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Sample records for active south pole

  1. 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.

  2. 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...

  3. 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.

  4. South Pole Telescope optics.

    PubMed

    Padin, S; Staniszewski, Z; Keisler, R; Joy, M; Stark, A A; Ade, P A R; Aird, K A; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; Dobbs, M A; Halverson, N W; Heimsath, S; Hills, R E; Holzapfel, W L; Lawrie, C; Lee, A T; Leitch, E M; Leong, J; Lu, W; Lueker, M; McMahon, J J; Meyer, S S; Mohr, J J; Montroy, T E; Plagge, T; Pryke, C; Ruhl, J E; Schaffer, K K; Shirokoff, E; Spieler, H G; Vieira, J D

    2008-08-20

    The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber. PMID:18716649

  5. South Pole Telescope optics.

    PubMed

    Padin, S; Staniszewski, Z; Keisler, R; Joy, M; Stark, A A; Ade, P A R; Aird, K A; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; Dobbs, M A; Halverson, N W; Heimsath, S; Hills, R E; Holzapfel, W L; Lawrie, C; Lee, A T; Leitch, E M; Leong, J; Lu, W; Lueker, M; McMahon, J J; Meyer, S S; Mohr, J J; Montroy, T E; Plagge, T; Pryke, C; Ruhl, J E; Schaffer, K K; Shirokoff, E; Spieler, H G; Vieira, J D

    2008-08-20

    The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

  6. Mercury's South Pole

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Mercury's south pole was photographed by one of Mariner 10's TV cameras as the spacecraft made its second close flyby of the planet September 21. The pole is located inside the large crater (180 kilometers, 110 miles) on Mercury's limb (lower center). The crater floor is shadowed and its far rim, illuminated by the sun, appears to de disconnected from the edge of the planet. Just above and to the right of the South Pole is a double ring basin about 100 kilometers (125 miles) in diameter. A bright ray system, splashed out of a 50 kilometer (30 mile) crater is seen at upper right. The stripe across the top is an artifact introduced during computer processing. The picture (FDS 166902) was taken from a distance of 85,800 kilometers (53,200 miles) less than two hours after Mariner 10 reached its closest point to the planet.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  7. 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.

  8. 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.

  9. The morphology of an active zone near Enceladus' south pole and implications

    NASA Astrophysics Data System (ADS)

    Giese, Bernd; Helfenstein, Paul; Thomas, Peter C.; Ingersoll, Andrew P.; Perry, Jason; Wagner, Roland; Neukum, Gerhard; Porco, Carolyn C.

    2010-05-01

    On Cassini's 121st orbit, the onboard ISS camera acquired high-resolution (15-30 m/pxl) images in Enceladus' south polar province. The imaging sequence was specifically designed to study one of the source regions of Enceladus' erupting plumes, Baghdad Sulcus. To facilitate the analysis, we derived a digital elevation model in an active section (76°S/323°E) across Baghdad Sulcus. The model reveals that there is a V-shaped trough up to 500 m deep in the center of this section, with flanking slopes of 30° (SW-facing) and > 32° (NE-facing, this slope is in shadow). The slopes do approach angle of repose, but the morphology on the SW slope (blocky terrain with lineation patterns and even benches at angles to the maximum slope) suggests that this is not a slope undergoing angle-of-repose control. The trough, therefore, may owe its shape primarily to faulting, with only some modification by deposition of icy particles by the plume-forming gas. Blocky covering, which includes block sizes of up to 50 m, is not restricted to the trough but also occurs at about the same size and frequency distribution away from it. This suggests that the blocks are not related to the venting process, which concentrates in the trough. Rather, the association of the blocky surfaces with multiple patterns of lineations (presumably fractures and faults) suggests they are outcrops of fault-related ice blocks or lithified detritus undergoing some form of erosion. A potential erosion process may include seismic shaking. The V-shaped trough is partly accompanied by an elevated flanking ridge, which is indicative for rift zones and hints at an extensional origin of Baghdad Sulcus. Alternatively, fault-block rotation at large strains could have led to the elevated ridge.

  10. Light propagation in the South Pole ice

    SciTech Connect

    Williams, Dawn; Collaboration: IceCube Collaboration

    2014-11-18

    The IceCube Neutrino Observatory is located in the ice near the geographic South Pole. Particle showers from neutrino interactions in the ice produce light which is detected by IceCube modules, and the amount and pattern of deposited light are used to reconstruct the properties of the incident neutrino. Since light is scattered and absorbed by ice between the neutrino interaction vertex and the sensor, IceCube event reconstruction depends on understanding the propagation of light through the ice. This paper presents the current status of modeling light propagation in South Pole ice, including the recent observation of an azimuthal anisotropy in the scattering.

  11. The South Pole Acoustic Test Setup (SPATS)

    NASA Astrophysics Data System (ADS)

    Laihem, Karim; IceCube Collaboration

    2012-11-01

    New detection techniques for (GZK) neutrinos are required for instrumenting a large detector volume needed to observe the low neutrino fluxes at the EeV energy range. Studies on a larger IceCube Neutrino Observatory at the South Pole have been intensively investigated in the last decade. A larger effective volume at a reasonable cost is possible if an acoustic array is a part of a large hybrid detector which includes radio and the existing optical array. The feasibility and the physics capabilities of an acoustic array at the South Pole depend on the knowledge of the acoustic properties of the ice such as the sound speed, the attenuation length, the background noise level and the transient rate. To investigate the ice properties, the first three acoustic strings of the South Pole Acoustic Test Setup (SPATS) have been deployed in the austral summer 2006/2007, then completed with an additional string in 2007/2008. With its four strings SPATS was able to evaluate in situ the acoustic properties of the South Pole ice in the 10-100 kHz frequency range. In this paper the performance of SPATS is described, results on the acoustic ice properties are presented and a new drilling method to deploy acoustic strings in ice is introduced.

  12. South Pole all-sky imager observations of dayside aurora activity induced by a solar wind dynamic pressure enhancement

    NASA Astrophysics Data System (ADS)

    Motoba, T.; Kadokura, A.; Ebihara, Y.; Sato, N.

    2008-12-01

    Ground observations of the optical aurora in the dayside cusp region have the distinct advantages of continuity of coverage and sufficient temporal-spatial sensitivity to monitor dayside signatures of solar wind/magnetosphere/ionosphere interaction mechanisms. The South Pole Station (SP, geomagnetic latitude (GMLat) = -74.3 degs, magnetic local time = UT-3.5 h) in Antarctica is a unique place for dayside aurora observations during austral winter season. We present the detailed features of enhancements of dayside aurora activity induced by a sudden increase in the solar wind dynamic pressure (Psw), using a ground-based all-sky imager (ASI) at SP. The interplanetary magnetic field (IMF) was northward during the Psw enhancement. Just after the arrival of the Psw enhancement on the Earth"fs magnetosphere, the 557.7 nm aurora activity on the dayside is suddenly intensified almost in the whole field of view of ASI. Further a few minutes later, the intensity of the auroral emissions shows a maximum, and then decays within about 5 minutes. Even after decay of the transient aurora activity at lower latitudes, the newly formed auroral emissions from the dayside cusp to the polar cap (GMLat -76 to -80 degs) develop during the Psw enhancement lasting about an hour. The polar aurora intensifications seem to be associated with lobe reconnection under the northward IMF conditions as well as the Psw enhancement. In this talk, two cases have been studied and the possible generation mechanisms will be discussed by comparing the ASI data at SP with other instruments.

  13. South-Pole Swiss Cheese

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 9 March 2004

    The Odyssey spacecraft has completed a full Mars year of observations of the red planet. For the next several weeks the Image of the Day will look back over this first mars year. It will focus on four themes: 1) the poles - with the seasonal changes seen in the retreat and expansion of the caps; 2) craters - with a variety of morphologies relating to impact materials and later alteration, both infilling and exhumation; 3) channels - the clues to liquid surface flow; and 4) volcanic flow features. While some images have helped answer questions about the history of Mars, many have raised new questions that are still being investigated as Odyssey continues collecting data as it orbits Mars.

    This image was collected December 29, 2003 during the southern summer season. This image shows the surface texture that the ice cap develops after long term sun exposure. The central portion of the image has an appearance similar to swiss cheese and represents surface ice loss.

    Image information: VIS instrument. Latitude 86.9, Longitude 356.4 East (3.6 West). 19 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

  14. A Warm South Pole? Yes, on Neptune!

    NASA Astrophysics Data System (ADS)

    2007-09-01

    Summer season on Neptune creates escape route for methane An international team of astronomers using ESO's Very Large Telescope has discovered that the south pole of Neptune is much hotter than the rest of the planet. This is consistent with the fact that it is late southern summer and this region has been in sunlight for about 40 years. ESO PR Photo 41/07 ESO PR Photo 41/07 Neptune's 'Hot' South Pole (VISIR/VLT) The scientists are publishing the first temperature maps of the lowest portion of Neptune's atmosphere, showing that this warm south pole is providing an avenue for methane to escape out of the deep atmosphere. "The temperatures are so high that methane gas, which should be frozen out in the upper part of Neptune's atmosphere (the stratosphere), can leak out through this region," said Glenn Orton, lead author of the paper reporting the results. "This solves a long-standing problem of identifying the source of Neptune's high stratospheric methane abundances." The temperature at the south pole is higher than anywhere else on the planet by about 10 degrees Celsius. The average temperature on Neptune is about minus 200 degrees Celsius. Neptune, the farthest planet of our solar system, is located about 30 times farther away from the Sun than Earth is. Only about 1/900th as much sunlight reaches Neptune as our planet. Yet, the small amount of sunlight it receives significantly affects the planet's atmosphere. The astronomers found that these temperature variations are consistent with seasonal changes. A Neptunian year lasts about 165 Earth years. It has been summer in the south pole of Neptune for about 40 years now, and they predict that as winter turns to summer in the north pole, an abundance of methane will leak out of a warm north pole in about 80 years. "Neptune's south pole is currently tilted toward the Sun, just like the Earth's south pole is tilted toward the Sun during summer in the Southern Hemisphere," explains Orton. "But on Neptune the antarctic

  15. 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.

  16. 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

  17. Aerosol measurements at the South Pole

    NASA Astrophysics Data System (ADS)

    Bodhaine, Barry A.; Deluisi, John J.; Harris, Joyce M.; Houmere, Pamela; Bauman, Sene

    1986-09-01

    Some results are given regarding the aerosol measurement program conducted by the NOAA at their atmospheric monitoring observatory at Amundsen-Scott Station, South Pole. The program consists of the continuous measurement of condensation nuclei (CN) concentration and aerosol scattering extinction coefficient. A time series of sodium, chlorine, and sulfur concentrations shows that the sulfur and CN records are similar and that the sodium, chlorine, and extinction coefficient records are similar. Large episodes of sodium are measured at the ground in the austral winter and are apparently caused by large-scale warming and weakening of the surface temperature inversion. The CN data show an annual cycle with a maximum exceeding 100 per cubic centimeter in the austral summer and a minimum of about 10 per cubic centimeter in the winter. The extinction coefficient data show an anual cycle markedly different from that of CN with a maximum in late winter, a secondary maximum in summer, and a minimum in May.

  18. CMB Observations with the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Keisler, Ryan

    2013-04-01

    I will describe a program of cosmological research centered on using measurements of the cosmic microwave background (CMB) to address questions relevant to physics: What is the absolute mass scale of neutrinos? How many species of neutrino-like particles were present in the early Universe? How does gravity behave on cosmological scales? Did inflation occur, and, if so, at what energy scale? A new generation of CMB experiments is targeting these questions, and I will focus on recent results from the South Pole Telescope (SPT). The SPT is a ground-based mm-wave observatory located at the geographic south pole in Antarctica, and in 2011 finished its initial, 2500 square-degree ``SPT-SZ'' survey. The data from this survey provided an unprecedented combination of resolution, area, and sensitivity, and has been used to make ground-breaking measurements of the CMB anisotropy and the gravitational lensing of the CMB. These measurements have, in conjunction with data from the WMAP satellite, led to strong constraints on the number of neutrino-like particle species present in the early universe and the shape of the power spectrum of primordial density fluctuations. The SPT-SZ data overlaps with the ongoing Dark Energy Survey (DES) footprint, and the joint dataset will provide new probes of large-scale structure, such as the relative velocities of massive galaxy clusters. In 2012, a new polarization-sensitive camera, SPTpol, was installed on the SPT, and I will summarize its performance and prospects for detecting the B-mode CMB polarization pattern. Finally, I will touch on what will be possible with a third-generation camera, SPT-3G. The leap in sensitivity provided by this camera will yield, for example, a constraint on the sum of the neutrino masses relevant for exploring the neutrino mass hierarchy.

  19. 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

  20. 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].

  1. Cluster observations with the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Plagge, Thomas Jeffrey

    The South Pole Telescope (SPT) is an instrument designed to survey galaxy clusters using the Sunyaev-Zel'dovich effect. In this thesis I describe the telescope, its first-generation receiver, and its readout and control systems. I also present Sunyaev-Zel'dovich measurements of 15 massive X-ray selected galaxy clusters obtained with the SPT. The cluster signals are measured at 150 GHz, and concurrent 220 GHz data are used to reduce astrophysical contamination. Radial profiles are computed using a technique that takes into account the effects of the beams and filtering. In several clusters, significant SZ decrements are detected out to a substantial fraction of the virial radius. The profiles are fit to the beta-model and to a generalized NFW pressure profile, and are scaled and stacked to probe their average behavior. The best-fit model parameters are consistent with previous studies: beta = 0.86 and rcore/r500 = 0.20 for the beta-model, and (alphan, betan, gamman, c500)=(1.0, 5.5, 0.5, 1.0) for the generalized NFW model. Both models fit the SPT data comparably well, and both are consistent with the average SZ profile out to the virial radius. The integrated Compton-y parameter YSZ is computed for each cluster using both model-dependent and model-independent techniques, and the results are compared to X-ray estimates of cluster parameters. YSZ is found to scale with YX and gas mass with low scatter. Since these observables have been found to scale with total mass, these results point to a tight mass-observable relation for the SPT cluster survey.

  2. 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.

  3. Evidence for Phyllosilicates near the Lunar South Pole

    NASA Astrophysics Data System (ADS)

    Vilas, Faith; Jensen, E.; Domingue, Deborah; McFadden, L.; Coombs, Cassandraa; Mendell, Wendell

    1998-01-01

    While theoretically water ice could be stable in permanently shadowed areas near the lunar poles, there is conflicting observational evidence for the existence of water ice at either pole. Clementine's bistatic radar resumed a weak signal commensurate with water ice in the South Pole Aitken Basin; however, groundbased radar searches have not detected such a signal at either pole. Lunar Prospector measured large amounts of H (attributed to water) at both poles; however, Galileo near-infrared spectral measurements of the north polar region did not detect the prominent 3.0 micron absorption feature due to interlayer and adsorbed water in phyllosilicates. Evidence for the existence of water at the lunar poles is still ambiguous and controversial. We present evidence, based on the analysis of Galileo SSI images, for the presence of phyllosilicates near the lunar south pole. Using the color image sequence (560 nm, 670 nm, 756 nm, and 889 nm) of Lunmap 14 taken during the Galileo Earth-Moon pass I, we have identified areas that show evidence for a 0.7 microns absorption feature present in Fe-bearing phyllosilicates.

  4. The temperature and width of an active fissure on Enceladus measured with Cassini VIMS during the 14 April 2012 South Pole flyover

    NASA Astrophysics Data System (ADS)

    Goguen, Jay D.; Buratti, Bonnie J.; Brown, Robert H.; Clark, Roger N.; Nicholson, Phillip D.; Hedman, Matthew M.; Howell, Robert R.; Sotin, Christophe; Cruikshank, Dale P.; Baines, Kevin H.; Lawrence, Kenneth J.; Spencer, John R.; Blackburn, David G.

    2013-09-01

    The width and temperature of the active fissures on Saturn’s satellite Enceladus provide key observable constraints on physical models of these geyser-like eruptions. We analyze a sequence of high spatial resolution near-infrared spectra acquired with VIMS at 0.025 s intervals during a 74 km altitude flyover of the South Pole of Enceladus by the Cassini spacecraft on 14 April 2012 UTC. A thermal-emission spectrum covering 3- to 5-μm wavelengths was detected as the field of view crossed one of the four major fissures, Baghdad Sulcus, within 1 km of 82.36S latitude and 28.24W longitude. We interpret this spectrum as thermal emission from a linear fissure with temperature 197 ± 20 K and width 9 m. At the above wavelengths, the spectrum is dominated by the warmest temperature component. Looking downward into the fissure at only 13° from the vertical, we conclude that our results measure the temperature of the interior fissure walls (and the H2O vapor) at depths within 40 m of the surface.

  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. 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

  7. 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.

  8. 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

  9. 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.

  10. Large-scale magnetic variances near the South Solar Pole

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.; Kota, J.; Smith, E.; Horbury, T.; Giacalone, J.

    1995-01-01

    We summarize recent Ulysses observations of the variances over large temporal scales in the interplanetary magnetic field components and their increase as Ulysses approached the South Solar Pole. A model of these fluctuations is shown to provide a very good fit to the observed amplitude and temporal variation of the fluctuations. In addition, the model predicts that the transport of cosmic rays in the heliosphere will be significantly altered by this level of fluctuations. In addition to altering the inward diffusion and drift access of cosmic rays over the solar poles, we find that the magnetic fluctuations also imply a large latitudinal diffusion, caused primarily by the associated field-line random walk.

  11. Craters near the south pole of Callisto

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image of the south polar region of the Jovian satellite Callisto was taken in twilight by the Galileo spacecraft on its eighth orbit around Jupiter. Craters ranging in size from 60 kilometers (36 miles) down to the limit of resolution are visible in this image. Scientists count the number of craters on a planetary surface to estimate its relative (and sometimes absolute) age. Note that many of the craters are not as sharp in appearance as the two large craters near the bottom of the image. This is an indication that some process has eroded the craters since their formation.

    This image is centered at 82.5 south latitude and 62.6 west longitude, and covers an area approximately 370 kilometers (220 miles) by 280 kilometers (170 miles). North is toward the top of the image. This image was taken on May 6, 1997 by the Solid State Imaging system (CCD) on board NASA's Galileo spacecraft at a resolution of 676 meters (417 feet) per picture element.

    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 URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  12. TES Observations of the South Pole

    NASA Astrophysics Data System (ADS)

    Titus, T. N.; Kieffer, H. H.; Mullins, K. F.

    1998-09-01

    The recession of the south polar cap has been observed telescopically and from spacecraft in both the visible and thermal regions. Although a simple cap-edge versus time plot has commonly been used, without regard as to the longitude of measurement, Mariner 9, Viking, and HST observations clearly show that the retreating edge is irregular and asymmetric. The data used in this analysis is from the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES). Repeated TES coverage over the period L_s 185 through L_s 270 acquired much of the cap recession. During this period of time, TES was taking data in the array normal spin (ANS) mode, scanning acrossed the planet as the satellite made one complete roll every 100 minutes. Therefore, the data was irregularly sampled in both space and time. Also, because of the changes in the spacecraft orbit, the spatial resolution of the data is variable, ranging from 25 to 125 kilometers. We have constructed a map of the south polar region that contains the date when the last CO_2 sublimates, hereafter called the crocus date. The crocus date is based on sliding a representative temperature - versus - time curve along the observations for each location in the polar region and selecting the season of maximum temperature change. Recessions in the classic area ``Mountains of Mitchell'' are delayed significantly, disappearing approximately at L_s 260. High resolution (26 Km) brightness temperature data at L_s 244 confirms that solid CO_2 is the dominant cold component. One region (approx. 72-80 S, 180-250 W) within the annual polar cap became dark long before the temperatures begin to rise; in comparison with most areas that showed a gradual increase in brightness until a rapid darkening as the temperature rose well above CO_2 frost value. This dark region, here after called the Kidney Bean region, appears to be a major contributor to the asymmetric polar recession. The cause of the Kidney Bean region's unexpected behavior is

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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. PMID:24336567

  2. Narrow-band ELF events observed from South Pole Station

    NASA Astrophysics Data System (ADS)

    Heavisides, J.; Weaver, C.; Lessard, M.; Weatherwax, A. T.

    2012-12-01

    Extremely Low Frequency (ELF) waves are typically in the range of 3 Hz - 3 kHz and can play a role in acceleration and pitch-angle scattering of energetic particles in the radiation belts. Observations of a not uncommon, but not well studied ELF phenomenon are presented with ground-based data from South Pole Station. The narrow-band waves last approximately one or two minutes maintaining bandwidth over the course of the event, begin around 100 Hz, decrease to about 70 Hz, and typically show a higher frequency harmonic. The waves have only been documented at four locations - Heacock, 1974 (Alaska); Sentman and Ehring, 1994 (California); Wang et al, 2005 and Wang et al, 2011 (Taiwan); and Kim et al, 2006 (South Pole). The waves observed at the South Pole are not detected when the Sun drops below a 10 degree elevation angle, which is not true for the other locations. We extend the study of Kim et al, 2006, and explore possible generation mechanisms including sunlit ionosphere and ion cyclotron wave modes, as well as correspondence with energetic particle precipitation.

  3. Sample return from the lunar South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Duke, M. B.

    2003-06-01

    Automated sample return missions to the South Pole — Aitken Basin on the lunar far side are proposed as the best means of addressing major problems concerning the early impact history of the inner solar system, the nature of very large impact events, and the early differentiation of rocky planets. The opportunity to propose such missions has been opened by the recommendations of the U. S. National Research Council's Decadal Study of Solar System Exploration and the creation by NASA of the New Frontiers Program, which will support missions of intermediate cost, between the Discovery Program and large missions. A proposal for a South Pole — Aitken Basin Sample Return Mission was submitted to the Discovery Program in 2000, but not fimded. The New Frontiers Program, with a somewhat less stringent budget constraint, should allow several of the potential risks associated with the Discovery proposal to be addressed, including scientific and programmatic risks. A principal goal of current mission studies is to determine whether, within the New Frontiers Program's cost constraints, two separate samples could be collected from areas of different post-Basin geological history. If accepted by the New Frontiers Program, a South Pole — Aitken Basin sample return mission could be flown as early as 2008-2009.

  4. 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.

  5. 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

  6. IMF sector behavior estimated from geomagnetic data at South Pole

    SciTech Connect

    Matsushita, S.; Xu, W.h.

    1981-05-01

    IMF sector behavior which has previously been estimated from the geomagnetic data at Godhavn is confirmed by study of the data at South Pole for 1959--1970 with the same estimation technique, taking the difference between northern and southern hemispheres into consideration. A method to improve (about 18%) the agreement between assigned and actual sector structures by study of the data at the two stations is suggested. Geomagnetic disturbance effects on sector estimation are discussed, and reversed sector effects in winter are given special emphasis.

  7. 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.

  8. A new air-Cherenkov array at the South Pole

    NASA Astrophysics Data System (ADS)

    Dickinson, J. E.; Gill, J. R.; Hart, S. P.; Hill, G. C.; Hinton, J. A.; Lloyd-Evans, J.; Potter, D.; Pryke, C.; Rochester, K.; Schwarz, R.; Watson, A. A.

    2000-01-01

    VULCAN comprises a 9 element array of air-Cherenkov radiation detectors established at the South Pole. VULCAN operates in coincidence with the air-shower array SPASE-2 and the two Antarctic Muon And Neutrino Detector Arrays, AMANDA A and B, supplementing the data gathered by these instruments with a measurement of the lateral distribution of air-Cherenkov light from extensive air-showers. An overview of the aims and methods of the whole coincidence experiment (SPASE-2, VULCAN and AMANDA) can be found in an accompanying paper (Dickinson et al., Nucl. Instr. and Meth. A (1999), to be published).

  9. Edge detection, cosmic strings and the south pole telescope

    SciTech Connect

    Stewart, Andrew; Brandenberger, Robert E-mail: rhb@physics.mcgill.ca

    2009-02-15

    We develop a method of constraining the cosmic string tension G{mu} which uses the Canny edge detection algorithm as a means of searching CMB temperature maps for the signature of the Kaiser-Stebbins effect. We test the potential of this method using high resolution, simulated CMB temperature maps. By modeling the future output from the South Pole Telescope project (including anticipated instrumental noise), we find that cosmic strings with G{mu} > 5.5 Multiplication-Sign 10{sup -8} could be detected.

  10. 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.

  11. Extragalactic point source statistics measured with the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Vieira, Joaquin D.

    The South Pole Telescope (SPT) has surveyed hundreds of square degrees to milli-Jansky levels at 1.4 mm and 2.0 mm. We report here on sources of point- like emission detected in the 1.4 and 2.0 mm bands in an 87 deg 2 field, centered at R.A. 5 h 30 m , decl. -55°, and observed in 2008. Based on the ratio of flux in these two bands, we are able to separate the detected sources into two populations, one consistent with synchrotron emission from active galactic nuclei (AGN) and one consistent with thermal emission from dust. We present source counts for each population from 11 to 640 mJy at 1.4 mm and from 4.4 to 800 mJy at 2.0 mm. We detect 119 synchrotron-dominated sources and 49 dust-dominated sources at S/N > 4.5 in at least one band. All of the most significantly detected members of the synchrotron-dominated population are associated with sources in previously published radio catalogs and/or in our own long-wavelength follow-up observations. Some of the dust-dominated sources are associated with nearby ( z [Special characters omitted.] 1) galaxies whose dust emission is also detected by the Infrared Astronomy Satellite (IRAS). However, most of the bright, dust-dominated sources have no counterparts in any existing catalog. We argue that these sources represent the rarest, brightest, and possibly strongly-lensed members of the population commonly referred to as sub-millimeter galaxies (SMGs). Because these sources are selected at longer wavelengths than in typical SMG surveys, they are expected to have a higher mean redshift distribution than objects currently in the literature, and may provide a new window on galaxy formation in the early universe.

  12. 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.

  13. Submillimeter Astronomy from the South Pole (AST/RO)

    NASA Astrophysics Data System (ADS)

    Stark, Antony A.

    2013-01-01

    The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), a 1.7 m diameter offset Gregorian telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 μm, saw first light in 1995 and operated until 2005. It was the first radio telescope to operate continuously throughout the winter on the Antarctic Plateau. It served as a site testing instrument and prototype for later instruments, as well as executing a wide variety of scientific programs that resulted in six doctoral theses and more than one hundred scientific publications. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Especially significant are the exceptionally low values of sky noise found at this site, a result of the small water vapor content of the atmosphere. Multiple submillimeter-wave and Terahertz detector systems were in operation on AST/RO, including heterodyne and bolometric arrays. AST/RO's legacy includes comprehensive submillimeter-wave site testing of the South Pole, spectroscopic studies of 492 GHz and 809 GHz neutral atomic carbon and 460 GHz and 806 GHz carbon monoxide in the Milky Way and Magellanic Clouds, and the first detection of the 1.46 THz [N II] line from a ground-based observatory.

  14. 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

    2008-11-01

    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.

  15. Position of the South Magnetic Pole, January 1986

    NASA Astrophysics Data System (ADS)

    Barton, C. E.

    The present location of the South Magnetic Pole (SMP) in the southern ocean provides an opportunity to determine its position well removed from local (coastal) anomalies. An experiment is being conducted jointly by the Australian Bureau of Mineral Resources and Antarctic Division, Department of Science to make direct shipboard observations of the position and daily motion of the SMP. The technique involves determination of the horizontal component of the field (H) by using a gimbal-mounted three-axis fluxgate magnetometer. First-order compensation for the magnetic effects of the vessel is provided by a system of Helmholtz coils. During observations, the vessel is spun about a vertical axis so that any residual horizontal field due to the vessel can be eliminated by integration along two horizontal axes fixed in space.

  16. 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.

  17. 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.

  18. Observations of thermal emission from the south pole of Enceladus in August 2010

    NASA Astrophysics Data System (ADS)

    Spencer, J. R.; Howett, C. J. A.; Verbiscer, A. J.; Hurford, T. A.; Segura, M. E.; Pearl, J. C.

    2011-10-01

    The Cassini CIRS instrument continues its observations of the thermal emission from the active "tiger stripe" fractures at the south pole of Enceladus. On August 13th 2010, on orbit 136, the "E11" Enceladus encounter provided a particularly favorable geometry for remote sensing of the south pole, and yielded some of the most detailed observations of tiger stripe thermal emission of the entire mission. Maps of 6.7 - 16.7 !m thermal emission from one of the brightest regions of Damascus Sulcus reveal large variations in brightness along the length of the fracture with a peak near the source of Plume 2 [7]. The emission from the brightest region is close to a blackbody, with best-fit temperatures in the range 167 - 185 K, depending on the exact wavelength range and spatial subset of the data that is fitted. Lower-temperature radiation is also seen from the flanks of the sulcus.

  19. Status and recent results of the South Pole Acoustic Test Setup

    NASA Astrophysics Data System (ADS)

    Karg, Timo; IceCube Collaboration

    2012-01-01

    The South Pole Acoustic Test Setup (SPATS) has been deployed to study the feasibility of acoustic neutrino detection in Antarctic ice around the South Pole. An array of four strings equipped with acoustic receivers and transmitters, permanently installed in the upper 500 m of boreholes drilled for the IceCube neutrino observatory, and a retrievable transmitter that can be used in the water filled holes before the installation of the IceCube optical strings are used to measure the ice acoustic properties. These include the sound speed and its depth dependence, the attenuation length, the noise level, and the rate and nature of transient background sources in the relevant frequency range from 10 to 100 kHz. SPATS is operating successfully since January 2007 and has been able to either measure or constrain all parameters. We present the latest results of SPATS and discuss their implications for future acoustic neutrino detection activities in Antarctica.

  20. An atmospheric history of ethane from South Pole firn air

    NASA Astrophysics Data System (ADS)

    Verhulst, K. R.; Aydin, K. M.; Lang, P.; Saltzman, E. S.

    2009-12-01

    Ethane (C2H6) is the most abundant non-methane hydrocarbon in the atmosphere and is important to tropospheric photochemistry. Sources of ethane include natural gas and oil leaks, automotive emissions and biomass burning, with smaller contributions from oceanic, vegetative, and soil emissions. The primary loss pathway for ethane is via reaction with hydroxyl radical, which controls ethane seasonality and lifetime (1-2 months during summer). There is a relatively limited database of atmospheric ethane measurements, which is insufficient to characterize long-term trends in the sources and sinks of this compound or to determine anthropogenic influence on the ethane budget. In this study, an atmospheric history of ethane over the past century is reconstructed from South Pole firn air measurements, in conjunction with a 1-D firn air diffusion model. Eighty firn air samples were collected in glass flasks from two adjacent holes drilled to 118 m at South Pole, Antarctica during the 2008/2009 season. The flasks were shipped back and analyzed by high resolution GC/MS at UCI. Firn air dating was based on the measured CO2 profile and known atmospheric history of CO2. Ethane levels in the firn increased from about 132 ppt in the deepest sample, to 259 ppt at 106 m, then decreased to 230 ppt at 30 m. Dating based on mean CO2 ages indicates that the ethane levels over Antarctica roughly doubled (from 130 to 260 ppt) between 1930 and the 1980’s. Over this time period, ethane increased at a rate of about 0.7 ppt yr-1 from 1930-1950 and 3.2 ppt yr-1 from 1950-1987. Ethane levels stabilized during the 1980’s and declined by approximately 1.8 ppt yr-1 from 1988-2004. Surface air measurements from several high latitude southern hemisphere sites indicate that the modern mean atmospheric ethane level is approximately 200 ppt.

  1. 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.

  2. Mass wasting in craters near the south pole of Callisto

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Craters ranging in diameter from the limit of resolution, approximately 1.35 kilometers (0.82 miles), up to the remnants of a heavily degraded two-ringed basin (center of the image), approximately 90 kilometers (55 miles) in diameter, can be seen in this image of a region near Callisto's south pole. Craters in this image exhibit a wide variety of degradational (erosional) states, including what appear to be landslide or slump deposits, best seen in the southwestern part of the bright 21 kilometer crater Randver, just east of the center of the image. The relative youth of Randver is evidenced by its bright and easily identifiable ejecta blanket (the materials ejected during the formation of the crater). The northeast facing slopes in this region are typically the brightest portion of the crater rims. Craters in the south and southwestern portions of this image are the most highly modified and degraded, and are therefore considered to be the oldest craters in the area.

    North is to the top of the image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter on May 6, 1997. The center of the image is located 73.2 degrees south latitude, 54.4 degrees west longitude, and was taken when the spacecraft was approximately 35,464 kilometers (21,633 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 URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  3. 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.

  4. Topographic-Compositional Relationships within the South Pole Aitken Basin

    NASA Astrophysics Data System (ADS)

    Lucey, P. G.; Holtzmann, J.; Blewett, D. T.; Taylor, G. J.; Hawke, B. R.

    1999-01-01

    The South Pole Aitken (SPA) Basin is an immense structure that dominates the geology of much of the farside of the Moon. Its floor is composed mostly of impact deposits, though it also has numerous relatively small regions of mare basalt. The basin floor exhibits a lower albedo and higher mafic mineral abundance than the surrounding highlands [ I ]. The origin of this mafic anomaly is a major question in lunar geology. Hypotheses for the presence of the mafic anomaly were briefly reviewed in [2] and include mare deposits mixed and obscured by basin or crater ejecta (cryptomaria), a large impact melt sheet that may have differentiated, exposed lower crustal material, and a significant component of excavated mantle. A study of mineralogy as revealed in Clementine UV-VIS imagery for limited portions of the basin found a predominantly low-Capyroxene (noritic) character [2], ruling out cryptomaria as an important contributor to the mafic enhancement. A few small cryptomaria, revealed by dark-halo impact craters and light plains units with high-FeO contents, have been found in SPA; however, it appears that extensive cryptomaria are lacking in this basin. The uniformly noritic lithology within SPA led to favor exposed lower crust or a homogenized melt sheet as the explanation for the mafic anomaly. Models of basin formation predict that a basin the size of SPA should have excavated through the entire lunar crust (assuming nonoblique impact), potentially exposing or mixing a large component of material from the mantle. Comparison of SPA floor FeO and Ti02 (derived from Clementine UV-VIS observations) and also Th (from Lunar Prospector) with model-mantle chemistries appears to be consistent with a mixture of approximately equal proportions of lower-crust and mantle material. In the present study, we examine the relationship between the basin's topography and composition in order to provide further insight on the origin of the basin floor material. Data: Clementine UV

  5. 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.

