Science.gov

Sample records for physical weathering processes

  1. Author's personal copy Revisiting dirt cracking as a physical weathering process in warm deserts

    E-print Network

    Dorn, Ron

    Author's personal copy Revisiting dirt cracking as a physical weathering process in warm deserts August 2011 Keywords: Calcrete Desert geomorphology Dust Nanoscale Physical weathering A half century ago and bedrock shatters. Although desert physical weathering by "dirt cracking" has occasionally been cited

  2. Revisiting dirt cracking as a physical weathering process in warm deserts

    NASA Astrophysics Data System (ADS)

    Dorn, Ronald I.

    2011-12-01

    A half century ago C.D. Ollier proposed that insolation-driven temperature changes expand and contract fill in fissures enough to widen cracks, a process that would permit progressively deeper penetration of fissure fills, that would in turn generate a positive feedback of greater and greater strain until desert boulders and bedrock shatters. Although desert physical weathering by "dirt cracking" has occasionally been cited, this hypothesized process remains without support from subsequent research. Here, field observations, electron microscopy, X-ray powder diffraction, particle-size analysis, and laboratory experiments shed new light on dirt cracking. Little clear evidence supports the original notion of expansive pressures from thermal fluctuations. However, mineralogical, high resolution transmission electron microscopy, back-scattered electron microscopy, and experimental evidence support two alternative processes of widening fractures: wetting and drying of fills inside fissures; and the precipitation and remobilization of calcium carbonate. A re-envisioned dirt-cracking wedging process starts with calcium carbonate precipitating in fissures less than 5 ?m wide. First precipitation, and then ongoing dissolution of this laminar calcrete, opens enough space for dust to penetrate into these narrow fractures. Wetting of expansive clays in the fissure fill exerts enough pressure to widen and deepen the fissure, allowing the carbonate precipitation process to penetrate even deeper and allowing even more dust to move into a fracture. As the dust infiltrates, its texture changes from a chaotic mix of particles to an alignment of clays parallel to fissure sides. This parallel alignment could increase the efficiency of fill wedging. Ollier's concept of a positive feedback remains supported; each increment of fracture deepening and widening permits more, even deeper infiltration of laminar calcrete and dust. Field and electron microscope observations of rock spalling in the winter of 2010 are consistent with Ollier's hypothesis that dirt cracking is a common physical weathering process in deserts that splits rocks of all different sizes.

  3. Weather Information Processing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Science Communications International (SCI), formerly General Science Corporation, has developed several commercial products based upon experience acquired as a NASA Contractor. Among them are METPRO, a meteorological data acquisition and processing system, which has been widely used, RISKPRO, an environmental assessment system, and MAPPRO, a geographic information system. METPRO software is used to collect weather data from satellites, ground-based observation systems and radio weather broadcasts to generate weather maps, enabling potential disaster areas to receive advance warning. GSC's initial work for NASA Goddard Space Flight Center resulted in METPAK, a weather satellite data analysis system. METPAK led to the commercial METPRO system. The company also provides data to other government agencies, U.S. embassies and foreign countries.

  4. Space Weathering Processes on Mercury

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Pieters, C. M.

    2002-01-01

    Like the Moon, Mercury has no atmosphere to protect it from the harsh space environment and therefore it is expected that it will incur the effects of space weathering. These weathering processes are capable of both creating regolith and altering its optical properties. However, there are many important differences between the environments of Mercury and the Moon. These environmental differences will almost certainly affect the weathering processes as well as the products of those processes. It should be possible to observe the effects of these differences in Vis/NIR spectra of the type expected to be returned by MESSENGER. More importantly, understanding these weathering processes and their consequences is essential for evaluating the spectral data returned from MESSENGER and other missions in order to determine the mineralogy and the iron content of the Mercurian surface. Theoretical and experimental work has been undertaken in order to better understand these consequences.

  5. Soil Genesis and Development, Lesson 2 - Processes of Weathering

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weathering processes — which include physical, chemical, and biological — contribute to the development of soil. The learning objectives of the lesson are: 1) Define and distinguish physical, chemical, and biological weathering processes; and 2) Describe how rock and mineral properties and environm...

  6. Book Review: Space Weather: Physics and Effects

    NASA Astrophysics Data System (ADS)

    Wilkinson, Phil

    2007-11-01

    At 438 pages, Space Weather: Physics and Effects, edited by Volker Bothmer and Ioannis A. Daglis, seems like a daunting read. But its thickness belies its conversational tone, and its content provides a different presentation of material aimed at drawing in a new audience while satisfying the present space weather audience's interest in their subject. I found reading this book a pleasure.

  7. Physical and chemical weathering. [of Martian surface and rocks

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Arvidson, Raymond E.; Zolotov, Mikhail IU.

    1992-01-01

    Physical and chemical weathering processes that might be important on Mars are reviewed, and the limited observations, including relevant Viking results and laboratory simulations, are summarized. Physical weathering may have included rock splitting through growth of ice, salt or secondary silicate crystals in voids. Chemical weathering probably involved reactions of minerals with water, oxygen, and carbon dioxide, although predicted products vary sensitively with the abundance and physical form postulated for the water. On the basis of kinetics data for hydration of rock glass on earth, the fate of weathering-rind formation on glass-bearing Martian volcanic rocks is tentatively estimated to have been on the order of 0.1 to 4.5 cm/Gyr; lower rates would be expected for crystalline rocks.

  8. Physical weathering and modification of a rhyolitic hyaloclastite in Iceland

    NASA Astrophysics Data System (ADS)

    de Vet, S. J.; Mittelmeijer-Hazeleger, M. C.; Braakhekke, J. J. M.; Cammeraat, L. H.

    2014-06-01

    Fragmental volcanic glass or `hyaloclastite' is a common glaciovolcanic eruption product that is formed in large abundance during basaltic, andesitic and rhyolitic subglacial eruptions. The physical weathering of rhyolitic hyaloclastites differs notably from basaltic hyaloclastites due to differences in cementation and edifice consolidation. As rhyolitic glasses are also much rarer, comparatively little is known about their physical weathering and fracturing characteristics. In the presented study, we provide a process-oriented analysis of the physical modification of subglacially erupted rhyolitic hyaloclastites from the Bláhnúkur edifice in Torfajökull (Iceland). Frost weathering experiments were performed to determine how vesicular glass particles fragment to finer particle sizes. The surficial porosity of the glass drives such frost weathering through the process of pore pressurisation and was quantified using high-pressure mercury intrusion. Uniaxial compression experiments were carried out to understand how the glass structure responds to the application of external stress. The observed fracturing in both experimental treatments was found to adhere to fractal statistics, which allowed the compression experiments to be used in conjunction with the frost weathering experiments for inferring the fracturing characteristics of rhyolitic volcanic glasses. Transport processes by wind and gravity were simulated by long-duration abrasion experiments in rock tumblers (through granular avalanching), but these low-energy particle interactions were not found to significantly abrade particles. A notable result from our fragmentation experiments was the production of <10 ?m particles. This size range is considered respirable and illustrates how physical weathering can continuously create potentially harmful ash textures; a process which is often overlooked in health hazard assessments after volcanic eruptions. Fragmentation by post-eruptive weathering can lead to overestimations of the fine ash fraction produced by syneruptive fragmentation and granulometric studies therefore need to be appreciative of the effects of such secondary fracturing processes.

  9. Space Weather: Physics and Effects

    NASA Astrophysics Data System (ADS)

    Hughes, W. Jeffrey

    2009-03-01

    With the launching of Sputnik, Explorer 1, and the other early satellites, the new discipline of space physics was born, about 50 years ago. Although earlier ground-based observations had provided strong hints about the nature of our space environment above the upper atmosphere, those early satellites initiated a series of surprises and discoveries, including Van Allen's discovery of the Earth's radiation belts. Young scientists were attracted to this new field, and it grew quickly. When the Journal of Geophysical Research was divided into two sections, in 1964, one section was devoted to space physics. The field explored not only new regions of space but also a new state of matter: the rarefied, fully ionized plasma that fills space and interacts intimately with magnetic fields.

  10. A Chapter In Space Weather: Physics and Effects

    E-print Network

    Vassiliadis, Dimitrios

    at NASA/Goddard Space Flight Center #12;- 2 - Abstract. Forecasting space weather events presents- 1 - A Chapter In Space Weather: Physics and Effects by V. Bothmer and I.A. Daglis (editors) Springer Praxis September 2005 Draft date: March 9, 2007 Forecasting Space Weather Dimitris Vassiliadis ST

  11. The Chemistry and Physics of Space Weathering

    NASA Astrophysics Data System (ADS)

    Britt, D. T.; Schelling, P. K.; Blair, R.

    2015-11-01

    Local chemistry and the nature of the energy input drive space weathering. Weathering products are not random, but the predictable outcome of reactions that depend on chemical feedstock, mineral kinetics, catalytic components, and energetic inputs.

  12. Detecting Anthropogenic Disturbance on Weathering and Erosion Processes

    NASA Astrophysics Data System (ADS)

    Vanacker, V.; Schoonejans, J.; Bellin, N.; Ameijeiras-Mariño, Y.; Opfergelt, S.; Christl, M.

    2014-12-01

    Anthropogenic disturbance of natural vegetation can profoundly alter the physical, chemical and biological processes within soils. Rapid removal of topsoil during intense farming can result in an imbalance between soil production through chemical weathering and physical erosion, with direct implications on local biogeochemical cycling. However, the feedback mechanisms between soil erosion, chemical weathering and biogeochemical cycling in response to anthropogenic forcing are not yet fully understood. In this paper, we analyze dynamic soil properties for a rapidly changing anthropogenic landscape in the Spanish Betic Cordillera; and focus on the coupling between physical erosion, soil production and soil chemical weathering. Modern erosion rates were quantified through analysis of sediment deposition volumes behind check dams, and represent catchment-average erosion rates over the last 10 to 50 years. Soil production rates are derived from in-situ produced 10Be nuclide concentrations, and represent long-term flux rates. In each catchment, soil chemical weathering intensities were calculated for two soil-regolith profiles. Although Southeast Spain is commonly reported as the European region that is most affected by land degradation, modern erosion rates are low (140 t ha-1 yr-1). About 50 % of the catchments are losing soils at a rate of less than 60 t km-2 yr-1. Our data show that modern erosion rates are roughly of the same magnitude as the long-term or cosmogenically-derived erosion rates in the Betic Cordillera. Soils developed on weathered metamorphic rocks have no well-developed profile characteristics, and are generally thin and stony. Nevertheless, soil chemical weathering intensities are high; and question the occurrence of past soil truncation.

  13. Landslides as weathering reactors; links between physical erosion and weathering in rapidly eroding mountain belts

    NASA Astrophysics Data System (ADS)

    Emberson, R.; Hovius, N.; Galy, A.

    2014-12-01

    The link between physical erosion and chemical weathering is generally modelled with a surface-blanketing weathering zone, where the supply of fresh minerals is tied to the average rate of denudation. In very fast eroding environments, however, sediment production is dominated by landsliding, which acts in a stochastic fashion across the landscape, contrasting strongly with more uniform denudation models. If physical erosion is a driver of weathering at the highest erosion rates, then an alternative weathering model is required. Here we show that landslides can be effective 'weathering reactors'. Previous work modelling the effect of landslides on chemical weathering (Gabet 2007) considered the fresh bedrock surfaces exposed in landslide scars. However, fracturing during the landslide motion generates fresh surfaces, the total surface area of which exceeds that of the exposed scar by many orders of magnitude. Moreover, landslides introduce concavity into hillslopes, which acts to catch precipitation. This is funnelled into a deposit of highly fragmented rock mass with large reactive surface area and limited hydraulic conductivity (Lo et al. 2007). This allows percolating water reaction time for chemical weathering; any admixture of macerated organic debris could yield organic acid to further accelerate weathering. In the South island of New Zealand, seepage from recent landslide deposits has systematically high solute concentrations, far outstripping concentration in runoff from locations where soils are present. River total dissolved load in the western Southern Alps is highly correlated with the rate of recent (<35yrs) landsliding, suggesting that landslides are the dominant locus of weathering in this rapidly eroding landscape. A tight link between landsliding and weathering implies that localized weathering migrates through the landscape with physical erosion; this contrasts with persistent and ubiquitous weathering associated with soil production. Solute fluxes from fast eroding landscapes therefore likely depend on climatic or tectonic forcing of mass wasting; greater precipitation would drive increased weathering, while earthquakes, in generating landslides (Dadson et al. 2003; Chen & Hawkins 2009), may be important in setting long term solute fluxes.

  14. Olivine Weathering: Abiotic Versus Biotic Processes as Possible Biosignatures

    NASA Technical Reports Server (NTRS)

    Longazo, T. G.; Wentworth, S. J.; McKay, D. S.; Southam, G.; Clemett, S. J.

    2001-01-01

    A preliminary study to determine how abiotic versus biotic processes affect the weathering of olivine crystals. Perhaps the differences between these weathering processes could be used as biosignatures. Additional information is contained in the original extended abstract.

  15. Salt-Induced Physical Weathering of Stone

    NASA Astrophysics Data System (ADS)

    Schiro, M.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.

    2010-12-01

    Salt weathering is recognized as an important mechanism that contributes to the modeling and shaping of the earth’s surface, in a range of environments spanning from the Sahara desert to Antarctica. It also contributes to the degradation and loss of cultural heritage, particularly carved stone and historic buildings. Soluble salts have recently been suggested to contribute to the shaping of rock outcrops on Mars and are being identified in other planetary bodies such as the moons of Jupiter (Europa and IO)1. Soluble salts such as sulfates, nitrates, chlorides and carbonates of alkali and alkali earth metals can crystallize within the porous system of rocks and building stones, exerting sufficient pressure against the pore walls to fracture the substrate. This physical damage results in increased porosity, thus providing a higher surface area for salt-enhanced chemical weathering. To better understand how salt-induced physical weathering occurs, we have studied the crystallization of the particularly damaging salt, sodium sulfate2, in a model system (a sintered porous glass of controlled porosity and pore size). For this elusive task of studying sub-surface crystallization in pores, we combined a variety of instruments to identify which phases crystallized during evaporation and calculated the supersaturation and associated crystallization pressure that caused damage. The heat of crystallization was measured using differential scanning calorimetry (DSC), providing the timing of crystallization events and phase transitions3, while the evaporation rate was recorded using thermal gravimetry (TG). These methods enabled calculation of the sodium sulfate concentration in solution at every point during evaporation. Two-dimensional X-ray diffraction (2D-XRD) performs synchrotron-like experiments in a normal lab by using a Molybdenum X-ray source (more than 5 times more penetrative than conventional Copper source). Using this method, we determined that the first phase to form within our porous system was the metastable heptahydrate (NaSO4?7H2O)4, followed by mirabilite (NaSO4?10H2O), and finally thenardite (NaSO4). Combining this sequence with data from TG/DSC, we calculated the supersaturation of the solution with respect to each crystallizing phase as well as the associated crystallization pressure5. In situ environmental scanning electron microscopy (ESEM) complemented 2D-XRD data by giving high magnification images of crystallization and phase transitions during dissolution/precipitation cycles. These results give us a clear understanding of sodium sulfate behavior during evaporative crystallization. Further studies will examine different salts and different substrates. This research will help us to better understand the crystallization of salts and associated weathering in cultural heritage, natural environments and possibly, in other planetary bodies. [1] Rodriguez-Navarro, C. (1998) Geophys. Res. Lett., 25, 3249-3252. [2] Rodriguez-Navarro, C., et al. (2000), Cement Concrete Res., 30, 1527-1534. [3] Espinosa, R., Scherer, G., (2008), Environ. Geol., 56, 605-621. [4] Hamilton, A., Hall, C., (2008), J. Anal. Atom. Spectrom., 23, 840-844. [5] Steiger, M., Asmussen, S., (2008), Geochim. Cosmochim. Acta, 72, 4291-4306.

  16. Physical mechanisms of solar variability influence on weather and climate

    NASA Astrophysics Data System (ADS)

    Avakyan, Sergei

    2010-05-01

    Numerous researches into correlation of weather and climate characteristics with solar and geomagnetic activity confirm that such correlation does exist. However there is some uncertainty in interpretation of the Sun-weather-climate relations. The paper considers the main causes of this uncertainty which are as follows - the lack of permanent monitoring data on ionizing solar EUV/X-ray radiation including periods of flares; and also the data on electron fluxes of keV energy precipitating from radiation belts first of all during geomagnetic storms; - multiplicity of Sun-weather-climate links; - the lack of understanding what are the mechanisms of solar-geomagnetic activity (flares and storms) influence on weather and climate characteristics; By now mainly the research on galactic cosmic rays (GSR) including Forbush effects and solar cosmic rays (SCR) influences on atmosphere transparence characteristics and further on climate-weather characteristics have been carried out. The GCR flux increase causes the growth of low (usually optically thick) cloudness and therefore produces in generally cooling effect on the mean surface air temperature. The appearance of SCR causes the reduction of stratospheric and tropospheric transparence and produces also usually cooling effect However these events are rare and corresponding variations of fluxes energy are small. At the same time such strong and frequent manifestations of solar activity as flares and magnetic storms are not so far taken into account since it is not known what physical mechanisms could be responsible for energy transfer from solar flares and magnetic storms to the lower atmosphere. The paper describes a novel radio-optical mechanism responsible for the solar-terrestrial links which acts as a three-stage trigger and which could be useful for solving the problem "Sun- weather-climate". This physical mechanism is based on taking into account the excitation of Rydberg states of atoms and molecules in generation of the ionospheric microwave radiation and in realization of the dissociative recombination of cluster ions in troposphere. The mechanism enables agents of solar and geomagnetic activities affect atmospheric processes with help the flux of microwaves from ionosphere. This first agent under consideration is variation of fluxes of solar EUV and X -ray radiation during flares. The second agent is fluxes of electrons and protons which precipitate from radiation belts as a result of geomagnetic storms.. Our novel radiooptical trigger mechanism of influence of solar and geomagnetic activity on the formation of weather and climate changes consists of three stages. The first stage is an increase in generation of the microwave radiation which penetrates from the ionosphere to the earth surface. The microwave radiation arises from the transitions between Rydberg states which are exited by the energetic ionospheric electrons namely photoelectrons, secondary electrons and Auger electrons. The second stage is a change in the proportion of water vapour to water clusters caused by increased microwave radiation. The third stage is a change of the atmosphere transparence in the absorption bands of water vapour and clusters and appearance of optically-thin clouds at high and middle altitudes. These clouds cause a net warming due to their relative transparency at short wavelengths but opacity in the IR region The atmosphere transparence determines the fluxes of solar irradiance coming down as well as flux of the thermal radiation coming out from the underlying surface. We emphasize that all stages of the proposed mechanism are experimentally confirmed: the microwave ionospheric emission, which intensifies during solar and magnetic storms, was detected; the regulation of humidity at altitude higher than 2 km by the solar microwave emission and during of solar flares was registered; a direct influence of solar flares and magnetic storms on the total cloudiness is distinctly registered at least in some geographic areas.

  17. Understanding Space Weather and the Physics Behind It

    NASA Astrophysics Data System (ADS)

    Knipp, D. J.; Gross, N. A.

    2011-12-01

    A new textbook on space weather, Understanding Space Weather and the Physics Behind It, aimed at upper-level undergraduates and beginning graduate students, contains numerous examples of basic physics applications in space weather. We will highlight a few of the examples from the text. In addition, new material is being developed to support the many references to NOAA Space Weather Prediction Center (SWPC) graphics and scales. Our intent is to provide background and improved understanding of the underpinnings of the operational images. In this presentation we provide a set of questions, tools, and exercises that guide inquiry into the observations and proxies behind some of elements on SWPC's home page. Our materials include observation sequences for the types of space weather disturbances discussed in SWPC's Report of Solar and Geophysical Activity and the NOAA Space Weather Scales. Our instructional materials are in standard electronic document formats and in "dashboard" format supported by tools from the Integrated Space Weather Analysis platform at NASA's Community Coordinated Modeling Center.

  18. Multilayer Scintillation Detector for Nuclear Physics Monitoring of Space Weather

    NASA Astrophysics Data System (ADS)

    Batischev, A. G.; Aleksandrin, S. Yu.; Gurov, Yu. B.; Koldashov, S. V.; Lapushkin, S. V.; Mayorov, A. G.

    The physical characteristics of the multilayer scintillation spectrometer (MSS) for identification and energy measurement of cosmic electrons, positrons and nuclei are considered in this paper. This spectrometer is made on the basis of several plastic scintillator plates with various thick viewed by photomultipliers. Two upper layers are strips of orthogonal scintillators. The nuclei energy measurement range is 3 - 100 MeV/nucleon. Spectrometer is planning for space weather monitoring and investigation of solar-magnetospheric and geophysics effects on satellite. MSS time resolution is about 1 microsecond and it can measure the time profiles of fast processes in the Earth's magnetosphere. Spectrometer experimental characteristics were estimated by means of computer simulation. The ionization loss fluctuations, ion charge exchange during pass through detector and, especially, scintillation quenching effect (Bircs effect) were taken into account in calculations.

  19. Influence of weather-climatic conditions on biospheric processes

    NASA Astrophysics Data System (ADS)

    Govorushko, S. M.

    2012-12-01

    The significance of meteorological processes and phenomena in the biosphere functioning is revealed. The influence of various weather conditions on human health is considered; the factors and mechanisms of their action are described. The impact of meteorological processes on animals is discussed and concrete examples of such impacts are presented. The influence of meteorological processes and phenomena on plants at different stages of their life (pollination, growth, ripening, transport of seeds, damage, and death) and on some abiotic natural components is shown. It is inferred that weather-climatic conditions have a great influence on biospheric processes.

