-gabbro (dominated by high-Ca pyroxene and olivine). The anorthositic crust has effectively been removed from the interior of the basin. The style of volcanism within the basin extends over several 100 Myr and includes mare basalt and pyroclastic deposits. Several areas of ancient (pre-Orientale) volcanism, or cryptomaria, have also been identified. The nonmare mafic lithology that occurs across the basin is shown to be noritic in composition and is pervasive laterally and vertically. We interpret this to represent impact melt/breccia deposits derived from the lower crust. A few localized areas are identified within the basin that contain more diverse lithologies (gabbro, olivine-gabbro), some of which may represent material from the deepest part of the lower crust and perhaps uppermost mantle involved in the SPA event. Copyright 2001 by the American Geophysical Union.

  13. Analysis of Stationary, Photovoltaic-based Surface Power System Designs at the Lunar South Pole

    NASA Technical Reports Server (NTRS)

    Freeh, Joshua E.

    2009-01-01

    Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.

  14. Photometry of the 4686 A emission line of gamma(2) Velorum from the South Pole

    NASA Technical Reports Server (NTRS)

    Taylor, Maryjane

    1990-01-01

    An automated optical telescope located at the Amundsen-Scott South Pole station on Antarctica, has been used to obtain more than 78 h of photometry of the He II emission line (4686 A) of the spectroscopic binary gamma(2) Velorum. These data were obtained on seven different days during the 1987 austral winter; the longest continuous run spans 19 h. Two independent period search techniques have been used to search for periodic behavior in the strength of the He II emission line of this Wolf-Rayet star. They are: (1) power spectrum analysis and (2) a first-order sine function fit to the data using least squares. Various multiplicities of a period on the order of 1.3 h with amplitudes of a few percent are found in most of these data. According to recent theoretical models of Wolf-Rayet stars, fluctuations in the He II emission line may indicate vibrational instability in gamma(2) Vel. These pulsations may, in turn, give rise to shocks which propagate outward and which may provide the necessary conditions for periodic changes in the state of a given region of the atmosphere to occur.

  15. A record of ozone variability in South Pole Antarctic snow: Role of nitrate oxygen isotopes

    NASA Astrophysics Data System (ADS)

    McCabe, Justin R.; Thiemens, Mark H.; Savarino, Joel

    2007-06-01

    The information contained in polar nitrate has been an unresolved issue for over a decade. Here we demonstrate that atmospheric nitrate's oxygen isotopic composition (Δ17O-NO3) reflects stratospheric chemistry in winter and tropospheric chemistry in summer. Surface snow isotope mass balance indicates that nitrate oxygen isotopic composition is the result of a mixture of 25% stratospheric and 75% tropospheric origin. Analysis of trends in Δ17O-NO3 in a 6 m snow pit that provides a 26-year record reveals a strong 2.70-year cycle that anticorrelates (R = -0.77) with October-November-December column ozone. The potential mechanisms linking the records are either denitrification or increased boundary layer photochemical ozone production. We suggest that the latter is dominating the observed trend and find that surface ozone and Δ17O-NO3 correlate well before 1991 (R = 0.93). After 1991, however, the records show no significant relationship, indicating an altered oxidative environment consistent with current understanding of a highly oxidizing atmosphere at the South Pole. The disappearance of seasonal Δ17O-NO3 trends in the surface layer at depth remain unresolved and demand further investigation of how postdepositional processes affect nitrate's oxygen isotope composition. Overall, the findings of this study present a new paleoclimate technique to investigate Antarctic nitrate records that appear to reflect trends in stratospheric ozone depletion by recording tropospheric surface ozone variability.

  16. Cloud radiative properties over the South Pole from AVHRR infrared data

    SciTech Connect

    Lubin, D.; Harper, D.A.

    1996-12-01

    Over the Antarctic plateau, the radiances measured by the AVHRR middle infrared (11 and 12 {mu}m) channels are shown to depend on effective cloud temperature, emissivity, ice water path, and effective radius of the particle size distribution. The usefulness of these dependencies is limited by radiometric uncertainties of up to 2 K in brightness temperature and by the fact that the radiative transfer solutions are not single valued over all possible ranges of temperature, effective radius, and ice water path. Despite these limitations, AVHRR imagery can be used to characterize cloud optical properties over the Antarctic continent if surface weather observations and/or radiosonde data can be collocated with the satellite overpasses. From AVHRR imagery covering the South Pole during 1992, the mean cloud emissivity is estimated at 0.43 during summer and 0.37 during winter, while the mean summer and winter effective radii are estimated at 12.3 and 5.6 {mu}m. respectively. When a radiative transfer model is used to evaluate these results in comparison with surface pyrgeometer measurements, the comparison suggests that the AVHRR retrieval method captures the overall seasonal behavior in cloud properties. During months when the polar vortex persists, AVHRR infrared radiances may be noticeably influenced by polar stratospheric clouds. 26 refs., 12 figs., 3 tabs.

  17. The Spitzer-IRAC/MIPS Extragalactic Survey (SIMES) in the South Ecliptic Pole Field

    NASA Astrophysics Data System (ADS)

    Baronchelli, I.; Scarlata, C.; Rodighiero, G.; Franceschini, A.; Capak, P. L.; Mei, S.; Vaccari, M.; Marchetti, L.; Hibon, P.; Sedgwick, C.; Pearson, C.; Serjeant, S.; Menéndez-Delmestre, K.; Salvato, M.; Malkan, M.; Teplitz, H. I.; Hayes, M.; Colbert, J.; Papovich, C.; Devlin, M.; Kovacs, A.; Scott, K. S.; Surace, J.; Kirkpatrick, J. D.; Atek, H.; Urrutia, T.; Scoville, N. Z.; Takeuchi, T. T.

    2016-03-01

    We present the Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole field. The large area covered (7.7 deg2), together with one of the lowest Galactic cirrus emissions in the entire sky and a very extensive coverage by Spitzer, Herschel, Akari, and GALEX, make the SIMES field ideal for extragalactic studies. The elongated geometry of the SIMES area (≈4:1), allowing for significant cosmic variance reduction, further improves the quality of statistical studies in this field. Here we present the reduction and photometric measurements of the Spitzer/IRAC data. The survey reaches depths of 1.93 and 1.75 μJy (1σ) at 3.6 and 4.5 μm, respectively. We discuss the multiwavelength IRAC-based catalog, completed with optical, mid-, and far-IR observations. We detect 341,000 sources with {F}3.6μ {{m}}≥slant 3σ . Of these, 10% have an associated 24 μm counterpart, while 2.7% have an associated SPIRE source. We release the catalog through the NASA/IPAC Infrared Science Archive. Two scientific applications of these IRAC data are presented in this paper. First, we compute integral number counts at 3.6 μm. Second, we use the [3.6]-[4.5] color index to identify galaxy clusters at z > 1.3. We select 27 clusters in the full area, a result consistent with previous studies at similar depth.

  18. High-resolution local gravity model of the south pole of the Moon from GRAIL extended mission data.

    PubMed

    Goossens, Sander; Sabaka, Terence J; Nicholas, Joseph B; Lemoine, Frank G; Rowlands, David D; Mazarico, Erwan; Neumann, Gregory A; Smith, David E; Zuber, Maria T

    2014-05-28

    We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6° by 1/6° (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40°. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models.

  19. High-resolution Local Gravity Model of the South Pole of the Moon from GRAIL Extended Mission Data

    NASA Technical Reports Server (NTRS)

    Goossens, Sander Johannes; Sabaka, Terence J.; Nicholas, Joseph B.; Lemoine, Frank G.; Rowlands, David D.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

    2014-01-01

    We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6deg by 1/6deg (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40deg. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models.

  20. Ground-based instrumentation for measurements of atmospheric conduction current and electric field at the South Pole

    NASA Technical Reports Server (NTRS)

    Byrne, G. J.; Benbrook, J. R.; Bering, E. A.; Few, A. A.; Morris, G. A.; Trabucco, W. J.; Paschal, E. W.

    1993-01-01

    Attention is given to instruments constructed to measure the atmospheric conduction current and the atmospheric electric field - two fundamental parameters of the global-electric circuit. The instruments were deployed at the Amundsen-Scott South Pole Station in January 1991 and are designed to operate continuously for up to one year without operator intervention. The atmospheric current flows into one hemisphere, through the electronics where it is measured, and out the other hemisphere. The electric field is measured by a field mill of the rotating dipole type. Sample data from the first days of operation at the South Pole indicate variations in the global circuit over time scales from minutes to hours to days.

  1. Quantification of several atmospheric gases from high resolution infrared solar spectra obtained at the South Pole in 1980 and 1986

    NASA Technical Reports Server (NTRS)

    Goldman, Aaron; Murcray, Frank J.; Murcray, Frank H.; Murcray, David G.; Rinsland, Curtis P.

    1988-01-01

    High-resolution solar absorption spectra recorded at the Amundsen-Scott South Pole Station were analyzed to obtain total column amounts of O3, N2O, HNO3, CO2, CH4, and CF2Cl2, and to investigate the differences in the values obtained in December 1980 with those obtained in December 1986. In addition, vertical column amounts for HCl, NO, NO2, and C2H6 were derived for December 1986. One interesting feature of these results is that the total column amounts of HCl measured for several days at the South Pole (/6.4 + or - 0.8/ x 10 to the 15th molecules/sq cm) were high compared with the HCl column amounts reported for lower latitudes.

  2. Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schroedinger Basin

    NASA Technical Reports Server (NTRS)

    Mest, S. C.; Berman, D. C.; Petro, N. E.

    2009-01-01

    In this study we use recent images and topographic data to map the geology and geomorphology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-4] in accordance with the Lunar Geologic Mapping Program. Mapping of LQ-30 began during Mest's postdoctoral appointment and has continued under the PG&G Program, from which funding became available in February 2009. Preliminary map-ping and analyses have been done using base materials compiled by Mest, but properly mosaicked and spatially registered base materials are being compiled by the USGS and should be received by the end of June 2009. The overall objective of this research is to constrain the geologic evolution of the lunar South Pole (LQ-30: 60deg -90deg S, 0deg - +/-180deg ) with specific emphasis on evaluation of a) the regional effects of basin formation on the structure and composition of the crust and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Constraining the geologic history of the lunar South Pole and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the vertical and lateral structure of the lunar regolith and crust, assessing the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of resources (e.g., H, Fe, Th) and their relationships with surface materials.

  3. Infrared measurements of increased CF/sub 2/Cl/sub 2/ (CFC-12) absorption above the South Pole

    SciTech Connect

    Rinsland, C.P.; Goldman, A.; Murcray, F.J.; Murcray, F.H.; Murcray, D.G.; Levine, J.S.

    1988-02-01

    High-resolution ground-based solar spectra recorded at the Amundsen-Scott South Pole station in Dec. 1980 and Nov. 1986 have been analyzed in the region of the CF/sub 2/Cl/sub 2/ (chlorofluorocarbon 12) atgn/sub 8/ band Q branches at 1161 cm/sup arrow-right-left//sup 1/. An increase in the CF/sub 2/Cl/sub 2/ total vertical column above the South Pole of 1.24 atmapprox. = 0.15 over the 6-yr period, corresponding to an average rate of increase of 3.6 atmapprox. = 2.1%, is derived. This rate of increase is lower than indicated by in situ measurements at the South Pole over the same time period, but there is agreement when the rather error bars of the spectral measurement results are considered. Spectroscopic parameters that can successfully model CF/sub 2/Cl/sub 2/ absorption at low temperatures are needed to improve retrieval accuracies and could be applied to a number of pre-1980 atmospheric spectral data sets in the literature to obtain an improved record of early CF/sub 2/Cl/sub 2/ concentration trends for comparison with estimates of historical release rates.

  4. High-resolution local gravity model of the south pole of the Moon from GRAIL extended mission data

    PubMed Central

    Goossens, Sander; Sabaka, Terence J; Nicholas, Joseph B; Lemoine, Frank G; Rowlands, David D; Mazarico, Erwan; Neumann, Gregory A; Smith, David E; Zuber, Maria T

    2014-01-01

    We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6° by 1/6° (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40°. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models. Key Points We present a high-resolution gravity model of the south pole of the Moon Improved correlations with topography to higher degrees than global models Improved fits to the data and reduced striping that is present in global models PMID:26074637

  5. MEASUREMENTS OF SECONDARY COSMIC MICROWAVE BACKGROUND ANISOTROPIES WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

    Lueker, M.; Reichardt, C. L.; Benson, B. A.; Cho, H.-M.; George, E. M.; Holzapfel, W. L.; Schaffer, K. K.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Zahn, O.; Ade, P. A. R.; Aird, K. A.; De Haan, T.; Dobbs, M. A.; Holder, G. P.; Hall, N. R.; Halverson, N. W.

    2010-08-20

    We report cosmic microwave background (CMB) power-spectrum measurements from the first 100 deg{sup 2} field observed by the South Pole Telescope (SPT) at 150 and 220 GHz. On angular scales where the primary CMB anisotropy is dominant, l {approx}< 3000, the SPT power spectrum is consistent with the standard {Lambda}CDM cosmology. On smaller scales, we see strong evidence for a point-source contribution, consistent with a population of dusty, star-forming galaxies. After we mask bright point sources, anisotropy power on angular scales of 3000 < l < 9500 is detected with a signal-to-noise ratio {approx}>50 at both frequencies. We combine the 150 and 220 GHz data to remove the majority of the point-source power and use the point-source-subtracted spectrum to detect Sunyaev-Zel'dovich (SZ) power at 2.6{sigma}. At l = 3000, the SZ power in the subtracted bandpowers is 4.2 {+-} 1.5 {mu}K{sup 2}, which is significantly lower than the power predicted by a fiducial model using WMAP5 cosmological parameters. This discrepancy may suggest that contemporary galaxy cluster models overestimate the thermal pressure of intracluster gas. Alternatively, this result can be interpreted as evidence for lower values of {sigma}{sub 8}. When combined with an estimate of the kinetic SZ contribution, the measured SZ amplitude shifts {sigma}{sub 8} from the primary CMB anisotropy derived constraint of 0.794 {+-} 0.028 down to 0.773 {+-} 0.025. The uncertainty in the constraint on {sigma}{sub 8} from this analysis is dominated by uncertainties in the theoretical modeling required to predict the amplitude of the SZ power spectrum for a given set of cosmological parameters.

  6. Polar stratospheric clouds at the South Pole in 1990: Lidar observations and analysis

    SciTech Connect

    Collins, R.L.; Bowman, K.P.; Gardner, C.S. )

    1993-01-20

    In December 1989 a Rayleigh/sodium lidar (589 nm) was installed at the Amundsen-Scott South Pole station, and was used to measure stratospheric aerosol, temperature, and mesospheric sodium profiles through October 1990. Observations of stratospheric aerosol and temperature are presented in this paper. Polar stratospheric clouds (PSCs) were first observed in late May at about 20 km. As the lower stratosphere cooled further, PSCs were observed throughout the 12-27 km altitude region, and remained there from mid-June until late August. Observations in early September detected no PSCs above 21 km. An isolated cloud was observed in mid-October. Throughout the winter the clouds had small backscatter ratios (< 10). Observations made at two wavelengths in July show that the clouds are predominately composed of nitric acid trihydrate with associated Angstrom coefficients between 0.2 and 3.7. Comparison of the lidar data and balloon borne frost point measurements in late August indicate that the nitric acid mixing ratio was less than 1.5 ppbv. Observations over periods of several hours show downward motions in the cloud layers similar to the phase progressions of upwardly-propagating gravity waves. The vertical phase velocities of these features ([approx] 4 cm/s) are significantly faster than the expected settling velocities of the cloud particles. Both the backscatter ratio profiles and the radiosonde horizontal wind profiles show 1-4 km vertical structures. This suggests that the kilometer-scale vertical structure of the PSCs is maintained by low frequency gravity waves propagating through the cloud layers. 24 refs., 9 figs., 4 tabs.

  7. Measurement of Galaxy Cluster Integrated Comptonization and Mass Scaling Relations with the South Pole Telescope

    SciTech Connect

    Saliwanchik, B. R.; et al.

    2015-01-22

    We describe a method for measuring the integrated Comptonization (Y (SZ)) of clusters of galaxies from measurements of the Sunyaev-Zel'dovich (SZ) effect in multiple frequency bands and use this method to characterize a sample of galaxy clusters detected in the South Pole Telescope (SPT) data. We use a Markov Chain Monte Carlo method to fit a β-model source profile and integrate Y (SZ) within an angular aperture on the sky. In simulated observations of an SPT-like survey that include cosmic microwave background anisotropy, point sources, and atmospheric and instrumental noise at typical SPT-SZ survey levels, we show that we can accurately recover β-model parameters for inputted clusters. We measure Y (SZ) for simulated semi-analytic clusters and find that Y (SZ) is most accurately determined in an angular aperture comparable to the SPT beam size. We demonstrate the utility of this method to measure Y (SZ) and to constrain mass scaling relations using X-ray mass estimates for a sample of 18 galaxy clusters from the SPT-SZ survey. Measuring Y (SZ) within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y (SZ) at a fixed mass. Measuring Y (SZ) within a 0.3 Mpc projected radius (equivalent to 0.'75 at the survey median redshift z = 0.6), we find a scatter of 26% ± 9%. Prior to this study, the SPT observable found to have the lowest scatter with mass was cluster detection significance. We demonstrate, from both simulations and SPT observed clusters that Y (SZ) measured within an aperture comparable to the SPT beam size is equivalent, in terms of scatter with cluster mass, to SPT cluster detection significance.

  8. A Measurement of Secondary Cosmic Microwave Background Anisotropies with Two Years of South Pole Telescope Observations

    NASA Astrophysics Data System (ADS)

    Reichardt, C. L.; Shaw, L.; Zahn, O.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Dudley, J.; George, E. M.; Halverson, N. W.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hou, Z.; Hrubes, J. D.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Luong-Van, D.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Millea, M.; Mohr, J. J.; Montroy, T. E.; Natoli, T.; Padin, S.; Plagge, T.; Pryke, C.; Ruhl, J. E.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Staniszewski, Z.; Stark, A. A.; Story, K.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2012-08-01

    We present the first three-frequency South Pole Telescope (SPT) cosmic microwave background (CMB) power spectra. The band powers presented here cover angular scales 2000 < l < 9400 in frequency bands centered at 95, 150, and 220 GHz. At these frequencies and angular scales, a combination of the primary CMB anisotropy, thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, radio galaxies, and cosmic infrared background (CIB) contributes to the signal. We combine Planck/HFI and SPT data at 220 GHz to constrain the amplitude and shape of the CIB power spectrum and find strong evidence for nonlinear clustering. We explore the SZ results using a variety of cosmological models for the CMB and CIB anisotropies and find them to be robust with one exception: allowing for spatial correlations between the thermal SZ effect and CIB significantly degrades the SZ constraints. Neglecting this potential correlation, we find the thermal SZ power at 150 GHz and l = 3000 to be 3.65 ± 0.69 μK2, and set an upper limit on the kinetic SZ power to be less than 2.8 μK2 at 95% confidence. When a correlation between the thermal SZ and CIB is allowed, we constrain a linear combination of thermal and kinetic SZ power: D tSZ 3000 + 0.5D 3000 kSZ = 4.60 ± 0.63 μK2, consistent with earlier measurements. We use the measured thermal SZ power and an analytic, thermal SZ model calibrated with simulations to determine σ8 = 0.807 ± 0.016. Modeling uncertainties involving the astrophysics of the intracluster medium rather than the statistical uncertainty in the measured band powers are the dominant source of uncertainty on σ8. We also place an upper limit on the kinetic SZ power produced by patchy reionization; a companion paper uses these limits to constrain the reionization history of the universe.

  9. Maps of the Magellanic Clouds from Combined South Pole Telescope and PLANCK Data

    NASA Astrophysics Data System (ADS)

    Crawford, T. M.; Chown, R.; Holder, G. P.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H.-M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2016-12-01

    We present maps of the Large and Small Magellanic Clouds from combined South Pole Telescope (SPT) and Planck data. The Planck satellite observes in nine bands, while the SPT data used in this work were taken with the three-band SPT-SZ camera, The SPT-SZ bands correspond closely to three of the nine Planck bands, namely those centered at 1.4, 2.1, and 3.0 mm. The angular resolution of the Planck data ranges from 5 to 10 arcmin, while the SPT resolution ranges from 1.0 to 1.7 arcmin. The combined maps take advantage of the high resolution of the SPT data and the long-timescale stability of the space-based Planck observations to deliver robust brightness measurements on scales from the size of the maps down to ∼1 arcmin. In each band, we first calibrate and color-correct the SPT data to match the Planck data, then we use noise estimates from each instrument and knowledge of each instrument’s beam to make the inverse-variance-weighted combination of the two instruments’ data as a function of angular scale. We create maps assuming a range of underlying emission spectra and at a range of final resolutions. We perform several consistency tests on the combined maps and estimate the expected noise in measurements of features in them. We compare maps from this work to those from the Herschel HERITAGE survey, finding general consistency between the data sets. All data products described in this paper are available for download from the NASA Legacy Archive for Microwave Background Data Analysis server.

  10. Variability in pulmonary function following rapid altitude ascent to the Amundsen-Scott South Pole station.

    PubMed

    Lalande, S; Anderson, P J; Miller, A D; Ceridon, M L; Beck, K C; O'Malley, K A; Johnson, J B; Johnson, B D

    2011-09-01

    The impact of acute altitude exposure on pulmonary function is variable. A large inter-individual variability in the changes in forced expiratory flows (FEFs) is reported with acute exposure to altitude, which is suggested to represent an interaction between several factors influencing bronchial tone such as changes in gas density, catecholamine stimulation, and mild interstitial edema. This study examined the association between FEF variability, acute mountain sickness (AMS) and various blood markers affecting bronchial tone (endothelin-1, vascular endothelial growth factor (VEGF), catecholamines, angiotensin II) in 102 individuals rapidly transported to the South Pole (2835 m). The mean FEF between 25 and 75% (FEF(25-75)) and blood markers were recorded at sea level and after the second night at altitude. AMS was assessed using Lake Louise questionnaires. FEF(25-75) increased by an average of 12% with changes ranging from -26 to +59% from sea level to altitude. On the second day, AMS incidence was 36% and was higher in individuals with increases in FEF(25-75) (41 vs. 22%, P = 0.05). Ascent to altitude induced an increase in endothelin-1 levels, with greater levels observed in individuals with decreased FEF(25-75). Epinephrine levels increased with ascent to altitude and the response was six times larger in individuals with decreased FEF(25-75). Greater levels of endothelin-1 in individuals with decreased FEF(25-75) suggest a response consistent with pulmonary hypertension and/or mild interstitial edema, while epinephrine may be upregulated in these individuals to clear lung fluid through stimulation of β(2)-adrenergic receptors.

  11. Maps of the Magellanic Clouds from combined South Pole Telescope and Planck Data

    SciTech Connect

    Crawford, T. M.; Chown, R.; Holder, G. P.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H. -M.; Crites, A. T.; Haan, T. de; Dobbs, M. A.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2016-12-01

    We present maps of the Large and Small Magellanic Clouds from combined South Pole Telescope (SPT) and Planck data. Both instruments are designed to make measurements of the cosmic microwave background but are sensitive to any source of millimeter-wave (mm-wave) emission. The Planck satellite observes in nine mm-wave bands, while the SPT data used in this work were taken with the three-band SPT-SZ camera. The SPT-SZ bands correspond closely to three of the nine Planck bands, namely those centered at 1.4, 2.1, and 3.0 mm. The angular resolution of the Planck data in these bands ranges from 5 to 10 arcmin, while the SPT resolution in these bands ranges from 1.0 to 1.7 arcmin. The combined maps take advantage of the high resolution of the SPT data and the long-timescale stability of the space-based Planck observations to deliver high signal-to-noise and robust brightness measurements on scales from the size of the maps down to ~1 arcmin. In each of the three bands, we first calibrate and color-correct the SPT data to match the Planck data, then we use noise estimates from each instrument and knowledge of each instrument's beam, or point-spread function, to make the inverse-variance-weighted combination of the two instruments' data as a function of angular scale. We create maps assuming a range of underlying emission spectra (for the color correction) and at a range of final resolutions. We perform several consistency tests on the combined maps and estimate the expected noise in measurements of features in the maps. We compare the maps of the Large Magellanic Cloud (LMC) from this work to maps from the Herschel HERITAGE survey, finding general consistency between the datasets. Furthermore, the broad wavelength coverage provides evidence of different emission mechanisms at work in different environments in the LMC.

  12. Sulfate in air and snow at the South Pole: Implications for transport and deposition at sites with low snow accumulation

    NASA Astrophysics Data System (ADS)

    Harder, Susan; Warren, Stephen G.; Charlson, Robert J.

    2000-09-01

    Air and surface snow were sampled at Amundsen-Scott Station at the South Pole from July through December of 1992. Four-day averages of non-sea-salt sulfate (nss-SO4=) aerosol show a strong seasonal trend, increasing by a factor of about 30 from winter to summer as oceanic biogenic sources become more active and atmospheric transport pathways change. Three-dimensional sampling of small-scale surface topography (sastrugi) provides evidence supporting wind pumping and filtration of aerosol by snow as a significant mechanism for dry deposition at this site. The estimated monthly flux of nss-SO4= to the snow surface also increases from winter to spring, but by only a factor of 2, suggesting that the efficiency of deposition for this aerosol-borne species from the near-surface air to the snow is greater in winter. The strong surface-based temperature inversion in winter inhibits vertical motion and may limit the rate of delivery of aerosol to the boundary layer from the free troposphere. Because the snow surface is a sink for aerosol, near-surface measurements of aerosol in the stable inversion layer may not be representative of the free troposphere. Air and snow data in summer (when the inversion is weak) are used to estimate a tropospheric residence time of 4-20 days for nss SO4=.

  13. Imaging of a Newly Forming Polar Hood Over The South Pole of Titan By VIMS/Cassini

    NASA Astrophysics Data System (ADS)

    Le Mouelic, S.; Rodriguez, S.; Sotin, C.; West, R. A.; Rannou, P.; Barnes, J. W.; Brown, R. H.; Cornet, T.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.

    2012-12-01

    Since August 2009 equinox, the southern hemisphere of Titan entered in fall. A polar hood corresponding to an area of denser haze appears to be progressively forming right above the south pole of Titan, according to the latest observations made by the optical imaging instruments onboard Cassini spacecraft. This behavior is predicted to occur by the GCMs, when the south pole is progressively entering into darkness with the coming southern winter. We focus here on the observations made by the Visual and Infrared Mapping Spectrometer (VIMS). The newly observed phenomenon clearly appears in hyperspectral images acquired by VIMS during the T83 (22 May 2012), T84 (6 June 2012) and T85 (24 July 2012) targeted flybys. No equivalent feature had been observed before in the entire VIMS data set since the insertion of the Cassini spacecraft in Saturn orbit in July 2004. The altitude of this newly observed polar hood during the T83 observation is higher than 250 km, indicating that it does not correspond to any usual cloud observed so far. The inclined orbit of Cassini has allowed observations of this polar hood on the limb of Titan (T83, T84, T85) with a phase angle less than 36°, and directly from above with a phase angle of 96° during an untargeted flyby on 27 June 2012. A vast polar cloud was observed above the north pole at the beginning of the Cassini mission, but considering that a season on Titan lasts seven years, the feature that is currently forming over the south pole might corresponds to the very first stages of what was observed in the north. The Cassini solstice mission will allow the continuous monitoring of this phenomenon up to 2017.

  14. Eocene paleomagnetic pole for South America: Northward continental motion in the Cenozoic, opening of Drake Passage and Caribbean convergence

    NASA Astrophysics Data System (ADS)

    Somoza, RubéN.

    2007-03-01

    A paleomagnetic study of Eocene volcanic rocks in Patagonia yields high unblocking temperature and high-coercivity magnetizations. Combining these results with those of a previous study on Patagonian Eocene basalts yields a high-precision, high-quality pole located at latitude 81°S, longitude 337.4°E, A95 = 5.7°. Critically, this paleopole is indistinguishable from that of the Late Cretaceous (circa 85-65 Ma) pole position of South America, indicating that the plate was essentially motionless with respect to the spin axis for a period of ˜45 m.y. The pole position places South America at higher (˜5°) than present-day latitudes during the Eocene, indicating that northward continental motion toward present-day latitudes must have been accomplished sometime since the late Eocene. Paleomagnetic and tectonic correlation admits the hypothesis that Cenozoic northward drift was associated with Oligocene-Miocene extension in the southern continental edge, leading to the opening of the Drake Passage, and it agrees with the timing of foredeep formation and development of fold-thrust belts in the northern continental edge. This positive correlation between the paleomagnetically predicted drift of a major continent with extension at its trailing edge and convergence at its leading edge during times for which seafloor tectonic fabric and the geological record are particularly well preserved illustrates the utility of paleomagnetism in constraining paleogeographic and tectonic reconstructions for pre-Cretaceous times.

  15. GRAIL Investigation of the Subsurface Structure of South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Ertel, A.; Nimmo, F.; Besserer, J.; Hurwitz, D. M.

    2014-12-01

    The GRAIL mission [1] has revealed a lunar crust that is globally less dense and presumably more porous [2] than anticipated. Measurements of the inferred (effective) density as a function of wavelength provide a way of probing the vertical density structure of the crust. Both the mean vertical density stratification [3] and spatial variations in the density structure [4] have been determined. Here we used an admittance approach [4] to investigate the subsurface structure of South Pole-Aikten (SPA) Basin. The SPA-forming impact was large enough to generate enormous quantities of melt [5,6] and a global ejecta layer [7]. The pre-existing crust was probably completely removed [8]; GRAIL data indicate a depth to the base of the crust (or other density interface) at a depth of about 13-20 km beneath the basin center [2]. Cooling and crystallization of the melt pool will have generated a distinct stratigraphy and density structure [6,5]. This predicted density structure can then be compared to that inferred from the GRAIL observations. We determined the effective density spectrum of SPA using a localized multitaper approach [4]. The effective density decreases from 2.7 g/cc at spherical harmonic degree l=250 to 2.6 g/cc at l=550, indicating an increase in density with depth. Two model predictions from [5] yield effective densities in the range 3.0-3.2 g/cc. The discrepancy between the predictions and the observations could be explained by 1) incorporations of large volumes of crustal material into the recrystallizing melt-sheet; or 2) ~20% fracture porosity extending to depths of 10 km or more. The latter possibility is more likely given SPA early formation and subsequent reprocessing and delivery of low-density material by impacts. [1] Zuber et al. 2013 [2] Wieczorek et al. 2013 [3] Han et al. 2013 [4] Besserer et al. 2014 [5] Hurwitz and Kring 2014 [6] Vaughan and Head 2013 [7] Petro and Pieters 2004 [8] Potter et al. 2012

  16. Moonrise: Sampling the South Pole-Aitken Basin to Address Problems of Solar System Significance

    NASA Technical Reports Server (NTRS)

    Zeigler, R. A.; Jolliff, B. L.; Korotev, R. L.; Shearer, C. K.

    2016-01-01

    A mission to land in the giant South Pole-Aitken (SPA) Basin on the Moon's southern farside and return a sample to Earth for analysis is a high priority for Solar System Science. Such a sample would be used to determine the age of the SPA impact; the chronology of the basin, including the ages of basins and large impacts within SPA, with implications for early Solar System dynamics and the magmatic history of the Moon; the age and composition of volcanic rocks within SPA; the origin of the thorium signature of SPA with implications for the origin of exposed materials and thermal evolution of the Moon; and possibly the magnetization that forms a strong anomaly especially evident in the northern parts of the SPA basin. It is well known from studies of the Apollo regolith that rock fragments found in the regolith form a representative collection of many different rock types delivered to the site by the impact process (Fig. 1). Such samples are well documented to contain a broad suite of materials that reflect both the local major rock formations, as well as some exotic materials from far distant sources. Within the SPA basin, modeling of the impact ejection process indicates that regolith would be dominated by SPA substrate, formed at the time of the SPA basin-forming impact and for the most part moved around by subsequent impacts. Consistent with GRAIL data, the SPA impact likely formed a vast melt body tens of km thick that took perhaps several million years to cool, but that nonetheless represents barely an instant in geologic time that should be readily apparent through integrated geochronologic studies involving multiple chronometers. It is anticipated that a statistically significant number of age determinations would yield not only the age of SPA but also the age of several prominent nearby basins and large craters within SPA. This chronology would provide a contrast to the Imbrium-dominated chronology of the nearside Apollo samples and an independent test of

  17. Maps of the Magellanic Clouds from combined South Pole Telescope and Planck Data

    DOE PAGES

    Crawford, T. M.; Chown, R.; Holder, G. P.; ...

    2016-12-01

    We present maps of the Large and Small Magellanic Clouds from combined South Pole Telescope (SPT) and Planck data. Both instruments are designed to make measurements of the cosmic microwave background but are sensitive to any source of millimeter-wave (mm-wave) emission. The Planck satellite observes in nine mm-wave bands, while the SPT data used in this work were taken with the three-band SPT-SZ camera. The SPT-SZ bands correspond closely to three of the nine Planck bands, namely those centered at 1.4, 2.1, and 3.0 mm. The angular resolution of the Planck data in these bands ranges from 5 to 10more » arcmin, while the SPT resolution in these bands ranges from 1.0 to 1.7 arcmin. The combined maps take advantage of the high resolution of the SPT data and the long-timescale stability of the space-based Planck observations to deliver high signal-to-noise and robust brightness measurements on scales from the size of the maps down to ~1 arcmin. In each of the three bands, we first calibrate and color-correct the SPT data to match the Planck data, then we use noise estimates from each instrument and knowledge of each instrument's beam, or point-spread function, to make the inverse-variance-weighted combination of the two instruments' data as a function of angular scale. We create maps assuming a range of underlying emission spectra (for the color correction) and at a range of final resolutions. We perform several consistency tests on the combined maps and estimate the expected noise in measurements of features in the maps. We compare the maps of the Large Magellanic Cloud (LMC) from this work to maps from the Herschel HERITAGE survey, finding general consistency between the datasets. Furthermore, the broad wavelength coverage provides evidence of different emission mechanisms at work in different environments in the LMC.« less

  18. South Pole Antarctica observations and modeling results: New insights on HO x radical and sulfur chemistry

    NASA Astrophysics Data System (ADS)

    Mauldin, Roy; Kosciuch, Edward; Eisele, Fred; Huey, Greg; Tanner, David; Sjostedt, Steve; Blake, Don; Chen, Gao; Crawford, Jim; Davis, Douglas

    2010-02-01

    Measurements of OH, H 2SO 4, and MSA at South Pole (SP) Antarctica were recorded as a part of the 2003 Antarctic Chemistry Investigation (ANTCI 2003). The time period 22 November, 2003-2 January, 2004 provided a unique opportunity to observe atmospheric chemistry at SP under both natural conditions as well as those uniquely defined by a solar eclipse event. Results under natural solar conditions generally confirmed those reported previously in the year 2000. In both years the major chemical driver leading to large scale fluctuations in OH was shifts in the concentration levels of NO. Like in 2000, however, the 2003 observational data were systematically lower than model predictions. This can be interpreted as indicating that the model mechanism is still missing a significant HO x sink reaction(s); or, alternatively, that the OH calibration source may have problems. Still a final possibility could involve the integrity of the OH sampling scheme which involved a fixed building site. As expected, during the peak in the solar eclipse both NO and OH showed large decreases in their respective concentrations. Interestingly, the observational OH profile could only be approximated by the model mechanism upon adding an additional HO x radical source in the form of snow emissions of CH 2O and/or H 2O 2. This would lead one to think that either CH 2O and/or H 2O 2 snow emissions represent a significant HO x radical source under summertime conditions at SP. Observations of H 2SO 4 and MSA revealed both species to be present at very low concentrations (e.g., 5 × 10 5 and 1 × 10 5 molec cm -3, respectively), but similar to those reported in 2000. The first measurements of SO 2 at SP demonstrated a close coupling with the oxidation product H 2SO 4. The observed low concentrations of MSA appear to be counter to the most recent thinking by glacio-chemists who have suggested that the plateau's lower atmosphere should have elevated levels of MSA. We speculate here that the absence

  19. Cassini VIMS Spectra of the Thermal Emission from Hot Spots Along Enceladus South Pole Fissures

    NASA Astrophysics Data System (ADS)

    Goguen, Jay D.; Buratti, Bonnie J.; Cassini VIMS Team

    2016-10-01

    Most of the south pole fissure region has not been directly illuminated by sunlight since the sub-solar point moved into the northern hemisphere in 2009, thereby eliminating the background of reflected sunlight at VIMS wavelengths and making the fissure thermal emission readily measureable. Since then, VIMS has measured spectra of at least 11 hot spots along the fissures. Most of these measurements were acquired in ride-along mode with CIRS as the prime instrument. During at least 2 encounters, VIMS and CIRS acquired simultaneous or near-simultaneous spectra of the same fissure location. VIMS spectra include multiple hot spots along Damascus, Baghdad, Cairo, and a likely hot spot on Alexandria.All of the VIMS spectra examined to date are consistent with this scenario of a self-regulating fissure maximum T~200 K with brighter VIMS emissions corresponding to fissures up to ~20 m wide. Emission from the warm fissure interior walls dominate the VIMS spectra with <15% contributed by conductive heating of the adjacent terrain at VIMS wavelengths.CIRS spectra report slightly cooler T's due to CIRS increased sensitivity to lower T emission at longer wavelengths and averaging over contributions from both the hottest and cooler areas. Combined analysis of the CIRS and VIMS spectra spanning 3 to 500 micron wavelengths promises to reveal the distribution of [T, area] near the fissures that cannot be spatially resolved. This [T, area] distribution holds the key to understanding how heat is transferred to the surface within a few 100 m of the fissures.The VIMS-detected emission is concentrated in localized hot spots along the fissures and does not seem to be distributed continuously along them. CIRS spectra suggest a more continuous distribution of the emission along the fissure length. Jets locations also are distributed along the fissure length and it appears that the VIMS-detected hot spots in general correlate with jet locations, but not all of the jet locations have been

  20. A MEASUREMENT OF GRAVITATIONAL LENSING OF THE MICROWAVE BACKGROUND USING SOUTH POLE TELESCOPE DATA

    SciTech Connect

    Van Engelen, A.; De Haan, T.; Dobbs, M. A.; Dudley, J.; Holder, G. P.; Keisler, R.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Hoover, S.; Zahn, O.; Aird, K. A.; Cho, H. M.; George, E. M.; Holzapfel, W. L.; Halverson, N. W.; Hou, Z.; and others

    2012-09-10

    We use South Pole Telescope data from 2008 and 2009 to detect the non-Gaussian signature in the cosmic microwave background (CMB) produced by gravitational lensing and to measure the power spectrum of the projected gravitational potential. We constrain the ratio of the measured amplitude of the lensing signal to that expected in a fiducial {Lambda}CDM cosmological model to be 0.86 {+-} 0.16, with no lensing disfavored at 6.3{sigma}. Marginalizing over {Lambda}CDM cosmological models allowed by the Wilkinson Microwave Anisotropy Probe (WMAP7) results in a measurement of A{sub lens} 0.90 {+-} 0.19, indicating that the amplitude of matter fluctuations over the redshift range 0.5 {approx}< z {approx}< 5 probed by CMB lensing is in good agreement with predictions. We present the results of several consistency checks. These include a clear detection of the lensing signature in CMB maps filtered to have no overlap in Fourier space, as well as a 'curl' diagnostic that is consistent with the signal expected for {Lambda}CDM. We perform a detailed study of bias in the measurement due to noise, foregrounds, and other effects and determine that these contributions are relatively small compared to the statistical uncertainty in the measurement. We combine this lensing measurement with results from WMAP7 to improve constraints on cosmological parameters when compared to those from WMAP7 alone: we find a factor of 3.9 improvement in the measurement of the spatial curvature of the universe, {Omega}{sub k} = -0.0014 {+-} 0.0172; a 10% improvement in the amplitude of matter fluctuations within {Lambda}CDM, {sigma}{sub 8} = 0.810 {+-} 0.026; and a 5% improvement in the dark energy equation of state, w = -1.04 {+-} 0.40. When compared with the measurement of w provided by the combination of WMAP7 and external constraints on the Hubble parameter, the addition of the lensing data improves the measurement of w by 15% to give w -1.087 {+-} 0.096.

  1. COSMIC MICROWAVE BACKGROUND CONSTRAINTS ON THE DURATION AND TIMING OF REIONIZATION FROM THE SOUTH POLE TELESCOPE

    SciTech Connect

    Zahn, O.; Reichardt, C. L.; Shaw, L.; George, E. M.; Holzapfel, W. L.; Lidz, A.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Cho, H. M.; De Haan, T.; Dobbs, M. A.; Dudley, J.; Holder, G. P.; Dore, O.; Halverson, N. W.; and others

    2012-09-01

    The epoch of reionization is a milestone of cosmological structure formation, marking the birth of the first objects massive enough to yield large numbers of ionizing photons. However, the mechanism and timescale of reionization remain largely unknown. Measurements of the cosmic microwave background (CMB) Doppler effect from ionizing bubbles embedded in large-scale velocity streams-known as the patchy kinetic Sunyaev-Zel'dovich (kSZ) effect-can be used to constrain the duration of reionization. When combined with large-scale CMB polarization measurements, the evolution of the ionized fraction, x-bar{sub e}, can be inferred. Using new multi-frequency data from the South Pole Telescope (SPT), we show that the ionized fraction evolved relatively rapidly. For our basic foreground model, we find the kSZ power sourced by reionization at l = 3000 to be D{sup patchy}{sub 3000} {<=} 2.1 {mu}K{sup 2} at 95% confidence. Using reionization simulations, we translate this to a limit on the duration of reionization of {Delta}z{identical_to}z{sub x}-bar{sub e=0.20}-z{sub x}-bar{sub e=0.99}{<=}4.4 (95% confidence). We find that this constraint depends on assumptions about the angular correlation between the thermal SZ power and the cosmic infrared background (CIB). Introducing the degree of correlation as a free parameter, we find that the limit on kSZ power weakens to D{sup patchy}{sub 3000} {<=} 4.9 {mu}K{sup 2}, implying {Delta}z {<=} 7.9 (95% confidence). We combine the SPT constraint on the duration of reionization with the Wilkinson Microwave Anisotropy Probe measurement of the integrated optical depth to probe the cosmic ionization history. We find that reionization ended with 95% confidence at z > 7.2 under the assumption of no tSZ-CIB correlation, and z > 5.8 when correlations are allowed. Improved constraints from the full SPT data set in conjunction with upcoming Herschel and Planck data should detect extended reionization at >95% confidence provided {Delta}z {>=} 2

  2. IMPROVED CONSTRAINTS ON COSMIC MICROWAVE BACKGROUND SECONDARY ANISOTROPIES FROM THE COMPLETE 2008 SOUTH POLE TELESCOPE DATA

    SciTech Connect

    Shirokoff, E.; Reichardt, C. L.; Benson, B. A.; George, E. M.; Holzapfel, W. L.; Shaw, L.; Millea, M.; Ade, P. A. R.; Aird, K. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Cho, H. M.; De Haan, T.; Dobbs, M. A.; Dudley, J.; Holder, G. P.; Halverson, N. W.

    2011-07-20

    We report measurements of the cosmic microwave background (CMB) power spectrum from the complete 2008 South Pole Telescope (SPT) data set. We analyze twice as much data as the first SPT power spectrum analysis, using an improved cosmological parameter estimator which fits multi-frequency models to the SPT 150 and 220 GHz bandpowers. We find an excellent fit to the measured bandpowers with a model that includes lensed primary CMB anisotropy, secondary thermal (tSZ) and kinetic (kSZ) Sunyaev-Zel'dovich anisotropies, unclustered synchrotron point sources, and clustered dusty point sources. In addition to measuring the power spectrum of dusty galaxies at high signal-to-noise, the data primarily constrain a linear combination of the kSZ and tSZ anisotropy contributions at 150 GHz and l = 3000: D{sup tSZ}{sub 3000} + 0.5 D{sup kSZ}{sub 3000} = 4.5 {+-} 1.0 {mu}K{sup 2}. The 95% confidence upper limits on secondary anisotropy power are D{sup tSZ}{sub 3000} < 5.3 {mu}K{sup 2} and D{sup kSZ}{sub 3000} < 6.5 {mu}K{sup 2}. We also consider the potential correlation of dusty and tSZ sources and find it incapable of relaxing the tSZ upper limit. These results increase the significance of the lower than expected tSZ amplitude previously determined from SPT power spectrum measurements. We find that models including non-thermal pressure support in groups and clusters predict tSZ power in better agreement with the SPT data. Combining the tSZ power measurement with primary CMB data halves the statistical uncertainty on {sigma}{sub 8}. However, the preferred value of {sigma}{sub 8} varies significantly between tSZ models. Improved constraints on cosmological parameters from tSZ power spectrum measurements require continued progress in the modeling of the tSZ power.