  6. 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,.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Lunar South Pole Topography Derived from Clementine Imagery

    NASA Astrophysics Data System (ADS)

    Rosiek, M. R.; Kirk, R.; Howington-Kraus, A.

    1999-01-01

    During the Clementine Mission both oblique and vertical multispectral images were collected. The oblique and vertical images from a single spectral band collected during the same orbit form a stereo pair that can be used to derive the topography. These stereo pairs are being used to derive the topography of an area (90 deg S to 650S latitude) surrounding the lunar south pole. Work on the lunar north pole topography will start after completion of the south pole topography. This report provides an update on the initial results for the lunar south pole topography. In 1994, the Clementine spacecraft acquired digital images of the Moon at visible and near-infrared wavelengths. Onboard there were four camera systems and a laser altimeter. During the first pass, periapsis was at 30S and the highest resolution images were obtained in the southern hemisphere. Over the northern polar area, a series of oblique and vertical images were obtained with the ultraviolet-visible (UV-VIS) camera on each orbit. During the second pass, periapsis was at 30N and the image acquisition strategy was reversed. The UV-VIS camera image size was 384 x 288 pixels with five spectral bands and one broad band. The 750-nm-band stereo pairs are the primary image source for this study. The ground sample distances (GSD) for oblique images range from 300 to 400m. The GSD for the vertical images, acquired at the end of an orbit, are slightly larger and range from 325 to 450 m. Using the formula for stereo-height accuracy, an estimate of height accuracy is 180m. This formula is IFOVMAX)/(K*B/H with IFOVMAX defined as Maximum Instantaneous Field of View; B/H is the base-to-height ratio and K is an estimate of pixel measurement accuracy on the imagery. The Clementine laser altimeter (LIDAR) data were used previously to produce a global topographic model of the Moon . The model has a vertical accuracy of about 100 m and a spatial resolution of 2.5 deg. Altimetry data were collected between 79S and 810N

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. The 1500m South Pole Ice Core: Recovering a 40,000 year environmental record

    NASA Astrophysics Data System (ADS)

    Neumann, T.; Casey, K.; Fudge, T. J.; Steig, E. J.; Saltzman, E. S.; Aydin, M.; Twickler, M.; Souney, J. M., Jr.

    2014-12-01

    The stable-isotope, aerosol and atmospheric gas records in ice cores provide exceptional archives of past climate. Supported by the U.S. National Science Foundation, a new 1500 m, approximately 40,000 year old ice core will be recovered from South Pole during the current 2014-2015 austral summer season (to ~ 700 m) and next 2015-2016 austral summer season (~ 700 m to 1500 m) using the new U.S. Intermediate Depth Drill. The combination of low temperature, relatively high accumulation rate, and low impurity concentrations at South Pole will yield a detailed record of atmospheric trace gases. The South Pole ice core will also provide a record of the climate history of a unique area of the East Antarctic plateau that is partly influenced by weather systems that cross the West Antarctic ice sheet. The South Pole ice core site is at a flank site where the ice flows at approximately 10 m/yr. The ice core recovered originated as snow at progressively greater distances from the coring site. New ground-penetrating radar collected over the drill site location shows no anthropogenic influence over the past ~50 years or upper 15 m. In this submission, we describe the climate and glaciologic setting of the South Pole, and the details of the ultimate coring site.

  19. 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.

  20. Optical auroral conjugacy: Viking UV imager - South Pole station ground data

    SciTech Connect

    Burns, G.B.; McEwen, D.J. ); Eather, R.A. ); Berkey, F.T. ); Murphree, J.S. )

    1990-05-01

    High time resolution satellite UV images of the northern auroral oval are compared with South Pole station keogram camera and all-sky camera observations to determine the displacement of the South Pole conjugate point from its location calculated using the international geomagnetic reference field magnetic field model. The results presented extend the study of optical conjugacy to high magnetic latitudes in a solstice period, and to sunlit auroral events. Three high-latitude events were analyzed: a poleward expansion, an arc poleward of the midnight oval, and a substantial movement in the afternoon auroral oval. They were determined to occur on closed field lines. A range of displacement for the South Pole conjugate point of 5.3{degree} in latitude and 1.9 hours in MLT was measured.

  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. Atmospheric iridium at the South Pole as a measure of the meteoritic component

    NASA Astrophysics Data System (ADS)

    Tuncel, G.; Zoller, W. H.

    1987-10-01

    A determination of the average particle-borne Ir concentration in the South Pole atmosphere is presented. The average values of (7.3 + or - 3.1) x 10 to the -17th g/cu m suggests that the concentration of extraterrestrial material in the South Pole atmosphere is not large enough to explain the enrichments of anomalously enriched elements; however, meteoritic material contributes significantly to the observed concentrations of Co, Fe, and Mn. An accretion rate for background extraterrestrial material of 11,000 tons annually is estimated.

  3. 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.

  4. 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

  5. Reanalysis of Clementine Bistatic Radar Data from the Lunar South Pole

    NASA Technical Reports Server (NTRS)

    Simpson, Richard A.; Tyler, G. Leonard

    1998-01-01

    On 9 April 1994 the Clementine spacecraft high-gain antenna was aimed toward the Moon's surface and the resulting 13-cm wavelength radio echoes were received on Earth. Using these data, we have found that the lunar surface generally follows a Lambertian bistatic scattering function sigma(sub 0) = K(sub D)cos(theta(sub i) with K(sub D) approx. 0.003 for the opposite (expected) sense of circular polarization and K(sub D) approx. 0.001 for the same (unexpected) sense. But there are important deviations-of up to 50% in some parts of the echo spectrum-from this simple form. Based on an earlier analysis of these same data, Nozette et al. claimed detection of an enhancement in echoes with right circular polarization from regions near the South Pole in a near-backscatter geometry. Such behavior would be consistent with presence of perhaps large quantities of water ice near the Pole. We have been unable to reproduce that result. Although we find weak suggestions of enhanced echoes at the time of South Pole backscatter, similar features are present at earlier and later times, adjacent frequencies, and in left circular polarization. If enhanced backscatter is present, it is not unique to the South Pole; if not unique to the Pole, then ice is less likely as an explanation for the enhancement.

  6. 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.

  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. 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.

  9. 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.

  10. 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

  11. 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.

  12. The geologically recent giant impact basins at Vesta's south pole.

    PubMed

    Schenk, Paul; O'Brien, David P; Marchi, Simone; Gaskell, Robert; Preusker, Frank; Roatsch, Thomas; Jaumann, Ralf; Buczkowski, Debra; McCord, Thomas; McSween, Harry Y; Williams, David; Yingst, Aileen; Raymond, Carol; Russell, Chris

    2012-05-11

    Dawn's global mapping of Vesta reveals that its observed south polar depression is composed of two overlapping giant impact features. These large basins provide exceptional windows into impact processes at planetary scales. The youngest, Rheasilvia, is 500 kilometers wide and 19 kilometers deep and finds its nearest morphologic analog among large basins on low-gravity icy satellites. Extensive ejecta deposits occur, but impact melt volume is low, exposing an unusual spiral fracture pattern that is likely related to faulting during uplift and convergence of the basin floor. Rheasilvia obliterated half of another 400-kilometer-wide impact basin, Veneneia. Both basins are unexpectedly young, roughly 1 to 2 billion years, and their formation substantially reset Vestan geology and excavated sufficient volumes of older compositionally heterogeneous crustal material to have created the Vestoids and howardite-eucrite-diogenite meteorites.

  13. The geologically recent giant impact basins at Vesta's south pole.

    PubMed

    Schenk, Paul; O'Brien, David P; Marchi, Simone; Gaskell, Robert; Preusker, Frank; Roatsch, Thomas; Jaumann, Ralf; Buczkowski, Debra; McCord, Thomas; McSween, Harry Y; Williams, David; Yingst, Aileen; Raymond, Carol; Russell, Chris

    2012-05-11

    Dawn's global mapping of Vesta reveals that its observed south polar depression is composed of two overlapping giant impact features. These large basins provide exceptional windows into impact processes at planetary scales. The youngest, Rheasilvia, is 500 kilometers wide and 19 kilometers deep and finds its nearest morphologic analog among large basins on low-gravity icy satellites. Extensive ejecta deposits occur, but impact melt volume is low, exposing an unusual spiral fracture pattern that is likely related to faulting during uplift and convergence of the basin floor. Rheasilvia obliterated half of another 400-kilometer-wide impact basin, Veneneia. Both basins are unexpectedly young, roughly 1 to 2 billion years, and their formation substantially reset Vestan geology and excavated sufficient volumes of older compositionally heterogeneous crustal material to have created the Vestoids and howardite-eucrite-diogenite meteorites. PMID:22582256

  14. 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

  15. Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface?

    NASA Astrophysics Data System (ADS)

    Le Gall, A. A.; Leyrat, C.; Janssen, M. A.; Stolzenbach, A.; Wye, L. C.; West, R. D.; Lorenz, R. D.; Mitchell, K. L.

    2012-12-01

    At the beginning of the Cassini mission, the ISS (Imaging Science Subsystem) and CIRS (Composite Infra-Red Spectrometer) instruments discovered a geologically active region at the south pole of Saturn's moon Enceladus (e.g. Porco et al., 2005). Plumes venting material emanate from this region. Six years later, on November 6, 2011, the first-ever Synthetic Aperture Radar (SAR) image of Enceladus was acquired during the E16 flyby of the moon at the wavelength of 2-cm (Mitchell et al., AGU 2011). The SAR swath is located within the seemingly young South Pole Terrains, not far from the active sulci also known as the "tiger stripes" identified as the sources of the plumes. Concurrently to the SAR image, radiometry data were collected in the passive mode of the instrument with a ground footprint of 25-40 km across the track and ~5 km along. The Cassini radiometer records the thermal emission from the surface in the microwave domain, at 2-cm. More specifically, it measures the brightness temperature of the surface that varies both with the emissivity and the vertical temperature profile below the surface down to a depth, which depends on the electrical properties of the subsurface. Typically, radio instruments sense 10 to 100 wavelengths into an icy crust and can thus provide unique insight into the compositional, thermal and physical (porosity, roughness) state of planetary regoliths at depths much greater than the ones sampled by thermal IR spectrometers. In particular, microwave radiometer can be used to detect possible endogenic activity beneath the surface. The measured calibrated brightness temperatures during E16 cover a range from 33 to 60 K. In order to analyze these dataset, we have modeled the expected thermal emission from Enceladus' surface. In absence of endogenic emission, the temperature structure of any airless satellite results from a balance between solar insolation, heat transport within the subsurface and reradiation outward. The developed thermal

  16. Thermal stability of internal liquid water reservoir at Enceladus' South pole

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    The total heat power released at Enceladus' South pole is about 50 times larger than the available radiogenic power, implying that an additional source of energy exists. Tidal dissipation is the most likely candidate, but the observed power and its particular location at the south pole can be reproduced only if a liquid layer exists at depth (Tobie et al. Icarus 2008). Moreover, this liquid reservoir should spread over at least half of the southern hemisphere to induce sufficient tidal deformation at the pole. In order to determine the stability of this internal liquid reservoir and its effects on the dynamics of the overlying ice shell, we have developed a new tool that solves simultaneously mantle convection and tidal dissipation in 3D spherical geometry (Behounkova et al. JGR, in press, 2010). Using this new 3D technique, we demonstrate that the tidal strain rates are strongly enhanced in hot upwellings when compared with classical methods of tidal dissipation computation, and therefore that lateral variations of viscosity must be explicitly taken into account to correctly describe the dissipation field. Moreover, our 3D simulations show that tidal dissipation in Enceladus tends to focus hot upwellings at the South pole and cold downwellings in the equatorial region, and that the heat flux at the base of the ice shell is strongly reduced at the pole, thus favoring the preservation of a liquid reservoir at depth. By systematically varying the orbital and internal parameters, we investigate the conditions under which a liquid reservoir can be thermally stable in Enceladus' interior and what is its possible extension at equilibrium.

  17. 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

  18. Test of Lorentz Invariance at the Amundsen - Scott South Pole Station

    NASA Astrophysics Data System (ADS)

    Smiciklas, Marc; Vernaza, Andrew; Romalis, Michael

    2013-05-01

    Tests of Lorentz and CPT symmetry provide one of the few ways to experimentally access Planck-scale physics. Currently the most sensitive Lorentz symmetry tests for fermions are performed with atomic spin co-magnetometers. Earth rotation represents a large background for such experiments due to gyroscopic spin interaction. To improve the limits on vector and tensor Lorentz-violating interactions we have installed a 21Ne-Rb co-magnetometer at the Amundsen - Scott South Pole Station. The experiment is mounted on a precision air-bearing rotating platform aligned to the local vertical to eliminate most Earth-bound sources of systematic errors. We plan to collect data over the austral winter. We will describe the experience of operating the experiment at the South Pole and present the latest results. Supported by NSF ANT-1142032.

  19. 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.

  20. Imaging the South Pole-Aitken basin in backscattered neutral hydrogen atoms

    NASA Astrophysics Data System (ADS)

    Vorburger, A.; Wurz, P.; Barabash, S.; Wieser, M.; Futaana, Y.; Bhardwaj, A.; Asamura, K.

    2015-09-01

    The lunar surface is very efficient in reflecting impinging solar wind ions as energetic neutral atoms (ENAs). A global analysis of lunar hydrogen ENAs showed that on average 16% of the solar wind protons are reflected, and that the reflected fraction can range from less than 8% to more than 24%, depending on location. It is established that magnetic anomalies reduce the flux of backscattered hydrogen ENAs by screening-off a fraction of the impinging solar wind. The effects of the surface properties, such as porosity, roughness, chemical composition, and extent of weathering, were not known. In this paper, we conduct an in-depth analysis of ENA observations of the South Pole-Aitken basin to determine which of the surface properties might be responsible for the observed variation in the integral ENA flux. The South Pole-Aitken basin with its highly variable surface properties is an ideal object for such studies. It is very deep, possesses strikingly elevated concentrations in iron and thorium, has a low albedo and coincides with a cluster of strong magnetic anomalies located on the northern rim of the basin. Our analysis shows that whereas, as expected, the magnetic anomalies can account well for the observed ENA depletion at the South Pole-Aitken basin, none of the other surface properties seem to influence the ENA reflection efficiency. Therefore, the integral flux of backscattered hydrogen ENAs is mainly determined by the impinging plasma flux and ENA imaging of backscattered hydrogen captures the electrodynamics of the plasma at the surface. We cannot exclude minor effects by surface features. We create two maps of surface reflected ENAs at the South Pole-Aitken basin. We compare these ENA maps to elevation, albedo, composition and magnetic field maps. The ENA maps only significantly correlate with the magnetic field map. ENA imaging captures solely the electrodynamics of the plasma at the surface.

  1. 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.

  2. Aeolian processes as drivers of landform evolution at the South Pole of Mars

    NASA Astrophysics Data System (ADS)

    Smith, Isaac B.; Spiga, Aymeric; Holt, John W.

    2015-07-01

    We combine observations of surface morphology, topography, subsurface stratigraphy, and near surface clouds with mesoscale simulations of south polar winds and temperature to investigate processes governing the evolution of spiral troughs on the South Pole of Mars. In general we find that the south polar troughs are cyclic steps that all formed during an erosional period, contrary to the troughs at the North Pole, which are constructional features. The Shallow Radar instrument (SHARAD) onboard Mars Reconnaissance Orbiter detects subsurface stratigraphy indicating relatively recent accumulation that occurred post trough formation in many locations. Using optical instruments, especially the Thermal Emission Imaging System (THEMIS), we find low altitude trough clouds in over 500 images spanning 6 Mars years. The locations of detected clouds correspond to where recent accumulation is detected by SHARAD, and offers clues about surface evolution. The clouds migrate by season, moving poleward from 71° S at ~ Ls 200° until Ls 318°, when the last cloud is detected. Our atmospheric simulations find that the fastest winds on the pole are found roughly near the external boundary of the seasonal CO2 ice cap. Thus, we find that the migration of clouds (and katabatic jumps) corresponds spatially to the retreat of the CO2 seasonal ice as detected by Titus (2005) and that trough morphology, through recent accumulation, is integrally related to this seasonal retreat.

  3. Balloon measurements above the South Pole: Study of ionospheric transmission of ULF waves

    SciTech Connect

    Bering, E.A. III; Benbrook, J.R.; Liao, B.

    1995-05-01

    The authors report here an experimental study of the Hughes and Southwood model of the transmission of electromagnetic signals from the ionosphere/magnetosphere to the lower atmosphere. The electric field data were obtained from one of eight high-latitude balloon payloads launched above the south geographic pole during the South Pole Balloon Campaign in the 1985-1986 austral summer. The magnetic field data are from the South Pole magnetometer. The balloon payloads were instrumented with double-probe electric field detectors and bremsstrahlung X ray detectors. One of the events from flight 7 (January 8, 1986, at 1500-1800 UT (1130-1430 MLT)) had an amplitude in the range of 10-20 mV/m and a period of several minutes. In the magnetosphere, the wave was probably an Alfven mode. The wave event was superimposed on background fluctuations that can be attributed to turbulence. The results agree with the predictions of the model in that the best coherence is observed between parallel components of E versus B. The results disagree with the predictions of the model in two respects. First, the authors find a frequency structure not predicted by the model, and second, they find intervals where the electric and magnetic field polarizations are of opposite handedness. The first discrepancy was modeled by taking account of the measured electrostatic turbulence. The second problem remains a puzzle. 47 refs., 10 figs.

  4. 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.

  5. 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

  6. 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.

  7. Following up on the Discovery of Water Vapor at Europa's South Pole with HST

    NASA Astrophysics Data System (ADS)

    Roth, L.; Retherford, K. D.; Saur, J.; Strobel, D. F.; Feldman, P. D.; McGrath, M. A.; Nimmo, F.; Spencer, J. R.; Grava, C.; Bloecker, A.

    2014-12-01

    We will present new Hubble Space Telescope (HST) observations of Europa's UV aurora obtained within two campaigns in 2014 to follow up on the water vapor plume detection. HST aurora images taken in 2012 have revealed coincident signals from atomic hydrogen and oxygen pointing to the existence of transient water vapor plumes near the south pole. The water vapor was detected only during one HST visit in December 2012 when Europa was near apocenter position and was speculated to be correlated with changing tidal stresses along Europa's orbit. In a first follow-up campaign new aurora images were taken by HST early in 2014 with Europa near apocenter, but the initial detection was not confirmed. More HST aurora images will be obtained in the course of a larger Hubble observing campaign starting in November 2014. We will review all HST aurora imaging observations to date and discuss potential sources for varying plume activity and changing detectability by HST. In particular, we will examine various explanations for the non-detections in the early 2014 observations near apocenter.

  8. Volume of Impact Melt Generated by the Formation of the South Pole-Aitken Basin

    NASA Technical Reports Server (NTRS)

    Petro, Noah E.

    2011-01-01

    The South Pole-Aitken Basin (SPA) is the largest, deepest, and oldest identified basin on the Moon and as such contains surfaces that are unique due to their age, composition, and depth of origin in the lunar crust [1-5] (Figure 1). SPA has been a target of intense interest as an area for robotic sample return in order to determine the age of the basin and the composition and origin of its interior [6-8]. In response to this interest there have been several efforts to estimate the likely provenance of regolith material within central SPA [9-12]. These model estimates suggest that, despite the formation of basins and craters following SPA, the regolith within SPA is dominated by locally derived material. An assumption of these models has been that the locally derived material is primarily SPA impact-melt as opposed to local basement material (e.g. unmelted lower crust). However, the definitive identification of SPA derived impact melt on the basin floor, either by remote sensing [5, 13] or via photogeology [2, 14] is extremely difficult due to the number of subsequent impacts and volcanic activity [4].

  9. 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.

  10. The South pole region of the moon as seen by clementine.

    PubMed

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

    1994-12-16

    The Clementine mission has provided the first comprehensive set of high-resolution images of the south pole region of the moon. Within 5 degrees 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 Schrödinger Basin (320 kilometers in diameter), centered at 75 degrees 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 Schrödinger Basin probably erupted between 1 and 2 billion years ago.

  11. 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.

  12. 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.

  13. 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.

  14. Ulysses and IMP-8 Observations of Cosmic Rays and So-lar Energetic Particles from the South Pole to the North Pole of the Sun near Solar Maximum*

    NASA Astrophysics Data System (ADS)

    McKibben, R. B.; Connell, J. J.; Lopate, C.; Zhang, M.

    2001-12-01

    The High Energy Telescope (HET) of the Ulysses COSPIN experiment measures intensities of galactic cosmic rays and solar energetic particles (SEPs) with good energy and charge resolution at energies above about 30 MeV/n. Since passing over the South Polar regions of the Sun near solar maximum in late 2000 Ulysses has been rapidly traversing solar latitude in its so-called Fast Latitude Scan (FLS), passing through perihelion near the sun's equator in May 2001. Maximum northern latitude (80.2 deg N) will be reached in October 2001. HET observations since the onset of solar activity, including the South Polar pass and the first part of the FLS, show that SEPs from large events were commonly observed at both Ulysses and Earth (IMP-8) regardless of the radial, latitudinal, or longitudinal separations between Ulysses and Earth. During the decay phases of the events intensities were often almost equal at Ulysses and IMP, even when Ulysses was over the Sun's South Pole and the associated flare site was in the northern hemisphere. This suggests that propagation of particles across the average interplanetary magnetic field in the inner heliosphere is effective enough to relax longitudinal and latitudinal particle intensity gradients within a few days. For galactic cosmic rays, observations from the FLS so far show that latitudinal gradients resulting from solar modulation at solar maximum are <1%/degree, and are in fact consistent with zero to the accuracy of our measurements. The small gradients also suggest effective propagation in the latitudinal direction. We will report observations from the continuing FLS, give a first report of Ulysses observations over the sun's North Polar Regions, and discuss the significance of the results for models of energetic charged particle propagation through the heliosphere. * This work was supported in part by NASA Contract JPL-955432 and by NASA Grant NAG5-8032.

  15. Major ions and radionuclides in aerosol particles from the South Pole during ISCAT-2000

    NASA Astrophysics Data System (ADS)

    Arimoto, R.; Hogan, A.; Grube, P.; Davis, D.; Webb, J.; Schloesslin, C.; Sage, S.; Raccah, F.

    2004-10-01

    As part of ISCAT 2000, bulk, high-volume, aerosol samples were collected at the South Pole (SP) nominally over 24-h intervals, and they were analyzed for major ions, several trace elements, and three naturally occurring radionuclides. The mean concentrations of Na (<17 ng m-3), sulfate (98 ng m-3), and methanesulfonate (MSA, 4.4 ng m-3) all were lower in ISCAT 2000 compared with ISCAT 1998, suggesting weaker marine influences during the latter study. In contrast, the 210Pb activity (0.20 mBq m-3) was more than two-times higher in ISCAT 2000 than in 1998, and nitrate concentrations (150 ng m-3) were approximately four-times higher, suggesting stronger continental influences in the second study. These differences between experiments are consistent with an analysis of meteorological transport and exchange. 7Be activities were generally comparable for ISCAT-1998 and 2000, suggesting that there were, on average, similar upper tropospheric/lower stratospheric influences on surface air during the two experiments: long-term records of 7Be, however, show pronounced annual and lower-frequency cycles. The concentration ratios of MSA to nss-sulfate (R) were similar in the two campaigns, and a regression analysis suggests that a non-biogenic source or sources account for up to ∼30% of the nonsea-salt sulfate. Various possible explanations for the low values of R (=0.08) relative to other Antarctic sites are discussed, including differences in R due to where the oxidation of DMS takes place (that is, in the marine boundary layer or in the buffer layer/free troposphere), chemical fractionation during transport, and the transport of sulfur compounds from lower latitudes and possibly from Mt. Erebus.

  16. 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

  17. 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.

  18. Remote sensing of dust in deep ice at the South Pole

    SciTech Connect

    He, Y.D.; Price, P.B.

    1998-07-01

    A three-dimensional array of phototubes in deep ice at the South Pole called the Antarctic Muon and Neutrino Detector Array (AMANDA) is recording Cherenkov light pulses that serve as tracers of high-energy neutrinos from throughout the Universe. The performance of this neutrino observatory will ultimately be constrained by the optical properties of the ice at near-ultraviolet and visible wavelengths. At depths greater than {approximately}1.4 km, air bubbles are absent and light travels great distances, limited only by absorption and scattering by dust in the ice. In this paper, the Mie theory is used to predict the magnitude and wavelength dependence of the scattering and absorption coefficients and mean cosine of the scattering angle for deep South Pole ice. The results depend on the composition, size distribution, and depth profile of insoluble mineral grains, sea salt grains, liquid acid droplets, and soot particles. With most probable values for mineral grains, sea salt, acid, and soot, we fit optical data in the wavelength interval of 300{endash}500 nm for depths of 1.6{endash}1.83 km, taken with pulsed laser beams as light sources and with AMANDA phototubes as receivers. Our work provides quantitative evidence that aerosols deposited in snow and compacted into the ice account for the optical properties at wavelengths {approximately}300{endash}500 nm. We finally predict optical properties of the South Pole ice at 2.5 km, a depth future AMANDA strings may reach. We expect that at 2.5 km the effective scattering, which is predominantly due to acid droplets, decreases by a factor of {approximately}1.5 relative to that at 1.7 km and that absorption, which is predominantly due to the mineral and soot, decreases by a factor of {approximately}3{endash}5 relative to that at 1.7 km. {copyright} 1998 American Geophysical Union

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  20. 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

  1. 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.

  2. NEXT-Lunar Lander -an Opportunity for a Close Look at the Lunar South Pole

    NASA Astrophysics Data System (ADS)

    Homeister, Maren; Thaeter, Joachim; Scheper, Marc; Apeldoorn, Jeffrey; Koebel, David

    The NEXT-Lunar Lander mission, as contracted by ESA and investigated by OHB-System and its industrial study team, has two main purposes. The first is technology demonstration for enabling technologies like propulsion-based soft precision landing for future planetary landing missions. This involves also enabling technology experiments, like fuel cell, life science and life support, which are embedded in the stationary payload of the lander. The second main and equally important aspect is the in-situ investigation of the surface of the Moon at the lunar South Pole by stationary payload inside the Lander, deployable payload to be placed in the vicinity of the lander and mobile payload carried by a rover. The currently assessed model payload includes 15 instruments on the lander and additional five on the rover. They are addressing the fields geophysics, geochemistry, geology and radio astronomy preparation. The mission is currently under investigation in frame of a phase A mission study contract awarded by ESA to two independent industrial teams, of which one is led by OHB-System. The phase A activities started in spring 2008 and were conducted until spring 2010. A phase B is expected shortly afterwards. The analysed mission architectures range from a Soyuz-based mission to a Shared-Ariane V class mission via different transfer trajectories. Depending on the scenario payload masses including servicing of 70 to 150 kg can be delivered to the lunar surface. The lander can offer different services to the payload. The stationary payload is powered and conditioned by the lander. Examples for embarked payloads are an optical camera system, a Radio Science Experiment and a radiation monitor. The lander surface payload is deployed to the lunar surface by a 5 DoF robotic arm and will be powered by the Lander. To this group of payloads belong seismometers, a magnetometer and an instrumented Mole. The mobile payload will be carried by a rover. The rover is equipped with its own

  3. 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.

  4. Public science for a global empire: The British quest for the South Magnetic Pole.

    PubMed

    Larson, Edward J

    2011-03-01

    It is well known to historians of science that, early in the nineteenth century, terrestrial magnetism became both a popular science and a significant research enterprise in Europe. For Britain, as a maritime power, it offered benefits for navigation. Theoretical physicists claimed that, with enough observations of magnetic variation, intensity, and dip taken throughout the world over time, they could deduce regular mathematical laws to explain the phenomena. Because of the lack of data from the region, particular attention focused on field research in deep southern latitudes. Finding the precise location of the South Magnetic Pole became a prime goal for some enthusiasts. With burgeoning colonies in Africa and the Antipodes, Britain assumed a leading role in this effort. British scientists looked to their government for funding and called on the Admiralty to dispatch expeditions. It is less well known that both popular and scientific interest in terrestrial magnetism continued throughout the nineteenth century and into the early twentieth century. The H.M.S. Erebus and H.M.S. Terror (1839-1843), H.M.S. Challenger (1872-1876), and R.Y. Discovery (1901-1904) sailed to the Antarctic as part of Britain's extended "Magnetic Crusade," which culminated with Royal Society geologist T. W. Edgeworth David of the Nimrod expedition reaching the South Magnetic Pole in 1909. PMID:21667775

  5. Intradiurnal wind variations observed in the lower thermosphere over the South Pole

    NASA Astrophysics Data System (ADS)

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

    2000-05-01

    The first meteor radar measurements of meridional winds in the lower thermosphere (about 95 +/- 5 km), along four azimuth directions: 0°, 90°E, 180° and 90°W; approximately 2° from the geographic South Pole were made during two observational campaigns: January 19, 1995-January 26, 1996, and November 21, 1996-January 27, 1997. Herein we report analyses of the measurement results, obtained during the first campaign, which cover the whole one-year period, with particular emphasis on the transient nature and seasonal behavior of the main parameters of the intradiurnal wind oscillations. To analyze the data, two complementary methods are used: the well-known periodogram (FFT) technique and the S-transform technique. The most characteristic periods of the intradiurnal oscillations are found to be rather uniformly spread between about 7 h and 12 h. All of these oscillations are westward-propagating with zonal wave number s=1 and their usual duration is confined to several periods. During the austral winter season the oscillations with periods less than 12 h are the most intensive, while during summer season the 12-h oscillations dominate. Lamb waves and internal-gravity wave propagation, non-linear interaction of the short-period tides, excitation in situ of the short period waves may be considered as possible processes which are responsible for intradiurnal wind oscillations in the lower thermosphere over South Pole.

  6. Direct Observations of NO in South Pole Snowpack During ISCAT 2000

    NASA Astrophysics Data System (ADS)

    Buhr, M.; Davis, D.; Lombardi, K.; Lefer, B.; Shetter, R.; Huey, G.; Tanner, D.; McConnell, J.; Dibb, J.

    2001-12-01

    Based on the ISCAT 1998 field study, it was concluded that the abnormally high levels of NO observed at South Pole were due to large natural emissions of NO from the snow. The latter process was believed to be the result of photolysis of nitrate ions in the snowpack. During ISCAT 1998, however, no snowpack measurements were available. Reported here are the first snowpack observations of NO, NO2, and NOx. These measurements were made using two different chemiluminescent instruments. The measurements themselves were recorded at two different locations at South Pole, the first was approximately 100 meters from the Atmospheric Research Observatory (ARO) building, the second was 5 meters from the ARO. Measurements were recorded at snowpack depths ranging from 1 to 100cm. The time period covered by these observations was from December 10, 2000 to March 24, 2001. Details concerning measured NO and its relationship to snowpack measured levels of NO2, NOx, O3, and NO3- will be presented.

  7. 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.

  8. Co-activation based parcellation of the human frontal pole.

    PubMed

    Ray, K L; Zald, D H; Bludau, S; Riedel, M C; Bzdok, D; Yanes, J; Falcone, K E; Amunts, K; Fox, P T; Eickhoff, S B; Laird, A R

    2015-12-01

    Historically, the human frontal pole (FP) has been considered as a single architectonic area. Brodmann's area 10 is located in the frontal lobe with known contributions in the execution of various higher order cognitive processes. However, recent cytoarchitectural studies of the FP in humans have shown that this portion of cortex contains two distinct cytoarchitectonic regions. Since architectonic differences are accompanied by differential connectivity and functions, the frontal pole qualifies as a candidate region for exploratory parcellation into functionally discrete sub-regions. We investigated whether this functional heterogeneity is reflected in distinct segregations within cytoarchitectonically defined FP-areas using meta-analytic co-activation based parcellation (CBP). The CBP method examined the co-activation patterns of all voxels within the FP as reported in functional neuroimaging studies archived in the BrainMap database. Voxels within the FP were subsequently clustered into sub-regions based on the similarity of their respective meta-analytically derived co-activation maps. Performing this CBP analysis on the FP via k-means clustering produced a distinct 3-cluster parcellation for each hemisphere corresponding to previously identified cytoarchitectural differences. Post-hoc functional characterization of clusters via BrainMap metadata revealed that lateral regions of the FP mapped to memory and emotion domains, while the dorso- and ventromedial clusters were associated broadly with emotion and social cognition processes. Furthermore, the dorsomedial regions contain an emphasis on theory of mind and affective related paradigms whereas ventromedial regions couple with reward tasks. Results from this study support previous segregations of the FP and provide meta-analytic contributions to the ongoing discussion of elucidating functional architecture within human FP. PMID:26254112

  9. Responses of polar mesospheric cloud brightness to stratospheric gravity waves at the South Pole and Rothera, Antarctica

    NASA Astrophysics Data System (ADS)

    Chu, Xinzhao; Yamashita, Chihoko; Espy, Patrick J.; Nott, Graeme J.; Jensen, Eric J.; Liu, Han-Li; Huang, Wentao; Thayer, Jeffrey P.