  20. Sensitivity of mineral dissolution rates to physical weathering : A modeling approach

    NASA Astrophysics Data System (ADS)

    Opolot, Emmanuel; Finke, Peter

    2015-04-01

    There is continued interest on accurate estimation of natural weathering rates owing to their importance in soil formation, nutrient cycling, estimation of acidification in soils, rivers and lakes, and in understanding the role of silicate weathering in carbon sequestration. At the same time a challenge does exist to reconcile discrepancies between laboratory-determined weathering rates and natural weathering rates. Studies have consistently reported laboratory rates to be in orders of magnitude faster than the natural weathering rates (White, 2009). These discrepancies have mainly been attributed to (i) changes in fluid composition (ii) changes in primary mineral surfaces (reactive sites) and (iii) the formation of secondary phases; that could slow natural weathering rates. It is indeed difficult to measure the interactive effect of the intrinsic factors (e.g. mineral composition, surface area) and extrinsic factors (e.g. solution composition, climate, bioturbation) occurring at the natural setting, in the laboratory experiments. A modeling approach could be useful in this case. A number of geochemical models (e.g. PHREEQC, EQ3/EQ6) already exist and are capable of estimating mineral dissolution / precipitation rates as a function of time and mineral mass. However most of these approaches assume a constant surface area in a given volume of water (White, 2009). This assumption may become invalid especially at long time scales. One of the widely used weathering models is the PROFILE model (Sverdrup and Warfvinge, 1993). The PROFILE model takes into account the mineral composition, solution composition and surface area in determining dissolution / precipitation rates. However there is less coupling with other processes (e.g. physical weathering, clay migration, bioturbation) which could directly or indirectly influence dissolution / precipitation rates. We propose in this study a coupling between chemical weathering mechanism (defined as a function of reactive area, solution composition, temperature, mineral composition) and the physical weathering module in the SoilGen model which calculates the evolution of particle size (used for surface area calculation) as influenced by temperature gradients. The solution composition in the SoilGen model is also influenced by other processes such as atmospheric inputs, organic matter decomposition, cation exchange, secondary mineral formation and leaching. We then apply this coupled mechanism on a case study involving 3 loess soil profiles to analyze the sensitivity of mineral weathering rates to physical weathering. Initial results show some sensitivity but not that dramatic. The less sensitivity was attributed to dominance of resistant primary minerals (> 70% quartz). Scenarios with different sets of mineralogy will be tested and sensitivity results in terms of silicate mineral dissolution rates and CO2-consumption will be presented in the conference. References Sverdrup H and Warfvinge P., 1993. Calculating field weathering rates using a mechanistic geochemical model PROFILE. Applied Geochemistry, 8:273-283. White, A.F., 2009. Natural weathering rates of silicate minerals. In: Drever, J.I. (Ed.), Surface and Ground Water, Weathering and Soils. In: Holland, H.D., Turekian, K.K. (Eds.), Treatise on Geochemistry. vol. 5. Elsevier-Pergamon, Oxford, pp. 133-168.

  1. Solar Physics, Space Weather, and Wide-field X-ray Telescopes

    E-print Network

    Van Stryland, Eric

    Solar Physics, Space Weather, and Wide-field X-ray Telescopes CREOL & FPCE: The College of Optics of the Earth). The detrimental effects of solar storm induced "space weather" ranges from disruption of our-Energy Solar Physics · Space Weather and its Detrimental Effects · X-ray Astronomy and Grazing Incidence X

  2. Physical weathering of marbles caused by anisotropic thermal expansion

    NASA Astrophysics Data System (ADS)

    Siegesmund, S.; Ullemeyer, K.; Weiss, T.; Tschegg, E. K.

    Marbles as building stones as well as in their natural environments show complex weathering phenomena. The most important damage scenario is based on the highly anisotropic thermal expansion coefficient ? of calcite, i.e. extreme expansion parallel and contraction normal to the crystallographic c-axis. Therefore, the rock fabric and especially the lattice-preferred orientation (texture) of calcite and/or dolomite as the predominant mineral phases in marbles have a significant influence on the mechanical weathering. The textures of marbles from five different locations vary from a more or less perfect prolate to moderate oblate shape of the [006] pole figure tensor. Accordingly, the texture-derived bulk thermal dilatation anisotropy covers a broad range from -0.048 to 0.680. The modelled thermal dilatations correlate with those obtained from experimental measurements. The difference in magnitude is basically explained by the microcrack fabrics which was not considered in the computations. All samples show a deterioration due to thermal treatment regardless of the strength of texture. The directional dependence of (a) the total magnitude of the thermal dilatation coefficient and (b) of the residual strain is highest in marbles with a strong texture, whereas the Carrara marble with a weak texture exhibits a uniform crack formation. The progressive loss of cohesion along grain boundaries due to dilatancy may serve as an example for the initial stage of physical weathering.

  3. Physical disintegration of biochar: An overlooked process

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data collected from both artificially and field (naturally) weathered biochar suggest that a potentially significant pathway of biochar disappearance is through physical breakdown of the biochar structure. Through scanning electron microscopy (SEM) we characterized this physical weathering which inc...

  4. Weather.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2000

    2000-01-01

    This subject guide to weather resources includes Web sites, CD-ROMs and software, videos, books, audios, magazines, and professional resources. Related disciplines are indicated, age levels are specified, and a student activity is included. (LRW)

  5. Attributing Weather Extremes to `Climate Change': a Review For Progress in Physical Geography

    E-print Network

    Hulme, Mike

    Attributing Weather Extremes to `Climate Change': a Review For Progress in Physical Geography Mike of their daily weather. Many cultural beliefs and practices throughout human history have been inspired by this desire. And when weather `misbehaves', or delivers meteorological devastation through windstorm, torrent

  6. Weathering processes and landforms The International Encyclopedia of Geography: People, the Earth,

    E-print Network

    Dorn, Ron

    ForReview Only Weathering processes and landforms Journal: The International Encyclopedia, and Technology #12;ForReview Only Weathering processes and landforms Tyler J. Thompson Arizona State University to the processes of rock decay. [We use the term `rock decay' rather than `weathering' throughout this entry

  7. Process evaluation: Weatherization Residential Assistance Partnership (WRAP Program)

    SciTech Connect

    Not Available

    1990-10-01

    The Weatherization Residential Assistance Partnership,'' or WRAP program, is a fuel-blind conservation program designed to assist Northeast Utilities' low-income customers to use energy safely and efficiently. Innovative with respect to its collaborative approach and its focus on utilizing and strengthening the existing low-income weatherization service delivery network, and WRAP program offers an interesting model to other utilities which traditionally have relied on for-profit energy service contractors and highly centralized program implementation structures. This report presents the findings of a process evaluation and WRAP customer survey conducted by the Technical Development Corporation (TDC). TDC's work is one part of a multi-part evaluation project being conducted under the management of ICF Resources, Inc.

  8. Process evaluation: Weatherization Residential Assistance Partnership (WRAP Program). [Final report

    SciTech Connect

    Not Available

    1990-10-01

    The ``Weatherization Residential Assistance Partnership,`` or WRAP program, is a fuel-blind conservation program designed to assist Northeast Utilities` low-income customers to use energy safely and efficiently. Innovative with respect to its collaborative approach and its focus on utilizing and strengthening the existing low-income weatherization service delivery network, and WRAP program offers an interesting model to other utilities which traditionally have relied on for-profit energy service contractors and highly centralized program implementation structures. This report presents the findings of a process evaluation and WRAP customer survey conducted by the Technical Development Corporation (TDC). TDC`s work is one part of a multi-part evaluation project being conducted under the management of ICF Resources, Inc.

  9. Van Allen Probes Science Gateway and Space Weather Data Processing

    NASA Astrophysics Data System (ADS)

    Romeo, G.; Barnes, R. J.; Weiss, M.; Fox, N. J.; Mauk, B.; Potter, M.; Kessel, R.

    2014-12-01

    The Van Allen Probes Science Gateway acts as a centralized interface to the instrument Science Operation Centers (SOCs), provides mission planning tools, and hosts a number of science related activities such as the mission bibliography. Most importantly, the Gateway acts as the primary site for processing and delivering the VAP Space Weather data to users. Over the past year, the web-site has been completely redesigned with the focus on easier navigation and improvements of the existing tools such as the orbit plotter, position calculator and magnetic footprint tool. In addition, a new data plotting facility has been added. Based on HTML5, which allows users to interactively plot Van Allen Probes summary and space weather data. The user can tailor the tool to display exactly the plot they wish to see and then share this with other users via either a URL or by QR code. Various types of plots can be created, including simple time series, data plotted as a function of orbital location, and time versus L-Shell. We discuss the new Van Allen Probes Science Gateway and the Space Weather Data Pipeline.

  10. Evidence of Space Weathering Processes Across the Surface of Vesta

    NASA Technical Reports Server (NTRS)

    Pieters, Carle M.; Blewett, David T.; Gaffey, Michael; Mittlefehldt, David W.; CristinaDeSanctis, Maria; Reddy, Vishnu; Coradini, Angioletta; Nathues, Andreas; Denevi, Brett W.; Li, Jian-Yang; McCord, Thomas B.; Marchi, Simone; Palmer, Eric E.; Sunshine, Jessica M.; Filacchione, Gianrico; Ammannito, Eleonora; Raymond, Carol A.; Russell, Christopher T.

    2011-01-01

    As NASA s Dawn spacecraft explores the surface of Vesta, it has become abundantly clear that Vesta is like no other planetary body visited to date. Dawn is collecting global data at increasingly higher spatial resolution during its one-year orbital mission. The bulk properties of Vesta have previously been linked to the HED meteorites through remote mineral characterization of its surface from Earth-based spectroscopy. A principal puzzle has been why Vesta exhibits relatively unweathered diagnostic optical features compared to other large asteroids. Is this due to the composition of this proto-planet or the space environment at Vesta? Alteration or weathering of materials in space normally develops as the products of several processes accumulate on the surface or in an evolving particulate regolith, transforming the bedrock into fragmental material with properties that may be measurably different from the original. Data from Dawn reveal that the regolith of Vesta is exceptionally diverse. Regional surface units are observed that have not been erased by weathering with time. Several morphologically-fresh craters have excavated bright, mafic-rich materials and exhibit bright ray systems. Some of the larger craters have surrounding subdued regions (often asymmetric) that are lower in albedo and relatively red-sloped in the visible while exhibiting weaker mafic signatures. Several other prominent craters have rim exposures containing very dark material and/or display a system of prominent dark rays. Most, but not all, dark areas associated with craters exhibit significantly lower spectral contrast, suggesting that either a Vesta lithology with an opaque component has been exposed locally or that the surface has been contaminated by a relatively dark impactor. Similarly, most, but not all, bright areas associated with craters exhibit enhanced mafic signatures compared to surroundings. On a regional scale, the large south polar structure and surrounding terrain exhibit relatively strong mafic absorption features, suggesting either a concentration of mafic materials or that materials exposed have been less affected by space weathering products. These combined initial observations indicate some space weathering processes are active in this part of the main asteroid belt, but are highly variable across the surface of Vesta. Such processes include: impacts from wandering asteroidal debris and local mixing at both micro- and macro-scales, irradiation by solar wind and galactic particles, production and distribution of impact breccias or melt products, and local movement of materials to gravity lows (gradual as well as sudden).

  11. Distinctive space weathering on Vesta from regolith mixing processes.

    PubMed

    Pieters, C M; Ammannito, E; Blewett, D T; Denevi, B W; De Sanctis, M C; Gaffey, M J; Le Corre, L; Li, J-Y; Marchi, S; McCord, T B; McFadden, L A; Mittlefehldt, D W; Nathues, A; Palmer, E; Reddy, V; Raymond, C A; Russell, C T

    2012-11-01

    The surface of the asteroid Vesta has prominent near-infrared absorption bands characteristic of a range of pyroxenes, confirming a direct link to the basaltic howardite-eucrite-diogenite class of meteorites. Processes active in the space environment produce 'space weathering' products that substantially weaken or mask such diagnostic absorption on airless bodies observed elsewhere, and it has long been a mystery why Vesta's absorption bands are so strong. Analyses of soil samples from both the Moon and the asteroid Itokawa determined that nanophase metallic particles (commonly nanophase iron) accumulate on the rims of regolith grains with time, accounting for an observed optical degradation. These nanophase particles, believed to be related to solar wind and micrometeoroid bombardment processes, leave unique spectroscopic signatures that can be measured remotely but require sufficient spatial resolution to discern the geologic context and history of the surface, which has not been achieved for Vesta until now. Here we report that Vesta shows its own form of space weathering, which is quite different from that of other airless bodies visited. No evidence is detected on Vesta for accumulation of lunar-like nanophase iron on regolith particles, even though distinct material exposed at several fresh craters becomes gradually masked and fades into the background as the craters age. Instead, spectroscopic data reveal that on Vesta a locally homogenized upper regolith is generated with time through small-scale mixing of diverse surface components. PMID:23128227

  12. Planetary surface weathering

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1986-01-01

    The weathering of planetary surfaces is treated. Both physical and chemical weathering (reactions between minerals or mineraloids and planetary volatiles through oxidation, hydration, carbonation, or solution processes) are discussed. Venus, earth, and Mars all possess permanent atmospheres such that weathering should be expected to significantly affect their respective surfaces. In contrast, Mercury and the moon lack permanent atmospheres but conceivably could experience surface weathering in response to transient atmospheres generated by volcanic or impact cratering events. Weathering processes can be postulated for other rocky objects including Io, Titan, asteroids, and comets.

  13. Modelling weathering processes at the catchment scale: The WITCH numerical model

    E-print Network

    Mailhes, Corinne

    Centre de Ge´ochimie de la Surface, Strasbourg, France Abstract A numerical model of chemical weatheringModelling weathering processes at the catchment scale: The WITCH numerical model Yves Godde´ris a. Introduction Since the early work by Walker et al. (1981), continental silicate weathering has been recognized

  14. Real-time Storm Detection and Weather Forecast Activation through Data Mining and Events Processing

    E-print Network

    Plale, Beth

    Real-time Storm Detection and Weather Forecast Activation through Data Mining and Events Processing events and launch focused modeling computations for prediction and forecasts of these evolving weather in severe storm modeling through either executing weather forecast runs on a static schedule or through

  15. Do Weather-Induced Moods Affect the Processing of Earnings News? Stanford University

    E-print Network

    Golden, Kenneth M.

    Do Weather-Induced Moods Affect the Processing of Earnings News? Ed deHaan* Stanford University unpleasant weather affects capital market participants' responses to information events. We draw from psychology to develop a new prediction that weather-induced moods reduce market participants' activity levels

  16. Efficient Methods of Doppler Processing for Coexisting Land and Weather Clutter

    E-print Network

    Candan, Cagatay

    Efficient Methods of Doppler Processing for Coexisting Land and Weather Clutter C¸ a~gatay Candan@metu.edu.tr, aoyilmaz@metu.edu.tr Abstract--The joint suppression of returns from land and weather clutter is required in many radar applications. Although the optimal method of land-weather clutter suppression is known

  17. Evidence for Physical Weathering of Iron Meteorite Meridiani Planum (Heat Shield Rock) on Mars

    NASA Astrophysics Data System (ADS)

    Ashley, J. W.; McCoy, T. J.; Schröder, C.

    2009-12-01

    Meteorites on the surfaces of other solar system bodies can provide natural experiments for monitoring weathering processes. In the case of Mars, clues to the more subtle aspects of water occurrence and reaction may be revealed by the effects of highly sensitive aqueous alteration processes, while physical processes may be recorded through aeolian abrasion effects. Over the past 2000 sols, the two Mars Exploration Rover (MER) spacecraft have formally identified a minimum of 11 meteorite candidates [1-3], with many more unofficial candidates likely, posing an intriguing set of questions concerning their chemical, mineralogical, and morphological conditions. Five meteorite candidates, including the newly discovered MER-B rock Block Island, and one confirmed meteorite [Meridiani Planum (MP; originally Heat Shield Rock)] [4] have been investigated with the rover arm instruments. All contain levels of ferric iron, which should not be present in pristine samples (i.e. without fusion crust and/or alteration phases). Moreover, preliminary morphologic evidence contributes to the case of possible chemical weathering in Block Island. Scrutiny of a Microscopic Imager (MI) mosaic of MP shows clear evidence for both localized aeolian sculpting, and the Widmanstätten pattern common to sliced and acid-etched surfaces of many iron-nickel meteorites. These latter features are manifest as millimeter-sized chevrons and subparallel linearities, most prominent across a partially brushed surface approximately 3 x 2 cm in area. Similar patterns are observed on a number of hot and cold desert meteorites (e.g. Drum Mountain and Ft. Stockton), and are attributed to physical ablation by sand grains differentially weathering the kamacite and taenite lamellae within the rock. A similar or identical process is interpreted as responsible for the features observed in MP. Other macro-scale features on MP are of questionable weathering origin. While some prefer a regmaglypt interpretation for the cavities in MP, others question whether differential weathering (either aqueous or physical) of softer sulfide (troilite) nodules or other inclusions such as schreibersite [5] in the metal matrix may be at least partly responsible. A discontinuous coating of darker material, interpreted to be oxide (though it is uncertain whether this is relict fusion crust or weathering rind), appears in the MI images also to have been polished and sculpted by abrasive forces. Laboratory experiments designed to address the requirements for iron shaping by wind abrasion would help provide constraints on the wind velocities involved in these processes. Preliminary results for Block Island display many features that are also consistent with aeolian abrasion. References: [1] Schröder C. et al. (2008) JGR 113, E06S22, doi:10.1029/2007JE002990. [2] Ashley J. W. et al. (2009) LPSC XL. [3] Schröder C. et al. (2009) LPSC XL. [4] Connolly H.C.J. et al. (2006) Meteoritical Bulletin #90, Meteoritics and Planet Sci. 41(9): p. 1383-1418. [5] Fleischer I. et al. (2009) Meteoritics and Planet Sci. 44, p. A70.

  18. Book Review: Dolores Knipp’s Understanding Space Weather and the Physics Behind It

    NASA Astrophysics Data System (ADS)

    Moldwin, Mark

    2012-08-01

    Delores Knipp's textbook Understanding Space Weather and the Physics Behind It provides a comprehensive resource for space physicists teaching in a variety of academic departments to introduce space weather to advanced undergraduates. The book benefits from Knipp's extensive experience teaching introductory and advanced undergraduate physics courses at the U.S. Air Force Academy. The fundamental physics concepts are clearly explained and are connected directly to the space physics concepts being discussed. To expand upon the relevant basic physics, current research areas and new observations are highlighted, with many of the chapters including contributions from a number of leading space physicists.

  19. Space Weathering on 4 Vesta: Processes and Products

    NASA Technical Reports Server (NTRS)

    Pieters, C. M.; Blewett, D. T.; Gaffey, M.; Mittlefehldt, D. W.; De Sanctis, M. C.; Reddy, V.; Nathues, A.; Denevi, B. W.; Li, J. Y.; McCord, T. B.; Marchi, S.; Palmer, E. E.; Sunshine, J. M.; Ammannito, E.; Raymond, C. A.; Russell, C. T.

    2012-01-01

    The bulk properties of Vesta have previously been linked directly to the howardite, eucrite, and diogenite (HED) meteorites through remote mineral characterization of its surface from Earth-based spectroscopy [e.g., 1]. A long-standing enigma has been why does Vesta s surface appear to have suffered so little alteration from the space environment, whereas materials exposed on the Moon and some S-type asteroids are significantly changed (grains develop rims containing nano-phase opaques [e.g. 2]). The Dawn spacecraft is well suited to address this issue and is half through its extended mapping phase of this remarkable proto-planet [3]. On a local scale Dawn sees evidence of recent exposures at craters, but distinctive surface materials blend into background at older craters. The presence of space weathering processes are thus evident at Vesta, but the character and form are controlled by the unique environment and geologic history of this small body.

  20. Weathering processes implied from analysis of small Martian avalanche chutes

    NASA Technical Reports Server (NTRS)

    Sullivan, R.

    1992-01-01

    It has been proposed that the smaller features of martian spur and gully slope morphology, located along the upper walls of Valles Marineris, are avalanche chutes. A three-dimensional stability back-analysis technique was developed and applied to these small avalanche chutes, yielding average values of cohesion and angle of internal friction for the mobile layer materials on these slopes at the time of each slope failure. Generally, the analysis showed that at the time of each slope failure material strengths had been reduced to those of moderately cohesive debris down through depths of tens of meters. These results have implications and possible constraints for the nature and rate of martian weathering processes.