  3. A MEASUREMENT OF SECONDARY COSMIC MICROWAVE BACKGROUND ANISOTROPIES WITH TWO YEARS OF SOUTH POLE TELESCOPE OBSERVATIONS

    SciTech Connect

    Reichardt, C. L.; George, E. M.; Holzapfel, W. L.; Shaw, L.; Zahn, O.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Hoover, S.; Cho, H. M.; De Haan, T.; Dobbs, M. A.; Dudley, J.; Holder, G. P.; Halverson, N. W.; Hou, Z.; and others

    2012-08-10

    We present the first three-frequency South Pole Telescope (SPT) cosmic microwave background (CMB) power spectra. The band powers presented here cover angular scales 2000 < l < 9400 in frequency bands centered at 95, 150, and 220 GHz. At these frequencies and angular scales, a combination of the primary CMB anisotropy, thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, radio galaxies, and cosmic infrared background (CIB) contributes to the signal. We combine Planck/HFI and SPT data at 220 GHz to constrain the amplitude and shape of the CIB power spectrum and find strong evidence for nonlinear clustering. We explore the SZ results using a variety of cosmological models for the CMB and CIB anisotropies and find them to be robust with one exception: allowing for spatial correlations between the thermal SZ effect and CIB significantly degrades the SZ constraints. Neglecting this potential correlation, we find the thermal SZ power at 150 GHz and l = 3000 to be 3.65 {+-} 0.69 {mu}K{sup 2}, and set an upper limit on the kinetic SZ power to be less than 2.8 {mu}K{sup 2} at 95% confidence. When a correlation between the thermal SZ and CIB is allowed, we constrain a linear combination of thermal and kinetic SZ power: D{sup tSZ}{sub 3000} + 0.5D{sub 3000}{sup kSZ} = 4.60 {+-} 0.63 {mu}K{sup 2}, consistent with earlier measurements. We use the measured thermal SZ power and an analytic, thermal SZ model calibrated with simulations to determine {sigma}{sub 8} = 0.807 {+-} 0.016. Modeling uncertainties involving the astrophysics of the intracluster medium rather than the statistical uncertainty in the measured band powers are the dominant source of uncertainty on {sigma}{sub 8}. We also place an upper limit on the kinetic SZ power produced by patchy reionization; a companion paper uses these limits to constrain the reionization history of the universe.

  4. Geomorphological map of the South Belet region of Titan: An exploration of Mid-Latitude-to-Pole transition zones

    NASA Astrophysics Data System (ADS)

    Schoenfeld, Ashley Marie; M. C Lopes, Rosaly; Malaska, Michael; Solomonidou, Anezina; Birch, Samuel; Hayes, Alexander; Williams, David A.; Janssen, Michael A.; Le Gall, Alice; Turtle, Elizabeth P.; Cassini RADAR Team

    2016-10-01

    We carried out detailed geomorphological mapping of Titan's mid-latitude region south of the Belet Sand Sea. We used radar data collected by Cassini's Synthetic Aperture Radar (SAR) as our basemap, supplemented by spectro-images from VIMS, images from ISS, SARtopo, and microwave emissivity datasets. We mapped at a scale of 1:800,000 in all areas of the South Belet region covered by SAR swaths, taking into consideration the 300 m/pixel resolution of the swaths. For the mid-latitudes, we have defined five broad classes of terrains following Malaska et al. (2016). These terrain classes are craters, hummocky/mountainous, labyrinth, plains, and dunes. We have found that the hummocky/mountainous terrains are the oldest, with a radiometric signature consistent with icy materials. Dunes are the youngest units and return a radiometric signature consistent with organic sediments. The South Belet region of Titan is primarily covered by the dune and plain units (specifically the undifferentiated plains) typical of the mid-latitudes (Malaska et al. 2016). Previous mapping efforts of the mid-latitude regions of Titan (Lopes et al. 2016; Malaska et al. 2016) have indicated that these regions are predominately modified and influenced by aeolian activities. A plain unit designated "scalloped plains" is prominently featured between the 50°S and 60°S latitudes of this region. In this area we also find a terrain unit (dark irregular plains) that has been interpreted as damp materials saturated with liquid hydrocarbons (Malaska et al 2016; Hayes et al. 2008). We also note a higher identification of fluvial channels starting at this latitude zone and extending poleward. We suggest that these features demark the transition zone between mid-latitude/equatorial aeolian-dominated processes and fluvial-dominated processes prevailing at the poles.References: Lopes, R.M.C., et al.: Icarus, 270, 162-182, 2016; Malaska, M., et al.: Icarus, 270, 130-161, 2016; Hayes, A. et al.: Geophys. Res

  5. Spring and Summer Changes at the South Pole as Seen by the Mars Orbiter Camera

    NASA Technical Reports Server (NTRS)

    Ingersoll, A. P.; Murray, B. C.; Byrne, S.; DeJong, E.; Danielson, G. E.; Herkenhoff, K. E.; Kieffer, H. H.; Soderblom, L. A.

    2000-01-01

    The Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft has been able to follow individual features as the CO2 frost disappears and exposes the material underneath. Because the orbit of MGS is inclined at an angle of 93 degrees relative to the equator, the spacecraft gets especially good coverage of the ring at 87 degrees latitude. The following is a list of phenomena that have been seen during the spring and summer at the South Pole: (1) Circular depressions that are approximately ten meters deep and hundreds of meters in diameter. They are found only within the residual polar cap, the part that survives the summer. The high areas between the depressions are flat-topped mesas whose sides are concave circular arcs. In some places the depressions form patterns that exhibit north-south symmetry, suggesting some control by sunlight; (2) Dark layers that are exposed on the walls of the mesas. Each layer is at most a few meters thick. The dark layers might accumulate during climatic episodes of high atmospheric dust content, or they might accumulate during the annual cycling of dusty CO2; (3) Albedo differences that develop during the summer within the residual cap. These include subtle darkening of the floors of the depressions relative to the mesas and occasional major darkening of the floors, especially near the edge of the cap. The floors and mesas form a distinct stratum, suggesting they represent a distinct compositional boundary. For instance the floors may be water and the mesas may be CO2; (4) Small dark features that appear in spring on the seasonal frost outside the residual cap. Some of the features have parallel tails that are clearly shaped by the wind. Others are more symmetric, like dark snowflakes, with multiple branching arms. After the CO2 frost has disappeared the arms are seen as troughs and the centers as topographic lows; (5) Polygons whose sides are dark troughs. Those that are outside the residual cap seem to disappear when

  6. Temperature profile for glacial ice at the South Pole: Implications for life in a nearby subglacial lake

    PubMed Central

    Price, P. Buford; Nagornov, Oleg V.; Bay, Ryan; Chirkin, Dmitry; He, Yudong; Miocinovic, Predrag; Richards, Austin; Woschnagg, Kurt; Koci, Bruce; Zagorodnov, Victor

    2002-01-01

    Airborne radar has detected ≈100 lakes under the Antarctic ice cap, the largest of which is Lake Vostok. International planning is underway to search in Lake Vostok for microbial life that may have evolved in isolation from surface life for millions of years. It is thought, however, that the lakes may be hydraulically interconnected. If so, unsterile drilling would contaminate not just one but many of them. Here we report measurements of temperature vs. depth down to 2,345 m in ice at the South Pole, within 10 km from a subglacial lake seen by airborne radar profiling. We infer a temperature at the 2,810-m deep base of the South Pole ice and at the lake of −9°C, which is 7°C below the pressure-induced melting temperature of freshwater ice. To produce the strong radar signal, the frozen lake must consist of a mix of sediment and ice in a flat bed, formed before permanent Antarctic glaciation. It may, like Siberian and Antarctic permafrost, be rich in microbial life. Because of its hydraulic isolation, proximity to South Pole Station infrastructure, and analog to a Martian polar cap, it is an ideal place to test a sterile drill before risking contamination of Lake Vostok. From the semiempirical expression for strain rate vs. shear stress, we estimate shear vs. depth and show that the IceCube neutrino observatory will be able to map the three-dimensional ice-flow field within a larger volume (0.5 km3) and at lower temperatures (−20°C to −35°C) than has heretofore been possible. PMID:12060731

  7. Temperature profile for glacial ice at the South Pole: implications for life in a nearby subglacial lake.

    PubMed

    Price, P Buford; Nagornov, Oleg V; Bay, Ryan; Chirkin, Dmitry; He, Yudong; Miocinovic, Predrag; Richards, Austin; Woschnagg, Kurt; Koci, Bruce; Zagorodnov, Victor

    2002-06-11

    Airborne radar has detected approximately 100 lakes under the Antarctic ice cap, the largest of which is Lake Vostok. International planning is underway to search in Lake Vostok for microbial life that may have evolved in isolation from surface life for millions of years. It is thought, however, that the lakes may be hydraulically interconnected. If so, unsterile drilling would contaminate not just one but many of them. Here we report measurements of temperature vs. depth down to 2,345 m in ice at the South Pole, within 10 km from a subglacial lake seen by airborne radar profiling. We infer a temperature at the 2,810-m deep base of the South Pole ice and at the lake of -9 degrees C, which is 7 degrees C below the pressure-induced melting temperature of freshwater ice. To produce the strong radar signal, the frozen lake must consist of a mix of sediment and ice in a flat bed, formed before permanent Antarctic glaciation. It may, like Siberian and Antarctic permafrost, be rich in microbial life. Because of its hydraulic isolation, proximity to South Pole Station infrastructure, and analog to a Martian polar cap, it is an ideal place to test a sterile drill before risking contamination of Lake Vostok. From the semiempirical expression for strain rate vs. shear stress, we estimate shear vs. depth and show that the IceCube neutrino observatory will be able to map the three-dimensional ice-flow field within a larger volume (0.5 km(3)) and at lower temperatures (-20 degrees C to -35 degrees C) than has heretofore been possible.

  8. A revised 1000 year atmospheric δ13C-CO2 record from Law Dome and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Rubino, M.; Etheridge, D. M.; Trudinger, C. M.; Allison, C. E.; Battle, M. O.; Langenfelds, R. L.; Steele, L. P.; Curran, M.; Bender, M.; White, J. W. C.; Jenk, T. M.; Blunier, T.; Francey, R. J.

    2013-08-01

    We present new measurements of δ13C of CO2 extracted from a high-resolution ice core from Law Dome (East Antarctica), together with firn measurements performed at Law Dome and South Pole, covering the last 150 years. Our analysis is motivated by the need to better understand the role and feedback of the carbon (C) cycle in climate change, by advances in measurement methods, and by apparent anomalies when comparing ice core and firn air δ13C records from Law Dome and South Pole. We demonstrate improved consistency between Law Dome ice, South Pole firn, and the Cape Grim (Tasmania) atmospheric δ13C data, providing evidence that our new record reliably extends direct atmospheric measurements back in time. We also show a revised version of early δ13C measurements covering the last 1000 years, with a mean preindustrial level of -6.50‰. Finally, we use a Kalman Filter Double Deconvolution to infer net natural CO2 fluxes between atmosphere, ocean, and land, which cause small δ13C deviations from the predominant anthropogenically induced δ13C decrease. The main features found from the previous δ13C record are confirmed, including the ocean as the dominant cause for the 1940 A.D. CO2 leveling. Our new record provides a solid basis for future investigation of the causes of decadal to centennial variations of the preindustrial atmospheric CO2 concentration. Those causes are of potential significance for predicting future CO2 levels and when attempting atmospheric verification of recent and future global carbon emission mitigation measures through Coupled Climate Carbon Cycle Models.

  9. Mineralogy of the Mafic Anomaly in the South Pole-Aitken Basin: Implications for excavation of the lunar mantle

    NASA Technical Reports Server (NTRS)

    Pieters, C. M.; Tompkins, S.; Head, J. W.; Hess, P. C.

    1997-01-01

    Mineralogy of South Pole-Aitken Basin (SPA) (the largest confirmed impact basin on the Moon) is evaluated using five-color images from Clementine. Although olivine-rich material as well as basalts rich in clinopyroxene are readily identified elsewhere on the farside, the dominant rock type observed across the interior of SPA is of a very noritic composition. This mineralogy suggests that lower crust rather than the mantle is the dominant source of the mafic component at SPA. The lack of variation in observed noritic composition is probably due to basin formation processes, during which extensive melting and mixing of target materials are likely to occur.

  10. Quantification of HCl from High Resolution Infrared Solar Spectra Obtained at the South Pole in December 1986

    NASA Technical Reports Server (NTRS)

    Goldman, A.; Murcray, F. J.; Murcray, F. H.; Murcray, D. G.

    1987-01-01

    Ground-based infrared solar spectra at 0.02/ cm resolution obtained at the Amundsen-Scott South Pole station in December 1986 have been analysed for the atmospheric content of HCl. Nonlinear least-squares spectral fitting applied to the spectra yields a total HCl column amount of (6.4 +/- 0.8) x 10(exp 15) molec/sq cm, most being stratospheric. This amount is larger than that extrapolated from earlier results on the latitudinal distribution of atmospheric HCl.

  11. Infrared measurements of several nitrogen species above the South Pole in December 1980 and November-December 1986

    NASA Technical Reports Server (NTRS)

    Murcray, F. J.; Murcray, F. H.; Goldman, A.; Murcray, D. G.; Rinsland, C. P.

    1987-01-01

    This paper reports the results of the determinations of total column amounts of HNO3 for December 1980 and November 1986, and NO and NO2 for November-December 1986, deduced from ground-based high-resolution IR solar absorption spectra recorded from the Amundsen-Scott South Pole Station. The measurements were obtained shortly after the austral spring ozone minimum and define, for the first time, the ambient levels of these nitrogen species immediately following the break up of the polar vortex.

  12. Regional elemental abundances within South Pole-Aitken basin as measured with lunar prospector gamma-ray spectrometer data.

    SciTech Connect

    Lawrence, David J. ,; Pieters, Carlé M.; Elphic, R. C.; Gasnault, O. M.; Prettyman, T. H.; Feldman, W. C.

    2003-01-01

    South Pole-Aitken (SPA) basin has been a target of intense study since it is one of the largest impact basins in the solar system. It is thought that SPA basin excavated deep into the lunar crust and possibly even the mantle. Such conclusions have been supported by the observed mafic and thorium composition anomalies seen across the entire basin. One of the major goals of lunar and planetary science has been to measure and understand the composition of the non-mare materials within SPA basin. It is expected that this information will help to increase our understanding of the formation and differentiation processes that occurred early on the Moon.

  13. Geological and geochemical analysis of stratigraphic units in the South Pole - Aitken Basin

    NASA Astrophysics Data System (ADS)

    Borst, A.; Bexkens, F.; Foing, B.; Koschny, D.; Davies, G.; van Westrenen, W.

    2009-04-01

    The South Pole-Aitken (SPA) Basin, located on the Lunar far side, is one of the oldest and largest recognized impact structure in the solar system. This PreNectarian basin (>3.9 Ga) measures 2500 km in diameter with depths up to 13 km. A large mafic province was formed by the impact that effectively removed the upper crust [1]. Hence, deep-seated lower crustal and possibly even mantle materials are exposed in the severely modified Basin interior, providing the unique opportunity to probe and study the composition and structure of the Lunar interior. Consequently, the SPA Basin is a frequently proposed site for future sample return missions and detailed multispectral studies will required to aid landing site selection [2]. Previous studies on the multispectral dataset of Clementine (1994) by Pieters and Tompkins [1,3] revealed fresh mafic compositions of both low-Ca pyroxene or high-Ca pyroxene dominated rocks, referred to as norites and gabbros respectively. Some regions contained spectral features of olivine (troctolite), such as in Olivine Hill, which could suggest the presence of mantle derived deposits tapped during SPA impact. Using an algorithm developed by Pieters et al. [1] we have produced images for three subregions, covering the central and northern part of the SPA Basin. The algorithm is based on three diagnostic features in the UV/VIS spectrum of Clementine's 11 band multispectral dataset. The parameters are assigned to an RGB composite and allow distinction between mature soils, anorthosite (blue), norite (pink) and gabbro/troctolite compositions (green). Furthermore, we have used Clementine's Near Infrared database to produce a NIR band ratio image (2000 nm/1250 nm), as a parameter to distinguish between olivine and pyroxene-rich materials where we aim to detect traces of excavated mantle material (modified from LeMoeulic et al. [4]). Regretfully, we found that the NIR ratio method does not confirm olivine-rich material exposed in Olivine Hill as it

  14. Light Plains in the South-Pole Aitken Basin: Surface Ages and Mineralogical Composition

    NASA Astrophysics Data System (ADS)

    Thiessen, F.; Hiesinger, H.; van der Bogert, C. H.; Pasckert, J. H.; Robinson, M. S.

    2012-04-01

    We studied light plains in the north-eastern South-Pole Aitken basin to investigate their origin, ages, and mineralogical composition. Light plains, also known as the Cayley Formation, occur on the near- and farside of the Moon. Due to their smooth texture, lower crater densities, and occurrence as crater fills, they were thought to be of volcanic origin [e.g., 1]. However, Apollo 16 samples of light plains deposits were in fact highly brecciated rocks [2]. Therefore, the Imbrium and Orientale impacts were thought to have formed light plains because they reshaped the surface thousands of kilometers from their impact sites. Subsequent studies revealed varying surface ages of light plains [e.g., 3] and different mineralogical compositions, which are in some cases more highland-like and in others more mare-like. Hence, an origin solely from the Imbrium and/or Orientale impacts is unlikely. Thus, the question whether light plains formed due to large impacts or regional cratering, or through endogenic processes remains open. We performed crater size-frequency measurements [e.g., 4] on Lunar Reconnaissance Orbiter Wide Angle Camera images and obtained absolute model ages between 3.43 and 3.81 Ga. We observed neither a distinctive peak of light plains ages nor clustering of similar ages in any specific regions of the studied area. Due to the fact that the derived ages vary as much as 380 Ma, an origin by a single event seems unlikely. Moreover, some ages even post-date the Imbrium and Orientale impacts, and thus an origin related to those impacts is not likely. Examination of multispectral data from Clementine [5] shows that the Ti abundances vary between 0.2 and 3 wt % and Fe abundances between 12.5 and 19 wt %. We observed a regional difference in distribution: light plains units within the Apollo basin have lower Fe and Ti values and are more highland-like, whereas light plains outside the Apollo basin show higher Fe and Ti values and are more mare-like. Furthermore, M

  15. Design and initial performance of the Askaryan Radio Array prototype EeV neutrino detector at the South Pole

    NASA Astrophysics Data System (ADS)

    Ara Collaboration; Allison, P.; Auffenberg, J.; Bard, R.; Beatty, J. J.; Besson, D. Z.; Böser, S.; Chen, C.; Chen, P.; Connolly, A.; Davies, J.; Duvernois, M.; Fox, B.; Gorham, P. W.; Grashorn, E. W.; Hanson, K.; Haugen, J.; Helbing, K.; Hill, B.; Hoffman, K. D.; Hong, E.; Huang, M.; Huang, M. H. A.; Ishihara, A.; Karle, A.; Kennedy, D.; Landsman, H.; Liu, T. C.; Macchiarulo, L.; Mase, K.; Meures, T.; Meyhandan, R.; Miki, C.; Morse, R.; Newcomb, M.; Nichol, R. J.; Ratzlaff, K.; Richman, M.; Ritter, L.; Rott, C.; Rotter, B.; Sandstrom, P.; Seckel, D.; Touart, J.; Varner, G. S.; Wang, M.-Z.; Weaver, C.; Wendorff, A.; Yoshida, S.; Young, R.

    2012-02-01

    We report on studies of the viability and sensitivity of the Askaryan Radio Array (ARA), a new initiative to develop a Teraton-scale ultra-high energy neutrino detector in deep, radio-transparent ice near Amundsen-Scott station at the South Pole. An initial prototype ARA detector system was installed in January 2011, and has been operating continuously since then. We describe measurements of the background radio noise levels, the radio clarity of the ice, and the estimated sensitivity of the planned ARA array given these results, based on the first five months of operation. Anthropogenic radio interference in the vicinity of the South Pole currently leads to a few-percent loss of data, but no overall effect on the background noise levels, which are dominated by the thermal noise floor of the cold polar ice, and galactic noise at lower frequencies. We have also successfully detected signals originating from a 2.5 km deep impulse generator at a distance of over 3 km from our prototype detector, confirming prior estimates of kilometer-scale attenuation lengths for cold polar ice. These are also the first such measurements for propagation over such large slant distances in ice. Based on these data, ARA-37, the ˜200 km2 array now in its initial construction phase, will achieve the highest sensitivity of any planned or existing neutrino detector in the 1016-1019 eV energy range.

  16. Sulfur activation in electric pole insulators in Hiroshima

    SciTech Connect

    Pace, J.V. III; Kerr, G.D.

    1983-01-01

    The scalar neutron fluences at Hiroshima were folded with directional S(n,p)P responses to obtain a more precise prediction of the sulfur activation. The weapon detonated over Hiroshima had a twelve to fifteen degree tilt relative to the vertical. The effect of the tilt on sulfur activation was accounted for by making a two-dimensional, cylindrical, semi-infinite air calculation. Results showed that the directional S(n,p)P responses varied by five to fifteen percent from the top of the insulation to the side for different energy groups. 4 references. (ACR)

  17. Meteorites and Microbes: Meteorite Collection and Ice Sampling at Patriot Hills, Thiel Mountains, and South Pole, Antarctica

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    During the Antarctica 2000 Expedition, sponsored by the Planetary Studies Foundation, meteorites and ice microbiota were collected from the Patriot Hills, and Thiel Mountains of Antarctica and snow samples were at the South Pole. Psychrophilic and psychrotrophic microbiota were obtained from blue ice, cryoconite and ice-bubble systems. Twenty frozen meteorites were collected using aseptic techniques from the blue ice fields near the Moulton Escarpment of the Thiel Mountains (85 S, 94 W) and from the Morris Moraine of the Patriot Hills (80 S, 81 W) Ellsworth Mountains. These ice and meteorite samples are of potential significance to Astrobiology. They may help refine chemical and morphological biomarkers and refine characteristics of microbial life in one of the harshest environments on Earth. We discuss the Antarctica 2000 Expedition and provide preliminary results of the investigation of the meteorites and ice microbiota recovered.

  18. Marine and terrestrial influences on interannual CO{sub 2} variations at Mauna Loa and the South Pole

    SciTech Connect

    Dettinger, M.D.; Ghil, M.

    1997-11-01

    Data are presented and very briefly discussed regarding interannual variations of atmospheric carbon dioxide (CO{sub 2}) concentrations. Interannual variations are isolated from monthly concentrations by using singular-spectrum analysis of CO{sub 2} and atmospheric carbon isotopic ratios at Mauna Loa, Hawaii, United States and at the South Pole. Interannual variations are shared at the two sites, and can be used to differentiate between marine and land-surface responses to different interannual climate variations on global scales. Two time-scales are compared: (1) quasi-quadrennial (QQ) and (2) 3-year. Phase relations indicate that QQ variations are dominated by terrestrial influences, whereas the 3-year variations reflect marine (upwelling) influences in the eastern Pacific. The contrasting CO{sub 2} responses on these two time scales thus provide a useful measure of differences in global climate responses, and especially in terrestrial-ecosystem responses to different tropical forcings. 1 fig.

  19. Recent Global Measurements of Atmospheric COS and Historic Trends Inferred from Firn Air at the South Pole

    NASA Astrophysics Data System (ADS)

    Montzka, S. A.; Lind, J. A.; Dutton, G. S.; Hall, B. D.; Mondeel, D. J.; Butler, J. H.; Elkins, J. W.

    2001-12-01

    Available measurements of carbonyl sulfide provide a picture of atmospheric distributions and seasonal variations that are somewhat inconsistent with our current understanding of COS sources and sinks [see Kjellstrom, J. Atmos. Chem., 1998]. Over the past 1.5 years, we have made measurements of COS at 10 ground-based sampling stations to address some of these concerns. In addition, we have measured COS in firn air from the South Pole in an attempt to reconstruct an atmospheric history of this gas dating back to the early 1900s. The recent data show large seasonal variations at most sites in both hemispheres; summer mixing ratios at Arctic and continental US sites are 20-30% lower than observed in spring. In the northern hemisphere (NH), the timing of the seasonality lends support to strong summertime losses of COS owing to uptake by vegetation and/or soils. The only regular seasonality noted previously for COS in the NH was by total column absorption measurements at mid-latitudes that indicated slightly higher ( ~3%) mean tropospheric mixing ratios in summer. In the southern hemisphere (SH), smaller ( ~10% peak-to-peak) variations are observed at Tasmania and show a maximum during austral summer, perhaps owing to enhanced oceanic flux during that season. No seasonality is apparent at American Samoa (14 S), where larger sample-to-sample variations are observed. Our data suggest annual mean surface mixing ratios for COS that are slightly higher in the SH (by ~2%), but the NH/SH ratio varies by about +/-6% depending upon the season. Data from air trapped in the snow pack (firn) at South Pole suggest that COS mixing ratios in the early 1990's were ~20% lower than observed today. The mixing ratio increases appear to have occurred predominantly in the early part of that century.

  20. The Accuracy of Praziquantel Dose Poles for Mass Treatment of Schistosomiasis in School Girls in KwaZulu-Natal, South Africa

    PubMed Central

    Baan, Marije; Galappaththi-Arachchige, Hashini Nilushika; Gagai, Silindile; Aurlund, Christine G.; Vennervald, Birgitte J.; Taylor, Myra; van Lieshout, Lisette; Kjetland, Eyrun F.

    2016-01-01

    Background More than 260 million people live with schistosomiasis and regular mass-treatment should be implemented to prevent morbidity. Praziquantel, dosed at 40 milligrams per kilogram bodyweight, is the drug of choice. During the last decades the WHO Tablet Pole–which estimates tablet need by height as representing weight–has been used as a practical and cheap tool in mass treatment. In South Africa this method could be inaccurate given the prevalence of overweight and obesity. In this study in female pupils in KwaZulu-Natal, South Africa, we explored the accuracy of the WHO Tablet Pole and the recently developed Modified Dose Pole for adults with two additional intervals and correction for body mass index (BMI). Methodology In randomly selected primary and secondary schools of schistosomiasis-endemic areas, height and weight of female pupils were measured. The WHO Tablet Pole and Modified Dose Pole were used to indicate the amount of praziquantel according to height and the dose in milligrams per kilogram bodyweight was calculated. The BMI correction was performed by adding 600 milligrams (1 tablet) to the indicated dose if a person was overweight/obese. Principal Findings 3157 female students were investigated and 35% were found to be overweight/obese. Using the WHO Tablet Pole, 73% would have received an adequate dose (range 30–60 mg/kg). When correcting for BMI, this would have been 94%. Using the Modified Dose Pole with BMI correction, 97% would have been adequately treated. Conclusions This study shows that the WHO Tablet Pole will be inaccurate in estimating the dose of praziquantel in South African girls due to high prevalence of overweight/obesity. Under-dosing of individuals who appear overweight/obese could be largely prevented by adding an extra praziquantel tablet to the recommended dose. Further research must be done to explore if subjective weight estimates are reliable. PMID:27139497

  1. A Cretaceous pole from south China, and the Mesozoic hairpin turn of the Eurasian apparent polar wander path

    NASA Astrophysics Data System (ADS)

    Enkin, Randolph J.; Chen, Yan; Courtillot, Vincent; Besse, Jean; Xing, Lisheng; Zhang, Zhenhai; Zhuang, Zhonghai; Zhang, Jingxin

    1991-03-01

    To contribute to the apparent polar wander path (APWP) of the South China Block and Eurasia in general, we collected paleomagnetic samples from Mesozoic red beds around the city of Ya' an (30°N, 103°E) in the western tip of the Sichuan Basin. In this paper we present the results from 373 oriented cores taken from one section representing 3 km of sedimentary rocks. The section is dated with continental ostracods and with a magnetostratigraphic correlation between a densely sampled 272-m sequence and the polarity time scale, giving an upper Jurassic to Upper Cretaceous or Lower Tertiary age. The remanent direction is remarkably stable throughout the section (D=2.0°, I=34.2°, k=63.1,α95=3.6°, N=26/28 sites). While this fact might suggest that the section has been remagnetized, paleomagnetic and rock magnetic tests indicate that the remanence is primary. The pole position (78.6°N, 273.4°E, dp=2.4°, dm=4.1°) corresponds to a rather low paleolatitude (λ=18.8°±2.4°) but is consistent with other Cretaceous poles from China. If one accepts the Eurasian APWP of Irving and Irving (1982), this result would imply that more than 1000 km of shortening took place between South China and Eurasia, following the acquisition of the remanence. However, there is no geological evidence for this large shortening. We propose that the remanence was acquired within the time corresponding to the tip of the hairpin turn (˜150-50 Ma) in the revised APWP of Besse and Courtillot (this issue). The local geology suggests that the syncline from which the samples were taken has been rotated by 15°±5° counterclockwise, which is reflected in a similar discrepancy between the measured paleodeclination and that predicted by the Besse and Courtillot (this issue) Eurasian APWP. After correcting for this rotation, the pole position is 70.9°N, 225.2°E (dp=2.4°, dm=6.5°). We conclude that Eurasia was fully assembled by the end of the Jurassic and that the Mesozoic Eurasian hairpin turn

  2. High Altitude Weather Balloons to Support Rayleigh and Sodium Lidar Studies of the Troposphere, Stratosphere and Mesosphere at the Amundsen-Scott South Pole Station

    NASA Technical Reports Server (NTRS)

    Papen, George

    1995-01-01

    This proposal funded 100 high altitude weather balloons costing $15,500 to support the deployment of a Rayleigh/Raman/Na lidar at the South Pole. One year of measurements have been completed and it is estimated that the balloons will provide another 1-2 years of data.

  3. Recent Mission Datasets Shed New Light on the Character and Fate of the South Pole-Aitken Basin Impact Melt Sheet

    NASA Astrophysics Data System (ADS)

    Jolliff, B. L.; Petro, N. E.; Shearer, C. K.; Pieters, C. M.; Head, J. W.

    2016-05-01

    Characterizing and accessing impact melt rocks of the South Pole-Aitken basin is of high priority for understanding the history of the Moon, the giant basin forming process, and establishing the chronology of giant impacts in the early solar system.

  4. Temporal pole activity during understanding other persons' mental states correlates with neuroticism trait.

    PubMed

    Jimura, Koji; Konishi, Seiki; Asari, Tomoki; Miyashita, Yasushi

    2010-04-30

    Comprehension of other persons' mental states is one of the representative cognitive functions involved in social situations. It has been suggested that this function sometimes recruits emotional processes. The present fMRI study examined the neural mechanisms associated with understanding others' mental states, and the conditions that determine the recruitment of the emotional processes. The false belief paradigm, a traditional behavioral paradigm to investigate comprehension of others, was applied to an event-related fMRI analysis, allowing for the extraction of brain activity time-locked to successful understanding of others' mental states. Prominent brain activity was observed in multiple cortical regions including the medial prefrontal cortex, temporo-parietal junction, precuneus, and temporal pole. Then, correlational analyses were performed between the activations and individuals' scores of neuroticism, a personality trait that reflects emotional instability in daily life. It was revealed that the neuroticism scores were positively correlated with the activity in the temporal pole region, but not in the other regions. These results suggest that the emotional processes implemented in the temporal pole are recruited during successful understanding of other persons' mental states, and that the recruitment may be modulated by an emotional personality trait of individual subjects.

  5. Statistics of MF-Burst Emissions: Analysis of Data from South Pole Station and from Multiple Northern Hemisphere Stations

    NASA Astrophysics Data System (ADS)

    Labelle, J.; Jackson, E.; Tantiwiwat, M.; Linder, J.; Ye, S.; Weatherwax, A.

    2004-05-01

    Medium-frequency burst (MF-burst) is a broadband impulsive emission at 1-5 MHz observed at ground level during auroral substorm onsets [Weatherwax et al., 1994; LaBelle et al., 1997; review by LaBelle and Treumann, 2002]. Its amplitude is comparable to that of auroral hiss, with which it often coincides. Polarization measurements indicate that MF-burst propagates in the LO mode in the ionosphere [Shepherd et al., 1997], but aside from that its generation mechanism is unknown. In order to measure MF-burst and related auroral emissions, Dartmouth College operates LF/MF/HF radio receivers at South Pole Station and at various northern hemisphere observatories. South Pole is one of the best sites worldwide for observing MF-burst, because of the low level of man-made and natural noise in the 1-5 MHz band. This low noise level allows easy identification of events and semi-automatic data analysis; exploiting these, we present statistics of MF-burst amplitudes, frequencies, dates and local times of occurrence, etc., for one full year of data collected in 2003. To complement this single-station statistical study, we examine MF-burst data from 1997-8 when simultaneous data from up to five northern hemisphere stations, separated by 200-400 km north-south, exist. 80--90% of the MF-burst events occur at a single station; however, some events occur on up to four of the five stations simultaneously. In MF-burst emissions which occur at multiple stations, the onset of the emission often shifts poleward as the substorm onset progresses. We examine the statistics of this poleward shift in comparison to other substorm diagnostics. References: Weatherwax, A.T., J. LaBelle, and M.L. Trimpi, A new type of auroral radio emission at 1.4-3.7 MHz observed from the ground, Geophys. Res. Lett., 21, 2753, 1994. LaBelle, J., S.G. Shepherd, and M.L. Trimpi, Observations of auroral medium frequency burst emissions, J. Geophys. Res., 102, 22221, 1997. Shepherd, S.G., J. LaBelle, and M.L. Trimpi

  6. South Pole Hydrogen Distribution for Present Lunar Conditions: Implications for Past Impacts

    NASA Technical Reports Server (NTRS)

    Elphic, R. C.; Paige, D. A.; Siegler, M. A.; Vasavada, A. R.; Eke, V. R.; Teodoro, L. F. A.; Lawrence, D. J.

    2010-01-01

    It has been known since the Lunar Prospector mission that the poles of the Moon evidently harbor enhanced concentrations of hydrogen [1,2]. The physical and chemical form of the hydrogen has been much debated. Using imagery from Clementine it was possible to roughly estimate permanently-shadowed regions (PSRs), and to perform image reconstructions of the Lunar Prospector epithermal neutron flux maps [3,4]. The hydrogen concentrations resulting from these reconstructions were consistent with a few weight percent water ice in selected locations. With the LCROSS impact, we now know that hydrogen in the form of ice does exist in lunar polar cold traps [5]. Armed with this information, and new data from LRO/Diviner, we can examine whether the pre-sent-day distribution of hydrogen in the form of water ice is consistent with a past large impact that delivered a large mass of volatiles to the lunar surface. These volatiles, mixed with solid impact ejecta, would then be lost from locations having high mean temperatures but would otherwise remain trapped in locations with sufficiently low mean annual temperatures [6]. The time scales for loss would depend on the location-dependent temperatures as well as impact history.

  7. Influence analysis of time delay to active mass damper control system using pole assignment method

    NASA Astrophysics Data System (ADS)

    Teng, J.; Xing, H. B.; Lu, W.; Li, Z. H.; Chen, C. J.

    2016-12-01

    To reduce the influence of time delay on the Active Mass Damper (AMD) control systems, influence analysis of time delay on system poles and stability is applied in the paper. A formula of the maximum time delay for ensuring system stability is established, by which the influence analysis of control gains on system stability is further arisen. In addition, the compensation controller is designed based on the given analysis results and pole assignment. A numerical example and an experiment are illustrated to verify that the performance of time-delay system. The result is consistent to that of the long-time delay control system, as well as to proof the better effectiveness of the new method proposed in this article.

  8. Candidate Clusters of Galaxies at z > 1.3 Identified in the Spitzer South Pole Telescope Deep Field Survey

    NASA Astrophysics Data System (ADS)

    Rettura, A.; Martinez-Manso, J.; Stern, D.; Mei, S.; Ashby, M. L. N.; Brodwin, M.; Gettings, D.; Gonzalez, A. H.; Stanford, S. A.; Bartlett, J. G.

    2014-12-01

    We present 279 galaxy cluster candidates at z > 1.3 selected from the 94 deg2 Spitzer South Pole Telescope Deep Field (SSDF) survey. We use a simple algorithm to select candidate high-redshift clusters of galaxies based on Spitzer/IRAC mid-infrared data combined with shallow all-sky optical data. We identify distant cluster candidates adopting an overdensity threshold that results in a high purity (80%) cluster sample based on tests in the Spitzer Deep, Wide-Field Survey of the Boötes field. Our simple algorithm detects all three 1.4 < z <= 1.75 X-ray detected clusters in the Boötes field. The uniqueness of the SSDF survey resides not just in its area, one of the largest contiguous extragalactic fields observed with Spitzer, but also in its deep, multi-wavelength coverage by the South Pole Telescope (SPT), Herschel/SPIRE, and XMM-Newton. This rich data set will allow direct or stacked measurements of Sunyaev-Zel'dovich effect decrements or X-ray masses for many of the SSDF clusters presented here, and enable a systematic study of the most distant clusters on an unprecedented scale. We measure the angular correlation function of our sample and find that these candidates show strong clustering. Employing the COSMOS/UltraVista photometric catalog in order to infer the redshift distribution of our cluster selection, we find that these clusters have a comoving number density nc = (0.7+6.3-0.6) × 10-7 h3 {Mpc}-3 and a spatial clustering correlation scale length r 0 = (32 ± 7) h -1 Mpc. Assuming our sample is comprised of dark matter halos above a characteristic minimum mass, M min, we derive that at z = 1.5 these clusters reside in halos larger than Mmin = 1.5+0.9-0.7 × 1014 h-1 M⊙ . We find that the mean mass of our cluster sample is equal to Mmean = 1.9+1.0-0.8 × 1014 h-1 M⊙ ; thus, our sample contains the progenitors of present-day massive galaxy clusters.

  9. CANDIDATE CLUSTERS OF GALAXIES AT z > 1.3 IDENTIFIED IN THE SPITZER SOUTH POLE TELESCOPE DEEP FIELD SURVEY

    SciTech Connect

    Rettura, A.; Stern, D.; Martinez-Manso, J.; Gettings, D.; Gonzalez, A. H.; Mei, S.; Ashby, M. L. N.; Brodwin, M.; Stanford, S. A.; Bartlett, J. G.

    2014-12-20

    We present 279 galaxy cluster candidates at z > 1.3 selected from the 94 deg{sup 2} Spitzer South Pole Telescope Deep Field (SSDF) survey. We use a simple algorithm to select candidate high-redshift clusters of galaxies based on Spitzer/IRAC mid-infrared data combined with shallow all-sky optical data. We identify distant cluster candidates adopting an overdensity threshold that results in a high purity (80%) cluster sample based on tests in the Spitzer Deep, Wide-Field Survey of the Boötes field. Our simple algorithm detects all three 1.4 < z ≤ 1.75 X-ray detected clusters in the Boötes field. The uniqueness of the SSDF survey resides not just in its area, one of the largest contiguous extragalactic fields observed with Spitzer, but also in its deep, multi-wavelength coverage by the South Pole Telescope (SPT), Herschel/SPIRE, and XMM-Newton. This rich data set will allow direct or stacked measurements of Sunyaev-Zel'dovich effect decrements or X-ray masses for many of the SSDF clusters presented here, and enable a systematic study of the most distant clusters on an unprecedented scale. We measure the angular correlation function of our sample and find that these candidates show strong clustering. Employing the COSMOS/UltraVista photometric catalog in order to infer the redshift distribution of our cluster selection, we find that these clusters have a comoving number density n{sub c}=(0.7{sub −0.6}{sup +6.3})×10{sup −7} h{sup 3} Mpc{sup −3} and a spatial clustering correlation scale length r {sub 0} = (32 ± 7) h {sup –1} Mpc. Assuming our sample is comprised of dark matter halos above a characteristic minimum mass, M {sub min}, we derive that at z = 1.5 these clusters reside in halos larger than M{sub min}=1.5{sub −0.7}{sup +0.9}×10{sup 14} h{sup −1} M{sub ⊙}. We find that the mean mass of our cluster sample is equal to M{sub mean}=1.9{sub −0.8}{sup +1.0}×10{sup 14} h{sup −1} M{sub ⊙}; thus, our sample contains the progenitors of

  10. A Measurement of Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters Using Data from the South Pole Telescope

    DOE PAGES

    Baxter, E. J.; Keisler, R.; Dodelson, S.; ...

    2015-06-22

    Clusters of galaxies are expected to gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters with CMB data alone. Here we present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope (SPT). We also develop a maximum likelihood approach to extract the CMB cluster lensing signal and validate the method on mock data. We quantify the effects on our analysis of several potential sources of systematic error andmore » find that they generally act to reduce the best-fit cluster mass. It is estimated that this bias to lower cluster mass is roughly 0.85σ in units of the statistical error bar, although this estimate should be viewed as an upper limit. Furthermore, we apply our maximum likelihood technique to 513 clusters selected via their Sunyaev–Zeldovich (SZ) signatures in SPT data, and rule out the null hypothesis of no lensing at 3.1σ. The lensing-derived mass estimate for the full cluster sample is consistent with that inferred from the SZ flux: M200,lens = 0.83+0.38-0.37 M200,SZ (68% C.L., statistical error only).« less

  11. SPITZER MIPS 24 and 70 {mu}m IMAGING NEAR THE SOUTH ECLIPTIC POLE: MAPS AND SOURCE CATALOGS

    SciTech Connect

    Scott, Kimberly S.; Stabenau, Hans F.; Devlin, Mark J.; Truch, Matthew D. P.; Braglia, Filiberto G.; Chapin, Edward L.; Marsden, Gaelen; Scott, Douglas; Valiante, Elisabetta; Borys, Colin; Viero, Marco P.

    2010-12-15

    We have imaged an 11.5 deg{sup 2} region of sky toward the South Ecliptic Pole (R.A. =04{sup h}43{sup m}, decl. =-53{sup 0}40', J2000) at 24 and 70 {mu}m with MIPS, the Multiband Imaging Photometer for Spitzer. This region is coincident with a field mapped at longer wavelengths by AKARI and BLAST. We discuss our data reduction and source extraction procedures. The median 1{sigma} depths of the maps are 47 {mu}Jy beam{sup -1} at 24 {mu}m and 4.3 mJy beam{sup -1} at 70 {mu}m. At 24 {mu}m, we identify 93,098 point sources with signal-to-noise ratio (S/N) {>=}5 and an additional 63 resolved galaxies; at 70 {mu}m we identify 891 point sources with S/N {>=}6. From simulations, we determine a false detection rate of 1.8% (1.1%) for the 24 {mu}m (70 {mu}m) catalog. The 24 and 70 {mu}m point-source catalogs are 80% complete at 230 {mu}Jy and 11 mJy, respectively. These mosaic images and source catalogs will be available to the public through the NASA/IPAC Infrared Science Archive.

  12. A Measurement of Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters Using Data from the South Pole Telescope

    SciTech Connect

    Baxter, E. J.; Keisler, R.; Dodelson, S.; Aird, K. A.; Allen, S. W.; Ashby, M. L.N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. -M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dietrich, J. P.; de Haan, T.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Harrington, N. L.; Hennig, C.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Jones, C.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-06-22

    Clusters of galaxies are expected to gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters with CMB data alone. Here we present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope (SPT). We also develop a maximum likelihood approach to extract the CMB cluster lensing signal and validate the method on mock data. We quantify the effects on our analysis of several potential sources of systematic error and find that they generally act to reduce the best-fit cluster mass. It is estimated that this bias to lower cluster mass is roughly 0.85σ in units of the statistical error bar, although this estimate should be viewed as an upper limit. Furthermore, we apply our maximum likelihood technique to 513 clusters selected via their Sunyaev–Zeldovich (SZ) signatures in SPT data, and rule out the null hypothesis of no lensing at 3.1σ. The lensing-derived mass estimate for the full cluster sample is consistent with that inferred from the SZ flux: M200,lens = 0.83+0.38-0.37 M200,SZ (68% C.L., statistical error only).

  13. Local Lunar Gravity Field Analysis over the South Pole-aitken Basin from SELENE Farside Tracking Data

    NASA Technical Reports Server (NTRS)

    Goossens, Sander Johannes; Ishihara, Yoshiaki; Matsumoto, Koji; Sasaki, Sho

    2012-01-01

    We present a method with which we determined the local lunar gravity field model over the South Pole-Aitken (SPA) basin on the farside of the Moon by estimating adjustments to a global lunar gravity field model using SELENE tracking data. Our adjustments are expressed in localized functions concentrated over the SPA region in a spherical cap with a radius of 45deg centered at (191.1 deg E, 53.2 deg S), and the resolution is equivalent to a 150th degree and order spherical harmonics expansion. The new solution over SPA was used in several applications of geophysical analysis. It shows an increased correlation with high-resolution lunar topography in the frequency band l = 40-70, and admittance values are slightly different and more leveled when compared to other, global gravity field models using the same data. The adjustments expressed in free-air anomalies and differences in Bouguer anomalies between the local solution and the a priori global solution correlate with topographic surface features. The Moho structure beneath the SPA basin is slightly modified in our solution, most notably at the southern rim of the Apollo basin and around the Zeeman crater

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

    PubMed

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

    1994-01-01

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

  15. Infrared Measurements of Several Nitrogen Species Above the South Pole in December 1980 and November - December 1986

    NASA Technical Reports Server (NTRS)

    Murcray, F. J.; Murcray, F. H.; Goldman, A.; Murcray, D. G.; Rinsland, C. P.

    1987-01-01

    In December 1980 and November-December 1986, the University of Denver atmospheric spectroscopy group recorded numerous high-resolution infrared solar absorption spectra from the Amundsen-Scott south pole station. These spectra were obtained by Frank J. Murcray and Frank H. Murcray with a Michelson-type Fourier transform spectrometer and show absorption features of a number of minor and trace atmospheric gases with a minimum of atmospheric water vapor absorption. Quantifications of the total column amounts of O3, CH4, N2O, and H2O from the 1980 observations and RCI from the 1986 observations have been reported along with an atlas of the 750-960/ cm spectral region. In the present study, we report measurements of HNO3 total column amounts deduced from both data sets and NO, and NO2 total column amounts from the 1986 data set. Nitric acid may be important in the chemistry which creates the spring Antarctic ozone minimum, since it may condense in the cold winter polar stratosphere and become the dominant component of polar stratospheric clouds. The present measurements were obtained shortly after the austral spring ozone minimum and define for the first time the ambient levels of these nitrogen species immediately following the breakup of the polar vortex.