    2009-03-01

    We present the first observational proof that polar mesospheric cloud (PMC) brightness responds to stratospheric gravity waves (GWs) differently at different latitudes by analyzing the Fe Boltzmann lidar data collected from the South Pole and Rothera (67.5°S, 68.0°W), Antarctica. Stratospheric GW strength is characterized by the root-mean-square (RMS) relative density perturbation in the 30-45 km region and PMC brightness is represented by the total backscatter coefficient (TBC) in austral summer from November to February. The linear correlation coefficient (LCC) between GW strength and PMC brightness is found to be +0.09 with a 42% confidence level at the South Pole and -0.49 with a 98% confidence level at Rothera. If a PMC case potentially affected by a space shuttle exhaust plume is removed from the Rothera dataset, the negative correlation coefficient and confidence level increase to -0.61 and 99%, respectively. The Rothera negative correlation increases when shorter-period waves are included while no change is observed in the South Pole correlation. Therefore, observations show statistically that Rothera PMC brightness is negatively correlated with the stratospheric GW strength but no significant correlation exists at the South Pole. A positive correlation of +0.74 with a confidence level of 99.98% is found within a distinct subset of the South Pole data but the rest of the dataset exhibits a random distribution, possibly indicating different populations of ice particles at the South Pole. Our data show that these two locations have similar GW strength and spectrum in the 30-45 km region during summer. The different responses of PMC brightness to GW perturbations are likely caused by the latitudinal differences in background temperatures in the ice crystal growth region between the PMC altitude and the mesopause. At Rothera, where temperatures in this region are relatively warm and supersaturations are not as large, GW-induced temperature perturbations can

  10. Multi-instrument observations of dayside auroral emission dynamics at South Pole

    NASA Astrophysics Data System (ADS)

    Azeem, I.; Sivjee, G. G.; McEwen, D. J.

    2008-05-01

    Dayside Aurora has been continuously (24 hour) monitored from South Pole during six month of polar winter night, from mid April to mid September. Oscillating auroral phenomenon has been observed via a 6-channel photometer scanning along the magnetic meridian towards the magnetic pole and a CCD spectrograph (CCDS) operating in the near-infrared (700nm - 960 nm) region along the local magnetic zenith. In this paper we present the dynamics of 630 nm and 844.6 nm auroral emission lines in the dayside aurora (in the 1200-1800 MLT sector) in response to modulations in the interplanetary magnetic field (IMF). Examination of CCDS and meridian scanning photometer data shows intensification of both the red (630.0 nm) and OI (844.6) line emissions in the cusp region near 1200 MLT accompanied by modulation of the line intensity at a period of 10-25 minutes. The associated IMF disturbance also shows 10-25 minute period pulsations. These observations of red and OI line emissions and IMF pulsations are discussed within the context of magnetosphere-ionosphere (MI) coupling.

  11. A cylindrical current sheet over the South solar pole observed by Ulysses

    NASA Astrophysics Data System (ADS)

    Khabarova, Olga; Kislov, Roman; Malova, Helmi; Obridko, Vladimir

    2016-04-01

    We provide the first evidence for the existence of a quasi-stable cylindrical current sheet over the South solar pole as observed by Ulysses in 2006, near the solar minimum, when it reached maximal heliolatitude of 79.7 degrees at 2.4 AU. It took place inside a fast speed stream from the coronal hole, and the tube was presumably crossed rather far from the center within two degrees of heliolatitude and ~10 degrees of heliolongitude. During the spacecraft passage throughout the structure, the solar wind velocity was approximately twice as little, the solar wind density was 20 times lower than the surrounded plasma values, but the temperature was twice as large in the point closest to the pole. The interplanetary magnetic field (IMF) strongly decreased due to sharp variations in the IMF radial component (RTN) that changed its sign twice, but other components did not show changes out of usual stochastic behavior. Both the behavior of the IMF, rotation of the plasma flow direction and other features indicate the occurrence of cylindrical current sheet. We discuss its solar origin and present modeling that can explain the observations.

  12. 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.

  13. 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.

  14. South pole bang-time diagnostic on the National Ignition Facility (invited).

    PubMed

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

    2012-10-01

    The south pole bang-time 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 diamond photoconductive detectors with different filtrations and sensitivities record the time-varying x rays emitted by the target. Wavelength selecting highly oriented pyrolytic graphite 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 time integral of the corrected peak signal. PMID:23126941

  15. Imaging the South Pole - Aitken Basin in Backscattered Energetic Neutral Hydrogen Atoms

    NASA Astrophysics Data System (ADS)

    Vorburger, Audrey; Wurz, Peter; Barabash, Stas; Wieser, Martin; Futaana, Yoshifumi; Bhardwaj, Anil; Asamura, Kazushi

    2015-04-01

    The Moon, not being protected by a global magnetic field or an atmosphere, is constantly bombarded by solar wind ions. Until a few years ago, it was tacitly assumed that the impinging solar wind ions are almost completely absorbed ( < 1% reflection) by the lunar surface (e.g. Crider and Vondrak, Adv. Space Res., (2002); Feldman et al., J. Geophys. Res., (2000)). Recent observations by IBEX and the Sub-keV Atom Reflecting Analyzer (SARA) onboard Chandrayaan-1 invalidated this assumption, though: In fact, these measurements showed that the lunar surface very efficiently reflects impinging solar wind ions as energetic neutral atoms (ENAs) (e.g. McComas et al., GRL, 2009; Wieser et al., PSS, 2009). Most recently, a global analysis of lunar hydrogen ENAs measured by SARA showed that on average 16% of the solar wind protons are reflected, and that the reflected fraction can range from less than 8% to more than 24%, depending on location (Vorburger et al., J. Geophys. Res., 2013). Whereas it is established that magnetic anomalies reduce the flux of backscattered hydrogen ENAs by screening-off a fraction of the impinging solar wind ions (e.g. Wieser et al., Planet. Space Sci., (2009); Lue et al., Geophys. Res. Lett., (2011); Vorburger et al., J. Geophys. Res., (2012); Futaana et al., Geophys. Res. Lett., (2013)), the effects of other surface properties such as porosity, roughness, chemical composition, and extent of weathering, was not known. To investigate the effects of these surface properties on the properties of scattered ENAs, we conducted an in-depth analysis of ENA observations near the South Pole - Aitken basin using the complete dataset collected by SARA. The South Pole - Aitken basin is an ideal object for such a study, because it highly differs in many properties from the surrounding terrain. It is very deep (~13 km), possesses strikingly elevated concentrations in iron (~15 wt%) and thorium (~7 wt%), has a low albedo and coincides with a cluster of strong

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. A catalog of K giants at the South Galactic Pole - Broadband and DDO photometry and radial velocities

    NASA Astrophysics Data System (ADS)

    Flynn, C.; Freeman, K. C.

    1993-03-01

    We describe a sample of K giants at the South Galactic Pole, selected to examine the chemical and kinematical properties of stars perpendicular to the galactic plane and to measure the local column density of the disk. We report velocities, abundances, absolute magnitudes, and broadband BV photometry for over 500 giants.

  1. 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).

  2. Foucault pendulum at the south pole: Proposal for an experiment to detect the earth's general relativistic gravitomagnetic field

    SciTech Connect

    Braginsky, V.B.; Polnarev, A.G.; Thorne, K.S.

    1984-08-27

    An experiment is proposed for measuring the earth's gravitomagnetic field by monitoring its effect on the plane of swing of a Foucault pendulum at the south pole (''dragging of inertial frames by earth's rotation''). With great effort a 10% experiment in a measurement time of several months might be achieved.

  3. 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.

  4. 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.

  5. Simultaneous mesospheric wind measurements near South Pole by optical and meteor radar methods

    NASA Astrophysics Data System (ADS)

    Hernandez, G.; Forbes, J. M.; Smith, R. W.; Portnyagin, Y.; Booth, J. F.; Makarov, N.

    Simultaneous and co-located measurements of mesospheric winds near South Pole, by high-resolution optical and meteor radar methods, show that these two methods determine very similar motions at slightly different heights of observation. The measured atmospheric motions by the two techniques show that a) The mean wind during 12 days in June, 1995 was found to have a 7 m/s amplitude flowing towards the 5°E longitude direction. The latter direction is different from the 30E° direction found earlier during August 1991 and 1992. b) The observed dominant oscillations in the wind at both heights of observation are those of zonal wavenumber one character. Westward phase propagation was determined for the observed short-period (∼0 hours) oscillations and eastward phase propagation for the longer-period (∼3 days) oscillations, respectively. Because of the neighboring heights of observation by the optical and meteor radar methods, the in situ vertical wavelengths of propagation of the observed waves have been determined to be greater than 100 km for the 10-hr oscillations and near 65 km for the longer period oscillations. With this new information we are able to independently establish the earlier assignment of the nearly 10-hr oscillations as the different meridional modes of a zonal wavenumber one Lamb wave. The determined vertical wavelength and eastward phase progression of the longer periodicity waves indicate these oscillations are likely to be the gravest inertio-gravity wave, which has the appropriate equivalent depths at these periods of oscillation. The simultaneous absence of statistically significant kinetic temperature and optical-tracer emission rate oscillations at the frequencies corresponding to the wind motions, provides independent support to the earlier deductions on the ability of the atmosphere near the rotational poles to support only certain zonal character oscillations.

  6. GROOVED TERRAIN NEAR THE SOUTH POLE OF MARS; Clue to an Unmodeled Amazonian Climate-Episode?

    NASA Astrophysics Data System (ADS)

    Crawford, Z.; Murray, B.; Byrne, S.; Koutnik, M.

    2002-12-01

    We have used detailed MOLA profiles and precisely co-located MOC/NA images to study extensively the large-scale aligned grooves and peculiar crosscutting features apparent on the surface of the South Polar Layered Deposits in the vicinity of 83-87 S, 190-240 W and also at the head of Chasma Australe at 86-87 S, 265-270 W. We denote these features informally as the South Polar Grooved Terrain Images of the grooves, and associated peculiar cross-cutting ridges which we informally term snakes, are available at http://www.gps.caltech.edu/~marssurf/polar/wirebrush.html and will be illustrated during the talk. These surficial grooves, which we have found only in the South, are very likely of exogenic origin, in contrast to the snakes with appear to us to be of deformational origin. The grooves very probably testify to an unrecognized past Amazonian south polar environmental episode which conceivably could have involved unusual past winds, or ancient ice sheet motion, or episodes of catastrophic flooding originating from beneath earlier water-ice residual caps. Any such origins would have profound implications for past Amazonian climate episodes not yet recognized nor modeled. For example, the large-scale curvature of the grooves might suggest Coriolis effects on strong (~80 m/sec) downslope polar winds, but the grooves appear to pass across rather than around local topography. In contrast, ancient ice sheets characterized by vigorous ice streams conceivably could have carved grooves across the underlying terrain, as Lucchitta [2001] has suggested may have been the case in Kasai Valles. Indeed, Head and colleagues [e.g., Head and Pratt, 2001; Milkovich et al., 2002; Ghatan and Head, 2002] argue for extensive Hesperian-age meltback and glacial flow of earlier Hesperian ice-rich sediments near the South Pole due to volcanism and possibly climate change. However, the Amazonian grooves also occur at the head of Chasma Australe. Did ancient ice sheets also create Chasma

  7. 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

  8. 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.

  9. Characterisation of Landing Sites at the Rim of the Lunar South Pole Aitken Basin

    NASA Astrophysics Data System (ADS)

    Koebel, David; Bonerba, Michele; Wieser, Matthias; Homeister, Maren; Borowy, Carsten

    The lunar South polar region is of high scientific interest and advantageous in many aspects for exploration missions. The polar terrain is located at the rim of the Aitken Basin, being the largest impact crater in the solar system, where material from the lunar mantle has been ejected to the surface. This basin features a diameter of 2,500 km and variations in altitude as large as 14 km. Since the solar elevation never exceeds 1.5 at the pole, there exist mountain peaks in this area that are characterised by near eternal illumination. These summits provide a benign thermal environment for any long-term robotic or manned lander mission, and ideal conditions for photovoltaic power generation. The smaller impact craters in the polar region, on the other hand, possess depths with constant darkness. These craters are evidently harbouring water resources that remain conserved through the cryogenic temperatures inside them. The ice originates from the bombardment of comets throughout the billions of years after the formation of the lunar crust. For this terrain updated analyses of the solar illumination and ground station visibility conditions have been performed. These are based on the refined lunar digital elevation model provided by the Japanese Kaguya/Selene mission, originating from its LASER altimeter instrument. The resulting maps for the South polar region will be presented in this paper. Some considerations on the geology of interesting locations within the SPA are complemented. With these prerequisites, several possible landing sites for a future lunar mission have been selected. A detailed analysis of illumination timelines will be presented for these sites.

  10. Cosmic noise absorption and ionospheric currents at the South Pole and Frobisher Bay: Initial results

    SciTech Connect

    Rosenberg, T.J. ); Wolfe, A. AT T Bell Laboratories, Murray Hill, NJ ); Lanzerotti, L.J. )

    1987-01-01

    Studies of the conjugacy of auroral and ionospheric phenomena at very high latitudes are an important aspect of magnetospheric physics research. The extent to which auroral phenomena in opposite hemispheres are similar in occurrence and in the details of their temporal, spatial, and spectral characteristics can be used to infer the commonality of the source(s) of the disturbances. At one extreme in this consideration is the questions of whether sources lie on open or closed magnetic field lines. The University of Maryland and AT T Bell Laboratories have operated riometers and fluxgate magnetometers, respectively, at South Pole since 1982. Corresponding measurements at Frobisher Bay were begun in mid-1985. Riometers record the absorption of cosmic radio noise in the ionosphere produced by the enhances precipitation of energetic charged particles. The studies of the riometer data relate mainly to the effects of the influx of magnetospheric electrons, which give rise to auroral absorption of the cosmic signals. Intense currents (electrojets) that often flow in the ionosphere in association with auroral absorption events produce magnetic field changes that can be recorded on the ground by appropriately sited magnetometers. This report presents some initial results of the comparison of the two data sets.

  11. Constraints on the volatile distribution within Shackleton crater at the lunar south pole.

    PubMed

    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

    2012-06-20

    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.

  12. 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.

  13. Constraints on the volatile distribution within Shackleton crater at the lunar south pole.

    PubMed

    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

    2012-06-21

    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. PMID:22722197

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Europa's South Pole Region: A sequential reconstruction of surface modification processes

    NASA Astrophysics Data System (ADS)

    Riley, Jeannie; Greenberg, Richard; Sarid, Alyssa

    2006-08-01

    High-resolution images of a region near the south pole of Europa allow reconstruction of a series of events, tectonic and thermal, that displaced and modified the surface. This approach is complementary to regional geological mapping, which is based on less detailed images, but covers a broader sample of the surface. The events reconstructed in this locale resurfaced about half the area or more, so they probably ranged over a substantial fraction of the age of Europa's surface, which in itself is quite young (< 50 Myr) due to the cumulative effects of such local (or regional) reprocessing events acting over the entire globe. Chaotic terrain was formed (probably by thermal processes) both early and late in the sequence. Trends in changing geological processes that had been inferred from lower-resolution images in regional geological mapping efforts, especially an increase in formation of chaotic terrain with time, which had been widely interpreted as implying a thickening of the ice crust, are not evident in this area. The impression that chaotic terrain is a relatively recent phenomenon may come from the fact that older chaotic terrain can be more difficult to identify, especially in the lower-resolution images used for geological mapping. This study reinforces the conclusion that both chaotic terrain and tectonic features have been formed by competing processes that have resurfaced Europa through much of its geologic history.

  20. 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.

  1. 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.

  2. 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.

  3. A review of the practices and results of the UTMB to South Pole teledermatology program over the past six years.

    PubMed

    Sun, Angel; Lanier, Russell; Diven, Dayna

    2010-01-01

    There is no place on earth more remote and inaccessible than Antarctica. In 2002, Raytheon Polar Services Co. (RPS) awarded The University of Texas Medical Branch (UTMB) at Galveston the contract to provide specialty medical services via telemedicine to the approximately 3,500 National Science Foundation (NSF) researchers and support personnel who rotate through Antarctica in a given year. We present the practices and results of the UTMB to the South Pole teledermatology program over the past six years, from 2003 to 2008. Issues encountered include logistics of sending out biopsies for pathologic diagnosis, limited bandwidth, and satellite availability for data transmission. The UTMB to the South Pole teledermatology program demonstrates the clinical practicality of telemedicine in providing dermatologic care to remote populations in extreme climate conditions. PMID:20137758

  4. 225-GHz atmospheric opacity of the South Pole sky derived from continual radiometric measurements of the sky-brightness temperature.

    PubMed

    Chamberlin, R A; Bally, J

    1994-02-20

    We report measurements of the atmospheric opacity of the South Pole at 225 GHz for the period from day 3 to day 180 in 1992. These opacity data were derived from continual radiometric measurements of the sky-brightness temperature as a function of the zenith angle. These radiometric measurements were performed with a 225-GHz heterodyne atmospheric radiometer on loan from the National Radio Astronomy Observatory. This radiometer was previously used to characterize other candidate millimeter and submillimeter radio-telescope sites. We found that the atmospheric opacity was below 0.098 air mass(-1) 75% of the time from day 3 to day 70 in 1992, and below 0.055 air mass(-1) 75% of the time from day 70 to day 180 in 1992. Thus, our data demonstrate that the South Pole is an excellent site for performing millimeter-and submillimeter-wavelength radio astronomy.

  5. 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.

  6. The Abundance of C6H6 and HC3N over Titan's South Pole as winter approaches

    NASA Astrophysics Data System (ADS)

    Bjoraker, Gordon; Cottini, Valeria; Achterberg, Richard; Coustenis, Athena

    2016-06-01

    Benzene and cyanoacetylene have increased dramatically near Titan's South Pole since 2011. First detected near the South Pole in limb measurements, CIRS can now see strong emission lines of these species in nadir observations. This is remarkable because at the same time stratospheric temperatures at the 1-mbar level (185 km) at 70°S have dropped more than 30K in the past 5 years. CIRS obtained measurements of emission from these molecules as a function of latitude during the T104 flyby on 2014 August 20. These data show the strongest emission at 83°S, falling off rapidly towards 70°S. Recently, during T117 on 2016 February 16, CIRS obtained limb spectra at 80°S. These observations show peak emission for C6H6 between 200 and 250 km, while HC3N peaks between 250 and 300 km (0.25 to 0.1 mbars) where the stratospheric temperature is near 160 K. These molecules are tracers of meridional transport in Titan's stratosphere and their confinement near the South Pole is reminiscent of the Antarctic ozone hole on Earth.

  7. 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

  8. Organic trace gases of oceanic origin observed at South Pole during ISCAT 2000

    NASA Astrophysics Data System (ADS)

    Swanson, Aaron L.; Davis, Douglas D.; Arimoto, Richard; Roberts, Pauline; Atlas, Elliot L.; Flocke, Frank; Meinardi, Simone; Sherwood Rowland, F.; Blake, Donald R.

    2004-10-01

    Volatile organic compounds (VOCs) were measured at the South Pole (SP) from late Austral spring to mid-summer 2000 as part of the Investigation of Sulfur Chemistry in the Antarctic Troposphere Program (ISCAT-2000). This paper focuses on VOCs that are directly emitted from the ocean, specifically dimethyl sulfide (DMS), methyl nitrate (CH3ONO2), methyl iodide (CH3I) and bromoform (CHBr3). A partial seasonal cycle of these gases was also recorded during the year following ISCAT-2000. During the summer, the SP periodically receives relatively fresh marine air containing short-lived oceanic trace gases, such as DMS (τ≈1 day). However, DMS was not detected at the SP until January even though DMS emissions from the Southern Ocean typically start peaking in November and elevated levels of other ocean-derived VOCs, including CH3ONO2 and CHBr3, were observed in mid-November. We speculate that in November and December most of the DMS is oxidized before it reaches the SP: a strong correlation between CH3ONO2 and methane sulfonate (MSA), an oxidation product of DMS, supports this hypothesis. Based on a limited number of samples taken over the course of one year, CH3ONO2 apparently accumulates to a quasi-steady-state level over the SP in winter, most likely due to continuing emissions of the compound coupled with a lower rate of photochemical destruction. Oceanic emissions were concluded to be the dominant source of alkyl nitrates at the SP; this is in sharp contrast to northern high latitudes where total alkyl nitrate mixing ratios are dominated by urban sources.

  9. 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. PMID:21327792

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

    NASA Astrophysics Data System (ADS)

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

    2000-10-01

    Because the orbit of the Mars Global Surveyor (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 by the Mars Orbiter Camera (MOC) during the spring and summer at the South Pole. (1) Circular depressions, described by Thomas et al. [Nature 404, 161-164, 2000], which are 10 meters deep and 100's of meters in diameter. (2) Layers several meters thick that are exposed on the walls of the mesas. (3) Late summer darkening of the walls of the mesas, which are half as bright as the flat tops. (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 circular, like black spiders with multiple branching arms. After the CO2 frost has disappeared the arms are seen as troughs. (5) Polygons whose sides are dark troughs. Those that are outside the residual cap seem to disappear when the frost disappears. (6) Irregular depressions outside the residual cap. They look like degraded versions of the circular depressions inside the residual cap, and may be a remnant of the cap's changing location. (7) Areas of burial and exhumation of circular depressions. Thomas et al. give an example with a sharp boundary: On one side the depressions are buried and on the other side they are exposed. In other cases there are rounded troughs up to 1 kilometer wide, which are dark in summer and appear to have eroded down below the floor of the circular depressions.

  11. MEASUREMENT OF GALAXY CLUSTER INTEGRATED COMPTONIZATION AND MASS SCALING RELATIONS WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

    Saliwanchik, B. R.; Montroy, T. E.; Aird, K. A.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Bocquet, S.; Desai, S.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; Dobbs, M. A.; Dudley, J. P.; Foley, R. J.; Forman, W. R.; and others

    2015-02-01

    We describe a method for measuring the integrated Comptonization (Y {sub 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 {sub 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 {sub SZ} for simulated semi-analytic clusters and find that Y {sub 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 {sub 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 {sub SZ} within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y {sub SZ} at a fixed mass. Measuring Y {sub 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 {sub 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.

  12. GALAXY CLUSTERS SELECTED WITH THE SUNYAEV-ZEL'DOVICH EFFECT FROM 2008 SOUTH POLE TELESCOPE OBSERVATIONS

    SciTech Connect

    Vanderlinde, K.; De Haan, T.; Dudley, J. P.; Shaw, L.; Dobbs, M. A.; Crawford, T. M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crites, A. T.; Gladders, M. D.; Ade, P. A. R.; Aird, K. A.; Brodwin, M.; Foley, R. J.; Desai, S.; George, E. M.; Hall, N. R.; Halverson, N. W.

    2010-10-20

    We present a detection-significance-limited catalog of 21 Sunyaev-Zel'dovich-selected galaxy clusters. These clusters, along with one unconfirmed candidate, were identified in 178 deg{sup 2} of sky surveyed in 2008 by the South Pole Telescope (SPT) to a depth of 18 {mu}K arcmin at 150 GHz. Optical imaging from the Blanco Cosmology Survey (BCS) and Magellan telescopes provided photometric (and in some cases spectroscopic) redshift estimates, with catalog redshifts ranging from z = 0.15 to z>1, with a median z = 0.74. Of the 21 confirmed galaxy clusters, 3 were previously identified as Abell clusters, 3 were presented as SPT discoveries in Staniszewski et al., and 3 were first identified in a recent analysis of BCS data by Menanteau et al.; the remaining 12 clusters are presented for the first time in this work. Simulated observations of the SPT fields predict the sample to be nearly 100% complete above a mass threshold of M{sub 200} {approx} 5 x 10{sup 14} M{sub sun} h {sup -1} at z = 0.6. This completeness threshold pushes to lower mass with increasing redshift, dropping to {approx}4 x 10{sup 14} M{sub sun} h {sup -1} at z = 1. The size and redshift distribution of this catalog are in good agreement with expectations based on our current understanding of galaxy clusters and cosmology. In combination with other cosmological probes, we use this cluster catalog to improve estimates of cosmological parameters. Assuming a standard spatially flat wCDM cosmological model, the addition of our catalog to the WMAP seven-year results yields {sigma}{sub 8} = 0.81 {+-} 0.09 and w = -1.07 {+-} 0.29, a {approx}50% improvement in precision on both parameters over WMAP7 alone.

  13. 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.

  14. SUNYAEV-ZEL'DOVICH CLUSTER PROFILES MEASURED WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

    Plagge, T.; Cho, H.-M.; George, E. M.; Holzapfel, W. L.; Benson, B. A.; Aird, K. A.; Hrubes, J. D.; Ade, P. A. R.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Keisler, R.; De Haan, T.; Dobbs, M. A.; Holder, G. P.; Hall, N. R.; Halverson, N. W.; Joy, M.

    2010-06-20

    We present Sunyaev-Zel'dovich (SZ) measurements of 15 massive X-ray-selected galaxy clusters obtained with the South Pole Telescope (SPT). The SZ cluster signals are measured at 150 GHz, and concurrent 220 GHz data are used to reduce astrophysical contamination. Radial profiles are computed using a technique that takes into account the effects of the beams and filtering. In several clusters, significant SZ decrements are detected out to a substantial fraction of the virial radius. The profiles are fit to the {beta}-model and to a generalized Navarro-Frenk-White (NFW) pressure profile, and are scaled and stacked to probe their average behavior. We find model parameters that are consistent with previous studies: {beta} = 0.86 and r{sub core}/r{sub 500} = 0.20 for the {beta}-model, and ({alpha}{sub n}, {beta}{sub n}, {gamma}{sub n}, c{sub 500}) = (1.0, 5.5, 0.5, 1.0) for the generalized NFW model. Both models fit the SPT data comparably well, and both are consistent with the average SZ profile out to beyond r{sub 500}. The integrated Compton-y parameter Y{sub SZ} is computed for each cluster using both model-dependent and model-independent techniques, and the results are compared to X-ray estimates of cluster parameters. We find that Y{sub SZ} scales with Y{sub X} and gas mass with low scatter. Since these observables have been found to scale with total mass, our results point to a tight mass-observable relation for the SPT cluster survey.

  15. Thorium Abundances of Basalt Ponds in South Pole-Aitken Basin: Insights into the Composition and Evolution of the Far Side Lunar Mantle

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    We used forward modeling of Lunar Prospector thorium (Th) data derived from basalts in South Pole-Aitken basin to demonstrate that large expanses of basalt could be reliably used to obtain compositional information about the far side lunar mantle.

  16. Movement of the Earth pole and the seismic activity in 2001-2012

    NASA Astrophysics Data System (ADS)

    Andreev, Aleksey; Zabbarova, Regina; Lapaeva, Valentina; Nefedyev, Yuri

    2014-05-01

    The relationship between the parameters which characterize the movement of the Earth pole and seismic activity are considered. The correlation of the considered parameters is studied. The discussions about the relationship of poles movement and irregularity in speed of Earth rotation with seismic activity were actively performed in 60- 70th years of last century. Mainly, the influence of seismicity on pole movement was considered in this works. In particular, the question about excitation of a pole by earthquakes chandler's fluctuations was studied. An interest in the similar researches continues till now. The chandler's movements investigations and their relation with rotation of the Earth and seismicity were proceeded. The correlation between appearance of earthquakes and abnormal evasion of time and latitude for the observatories located near an epicenter was also discussed. What changes in position of the Earth pole do occur as a result of the strongest earthquakes? To answer on this question it is necessary to study variations of "an average pole", where the basic periodic components in movement of a pole having amplitude 0.1"-0.3" are accepted. To perform the analysis of the pole co-ordinates (X and Y) the International service of the Earth rotation for 1995-2012 have been considered. Linear Orlov-Saharov transformation has been applied to an exception of the periodic movement. On the basis of this positions changes of an average pole (aperiodicity displacement and long periodical variations of an axis of rotation in a Earth body) have been calculated with an interval of 0.1 years. Was found the changes of position of an average pole of the Earth was preceded the most considerable seismic events of the beginning of 21 century. As a whole, the increase of seismic activity has begun after 2002 only. For example, there were 2 strong earthquakes with magnitude 7 and more (Salvador, India) in 2001 , 2 earthquakes (Tajikistan, Taiwan) occurred in 2002, and 5

  17. a Search for the Cosmic Dust Increment to Aerosol Particles at the Geographic South Pole.

    NASA Astrophysics Data System (ADS)

    Witkowski, Robert Edward

    1988-12-01

    An electrostatic precipitation (ESP) particle collector was constructed and deployed to sample the South Pole, Antarctica atmosphere for submicron-size cosmic dust particles. It was in operation between December, 1983 and January, 1987 at the National Oceanic and Atmospheric Administration (NOAA) Clean Air Facility (CAF). The collector is most efficient for particles in the 0.3 mu m size range. An arrangement of isolation shutters and removable sampling plates allows for sample transfer, without contamination, to a remote laboratory for individual particle characterization by Scanning Transmission Electron Microscopy (STEM) coupled with Energy Dispersive Spectrometry (EDS) for elemental analysis and Selected Area Electron Diffraction (SAED) for crystallographic identifications. Beside the readily identifiable contaminants, including sulfuric acid droplets that make up a significant background and sooty carbonaceous-type material, a variety of rod-shaped grains and spheres have been noted. In addition, an iron-containing mineral has been observed as fragile filamentary or needle-like crystalline aggregates. Some rather rare particles that display single element EDS signature peaks of Ti, Cr, Co, Mg, Si, and Pb and a possible Cr, Fe intermetallic or mineral particle also have been observed. While it would not be surprising for cosmic dust grains to be small in size and to have simple compositions, any concrete evidence of an extraterrestrial origin for any of these grains is lacking. Two other types of particles show a stronger possibility of cosmic origin. These are an Al, Fe particle collected during a Perseids Meteor Event and a unique particle that contains Mg, Al, Si, S, Ca, Fe and Ni in chondritic proportions. After completion of the particle collection program, the collector was shut down and returned to the laboratory for evaluation. An area of one of the stainless steel plates from the first chamber of the collector, the particle -charging section, was

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. Effect of the upper limbs muscles activity on the mechanical energy gain in pole vaulting.

    PubMed

    Frère, Julien; Göpfert, Beat; Slawinski, Jean; Tourny-chollet, Claire

    2012-04-01

    The shoulder muscles are highly solicited in pole vaulting and may afford energy gain. The objective of this study was to determine the bilateral muscle activity of the upper-limbs to explain the actions performed by the vaulter to bend the pole and store elastic energy. Seven experienced athletes performed 5-10 vaults which were recorded using two video cameras (50Hz). The mechanical energy of the centre of gravity (CG) was computed, while surface electromyographic (EMG) profiles were recorded from 5 muscles bilateral: deltoideus, infraspinatus, biceps brachii, triceps, and latissimus dorsi muscles. The level of intensity from EMG profile was retained in four sub phases between take-off (TO1) and complete pole straightening (PS). The athletes had a mean mechanical energy gain of 22% throughout the pole vault, while the intensities of deltoideus, biceps brachii, and latissimus dorsi muscles were sub phases-dependent (p<0.05). Stabilizing the glenohumeral joint (increase of deltoideus and biceps brachii activity) and applying a pole bending torque (increase of latissimus dorsi activity) required specific muscle activation. The gain in mechanical energy of the vaulter could be linked to an increase in muscle activation, especially from latissimusdorsi muscles.

  5. 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

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

    NASA Astrophysics Data System (ADS)

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

    2000-08-01

    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

  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. PMID:12060731

  8. Mid-infrared measurements of the atmospheric emission over the South Pole using a radiometrically calibrated Fourier transform spectrometer.

    PubMed

    Van Allen, R; Murcray, F J; Liu, X

    1996-03-20

    We conducted year-round measurements of the downwelling atmospheric infrared emission over the South Pole in 1992. The instrument covered the 550-1600-wave-number region with 1-wave-number resolution. We calculated the water vapor content for clear-sky cases and found a good correlation with the surface temperature, with values ranging from 0.2 to 0.8 mm. Ozone-sonde profiles were compared with total column abundances of O(3) retrieved from the spectra. The experiment is explained in detail, including the instrumentation, calibration, and retrieval methods used. The calibrated spectra contain information about several trace gases, water, clouds, temperature profiles, and aerosols.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. High Resolution Mapping of the Lunar South Pole-Aitken Basin Interior

    NASA Astrophysics Data System (ADS)

    Archinal, B. A.; Gaddis, L. R.; Hare, T. M.; Rosiek, M.; Howington-Kraus, E.; Lee, E.; Weller, L.; Kirk, R. L.; Edmundson, K.; Becker, T.; Jolliff, B. L.; Tran, T.; Robinson, M.; LROC Science Team

    2010-12-01

    We are making geodetically controlled high-resolution digital terrain models (DTMs) and image orthomosaics of the Constellation (Cx) Program region of interest (ROI) in the lunar South Pole-Aitken Basin interior (“SAB”) (center at 200.06° E, 60.00° S). This work is part of the Lunar Mapping and Modeling Program (LMMP), a NASA-funded effort to create useful cartographic products from past and current lunar datasets and to serve them on a web portal. The SAB is one of 50 ROIs chosen by Cx as potential sites for future robotic or human landings or analogs thereof. Source data for our products includes publically released ~50 cm/pixel Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera images and Lunar Orbiter Laser Altimeter (LOLA) spot elevation measurements and preliminary global 16 posts/° DTM. Products generated so far include: a) a preliminary stereo DTM covering ~25% of the center 20 km square area of the ROI, with post spacing (resolution) of 1.5 m and ~86x10^6 posts; b) a preliminary mosaic of 90% of the 40 km square ROI, with a resolution of 2 m, orthorectified with LOLA data or, where possible, the stereo DTM; c) preliminary DTMs generated via the use of photoclinometry (“shape from shading”), covering small areas with post spacing of 50 cm; and d) slope and roughness maps derived from a and c. All products are in the lunar mean Earth/polar axis coordinate system and the preliminary global reference frame of the current LOLA DTM. The absolute accuracy of these products is limited by the horizontal and vertical accuracy of the LOLA DTM, to which they are tied (DTMs and mosaics) or on which they are projected (mosaics). The expected vertical precision of the stereo DTM is ~20 cm. The products will soon be publically available via the LMMP portal and also via the USGS planetary GIS site, http://webgis.wr.usgs.gov/. Final versions tied to the LOLA nominal mission global DTM will be available in 2011 October. Preliminary analyses of these

  15. Cassini Vims Observations Of Thermal Emission From The Warmest 'Tiger Stripes' Near The South Pole On Enceladus

    NASA Astrophysics Data System (ADS)

    Goguen, Jay D.; Buratti, B. J.; Brown, R. H.; Clark, R. N.; Nicholson, P. D.; Hedman, M. M.; Sotin, C.; Cruikshank, D. P.; Baines, K. H.; Lawrence, K. J.; Spencer, J. R.; Blackburn, D.