  1. wradlib - an Open Source Library for Weather Radar Data Processing

    NASA Astrophysics Data System (ADS)

    Pfaff, Thomas; Heistermann, Maik; Jacobi, Stephan

    2014-05-01

    Even though weather radar holds great promise for the hydrological sciences, offering precipitation estimates with unrivaled spatial and temporal resolution, there are still problems impeding its widespread use, among which are: almost every radar data set comes with a different data format with public reading software being available only rarely. standard products as issued by the meteorological services often do not serve the needs of original research, having either too many or too few corrections applied. Especially when new correction methods are to be developed, researchers are often forced to start from scratch having to implement many corrections in addition to those they are actually interested in. many algorithms published in the literature cannot be recreated using the corresponding article only. Public codes, providing insight into the actual implementation and how an approach deals with possible exceptions are rare. the radial scanning setup of weather radar measurements produces additional challenges, when it comes to visualization or georeferencing of this type of data. Based on these experiences, and in the hope to spare others at least some of these tedious tasks, wradlib offers the results of the author's own efforts and a growing number of community-supplied methods. wradlib is designed as a Python library of functions and classes to assist users in their analysis of weather radar data. It provides solutions for all tasks along a typical processing chain leading from raw reflectivity data to corrected, georeferenced and possibly gauge adjusted quantitative precipitation estimates. There are modules for data input/output, data transformation including Z/R transformation, clutter identification, attenuation correction, dual polarization and differential phase processing, interpolation, georeferencing, compositing, gauge adjustment, verification and visualization. The interpreted nature of the Python programming language makes wradlib an ideal tool for interactive data exploration and analysis. Based on the powerful scientific python stack (numpy, scipy, matplotlib) and in parts augmented by functions compiled in C or Fortran, most routines are fast enough to also allow data intensive re-analyses or even real-time applications. From the organizational point of view, wradlib is intended to be community driven. To this end, the source code is made available using a distributed version control system (DVCS) with a publicly hosted repository. Code may be contributed using the fork/pull-request mechanism available to most modern DVCS. Mailing lists were set up to allow dedicated exchange among users and developers in order to fix problems and discuss new developments. Extensive documentation is a key feature of the library, and is available online at http://wradlib.bitbucket.org. It includes an individual function reference as well as examples, tutorials and recipes, showing how those routines can be combined to create complete processing workflows. This should allow new users to achieve results quickly, even without much prior experience with weather radar data.

  2. Anvil Tool in the Advanced Weather Interactive Processing System

    NASA Technical Reports Server (NTRS)

    Barrett, Joe, III; Bauman, William, III; Keen, Jeremy

    2007-01-01

    Meteorologists from the 45th Weather Squadron (45 WS) and Spaceflight Meteorology Group (SMG) have identified anvil forecasting as one of their most challenging tasks when predicting the probability of violations of the lightning Launch Commit Criteria and Space Shuttle Flight Rules. As a result, the Applied Meteorology Unit (AMU) created a graphical overlay tool for the Meteorological Interactive Data Display Systems (MIDDS) to indicate the threat of thunderstorm anvil clouds, using either observed or model forecast winds as input. In order for the Anvil Tool to remain available to the meteorologists, the AMU was tasked to transition the tool to the Advanced Weather interactive Processing System (AWIPS). This report describes the work done by the AMU to develop the Anvil Tool for AWIPS to create a graphical overlay depicting the threat from thunderstorm anvil clouds. The AWIPS Anvil Tool is based on the previously deployed AMU MIDDS Anvil Tool. SMG and 45 WS forecasters have used the MIDDS Anvil Tool during launch and landing operations. SMG's primary weather analysis and display system is now AWIPS and the 45 WS has plans to replace MIDDS with AWIPS. The Anvil Tool creates a graphic that users can overlay on satellite or radar imagery to depict the potential location of thunderstorm anvils one, two, and three hours into the future. The locations are based on an average of the upper-level observed or forecasted winds. The graphic includes 10 and 20 nm standoff circles centered at the location of interest, in addition to one-, two-, and three-hour arcs in the upwind direction. The arcs extend outward across a 30 degree sector width based on a previous AMU study which determined thunderstorm anvils move in a direction plus or minus 15 degrees of the upper-level (300- to 150-mb) wind direction. This report briefly describes the history of the MIDDS Anvil Tool and then explains how the initial development of the AWIPS Anvil Tool was carried out. After testing was performed by SMG, 45 WS, and AMU, a number of needed improvements were identified. A bug report document was created that showed the status of each bug and desired improvement. This report lists the improvements that were made to increase the accuracy and user-friendliness of the tool. Final testing was carried out and documented and then the final version of the software and Users Guide was provided to SMG and the 45 WS. Several possible future improvements to the tool are identified that would increase the flexibility of the tool. This report contains a brief history of the development of the Anvil Tool in MIDDS, and then describes the transition and development of software to AWIPS.

  3. The physics of Martian weather and climate: a review.

    PubMed

    Read, P L; Lewis, S R; Mulholland, D P

    2015-12-01

    The planet Mars hosts an atmosphere that is perhaps the closest in terms of its meteorology and climate to that of the Earth. But Mars differs from Earth in its greater distance from the Sun, its smaller size, its lack of liquid oceans and its thinner atmosphere, composed mainly of CO2. These factors give Mars a rather different climate to that of the Earth. In this article we review various aspects of the martian climate system from a physicist's viewpoint, focusing on the processes that control the martian environment and comparing these with corresponding processes on Earth. These include the radiative and thermodynamical processes that determine the surface temperature and vertical structure of the atmosphere, the fluid dynamics of its atmospheric motions, and the key cycles of mineral dust and volatile transport. In many ways, the climate of Mars is as complicated and diverse as that of the Earth, with complex nonlinear feedbacks that affect its response to variations in external forcing. Recent work has shown that the martian climate is anything but static, but is almost certainly in a continual state of transient response to slowly varying insolation associated with cyclic variations in its orbit and rotation. We conclude with a discussion of the physical processes underlying these long- term climate variations on Mars, and an overview of some of the most intriguing outstanding problems that should be a focus for future observational and theoretical studies. PMID:26534887

  4. The physics of Martian weather and climate: a review

    NASA Astrophysics Data System (ADS)

    Read, P. L.; Lewis, S. R.; Mulholland, D. P.

    2015-12-01

    The planet Mars hosts an atmosphere that is perhaps the closest in terms of its meteorology and climate to that of the Earth. But Mars differs from Earth in its greater distance from the Sun, its smaller size, its lack of liquid oceans and its thinner atmosphere, composed mainly of CO2. These factors give Mars a rather different climate to that of the Earth. In this article we review various aspects of the martian climate system from a physicist’s viewpoint, focusing on the processes that control the martian environment and comparing these with corresponding processes on Earth. These include the radiative and thermodynamical processes that determine the surface temperature and vertical structure of the atmosphere, the fluid dynamics of its atmospheric motions, and the key cycles of mineral dust and volatile transport. In many ways, the climate of Mars is as complicated and diverse as that of the Earth, with complex nonlinear feedbacks that affect its response to variations in external forcing. Recent work has shown that the martian climate is anything but static, but is almost certainly in a continual state of transient response to slowly varying insolation associated with cyclic variations in its orbit and rotation. We conclude with a discussion of the physical processes underlying these long- term climate variations on Mars, and an overview of some of the most intriguing outstanding problems that should be a focus for future observational and theoretical studies.

  5. Development of alteration rinds by oxidative weathering processes in Beacon Valley, Antarctica, and implications for Mars

    E-print Network

    Marchant, David R.

    Development of alteration rinds by oxidative weathering processes in Beacon Valley, Antarctica by subsequent aqueous weathering processes. The hyper-arid and hypo- thermal environment of Beacon Valley report on the nature of initial chemical alteration of the Ferrar Dolerite in Beacon Valley, Antarctica

  6. Zeolite Formation and Weathering Processes in Dry Valleys of Antartica: Martian Analogs

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Wentworth, S. J.; McKay, D. S.; Socki, R. A.

    2004-01-01

    Terrestrial weathering processes in cold-desert climates such as the Dry Valleys of Antarctica may provide an excellent analog to chemical weathering and diagenesis of soils on Mars. Detailed studies of soil development and the chemical and mineralogical alterations occurring within soil columns in Wright Valley, Antarctica show incredible complexity in the upper meter of soil. Previous workers noted the ice-free Dry Valleys are the best terrestrial approximations to contemporary Mars. Images returned from the Pathfinder and Spirit landers show similarities to surfaces observed within the Dry Valleys. Similarities to Mars that exist in these valleys are: mean temperatures always below freezing (-20 C), no rainfall, sparse snowfall-rapidly removed by sublimation, desiccating winds, diurnal freeze-thaw cycles (even during daylight hours), low humidity, oxidative environment, relatively high solar radiation and low magnetic fields . The Dry Valley soils contain irregular distributions and low abundances of soil microorganisms that are somewhat unusual on Earth. Physical processes-such as sand abrasion-are dominant mechanisms of rock weathering in Antarctica. However, chemical weathering is also an important process even in such extreme climates. For example, ionic migration occurs even in frozen soils along liquid films on individual soil particles. It has also been shown that water with liquid-like properties is present in soils at temperatures on the order of approx.-80 C and it has been observed that the percentage of oxidized iron increases with increasing soil age and enrichments in oxidized iron occurs toward the surface. The presence of evaporates is evident and appear similar to "evaporite sites" within the Pathfinder and Spirit sites. Evaporites indicate ionic migration and chemical activity even in the permanently frozen zone. The presence of evaporates indicates that chemical weathering of rocks and possibly soils has been active. Authogenic zeolites have been identified within the soil columns because they are fragile; i.e. they are euhedral, unabraded, and unfractured, strongly suggesting in situ formation. Their presence in Antarctic samples is another indication that diagenic processes are active in cold-desert environments. The presence of zeolites, and other clays along with halites, sulfates, carbonates, and hydrates are to be expected within the soil columns on Mars at the Gusev and Isidis Planitia regions. The presence of such water-bearing minerals beneath the surface supplies one of the requirements to support biological activity on Mars.

  7. Low-Frequency Weather and the Emergence of the Climate Department of Physics, McGill University, Montreal, Quebec, Canada

    E-print Network

    Lovejoy, Shaun

    Low-Frequency Weather and the Emergence of the Climate S. Lovejoy Department of Physics, Mc, Paris, France Météo France, Paris, France We survey atmospheric variability from weather scales up quenched, leading to a scaling "low-frequency weather" regime extending out to c 10­100 years

  8. The Space Physics of Life: Searching for Biosignatures on Habitable Icy Worlds Affected by Space Weathering

    NASA Technical Reports Server (NTRS)

    Cooper, John F.

    2006-01-01

    Accessible surfaces of the most likely astrobiological habitats (Mars, Europa, Titan) in the solar system beyond Earth are exposed to various chemical and hydrologic weathering processes directly or indirectly induced by interaction with the overlying space environment. These processes can be both beneficial, through provision of chemical compounds and energy, and destructive, through chemical dissociation or burial, to detectable presence of biosignatures. Orbital, suborbital, and surface platforms carrying astrobiological instrumentation must survive, and preferably exploit, space environment interactions to reach these habitats and search for evidence of life or its precursors. Experience from Mars suggests that any detection of biosignatures must be accompanied by characterization of the local chemical environment and energy sources including irradiation by solar ultraviolet photons and energetic particles from the space environment. Orbital and suborbital surveys of surface chemistry and astrobiological potential in the context of the space environment should precede targeted in-situ measurements to maximize probability of biosignature detection through site selection. The Space Physics of Life (SPOL) investigation has recently been proposed to the NASA Astrobiology Institute and is briefly described in this presentation. SPOL is the astrobiologically relevant study of the interactions and relationships of potentially? or previously inhabited, bodies of the solar system with the surrounding environments. This requires an interdisciplinary effort in space physics, planetary science, and radiation biology. The proposed investigation addresses the search for habitable environments, chemical resources to support life, and techniques for detection of organic and inorganic signs of life in the context of the space environment.

  9. Effect of Weathering Processes on Mineralogical and Mechanical Properties of Volcanic Rocks Used as Ballast Material for Railway Between Sabuncupinar and Kütahya in Western Turkey

    NASA Astrophysics Data System (ADS)

    Abiddin Erguler, Zeynal; Ad?güzel, Ömer; Derman, Mustafa

    2015-04-01

    Geomaterials used in engineering projects and man-made structures such as railway ballasts, buildings, historical structures, monuments and tombstones naturally weather as a result of various physico-chemical factors. Due to being long-term exposure to the anthroposphere, geomaterials used for these purposes provides important information to the researchers for understanding the effect of weathering processes on their time dependent physical, mineralogical and mechanical changes. Thus, researchers frequently can take advantage of available engineering time of man-made structures to assess weathering properties of the geomaterials used in their construction in terms of time dependent durability and stability of these structures. Considering the fact that railway ballasts produced from natural deposits of limestone, dolomite, granite, basalt etc., supply an important contribution for evaluation weathering processes, a research was carried out to determine the effect of weathering as a function of time on physical, mineralogical and mechanical properties of ballasts used for railway between Kütahya and Sabuncup?nar in western Turkey. For this purpose, fresh and weathered rock samples exposed to physical and chemical weathering processes at different times were collected from quarry located in Sabuncup?nar and nearby railway. This volcanic rock was previously classified as basalt based on the detailed mineralogical and geochemical analyses performed at the laboratories of the Mineral Research & Exploration General Directorate located in Ankara (Turkey). In-situ characteristics of sampling site were also investigated at different locations of quarry site by line surveying technique to describe the influence of discontinuity conditions on the weathering rate of selected rocks. Several techniques were utilized to determine time dependent deterioration in mineralogical and chemical composition of these samples for understanding their weathering rate. The porosity, water absorption by weight, weight loss after slake durability index and freezing-thawing tests and Los Angeles abrasion value of these samples subjected to weathering processes at different time intervals at field conditions were also determined to measure the time dependent resistance of collected ballast materials against natural weathering processes. When all results obtained from mineralogical and chemical analyses, field observations and further laboratory tests are considered, it can be concluded that collected ballast materials provide important information for understanding weathering rate of basalt. Furthermore, despite of being exposure to the anthroposphere for very long time, the very little water absorption content, resistance to extreme weather conditions and very angular characteristics of collected samples indicate that these previously used materials can still serve the purpose as ballast materials in accordance to related standards (TS 7043 and EN 13450).

  10. Weathering processes and pickeringite formation in a sulfidic schist: a consideration in acid precipitation neutralization studies

    SciTech Connect

    Parnell, R.A. Jr.

    1983-01-01

    Extremely low abrasion pH values (2.8-3.3) characterize the weathering products of the Partridge Formation, a Middle-Ordovician metamorphosed, black, sulfidic shale. The local occurrence is observed of two sulfates that are rare in the Northeast: pickeringite and jarosite. X-ray diffraction studies of the weathering residues and the sulfate efflorescences have also identified dioctahedral and trioctahedral illite, kaolinite, vermiculite, and an 11-12 Angstrom phase, thought to be a type of randomly-interstratified biotite-vermiculite. From the mineralogical studies, qualitative weathering processes for the schist are formulated. A probable mechanism for the intense chemical weathering of the schist appears to be oxidation of iron sulfides to form iron oxide-hydroxides, sulfates, and sulfuric acid. This natural weathering process is proposed as an analog to anthropogenic low pH rock weathering resulting from acid precipitation. In the Northeast, natural weathering rates, may, in places, significantly affect the water chemistry and mineralogy used to quantify total (natural plus anthropogenic) weathering and leaching rates. 27 references, 4 figures.

  11. At the Earth's surface,a complex suite of chemical,biological,and physical processes

    E-print Network

    Chorover, Jon

    profiles; providing expertise in field-based data collection; and training a new cohort of weatheringAt the Earth's surface,a complex suite of chemical,biological,and physical processes combines; stan- dardizing data and sample collection for weathering systems; decoupling complex bio- physico

  12. New Space Weather and Nonlinear Waves and Processes Prize announced for 2013

    NASA Astrophysics Data System (ADS)

    Thompson, Victoria

    2012-01-01

    At the 2011 Fall Meeting in San Francisco, Calif., AGU announced the creation of a new award: the Space Weather and Nonlinear Waves and Processes Prize. The prize, which is being made possible by a generous contribution from longtime AGU members and NASA Jet Propulsion Laboratory (JPL), California Institute of Technology, scientists Bruce Tsurutani and Olga Verkhoglyadova, will recognize an AGU member scientist and will come with a $10,000 award. Tsurutani has served as a researcher with JPL since 1972 and is currently a senior research scientist. He was also the president of AGU's Space Physics and Aeronomy section from 1990 to 1992 and is a recipient of AGU's John Adam Fleming Medal, given “for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences.” Verkhoglyadova served as a professor of space physics in the Department of Astrophysics and Space Physics at Taras Shevchenko National University of Kyiv, in the Ukraine, prior to coming to the United States. Their leadership and dedication to AGU and to their field are apparent in their passion for this prize.

  13. The Evolution of Soil Hydrological and Physical Properties under the Impact of Mineral Weathering and Organic Matter Sequestration

    NASA Astrophysics Data System (ADS)

    Tan, F.; Lunn, E.; Fisher, B.; Yoo, K.; Imhoff, P. T.; Michael, H. A.

    2014-12-01

    Soil water characteristic (SWC) curve is important for modeling unsaturated flow and reactive transport. SWC also likely influences mineral weathering by affecting water-mineral interactions in the critical zone. The depth profiles of SWC could form as a result of long-term chemical weathering and physical erosion processes. We measured SWCs on samples collected from soil pit and drill cores which captured the weathering profiles from ground surface to slightly weathered bedrock (~7m depth) on a hillslope in Laurel Preserve in West Chester, PA. The weathering profile represents the co-evolution of hydrological and physical properties with varied degrees of weathering and organic matter (OM) content. A WP4C Dewpoint Potentiameter was used to obtain the SWCs (matric potential range: -300 ~ -1.5MPa) for original and OM-removed samples, where OM was removed by heating samples to 350? for 24 h. From the WP4C measurement, soil samples from shallower depths (?44cm) retained more water at a given matric potential, with water contents at shallower depths generally ~2-3 times more than that for saprolite samples from deeper depths at similar matric potentials, indicating that soil water retention increased with degree of weathering. The SWCs measured by WP4C were used to estimate the specific surface area (SSA) using the Tuller and Or (TO) model (Tuller and Or, 2005) , which is based on the assumption that water forms a film on micropore surfaces at the dry end (matric potential ? -1.5MPa). The SSA estimation from the TO model followed the same trend as SSA measured with the N2-BET method. However, the estimated SSA was greater than BET-based SSA, indicating possible underestimation of SSA by the N2-BET method. The comparison of SWC and SSA between original and OM-removed samples indicated the presence of a threshold depth of ~40cm. At depths shallower than 40cm, especially at A horizon (OM ? 9.5Wt%), OM removal significantly decreased estimated SSA and water content at similar matric potentials, while at deeper depths (OM ? 2.7Wt%), the OM-removal treatment resulted in either no change or a slight increase in SSA. The possible existence of a threshold depth indicates that the interactions between OM-mineral sorption and water-mineral interaction differ with depth and are particularly strong within OM-rich surface soils.

  14. CHEMICAL WEATHERING AND SOLUTION CHEMISTRY IN ACID FOREST SOILS: DIFFERENTIAL INFLUENCE OF SOIL TYPE, BIOTIC PROCESSES, AND H+ DEPOSITION

    EPA Science Inventory

    In the investigation, weathering rates were calculated for three eastern North American forest soils using five separate estimation techniques. In addition, leaching experiments were performed to examine the influence of selected environmental variables on the weathering process....

  15. Interstellar Dust: Physical Processes

    NASA Technical Reports Server (NTRS)

    Jones, A. P.; Tielens, A. G. G. M.

    1993-01-01

    Dust is formed in stellar environments, and destroyed by sputtering, shattering and vaporization in shock waves due to cloud-cloud collisions and supernova blast waves. Dust is also destroyed during star formation. We review the dust formation and destruction balance. The calculated destruction time-scale is less than or equal to one billion years and the star dust injection time-scale is approx. 2.5 billion years. Hence, the fractions of elemental carbon and silicon locked up in stardust are less than 0.3 and less than 0.15, respectively. An efficient ISM dust formation route is therefore implied. In particular, in dense clouds dust grows; through the processes of coagulation and the accretion of gas phase molecules e.g. H20, CO, CH4. These icy materials may then be photoprocessed to refractory materials in more diffuse regions. The resulting carbonaceous grain mantle may actually be the glue that holds the coagulated grains together.

  16. Chemical Weathering of Soils from the Dry Valleys of Antarctica: a Terrestrial Analog of Martian Weathering Processes

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.

    1985-01-01

    Martian soil subjected to chemical weathering processes could contain the following likely constituents: (1) fresh primary silicate material; (2) partially altered primary silicates; (3) secondary minerals, possibly including clay minerals, evaporites, carbonates, sulfates, hydrates, and zeolites; and (4) altered volcanic glass or impact glass. The soil may also include palogonite and other alteration products and secondary minerals. It is unlikely therefore that an equilibrium assemblage of minerals would be present. From the detailed study of the soils from the Dry Valleys of Antarctica, it is obvious that the complex processes in operation produce major changes in the parent materials, depending upon where the constituents reside and the degree to which weathering and diagenesis operates. It is clear that natural near surface environments, even in very cold and dry regions, may produce extremely complex soils. Extreme caution must be taken when interpreting the results and drawing conclusions, especially about possible processes operating in regoliths in cold, arid environments similar to those of the Dry Valleys or Mars.

  17. Understanding Magnetic Reconnection: The Physical Mechanism Driving Space Weather

    NASA Astrophysics Data System (ADS)

    Black, Carrie; Antiochos, Spiro K.; Karpen, Judith T.; Germaschewski, Kai; Bessho, Naoki

    2015-04-01

    The explosive energy release in solar eruptive events is believed to be due to magnetic reconnection. In the standard model for coronal mass ejections (CME) and/or solar flares, the free energy for the event resides in the strongly sheared magnetic field of a filament channel. The pre-eruption force balance consists of an upward force due to the magnetic pressure of the sheared field countered by the downward tension of the overlying unsheared field. Magnetic reconnection disrupts this force balance. Therefore, to understand CME/flare initiation, it is critical to model the onset of reconnection driven by the build-up of magnetic shear. In MHD simulations, the application of a magnetic-field shear is trivial. However, kinetic effects are important in the diffusion region and thus, it is important to examine this process with PIC simulations as well. The implementation of such a driver in PIC methods is nontrivial, however, and indicates the necessity of a true multiscale model for such processes in the solar environment. The field must be sheared self-consistently and indirectly to prevent the generation of waves that destroy the desired system. In the work presented here, we show reconnection in an X-Point geometry due to a velocity shear driver perpendicular to the plane of reconnection.This material is based upon work supported by the National Science Foundation under Award No. AGS-1331356 and NASA's Living With a Star Targeted Research and Technology program.