  16. Comparison of the Geologic Setting of the South Pole-Aitken Basin Interior with Apollo 16: Implications for Regolith Components

    NASA Technical Reports Server (NTRS)

    Petro, N. E.; Pieters, C. M.

    2004-01-01

    The interior of the South Pole-Aitken Basin (SPA) contains ancient cratered terrain that is possibly remnant of the original interior of the basin. This terrain has been modified by the addition of and mixing with foreign material introduced by later basins and craters of all sizes (lateral and vertical mixing). Since much of our thinking about ancient regolith is based on detailed analysis of samples from one nearside ancient heavily cratered highland site, Apollo 16 (Ap16), it is instructive to compare the interior of SPA with the Ap16 landing site. For this comparison we use a central location within SPA (SPA-1 at 60 deg. S, 160 deg. W). Two models have recently been presented that allow estimation of the amount of original SPA interior material likely to remain in the regolith of SPA. Although the details of each model are different, results consistently range from 50-82% original material in the regolith. The models also allow the contribution from individual basins to be predicted.

  17. Updated results from the RICE experiment and future prospects for ultra-high energy neutrino detection at the south pole

    NASA Astrophysics Data System (ADS)

    Kravchenko, I.; Hussain, S.; Seckel, D.; Besson, D.; Fensholt, E.; Ralston, J.; Taylor, J.; Ratzlaff, K.; Young, R.

    2012-03-01

    The RICE experiment seeks observation of ultra-high energy (UHE; Eν>1017eV) neutrinos interacting in Antarctic ice, by measurement of the radio frequency (RF) Cherenkov radiation resulting from the collision of a neutrino with an ice molecule. RICE was initiated in 1999 as a first-generation prototype for an eventual, large-scale in-ice UHE neutrino detector. Herein, we present updated limits on the diffuse UHE neutrino flux, based on 12 years of data taken between 1999 and 2010. We find no convincing neutrino candidates, resulting in 95% confidence-level model-dependent limits on the flux Eν2dϕ/dEν<0.5×10-6GeV/(cm2s-sr) in the energy range 1017south pole. ARA seeks to improve on the RICE sensitivity by approximately 2 orders of magnitude by 2017 and thereby establish the cosmogenic neutrino flux. As detailed herein, RICE studies of Antarctic ice demonstrate that both birefringence and internal layer RF scattering result in no significant loss of ARA neutrino sensitivity, and, for the first time, verify in situ the decrease in attenuation length with depth into the Antarctic ice sheet.

  18. From the South Pole to the Northern Plains: The Argyre Planitia Story

    NASA Technical Reports Server (NTRS)

    Parker, T. J.; Grant, J. A.; Anderson, F. S.; Banerdt, W. B.

    2003-01-01

    Parker (1985, 1994) first described evidence for catastrophic flooding from a large lake or sea within Argyre Planitia through the Uzboi-Holden- Ladon-Margaritifer Valles system during the Noachian. The channel connection to Argyre had been recognized during the mid-1970s, based primarily on Russian orbiter images taken at that time. The most critical reviews of these inferences related to the relative timing of the plains materials, sinuous ridges, and debris aprons in southern Argyre, and the connection, via Uzboi Vallis, of ponding within Argyre to flooding through the Chryse Trough. The prevailing "competing" hypothesis for formation of materials within Argyre is that they are a result of south circumpolar glacial processes, with glacial scour and stagnation producing the pitting and sinuous ridges (eskers) on the basin floor rather than lacustrine erosion and deposition followed much later by a process akin to rock glacier formation of the debris aprons in a colder Amazonian climate. Argyre was part of a larger surface hydrological system that also included two large valley networks draining the Margaritifer Sinus region northwest of Argyre. The morphometry of these systems suggest a combination of precipitation and groundwater sapping, with surface runoff for their formation.

  19. Neutrino Data from IceCube and its Predecessor at the South Pole, the Antarctic Muon and Neutrino Detector Array (AMANDA)

    DOE Data Explorer

    Abbasi, R.

    IceCube is a neutrino observatory for astrophysics with parts buried below the surface of the ice at the South Pole and an air-shower detector array exposed above. The international group of sponsors, led by the National Science Foundation (NSF), that designed and implemented the experiment intends for IceCube to operate and provide data for 20 years. IceCube records the interactions produced by astrophysical neutrinos with energies above 100 GeV, observing the Cherenkov radiation from charged particles produced in neutrino interactions. Its goal is to discover the sources of high-energy cosmic rays. These sources may be active galactic nuclei (AGNs) or massive, collapsed stars where black holes have formed.[Taken from http://www.icecube.wisc.edu/] The data from IceCube's predecessor experiment and detector, AMANDA, IceCube’s predecessor detector and experiment is also available at this website. AMANDA pioneered neutrino detection in ice. Over a period of years in the 1990s, detecting “strings” were buried and activated and by 2000, AMANDA was successfully recording an average of 1,000 neutrino events per year. This site also makes available many images and video from the two experiments.

  20. Real-Time Teleguidance of a Non-Surgeon Crew Medical Officer Performing Orthopedic Surgery at the Amundsen-Scott South Pole Station During Winter-Over

    NASA Technical Reports Server (NTRS)

    Otto, Christian

    2010-01-01

    The Amundsen-Scott South Pole Research station located at the geographic South Pole, is the most isolated, permanently inhabited human outpost on Earth. Medical care is provided to station personnel by a non-surgeon crew medical officer (CMO). During the winter-over period from February to October, the station is isolated, with no incoming or outgoing flights due to severe weather conditions. In late June, four months after the station had closed for the austral winter, a 31 year old meteorologist suffered a complete rupture of his patellar tendon while sliding done an embankment. An evacuation was deemed to be too risky to aircrews due to the extreme cold and darkness. A panel of physicians from Massachusetts General Hospital, Johns Hopkins University and the University of Texas Medical Branch were able to assess the patient remotely via telemedicine and agreed that surgery was the only means to restore mobility and prevent long term disability. The lack of a surgical facility and a trained surgical team were overcome by conversion of the clinic treatment area, and intensive preparation of medical laypersons as surgical assistants. The non-surgeon CMO and CMO assistant at South Pole, were guided through the administration of spinal anesthetic, and the two-hour operative repair by medical consultants at Massachusetts General Hospital. Real-time video of the operative field, directions from the remote consultants and audio communication were provided by videoconferencing equipment, operative cameras, and high bandwidth satellite communications. In real-time, opening incision/exposure, tendon relocation, hemostatsis, and operative closure by the CMO was closely monitored and guided and by the remote consultants. The patient s subsequent physical rehabilitation over the ensuing months of isolation was also monitored remotely via telemedicine. This was the first time in South Pole s history that remote teleguidance had been used for surgery and represents a model for

  1. The Nonmigrating Semidiurnal Tide With Zonal Wavenumber One Observed Over South Pole and its Relationship With the Stationary Planetary Wave With Zonal Wavenumber One

    NASA Astrophysics Data System (ADS)

    Lau, E. M.; Palo, S. E.; Avery, S. K.; Avery, J. P.; Makarov, N. A.

    2006-12-01

    Early observations of the dynamical features of the mesosphere and lower thermosphere (MLT) over the geographic South Pole revealed the existence of a nonmigrating component of the semidiurnal tide with zonal wavenumber one. Further observational studies have documented the seasonal and interannual behavior of this semidiurnal tide component. These observations have determined that this tide maximizes during the austral summer reaching amplitudes around 20~m/s and disappears during the winter. Moreover, significant amplitude variations have been measured during the summer months. Several hypotheses have been formulated to explain the source of this semidiurnal tide component but recent studies favor the nonlinear interaction of a stationary planetary wave with zonal wavenumber one and the migrating semidiurnal tide as the source of the observed oscillation. Continuous observations of the MLT dynamics over the South Pole have been possible since the installation of a meteor radar at the Amundsen-Scott South Pole station in 2001. The seasonal, interannual, and spatial behavior of the semidiurnal tide with zonal wavenumber one has been and continues to be observed using this meteor radar. In this paper we explore the relationship between our meteor radar measurements of the aforementioned semidiurnal tide component and observations of the stationary planetary wave with zonal wavenumber one obtained from other sources.

  2. The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales

    NASA Astrophysics Data System (ADS)

    Shirokoff, Erik D.

    The South Pole Telescope (SPT) is a dedicated 10-meter diameter telescope optimized for mm-wavelength surveys of the Cosmic Microwave Background (CMB) with arcminute resolution. The first instrument deployed at SPT features a 960 element array of horn-coupled bolometers. These devices consist of fully lithographed spider-web absorbers and aluminum-titanium bilayer transition edge sensors fabricated on adhesive-bonded silicon wafers with embedded metal backplanes. The focal plane is cooled using a closed cycle pulse-tube refrigerator, and read-out using Frequency Domain Multiplexed Superconducting Quantum Interference Devices (SQUIDs.) Design features were chosen to optimize sensitivy in the atmospheric observing bands available from the ground, and for stability with the frequency domain multiplexed readout system employed at SPT, and performance was verified with a combination of laboratory tests and field observations. In 2008 the SPT surveyed 200 square-degrees at 150 and 220 GHz. These data have been analyzed using a cross-spectrum analysis and multi-band Markov Chain Monte Carlo parameter fitting using a model that includes lensed primary CMB anisotropy, secondary thermal (tSZ) and kinetic (kSZ) Sunyaev-Zel'dovich anisotropies, unclustered synchrotron point sources, and clustered dusty point sources. In addition to measuring the power spectrum of dusty galaxies at high signal-to-noise, the data primarily constrain a linear combination of the kSZ and tSZ anisotropy contributions (at 150 GHz and ℓ=3000): D tSZ3000 + 0.5 DkSZ3000 = 4.5 +/- 1.0 mu K2, and place the lowest limits yet measured on secondary anisotropy power.

  3. Acute Mountain Sickness Symptom Severity at the South Pole: The Influence of Self-Selected Prophylaxis with Acetazolamide

    PubMed Central

    Johnson, Jacob B.; Richert, Maile; Miller, Andrew D.

    2016-01-01

    Introduction Acetazolamide, a carbonic anhydrase inhibitor, remains the only FDA approved pharmaceutical prophylaxis for acute mountain sickness (AMS) though its effectiveness after rapid transport in real world conditions is less clear. Methods Over 2 years, 248 healthy adults traveled by airplane from sea level (SL) to the South Pole (ALT, ~3200m) and 226 participants provided Lake Louise Symptom Scores (LLSS) on a daily basis for 1 week; vital signs, blood samples, and urine samples were collected at SL and at ALT. Acetazolamide was available to any participant desiring prophylaxis. Comparisons were made between the acetazolamide with AMS (ACZ/AMS) (n = 42), acetazolamide without AMS (ACZ/No AMS)(n = 49), no acetazolamide with AMS (No ACZ/AMS) (n = 56), and the no acetazolamide without AMS (No ACZ/No AMS) (n = 79) groups. Statistical analysis included Chi-squared and one-way ANOVA with Bonferroni post-hoc tests. Significance was p≤0.05. Results No significant differences were found for between-group characteristics or incidence of AMS between ACZ and No ACZ groups. ACZ/AMS reported greater LLSS, BMI, and red cell distribution width. ACZ/No AMS had the highest oxygen saturation (O2Sat) at ALT. No significant differences were found in serum electrolyte concentrations or PFT results. Discussion Acetazolamide during rapid ascent provided no apparent protection from AMS based on LLSS. However, it is unclear if this lack of effect was directly associated with the drug or if perhaps there was some selection bias with individuals taking ACZ more likely to have symptoms or if there may have been more of perceptual phenomenon related to a constellation of side effects. PMID:26848757

  4. Galaxy populations in the 26 most massive galaxy clusters in the South Pole Telescope SPT-SZ survey

    NASA Astrophysics Data System (ADS)

    Zenteno, A.; Mohr, J. J.; Desai, S.; Stalder, B.; Saro, A.; Dietrich, J. P.; Bayliss, M.; Bocquet, S.; Chiu, I.; Gonzalez, A. H.; Gangkofner, C.; Gupta, N.; Hlavacek-Larrondo, J.; McDonald, M.; Reichardt, C.; Rest, A.

    2016-10-01

    We present a study of the optical properties of the 26 most massive galaxy clusters within the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) 2500 deg2 survey spanning the redshift range 0.10 < z < 1.13. We measure the radial profiles, the luminosity functions (LFs), and the halo occupation numbers (HONs) using optical data of typical depth m* + 2. The stacked radial profiles are consistent with a Navarro-Frenk-White profile of concentration 2.84^{+0.40}_{-0.37} for the red sequence (RS) and 2.36^{+0.38}_{-0.35} for the total population. Stacking the data in multiple redshift bins shows slight redshift evolution in the concentration when both the total population is used, and when only RS galaxies are used (at 2.1σ and 2.8σ, respectively). The stacked LF shows a faint end slope α = -1.06^{+0.04}_{-0.03} for the total and α = -0.80^{+0.04}_{-0.03} for the RS population. The redshift evolution of m* is consistent with a passively evolving composite stellar population (CSP) model. Adopting the CSP model predictions, we explore the redshift evolution of the Schechter parameters α and φ*. We find α for the total population to be consistent with no evolution (0.3σ), and mildly significant evidence of evolution for the red galaxies (1.1-2.1σ). The data show that the density φ*/E2(z) decreases with redshift, in tension with the self-similar expectation at a 2.4σ level for the total population. The measured HON-mass relation has a lower normalization than previous low redshift studies. Finally, our data support HON redshift evolution at a 2.1σ level, with clusters at higher redshift containing fewer galaxies than their low-z counterparts.

  5. Measurements of OH, HO 2+RO 2, H 2SO 4, and MSA at the South Pole during ISCAT 2000

    NASA Astrophysics Data System (ADS)

    Mauldin, R. L.; Kosciuch, E.; Henry, B.; Eisele, F. L.; Shetter, R.; Lefer, B.; Chen, G.; Davis, D.; Huey, G.; Tanner, D.

    2004-10-01

    Measurements of hydroxyl radical (OH), sulfuric acid (H2SO4) and methane sulfonic acid (MSA) together with the first HO2+RO2 observations at the South Pole are presented. These results were recorded as part of the Investigation of Sulfur Chemistry in the Antarctic Troposphere 2000 (ISCAT 2000) study. OH concentrations were found to be highly elevated, having a mean value over the time period of 15 November-30 December 2000 of 2.5×106 molecule cm-3, thus confirming the results from ISCAT 1998. Although data were more limited for the sum of HO2+RO2, a mean value of ∼7×107 molecule cm-3 was estimated. Typically, OH and HO2+RO2 both showed large day-to-day variability. Box model simulations suggest that most of this variability was a direct result of elevated and highly variable levels of nitric oxide. Comparisons of OH with overhead O3 column density measurements revealed that for certain time periods as much as a 30% enhancement occurred in OH as a result of decreases in column O3 levels. Like ISCAT 1998, the observational data for H2SO4 and MSA generally showed very low concentrations with mean values of 2.7×105 and 8×104 molecule cm-3, respectively. When compared against measured levels of particulate sulfate and methane sulfonate, these low gas phase concentrations indicate, as suggested by the more limited data from the ISCAT 1998 study, that local production of gas phase sulfur species contributes little to particle composition.

  6. Constraints on primordial magnetic fields from Planck data combined with the South Pole Telescope CMB B -mode polarization measurements

    NASA Astrophysics Data System (ADS)

    Zucca, Alex; Li, Yun; Pogosian, Levon

    2017-03-01

    A primordial magnetic field (PMF) present before recombination can leave specific signatures on the cosmic microwave background (CMB) fluctuations. Of particular importance is its contribution to the B-mode polarization power spectrum. Indeed, vortical modes sourced by the PMF can dominate the B-mode power spectrum on small scales, as they survive damping up to a small fraction of the Silk length. Therefore, measurements of the B-mode polarization at high ℓ , such as the one recently performed by the South Pole Telescope (SPT), have the potential to provide stringent constraints on the PMF. We use the publicly released SPT B-mode polarization spectrum, along with the temperature and polarization data from the Planck satellite, to derive constraints on the magnitude, the spectral index and the energy scale at which the PMF was generated. We find that, while Planck data constrains the magnetic amplitude to B1 Mpc<3.3 nG at the 95% confidence level (C.L.), the SPT measurement improves the constraint to B1 Mpc<1.5 nG . The magnetic spectral index, nB, and the time of the generation of the PMF are unconstrained. For a nearly scale-invariant PMF, predicted by the simplest inflationary magnetogenesis models, the bound from Planck +SPT is B1 Mpc<1.2 nG at 95% C.L. For PMF with nB=2 , which is expected for fields generated in post-inflationary phase transitions, the 95% C.L. bound is B1 Mpc<0.002 nG , corresponding to the magnetic fraction of the radiation density ΩB γ<10-3 or the effective field Beff<100 nG . The patches for the Boltzmann code camb and the Markov chain Monte Carlo engine CosmoMC, incorporating the PMF effects on CMB, are made publicly available.

  7. Magnetization in the South Pole-Aitken basin: Implications for the lunar dynamo and true polar wander

    NASA Astrophysics Data System (ADS)

    Nayak, Michael; Hemingway, Doug; Garrick-Bethell, Ian

    2017-04-01

    A number of magnetic anomalies are present along the northern edge of the lunar South Pole-Aitken (SPA) basin. A variety of hypotheses for their formation have been proposed, but an in-depth study of their properties has not been performed. Here we use two different methods to invert for their source body characteristics: one that completely searches a small parameter space of less than ten uniform-strength dipoles per anomaly, and another that uses grids of hundreds of dipoles with variable magnetization strengths. Both methods assume uniform magnetization directions at each anomaly and with one exception, produce nearly the same results. We introduce new Monte Carlo methods to quantify errors in our inversions arising from Gaussian time-dependent changes in the external field and the uncertain geometry of the source bodies. We find the errors from uncertainty in source body geometry are almost always higher. We also find a diverse set of magnetization directions around SPA, which we combine with other physical arguments to conclude that the source bodies were likely magnetized in a dynamo field. Igneous intrusions are a reasonable explanation (Purucker et al., 2012) for the directional variability, since they could be intruded over different magnetic epochs. However, the directional variability also implies either surprisingly large amounts of true polar wander or a dynamo not aligned with the lunar spin axis. We also explore the possibility that true polar wander caused by the SPA impact could allow iron-rich SPA ejecta to record a diverse set of magnetic field directions. Some of this material may have also become "sesquinary" ejecta and re-impacted across the Moon on 104-106 year timescales to capture such changes. No completely satisfactory answer emerges, except that the dipole-axis of the lunar dynamo may have been variable in direction.

  8. Ulysses observations of energetic ions over the south pole of the Sun

    NASA Technical Reports Server (NTRS)

    Sanderson, T. R.; Marsden, R. G.; Bothmer, V.; Trattner, K. J.; Wenzel, K.P.; Balogh, A.; Forsyth, R. J.; Goldstein, B. E.

    1995-01-01

    The Ulysses spacecraft began its journey out-of-the-ecliptic in February of 1992, when it encountered the planet Jupiter. In April of 1993, the spacecraft had reached 29 deg S, and from then on was completely immersed in the flow from the southern polar coronal hole. Accelerated ions were observed, recurring with a main peak once per solar rotation, with the intensity at the peak slowly decreasing with increasing latitude. This decrease continued to the end of 1993, when the spacecraft was at approximately 50 deg S. During the first three months of 1994 the intensity of the accelerated ions rose again, due either to an increase in magnetic activity on the sun or a reconfiguration of the heliospheric magnetic field. Recurrent accelerated ions were still being seen at the beginning of July 1994, when the spacecraft was at a latitude of 70 deg S, although with reduced intensity. The accelerated ions were no longer seen at latitudes higher than 70 deg S, the ion intensity staying constant at around the cosmic ray background level. This continued on until the highest latitude reached, 80.2 deg S, on 13 September 1994. The spacecraft then began its journey back towards lower latitudes, a small increase in the particle intensity being observed at the end of October whilst at approximately 72 deg S, and thereafter no more increases until the end of 1994, when the spacecraft was at approximately 45 deg S. We present interpretations for this asymmetry in latitude dependence.

  9. Temporal pole activity during perception of sad faces, but not happy faces, correlates with neuroticism trait.

    PubMed

    Jimura, Koji; Konishi, Seiki; Miyashita, Yasushi

    2009-03-27

    It is known that the temporal cortex is involved in perception of emotional facial expressions, and the involvement is relatively independent of the emotional valence of those expressions. The present study revealed a valence-dependent aspect of the temporal cortex through individual differences analyses involving the neuroticism trait, one of the representative affective personality traits. Functional MRI was administered while subjects classified expressions of faces, and neuroticism scores were obtained from individual subjects. Significant brain activity was observed in the temporal pole (TP) during perception of both happy and sad expressions relative to neutral expressions. Correlational analyses revealed that TP activity during perception of sad expressions, but not happy expressions, correlated with the neuroticism scores. These results demonstrate differential roles for the temporal cortex in perception of happy and sad faces, and suggest that TP recruitment during understanding of negative emotions is dependent on the personality of the individuals.

  10. Gaia Data Release 1. The Cepheid and RR Lyrae star pipeline and its application to the south ecliptic pole region

    NASA Astrophysics Data System (ADS)

    Clementini, G.; Ripepi, V.; Leccia, S.; Mowlavi, N.; Lecoeur-Taibi, I.; Marconi, M.; Szabados, L.; Eyer, L.; Guy, L. P.; Rimoldini, L.; Jevardat de Fombelle, G.; Holl, B.; Busso, G.; Charnas, J.; Cuypers, J.; De Angeli, F.; De Ridder, J.; Debosscher, J.; Evans, D. W.; Klagyivik, P.; Musella, I.; Nienartowicz, K.; Ordóñez, D.; Regibo, S.; Riello, M.; Sarro, L. M.; Süveges, M.

    2016-11-01

    Context. The European Space Agency spacecraft Gaia is expected to observe about 10 000 Galactic Cepheids and over 100 000 Milky Way RR Lyrae stars (a large fraction of which will be new discoveries), during the five-year nominal lifetime spent scanning the whole sky to a faint limit of G = 20.7 mag, sampling their light variation on average about 70 times. Aims: We present an overview of the Specific Objects Study (SOS) pipeline developed within the Coordination Unit 7 (CU7) of the Data Processing and Analysis Consortium (DPAC), the coordination unit charged with the processing and analysis of variable sources observed by Gaia, to validate and fully characterise Cepheids and RR Lyrae stars observed by the spacecraft. The algorithms developed to classify and extract information such as the pulsation period, mode of pulsation, mean magnitude, peak-to-peak amplitude of the light variation, subclassification in type, multiplicity, secondary periodicities, and light curve Fourier decomposition parameters, as well as physical parameters such as mass, metallicity, reddening, and age (for classical Cepheids) are briefly described. Methods: The full chain of the CU7 pipeline was run on the time series photometry collected by Gaia during 28 days of ecliptic pole scanning law (EPSL) and over a year of nominal scanning law (NSL), starting from the general Variability Detection, general Characterization, proceeding through the global Classification and ending with the detailed checks and typecasting of the SOS for Cepheids and RR Lyrae stars (SOS Cep&RRL). We describe in more detail how the SOS Cep&RRL pipeline was specifically tailored to analyse Gaia's G-band photometric time series with a south ecliptic pole (SEP) footprint, which covers an external region of the Large Magellanic Cloud (LMC), and to produce results for confirmed RR Lyrae stars and Cepheids to be published in Gaia Data Release 1 (Gaia DR1). Results: G-band time series photometry and characterisation by the

  11. Detection and Extent of Ancient, Buried Mare Deposits in South Pole-Aitken Basin (SPA):Implications for Robotic Sampling

    NASA Astrophysics Data System (ADS)

    Petro, N. E.; Jolliff, B. L.; Gaddis, L. R.; Pieters, C. M.

    2010-12-01

    The origin of the large mafic anomaly associated with the interior of the South Pole-Aitken Basin has been inferred to be largely the result of iron-rich lower crustal/upper mantle material exposed at the surface and/or a combination of ancient mare basalts covered by younger crater/basin ejecta (cryptomare) interspersed with younger basalts [1-3]. However, the relative influence of either source is poorly constrained, due in part to the unknown abundance of cryptomare within SPA. Early geologic mapping of the interior of SPA identified several plains units, thought to represent basin ejecta deposits [4, 5]. Newer remotely sensed VIS-NIR wavelength data suggested the presence of more extensive deposits of ancient, buried basalts [2, 3, 6]. Mare basalts, when mantled by non-local, low-FeO material may appear to be non-mare plains units [7, 8]. Within SPA, because the regional basement material is inherently enriched in FeO, the mantling material imparts a dark, FeO-enriched, signature. In a survey of rock types within SPA, Pieters et al. [3] identified such a plains unit south of the Apollo Basin with a surface that is both dark and that contains an FeO-rich spectral signature. However, several small craters in the plains unit expose underlying basaltic materials or cryptomaria in this extensive (>75,000 km2), ancient (~3.89 Ga) unit [6, 9]. The positive identification and characterization of cryptomaria within SPA are facilitated by high-spatial and spectral resolution data from recent orbital missions (e.g., Kaguya, Chandrayaan-1, LRO). Hyperspectral data from the Moon Mineralogy Mapper and Multiband Imager for SPA show the presence of two primary mafic materials; a high-Ca pyroxene (gabbroic) signature is pervasive across the center of the basin and a noritic signature is present across the rest of SPA. High spatial resolution (10-0.5 m) images from the Kaguya Terrain Camera and LRO Narrow Angle Camera facilitate surface age dating and morphologic assessment of

  12. South Pole-Aitken Sample Return Mission: Collecting Mare Basalts from the Far Side of the Moon

    NASA Technical Reports Server (NTRS)

    Gillis, J. J.; Jolliff, B. L.; Lucey, P. G.

    2003-01-01

    We consider the probability that a sample mission to a site within the South Pole-Aitken Basin (SPA) would return basaltic material. A sample mission to the SPA would be the first opportunity to sample basalts from the far side of the Moon. The near side basalts are more abundant in terms of volume and area than their far-side counterparts (16:1), and the basalt deposits within SPA represent approx. 28% of the total basalt surface area on the far side. Sampling far-side basalts is of particular importance because as partial melts of the mantle, they could have derived from a mantle that is mineralogically and chemically different than determined for the nearside, as would be expected if the magma ocean solidified earlier on the far side. For example, evidence to support the existence of high-Th basalts like those that appear to be common on the nearside in the Procellarum KREEP Terrane has been found. Although SPA is the deepest basin on the Moon, it is not extensively filled with mare basalt, as might be expected if similar amounts of partial melting occurred in the mantle below SPA as for basins on the near side. These observations may mean that mantle beneath the far-side crust is lower in Th and other heat producing elements than the nearside. One proposed location for a sample-return landing site is 60 S, 160 W. This site was suggested to maximize the science return with respect to sampling crustal material and SPA impact melt, however, basaltic samples would undoubtedly occur there. On the basis of Apollo samples, we should expect that basaltic materials would be found in the vicinity of any landing site within SPA, even if located away from mare deposits. For example, the Apollo 16 mission landed in an ancient highlands region 250-300 km away from the nearest mare-highlands boundary yet it still contains a small component of basaltic samples (20 lithic fragments ranging is size from <1 to .01 cm). A soil sample from the floor of SPA will likely contain an

  13. Incidence and Symptoms of High Altitude Illness in South Pole Workers: Antarctic Study of Altitude Physiology (ASAP)

    PubMed Central

    Anderson, Paul J.; Miller, Andrew D.; O’Malley, Kathy A.; Ceridon, Maile L.; Beck, Kenneth C.; Wood, Christina M.; Wiste, Heather J.; Mueller, Joshua J.; Johnson, Jacob B.; Johnson, Bruce D.

    2011-01-01

    Introduction: Each year, the US Antarctic Program rapidly transports scientists and support personnel from sea level (SL) to the South Pole (SP, 2835 m) providing a unique natural laboratory to quantify the incidence of acute mountain sickness (AMS), patterns of altitude related symptoms and the field effectiveness of acetazolamide in a highly controlled setting. We hypothesized that the combination of rapid ascent (3 hr), accentuated hypobarism (relative to altitude), cold, and immediate exertion would increase altitude illness risk. Methods: Medically screened adults (N = 246, age = 37 ± 11 yr, 30% female, BMI = 26 ± 4 kg/m2) were recruited. All underwent SL and SP physiological evaluation, completed Lake Louise symptom questionnaires (LLSQ, to define AMS), and answered additional symptom related questions (eg, exertional dyspnea, mental status, cough, edema and general health), during the 1st week at altitude. Acetazolamide, while not mandatory, was used by 40% of participants. Results: At SP, the barometric pressure resulted in physiological altitudes that approached 3400 m, while T °C averaged −42, humidity 0.03%. Arterial oxygen saturation averaged 89% ± 3%. Overall, 52% developed LLSQ defined AMS. The most common symptoms reported were exertional dyspnea-(87%), sleeping difficulty-(74%), headache-(66%), fatigue-(65%), and dizziness/lightheadedness-(46%). Symptom severity peaked on days 1–2, yet in >20% exertional dyspnea, fatigue and sleep problems persisted through day 7. AMS incidence was similar between those using acetazolamide and those abstaining (51 vs. 52%, P = 0.87). Those who used acetazolamide tended to be older, have less altitude experience, worse symptoms on previous exposures, and less SP experience. Conclusion: The incidence of AMS at SP tended to be higher than previously reports in other geographic locations at similar altitudes. Thus, the SP constitutes a more intense altitude exposure than might be expected considering physical

  14. 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.

  15. Species-specific calls evoke asymmetric activity in the monkey's temporal poles.

    PubMed

    Poremba, Amy; Malloy, Megan; Saunders, Richard C; Carson, Richard E; Herscovitch, Peter; Mishkin, Mortimer

    2004-01-29

    It has often been proposed that the vocal calls of monkeys are precursors of human speech, in part because they provide critical information to other members of the species who rely on them for survival and social interactions. Both behavioural and lesion studies suggest that monkeys, like humans, use the auditory system of the left hemisphere preferentially to process vocalizations. To investigate the pattern of neural activity that might underlie this particular form of functional asymmetry in monkeys, we measured local cerebral metabolic activity while the animals listened passively to species-specific calls compared with a variety of other classes of sound. Within the superior temporal gyrus, significantly greater metabolic activity occurred on the left side than on the right, only in the region of the temporal pole and only in response to monkey calls. This functional asymmetry was absent when these regions were separated by forebrain commissurotomy, suggesting that the perception of vocalizations elicits concurrent interhemispheric interactions that focus the auditory processing within a specialized area of one hemisphere.

  16. MoonRise: Sampling South Pole-Aitken Basin as a Recorder of Solar System Events (Invited)

    NASA Astrophysics Data System (ADS)

    Jolliff, B. L.; Shearer, C., Jr.; Gaddis, L. R.; Pieters, C. M.; Head, J. W.; Haruyama, J.; Jaumann, R.; Ohtake, M.; Osinski, G.; Papanastassiou, D. A.; Petro, N. E.; Moonrise Science Team

    2010-12-01

    The MoonRise mission, now in a phase A concept study, would launch in 2016 and return samples from the Moon’s South Pole-Aitken basin (SPA) in 2017. These samples would be used to (1) determine the chronology of SPA and test the “cataclysm” hypothesis for bombardment of the inner Solar System some hundreds of millions of years following planetary accretion, (2) investigate the deep crust and upper mantle of the Moon to better understand planetary differentiation, and (3) provide ground truth for orbital remote sensing and geophysics of the SPA basin to better understand giant basin-forming impact processes and the effects of such impacts on an early-formed planetary crust. The key objective that drives site selection for the MoonRise mission is to obtain rock samples that crystallized from the SPA impact-melt complex to date the formation of the basin. Many large impacts, however, occurred subsequent to SPA formation, and volcanic lavas erupted into the interior of SPA over several hundred million years, producing a complex set of geologic formations. Fortunately, the very same impact process also generates a rich diversity of rock types in the regolith that provide a record of all these events. Our focus for landing site selection is in the interior of SPA where the distinctive geochemical signature is strongest. This compositional signature, coupled with modeling of impact ejecta ballistic sedimentation and distribution, ensures that landing sites and sampling locations in the interior of SPA will contain abundant rock fragments derived from the original SPA melt sheet. The wealth of recent remote sensing data provides context to evaluate geologic formations and to establish provenance for the samples. Admixture of impactites derived from younger basins such as Apollo, Poincaré, Planck, Ingenii, Orientale and Schrödinger, as well as other large impact craters, will contribute to a chronology that is bounded by the earliest and the latest of the recognized

  17. 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.

  18. Seasonal variations of the Na and Fe layers at the South Pole and their implications for the chemistry and general circulation of the polar mesosphere

    NASA Astrophysics Data System (ADS)

    Gardner, Chester S.; Plane, John M. C.; Pan, Weilin; Vondrak, Tomas; Murray, Benjamin J.; Chu, Xinzhao

    2005-05-01

    Lidar observations, conducted at the South Pole by University of Illinois researchers, are used to characterize the seasonal variations of mesospheric Na and Fe above the site. The annual mean layer abundances are virtually identical to midlatitude values, and the mean centroid height is just 100 m higher for Na and 450 m higher for Fe compared with 40°N. The most striking feature of the metal profiles is the almost complete absence of Na and Fe below 90 km during midsummer. This leads to summertime layers with significantly higher peaks, narrower widths, and smaller abundances than are observed at lower latitudes. The measurements are compared with detailed chemical models of these species that were developed at the University of East Anglia. The models accurately reproduce most features of these observations and demonstrate the importance of rapid uptake of the metallic species on the surfaces of polar mesospheric clouds and meteoric smoke particles. The models show that vertical downwelling in winter, associated with the meridional circulation system, must be less than about 1 cm s-1 in the upper mesosphere in order to avoid displacing the minor constituents O, H, and the metal layers too far below 85 km. They also show that an additional source of gas-phase metallic species, that is comparable to the meteoric input, is required during winter to correctly model the Na and Fe abundances. This source appears to arise from the wintertime convergence of the meridional flow over the South Pole.

  19. Study of the National Science Foundation's South Pole Station as an analogous data base for the logistical support of a Moon laboratory

    NASA Technical Reports Server (NTRS)

    Hickam, H. H., Jr.

    1993-01-01

    The day will come when the United States will want to return to the Earth's Moon. When that occurs, NASA may look to the Apollo program for technical and inspirational guidance. The Apollo program, however, was designed to be an end to itself--the landing of a man on the Moon and his return safely within the decade of the 1960's. When that was accomplished, the program folded because it was not self-sustaining. The next time we return to the Moon, we should base our planning on a program that is designed to be a sustained effort for an indefinite period. It is the thrust of this report that the South Pole Station of the National Science Foundation can be used to develop analogs for the construction, funding, and logistical support of a lunar base. Other analogs include transportation and national efforts versus international cooperation. A recommended lunar base using the South Pole Station as inspiration is provided, as well as details concerning economical construction of the base over a 22-year period.

  20. Detrended Topographic Data of the South-pole Aitken Basin (SPA): Comparisons with Apollo 16 and Schiller-Schickard as Indications of the Formation and Evolution of the Spa Interior

    NASA Technical Reports Server (NTRS)

    Petro, N. E.; Hollibaugh-Baker, D.; Jolliff, B. L.

    2017-01-01

    Data from recent lunar orbital missions have provided critical insight into the surface composition, morphology, and geologic history of the Moon. A key region that has benefited from this new data is the South Pole-Aitken Basin (SPA), a key area for future sample return]. A key area of investigation of SPA has been the characterization of its surface, detailing the interior composition, geologic evolution, and possible exposure of deep-seated materials. Recently we have applied a number of datasets to ascertain the origin of surfaces in central SPA and identify units that represent the ancient SPA-derived impact melt and those that represent volcanic activity. Here we apply a technique that utilizes high-resolution topographic data to remove local slopes to highlight subtle topographic variations. Such detrended data allows us to characterize units that are either ancient (SPA impact melt) or that represent subsequent volcanic activity.

  1. Opposing motor activities are required for the organization of the mammalian mitotic spindle pole

    PubMed Central

    1996-01-01

    We use both in vitro and in vivo approaches to examine the roles of Eg5 (kinesin-related protein), cytoplasmic dynein, and dynactin in the organization of the microtubules and the localization of NuMA (Nu-clear protein that associates with the Mitotic Apparatus) at the polar ends of the mammalian mitotic spindle. Perturbation of the function of Eg5 through either immunodepletion from a cell free system for assembly of mitotic asters or antibody microinjection into cultured cells leads to organized astral microtubule arrays with expanded polar regions in which the minus ends of the microtubules emanate from a ring-like structure that contains NuMA. Conversely, perturbation of the function of cytoplasmic dynein or dynactin through either specific immunodepletition from the cell free system or expression of a dominant negative subunit of dynactin in cultured cells results in the complete lack of organization of microtubules and the failure to efficiently concentrate the NuMA protein despite its association with the microtubules. Simultaneous immunodepletion of these proteins from the cell free system for mitotic aster assembly indicates that the plus end- directed activity of Eg5 antagonizes the minus end-directed activity of cytoplasmic dynein and a minus end-directed activity associated with NuMA during the organization of the microtubules into a morphologic pole. Taken together, these results demonstrate that the unique organization of the minus ends of microtubules and the localization of NuMA at the polar ends of the mammalian mitotic spindle can be accomplished in a centrosome-independent manner by the opposing activities of plus end- and minus end-directed motors. PMID:8896597

  2. The Totem Pole Recycled.

    ERIC Educational Resources Information Center

    Sewall, Susan Breyer

    1991-01-01

    Presents an activity that integrates science, environmental education, art, and social studies. Students identify and research an endangered species and construct a totem pole depicting the species using a recyclable material. (MDH)

  3. Food composition activities in South Africa.

    PubMed

    Wolmarans, Petro; Chetty, Joelaine; Danster-Christians, Natasha

    2013-10-01

    Researchers at the South African Medical Research Council used the Bangkok Declaration, Thailand, 2009, as a guideline for their food composition activities. The vision is to build a comprehensive food composition database for the country. Activities are directed at increasing the number of food items with country-specific nutrient information; encouraging research organisations, universities and the food industry to become involved in nutrient data generation and the generation of yield factors for South African dishes. The introduction of the South African Food Data System (SAFOODS) website and a symposium were major food composition activities. Educating users on the correct application of food composition data is an important endeavour. The national South African Food Data Advisory Group (SAFDAG) formed in 2008, advises and supports food composition activities at SAFOODS. In conclusion, with the support of SAFDAG, SAFOODS activities are aimed at compiling a country-specific food composition database and promoting its scientific use.

  4. Tectonic Maps of the Poles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These tectonic relief maps of the north (left, view large [540k]) and south (right, view large [411k]) poles are the result of new satellite-based technologies which are being used to analyze tectonic activity in the Earth's crust. These maps, known as Digital Tectonic Activity Maps (DTAMs), synoptically depict the architecture of the Earth's crust including current and past tectonic activity. This is significant because it permits researchers to view broad zones of activity over the entire surface of the Earth, rather than focusing on single boundary features. By looking at these 'big pictures,' scientists can possibly identify regions of activity which were not previously recognized or mapped using traditional methods. For more information, see: DTAM web site Putting Earthquakes in Their Place Images courtesy Brian Montgomery, NASA GSFC; data by Paul Lowman and Jacob Yates, NASA GSFC

  5. THE FIRST PUBLIC RELEASE OF SOUTH POLE TELESCOPE DATA: MAPS OF A 95 deg{sup 2} FIELD FROM 2008 OBSERVATIONS

    SciTech Connect

    Schaffer, K. K.; Crawford, T. M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crites, A. T.; Hoover, S.; Keisler, R.; Aird, K. A.; Hrubes, J. D.; Cho, H. M.; De Haan, T.; Dobbs, M. A.; Holder, G. P.; George, E. M.; Holzapfel, W. L.; Halverson, N. W.; Joy, M.; Knox, L.; and others

    2011-12-10

    The South Pole Telescope (SPT) has nearly completed a 2500 deg{sup 2} survey of the southern sky in three frequency bands. Here, we present the first public release of SPT maps and associated data products. We present arcminute-resolution maps at 150 GHz and 220 GHz of an approximately 95 deg{sup 2} field centered at R.A. 82.{sup 0}7, decl. -55 Degree-Sign . The field was observed to a depth of approximately 17 {mu}K arcmin at 150 GHz and 41 {mu}K arcmin at 220 GHz during the 2008 austral winter season. Two variations on map filtering and map projection are presented, one tailored for producing catalogs of galaxy clusters detected through their Sunyaev-Zel'dovich effect signature and one tailored for producing catalogs of emissive sources. We describe the data processing pipeline, and we present instrument response functions, filter transfer functions, and map noise properties. All data products described in this paper are available for download at http://pole.uchicago.edu/public/data/maps/ra5h30dec-55 and from the NASA Legacy Archive for Microwave Background Data Analysis server. This is the first step in the eventual release of data from the full 2500 deg{sup 2} SPT survey.

  6. A measurement of the secondary-CMB and millimeter-wave-foreground bispectrum using 800 deg{sup 2} of south pole telescope data

    SciTech Connect

    Crawford, T. M.; Schaffer, K. K.; Bhattacharya, S.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crites, A. T.; Hoover, S.; Aird, K. A.; Hrubes, J. D.; Cho, H-M.; De Haan, T.; Dobbs, M. A.; Dudley, J.; Holder, G. P.; George, E. M.; Holzapfel, W. L.; Halverson, N. W.; Hou, Z.; and others

    2014-04-01

    We present a measurement of the angular bispectrum of the millimeter-wave sky in observing bands centered at roughly 95, 150, and 220 GHz, on angular scales of 1' ≲ θ ≲ 10' (multipole number 1000 ≲ l ≲ 10,000). At these frequencies and angular scales, the main contributions to the bispectrum are expected to be the thermal Sunyaev-Zel'dovich (tSZ) effect and emission from extragalactic sources, predominantly dusty, star-forming galaxies (DSFGs) and active galactic nuclei. We measure the bispectrum in 800 deg{sup 2} of three-band South Pole Telescope data, and we use a multi-frequency fitting procedure to separate the bispectrum of the tSZ effect from the extragalactic source contribution. We simultaneously detect the bispectrum of the tSZ effect at >10σ, the unclustered component of the extragalactic source bispectrum at >5σ in each frequency band, and the bispectrum due to the clustering of DSFGs—i.e., the clustered cosmic infrared background (CIB) bispectrum—at >5σ. This is the first reported detection of the clustered CIB bispectrum. We use the measured tSZ bispectrum amplitude, compared to model predictions, to constrain the normalization of the matter power spectrum to be σ{sub 8} = 0.787 ± 0.031 and to predict the amplitude of the tSZ power spectrum at l = 3000. This prediction improves our ability to separate the thermal and kinematic contributions to the total SZ power spectrum. The addition of bispectrum data improves our constraint on the tSZ power spectrum amplitude by a factor of two compared to power spectrum measurements alone and demonstrates a preference for a nonzero kinematic SZ (kSZ) power spectrum, with a derived constraint on the kSZ amplitude at l = 3000 of A {sub kSZ} = 2.9 ± 1.6 μK{sup 2}, or A {sub kSZ} = 2.6 ± 1.8 μK{sup 2} if the default A {sub kSZ} > 0 prior is removed.

  7. Reorientation of the early lunar pole

    NASA Astrophysics Data System (ADS)

    Takahashi, Futoshi; Tsunakawa, Hideo; Shimizu, Hisayoshi; Shibuya, Hidetoshi; Matsushima, Masaki

    2014-06-01

    Palaeomagnetic measurements suggest that an active core dynamo operated on the Moon from 4.2 to 3.56 billion years ago. Since the Apollo era, many magnetic anomalies have been observed on the Moon. The magnetization of the lunar crust in some of these regions could preserve the signature of an early dipolar magnetic field generated by a core dynamo. Thus, the magnetic anomalies may yield information about the position of the palaeomagnetic pole during the time that the dynamo operated. Here we present a comprehensive survey of magnetic anomalies on the lunar surface using magnetometer data obtained by the Lunar Prospector and Kaguya lunar orbiters. We extract magnetization vectors from 24 magnetic anomalies using an iterative inversion method and derive the palaeomagnetic poles. We find that the north poles, as well as the antipodal south poles, cluster in two distinct locations: one near the present rotation axis and the other at mid-latitude. The clustering is consistent with a dipole-dominated magnetic field generated in the lunar core by a dynamo that was reversing, much like that of Earth. Furthermore, the two pole clusters imply that the Moon experienced a polar wander event during its ancient history due to the reorientation of the Moon with respect to its spin axis by 45°-60°.