    2012-10-01

    The discovery and continuing investigation of the long linear fissures near Enceladus’ south pole is a major highlight of the Cassini mission to Saturn. Known as the ‘tiger stripes’, these fissures are the source of water dominated plumes and extensive thermal emission (Spencer et al, 2006; Porco et al, 2006). This paper presents new observational constraints on the highest temperature component of the tiger stripes thermal emission using VIMS (Visible and Infrared Mapping Spectrometer) spectra. Because VIMS detects the thermal emission at 4 to 5 micrometer wavelengths, VIMS is sensitive to the rising edge of Planck function for temperatures near 200 K, making the new VIMS spectra complementary to the CIRS observations acquired at longer wavelengths. Although the thermal emission spectra of the hottest areas is only a small piece of the Enceladus and tiger stripe puzzle, it is an important missing piece that we will use to model how and where the detected heat is generated and the physical processes that transport the heat to the observable surface. Our first definitive detection of thermal emission from Baghdad Sulcus was reported in Blackburn et al (LPSC 2012) from VIMS data acquired during E11 (August 2010). Due to seasonal change during the mission, the Enceladus S. pole region has entered the perpetual winter night and reflected sunlight does not interfere with VIMS measurements of the faint thermal emission as it did early in the mission. During the 75 km altitude targeted encounter E18 (April 2012), VIMS acquired a 2 minute long sequence of 25 ms integration time spectra through a single high resolution pixel as Cassini passed over the South pole. The resulting data has the best spatial resolution of the thermal emission acquired to date. This work was supported in part by a grant from NASA’s Outer Planets Research Program.

  16. Observations and modeling of ionospheric scintillations at South Pole during six X-class solar flares in 2013

    NASA Astrophysics Data System (ADS)

    Priyadarshi, S.; Zhang, Q.-H.; Ma, Y.-Z.; Wang, Y.; Xing, Z.-Y.

    2016-06-01

    Using two B-spline basis functions of degree 4 and the ionospheric scintillation data from a Global Positioning Satellite System (GPS) scintillation receiver at South Pole, we reproduced ionospheric scintillation indices for the periods of the six X-class solar flares in 2013. These reproduced indices have filled the data gaps, and they are serving as a smooth replica of the real observations. In either event, these modeled scintillation indices are minimizing the geometrical effects between GPS satellite and the receiver. Six X-class solar flares have been studied during the summer and winter months, using the produced scintillation indices based on the observations from the GPS receiver at South Pole and the in situ plasma measurement from the associated passing of Defense Meteorological Satellite Program. Our results show that the solar flare peak suppresses the scintillation level and builds time-independent scintillation patterns; however, after a certain time from the solar flare peak, complicated scintillation patterns develop at high-latitude ionosphere and spread toward the polar cap boundary region. Substantial consistency has been found between moderate proton fluxes and scintillation enhancement.

  17. 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)

  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. 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.

  20. Mid-infrared measurements of the atmospheric emission over the South Pole using a radiometrically calibrated Fourier transform spectrometer.

    PubMed

    Van Allen, R; Murcray, F J; Liu, X

    1996-03-20

    We conducted year-round measurements of the downwelling atmospheric infrared emission over the South Pole in 1992. The instrument covered the 550-1600-wave-number region with 1-wave-number resolution. We calculated the water vapor content for clear-sky cases and found a good correlation with the surface temperature, with values ranging from 0.2 to 0.8 mm. Ozone-sonde profiles were compared with total column abundances of O(3) retrieved from the spectra. The experiment is explained in detail, including the instrumentation, calibration, and retrieval methods used. The calibrated spectra contain information about several trace gases, water, clouds, temperature profiles, and aerosols. PMID:21085269

  1. University of california at Santa Barbara Anisotropy Program: degree scale results from the South Pole 1990-1991.

    PubMed Central

    Gaier, T; Schuster, J; Gundersen, J; Meinhold, P; Lubin, P

    1993-01-01

    We report on the preliminary result of a search for anisotropy in the cosmic background radiation (CBR). Our receiver operates with four equally spaced channels from 25 to 35 GHz with a beam size of approximately 1.5 degrees full width at half maximum. The system operated successfully for 500 hr at the South Pole during 1990-1991 austral summer. The data from one region, representing 25 hr after editing, are presented here. A strong signal is present in the lower-frequency channels with a spectrum unlike CBR fluctuations. The highest-frequency channel has the smallest contribution from this signal and has been used to set a 95% confidence level upper limit DeltaT/T

  2. A MEASUREMENT OF THE CORRELATION OF GALAXY SURVEYS WITH CMB LENSING CONVERGENCE MAPS FROM THE SOUTH POLE TELESCOPE

    SciTech Connect

    Bleem, L. E.; Becker, M. R.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Van Engelen, A.; Holder, G. P.; De Haan, T.; Dobbs, M. A.; Aird, K. A.; Armstrong, R.; Ashby, M. L. N.; Biesiadzinski, T.; Brodwin, M.; Busha, M. T.; Cho, H. M.; Desai, S.; Dore, O.; and others

    2012-07-01

    We compare cosmic microwave background lensing convergence maps derived from South Pole Telescope (SPT) data with galaxy survey data from the Blanco Cosmology Survey, WISE, and a new large Spitzer/IRAC field designed to overlap with the SPT survey. Using optical and infrared catalogs covering between 17 and 68 deg{sup 2} of sky, we detect a correlation between the SPT convergence maps and each of the galaxy density maps at >4{sigma}, with zero correlation robustly ruled out in all cases. The amplitude and shape of the cross-power spectra are in good agreement with theoretical expectations and the measured galaxy bias is consistent with previous work. The detections reported here utilize a small fraction of the full 2500 deg{sup 2} SPT survey data and serve as both a proof of principle of the technique and an illustration of the potential of this emerging cosmological probe.

  3. Potential sample sites for South Pole-Aitken basin impact melt within the Schrödinger basin

    NASA Astrophysics Data System (ADS)

    Hurwitz, Debra; Kring, David A.

    2015-10-01

    Determining the age of the South Pole-Aitken (SPA) basin ranks among the highest priorities in lunar science. This datum would constrain the timing of the oldest and largest basin-forming event on the Moon, information that is essential to any evaluation of the collisional evolution of the early Solar System. To locate material that preserves the age of SPA, a geochemical model of SPA impact melt is integrated with chemical and mineralogical analyses of the lunar surface determined from orbit. Results suggest the southern wall of Schrödinger basin contains material with the mineralogical and geochemical signatures of SPA melt and, thus, represents a candidate destination for sampling material that can constrain the age of the SPA impact.

  4. 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

  5. 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.

  6. 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.

  7. Researcher and Educator Long Term Collaboration with NOAA ESRL Regarding Atmospheric Ozone Changes at the South Pole Through the NSF PolarTREC Program

    NASA Astrophysics Data System (ADS)

    Bergholz, E.; Johnson, B.; Hofmann, D.

    2008-12-01

    The NOAA/ESRL team at South Pole has been monitoring the development of the annual ozone hole over two decades using balloon-borne and ground-based instruments. Collaboration with educators has become an important aspect of NOAA/ESRL to educate the public about ozone loss and ozone hole formation. Researcher Bryan Johnson and educator Elke Bergholz worked together at South Pole in 1998/1999 as part of the NSF teacher outreach program called Teachers Experiencing Antarctica (TEA). It has been almost a decade when they collaborated again concerning the ozone changes at South Pole as part of the International Polar Year (IPY) and the PolarTREC (http://www.polartrec.com) teacher outreach program sponsored by NSF. The TEA and PolarTREC programs selected teachers to travel to polar locations to work with research scientists collecting data and running experiments at various Arctic and Antarctic field sites. While in the field, daily contact with classrooms and students around the globe was done through internet journals, answering emails from students, and webinars. This will be followed up with presentations to schools and the public relating Ms Bergholz's experience and new "hands-on" understanding of ozone measurements and ozone depletion over Antarctica, and discussing what changes in ozone we have seen at South Pole since the first outreach program nearly a decade ago.

  8. 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.

  9. 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.

  10. Researcher and Educator Long Term Collaboration with NOAA ESRL Regarding Atmospheric Ozone Changes at the South Pole Through the NSF PolarTREC Program

    NASA Astrophysics Data System (ADS)

    Bergholz, E. H.; Hofmann, D. J.; Johnson, B. J.

    2009-12-01

    The NOAA/ESRL team at South Pole has been monitoring the development of the annual ozone hole over two decades using balloon-borne and ground based instruments. Collaboration with educators has become an important aspect of NOAA/ESRL to educate the public about ozone loss and ozone hole formation. Researcher Bryan Johnson and educator Elke Bergholz worked together at South Pole in 1998/1999 as part of the NSF teacher outreach program called Teachers Experiencing Antarctica (TEA).It has been almost a decade when they collaborated again concerning the ozone changes at South Pole as part of the International Polar Year (IPY) and the PolarTREC ( http://wwpolartrec.com ) teacher outreach program sponsored by NSF. The TEA and PolarTREC programs selected teachers to travel to polar locations to work with research scientists collecting data and running experiments at various Arctic and Antarctic field sites, including Elke Bergholz working at the South Pole with the NOAA/ESRL team. While in the field, daily contact with classrooms and students around the globe was done through the internet journals, answering emails from students, and webinars. This has been followed up with presentations to schools and the public relating Ms. Bergholz’s experience and new “hands-on” understanding of ozone instruments and ozone depletion over Antarctica, and discussing what changes in the ozone we have seen at South Pole since the first outreach program nearly a decade ago. The lesson plans are available through the PolarTREC website or by contacting Elke Bergholz at ebergholz@unis.org.

  11. Constraining AGN Feedback in Massive Ellipticals with South Pole Telescope Measurements of the Thermal Sunyaev-Zel'dovich Effect

    NASA Astrophysics Data System (ADS)

    Spacek, Alexander; Scannapieco, Evan; Cohen, Seth; Joshi, Bhavin; Mauskopf, Philip

    2016-03-01

    Energetic feedback due to active galactic nuclei (AGNs) is likely to play an important role in the observed anti-hierarchical trend in the evolution of galaxies, and yet the energy injected into the circumgalactic medium by this process is largely unknown. One promising approach to constrain this feedback is through measurements of spectral distortions in the cosmic microwave background due to the thermal Sunyaev-Zeldovich (tSZ) effect, whose magnitude is directly proportional to the energy input by AGNs. With current instruments, making such measurements requires stacking large numbers of objects to increase signal-to-noise. While one possible target for such stacks is AGNs themselves, these are relatively scarce sources that contain contaminating emission that complicates tSZ measurements. Here we adopt an alternative approach and co-add South Pole Telescope SZ (SPT-SZ) survey data around a large set of massive quiescent elliptical galaxies at z≥slant 0.5, which are much more numerous and less contaminated than active AGNs, yet are subject to the same feedback processes from the AGNs they hosted in the past. We use data from the Blanco Cosmology Survey and VISTA Hemisphere Survey to create a large catalog of galaxies split up into two redshift bins: one with 3394 galaxies at 0.5≤slant z≤slant 1.0 and one with 924 galaxies at 1.0≤slant z≤slant 1.5, with typical stellar masses of 1.5× {10}11{M}⊙ . We then co-add the emission around these galaxies, resulting in a measured tSZ signal at 2.2σ significance for the lower redshift bin and a contaminating signal at 1.1σ for the higher redshift bin. To remove contamination due to dust emission, we use SPT-SZ source counts to model a contaminant source population in both the SPT-SZ bands and Planck high-frequency bands for a subset of 937 galaxies in the low-redshift bin and 240 galaxies in the high-redshift bin. This increases our detection to 3.6σ for low redshifts and 0.9σ for high redshifts. We find the

  12. Submillimeter spectroscopy of the Carina Nebula: Observations, operations and upgrades of the South Pole Imaging Fabry-Perot Interferometer

    NASA Astrophysics Data System (ADS)

    Oberst, Thomas Edward

    2009-06-01

    We present the results of a ~ 250 arcmin 2 mapping of the 205 μm [NII] fine- structure line emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Telescope and Remote Observatory (AST/RO) at South Pole. New upgrades and modifications to the SPIFI instrument are discussed, and full details of SPIFI-AST/RO integration and calibration are provided. At the time of these observations, SPIFI had a spectral resolving power of ~ 4250, a FWHM beam size of ~ 54'', and a noise equivalent power (NEP) referred to the front end of the receiver of ~ 2.5 × 10 -15 W Hz -1/2 (~ 1.4 times the background limit). These data constitute the first ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the Cosmic Background Explorer (COBE) Far Infrared Absolute Spectrophotometer (FIRAS) and the Kuiper Airborne Observatory (KAO) in the early 1990s. We supplement the 205 μm data with new reductions of far-infrared fine- structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 m [NII], 146 μm [OI], and 158 μm [CII]; the 146 μm [OI] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum and CO maps. The 122/205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158/205 [CII]/[NII] line ratio is used to probe the fraction of C + arising from photodissociation regions (PDRs). The [OI] and [CII] lines are used to construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49. This is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept

  13. 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

  14. Ulysses observations of energetic ions over the south pole of the sun

    SciTech Connect

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

    1996-07-20

    We present here observations of energetic ions during the following phases of the Ulysses prime mission: the first south polar pass, the low-latitude pass and part of the first north polar pass. Peaks are observed in the energetic ion intensity which recur either once per solar rotation during the ascent to high southern latitudes, or twice per rotation during the low latitude pass. The intensity of the peaks also rises with each major solar event, decaying slowly thereafter over a period of several rotations. The peaks are observed up to {approx}70 deg. during the ascent to high southern latitudes, but not seen again until around 45 deg. during the descent, this asymmetry most likely being caused by a decrease in the number of solar events.

  15. Electric Pole Maintenance in Nagoya City Science Museum as a Cooperative Activity of Industry, School and Local Government

    NASA Astrophysics Data System (ADS)

    Mabuchi, Koichi

    The object of this paper is to suggest an education model as a cooperative activity of industry, school and local government in science museums. Nagoya City Science Museum has opened the new exhibit on electric pole maintenance since 2002, which makes a visitor a temporary electrician working at a height of 3 meters. The exhibit, named “Be an Electrician”, is focusing on stimulating young people's interest in industrial technology. The electric pole and equipments on the pole like transformer, electric wires and so forth were donated from an electric power company to the museum. The museum manages volunteers including an active electrician and students to study engineering, who instruct the visitors in the bucket how to change the insulator on the pole. The active electrician also instructs some technical high school students in practical works at height. This new exhibit indicates the science museum positioned between companies and schools will make it possible to extend internship.

  16. SPT-3G: a next-generation cosmic microwave background polarization experiment on the South Pole telescope

    NASA Astrophysics Data System (ADS)

    Benson, B. A.; Ade, P. A. R.; Ahmed, Z.; Allen, S. W.; Arnold, K.; Austermann, J. E.; Bender, A. N.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Cliche, J. F.; Crawford, T. M.; Cukierman, A.; de Haan, T.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Gilbert, A.; Halverson, N. W.; Hanson, D.; Harrington, N. L.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Irwin, K. D.; Keisler, R.; Knox, L.; Kubik, D.; Kuo, C. L.; Lee, A. T.; Leitch, E. M.; Li, D.; McDonald, M.; Meyer, S. S.; Montgomery, J.; Myers, M.; Natoli, T.; Nguyen, H.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Reichardt, C.; Ruhl, J. E.; Saliwanchik, B. R.; Simard, G.; Smecher, G.; Sayre, J. T.; Shirokoff, E.; Stark, A. A.; Story, K.; Suzuki, A.; Thompson, K. L.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Wang, G.; Yefremenko, V.; Yoon, K. W.

    2014-07-01

    We describe the design of a new polarization sensitive receiver, spt-3g, for the 10-meter South Pole Telescope (spt). The spt-3g receiver will deliver a factor of ~20 improvement in mapping speed over the current receiver, spt-pol. The sensitivity of the spt-3g receiver will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of the individual modes, i.e., maps. This will lead to precise (~0.06 eV) constraints on the sum of neutrino masses with the potential to directly address the neutrino mass hierarchy. It will allow a separation of the lensing and inflationary B-mode power spectra, improving constraints on the amplitude and shape of the primordial signal, either through spt-3g data alone or in combination with bicep2/keck, which is observing the same area of sky. The measurement of small-scale temperature anisotropy will provide new constraints on the epoch of reionization. Additional science from the spt-3g survey will be significantly enhanced by the synergy with the ongoing optical Dark Energy Survey (des), including: a 1% constraint on the bias of optical tracers of large-scale structure, a measurement of the differential Doppler signal from pairs of galaxy clusters that will test General Relativity on ~200Mpc scales, and improved cosmological constraints from the abundance of clusters of galaxies

  17. 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).

  18. Observations of summertime NO fluxes and boundary-layer height at the South Pole during ISCAT 2000 using scalar similarity

    NASA Astrophysics Data System (ADS)

    Oncley, S. P.; Buhr, M.; Lenschow, D. H.; Davis, D.; Semmer, S. R.

    2004-10-01

    Eddy-covariance heat flux as well as temperature and NO concentration gradients were measured during the ISCAT 2000 (Investigation of Sulfur Chemistry in the Antarctic Troposphere) field study at the South Pole (SP). These quantities allowed for the use of the modified Bowen ratio technique to estimate the surface flux of NO and, from photochemical considerations, the NOx flux. The meteorological measurement package employed in these experiments consisted of sonic anemometer/thermometers (ATI K-probes) and temperature/humidity sensors (NCAR). A chemiluminescent analyzer housed in an environmental enclosure was used to measure NO. All sampling took place on a 22 m meteorological tower. The time period over which flux measurements were recorded was 26 November through 30 November 2000. The average value of the NO flux was estimated to be 2.6 ± 0.3 ×108 moleccm-2s-1; whereas, for NOx the average flux was 3.9 ± 0.4 ×108 moleccm-2s-1. To assist in the interpretation of these results, the height of the atmospheric boundary-layer at the SP from 23 November to 28 December 2000 was also estimated.

  19. 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.

  20. SOUTH POLE TELESCOPE DETECTIONS OF THE PREVIOUSLY UNCONFIRMED PLANCK EARLY SUNYAEV-ZEL'DOVICH CLUSTERS IN THE SOUTHERN HEMISPHERE

    SciTech Connect

    Story, K.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Aird, K. A.; Andersson, K.; Bazin, G.; Armstrong, R.; Desai, S.; Bonamente, M.; Brodwin, M.; Foley, R. J.; Clocchiatti, A.; De Haan, T.; Dobbs, M. A.; Dudley, J. P.; George, E. M.

    2011-07-10

    We present South Pole Telescope (SPT) observations of the five galaxy cluster candidates in the southern hemisphere which were reported as unconfirmed in the Planck Early Sunyaev-Zel'dovich (ESZ) sample. One cluster candidate, PLCKESZ G255.62-46.16, is located in the 2500 deg{sup 2} SPT SZ survey region and was reported previously as SPT-CL J0411-4819. For the remaining four candidates, which are located outside of the SPT SZ survey region, we performed short, dedicated SPT observations. Each of these four candidates was strongly detected in maps made from these observations, with signal-to-noise ratios ranging from 6.3 to 13.8. We have observed these four candidates on the Magellan-Baade telescope and used these data to estimate cluster redshifts from the red sequence. Resulting redshifts range from 0.24 to 0.46. We report measurements of Y{sub 0.'75}, the integrated Comptonization within a 0.'75 radius, for all five candidates. We also report X-ray luminosities calculated from ROSAT All-Sky Survey catalog counts, as well as optical and improved SZ coordinates for each candidate. The combination of SPT SZ measurements, optical red-sequence measurements, and X-ray luminosity estimates demonstrates that these five Planck ESZ cluster candidates do indeed correspond to real galaxy clusters with redshifts and observable properties consistent with the rest of the ESZ sample.

  1. 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.; Aird, K. A.; Allen, S. W.; Ashby, M. L.N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; et al

    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

  2. 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.

  3. 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

  4. Meteorites and microbes: meteorite collection and ice sampling at Patriot Hills, Thiel Mountains, and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Sipiera, Paul P.; Hoover, Richard B.; Jerman, Gregory A.

    2000-12-01

    In 1998, the Patriot Hills area of the Ellsworth Mountains of Antarctica was selected by the Planetary Studies Foundation (PSF) of Algonquin, Illinois USA as a potential site for the collection of meteorites. The eight person expedition searched several sites in and around the Patriot Hills, but met with little success in finding meteorites. In January 2000, the PSF chose to continue its efforts in the Thiel Mountains, an area of known meteorite concentrations. The goal was to collect as many meteorites as possible by extending the previously searched blue ice areas at the Moulton Escarpment. Earlier search teams collectively recovered 36 meteorites. In the five days of fieldwork at the Moulton Escarpment, the PSF team collected 19 confirmed stone meteorites, and 2 possible achondrites. Upon return to Patriot Hills another small stone meteorite, consisting of 6 small fragments totalling 1.7 grams, was collected in the Morris Moraine where a 23 mg meteorite fragment was found in 1998. In addition, ice samples were collected at Patriot Hills, Thiel Mountains, and the South Pole. The presence of several micro-organisms has been identified in these samplings and will be evaluated as possible contaminants of Antarctic meteorites.

  5. 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.

  6. The GIS-based geologic investigation of the South Pole-Aitken basin region of the Moon using SELENE elemental information

    NASA Astrophysics Data System (ADS)

    Kim, K. J.; Dohm, J. M.; Williams, J.; Ruiz, J.; Yu, B.; Hare, T. M.; Hasebe, N.; Yamashita, N.; Karouji, Y.; Kobayashi, S.; Hareyama, M.; Shibamura, E.; Kobayashi, M.; D'Uston, C.; Gasnault, O.; Forni, O.; Reedy, R. C.

    2010-12-01

    Using Geographic Information Systems (GIS), we performed comparative analysis among stratigraphic information and the Kaguya (SELENE) GRS data of the South Pole-Aitken (SPA) basin and its surroundings. Results indicate that the rock materials up to ~ 1m depth (including ancient crater materials, mare basalts, and possible SPA impact melt) are average to slightly above average in K and Th with respect to the rest of the Moon. The heavily cratered highlands outside of SPA represent ancient deep-seated crustal and possibly mantle igneous materials harvested in part from the giant SPA impact event as ejecta, as well as subsequent impact cratering events up until the end of the Late Heavy Bombardment, which includes intensive impact-related mixing of ejecta materials and lava flows. The geologic history of the SPA basin is distinct from the Procellarum-Imbrium region. The former records mainly pre-Nectarian activity such as the giant impact with minor mare volcanism during the Upper Imbriam, whereas the latter was largely resurfaced by activity such as the Imbrium impact event and subsequent emplacement of voluminous mare-forming lavas during the Lower Imbriam and Upper Imbriam, Eraatosthenian, and Copernican, respectively. These distinct geologic histories bear on the mineralogic and elemental abundances, as shown in our investigation through this GIS-based comparative analysis among the stratigraphic and Kaguya (SELENE) GRS data.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. WEAK-LENSING MASS MEASUREMENTS OF FIVE GALAXY CLUSTERS IN THE SOUTH POLE TELESCOPE SURVEY USING MAGELLAN/MEGACAM

    SciTech Connect

    High, F. W.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Hoekstra, H.; Leethochawalit, N.; De Haan, T.; Abramson, L.; Aird, K. A.; Armstrong, R.; Ashby, M. L. N.; Conroy, M.; Bautz, M.; Bayliss, M.; Bazin, G.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; and others

    2012-10-10

    We use weak gravitational lensing to measure the masses of five galaxy clusters selected from the South Pole Telescope (SPT) survey, with the primary goal of comparing these with the SPT Sunyaev-Zel'dovich (SZ) and X-ray-based mass estimates. The clusters span redshifts 0.28 < z < 0.43 and have masses M{sub 500} > 2 Multiplication-Sign 10{sup 14} h {sup -1} M{sub Sun }, and three of the five clusters were discovered by the SPT survey. We observed the clusters in the g'r'i' passbands with the Megacam imager on the Magellan Clay 6.5 m telescope. We measure a mean ratio of weak-lensing (WL) aperture masses to inferred aperture masses from the SZ data, both within an aperture of R{sub 500,SZ} derived from the SZ mass, of 1.04 {+-} 0.18. We measure a mean ratio of spherical WL masses evaluated at R{sub 500,SZ} to spherical SZ masses of 1.07 {+-} 0.18, and a mean ratio of spherical WL masses evaluated at R{sub 500,WL} to spherical SZ masses of 1.10 {+-} 0.24. We explore potential sources of systematic error in the mass comparisons and conclude that all are subdominant to the statistical uncertainty, with dominant terms being cluster concentration uncertainty and N-body simulation calibration bias. Expanding the sample of SPT clusters with WL observations has the potential to significantly improve the SPT cluster mass calibration and the resulting cosmological constraints from the SPT cluster survey. These are the first WL detections using Megacam on the Magellan Clay telescope.

  12. ALMA Imaging and Gravitational Lens Models of South Pole Telescope—Selected Dusty, Star-Forming Galaxies at High Redshifts

    NASA Astrophysics Data System (ADS)

    Spilker, J. S.; Marrone, D. P.; Aravena, M.; Béthermin, M.; Bothwell, M. S.; Carlstrom, J. E.; Chapman, S. C.; Crawford, T. M.; de Breuck, C.; Fassnacht, C. D.; Gonzalez, A. H.; Greve, T. R.; Hezaveh, Y.; Litke, K.; Ma, J.; Malkan, M.; Rotermund, K. M.; Strandet, M.; Vieira, J. D.; Weiss, A.; Welikala, N.

    2016-08-01

    The South Pole Telescope has discovered 100 gravitationally lensed, high-redshift, dusty, star-forming galaxies (DSFGs). We present 0.″5 resolution 870 μ {{m}} Atacama Large Millimeter/submillimeter Array imaging of a sample of 47 DSFGs spanning z=1.9{--}5.7, and construct gravitational lens models of these sources. Our visibility-based lens modeling incorporates several sources of residual interferometric calibration uncertainty, allowing us to properly account for noise in the observations. At least 70% of the sources are strongly lensed by foreground galaxies ({μ }870μ {{m}}\\gt 2), with a median magnification of {μ }870μ {{m}}=6.3, extending to {μ }870μ {{m}}\\gt 30. We compare the intrinsic size distribution of the strongly lensed sources to a similar number of unlensed DSFGs and find no significant differences in spite of a bias between the magnification and intrinsic source size. This may indicate that the true size distribution of DSFGs is relatively narrow. We use the source sizes to constrain the wavelength at which the dust optical depth is unity and find this wavelength to be correlated with the dust temperature. This correlation leads to discrepancies in dust mass estimates of a factor of two compared to estimates using a single value for this wavelength. We investigate the relationship between the [C ii] line and the far-infrared luminosity and find that the same correlation between the [C ii]/{L}{{FIR}} ratio and {{{Σ }}}{{FIR}} found for low-redshift star-forming galaxies applies to high-redshift galaxies and extends at least two orders of magnitude higher in {{{Σ }}}{{FIR}}. This lends further credence to the claim that the compactness of the IR-emitting region is the controlling parameter in establishing the “[C ii] deficit.”

  13. Orion/MoonRise: A proposed human & robotic sample return mission from the Lunar South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Alkalai, L.; Solish, B.; Elliott, J.; McElrath, T.; Mueller, J.; Parker, J.

    This paper describes a new mission concept called Orion/MoonRise that proposes to return samples from the Lunar far-side South Pole-Aitken Basin (SPAB) using a combination of a robotic Sample Return Vehicle (SRV) based on the MoonRise mission concept developed at National Aeronautics and Space Administration's (NASA) Jet Propulsion Laboratory, and the Orion Multi-Purpose Crew Vehicle currently under development by NASA at Lockheed Martin. The mission concept proposes significant challenges for both robotic and human parts of the mission. Whereas there are many ways to execute this mission concept, one approach is for the Orion and the SRV to launch separately. We assume that the Orion will be staged at the Earth-Moon Lagrange Point 2 (EM-L2) and the SRV at EM-L1. Once both are in place, the SRV descends to the SPAB while the Orion provides critical relay coverage with ground control on Earth. During surface operations, the Orion crew tele-operate the lander sampling system and possibly deploy a sample fetch rover. Once the samples are collected, the Lunar Ascent Vehicle (LAV) launches towards the EM-L2 to rendezvous with Orion. The samples are then brought back to Earth for detailed sample curation and analysis by the scientific community. The Orion/MoonRise mission concept has many strengths worth noting: it provides a very exciting mission to be performed in cis-Lunar space, as a precursor to future human exploration beyond the Earth-Moon System and as a technology demonstration for future sample return from Mars; it implements a mission that is of tremendous value to the planetary science community; it provides an exciting and challenging mission for astronauts to perform and demonstrate in deep-space including remote teleoperations and sample rendezvous and capture; and finally it provides an exciting opportunity for the broad engagement of the general public.

  14. New Style Geologic Map of Mostly Later Holocene and Recent Features of the Greater South Pole Basin

    NASA Astrophysics Data System (ADS)

    Wise, D. U.; Cianfarra, P.; Salvini, F.

    2008-12-01

    Topographic contour maps of the East Antarctic Plateau show a prominent but apparently unrecognized basin of ~700,000 km2 that lies ~200 m below surrounding surfaces. The basin's defining hallmark is a remarkably straight, 900 km-long headwall or headslope, passing almost under the pole and linking upper reaches of the Recovery and Foundation ice streams, the two separated by a central platform (CP). Throughout the basin a distinctive regional snow and firn unit, identifiable on satellite images by ~2km wavelength, zebra-striped megadunes, forms the basal horizon for a new type of geologic map for the Plateau. This unit underlies all other features, probably as an inactive paleo-climatic relic of diachronous Holocene age. Most deposits covering it consist of several generations of successively overprinted longitudinal dunes commonly intermingling with wind eroded channels, ice deformational features, and regionally curving snow streamers. Above this complex, a widespread but discontinuous, smooth surfaced deposit covers megadunes, local basins, major divides and floors of linear sags or extension zones. The young unit is irregularly disrupted and sheared over active ice streams. Over all these features are widespread, near-modern to modern fields or patches of active, longitudinal dunes with 100-300 m wavelengths. A prominent, graben-like, linear sag zone occurs along the headwall's brow line but unlike those of traditional grabens, its edges show no visible fault offset at present resolutions. At the foot of the headslope, a large bergshrund-like area is localized above the sub-glacial Recovery Lakes. Thick fill in this area covers the megadune unit only to be disrupted by still younger sag zones. On the CP floor, a number of sharp-edged, shear-bounded 100-300 km wide sub-provinces are defined by differences in thickness and types of megadune cover and by amounts of extension or crevassing. At the heads of some zones, shear lines encroach upslope into young cover

  15. 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

  16. 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

  17. A MEASUREMENT OF THE DAMPING TAIL OF THE COSMIC MICROWAVE BACKGROUND POWER SPECTRUM WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

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

    2011-12-10

    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) using data from the South Pole Telescope (SPT). The data consist of 790 deg{sup 2} of sky observed at 150 GHz during 2008 and 2009. Here we present the power spectrum over the multipole range 650 < l < 3000, where it is dominated by primary CMB anisotropy. We combine this power spectrum with the power spectra from the seven-year Wilkinson Microwave Anisotropy Probe (WMAP) data release to constrain cosmological models. We find that the SPT and WMAP data are consistent with each other and, when combined, are well fit by a spatially flat, {Lambda}CDM cosmological model. The SPT+WMAP constraint on the spectral index of scalar fluctuations is n{sub s} = 0.9663 {+-} 0.0112. We detect, at {approx}5{sigma} significance, the effect of gravitational lensing on the CMB power spectrum, and find its amplitude to be consistent with the {Lambda}CDM cosmological model. We explore a number of extensions beyond the {Lambda}CDM model. Each extension is tested independently, although there are degeneracies between some of the extension parameters. We constrain the tensor-to-scalar ratio to be r < 0.21 (95% CL) and constrain the running of the scalar spectral index to be dn{sub s} /dln k = -0.024 {+-} 0.013. We strongly detect the effects of primordial helium and neutrinos on the CMB; a model without helium is rejected at 7.7{sigma}, while a model without neutrinos is rejected at 7.5{sigma}. The primordial helium abundance is measured to be Y{sub p} = 0.296 {+-} 0.030, and the effective number of relativistic species is measured to be N{sub eff} = 3.85 {+-} 0.62. The constraints on these models are strengthened when the CMB data are combined with measurements of the Hubble constant and the baryon acoustic oscillation feature. Notable improvements include n{sub s} = 0.9668 {+-} 0.0093, r < 0.17 (95% CL), and N{sub eff} = 3.86 {+-} 0.42. The SPT+WMAP data show a mild preference for low power

  18. South Pole-Aitken Basin: Evidence for Post-Basin Resurfacing from Lunar Orbiter Laser Altimeter (LOLA) Data

    NASA Astrophysics Data System (ADS)

    Head, J. W.; Fassett, C.; Kadish, S.; Smith, D. E.; Zuber, M. T.; Neumann, G. A.; Mazarico, E.