  18. Conversion of bedrock to soil and feedback processes between the surface and the weathering front in a deeply weathered regolith, Central Sri Lankan Highlands

    NASA Astrophysics Data System (ADS)

    Behrens, Ricarda; Bouchez, Julien; Schuessler, Jan A.; Dultz, Stefan; Hewawasam, Tilak; von Blanckenburg, Friedhelm

    2014-05-01

    In the Sri Lankan highlands denudation rates and chemical weathering rates represent the low-end-member in global weathering rates [1, 2]. Here we explore the causes for these low rates by a detailed soil-mineralogical study of a highly weathered deep saprolite profile developed from charnockite bedrock. Spheroidal weathering of the bedrock characterized the weathering front where rounded corestones are produced at the rock-saprolite interface. The first mineral attacked by weathering was found to be pyroxene but plagioclase is the first mineral depleted to near-completion at the corestone-saprolite-boundary. Weathering of pyroxene is initiated by in situ iron oxidation, leading to an increase of porosity due to micro-cracking [3]. The accrued micro cracks allow for fluid transport and the dissolution of biotite and plagioclase. The strong plagioclase weathering leads to formation of high secondary porosity over a small distance and the final disaggregation of bedrock to saprolite. Sequential extraction showed that the first secondary phases are amorphous oxides from which secondary minerals (gibbsite, kaolinite, goethite and minor amounts of smectites) precipitate. Modeling of the strain formation due to increasing volume during iron oxidation in pyroxene and biotite showed that spheroidal weathering can be explained with this process only if the formation of secondary porosity, due to a negative volume budget during primary mineral weathering to secondary phases, occurs. As oxidation is the first occurring reaction, O2 is a rate limiting factor for chemical weathering in this setting. Hence the supply of oxygen and the consumption at depth connects processes at the weathering front with those at the surface as a feedback mechanism. Advective and diffusive transport modeling shows that the feedback will be much more pronounced with dominating diffusive transport. Due to the low porosity of the bedrock the O2 transport in the pristine bedrock occurs via diffusion. The slow weathering rate is, beside tectonic quiescence, related to this feedback and to lithological factors such as low porosity and the amount of Fe-bearing primary minerals. 1. Hewawasam, T., et al., Slow advance of the weathering front during deep, supply-limited saprolite formation in the tropical Highlands of Sri Lanka. Geochimica et Cosmochimica Acta, 2013. 118: p. 202-230. 2. von Blanckenburg, F., T. Hewawasam, and P. Kubik, Cosmogenic nuclide evidence for low weathering and denudation in the wet tropical Highlands of Sri Lanka. J. Geoph. Res., 2004. 109: p. doi10.1029/2003JF000049. 3. Buss, H.L., et al., Weathering of the Rio Blanco quartz diorite, Luquillo Mountains, Puerto Rico: Coupling oxidation, dissolution, and fracturing. Geochimica et Cosmochimica Acta, 2008. 72(18): p. 4488-4507.

  19. Geochemistry of river-borne clays entering the East China Sea indicates two contrasting types of weathering and sediment transport processes

    NASA Astrophysics Data System (ADS)

    Bi, Lei; Yang, Shouye; Li, Chao; Guo, Yulong; Wang, Quan; Liu, James T.; Yin, Ping

    2015-09-01

    The East China Sea is characterized by wide continental shelf receiving a huge input of terrigenous matter from both large rivers and mountainous rivers, which makes it an ideal natural laboratory for studying sediment source-to-sink transport processes. This paper presents mineralogical and geochemical data of the clays and bulk sediments from the rivers entering the East China Sea, aiming to investigate the general driving mechanism of silicate weathering and sediment transport processes in East Asian continental margin. Two types of river systems, tectonically stable continental rivers and tectonically active mountainous rivers, coexist in East Asia. As the direct weathering products, clays can better reflect the silicate weathering regimes within the two river systems. Provenance rock types are not the dominant factor causing silicate weathering intensity difference existed in the East Asian rivers. The silicate weathering intensity of tectonically stable river basins is primarily driven by monsoon climate, and the sediment transfer is relatively slow because of natural trapping process and increasing damming effect. The geochemistry of these river-borne sediments can thus indicate paleo-weathering intensities in East Asian continent. In contrast, silicate weathering intensity in tectonically active mountainous rivers is greatly limited by strong physical erosion despite the high temperature and highest monsoon rainfall. The factors controlling silicate weathering in tectonically active catchments are complex and thus, it should be prudent to use river sediment records to decipher paleoclimate change. These two different silicate weathering regimes and sediment transport processes are manifestations of the landscape evolution and overall dominate the sedimentation in Asian continental margin.

  20. Understanding space weather to shield society

    E-print Network

    Schrijver, Karel

    Understanding space weather to shield society Improving understanding and forecasts of space weather requires addressing scientific challenges within the network of physical processes that connect the Sun to society. The roadmap team identified the highest-priority areas within the Sun-Earth space-weather

  1. Reconstructing chemical weathering, physical erosion and monsoon intensity since 25 Ma in the northern South China Sea: A review

    E-print Network

    Clift, Peter

    Reconstructing chemical weathering, physical erosion and monsoon intensity since 25 Ma October 2013 Accepted 7 January 2014 Available online 15 January 2014 Keywords: Monsoon Erosion Weathering changing chemical erosion in the northern South China Sea since the Oligocene, using the links between

  2. TIMBER HARVESTING AND LONG-TERM PRODUCTIVITY: WEATHERING PROCESSES AND SOIL DISTURBANCE

    EPA Science Inventory

    Both timber harvesting and amelioration practices can cause chemical and physical changes in soil. hese changes can affect factors which alter soil mineral stability and weathering rates, potentially changing inputs to the nutrient cycle. his paper discusses possible effects of h...

  3. The Spatial Variability of Weathering Processes in a Peruvian River System

    NASA Astrophysics Data System (ADS)

    Torres, M. A.; Ballew, N.; Clark, K.; West, A.

    2011-12-01

    The role of floodplains in the weathering of sediment exported from mountainous regions is poorly understood and has the potential to play a significant role in the overall weathering budget of large river systems. While high rates of floodplain weathering have been measured in the Himalayan system [1], there are conflicting results concerning the importance of floodplain weathering in the Amazon system [2-3]. To address this issue, the dissolved major element chemistry of the Kosñipata-Madre de Dios river system in Peru was measured monthly in nested catchments spanning the headwater-floodplain transition in order to determine spatially-resolved weathering rates and to examine any associated changes in weathering processes. Analysis of the dissolved major element data reveals a change in the dominant weathering process controlling the Ca2+ and Mg2+ fluxes associated with the headwater-floodplain transition. Based on (Ca2+ + Mg2+) / HCO3- ratios near 0.5, Ca2+ and Mg2+ fluxes in the floodplain are controlled by carbonate dissolution by carbonic acid. In the Andean catchments, variable (Ca2+ + Mg2+) / HCO3- ratios, (Ca2+ + Mg2+) / SO42- ratios near 1, and high SO42- concentrations suggest that either carbonate dissolution by sulfuric acid or sulfate mineral dissolution is the main control on Ca2+ and Mg2+ fluxes. This observed change is significant as it has important implications for the net consumption of CO2 by silicate weathering in this river system. [1] West, AJ et al, 2002, Geology 30: 355-358, [2] Gaillardet, J et al, 2006, Geochim. Cosmochim. Acta 70: 189, [3] Moquet, J et al, 2011, Chem. Geol 287: 1-26

  4. doi:10.1016/S0016-7037(03)00382-X Long-term rates of chemical weathering and physical erosion from cosmogenic nuclides

    E-print Network

    Kirchner, James W.

    doi:10.1016/S0016-7037(03)00382-X Long-term rates of chemical weathering and physical erosion from weathering and physical erosion is important for under- standing the long-term evolution of soils, landscapes, and Earth's climate. Here we describe how long-term chemical weathering rates can be measured for actively

  5. [Role of microscopic fungi in the process of weathering of pegmatite deposit rocks and minerals].

    PubMed

    Avakian, Z A; Karavaiko, G I; Mel'nikova, E O; Krutsko, V S; Ostroushko, Iu I

    1981-01-01

    The object of this work was to study the effect of microscopic fungi isolated from the weathering zone of a pegmatite deposit on the transport of elements and the degradation of rocks and minerals. Regardless of the chemical composition of rocks and minerals, microscopic fungi accelerated the leaching of elements as compared to the purely chemical process. The extraction of Li, Si, Al and Fe under the action of microorganisms increased by factors of 1.4-1.7, 2.7-4.0, 5.0-8.7 and 4-18, respectively. In the case of chemical weathering, the extraction of elements occurred at a high rate only at the beginning; then the process either decelerated or stopped. The mechanism of action of microscopic fungi on rocks and minerals is discussed as well as the role of these microorganisms in the weathering of spodumene and the surrounding rocks, pegmatites an shales, which occurs in the zone of hypergenesis. PMID:7194415

  6. Physical Processing of Cometary Nuclei

    NASA Astrophysics Data System (ADS)

    Weissman, Paul R.; Stern, S. Alan

    1997-12-01

    Cometary nuclei preserve a cosmo-chemical record of conditions and processes in the primordial solar nebula, and possibly even the interstellar medium. However, that record is not perfectly preserved over the age of the solar system due to a variety of physical processes which act to modify cometary surfaces and interiors. Possible structural and/or internal processes include: collisional accretion, disruption, and reassembly during formation; internal heating by long and short-lived radionuclides; amorphous to crystalline phase transitions, and thermal stresses. Identified surface modification processes include: irradiation by galactic cosmic rays, solar protons, UV photons, and the Sun's T Tauri stage mass outflow; heating by passing stars and nearby supernovae; gardening by debris impacts; the accretion of interstellar dust and gas and accompanying erosion by hypervelocity dust impacts and sputtering; and solar heating with accompanying crust formation. These modification processes must be taken into account in both the planning and the interpretation of the results of a Comet Nucleus Sample Return Mission. Sampling of nuclei should be done at as great a depth below the surface crust as technically feasible, and at vents or fissures leading to exposed volatiles at depth. Samples of the expected cometary crust and near-surface layers also need to be returned for analysis to achieve a better understanding of the effects of these physical processes. We stress that comets are still likely less modified dm any other solar system bodies, but the degree of modification can vary greatly from one comet to the next.

  7. Physical limits on information processing

    E-print Network

    Stephen D. H. Hsu

    2006-08-04

    We derive a fundamental upper bound on the rate at which a device can process information (i.e., the number of logical operations per unit time), arising from quantum mechanics and general relativity. In Planck units a device of volume V can execute no more than the cube root of V operations per unit time. We compare this to the rate of information processing performed by nature in the evolution of physical systems, and find a connection to black hole entropy and the holographic principle.

  8. Vadose Zone Processes and Chemical Transport Effects of Spent Mushroom Substrate Weathering on the Chemistry of Underlying Soils

    E-print Network

    Chorover, Jon

    Vadose Zone Processes and Chemical Transport Effects of Spent Mushroom Substrate Weathering on the Chemistry of Underlying Soils Mingxin Guo, Jon Chorover,* and Richard H. Fox ABSTRACT mushroom production mushroom substrate (SMS) before its reuse. During the weathering process, leachate containing high

  9. Physical processing of cometary nuclei

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Stern, S. Alan

    1989-01-01

    Cometary nuclei were formed far from the Sun in the colder regions of the solar nebula, and have been stored in distant orbits in the Oort cloud over most of the history of the solar system. It had been thought that this benign environment would preserve comets in close to their original pristine state. However, recent studies have identified a number of physical processes that have likely acted to modify cometary nuclei in a variety of significant ways. It is important to consider all of these possible processes, both in deciding on a site on the nucleus for collection of cometary samples, and in interpreting the results of analyses of returned cometary samples. Although it can no longer be said that comets are pristine samples of original solar nebula material, they are still the best obtainable samples of that unique period in the formation of the planetary system.

  10. Using MSG-SEVIRI Cloud Physical Properties and Weather Radar Observations for the Detection of Cb/TCu Clouds

    E-print Network

    Schmeits, Maurice

    Using MSG-SEVIRI Cloud Physical Properties and Weather Radar Observations for the Detection of Cb/towering cumulus (Cb/TCu) cloud detection method for the months of May­September is presented that combines. First, a pixel-based convective cloud mask (CCM) is con- structed on the basis of cloud physical

  11. Deducing Weathering Processes Using Silicon Isotopes in the Ganges Alluvial Plain, India

    NASA Astrophysics Data System (ADS)

    Frings, P.; De La Rocha, C. L.; Fontorbe, G.; Chakrapani, G.; Clymans, W.; Conley, D. J.

    2014-12-01

    The Ganges Alluvial Plain ('GAP') is the sedimentary infill of the foreland basin created during Himalayan orogeny. Freshly eroded material from the Himalaya and southern cratonic tributaries is deposited into a system with long water-sediment interaction times, creating potential for further generation of river weathering fluxes. To quantify weathering processes in the GAP, 51 sites including all major tributaries were sampled in a September 2013 campaign and analysed for major and minor ions, Ge/Si ratios and ?30Si, ?13C and ?18O. Net dissolved Si (DSi) and major cation yields are 2 to 5 times lower in the GAP than the Himalaya, and at a whole basin scale approximate the global average, indicating that the plain apparently moderates the efficiency of Himalayan weathering rates. Mainstem ?30Si spans 0.81 to 1.93‰ (see figure) and gives the impression of a system buffered to moderate DSi and ?30Si. Ge/Si ratios (µmol/mol) are higher than expected in the Himalaya (>3), reflecting input of Ge-enriched water from hot springs, and decline to ~1.4 in the GAP. For the Himalayan sourced rivers, ?30Si increases with distance from the Himalayan front, and can not be explained entirely by conservative mixing with higher ?30Si peninsular and GAP streams. To a first degree, the ?30Si data suggest incorporation of Si into secondary minerals as the key fractionating process, and that this occurs both in situ during initial weathering and progressively in the GAP. Partitioning of solutes between sources is complicated in the GAP. Consistent with previous work, carbonate weathering dominates the ion fluxes, but with substantial contributions from saline/alkaline soil salts, the chlorination of wastewater and highly variable rainfall chemistry. Due to these contributions, precisely inferring the input from silicate weathering is difficult. We introduce a novel method to infer silicate-weathering rates that exploits the fractionation of Si during clay formation to account for the loss of DSi from solution.

  12. A New Multi-Wavelength Synoptic Network for Solar Physics and Space Weather

    NASA Astrophysics Data System (ADS)

    Hill, Frank; Roth, Markus; Thompson, Michael

    2013-04-01

    Continuous solar observations are important for many research topics in solar physics, such as magnetic field evolution, flare and CME characteristics, and p-mode oscillation measurements. In addition, space weather operations require constant streams of solar data as input. The deployment of a number of identical instruments around the world in a network has proven to be a very effective strategy for obtaining nearly continuous solar observations. The financial costs of a network are 1-2 orders of magnitude lower than space-based platforms; network instrumentation can be easily accessed for maintenance and upgrades; and telemetry bandwidth is readily available. Currently, there are two solar observing networks with consistent instruments: BiSON and GONG, both designed primarily for helioseismology. In addition, GONG has been augmented with continual magnetic field measurements and H-alpha imagery, with both being used for space weather operational purposes. However, GONG is now 18 years old and getting increasingly more challenging to maintain. There are also at least three scientific motivations for a multi-wavelength network: Recent advances in helioseismology have demonstrated the need for multi-wavelength observations to allow more accurate interpretation of the structure and dynamics below sunspots. Vector magnetometry would greatly benefit from multi-wavelength observations to provide height information and resolve the azimuthal ambiguity. Finally, space weather operations always need a consistent reliable source of continual solar data. This presentation will outline the scientific need for a multi-wavelength network, and discuss some concepts for the design of the instrumentation. A workshop on the topic will be held in Boulder this April.

  13. Inclusions in precious Australian opals offer a unique access to Martian-like weathering processes

    NASA Astrophysics Data System (ADS)

    Roberts, Gemma; Rey, Patrice; Carter, Elizabeth

    2015-04-01

    Spectral signatures of the surface of Mars indicate a variety of hydrated minerals, including Al- and Fe/Mg-rich phyllosilicates, iron oxides, sulfates, and opaline silica. Their formation has been attributed to a long-lived low-temperature aqueous weathering history (e.g. Bishop et al., 2008; Ehlmann et al., 2013) followed by a period of intense acidic oxidative weathering (e.g. Carter et al., 2013). Very acidic weathering, driven by volcanic-derived sulfuric acid, is possible on a regional scale on Mars because of the lack of carbonate. On Earth, however, low-pH weathering on a regional scale is unusual because of the abundance of carbonate. Finding regional-scale Martian analogues on Earth is therefore a challenge. The Great Artesian Basin (GAB) in central Australia formed during the Early Cretaceous from the deposition of pyrite-rich volcaniclastic sediments in a cold, muddy, anoxic and shallow continental sea. Following mid-Cretaceous sea regression, a deep (~100 m) weathering profile recorded a protracted episode (~from 97 to 60 Ma) of oxidative weathering during continuous uplift and denudation, which stopped 60 myr ago. Since then, the weathering profile, which consists of Al- and Fe-rich phyllosilicates, iron oxides, and sulfates, has been constantly reworked. Interestingly, this profile hosts the bulk of the world's precious opal deposits. Since no opal deposit can be found in post-60 Ma rock formations, it is most likely that opal is part of the weathering profile developed during the drying out of central Australia. We analysed the mineral inclusions from six opal samples from the GAB to better document the early oxidative weathering. Using VNIR and Raman spectroscopy we were able to identify a variety of minerals including ferrihydrite, barite, gypsum and alunite replaced by goethite. This mineralogical assemblage is indicative of acidic oxidative conditions that points to Martian-like acidic weathering. We propose that acidity was derived from the oxidation of biogenic pyrite, and that the quasi absence of carbonates allowed very acidic conditions to take hold at a regional scale. If this model is valid, central Australia may be one of the best terrestrial analogues for the understanding of some of Mars' weathering processes. References Bishop, J.L., Noe Dobrea, E.Z., McKeown, N.K., Parente, M., Ehlmann, B.L., Michalski, J.R., Milliken, R.E., Poulet, F., Swayze, G.A., Mustard, J.F., Murchie, S.L. and Bibring, J.-P. (2008): Phyllosilicate Diversity and Past Aqueous Activity Revealed at Mawrth Vallis, Mars, Science 321(5890), 830-833. Carter, J., Poulet, F., Bibring, J.-P., Mangold, N., Murchie, S. (2013): Hydrous minerals of Mars as seen by the CRISM and OMEGA imaging spectrometer: Updated global view, Journal of Geophysical Research: Planets 118, 831-858. Ehlmann, B. L., Berger, G., Mangold, N., Michalski, J. R., Catling, D. C., Ruff, S. W., Chassefière, E., Niles, P. B., Chevrier, V., Poulet, F. (2013): Geochemical Consequences of Widespread Clay Minerals Formation in Mars' Ancient Crust, Space Science Review 174, 329-364.

  14. Chemical weathering and soil production 1 Copyright 2006 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms (in press)

    E-print Network

    Heimsath, Arjun M.

    Chemical weathering and soil production 1 Copyright © 2006 John Wiley & Sons, Ltd. Earth Surf and chemical processes (e.g. Riebe et al., 2001, 2003a; Anderson et al., 2002; Stallard and Edmond, 1983 downslope. Chemical weathering ­ the dissolution and precipitation of minerals via subsurface flow ­ occurs

  15. The Relationships between Weather-Related Factors and Daily Outdoor Physical Activity Counts on an Urban Greenway

    PubMed Central

    Wolff, Dana; Fitzhugh, Eugene C.

    2011-01-01

    The purpose of this study was to examine relationships between weather and outdoor physical activity (PA). An online weather source was used to obtain daily max temperature [DMT], precipitation, and wind speed. An infra-red trail counter provided data on daily trail use along a greenway, over a 2-year period. Multiple regression analysis was used to examine associations between PA and weather, while controlling for day of the week and month of the year. The overall regression model explained 77.0% of the variance in daily PA (p < 0.001). DMT (b = 10.5), max temp-squared (b = ?4.0), precipitation (b = ?70.0), and max wind speed (b = 1.9) contributed significantly. Conclusion: Aggregated daily data can detect relationships between weather and outdoor PA. PMID:21556205

  16. Anvil Forecast Tool in the Advanced Weather Interactive Processing System (AWIPS)

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III; Hood, Doris

    2009-01-01

    Launch Weather Officers (LWOs) from the 45th Weather Squadron (45 WS) and forecasters from the National Weather Service (NWS) Spaceflight Meteorology Group (SMG) have identified anvil forecasting as one of their most challenging tasks when predicting the probability of violating the Lightning Launch Commit Criteria (LLCC) (Krider et al. 2006; Space Shuttle Flight Rules (FR), NASA/JSC 2004)). As a result, the Applied Meteorology Unit (AMU) developed a tool that creates an anvil threat corridor graphic that can be overlaid on satellite imagery using the Meteorological Interactive Data Display System (MIDDS, Short and Wheeler, 2002). The tool helps forecasters estimate the locations of thunderstorm anvils at one, two, and three hours into the future. It has been used extensively in launch and landing operations by both the 45 WS and SMG. The Advanced Weather Interactive Processing System (AWIPS) is now used along with MIDDS for weather analysis and display at SMG. In Phase I of this task, SMG tasked the AMU to transition the tool from MIDDS to AWIPS (Barrett et aI., 2007). For Phase II, SMG requested the AMU make the Anvil Forecast Tool in AWIPS more configurable by creating the capability to read model gridded data from user-defined model files instead of hard-coded files. An NWS local AWIPS application called AGRID was used to accomplish this. In addition, SMG needed to be able to define the pressure levels for the model data, instead of hard-coding the bottom level as 300 mb and the top level as 150 mb. This paper describes the initial development of the Anvil Forecast Tool for MIDDS, followed by the migration of the tool to AWIPS in Phase I. It then gives a detailed presentation of the Phase II improvements to the AWIPS tool.