  8. CMB B-mode Polarization Measurements and constraints on Primordial Gravitational Waves from the BICEP/Keck Program at South Pole

    NASA Astrophysics Data System (ADS)

    Kovac, John; Bicep/Keck Collaboration

    2017-01-01

    The BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes designed to probe the degree-scale B-mode signature of primordial gravitational waves. These highly-targeted experiments have produced the world's deepest maps of CMB polarization, leading to the most stringent constraints on the tensor-to-scalar ratio to date: r < 0 . 09 from B-modes alone, and r < 0 . 07 in combination with other datasets. These limits are rapidly improving with ongoing measurements at the multiple frequencies needed to separate Galactic foregrounds from the CMB, and in combination with higher-resolution experiments to remove B-modes induced by gravitational lensing. I will review the current status of measurements and results, and will discuss the challenges that will be confronted as measurements reach sensitivities to primordial gravitational waves at a level r < 0 . 01 and below within the next several years.

  9. Immune activation and response to pembrolizumab in POLE-mutant endometrial cancer

    PubMed Central

    Mehnert, Janice M.; Panda, Anshuman; Zhong, Hua; Hirshfield, Kim; Damare, Sherri; Lane, Katherine; Sokol, Levi; Stein, Mark N.; Rodriguez-Rodriquez, Lorna; Kaufman, Howard L.; Ali, Siraj; Ross, Jeffrey S.; Pavlick, Dean C.; Bhanot, Gyan; White, Eileen P.; DiPaola, Robert S.; Lovell, Ann; Cheng, Jonathan

    2016-01-01

    Antibodies that target the immune checkpoint receptor programmed cell death protein 1 (PD-1) have resulted in prolonged and beneficial responses toward a variety of human cancers. However, anti–PD-1 therapy in some patients provides no benefit and/or results in adverse side effects. The factors that determine whether patients will be drug sensitive or resistant are not fully understood; therefore, genomic assessment of exceptional responders can provide important insight into patient response. Here, we identified a patient with endometrial cancer who had an exceptional response to the anti–PD-1 antibody pembrolizumab. Clinical grade targeted genomic profiling of a pretreatment tumor sample from this individual identified a mutation in DNA polymerase epsilon (POLE) that associated with an ultramutator phenotype. Analysis of The Cancer Genome Atlas (TCGA) revealed that the presence of POLE mutation associates with high mutational burden and elevated expression of several immune checkpoint genes. Together, these data suggest that cancers harboring POLE mutations are good candidates for immune checkpoint inhibitor therapy. PMID:27159395

  10. Vesta's north pole quadrangle Av-1 (Albana): Geologic map and the nature of the south polar basin antipodes

    NASA Astrophysics Data System (ADS)

    Blewett, David T.; Buczkowski, Debra L.; Ruesch, Ottaviano; Scully, Jennifer E.; O'Brien, David P.; Gaskell, Robert; Roatsch, Thomas; Bowling, Timothy J.; Ermakov, Anton; Hiesinger, Harald; Williams, David A.; Raymond, Carol A.; Russell, Christopher T.

    2014-12-01

    As part of systematic global mapping of Vesta using data returned by the Dawn spacecraft, we have produced a geologic map of the north pole quadrangle, Av-1 Albana. Extensive seasonal shadows were present in the north polar region at the time of the Dawn observations, limiting the ability to map morphological features and employ color or spectral data for determination of composition. The major recognizable units present include ancient cratered highlands and younger crater-related units (undivided ejecta, and mass-wasting material on crater floors). The antipode of Vesta's large southern impact basins, Rheasilvia and Veneneia, lie within or near the Av-1 quadrangle. Therefore it is of particular interest to search for evidence of features of the kind that are found at basin antipodes on other planetary bodies. Albedo markings known as lunar swirls are correlated with basin antipodes and the presence of crustal magnetic anomalies on the Moon, but lighting conditions preclude recognition of such albedo features in images of the antipode of Vesta's Rheasilvia basin. “Hilly and lineated terrain,” found at the antipodes of large basins on the Moon and Mercury, is not present at the Rheasilvia or Veneneia antipodes. We have identified small-scale linear depressions that may be related to increased fracturing in the Rheasilvia and Veneneia antipodal areas, consistent with impact-induced stresses (Buczkowski, D. et al. [2012b]. Analysis of the large scale troughs on Vesta and correlation to a model of giant impact into a differentiated asteroid. Geol. Soc. of America Annual Meeting. Abstract 152-4; Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre.20123). The general high elevation of much of the north polar region could, in part, be a result of uplift caused by the Rheasilvia basin-forming impact, as predicted by numerical modeling (Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre

  11. Analysis of landing site attributes for future missions targeting the rim of the lunar South Pole Aitken basin

    NASA Astrophysics Data System (ADS)

    Koebel, David; Bonerba, Michele; Behrenwaldt, Daniel; Wieser, Matthias; Borowy, Carsten

    2012-11-01

    For the South polar lunar region between -85 and -90° Latitude an updated analyses of the solar illumination and ground station visibility conditions has been performed in the frame of a feasibility study for an ESA Lunar Lander mission. The analyses are based on the refined lunar digital elevation model provided by the Japanese Kaguya/Selene mission, originating from its LASER altimeter instrument. For the South polar region maps of integral solar illumination are presented for a mission epoch in 2016. The analysis modelling was validated with the help of a Kaguya High Definition video. The solar illumination is driving for the power subsystems of any robotic lander craft or manned lunar outpost, in case they rely on conventional photovoltaic power generation with battery buffering of shadowed periods. In addition the visibility of the terrain from a terrestrial ESA ground station was analysed. The results are presented as an integral ground contact duration map, being crucial for the operations of any lunar outpost. Considering these two quality criteria, several possible landing sites for a future lunar mission have been pre-selected. For these sites a detailed analysis of quasi-continuous illumination conditions is presented. This includes magnified maps of the pre-selected areas, showing any location's longest illumination intervals that are allowed to be interrupted by shadows with limited duration only. As a final quality criterion, the terrain topology has been analysed for its impact on the landing trajectory. From a trade-off between the three quality criteria the connecting ridge between the Shackleton and the de Gerlache was determined to provide the most favourable landing site quality. This site is located at 89°28' South, 136°40' West, and 1947 m altitude, and features and integral illumination of 85.7%. With battery energy to sustain shadows of 120 h, total mission duration of 9.37 sidereal months can be guaranteed.

  12. Constraints on the CMB temperature evolution using multiband measurements of the Sunyaev-Zel'dovich effect with the South Pole Telescope

    SciTech Connect

    Saro, A.; Liu, J.; Mohr, J. J.; Aird, K. A.; Ashby, M. L. N.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Dolag, K.; Dudley, J. P.; Foley, R. J.; Gangkofner, D.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hennig, C.; Hlavacek-Larrondo, J.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mocanu, L.; Montroy, T. E.; Murray, S. S.; Nurgaliev, D.; Padin, S.; Patej, A.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Story, K.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2014-04-08

    The adiabatic evolution of the temperature of the cosmic microwave background (CMB) is a key prediction of standard cosmology. We study deviations from the expected adiabatic evolution of the CMB temperature of the form T(z) = T0(1 + z)1 - α using measurements of the spectrum of the Sunyaev–Zel'dovich effect with the South Pole Telescope (SPT). We present a method for using the ratio of the Sunyaev–Zel'dovich signal measured at 95 and 150 GHz in the SPT data to constrain the temperature of the CMB. We demonstrate that this approach provides unbiased results using mock observations of clusters from a new set of hydrodynamical simulations. We apply this method to a sample of 158 SPT-selected clusters, spanning the redshift range 0.05 < z < 1.35, and measure $\\alpha = 0.017^{+0.030}_{-0.028}$, consistent with the standard model prediction of α = 0. In combination with other published results, we find α = 0.005 ± 0.012, an improvement of ~10 percent over published constraints. This measurement also provides a strong constraint on the effective equation of state in models of decaying dark energy weff = -0.994 ± 0.010.

  13. Joint Investigation of Mesospheric Gravity Wave Characteristics and Dynamics over South Pole Station (90°S) during the Austral Winter 2010

    NASA Astrophysics Data System (ADS)

    Pautet, P.; Taylor, Michael J.; Williams, B. P.; Palo, S. E.

    2010-12-01

    Atmospheric gravity waves propagating from the troposphere up to the lower thermosphere play a key role in the thermal structure and large-scale circulation of the mid-atmosphere. These waves have been extensively studied using wide-angle CCD imagers, but mostly from sites located at low and mid-latitudes. To better quantify the effects of gravity waves at MLT heights (~80-100 km) over Antarctica, and improve the knowledge on their propagation characteristics, wave momentum flux, and geographic variability, several optical instruments were deployed at the Amundsen-Scott South Pole Station (90°S) and jointly operated during the austral winter 2010 (April to August). An all-sky OH imager and a wide field of view (120°) mesospheric temperature mapper (Utah State University) collocated with a meteor radar and an all-sky Na imager (University of Colorado, NWRA) provided key measurements to study the main characteristics of the short-period gravity waves propagating over the station, including horizontal wavelength, propagation direction, observed period and phase speed, and mesospheric winds. In this presentation we will summarize preliminary results obtained during the winter 2010 season.

  14. OPTICAL REDSHIFT AND RICHNESS ESTIMATES FOR GALAXY CLUSTERS SELECTED WITH THE SUNYAEV-Zel'dovich EFFECT FROM 2008 SOUTH POLE TELESCOPE OBSERVATIONS

    SciTech Connect

    High, F. W.; Stalder, B.; Song, J.; Ade, P. A. R.; Aird, K. A.; Allam, S. S.; Buckley-Geer, E. J.; Armstrong, R.; Barkhouse, W. A.; Benson, B. A.; Bertin, E.; Bhattacharya, S.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Brodwin, M.; Challis, P.; De Haan, T.

    2010-11-10

    We present redshifts and optical richness properties of 21 galaxy clusters uniformly selected by their Sunyaev-Zel'dovich (SZ) signature. These clusters, plus an additional, unconfirmed candidate, were detected in a 178 deg{sup 2} area surveyed by the South Pole Telescope (SPT) in 2008. Using griz imaging from the Blanco Cosmology Survey and from pointed Magellan telescope observations, as well as spectroscopy using Magellan facilities, we confirm the existence of clustered red-sequence galaxies, report red-sequence photometric redshifts, present spectroscopic redshifts for a subsample, and derive R{sub 200} radii and M{sub 200} masses from optical richness. The clusters span redshifts from 0.15 to greater than 1, with a median redshift of 0.74; three clusters are estimated to be at z>1. Redshifts inferred from mean red-sequence colors exhibit 2% rms scatter in {sigma}{sub z}/(1 + z) with respect to the spectroscopic subsample for z < 1. We show that the M{sub 200} cluster masses derived from optical richness correlate with masses derived from SPT data and agree with previously derived scaling relations to within the uncertainties. Optical and infrared imaging is an efficient means of cluster identification and redshift estimation in large SZ surveys, and exploiting the same data for richness measurements, as we have done, will be useful for constraining cluster masses and radii for large samples in cosmological analysis.

  15. Thermal behavior of regolith at cold traps on the moon's south pole: Revealed by Chang'E-2 microwave radiometer data

    NASA Astrophysics Data System (ADS)

    Wei, Guangfei; Li, Xiongyao; Wang, Shijie

    2016-03-01

    The long-term stability of water ice at cold traps depends on subsurface temperature and regolith thermophysical properties. Based on Chang'E-2 microwave radiometer data, we have inverted attenuation coefficient, thermal gradient and instantaneous temperature profiles at permanently shaded craters (Cabeus, Haworth and Shoemaker) on the Moon's south pole. The nonuniformity of the inverted attenuation coefficient within the craters reflects the inhomogeneous thermophysical properties of regolith. In addition, thermal gradient decreased significantly from the crater walls to the bottoms, which may be caused by scattered sunlight, internal heat flux and earthshine effect. Considering continuous supplement of water ice (with volumetric fraction 0-10%) at cold traps, it changes subsurface thermophysical properties but has little effect on thermal gradient. We also assumed that abundant ice (10%) mixed with regolith, the inversion results showed that the maximum difference of diurnal temperatures between "wet" and dry regolith were no more than 0.5 K. That is, the effect of water ice on subsurface thermal behavior can be neglected.

  16. Measurements of several atmospheric gases above the South Pole in December 1986 from high-resolution 3- to 4-micron solar spectra

    NASA Technical Reports Server (NTRS)

    Goldman, Aaron; Murcray, Frank J.; Murcray, Frank H.; Murcray, David G.; Rinsland, Curtis P.

    1988-01-01

    This paper reports the quantitative analysis of absorption features of a number of atmospheric gases in 0.02/cm resolution 3- to 4-micron solar spectra recorded at the Amundsen-Scott South Pole Station. The measurements were obtained shortly after the austral spring ozone minimum and define, for the first time, the ambient levels of the species immediately following the breakup of the polar vortex. The retrieved total vertical column amounts in molecules per sq cm are: 2.4 + or - 0.4 x 10 to the 21st for H2(O-16), 4.5 + or - 0.5 x 10 to the 18th for H2(O-18), 3.9 + or - 0.4 x 10 to the 17th for HDO, 2.1 + or - 0.2 x 10 to the 19th for CH4, 5.1 + or - 0.5 x 10 to the 21st for CO2, 3.9 + or - 0.4 x 10 to the 18th for N2O, and 3.7 + or - 0.5 x 10 to the 15th for C2H6. Identification of (C-12)H3D absorption features and a search for H2CO absorption in the spectral data are also described.

  17. High-resolution local magnetic field models for the Martian South Pole from Mars Global Surveyor data

    NASA Astrophysics Data System (ADS)

    Plattner, A.; Simons, F. J.

    2015-09-01

    We present two high-resolution local models for the crustal magnetic field of the Martian south polar region. Models SP130 and SP130M were derived from three-component measurements made by Mars Global Surveyor at nighttime and at low altitude (<200 km). The availability area for these data covers the annulus between latitudes -76° and -87° and contains a strongly magnetized region (southern parts of Terra Sirenum) adjacent to weakly magnetized terrains (such as Prometheus Planum). Our localized field inversions take into account the region of data availability, a finite spectral bandlimit (spherical harmonic degree L = 130), and the varying satellite altitude at each observation point. We downward continue the local field solutions to a sphere of Martian polar radius 3376 km. While weakly magnetized areas in model SP130 contain inversion artifacts caused by strongly magnetized crust nearby, these artifacts are largely avoided in model SP130M, a mosaic of inversion results obtained by independently solving for the fields over individual subregions. Robust features of both models are magnetic stripes of alternating polarity in southern Terra Sirenum that end abruptly at the rim of Prometheus Planum, an impact crater with a weak or undetectable magnetic field. From a prominent and isolated dipole-like magnetic feature close to Australe Montes, we estimate a paleopole with a best fit location at longitude 207° and latitude 48°. From the abruptly ending magnetic field stripes, we estimate average magnetization values of up to 15 A/m.

  18. The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends

    NASA Astrophysics Data System (ADS)

    Chamberlin, R. A.; Grossman, E. N.

    2012-07-01

    We use a fifty-year record of wintertime radiosonde observations at the South Pole to estimate the precipitable water vapor column (PWV) over the entire period. Humidity data from older radiosondes is of limited reliability; however, we think an estimation of PWV is possible using temperature data because the wintertime lower troposphere is very close to saturated. From temperature data we derived PWVSAT which is the PWV if the troposphere was saturated over the entire column. Comparisons to recent radiosonde humidity data indicate that PWV ≃ 0.88PWVSAT. Since 1998 a CMU/NRAO 860 GHz atmospheric radiometer has been operating at the South Pole producing zenith opacity data, τo. It is expected that τo ∝ PWV, and also τo ∝ PWVSAT, since the lower atmospheric column is near to saturation. We compare trends in τo, PWVSAT, and PWV. PWV and PWVSAT showed little trend in the last fifty years, 1961 to 2010, except perhaps in the last two decades, when PWVSAT was below average, followed by an increasing trend to above average. This increasing trend in the last decade was also observed in τo, except for the final two years when it appears that something changed in the instrument response. PWVSAT is a useful metric for estimating PWV in the earlier years of wintertime South Pole radiosonde, and it is generally useful for evaluating the wintertime performance of radiosonde humidity and atmospheric opacity instrumentation.

  19. Influence of Hypoxic Interval Training and Hyperoxic Recovery on Muscle Activation and Oxygenation in Connection with Double-Poling Exercise

    PubMed Central

    Zinner, Christoph; Hauser, Anna; Born, Dennis-Peter; Wehrlin, Jon P.; Holmberg, Hans-Christer; Sperlich, Billy

    2015-01-01

    Here, we evaluated the influence of breathing oxygen at different partial pressures during recovery from exercise on performance at sea-level and a simulated altitude of 1800 m, as reflected in activation of different upper body muscles, and oxygenation of the m. triceps brachii. Ten well-trained, male endurance athletes (25.3±4.1 yrs; 179.2±4.5 cm; 74.2±3.4 kg) performed four test trials, each involving three 3-min sessions on a double-poling ergometer with 3-min intervals of recovery. One trial was conducted entirely under normoxic (No) and another under hypoxic conditions (Ho; FiO2 = 0.165). In the third and fourth trials, the exercise was performed in normoxia and hypoxia, respectively, with hyperoxic recovery (HOX; FiO2 = 1.00) in both cases. Arterial hemoglobin saturation was higher under the two HOX conditions than without HOX (p<0.05). Integrated muscle electrical activity was not influenced by the oxygen content (best d = 0.51). Furthermore, the only difference in tissue saturation index measured via near-infrared spectroscopy observed was between the recovery periods during the NoNo and HoHOX interventions (P<0.05, d = 0.93). In the case of HoHo the athletes’ Pmean declined from the first to the third interval (P < 0.05), whereas Pmean was unaltered under the HoHOX, NoHOX and NoNo conditions. We conclude that the less pronounced decline in Pmean during 3 x 3-min double-poling sprints in normoxia and hypoxia with hyperoxic recovery is not related to changes in muscle activity or oxygenation. Moreover, we conclude that hyperoxia (FiO2 = 1.00) used in conjunction with hypoxic or normoxic work intervals may serve as an effective aid when inhaled during the subsequent recovery intervals. PMID:26468885

  20. Fingerprinting Volcanic and Anthropogenic Sulfur Dioxide in the Air: A 25 Year Record of Sulfate Aerosols from the South Pole Snowpit, Antarctica

    NASA Astrophysics Data System (ADS)

    Shaheen, R.; Abaunza-Quintero, M.; Jackson, T. L.; McCabe, J.; Savarino, J. P.; Thiemens, M. H.

    2012-12-01

    Sulfate aerosols, unlike greenhouse gases, cause cooling effect (-0.4 ± 0.2 W.m-2) by scattering incoming solar radiation and by acting as cloud condensation nuclei (IPCC 2007). Volcanic eruptions with explosivity Indices >5 inject large amounts of SO2 and particles into the stratosphere causing a significant decrease in temperature. For example a 0.7oC decrease in Earth's temperature was observed following the Pinatubo eruption in 1991. Stratospheric injection of sulfate aerosols has been suggested as a geoengineering effort to mitigate global warming caused by a significant increase in greenhouse gases. To understand the impact of volcanic events on the stratospheric sulfate aerosol layer and subsequent changes in the dynamics of the upper atmosphere, a long term and high temporal resolution record of sulfate aerosol is needed. Here we present a 25 year (1978 to 2003) high resolution record of sulfate aerosols which covers largest volcanic eruptions of the 20th century namely, El-Chichón 1982 and Pinatubo 1991. Sulfate aerosol samples were obtained from a 1x1m snowpit at the South Pole, Antarctica with approximately 6 month time steps. Sulfate concentrations vary from 30 to 70 ppb depending on the season with exceptions during volcanic events which contributed a three to four folds increase in sulfate concentration Sulfate concentrations of120 ppb following El Chichón and 190 ppb after Pinatubo eruptions were observed. The oxygen isotopic anomaly varied from 0.7‰ to 3.9‰ with the highest anomaly occurring after the Pinatubo eruption. The positive Δ17O of sulfate derives from aqueous phase oxidation of SO2 by H2O2 and O3 oxidation and involves transfer of the isotopic anomaly from the oxidant to the product sulfate. Coupled with kinetic analysis the relative reaction rates the relative proportions of oxidation can be calculated. All other sulfate sources such as sea salt sulfates, primary sulfates from fossil fuel combustion, metal catalyzed oxidation of S

  1. HIGH-REDSHIFT COOL-CORE GALAXY CLUSTERS DETECTED VIA THE SUNYAEV-ZEL'DOVICH EFFECT IN THE SOUTH POLE TELESCOPE SURVEY

    SciTech Connect

    Semler, D. R.; Suhada, R.; Bazin, G.; Bocquet, S.; Desai, S.; Aird, K. A.; Ashby, M. L. N.; Bayliss, M.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; Dobbs, M. A.; and others

    2012-12-20

    We report the first investigation of cool-core properties of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect. We use 13 galaxy clusters uniformly selected from 178 deg{sup 2} observed with the South Pole Telescope (SPT) and followed up by the Chandra X-ray Observatory. They form an approximately mass-limited sample (>3 Multiplication-Sign 10{sup 14} M{sub Sun} h {sup -1}{sub 70}) spanning redshifts 0.3 < z < 1.1. Using previously published X-ray-selected cluster samples, we compare two proxies of cool-core strength: surface brightness concentration (c{sub SB}) and cuspiness ({alpha}). We find that c{sub SB} is better constrained. We measure c{sub SB} for the SPT sample and find several new z > 0.5 cool-core clusters, including two strong cool cores. This rules out the hypothesis that there are no z > 0.5 clusters that qualify as strong cool cores at the 5.4{sigma} level. The fraction of strong cool-core clusters in the SPT sample in this redshift regime is between 7% and 56% (95% confidence). Although the SPT selection function is significantly different from the X-ray samples, the high-z c{sub SB} distribution for the SPT sample is statistically consistent with that of X-ray-selected samples at both low and high redshifts. The cool-core strength is inversely correlated with the offset between the brightest cluster galaxy and the X-ray centroid, providing evidence that the dynamical state affects the cool-core strength of the cluster. Larger SZ-selected samples will be crucial in understanding the evolution of cluster cool cores over cosmic time.

  2. REDSHIFTS, SAMPLE PURITY, AND BCG POSITIONS FOR THE GALAXY CLUSTER CATALOG FROM THE FIRST 720 SQUARE DEGREES OF THE SOUTH POLE TELESCOPE SURVEY

    SciTech Connect

    Song, J.; Zenteno, A.; Desai, S.; Bazin, G.; Stalder, B.; Ashby, M. L. N.; Bayliss, M.; Bleem, L. E.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Aird, K. A.; Armstrong, R.; Bertin, E.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; and others

    2012-12-10

    We present the results of the ground- and space-based optical and near-infrared (NIR) follow-up of 224 galaxy cluster candidates detected with the Sunyaev-Zel'dovich (SZ) effect in the 720 deg{sup 2} of the South Pole Telescope (SPT) survey completed in the 2008 and 2009 observing seasons. We use the optical/NIR data to establish whether each candidate is associated with an overdensity of galaxies and to estimate the cluster redshift. Most photometric redshifts are derived through a combination of three different cluster redshift estimators using red-sequence galaxies, resulting in an accuracy of {Delta}z/(1 + z) = 0.017, determined through comparison with a subsample of 57 clusters for which we have spectroscopic redshifts. We successfully measure redshifts for 158 systems and present redshift lower limits for the remaining candidates. The redshift distribution of the confirmed clusters extends to z = 1.35 with a median of z{sub med} = 0.57. Approximately 18% of the sample with measured redshifts lies at z > 0.8. We estimate a lower limit to the purity of this SPT SZ-selected sample by assuming that all unconfirmed clusters are noise fluctuations in the SPT data. We show that the cumulative purity at detection significance {xi} > 5({xi} > 4.5) is {>=}95% ({>=}70%). We present the red brightest cluster galaxy (rBCG) positions for the sample and examine the offsets between the SPT candidate position and the rBCG. The radial distribution of offsets is similar to that seen in X-ray-selected cluster samples, providing no evidence that SZ-selected cluster samples include a different fraction of recent mergers from X-ray-selected cluster samples.

  3. Thorium abundances of basalt ponds in South Pole-Aitken basin: Insights into the composition and evolution of the far side lunar mantle

    USGS Publications Warehouse

    Hagerty, J.J.; Lawrence, D.J.; Hawke, B.R.

    2011-01-01

    Imbrian-aged basalt ponds, located on the floor of South Pole-Aitken (SPA) basin, are used to provide constraints on the composition and evolution of the far side lunar mantle. We use forward modeling of the Lunar Prospector Gamma Ray Spectrometer thorium data, to suggest that at least five different and distinct portions of the far side lunar mantle contain little or no thorium as of the Imbrian Period. We also use spatial correlations between local thorium enhancements and nonmare material on top of the basalt ponds to support previous assertions that lower crustal materials exposed in SPA basin have elevated thorium abundances, consistent with noritic to gabbronoritic lithologies. We suggest that the lower crust on the far side of the Moon experienced multiple intrusions of thorium-rich basaltic magmas, prior to the formation of SPA basin. The fact that many of the ponds on the lunar far side have elevated titanium abundances indicates that the far side of the Moon experienced extensive fractional crystallization that likely led to the formation of a KREEP-like component. However, because the Imbrian-aged basalts contain no signs of elevated thorium, we propose that the SPA impact event triggered the transport of a KREEP-like component from the lunar far side and concentrated it on the nearside of the Moon. Because of the correlation between basaltic ponds and basins within SPA, we suggest that Imbrian-aged basaltic volcanism on the far side of the Moon was driven by basin-induced decompressional melting. Copyright ?? 2011 by the American Geophysical Union.

  4. Cluster Mass Calibration at High Redshift: HST Weak Lensing Analysis of 13 Distant Galaxy Clusters from the South Pole Telescope Sunyaev-Zel'dovich Survey

    SciTech Connect

    Schrabback, T.; et al.

    2016-11-11

    We present an HST/ACS weak gravitational lensing analysis of 13 massive high-redshift (z_median=0.88) galaxy clusters discovered in the South Pole Telescope (SPT) Sunyaev-Zel'dovich Survey. This study is part of a larger campaign that aims to robustly calibrate mass-observable scaling relations over a wide range in redshift to enable improved cosmological constraints from the SPT cluster sample. We introduce new strategies to ensure that systematics in the lensing analysis do not degrade constraints on cluster scaling relations significantly. First, we efficiently remove cluster members from the source sample by selecting very blue galaxies in V-I colour. Our estimate of the source redshift distribution is based on CANDELS data, where we carefully mimic the source selection criteria of the cluster fields. We apply a statistical correction for systematic photometric redshift errors as derived from Hubble Ultra Deep Field data and verified through spatial cross-correlations. We account for the impact of lensing magnification on the source redshift distribution, finding that this is particularly relevant for shallower surveys. Finally, we account for biases in the mass modelling caused by miscentring and uncertainties in the mass-concentration relation using simulations. In combination with temperature estimates from Chandra we constrain the normalisation of the mass-temperature scaling relation ln(E(z) M_500c/10^14 M_sun)=A+1.5 ln(kT/7.2keV) to A=1.81^{+0.24}_{-0.14}(stat.) +/- 0.09(sys.), consistent with self-similar redshift evolution when compared to lower redshift samples. Additionally, the lensing data constrain the average concentration of the clusters to c_200c=5.6^{+3.7}_{-1.8}.

  5. North Pole Region of the Moon as Seen by Clementine

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Lunar mosaic of 1500 Clementine images of the north polar region of the moon. The projection is orthographic centered on the north pole. The polar regions of the moon are of special interest because of the postulated occurrence of ice in permanently shadowed areas. The north pole of the moon is absent of the very rugged terrain seen at the south pole.

  6. Lunar Reconnaissance Orbiter Camera Observations Relating to Science and Landing Site Selection in South Pole-Aitken Basin for a Robotic Sample Return Mission

    NASA Technical Reports Server (NTRS)

    Jolliff, B. L.; Clegg-Watkins, R. N.; Petro, N. E.; Lawrence, S. L.

    2016-01-01

    The Moon's South Pole-Aitken basin (SPA) is a high priority target for Solar System exploration, and sample return from SPA is a specific objective in NASA's New Frontiers program. Samples returned from SPA will improve our understanding of early lunar and Solar System events, mainly by placing firm timing constraints on SPA formation and the post-SPA late-heavy bombardment (LHB). Lunar Reconnaissance Orbiter Camera (LROC) images and topographic data, especially Narrow Angle Camera (NAC) scale (1-3 mpp) morphology and digital terrain model (DTM) data are critical for selecting landing sites and assessing landing hazards. Rock components in regolith at a given landing site should include (1) original SPA impact-melt rocks and breccia (to determine the age of the impact event and what materials were incorporated into the melt); (2) impact-melt rocks and breccia from large craters and basins (other than SPA) that represent the post-SPA LHB interval; (3) volcanic basalts derived from the sub-SPA mantle; and (4) older, "cryptomare" (ancient buried volcanics excavated by impact craters, to determine the volcanic history of SPA basin). All of these rock types are sought for sample return. The ancient SPA-derived impact-melt rocks and later-formed melt rocks are needed to determine chronology, and thus address questions of early Solar System dynamics, lunar history, and effects of giant impacts. Surface compositions from remote sensing are consistent with mixtures of SPA impactite and volcanic materials, and near infrared spectral data distinguish areas with variable volcanic contents vs. excavated SPA substrate. Estimating proportions of these rock types in the regolith requires knowledge of the surface deposits, evaluated via morphology, slopes, and terrain ruggedness. These data allow determination of mare-cryptomare-nonmare deposit interfaces in combination with compositional and mineralogical remote sensing to establish the types and relative proportions of materials

  7. Observations of the azimuthal dependence of normal mode coupling below 4 mHz at the South Pole and its nearby stations: Insights into the anisotropy beneath the Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    Hu, Xiao Gang

    2016-08-01

    Normal mode coupling pair 0S26-0T26 and 0S27-0T27 are significantly present at the South Pole station QSPA after the 2011/03/11 Mw9.1 Tohoku earthquake. In an attempt to determine the mechanisms responsible for the coupling pairs, I first investigate mode observations at 43 stations distributed along the polar great-circle path for the earthquake and observations at 32 Antarctic stations. I rule out the effect of Earth's rotation as well as the effect of global large-scale lateral heterogeneity, but argue instead for the effect of small-scale local azimuthal anisotropy in a depth extent about 300 km. The presence of quasi-Love waveform in 2-5 mHz at QSPA and its nearby stations confirms the predication. Secondly, I analyze normal mode observations at the South Pole location after 28 large earthquakes from 1998 to 2015. The result indicates that the presence of the mode coupling is azimuthal dependent, which is related to event azimuths in -46° to -18°. I also make a comparison between the shear-wave splitting measurements of previous studies and the mode coupling observations of this study, suggesting that their difference can be explained by a case that the anisotropy responsible for the mode coupling is not just below the South Pole location but located below region close to the Transantarctic Mountains (TAM). Furthermore, more signals of local azimuthal anisotropy in normal-mode observations at QSPA and SBA, such as coupling of 0S12-0T11 and vertical polarization anomaly for 0T10, confirms the existence of deep anisotropy close to TAM, which may be caused by asthenospheric mantle flow and edge convection around cratonic keel of TAM.

  8. Screening of the 'Pathogen Box' identifies an approved pesticide with major anthelmintic activity against the barber's pole worm.

    PubMed

    Preston, Sarah; Jiao, Yaqing; Jabbar, Abdul; McGee, Sean L; Laleu, Benoît; Willis, Paul; Wells, Timothy N C; Gasser, Robin B

    2016-12-01

    There is a substantial need to develop new medicines against parasitic diseases via public-private partnerships. Based on high throughput phenotypic screens of largely protozoal pathogens and bacteria, the Medicines for Malaria Venture (MMV) has recently assembled an open-access 'Pathogen Box' containing 400 well-curated chemical compounds. In the present study, we tested these compounds for activity against parasitic stages of the nematode Haemonchus contortus (barber's pole worm). In an optimised, whole-organism screening assay, using exsheathed third-stage (xL3) and fourth-stage (L4) larvae, we measured the inhibition of larval motility, growth and development of H. contortus. We also studied the effect of the 'hit' compound on mitochondrial function by measuring oxygen consumption. Among the 400 Pathogen Box compounds, we identified one chemical, called tolfenpyrad (compound identification code: MMV688934) that reproducibly inhibits xL3 motility as well as L4 motility, growth and development, with IC50 values ranging between 0.02 and 3 μM. An assessment of mitochondrial function showed that xL3s treated with tolfenpyrad consumed significantly less oxygen than untreated xL3s, which was consistent with specific inhibition of complex I of the respiratory electron transport chain in arthropods. Given that tolfenpyrad was developed as a pesticide and has already been tested for absorption, distribution, excretion, biotransformation, toxicity and metabolism, it shows considerable promise for hit-to-lead optimisation and/or repurposing for use against H. contortus and other parasitic nematodes. Future work should assess its activity against hookworms and other pathogens that cause neglected tropical diseases.

  9. Magnet pole tips

    DOEpatents

    Thorn, Craig E.; Chasman, Chellis; Baltz, Anthony J.

    1984-04-24

    An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  10. Magnet pole tips

    DOEpatents

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-11-19

    An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  11. Orbiter escape pole

    NASA Technical Reports Server (NTRS)

    Goodrich, Winston D. (Inventor); Wesselski, Clarence J. (Inventor); Pelischek, Timothy E. (Inventor); Becker, Bruce H. (Inventor); Kahn, Jon B. (Inventor); Grimaldi, Margaret E. (Inventor); McManamen, John P. (Inventor); Castro, Edgar O. (Inventor)

    1989-01-01

    A Shuttle type of aircraft (10) with an escape hatch (12) has an arcuately shaped pole housing (16) attachable to an interior wall and ceiling with its open end adjacent to the escape hatch. The pole housing 16 contains a telescopically arranged and arcuately shaped primary pole member (22) and extension pole member (23) which are guided by roller assemblies (30,35). The extension pole member (23) is slidable and extendable relative to the primary pole member (22). For actuation, a spring actuated system includes a spring (52) in the pole housing. A locking member (90) engages both pole members (22,23) through notch portions (85,86) in the pole members. The locking member selectively releases the extension pole member (23) and the primary pole member (22). An internal one-way clutch or anti-return mechanism prevents retraction of the extension pole member from an extended position. Shock absorbers (54)(150,152) are for absoring the energy of the springs. A manual backup deployment system is provided which includes a canted ring (104) biased by a spring member (108). A lever member (100) with a slot and pin connection (102) permits the mechanical manipulation of the canted ring to move the primary pole member. The ring (104) also prevents retraction of the main pole. The crew escape mechanism includes a magazine (60) and a number of lanyards (62), each lanyard being mounted by a roller loop (68) over the primary pole member (22). The strap on the roller loop has stitching for controlled release, a protection sheath (74) to prevent tangling and a hook member (69) for attachment to a crew harness.

  12. New Model Predicts Fire Activity in South America

    NASA Video Gallery

    UC Irvine scientist Jim Randerson discusses a new model that is able to predict fire activity in South America using sea surface temperature observations of the Pacific and Atlantic Ocean. The find...

  13. Poles apart: Scott, Amundsen and science.

    PubMed

    Larson, Edward J

    2011-12-01

    One hundred years ago, teams led by Roald Amundsen and Robert Scott may have been heading in the same direction but they were poles apart in the way they sought their goals. Amundsen led a five-person team of expert Nordic skiers and dog-sledders with a single goal: getting to the South Pole first. He planned and executed the effort brilliantly. Scott, in contrast, led a complex and multi-faceted Antarctic expedition with 33 explorers and scientists, many of whom were focused on ambitious and often taxing scientific research projects that had nothing whatsoever to do with reaching the Pole. Although Scott failed to reach the South Pole first and died with four men on the return trip, his expedition made significant contributions to Antarctic science. Indeed, at least some of Scott's failure to reach the Pole first and the subsequent death of his polar party on the return trip can be attributed to burden of trying to do too much and not focusing on reaching the pole.

  14. 1. Launch facility, delta 6, approach road and gate, pole ...

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

    1. Launch facility, delta 6, approach road and gate, pole marking the hardened intersite cable system in right center, commercial power pole outside fence in left center, view towards south - Ellsworth Air Force Base, Delta Flight, Launch Facility D-6, 4 miles north of Badlands National Park Headquarters, 4.5 miles east of Jackson County line on county road, Interior, Jackson County, SD

  15. 9. VIEW SHOWING TRUSSES FROM DECK WITH 4' RANGE POLE ...

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

    9. VIEW SHOWING TRUSSES FROM DECK WITH 4' RANGE POLE AT SECOND VERTICAL POST ON SOUTH SIDE, LOOKING WEST - White River Bridge, Spanning White River at U.S. Highway 70, De Valls Bluff, Prairie County, AR

  16. Detail of northeast corner showing metal plates and poles of ...

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

    Detail of northeast corner showing metal plates and poles of unknown purpose. - Fitzsimons General Hospital, Nurses' Quarters, Southwest Corner of West Harlow Avenue, & South Eighth Street, Aurora, Adams County, CO

  17. NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVEGROUND PORTION IS ON ...

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

    NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVE-GROUND PORTION IS ON THE LEFT. VIEW FACING SOUTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  18. Expansion of student activities in Africa: from south to north

    NASA Astrophysics Data System (ADS)

    Cherif, Rim; Ben Salem, Amine; Gueddana, Amor; Zghal, Mourad; Naidoo, Darryl; Forbes, Andrew; Heidt, Alexander M.; Rohwer, Erich G.

    2014-07-01

    Optics and photonics research in Africa has gradually grown in the past ten years with a very active optical community involved in state-of-the-art research. Despite relatively low resources, optics research in the continent is competitive with many international benchmarks and has had a significant impact within the African continent. In the past five years, a group of dynamic students have developed the student chapter network from Tunisia to South Africa. The first student chapters of the optical society of America (OSA) and the international society for optics and photonics (SPIE) were established in South Africa (in the Council for Scientific and Industrial Research (CSIR) and in the University of Stellenbosch), followed by a chapter in Tunisia (Engineering school of communications of Tunis, Sup'Com). In this paper, we will present the major activities of the student chapters of Tunisia and South Africa, and how they are promoting optics and photonics in Africa.

  19. Epithermal Neutron Observations and Lunar South Pole Targeting for LCROSS Impact Planning using the Lunar Reconnaissance Orbiter (LRO), Lunar Exploring Neutron Detector (LEND)

    NASA Technical Reports Server (NTRS)

    McClanahan, T. P.; Mitrofanov, I.; Boynton, W. V.; Chin, G.; Colaprete, A.; Evans, L. G.; Garvin, J.; Harshman, K.; Litvak, R.; Malakhov, A.; Milikh, G. M.; Nandikotkur, G.; Sagdeev, R.; Sanin, A. B.; Smith, D. E.; Starr, R. D.; Trombka, J.

    2009-01-01

    LCROSS impact targeting and planning efforts included quantifying South Polar epithermal neutron flux depressions in early LEND mapped results to maximize the expected plume Hydrogen (H) yield. Epithermal neutron surface fluxes are a key geochemical indicator of surface Hydrogen (H) concentration inferred to be elevated in polar permanent shadow regions (PSR). LCROSS impact target regions were delineated as (PSR) using illumination modeling of polar topography. To quantify targets potential yield for LCROSS, LEND epithermal neutron flux observations were integrated over LCROSS targets of interest and compared to background observations. Discussion will define methods review impact prior estimates and contrast post impact results.

  20. South African Curriculum Reform: Education for Active Citizenship

    ERIC Educational Resources Information Center

    Smith, Juliana; Arendse, Agnetha

    2016-01-01

    The changing societal context in South Africa (SA) has necessitated curriculum reform to deal with the challenges of education, from apartheid to democracy, with the aim of promoting active citizenship education. The aim of the paper is thus to illuminate to what extent the Grade 11 Life Orientation (LO) curriculum prepares learners for active…

  1. Periodicities in the north-south asymmetry of solar activity

    NASA Astrophysics Data System (ADS)

    Vizoso, G.; Ballester, J. L.

    1989-09-01

    A Blackman-Tukey power spectrum is performed on the values of the north-south asymmetry in the sudden disappearance of solar prominences, and the results are reported. The findings confirm the proposed existence of a periodicity of around 11 years and fails to confirm another short periodicity of around 2.3 years. The results of the power spectrum performed using values of the flare number and flare index north-south asymmetry provide a significant peak of 3.1-3.2 years. This short periodicity could be related to those found by Ramanuja Rao (1973) in several indices of solar activity.

  2. Correlates of lifestyle: physical activity among South Asian Indian immigrants.

    PubMed

    Daniel, Manju; Wilbur, JoEllen; Fogg, Louis F; Miller, Arlene Michaels

    2013-01-01

    South Asian immigrants are at increased risk for cardiovascular disease and diabetes, but little is known about their physical activity patterns. In this cross-sectional study, 110 participants were recruited to describe lifestyle physical activity behavior of this at-risk population. Education (p = .042), global health (p = .045), and self-efficacy (p = .000) had significant positive independent effects on leisure-time physical activity. Depression (p = .035) and waist circumference (p = .012) had significant negative independent effects, and frequency of experiencing discrimination a significant positive independent effect (p = .007) on daily step counts. Culture-sensitive physical activity interventions need to target South Asian Indian immigrants who are less educated, in poor health, concerned about racial discrimination, and have low self-efficacy.

  3. Physical state and temporal evolution of icy surfaces in the Mars South Pole by retrieving their bidirectional reflectance from CRISM observations

    NASA Astrophysics Data System (ADS)

    Douté, Sylvain Michel; Pilorget, Cedric; Fernando, Jennifer

    2016-10-01

    On Mars H2O and CO2 ices can be found as seasonal or perennial deposits notably in the polar regions. At the moment little is known about their bidirectional reflectance factor (BRF) despite the significance of such information for characterizing the composition, physical state and energy balance of the icy surfaces from the bolometric albedo. The BRF is potentially accessible thanks to the near-simultaneous multi-angle, hyperspectral observations of the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) implying 11 viewing angles in visible and infrared ranges. However, its extraction from the CRISM measurements is especially challenging. Indeed, the atmospheric aerosols (mineral dust, sometimes H2O ice) have a strong contribution in the CRISM measurements that must be corrected. At high latitudes, their contribution is accentuated because the sun is low above the horizon. Besides, the BRF of ices is expected to be highly anisotropic especially under grazing illumination creating difficulties with the traditional Lambertian surface assumption commonly used for atmospheric correction. In previous research we put forward the Multi-angle Approach for Retrieval of Surface Reflectance from CRISM Observations (MARS-ReCO), an algorithm that characterizes and corrects the aerosol scattering effects. The aerosol optical depth (AOD) and the BRF of surface materials are retrieved conjointly and coherently as a function of wavelength. In this work, we apply MARS-ReCO on time series of CRISM sequences over different regions of interest in the outskirts of the south permanent polar cap. The time series span from mid-spring to late summer during which the CO2 ice sublimates revealing H2O frost and defrosted terrains. No ground truth is available for the investigated regions but cross-validation with other datasets such as observations by OMEGA (mapping spectrometer on MEX) can be applied. Thanks to the atmospheric correction, we are able to identify various classes of

  4. Periodically poled silicon

    NASA Astrophysics Data System (ADS)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Jalali, Bahram

    2009-03-01

    We propose a new class of photonic devices based on periodic stress fields in silicon that enable second-order nonlinearity as well as quasi-phase matching. Periodically poled silicon (PePSi) adds the periodic poling capability to silicon photonics and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on second-order nonlinear effects. As an example of the utility of the PePSi technology, we present simulations showing that midwave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50%.

  5. Pole pulling apparatus and method

    DOEpatents

    McIntire, Gary L.

    1989-01-01

    An apparatus for removal of embedded utility-type poles which removes the poles quickly and efficiently from their embedded position without damage to the pole or surrounding structures. The apparatus includes at least 2 piston/cylinder members equally spaced about the pole, and a head member affixed to the top of each piston. Elongation of the piston induces rotation of the head into the pole to increase the gripping action and reduce slippage. Repeated actuation and retraction of the piston and head member will "jack" the pole from its embedded position.

  6. A LINE POLE 20, STUBBED HISTORIC POLE WITH ORIGINAL GLASS ...

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

    A LINE POLE 20, STUBBED HISTORIC POLE WITH ORIGINAL GLASS PIN-TYPE INSULATORS AND INTACT COMMUNICATION LINE CROSS ARM. VIEW TO WEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  7. Effect of the pole--human body interaction on pole vaulting performance.

    PubMed

    Arampatzis, Adamantios; Schade, Falk; Brüggemann, Gert-Peter

    2004-09-01

    The purposes of this study were: (a) to examine the interactions between the athlete and the pole and the possibility for the athlete to take advantage of the pole's elasticity by means of muscular work and (b) to develop performance criteria during the interaction between the athlete and the pole in pole vaulting. Six athletes performed 4-11 trials each, at 90% of their respective personal best performance. All trials were recorded using four synchronized, genlocked video cameras operating at 50 Hz. The ground reaction forces exerted on the bottom of the pole were measured using a planting box fixed on a force plate (1000 Hz). The interaction between athlete and pole may be split into two parts. During the first part, energy is transferred into the pole and the total energy of the athlete decreases. The difference between the energy decrease of the athlete and the pole energy is an indicator of the energy produced by the athletes by means of muscular work (criterion 1). During the second part of the interaction, energy is transferred back to the athlete and the total energy of the athlete increases. The difference between the returned pole energy and the amount of energy increase of the athlete defines criterion 2. In general, the function of the pole during the interaction is: (a) store part of the kinetic energy that the athlete achieved during the run up as strain energy and convert this strain energy into potential energy of the athlete, (b) allow the active system (athlete) to produce muscular work to increase the total energy potential.