    2010-12-01

    The lunar farside South Pole-Aitken Basin is the largest and oldest documented basin on the Moon and is thus of interest from the point of view of the scale of production of impact melt at large basin-event sizes and its ring structure and potential depth of sampling at such a large diameter. We used new LOLA data from the Lunar Reconnaissance Orbiter 1) to characterize the basin interior topography, 2) to assess the nature of the nearby and relatively pristine Orientale basin and compare it to the SPA interior, and 3) to compile a new global crater database of all lunar craters ≥20 km in diameter and to assess the population of impact craters superposed on the SPA interior and exterior. We find that impact crater size-frequency distribution plots show that the exterior of the SPA basin is similar to the most heavily cratered regions of the Moon, but that the interior of the basin has a deficiency of craters in the 20-64 km diameter crater range. One interpretation of these data is that some resurfacing process (or processes) has modified the superposed crater population. Among the candidates are 1) impact crater proximity weathering/degradation by adjacent (e.g., Apollo) and nearby (e.g., Orientale) impact basin ejecta, 2) volcanic resurfacing by early non-mare volcanism, cryptomaria and/or maria, and 3) viscous relaxation removing crater topography. We consider viscous relaxation of crater topography to be the least likely due to the wavelength dependence of the process (rim-crests should be preserved and thus detected in our crater counts). Careful analysis of the impact ejecta thickness radial decay suggests that it is an important resurfacing mechanism within a basin radius from the rim crest, but is unlikely to be sufficient to explain the observed deficiency. Morphometric analysis of impact craters, modeling, and simulations of volcanic flooding suggest that the deficiency may be related to the patchy distribution of cryptomaria, suspected from mineralogic

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

    SciTech Connect

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

    2005-05-01

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

  20. Extragalactic Millimeter-wave Sources in South Pole Telescope Survey Data: Source Counts, Catalog, and Statistics for an 87 Square-degree Field

    NASA Astrophysics Data System (ADS)

    Vieira, J. D.; Crawford, T. M.; Switzer, E. R.; Ade, P. A. R.; Aird, K. A.; Ashby, M. L. N.; Benson, B. A.; Bleem, L. E.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Cho, H.-M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W.; George, E. M.; Gladders, M.; Hall, N. R.; Halverson, N. W.; High, F. W.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Marrone, D. P.; McIntyre, V.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Padin, S.; Plagge, T.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Schaffer, K. K.; Shaw, L.; Shirokoff, E.; Spieler, H. G.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Vanderlinde, K.; Walsh, W.; Williamson, R.; Yang, Y.; Zahn, O.; Zenteno, A.

    2010-08-01

    We report the results of an 87 deg2 point-source survey centered at R.A. 5h30m, decl. -55° taken with the South Pole Telescope at 1.4 and 2.0 mm wavelengths with arcminute resolution and milli-Jansky depth. Based on the ratio of flux in the two bands, we separate the detected sources into two populations, one consistent with synchrotron emission from active galactic nuclei and the other consistent with thermal emission from dust. We present source counts for each population from 11 to 640 mJy at 1.4 mm and from 4.4 to 800 mJy at 2.0 mm. The 2.0 mm counts are dominated by synchrotron-dominated sources across our reported flux range; the 1.4 mm counts are dominated by synchrotron-dominated sources above ~15 mJy and by dust-dominated sources below that flux level. We detect 141 synchrotron-dominated sources and 47 dust-dominated sources at signal-to-noise ratio S/N >4.5 in at least one band. All of the most significantly detected members of the synchrotron-dominated population are associated with sources in previously published radio catalogs. Some of the dust-dominated sources are associated with nearby (z Lt 1) galaxies whose dust emission is also detected by the Infrared Astronomy Satellite. However, most of the bright, dust-dominated sources have no counterparts in any existing catalogs. We argue that these sources represent the rarest and brightest members of the population commonly referred to as submillimeter galaxies (SMGs). Because these sources are selected at longer wavelengths than in typical SMG surveys, they are expected to have a higher mean redshift distribution and may provide a new window on galaxy formation in the early universe.

  1. Formation of South Pole-Aitken Basin as the Result of an Oblique Impact: Implications for Melt Volume and Source of Exposed Materials

    NASA Technical Reports Server (NTRS)

    Petro, N. E.

    2012-01-01

    The South Pole-Aitken Basin (SPA) is the largest, deepest, and oldest identified basin on the Moon and contains surfaces that are unique due to their age, composition, and depth of origin in the lunar crust [1-3] (Figure 1). SPA has been a target of interest as an area for robotic sample return in order to determine the age of the basin and the composition and origin of its interior [3-6]. As part of the investigation into the origin of SPA materials there have been several efforts to estimate the likely provenance of regolith material in central SPA [5, 6]. These model estimates suggest that, despite the formation of basins and craters following SPA, the regolith within SPA is dominated by locally derived material. An assumption inherent in these models has been that the locally derived material is primarily SPA impact-melt as opposed to local basement material (e.g. unmelted lower crust). However, the definitive identification of SPA derived impact melt on the basin floor, either by remote sensing [2, 7] or via photogeology [8] is extremely difficult due to the number of subsequent impacts and volcanic activity [3, 4]. In order to identify where SPA produced impact melt may be located, it is important to constrain both how much melt would have been produced in a basin forming impact and the likely source of such melted material. Models of crater and basin formation [9, 10] present clear rationale for estimating the possible volumes and sources of impact melt produced during SPA formation. However, if SPA formed as the result of an oblique impact [11, 12], the volume and depth of origin of melted material could be distinct from similar material in a vertical impact [13].

  2. 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

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. C2-C4 alkanes measured in a South Pole ice core: Are atmospheric histories of light hydrocarbons preserved in Antarctic ice?

    NASA Astrophysics Data System (ADS)

    Williams, M. B.; Aydin, M.; Saltzman, E. S.

    2007-12-01

    Non-methane hydrocarbons play a significant role in global atmospheric photochemical system, but we have little knowledge about their atmospheric variability on long time scales. In this study, we analyze ethane (C2H6), propane (C3H8) and n-butane (C4H10) in a South Pole ice core, to examine the potential for using polar ice cores to reconstruct atmospheric histories of these gases. Air was dry- extracted from 124 ice core samples from the SPRESSO core, a 295 m core drilled in 2002 near South Pole as part of the ITASE campaign. The mean gas ages estimated for these samples range from 150 B.C.E. to 1720 C.E. The average mixing ratios for ethane, propane, and n-butane are 798±417 ppt, 234±89 ppt and 117±48 ppt, respectively. Point to point variability generally lies within the estimate of analytical uncertainty. These measurements demonstrate that 1) recoverable amounts of light hydrocarbons exist in polar ice, and 2) there is no evidence of down-core trends to suggest systematic loss or production with time. However, the hydrocarbon levels in this ice core are considerably higher than those in modern air over Antarctica (by factors of 2, 7, and 10 respectively for ethane, propane, and n-butane). The ice core data are not normally distributed, but appear to have a lower limit with superimposed variability. These "baseline levels" are roughly 300 ppt (C2H6), 80 ppt (C3H8), and 40 ppt (C4H10) and are consistent with modern ambient air and firn air levels measured at South Pole. A working hypothesis to explain these results is that alkane levels in ice reflect a combination of two components: 1) entrapped air possibly recording the atmospheric histories of these gases, and 2) some source of alkane contamination that is generated at or near bubble close-off, but does not continue at depth. It is unlikely that the elevated alkane levels reflect contamination during storage, extraction, or analysis.

  9. Inflatable Pole

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    1995-01-01

    Lightweight, portable tool reaches object at height or across gap. Extends reach up to 20 feet (6 meters). When not in use, tool collapses to 3 to 5 percent of its inflated length. Developed for use as self-rescue device by astronaut who becomes untethered outside spacecraft: astronaut uses pole to reach grapple on spacecraft and pull to it. Useful on Earth as rescue device or in performing routine tasks like changing high light bulb without ladder. When task with inflatable pole completed, operator opens vent valve to deflate tube. Operator then opens gun, removes fabric cover, and repacks tube.

  10. 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.

  11. Fingerprinting El Nino Southern Ocean events using oxygen triple isotopic composition of aerosol sulfate from the South Pole snow pit samples

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    According to the Intergovernmental Panel on Climate Change 4th assessment report [IPCC 2007], aerosols are the largest source of uncertainty in modeling the earth's radiative budget. Sulfate aerosols contributes to global cooling that may mask warming effect by greenhouse gases, therefore, high resolution record of aerosol sulfate can help to understand the impact of anthropogenic activities and natural variations on climate change. Sulfate aerosols were extracted from the ice pit samples obtained from the South Pole (1979-2002) at a high resolution temporal record of the winter and summer seasons. To insure highest measurement ability of very small samples (few nano moles) a hydrogen peroxide cleaning method was developed to remove organic impurities from aerosols which otherwise significantly affect O-triple isotopic measurement of the sulfates. Preliminary data indicated non sea salt contributions of 70-95% with a range in δ18OVSMOW = -1.86 -12% and Δ17O = 0.8-3.7% for the years 1990-2001. The positive Δ17O of sulfate derives from aqueous phase oxidation of SO2 by H2O2 and O3 and involves transfer of the isotopic anomaly from the oxidant to the product sulfate. All other sulfate sources (sea salt sulfates and primary sulfates from fossil fuel combustion), including gas-phase oxidation by OH in the troposphere, metal catalyzed oxidation of S(IV) to S(VI), are strictly mass dependent (Δ17O = 0%). The magnitude of the transfer of the Δ17O varies according to the relative contribution from H2O2 at pH < 6 (Δ17O = 1%) and O3 at pH > 6 (Δ17O = 8%). Seasonal variations of these oxidants and their contribution to S(IV) oxidation will be discussed. Since our samples include the time period 1977-2002, each year divided into two parts (winter and summer season's aerosols), in addition to seasonal variation in sulfate oxidation pathways, we may also be able to assess if the oxidation cycle of sulfate changes during El Niño years.

  12. 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.

  13. News and Views: SCUBA-2 shows its mettle; Exoplanet hit by stellar flare - loses atmosphere; Supercomputing to serve weather forecasting; South Pole detectors will predict solar proton events

    NASA Astrophysics Data System (ADS)

    2012-08-01

    A dramatic demonstration of the effects of a flare from a star on the atmosphere of a closely orbiting gas giant exoplanet has come from combining data from the Hubble Space Telescope and NASA'a Swift gamma-ray observatory. The Science and Technology Facilities Council (STFC), the Met Office and the Natural Environment Research Council (NERC) are together designing and building a next-generation weather forecasting model that will exploit ultra-fast supercomputers and boost the effectiveness of forecasts. The goal is to save money - and lives. Energetic particles from the Sun are a known hazard to astronauts and passengers and crew of high-altitude aircraft on polar flightpaths. Now researchers plan to predict such events using neutron detectors at Earth's South Pole.

  14. 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

  15. 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

  16. Pre-recessional (Ls 160-200) Polar Water Ice Clouds at the Martian South Pole: Potential Tracers of East-West Asymmetry?

    NASA Astrophysics Data System (ADS)

    Brown, A. J.; Hollingsworth, J. L.; Kahre, M. A.; Haberle, R. M.

    2008-12-01

    CRISM observations of the south polar region during the pre-spring recession period (Ls 160-200) show tenuous water ice signatures mixed with CO2 ice signatures over the polar cap between latitudes [1]. Water ice has been identified using the 1.5 micron absorption band, which is discernable within the CO2 1.435 micron band complex due to the narrow nature of the CO2 ice absorptions [2, 3]. A surface deposit of water ice is not favored due to the apparent fine grained nature of the water ice, which is indicated by the weak 1.5 micron absorption band, and the disappearance of the clouds prior to retreat of the south polar CO2 ice beneath them. CRISM observations show the pre-recessional water ice clouds appear to go through a steady growth phase from Ls 160-190 and have a short terminal phase from Ls 200-205 [1, 2]. The clouds never quite encircle the whole pole, and never penetrate the 80 degree latitude line. They are strongest at, and appear to originate from, the 90-150 degree meridian range. From Mars GCM simulations, similar patterns appear to originate from east-west asymmetries in the early spring circulation and low-level thermal environments of the high-latitude/polar regions of the southern hemisphere that arise due to asymmetries of large-scale orography and its effects on the atmosphere and climate. We are currently investigating the optical thickness of the water ice clouds using CRISM full resolution emission phase function observations and intend to examine the H2O absorption bands at 3.2 microns to further elucidate the cloud properties. The potential to trace asymmetric polar atmospheric fluxes using these water ice clouds as tracers may lead to a better understanding of the enigmatic cryptic region and the displacement of the south pole residual cap [5]. [1] Brown, A.J. (2007) Fall AGU abstract P33A-1016 [2] Brown, A.J. and Calvin, W. JGR in preparation [3] Langevin, Y. et al. (2006) JGR 112 doi:10.1029/2006JE002841 [4] Hollingsworth, J.L. et al

  17. 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.

  18. A study of boundary layer behavior associated with high NO concentrations at the South Pole using a minisodar, tethered balloon, and sonic anemometer

    NASA Astrophysics Data System (ADS)

    Neff, W.; Helmig, D.; Grachev, A.; Davis, D.

    This paper focuses on the use of an acoustic sounder, or sodar, during the 2003 Antarctic Tropospheric Chemistry Investigation (ANTCI), to document the behavior of very shallow (<50 m) stable boundary layers thought to be one of the critical factors for explaining the very high levels of nitric oxide (NO) found in past field experiments at the South Pole. The use of a tethered balloon, profiling wind, temperature, NO, and ozone provided for a detailed interpretation of sodar data for the period 12-30 December 2003. For the same period, sonic anemometer 2-m turbulence measurements, averaged to 0.5 h, linked surface processes to the evolution of the boundary layer in response to changing radiative balance and synoptic weather changes. A mixing-layer detection method was developed and applied to half-hour average sodar amplitude profiles for the period 23 November-30 December 2003. These data also allowed for testing of simple diagnostic equations for the mixing-layer depth as well as estimates of vertical diffusion rates under stable conditions, the latter being important for the effective depth of the mixing layer vis-à-vis the nonlinear NO chemistry postulated from earlier analyses. With the extended sampling period, two sub-seasonal regimes were examined: (1) a late-December period, with the full suite of supporting measurements, where the earlier results that shallow mixing layers associated with light winds and strong surface stability can be among the dominant factors leading to high NO levels were repeated and (2) a late November period that revealed additional complexities with very high NO concentrations appearing at times in concert with higher winds, weaker surface stability, and deeper mixing layers. The latter results are only consistent with a more complicated picture of how NO can build to very high levels that involves invoking the previously expressed dependence of elevated NO levels on nonlinear NO x (NO x=NO+NO 2) chemistry, greater fluxes of NO x

  19. Measurement of stratospheric trace gases by millimeter-wave spectroscopy for an annual cycle at the South Pole

    SciTech Connect

    De Zafra, R.L.; Trimble, C.; Reeves, M.

    1994-12-31

    Chemistry and transport processes in the south polar stratosphere have been intensively studied since discovery of the seasonal {open_quotes}ozone hole{close_quotes} appearing over Antarctica. Nevertheless, large gaps still exist in our knowledge of the dynamical and chemical behavior of the polar winter vortex. This behavior is responsible for much of the prior processing of air, and the processing makes possible the formation of a springtime ozone hole. The work described here was intended to fill some of these gaps by frequently monitoring the behavior of several trace gases over as much of a full year cycle as possible, from a central position within the annually forming winter vortex region. The species covered (not all for the full duration of the observations) were ozone, nitrogen dioxide, nitrous oxide, nitric acid, and chlorine monoxide. An upper limit for hydrogen peroxide was also determined by an unsuccessful attempt to detect it. 7 refs.

  20. 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.

  1. SPT-CL J0546-5345: A MASSIVE z>1 GALAXY CLUSTER SELECTED VIA THE SUNYAEV-ZEL'DOVICH EFFECT WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

    Brodwin, M.; Ashby, M. L. N.; Fazio, G. G.; Foley, R. J.; Ruel, J.; Ade, P. A. R.; Aird, K. A.; Andersson, K.; Bautz, M.; Bazin, G.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; De Haan, T.; Dobbs, M. A.; Dudley, J. P.; Desai, S.

    2010-09-20

    We report the spectroscopic confirmation of SPT-CL J0546-5345 at (z) = 1.067. To date this is the most distant cluster to be spectroscopically confirmed from the 2008 South Pole Telescope (SPT) catalog, and indeed the first z>1 cluster discovered by the Sunyaev-Zel'dovich Effect (SZE). We identify 21 secure spectroscopic members within 0.9 Mpc of the SPT cluster position, 18 of which are quiescent, early-type galaxies. From these quiescent galaxies we obtain a velocity dispersion of 1179{sup +232}{sub -167} km s{sup -1}, ranking SPT-CL J0546-5345 as the most dynamically massive cluster yet discovered at z>1. Assuming that SPT-CL J0546-5345 is virialized, this implies a dynamical mass of M{sub 200} = 1.0{sup +0.6}{sub -0.4} x 10{sup 15} M{sub sun}, in agreement with the X-ray and SZE mass measurements. Combining masses from several independent measures leads to a best-estimate mass of M{sub 200} = (7.95 {+-} 0.92) x 10{sup 14} M{sub sun}. The spectroscopic confirmation of SPT-CL J0546-5345, discovered in the wide-angle, mass-selected SPT cluster survey, marks the onset of the high-redshift SZE-selected galaxy cluster era.

  2. ANGULAR POWER SPECTRA OF THE MILLIMETER-WAVELENGTH BACKGROUND LIGHT FROM DUSTY STAR-FORMING GALAXIES WITH THE SOUTH POLE TELESCOPE

    SciTech Connect

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

    2010-08-01

    We use data from the first 100 deg{sup 2} field observed by the South Pole Telescope (SPT) in 2008 to measure the angular power spectrum of temperature anisotropies contributed by the background of dusty star-forming galaxies (DSFGs) at millimeter wavelengths. From the auto- and cross-correlation of 150 and 220 GHz SPT maps, we significantly detect both Poisson distributed and, for the first time at millimeter wavelengths, clustered components of power from a background of DSFGs. The spectral indices of the Poisson and clustered components are found to be {alpha}-bar{sup P}{sub 150-220}=3.86{+-}0.23 and {alpha} {sup C}{sub 150-220} = 3.8 {+-} 1.3, implying a steep scaling of the dust emissivity index {beta} {approx} 2. The Poisson and clustered power detected in SPT, BLAST (at 600, 860, and 1200 GHz), and Spitzer (1900 GHz) data can be understood in the context of a simple model in which all galaxies have the same graybody spectrum with dust emissivity index of {beta} = 2 and dust temperature T{sub d} = 34 K. In this model, half of the 150 GHz background light comes from redshifts greater than 3.2. We also use the SPT data to place an upper limit on the amplitude of the kinetic Sunyaev-Zel'dovich power spectrum at l = 3000 of 13 {mu}K{sup 2} at 95% confidence.

  3. SPT-CL J0205-5829: A z = 1.32 EVOLVED MASSIVE GALAXY CLUSTER IN THE SOUTH POLE TELESCOPE SUNYAEV-ZEL'DOVICH EFFECT SURVEY

    SciTech Connect

    Stalder, B.; Ashby, M. L. N.; Ruel, J.; Bayliss, M.; Suhada, R.; Andersson, K.; Bazin, G.; Brodwin, M.; Aird, K. A.; Armstrong, R.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; and others

    2013-02-15

    The galaxy cluster SPT-CL J0205-5829 currently has the highest spectroscopically confirmed redshift, z = 1.322, in the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. XMM-Newton observations measure a core-excluded temperature of T{sub X} = 8.7{sup +1.0} {sub -0.8} keV producing a mass estimate that is consistent with the Sunyaev-Zel'dovich-derived mass. The combined SZ and X-ray mass estimate of M {sub 500} = (4.8 {+-} 0.8) Multiplication-Sign 10{sup 14} h {sup -1} {sub 70} M {sub Sun} makes it the most massive known SZ-selected galaxy cluster at z > 1.2 and the second most massive at z > 1. Using optical and infrared observations, we find that the brightest galaxies in SPT-CL J0205-5829 are already well evolved by the time the universe was <5 Gyr old, with stellar population ages {approx}>3 Gyr, and low rates of star formation (<0.5 M {sub Sun} yr{sup -1}). We find that, despite the high redshift and mass, the existence of SPT-CL J0205-5829 is not surprising given a flat {Lambda}CDM cosmology with Gaussian initial perturbations. The a priori chance of finding a cluster of similar rarity (or rarer) in a survey the size of the 2500 deg{sup 2} SPT-SZ survey is 69%.

  4. 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.

  5. 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.

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

    PubMed

    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.

  7. 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

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

    PubMed

    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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. The Blanco Cosmology Survey: Data Reduction, Calibration and Photometric Redshift Estimation to Four Distant Galaxy Clusters Discovered by the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Ngeow, Chow Choong; Mohr, J.; Zenteno, A.; Data Management, DES; BCS; SPT Collaborations

    2009-01-01

    The Blanco Cosmology Survey (BCS) is designed to enable a study of the cosmic acceleration using multiple techniques. To date, BCS has acquired Sloan griz band imaging data from 60 nights (15 nights per year from 2005 to 2008) using the Blanco 4m Telescope located at CTIO. The astronomical imaging data taken from this survey have been processed on high performance computer TeraGrid platforms at NCSA, using the automated Dark Energy Survey (DES) data management (DM) system. The DES DM system includes (1) middlewares for controlling and managing the processing jobs, and serve as an application container encapsulating the scientific codes; and (2) DES archive, which includes filesystem nodes, a relational database and a data access framework, to support the pipeline processing, data storage and scientific analyzes. Photometric solution module (PSM) were run on photometric nights to determine the zeropoints (ZP) and other photometric solutions. We remapped and coadded the images that lie within the pre-defined coadd tiles in the sky. When running the coaddition pipeline, we determined the ZP for each images using the photometric ZP from PSM, the magnitude offsets between overlapping images, and the sky brightness ratio for CCDs within a given exposure. We also applied aperture correction and color-term correction to the coadded catalogs. Satisfactory photometric and astrometric precision were achieved. These enabled initial estimation of photometric redshifts using ANNz codes, trained from 5000 galaxies with spectroscopic redshifts. RMS in the photometric redshifts ranges from 0.05 to 0.1 in sigma_z/(1+z) for redshift extended to z=1. We used the BCS data to optically confirm and estimate redshifts for four of the highest S/N galaxy clusters discovered with the South Pole Telescope using the Sunyaev-Zel'dovich Effect.

  14. A SUNYAEV-ZEL'DOVICH-SELECTED SAMPLE OF THE MOST MASSIVE GALAXY CLUSTERS IN THE 2500 deg{sup 2} SOUTH POLE TELESCOPE SURVEY

    SciTech Connect

    Williamson, R.; Benson, B. A.; High, F. W.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Vanderlinde, K.; Ade, P. A. R.; Aird, K. A.; Andersson, K.; Bazin, G.; Armstrong, R.; Ashby, M. L. N.; Brodwin, M.; Bautz, M.; Bertin, E.; Bonamente, M.; Chapman, S. C.; Clocchiatti, A.

    2011-09-10

    The South Pole Telescope (SPT) is currently surveying 2500 deg{sup 2} of the southern sky to detect massive galaxy clusters out to the epoch of their formation using the Sunyaev-Zel'dovich (SZ) effect. This paper presents a catalog of the 26 most significant SZ cluster detections in the full survey region. The catalog includes 14 clusters which have been previously identified and 12 that are new discoveries. These clusters were identified in fields observed to two differing noise depths: 1500 deg{sup 2} at the final SPT survey depth of 18 {mu}K arcmin at 150 GHz and 1000 deg{sup 2} at a depth of 54 {mu}K arcmin. Clusters were selected on the basis of their SZ signal-to-noise ratio (S/N) in SPT maps, a quantity which has been demonstrated to correlate tightly with cluster mass. The S/N thresholds were chosen to achieve a comparable mass selection across survey fields of both depths. Cluster redshifts were obtained with optical and infrared imaging and spectroscopy from a variety of ground- and space-based facilities. The redshifts range from 0.098 {<=} z {<=} 1.132 with a median of z{sub med} = 0.40. The measured SZ S/N and redshifts lead to unbiased mass estimates ranging from 9.8 x 10{sup 14} M{sub sun} h{sup -1}{sub 70} {<=} M{sub 200}({rho}{sub mean}) {<=} 3.1 x 10{sup 15} M{sub sun} h{sup -1}{sub 70}. Based on the SZ mass estimates, we find that none of the clusters are individually in significant tension with the {Lambda}CDM cosmological model. We also test for evidence of non-Gaussianity based on the cluster sample and find the data show no preference for non-Gaussian perturbations.

  15. Probing star formation in the dense environments of z ˜ 1 lensing haloes aligned with dusty star-forming galaxies detected with the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Welikala, N.; Béthermin, M.; Guery, D.; Strandet, M.; Aird, K. A.; Aravena, M.; Ashby, M. L. N.; Bothwell, M.; Beelen, A.; Bleem, L. E.; de Breuck, C.; Brodwin, M.; Carlstrom, J. E.; Chapman, S. C.; Crawford, T. M.; Dole, H.; Doré, O.; Everett, W.; Flores-Cacho, I.; Gonzalez, A. H.; González-Nuevo, J.; Greve, T. R.; Gullberg, B.; Hezaveh, Y. D.; Holder, G. P.; Holzapfel, W. L.; Keisler, R.; Lagache, G.; Ma, J.; Malkan, M.; Marrone, D. P.; Mocanu, L. M.; Montier, L.; Murphy, E. J.; Nesvadba, N. P. H.; Omont, A.; Pointecouteau, E.; Puget, J. L.; Reichardt, C. L.; Rotermund, K. M.; Scott, D.; Serra, P.; Spilker, J. S.; Stalder, B.; Stark, A. A.; Story, K.; Vanderlinde, K.; Vieira, J. D.; Weiß, A.

    2016-01-01

    We probe star formation in the environments of massive (˜1013 M⊙) dark matter haloes at redshifts of z ˜ 1. This star formation is linked to a submillimetre clustering signal which we detect in maps of the Planck High Frequency Instrument that are stacked at the positions of a sample of high redshift (z > 2) strongly lensed dusty star-forming galaxies (DSFGs) selected from the South Pole Telescope (SPT) 2500 deg2 survey. The clustering signal has submillimetre colours which are consistent with the mean redshift of the foreground lensing haloes (z ˜ 1). We report a mean excess of star formation rate (SFR) compared to the field, of (2700 ± 700) M⊙ yr-1 from all galaxies contributing to this clustering signal within a radius of 3.5 arcmin from the SPT DSFGs. The magnitude of the Planck excess is in broad agreement with predictions of a current model of the cosmic infrared background. The model predicts that 80 per cent of the excess emission measured by Planck originates from galaxies lying in the neighbouring haloes of the lensing halo. Using Herschel maps of the same fields, we find a clear excess, relative to the field, of individual sources which contribute to the Planck excess. The mean excess SFR compared to the field is measured to be (370 ± 40) M⊙ yr-1 per resolved, clustered source. Our findings suggest that the environments around these massive z ˜ 1 lensing haloes host intense star formation out to about 2 Mpc. The flux enhancement due to clustering should also be considered when measuring flux densities of galaxies in Planck data.

  16. Mutagenic activity of south Indian food items.

    PubMed

    Sivaswamy, S N; Balachandran, B; Balanehru, S; Sivaramakrishnan, V M

    1991-08-01

    Dietary components and food dishes commonly consumed in South India were screened for their mutagenic activity. Kesari powder, calamus oil, palm drink, toddy and Kewra essence were found to be strongly mutagenic; garlic, palm oil, arrack, onion and pyrolysed portions of bread toast, chicory powder were weakly mutagenic, while tamarind and turmeric were not. Certain salted, sundried and oil fried food items were also mutagenic. Cissus quadrangularis was mutagenic, while 'decoctions' of cumin seeds, aniseeds and ginger were not. Several perfumes, essential oils and colouring agents, which are commonly used were also screened and many of them exhibited their mutagenic potential by inducing the 'reverse mutation' in Salmonella typhimurium tester strains.

  17. 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

  18. X-RAY PROPERTIES OF THE FIRST SUNYAEV-ZEL'DOVICH EFFECT SELECTED GALAXY CLUSTER SAMPLE FROM THE SOUTH POLE TELESCOPE

    SciTech Connect

    Andersson, K.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Ade, P. A. R.; Aird, K. A.; Armstrong, B.; Desai, S.; Brodwin, M.; Foley, R. J.; Forman, W. R.; De Haan, T.; Dobbs, M. A.; Dudley, J. P.; Garmire, G.; George, E. M.

    2011-09-01

    We present results of X-ray observations of a sample of 15 clusters selected via their imprint on the cosmic microwave background from the thermal Sunyaev-Zel'dovich (SZ) effect. These clusters are a subset of the first SZ-selected cluster catalog, obtained from observations of 178 deg{sup 2} of sky surveyed by the South Pole Telescope (SPT). Using X-ray observations with Chandra and XMM-Newton, we estimate the temperature, T{sub X} , and mass, M{sub g} , of the intracluster medium within r{sub 500} for each cluster. From these, we calculate Y{sub X} = M{sub g}T{sub X} and estimate the total cluster mass using an M{sub 500}-Y{sub X} scaling relation measured from previous X-ray studies. The integrated Comptonization, Y{sub SZ}, is derived from the SZ measurements, using additional information from the X-ray-measured gas density profiles and a universal temperature profile. We calculate scaling relations between the X-ray and SZ observables and find results generally consistent with other measurements and the expectations from simple self-similar behavior. Specifically, we fit a Y{sub SZ}-Y{sub X} relation and find a normalization of 0.82 {+-} 0.07, marginally consistent with the predicted ratio of Y{sub SZ}/Y{sub X} = 0.91 {+-} 0.01 that would be expected from the density and temperature models used in this work. Using the Y{sub X} -derived mass estimates, we fit a Y{sub SZ}-M{sub 500} relation and find a slope consistent with the self-similar expectation of Y{sub SZ}{proportional_to}M {sup 5/3} with a normalization consistent with predictions from other X-ray studies. We find that the SZ mass estimates, derived from cosmological simulations of the SPT survey, are lower by a factor of 0.78 {+-} 0.06 relative to the X-ray mass estimates. This offset is at a level of 1.3{sigma} when considering the {approx}15% systematic uncertainty for the simulation-based SZ masses. Overall, the X-ray measurements confirm that the scaling relations of the SZ-selected clusters are

  19. Lunar impact basins: New data for the western limb and far side (Orientale and South Pole-Aitken basins) from the first Galileo flyby

    NASA Astrophysics Data System (ADS)

    Head, James W.; Murchie, Scott; Mustard, John F.; Pieters, Carle M.; Neukum, Gerhard; McEwen, Alfred; Greeley, Ronald; Nagel, Engelbert; Belton, Michael J. S.

    1993-09-01

    Compositional aspects of impact basin materials can be analyzed using multispectral image data acquired by the Galileo solid state imaging (SSI) experiment during the December 1990 lunar encounter. These data provide important information on the spectral properties of the western lunar limb and parts of the far side. The SSI images cover the wavelength range 0.4-1.0 μm, allowing measurement of spectral slope and estimation of the strength of the 1 μm absorption due to iron in the mafic minerals olivine and pyroxene. Among deposits of the 930-km-diameter Orientale basin, exterior ejecta comprising the Hevelius Formation is relatively homogeneous and spectrally similar to mature Apollo 16 soils, suggesting an upper crustal source. The centrally located Maunder Formation is distinct from the younger mare basalts but comparable to the Hevelius Formation in its spectral reflectance properties, supporting an interpretation as basin impact melt. The Montes Rook Formation, located in an annulus between the Maunder and the Hevelius, shows a slightly stronger mafic absorption and may be the deepest crustal material excavated. The distal Orientale deposits show local mafic enhancements (in the Schiller-Schickard and Mendel-Rydberg regions) interpreted to represent pre-Orientale mare deposits, or cryptomaria, intermixed with overlying basin ejecta. In this case, maria of sizes comparable to those presently observed were widespread in this region before the Orientale impact. Mixing-model analyses are consistent with the ballistic erosion and sedimentation model for ejecta emplacement in the distal regions beyond the continuous ejecta deposit. On the southern lunar farside, a high area with an enhanced mafic absorption corresponds to the interior and rim of the pre-Nectarian South Pole-Aitken impact basin, 2000-2500 km in diameter. The anomaly is interpreted to be due to several factors, including excavation into the more mafic lower crust, and the presence of extensive early

  20. The North Galactic Pole +30° Zone Galaxies. I. A Comparative Study of Galaxies with Different Nuclear Activity

    NASA Astrophysics Data System (ADS)

    Petrosian, Artashes; McLean, Brian; Allen, Ron; Kunth, Daniel; Leitherer, Claus

    2008-03-01

    A database containing 618 active and star-forming (A/SF) galaxies and 564 normal galaxies in a 120° × 6° wide strip crossing the north Galactic pole was constructed in order to compare the global properties of "active" galaxies against a control sample of "normal" galaxies. This database combines a literature and catalog search with new optical measurements from the Fpg (red) and Jpg (blue) band images of the STScI Digitized Sky Survey (DSS). We provide alternative names, accurate coordinates, morphological type, activity classes, red and blue apparent magnitudes, 2MASS near-infrared J-H and H-K colors, apparent diameters, axial ratios, position angles, and number counts of neighboring objects in a circle of radius 50 kpc. We also present an atlas of 103 interacting and merging systems among these galaxies. The integrated properties of A/SF and normal galaxies in this sample are compared using a multivariate factor analysis, which reveals that A/SF galaxies are objects with relatively late morphological types, and are more inclined and have bluer optical colors than normal galaxies. In this sample, all merging and interacting galaxies are A/SF objects. Star-forming galaxies are objects with relatively late morphological types, lower absolute luminosities and linear sizes, bluer colors, and higher inclination than sample X-ray or radio sources, as well as Seyfert galaxies. The near-infrared colors of the sample galaxies are independent parameters and do not correlate with activity level or any other parameter of the galaxies.

  1. 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.

  2. 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.

  3. 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.