  17. Laboratory Hydrothermal Alteration of Basaltic Tephra by Acid Sulfate Solutions: An Analog Process for Martian Weathering

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, D. W.; Morris, R. V.

    2003-01-01

    The objective of this study is to conduct simulated Mars-like weathering experiments in the laboratory to determine the weathering products that might form during oxidative, acidic weathering of Mars analog materials.

  18. Chemical and Physical Weathering in a Hot-arid, Tectonically Active Alluvial System (Anza-Borrego Desert, CA)

    NASA Astrophysics Data System (ADS)

    Joo, Y. J.; Elwood Madden, M.; Soreghan, G. S.

    2014-12-01

    Climate and tectonics are primary controls on bedrock erosion, and sediment production, transport, and deposition. Additionally, silicate weathering in tectonically active regions is known to play a significant role in global climate owing to the high rates of physical erosion and exposure of unweathered bedrock to chemical weathering, which removes CO2 from the atmosphere. Therefore, the feedback between weathering and climate is key to understanding climate change through Earth history. This study investigates chemical and physical weathering of alluvial sediments in the Anza-Borrego Desert, California, located in the southern part of the San Andreas Fault System. This setting provides an ideal opportunity to study weathering in a hot and arid climate with mean annual temperatures of ~23 °C and mean annual precipitation of ~160 mm in the basin. Samples were collected along a proximal-to-distal transect of an alluvial-fan system sourced exclusively from Cretaceous tonalite of the Peninsular Range. The single bedrock lithology enables exploration of the effects of other variables — climate, transport distance, drainage area, and tectonics— on the physical and chemical properties of the sediments. Although minimal overall (CIA = 56-61), the degree of chemical weathering increases down transect, dominated by plagioclase dissolution. BET surface area of the mud (<63µm) fraction decreases distally, which is consistent with coarsening grain-size. Chemical alteration and BET surface area both increase in a distal region, within the active Elsinore Fault zone. Extensive fracturing here, together with a more-humid Pleistocene climate likely facilitated in-situ bedrock weathering; specifically, dissolution of primary minerals (e.g. plagioclase), preceding the arid alluvial erosion, transport, and deposition in the Holocene. This study further seeks to disentangle the complex record of the climate and tectonic signals imprinted in these sediments.

  19. Personal Insights and Anecdotes about the Weatherization Assistance Program Process Field Study

    SciTech Connect

    Treitler, Inga

    2014-09-01

    The present report is based on the research conducted for the Process Field Study between March and September 2011. The Process Field Study documents how Weatherization Assistance Program (WAP) services were delivered to clients, and the quality with which those services were delivered. The assessments were conducted by visiting 19 agencies in 19 states around the country interviewing agency managers, staff, and contractors; observing program intake along, with 43 audits, 45 measure installation and 37 final inspections; and conducting debriefing interviews with clients and weatherization staff following the observation of service delivery. In this report, we turn to detailed observations of a few field interactions. The client stories from our observations illustrate some of the ways clients and crew interact to build the success of the program, but shows there will always be unanticipated obstacles to building trust and getting the program to the public. Stories of staff and crew career paths indicate that weatherization technology and techniques are being learned and used by technicians out of the new home construction industry and that their new knowledge provides them with technical tools and methods that many hope to take back into the construction industry if and when they return. This report is organized according to the four stages of weatherization: intake, audit, installation, and inspection. It contributes to our understanding of the area where policy, environment, culture, and individual decisions influence social innovation. The anecdotes reveal the realities of implementing programs for the benefit of the greater good at minimal cost and sacrifice in times of ever restricting budgets. As the authors revisited their field notes and compiled memorable narratives to communicate the essence of the weatherization experience, they identified three key takeaways that summarize the major issues. First, in WAP as in all services there will always be challenges to reaching the community needing to be served. Second, crew and staff learn new skills and gain experience that can be and are applied in jobs elsewhere. Finally, in the best cases, changes from the weatherization experience permeate communities in unanticipated ways.

  20. USING SPATIOTEMPORAL RELATIONAL RANDOM FORESTS TO IMPROVE OUR UNDERSTANDING OF SEVERE WEATHER PROCESSES

    E-print Network

    McGovern, Amy

    USING SPATIOTEMPORAL RELATIONAL RANDOM FORESTS TO IMPROVE OUR UNDERSTANDING OF SEVERE WEATHER, AND JOHN K. WILLIAMS5 Abstract. Major severe weather events can cause a significant loss of life the mining of severe weather data. Because weather is inherently a spatiotemporal phenomenon, mining

  1. Process Coupling Between Mineral Transformation and U Speciation in Acid Waste Weathered Sediments

    NASA Astrophysics Data System (ADS)

    Perdrial, N.; Kanematsu, M.; Wang, G.; Um, W.; O'Day, P. A.; Chorover, J.

    2013-12-01

    The need for better prediction of contaminant transport motivates multi-faceted lines of inquiry to build a strong bridge between molecular- and field-scale information. At Hanford (WA), millions of liters of U-containing acidic wastes have been discharged to the soil. In order to predict reactive contaminant migration in the soil, it is necessary to determine the process coupling that occurs between mineral transformation and uranium speciation in these acid-uranium waste weathered sediments. Furthermore, we seek to establish linkages between molecular-scale contaminant speciation and meso-scale contaminant lability, release and reactive transport. Unweathered Hanford sediments were reacted for 365 days with acidic (pH 3), uranium bearing waste solutions in batch experiments. The presence and absence of phosphate in the waste as a control on uranium speciation was also investigated. At dedicated reaction times (7, 14, 30, 90, 180 and 365 days) solid and solution chemistry were analyzed to determine weathering trajectories and contaminant speciation. As observed by XRD and U-EXAFS, when present, PO4 exerted a strong controls over uranium speciation at all pH with the rapid precipitation of meta-ankoleite [K(UO2PO4).3H2O] and near complete immobilization of U. Over prolonged reaction time, however, small fractions of boltwoodite [K(UO2)(HSiO4).3H2O] increased in PO4-high U systems. When PO4 was excluded from the reaction systems, U speciation was indirectly controlled by the pH of the reactant solution and its effect on primary mineral weathering. In this case, U immobilization remained limited with 25 to 50% of the uranium precipitated as becquerelite ([Ca(UO2)6O4(OH)6.3H2O] or the K equivalent - compreignacite) and suspected boltwoodite. Differences between the systems are attributed to process coupling between acid chemistry and U geochemistry. Carbonate weathering contributed to rapidly buffer the pH to pH 7-8 in the absence of PO4 and to 6-7 in its presence, promoting subsequent silicate weathering that makes aqueous Si available for boltwoodite precipitation. Comparison with homogeneous nucleation experiments and thermodynamic calculations confirmed the strong phosphate control over U speciation and the multispeciation of U in its absence.

  2. SESE 2009 Faculty Retreat 1 Earth Surface Processes Surface Process Studies in SESE

    E-print Network

    Rhoads, James

    -biota feedbacks, relationships among chemical, physical and biological weathering Greatest Research Targets, and relations to earthquakes. 4. Quantifying how climate drives weathering processes, and influences: climate change, environmental issues and human impacts. 7. Biological aspects of weathering: climate

  3. Will Somebody do the Dishes? Weathering Analogies, Geologic Processes and Geologic Time

    NASA Astrophysics Data System (ADS)

    Stelling, P.; Wuotila, S.; Giuliani, M.

    2006-12-01

    A good analogy is one of the most powerful tools in any instructors' arsenal, and encouraging students to explore the links between an analogy and a scientific concept can cement both ideas in a student's mind. A common analogy for weathering and erosion processes is doing the dishes. Oxidation, hydration, and solution reactions can be intimidating on the chalkboard but easily understood in the context of cleaning up after dinner. Rather than present this analogy as a lecture demonstration, students are encouraged to experimentally determine which type of weathering works best on their dirty dishes. The experiment must use at least four identically dirty dishes: three experimental dishes and one control dish. The experimental dishes are subjected to simulated weathering and erosion processes of the student's design. Common techniques developed by students are cold or warm water baths, baths with and without acid (lemon juice or soda), and freeze-thaw cycles. Occasionally creative experiments result in unexpected discoveries, such the inefficiency of abrasion from wind-blown sand, especially when compared to soaking dishes in Canadian Whiskey. The effectiveness of each experimental run is determined by comparison to the control plate after loose debris is removed from each. The dish with the smallest aerial extent of remaining food is the declared the most effective. Discussion sections of the experimental write-up includes a description of which geologic processes were being simulated in each experiment, comparisons of the effectiveness of each techniques, and statements of how these experiments differ from reality. In order to advance this project, a second stage of the assignment, a direct comparison of weathering and erosion techniques on food and on geologic materials, will be added this fall. Ideally, students will empirically derive erosion rates and calculate the time required to remove the volume of material represented by a geologically important feature, such as Mt. Rainier or the Grand Canyon. In the end, students completing this project gain an understanding of how geologic processes work, the time scales required, the differences between analogies and the real thing, and arguably the most important aspect, a best-practices approach to doing the dishes.

  4. Space-weathering processes and products on volatile-rich asteroids

    NASA Astrophysics Data System (ADS)

    Britt, D.; Schelling, P.; Consolmagno, G.; Bradley, T.

    2014-07-01

    Space weathering is a generic term for the effects on atmosphereless solid bodies in the solar system from a range of processes associated with direct exposure to the space environment. These include impact processes (shock, vaporization, fragmentation, heating, melting, and ejecta formation), radiation damage (from galactic and solar cosmic rays), solar-wind effects (irradiation, ion implantation, and sputtering), and the chemical reactions driven by these processes. The classic example of space weathering is the formation of the lunar spectral red slope associated with the production of nanophase Fe (npFe0) in the dusty lunar regolith (C.R. Chapman, 2004, Annual Review of Earth & Planet. Sci. 32, C.M. Pieters, 2000, MAPS 35). Similar npFe0 has been recovered from asteroid (25143) Itokawa and some asteroid classes do exhibit modest spectral red slopes (T. Noguchi, 2011, Science 333). Space weathering can be thought of as driven by a combination of the chemical environment of space (hard vacuum, low oxygen fugacity, solar-wind implantation of hydrogen) along with thermal energy supplied by micrometeorite impacts. The forward modeling of space weathering as thermodynamically-driven decomposition of common rock-forming minerals suggests the production of a range of daughter products: (1) The silicate products typically lose oxygen, other volatile elements (i.e., sulfur and sodium), and metallic cations, producing minerals that are typically more disordered and less optically active than the original parent materials. (2) The decomposed metallic cations form in nano-sized blebs including npFe0, on the surfaces or in condensing rims of mineral grains. This creates a powerful optical component as seen in the lunar red slope. Surfaces with exposed npFe0 are an ideal environment for catalyzing further reactions. (3) The liberated volatile elements and gases (O, S, Na) may form an observable exosphere (e.g., Moon and Mercury) and can either escape from the body or recombine with available solar-wind-implanted hydrogen to form trace amounts of water and OH. Mineral decomposition can be thought of as the first stage of space weathering. It produces weathered surfaces somewhat depleted in volatile elements, creates a predictable set of minor or trace minerals, and leaves the surfaces with catalytic species, primarily npFe0. However, a second stage of further reactions and weathering depends upon the presence of ''feed-stock'' components that can participate in catalyzed chemical reactions on exposed surfaces. For volatile-rich small bodies, the available materials are not only silicates, but a volatile feedstock that can include water, carbon monoxide, ammonia, to name a few. Thermodynamically-driven decomposition of silicates will produce trace amounts of npFe0 which are ideal sites for Fischer-Tropsch type (FTT) catalytic reactions that can produce organics in situ on the asteroids including alkanes, polyaromatic hydrocarbons, and amino acids (J.E. Elsila, 2012, MAPS 47). The mix and range of products depends on the composition and morphology of the mineral surface, energy inputs produced by the micrometeorite impacts or other processes, and the composition of the input volatile feedstock. FFT reactions generate long-chain carbon compounds and amino acids. Secondary reactions that generate more complex carbon compounds and amino acids are likely to occur as the organic material matures. Weathering maturity can be thought of as a function of the abundance and diversity of the weathering products. Since the npFe0 is not destroyed in the reaction, continued micrometeorite bombardment would result in continuing processing and recombination of the existing organic feedstock. More weathering would result in progressively longer-chain carbon compounds as well as more complex and diverse amino acids, and eventually the kerogen-like insoluble-organic matter that forms a large fraction of carbonaceous meteorites. This insight has several major implications for our planetary science and, potentially, the formation of the precursors of l

  5. Some topics on geochemistry of weathering: a review.

    PubMed

    Formoso, Milton L L

    2006-12-01

    Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au). Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering. PMID:17143414

  6. Chemical weathering and diagenesis of a cold desert soil from Wright Valley, Antarctica - An analog of Martian weathering processes

    NASA Technical Reports Server (NTRS)

    Gibson, E. K.; Mckay, D. S.; Wentworth, S. J.

    1983-01-01

    Weathering, diagenesis, and chemical alteration of a soil profile from the Dry Valleys of Antarctica are investigated as an analog to soil development within the Martian regolith. Soil samples from a soil pit one meter deep on Prospect Mesa, Wright Valley, are examined for their major element concentrations, water-soluble cations and anions, carbon, sulfur, and water concentrations, and related petrographic characteristics of weathering in a cold, dry environment. A petrographic study of the samples suggests that most silicate mineral and lithic fragments exhibit some degree of alteration. Chemical alteration occurs both in samples above and within the permanently frozen zone. The concentrations of water-soluble cations, for example, Na(+), K(+), Ca(2+), and anions, Cl(-), SO4(2-), NO3(-), are found to decrease significantly from the surface to the permanently frozen zone, suggesting a major movement of water-soluble species. It is also found that enrichments in secondary mineral abundances correlate with the water soluble ion concentrations. The formation of zeolites is seen throughout the soil column; these, it is thought, may be reservoirs for volatile storage within the regolith.

  7. Interface-coupled dissolution-precipitation processes during acidic weathering of multicomponent minerals

    NASA Astrophysics Data System (ADS)

    Ruiz-Agudo, Encarnacion; King, Helen E.; Patiño-López, Luis D.; Putnis, Christine V.; Geisler, Thorsten; Rodriguez-Navarro, Carlos M.; Putnis, Andrew

    2015-04-01

    The chemical weathering of carbonate and silicate minerals on the Earth's surface controls important geochemical processes such as erosion rates and soil formation, ore genesis or climate evolution. The dissolution of most of these minerals is typically incongruent, and results in the formation of surface coatings (altered layers, also known as leached layers). These coatings may significantly affect mineral dissolution rates over geological timescales, and therefore a great deal of research has been conducted on them. However, the mechanism of leached layer formation is a matter of vigorous debate. Here we report on an in situ atomic force microscopy (AFM) and real-time Mach-Zehnder phase-shift interferometry (PSI) study of the dissolution of wollastonite, CaSiO3, and dolomite, CaMg(CO3)2, as an example of surface coating formation during acidic weathering of multicomponent minerals. Our in situ results provide clear direct experimental evidence that leached layers are formed in a tight interface-coupled two-step process: stoichiometric dissolution of the pristine mineral surfaces and subsequent precipitation of a secondary phase (silica in the case of wollastonite, or hydrated magnesium carbonate in the case of dolomite) from a supersaturated boundary layer of fluid in contact with the mineral surface. This occurs despite the bulk solution remaining undersaturated with respect to the secondary phase. The validation of such a mechanism given by the results reported here completely changes the conceptual framework concerning the mechanism of chemical weathering, and differs significantly from the concept of preferential leaching of cations postulated by most currently accepted incongruent dissolution models.

  8. Rapid changes in the physical properties of rock and concrete during intertidal exposure; implications for weathering and engineering durability

    NASA Astrophysics Data System (ADS)

    Coombes, Martin A.; Naylor, Larissa A.; Feal-Pérez, Alejandra

    2010-05-01

    Water absorption is an important parameter affecting the susceptibility of rocky shore substrates and construction materials to wetting-drying, salt weathering and dissolution processes exposed in the intertidal zone. Strength is also an important determinant of durability and resistance to erosion processes such as abrasion. Here we examine changes in the water absorption properties and strength of representative materials used in the construction of coastal defences after 8 months exposure in the intertidal zone. Blocks of Portland limestone, Cornish granite and marine concrete were attached to shore platforms in Cornwall, UK, at Mean Tide Level. After 8 months exposure, Water Absorption Capacity (WAC) was determined (in both fresh water and synthetic seawater) for exposed and control samples, and strength was measured using Point Load and Equotip surface hardness tests. Differences between exposed and control samples were examined with ANOVA, using material type (3 levels; limestone, granite and concrete) and treatment (2 levels; control and field exposed) as fixed factors. There were significant differences in the WAC of field exposed materials compared to unexposed controls after 8 months (p = 0.02). Post-hoc Student Newman Kuels (SNK) tests also revealed significant material x treatment combinations in both fresh and synthetic seawater (p < 0.01). Field exposed concrete had lower water absorption compared to controls (p < 0.05), which was associated with the development of a surface bio-chemical crust (observed using SEM) and an increase in surface hardness (Equotip test, Student's t-test p = 0.05). In contrast, WAC of limestone in fresh and synthetic seawater was higher for exposed samples compared to controls, but was only significant in fresh water (p = 0.05). SEM examination suggests that extensive borehole erosion of exposed limestone probably explains these differences. Surface hardness of exposed limestone was lower than controls, which may also be associated with boring activity, but this was not statistically significant after 8 months. Water Absorption Capacity and surface hardness were no different between controls and field exposed granite samples. Point Load tests showed no detectable changes in bulk material strength of any material after 8 months exposure. Results are discussed with respect to early-stage physical changes of natural rock and artificial materials exposed in the intertidal zone during the construction of hard coastal defences. In particular, the role of material composition in determining responses to exposure, and temporal changes in the susceptibility of natural rock and concrete to different intertidal weathering and erosion processes, are discussed.

  9. Weathering and weathering rates of natural stone

    NASA Astrophysics Data System (ADS)

    Winkler, Erhard M.

    1987-06-01

    Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the rocks' permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of the causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between disolution, crack-corrosion, and expansion-contraction cycies triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

  10. Weathering and weathering rates of natural stone

    SciTech Connect

    Winkler, E.M. )

    1987-01-01

    Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the ricks permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of th causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between dissolution, crack-corrosion, and the expansion-contraction cycles triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

  11. Evaluating sensitivity of silicate mineral dissolution rates to physical weathering using a soil evolution model (SoilGen2.25)

    NASA Astrophysics Data System (ADS)

    Opolot, E.; Finke, P. A.

    2015-08-01

    Silicate mineral dissolution rates depend on the interaction of a number of factors categorized either as intrinsic (e.g. mineral surface area, mineral composition) or extrinsic (e.g. climate, hydrology, biological factors, physical weathering). Estimating the integrated effect of these factors on the silicate mineral dissolution rates therefore necessitates the use of fully mechanistic soil evolution models. This study applies a mechanistic soil evolution model (SoilGen) to explore the sensitivity of silicate mineral dissolution rates to the integrated effect of other soil forming processes and factors. The SoilGen soil evolution model is a 1-D model developed to simulate the time-depth evolution of soil properties as a function of various soil forming processes (e.g. water, heat and solute transport, chemical and physical weathering, clay migration, nutrient cycling and bioturbation) driven by soil forming factors (i.e., climate, organisms, relief, parent material). Results from this study show that although soil solution chemistry (pH) plays a dominant role in determining the silicate mineral dissolution rates, all processes that directly or indirectly influence the soil solution composition equally play an important role in driving silicate mineral dissolution rates. Model results demonstrated a decrease of silicate mineral dissolution rates with time, an obvious effect of texture and an indirect but substantial effect of physical weathering on silicate mineral dissolution rates. Results further indicated that clay migration and plant nutrient recycling processes influence the pH and thus the silicate mineral dissolution rates. Our silicate mineral dissolution rates results fall between field and laboratory rates but were rather high and more close to the laboratory rates owing to the assumption of far from equilibrium reaction used in our dissolution rate mechanism. There is therefore need to include secondary mineral precipitation mechanism in our formulation. In addition, there is need for a more detailed study that is specific to field sites with detailed measurements of silicate mineral dissolution rates, climate, hydrology and mineralogy to enable the calibration and validation of the model. Nevertheless, this study is another important step to demonstrate the critical need to couple different soil forming processes with chemical weathering in order to explain differences observed between laboratory and field measured silicate mineral dissolution rates.

  12. Evaluating sensitivity of silicate mineral dissolution rates to physical weathering using a soil evolution model (SoilGen2.25)

    NASA Astrophysics Data System (ADS)

    Opolot, E.; Finke, P. A.