  8. A moving-barber-pole illusion.

    PubMed

    Sun, Peng; Chubb, Charles; Sperling, George

    2014-05-01

    In the barber-pole illusion (BPI), a diagonally moving grating is perceived as moving vertically because of the shape of the vertically oriented window through which it is viewed-a strong shape-motion interaction. We introduce a novel stimulus-the moving barber pole-in which a diagonal, drifting sinusoidal carrier is windowed by a raised, vertical, drifting sinusoidal modulator that moves independently of the carrier. In foveal vision, the moving-barber-pole stimulus can be perceived as several active barber poles drifting horizontally but also as other complex dynamic patterns. In peripheral vision, pure vertical motion (the moving-barber-pole illusion [MBPI]) is perceived for a wide range of conditions. In foveal vision, the MBPI is observed, but only when the higher-order modulator motion is masked. Theories to explain the BPI make indiscriminable predictions in a standard barber-pole display. But, in moving-barber-pole stimuli, the motion directions of features (e.g., end stops) of the first-order carrier and of the higher-order modulator are all different from the MBPI. High temporal frequency stimuli viewed peripherally greatly reduce the effectiveness of higher-order motion mechanisms and, ideally, isolate a single mechanism responsible for the MBPI. A three-stage motion-path integration mechanism that (a) computes local motion energies, (b) integrates them for a limited time period along various spatial paths, and (c) selects the path with the greatest motion energy, quantitatively accounts for these high-frequency data. The MBPI model also accounts for the perceived motion-direction in peripherally viewed moving-barber-pole stimuli that do and do not exhibit the MBPI over the entire range of modulator (0-10 Hz) and carrier (2.5-10 Hz) temporal frequencies tested.

  9. SOPHOS -- SOuth Pole High-altitude ObServatory: Prototyping A Large Diameter, Sparsely Filled, Phased Array Telescope on a Tethered Aerostat in Antarctica

    NASA Astrophysics Data System (ADS)

    Ford, Holland; Bally, J.; Bartko, F.; Bely, P.; Brown, R.; Burg, R.; Crocker, J.; Dopita, M.; Illingworth, G.; Tilly, J.; White, R.

    1993-12-01

    Extrapolations of the cost and weight of the present Hubble Space Telescope to larger diameters lead to telescopes which are very heavy and expensive. We plan to build a prototype of a diffraction limited, large space telescope and fly the prototype on a tethered aerostat in Antarctica. During the austral winter the cold, stable, dry, high altitude environment over the Antarctic plateau provides a relatively inexpensive way to test prototypes of space instrumentation. A standard 71 m aerostat can lift a 2000 to 4000 lb payload to a height of 6 km above the 3 km high Antarctic plateau, depending on the weight of the tether. The tether can carry 20 kwatts of power to the telescope and aerostat, and can transmit data at high rates through a fiber. As an intermediate step, we plan to fly a passively cooled 2.4-m IR telescope. At a pressure of 300mb, the overburden of Antarctic water vapor is expected to be under 10 microns of precipitable water. Very long duration exposures in a low background environment will permit the balloon telescope to image fainter objects than any instrument on the Earth or presently in Space. We intend to use the IR and optical telescopes for optical and near IR high angular resolution imaging of the centers of active galaxies, high redshift galaxies, and circumstellar disks and brown dwarfs around nearby stars. Our present concept for the final optical telescope is a sparsely filled array of six 80-cm mirrors on a 6-m diameter circle. Each mirror will be a segment of an f/1 RC primary. The mirrors will have an unequal spacing around the circumference which optimizes spatial coverage of the UV plane. The tethered aerostat will provide a high altitude polar platform which will be invaluable for optical, IR and sub-mm, solar, meterological, and atmospheric chemistry observations.

  10. Single phase two pole/six pole motor

    DOEpatents

    Kirschbaum, H.S.

    1984-09-25

    A single phase alternating current two pole/six pole motor is provided with a main stator winding having six coils disposed unequally around the periphery of the machine. These coils are divided into two groups. When these groups are connected such that their magnetomotive forces are additive, two pole motor operation results. When the polarity of one of the groups is then reversed, six pole motor operation results. An auxiliary stator winding which is similar to the main stator winding is displaced from the main stator winding by 90 electrical degrees on a two pole basis. 12 figs.

  11. Single phase two pole/six pole motor

    DOEpatents

    Kirschbaum, Herbert S.

    1984-01-01

    A single phase alternating current two pole/six pole motor is provided with a main stator winding having six coils disposed unequally around the periphery of the machine. These coils are divided into two groups. When these groups are connected such that their magnetomotive forces are additive, two pole motor operation results. When the polarity of one of the groups is then reversed, six pole motor operation results. An auxiliary stator winding which is similar to the main stator winding is displaced from the main stator winding by 90 electrical degrees on a two pole basis.

  12. Rad Pole Cam Development

    SciTech Connect

    Heckendorn, F. M.; Odell, D. M. C; Harpring, L. J.; Peterson, K. D.

    2005-10-05

    The RadPoleCam was developed to provide Department Of Energy (DOE) first responders the capability to assess the radiological and visual condition of remote or inaccessible locations. Real time gamma isotopic identification is provided to the first responder in the form of audio feedback (i.e. spoken through head phones) from a gamma detector mounted on a collapsible pole that can extend from 1 to 9 meters (6 to 29 feet). Simultaneously, selectable direct and side looking visual images are provided from the 5cm (2in) diameter, waterproof probe tip. The lightweight, self contained, ruggedized, system will provide a rapidly deployable field system for visual and radiological search and assessment of confined spaces and extended reach locations.

  13. Moon - North Pole Mosaic

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This view of the Moon's north pole is a mosaic assembled from 18 images taken by Galileo's imaging system through a green filter as the spacecraft flew by on December 7, 1992. The left part of the Moon is visible from Earth; this region includes the dark, lava-filled Mare Imbrium (upper left); Mare Serenitatis (middle left); Mare Tranquillitatis (lower left), and Mare Crisium, the dark circular feature toward the bottom of the mosaic. Also visible in this view are the dark lava plains of the Marginis and Smythii Basins at the lower right. The Humboldtianum Basin, a 650-kilometer (400-mile) impact structure partly filled with dark volcanic deposits, is seen at the center of the image. The Moon's north pole is located just inside the shadow zone, about a third of the way from the top left of the illuminated region.

  14. Control of subterranean termites (Isoptera: Rhinotermitidae) infesting power poles.

    PubMed

    Horwood, Martin A; Westlake, Terry; Kathuria, Amrit

    2010-12-01

    A trial was conducted to determine the efficacy of termiticidal dusts (arsenic trioxide, triflumuron, and Metarhizium anisopliae), a timber fumigant (dazomet) and liquid termiticides (bifenthrin, chlorfenapyr, chlorpyrifos, fipronil, and imidacloprid) for controlling subterranean termites (Isoptera: Rhinotermitidae) infesting in-service power poles in New South Wales, Australia. Dusts were applied to parts of the pole where termites were present. Fumigant was inserted into holes drilled into the base of the pole. Liquid termiticides were mixed with soil around the base of the pole and injected into internal voids if present. Poles were inspected for up to 5 yr, and the time taken for reinfestation to occur was recorded. Before the start of the trial, the major Australian pole owners were surveyed to obtain an estimate of the annual national cost of termite infestation to the power supply industry. The annual costs of termite treatment and replacing damaged poles were estimated at AU$2 million and AU$13 million, respectively. Infestation rates were lower for all treatments compared with controls within the first 12 mo of the study. Dazomet, arsenic trioxide, fipronil, and chlorpyrifos were the most efficacious treatments. Efficacy was positively related to the amount of termiticide applied and negatively related to the infestation severity but was unaffected by geographical location. Survival curves were calculated of the time elapsed before the recurrence of termite infestations (survival absence of reinfestation). Survival was highest for poles treated with liquid termiticides.

  15. Lunar Flashlight: Illuminating the Lunar South Pole

    NASA Technical Reports Server (NTRS)

    Hayne, P. O.; Greenhagen,, B. T.; Paige, D. A.; Camacho, J. M.; Cohen, B. A.; Sellar, G.; Reiter, J.

    2016-01-01

    Recent reflectance data from LRO instruments suggest water ice and other volatiles may be present on the surface in lunar permanentlyshadowed regions, though the detection is not yet definitive. Understanding the composition, quantity, distribution, and form of water and other volatiles associated with lunar permanently shadowed regions (PSRs) is identified as a NASA Strategic Knowledge Gap (SKG) for Human Exploration. These polar volatile deposits are also scientifically interesting, having the potential to reveal important information about the delivery of water to the Earth- Moon system.

  16. Ice Runways Near the South Pole

    DTIC Science & Technology

    1989-06-01

    further trial landings. A 1000-gallon fuel cache was, however, placed by LC-130 beside Lhasa Nunatak and this proved a great help for flights in connection...obstructions were too short. Site 11: Davis Nunataks (Plunket Point map sheet) 85037’S, 167001 E, elevation 2400 m (7900 ft), TMA 775 F33 122. The main...could be found to permanent building sites on adjacent nunataks . The upper part of Reedy Glacier is badly crevassed, so it would not be easy to establish

  17. Economic Analysis of the South Pole Traverse

    DTIC Science & Technology

    2014-05-29

    will use $36M as the average for 2008–11, the sea - sons of interest here. This represents $14,400 per on-continent flying hour (Table 3). Table 3...passenger flights by Bassler and Twin Otter aircraft notwithstanding). Identifying and apportioning these airfield costs would require substantial

  18. Lunar Flashlight: Illuminating the Moon's South Pole

    NASA Technical Reports Server (NTRS)

    Hayne, P. O.; Cohen, B. A.; Greenhagen, B. T.; Paige, D. A.; Camacho, J. M.; Sellar, R. G.; Reiter, J.

    2016-01-01

    Recent reflectance data from LRO instruments suggest water ice and other volatiles may be present on the surface in lunar permanently shadowed regions, though the detection is not yet definitive. Understanding the composition, quantity, distribution, and form of water and other volatiles associated with lunar permanently shadowed regions (PSRs) is identified as a NASA Strategic Knowledge Gap (SKG) for Human Exploration. These polar volatile deposits are also scientifically interesting, having the potential to reveal important information about the delivery of water to the Earth-Moon system.

  19. GRAND MINIMA AND NORTH-SOUTH ASYMMETRY OF SOLAR ACTIVITY

    SciTech Connect

    Olemskoy, S. V.; Kitchatinov, L. L.

    2013-11-01

    A solar-type dynamo model in a spherical shell is developed with allowance for random dependence of the poloidal field generation mechanism on time and latitude. The model shows repeatable epochs of a strongly decreased amplitude of magnetic cycles similar to the Maunder minimum of solar activity. Random dependence of dynamo parameters on latitude breaks the equatorial symmetry of generated fields. The model shows the correlation of the occurrence of grand minima with deviations in the dynamo field from dipolar parity. An increased north-south asymmetry of magnetic activity can, therefore, be an indicator of transitions to grand minima. Qualitative interpretation of this correlation is suggested. Statistics of grand minima in the model are close to the Poisson random process, indicating that the onset of a grand minimum is statistically independent of preceding minima.

  20. Analysis of Sunyaev-Zel'dovich effect mass-observable relations using South Pole Telescope observations of an X-ray selected sample of low-mass galaxy clusters and groups

    SciTech Connect

    Liu, J.; Mohr, J.; Saro, A.; Aird, K. A.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Foley, R. J.; Gangkofner, D.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hennig, C.; Hlavacek-Larrondo, J.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Luong-Van, D.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Story, K.;  uhada, R.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-02-25

    We use microwave observations from the South Pole Telescope (SPT) to examine the Sunyaev–Zel'dovich effect (SZE) signatures of a sample of 46 X-ray selected groups and clusters drawn from ~6 deg2 of the XMM–Newton Blanco Cosmology Survey. These systems extend to redshift z = 1.02 and probe the SZE signal to the lowest X-ray luminosities (≥1042 erg s-1) yet; these sample characteristics make this analysis complementary to previous studies. We develop an analysis tool, using X-ray luminosity as a mass proxy, to extract selection-bias-corrected constraints on the SZE significance and Y_500 mass relations. The former is in good agreement with an extrapolation of the relation obtained from high-mass clusters. However, the latter, at low masses, while in good agreement with the extrapolation from the high-mass SPT clusters, is in tension at 2.8σ with the Planck constraints, indicating the low-mass systems exhibit lower SZE signatures in the SPT data. We also present an analysis of potential sources of contamination. For the radio galaxy point source population, we find 18 of our systems have 843 MHz Sydney University Molonglo Sky Survey sources within 2 arcmin of the X-ray centre, and three of these are also detected at significance >4 by SPT. Of these three, two are associated with the group brightest cluster galaxies, and the third is likely an unassociated quasar candidate. We examine the impact of these point sources on our SZE scaling relation analyses and find no evidence of biases. We also examine the impact of dusty galaxies using constraints from the 220 GHz data. The stacked sample provides 2.8σ significant evidence of dusty galaxy flux, which would correspond to an average underestimate of the SPT Y_500 signal that is (17 ± 9)per cent in this sample of low-mass systems. Finally, we explore the impact of future data from SPTpol and XMM-XXL, showing that it will lead to a factor of 4 to 5 tighter constraints on

  1. Six pole/eight pole single-phase motor

    DOEpatents

    Kirschbaum, Herbert S.

    1984-01-01

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups which are connected to form eight poles for eight-pole operation and to form six poles for six-pole operation. Each group contains four series connected coil elements with each element spanning approximately one-seventh of the periphery of the machine. The coil groups are spaced 180 mechanical degrees apart such that each end coil of one group overlaps one of the end coils of the other group. An auxiliary stator winding having two coil groups with the same relative angular displacement as the main stator winding coil groups is included.

  2. Periodically poled silicon

    NASA Astrophysics Data System (ADS)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

    2010-02-01

    Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

  3. Moon - North Pole

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This view of the north polar region of the Moon was obtained by Galileo's camera during the spacecraft's flyby of the Earth-Moon system on December 7 and 8, 1992. The north pole is to the lower right of the image. The view in the upper left is toward the horizon across the volcanic lava plains of Mare Imbrium. The prominent crater with the central peak is Pythagoras, an impact crater some 130 kilometers (80 miles) in diameter. The image was taken at a distance of 121,000 kilometers (75,000 miles) from the Moon through the violet filter of Galileo's imaging system. According to team scientists, the viewing geometry provided by the spacecraft's pass over the north pole and the low sun-angle illumination provide a unique opportunity to assess the geologic relationships among the smooth plains, cratered terrain and impact ejecta deposits in this region of the Moon. JPL manages the Galileo Project for NASA's Office of Space Science and Applications.

  4. MODIS Views North Pole

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image over the North Pole was acquired by the MODerate-resolution Imaging Spectroradiometer (MODIS), flying aboard the Terra spacecraft, on May 5, 2000. The scene was received and processed by Norway's MODIS Direct Broadcast data receiving station, located in Svalbard, within seconds of photons hitting the sensor's detectors. (Click for more details about MODIS Direct Broadcast data.) In this image, the sea ice appears white and areas of open water, or recently refrozen sea surface, appear black. The irregular whitish shapes toward the bottom of the image are clouds, which are often difficult to distinguish from the white Arctic surface. Notice the considerable number of cracks, or 'leads,' in the ice that appear as dark networks of lines. Throughout the region within the Arctic Circle leads are continually opening and closing due to the direction and intensity of shifting wind and ocean currents. Leads are particularly common during the summer, when temperatures are higher and the ice is thinner. In this image, each pixel is one square kilometer. Such true-color views of the North Pole are quite rare, as most of the time much of the region within the Arctic Circle is cloaked in clouds. Image by Allen Lunsford, NASA GSFC Direct Readout Laboratory; Data courtesy Tromso receiving station, Svalbard, Norway

  5. Formation of a Bright Polar Hood over the Summer North Pole of Saturn in 2016

    NASA Astrophysics Data System (ADS)

    Sayanagi, Kunio M.; Blalock, John J.; Ingersoll, Andrew P.; Dyudina, Ulyana A.; Ewald, Shawn P.

    2016-10-01

    We report that a bright polar hood has formed over the north pole of Saturn, seen first in images captured by the Cassini ISS camera in 2016. When the north pole was observed during the previous period of Cassini spacecraft's high-inclination orbits in 2012-2013, the concentration of light-scattering aerosols within 2-degree latitude of the north pole appeared to be less than that of the surrounding region, and appeared as a dark hole in all ISS filters, in particular in the shorter wavelength filters BL1 (460 nm), and VIO (420 nm). The north pole's appearance in 2012 was in contrast to that of the south pole in 2007, when the south pole had a bright polar hood in those short wavelengths; the south pole appeared dark in all other ISS filters in 2007. The difference between the south pole in 2007 and the north pole in 2012 was interpreted to be seasonal; in 2007, Saturn was approaching the equinox of 2009 and the south pole had been continuously illuminated since the previous equinox in 1995. In 2012, the north pole had been illuminated for only ~3 years after the long winter polar night. The bright hood over the summer south pole in 2007 was hypothesized to consist of aerosols produced by ultraviolet photodissociation of hydrocarbon molecules. Fletcher et al (2015) predicted that a similar bright hood should form over the north pole as Saturn approaches the 2017 solstice. In 2016, the Cassini spacecraft raised its orbital inclination again in preparation for its Grande Finale phase of the mission, from where it has a good view of the north pole. New images captured in 2016 show that the north pole has developed a bright polar hood. We present new images of the north polar region captured in 2016 that show the north pole, and other seasonally evolving high-latitude features including the northern hexagon. Our research has been supported by the Cassini Project, NASA grants OPR NNX11AM45G, CDAPS NNX15AD33G PATM NNX14AK07G, and NSF grant AAG 1212216.

  6. Albedo of Permanently Shadowed Regions of the Lunar Poles

    NASA Astrophysics Data System (ADS)

    Riner, M. A.; Lucey, P. G.; Bussey, B.; Cahill, J. T.; McGovern, A.

    2012-12-01

    Due to the slight tilt in the Moon's spin axis, some topographic depressions near the lunar poles experience permanent shadow and may serve as cold traps, harboring water ice and/or other volatile compounds [1]. Permanently shadowed regions (PSRs) provide an opportunity toward understanding the amount, nature and transport of volatiles on the Moon and may also be a potential resource for human exploration. While many different data sets have suggested the presence of water ice in PSRs near the lunar poles many questions remain. For example, ice does not appear to be uniformly distributed across identified PSRs. More work is needed to understand the distribution of ice in PSRs and how delivery and retention mechanisms influence the distribution. The active illumination of the Lunar Orbiter Laser Altimeter (LOLA) provides a unique contribution toward exploration PSR exploration. While LOLA is principally a laser altimeter used for quantitative topography and related cartographic and geodetic applications [2], LOLA also measures the intensity and width of the return laser pulse (1064 nm) from the surface. Here we use a global mosaic (4 pixels per degree) of LOLA albedo data corrected for instrumental drift, irregular variations, and calibrated to normal albedo using local equatorial measurements of normal albedo obtained by the Kaguya Multiband Imager [3]. Recent work using LOLA albedo shows the floor of Shackleton crater, near the lunar south pole, is brighter than the surrounding terrain (and the interior of nearby craters) at 1064 nm [4]. This albedo difference may be due to decreased space weathering due to shadowing from the Sun or to a 1 μm thick layer with 20% water ice a the surface of the crater floor [4]. Here we use LOLA dayside reflectance measurements to examine the albedo of PSRs catalogued by [5] derived from illumination modeling of a hybrid 100 m/pixel LOLA-LROC digital terrain model (DTM) up to 83° north and south latitudes. The upper latitude

  7. Active overbank deposition during the last century, South River, Virginia

    NASA Astrophysics Data System (ADS)

    Pizzuto, Jim; Skalak, Katherine; Pearson, Adam; Benthem, Adam

    2016-03-01

    We quantify rates of overbank deposition over decadal to centennial timescales along the South River in Virginia using four independent methods. Detailed mercury profiles sampled adjacent to the stream channel preserve the peak historic mercury concentration on suspended sediment dating from 1955 to 1961 and suggest sedimentation rates of 8 to 50 cm/100 years. Sediment accumulation over the roots of trees suggest rates of 0 to 100 cm/100 years, with significantly higher values on levees and lower values on floodplains farther from the channel. Profiles of 137Cs and 210Pb from two eroding streambanks are fit with an advection-diffusion model calibrated at an upland reference site; these methods suggest sedimentation rates of 44 to 73 cm/100 years. Mercury inventories from 107 floodplain cores, combined with a previously published reconstruction of the history of mercury concentration on suspended sediment, provide spatially comprehensive estimates of floodplain sedimentation: median sedimentation rates are 3.8 cm/100 years for the < 0.3-year floodplain, 1.37 cm/100 years for the 0.3- to 2-year floodplain, 0.4 cm/100 years for the 2- to 5-year floodplain, and 0.1 cm/100 years for the 5- to 62-year floodplain. While these sedimentation rates are relatively low, the total mass of sediment stored from 1930 to 2007 is 4.9 ± 1.7 (95% confidence interval) × 107 kg, corresponding to an average thickness of 2.5 cm (3.2 cm/100 years). These results demonstrate that floodplains of our 4.5-km-long study reach have stored 8 to 12% of the total suspended sediment supplied to the study reach of the South River. Hydrologic Engineering Center-River Analysis System (HEC-RAS) modeling demonstrates that the floodplain of the South River remains hydraulically connected to the channel: 56% of the 100-year floodplain is inundated every two years, and 83% of the floodplain is inundated every five years. These results, combined with previously published data, provide the basis for a

  8. Posterior pole tumor update.

    PubMed

    Ou, Judy I; Wheeler, Sharon M; O'Brien, Joan M

    2002-12-01

    This chapter focuses on the diagnosis and management of choroidal melanoma in light of recent findings from the COMS. Retinoblastoma is emphasized to describe recent trends in primary treatment away from EBRT and toward chemoreduction with local therapy. In addition, vascular and glial tumors of the retina and tumors of the retinal pigment epithelium are described because of the association between these lesions and systemic disease. Recent advances in treatment and genetic testing for these diseases are discussed. Finally, ocular metastasis, intraocular lymphoid tumors, and intraocular leukemia are included because of their importance in determining systemic treatment and prognosis. The chapter gives an overview of important posterior pole tumors and highlights recent developments in the management of each intraocular disease process.

  9. Detail of double pole utility tower at the edge of ...

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

    Detail of double pole utility tower at the edge of the mesa. National Old Trails Road right-of-way crosses in foreground over a dry laid basaltic rock retaining wall. View south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  10. Longer life for wood poles

    SciTech Connect

    Hopkinson, J.; Tackaberry, R.

    1982-11-01

    Investigates the use of liquid fumigants on in-service wooden utility poles in order to prevent decay. Reveals that although utility poles are pressure-treated with chemicals before they go into service as supports for transmission and distribution lines, they are frequently invaded by one or more of 225 species of fungus. Indicates that while the average service life of poles is 15-25 yrs, retreatment with fumigants may extend it to 35-40 yrs. Discusses trees and treatment, fungi, pole inspection, and fumigation. Points out that the Bonneville Power Administration estimates that it can save $2.2 million per year by retreating 15,000 poles instead of having to replace 1500 of them per year for 10 yrs. Reports that research results on decay and fumigation have helped more than 160 electric utilities who are using the fumigants. Concludes that although some decay-prone areas in poles, such as seasoning checks and woodpecker holes, will continue to invite the fungal menace, the increasing effort to inspect and fumigate poles on a large scale will ensure safer and more reliable power lines, while eliminating much of the conventional expenditure on replacing decayed poles.

  11. English Language Proficiency and Physical Activity among Mexican-Origin Women in South Texas and South Carolina

    PubMed Central

    Salinas, Jennifer J.; Hilfinger Messias, DeAnne K.; Morales-Campos, Daisy; Parra-Medina, Deborah

    2015-01-01

    Objectives To examine the relationship between English language proficiency (ELP), physical activity and physical activity-related psychosocial measures (i.e. exercise self-efficacy, exercise social support, perceptions of environmental supports) among Mexican-origin women in South Carolina and Texas. Design Adjusted robust regression and interaction modeling to evaluate baseline questionnaire data on self-reported ELP with CHAMPS leisure-time moderate-to-vigorous physical activity (MVPA), accelerometry data, Physical Activity Self-Efficacy, Physical Activity Social Support and Environmental Support for Physical Activity in 118 Mexican-origin women. Results The adjusted regression revealed a significant association between ELP and perceived physical activity self-efficacy (β= 234.2, p=.004), but not with physical activity social support. In South Carolina, CHAMPS leisure-time MVPA (411.4 versus 114.3 minutes, p<.05) was significantly different between women in the high ELP quartile and those in the very low quartile. Among high ELP Mexican-origin women, participants in Texas reported significantly higher MVPA measured by accelerometry (p=.042) than those in South Carolina. Conclusion Our findings indicate that ELP was associated with physical activity and that contextual factors may also play a role. PMID:24509031

  12. The polarization of the G-protein activated potassium channel GIRK5 to the vegetal pole of Xenopus laevis oocytes is driven by a di-leucine motif.

    PubMed

    Díaz-Bello, Beatriz; Rangel-García, Claudia I; Salvador, Carolina; Carrisoza-Gaytán, Rolando; Escobar, Laura I

    2013-01-01

    The G protein-coupled inwardly-rectifying potassium channels (known as GIRK or Kir3) form functional heterotetramers gated by G-βγ subunits. GIRK channels participate in heart rate modulation and neuronal postsynaptic inhibition in mammals. In Xenopus laevis oocytes, GIRK5 is a functional homomultimer. Previously, we found that phosphorylation of a tyrosine (Y16) at its N-terminus downregulates the surface expression of GIRK5. In this work, we elucidated the subcellular localization and trafficking of GIRK5 in oocytes. Several EGFP-GIRK5 chimeras were produced and an ECFP construct was used to identify the endoplasmic reticulum (ER). Whereas GIRK5-WT was retained in the ER at the animal pole, the phospho-null GIRK5-Y16A was localized to the vegetal pole. Interestingly, a construct with an N-terminal Δ25 deletion produced an even distribution of the channel in the whole oocyte. Through an alanine-scan, we identified an acidic cluster/di-leucine sorting-signal recognition motif between E17 and I22. We quantified the effect of each amino acid residue within this di-leucine motif in determining the distribution of GIRK5 to the animal and vegetal poles. We found that Y16 and I22 contributed to functional expression and were dominant in the polarization of GIRK5. We thus conclude that the N-terminal acidic di-leucine motif of GIRK5 determines its retention and polarized trafficking within Xl oocytes.

  13. Third Pole Environment (TPE) -Latest Progress

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Yao, T.; Zhang, F.; Yang, X.; Wang, W.; Ping, F.

    2014-12-01

    Centered on the Tibetan Plateau, the Third Pole region is a unique geographical unit, which represents one of the largest ice masses on the Earth. The region has great impacts on environmental changes in China, the Northern Hemisphere and the globe.It also demonstrates sensitive feedbacks to global changes and the impacts of anthropogenic activities in surrounding regions. Like the Arctic and Antarctica, the Third Pole region is an especially sensitive area that draws great attention from the scientific community. In 2009, with support from the Chinese Academy of Sciences and international organizations, the Third Pole Environment (TPE) program, led by Chinese scientists, was officially launched. The program focuses on the theme of "water-ice-air-ecosystem-human" interactions, with the aim to address the following scientific questions, such as the spatial and temporal characteristics of past environmental changes in the Third pole, the interactions between hydrosphere and cryosphere and hazard processes, the ecological systems' impacts on and response to environmental changes, and the impacts of anthropogenic activities on environmental changes in the region and adaptation strategies. The goal of the program is to reveal environmental change processes and mechanisms on the Third Pole and their influences on and responses to global changes, and thus to serve for enhancement of human adaptation to the changing environment and realization of human-nature harmony. Under the leadership of the co-chairs, and relying on Scientific Committee and the TPE office, the program has accomplished a number of scientific tasks since its inauguration. TPE has made tremendous progress in the research of glacier changes, interactions between the westerlies and monsoon, establishment of field stations, data sharing and education.

  14. On the properties of faculae at the poles of the Sun

    NASA Astrophysics Data System (ADS)

    Blanco Rodríguez, J.; Okunev, O. V.; Puschmann, K. G.; Kneer, F.; Sánchez-Andrade Nuño, B.

    2007-10-01

    Context: Faculae at the poles of the Sun, or polar faculae (PFe), take part in the solar magnetic cycle. Their occurrence maximum is shifted by 5-6 years with respect to the sunspot cycle. PFe are stable phenomena, with lifetimes of several hours to days, and harbour magnetic fields of kilo-Gauss strength. Yet their role for the global magnetic field at the solar poles is unknown. Aims: To contribute to the knowledge of the physical properties of PFe and to the understanding of their role in the global magnetism of the Sun. Methods: PFe were observed on 21-24 August 2005 with the Vacuum Tower Telescope at the Observatorio del Teide. The “Göttingen” Fabry-Perot spectrometer was used with a Stokes V polarimeter to scan the Fe i 6173 Å line (Landé factor g = 2.5) and the Hα line in two-dimensional fields of view (FOVs). A large observational coverage of the polar caps was obtained. The data were analysed with speckle methods. Magnetic field strengths were determined with the weak field approximation, with the approximation of the strong field regime, and with the centre of gravity (COG) method. Velocities were measured with the COG method and from the zero-crossing of the Stokes V profiles. Results: PFe show a decrease of the continuum and broadband intensity contrast towards the disc centre and no decrease of contrast towards the limb, similar to as faculae in active regions near the equator. Extrapolating from the observed FOVs to the total areas of PF occurrence around the solar poles, we find 4 120 PFe in the northern polar cap and, asymmetrically to this number, 1 250 PFe near the south pole. The total area coverages by PFe are ~7.6×108 km2 and ~3.4×108 km2 near the solar north and south poles, respectively. Some of the PFe exhibit magnetic polarities opposite to the global polarity at the time of observation. The resulting total magnetic fluxes in PFe fall short by an order of magnitude from those found in the literature for the fluxes at the polar

  15. Lightweight extendable and retractable pole

    DOEpatents

    Warren, J.L.; Brandt, J.E.

    1994-08-02

    A lightweight extendable and retractable telescopic pole is disclosed comprising a plurality of non-metallic telescoping cylinders with sliding and sealing surfaces between the cylinders, a first plug member on the upper end of the smallest cylinder, and a second plug member on the lower end of the largest cylinder, whereby fluid pressure admitted to the largest cylinder will cause the telescoping cylinders to slide relative to one another causing the pole to extend. An elastomeric member connects the first plug member with one of the intermediate cylinders to urge the cylinders back into a collapsed position when the fluid pressure in the cylinders is vented. Annular elastomer members are provided which seal one cylinder to another when the pole is fully extended and further serve to provide a cushion to prevent damage to the cylinders when the pole is urged back into its retractable position by the elastomeric members and the venting of the pressure. A value mechanism associated with the pole is provided to admit a fluid under pressure to the interior of the telescoping cylinders of the pole while pressurizing a pressure relief port having an opening larger than the inlet port in a closed position whereby removal of the pressure on the relief port will cause the relief port to open to quickly lower the pressure in the interior of the telescoping cylinders to thereby assist in the rapid retraction of the extended pole. 18 figs.

  16. Lightweight extendable and retractable pole

    DOEpatents

    Warren, John L.; Brandt, James E.

    1994-01-01

    A lightweight extendable and retractable telescopic pole is disclosed comprising a plurality of non-metallic telescoping cylinders with sliding and sealing surfaces between the cylinders, a first plug member on the upper end of the smallest cylinder, and a second plug member on the lower end of the largest cylinder, whereby fluid pressure admitted to the largest cylinder will cause the telescoping cylinders to slide relative to one another causing the pole to extend. An elastomeric member connects the first plug member with one of the intermediate cylinders to urge the cylinders back into a collapsed position when the fluid pressure in the cylinders is vented. Annular elastomer members are provided which seal one cylinder to another when the pole is fully extended and further serve to provide a cushion to prevent damage to the cylinders when the pole is urged back into its retractable position by the elastomeric members and the venting of the pressure. A value mechanism associated with the pole is provided to admit a fluid under pressure to the interior of the telescoping cylinders of the pole while pressurizing a pressure relief port having an opening larger than the inlet port in a closed position whereby removal of the pressure on the relief port will cause the relief port to open to quickly lower the pressure in the interior of the telescoping cylinders to thereby assist in the rapid retraction of the extended pole.

  17. Recycling of treated wood poles

    SciTech Connect

    Fansham, P.

    1995-11-01

    There are approximately 150 million utilities poles in service in North America. Of the 3 million poles removed from service each year, many poles still contain a sound and structurally intact core and only the outer layer has deteriorated. Since most of the old poles are treated with either pentachlorophenol or creosote there are limited disposal options available to pole users. The practice of giving old poles away to farmers or other interested parties in falling into disfavour since this practice does not absolve the utility of the environmental liability associated with the treated wood. TWT has commercialised a thermolysis (Pyrolysis) based process capable of removing oil based preservatives from treated wood. The patented process involves: the shaving of the weathered pole exterior; the rapid distillation of oil based preservatives in an oxygen depleted environment; condensation of the vapours; and separation of liquids. TWT has constructed a 30,000 pole per year facility east of Calgary and has provided recycled poles for the construction of two power lines now in use by TransAlta Utilities Corporation, Canada`s largest investor owned electric utility. TWT has tested two thermolysis (Pyrolysis) technologies and has determined that contact thermolysis using a heated auger design performed better and with less plugging than a fast fluid bed reactor. The fluid bed reactor is prone to coke formation and contamination of the oil by fine char particles. Residual PCP concentration in the shavings was reduced from 9500 ppm to 10 ppm. Leachate testing on the char yielded a PCP concentration of 1.43 ppm in the Leachate, well below the EPA standard maximum of 100 ppm.

  18. Six pole/eight pole single-phase motor

    DOEpatents

    Kirschbaum, H.S.

    1984-07-31

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups which are connected to form eight poles for eight-pole operation and to form six poles for six-pole operation. Each group contains four series connected coil elements with each element spanning approximately one-seventh of the periphery of the machine. The coil groups are spaced 180 mechanical degrees apart such that each end coil of one group overlaps one of the end coils of the other group. An auxiliary stator winding having two coil groups with the same relative angular displacement as the main stator winding coil groups is included. 10 figs.

  19. Enhanced complement activation is part of the unfavourable cardiovascular risk profile in South Asians

    PubMed Central

    Siezenga, M A; Chandie Shaw, P K; van der Geest, R N; Mollnes, T E; Daha, M R; Rabelink, T J; Berger, S P

    2009-01-01

    South Asian immigrants in western societies exhibit a high burden of diabetes and subsequent vascular complications. Diabetic vascular complications are associated with vascular inflammation. We hypothesize that enhanced complement activation is involved. Therefore, levels of complement C3 and SC5b-9 – the soluble end product of complement activation – in a group of 200 South Asians were compared with an age- and sex-matched control group of native Caucasians. In addition, the association between complement levels and albuminuria, an indicator of renal damage and a cardiovascular risk marker, was assessed in the diabetic South Asian group. Compared with native Caucasians, South Asians had significantly higher levels of both serum C3 and plasma SC5b-9, even when only non-diabetic South Asians were considered. Diabetic South Asians had significantly higher C3 levels compared with non-diabetic South Asians. In diabetic South Asians, higher levels of SC5b-9 were associated with an increased prevalence of albuminuria (odds ratio 5·4, 95% confidence interval 1·8–15·8). These results suggest that enhanced complement activation is part of the unfavourable cardiovascular risk profile in South Asians. PMID:19659775

  20. Is it possible to reduce the knee joint compression force during level walking with hiking poles?

    PubMed

    Jensen, S B; Henriksen, M; Aaboe, J; Hansen, L; Simonsen, E B; Alkjaer, T

    2011-12-01

    Walking with hiking poles has become a popular way of exercising. Walking with poles is advocated as a physical activity that significantly reduces the loading of the hip, knee and ankle joints. We have previously observed that pole walking does not lead to a reduction of the load on the knee joint. However, it is unclear whether an increased force transmitted through the poles can reduce the load on the knee joint. Thus, the purpose of the present study was to investigate if an increased load transmitted through the arms to the poles could reduce the knee joint compression force during level walking with poles. We hypothesized that an increased pole force would result in a reduction of the knee joint compression force. Gait analyses from 10 healthy subjects walking with poles were obtained. The pole force was measured simultaneously during the gait analyses. The knee joint compression forces were estimated by using a biomechanical knee joint model. The results showed that the subjects were able to increase the pole force by 2.4 times the normal pole force. However, this did not lead to a reduction in the knee joint compressive force and we rejected our hypothesis. In conclusion, the use of poles during level walking does not seem to reduce knee joint compressive loads. However, it is possible that the use of poles in other populations (e.g. osteoarthritis patients) and in terrain would unload the knee joint. This should be investigated in the future.

  1. Synchronized Lunar Pole Impact Plume Sample Return Trajectory Design

    NASA Technical Reports Server (NTRS)

    Genova, Anthony L.; Foster, Cyrus; Colaprete, Tony

    2016-01-01

    The presented trajectory design enables two maneuverable spacecraft launched onto the same trans-lunar injection trajectory to coordinate a steep impact of a lunar pole and subsequent sample return of the ejecta plume to Earth. To demonstrate this concept, the impactor is assumed to use the LCROSS missions trajectory and spacecraft architecture, thus the permanently-shadowed Cabeus crater on the lunar south pole is assumed as the impact site. The sample-return spacecraft is assumed to be a CubeSat that requires a complimentary trajectory design that avoids lunar impact after passing through the ejecta plume to enable sample-return to Earth via atmospheric entry.

  2. Paleo-Pole Positions from Martian Magnetic Anomaly Data

    NASA Technical Reports Server (NTRS)

    Taylor, Patrick T.; Frawley, James J.

    2003-01-01

    Magnetic component anomaly maps were made from five mapping cycles of the Mars Global Surveyor s magnetometer data. Our goal was to find and isolate positive and negative anomaly pairs which would indicate magnetization of a single source body. From these anomalies we could compute the direction of the magnetizing vector and subsequently the location of the magnetic pole existing at the time of magnetization. We found nine suitable anomaly pairs and from these we computed four North and 3 South poles with two at approximately 60 degrees north latitude. These results suggest that during the existence of the Martian main magnetic field it experienced several reversals.

  3. Paleo-Pole Positions from Martian Magnetic Anomaly Data

    NASA Technical Reports Server (NTRS)

    Frawley, James J.; Taylor, Patrick T.

    2004-01-01

    Magnetic component anomaly maps were made from five mapping cycles of the Mars Global Surveyor's magnetometer data. Our goal was to find and isolate positive and negative anomaly pairs which would indicate magnetization of a single source body. From these anomalies we could compute the direction of the magnetizing vector and subsequently the location of the magnetic pole existing at the time of magnetization. We found nine suitable anomaly pairs and from these we computed paleo-poles that were nearly equally divided between north, south and mid-latitudes. These results suggest that during the existence of the martian main magnetic field it experienced several reversals and excursions.

  4. Metabolic activity of subseafloor microbes in the South Pacific Gyre

    NASA Astrophysics Data System (ADS)

    Morono, Y.; Ito, M.; Terada, T.; Inagaki, F.

    2013-12-01

    The South Pacific Gyre (SPG) is characterized as the most oligotrophic open ocean environment. The sediment is rich in oxygen but poor in energy-sources such as reduced organic matter, and hence harbors very low numbers of microbial cells in relatively shallow subseafloor sediment (D'Hondt et al., 2009; Kallmeyer et al., 2012). In such an energy-limited sedimentary habitat, a small size of microbial community persists living functions with extraordinary low oxygen-consumption rate (Røy et al., 2012). During IODP Expedition 329, a series of sediment samples were successfully recovered from 7 drill sites (U1365-1371) from the seafloor to basement in the SPG, providing an unprecedented opportunity to study metabolic activity of the aerobic subseafloor microbial communities. We initiated incubation onboard by adding stable isotope-labeled substrates to the freshly collected sediment sample, such as 13C and/or 15N-labeled bicarbonate, glucose, amino acids, acetate, and ammonium under the (micro-) aerobic condition. One of the technological challenges in this study is to harvest microbial cells from very low-biomass sediment samples for the analysis using nano-scale secondary ion mass spectrometry (NanoSIMS). To address the technical issue, we improved existing cell separation technique for the SPG sediment samples with small inorganic zeolitic grains. By monitoring cell recovery rates through an image-based cell enumeration technique (Morono et al., 2009), we found that cell recovery rates in the SPG sediment samples are generally lower than those in other oceanographic settings (i.e., organic-rich ocean margin sediments). To gain higher cell recovery ratio, we applied multiple density gradient layers, resulting in the cell recovery ratio up to around 80-95% (Morono et al., in press). Then, using the newly developed cell separation technique, we successfully sorted enough number of microbial cells in small spots on the membrane (i.e., 103 to 105 cells per spot). Nano

  5. Gamma Oscillations in the Temporal Pole in Response to Eyes

    PubMed Central

    Uono, Shota; Matsuda, Kazumi; Usui, Keiko; Usui, Naotaka; Inoue, Yushi; Toichi, Motomi

    2016-01-01

    The eyes of an individual act as an indispensable communication medium during human social interactions. Functional neuroimaging studies have revealed that several brain regions are activated in response to eyes and eye gaze direction changes. However, it remains unclear whether the temporal pole is one of these regions. Furthermore, if the temporal pole is activated by these stimuli, the timing and manner in which it is activated also remain unclear. To investigate these issues, we analyzed intracranial electroencephalographic data from the temporal pole that were obtained during the presentation of eyes and mosaics in averted or straight directions and their directional changes. Time–frequency statistical parametric mapping analyses revealed that the bilateral temporal poles exhibited greater gamma-band activation beginning at 215 ms in response to eyes compared with mosaics, irrespective of the direction. Additionally, the right temporal pole showed greater gamma-band activation beginning at 197 ms in response to directional changes of the eyes compared with mosaics. These results suggest that gamma-band oscillations in the temporal pole were involved in the processing of the presence of eyes and changes in eye gaze direction at a relatively late temporal stage compared with the posterior cortices. PMID:27571204

  6. Present Day Activity of South Polar Gullies on Mars

    NASA Astrophysics Data System (ADS)

    Raack, J.; Reiss, D.; Ruesch, O.; Hiesinger, H.

    2012-04-01

    Here we report on clearly identified seasonal changes of gullies observed within the last two martian years (MY) on slopes of a south polar pit, which is located in a filled crater (diameter ~54 km) north of Sisyphi Cavi at ~68.5°S and ~1.5°E. Using new high-resolution imaging (High Resolution Imaging Science Experiment, HiRISE), temperature (Thermal Emission Spectrometer, TES) and spectral data (Compact Reconnaissance Imaging Spectrometer for Mars, CRISM; Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité, OMEGA), we analyzed the exact timing of changes of gullies and detect the possible medium (CO2, H2O or dry) and mechanism which initiate present day gully activity. Two locations in the study region with clear modifications of gullies were identified in MY 29 between LS 226° and LS 247° and between LS 209° and LS 247°. In MY 30 changes occur in both locations between LS 218° and LS 249°. Modifications are the formation of a new small apron and new deposits within the channel, both associated with the deposition of dark material. Erosion in gully alcoves or channels was not observed. TES data show temperatures between ~180 and ~240 K within the period of gully modifications. Maximum temperatures in the region rise up to ~285 K between LS ~270° and ~310°. Spectral data show a CO2-cover of the study region until LS 227°. CO2-ice free surface are spectrally observed for the first time at LS 249°. H2O was not spectrally detected in the study region and a mixture of CO2 and H2O as presented in [1] cannot be clearly detected. Unfortunately, there are no spectral data available between LS 227° and 249°. Modifications of gullies imply seasonal volatile activity. The activity can be narrowed down to occur between LS 226° and 247° at mean temperatures between ~180 and ~240 K. This is in the range of temperatures where CO2 sublimates back into the atmosphere. Based on the temperature range, the most likely candidate for the observed new

  7. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    PubMed

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.

  8. The science of the lunar poles

    NASA Astrophysics Data System (ADS)

    Lucey, P. G.

    2011-12-01

    imaging of interiors of polar shadowed craters has been accomplished by many instruments from the ultraviolet to the radar. Imaging radars on Chandrayaan-1 and LRO have identified anomalous craters that may contain rich water ice deposits. Neutron spectrometers on Lunar Prospector and LRO directly detected hydrogen enhancements at both poles. Spectacularly, the LCROSS impact experiment detected a wide range of volatile elements and species at Cabeus crater in the lunar south polar region. While these measurements have catapulted polar science forward, much remains to be understood about the polar system, both from analysis of the current data, and new missions planned and in development. The general state of the lunar atmosphere is planned to be addressed by the UV and neutral mass spectrometers carried by the planned NASA LADEE (Lunar Atmosphere And Dust Environment Explorer) spacecraft creating an important baseline. But more data is necessary, from an in situ direct assay of polar volatiles to measurements of species and fluxes into and out of the cold traps over lengthy timescales.

  9. Single phase four pole/six pole motor

    DOEpatents

    Kirschbaum, Herbert S.