  4. COSMOLOGICAL CONSTRAINTS FROM SUNYAEV-ZEL'DOVICH-SELECTED CLUSTERS WITH X-RAY OBSERVATIONS IN THE FIRST 178 deg{sup 2} OF THE SOUTH POLE TELESCOPE SURVEY

    SciTech Connect

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

    2013-02-15

    We use measurements from the South Pole Telescope (SPT) Sunyaev-Zel'dovich (SZ) cluster survey in combination with X-ray measurements to constrain cosmological parameters. We present a statistical method that fits for the scaling relations of the SZ and X-ray cluster observables with mass while jointly fitting for cosmology. The method is generalizable to multiple cluster observables, and self-consistently accounts for the effects of the cluster selection and uncertainties in cluster mass calibration on the derived cosmological constraints. We apply this method to a data set consisting of an SZ-selected catalog of 18 galaxy clusters at z > 0.3 from the first 178 deg{sup 2} of the 2500 deg{sup 2} SPT-SZ survey, with 14 clusters having X-ray observations from either Chandra or XMM-Newton. Assuming a spatially flat {Lambda}CDM cosmological model, we find the SPT cluster sample constrains {sigma}{sub 8}({Omega} {sub m}/0.25){sup 0.30} = 0.785 {+-} 0.037. In combination with measurements of the cosmic microwave background (CMB) power spectrum from the SPT and the seven-year Wilkinson Microwave Anisotropy Probe data, the SPT cluster sample constrains {sigma}{sub 8} = 0.795 {+-} 0.016 and {Omega} {sub m} = 0.255 {+-} 0.016, a factor of 1.5 improvement on each parameter over the CMB data alone. We consider several extensions beyond the {Lambda}CDM model by including the following as free parameters: the dark energy equation of state (w), the sum of the neutrino masses ({Sigma}m {sub {nu}}), the effective number of relativistic species (N {sub eff}), and a primordial non-Gaussianity (f {sub NL}). We find that adding the SPT cluster data significantly improves the constraints on w and {Sigma}m {sub {nu}} beyond those found when using measurements of the CMB, supernovae, baryon acoustic oscillations, and the Hubble constant. Considering each extension independently, we best constrain w = -0.973 {+-} 0.063 and the sum of neutrino masses {Sigma}m {sub {nu}} < 0.28 eV at 95

  5. GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV-ZEL'DOVICH EFFECT IN THE FIRST 720 SQUARE DEGREES OF THE SOUTH POLE TELESCOPE SURVEY

    SciTech Connect

    Reichardt, C. L.; Stalder, B.; Ashby, M. L. N.; Bleem, L. E.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Montroy, T. E.; Aird, K. A.; Andersson, K.; Bazin, G.; Armstrong, R.; Bautz, M.; Bayliss, M.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; and others

    2013-02-15

    We present a catalog of galaxy cluster candidates, selected through their Sunyaev-Zel'dovich (SZ) effect signature in the first 720 deg{sup 2} of the South Pole Telescope (SPT) survey. This area was mapped with the SPT in the 2008 and 2009 austral winters to a depth of {approx}18 {mu}K{sub CMB}-arcmin at 150 GHz; 550 deg{sup 2} of it was also mapped to {approx}44 {mu}K{sub CMB}-arcmin at 95 GHz. Based on optical imaging of all 224 candidates and near-infrared imaging of the majority of candidates, we have found optical and/or infrared counterparts for 158, which we then classify as confirmed galaxy clusters. Of these 158 clusters, 135 were first identified as clusters in SPT data, including 117 new discoveries reported in this work. This catalog triples the number of confirmed galaxy clusters discovered through the SZ effect. We report photometrically derived (and in some cases spectroscopic) redshifts for confirmed clusters and redshift lower limits for the remaining candidates. The catalog extends to high redshift with a median redshift of z = 0.55 and maximum confirmed redshift of z = 1.37. Forty-five of the clusters have counterparts in the ROSAT bright or faint source catalogs from which we estimate X-ray fluxes. Based on simulations, we expect the catalog to be nearly 100% complete above M {sub 500} Almost-Equal-To 5 Multiplication-Sign 10{sup 14} M {sub Sun} h {sup -1} {sub 70} at z {approx}> 0.6. There are 121 candidates detected at signal-to-noise ratio greater than five, at which the catalog purity is measured to be 95%. From this high-purity subsample, we exclude the z < 0.3 clusters and use the remaining 100 candidates to improve cosmological constraints following the method presented by Benson et al. Adding the cluster data to CMB + BAO + H {sub 0} data leads to a preference for non-zero neutrino masses while only slightly reducing the upper limit on the sum of neutrino masses to {Sigma}m {sub {nu}} < 0.38 eV (95% CL). For a spatially flat w

  6. 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...

  7. 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

  8. Barriers to Participation in Physical Activity Among South Sudanese Children in South Australia: Parents' Perspectives.

    PubMed

    Mude, William; Mwanri, Lillian

    2016-01-01

    Physical inactivity is one of the determinants of childhood obesity. Although its facilitators are well documented for the general community, limited evidence exists informing newly arrived and emerging migrant communities in Australia. To explore parents' perspectives of barriers to participation in physical activity among South Sudanese children in South Australia. Qualitative, face-to-face interviews were conducted with parents. Data were transcribed, coded, and analyzed thematically using NVivo software. Multiple and complex barriers to physical activity participation were described. Enabling and supportive programs are needed to improve physical activity participation and health outcomes of new migrants. PMID:27536934

  9. 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

  10. 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

  11. 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.

  12. Forbush Effects on the Martian Surface and Earth's Poles

    NASA Astrophysics Data System (ADS)

    Posner, A.; Guo, J.; Heber, B.; Wimmer-Schweingruber, R. F.; Zeitlin, C.; Zheng, Y.; MacNeice, P. J.; Odstrcil, D.; Rastaetter, L.; Steigies, C. T.; Andrews, J. P.; Appel, J. K.; Beaujean, R.; Berger, L.; Boettcher, S. I.; Brinza, D. E.; Bullock, M.; Burmeister, S.; Cucinotta, F.; Dresing, N.; Drews, C.; Ehresmann, B.; Epperly, M. E.; Hassler, D.; Herbst, K.; Kim, M. H. Y.; Kohler, J.; Kühl, P.; Lohf, H.; Martin-Garcia, C.; Müller-Mellin, R.; Neal, K.; Rafkin, S. C.; Reitz, G.; Smith, K. D.; Tyler, Y.; weigle, G., II

    2015-12-01

    We analyzed MSL/RAD observation of Forbush effects on the surface of Mars over a full Mars year from landing through the Mars opposition period in 2014. For the extended Mars opposition phase we compared the observed Forbush effects with those identified at Earth's south pole utilizing observations of the South Pole neutron monitor. Identification of the drivers of Forbush effects, recurrent and transient solar wind structures in the inner heliosphere, is aided by WSA-ENLIL simulations. We show that a remarkable correlations of count rates of (secondary) cosmic rays at Mars' surface and at the Earth's south pole is established for a minimum duration of 6 months around the Mars opposition, in particular when time shifted with propagation and/or corotation delays of the drivers of cosmic ray decreases in the solar wind. Moreover, the magnitude of Forbush effects on Mars is larger statistically than the equivalent near Earth's poles.

  13. 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.

  14. Anticandidal activity of certain South Indian medicinal plants.

    PubMed

    Vaijayanthimala, J; Anandi, C; Udhaya, V; Pugalendi, K V

    2000-05-01

    The anticandidal activity of 20 household South Indian medicinal plants and/or plant products was studied using 30 Candida albicans isolates obtained from vaginal candidiasis patients of Rajah Muthiah Medical College and Hospital and compared with the anticandidal activity of garlic. Water and ethanol extracts were prepared and their minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) were determined. Water extracts of three plants did not show any anticandidal activity, while Murrya koenigii did not exhibit any anticandidal activity in either extract. Other plants exhibited more activity in ethanol extracts showing that their active principle is more soluble in a non-polar solvent. PMID:10815017

  15. 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%.

  16. 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…

  17. 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.

  18. 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. PMID:24219639

  19. 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.

  20. 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

  1. A LINE POLE 3, HISTORIC POLE WITH ORIGINAL GLASS PINTYPE ...

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

    A LINE POLE 3, HISTORIC POLE WITH ORIGINAL GLASS PIN-TYPE INSULATORS. VIEW TO NORTHEAST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  2. 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

  3. Quadriceps tendon rupture and periosteal sleeve avulsion fracture of the proximal patella pole in an active adolescent.

    PubMed

    Bimmel, R; Reddy, K

    2008-07-01

    A unique case of anterior knee pain in an active adolescent is described: a periosteal sleeve avulsion and quadriceps rupture in a young basketball player. The trauma mechanism was without any direct trauma on the knee. A review of overuse-related anterior knee pain in the young and active is presented. A quadriceps rupture with a periosteal sleeve avulsion fracture in an active adolescent is very rare. To our knowledge there are no similar cases described. This article presents a case of a 14-year-old adolescent boy who sustained a quadriceps rupture with a periosteal sleeve avulsion.

  4. Diurnal patterns in lightning activity over South America

    NASA Astrophysics Data System (ADS)

    Ávila, Eldo E.; Bürgesser, Rodrigo E.; Castellano, Nesvit E.; Nicora, M. Gabriela

    2015-04-01

    Satellite observations of lightning flash distribution data are used to examine the diurnal cycle of lightning activity over the tropical and subtropical regions of South America. A harmonic analysis is used to study the spatial variations in the peak and strength of diurnal lightning activity across this area. Results show that in the northern and central regions of South America, the times of maxima in lightning activity was concentrated from late afternoon to evening hours (between 14:00 and 18:00 local time), which may be associated with the peaking of the local convective activity connected with heating of the surface caused by daytime insolation. In subtropical South America, particularly in the area limited by 25°S, 35°S of latitude and 70°W, 50°W of longitude, the time of maximum lightning activity was shifted to nocturnal hours, extending from close to midnight to early morning hours. This behavior can be associated to the peak in mesoscale convective systems in the region which occurs in the morning hours. The annual flash densities in the tropical and subtropical parts of the continent were found to have comparable magnitudes. However, the contribution of the continental tropics to the global electric circuit dominates over the continental subtropics contribution throughout all seasons, since the surface covered by the tropical region is more than twice the area covered by the subtropical region.

  5. 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.

  6. 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.

  7. 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.

  8. Asteroid 45 Eugenia - Lightcurves and the pole orientation

    NASA Technical Reports Server (NTRS)

    Taylor, R. C.; Birch, P. V.; Surdej, J.; Pospieszalska-Surdej, A.

    1988-01-01

    Three lightcurves obtained in 1969 and six from 1984 are presented for the 250-km U-type asteroid Eugenia. The asteroid's north pole is within + or - 10 deg of ecliptic longitude 106 deg and a latitude of +26 deg, in keeping with an amplitude-aspect pole analysis. While only one maximum and one minimum are present when observations are closest to both the north and south poles, there are two of each at other oppositions. It is suggested that this effect may be due to the surface albedo features of Eugenia.

  9. Antimicrobial activity of selected South African medicinal plants

    PubMed Central

    2012-01-01

    Background Nearly 3,000 plant species are used as medicines in South Africa, with approximately 350 species forming the most commonly traded and used medicinal plants. In the present study, twelve South African medicinal plants were selected and tested for their antimicrobial activities against eight microbial species belonging to fungi, Mycobacteria, Gram-positive and Gram-negative bacteria. Methods The radiometric respiratory technique using the BACTEC 460 system was used for susceptibility testing against Mycobacterium tuberculosis, and the liquid micro-broth dilution was used for other antimicrobial assays. Results The results of the minimal inhibitory concentration (MIC) determinations indicated that the methanol extracts from Acacia karoo, Erythrophleum lasianthum and Salvia africana were able to prevent the growth of all the tested microorganisms. All other samples showed selective activities. MIC values below 100 μg/ml were recorded with A. karoo, C. dentate, E. lasianthum, P. obligun and S. africana on at least one of the nine tested microorganisms. The best activity (MIC value of 39.06 μg/ml) was noted with S. africana against E. coli, S. aureus and M. audouinii, and Knowltonia vesitoria against M. tuberculosis. Conclusion The overall results of the present work provide baseline information for the possible use of the studied South African plant extracts in the treatment of microbial infections. PMID:22704594

  10. 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.

  11. 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.

  12. 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.

  13. Postpartum ovarian activity in South Asian zebu cattle.

    PubMed

    Brar, P S; Nanda, A S

    2008-07-01

    Timely onset of postpartum ovarian activity is vital for optimal reproductive performance of dairy cows. Much depends upon genetic constitution of an animal although several factors interplay to govern the onset of postpartum ovarian activity. South Asian zebu cattle have much longer service period when compared with other exotic or crossbred cattle reared in the same Asian environment, which suggests differences in their genetic makeup. However, the cows with same genetic configuration expressed better reproductive potential when reared under different environment, such as in Brazil and Mexico, which suggests the role of extrinsic factors such as management, nutrition, environment and disease conditions. Better management of animals (provision of proper shade, water and housing, efficient oestrous detection and timely insemination), good quality nutrition supplemented with appropriate minerals and vitamins, prevention of diseases (vaccination, deworming, suitable therapeutic interventions) and application of biotechnology have helped in improving postpartum ovarian activity and, therefore, reproductive performance of zebu cattle in Asia. No comprehensive study appears to have been carried out on the various aspects of reproduction in zebu cattle reared under South Asian socio-agro-climatic conditions. This paper is a modest effort to collect what ever information available and to critically review the postpartum ovarian activity in zebu cattle with special reference to the effect of the various managemental practices and pharmacological interventions. PMID:18638125

  14. A Devonian paleomagnetic pole from red beds of the Tarim Block, China

    SciTech Connect

    Li, Yianping; McWilliams, M.; Sharps, R.; Cox, A. ); Li, Yongan; Li, Qiang; Gao, Zhengjia ); Zhang, Zhengkun ); Zhai, Yongjian )

    1990-11-10

    The authors present new Devonian paleomagnetic results from 59 sites in three stratigraphic sections exposed on the northwestern margin of the Tarim Block. At one section, 1,998 m of red sandstone is continuously exposed; the other two sections can be correlated with the first on both magnetostratigraphic and lithologic grounds. Progressive thermal demagnetization reveals three characteristic magnetizations. One is a Late Permian overprint which is isolated below 578C at sites near contacts with Late Permian dikes. The other two components are approximately antipodal, have a much higher unblocking temperature than the overprint, and are directionally distinct from the Late Permian overprint. They believe that these are characteristic Devonian magnetizations. Within the continuous 1,998 m section, results denote a 395 m reversed polarity zone overlying a 1,603 m normal polarity zone. One reversed event is recorded at the base of the section. A paleomagnetic pole calculated by averaging results from 47 normal and reversed sites lies at {lambda}{sub p}=16.5{degree}N, {phi}{sub p}=165.0{degree}E, K=25, and A{sub 95}=4.3{degree}. This pole is statistically distinct from a previously reported Late Devonian pole for Tarim. On the basis of field geologic and rock magnetic studies, they believe that the previously reported pole, in addition to results from one of their three sections, reflects at least partial contamination in the form of a thermal overprint caused by Late Permian igneous activity. An analysis of Devonian to Late Carboniferous polar wander suggests that the Tarim Block was attached to a subducting plate, and moved northward and rotated clockwise during the late Paleozoic. Comparison of the Devonian paleolatitudes of Siberian, Kazakhstan, Tarim and South China Blocks indicates that both the Tarim and South China Blocks were located in equatorial regions and were far south of the northern Angaran plate (Siberia and Kazakhstan).

  15. 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.

  16. 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.

  17. 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

  18. 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

    NASA Astrophysics Data System (ADS)

    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.; Šuhada, R.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-04-01

    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 Y500 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 Y500 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 these SZE mass-observable relations.

  19. Lifestyle physical activity behavior among South Asian Indian immigrants.

    PubMed

    Daniel, Manju; Wilbur, JoEllen; Marquez, David; Farran, Carol

    2013-12-01

    Little is known of the physical activity behavior of South Asian Indian immigrants (SAIs), though they have more than twice the risk for cardiovascular disease and diabetes than Whites. This was a cross-sectional descriptive face-to-face survey design, comparing between men and women in leisure time (LTPA), household (HPA), and occupational physical activity (OPA). Participants also wore a Lifecorder EX (NL2200) accelerometer for 7 days. Just over half (51.8 %) of the participants met the recommended PA guidelines (≥150 min moderate-intensity or ≥75 min vigorous-intensity) through LTPA. The average number of daily steps was 6,904.3, which is in the "low active" classification. Increasing lifestyle PA among SAIs is important; PA interventions appealing to gender and culture and with an aerobic component are needed.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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 Central

    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. PMID:23717539

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Antiviral activity of some South American medicinal plants.

    PubMed

    Abad, M J; Bermejo, P; Sanchez Palomino, S; Chiriboga, X; Carrasco, L

    1999-03-01

    Folk medicinal plants are potential sources of useful therapeutic compounds including some with antiviral activities. Extracts prepared from 10 South American medicinal plants (Baccharis trinervis, Baccharis teindalensis, Eupatorium articulatum, Eupatorium glutinosum, Tagetes pusilla, Neurolaena lobata, Conyza floribunda, Phytolacca bogotensis, Phytolacca rivinoides and Heisteria acuminata) were screened for in vitro antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. The most potent inhibition was observed with an aqueous extract of B. trinervis, which inhibited HSV-1 replication by 100% at 50-200 micrograms/mL, without showing cytotoxic effects. Good activities were also found with the ethanol extract of H. acuminata and the aqueous extract of E. articulatum, which exhibited antiviral effects against both DNA and RNA viruses (HSV-1 and VSV, respectively) at 125-250 micrograms/mL. The aqueous extracts of T. pusilla (100-250 micrograms/mL), B. teindalensis (50-125 micrograms/mL) and E. glutinosum (50-125 micrograms/mL) also inhibited the replication of VSV, but none of the extracts tested had any effect on poliovirus replication. PMID:10190189

  12. 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

  13. Enhanced Hydrogen Abundances Near Both Lunar Poles

    NASA Astrophysics Data System (ADS)

    Feldman, W. C.; Maurice, S.; Lawrence, D. J.; Getenay, I.; Elphic, R. C.; Barraclough, B. L.; Binder, A. B.

    1999-01-01

    spatial-scale enhancements in H abundances at both lunar poles. Maps were constructed of epithermal-neutrons corrected for elemental abundance variations by subtracting 7% of measured thermal-neutron counting rates. Although the spatial resolution of the LPNS at 30-km altitude is about 55 km FWHM, we binned all the data in 0.5 deg x 0.5 deg spatial pixels and then applied a 30-km FWHM Gaussian smoothing algorithm. Resultant polar maps of corrected epithermal counting rates are shown. Inspection reveals discrete depressions in counting rates that are superimposed on more generally distributed depressions that surround both poles. Comparison with the radar-measured polar topography shows that the areas of most depressed epithermal counts rates in the south overlie craters that have floors in permanent shade. Furthermore, these depressions are neither cylindrically symmetric about either pole nor do they minimize at the poles. Similar maps of fast neutrons (not shown here) reveal a single, statistically significant depression centered on the maximum depression of the epithermal neutrons at about 88 S, 20 E. Comparison between high-altitude and low-altitude epithermal maps reveals a larger depression at low altitudes in the south but the same magnitude of depression in the north. Hydrogen enhancements in the south must therefore have spatial scales comparable to the spatial resolution of LPNS, 55-km FWHM, yet consist of smaller clumps more uniformly distributed over the LPNS field of view in the north. A quantitative comparison between measured epithermal counting rates and numerical simulations using the measured polar topography yields the following: (1) H abundances within the permanently shaded craters near the south pole are equivalent to a water-ice mass fraction of 1.5 +/- 0.8%, (2) the enhanced H within these craters must not be buried beneath the surface by more than -log /square cm (5 cm at a density of 2g / cubic centimeter (3) the H abundance near both poles

  14. 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.

  15. 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.

  16. 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.

  17. Volcanic activity within the Vestmannaeyjar archipelago, south of Iceland

    NASA Astrophysics Data System (ADS)

    Hoskuldsson, A.; Kjartansson, E.; Hey, R.; Driscoll, N.

    2006-12-01

    Bathymetric research with multibeam techniques and chirp profiles reveal the volcanic topography of the Vestmannaeyjar archipelago just off the south coast of Iceland. Within the archipelago two historic eruptions have occurred, Surtsey 1963-1967 and the one of Heimaey in 1973. Five other eruptive vents have been identified as Holocene, Storhöfdi ~8000 BP, Sæfell ~6220 BP, Helgafell ~5900 BP and the islands Bjarnarey and Ellirey ~4500 BP. High precision multibeam data reveal several other eruptive vents and their geometry in the area. From the geometry it can be concluded that prehistoric volcanic activity in the area is dominated by phreatomagmatic activity. Tuff cones up to 2 km in diameter are observed in the area of Heimaey. Eustatic sea level changes can be inferred from these volcanic formations (Rofubodi vent) , indicating that a rise of up to 80 m has occurred since late Pleistocene times (~12000 years BP). Further our data show that sea level rise occurred in steps, as is manifested by the Alsey reef, now submerged and extending north of that island. The data also allow us to identify four major submarine lava flows in the area. One from the Eldfell eruption in 1973, one from the Helgafell eruption 5900 BP, one from the Storhofdi eruption ~8000BP and finally a lava flow that is extending from Faxasker towards the north west. The Vestmannaeyjar archipelago is forming a ridge extending NE to SW. The ridge is about 5 km wide and 30 km long. The ridge rises from a depth of some 72 m in the west but falls off to about 130 m in the east. The eastern border is more prominent than the western one. The Vestmannaeyjar ridge ends abruptly in the north, just prior to reaching the main outwash delta from the main island Iceland. A narrow trough has been formed in the area, Allinn, as the outwash delta propagates towards the ridge. Our data also allow for interpretation on relative timing of the volcanic formations. It has been shown that the LGM ice sheet extended to

  18. 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

  19. Gamma Oscillations in the Temporal Pole in Response to Eyes.

    PubMed

    Sato, Wataru; Kochiyama, Takanori; 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

  20. 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.

  1. Constraining the African pole of rotation

    NASA Astrophysics Data System (ADS)

    Asfaw, Laike M.

    1992-08-01

    In the absence of well defined transform faults in the East African rift system for constraining the plate kinematic reconstruction, the pole of relative motion for the African (Nubian) and Somalian plates has been determined from residual motion. If Africa and Somalia are to continue to drift apart along the East African rift system (which would then evolve into a series of ridges offset by transform faults) then incipient transform faults that may reflect the direction of relative motion should already be in place along the East African rift system. The incipient transforms along the East African rift system are characterized by shear zones, such as the Zambezi shear zone in the south and the Aswa and Hamer shear zones in the north. Some of these shear zones have been associated with recent strike-slip faulting in the NW-SE direction during periods of earthquakes. Provided that these, consistently NW-SE oriented, strike-slip movements in the shear zones give the direction of relative motion of the adjacent plates, then they can be used to constrain the position of the Africa-Somalia Euler pole. Due to the fact that identifying transform faults in the East African rift system is difficult and because the genesis of transform faults characterizing a plate boundary at an inception stage is not well known, the discussion here is limited to the northern segment of the East African rift system where shear zones are better characterized by the existing geophysical data. The characterizing features vary with latitude, indicating the complexity of the problem of the genesis of transform faults. I believe, however, that the relatively well defined intra-continental transform fault in the northern East African rift system, which is characterized by strike-slip faulting and earthquakes, constrains the pole of relative motion for the African and Somalian plates to a position near 1.5°S and 29.0°E.

  2. 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.

  3. 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.

  4. Calligraphic Poling for WGM Resonators

    NASA Technical Reports Server (NTRS)

    Mohageg, Makan; Strekalov, Dmitry; Savchenkov, Anatoliy; Matsko, Andrey; Ilchenko, Vladimir; Maleki, Lute

    2007-01-01

    By engineering the geometry of a nonlinear optical crystal, the effective efficiency of all nonlinear optical oscillations can be increased dramatically. Specifically, sphere and disk shaped crystal resonators have been used to demonstrate nonlinear optical oscillations at sub-milliwatt input power when cs light propagates in a Whispering Gallery Mode (WGM) of such a resonant cavity. in terms of both device production and experimentation in quantum optics, some nonlinear optical effects with naturally high efficiency can occult the desired nonlinear scattering process. the structure to the crystal resonator. In this paper, I will discuss a new method for generating poling structures in ferroelectric crystal resonators called calligraphic poling. The details of the poling apparatus, experimental results and speculation on future applications will be discussed.

  5. 78 FR 16247 - Foreign-Trade Zone 38-Spartanburg County, South Carolina; Authorization of Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-14

    ... Production Activity; ZF Transmissions Gray Court, LLC (Automatic Transmissions); Gray Court, South Carolina... Transmissions Gray Court, LLC, within FTZ 38--Site 20, in Gray Court, South Carolina. The notification was... Federal Register inviting public comment (77 FR 70992-70993, 11-28-2012). The FTZ Board has...

  6. 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.

  7. 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

  8. 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.

  9. 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. PMID:26503008

  10. Is the South Pacific helium-3 plume dynamically active?

    NASA Astrophysics Data System (ADS)

    Stommel, Henry

    1982-11-01

    It is suggested that the hydrothermal vents of the South Pacific Rise produce a beta-governed circulation at mid-depth, and that perhaps the associated plume of excess 3He (Lupton and Craig [1]) points westward because of the dynamics of this circulation rather than as a passive tracer.

  11. Student Activism and Student Exclusions in South Africa

    ERIC Educational Resources Information Center

    Koen, Charlton; Cele, Mlungisi; Libhaber, Arial

    2006-01-01

    On average, about 25 percent of students leave higher education (HE) institutions annually in South Africa because they are excluded on academic and financial grounds. To resist such putouts, student boycotts and protests are common despite the fact that student organizations were incorporated into decision-making processes at HE institutions…

  12. Poling force analysis in diagonal stride at different grades in cross country skiers.

    PubMed

    Pellegrini, B; Bortolan, L; Schena, F

    2011-08-01

    The aim of this study was to characterize the dynamic parameters of poling action during low to moderate uphill skiing in the diagonal stride technique. Twelve elite cross country skiers performed an incremental test using roller skis on a treadmill at 9 km/h at seven different grades, from 2° to 8°. The pole ground reaction force and the pole inclination were measured, and the propulsive force component and poling power were then calculated. The duration of the active poling phase remained unchanged, while the recovery time decreased with the increase in the slope. The ratio between propulsive and total poling forces (effectiveness) was approximately 60% and increased with the slope. Multiple regression estimated that approximately 80% of the variation of the poling power across slopes was explained by the increase of the poling force, the residual variation was explained by the decrease of the pole inclination, while a small contribution was provided by the increase of the poling relative to the cycle time. The higher power output required to ski at a steeper slope was partially supplied by a greater contribution of the power generated through the pole that arises not only by an increase of the force exerted but also by an increase of its effectiveness.

  13. 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.

  14. 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. PMID:26251183

  15. Mechanical behaviour of cross-country ski racing poles during double poling.

    PubMed

    Stöggl, Thomas; Karlöf, Lars

    2013-11-01

    The purpose of this study was to evaluate the behaviour of cross-country ski poles during double poling on a treadmill using three-dimensional kinematics. The results were compared with standard laboratory tests of the pole manufacturers. A total of 18 skiers were analysed at two speeds (85% and 95% of the maximal speed) at grades of 1.5% and 7%. Variables describing cycle characteristics, bending stiffness, bending behaviour, and trajectories of the pole markers were analysed. Triangular-shaped poles demonstrated the greatest stiffness and lowest variability in maximal bending. Softer poles demonstrated greater variability in bending behaviour and lost ground contact at high skiing speeds, which for some skiers resulted in failure to complete high-speed tests. Considerable variations in pole behaviour for similar poles between skiers were observed, which might be attributed to differences in technique, indicating that mechanical properties of the poles did not exclusively determine pole behaviour in the dynamic situation. The greatest magnitude of pole bending was in the middle part of the pole, which differed from the standard static pole analysis of the manufacturer. Increases in grade demonstrated the greatest effect on pole bending. Distinct differences from the pole manufacturers' laboratory measures were apparent, suggesting that basic pole testing might be adapted.

  16. Compositional mapping of Titan's North Pole with VIMS

    NASA Astrophysics Data System (ADS)

    MacKenzie, Shannon; Barnes, Jason W.; Sotin, Christophe; Soderblom, Jason M.; Le Mouélic, Stéphane; Rodriguez, Sebastien; Baines, Kevin; Buratti, Bonnie J.; Clark, Roger Nelson

    2016-10-01

    Titan's methane lakes and seas are almost exclusively found at the moon's north polar region. The factors that drive this distribution are not yet well understood. The poles are generally lower in elevation and a few Kelvin colder than the equator. But the south pole looks very different from the north with only one large lake and a few smaller bodies. To further illuminate what processes might make the north pole unique, we investigate the region's compositional variability and the connection to morphology by analyzing the entirety of the publically available data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) that cover the north pole. Because VIMS can only observe the surface in seven IR windows, we identify the relative composition ("spectral units") of the north polar terrain (90N - 45N) and compare our results to those of Birch et al. (Icarus, in revision), who defined geomorphological units in Cassini RADAR north polar data. We find interesting correlations and examples of distinct composition boundaries in VIMS that aren't reflected in the RADAR data. These results provide a more complete context for lake formation/retention hypotheses as well as identify features for further study.

  17. 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,…

  18. Photometric Properties of Enceladus' South Polar Terrain

    NASA Astrophysics Data System (ADS)

    Annex, Andrew; Verbiscer, A. J.; Helfenstein, P.

    2012-10-01

    Cassini images reveal in exquisite detail the complex and varied terrains within the geologically active south pole of Enceladus. The region is dominated by four parallel rifts or sulci, informally known as tiger stripes, from which plumes comprised primarily of water vapor erupt [1,2]. The rich data set of Cassini images acquired at high spatial resolution (< 0.5 km/pixel) and a variety of viewing and illumination geometries enables the quantitative analysis of surface scattering properties through disk-resolved photometry. Here we investigate the photometric properties of individual terrain units [3] through fits of the Hapke photometric model [4] to data acquired in the clear (CL1 CL2), UV3, GRN, and IR3 filters, centered at 0.61, 0.34, 0.57, and 0.93 μm, respectively. Terrain units include the tiger stripe smooth and platy plank formations, tiger stripe medial dorsum structures, relict tiger stripe structures, south pole funiscular (ropy) plains, south pole lateral fold-and-wedge formations, and the south pole reticulated plains. Despite the constant, ubiquitous infall of plume particles onto the surface, differences in scattering properties, texture, and albedo among terrain units can be discerned. Work supported by NASA's Cassini Data Analysis Program. [1] Porco et al. 2006 Science 311, 1393-1401. [2] Hansen et al. 2008 Nature 456, 477-479. [3] Spencer et al. 2009 in Saturn from Cassini-Huygens (M. K. Dougherty et al. Eds.) 683-724. [4] Hapke 2002 Icarus 157, 523-534.

  19. 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.

  20. 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…

  1. 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.

  2. Bacterial scaffold directs pole-specific centromere segregation

    PubMed Central

    Ptacin, Jerod L.; Gahlmann, Andreas; Bowman, Grant R.; Perez, Adam M.; von Diezmann, Alexander R. S.; Eckart, Michael R.; Moerner, W. E.; Shapiro, Lucy

    2014-01-01

    Bacteria use partitioning systems based on the ParA ATPase to actively mobilize and spatially organize molecular cargoes throughout the cytoplasm. The bacterium Caulobacter crescentus uses a ParA-based partitioning system to segregate newly replicated chromosomal centromeres to opposite cell poles. Here we demonstrate that the Caulobacter PopZ scaffold creates an organizing center at the cell pole that actively regulates polar centromere transport by the ParA partition system. As segregation proceeds, the ParB-bound centromere complex is moved by progressively disassembling ParA from a nucleoid-bound structure. Using superresolution microscopy, we show that released ParA is recruited directly to binding sites within a 3D ultrastructure composed of PopZ at the cell pole, whereas the ParB-centromere complex remains at the periphery of the PopZ structure. PopZ recruitment of ParA stimulates ParA to assemble on the nucleoid near the PopZ-proximal cell pole. We identify mutations in PopZ that allow scaffold assembly but specifically abrogate interactions with ParA and demonstrate that PopZ/ParA interactions are required for proper chromosome segregation in vivo. We propose that during segregation PopZ sequesters free ParA and induces target-proximal regeneration of ParA DNA binding activity to enforce processive and pole-directed centromere segregation, preventing segregation reversals. PopZ therefore functions as a polar hub complex at the cell pole to directly regulate the directionality and destination of transfer of the mitotic segregation machine. PMID:24778223

  3. 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.

  4. 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.

  5. Influence of Titan's climate-driven surface mass redistribution on spin pole precession

    NASA Astrophysics Data System (ADS)

    Bills, B. G.; Nimmo, F.; Aharonson, O.

    2010-12-01

    The spin pole of Titan is very close to a classic Cassini state, or tidally damped configuration. However, the observed obliquity is larger than would be expected for a body with the moments of inertia inferred from the observed gravity field. This suggests that some agent is acting to excite the motion of the spin pole, and frustrate its approach to a steady state, in which the spin pole and orbit pole of Titan would be co-planar with Saturn’s spin pole. A possible excitation mechanism is climate driven mass transport Titan’s orbit plane lies very nearly in the equator plane of Saturn, and the main influence on the seasonal distribution of insolation comes from slow changes in the orbit of Saturn. Saturn’s current obliquity is 26.7 degrees and its orbital eccentricity is 0.054. The distribution of liquid methane lakes on Titan is notably asymmetric, with many more in the north than in the south. It is also true that the current insolation pattern is rather asymmetric, with higher peak values in the south than in the north. If the changing orbit of Saturn drives the liquid hydrocarbons from south to north and back again on the 45 kyr apsidal precession period, this will also influence the moments of inertia of Titan and thereby excite modes of spin pole precessional motion. The hypothesis we seek to test is that this climate-driven mass transport is adequate to excite the observed departure of Titan’s spin pole orientation from a Cassini state. The proposed mechanism for additional driving of Titan’s spin pole precession differs from the mode of excitation of obliquity variations on Earth and Mars, where the dominant effect is variation in the orientation of the orbit plane. What we envision here is instead a parametric excitation of the spin pole motion. In a damped, forced spin pole state, the changes in polar moment will mainly change the obliquity (angular separation of spin and orbit poles), while dissipation will rotate the spin pole out of the

  6. Self-Tuning Power System Stabilizer Design Based on Pole-Assignment and Pole-Shifting Techniques

    NASA Astrophysics Data System (ADS)

    Ataei, M.; Hooshmand, R.; Parastegari, M.