    2015-11-01

    Silicate mineral dissolution rates depend on the interaction of a number of factors categorized either as intrinsic (e.g. mineral surface area, mineral composition) or extrinsic (e.g. climate, hydrology, biological factors, physical weathering). Estimating the integrated effect of these factors on the silicate mineral dissolution rates therefore necessitates the use of fully mechanistic soil evolution models. This study applies a mechanistic soil evolution model (SoilGen) to explore the sensitivity of silicate mineral dissolution rates to the integrated effect of other soil-forming processes and factors. The SoilGen soil evolution model is a 1-D model developed to simulate the time-depth evolution of soil properties as a function of various soil-forming processes (e.g. water, heat and solute transport, chemical and physical weathering, clay migration, nutrient cycling, and bioturbation) driven by soil-forming factors (i.e., climate, organisms, relief, parent material). Results from this study show that although soil solution chemistry (pH) plays a dominant role in determining the silicate mineral dissolution rates, all processes that directly or indirectly influence the soil solution composition play an equally important role in driving silicate mineral dissolution rates. Model results demonstrated a decrease of silicate mineral dissolution rates with time, an obvious effect of texture and an indirect but substantial effect of physical weathering on silicate mineral dissolution rates. Results further indicated that clay migration and plant nutrient recycling processes influence the pH and thus the silicate mineral dissolution rates. Our silicate mineral dissolution rates results fall between field and laboratory rates but were rather high and more close to the laboratory rates possibly due to the assumption of far from equilibrium reaction used in our dissolution rate mechanism. There is therefore a need to include secondary mineral precipitation mechanism in our formulation. In addition, there is a need for a more detailed study that is specific to field sites with detailed measurements of silicate mineral dissolution rates, climate, hydrology, and mineralogy to enable the calibration and validation of the model. Nevertheless, this study is another important step to demonstrate the critical need to couple different soil-forming processes with chemical weathering in order to explain differences observed between laboratory and field measured silicate mineral dissolution rates.

  13. Major ion chemistry of the Son River, India: Weathering processes, dissolved fluxes and water quality assessment

    NASA Astrophysics Data System (ADS)

    Maharana, Chinmaya; Gautam, Sandeep Kumar; Singh, Abhay Kumar; Tripathi, Jayant K.

    2015-08-01

    River Son, draining diverse lithologies in the subtropical climate of the peninsular sub-basin of the Ganga basin, is one of the major tributaries of the Ganga River. The chemistry of major ions in the surface water of the Son River was studied in detail to determine various source(s) and processes controlling its water chemistry, seasonal and spatial variations in water chemistry, dissolved fluxes and chemical denudation rate (CDR). The study shows that Ca2+, Mg2+ and HCO 3- are major ionic species in the river water. Most of the measured parameters exhibit a relatively lower concentration in the post-monsoon as compared to pre-monsoon season. The water chemistry highlights the influence of continental weathering aided by secondary contributions from ground water, saline/alkaline soils and anthropogenic activities in the catchment. Results also reflect the dominance of carbonate weathering over silicate weathering in controlling water composition. The Son River delivers about 4.2 million tons of dissolved loads annually to the Ganga River, which accounts for ˜6% of the total annual load carried by the Ganga River to the Bay of Bengal. The average CDR of the Son River is 59.5 tons km -2 yr -1, which is less than the reported 72 tons km -2 yr -1 of the Ganga River and higher than the global average of 36 tons km -2 yr -1. The water chemistry for the pre-monsoon and post-monsoon periods shows a strong seasonal control on solute flux and CDR values. The water chemistry indicates that the Son River water is good to excellent in quality for irrigation and also suitable for drinking purposes.

  14. Process Physics Inertia, Gravity and the Quantum

    E-print Network

    Cahill, R T

    2001-01-01

    Process Physics models reality as self-organising relational or semantic information using a self-referentially limited neural network model. This generalises the traditional non-process syntactical modelling of reality by taking account of the limitations and characteristics of self-referential syntactical information systems, discovered by Goedel and Chaitin, and the analogies with the standard quantum formalism and its limitations. In process physics space and quantum physics are emergent and unified, and time is a distinct non-geometric process. Quantum phenomena are caused by fractal topological defects embedded in and forming a growing three-dimensional fractal process-space. Various features of the emergent physics are briefly discussed including: quantum gravity, quantum field theory, limited causality and the Born quantum measurement metarule, inertia, time-dilation effects, gravity and the equivalence principle, a growing universe with a cosmological constant, black holes and event horizons, and the...

  15. Process Physics: Inertia, Gravity and the Quantum

    E-print Network

    Reginald T. Cahill

    2001-10-29

    Process Physics models reality as self-organising relational or semantic information using a self-referentially limited neural network model. This generalises the traditional non-process syntactical modelling of reality by taking account of the limitations and characteristics of self-referential syntactical information systems, discovered by Goedel and Chaitin, and the analogies with the standard quantum formalism and its limitations. In process physics space and quantum physics are emergent and unified, and time is a distinct non-geometric process. Quantum phenomena are caused by fractal topological defects embedded in and forming a growing three-dimensional fractal process-space. Various features of the emergent physics are briefly discussed including: quantum gravity, quantum field theory, limited causality and the Born quantum measurement metarule, inertia, time-dilation effects, gravity and the equivalence principle, a growing universe with a cosmological constant, black holes and event horizons, and the emergence of classicality.

  16. Displaying Composite and Archived Soundings in the Advanced Weather Interactive Processing System

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III; Volkmer, Matthew R.; Blottman, Peter F.; Sharp, David W.

    2008-01-01

    This presentation describes work done by the Applied Meteorology Unit (AMU) to add composite soundings to the Advanced Weather Interactive Processing System (AWIPS). This allows National Weather Service (NWS) forecasters to compare the current atmospheric state with climatology. In a previous task, the AMU created composite soundings for four rawinsonde observation stations in Florida, for each of eight flow regimes. The composite soundings were delivered to the NWS Melbourne (MLB) office for display using the NSHARP software program. NWS MLB requested that the AMU make the composite soundings available for display in AWIPS. The AMU first created a procedure to customize AWIPS so composite soundings could be displayed. A unique four-character identifier was created for each of the 32 composite soundings. The AMIU wrote a Tool Command Language/Tool Kit (TclITk) software program to convert the composite soundings from NSHARP to Network Common Data Form (NetCDF) format. The NetCDF files were then displayable by AWIPS.

  17. Physical Processes Controlling Earth's Climate

    NASA Technical Reports Server (NTRS)

    Genio, Anthony Del

    2013-01-01

    As background for consideration of the climates of the other terrestrial planets in our solar system and the potential habitability of rocky exoplanets, we discuss the basic physics that controls the Earths present climate, with particular emphasis on the energy and water cycles. We define several dimensionless parameters relevant to characterizing a planets general circulation, climate and hydrological cycle. We also consider issues associated with the use of past climate variations as indicators of future anthropogenically forced climate change, and recent advances in understanding projections of future climate that might have implications for Earth-like exoplanets.

  18. Weather Modification: Finding Common Ground.

    NASA Astrophysics Data System (ADS)

    Garstang, Michael; Bruintjes, Roelof; Serafin, Robert; Orville, Harold; Boe, Bruce; Cotton, William; Warburton, Joseph

    2005-05-01

    Research and operational approaches to weather modification expressed in the National Research Council's 2003 report on “Critical Issues in Weather Modification Research” and in the Weather Modification Association's response to that report form the basis for this discussion. There is agreement that advances in the past few decades over a broad front of understanding physical processes and in technology have not been comprehensively applied to weather modification. Such advances need to be capitalized upon in the form of a concerted and sustained national effort to carry out basic and applied research in weather modification. The need for credible scientific evidence and the pressure for action should be resolved. Differences in the perception of current knowledge, the utility of numerical models, and the specific needs of research and operations in weather modification must be addressed. The increasing demand for water and the cost to society inflicted by severe weather require that the intellectual, technical, and administrative resources of the nation be combined to resolve whether and to what degree humans can influence the weather.The National Center for Atmospheric Research is sponsored by the National Science Foundation


  19. A novel process for recovering rare earth from weathered black earth

    SciTech Connect

    Chi, R.; Zhu, G.; Zhou, Z.; Xu, Z.

    2000-02-01

    A novel process for recovering rare-earth (RE) elements from weathered-black-earth slime is developed. This process involves the initial removal of Mn by reduction leaching using SO{sub 2} followed by ammonium chloride roasting of the residual solids from the leaching process. The controlled roasting selectively converts RE oxides to water-soluble RE chlorides. The roasted materials are then dispersed in warm water (75 C) to extract RE, while water-insoluble iron oxides remain in gangue sludge, minimizing iron impurities in final RE products and hence simplifying the purification process. Lead chloride precipitates are obtained by cooling the leachate to {minus}10 C, and RE is recovered using oxalic acid precipitation. With this new process, a product of 92 pct purity at a RE recovery greater than 65 pct is obtained. In addition, Mn and Pb are recovered as by-products, with a recovery of 64 and 54 pct, respectively. The effect of operating variables on RE recovery is examined and the process chemistry described.

  20. Identifying weathering processes by Si isotopes in two small catchments in the Black Forest (Germany)

    NASA Astrophysics Data System (ADS)

    Steinhoefel, G.; Breuer, J.; von Blanckenburg, F.; Horn, I.; Kaczorek, D.; Sommer, M.

    2013-12-01

    Stable Si isotopes are potentially an ideal proxy to investigate weathering as the release or precipitation of Si during abiotic or biotic processes causes significant shifts in the isotope signature depending on the weathering intensity. In this study, we determine the Si isotope signature of spring and stream waters and of the principle Si pools of typical soil profiles within two small catchments located on sandstone and paragneiss, respectively, in the cold, perhumid Black Forest (Germany). The Si isotope data were obtained on a Neptune MC-ICP-MS in solution for the water samples and in situ by coupling a UV femtosecond laser ablation system for solid samples, respectively. Bulk soils show a largely homogeneous Si isotope signature for different horizons and locations, which is close to those of bulk bedrocks with ?30Si value around -0.3‰. Soil clay formation is associated with limited Si mobility, which preserves initial Si isotope signatures of parental minerals. Biogenic mineral, i.e. phytoliths, exhibit negative Si isotope signature of about -0.4‰. An exception are the topsoil layers in the paragneiss catchment where the organic-rich environment promotes high Si mobility leading to a significant depletion of heavy Si isotopes. Springs and streams, sampled in spring and late summer, vary between -0.7 to 1.1‰ in ?30Si showing spatial and temporal variations dependent on the water pathways. Groundwater originated from sandstone and overlying periglacial debris layers reveals constant ?30Si values of 0.3 to 0.5‰, which is attributed to kaolinite formation. In contrast, water passing the soil zone shows very variable signatures. Low ?30Si values down to -0.7‰ most likely reflects dissolution processes of clay minerals and phytoliths during spring. In late summer, positive ?30Si values expose the impact of preferential uptake of light Si isotopes by plants. In the paragneiss catchment, this effect is likely increased by co-precipitation of isotopically light Si with Fe-oxides, which shifts surface water to ?30Si values up to 1.1‰. The Si isotope signature of the main stream depends on variable proportion of inflowing surface water and groundwater. The results on these small catchments demonstrate that Si isotopes are a powerful tool to identify weathering processes and the sources of dissolved Si, which can now be used to constrain the isotope signature of large river systems.

  1. Environmental tracers for elucidating the weathering process in a phosphogypsum disposal site: Implications for restoration

    NASA Astrophysics Data System (ADS)

    Pérez-López, Rafael; Nieto, José M.; de la Rosa, Jesús D.; Bolívar, Juan P.

    2015-10-01

    This study provides geochemical data with the aim of identifying and tracing the weathering of phosphogypsum wastes stack-piled directly on salt-marshes of the Tinto River (Estuary of Huelva, SW Spain). With that purpose, different types of highly-polluted acid solutions were collected in the stack. Connection between these solutions and the estuarine environment was studied by geochemical tracers, such as rare earth elements (REE) and their North American Shale Composite (NASC)-normalized patterns and Cl/Br ratios. Phosphogypsum-related wastewaters include process water stored on the surface, pore-water contained in the phosphogypsum profile and edge outflow water emerging from inside the stack. Edge outflow waters are produced by waterlogging at the contact between phosphogypsum and the nearly impermeable marsh surface and discharge directly into the estuary. Process water shows geochemical characteristics typical of phosphate fertilizers, i.e. REE patterns with an evident enrichment of heavy-REE (HREE) with respect to middle-REE (MREE) and light-REE (LREE). By contrast, REE patterns of deeper pore-water and edge outflows are identical to those of Tinto River estuary waters, with a clear enrichment of MREE relative to LREE and HREE denoting influence of acid mine drainage. Cl/Br ratios of these solutions are very close to that of seawater, which also supports its estuarine origin. These findings clearly show that process water is not chemically connected with edge outflows through pore-waters, as was previously believed. Phosphogypsum weathering likely occurs by an upward flow of seawater from the marsh because of overpressure and permeability differences. Several recommendations are put forward in this study to route restoration actions, such as developing treatment systems to improve the quality of the edge outflow waters before discharging to the receiving environment.

  2. Biological processes and links to the physics

    NASA Astrophysics Data System (ADS)

    Hinrichsen, Hans-Harald

    2009-10-01

    Analysis of the temporal and spatial variability of biological processes and identification of the main variables that drive the dynamic regime of marine ecosystems is complex. Correlation between physical variables and long-term changes in ecosystems has routinely been identified, but the specific mechanisms involved remain often unclear. Reasons for this could be various: the ecosystem can be very sensitive to the seasonal timing of the anomalous physical forcing; the ecosystem can be contemporaneously influenced by many physical variables and the ecosystem can generate intrinsic variability on climate time scales. Marine ecosystems are influenced by a variety of physical factors, e.g., light, temperature, transport, turbulence. Temperature has a fundamental forcing function in biology, with direct influences on rate processes of organisms and on the distribution of mobile species that have preferred temperature ranges. Light and transport also affect the physiology and distribution of marine organisms. Small-scale turbulence determines encounter between larval fish and their prey and additionally influences the probability of successful pursuit and ingestion. The impact of physical forcing variations on biological processes is studied through long-term observations, process studies, laboratory experiments, retrospective analysis of existing data sets and modelling. This manuscript reviews the diversity of physical influences on biological processes, marine organisms and ecosystems and their variety of responses to physical forcing with special emphasis on the dynamics of zooplankton and fish stocks.

  3. Creating Interactive Graphical Overlays in the Advanced Weather Interactive Processing System Using Shapefiles and DGM Files

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III; Lafosse, Richard; Hood, Doris; Hoeth, Brian

    2007-01-01

    Graphical overlays can be created in real-time in the Advanced Weather Interactive Processing System (AWIPS) using shapefiles or Denver AWIPS Risk Reduction and Requirements Evaluation (DARE) Graphics Metafile (DGM) files. This presentation describes how to create graphical overlays on-the-fly for AWIPS, by using two examples of AWIPS applications that were created by the Applied Meteorology Unit (AMU) located at Cape Canaveral Air Force Station (CCAFS), Florida. The first example is the Anvil Threat Corridor Forecast Tool, which produces a shapefile that depicts a graphical threat corridor of the forecast movement of thunderstorm anvil clouds, based on the observed or forecast upper-level winds. This tool is used by the Spaceflight Meteorology Group (SMG) at Johnson Space Center, Texas and 45th Weather Squadron (45 WS) at CCAFS to analyze the threat of natural or space vehicle-triggered lightning over a location. The second example is a launch and landing trajectory tool that produces a DGM file that plots the ground track of space vehicles during launch or landing. The trajectory tool can be used by SMG and the 45 WS forecasters to analyze weather radar imagery along a launch or landing trajectory. The presentation will list the advantages and disadvantages of both file types for creating interactive graphical overlays in future AWIPS applications. Shapefiles are a popular format used extensively in Geographical Information Systems. They are usually used in AWIPS to depict static map backgrounds. A shapefile stores the geometry and attribute information of spatial features in a dataset (ESRI 1998). Shapefiles can contain point, line, and polygon features. Each shapefile contains a main file, index file, and a dBASE table. The main file contains a record for each spatial feature, which describes the feature with a list of its vertices. The index file contains the offset of each record from the beginning of the main file. The dBASE table contains records for each attribute. Attributes are commonly used to label spatial features. Shapefiles can be viewed, but not created in AWIPS. As a result, either third-party software can be installed on an AWIPS workstation, or new software must be written to create shapefiles in the correct format.

  4. Meteorites on Mars as Planetary Research Tools with Special Considerations for Martian Weathering Processes

    NASA Astrophysics Data System (ADS)

    Ashley, James Warren

    2011-09-01

    The occurrence of exogenic, meteoritic materials on the surface of any world presents opportunities to explore a variety of significant problems in the planetary sciences. In the case of Mars, meteorites found on its surface may help to (1) constrain atmospheric conditions during their time of arrival; (2) provide insights into possible variabilities in meteoroid type sampling between Mars and Earth space environments; (3) aid in our understanding of soil, dust, and sedimentary rock chemistry; (4) assist with the calibration of crater-age dating techniques; and (5) provide witness samples for chemical and mechanical weathering processes. The presence of reduced metallic iron in approximately 88 percent of meteorite falls renders the majority of meteorites particularly sensitive to oxidation by H2O interaction. This makes them excellent markers for H2O occurrence. Several large meteorites have been discovered at Gusev Crater and Meridiani Planum by the Mars Exploration Rovers (MERs). Significant morphologic characteristics interpretable as weathering features in the Meridiani suite of iron meteorites include a (1) large pit lined with delicate iron protrusions suggestive of inclusion removal by corrosive interaction; (2) differentially eroded kamacite and taenite lamellae on three of the meteorites, providing relative timing through cross-cutting relationships with deposition of (3) an iron oxide-rich dark coating; and (4) regmaglypted surfaces testifying to regions of minimal surface modification; with other regions in the same meteorites exhibiting (5) large-scale, cavernous weathering. Iron meteorites found by Mini-TES at both Meridiani Planum and Gusev Crater have prompted laboratory experiments designed to explore elements of reflectivity, dust cover, and potential oxide coatings on their surfaces in the thermal infrared using analog samples. Results show that dust thickness on an iron substrate need be only one tenth as great as that on a silicate rock to obscure its infrared signal. In addition, a database of thermal emission spectra for 46 meteorites was prepared to aid in the on-going detection and interpretation of these valuable rocks on Mars using Mini-TES instruments on both MER spacecraft. Applications to the asteroidal sciences are also relevant and intended for this database.

  5. The Application of a Speciation Mass-Balance Model (PHREEQCi) For Linking Subglacial Chemical Weathering Processes and Subglacial Hydrology

    NASA Astrophysics Data System (ADS)

    Mitchell, A. C.; Brown, G. H.; Fuge, R.

    2004-05-01

    The determination of solute sources in glacierised environments is critical for the continued use of hydrochemistry as an indicator of hydrological flow-paths, and for our understanding of processes of chemical denudation, metal and nutrient cycling in glacierised environments, and global biogeochemical cycles. This study develops previous methods of solute provenance determination in glacial hydrochemical systems by utilising PHREEQCi, a computer based speciation mass-balance (SMB) model, with hydrochemical, hydrological and mineralogical field data, from Haut Glacier d'Arolla, Switzerland. The aim is to investigate the utility of SMB models and the feasibility of previously hypothesised subglacial weathering reactions, with regard the relationship between macro changes in hydrology, and micro changes in subglacial chemical weathering processes. Two modelling schemes were developed; reactions between supraglacial and bulk meltwaters (S-BM), and reactions between supraglacial and in-situ borehole meltwaters (S-BHM). SMB modelling produced a broad range of feasible weathering scenarios, but not one unique weathering scenario, which could account for the observed changes in water chemistry between input and output waters in subglacial environments over contrasting periods of the ablation season. There were few differences between S-BM and S-BHM weathering scenarios, so these hypothetical models appear feasible for both quick-flow and delayed-flow waters, where the reaction processes are the same, but the reaction magnitude differs. These hypothetical models suggest a number of key features characterise subglacial weathering processes: (i) Silicate minerals should incongruently dissolve in the subglacial environment, and by the nature of their slow reaction kinetics, are probably indicative of waters that have had a slow transit time through the distributed subglacial hydrological system. (ii) Carbon dioxide and oxygen was required by all feasible S-BM and S-BHM models to allow primary silicate, carbonate and pyrite dissolution, irrespective of hydrological setting. This suggests that delayed-flow waters obtain carbon and oxygen from limited atmospheric contact in the distributed system, release from ice bubbles, the aeration of input waters in channellised englacial environments, or addition from microbial sources or organic carbon. This contrasts with previous models of solute acquisition in subglacial environments which have assumed weathering in the distributed system proceeds by protons derived from sulphide oxidation. (iii) Feasible S-BM and S-BHM models can be obtained without calcite dissolution, and modal weathering masses from all the models indicates calcite and Ca-feldspar weathering is equal. This contrasts with previous models of solute provenance in subglacial environments which have assumed all Ca derives from carbonate weathering. While SMB models are mathematically feasible, the authors wish to stress they are hypothetical and cannot be fully corroborated. Nevertheless, this initial study indicates SMB models provide a powerful method for exploring multiple potential subglacial weathering processes, which may further utilise the sensitivity of subglacial weathering processes to macro changes in subglacial hydrology.