    1984-01-01

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils.

  10. Single phase four pole/six pole motor

    DOEpatents

    Kirschbaum, H.S.

    1984-10-09

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils. 10 figs.

  11. Low loss pole configuration for multi-pole homopolar magnetic bearings

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A. (Inventor); Hakun, Claef F. (Inventor)

    2001-01-01

    A new pole configuration for multi-pole homopolar bearings proposed in this invention reduces rotational losses caused by eddy-currents generated when non-uniform flux distributions exist along the rotor surfaces. The new homopolar magnetic bearing includes a stator with reduced pole-to-pole and exhibits a much more uniform rotor flux than with large pole-to-pole gaps. A pole feature called a pole-link is incorporated into the low-loss poles to provide a uniform pole-to-pole gap and a controlled path for pole-to-pole flux. In order to implement the low-loss pole configuration of magnetic bearings with small pole-to-pole gaps, a new stator configuration was developed to facilitate installation of coil windings. The stator was divided into sector shaped pieces, as many pieces as there are poles. Each sector-shaped pole-piece can be wound on a standard coil winding machine, and it is practical to wind precision layer wound coils. To achieve maximum actuation efficiency, it is desirable to use all the available space for the coil formed by the natural geometric configuration. Then, the coils can be wound in a tapered shape. After winding, the sectored-pole-pieces are installed into and fastened by bonding or other means, to a ring of material which encloses the sectored-pole-pieces, forming a complete stator.

  12. Daily and seasonal activity patterns of free range South-American rattlesnake (Crotalus durissus).

    PubMed

    Tozetti, Alexandro M; Martins, Marcio

    2013-09-01

    This study aimed at describing daily and seasonal variation in the activity of a population of South-American rattlesnakes (Crotalus durissus) in a savanna like habitat (Cerrado) in Southeastern Brazil. Seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. Our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of rattlesnakes. Our findings indicate that rattlesnakes spend most of the day resting and most of the night in ambush posture. The South-American rattlesnake is active throughout the year with a discrete peak in activity of males during the matting season. The possibility of maintaining activity levels even during the coldest and driest season can facilitate the colonization of several habitats in South America. This possibility currently facilitates the colonization of deforested areas by rattlesnakes.

  13. Tech Prep. South Dakota Career Activities for the Classroom, 4th Edition, 1998-1999.

    ERIC Educational Resources Information Center

    Kucker, Marsha, Comp.

    This document presents a sampling of projects and activities that have been implemented in Tech Prep training in South Dakota, or will be implemented during the upcoming school year. The projects and activities are categorized into 12 areas: career clusters; career units and activities; curriculum materials; employability skills; entrepreneurship;…

  14. Calligraphic Poling of Ferroelectric Material

    NASA Technical Reports Server (NTRS)

    Mohageg, Makan; Strekalov, Dmitry; Savchenkov, Anatoliy; Matsko, Adrey; Maleki, Lute; Iltchenko, Vladimir

    2007-01-01

    Calligraphic poling is a technique for generating an arbitrary, possibly complex pattern of localized reversal in the direction of permanent polarization in a wafer of LiNbO3 or other ferroelectric material. The technique is so named because it involves a writing process in which a sharp electrode tip is moved across a surface of the wafer to expose the wafer to a polarizing electric field in the desired pattern. The technique is implemented by use of an apparatus, denoted a calligraphic poling machine (CPM), that includes the electrode and other components as described in more detail below.

  15. POLE mutations in families predisposed to cutaneous melanoma.

    PubMed

    Aoude, Lauren G; Heitzer, Ellen; Johansson, Peter; Gartside, Michael; Wadt, Karin; Pritchard, Antonia L; Palmer, Jane M; Symmons, Judith; Gerdes, Anne-Marie; Montgomery, Grant W; Martin, Nicholas G; Tomlinson, Ian; Kearsey, Stephen; Hayward, Nicholas K

    2015-12-01

    Germline mutations in the exonuclease domain of POLE have been shown to predispose to colorectal cancers and adenomas. POLE is an enzyme involved in DNA repair and chromosomal DNA replication. In order to assess whether such mutations might also predispose to cutaneous melanoma, we interrogated whole-genome and exome data from probands of 34 melanoma families lacking pathogenic mutations in known high penetrance melanoma susceptibility genes: CDKN2A, CDK4, BAP1, TERT, POT1, ACD and TERF2IP. We found a novel germline mutation, POLE p.(Trp347Cys), in a 7-case cutaneous melanoma family. Functional assays in S. pombe showed that this mutation led to an increased DNA mutation rate comparable to that seen with a Pol ε mutant with no exonuclease activity. We then performed targeted sequencing of POLE in 1243 cutaneous melanoma cases and found that a further ten probands had novel or rare variants in the exonuclease domain of POLE. Although this frequency is not significantly higher than that in unselected Caucasian controls, we observed multiple cancer types in the melanoma families, suggesting that some germline POLE mutations may predispose to a broad spectrum of cancers, including melanoma. In addition, we found the first mutation outside the exonuclease domain, p.(Gln520Arg), in a family with an extensive history of colorectal cancer.

  16. Knee joint forces during downhill walking with hiking poles.

    PubMed

    Schwameder, H; Roithner, R; Müller, E; Niessen, W; Raschner, C

    1999-12-01

    The aim of this study was to determine external and internal loads on the knee joint during downhill walking with and without hiking poles. Kinematic, kinetic and electromyographic data were collected from eight males during downhill walking on a ramp declined at 25 degrees. Planar knee joint moments and forces were calculated using a quasi-static knee model. The results were analysed for an entire pole-cycle as well as differentiated between single and double support phases and between each step of a pole-cycle. Significant differences between downhill walking with and without hiking poles were observed for peak and average magnitudes of ground reaction force, knee joint moment, and tibiofemoral compressive and shear forces (12-25%). Similar reductions were found in patellofemoral compressive force, the quadriceps tendon force and the activity of the vastus lateralis; however, because of a high variability, these differences were not significant. The reductions seen during downhill walking with hiking poles compared with unsupported downhill walking were caused primarily by the forces applied to the hiking poles and by a change in posture to a more forward leaning position of the upper body, with the effect of reducing the knee moment arm.

  17. Centralising Space: The Physical Education and Physical Activity Experiences of South Asian, Muslim Girls

    ERIC Educational Resources Information Center

    Stride, Annette

    2016-01-01

    This paper explores the physical education (PE) and physical activity experiences of a group of South Asian, Muslim girls, a group typically marginalised in PE and physical activity research. The study responds to ongoing calls for research to explore across different spaces in young people's lives. Specifically, I draw on a…

  18. Effect of habitat and foraging height on bat activity in the coastal plain of South Carolina.

    SciTech Connect

    Menzel, Jennifer, M.; Menzel, Michael A.; Kilgo, John C.; Ford, W. Mark; Edwards, John W.; McCracken, Gary F.

    2005-07-01

    A comparison of bat activity levels in the Coastal Plain of South Carolina among 5 habitat types: forested riparian areas, clearcuts, young pine plantations, mature pine plantations and pine savannas, using time expansion radio-microphones and integrated detectors to simultaneously monitor bat activity at three heights in each habitat type.

  19. 78 FR 52868 - Pole Attachment Complaint Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 1 Pole Attachment Complaint Procedures AGENCY: Federal Communications Commission... regulations concerning pole attachments outlined in the DATES section. DATES: Effective August 27, 2013,...

  20. THE SPITZER-WISE SURVEY OF THE ECLIPTIC POLES

    SciTech Connect

    Jarrett, T. H.; Masci, F.; Cutri, R. M.; Marsh, K.; Padgett, D.; Tsai, C. W.; Cohen, M.; Wright, E.; Petty, S.; Stern, D.; Eisenhardt, P.; Mainzer, A.; Ressler, M.; Benford, D.; Blain, A.; Carey, S.; Surace, J.; Lonsdale, C.; Skrutskie, M.; Stanford, S.

    2011-07-10

    We have carried out a survey of the north and south ecliptic poles, EP-N and EP-S, respectively, with the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer (WISE). The primary objective was to cross-calibrate WISE with the Spitzer and Midcourse Space Experiment (MSX) photometric systems by developing a set of calibration stars that are common to these infrared missions. The ecliptic poles were continuous viewing zones for WISE due to its polar-crossing orbit, making these areas ideal for both absolute and internal calibrations. The Spitzer IRAC and MIPS imaging survey covers a complete area of 0.40 deg{sup 2} for the EP-N and 1.28 deg{sup 2} for the EP-S. WISE observed the whole sky in four mid-infrared bands, 3.4, 4.6, 12, and 22 {mu}m, during its eight-month cryogenic mission, including several hundred ecliptic polar passages; here we report on the highest coverage depths achieved by WISE, an area of {approx}1.5 deg{sup 2} for both poles. Located close to the center of the EP-N, the Sy-2 galaxy NGC 6552 conveniently functions as a standard calibrator to measure the red response of the 22 {mu}m channel of WISE. Observations from Spitzer-IRAC/MIPS/IRS-LL and WISE show that the galaxy has a strong red color in the mid-infrared due to star-formation and the presence of an active galactic nucleus (AGN), while over a baseline >1 year the mid-IR photometry of NGC 6552 is shown to vary at a level less than 2%. Combining NGC 6552 with the standard calibrator stars, the achieved photometric accuracy of the WISE calibration, relative to the Spitzer and MSX systems, is 2.4%, 2.8%, 4.5%, and 5.7% for W1 (3.4 {mu}m), W2 (4.6 {mu}m), W3 (12 {mu}m), and W4 (22 {mu}m), respectively. The WISE photometry is internally stable to better than 0.1% over the cryogenic lifetime of the mission. The secondary objective of the Spitzer-WISE Survey was to explore the poles at greater flux-level depths, exploiting the higher angular resolution Spitzer observations and the

  1. Clouds Over the North Pole

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 29 June 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    Like yesterday's image, the linear 'ripples' are water-ice clouds. As spring is deepening at the North Pole these clouds are becoming more prevalent.

    Image information: VIS instrument. Latitude 68.9, Longitude 135.5 East (224.5 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter

  2. Kick, Glide, Pole! Cross-Country Skiing Fun (Part II)

    ERIC Educational Resources Information Center

    Duoos, Bridget A.

    2012-01-01

    Part I of Kick, Glide, Pole! Cross-Country Skiing Fun, which was published in last issue, discussed how to select cross-country ski equipment, dress for the activity and the biomechanics of the diagonal stride. Part II focuses on teaching the diagonal stride technique and begins with a progression of indoor activities. Incorporating this fun,…

  3. Flavor precursors and sensory-active sulfur compounds in alliaceae species native to South Africa and South America.

    PubMed

    Kubec, Roman; Krejčová, Petra; Mansur, Leví; García, Nicolás

    2013-02-13

    Profiles of S-substituted cysteine flavor precursors were determined in 42 Alliaceae species native to South Africa and South America. It was found that the pool of cysteine derivatives present in these plants is remarkably very simple, with S-((methylthio)methyl)cysteine 4-oxide (marasmin) being the principal flavor precursor, typically accounting for 93-100% of the pool. Out of the other cysteine derivatives, only minor quantities of methiin were present in some species. The marasmin-derived thiosulfinate marasmicin (2,4,5,7-tetrathiaoctane 4-oxide), a major sensory-active compound of the freshly disrupted plants, was isolated, and its organoleptic properties were evaluated. Furthermore, sulfur-containing volatiles formed upon boiling of these alliaceous species were studied by GC-MS. The profile of the volatiles formed was relatively simple, with 2,3,5-trithiahexane and 2,4,5,7-tetrathiaoctane being the major components. Despite the traditional belief, ingestion of the marasmin-rich plants was always accompanied by development of a strong "garlic breath". We believe that especially several Tulbaghia species deserve to attract much greater attention from the food industry thanks to their pungent garlicky taste and unusual yet pleasant alliaceous smell.

  4. The physical activity profiles of South Asian ethnic groups in England

    PubMed Central

    Bhatnagar, Prachi; Townsend, Nick; Shaw, Alison; Foster, Charlie

    2016-01-01

    Background To identify what types of activity contribute to overall physical activity in South Asian ethnic groups and how these vary according to sex and age. We used the White British ethnic group as a comparison. Methods Self-reported physical activity was measured in the Health Survey for England 1999 and 2004, a nationally representative, cross-sectional survey that boosted ethnic minority samples in these years. We merged the two survey years and analysed data from 19 476 adults. The proportions of total physical activity achieved through walking, housework, sports and DIY activity were calculated. We stratified by sex and age group and used analysis of variances to examine differences between ethnic groups, adjusted for the socioeconomic status. Results There was a significant difference between ethnic groups for the contributions of all physical activity domains for those aged below 55 years, with the exception of walking. In women aged 16–34 years, there was no significant difference in the contribution of walking to total physical activity (p=0.38). In the 35–54 age group, Bangladeshi males have the highest proportion of total activity from walking (30%). In those aged over 55 years, the proportion of activity from sports was the lowest in all South Asian ethnic groups for both sexes. Conclusions UK South Asians are more active in some ways that differ, by age and sex, from White British, but are similarly active in other ways. These results can be used to develop targeted population level interventions for increasing physical activity levels in adult UK South Asian populations. PMID:26677257

  5. Development of a multi-pole magnetorheological brake

    NASA Astrophysics Data System (ADS)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-06-01

    This paper presents a new approach in the design and optimization of a novel multi-pole magnetorheological (MR) brake that employs magnetic flux more effectively on the surface of the rotor. MR brakes with conventional single ring-type electromagnetic poles have reached the limits of torque enhancement. One major reason is the limitation of the magnetic field strength within the active area of the MR fluid due to the geometric constraints of the coil. The multi-pole MR brake design features multiple electromagnetic poles surrounded by several coils. As a result, the active chaining areas for the MR fluid are greatly increased, and significant brake torque improvement is achieved. The coil structure, as a part of the stator, becomes flexible and customizable in terms of space usage for the winding and bobbin design. In addition, this brake offers extra options in its dimensions for torque enhancement because either the radial or the axial dimensions of the rotor can be increased. Magnetic circuit analysis was conducted to analyze the effects of the design parameters on the field torque. After that, simulations were done to find the optimal design under all major geometric constraints with a given power supply. The results show that the multi-pole MR brake provides a considerable braking torque increase while maintaining a compact and solid design. This is confirmation of its feasibility in actual braking applications.

  6. Fluxes of fast and epithermal neutrons from Lunar Prospector: evidence for water ice at the lunar poles.

    PubMed

    Feldman, W C; Maurice, S; Binder, A B; Barraclough, B L; Elphic, R C; Lawrence, D J

    1998-09-04

    Maps of epithermal- and fast-neutron fluxes measured by Lunar Prospector were used to search for deposits enriched in hydrogen at both lunar poles. Depressions in epithermal fluxes were observed close to permanently shaded areas at both poles. The peak depression at the North Pole is 4.6 percent below the average epithermal flux intensity at lower latitudes, and that at the South Pole is 3.0 percent below the low-latitude average. No measurable depression in fast neutrons is seen at either pole. These data are consistent with deposits of hydrogen in the form of water ice that are covered by as much as 40 centimeters of desiccated regolith within permanently shaded craters near both poles.

  7. The Evolution of Student Activism and Its Influence on Tuition Fees in South Korean Universities

    ERIC Educational Resources Information Center

    Shin, Jung Cheol; Kim, Hoon-Ho; Choi, Hong-Sam

    2014-01-01

    This article briefly overviews the student movement working for political democratisation during the authoritarian governments in South Korea. The article focuses on how student activism has changed as a reflection of political developments from the dictatorship through to the civilian democratic governments. Further, it analyses how tuition-fee…

  8. Method and apparatus for assembling a permanent magnet pole assembly

    DOEpatents

    Carl, Jr., Ralph James; Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Dawson, Richard Nils; Qu, Ronghai; Avanesov, Mikhail Avramovich

    2009-08-11

    A pole assembly for a rotor, the pole assembly includes a permanent magnet pole including at least one permanent magnet block, a plurality of laminations including a pole cap mechanically coupled to the pole, and a plurality of laminations including a base plate mechanically coupled to the pole.

  9. Membrane recycling at the infranuclear pole of the outer hair cell

    NASA Astrophysics Data System (ADS)

    Harasztosi, Csaba; Harasztosi, Emese; Gummer, Anthony W.

    2015-12-01

    Rapid endocytic activity of outer hair cells (OHCs) in the guinea-pig cochlea has been already studied using the fluorescent membrane marker FM1-43. It was demonstrated that vesicles were endocytosed at the apical pole of OHCs and transcytosed to the basolateral membrane and through a central strand towards the nucleus. The significance of endocytic activity in the infranuclear region is still not clear. Therefore, in this study endocytic activity at the synaptic pole of OHCs was investigated. Confocal laser scanning microscopy was used to visualize dye uptake of OHCs isolated from the guinea-pig cochlea. Signal intensity changes were quantified in the apical and basal poles relative to the signal at the membrane. Data showed no significant difference in fluorescent signal intensity changes between the opposite poles of the OHC. These results suggest that endocytic activities in both the basal and the apical poles contribute equally to the membrane recycling of OHCs.

  10. Catapult effect in pole vaulting: is muscle coordination determinant?

    PubMed

    Frère, Julien; Göpfert, Beat; Hug, François; Slawinski, Jean; Tourny-Chollet, Claire

    2012-02-01

    This study focused on the phase between the time of straightened pole and the maximum height (HP) of vaulter and aimed at determining the catapult effect in pole vaulting on HP. Seven experienced vaulters performed 5-10 vaults recorded by two video cameras, while the surface electromyography (sEMG) activity of 10 upper limbs muscles was recorded. HP was compared with an estimated maximum height (HP(est)) allowing the computation of a push-off index. Muscle synergies were extracted from the sEMG activity profiles using a non-negative matrix factorization algorithm. No significant difference (p>0.47) was found between HP(est) (4.64±0.21m) and HP (4.69±0.23m). Despite a high inter-individual variability in sEMG profiles, two muscle synergies were extracted for all the subjects which accounted for 96.1±2.9% of the total variance. While, the synergy activation coefficients were very similar across subjects, a higher variability was found in the muscle synergy vectors. Consequently, whatever the push-off index among the pole vaulters, the athletes used different muscle groupings (i.e., muscle synergy vectors) which were activated in a similar fashion (i.e., synergy activation coefficients). Overall, these results suggested that muscle coordination adopted between the time of straightened pole and the maximum height does not have a major influence on HP.

  11. Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

    PubMed

    Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

    2013-11-01

    We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

  12. Lunar Pole Illumination and Communications Statistics Computed from GSSR Elevation Data

    NASA Technical Reports Server (NTRS)

    Bryant, Scott

    2010-01-01

    The Goldstone Solar System RADAR (GSSR) group at JPL produced a Digital Elevation Model (DEM) of the lunar south pole using data obtained in 2006. This model has 40-meter horizontal resolution and about 5-meter relative vertical accuracy. This paper uses that Digital Elevation Model to compute average solar illumination and Earth visibility near the lunar south pole. This data quantifies solar power and Earth communications resources at proposed lunar base locations. The elevation data were converted into local terrain horizon masks, then converted into selenographic latitude and longitude coordinates. The horizon masks were compared to latitude, longitude regions bounding the maximum Sun and Earth motions relative to the moon. Proposed lunar south pole base sites were examined in detail, with the best site showing multi-year averages of solar power availability of 92% and Direct-To-Earth (DTE) communication availability of about 50%. Results are compared with a theoretical model, and with actual sun and Earth visibility averaged over the years 2009 to 2028. Results for the lunar North pole were computed using the GSSR DEM of the lunar North pole produced in 1997. The paper also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

  13. Can Indian Ocean SST variability impact TC activity in the South Pacific? A Spatial Analysis

    NASA Astrophysics Data System (ADS)

    Magee, Andrew D.; Verdon-Kidd, Danielle C.; Kiem, Anthony S.

    2015-04-01

    Tropical Cyclones (TCs) represent a significant natural hazard to the 15 island nations and 2.7 million inhabitants of the South Pacific, accounting for 76% of reported disasters in the region since 1950. This vast area, dominated by the coupled ocean-atmosphere interactions of the South Pacific fuels the highly variable nature of TCs (both spatially and temporally), leading to difficulties in planning for and responding to these extreme events. While it is well known that the El Niño/Southern Oscillation (ENSO) plays a significant role in modulating the background state on which TCs form, there are other large-scale climate drivers operating on annual timescales or longer within the South Pacific (e.g. ENSO Modoki and the Interdecadal Pacific Oscillation) and outside the Pacific Basin (e.g. the Indian Ocean Dipole and the Southern Annular Mode) that may also influence TC formation. In response to this issue, the impact of these large-scale climate drivers upon the spatial characteristics of tropical cyclogenesis is assessed for the South Pacific region (5o-35oS, 145oE-130oW) over a 67-year period (1945-2011). It is shown, that in addition to the impact of 'Pacific-centric' climate drivers, eastern Indian Ocean sea surface temperatures significantly impact the spatial characteristics of tropical cyclogenesis in the South Pacific. In particular, warming (cooling) in the eastern Indian Ocean is found to result in an eastward (westward) shift in the average location of tropical cyclogenesis in the South Pacific (up to 712km between extreme phases). One mechanism that may account for this east/west modulation of TC activity in the South Pacific is the propagation of warmer water from the Timor Sea through the Coral Sea to the Pacific, resulting in a strengthening of the Pacific Warm Pool and associated meteorological characteristics connected with tropical cyclogenesis. Understanding how other large-scale climate modes interact with Indian Ocean processes is important

  14. Melanogenesis and antityrosinase activity of selected South african plants.

    PubMed

    Mapunya, Manyatja Brenda; Nikolova, Roumiana Vassileva; Lall, Namrita

    2012-01-01

    Melanin is the pigment that is responsible for the colour of eyes, hair, and skin in humans. Tyrosinase is known to be the key enzyme in melanin biosynthesis. Overactivity of this enzyme leads to dermatological disorders such as age spots, melanoma and sites of actinic damage. Ten plants belonging to four families (Asphodelaceae, Anacardiaceae, Oleaceae, and Rutaceae) were investigated for their effect on tyrosinase using both L-tyrosine and L-DOPA as substrates. Ethanol leaf extracts (500 μg/mL) of Aloe ferox, Aloe aculeata, Aloe pretoriensis, and Aloe sessiliflora showed 60%, 31%, 17%, and 13% inhibition of tyrosinase activity respectively, when L-tyrosine was used as a substrate. Harpephyllum caffrum (leaves) at a concentration of 500 μg/mL had an inhibitory effect of 70% on tyrosinase when L-DOPA was used as a substrate. The IC(50) of Harpephyllum caffrum (leaves and bark) were found to be 51 ± 0.002 and 40 ± 0.035 μg/mL, respectively. Following the results obtained from the tyrosinase assay, extracts from Harpephyllum caffrum were selected for further testing on their effect on melanin production and their cytotoxicity on melanocytes in vitro. The IC(50) of both extracts was found to be 6.25 μg/mL for melanocyte cells. Bark extract of Harpephyllum caffrum showed 26% reduction in melanin content of melanocyte cells at a concentration of 6.25 μg/mL. The leaf extract of this plant showed some toxicity on melanocyte cells. Therefore, the bark extract of Harpephyllum caffrum could be considered as an antityrosinase agent for dermatological disorders such as age spots and melasoma.

  15. A LINE POLE 77A, HISTORIC POLE WITH HISTORIC REPLACEMENT PINTYPE ...

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

    A LINE POLE 77A, HISTORIC POLE WITH HISTORIC REPLACEMENT PIN-TYPE INSULATORS MADE OF BROWN PORCELAIN. VIEW TO WEST-SOUTHWEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  16. The possibility existence of volatile compounds in the area of NSR S5 spot of local suppression of epithermal neutron flux in the South Pole region of the Moon.

    NASA Astrophysics Data System (ADS)

    Feoktistova, Ekaterina

    2016-07-01

    6 statistically significant areas in which it was recorded a lower value of the flow of epithermal neutrons was found in the polar regions of the moon according to LEND: 5 areas are located in the south polar region (the area NSR S1 - 5 [1]) and one (area NSR N1[1]) to the north. One of these areas - the area NSR S5 - is located in the landing sector Luna - Globe mission [2], the launch of which is planned by Russian Space Agency in 2018. In this paper, we investigated the temperature regime, illumination conditions and the possibility of the existence of deposits of volatile compounds in this area. To study we selected a number of substances was detected in the LCROSS impact site in the crater Cabeus, particularly compounds such as H2O, CO2, SO2, CH3OH, NH3, C2H4, H2S, CH4 · 5.75H2O and CO · 5.75H2O [3]. We divided the area of NSR S5 spot into a grid with a number of elements. Step in longitude grid was 0.15 degrees, a step in latitude 0.05 degrees. The total number of the elements of the area of the crater is 36000. The height, slope and orientation of each element were calculated based on a LOLA DEM [4] using an algorithm described in [5]. Our results show that the compounds of deposits such as H2O, CO2, SO2, CH3OH, NH3, C2H4, H2S, CH4 · 5.75H2O and CO · 5.75H2O may exist in NSR S5. Thus, the local suppression the epithermal neutron flux in this region may be due to the presence of hydrogen-containing compounds deposits. [1] Mitrofanov et al. (2012) JGR 117, E003956 [2] Ivanov et al. (2014) Solar System Res. 48, 391 - 402 [3] Colaprete et al. (2010) Science 330, 463-468 [4] http://wwwpds.wustl.edu/ [5] Zevenbergen, L.W., Thorne (1987) Earth Surface Processes and Landforms 12(1), 47-56.

  17. Implementation of the ART approach in South Africa: an activity report.

    PubMed

    Mickenautsch, S; Rudolph, M J

    2001-07-01

    The Atraumatic Restorative Treatment (ART) approach has been adopted in public dental services in South Africa as an appropriate and economical means to provide basic restorative care in communities where it was not possible before. The approach also offers a less-traumatic treatment concept for fearful patients and children in the private dental practice. In 2000, the Division of Community Dentistry, University of the Witwatersrand, implemented a training, research and service programme in the ART approach. The aim of these activities was the promotion of ART at various levels within the oral health care system in the Republic of South Africa. The objectives of the programme were to initiate and provide training of oral health workers in ART, to evaluate the outcome of training and service programmes and to disseminate results. This paper describes the Division's ART activities in 2000, regarding public, private and refugee health services.

  18. Lunar Pole Illumination and Communications Maps Computed from GSSR Elevation Data

    NASA Technical Reports Server (NTRS)

    Bryant, Scott

    2009-01-01

    A Digital Elevation Model of the lunar south pole was produced using Goldstone Solar System RADAR (GSSR) data obtained in 2006.12 This model has 40-meter horizontal resolution and about 5-meter relative vertical accuracy. This Digital Elevation Model was used to compute average solar illumination and Earth visibility with 100 kilometers of the lunar south pole. The elevation data were converted into local terrain horizon masks, then converted into lunar-centric latitude and longitude coordinates. The horizon masks were compared to latitude, longitude regions bounding the maximum Sun and Earth motions relative to the moon. Estimates of Earth visibility were computed by integrating the area of the region bounding the Earth's motion that was below the horizon mask. Solar illumination and other metrics were computed similarly. Proposed lunar south pole base sites were examined in detail, with the best site showing yearly solar power availability of 92 percent and Direct-To-Earth (DTE) communication availability of about 50 percent. Similar analysis of the lunar south pole used an older GSSR Digital Elevation Model with 600-meter horizontal resolution. The paper also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

  19. 47 CFR 32.2411 - Poles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Poles. 32.2411 Section 32.2411 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2411 Poles. This...

  20. Vibration Monitoring of Power Distribution Poles

    SciTech Connect

    Clark Scott; Gail Heath; John Svoboda

    2006-04-01

    Some of the most visible and least monitored elements of our national security infrastructure are the poles and towers used for the distribution of our nation’s electrical power. Issues surrounding these elements within the United States include safety such as unauthorized climbing and access, vandalism such as nut/bolt removal or destructive small arms fire, and major vandalism such as the downing of power poles and towers by the cutting of the poles with a chainsaw or torches. The Idaho National Laboratory (INL) has an ongoing research program working to develop inexpensive and sensitive sensor platforms for the monitoring and characterization of damage to the power distribution infrastructure. This presentation covers the results from the instrumentation of a variety of power poles and wires with geophone assemblies and the recording of vibration data when power poles were subjected to a variety of stimuli. Initial results indicate that, for the majority of attacks against power poles, the resulting signal can be seen not only on the targeted pole but on sensors several poles away in the distribution network and a distributed sensor system can be used to monitor remote and critical structures.

  1. New pole placement algorithm - Polynomial matrix approach

    NASA Technical Reports Server (NTRS)

    Shafai, B.; Keel, L. H.

    1990-01-01

    A simple and direct pole-placement algorithm is introduced for dynamical systems having a block companion matrix A. The algorithm utilizes well-established properties of matrix polynomials. Pole placement is achieved by appropriately assigning coefficient matrices of the corresponding matrix polynomial. This involves only matrix additions and multiplications without requiring matrix inversion. A numerical example is given for the purpose of illustration.

  2. Macro Fiber Piezocomposite Actuator Poling Study

    NASA Technical Reports Server (NTRS)

    Werlink, Rudy J.; Bryant, Robert G.; Manos, Dennis

    2002-01-01

    The performance and advantages of Piezocomposite Actuators are to provide a low cost, in-situ actuator/sensor that is flexible, low profile and high strain per volt performance in the same plane of poled voltage. This paper extends reported data for the performance of these Macrofiber Composite (MFC) Actuators to include 4 progressively narrower Intedigitized electrode configurations with several line widths and spacing ratios. Data is reported for max free strain, average strain per applied volt, poling (alignment of the electric dipoles of the PZT ceramic) voltage vs. strain and capacitance, time to poling voltage 95% saturation. The output strain per volt progressively increases as electrode spacing decreases, with saturation occurring at lower poling voltages. The narrowest spacing ratio becomes prone to voltage breakdown or short circuits limiting the spacing width with current fabrication methods. The capacitance generally increases with increasing poling voltage level but has high sensitivity to factors such as temperature, moisture and time from poling which limit its usefulness as a simple indicator. The total time of applied poling voltage to saturate or fully line up the dipoles in the piezoceramic was generally on the order of 5-20 seconds. Less sensitivity to poling due to the applied rate of voltage increase over a 25 to 500 volt/second rate range was observed.

  3. Activity of the mangrove snail Cerithidea decollata (Gastropoda: Potamididae) in a warm temperate South African estuary

    NASA Astrophysics Data System (ADS)

    Hodgson, Alan N.; Dickens, John

    2012-08-01

    A population of Cerithidea decollata, an intertidal marine gastropod usually found within mangroves, was studied within an area of Juncus kraussii in the upper reaches of the warm temperate Knysna estuary, which is at the southern-most limit of the recorded distribution of this snail. Activity (migratory and homing behaviour, distances travelled during foraging) of the snails was monitored over spring and neap tides in four seasons. Migratory patterns of the snails were affected by season, time of low tide (day vs night), tidal magnitude (spring vs neap) and zonation. In the summer and spring, a greater proportion of snails migrated from J. kraussii leaves onto the mud during the day at spring low tide. During neap tides in these two seasons, most snails did not climb J. kraussii leaves and remained on the mud, which was nearly always exposed. In autumn a few snails only were active and in winter snails were almost completely inactive, probably due to low air temperatures. Snails travelled greater distances on the mud on spring tides, during the diurnal low tides, and in the summer. No snails were found to home to individual J. kraussii leaves; however, homing behaviour was recorded to wooden poles within the Juncus wetland.

  4. Titan's South Polar Vortex in Motion

    NASA Video Gallery

    This movie captured by NASA'S Cassini spacecraft shows a south polar vortex, or a swirling mass of gas around the pole in the atmosphere, at Saturn’s moon Titan. The swirling mass appears to exec...

  5. A model for promoting physical activity among rural South African adolescent girls

    PubMed Central

    Kinsman, John; Norris, Shane A.; Kahn, Kathleen; Twine, Rhian; Riggle, Kari; Edin, Kerstin; Mathebula, Jennifer; Ngobeni, Sizzy; Monareng, Nester; Micklesfield, Lisa K.

    2015-01-01

    Background In South Africa, the expanding epidemic of non-communicable diseases is partly fuelled by high levels of physical inactivity and sedentary behaviour. Women especially are at high risk, and interventions promoting physical activity are urgently needed for girls in their adolescence, as this is the time when many girls adopt unhealthy lifestyles. Objective This qualitative study aimed to identify and describe facilitating factors and barriers that are associated with physical activity among adolescent girls in rural, north-eastern South Africa and, based on these, to develop a model for promoting leisure-time physical activity within this population. Design The study was conducted in and around three secondary schools. Six focus group discussions were conducted with adolescent girls from the schools, and seven qualitative interviews were held with sports teachers and youth leaders. The data were subjected to thematic analysis. Results Seven thematic areas were identified, each of which was associated with the girls’ self-reported levels of physical activity. The thematic areas are 1) poverty, 2) body image ideals, 3) gender, 4) parents and home life, 5) demographic factors, 6) perceived health effects of physical activity, and 7) human and infrastructural resources. More barriers to physical activity were reported than facilitating factors. Conclusions Analysis of the barriers found in the different themes indicated potential remedial actions that could be taken, and these were synthesised into a model for promoting physical activity among South African adolescent girls in resource-poor environments. The model presents a series of action points, seen both from the ‘supply-side’ perspective (such as the provision of resources and training for the individuals, schools, and organisations which facilitate the activities) and from the ‘demand-side’ perspective (such as the development of empowering messages about body image for teenage girls, and

  6. Baryon transition form factors at the pole

    NASA Astrophysics Data System (ADS)

    Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.

    2016-12-01

    Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the GM, GE, and GC form factors for the Δ (1232 ) resonance excitation at the Breit-Wigner resonance and pole positions up to Q2=5 GeV2 . We also explore the E /M and S /M ratios as functions of Q2. For pole and residue extraction, we apply the Laurent + Pietarinen method.

  7. Baryon transition form factors at the pole

    SciTech Connect

    Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.

    2016-12-01

    Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.

  8. Characterization of thermally poled germanosilicate thin films

    NASA Astrophysics Data System (ADS)

    Ozcan, A.; Digonnet, M. J. F.; Kino, G. S.; Ay, F.; Aydinli, A.

    2004-10-01

    We report measurements of the nonlinearity profile of thermally poled low-loss germanosilicate films deposited on fused-silica substrates by PECVD, of interest as potential electro-optic devices. The profiles of films grown and poled under various conditions all exhibit a sharp peak ~0.5 μm beneath the anode surface, followed by a weaker pedestal of approximately constant amplitude down to a depth of 13-16 μm, without the sign reversal typical of poled undoped fused silica. These features suggest that during poling, the films significantly slow down the injection of positive ions into the structure. After local optimization, we demonstrate a record peak nonlinear coefficient of ~1.6 pm/V, approximately twice as strong as the highest reliable value reported in thermally poled fused silica glass, a significant improvement that was qualitatively expected from the presence of Ge.

  9. Investigation of seasonal Be-7 variation near the Martian Poles using Mars Odyssey GRS data

    NASA Astrophysics Data System (ADS)

    Kim, Kyeong Ja; Boynton, William; Hamara, Dave

    (7) Be variation near the Martian Poles using Mars Odyssey has been investigated for about two Martian years. (7) Be is a cosmogenic nuclide produced via nuclear spallation interaction with carbon and oxygen in the atmosphere of the Mars. Because CO _{2} is main constituent of the atmosphere of the Mars and it condenses during winter season and sublimes in spring, and also it is transferred from the northern hemisphere to southern hemisphere. We assumed that the pattern of air movement could be monitored by the (7) Be production in the atmosphere. Since (7) Be peak is superimposed with (10) B which has a wide peak area and is from the background material of HPGe crystal. For this study, (7) Be peak area is defined using the thick target experiment and the influenced region due to (10) B is eliminated for (7) Be peak analysis. Our results show that the variation of (7) Be activity at 15 degree gives a lot of noise except the time associated with (7) Be spike due to solar particle event. However, the variations of (7) Be activity for 30 degree show that there is a peak rise at L _{s}100 for North Pole and L _{s}180 for South Pole. In the case of (7) Be activities at mid latitudes for L _{s}125 and L _{s}190 are distinctively higher than the rest of the seasonal zones. This implies that (7) Be activity was higher at the summer of northern hemisphere and fall season of southern hemisphere. This could be a significant and real effect associated with air density increase; therefore, the production of (7) Be increases for these seasons. Our results also show that there were two (7) Be spikes due to solar particle events observed. These spikes are distinctively high compared to the effect from the Martian atmospheric density changes. Our result of (7) Be activity of Mars could be less significant in understanding air circulation. However, this result indicated that a possible study where atmospheric density is high could be investigated with this technique including the

  10. Summary of Environmental Monitoring and Assessment Program (EMAP) activities in South Dakota, 2000-2004

    USGS Publications Warehouse

    Heakin, Allen J.; Neitzert, Kathleen M.; Shearer, Jeffrey S.

    2006-01-01

    The U.S. Environmental Protection Agency (USEPA) initiated data-collection activities for the Environmental Monitoring and Assessment Program-West (EMAP-West) in South Dakota during 2000. The objectives of the study were to develop the monitoring tools necessary to produce unbiased estimates of the ecological condition of surface waters across a large geographic area of the western United States, and to demonstrate the effectiveness of those tools in a large-scale assessment. In 2001, the U.S. Geological Survey (USGS) and the South Dakota Department of Game, Fish and Parks (GF&P) established a cooperative agreement and assumed responsibility for completing the remaining assessments for the perennial, wadable streams of the EMAP-West in the State. Stream assessment sites were divided into two broad categories-the first category of sites was randomly selected and assigned by the USEPA for South Dakota. The second category consisted of sites that were specifically selected because they appeared to have reasonable potential for representing the best available physical, chemical, and biological conditions in the State. These sites comprise the second category of assessment sites and were called 'reference' sites and were selected following a detailed evaluation process. Candidate reference site data will serve as a standard or benchmark for assessing the overall ecological condition of the randomly selected sites. During 2000, the USEPA completed 22 statewide stream assessments in South Dakota. During 2001-2003, the USGS and GF&P completed another 42 stream assessments bringing the total of randomly selected stream assessments within South Dakota to 64. In addition, 18 repeat assessments designed to meet established quality-assurance/quality-control requirements were completed at 12 of these 64 sites. During 2002-2004, the USGS in cooperation with GF&P completed stream assessments at 45 candidate reference sites. Thus, 109 sites had stream assessments completed in South

  11. The Animal Exhibits at the Field Museum. Activities for Focused Field Trips.

    ERIC Educational Resources Information Center

    Wickland, Thomas, J.

    Museum visits allow students to see animals from South America, North America, Africa, Asia, and the North Pole without rain, snow, or mosquitoes. This activity guide was developed for teachers, chaperones, and students to use with the animal exhibits in the Daniel F. and Ada L. Rice Wing of the Field Museum of Chicago. Activities are designed for…

  12. Holography with a Landau pole

    NASA Astrophysics Data System (ADS)

    Faedo, Antón F.; Mateos, David; Pantelidou, Christiana; Tarrío, Javier

    2017-02-01

    Holography for UV-incomplete gauge theories is important but poorly understood. A paradigmatic example is d = 4, N=4 super Yang-Mills coupled to N f quark flavors, which possesses a Landau pole at a UV scale ΛLP. The dual gravity solution exhibits a UV singularity at a finite proper distance along the holographic direction. Despite this, holographic renormalization can be fully implemented via analytic continuation to an AdS solution. The presence of a UV cut-off manifests itself in several interesting ways. At energies E ≪ ΛLP no pathologies appear, as expected from effective field theory. In contrast, at scales E ≲ ΛLP the gravitational potential becomes repulsive, and at temperatures T ≲ ΛLP the specific heat becomes negative. Although we focus on N=4 super Yang-Mills with flavor, our qualitative results apply to a much more general class of theories, since they only depend on the fact that the metric near the UV singularity is a hyper-scaling violating metric with exponent θ > d - 1.

  13. Geometric Modelling of Octagonal Lamp Poles

    NASA Astrophysics Data System (ADS)

    Chan, T. O.; Lichti, D. D.

    2014-06-01

    Lamp poles are one of the most abundant highway and community components in modern cities. Their supporting parts are primarily tapered octagonal cones specifically designed for wind resistance. The geometry and the positions of the lamp poles are important information for various applications. For example, they are important to monitoring deformation of aged lamp poles, maintaining an efficient highway GIS system, and also facilitating possible feature-based calibration of mobile LiDAR systems. In this paper, we present a novel geometric model for octagonal lamp poles. The model consists of seven parameters in which a rotation about the z-axis is included, and points are constrained by the trigonometric property of 2D octagons after applying the rotations. For the geometric fitting of the lamp pole point cloud captured by a terrestrial LiDAR, accurate initial parameter values are essential. They can be estimated by first fitting the points to a circular cone model and this is followed by some basic point cloud processing techniques. The model was verified by fitting both simulated and real data. The real data includes several lamp pole point clouds captured by: (1) Faro Focus 3D and (2) Velodyne HDL-32E. The fitting results using the proposed model are promising, and up to 2.9 mm improvement in fitting accuracy was realized for the real lamp pole point clouds compared to using the conventional circular cone model. The overall result suggests that the proposed model is appropriate and rigorous.

  14. Development of Mini-pole Superconducting Undulator

    SciTech Connect

    Jan, J. C.; Hwang, C. S.; Lin, P. H.; Chang, C. H.; Lin, F. Y.

    2007-01-19

    A mini-pole superconducting undulator with a 15mm period length (SU15) was developed at the National Synchrotron Radiation Research Center (NSRRC). The coil was wound by a superconducting (SC) NbTi wire with small dimensions and low Cu/SC ratio. The design field strength of SU15 with 158turns/pole was 1.4T at 215A, and the magnet gap was 5.6 mm. Extra trim coils and poles are mounted on the main iron pole. The trim coils directly compensate for the strength error of the peak field. The prototype racetrack iron pole was fabricated via electric discharge machining to produce a complete set of 40-poles. The coil was impregnated by epoxy and wrapped in Kapton to maintain insulation between coil and iron pole. A substitution beam duct was built and assembled with the magnet array and tested in the test Dewar. The conceptual design of bath liquid helium (LHe) cryostat has to tolerate more image current and radiation heating on the beam duct.

  15. What does the "mean pole" mean

    NASA Astrophysics Data System (ADS)

    Ries, J. C.; Petit, G.; Luzum, B. J.

    2015-12-01

    Rotational deformation (also called the pole tide) is the response of the solid earth and ocean to the Earth's wobble, which includes gravitational and surface displacement components. An important part of the model is the Conventional Mean Pole, which is required to remove the slow variation in the polar motion. This ensures that the rotational deformation model removes only the principal periodic motions (annual, Chandler and any other high frequency variations). Previously, no dependable mean pole product had been available. Consequently, for the 2010 Conventions, a cubic was fit to a filtered time series of polar motion and this model was adopted, along with a simple linear extrapolation into the future that was expected to be adequate until the next Conventions update. In light of the large changes in the mean pole due to recent ice mass losses, such extrapolations may not be reliable. To avoid this, the next Conventions update will include the use of a regularly updated mean pole table. Some subtleties in that choice will be noted. However, the original pole tide model was conceived when the mean pole was moving (more or less) linearly, largely in response to glacial isostatic adjustment (GIA). With the recent ice mass losses, particularly in Greenland, this motion is decidedly non-linear, and it is unclear whether the pole tide model correctly reflects this new reality. There are questions as to whether the mean pole should be the slow variation as conceived currently or should it reflect only the long-term linear motion (either based on a GIA model or a linear fit over an appropriate time span).

  16. Chemical Characterization and Antioxidant, Antimicrobial, and Anti-Inflammatory Activities of South Brazilian Organic Propolis

    PubMed Central

    Tiveron, Ana Paula; Rosalen, Pedro Luiz; Franchin, Marcelo; Lacerda, Risia Cristina Coelho; Bueno-Silva, Bruno; Benso, Bruna; Denny, Carina; Ikegaki, Masaharu; de Alencar, Severino Matias

    2016-01-01

    South Brazilian organic propolis (OP), which has never been studied before, was assessed and its chemical composition, scavenging potential of reactive oxygen species, antimicrobial and anti-inflammatory activities are herein presented. Based on the chemical profile obtained using HPLC, OP was grouped into seven variants (OP1–OP7) and all of them exhibited high scavenging activity, mainly against superoxide and hypochlorous acid species. OP1, OP2, and OP3 had the smallest minimal inhibitory concentration (MIC) against Gram-positive bacteria Streptococcus mutans, Streptococcus oralis, and Streptococcus aureus (12.5–100 μg/mL). OP1, OP2, OP3, and OP4 were more effective against Pseudomonas aeruginosa (Gram-negative), with MIC values ranging from 100 to 200 μg/mL. OP6 showed anti-inflammatory activity by decreasing NF-kB activation and TNF-α release in RAW 264.7 macrophages, and expressing the NF-κB-luciferase reporter stable gene. Therefore, south Brazilian OP can be considered an excellent source of bioactive compounds with great potential of application in the pharmaceutical and food industry. PMID:27802316

  17. Active Tectonics of Western Turkmenistan; Implications for the Onset of South Caspian Subduction

    NASA Astrophysics Data System (ADS)

    Hollingsworth, J.; Jackson, J.; Priestley, K.