    In order to improve dynamic stability of the power systems, the use of Power System Stabilizer (PSS) has been recently increased. For this purpose, there are varieties of methods for determining the controller coefficients of the system stabilizers. If these coefficients are tuned in each operational point by an adaptive mechanism, the robust performance of the system is improved. In this study, a new method for determining the coefficients of a self-tuning PSS with lead-lag controller based on pole-assignment and pole-shifting techniques is presented. In the design procedure, the required identification in self-tuning regulator is performed by using active and reactive power values. Moreover, the properties of the proposed methodology are compared with self-tuning PID stabilizer whose coefficients are determined by using pole assignment technique. Then, the advantages of the proposed stabilizer in which parameter adaptation is accomplished based on the proposed self-tuning method by combining the pole-assignment and pole-shifting techniques, is expressed with respect to other stabilizers. Finally, in order to show the effectiveness of the proposed methodology, some simulation results on a power system with definite parameters and different operational points are provided and compared by using ITAE performance index which denotes the integral of time multiplied by absolute error.

  7. 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

  8. Physical activity among South Asian women: a systematic, mixed-methods review

    PubMed Central

    2012-01-01

    Introduction The objective of this systematic mixed-methods review is to assess what is currently known about the levels of physical activity (PA) and sedentary time (ST) and to contextualize these behaviors among South Asian women with an immigrant background. Methods A systematic search of the literature was conducted using combinations of the key words PA, ST, South Asian, and immigrant. A mixed-methods approach was used to analyze and synthesize all evidence, both quantitative and qualitative. Twenty-six quantitative and twelve qualitative studies were identified as meeting the inclusion criteria. Results Studies quantifying PA and ST among South Asian women showed low levels of PA compared with South Asian men and with white European comparison populations. However making valid comparisons between studies was challenging due to a lack of standardized PA measurement. The majority of studies indicated that South Asian women did not meet recommended amounts of PA for health benefits. Few studies assessed ST. Themes emerging from qualitative studies included cultural and structural barriers to PA, faith and education as facilitators, and a lack of understanding of the recommended amounts of PA and its benefits among South Asian women. Conclusions Quantitative and qualitative evidence indicate that South Asian women do not perform the recommended level of PA for health benefits. Both types of studies suffer from limitations due to methods of data collection. More research should be dedicated to standardizing objective PA measurement and to understanding how to utilize the resources of the individuals and communities to increase PA levels and overall health of South Asian women. PMID:23256686

  9. 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.

  10. 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

  11. 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…

  12. Guidelines to Assist the Implementation of Differentiated Learning Activities in South African Secondary Schools

    ERIC Educational Resources Information Center

    de Jager, Thelma

    2013-01-01

    Despite previous research and recommendations in South Africa, secondary-school teachers still encounter economic, social and cultural challenges in implementing differentiated learning activities in the classroom. The diversity of learners with learning barriers inevitably leads to an increase in workload for the teachers. This article draws on…

  13. Evaluation of wild herbivore faeces from South Africa as a potential source of hydrolytically active microorganisms.

    PubMed

    Ndlela, Luyanda L; Schmidt, Stefan

    2016-01-01

    This study assessed faecal matter from three indigenous South African herbivores-zebra, giraffe and impala-as a potential source for hydrolytically active aerobic and facultatively anaerobic bacteria. Herbivore droppings were collected freshly in a local nature reserve in Pietermaritzburg, South Africa. Soil samples adjacent to faecal collection sites and faeces from a domestic herbivore, the Nguni cow, were included as controls. Hydrolase and dehydrogenase activity in faecal matter and soil samples were measured by the fluorescein diacetate and the triphenyltetrazolium chloride assay. Viable counts and counts for amylase, cellulase, esterase and protease producers were established using plate count agar and solid media containing cellulose, skim milk, starch and Tween 80. Zebra droppings produced the highest hydrolase and dehydrogenase activity. Faecal matter of the three indigenous herbivores generally produced higher hydrolytic activity than Nguni cow faeces and soil controls, thereby confirming that these materials are potential targets for hydrolytic enzyme mining. PMID:26900540

  14. 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.

  15. 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.

  16. 78 FR 52868 - Pole Attachment Complaint Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... regulations concerning pole attachments outlined in the DATES section. DATES: Effective August 27, 2013, the amendments to Sec. Sec. 1.1403(e) and 1.1404 published at 63 FR 12025, March 12, 1998,have been approved by... COMMISSION 47 CFR Part 1 Pole Attachment Complaint Procedures AGENCY: Federal Communications...

  17. 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.

  18. Pole position studied with artificial earth satellites.

    NASA Technical Reports Server (NTRS)

    Gaposchkin, E. M.

    1972-01-01

    Long-arc orbit computation of highest accuracy can provide pole positions. Optical Baker-Nunn and laser range observations of several satellites are combined. The accuracy of the pole position is comparable to that of the mean satellite-tracking station coordinates (plus or minus 5 m) when sufficient tracking data are available. Exploitation of the technique requires more accurate tracking data.

  19. 47 CFR 32.2411 - Poles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 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. 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...

  1. 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.

  2. Physical Activity in South Asians: An In-Depth Qualitative Study to Explore Motivations and Facilitators

    PubMed Central

    Jepson, Ruth; Harris, Fiona M.; Bowes, Alison; Robertson, Roma; Avan, Ghizala; Sheikh, Aziz

    2012-01-01

    Background People of South Asian backgrounds living in the UK have a five-fold increased risk of diabetes and a two-fold increased risk of heart disease when compared to the general population. Physical activity can reduce the risk of premature death from a range of conditions. The aim of the study was to explore the motivating and facilitating factors likely to increase physical activity for South Asian adults and their families, in order to develop successful interventions and services. Methodology/Principal Findings This was a qualitative study using focus groups and in-depth interviews. Participants were 59 purposively selected Bangladeshi-, Indian- and Pakistani-origin men and women with an additional 10 key informants. The setting was three urban areas of Scotland: Aberdeen, Glasgow and Edinburgh. We undertook a theoretically informed thematic analysis of data. Study participants described engaging in a range of physical activities, particularly football and the gym for men, and walking and swimming for women. The main motivators for taking part in physical activity were external motivators – i.e. undertaking physical activity as a means to an end, which included the opportunities that physical activity provided for social activity and enjoyment. The goals of weight reduction and improving mental and physical health and were also mentioned. Role models were seen as important to inspire and motivate people to undertake activities that they may otherwise lack confidence in. Few people undertook physical activity for its own sake (intrinsic motivation). Conclusions/Significance Attempts at promoting physical activity in people of South Asian origin need to take account of the social context of people's lives and the external motivators that encourage them to engage in physical activity. Undertaking group based physical activity is important and can be facilitated through religious, community, friendship or family networks. Role models may also prove

  3. Pole placement with constant gain output feedback

    NASA Technical Reports Server (NTRS)

    Sridhar, B.; Lindorff, D. P.

    1972-01-01

    Given a linear time invariant multivariable system with m inputs and p outputs, it was shown that p closed loop poles of the system can be preassigned arbitrarily using constant gain output feedback provided (A circumflex, B circumflex) is controllable. These data show that if (A circumflex, B circumflex, C circumflex) is controllable and observable, and Rank B circumflex = m, Rank C circumflex = p, then max (m,p) poles of the system can be assigned arbitarily using constant gain output feedback. Further, it is shown that in some cases more than max (m,p) poles can be arbitrarily assigned. A least square design technique is outlined to approximate the desired pole locations when it is not possible to place all the poles.

  4. 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.

  5. Alkaloid profiling and anticholinesterase activity of South American Lycopodiaceae species.

    PubMed

    Konrath, Eduardo Luis; Ortega, María Gabriela; de Loreto Bordignon, Sérgio; Apel, Miriam Anders; Henriques, Amélia Teresinha; Cabrera, José Luis

    2013-02-01

    The alkaloid extracts of four Huperzia and one Lycopodiella species, from Brazilian habitats, were tested for their in vitro anticholinesterase activities. IC(50) values showed a potent acetylcholinesterase inhibition for H. reflexa (0.11 ± 0.05 μg/mL), followed by H. quadrifariata (2.0 ± 0.3 μg/mL), H. acerosa (5.5 ± 0.9 μg/mL), H. heterocarpon (25.6 ± 2.7 μg/mL) and L. cernua (42.6 ± 1.5 μg/mL). A lower inhibition of butyrylcholinesterase was observed for all species with the exception of H. heterocarpon (8.3 ± 0.9 μg/mL), whose alkaloid extract presented a selectivity for pseudocholinesterase. Moreover, the chemical study of the bioactive extracts performed by GC-MS, revealed the presence of a number of Lycopodium alkaloids belonging to the lycopodane, flabellidane and cernuane groups. Surprisingly, the potent acetylcholinesterase inhibitors huperzines A and B were not detected in the extracts, suggesting that other alkaloids may be responsible for such an effect. PMID:22117191

  6. 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

  7. Should Physical Activity Recommendations for South Asian Adults Be Ethnicity-Specific? Evidence from a Cross-Sectional Study of South Asian and White European Men and Women

    PubMed Central

    Iliodromiti, Stamatina; Ghouri, Nazim; Celis-Morales, Carlos A.; Sattar, Naveed; Lumsden, Mary Ann; Gill, Jason M. R.

    2016-01-01

    International public health guidelines recommend that adults undertake at least 150 min.week−1 of moderate-intensity physical activity. However, the underpinning evidence has largely been obtained from studies of populations of white European descent. It is unclear whether these recommendations are appropriate for other ethnic groups, particularly South Asians, who have greater cardio-metabolic risk than white Europeans. The objective of our study was to determine the level of moderate-intensity physical activity required in South Asians adults to confer a similar cardio-metabolic risk profile to that observed in Europeans of similar age and body mass index (BMI) undertaking the currently recommended levels of 150 min.week−1. 148 South Asians and 163 white Europeans aged 18 to 70 years were recruited. Physical activity was measured objectively via vertical axis accelerations from hip-worn accelerometers. Factor analysis was used to summarize the measured risk biomarkers into a single underlying latent “factor” describing overall cardio-metabolic risk. Sex did not modify the association between physical activity and the cardio-metabolic risk factor, so data for both sexes were combined and models adjusted for age, sex, BMI and accelerometer wear time. We estimated that South Asian adults needed to undertake 232 (95% Confidence interval: 200 to 268) min.week−1 in order to obtain the same cardio-metabolic risk factor score as a white European undertaking 150 minutes of moderate-equivalent physical activity per week. The present findings suggest that South Asian men and women need to undertake ~230 minutes of moderate intensity physical activity per week. This equates to South Asians undertaking an extra 10–15 minutes of moderate intensity physical activity per day on top of existing recommendations. PMID:27529339

  8. Should Physical Activity Recommendations for South Asian Adults Be Ethnicity-Specific? Evidence from a Cross-Sectional Study of South Asian and White European Men and Women.

    PubMed

    Iliodromiti, Stamatina; Ghouri, Nazim; Celis-Morales, Carlos A; Sattar, Naveed; Lumsden, Mary Ann; Gill, Jason M R

    2016-01-01

    International public health guidelines recommend that adults undertake at least 150 min.week-1 of moderate-intensity physical activity. However, the underpinning evidence has largely been obtained from studies of populations of white European descent. It is unclear whether these recommendations are appropriate for other ethnic groups, particularly South Asians, who have greater cardio-metabolic risk than white Europeans. The objective of our study was to determine the level of moderate-intensity physical activity required in South Asians adults to confer a similar cardio-metabolic risk profile to that observed in Europeans of similar age and body mass index (BMI) undertaking the currently recommended levels of 150 min.week-1. 148 South Asians and 163 white Europeans aged 18 to 70 years were recruited. Physical activity was measured objectively via vertical axis accelerations from hip-worn accelerometers. Factor analysis was used to summarize the measured risk biomarkers into a single underlying latent "factor" describing overall cardio-metabolic risk. Sex did not modify the association between physical activity and the cardio-metabolic risk factor, so data for both sexes were combined and models adjusted for age, sex, BMI and accelerometer wear time. We estimated that South Asian adults needed to undertake 232 (95% Confidence interval: 200 to 268) min.week-1 in order to obtain the same cardio-metabolic risk factor score as a white European undertaking 150 minutes of moderate-equivalent physical activity per week. The present findings suggest that South Asian men and women need to undertake ~230 minutes of moderate intensity physical activity per week. This equates to South Asians undertaking an extra 10-15 minutes of moderate intensity physical activity per day on top of existing recommendations. PMID:27529339

  9. 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).

  10. Chandra Image Reveals Auroral X-rays at Poles of Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This Chandra image of Jupiter shows concentrations of aurora x-rays near the north and south poles due to a single `hot spot' that pulsates with a period of 45 minutes, similar to high-latitude radio pulsation previously detected by NASA's Galileo and Cassini spacecraft. Previous x-ray detections of Jupiter have been made with other x-ray telescopes, but did not reveal that the sources of the x-rays, energetic oxygen and sulfur ions, would be located so near the poles. Previous theories held that ions were mostly coming from Jupiter's moon, lo. Chandra's ability to pinpoint the source of the x-rays discards this theory since ions coming from near lo's orbit carnot reach the observed high latitudes. One possibility is that particles flowing out from the Sun are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from Jupiter's north pole to the south pole in an oscillating motion that could explain the pulsation.

  11. Feynman rules of higher-order poles in CHY construction

    NASA Astrophysics Data System (ADS)

    Huang, Rijun; Feng, Bo; Luo, Ming-xing; Zhu, Chuan-Jie

    2016-06-01

    In this paper, we generalize the integration rules for scattering equations to situations where higher-order poles are present. We describe the strategy to deduce the Feynman rules of higher-order poles from known analytic results of simple CHY-integrands, and propose the Feynman rules for single double pole and triple pole as well as duplex-double pole and triplex-double pole structures. We demonstrate the validation and strength of these rules by ample non-trivial examples.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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...

  17. 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…

  18. 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.

  19. Secondary metabolites from the South China Sea invertebrates: chemistry and biological activity.

    PubMed

    Zhang, Wen; Guo, Yue-Wei; Gu, Yucheng

    2006-01-01

    The increasing demand for new lead compounds in the pharmaceutical and agrochemical industries has driven scientists to search for new sources of bioactive natural products. Marine invertebrates are a rich source of novel, bioactive secondary metabolites and they have attracted a great deal of attention from scientists in the fields of chemistry, pharmacology, ecology, and molecular biology. During the past 25 years, many complex and structurally unique secondary metabolites have been isolated from the invertebrates inhabiting the South China Sea. These metabolites are responsible for various bioactivities such as anti-tumor, anti-inflammation and antioxidant activities, and/or they act on the cardiovascular system. This review will focus on the marine natural product chemistry of invertebrates from the South China Sea, aiming to give the reader a brief view of the compounds isolated from these invertebrates, as well as their biological activities. The article covers the literature published during the period from the beginning of 1980 to the end of 2005, with 340 citations and 811 compounds from invertebrates from the South China Sea, including sponges, coelenterates, molluscs and echinoderms.

  20. 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.

  1. 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.

  2. Observations of ionospheric flux ropes above South Pole

    NASA Technical Reports Server (NTRS)

    Lin, Z. M.; Benbrook, J. R.; Bering, E. A.; Byrne, G. J.; Friis-Christensen, E.; Liang, D.; Liao, B.; Theall, J.

    1990-01-01

    Numerical techniques have been used to investigate two different models of the current flow in ionospheric flux ropes, giving attention to the problem of mapping the electric field from the ionosphere down to balloon altitudes and to the isolated event that occurred at about 1625 UT on January 3, 1986. Also examined are Greenland magnetometer chain and Iqaluit magnetometer data, which imply that the isolated event was localized in longitude as well as 'global', in the sense that it occurred at conjugate points. IMP 8 solar wind plasma and IMF data indicate that the even occurred just as a strong southward turning of the IMF passed the earth.

  3. 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.

  4. 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.

  5. Ulysses above the sun's south pole: an introduction.

    PubMed

    Smith, E J; Marsden, R G; Page, D E

    1995-05-19

    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.

  6. Extreme Environments: The Ghetto and the South Pole.

    ERIC Educational Resources Information Center

    Pierce, Chester M.

    Extreme environments, such as polar regions or space crafts, provide an analogue for speculations concerning the needs of, educational provisions for, and environmental impacts on ghetto youth in kindergarten through the third grade. This discussion first centers on the common qualities of an extreme environment (whether exotic or mundane): forced…

  7. 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.

  8. 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

  9. Functions of maternal mRNA as a cytoplasmic factor responsible for pole cell formation in Drosophila embryos

    SciTech Connect

    Togashi, S.; Kobayashi, S.; Okada, M.

    1986-12-01

    Injection of mRNA extracted from Drosophila cleavage embryos or mature oocytes restored pole cell-forming ability to embryos that had been deprived of this ability by uv irradiation. However, mRNA extracted from blastoderms did not show the restoration activity. Pole cells thus formed in uv-irradiated embryos bear similarities to normal pole cells both in their morphology and their ability to migrate to the gonadal rudiments. But this mRNA does not appear to be capable of rescuing uv-induced sterility, or inducing pole cells in the anterior polar region.

  10. Physical Activity and Sedentary Behavior in an Ethnically Diverse Group of South African School Children

    PubMed Central

    McVeigh, Joanne; Meiring, Rebecca

    2014-01-01

    Few studies have examined physical activity and inactivity levels in an urban South African setting across 12 years of formal schooling. This information is important for implementing strategies to curb increasing trends of physical inactivity and related negative consequences, especially in low to middle income countries facing multiple challenges on overburdened health care systems. We examined levels of physical activity and sedentary behaviour cross-sectionally over 12 school years from childhood to adolescence in Black, White and Indian boys and girls. The aim of our study was to describe gender and race related patterns of physical and sedentary activity levels in a sample of South African children and to determine whether there were associations between these variables and body mass status. Physical activity questionnaires, previously validated in a South African setting, were used to gather information about activity and sedentary behaviours among 767 Black, White and Indian children (5-18 years of age) across the 12 grades of formal schooling. Body mass and height were also measured. Time spent in moderate-vigorous physical activity declined over the school years for all race groups and was consistently lower for girls than boys (p = 0.03), while time spent in sedentary activity increased with increasing grade (p < 0.001) for boys and girls and across all race groups. Associations between physical activity and body mass were observed for White children (r = -0.22, p < 0.001), but not for Black and Indian children (p > 0.05) whereas time spent in sedentary activities was significantly and positively correlated with body mass across all race groups: Indian (r = 0.25, p < 0.001), White (r = 0.22, p < 0.001) and Black (r = 0.37, p = 0.001). The strength of the associations was similar for boys and girls. Black and Indian children were less physically active than their white peers (p < 0.05), and Black children also spent more time in sedentary activity (p < 0

  11. 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.

  12. Cosmic ray density gradient and its dependence on the north-south asymmetry in solar activity

    NASA Technical Reports Server (NTRS)

    BADRUDDIN; Yadav, R. S.; Yadav, N. R.

    1985-01-01

    An analysis of the diurnal anisotropy on geomagnetically quiet days was performed using neutron monitor data at Deep River, Leeds, Rome and Tokyo, well distributed in latitude and longitude for the period 1964-79. The days were separated according to the polarity of IMF on that day. A significant difference in the amplitude and phase was found on towards and away polarity days, particularly during the years of high solar activity and large north-south asymmetry. These results (particularly time of maximum) on geomagnetically quiet days show some better relationship to the expected results as compared to the results obtained using all the days in a year.

  13. 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

  14. REGULARITY OF THE NORTH–SOUTH ASYMMETRY OF SOLAR ACTIVITY: REVISITED

    SciTech Connect

    Zhang, J.; Feng, W.

    2015-09-15

    Extended time series of Solar Activity Indices (ESAI) extended the Greenwich series of sunspot area from the year 1874 back to 1821. The ESAI's yearly sunspot area in the northern and southern hemispheres from 1821 to 2013 is utilized to investigate characteristics of the north–south hemispherical asymmetry of sunspot activity. Periodical behavior of about 12 solar cycles is also confirmed from the ESAI data set to exist in dominant hemispheres, linear regression lines of yearly asymmetry values, and cumulative counts of yearly sunspot areas in the hemispheres for solar cycles. The period is also inferred to appear in both the cumulative difference in the yearly sunspot areas in the hemispheres over the entire time interval and in its statistical Student's t-test. The hemispherical bias of sunspot activity should be regarded as an impossible stochastic phenomenon over a long time period.

  15. 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.

  16. Ra-226 and Pb-210/Ra-226 Activity Ratio in the Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Chi-Ju, L.; Yu-Chia, C.; Tsung-En, W.

    2004-05-01

    The surface water distributions and vertical profiles of Ra-226 in the northern South China Sea (SCS) have been measured. Surface water Ra-226 varies between 10 and 16 dpm/100 kg with higher values at stations adjacent to the landmass. Each Ra-226 profile shows an increase from the surface toward the bottom. Above 1000m depth Ra-226 is systematically about 5 dpm/100kg higher in the northern South China Sea than in the western North Pacific. This difference may be attributed to a strong Ra-226 source from the shelf and slope area of the SCS. Below this depth Ra-226 displays large variation within some of the profiles with lower limits being comparable to the activities of the western North Pacific but higher limits being systematically about 5 dpm/100kg higher. These high Ra-226 activities may reflect effects of the longer isolation time for the deep water in the SCS basin and strong Ra input from the underlying sediments. The Pb-210/Ra-226 activity ratio ranges between 1.4 and 2.7 in the surface water with higher activity ratio at the station closer to the Luzon Strait. The Pb-210 in excess over Ra-226 in the surface water due to atmospheric input may penetrate to a depth of about 200 to 500m. Below this depth, Pb-210/Ra-226 activity ratio ranges between 0.5 and 0.7 because Pb-210 is scavenged by settling particulates. Box model calculations within a mixed layer of 50m in the area yield a mean residence time of about 1 yr for Pb-210 if an atmospheric Pb-210 flux of 1 dpm/cm2/y is adopted. The activity ratio of about 0.5 to 0.7 in the deep water corresponds to a Pb-210 mean residence time of about 30 to 70 yrs with respect to particulate scavenging.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. Past and present active sedimentation and tectonics in the South Alboran Sea

    NASA Astrophysics Data System (ADS)

    d'Acremont, E.; Gorini, C.; El Abbassi, M.; Farran, M.; Leroy, S.; Mercier de Lépinay, B.; Migeon, S.; Poort, J.; Ammar, A.; Smit, J.; Do Couto, D.; Ercilla, G.; Alonso, B.

    2012-04-01

    Since the Tortonian, the thinned continental crust and the overlying sedimentary cover of the Alboran Sea are submitted to tectonic inversion due to the convergence between Eurasia and Africa. The past and present deformation is significant along the Moroccan margin where the MARLBORO-1 cruise in 2011, acquired 1100 km of mid-resolution seismic reflection along 20 profiles perpendicular and parallel to the margin, off Al Hoceima, to latitude 36°N. The study area located on the Xauen/Tofino banks and the South Alboran ridge off Morocco, shows signs of both past and present strong tectonic deformation, mass-movement deposits (mostly slides and mass flow deposits), and contourites. The lateral and longitudinal evolution of contourites and mass movement deposits and the geometric relationships between those deposits and active tectonic structures have been studied. In the distal margin, contourites and gravitational instabilities are the depositional systems that best record the tectonic signal of the area since at least the Messinian. On the two flanks of the Xauen/Tofino and South Alboran ridge, the sedimentary register affected by growth-faults is mainly composed of contourites. Internal strata pattern, spatial and temporal distribution of thickness and depocenters, and discontinuities help to infer sedimentary processes and their interaction with tectonics. In the southern Alboran Sea where the bathymetry shows abrupt slopes, the recurrent seismic activity seems to be the main factor triggering mass wasting as witnessed by the Mass transport complexes (MTCs). Recent MTCs originate from escarpments on the edge of the contourites. However, in most cases the seismic reflection data show the depositional bodies of numerous slides linked to the activity of growth-faults and thrusts observed on the Xauen and Tofino Bank's north flanks. Tectonic inversion is recorded since the late Miocene with an acceleration of the uplift and compressional activity evidenced during

  3. 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

  4. The effects of walking poles on shoulder function in breast cancer survivors.

    PubMed

    Sprod, Lisa K; Drum, Scott N; Bentz, Ann T; Carter, Susan D; Schneider, Carole M

    2005-12-01

    Breast cancer treatment often results in impaired shoulder function, in particular, decrements in muscular endurance and range of motion, which may lead to decreased quality of life. The purpose of this investigation was to determine the effects of walking pole use on shoulder function in female breast cancer survivors. Participants had previously been treated with 1 or a combination of the following: mastectomy, breast conservation therapy, axillary lymph node dissection, chemotherapy, or radiation. Participants were randomly placed in experimental (n = 6) and control (n = 6) groups and met with a cancer exercise specialist 2 times each week for 8 weeks. The experimental group used walking poles during the 20-minute aerobic portion of their workout, whereas the control group did not use walking poles but performed 20 minutes of aerobic exercise per workout session. Both groups participated in similar resistance training programs. Testing was done pre- and postexercise intervention to determine upper body muscular endurance and active range of motion at the glenohumeral joint. Repeated-measures analysis of variance (ANOVA) revealed significant improvements in muscular endurance as measured by the bench press (P = .046) and lat pull down (P = .013) in the walking pole group. No within-group improvements were found in the group that did not use walking poles. The data suggest that using a walking pole exercise routine for 8 weeks significantly improved muscular endurance of the upper body, which would clearly be beneficial in helping breast cancer survivors perform activities of daily living and regain an independent lifestyle.

  5. Radical scavenging activity of selected medicinal plants from Limpopo province of South Africa.

    PubMed

    Chauke, A M; Shai, L J; Mphahlele, P M; Mogale, M A

    2012-01-01

    Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC₅₀ value of 30 µg/ml, closely matching the ascorbic acid with an IC₅₀ value of 25 µg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC₅₀ values, while extracts with low phenolic concentrations had high IC₅₀ values.

  6. 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

  7. Switched RC Multi-Pole Filter

    NASA Technical Reports Server (NTRS)

    Shuler, Robert L.

    1999-01-01

    The design and experimental verification of a switched RC multi-pole filter is presented. This highly compact circuit easily obtains sub-Hz, adjustable response utilizing reasonable sized on-chip components, and multiplexing the main resistor and op amp among filter stages. Design considerations for anti-aliasing, noise avoidance, and dynamic op amp compensation are presented.

  8. 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.

  9. 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)

  10. Multiplicative-cascade dynamics in pole balancing

    NASA Astrophysics Data System (ADS)

    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), 10.1103/PhysRevLett.89.158702] 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.

  11. Restoring Akt1 activity in outgrowth endothelial cells from South Asian men rescues vascular reparative potential.

    PubMed

    Cubbon, Richard M; Yuldasheva, Nadira Y; Viswambharan, Hema; Mercer, Ben N; Baliga, Vivek; Stephen, Sam L; Askham, Jonathan; Sukumar, Piruthivi; Skromna, Anna; Mughal, Romana S; Walker, Andrew M N; Bruns, Alexander; Bailey, Marc A; Galloway, Stacey; Imrie, Helen; Gage, Matthew C; Rakobowchuk, Mark; Li, Jing; Porter, Karen E; Ponnambalam, Sreenivasan; Wheatcroft, Stephen B; Beech, David J; Kearney, Mark T

    2014-10-01

    Recent data suggest reduced indices of vascular repair in South Asian men, a group at increased risk of cardiovascular events. Outgrowth endothelial cells (OEC) represent an attractive tool to study vascular repair in humans and may offer potential in cell-based repair therapies. We aimed to define and manipulate potential mechanisms of impaired vascular repair in South Asian (SA) men. In vitro and in vivo assays of vascular repair and angiogenesis were performed using OEC derived from SA men and matched European controls, prior defining potentially causal molecular mechanisms. SA OEC exhibited impaired colony formation, migration, and in vitro angiogenesis, associated with decreased expression of the proangiogenic molecules Akt1 and endothelial nitric oxide synthase (eNOS). Transfusion of European OEC into immunodeficient mice after wire-induced femoral artery injury augmented re-endothelialization, in contrast with SA OEC and vehicle; SA OEC also failed to promote angiogenesis after induction of hind limb ischemia. Expression of constitutively active Akt1 (E17KAkt), but not green fluorescent protein control, in SA OEC increased in vitro angiogenesis, which was abrogated by a NOS antagonist. Moreover, E17KAkt expressing SA OEC promoted re-endothelialization of wire-injured femoral arteries, and perfusion recovery of ischemic limbs, to a magnitude comparable with nonmanipulated European OEC. Silencing Akt1 in European OEC recapitulated the functional deficits noted in SA OEC. Reduced signaling via the Akt/eNOS axis is causally linked with impaired OEC-mediated vascular repair in South Asian men. These data prove the principle of rescuing marked reparative dysfunction in OEC derived from these men.

  12. Evidence for a major, tectonically active structure beneath the coastal plain of North and South Carolina

    SciTech Connect

    Marple, R.T.; Talwani, P. . Geology Dept.); Olson, O.

    1994-03-01

    Evaluation of Landsat imagery, aerial photography, potential field data, and topographic maps have revealed a linear, [approximately]400-km-long, NNE-trending zone in the coastal plain of North and South Carolina. This zone is composed of subtle topographic highs, aeromagnetic anomalies, and in some locations mapped and inferred faults. It is also associated with a zone of river anomalies (ZRA). Various data suggest that the ZRA may be associated with tectonic activity on a large right-lateral strike-slip fault system. The ZRA in the South Carolina coastal plain is defined by an [approximately]15-km-wide NNE-trending zone that crosses NW-SE-flowing rivers. Along this zone the rivers are characterized by river bends that are convex toward the NNE, incised channels, changes in river patterns, and convex-upward longitudinal profiles. In the coastal plain and eastern Slate Belt of North Carolina the ZRA (width yet to be determined) displays a slightly more northeasterly trend that is highlighted by linear aeromagnetic anomalies and right-lateral offsets of larger rivers crossing its trend. This feature is not traceable across the southern flank of the Cape Fear Arch and north of this area the ZRA's trend is offset [approximately]15 km toward the east (right step geometry) from that of the ZRA in South Carolina. Analyses of geologic and geophysical data further indicate that these two zones may be the result of ongoing tectonic uplift along a NNE-trending right-lateral strike-slip fault zone possibly associated with recent seismicity near Charleston.

  13. POLE-ZERO Cancellation in Structures: Repeated Roots

    NASA Astrophysics Data System (ADS)

    MOTTERSHEAD, J. E.; LI, T.; HE, J.

    2000-03-01

    The conditions for the creation of nodes of normal modes of vibration from the cancellation of poles and zeros are established when either the poles or the zeros (or both) appear as repeated eigenvalues. The analysis is illustrated by numerical examples including the case of a pole-zero cancellation at every co-ordinate at the same frequency which is shown to occur whenever there are repeated poles. If there are repeated poles and repeated zeros at the same frequency then the number of poles must be either one more, one less or equal to the number of zeros.

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Determination of Scotia - South America Relative Plate Motion and Crustal Deformation From GPS Geodesy

    NASA Astrophysics Data System (ADS)

    Smalley, R.; Bevis, M.; Kendrick, E.; Dalziel, I.; Taylor, F.; Laurã, E.; Barriga, R.; Casassa, G.; Olivero, E.; Piana, E.

    2001-12-01

    We use Global Positioning System measurements to determine relative plate movements and crustal deformation across the Scotia - South America plate boundary. Our results clearly show active crustal deformation along the South America - Scotia transform boundary in eastern Tierra del Fuego. The 160 km subaerial section of the plate boundary there, to first order, is concentrated on a narrow region best modeled by a simple east-west oriented strike-slip plate boundary. We find no evidence for a significant component of active transpression or transtension between the South America and Scotia plates along this section of the plate boundary. The GPS data also enable us to estimate the first South America -Scotia pole that does not depend on closure for determination of the rotation rate.

  19. 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.

  20. 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...

  1. Universe Awareness Among Young Poles

    NASA Astrophysics Data System (ADS)

    Ratajczak, Milena

    Astronomy, the most accessible of all the sciences, grabs and holds the attention not only of the elders, but also that of the youngsters from all over the world. Sharing the same sky provides the unique opportunity to use it as a tool to inspire children, to encourage them to develop an interest in science and technology, but also to increase awareness of global citizenship and tolerance. We shall present a wide spectrum of educational activities dedicated to young children, especially those from less privileged backgrounds, carried out under the Universe Awareness (UNAWE) project in Poland. We will also introduce the way we follow to support teachers and educators in discovering our wonderful cosmos.