  6. Rock Abrasion as Seen by the MSL Curiosity Rover: Insights on Physical Weathering on Mars

    NASA Astrophysics Data System (ADS)

    Bridges, N.; Day, M. D.; Le Mouelic, S.; Martin-Torres, F. J.; Newsom, H. E.; Sullivan, R. J., Jr.; Ullan, A.; Wiens, R. C.; Zorzano, M. P.

    2014-12-01

    Mars is a dry planet, with actively blowing sand in many regions. In the absence of stable liquid water and an active hydrosphere, rates of chemical weathering are slow, such that aeolian abrasion is a dominant agent of landscape modification where sand is present and winds above threshold occur at sufficient frequency. Reflecting this activity, ventifacts, rocks that have been abraded by windborne particles, and wind-eroded outcrops, are common. They provide invaluable markers of the Martian wind record and insight into climate and landscape modification. Ventifacts are distributed along the traverse of the Mars Science Laboratory Curiosity rover. They contain one or more diagnostic features and textures: Facets, keels, basal sills, elongated pits, scallops/flutes, grooves, rock tails, and lineations. Keels at the junction of facets are sharp enough to pose a hazard MSL's wheels in some areas. Geomorphic and textural patterns on outcrops indicate retreat of windward faces. Moonlight Valley and other depressions are demarcated by undercut walls and scree boulders, with the valley interiors containing fewer rocks, most of which show evidence for significant abrasion. Together, this suggests widening and undercutting of the valley walls, and erosion of interior rocks, by windblown sand. HiRISE images do not show any dark sand dunes in the traverse so far, in contrast to the large dune field to the south that is migrating up to 2 m per year. In addition, ChemCam shows that the rock Bathurst has a rind rich in mobile elements that would be removed in an abrading environment. This indicates that rock abrasion was likely more dominant in the past, a hypothesis consistent with rapid scarp retreat as suggested by the cosmogenic noble gases in Yellowknife Bay. Ventifacts and evidence for bedrock abrasion have also been found at the Pathfinder, Spirit, and Opportunity sites, areas, like the Curiosity traverse so far, that lack evidence for current high sand fluxes. Yardangs are also common on the planet, regardless of whether local sand is mobile. This suggest that abrasion on Mars is an episodic process driven by the passage of sand in which rock retreat rates, based on fluxes of current active dunes, may reach 10s of microns per year. Such a process has acted, over long time scales, to imprint upon the surface a record of sand activity.

  7. Physical conditions for the r-process

    SciTech Connect

    Wanajo, S.; Tachibana, T.; Goriely, S.

    2012-11-12

    Recent works show that the r-process can proceed by competition between neutron capture and {beta}-decay in low temperature environments (< 5 Multiplication-Sign 10{sup 8} K; cold r-process) where photo-disintegration plays no role. This is in contrast to the traditional picture of the r-process in high temperature environments ({approx} 1 Multiplication-Sign 10{sup 9} K; hot r-process) where the (n, {gamma})-({gamma}, n) equilibrium holds. In this study, we explore nucleosynthesis calculations based on a site-independent model to elucidate the physical conditions leading to cold and hot r-processes.

  8. Characterizing the process and quantifying the rate of subaerial rock weathering on desert surfaces using roughness analysis

    NASA Astrophysics Data System (ADS)

    Mushkin, Amit; Sagy, Amir; Trabelci, Eran

    2013-04-01

    Subaerial weathering of rocks is a common process observed on desert surfaces on Earth and other planetary terrestrial surfaces such as on Mars. On Earth, this weathering process has been previously identified as one of the key erosion agent driving geomorphic surface evolution and the development of desert pavements. And yet, fundamental aspects of the process, such as the relative contribution of the different weathering modes that drive it (e.g., mechanical breakdown of rocks, chemical weathering, aeolian abrasion and exfoliation) as well as the rate by which this weathering process occurs have not been systematically examined. Here, we present a new approach for quantitatively addressing these fundamental aspects of process geomorphology on desert surfaces. We focus here on co-genetic desert alluvial surfaces of different ages, i.e. alluvial chronosequences, which provide excellent recorders for the evolution of boulder-strewn surfaces into smooth desert pavements through in-situ subaerial weathering of rocks. Our approach combines independent measures of two different surface attributes: High resolution (mm-scale) 3D ground-based laser scanning (LiDAR) of surface micro-topography, and numerical dating of surface age. Roughness analysis of the LiDAR data in power spectral density (PSD) space allows us to characterize the geometric manifestation of rock weathering on the surface and to distinguish between the different weathering modes. Numerical age constraints provide independent estimates for the time elapsed since the process began. Accordingly, we are able to constrain surface roughness evolution on alluvial fan desert chronosequences through time, and present PSD analysis of surface roughness as a new quantitative tool to examine the process of subaerial rock weathering in desert environments. In this study we present results from two late Quaternary alluvial chronosequences along the Dead Sea Transform in the hyper-arid Negev desert of southern Israel. LiDAR scanning was applied on representative areas (~30-50 m2) of 10 separate surfaces ranging from rough Holocene surfaces to fairly smooth surfaces with well-developed pavements displaying an OSL age of 87 kyr. We find typical and recurring time-dependent changes in the offset as well as shape of the PSD curves in both chronosequences: PSD offset is continuously reduced over time reflecting the overall reduction in the amplitude of roughness at all wavelengths. The PSD curves display progressive moderation of slopes at the longer wavelengths with the moderation point itself systematically shifted to shorter wavelengths. This characteristic evolution of PSD offset and slope moderation at longer wavelengths reflects the typical break up of boulder-sized clasts through time as the surfaces mature into well-developed desert pavements and points towards mechanical breakdown as the dominant weathering mode. In addition, we are able to determine the rate by which the larger clasts are removed from the system. We build on these new insights into process and rate of rock weathering to propose PSD analysis of surface roughness as a complementary method for constraining the age of desert alluvial surfaces in places where 'conventional' dating cannot be applied.

  9. Clouds, weather, climate, and modeling for K-12 and public audiences from the Center for Multi-scale Modeling of Atmospheric Processes

    NASA Astrophysics Data System (ADS)

    Foster, S. Q.; Johnson, R. M.; Randall, D. A.; Denning, A.; Russell, R. M.; Gardiner, L. S.; Hatheway, B.; Jones, B.; Burt, M. A.; Genyuk, J.

    2010-12-01

    The need for improving the representation of cloud processes in climate models has been one of the most important limitations of the reliability of climate-change simulations. Now in its fifth year, the National Science Foundation-funded Center for Multi-scale Modeling of Atmospheric Processes (CMMAP) at Colorado State University (CSU) is addressing this problem through a revolutionary new approach to representing cloud processes on their native scales, including the cloud-scale interaction processes that are active in cloud systems. CMMAP has set ambitious education and human-resource goals to share basic information about the atmosphere, clouds, weather, climate, and modeling with diverse K-12 and public audiences. This is accomplished through collaborations in resource development and dissemination between CMMAP scientists, CSU’s Little Shop of Physics (LSOP) program, and the Windows to the Universe (W2U) program at University Corporation for Atmospheric Research (UCAR). Little Shop of Physics develops new hands on science activities demonstrating basic science concepts fundamental to understanding atmospheric characteristics, weather, and climate. Videos capture demonstrations of children completing these activities which are broadcast to school districts and public television programs. CMMAP and LSOP educators and scientists partner in teaching a summer professional development workshops for teachers at CSU with a semester's worth of college-level content on the basic physics of the atmosphere, weather, climate, climate modeling, and climate change, as well as dozens of LSOP inquiry-based activities suitable for use in classrooms. The W2U project complements these efforts by developing and broadly disseminating new CMMAP-related online content pages, animations, interactives, image galleries, scientists’ biographies, and LSOP videos to K-12 and public audiences. Reaching nearly 20 million users annually, W2U is highly valued as a curriculum enhancement resource, because its content is written at three levels in English and Spanish. Links between science topics and literature, art, and mythology enable teachers of English Language Learners, literacy, and the arts to integrate science into their classrooms. In summary, the CMMAP NSF-funded Science and Technology Center has established a highly effective and productive partnership of scientists and educators focused on enhancing public science literacy about weather, climate, and global change. All CMMAP, LSOP, and W2U resources can be accessed online at no cost by the entire atmospheric science K-12 and informal science education community.

  10. Hands-on, online, and workshop-based K-12 weather and climate education resources from the Center for Multi-scale Modeling of Atmospheric Processes

    NASA Astrophysics Data System (ADS)

    Foster, S. Q.; Johnson, R. M.; Randall, D. A.; Denning, A.; Burt, M. A.; Gardiner, L.; Genyuk, J.; Hatheway, B.; Jones, B.; La Grave, M. L.; Russell, R. M.

    2009-12-01

    The need for improving the representation of cloud processes in climate models has been one of the most important limitations of the reliability of climate-change simulations. Now in its fourth year, the National Science Foundation-funded Center for Multi-scale Modeling of Atmospheric Processes (CMMAP) at Colorado State University (CSU) is addressing this problem through a revolutionary new approach to representing cloud processes on their native scales, including the cloud-scale interaction processes that are active in cloud systems. CMMAP has set ambitious education and human-resource goals to share basic information about the atmosphere, clouds, weather, climate, and modeling with diverse K-12 and public audiences. This is accomplished through collaborations in resource development and dissemination between CMMAP scientists, CSU’s Little Shop of Physics (LSOP) program, and the Windows to the Universe (W2U) program at University Corporation for Atmospheric Research (UCAR). Little Shop of Physics develops new hands on science activities demonstrating basic science concepts fundamental to understanding atmospheric characteristics, weather, and climate. Videos capture demonstrations of children completing these activities which are broadcast to school districts and public television programs. CMMAP and LSOP educators and scientists partner in teaching a summer professional development workshops for teachers at CSU with a semester's worth of college-level content on the basic physics of the atmosphere, weather, climate, climate modeling, and climate change, as well as dozens of LSOP inquiry-based activities suitable for use in classrooms. The W2U project complements these efforts by developing and broadly disseminating new CMMAP-related online content pages, animations, interactives, image galleries, scientists’ biographies, and LSOP videos to K-12 and public audiences. Reaching nearly 20 million users annually, W2U is highly valued as a curriculum enhancement resource, because its content is written at three levels in English and Spanish. Links between science topics and literature, art, and mythology enable teachers of English Language Learners, literacy, and the arts to integrate science into their classrooms. In summary, the CMMAP NSF-funded Science and Technology Center has established a highly effective and productive partnership of scientists and educators focused on enhancing public science literacy about weather, climate, and global change. All CMMAP, LSOP, and W2U resources can be accessed online at no cost by the entire atmospheric science K-12 and informal science education community.

  11. The Themis-Beagle families: Investigation of space-weathering processes on primitive surfaces

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Perna, D.; Lantz, C.; Barucci, M.

    2014-07-01

    In the past 20 years, enormous progress has been reached in the study of space-weathering (SW) effects on silicates and silicate asteroids. The so-called ordinary chondrite paradox, that is, lack of asteroids similar to the ordinary chondrites, which represent 80 % of meteorite falls, has been solved. These meteorites are now clearly related to S-type asteroids, as proved also by the direct measurements of the NEAR and HAYABUSA missions on the near-Earth asteroids Eros and Itokawa. Spectral differences between S-type asteroids and ordinary chondrites are caused by space-weathering effects, which produce a darkening in the albedo, a reddening of the spectra, and diminish the silicate absorption bands on the asteroids surfaces, exposed to cosmic radiation and solar wind. On the other hand, our understanding of space-weathering effects on primitive asteroids is still poor. Only few laboratory experiments have been devoted to the investigation of SW effects on dark carbonaceous chondrites and on complex organic materials. Irradiation of transparent organic materials produces firstly redder and darker materials that upon further processing turn flatter-bluish and darker (Kanuchova et al. 2012; Moroz et al. 2004). The Themis family is a natural laboratory to study primitive asteroids and space-weathering effects. The Themis family is located between 3.05 and 3.24 au, beyond the snow line, and it is composed of primitive asteroids. Themis is one of the most statistically reliable families in the asteroid belt. First discovered by Hirayama (1918), it has been identified as a family in all subsequent works, and it has 550 members as determined by Zappalà et al. (1995) and more than 4000 as determined by Nesvorny et al. (2010). The family formed probably about 2.3 Gyr ago as a result of a large-scale catastrophic disruption event of a parent asteroid 400 km in diameter colliding with a 190-km projectile (Marzari et al. 1995). Several Themis family members show absorption features associated to hydrated silicates, and, recently, water-ice and organics features have been detected on the surface of (24) Themis (Campins et al. 2010, Rivkin & Emery 2010). Hydrated silicates are produced by the aqueous-alteration process, which require low temperature (< 320 K) and the presence of liquid water in the past. The Themis family may be an important reservoir of water ice. Moreover, the main-belt comets 133P, 238P, and 176P seem to be related to the Themis family because of orbital proximities and spectral properties analogies. Within the old Themis family members, a young sub-family, Beagle, formed less than 10 Myr ago, has been identified. This sub-family has 65 members up to 2 km of diameter (Nesvorny et al. 2008). So, the Themis family is very important to shed light on the asteroid-comet continuum, to constrain the abundances of water ices in the outer part of the main belt, and to probe space-weathering effects on old Themis and young Beagle families' members. To investigate all these aspects, we carried out a spectroscopic survey in the visible and near-infrared range at the 3.6-m Italian telescope TNG (La Palma, Spain) during 6 nights in February and December 2012. We got new spectra of 8 Beagle and 22 Themis members using the DOLORES (with the LR-R and LR-B grisms) and the NICS (with the Amici prism) instruments. To look for possible coma around the targets, we also performed deep imaging in the R filter. Data are currently under analysis, and the results will be presented at the ACM meeting. None of the investigated spectra show water-ice absorption features at 1.5 and 2 microns, while few Themis members have visible absorption bands associated with hydrated silicates. The best meteoritic analogues to both Themis and Beagle members are the carbonaceous chondrites, especially CM2. The spectra of Beagle and Themis asteroids show significant differences: 'old' Themis members exhibit a wide range of spectra, including asteroids with blue/neutral and moderately red spectra (relative to the Sun), while the young Beagle members in

  12. Minerva, 4(2): 201-205 CONSIDERATIONS ABOUT WEATHERING EXPOSURE AND UV... 201

    E-print Network

    Zornberg, Jorge G.

    (UV)radiation.Whenthisoccurs, the degradation of polymers due to weathering manifests as physical and chemical changes. These processes mayMinerva, 4(2): 201-205 CONSIDERATIONS ABOUT WEATHERING EXPOSURE AND UV... 201 CONSIDERATIONS ABOUT WEATHERING EXPOSURE AND UV DEGRADATION OF POLYMERIC GEOMEMBRANES Paulo César Lodi Department of Civil

  13. Space plasma physics: I - Stationary processes

    NASA Technical Reports Server (NTRS)

    Hasegawa, Akira; Sato, Tetsuya

    1989-01-01

    The physics of stationary processes in space plasmas is examined theoretically in an introduction intended for graduate students. The approach involves the extensive use of numerical simulations. Chapters are devoted to fundamental principles, small-amplitude waves, and the stationary solar plasma system; typical measurement data and simulation results are presented graphically.

  14. Atomic-Scale Modeling and Theory of Space Weathering Processes: Mechanisms and Surface Properties

    NASA Astrophysics Data System (ADS)

    Schelling, P. K.; Britt, D. T.; Quadery, A. H.; Tucker, W. C.; Blair, R.

    2015-11-01

    We apply atomic-scale simulation to describe space weathering, including point-defect migration and surface properties. Distinct differences are reported between olivine and orthopyroxene. Surface properties including adhesion are described.

  15. The snowball Earth aftermath: Exploring the limits of continental weathering processes

    E-print Network

    xxxx Editor: P. DeMenocal Keywords: snowball Earth greenhouse cap dolostones weathering modelling to background Neoproterozoic levels. Regarding the origin of the cap dolostones, we show that continental

  16. Process for the physical segregation of minerals

    DOEpatents

    Yingling, Jon C.; Ganguli, Rajive

    2004-01-06

    With highly heterogeneous groups or streams of minerals, physical segregation using online quality measurements is an economically important first stage of the mineral beneficiation process. Segregation enables high quality fractions of the stream to bypass processing, such as cleaning operations, thereby reducing the associated costs and avoiding the yield losses inherent in any downstream separation process. The present invention includes various methods for reliably segregating a mineral stream into at least one fraction meeting desired quality specifications while at the same time maximizing yield of that fraction.

  17. Commercializing Space Weather using GAIM

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Schunk, Robert; Sojka, Jan J.

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the en-ergy transfer processes from the Sun's photons, particles, and fields. Of the space environment domains that are affected by space weather, the ionosphere is the key region that affects com-munication and navigation systems. The Utah State University (USU) Space Weather Center (SWC) was organized in 2009 to develop commercial space weather applications. It uses the Global Assimilation of Ionospheric Measurements (GAIM) system as the basis for providing improvements to communication and navigation systems. For example, in August 2009 SWC released, in conjunction with Space Environment Technologies, the world's first real-time space weather via an iPhone app, Space WX. It displays the real-time, current global ionosphere to-tal electron content along with its space weather drivers, is available through the Apple iTunes store, and is used around the world. The GAIM system is run operationally at SWC for global and regional (continental U.S.) conditions. Each run stream continuously ingests up to 10,000 slant TEC measurements every 15-minutes from approximately 500 stations in a Kalman filter to adjust the background output from the physics-based Ionosphere Forecast Model (IFM). Additionally, 80 real-time digisonde data streams from around the world provide ionosphere characterization up to the F-region peak. The combination of these data dramatically improves the current epoch ionosphere specification beyond the physics-based solution. The altitudinal range is 90-1500 km for output TEC, electron densities, and other data products with a few degrees resolution in latitude and longitude at 15-minute time granularity. We describe the existing SWC products that are used as commercial space weather information. SWC funding is provided by the State of Utah's Utah Science Technology and Research (USTAR) initiative. The SWC is physically located on the USU campus in Logan, Utah.

  18. Displaying Composite and Archived Soundings in the Advanced Weather Interactive Processing System

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III; Volkmer, Matthew R.; Blottman, Peter F.; Sharp, David W.

    2008-01-01

    In a previous task, the Applied Meteorology Unit (AMU) developed spatial and temporal climatologies of lightning occurrence based on eight atmospheric flow regimes. The AMU created climatological, or composite, soundings of wind speed and direction, temperature, and dew point temperature at four rawinsonde observation stations at Jacksonville, Tampa, Miami, and Cape Canaveral Air Force Station, for each of the eight flow regimes. The composite soundings were delivered to the National Weather Service (NWS) Melbourne (MLB) office for display using the National version of the Skew-T Hodograph analysis and Research Program (NSHARP) software program. The NWS MLB requested the AMU make the composite soundings available for display in the Advanced Weather Interactive Processing System (AWIPS), so they could be overlaid on current observed soundings. This will allow the forecasters to compare the current state of the atmosphere with climatology. This presentation describes how the AMU converted the composite soundings from NSHARP Archive format to Network Common Data Form (NetCDF) format, so that the soundings could be displayed in AWl PS. The NetCDF is a set of data formats, programming interfaces, and software libraries used to read and write scientific data files. In AWIPS, each meteorological data type, such as soundings or surface observations, has a unique NetCDF format. Each format is described by a NetCDF template file. Although NetCDF files are in binary format, they can be converted to a text format called network Common data form Description Language (CDL). A software utility called ncgen is used to create a NetCDF file from a CDL file, while the ncdump utility is used to create a CDL file from a NetCDF file. An AWIPS receives soundings in Binary Universal Form for the Representation of Meteorological data (BUFR) format (http://dss.ucar.edu/docs/formats/bufr/), and then decodes them into NetCDF format. Only two sounding files are generated in AWIPS per day. One file contains all of the soundings received worldwide between 0000 UTC and 1200 UTC, and the other includes all soundings between 1200 UTC and 0000 UTC. In order to add the composite soundings into AWIPS, a procedure was created to configure, or localize, AWIPS. This involved modifying and creating several configuration text files. A unique fourcharacter site identifier was created for each of the 32 soundings so each could be viewed separately. The first three characters were based on the site identifier of the observed sounding, while the last character was based on the flow regime. While researching the localization process for soundings, the AMU discovered a method of archiving soundings so old soundings would not get purged automatically by AWl PS. This method could provide an alternative way of localizing AWl PS for composite soundings. In addition, this would allow forecasters to use archived soundings in AWIPS for case studies. A test sounding file in NetCDF format was written in order to verify the correct format for soundings in AWIPS. After the file was viewed successfully in AWIPS, the AMU wrote a software program in the Tool Command Language/Tool Kit (Tcl/Tk) language to convert the 32 composite soundings from NSHARP Archive to CDL format. The ncgen utility was then used to convert the CDL file to a NetCDF file. The NetCDF file could then be read and displayed in AWIPS.

  19. Physical processes in spin polarized plasmas

    SciTech Connect

    Kulsrud, R.M.; Valeo, E.J.; Cowley, S.

    1984-05-01

    If the plasma in a nuclear fusion reactor is polarized, the nuclear reactions are modified in such a way as to enhance the reactor performance. We calculate in detail the modification of these nuclear reactions by different modes of polarization of the nuclear fuel. We also consider in detail the various physical processes that can lead to depolarization and show that they are by and large slow enough that a high degree of polarization can be maintained.