    2007-12-01

    The Kopeh Dagh and Balkan mountain ranges of West Turkmenistan are actively deforming as a result of Arabia- Eurasia collision. We combine observations of the geomorphology made from satellite and topographic data, with historical and recent seismicity to identify major active faults, and how they contribute to regional shortening. Between 55--57.5°E, partitioned (north-vergent) thrust and right-lateral strike-slip fault segments, comprising the Ashkabad fault zone, accommodate regional shortening and the westward-extrusion of the NW Kopeh Dagh-South Caspian block, relative to Central Iran and Eurasia. Reconstruction of displaced geology indicates 35~km total right-lateral motion across the Ashkabad fault zone. The Balkan region lies along-strike of the Ashkabad fault zone, west of 55°E. Fault plane solutions indicate shortening is partitioned onto the Balkan thrust and right-lateral Kum-Dagh fault zones. Thrust earthquakes are relatively deep (30--45~km) and lie along a north-dipping plane which extends 40±5~km north beneath the Balkan anticline. Receiver function data from Turkmenbashi and Nebit Dagh indicate these earthquakes occur in the base of the crust, and may therefore be related to bending of the NW Kopeh Dagh-South Caspian lithosphere as it is overthrust by Eurasia. Movement on a north-dipping blind thrust fault is consistent with the broad asymmetric (south-vergent) fold structure of the Balkan range. Recent uplift is also indicated by extensional faults which displace Quaternary geomorphology along the range crest. South of the Balkan range, right-lateral shear occurs across the Kum-Dagh fault zone which is expressed as a series of right-stepping anticlines (affecting Pliocene Red Series and younger sediments), forming important traps for hydrocarbons. An important structural change occurs near 55°E. To the west, Eurasia overthrusts the NW Kopeh Dagh- South Caspian block, while to the east the polarity of thrusting changes and the Kopeh Dagh

  18. Topography of the lunar poles from radar interferometry: a survey of cold trap locations.

    PubMed

    Margot, J L; Campbell, D B; Jurgens, R F; Slade, M A

    1999-06-04

    Detailed topographic maps of the lunar poles have been obtained by Earth-based radar interferometry with the 3.5-centimeter wavelength Goldstone Solar System Radar. The interferometer provided maps 300 kilometers by 1000 kilometers of both polar regions at 150-meter spatial resolution and 50-meter height resolution. Using ray tracing, these digital elevation models were used to locate regions that are in permanent shadow from solar illumination and may harbor ice deposits. Estimates of the total extent of shadowed areas poleward of 87.5 degrees latitude are 1030 and 2550 square kilometers for the north and south poles, respectively.

  19. Prevalence of HBV genotypes in South American immigrants affected by HBV-related chronic active hepatitis.

    PubMed

    Palumbo, Emilio; Scotto, Gaetano; Faleo, Giuseppina; Cibelli, Donatella Concetta; Angarano, Gioacchino

    2007-06-01

    This study evaluated the prevalence of HBV infection in a population of South American immigrants in Italy and to determine in patients with detectable serum HBV-DNA the HBV genotypes. Between April 2005 and April 2006 a total of 130 South American immigrants were tested for HBsAg. In HBsAg positive patients the biochemical and virological activity of infection and the possible presence of co-infections (HCV, HDV, HIV) were evaluated. In patients with detectable serum HBV DNA, the HBV genotype was determined by INNOLiPA. Among the 130 subjects tested, 14 (10.7%) resulted HBsAg positive. All were men, with a mean age of 22 years (range 19-37) and 12 (85.7 %) came from Brazil, while 2 (14.3%) came from Ecuador. All patients infected by HBV had elevated alanine-aminotransferase serum levels (mean level was 127 IU/L, range 74-312) and serum HBV DNA detectable by PCR-Real Time (mean level 1,037,652 copies/mL, range 19,876-1,377,648). Genotype distribution was as follow: genotype D, 9 (64.2%), genotype A, 5 (35.8%). All patients infected by genotype D came from Brazil, while among the patients infected by genotype A, three came from Brazil and two from Ecuador. Our study evidences a moderate prevalence of HBV-infection in South American immigrants with the identification of two genotypes, D and A. These genotypes are not the most prevalent in the South America and this is probably the expression of a possible geographical redistribution of HBV genotypes.

  20. Cold Hole Over Jupiter's Pole

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.

    These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.

    The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.

    The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.

    The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.

    These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at

  1. The in vitro pharmacological activities and a chemical investigation of three South African Salvia species.

    PubMed

    Kamatou, G P P; Viljoen, A M; Gono-Bwalya, A B; van Zyl, R L; van Vuuren, S F; Lourens, A C U; Başer, K H C; Demirci, B; Lindsey, K L; van Staden, J; Steenkamp, P

    2005-12-01

    Salvia species (sage) are well known in folk medicine throughout the world. In South Africa sage is used against fever and digestive disorders. Three closely related South African species (Salvia stenophylla, Salvia repens and Salvia runcinata) were investigated for their anti-oxidant (DPPH assay); anti-inflammatory (5-lipoxygenase and cyclo-oxygenase assays); antimalarial (tritiated hypoxanthine incorporation assay); antimicrobial (disc diffusion and micro-dilution assays) properties and toxicity profile (tetrazolium-based assay). The solvent extracts exhibited anti-oxidant, antimalarial and antibacterial and poor anti-inflammatory properties. The essential oils exhibited anti-inflammatory and antimalarial properties, but displayed poor anti-oxidant and antimicrobial activity. The extract of Salviastenophylla and the essential oil of Salvia runcinata displayed the highest toxicity profile. Overall, Salvia runcinata displayed the most favorable activity of all three taxa tested with an IC(50) value of 6.09 (anti-oxidant); 29.05 (antimalarial) and 22.82 microg/ml (anti-inflammatory). Analytical procedures (GC-MS and HPLC-UV) were employed to generate chromatographic profiles for the essential oils and solvent extracts respectively. The HPLC analysis revealed the presence of rosmarinic acid in all three taxa while carnosic acid was only present in Salvia repens and Salvia stenophylla. The GC-MS analysis showed that oils were qualitatively and quantitatively variable. beta-Caryophyllene was present in large amounts in all three taxa. Other components present include camphor, alpha-pinene and alpha-bisabolol. The results of the in vitro pharmacological activities provide a scientific basis to validate the use of these Salvia species in traditional medicine in South Africa.

  2. Baseline Acidity of Ancient Precipitation from the South Pole,

    DTIC Science & Technology

    1984-06-01

    post-depositional diffusion of ait ferences ( Langway et al. 1975). The first three through the firn was contributing significantly to the measured...C.C. Langway , the Canadian high Arctic. Nature, 295: 137-140. Jr. (1975) Chemistry of 700 years of precipitation Kolthoff, i.M., E.B.Sandell...sis. London: Macmillian Company, p. 55. port 341. ADA 014970. Kuivinen, K.C., B.R. Koci, G.W. Holdsworth Cragin, J.H., M.M. Herron, C.C. Langway , Jr

  3. South Pole of the Sun, March 20, 2007 (Anaglyph)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Left eye view of a stereo pair Click on the image for full resolution TIFF Figure 2: Right eye view of a stereo pair Click on the image for full resolution TIFF Figure 1: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun. This location enables us to view the Sun from the position of a virtual left eye in space. Figure 2: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-A spacecraft. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

    NASA's Solar TErrestrial RElations Observatory (STEREO) satellites have provided the first three-dimensional images of the Sun. For the first time, scientists will be able to see structures in the Sun's atmosphere in three dimensions. The new view will greatly aid scientists' ability to understand solar physics and thereby improve space weather forecasting.

    This image is a composite of left and right eye color image pairs taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B and STEREO-A spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual left eye in space. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

    The EUVI imager is sensitive to wavelengths of light in the extreme ultraviolet portion of the spectrum. EUVI bands at wavelengths of 304, 171 and 195 Angstroms have been mapped to the red blue and green visible portion of the spectrum; and processed to emphasize the three-dimensional structure of the solar material.

    STEREO, a two-year mission, launched October 2006, will provide a unique and revolutionary view of the Sun-Earth System. The two nearly identical observatories -- one ahead of Earth in its orbit, the other trailing behind -- will trace the flow of energy and matter from the Sun to Earth. They will reveal the 3D structure of coronal mass ejections; violent eruptions of matter from the sun that can disrupt satellites and power grids, and help us understand why they happen. STEREO will become a key addition to the fleet of space weather detection satellites by providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.

    STEREO is the third mission in NASA's Solar Terrestrial Probes program within NASA's Science Mission Directorate, Washington. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed and built the spacecraft and is responsible for mission operations. The imaging and particle detecting instruments were designed and built by scientific institutions in the U.S., UK, France, Germany, Belgium, Netherlands, and Switzerland. JPL is a division of the California Institute of Technology in Pasadena.

  4. South Pole of the Sun, March 20, 2007

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Left eye view of a stereo pair Click on the image for full resolution TIFF Figure 2: Right eye view of a stereo pair Click on the image for full resolution TIFF Figure 1: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun. This location enables us to view the Sun from the position of a virtual left eye in space. Figure 2: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-A spacecraft. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

    NASA's Solar TErrestrial RElations Observatory (STEREO) satellites have provided the first three-dimensional images of the Sun. For the first time, scientists will be able to see structures in the Sun's atmosphere in three dimensions. The new view will greatly aid scientists' ability to understand solar physics and thereby improve space weather forecasting.

    The EUVI imager is sensitive to wavelengths of light in the extreme ultraviolet portion of the spectrum. EUVI bands at wavelengths of 304, 171 and 195 Angstroms have been mapped to the red blue and green visible portion of the spectrum; and processed to emphasize the temperature difference of the solar material.

    STEREO, a two-year mission, launched October 2006, will provide a unique and revolutionary view of the Sun-Earth System. The two nearly identical observatories -- one ahead of Earth in its orbit, the other trailing behind -- will trace the flow of energy and matter from the Sun to Earth. They will reveal the 3D structure of coronal mass ejections; violent eruptions of matter from the sun that can disrupt satellites and power grids, and help us understand why they happen. STEREO will become a key addition to the fleet of space weather detection satellites by providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.

    STEREO is the third mission in NASA's Solar Terrestrial Probes program within NASA's Science Mission Directorate, Washington. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed and built the spacecraft and is responsible for mission operations. The imaging and particle detecting instruments were designed and built by scientific institutions in the U.S., UK, France, Germany, Belgium, Netherlands, and Switzerland. JPL is a division of the California Institute of Technology in Pasadena.

  5. SPT Lensing Likelihood: South Pole Telescope CMB lensing likelihood code

    NASA Astrophysics Data System (ADS)

    Feeney, Stephen M.; Peiris, Hiranya V.; Verde, Licia

    2014-11-01

    The SPT lensing likelihood code, written in Fortran90, performs a Gaussian likelihood based upon the lensing potential power spectrum using a file from CAMB (ascl:1102.026) which contains the normalization required to get the power spectrum that the likelihood call is expecting.

  6. Ulysses above the sun's south pole: an introduction

    NASA Technical Reports Server (NTRS)

    Smith, E. J.; Marsden, R. G.; Page, D. E.

    1995-01-01

    Ulysses has explored the field and particle environment of the sun's polar region. The solar wind speed was fast and nearly constant above -50 degrees latitude. Compositional differences were observed in slow (low-latitude) solar wind and in fast (high-latitude) solar wind. The radial magnetic field did not change with latitude, implying that polar cap magnetic fields are transported toward the equator. The intensity of galactic cosmic rays was nearly independent of latitude. Their access to the polar region is opposed by outward-traveling, large amplitude waves in the magnetic field.

  7. South Pole Telescope joins black-hole project

    NASA Astrophysics Data System (ADS)

    Allen, Michael

    2015-06-01

    Astronomers are one step closer to observing the event horizon of a black hole after Antarctica's largest telescope joined a worldwide collection of millimetre/submillimetre facilities pursuing this goal.

  8. Exposed water ice discovered near the south pole of Mars

    USGS Publications Warehouse

    Titus, T.N.; Kieffer, H.H.; Christensen, P.R.

    2003-01-01

    The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.

  9. Exposed water ice discovered near the south pole of Mars.

    PubMed

    Titus, Timothy N; Kieffer, Hugh H; Christensen, Phillip R

    2003-02-14

    The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.

  10. Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis

    PubMed Central

    2012-01-01

    Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Methods Extracts of a selection of plant taxa sourced in South Africa were tested for larvicidal properties in an applicable assay. Thirty 3rd instar Anopheles arabiensis larvae were exposed to various extract types (dichloromethane, dichloromethane/methanol) (1:1), methanol and purified water) of each species investigated. Mortality was evaluated relative to the positive control Temephos (Mostop; Agrivo), an effective emulsifiable concentrate larvicide. Results Preliminary screening of crude extracts revealed substantial variation in toxicity with 24 of the 381 samples displaying 100% larval mortality within the seven day exposure period. Four of the high activity plants were selected and subjected to bioassay guided fractionation. The results of the testing of the fractions generated identified one fraction of the plant, Toddalia asiatica as being very potent against the An. arabiensis larvae. Conclusion The present study has successfully identified a plant with superior larvicidal activity at both the crude and semi pure fractions generated through bio-assay guided fractionation. These results have initiated further research into isolating the active compound and developing a malaria vector control tool. PMID:22963538

  11. TEC variation during high and low solar activities over South American sector

    NASA Astrophysics Data System (ADS)

    Jonah, O. F.; de Paula, E. R.; Muella, M. T. A. H.; Dutra, S. L. G.; Kherani, E. A.; Negreti, P. M. S.; Otsuka, Y.

    2015-12-01

    Using dual frequency GPS receivers in the South American sector, the measurement of absolute ionospheric Total Electron Content (TEC) has been estimated applying the Nagoya ionospheric model for both the years of 2009 and 2001, which represent low and high solar activities, respectively. The diurnal, day-to-day, monthly, seasonal, latitudinal and longitudinal variations of TEC were studied for equatorial and low latitude regions of South America. The strength and characteristics of the Equatorial Ionization Anomaly (EIA) were equally analyzed. The analyses reveal the diurnal, seasonal and semidiurnal TEC variation, as well as the nighttime variability during the low and high solar activities. Wavelet power spectra analysis was employed to check the periodicities of the TEC data, F10.7 and zonal and meridional wind velocities measured by Meteor radar at ∼100 km altitude. Periods such as 27, 16, 8-10, 1-5 days were found to be dominant in the zonal and meridional wind velocity corresponding with those of TEC periodicities. Hence, besides the solar radiation, we suggest that there are contributions of tides and planetary waves in spatial and temporal TEC enhancement and variations during the geomagnetic quiet periods of both solar activities.

  12. The pole tide in deep oceans

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1990-01-01

    The fluid-dynamical theory of the pole tide is examined by describing the oceanic response to the Chandler wobble and assessing its implications for mantle anelasticity and low-frequency ocean dynamics. The Laplace tide equations accounting for bottom friction are given, and a spherical harmonic approach is delineated in which the time-independent portion of the tide height is expanded. Pole-tide height and related inertia products are linearly proportional to wobble amplitude, and the final equations are modified to account for mantle elasticity and oceanic loading. Results for pole tide effects are given for various earth models with attention to the role of boundary constraints. A dynamic effect is identified which lengthens the Chandler period by about 1 day more than static lengthening, a contribution that suggests a vigorous low-frequency response. The values derived are shown to agree with previous models that do not incorporate the effects of the pole tide.

  13. Multiplicative-cascade dynamics in pole balancing.

    PubMed

    Harrison, Henry S; Kelty-Stephen, Damian G; Vaz, Daniela V; Michaels, Claire F

    2014-06-01

    Pole balancing is a key task for probing the prospective control that organisms must engage in for purposeful action. The temporal structure of pole-balancing behaviors will reflect the on-line operation of control mechanisms needed to maintain an upright posture. In this study, signatures of multifractality are sought and found in time series of the vertical angle of a pole balanced on the fingertip. Comparisons to surrogate time series reveal multiplicative-cascade dynamics and interactivity across scales. In addition, simulations of a pole-balancing model generating on-off intermittency [J. L. Cabrera and J. G. Milton, Phys. Rev. Lett. 89, 158702 (2002)] were analyzed. Evidence of multifractality is also evident in simulations, though comparing simulated and participant series reveals a significantly greater contribution of cross-scale interactivity for the latter. These findings suggest that multiplicative-cascade dynamics are an extension of on-off intermittency and play a role in prospective coordination.

  14. Climate modulates internal wave activity in the Northern South China Sea

    NASA Astrophysics Data System (ADS)

    DeCarlo, Thomas M.; Karnauskas, Kristopher B.; Davis, Kristen A.; Wong, George T. F.

    2015-02-01

    Internal waves (IWs) generated in the Luzon Strait propagate into the Northern South China Sea (NSCS), enhancing biological productivity and affecting coral reefs by modulating nutrient concentrations and temperature. Here we use a state-of-the-art ocean data assimilation system to reconstruct water column stratification in the Luzon Strait as a proxy for IW activity in the NSCS and diagnose mechanisms for its variability. Interannual variability of stratification is driven by intrusions of the Kuroshio Current into the Luzon Strait and freshwater fluxes associated with the El Niño-Southern Oscillation. Warming in the upper 100 m of the ocean caused a trend of increasing IW activity since 1900, consistent with global climate model experiments that show stratification in the Luzon Strait increases in response to radiative forcing. IW activity is expected to increase in the NSCS through the 21st century, with implications for mitigating climate change impacts on coastal ecosystems.

  15. A Salient-Pole Synchronous Generator with Permanent Magnets between the Field Poles

    NASA Astrophysics Data System (ADS)

    Matsui, Yasuhiro; Hayamizu, Takahito; Shima, Kazuo; Fukami, Tadashi; Hanaoka, Ryoichi; Takata, Shinzo

    In this paper, a new salient-pole synchronous generator (SG) termed the PMa-SG is presented. In the PMa-SG, permanent magnets (PMs) are placed between the pole shoes to reduce the magnetic saturation in the field poles. By using finite element analysis (FEA), the internal magnetic fields and basic characteristics of a 2.8-MVA PMa-SG were compared with those of a conventional SG of the same size, and the reduction effect of the magnetic saturation of the PMs was examined. The FEA simulations were also validated by experiments on a 2.0-kVA prototype machine. The PMs placed between the pole shoes reduce the magnetic saturation in the pole bodies and pole tips and effectively increase the terminal voltage and output power.

  16. Assessment of structural integrity of wooden poles

    NASA Astrophysics Data System (ADS)

    Craighead, Ian A.; Thackery, Steve; Redstall, Martin; Thomas, Matthew R.

    2000-05-01

    Despite recent advances in the development of new materials, wood continues to be used globally for the support of overhead cable networks used by telecommunications and electrical utility companies. As a natural material, wood is subject to decay and will eventually fail, causing disruption to services and danger to public and company personnel. Internal decay, due to basidomycetes fungi or attack by termites, can progress rapidly and is often difficult to detect by casual inspection. The traditional method of testing poles for decay involves hitting them with a hammer and listening to the sound that results. However, evidence suggests that a large number of poles are replaced unnecessarily and a significant number of poles continue to fail unexpectedly in service. Therefore, a more accurate method of assessing the structural integrity of wooden poles is required. Over the last 25 years there have been a number of attempts at improving decay detection. Techniques such as ultrasound, drilling X rays etc. have been developed but have generally failed to improve upon the practicality and accuracy of the traditional testing method. The paper describes the use of signal processing techniques to analyze the acoustic response of the pole and thereby determine the presence of decay. Development of a prototype meter is described and the results of initial tests on several hundred poles are presented.

  17. HIPPO (HIAPER Pole-to-Pole Observations) Data from CDIAC's HIPPO Data Archive

    DOE Data Explorer

    The HIPPO (HIAPER Pole-to-Pole Observations) study of the carbon cycle and greenhouse gases measured meteorology, atmospheric chemistry, and aerosol constituents along transects from approximately pole-to-pole over the Pacific Ocean. HIPPO flew hundreds of vertical profiles from the ocean/ice surface to as high as the tropopause, at five times during different seasons over a three year period from 2009-2011. HIPPO provides the first high-resolution vertically-resolved global survey of a comprehensive suite of atmospheric trace gases and aerosols pertinent to understanding the carbon cycle and challenging global climate models.

  18. Spindle position control by embedded electromagnetic poles

    NASA Astrophysics Data System (ADS)

    Tsai, N.-C.; Lee, R.-M.

    2010-10-01

    A novel embedded cylindrical-array magnetic actuator (ECAMA) is proposed and verified by experiments to provide sufficient magnetic force for spindle deviation regulation of high-speed milling process. Four I-shape silicon steel columns enclosing the spindle constitute the backbone of the ECAMA. The shape of modified concave-type yokes is designed to reduce the average air gap between magnetic poles and the spindle. In contrast to the conventional AMB (active magnetic bearing) design for which coils are usually wound on the yokes, the copper wire is wound on the I-shape silicon steel columns. As a result, the overall wound coil turns can be much increased. In other words, stronger magnetic force can be induced by ECAMA. On the other hand, to reduce the cost of ECAMA, two pairs of self-sensing modules are employed to replace the gap sensors for measurement of spindle position deviation. In order to verify the efficacy of the proposed ECAMA and the self-sensing module, high-speed milling tests are undertaken. By inspection on the precision and quality of the finish surface of workpiece, the superiority of ECAMA and the self-sensing module are assured.

  19. Design of Optimal Low-Thrust Lunar Pole-Sitter Missions

    NASA Astrophysics Data System (ADS)

    Grebow, Daniel J.; Ozimek, Martin T.; Howell, Kathleen C.

    2011-01-01

    Using a thruster similar to Deep Space 1's NSTAR, pole-sitting low-thrust trajectories are discovered in the vicinity of the L 1 and L 2 libration points. The trajectories are computed with a seventh-degree Gauss-Lobatto collocation scheme that automatically positions thrusting and coasting arcs, and aligns the thruster as necessary to satisfy the problem constraints. The trajectories appear to lie on slightly deformed surfaces corresponding to the L 1 and L 2 halo orbit families. A collocation scheme is also developed that first incorporates spiraling out from low-Earth orbit, and finally spiraling down to a stable lunar orbit for continued uncontrolled surveillance of the lunar south pole. Using direct transcription via collocation, the pole-sitting coverage time is maximized to 554.18 days, and the minimum elevation angle associated with the optimal trajectory is 13.0°.

  20. Cover pole design for easy transport, assembly and field use.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover poles, also called Robel poles, are used to measure a variety of structural vegetation attributes commonly used in wildlife and livestock management. Although cover pole dimensions, measurement criteria, and interpretation of cover pole data vary depending on measurement objectives, the techni...

  1. The Impact of Human Activities on Microbial Quality of Rivers in the Vhembe District, South Africa

    PubMed Central

    Traoré, Afsatou N.; Mulaudzi, Khodani; Chari, Gamuchirai J.E.; Foord, Stefan H.; Mudau, Lutendo S.; Barnard, Tobias G.; Potgieter, Natasha

    2016-01-01

    Background: Water quality testing is dictated by microbial agents found at the time of sampling in reference to their acceptable risk levels. Human activities might contaminate valuable water resources and add to the microbial load present in water bodies. Therefore, the effects of human activities on the microbial quality of rivers collected from twelve catchments in the Vhembe District in South Africa were investigated, with samples analyzed for total coliform (TC) and Eschericha coli (E. coli) contents. Methods: Physical parameters and various human activities were recorded for each sampling site. The Quanti-Tray® method was adopted for the assessment of TC and E. coli contents in the rivers over a two-year period. A multiplex polymerase chain (PCR) method was used to characterize the strains of E. coli found. Results: The microbial quality of the rivers was poor with both TC and E. coli contents found to be over acceptable limits set by the South African Department of Water and Sanitation (DWS). No significant difference (p > 0.05) was detected between TC and E. coli risks in dry and wet seasons. All six pathogenic E. coli strains were identified and Enteroaggregative E. coli (EAEC), atypical Enteropathogenic E. coli (a-EPEC) and Enterotoxigenic E. coli (ETEC) were the most prevalent E. coli strains detected (respectively, 87%, 86% and 83%). Conclusions: The study indicated that contamination in the majority of sampling sites, due to human activities such as car wash, animal grazing and farming, poses health risks to communities using the rivers for various domestic chores. It is therefore recommended that more education by the respective departments is done to avert pollution of rivers and prevent health risks to the communities in the Vhembe District. PMID:27529265

  2. Platelet, monocyte and neutrophil activation and glucose tolerance in South African Mixed Ancestry individuals

    PubMed Central

    Davison, Glenda M.; Nkambule, Bongani B.; Mkandla, Zibusiso; Hon, Gloudina M.; Kengne, Andre P.; Erasmus, Rajiv T.; Matsha, Tandi E.

    2017-01-01

    Platelet activation has been described in patients with chronic inflammation, however in type 2 diabetes mellitus it remains controversial. We compared levels of platelet leucocyte aggregates, monocyte and granulocyte activation across glucose tolerance statuses in mixed ancestry South Africans. Individuals (206) were recruited from Bellville-South, Cape Town, and included 66% with normal glucose tolerance, 18.7% pre-diabetes, 8.7% screen-detected diabetes and 6.3% known diabetes. Monocyte and neutrophil activation were measured by calculating the percentage of cells expressing CD142 and CD69 while platelet monocyte aggregates were defined as CD14++ CD42b+ events and platelet neutrophil aggregates as CD16++ CD42b+ events. The percentage of monocytes and neutrophils expressing CD69 and CD142 was significantly higher in known diabetes and prediabetes, but, lowest in screen-detected diabetes (both p ≤ 0.016). The pattern was similar for platelet monocyte and neutrophil aggregates (both p ≤ 0.003). In robust linear regressions adjusted for age and gender, known diabetes was significantly and positively associated with the percentage of monocytes expressing CD69 [beta 11.06 (p = 0.016)] and CD42b (PMAs) [19.51 (0.003)] as well as the percentage of neutrophils expressing CD69 [14.19 (<0.0001)] and CD42b [17.7 (0.001)]. We conclude that monitoring platelet activation in diagnosed diabetic patients may have a role in the management and risk stratification. PMID:28091589

  3. 31 CFR 538.536 - Activities relating to the petroleum and petrochemical industries in the Republic of South Sudan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Activities relating to the petroleum... Policy § 538.536 Activities relating to the petroleum and petrochemical industries in the Republic of... and transactions relating to the petroleum and petrochemical industries in the Republic of South...

  4. 31 CFR 538.536 - Activities relating to the petroleum and petrochemical industries in the Republic of South Sudan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Activities relating to the petroleum... Policy § 538.536 Activities relating to the petroleum and petrochemical industries in the Republic of... and transactions relating to the petroleum and petrochemical industries in the Republic of South...

  5. 31 CFR 538.536 - Activities relating to the petroleum and petrochemical industries in the Republic of South Sudan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Activities relating to the petroleum... Policy § 538.536 Activities relating to the petroleum and petrochemical industries in the Republic of... and transactions relating to the petroleum and petrochemical industries in the Republic of South...

  6. Hemispheric View of Venus Centered at the North Pole

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The hemispheric view of Venus, as revealed by more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, is centered on the North Pole. The Magellan spacecraft imaged more than 98% of Venus at a resolution of about 100 meters; the effective resolution of this image is about 3 km. A mosaic of the Magellan images (most with illumination from the west) forms the image base. Gaps in the Magellan coverage were filled with images from the Earth-based Arecibo radar in a region centered roughly on 0 degree latitude and longitude, and with a neutral tone elsewhere (primarily near the south pole). The composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Gaps in the elevation data from the Magellan radar altimeter were filled with altimetry from the Venera spacecraft and the U.S. Pioneer Venus missions. An orthographic projection was used, simulating a distant view of one hemisphere of the planet. The Magellan mission was managed for NASA by Jet Propulsion Laboratory (JPL), Pasadena, CA. Data processed by JPL, the Massachusetts Institute of Technology, Cambridge, MA, and the U.S. Geological Survey, Flagstaff, AZ.

  7. Pole tide in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Medvedev, I. P.; Rabinovich, A. B.; Kulikov, E. A.

    2014-03-01

    The pole tide, which is driven by the Chandler Wobble, has a period of about 14 months and typical amplitudes in the World Ocean of ˜0.5 cm. However, in the Baltic Sea the pole tide is anomalously high. To examine this effect we used long-term hourly sea level records from 23 tide gauges and monthly records from 64 stations. The lengths of the series were up to 123 years for hourly records and 211 years for monthly records. High-resolution spectra revealed a cluster of neighboring peaks with periods from 410 to 440 days. The results of spectral analysis were applied to estimate the integral amplitudes of pole tides from all available tide gauges along the coast of the Baltic Sea. The height of the pole tide was found to gradually increase from the entrance (Danish Straits, 1.5-2 cm) to the northeast end of the sea. The largest amplitudes—up to 4.5-7 cm—were observed in the heads of the Gulf of Finland and the Gulf of Bothnia. Significant temporal fluctuations in amplitudes and periods of the pole tide were observed during the 19th and 20th centuries.

  8. Pion scattering poles and chiral symmetry restoration

    SciTech Connect

    Fernandez-Fraile, D.; Nicola, A. Gomez; Herruzo, E. T.

    2007-10-15

    Using unitarized chiral perturbation theory methods, we perform a detailed analysis of the {pi}{pi} scattering poles f{sub 0}(600) and {rho}(770) behavior when medium effects such as temperature or density drive the system towards chiral symmetry restoration. In the analysis of real poles below threshold, we show that it is crucial to extend properly the unitarized amplitudes so that they match the perturbative Adler zeros. Our results do not show threshold enhancement effects at finite temperature in the f{sub 0}(600) channel, which remains as a pole of broad nature. We also implement T=0 finite-density effects related to chiral symmetry restoration, by varying the pole position with the pion decay constant. Although this approach takes into account only a limited class of contributions, we reproduce the expected finite-density restoration behavior, which drives the poles towards the real axis, producing threshold enhancement and {pi}{pi} bound states. We compare our results with several model approaches and discuss the experimental consequences, both in relativistic heavy ion collisions and in {pi}{yields}{pi}{pi} and {gamma}{yields}{pi}{pi} reactions in nuclei.

  9. Geology of the area of induced seismic activity at Monticello Reservoir, South Carolina

    SciTech Connect

    Secor, D.T. Jr.; Smith, W.A.; Snoke, A.W.; Peck, L.S.; Pitcher, D.M.; Prowell, D.C.; Simpson, D.H.

    1982-08-10

    This study provides geological background information necessary for an evaluation of the earthquake hazard in an area of induced seismic activity at Monticello Reservoir, South Carolina. This region contains a thick stratified sequence of Proterozoic Z and Cambrian metasedimentary and metavolcanic rocks. In the early to middle Paleozoic, this sequence was recrystallized and deformed under metamorphic conditions that ranged from greenschist to amphibolite facies and experienced at least two episodes of folding. The region has been intruded by late kinematic to postkinematic granitoid plutons of Silurian and Carboniferous ages and by numerous northwest trending diabase diks of Late Traissic and Early Jurassic age. The region south of Monticello Reservoir in the Carolina slate belt experienced two episodes of faulting in the late Paleozoic and/or early to middle Mesozoic. The older group of faults trends approximately east, has only small displacements, and is characterized by extensive silicifiction of the fault zones. The younger group of faults trends approximately north has experienced dip slip displacements up to 1700 m and is characterized by carbonate mineralization in the fault zones. Both sets of faults are cut by an undeformed diabase dike of Late Triassic or Early Jurassic age. The induced seismic activity around Monticello Reservoir is occurring in a heterogeneous quartz monzonite pluton of Carboniferous age. The pluton contains large enclaves of country rock and is cut by numerous, diversely oriented small faults and joint. These local inhomogeneities in the pluton together with an irregular stress field are interpreted to control the diffuse seismic activity around the reservoir. In view of the apparent absence of lengthy faults it is unlikely that a large-magnitude earthquake will occur in response to the stress and pore pressure changes related to the impoundment of Monticello Reservoir.

  10. Titan's temporal evolution in stratospheric trace gases near the poles

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Jennings, D.; Achterberg, R.; Bampasidis, G.; Lavvas, P.; Nixon, C.; Teanby numeration="7">Teanby, N.; Anderson, C.; Cottini, V.; Flasar, F. M.

    2015-10-01

    We analyze spectra acquired by the Cassini/Composite Infrared Spectrometer (CIRS) at high resolution from October 2010 until September 2014 in nadir mode. Up until mid 2012, Titan's Northern atmosphere exhibited the enriched chemical content found since the Voyager days (November 1980), with a peak around the Northern Spring Equinox (NSE) in 2009. Since then, we have observed the appearance at Titan's south pole of several trace species for the first time, such as HC3N and C6H6, observed only at high northern latitudes before equinox. We investigate here latitudes poleward of 50°S and 50°N from 2010 (after the Southern Autumnal Equinox : SAE) until 2014.

  11. CROW{trademark} FIELD DEMONSTRATION WITH BELL LUMBER AND POLE

    SciTech Connect

    L. John Fahy; Lyle A. Johnson, Jr.

    1997-04-01

    Beginning in 1990, efforts were initiated for Western Research Institute (WRI) to implement an in situ remediation project for the contaminated aquifer at the Bell Lumber and Pole Company (Bell Pole) Site in New Brighton, Minnesota. The remediation project involves the application of the Contained Recovery of Oily Waste (CROW{trademark}) process, which consists of hot-water injection to displace and recover the non-aqueous phase liquids (NAPL) (Johnson and Sudduth 1989). Wood treating activities began at the Bell Pole Site in 1923 and have included the use of creosote and pentachlorophenol (PCP) in a fuel oil carrier. Creosote was used as a wood preservative from 1923 to 1958. Provalene 4-A, a non-sludging fuel-oil-type carrier for PCP, was used from 1952 until it was no longer commercially available in 1968. A 5-6% mixture of PCP in fuel oil has been used as a wood preservative since 1952, and a fuel-oil-type carrier, P-9, has been used since 1968. While reviewing the site evaluation information, it became apparent that better site characterization would enhance the outcome of the project. Additional coring indicated that the area's extent of the contaminated soils was approximately eight times greater than initially believed. Because of these uncertainties, a pilot test was conducted, which provided containment and organic recovery information that assisted in the design of the full-scale CROW process demonstration.

  12. New magnet pole shape for isochronous cyclotrons

    SciTech Connect

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-01-01

    A new design has been developed for shaping pole tips to produce the radially increasing fields required for isochronous cyclotrons. The conventional solid hill poles are replaced by poles mounted over a small secondary gap which tapers radially from maximum at the magnet edge to zero near the center. Field measurements with a model magnet and calculations with the code TRIM show an increase in field at the edge of the magnet without the usual corresponding large increase in fringing, and a radial field shape more nearly field independent than for conventional hills. The flying hills have several advantages for variable energy multiparticle cyclotrons: (1) a large reduction in the power dissipated by isochronizing trim coils; (2) a more constant shape and magnitude flutter factor, eliminating flutter coils and increasing the operating range; and (3) a sharper fall-off of the fringe field, simplifying beam extraction.

  13. A method to determine asteroid poles

    NASA Technical Reports Server (NTRS)

    Deangelis, G.

    1993-01-01

    The determination of spin axis and shape is well known to be of fundamental importance for studies about the rotational and physical properties of asteroids. In particular, knowledge that the pole coordinate distribution is random or not could indicate the probable non-Maxwellian distribution of asteroid spin axes, while the distribution in terms of size and shape could place important constraints on the theories about the collisional history of some individual asteroids, of asteroid families, and of the asteroid population as a whole. Many kinds of methods have been developed to determine pole coordinates. An EA method is presented, from which it is possible to obtain the solution with no trial poles, but with a simultaneous least square fit on both the E and A part. Results for rotational and shape parameters were obtained for 18 asteroids: the values of the obtained parameters are generally in close agreement with those of others.

  14. Log amplifier with pole-zero compensation

    DOEpatents

    Brookshier, William

    1987-01-01

    A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifier circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedback loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point or pole is offset by a compensating break point or zero.

  15. Determination of pole sensitivities by Danilevskii's method

    NASA Technical Reports Server (NTRS)

    Nail, J. B.; Mitchell, J. R.; Mcdaniel, W. L., Jr.

    1977-01-01

    In control theory, a synonymous term for pole sensitivity is eigenvalue sensitivity. Existing methods of calculating eigenvalues are cumbersome, and cannot be trusted for systems roughly greater than tenth order. The method proposed in the present paper is applicable to high-order system. (It has been routinely used to generate eigenvalue sensitivities for systems up to 26th order, using a UNIVAC 1106.) Danilevskii's method is shown to be suitable for performing the necessary evaluations. The result is a rational function that can be used to evaluate the sensitivities for all distinct poles.

  16. Evidence of water ice near the lunar poles

    SciTech Connect

    Feldman, W. C.; Maurice, S.; Lawrence, David J. ,; Little, R. C.; Lawrence, S. L.; Gasnault, O. M.; Wiens, R. C.; Barraclough, B. L.; Elphic, Richard C.,; Prettyman, T. H.; Steinberg, John Tyree; Binder, A. B.

    2001-01-01

    the large sunlit polar craters and the relatively high [H] in neighboring inter-crater plains. A closer look at the 'inter-crater' plains near the poles, shows that they are covered by many small craters that harbor permanent shade [4]. The temperatures within many of these craters are low enough [5] that they can disable sublimation as a viable loss process of [H{sub 2}O]. It is therefore tempting to postulate that the enhanced hydrogen within most regions of permanent shade is in the form of water molecules. This postulate is certainly viable within the bottoms of several large, permanently shaded craters near the south pole. Predicted temperatures within them [5] fall well below the 100 K temperature that is needed to stabilize water ice for aeons. The picture is different near the north pole. Here, there are relatively few permanently-shaded craters that are large enough to harbor temperatures that are sufficiently low to stabilize water ice indefinitely against sublimation [5]. Instead, the 'inter-crater' polar plains are a jumble of many permanently-shaded craters that have diameters less than 10 km [4]. Although simulations of temperatures within this class of craters show they are only marginally cold enough to indefinitely stabilize water ice [5], this terrane appears to have the highest [H]. Nevertheless, predicted temperatures are close enough to that needed to permanently stabilize [H{sub 2}O] to suggest that sublimation is indeed the process that discriminates between polar terrane that contains enhanced [H] and those that do not (see, e.g., the temperature estimates for doubly-shaded craters [6]). If correct, then an important fraction of the hydrogen near the north pole must be in the form of H{sub 2}O, which then resides within these small craters. Estimates using our improved data set of [H] within craters near the south pole remain unchanged from those derived from our previous analysis [2], [H] = 1700{+-}900 ppm. This translates to [H{sub 2}O]=1

  17. ULYSSES comes full circle, before revisiting the Sun's poles

    NASA Astrophysics Data System (ADS)

    1998-04-01

    slanted orbit took Ulysses to solar latitudes greater than 70 degrees for a total of 234 days -- first in the southern hemisphere and then in the north. Also of great interest was the rapid passage from the south to the north, via the Sun's equatorial region, during which Ulysses covered 160 degrees in solar latitude in less than a year. Nine onboard experiments have gathered data continuously since launch, for international teams totalling 150 scientists. Some instruments detect the outward-blowing solar wind and its magnetic field, which create the heliosphere. Others record cosmic rays coming in from the Galaxy, which are strongly influenced by the solar wind. Ulysses picks up natural radio signals emitted by the Sun, the planets and the heliosphere itself. Innovative techniques identify alien atoms and dust particles infiltrating the heliosphere from interstellar space. Ulysses is also a key member of a network of interplanetary spacecraft making observations of enigmatic bursts of gamma rays originating in the far reaches of the Universe. New facts about the fast solar wind were among Ulysses' most fundamental discoveries. The typical solar wind emerging from the Sun's equatorial zone is variable but relatively slow, at 350-400 kilometres per second. The fast wind blows at a steady 750 kilometres per second. It comes from cool regions of the solar atmosphere called coronal holes which (when the Sun is quiet) are close to the poles and fairly small. Yet Ulysses found the fast wind fanning out to fill two-thirds of the volume of the heliosphere. The boundary between the two windstreams is unexpectedly sharp. The magnetic field of the Sun turns out to be strangely uniform at all latitudes in the heliosphere. Close to the visible surface of the Sun, the magnetic field is strongest over the poles, but this intensification disappears at Ulysses' distance. Apparently magnetic pressure in the solar wind averages out the differences in field strength. On the other hand

  18. Aurora A kinase contributes to a pole-based error correction pathway

    PubMed Central

    Ye, Anna A.; Deretic, Jovana; Hoel, Christopher M.; Hinman, Albert W.; Cimini, Daniela; Welburn, Julie P.; Maresca, Thomas J.

    2015-01-01

    Summary Chromosome biorientation, where sister kinetochores attach to microtubules (MTs) from opposing spindle poles, is the configuration that best ensures equal partitioning of the genome during cell division. Erroneous kinetochore-microtubule (kt-MT) attachments are commonplace but often corrected prior to anaphase [1, 2]. Error correction, thought to be mediated primarily by the centromere-enriched Aurora B kinase (ABK) [3-5], typically occurs near spindle poles [6]; albeit, the relevance of this locale is unclear. Furthermore, polar ejection forces (PEFs), highest near poles [7], can stabilize improper attachments by pushing mal-oriented chromosome arms away from spindle poles [8, 9]. Hence, a conundrum: erroneous kt-MT attachments are weakened where PEFs are most likely to strengthen them. Here, we report that Aurora A kinase (AAK) opposes the stabilizing effect of PEFs. AAK activity contributes to phosphorylation of kinetochore substrates near poles and its inhibition results in chromosome mis-alignment and an increased incidence of erroneous kt-MT attachments. Furthermore, AAK directly phosphorylates a site in the N-terminal tail of Ndc80/Hec1 that has been implicated in reducing the affinity of the Ndc80 complex for MTs when phosphorylated [10-12]. We propose that an AAK activity gradient contributes to correcting mal-oriented kt-MT attachments in the vicinity of spindle poles. PMID:26166783

  19. Aurora A Kinase Contributes to a Pole-Based Error Correction Pathway.

    PubMed

    Ye, Anna A; Deretic, Jovana; Hoel, Christopher M; Hinman, Albert W; Cimini, Daniela; Welburn, Julie P; Maresca, Thomas J

    2015-07-20

    Chromosome biorientation, where sister kinetochores attach to microtubules (MTs) from opposing spindle poles, is the configuration that best ensures equal partitioning of the genome during cell division. Erroneous kinetochore-MT attachments are commonplace but are often corrected prior to anaphase. Error correction, thought to be mediated primarily by the centromere-enriched Aurora B kinase (ABK), typically occurs near spindle poles; however, the relevance of this locale is unclear. Furthermore, polar ejection forces (PEFs), highest near poles, can stabilize improper attachments by pushing mal-oriented chromosome arms away from spindle poles. Hence, there is a conundrum: erroneous kinetochore-MT attachments are weakened where PEFs are most likely to strengthen them. Here, we report that Aurora A kinase (AAK) opposes the stabilizing effect of PEFs. AAK activity contributes to phosphorylation of kinetochore substrates near poles and its inhibition results in chromosome misalignment and an increased incidence of erroneous kinetochore-MT attachments. Furthermore, AAK directly phosphorylates a site in the N-terminal tail of Ndc80/Hec1 that has been implicated in reducing the affinity of the Ndc80 complex for MTs when phosphorylated. We propose that an AAK activity gradient contributes to correcting mal-oriented kinetochore-MT attachments in the vicinity of spindle poles.

  20. On the design of pole modules for inverse systems

    NASA Technical Reports Server (NTRS)

    Wyman, B. F.; Sain, M. K.

    1985-01-01

    When a linear dynamical system admits more than one inverse, it is known that the pole module of any inverse must contain, either as a submodule or as a factor module, a module of fixed poles isomorphic to the zero module of the original system. Design of the pole module for such an inverse system is resolved by introducing a variable pole module for the inverse, by determining necessary and sufficient conditions for a desired module to be a variable pole module, and by studying the manner in which the fixed and variable modules assemble into the pole module of the inverse. If the fixed and variable pole spectra are disjoint, the pole module of the inverse system is a direct sum of the fixed- and variable-pole modules; if not, procedures for addressing the Jordan structure are presented.

  1. Child health insurance coverage and household activity toward child development in four South American countries.

    PubMed

    Wehby, George L

    2014-05-01

    We evaluate the association between child health insurance coverage and household activities that enhance child development. We use micro-level data on a unique sample of 2,370 children from four South American countries. Data were collected by physicians via in-person interviews with the mothers. The regression models compare insured and uninsured children seen within the same pediatric care practice for routine well-child care and adjust for several demographic and socioeconomic characteristics. We also stratify these analyses by selective household demographic and socioeconomic characteristics and by country. We find that insurance coverage is associated with increasingly engaging the child in development-enhancing household activity in the total sample. This association significantly varies with ethnic ancestry and is more pronounced for children of Native or African ancestry. When stratifying by country, a significant positive association is observed for Argentina, with two other countries having positive but insignificant associations. The results suggest that insurance coverage is associated with enhanced household activity toward child development. However, other data and research are needed to estimate the causal relationship.