  2. Qualitative study exploring healthy eating practices and physical activity among adolescent girls in rural South Africa

    PubMed Central

    2014-01-01

    Background Dietary behaviours and physical activity are modifiable risk factors to address increasing levels of obesity among children and adolescents, and consequently to reduce later cardiovascular and metabolic disease. This paper explores perceptions, attitudes, barriers, and facilitators related to healthy eating and physical activity among adolescent girls in rural South Africa. Methods A qualitative study was conducted in the rural Agincourt subdistrict, covered by a health and sociodemographic surveillance system, in Mpumalanga province, South Africa. Semistructured “duo-interviews” were carried out with 11 pairs of adolescent female friends aged 16 to 19 years. Thematic content analysis was used. Results The majority of participants considered locally grown and traditional foods, especially fruits and vegetables, to be healthy. Their consumption was limited by availability, and these foods were often sourced from family or neighbourhood gardens. Female caregivers and school meal programmes facilitated healthy eating practices. Most participants believed in the importance of breakfast, even though for the majority, limited food within the household was a barrier to eating breakfast before going to school. The majority cited limited accessibility as a major barrier to healthy eating, and noted the increasing intake of “convenient and less healthy foods”. Girls were aware of the benefits of physical activity and engaged in various physical activities within the home, community, and schools, including household chores, walking long distances to school, traditional dancing, and extramural activities such as netball and soccer. Conclusions The findings show widespread knowledge about healthy eating and the benefits of consuming locally grown and traditional food items in a population that is undergoing nutrition transition. Limited access and food availability are strong barriers to healthy eating practices. School meal programmes are an important

  3. POLE proofreading mutations elicit an anti-tumor immune response in endometrial cancer

    PubMed Central

    van Gool, Inge C; Eggink, Florine A; Freeman-Mills, Luke; Stelloo, Ellen; Marchi, Emanuele; de Bruyn, Marco; Palles, Claire; Nout, Remi A; de Kroon, Cor D; Osse, Elisabeth M; Klenerman, Paul; Creutzberg, Carien L; Tomlinson, Ian PM; Smit, Vincent THBM; Nijman, Hans W

    2015-01-01

    Purpose Recent studies have shown that 7-12% of endometrial cancers (ECs) are ultramutated due to somatic mutation in the proofreading exonuclease domain of the DNA replicase POLE. Interestingly, these tumors have an excellent prognosis. In view of the emerging data linking mutation burden, immune response and clinical outcome in cancer, we investigated whether POLE-mutant ECs showed evidence of increased immunogenicity. Experimental design We examined immune infiltration and activation according to tumor POLE proofreading mutation in a molecularly defined EC cohort including 47 POLE-mutant tumors. We sought to confirm our results by analysis of RNAseq data from the TCGA EC series and used the same series to examine whether differences in immune infiltration could be explained by an enrichment of immunogenic neoepitopes in POLE-mutant ECs. Results Compared to other ECs, POLE-mutants displayed an enhanced cytotoxic T cell response, evidenced by increased numbers of CD8+ tumor infiltrating lymphocytes and CD8A expression, enrichment for a tumor-infiltrating T cell gene signature, and strong upregulation of the T cell cytotoxic differentiation and effector markers T-bet, Eomes, IFNG, PRF and granzyme B. This was accompanied by upregulation of T cell exhaustion markers, consistent with chronic antigen exposure. In-silico analysis confirmed that POLE-mutant cancers are predicted to display more antigenic neo-epitopes than other ECs, providing a potential explanation for our findings. Conclusions Ultramutated POLE proofreading-mutant ECs are characterized by a robust intratumoral T cell response, which correlates with, and may be caused by an enrichment of antigenic neo-peptides. Our study provides a plausible mechanism for the excellent prognosis of these cancers. PMID:25878334

  4. 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.

  5. 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.

  6. Triglyceride concentration and waist circumference influence alcohol-related plasminogen activator inhibitor-1 activity increase in black South Africans.

    PubMed

    Pieters, Marlien; de Lange, Zelda; Hoekstra, Tiny; Ellis, Suria M; Kruger, Annamarie

    2010-12-01

    We investigated the association between alcohol consumption and plasminogen activator inhibitor-1 activity (PAI-1act) and fibrinogen concentration in a black South African population presenting with lower PAI-1act and higher fibrinogen than what is typically observed in white populations. We, furthermore, wanted to investigate the effect of urbanization, sex, central obesity, increased triglycerides, 4G/5G polymorphism (PAI-1 only) and BMI on the association of alcohol with PAI-1act and fibrinogen. Data from 2010 apparently healthy, randomly collected black South African volunteers from the Prospective Urban and Rural Epidemiological (PURE) study were cross-sectionally analyzed. Alcohol consumption was recorded using quantitative food frequency questionnaires and fasting blood samples were collected for biochemical analysis including PAI-1act and fibrinogen. Heavy alcohol consumption is associated with significantly increased PAI-1act, in the total population as well as in the women separately, and tended to be so in men. This alcohol-related PAI-1act increase was observed in volunteers with increased triglycerides and central obesity but not in volunteers with normal levels and waist circumference. Urbanization, the 4G/5G polymorphism and BMI did not affect the association of alcohol with PAI-1act. Moderate alcohol consumption is associated with decreased fibrinogen concentration. Sex and level of urbanization did not affect the association of alcohol with fibrinogen. Fibrinogen decreased in normal and overweight volunteers but not in obese and centrally obese volunteers following moderate alcohol consumption. Triglyceride levels and waist circumference influence alcohol-related PAI-1act increase potentially through modulating adipocyte and triglyceride-induced PAI-1 production. Obesity prevented alcohol-related fibrinogen decrease possibly by counteracting the anti-inflammatory effect of moderate alcohol consumption.

  7. Variation in antioxidant activities of polysaccharides from Fructus Jujubae in South Xinjiang area.

    PubMed

    Cui, Guoting; Zhang, Wuxia; Zhang, Amin; Mu, Haibo; Bai, Hongjin; Duan, Jinyou; Wu, Cuiyun

    2013-06-01

    The Fructus Jujubae has been widely used as favorable food and folk medicine in China and Russia. In this study, we compared the carbohydrate constituents and antioxidative effects of Fructus Jujubae polysaccharides from five different production areas in South Xinjiang. Results demonstrated that the average annual temperature (r=0.590) and frost-free period (r=0.779) were well correlated to the uronic acid content, while the neutral carbohydrate content showed negative correlation with precipitation amount (r=-0.567). Antioxidative tests indicated that Fructus Jujubae polysaccharides could scavenge chemicals-induced reactive oxygen species in a dose-dependent manner. In addition, these polysaccharides could rescue H₂O₂-induced HUVEC death. The antioxidative activity of polysaccharides from the Fructus Jujubae might contribute to their diverse medicinal and nutritional values. PMID:23507009

  8. Remarks on the origin of Castillejo-Dalitz-Dyson poles

    SciTech Connect

    Krivoruchenko, M. I.

    2010-07-15

    Castillejo-Dalitz-Dyson (CDD) poles are known to be connected with bound states and resonances. We discuss a new type of CDD pole associated with primitives i.e., poles of the P matrix that correspond to zeros of the D function on the unitary cut. The Low scattering equation is generalized for amplitudes with primitives. The relationship between the CDD poles and the primitives is illustrated by a description of the S-wave nucleon-nucleon phase shifts.

  9. 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.

  10. Pole and global shape of 25143 Itokawa.

    PubMed

    Demura, Hirohide; Kobayashi, Shingo; Nemoto, Etsuko; Matsumoto, Naoya; Furuya, Motohiro; Yukishita, Akira; Muranaka, Noboru; Morita, Hideo; Shirakawa, Ken; Maruya, Makoto; Ohyama, Hiroshi; Uo, Masashi; Kubota, Takashi; Hashimoto, Tatsuaki; Kawaguchi, Jun'ichiro; Fujiwara, Akira; Saito, Jun; Sasaki, Sho; Miyamoto, Hideaki; Hirata, Naru

    2006-06-01

    The locations of the pole and rotation axis of asteroid 25143 Itokawa were derived from Asteroid Multiband Imaging Camera data on the Hayabusa spacecraft. The retrograde pole orientation had a right ascension of 90.53 degrees and a declination of -66.30 degrees (52000 equinox) or equivalently 128.5 degrees and -89.66 degrees in ecliptic coordinates with a 3.9 degrees margin of error. The surface area is 0.393 square kilometers, the volume is 0.018378 cubic kilometers with a 5% margin of error, and the three axis lengths are 535 meters by 294 meters by 209 meters. The global Itokawa revealed a boomerang-shaped appearance composed of two distinct parts with partly faceted regions and a constricted ring structure. PMID:16741112

  11. 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.

  12. Photocouplings at the pole from pion photoproduction

    DOE PAGES

    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 termsmore » of poles and residues. In particular, the photocouplings at the pole can be extracted and are presented.« less

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. Child Health Insurance Coverage and Household Activity toward Child Development in Four South American Countries

    PubMed Central

    Wehby, George

    2013-01-01

    Objectives We evaluate the association between child health insurance coverage and household activities that enhance child development. Methods 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. Results 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. Conclusions 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. PMID:23807717

  18. Imidazole Alkaloids from the South China Sea Sponge Pericharax heteroraphis and Their Cytotoxic and Antiviral Activities.

    PubMed

    Gong, Kai-Kai; Tang, Xu-Li; Liu, Yi-Sheng; Li, Ping-Lin; Li, Guo-Qiang

    2016-01-01

    Marine sponges continue to serve as a rich source of alkaloids possessing interesting biological activities and often exhibiting unique structural frameworks. In the current study, chemical investigation on the marine sponge Pericharax heteroraphis collected from the South China Sea yielded one new imidazole alkaloid named naamidine J (1) along with four known ones (2-5). Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed a central 2-aminoimidazole ring, substituted by one or two functionalized benzyl groups in some combination of the C4 and C5 positions. The cytotoxicities against selected HL-60, HeLa, A549 and K562 tumor cell lines and anti-H1N1 (Influenza a virus (IAV)) activity for the isolates were evaluated. Compounds 1 and 2 exhibited cytotoxicities against the K562 cell line with IC50 values of 11.3 and 9.4 μM, respectively. Compound 5 exhibited weak anti-H1N1 (influenza a virus, IAV) activity with an inhibition ratio of 33%.

  19. 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.

  20. Pole EXpansion and Selected Inversion (PEXSI)

    2014-03-01

    The Pole EXpansion and Selected Inversion method (PEXSI) is a fast method for evaluating certain selected elements of a matrix function. PEXSI is highly scalable on distributed memory parallel machines. For sparse matrices, the PEXSI method can be more efficient than the widely used diagonalization method for evaluating matrix functions, especially when a relatively large number of eigenpairs are needed to be computed in the diagonalization methond

  1. 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

  2. Regularized estimation of Euler pole parameters

    NASA Astrophysics Data System (ADS)

    Aktuğ, Bahadir; Yildirim, Ömer

    2013-07-01

    Euler vectors provide a unified framework to quantify the relative or absolute motions of tectonic plates through various geodetic and geophysical observations. With the advent of space geodesy, Euler parameters of several relatively small plates have been determined through the velocities derived from the space geodesy observations. However, the available data are usually insufficient in number and quality to estimate both the Euler vector components and the Euler pole parameters reliably. Since Euler vectors are defined globally in an Earth-centered Cartesian frame, estimation with the limited geographic coverage of the local/regional geodetic networks usually results in highly correlated vector components. In the case of estimating the Euler pole parameters directly, the situation is even worse, and the position of the Euler pole is nearly collinear with the magnitude of the rotation rate. In this study, a new method, which consists of an analytical derivation of the covariance matrix of the Euler vector in an ideal network configuration, is introduced and a regularized estimation method specifically tailored for estimating the Euler vector is presented. The results show that the proposed method outperforms the least squares estimation in terms of the mean squared error.

  3. Evolution of sunspot activity and inversion of the Sun's polar magnetic field in the current cycle

    NASA Astrophysics Data System (ADS)

    Mordvinov, A. V.; Grigoryev, V. M.; Erofeev, D. V.

    2015-06-01

    A spatiotemporal analysis of the Sun's magnetic field was carried out to study the polar-field inversion in the current cycle in relation to sunspot activity. The causal relationship between these phenomena was demonstrated in a time-latitude aspect. After decay of long-lived activity complexes their magnetic fields were redistributed into the surrounding photosphere and formed unipolar magnetic regions which were transported to high latitudes. Zones of intense sunspot activity during 2011/2012 produced unipolar magnetic regions of the following polarities, whose poleward drift led to the inversion of the Sun's polar fields at the North and South Poles. At the North Pole the polar field reversal was completed by May 2013. It was demonstrated that mixed magnetic polarities near the North Pole resulted from violations of Joy's law at lower latitudes. Later sunspot activity in the southern hemisphere has led to a delay in magnetic polarity reversal at the South Pole. Thus, the north-south asymmetry of sunspot activity resulted in asynchronous polar field reversal in the current cycle.

  4. Paleomagnetism of the Ishikoshi Andesite: a Middle Miocene paleomagnetic pole for northeastern Japan and tectonic implications

    NASA Astrophysics Data System (ADS)

    Hoshi, Hiroyuki; Teranishi, Yuki

    2007-07-01

    To determine a Middle Miocene paleomagnetic pole for northeastern Japan and discuss its tectonic implications, we obtained new paleomagnetic results from Middle Miocene (about 14 Ma) dacite and andesite flows of the Ishikoshi Andesite. Characteristic remanent magnetizations were isolated from 12 lava sites by means of detailed alternating field and thermal demagnetizations. Analysis of demagnetization results and rock magnetic experiments indicated that magnetite or Ti-poor titanomagnetite is the main magnetic carrier. We obtained a formation mean direction ( D = 9.2°, I = 65.9°, α95 = 7.3°, k = 40.5, N = 11) and compared it with published paleomagnetic results from other areas of northeastern Japan to discuss tectonic rotation. This comparison provided a mean paleomagnetic pole (85.9°N, 236.6°E, A 95 = 6.2°, K = 115.9, N = 6) that we consider represents the Middle Miocene pole for northeastern Japan. It is statistically indistinguishable from coeval poles for southwestern Japan, South Korea, and northern China, and we therefore conclude that northeastern Japan as a whole has not been subjected to tectonic rotation since the Middle Miocene. A reassessment of geologic and paleomagnetic data suggests that a previous model of the Late Miocene or later counterclockwise rotation of northeastern Japan is based on tilt-uncorrected paleomagnetic directions from tilted rock units.

  5. 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

  6. 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

  7. Out-of-School Activities and Achievement among Middle School Students in the U.S. and South Korea

    ERIC Educational Resources Information Center

    Won, Seoung Joun; Han, Seunghee

    2010-01-01

    This study examined the relationships between American and South Korean students' achievement and their time spent in out-of-school activities. Analyzing nationally representative data for 8,912 U.S. and 5,309 Korean middle school students from the Trends in International Mathematics and Science Study (TIMSS) 2003, we found differences in…

  8. 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…

  9. 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…

  10. 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 interviews with…

  11. 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 result…

  12. Active tectonics west of New Zealand's Alpine Fault: South Westland Fault Zone activity shows Australian Plate instability

    NASA Astrophysics Data System (ADS)

    De Pascale, Gregory P.; Chandler-Yates, Nicholas; Dela Pena, Federico; Wilson, Pam; May, Elijah; Twiss, Amber; Cheng, Che

    2016-04-01

    The 300 km long South Westland Fault Zone (SWFZ) is within the footwall of the Central Alpine Fault (<20 km away) and has 3500 m of dip-slip displacement, but it has been unknown if the fault is active. Here the first evidence for SWFZ thrust faulting in the "stable" Australian Plate is shown with cumulative dip-slip displacements up to 5.9 m (with 3 m throw) on Pleistocene and Holocene sediments and gentle hanging wall anticlinal folding. Cone penetration test (CPT) stratigraphy shows repeated sequences within the fault scarp (consistent with thrusting). Optically stimulated luminescence (OSL) dating constrains the most recent rupture post-12.1 ± 1.7 ka with evidence for three to four events during earthquakes of at least Mw 6.8. This study shows significant deformation is accommodated on poorly characterized Australian Plate structures northwest of the Alpine Fault and demonstrates that major active and seismogenic structures remain uncharacterized in densely forested regions on Earth.

  13. Life cycle economics of wood pole utility structures

    SciTech Connect

    Stewart, A.H.; Goodman, J.R. )

    1990-04-01

    Due to the major expansions of the nation's electrification infrastructure, which closely followed World War II, many existing utility lines are now more than thirty years old and are approaching a critical stage in their useful life. This paper discusses the economics of life cycle management of wood pole utility structures. Recently developed technology which enables innovative management techniques for wood poles are discussed. Results of full-scale tests of in-service wood poles are reviewed which provide vital information on rates of pole degradation. These data enable realistic cost assessments for frequency of pole replacement and/or repair. Finally, methods for calculating life cycle costs are presented.

  14. Evidence of explosive seafloor volcanic activity from the Walvis Ridge, South Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Haxel, J. H.; Dziak, R. P.

    2005-07-01

    Hydrophones moored in the North Atlantic Ocean recorded a sequence of explosive, volcano-acoustic signals originated at the Walvis Ridge in the South Atlantic Ocean. 365 explosive signals were detected from the Walvis Ridge beginning 24 November 2001 continuing through March 2002. The largest swarm began on 19 December at 2329 GMT, and lasted 1.25 hrs producing 32 locatable events. Swarm locations are centered on the northern flank of an unnamed seamount (-32.96°S -5.22°W), northwest of Wüst Seamount. These signals are interpreted as volcanogenic explosions due to similarities with acoustic signals recorded from a confirmed submarine eruption in the Caribbean in 2001 (Kick'em Jenny volcano). The observations presented suggest recent magmatic activity along the Walvis Ridge may be unrelated to the Tristan da Cunha mantle plume. Furthermore, these events lend support for an extensional fracture-zone model resulting in the recurrence of volcanic activity along older segments of large-scale sea floor lineaments.

  15. Poling study of electro-optic polymers in silicon slot waveguides

    NASA Astrophysics Data System (ADS)

    Szep, Attila; Chen, Antao; Shi, Shouyuan; Lin, Zhou; Abeysinghe, Don

    2011-03-01

    Silicon slot waveguide based Mach Zender interferometric modulators were built with electro-optic (EO) polymers in the slot as the modulated media. In order to enhance the macroscopic electro-optic effect in the polymers the molecules that provide the large polarizability need to be aligned prior to operation to match the direction of the applied modulating field. This aligning process, also called as poling process, is difficult in the slot waveguide modulators due to the unique structure and small dimensionality of the slots in the waveguides. While hybrid silicon-EO polymer modulators have been demonstrated with ultra low drive voltage, the polymer EO activity was low compared to thin film performances. We compared alternatives to enhance the poling field over the electro optic polymer and concluded that the well known surface states in silicon affect the conductivity of silicon significantly when thin silicon is used as poling electrode. A solution to this negative effect was attempted by passivating the surface with a 5 nm thin TiO2 conforming atomic layer deposition over the silicon prior to spin casting and poling the EO polymers. We achieved a factor of 2 enhancement in the polymer's electro optic activity after poling as a result and achieved a low 0.52 V*cm voltage length product in the MZ modulator we built with this technique.

  16. Purification of fluorescently labeled Saccharomyces cerevisiae Spindle Pole Bodies

    PubMed Central

    Davis, Trisha N.

    2016-01-01

    Centrosomes are components of the mitotic spindle responsible for organizing microtubules and establishing a bipolar spindle for accurate chromosome segregation. In budding yeast, Saccharomyces cerevisiae, the centrosome is called the spindle pole body, a highly organized tri-laminar structure embedded in the nuclear envelope. Here we describe a detailed protocol for the purification of fluorescently labeled spindle pole bodes from S. cerevisiae. Spindle pole bodies are purified from yeast using a TAP-tag purification followed by velocity sedimentation. This highly reproducible TAP-tag purification method improves upon previous techniques and expands the scope of in vitro characterization of yeast spindle pole bodies. The genetic flexibility of this technique allows for the study of spindle pole body mutants as well as the study of spindle pole bodies during different stages of the cell cycle. The ease and reproducibility of the technique makes it possible to study spindle pole bodies using a variety of biochemical, biophysical, and microscopic techniques. PMID:27193850

  17. 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.

  18. The Effect of Polar Vortex Disturbances on Mesopause Gravity Wave Drag in Relation to Mesopause Pole-to-Pole Coupling

    NASA Astrophysics Data System (ADS)

    de Wit, R.; Hibbins, R. E.; Espy, P. J.

    2014-12-01

    Gravity waves (GWs) play an important role in the dynamics of the mesosphere/lower thermosphere (MLT) region, linking the lower to the upper atmosphere. GW filtering by the background zonal wind is furthermore believed to be the fundamental mechanism coupling the winter stratosphere to the summer polar mesopause, in which increased planetary wave (PW) activity in the former is related to enhanced temperatures in the latter through a chain of global MLT temperature anomalies. During major Sudden Stratospheric Warmings (SSWs) the interaction between PWs and the background flow leads to increased polar stratospheric temperatures and a reversal of the climatological winds from eastward to westward. As a result, large changes in GW filtering conditions occur, making SSWs an excellent tool to empirically test the inter-hemispheric coupling mechanism. In this study, mesopause GW forcing derived from meteor radar observations over Trondheim, Norway (63°N, 10°E) during the January 2013 major SSW is discussed in light of the polar vortex strength and selective filtering conditions over the same location to show the coupling between the polar winter stratosphere and MLT. Global temperature observations obtained with the Aura Microwave Limb Sounder (MLS) are subsequently used to study the temperature signature of the SSW in the MLT region over the winter pole in relation to the observed GW forcing. Furthermore, the temperature effect of the SSW throughout the middle atmosphere is tracked, away from the winter pole toward the summer pole, and compared to the temperature structure expected from the inter-hemispheric coupling mechanism.

  19. Interannual variability of tropical cyclone activity in the southern South China Sea

    NASA Astrophysics Data System (ADS)

    Zuki, Zabani M.; Lupo, Anthony R.

    2008-03-01

    A study of tropical storm activity in the southern South China Sea region was carried out for the period of 1960 to 2006 using data obtained from the UNISYS website archive, which was provided to them from the Joint Typhoon Warning Center (JWTC) best track data. This study was motivated by two particularly costly storms that impacted Malaysia during the 1996-2001 period. This study demonstrated that November and December were the most active months for tropical cyclone activity in this region. A majority of these storms attained tropical storm intensity. Also, a majority of the tropical cyclones originated within the study area near Malaysia as opposed to moving into the area. The long-term trend showed that there has been a slight increase in tropical cyclone activity in the region, but the trend was not statistically significant. A study of the interannual variability revealed that there was more (less) tropical cyclone activity in the region during La Niña (El Niño) years. Longer-term variability, such as that related to the Pacific Decadal Oscillation, was not found in the analysis here. Using spectral methods confirms that there was significant El Niño-related variability in climatological quantities such as monthly sea surface temperatures or pressures. Finally, the background climatological state was examined in order to determine whether or not the atmosphere in the region was more conducive to tropical cyclone formation or maintenance during active years. It was found that the most active years were associated with warmer SSTs in the study region, relatively weak 200-850 hPa wind shear, a warm-core structure, more water vapor, and more cyclonic low-level relative vorticity, and these were all La Niña-type years. Nonactive years were associated with weaker wind shear, less water vapor, and a more anticyclonic (vorticity) background, regardless of whether the SSTs were warmer or cooler, and most of these were El Niño-type years.

  20. The 1968 Edcouch-Elsa High School Walkout: Chicano Student Activism in a South Texas Community

    ERIC Educational Resources Information Center

    Barrera, James B.

    2004-01-01

    A nonviolent school boycott by 192 Chicanola students in 1968 at Edcouch-Elsa high school in the Rio Grande Valley region of Deep South Texas is examined. This walkout was the first major Chicano student protest in South Texas, and was a product of the 1960s Chicano movement.

  1. 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. PMID:22545338

  2. 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.

  3. Physical activity profiles and selected muscular fitness variables in English schoolchildren: A north-south divide?

    PubMed

    Ingle, Lee; Stephenson, Ashlie; Sandercock, Gavin R

    2016-11-01

    The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10-16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131 W vs. 1782 W; P < 0.0001), and reported being more physically active (mean PAQ-A: 2.9 vs. 2.5; P < 0.0001) than their male counterparts in the NE. In girls, the opposite trend was evident. Girls from the NE of England had a higher HG score, jumped higher, and were more powerful (mean peak power: 2114 W vs. 1839 W; P < .0001) than their peers from the SE. Regional variations in the habitual PA profiles and muscular fitness of schoolchildren from the SE and NE of England do exist. The systematic surveillance of children's PA and fitness profiles throughout England would help identify regional inequalities on a larger scale.

  4. 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.

  5. Log amplifier with pole-zero compensation

    DOEpatents

    Brookshier, W.

    1985-02-08

    A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifer circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedstock 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 is offset by a compensating break point or zero.

  6. Management of lower-pole caliceal stones.

    PubMed

    Gerber, Glenn S

    2003-09-01

    A series of 205 urologists answered questions about their choice of treatment for lower-caliceal stones. The preferred approaches were extracorporeal shockwave lithotripsy (SWL) for stones <1 cm and percutaneous nephrolithotomy (PCNL) for those >2 cm. For stones of 1 to 2 cm, 65% preferred SWL and 30% would advise PCNL. Thus, SWL is recommended for lower-caliceal stones more frequently than is justified by published success rates. Continued efforts need to be made to inform practicing urologists regarding the most appropriate therapy for patients with lower-pole stones >1 cm.

  7. 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.

  8. 9,11-Secosteroids with cytotoxic activity from the South China Sea gorgonian coral Subergorgia suberosa.

    PubMed

    Zhang, Jun; Liu, Ling-Li; Zhong, Ba-Lian; Liao, Xiao-Jian; Xu, Shi-Hai

    2015-06-01

    Nine new 9,11-secosterols (1-9), containing the same 3β,6α,11-trihydroxy-9,11-seco-5α-cholest-7-en-9-one steroidal nucleus, whereas possessing an array of structurally diverse side chains, along with fourteen known 9,11-secosterol compounds (10-23), were isolated from the South China Sea gorgonian coral Subergorgia suberosa, of which 3/4, 5/6, 7/8, and the known compounds 11/12, 20/21 were five pairs of inseparable C-24 epimers. Their structures were established by the extensive analyses of 1D and 2D NMR spectra, high-resolution chemical ionization mass spectrometry (HRCIMS), and by the comparison with literature data. Cytotoxic effect of these metabolites against the growth of HeLa cell lines was evaluated. The result showed that the inhibitory effect of compounds 1-23 varied considerably depending on the nature of the side chain in spite of sharing the same steroidal nucleus. Compound 19, featuring both the absence of hydroxyl group and the presence of double bond in the stigmasterol side chain, exhibited the most potent cytotoxicity with IC50 being 15.1 μM. The preliminary structure activity relationship studies identified some important structural features considerably influencing the biological effect deserved, providing valuable information for chemists and pharmacologists to design and synthesize more effective antitumor agents bearing the 9,11-secosteroid framework.

  9. 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.

  10. zic-1 Expression in Planarian Neoblasts after Injury Controls Anterior Pole Regeneration

    PubMed Central

    Vásquez-Doorman, Constanza; Petersen, Christian P.

    2014-01-01

    Mechanisms that enable injury responses to prompt regenerative outgrowth are not well understood. Planarians can regenerate essentially any tissue removed by wounding, even after decapitation, due to robust regulation of adult pluripotent stem cells of the neoblast population. Formation of pole signaling centers involving Wnt inhibitors or Wnt ligands promotes head or tail regeneration, respectively, and this process requires the use of neoblasts early after injury. We used expression profiling of purified neoblasts to identify factors needed for anterior pole formation. Using this approach, we identified zic-1, a Zic-family transcription factor, as transcriptionally activated in a subpopulation of neoblasts near wound sites early in head regeneration. As head regeneration proceeds, the Wnt inhibitor notum becomes expressed in the newly forming anterior pole in zic-1-expressing cells descended from neoblasts. Inhibition of zic-1 by RNAi resulted in a failure to express notum at the anterior pole and to regenerate a head, but did not affect tail regeneration. Both injury and canonical Wnt signaling inhibition are required for zic-1 expression, and double-RNAi experiments suggest zic-1 inhibits Wnt signaling to allow head regeneration. Analysis of neoblast fate determinants revealed that zic-1 controls specification of notum-expressing cells from foxD-expressing neoblasts to form the anterior pole, which organizes subsequent outgrowth. Specialized differentiation programs may in general underlie injury-dependent formation of tissue organizing centers used for regenerative outgrowth. PMID:24992682

  11. A possible relation between pulses of platform activation and plate kinematics

    NASA Astrophysics Data System (ADS)

    Sadowski, Georg Robert

    1987-11-01

    The idea of the cyclic evolution of platforms may have an explanation related to plate kinematics as a function of two main parameters: the spreading rate and rotation pole switches. These kinematic parameters as defined by other authors studying the South Atlantic appear to bear a coherent relationship with pulses of platform activation in South America and Africa. In Gondwana's history, after its break-up at least four major peaks of volcano-tectonic activity on the continents seem to be related to important changes in position of the rotation poles and the spreading rates of the South American and African plates. Mantle convection patterns such as those suggested by McKenzie on the Pacific floor can be seen as feasible mechanisms for explaining the origin and shape of large syneclises and archings.

  12. Maloriented bivalents have metaphase positions at the spindle equator with more kinetochore microtubules to one pole than to the other.

    PubMed

    LaFountain, James R; Oldenbourg, Rudolf

    2004-12-01

    To test the "traction fiber" model for metaphase positioning of bivalents during meiosis, kinetochore fibers of maloriented bivalents, induced during recovery from cold arrest, were analyzed with a liquid crystal polarizing microscope. The measured birefringence retardation of kinetochore fibers is proportional to the number of microtubules in a fiber. Five of the 11 maloriented bivalents analyzed exhibited bipolar malorientations that had at least four times more kinetochore microtubules to one pole than to the other pole, and two had microtubules directed to only one pole. Yet all maloriented bivalents had positions at or near the spindle equator. The traction fiber model predicts such maloriented bivalents should be positioned closer to the pole with more kinetochore microtubules. A metaphase position at the spindle equator, according to the model, requires equal numbers of kinetochore microtubules to both poles. Data from polarizing microscope images were not in accord with those predictions, leading to the conclusion that other factors, in addition to traction forces, must be involved in metaphase positioning in crane-fly spermatocytes. Although the identity of additional factors has not been established, one possibility is that polar ejection forces operate to exert away-from-the-pole forces that could counteract pole-directed traction forces. Another is that kinetochores are "smart," meaning they embody a position-sensitive mechanism that controls their activity.

  13. Active normal faulting along the Mt. Morrone south-western slopes (central Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Gori, Stefano; Giaccio, Biagio; Galadini, Fabrizio; Falcucci, Emanuela; Messina, Paolo; Sposato, Andrea; Dramis, Francesco

    2011-01-01

    In the present work we analyse one of the active normal faults affecting the central Apennines, i.e. the Mt. Morrone normal fault system. This tectonic structure, which comprises two parallel, NW-SE trending fault segments, is considered as potentially responsible for earthquakes of magnitude ≥ 6.5 and its last activation probably occurred during the second century AD. Structural observations performed along the fault planes have allowed to define the mainly normal kinematics of the tectonic structure, fitting an approximately N 20° trending extensional deformation. Geological and geomorphological investigations performed along the whole Mt. Morrone south-western slopes permitted us to identify the displacement of alluvial fans, attributed to Middle and Late Pleistocene by means of tephro-stratigraphic analyses and geomorphological correlations with dated lacustrine sequences, along the western fault branch. This allowed to evaluate in 0.4 ± 0.07 mm/year the slip rate of this segment. On the other hand, the lack of synchronous landforms and/or deposits that can be correlated across the eastern fault segment prevented the definition of the slip rate related to this fault branch. Nevertheless, basing on a critical review of the available literature dealing with normal fault systems evolution, we hypothesised a total slip rate of the fault system in the range of 0.4 ± 0.07 to 0.8 ± 0.09 mm/year. Moreover, basing on the length at surface of the Mt. Morrone fault system (i.e. 22-23 km) we estimated the maximum expected magnitude of an earthquake that might originate along this tectonic structure in the order of 6.6-6.7.

  14. Seasonal variations of temperature and composition at the Titan poles

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Jennings, Donald E.; Achterberg, Richard K.; Bampasidis, Georgios; Lavvas, Panayiotis; Nixon, Conor A.; Teanby, Nicholas A.; Cottini, Valeria; Anderson, Carrie M.; Flasar, F. Michael

    2015-11-01

    We present an analysis of spectra acquired by Cassini/CIRS at high resolution from October 2010 until September 2014 in nadir mode ([1] & refs therein). Since 2010 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) until 2014. For some of the most abundant and longest-lived hydrocarbons (C2H2, C2H6 and C3H8) and CO2, the evolution in the past 4 years at a given latitude is not significant within error bars until mid-2013. More recently, these molecules show a trend for increase in the south. This trend is dramatically more pronounced for the other trace species, especially in 2013-2014, and at 70°S relative to 50°S. These two regions then demonstrate that they are subject to different dynamical processes in and out of the polar vortex region. For most species, we find higher abundances at 50°N compared to 50°S, with the exception of C3H8, CO2, C6H6 and HC3N, which arrive at similar mixing ratios after mid-2013. While the 70°N data show generally no change except a small decrease for most species within 2014, the 70°S results indicate a strong enhancement in trace stratospheric gases after 2012. The 663 cm-1 HC3N and the C6H6 674 cm-1 emission bands appeared in late 2011/early 2012 in the south polar regions and have since then exhibited a dramatic increase in their abundances. At 70°S HC3N, HCN and C6H6 have increased by 3 orders of magnitude over the past 3-4 years while other molecules, including C2H4, C3H4 and C4H2, have increased less sharply (by 1-2 orders of magnitude). This is a strong indication of the rapid and sudden buildup of the gaseous inventory in the southern stratosphere during 2013-2014, as expected as the pole moves deeper into winter shadow. Subsiding gases that accumulate in the absence of ultraviolet

  15. Titan's temporal evolution in stratospheric trace gases near the poles

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Jennings, Donald E.; Achterberg, Richard K.; Bampasidis, Georgios; Lavvas, Panayiotis; Nixon, Conor A.; Teanby, Nicholas A.; Anderson, Carrie M.; Cottini, Valeria; Flasar, F. Michael

    2016-05-01

    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) until 2014. For some of the most abundant and longest-lived hydrocarbons (C2H2, C2H6 and C3H8) and C