  2. Formation of Hydrothermal nontronite associated with microbial activity at the South Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Ta, Kaiwen; Peng, Xiaotong; Chen, Shun; Xu, Hengchao; Li, Jiwei; Jiang, Lei; Du, Mengran

    2015-04-01

    Nontronite is an ubiquitous clay minerals in marine sediments, microbial mediation of hydrothermal nontronite have been increasing. The deposits collected from Southern Atlantic Ridge were very friable with an obvious laminated to stromatolitic to highly porous structure, varying from red, black to light yellow indicate redox condition may undergo range from micro-oxidizing to reducing. Although microbial activity are revealed to play an important role in the formation of clay minerals in sediment, little is currently known about microbial communities that reside in nontronite associated with hydrothermal activity. Here, we used Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), nano secondary ion mass spectrometer (nanoSIMS) and molecular techniques to focus on potential mediation role of microbial in the nontronite formation of low-temperature hydrothermal deposits in South Atlantic Mid-ocean ridge. Our data suggest that the presences of abundant lamellar nontronite structures, as well as microbe-like mineralized morphologies similar to consistent with a biogenic origin. Nontronite in the lower zone of Fe-Mn oxyhydroxides are inferred to have been suboxic environment and their formation appear to be significantly controlled by the locus of redox conditions. Keywords: Nontronite, Microbial activity, Hydrothermal deposits, Biogenic origin.

  3. Chemical Composition and Antibacterial Activity of Essential Oil of Cosmos bipinnatus Cav. Leaves from South Africa.

    PubMed

    Olajuyigbe, Olufunmiso; Ashafa, Anofi

    2014-01-01

    The chemical composition of essential oils isolated from the leaves of Cosmos bipinnatus and its antibacterial activity were analyzed by GC-MS and microbroth dilution assay respectively. The essential oil extracted from this plant was predominantly composed of monoterpenes (69.62%) and sesquiterpenes (22.73%). The antibacterial assay showed that the oil had significant inhibitory effects against both Gram-negative and Gram-positive bacteria isolates. The MIC of Gram-positive strains ranged between 0.16 and 0.31 mg/mL while those of Gram-negative bacteria ranged between 0.31 and 0.63 mg/mL. The Gram-positive bacteria were more susceptible to the essential oil than the Gram-negative bacteria. Most of the major components of this oil in other plants have been reported for antimicrobial activities. The antibacterial activity can be attributed to effects of the combination of several components of the oil. The results indicate that the C. bipinnatus might be exploited as natural antibacterial agent and have application in the treatment of several infectious diseases caused by these bacteria. Since this species is endemic to the eastern Free State, the plant could be collected during its bloom and used efficiently in the management of bacterial infections in South Africa.

  4. Chemical Composition and Antibacterial Activity of Essential Oil of Cosmos bipinnatus Cav. Leaves from South Africa

    PubMed Central

    Olajuyigbe, Olufunmiso; Ashafa, Anofi

    2014-01-01

    The chemical composition of essential oils isolated from the leaves of Cosmos bipinnatus and its antibacterial activity were analyzed by GC-MS and microbroth dilution assay respectively. The essential oil extracted from this plant was predominantly composed of monoterpenes (69.62%) and sesquiterpenes (22.73%). The antibacterial assay showed that the oil had significant inhibitory effects against both Gram-negative and Gram-positive bacteria isolates. The MIC of Gram-positive strains ranged between 0.16 and 0.31 mg/mL while those of Gram-negative bacteria ranged between 0.31 and 0.63 mg/mL. The Gram-positive bacteria were more susceptible to the essential oil than the Gram-negative bacteria. Most of the major components of this oil in other plants have been reported for antimicrobial activities. The antibacterial activity can be attributed to effects of the combination of several components of the oil. The results indicate that the C. bipinnatus might be exploited as natural antibacterial agent and have application in the treatment of several infectious diseases caused by these bacteria. Since this species is endemic to the eastern Free State, the plant could be collected during its bloom and used efficiently in the management of bacterial infections in South Africa. PMID:25587332

  5. Thermally anomalous features in the subsurface of Enceladus's south polar terrain

    NASA Astrophysics Data System (ADS)

    Le Gall, A.; Leyrat, C.; Janssen, M. A.; Choblet, G.; Tobie, G.; Bourgeois, O.; Lucas, A.; Sotin, C.; Howett, C.; Kirk, R.; Lorenz, R. D.; West, R. D.; Stolzenbach, A.; Massé, M.; Hayes, A. H.; Bonnefoy, L.; Veyssière, G.; Paganelli, F.

    2017-03-01

    Saturn's moon Enceladus is an active world. In 2005, the Cassini spacecraft witnessed for the first time water-rich jets venting from four anomalously warm fractures (called sulci) near its south pole1,2. Since then, several observations have provided evidence that the source of the material ejected from Enceladus is a large underground ocean, the depth of which is still debated3-6. Here, we report on the first and only opportunity that Cassini's RADAR instrument7,8 had to observe Enceladus's south polar terrain closely, targeting an area a few tens of kilometres north of the active sulci. Detailed analysis of the microwave radiometry observations highlights the ongoing activity of the moon. The instrument recorded the microwave thermal emission, revealing a warm subsurface region with prominent thermal anomalies that had not been identified before. These anomalies coincide with large fractures, similar or structurally related to the sulci. The observations imply the presence of a broadly distributed heat production and transport system below the south polar terrain with 'plate-like' features and suggest that a liquid reservoir could exist at a depth of only a few kilometres under the ice shell at the south pole. The detection of a possible dormant sulcus further suggests episodic geological activity.

  6. Temperament and living conditions: a comparison study of Poles and Koreans.

    PubMed

    Zajenkowska, Anna; Zajenkowski, Marcin

    2013-02-01

    The present investigation tested the temperament traits of 319 Polish and 315 South Korean students according to the regulative theory of temperament. Poland and South Korea are two countries with a similar rate of economic growth but with distinct cultures; for instance, they differ in terms of individualism and masculinity dimensions as well as living conditions. This means that they have achieved the same goal with different resources but presumably also with different side effects. The results indicate that the Poles had higher levels of briskness, sensor sensibility and endurance, as well as lower levels of emotional reactivity and perseveration in comparison with South Koreans. The structure of one's temperament determines one's ability to meet environmental requirements and also how one deals with stressful conditions. According to previous empirical data, Poles' temperament profile can be characterized as being less prone to stress perception and therefore more advantageous. It is possible that Koreans, as they have a less adaptive temperament structure, experience higher levels of stress in a more stimulating environment than Poles.

  7. 76 FR 60493 - Settlement Agreements for Recovery of Past Response Costs; Granite Timber Post and Pole Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... AGENCY Settlement Agreements for Recovery of Past Response Costs; Granite Timber Post and Pole Site, Philipsburg, Granite County, MT AGENCY: Environmental Protection Agency (EPA). ACTION: Notice and Request for... Mark Metesh (Settling Party), regarding the Granite Timber Site (Site), located 5 miles south...

  8. Why is g Larger at the Poles?

    ERIC Educational Resources Information Center

    Iona, Mario

    1978-01-01

    Explains that the larger value of g at the poles is not due only to differences in the radii of the earth, but that other factors are also responsible such as the rotation of the earth and the increase in the earth's density toward its center. (GA)

  9. Poling of Microwave Electro-Optic Devices

    NASA Technical Reports Server (NTRS)

    Singer, Kenneth D.

    1997-01-01

    The desire to transmit high frequency, microwave RF signals over fiber optic cables has necessitated the need for electro-optic modulation devices. However, in order to reap these potential benefits, it is necessary to develop the devices and their associated fabrication processes, particularly those processes associated with the poling of the devices. To this end, we entered into a cooperative research agreement with Richard Kunath of NASA LeRC. A graduate student in my group, Tony Kowalczyk, worked closely with the group at NASA to develop processes for construction of a microwave frequency electro-optic modulator. Materials were commercially obtained from Amoco Chemical and in collaboration with Lockheed-Martin. The photolithography processes were developed at NASA LeRC and the electric-field poling process was carried out in our laboratory at CWRU. During the grant period, the poling process conditions were investigated for these multilayer devices. Samples were poled and the resulting nonlinear optical properties were evaluated in our laboratory. Following the grant period, Kowalczyk went to NASA under a NRC fellowship, and I continued to collaborate as a consultant. Publications listed at the end of this report came out of this work. Another manuscript is in preparation and will be submitted shortly.

  10. New aspects of the equilibrium pole tide

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.; Steinberg, D. J.

    1986-01-01

    A new spherical harmonic algorithm is developed for the calculation of the loading and self-gravitating equilibrium pole tide. Based on a suggestion of Dahlen (1976), this approach minimizes the distortions in tide height caused by an incomplete representation of the ocean function. With slight modification this approach easily could be used to compute self-gravitating and loading lunisolar tides as well. Using the algorithm, the static pole tide is compared with tide observations at a variety of locations around the world, and statistically significant evidence for pole tide enhancements is found in midocean as well as the shallow seas. Also included is a reinvestigation of the effect of the static tide on the Chandler-wobble period. The difference between the wobble period of an oceanless elastic earth with a fluid core (Smith and Dahlen, 1981) and the period of an earth minus static oceans yields a 7.4-day discrepancy. It is concluded from tide observations that much of the discrepancy can probably be accounted for by nonequilibrium pole-tide behavior in the deep oceans.

  11. Numerical pole assignment by eigenvalue Jacobian inversion

    NASA Technical Reports Server (NTRS)

    Sevaston, George E.

    1986-01-01

    A numerical procedure for solving the linear pole placement problem is developed which operates by the inversion of an analytically determined eigenvalue Jacobian matrix. Attention is given to convergence characteristics and pathological situations. It is not concluded that the algorithm developed is suitable for computer-aided control system design with particular reference to the scan platform pointing control system for the Galileo spacecraft.

  12. Executive University Managers' Experiences of Strike and Protest Activity: A Qualitative Case Study of a South African University

    ERIC Educational Resources Information Center

    Dominguez-Whitehead, Y.

    2011-01-01

    Strike and protest activity at South African universities continues to be prevalent nearly two decades after the dismantling of apartheid, although there has been a shift away from directing strikes and protests against the government (during the apartheid era), to directing them against higher education institutions and management (since the…

  13. Effect of Active Learning Techniques on Students' Choice of Approach to Learning in Dentistry: A South African Case Study

    ERIC Educational Resources Information Center

    Khan, S.

    2011-01-01

    The purpose of this article is to report on empirical work, related to a techniques module, undertaken with the dental students of the University of the Western Cape, South Africa. I will relate how a range of different active learning techniques (tutorials; question papers and mock tests) assisted students to adopt a deep approach to learning in…

  14. A Survey of Automated Activities in the Libraries of Mexico, Central America and South America; Volume 4, World Survey Series.

    ERIC Educational Resources Information Center

    Patrinostro, Frank S., Comp.; Sanders, Nancy P., Ed.

    The intent of this fourth volume of the "Survey of Automated Activities in the Libraries of the World" is to identify and describe computer-based library projects in the Latin American countries. Information was drawn from survey questionnaires sent to individual libraries. However, few of the South American libraries responded, and as a…

  15. Protest, Performance and Politics: The Use of "Nano-Media" in Social Movement Activism in South Africa

    ERIC Educational Resources Information Center

    Dawson, Marcelle C.

    2012-01-01

    Considering the lack of coverage in the mass media of certain kinds of social movement activity, many movements make use of smaller scale, independent media to publicise their struggles. From the vantage point of social movements in South Africa, this paper addresses what Mojca Pajnik and John Downing call "nano-media". Based on…

  16. LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING EAST Generals Highway, Lodge ...

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

    LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING EAST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  17. LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING NORTHWEST Generals Highway, Lodge ...

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

    LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING NORTHWEST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  18. Acute effects of walking with Nordic poles in persons with mild to moderate low-back pain

    PubMed Central

    REVORD, LANDON P; LOMOND, KAREN V; LOUBERT, PETER V; HAMMER, ROGER L

    2016-01-01

    Regular walking with or without Nordic poles is effective over time at reducing discomfort in individuals with chronic low back pain (LBP). Nordic pole use increases balance and stability, distributes weight through the arms and torso, and decreases loading of the spine and lower limbs. The purpose of this study was to determine if Nordic poles would reduce perceived acute discomfort while self-paced walking in individuals with LBP. We also examined whether walking with or without poles increased heart rate (HR) and ratings of perceived exertion (RPE) or speed of movement. Subjects included 20 adults (12 males, 8 females; mean age of 45.1±16.3) who were experiencing LBP of at least six months’ duration (Oswestry Disability Index (ODI): mean 17 ± 8%, range 6–36% indicating minimal to moderate disability) with no current active flare-up. Participants walked a predetermined dirt-path course (805 m or 0.5 mi) with and without poles in randomized order. Data were analyzed using a 2 X 2 repeated measures ANOVA (Condition X Time), where Condition was poles vs no poles and Time was pre- and post-walk. HR and RPE increased significantly from walking the course, whereas pain did not change. There were also no differences between walking with or without poles for pain (ODI Sec #1: 0.2 points, p=0.324), HR (4 bpm, p=0.522) and RPE (0 points, p=0.759). The mean course time (sec) was slower with poles: 617±87 vs 566±65 (p<0.001). Unexpectedly, there was a noticeable drop in pain following the warm up which was done using poles (0.9 points, p<0.001). Nordic pole use is well tolerated in those with current back pain and can be encouraged, however it cannot be recommended as a superior method of addressing acute symptoms when walking. PMID:27990219

  19. Poling and characterization of a novel organic/polymer electro-optic material

    NASA Astrophysics Data System (ADS)

    Liao, Jinkun; Tang, Xianzhong; Lu, Rongguo; Tang, Xionggui; Li, Heping; Zhang, Xiaoxia; Liu, Yongzhi

    2010-10-01

    Electro-optic organic/polymer material is important for the fabrication of polymer integrated optic-electronic devices and organic sensors. Recently, a novel organic high μβ value chromophore FFC have been synthesized by molecular design. The absorption spectrum in 400-4000 cm-1 is measured for the material, and the measurement result shows that the absorption loss is negligibly small. An organic/polymer high electro-optic activity material FFC/PSU is obtained by dissolving guest FFC (wt. 20%) and a host polysulfone (PSU) in a solvent. The resolvability of cyclohexanone for the material is satisfactory by comparison with other solvents experimentally, and the preparation of FFC/PSU thin film is ease relatively. The materiel is poled by electric field-assisted contact poling, and the near optimum poling condition is determined by adjusting poling parameters as pre-curing duration, poling temperature and poling voltage etc. The electro-optic coefficient of the material is measured as high as 130pm/V by using the widely accepted simple reflection technique. The investigation indicates that the FFC/PSU has excellent characteristics, such as high electro-optic coefficient, low absorption loss, good thermal stability and capability for withstanding the subsequent process techniques, suitable for the fabrication of high-performance integrated optic-electronic devices and sensors.

  20. Environmental effects of supplemental wood preservative treatments of electric utility poles. Final report

    SciTech Connect

    Horn, M.E.

    1995-12-01

    A field study and associated risk assessment was conducted to evaluate the potential ecological and human health impacts related to the standard application of five supplemental wood preservatives to 20 electric utility transmission poles. Post-application monitoring for chemical residuals and microbiological effects was conducted over a 17 month post-application period (June 6, 1990--November 7, 1991). The utility wood poles in the study were located in wetland sites of the New York State Adirondack Park. All poles were western red cedar and all had been treated with pentachlorophenol (PCP) prior to installation. At the time supplemental preservatives were applied, the poles had been in service for approximately 40 years. Groundwater, surface water, and soil around each treated pole were monitored for release of active ingredients, organic carriers and subsequent degradation products of the commercial wood preservatives. The analytes were as follows: chlorpyrifos, 1,1,1-trichloroethane, creosote, 2,4-dinitrophenol, fluoride, chromium, arsenic, copper, naphthenate, sodium methyl dithiocarbamate and methyl isothiocyanate. Ecological response to chemical exposure was estimated by means of measuring soil gases (carbon dioxide and methane), soil macroinvertebrate populations and soil microbial biomass. Results from near-pole post-treatment sampling were compared to pre-treatment samples and reference plots used to establish preapplication biological conditions and background levels of wood preservative constituents.

  1. 226Ra activity in the mullet species Liza aurata and South Adriatic Sea marine.

    PubMed

    Antovic, N M; Antovic, I; Svrkota, N

    2010-08-01

    (226)Ra activity in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass (Posidonia oceanica) samples and the mullet (Mugilidae) species Liza aurata, as well as soil and sand from the Montenegrin Coast-was measured using the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. The results are used for calculation of the absorbed (and annual effective) dose rates in air due to the (226)Ra gamma radiation. The absorbed dose rates ranged from 5.94 to 97.16 nGy h(-1) (soil) and from 0.65 to 7.65 nGy h(-1) (sand). In seawater (226)Ra activity is found to be from 0.08 to 0.15 Bq l(-1), while in whole L. aurata individuals from 0.58 to 1.97 Bq kg(-1). Annual intake of (226)Ra by human consumers of this fish species has been estimated to provide an effective dose of 0.006 mSv y(-1).

  2. Education and Public Outreach activities in Radio astronomy with the SKA South Africa

    NASA Astrophysics Data System (ADS)

    Oozeer, N.; Bassett, B. A.; de Boer, K.

    2014-10-01

    A Human Capital Development (HCD) program is a crucial part of any large organisation, and especially for large new research facilities such as the Square Kilometre Array (SKA) Africa. HCD provides a way of developing and channeling new minds into a very demanding field that ensures sustainability of the project and a multitude of spin-off benefits. Apart from educating learners at various levels, the HCD program must also inspire and educate the general public about the projects via an active outreach program. We highlight the various types of outreach activities that have been carried out in South Africa and the other SKA Africa partner countries. While there exist many teaching models we introduce and explore a novel concept of peer teaching for research known as the Joint Exchange Development Initiative (JEDI) and present some of its results. The JEDI workshops have resulted in a considerable number of learners embarking on advanced careers in science and research, and the demand is still growing.

  3. DISCOVERY OF THE RECOMBINING PLASMA IN THE SOUTH OF THE GALACTIC CENTER: A RELIC OF THE PAST GALACTIC CENTER ACTIVITY?

    SciTech Connect

    Nakashima, S.; Nobukawa, M.; Uchida, H.; Tanaka, T.; Tsuru, T. G.; Koyama, K.; Murakami, H.; Uchiyama, H.

    2013-08-10

    We report Suzaku results for soft X-ray emission to the south of the Galactic center (GC). The emission (hereafter {sup G}C South{sup )} has an angular size of {approx}42' Multiplication-Sign 16' centered at (l, b) {approx} (0. Degree-Sign 0, - 1. Degree-Sign 4) and is located in the largely extended Galactic ridge X-ray emission (GRXE). The X-ray spectrum of GC South exhibits emission lines from highly ionized atoms. Although the X-ray spectrum of the GRXE can be well fitted with a plasma in collisional ionization equilibrium (CIE), that of GC South cannot be fitted with a plasma in CIE, leaving hump-like residuals at {approx}2.5 and 3.5 keV, which are attributable to the radiative recombination continua of the K-shells of Si and S, respectively. In fact, GC South spectrum is well fitted with a recombination-dominant plasma model; the electron temperature is 0.46 keV while atoms are highly ionized (kT = 1.6 keV) in the initial epoch, and the plasma is now in a recombining phase at a relaxation scale (plasma density Multiplication-Sign elapsed time) of 5.3 Multiplication-Sign 10{sup 11} s cm{sup -3}. The absorption column density of GC South is consistent with that toward the GC region. Thus, GC South is likely to be located in the GC region ({approx}8 kpc distance). The size of the plasma, the mean density, and the thermal energy are estimated to be {approx}97 pc Multiplication-Sign 37 pc, 0.16 cm{sup -3}, and 1.6 Multiplication-Sign 10{sup 51} erg, respectively. We discuss possible origins of the recombination-dominant plasma as a relic of past activity in the GC region.

  4. Discovery of the Recombining Plasma in the South of the Galactic Center: A Relic of the Past Galactic Center Activity?

    NASA Astrophysics Data System (ADS)

    Nakashima, S.; Nobukawa, M.; Uchida, H.; Tanaka, T.; Tsuru, T. G.; Koyama, K.; Murakami, H.; Uchiyama, H.

    2013-08-01

    We report Suzaku results for soft X-ray emission to the south of the Galactic center (GC). The emission (hereafter "GC South") has an angular size of ~42' × 16' centered at (l, b) ~ (0.°0, - 1.°4) and is located in the largely extended Galactic ridge X-ray emission (GRXE). The X-ray spectrum of GC South exhibits emission lines from highly ionized atoms. Although the X-ray spectrum of the GRXE can be well fitted with a plasma in collisional ionization equilibrium (CIE), that of GC South cannot be fitted with a plasma in CIE, leaving hump-like residuals at ~2.5 and 3.5 keV, which are attributable to the radiative recombination continua of the K-shells of Si and S, respectively. In fact, GC South spectrum is well fitted with a recombination-dominant plasma model; the electron temperature is 0.46 keV while atoms are highly ionized (kT = 1.6 keV) in the initial epoch, and the plasma is now in a recombining phase at a relaxation scale (plasma density × elapsed time) of 5.3 × 1011 s cm-3. The absorption column density of GC South is consistent with that toward the GC region. Thus, GC South is likely to be located in the GC region (~8 kpc distance). The size of the plasma, the mean density, and the thermal energy are estimated to be ~97 pc × 37 pc, 0.16 cm-3, and 1.6 × 1051 erg, respectively. We discuss possible origins of the recombination-dominant plasma as a relic of past activity in the GC region.

  5. Are Narrow Line Seyfert 1 Galaxies Viewed Pole-on?

    DTIC Science & Technology

    2011-04-01

    0.2’’ respectively. Figure 1 displays the position of each slit over a Barbosa et al. (2009) GMOS IFU image of the [S III] flux (which originates...C. Winge, H. Schmitt: Gemini/ GMOS IFU gas velocity ’tomography’ of the narrow line region of nearby active galaxies, MNRAS, 396 (2009) 2. [2] D...1995) 81. 4 P o S ( N L S 1 ) 0 5 0 Are NLS1s Pole-on? Travis C. Fischer 5 Figure 1: NGC 4051 GMOS IFU image showing integrated [SIII] flux

  6. Sexual identity in the American Deep South: the concordance and discordance of sexual activity, relationships, and identities.

    PubMed

    Baunach, Dawn Michelle; Burgess, Elisabeth O

    2013-01-01

    This research explores the association between sexual identity and sexual behavior and how that association varies across gender and race in the American Deep South. Multinomial logistic regression analysis is used to determine the likelihood of each sexual identity given past sexual behavior, sexual relationships, and other social characteristics. The more traditional cultural climate of the South appears to suppress identification as a sexual minority. Sexual identification in the Deep South is primarily a product of sexual activity and sexual relationships, although attitudes toward and contact with the lesbian, gay, bisexual, and transgender (LGBT) community play a minor role. Although most participants' sexual behaviors and identities were in concordance, sexual discordance was highest for White women and lowest for White men. Discordance was also associated with traditional men's roles attitudes, negative homosexuality attitudes, and contact with the LGBT community. It is hoped that these results encourage scholarship that deconstructs the sexual behavior and identity of all groups, not just oppressed groups.

  7. A new grand mean palaeomagnetic pole for the 1.11 Ga Umkondo large igneous province with implications for palaeogeography and the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Swanson-Hysell, N. L.; Kilian, T. M.; Hanson, R. E.

    2015-12-01

    We present a new grand mean palaeomagnetic pole (Plong: 222.1°, Plat: -64.0°, A95: 2.6°, N = 49) for the ca. 1110 Ma Umkondo large igneous province (LIP) of the Kalahari Craton. New palaeomagnetic data from 24 sills in Botswana and compiled reprocessed existing data are used to develop a palaeomagnetic pole as the Fisher mean of cooling unit virtual geomagnetic poles (VGPs). The mean and its associated uncertainty provide the best-constrained pole yet developed for the province. Comparing data from individual cooling units allows for evaluation of palaeosecular variation at this time in the Mesoproterozoic. The elongation of the population of VGPs is consistent with that predicted by the TK03.GAD model lending support to the dipolar nature of the field in the late Mesoproterozoic. In our new compilation, 4 of 59 (˜7 per cent) of the igneous units have northerly declinations while the rest are south-directed indicating that a geomagnetic reversal occurred during magmatic activity. Interpreting which of these polarities corresponds with a normal or reversed geomagnetic field relative to other continents can constrain the relative orientations between cratons with time-equivalent data. This interpretation is particularly important in comparison to Laurentia as it bears on Kalahari's involvement and position in the supercontinent Rodinia. The dominance of south-directed declinations within the Umkondo Province was previously used to suggest that these directions are the same polarity as reversed directions from the early magmatic stage of the Keweenawan Midcontinent Rift of Laurentia. Two Umkondo sills with northerly declinations have U-Pb baddeleyite ages of ca. 1109 Ma that are temporally close to dated Midcontinent Rift units having reversed directions. Based on this comparison, and palaeomagnetic data from younger units in the Kalahari Craton, we favour the option in which the sites with northerly declinations from the Umkondo Province correspond to the

  8. The North-South asymmetry of solar activity: A signature of two coupled chaotic oscillators?

    NASA Astrophysics Data System (ADS)

    Donner, Reik V.

    2010-05-01

    The phase-coherent oscillatory dynamics on the 11-year frequency band (Schwabe cycle) is a common feature in all characteristic observables of solar activity. In this work, a wavelet-based framework [1,2] is applied for studying the mutual phase synchronicity of these oscillations. As a problem of specific scientific interest, the variability recorded on both solar hemispheres is systematically studied. It is demonstrated that time-varying phase shifts between the activity on Northern and Southern hemispheres provides a major contribution to the so-called North-South asymmetry (NSA). The presented results indicate that the NSA observations are consistent with the assumption of a different long-term phase diffusion of two weekly chaotic coupled oscillators, which evolve coherently in time. The obtained quantitative results on the variability of interhemispheric phase shifts are critically compared with the outcome of other studies using complementary methods of time series analysis [3]. The statistical reliability and implications of the derived long-term phase shift variability result are discussed. By using sophisticated methods for time series continuation and extrapolation [4], the recently hypothesised relationship between strong phase asynchrony of hemispheric variability and the occurrence of great minima of solar activity [5] is critically reexamined. References: [1] R. Donner, M. Thiel, A&A 475, L33-L36 (2007) [2] R. Donner, in: Nonlinear Time Series Analysis in the Geosciences (ed. by R.V. Donner and S.M. Barbosa), Springer, Berlin, 2008, pp. 355-386 [3] N.V. Zolotova, D.I. Ponyavin, N. Marwan, J. Kurths, A&A 503, 197-201 (2009) [4] C. Komalapriya, M. Thiel, M.C. Romano, N. Marwan, U. Schwarz, J. Kurths, Phys. Rev. E 78, 066217 (2008) [5] N.V. Zolotova, D.I. Ponyavin, A&A 470, L17-L20 (2007)

  9. EDs in the Midwest and South activate disaster plans as deadly tornadoes sweep through the region.

    PubMed

    2012-05-01

    Hospitals in the Midwest and South activated their disaster plans in early March to deal with a phalanx of powerful tornadoes that leveled several small towns and killed at least two dozen people. Some hospitals had to activate plans for both internal and external disasters as their own facilities were threatened. One small critical-access hospital in West Liberty, KY, sustained significant damage and had to evacuate its patients to another facility. All the hospitals credit their disaster plans and practice drills with helping them to manage the crisis as efficiently as possible. Morgan County ARH Hospital in West Liberty, KY, went for several days without an operational lab or radiology department, but staff kept the ED open for absolute emergencies. Margaret Mary Community Hospital (MMCH) in Batesville, IN, received six tornado victims, but it was prepared for many more. Administrators credit advanced warning of the storms with helping them to prepare effectively, as well as to coordinate their response with other hospitals in the area. As a level 1 trauma center, the University of Louisville Hospital in Louisville, KY, received all the most seriously injured patients in the region, even while the facility itself was under a tornado warning. Staff had to route families away from the glassed-in waiting room to the basement until the tornado warning had passed. At one point during the crisis, there were 90 patients in the hospital's ED even though the department is only equipped with 29 beds. Administrators at Huntsville Hospital in Huntsville, AL, encouraged colleagues to take advantage of smaller-scale emergencies to activate parts of their disaster plans, and to focus disaster preparation drills on their hospital's top hazard vulnerabilities.

  10. Holocene fire activity and vegetation response in South-Eastern Iberia

    NASA Astrophysics Data System (ADS)

    Gil-Romera, Graciela; Carrión, José S.; Pausas, Juli G.; Sevilla-Callejo, Miguel; Lamb, Henry F.; Fernández, Santiago; Burjachs, Francesc

    2010-05-01

    Since fire has been recognized as an essential disturbance in Mediterranean landscapes, the study of long-term fire ecology has developed rapidly. We have reconstructed a sequence of vegetation dynamics and fire changes across south-eastern Iberia by coupling records of climate, fire, vegetation and human activities. We calculated fire activity anomalies (FAAs) in relation to 3 ka cal BP for 10-8 ka cal BP, 6 ka cal BP, 4 ka cal BP and the present. For most of the Early to the Mid-Holocene uneven, but low fire events were the main vegetation driver at high altitudes where broadleaved and coniferous trees presented a highly dynamic post-fire response. At mid-altitudes in the mainland Segura Mountains, fire activity remained relatively stable, at similar levels to recent times. We hypothesize that coastal areas, both mountains and lowlands, were more fire-prone landscapes as biomass was more likely to have accumulated than in the inland regions, triggering regular fire events. The wet and warm phase towards the Mid-Holocene (between ca 8 and 6 ka cal BP) affected the whole region and promoted the spread of mesophytic forest co-existing with Pinus, as FAAs appear strongly negative at 6 ka cal BP, with a less important role of fire. Mid and Late Holocene landscapes were shaped by an increasing aridity trend and the rise of human occupation, especially in the coastal mountains where forest disappeared from ca 2 ka cal BP. Mediterranean-type vegetation (evergreen oaks and Pinus pinaster- halepensis types) showed the fastest post-fire vegetation dynamics over time.

  11. North-south asymmetry of eolian features in Martian polar regions - Analysis based on crater-related wind markers

    NASA Technical Reports Server (NTRS)

    Thomas, P.

    1981-01-01

    Crater-related wind markers in the north and south polar regions of Mars are analyzed in a study of possible north-south asymmetries in wind activity. Features including crater splotches and associated streaks, and depositional, erosional, frost and frost-sediment streaks were identified and analyzed as wind direction indicators on Viking Orbiter and Mariner 9 images of areas poleward of + or - 40 deg latitude. The wind streaks reveal eolian activity at present to be strongest in the north in winter and in the south in spring, due to the hemispherical asymmetry in climate. The alignment of the more massive intercrater dune fields with the presently strongest wind may reflect a longer-term asymmetry in spring flows, as the reorientation times of the dunes exceeded the period of climate asymmetry cycles. Finally, a wider distribution of dune latitudes in the southern polar region is noted to be suggestive of the greater effectiveness of windflow from the south pole.

  12. Pole orientation, sidereal period, and sense of rotation of asteroids

    NASA Technical Reports Server (NTRS)

    Taylor, R. C.; Gehrels, T.

    1986-01-01

    Pole orientations of asteroids were determined. The method, called photometric astrometry, takes precise epochs of lightcurves into account. Pole determination research on asteroids 532 Herculina, 45 Eugenia, and 3 Juno continues. Discrepancies between various pole determination techniques presently being used are analyzed. The study of asteroid shapes and creating a generalized master pole determination technique also continues which will incorporate the best features of several current methods.

  13. Towards a research pole in photonics in Western Romania

    NASA Astrophysics Data System (ADS)

    Duma, Virgil-Florin; Negrutiu, Meda L.; Sinescu, Cosmin; Rominu, Mihai; Miutescu, Eftimie; Burlea, Amelia; Vlascici, Miomir; Gheorghiu, Nicolae; Cira, Octavian; Hutiu, Gheorghe; Mnerie, Corina; Demian, Dorin; Marcauteanu, Corina; Topala, Florin; Rolland, Jannick P.; Voiculescu, Ioana; Podoleanu, Adrian G.

    2014-07-01

    We present our efforts in establishing a Research Pole in Photonics in the future Arad-Timisoara metropolitan area projected to unite two major cities of Western Romania. Research objectives and related training activities of various institutions and groups that are involved are presented in their evolution during the last decade. The multi-disciplinary consortium consists principally of two universities, UAVA (Aurel Vlaicu University of Arad) and UMF (Victor Babes Medicine and Pharmacy University of Timisoara), but also of the Arad County Emergency University Hospital and several innovative SMEs, such as Bioclinica S.A. (the largest array of medical analysis labs in the region) and Inteliform S.R.L. (a competitive SME focused on mechatronics and mechanical engineering). A brief survey of the individual and joint projects of these institutions is presented, together with their teaching activities at graduate and undergraduate level. The research Pole collaborates in R&D, training and education in biomedical imaging with universities in USA and Europe. Collaborative activities, mainly on Optical Coherence Tomography (OCT) projects are presented in a multidisciplinary approach that includes optomechatronics, precision mechanics and optics, dentistry, medicine, and biology.

  14. 30 CFR 57.6701 - Tamping and loading pole requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tamping and loading pole requirements. 57.6701 Section 57.6701 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... poles shall be of wood or other nonconductive, nonsparking material. Couplings for poles shall...

  15. 30 CFR 56.6701 - Tamping and loading pole requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tamping and loading pole requirements. 56.6701 Section 56.6701 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Equipment/tools § 56.6701 Tamping and loading pole requirements. Tamping and loading poles shall be of...

  16. Determination of pole orientations and shapes of asteroids

    NASA Technical Reports Server (NTRS)

    Magnusson, Per; Barucci, M. Antonietta; Drummond, Jack D.; Lumme, Kari; Ostro, Steven J.

    1989-01-01

    The principles of asteroid light-curve inversion are discussed together with basic principles involved in approaches for deriving asteroid pole and shape parameters from photometry data. The merits of various pole determination techniques are described and compared. Results obtained so far on the pole orientations and shapes of asteroids are presented.

  17. Permanent magnet machine and method with reluctance poles and non-identical PM poles for high density operation

    DOEpatents

    Hsu, John S.

    2010-05-18

    A method and apparatus in which a stator (11) and a rotor (12) define a primary air gap (20) for receiving AC flux and at least one source (23, 40), and preferably two sources (23, 24, 40) of DC excitation are positioned for inducing DC flux at opposite ends of the rotor (12). Portions of PM material (17, 17a) are provided as boundaries separating PM rotor pole portions from each other and from reluctance poles. The PM poles (18) and the reluctance poles (19) can be formed with poles of one polarity having enlarged flux paths in relation to flux paths for pole portions of an opposite polarity, the enlarged flux paths communicating with a core of the rotor (12) so as to increase reluctance torque produced by the electric machine. Reluctance torque is increased by providing asymmetrical pole faces. The DC excitation can also use asymmetric poles and asymmetric excitation sources. Several embodiments are disclosed with additional variations.

  18. International Youth Conference on the Poles

    NASA Astrophysics Data System (ADS)

    Church, A. K.; Kuhn, T. S.; Baeseman, J.; Garmulewicz, A.; Raymond, M.; Salmon, R.

    2006-12-01

    The International Polar Year (IPY) is an international effort, involving more than 50 countries, to focus research in both the sciences and social sciences on the world's Polar Regions. In order to secure youth involvement in the IPY, the Youth Steering Committee (YSC) has been formed, aiming specifically to network young polar researchers from all backgrounds enabling collaboration and to involve this group in outreach focused towards other young people. A conference targeted directly at an audience of early career researchers and international youth will be central to fulfilling these aims. The YSC has therefore developed the concept of the International Youth Conference on the Poles (IYCP). Proposed for 2008, this conference will bring together youth from a diverse set of backgrounds and nationalities to discuss the issues affecting the Polar Regions, their effects on a global scale and ways of addressing these issues. The conference will also serve to highlight ongoing IPY research, especially research being undertaken by young researchers, and provide a perennial framework for youth involvement in polar research and policies. The IYCP will run for three days in May 2008, attracting an international youth audience, as well as representatives from polar organizations, teachers, politicians, policy makers, the general public and media. The IYCP will be divided into three sections. Youth Roundtable Discussions will bring youth together to discuss issues affecting the Polar Regions and potential solutions to these. A Young Researchers Conference will provide the opportunity for young researchers working in the Polar Regions to present their work to an interdisciplinary audience. The Polar Fair will provide an interactive environment for youth to learn about the Polar Regions. The IYCP will be of great importance to the IPY because it will serve as the principle venue during the Polar Year where youth from many different disciplines, backgrounds and countries will

  19. Concentrations and activity ratios of uranium isotopes in groundwater from Donana National Park, South of Spain

    SciTech Connect

    Bolivar, J. P.; Olias, M.; Gonzalez-Garcia, F.; Garcia-Tenorio, R.

    2008-08-07

    The levels and distribution of natural radionuclides in groundwaters from the unconfined Almonte-Marismas aquifer, upon which Donana National Park is located, have been analysed. Most sampled points were multiple piezometers trying to study the vertical distribution of the hydrogeochemical characteristics in the aquifer. Temperature, pH, electrical conductivity, dissolved oxygen and redox potential were determined in the field. A large number of parameters, physico-chemical properties, major and minor ions, trace elements and natural radionuclides (U-isotopes, Th-isotopes, Ra-isotopes and {sup 210}Po), were also analysed. In the southern zone, where aeolian sands crop out, water composition is of the sodium chloride type, and the lower U-isotopes concentrations have been obtained. As water circulates through the aquifer, bicarbonate and calcium concentrations increase slightly, and higher radionuclides concentrations were measured. Finally, we have demonstrated that {sup 234}U/{sup 238}U activity ratios can be used as markers of the type of groundwater and bedrock, as it has been the case for old waters with marine origin confined by a marsh in the south-east part of aquifer.

  20. Models of Active Glacial Isostasy Roofing Warm Subduction: Case of the South Patagonian Ice Field

    NASA Technical Reports Server (NTRS)

    Klemann, Volker; Ivins, Erik R.; Martinec, Zdenek; Wolf, Detlef

    2007-01-01

    Modern geodetic techniques such as precise Global Positioning System (GPS) and high-resolution space gravity mapping (Gravity Recovery and Climate Experiment, GRACE) make it possible to measure the present-day rate of viscoelastic gravitational Earth response to present and past glacier mass changes. The Andes of Patagonia contain glacial environments of dramatic mass change. These mass load changes occur near a tectonically active boundary between the Antarctic and South American plates. The mechanical strength of the continental side of this boundary is influenced by Neogene ridge subduction and by the subduction of a youthful oceanic slab. A ridge of young volcanos parallels the Pacific coastline. Release of volatiles (such as water) at depth along this ridge creates a unique rheological environment. To assess the influence of this rheological ridge structure on the observational land uplift rate, we apply a two dimensional viscoelastic Earth model. A numerical study is presented which examines the sensitivity of the glacial loading-unloading response to the complex structure at depth related to the subducting slab, the viscous wedge between slab and continental lithosphere, and the increase of elastic thickness from oceanic to continental lithosphere. A key feature revealed by our numerical experiments is a continuum flow wherein the slab subdues the material transport toward oceanic mantle and crust. The restricted flow is sensitive to the details of slab mechanical strength and penetration into the upper mantle. The reduced viscosity within the mantle wedge, however, enhances the load-induced material transport everywhere within the asthenosphere.

  1. Poled polymer films for nonlinear optics

    SciTech Connect

    Singer, K.D.; Kuzyk, M.G.; Holland, W.R.; Cahill, P.A.

    1989-01-01

    Second harmonic generation was measured for a thin corona-poled film of a dicyanovinyl azo dye incorporated in the side-chain methacrylate polymer. Measurements were performed at a wavelength of 1.58 ..mu..m as a function of incident angle for both p- and s-polarized incident light. From these measurements the form and magnitude of the second harmonic coefficient tensor were determined. The molecular distribution implied by the data is consistent with a thermodynamic potential containing only the dipolar orienting energy acting during poling. We have also demonstrated anomalous-dispersion phase-matched second harmonic generation for the first time using electric field induced second harmonic generation (EFISH) in a liquid solution of Foron Brilliant Blue S-R (FBB). Results are described. 10 refs., 4 figs., 2 tabs.

  2. Photocouplings at the pole from pion photoproduction

    DOE PAGES

    Ronchen, D.; Doring, M.; Huang, F.; ...

    2014-06-24

    The reactions γp → π0p and γp → π+n are analyzed in a semi-phenomenological approach up to E ~ 2.3 GeV. Fits to differential cross section and single and double polarization observables are performed. A good overall reproduction of the available photoproduction data is achieved. The Julich2012 dynamical coupled-channel model -which describes elastic πN scattering and the world data base of the reactions πN → ηN, KΛ, and KΣ at the same time– is employed as the hadronic interaction in the final state. Furthermore, the framework guarantees analyticity and, thus, allows for a reliable extraction of resonance parameters in termsmore » of poles and residues. In particular, the photocouplings at the pole can be extracted and are presented.« less

  3. Photocouplings at the pole from pion photoproduction

    SciTech Connect

    Ronchen, D.; Doring, M.; Huang, F.; Haberzettl, H.; Haidenbauer, J.; Hanhart, C.; Krewald, S.; MeiBner, U. -G.; Nakayama, K.

    2014-06-24

    The reactions γp → π0p and γp → π+n are analyzed in a semi-phenomenological approach up to E ~ 2.3 GeV. Fits to differential cross section and single and double polarization observables are performed. A good overall reproduction of the available photoproduction data is achieved. The Julich2012 dynamical coupled-channel model -which describes elastic πN scattering and the world data base of the reactions πN → ηN, KΛ, and KΣ at the same time– is employed as the hadronic interaction in the final state. Furthermore, the framework guarantees analyticity and, thus, allows for a reliable extraction of resonance parameters in terms of poles and residues. In particular, the photocouplings at the pole can be extracted and are presented.

  4. Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms

    PubMed Central

    Basson, Nicolaas J; Grobler, Sias R

    2008-01-01

    Background Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict. With this in mind we tested the antimicrobial activity of honeys produced from plants grown in South Africa for their antibacterial properties on selected standard strains of oral micro-organisms. Methods The honeys used were produced from the blossoms of Eucalyptus cladocalyx (Bluegum) trees, an indigenous South African plant Leucospermum cordifolium (Pincushion), a mixture of wild heather shrubs, mainly Erica species (Fynbos) and a Leptospermum scoparium (Manuka) honey. Only pure honey which had not been heated was used. The honeys were tested for their antimicrobial properties with a broth dilution method. Results Although the honeys produced some inhibitory effect on the growth of the micro-organisms, no exceptionally high activity occurred in the South African honeys. The carbohydrate concentration plays a key role in the antimicrobial activity of the honeys above 25%. However, these honeys do contain other antimicrobial properties that are effective against certain bacterial species at concentrations well below the hypertonic sugar concentration. The yeast C. albicans was more resistant to the honeys than the bacteria. The species S. anginosus and S. oralis were more sensitive to the honeys than the other test bacteria. Conclusion The honeys produced from indigenous wild flowers from South Africa had no exceptionally high activity that could afford medical grade status. PMID:18627601

  5. NASA satellite to track North Pole expedition

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The proposed expedition of a lone explorer and the use of Nimbus 6 (NASA meteorological research satellite) to track his journey is reported. The journey is scheduled to start March 4, 1978, and will cover a distance of 6.000 Km (3,728 miles) from northern Canada to the North Pole and return, traveling the length of Greenland's isolated interior. The mode of transportation for the explorer will be by dog sled. Instrumentation and tracking techniques are discussed.

  6. Pole Assignment for Second-Order Systems

    NASA Astrophysics Data System (ADS)

    CHU, E. K.

    2002-01-01

    This paper contains some results for pole assignment problems for the second-order system M ẍ(t)+D ẋ(t)+K x (t)=B u (t) . Specifically, Algorithm 0 constructs feedback matrices F1 and F2 such that the closed-loop quadratic pencil Pc( λ)= λ2M+ λ ( D+ BF2)+( K+ BF1) has a desired set of eigenvalues and the associated eigenvectors are well-conditioned. The method is a modification of the SVD-based method proposed by Juang and Maghami [1, 2] which is a second-order adaptation of the well-known robust eigenvalue assignment method by Kautsky et al. [3] for first-order systems. Robustness is achieved by minimising some not-so-well-known condition numbers of the eigenvalues of the closed-loop second-order pencil. We next consider the partial pole assignment problem. In 1997, Datta, Elhay and Ram proposed three biorthogonality relations for eigenvectors of symmetric definite quadratic pencils [4]. One of these relations was used to derive an explicit solution to the partial pole assignment problem by state feedback for the related single-input symmetric definite second-order control system. The solution shed new light on the stabilisation and control of large flexible space structures, for which only one small subset of the spectrum needs to be reassigned while retaining the complementary part of the spectrum. In this paper, the method has been generalised for multi-input and non-symmetric quadratic pencils. Finally, we discuss briefly the output feedback pole assignment problem.

  7. Laser range pole field evaluation report

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A field evaluation was made of the laser pole equipment. The basic plan for the evaluation was to expose the equipment to the actual people and environment for which it was intended and determine, through the use of the equipment, its resultant effectivity in terms of improved performance. Results show the equipment performed better than expected in the high elevation clean air of Colorado, and did as well in Tennessee.

  8. Geodetic and geological evidence of active tectonics in south-western Sicily (Italy)<