  20. Process-based evaluation of stochastic physics schemes

    NASA Astrophysics Data System (ADS)

    Sanchez, Claudio; Williams, Keith

    2014-05-01

    The interest and usefulness of probabilistic forecasts for the evolution of the atmosphere is growing. They are routinely used to provide the probability of tropical cyclone trajectories, heat waves, colder-than-average seasons and other tailored probabilities. The main tool to produce these forecasts is the Ensemble Prediction System (EPS) where different members of the ensemble aim to simulate a slightly different but plausible evolution of the atmosphere. However, current EPS don't generate enough dispersion amongst ensemble members, so-called 'ensemble spread', thus the system underestimates possible transitions between different weather regimes. The lack of dispersion and performance of atmospheric models partially comes from an incomplete description of the atmosphere, where some aspects of the interaction between subgrid process and large-scale flow are not fully represented. One of the preferred methods to represent the effects of subgrid variability on the large scale flow is the stochastic physics schemes. These schemes have been proven to be quite successful to increase the ensemble spread of an EPS and in some cases reduce climate biases. However, our understanding of the physical mechanisms that lead to these improvements remains poor. In this study we aim to understand the impact of the stochastic schemes Stochastic Kinetic Energy Basckscatter (SKEB) and Stochastic Parametrization of Tendencies (SPT) on a variety of atmospheric processes such as Mid-Latitude Cyclones (MLC), Convectively Coupled Equatorial Waves (CCEW), and the MJO. These schemes can produce notable improvements, but they can also produce unrealistic representation of some process. Upgrades based on these findings are proposed and tested.

  1. Physical processes causing the formation of penitentes

    NASA Astrophysics Data System (ADS)

    Claudin, P.; Jarry, H.; Vignoles, G.; Plapp, M.; Andreotti, B.

    2015-09-01

    Snow penitentes form in sublimation conditions by differential ablation. Here we investigate the physical processes at the initial stage of penitente growth and perform the linear stability analysis of a flat surface submitted to the solar heat flux. We show that these patterns do not simply result from the self-illumination of the surface—a scale-free process—but are primarily controlled by vapor diffusion and heat conduction. The wavelength at which snow penitentes emerge is derived and discussed. We found that it is controlled by aerodynamic mixing of vapor above the ice surface.

  2. Physical processes causing the formation of penitentes

    E-print Network

    P. Claudin; H. Jarry; G. Vignoles; M. Plapp; B. Andreotti

    2015-11-05

    Snow penitentes form in sublimation conditions by differential ablation. Here we investigate the physical processes at the initial stage of penitente growth and perform the linear stability analysis of a flat surface submitted to the solar heat flux. We show that these patterns do not simply result from the self-illumination of the surface --a scale-free process-- but are primarily controlled by vapor diffusion and heat conduction. The wavelength at which snow penitentes emerge is derived and discussed. We found that it is controlled by aerodynamic mixing of vapor above the ice surface.

  3. Physical processes causing the formation of penitentes.

    PubMed

    Claudin, P; Jarry, H; Vignoles, G; Plapp, M; Andreotti, B

    2015-09-01

    Snow penitentes form in sublimation conditions by differential ablation. Here we investigate the physical processes at the initial stage of penitente growth and perform the linear stability analysis of a flat surface submitted to the solar heat flux. We show that these patterns do not simply result from the self-illumination of the surface-a scale-free process-but are primarily controlled by vapor diffusion and heat conduction. The wavelength at which snow penitentes emerge is derived and discussed. We found that it is controlled by aerodynamic mixing of vapor above the ice surface. PMID:26465564

  4. Automating the initial physics chart checking process.

    PubMed

    Furhang, Eli E; Dolan, James; Sillanpaa, Jussi K; Harrison, Louis B

    2009-01-01

    The initial physics chart check, an essential quality assurance process, verifies that the physician intent is properly expressed in the treatment plan, the treatment plan is reasonable, and the Record and Verify (RV) system properly captures the plan parameters. In this work the process was automated by characterizing the initial physics chart check as a universal set of steps, compartmentalized into intra-plan and inter-plan reviews. The intra-plan review confirms the diagnosis-prescription-plan correlation, and verifies transfer accuracy of the signed treatment plan parameters into the RV system. The inter-plan review tabulates all RV parameters for similar cases, and highlights outliers. The tabulation of RV parameters for similar cases enables a summation of experience across staff members, and facilitates a comparison using the Statistical Process Control (SPC) formalism. A summary sheet, added to each reviewed chart, automatically documents deviations noted during the review process. Forty-five patient charts were analyzed using the software. The length of time for the entire initial chart-checking process was reduced from about an hour to a few minutes. The code developed in this work allows the user to consider the big picture, trusting the software to track details. PMID:19223834

  5. Research in Support of Operational Space Weather Forecasting

    NASA Astrophysics Data System (ADS)

    Viereck, R. A.

    2014-12-01

    Space Weather Operations can be defined as the specification and forecasting of the space environment for societal benefit. It is the potential benefit to society that is the justification for much space physics research and it helps to highlight the importance of the NASA Sun Earth Connections and Heliophysics programs. Scientific advances in the last few years have brought the first physics-base space weather forecast model into operations. Observations of the sun at higher cadences and improved spectral and temporal resolution have opened new windows on the processes that drive space weather. However, there are still some fundamental scientific questions, relevant to space weather forecasting, the answers to which still elude us. In this presentation I will review some of the most pressing needs of the space weather forecasters and the scientific advances and new observations that would greatly enhance the accuracy of space weather products and predictions.

  6. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 105, NO. A11, PAGES 25,05325,078, NOVEMBER 1, 2000 Global three-dimensional MHD simulation of a space weather

    E-print Network

    Groth, Clinton P. T.

    three-dimensional MHD simulation of a space weather event: CME formation, interplanetary propagation the potential, as well as current limitations, of the MHD-based space weather model for enhancing the understanding of coronal physics, solar wind plasma processes, magnetospheric physics, and space weather

  7. Weather variability, ecological processes and optimization of soil micro-environment for rangeland restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arid and semi-arid rangelands occupy over half of the earth’s surface and are characterized by relatively high variability in seasonal and annual patterns of precipitation. Invasive plants compete for soil and water resources and exacerbate inherent weather limitations for native plant establishmen...

  8. Anoxic dissolution processes of biotite: implications for Fe behavior during Archean weathering

    E-print Network

    Utsunomiya, Satoshi

    of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK. 3 Tel.: +81-29-2825361; fax: +81-29-2825927. www.g., [2]). Paleosols, ancient soils formed by weathering, can provide data regarding the composition on Precambrian paleo- sols, the evolutionary history of O2 is not fully deduced. Such a comprehension

  9. Free electron laser physical process code (FELPPC)

    SciTech Connect

    Thode, L.E.; Chan, K.C.D.; Schmitt, M.J.

    1995-02-01

    Even at the conceptual level, the strong coupling between subsystem elements complicates the understanding and design of a free electron laser (FEL). Given the requirements for high-performance FELS, the coupling between subsystems must be included to obtain a realistic picture of the potential operational capability. The concept of an Integrated Numerical Experiment (INEX) was implemented to accurately calculate the coupling between the FEL subsystems. During the late 1980`s, the INEX approach was successfully applied to a large number of accelerator and FEL experiments. Unfortunately, because of significant manpower and computational requirements, the integrated approach is difficult to apply to trade-off and initial design studies. However, the INEX codes provided a base from which realistic accelerator, wiggler, optics, and control models could be developed. The Free Electron Laser Physical Process Code (FELPPC) includes models developed from the INEX codes, provides coupling between the subsystem models, and incorporates application models relevant to a specific study. In other words, FELPPC solves the complete physical process model using realistic physics and technology constraints. FELPPC can calculate complex FEL configurations including multiple accelerator and wiggler combinations. When compared with the INEX codes, the subsystem models have been found to be quite accurate over many orders-of-magnitude. As a result, FELPPC has been used for the initial design studies of a large number of FEL applications: high-average-power ground, space, plane, and ship based FELS; beacon and illuminator FELS; medical and compact FELS; and XUV FELS.

  10. NASA's Advancements in Space-Based Spectrometry Lead to Improvements in Weather Prediction and Understanding of Climate Processes

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2010-01-01

    AIRS is a precision state of the art High Spectral Resolution Multi-detector IR grating array spectrometer that was launched into a polar orbit on EOS Aqua in 2002. AIRS measures most of the infra-red spectrum with very low noise from 650/cm to 2660/cm with a resolving power of 2400 at a spatial resolution of 13 km. The objectives of AIRS were to perform accurate determination of atmospheric temperature and moisture profiles in up to 90% partial cloud cover conditions for the purpose of improving numerical weather prediction and understanding climate processes. AIRS data has also been used to determine accurate trace gas profiles. A brief overview of the retrieval methodology used to analyze AIRS observations under partial cloud cover will be presented and sample results will be shown from the weather and climate perspectives.

  11. Weather-driven variation in dengue activity in Australia examined using a process-based modeling approach.

    PubMed

    Bannister-Tyrrell, Melanie; Williams, Craig; Ritchie, Scott A; Rau, Gina; Lindesay, Janette; Mercer, Geoff; Harley, David

    2013-01-01

    The impact of weather variation on dengue transmission in Cairns, Australia, was determined by applying a process-based dengue simulation model (DENSiM) that incorporated local meteorologic, entomologic, and demographic data. Analysis showed that inter-annual weather variation is one of the significant determinants of dengue outbreak receptivity. Cross-correlation analyses showed that DENSiM simulated epidemics of similar relative magnitude and timing to those historically recorded in reported dengue cases in Cairns during 1991-2009, (r = 0.372, P < 0.01). The DENSiM model can now be used to study the potential impacts of future climate change on dengue transmission. Understanding the impact of climate variation on the geographic range, seasonality, and magnitude of dengue transmission will enhance development of adaptation strategies to minimize future disease burden in Australia. PMID:23166197

  12. Space Weathering of Apollo 16 Sample 62255: Lunar Rocks as Witness Plates for Deciphering Regolith Formation Processes

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; McKay, D. S.; Keller, L. P.

    2004-01-01

    Space weathering, or alteration that occurs at the surfaces of materials exposed directly to space, has been one of the primary areas of focus of lunar studies for the past several years. It is caused by processes such as micrometeorite impacts and solar wind bombardment, and effects can include microcraters, spall zones, and vapor deposits. Much of the recent work on space weathering has been concentrated on nanoscale features, especially the amorphous rims commonly found on individual lunar soil grains. The rims typically contain nanophase Fe metal globules, which, along with Fe metal globules in agglutinates, have a profound effect on optical properties of lunar soils. The nanophase metallic iron globules cause the characteristic optical changes (reddening and darkening) found in mature lunar soils.

  13. Weather Watch

    ERIC Educational Resources Information Center

    Bratt, Herschell Marvin

    1973-01-01

    Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

  14. Novel natural and anthropogenic physical mechanisms of weather and climate changes

    NASA Astrophysics Data System (ADS)

    Voronin, Nikolai; Avakyan, Sergei

    2010-05-01

    A unified approach is suggested to the problem of impact of both space and several anthropogenic sources on the weather and climate changes. The united agent of this impact is examined i.e. microwave emission of the ionosphere, which resulted from ionospheric atoms and molecules excitation into highly excited (Rydberg) states by fast ionospheric electrons. Fast electrons with the energies more than 15 eV are formed with the photoionization of the upper atmosphere under the effect of X-ray/EUV solar radiation and with the ionization of the corpuscular precipitations from the radiation belts and magnetosphere both during of geomagnetic storms and under the anthropogenic influences. The latter (the work of powerful navigation and communication radio stations (because the most of them induce very low frequency (VLF) range: from few to few tens kilo Hertz.), electric power lines, starting space rockets, industrial activity) determines the locality of precipitations and accordingly the local action of the microwave radiation of the ionosphere on the weather characteristics. Surface transmitters with such frequency have power up to 1 Mw that cause precipitations and result in optical emission (the aurora of the class IBC II or more) above the transmitter. Indeed results of measurements performed by the satellites Intercosmos-Bulgaria 1300 at 1982 and DEMETER at 2005 confirm very high extent of disturbance of radiation belts and night ionosphere above the zone of work of VLF transmitters both in Northern Hemisphere (transmitters NLK, NAA in USA and UMS, RPS in Russia), and in Southern Hemisphere (transmitter NWC) especially during geomagnetic disturbances. Areas of stimulated electron precipitations and areas of perturbed ionosphere are linked either with the magnetic force line at which the surface VHL transmitter is situated or with the magnetic line at which effect of radio wave on the pitch angle of electron, captured in radiation belt, takes place. This area of stimulated perturbations reaches a half of million of square kilometers. Every time perturbations of lesser scale are observed in magnetic conjugate area. In accordance with our calculations the rate of ionization and excitation of ionosphere in the conjugate point and hence, generation of microwave radiation from Rydberg states reaches 10 % of the effect in the point of the transmitter work. We suggest three-stage radio-optical trigger mechanism for the ionospheric microwaves influence on the weather and climate. The first stage is an increase in generation of the microwave radiation which penetrates from the ionosphere to the earth surface. The second stage is a change in the proportion of water vapour to water clusters caused by increased microwave radiation. The third stage is a change of the atmosphere transparence in the absorption bands of water vapour and clusters. The atmosphere transparence due to cloudiness (usually optically thin (warming) clouds from solar flares and corpuscular of both natural and technological precipitations) determines fluxes of solar irradiance coming down as well as fluxes of the thermal radiation coming out from the underlying surface. The maximum of secular cycles of solar activity was observed in eighties of last century. Since 1985 the total solar irradiance and ionizing radiation fluxes have been decreasing but geomagnetic activity (aa - index) has been going up till 2003. Only during the last few years geomagnetic activity also started decreasing. This means that negative trends have begun both for solar and geomagnetic activities, and also there is a positive trend of GCR since 1998 which participate in generation of optically thick (cooling) clouds. We suppose that according to our mechanism the natural global warming will go down to lower levels.

  15. Doing It In The SWMF Way: From Separate Space Physics Simulation Programs To The Framework For Space Weather Simulation.

    NASA Astrophysics Data System (ADS)

    Volberg, O.; Toth, G.; Sokolov, I.; Ridley, A. J.; Gombosi, T. I.; de Zeeuw, D. C.; Hansen, K. C.; Chesney, D. R.; Stout, Q. F.; Powell, K. G.; Kane, K. J.; Oehmke, R. C.

    2003-12-01

    The NASA-funded Space Weather Modeling Framework (SWMF) is developed to provide "plug and play" type Sun-to-Earth simulation capabilities serving the space physics modeling community. In its fully developed form, the SWMF will comprise a series of interoperating models of physics domains, ranging from the surface of the Sun to the upper atmosphere of the Earth. In its current form the SWMF links together five models: Global Magnetosphere, Inner Heliosphere, Ionosphere Electrodynamics, Upper Atmosphere, and Inner Magnetosphere. The framework permits to switch models of any type. The SWMF is a structured collection of software building blocks that can be used or customized to develop Sun-Earth system modeling components, and to assemble them into application. The SWMF consist of utilities and data structures for creating model components and coupling them. The SWMF contains Control Model, which controls initialization and execution of the components. It is responsible for component registration, processor layout for each component and coupling schedules. A component is created from the user-supplied physics code by adding a wrapper, which provides the control functions and coupling interface to perform the data exchange with other components. Both the wrapper and coupling interface are constructed from the building blocks provided by the framework itself. The current SWMF implementation is based on the latest component technology and uses many important concepts of Object-Oriented Programming emulated in Fortran 90. Currently it works on Linux Beowulf clusters, SGI Origin 2000 and Compaq ES45 machines.

  16. Protein Folding as a Physical Stochastic Process

    E-print Network

    Kerson Huang

    2007-07-17

    We model protein folding as a physical stochastic process as follows. The unfolded protein chain is treated as a random coil described by SAW (self-avoiding walk). Folding is induced by hydrophobic forces and other interactions, such as hydrogen bonding, which can be taken into account by imposing conditions on SAW. The resulting model is termed CSAW (conditioned self-avoiding walk. Conceptually, the mathematical basis is a generalized Langevin equation. In practice, the model is implemented on a computer by combining SAW and Monte Carlo. To illustrate the flexibility and capabilities of the model, we consider a number of examples, including folding pathways, elastic properties, helix formation, and collective modes.

  17. Physics of a random biological process

    NASA Astrophysics Data System (ADS)

    Canessa, E.; Calmetta, A.

    1994-07-01

    We analyze the successive fluctuations of the daytime and nighttime sleep pattern of a newborn baby by using tools of far-from-equilibrium statistical physics. We find that this class of natural random biological process displays a remarkable long-range power-law correlation that extends for, at least, the first six months of life. Such a scaling behavior might help to characterize the underlying dynamics of the (early) growth and development of humans through analyzing the time series generated when asleep.

  18. An advanced physical coal cleaning process

    SciTech Connect

    Wang, Z.; Zhu, S.; Jiang, Z.Y.; Fu, X.

    1994-12-31

    Physical processes for deep-cleaning of coal have been developed, the application of which depends to a large extent upon their economic feasibility; the determinate factors are the cost of ultra-fine grinding to attain necessary liberation of locked mineral from the coal matrix and the cost of reagents consumed to effect separation of micronized coal and mineral particles in aqueous suspension. Modified stirred ball mill has been found to be the promising equipment for ultra-fine coal grinding with both low energy and metal consumption. Selective flocculation-flotation process, as given in the paper presented at the last Conference, is technically feasible for preparation of ultra-clean coal. Recent work has indicated that the reagent consumption can be further reduced to a level proximating that in conventional coal flotation, being more economic feasible for its applications. Ultra-clean coals have been recovered by this process from conventional coal concentrate or low-ash raw coal. It can also be applied to process middling product from a coal preparation plant for additional concentrate extracted at very high yield. For metallurgical coal with difficult washability or high content of middling fractions, the advent of this process will be attractive in both technically and economically.

  19. Anvil Forecast Tool in the Advanced Weather Interactive Processing System, Phase II

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III

    2008-01-01

    Meteorologists from the 45th Weather Squadron (45 WS) and Spaceflight Meteorology Group have identified anvil forecasting as one of their most challenging tasks when predicting the probability of violations of the Lightning Launch Commit Criteria and Space Light Rules. As a result, the Applied Meteorology Unit (AMU) created a graphical overlay tool for the Meteorological Interactive Data Display Systems (MIDDS) to indicate the threat of thunderstorm anvil clouds, using either observed or model forecast winds as input.

  20. The weathering and transformation process of lead in China's shooting ranges.

    PubMed

    Li, Yeling; Zhu, Yongbing; Zhao, Sanping; Liu, Xiaodong

    2015-09-01

    Corroding steel-core bullets from three shooting ranges in different climate zones of China were collected. Multiple technical methods (EMPA, SEM, XRD, and ICP-OES) were applied to investigate the structure, morphology, and weathering product of this type of bullet in China to analyze the weathering mechanisms in different types of soils. A scanning electron microscope (SEM) was used to view the morphology and microstructure of corrosion layers. On the corroded lead layer surface, unevenness, micro cracks, and spallation were usually present. Around the micro cracks, many types of euhedral and subhedral crystals of the secondary products of lead were formed, most of which were composed of cerussite (PbCO3), while hydrocerussite (Pb3(CO3)2(OH)2) was predominant in the bullet collected from the humid environment. X-ray power diffraction (XRD) results show that the secondary weathering products in the three shooting range soils are clearly different. In the Fangyan shooting range, which has a neutral and semi-arid soil, the lead weathering product was mainly hydrocerussite (Pb3(CO3)2(OH)2), while no substantial amount of crystal phase of lead compound could be found in acidic, damp soils from the Fenghuang shooting range, possibly due to the enhanced dissolution and mobilization of lead compounds at lower pH and higher content of organic matter in the soil. In hot and arid environment of the Baicheng shooting range, cerussite might have undergone thermal decomposition, thus generating shannonite (Pb2O(CO3)). These results indicate that the formation of secondary Pb minerals is largely affected by the climatic zone or the soil properties, which may have implications for range management practices. PMID:26283517

  1. Creating Interactive Graphical Overlays in the Advanced Weather Interactive Processing System (AWIPS) Using Shapefiles and DGM Files

    NASA Technical Reports Server (NTRS)

    Barrett, Joe H., III; Lafosse, Richard; Hood, Doris; Hoeth, Brian

    2007-01-01

    Graphical overlays can be created in real-time in the Advanced Weather Interactive Processing System (AWIPS) using shapefiles or DARE Graphics Metafile (DGM) files. This presentation describes how to create graphical overlays on-the-fly for AWIPS, by using two examples of AWIPS applications that were created by the Applied Meteorology Unit (AMU). The first example is the Anvil Threat Corridor Forecast Tool, which produces a shapefile that depicts a graphical threat corridor of the forecast movement of thunderstorm anvil clouds, based on the observed or forecast upper-level winds. This tool is used by the Spaceflight Meteorology Group (SMG) and 45th Weather Squadron (45 WS) to analyze the threat of natural or space vehicle-triggered lightning over a location. The second example is a launch and landing trajectory tool that produces a DGM file that plots the ground track of space vehicles during launch or landing. The trajectory tool can be used by SMG and the 45 WS forecasters to analyze weather radar imagery along a launch or landing trajectory. Advantages of both file types will be listed.

  2. Physical characteristics of welding arc ignition process

    NASA Astrophysics Data System (ADS)

    Shi, Linan; Song, Yonglun; Xiao, Tianjiao; Ran, Guowei

    2012-07-01

    The existing research of welding arc mainly focuses on the stable combustion state and the research on the mechanism of welding arc ignition process is quite lack. The tungsten inert gas(TIG) touch arc ignition process is observed via a high speed camera and the high time resolution spectral diagnosis system. The changing phenomenon of main ionized element provided the electrons in the arc ignition is found. The metallic element is the main contributor to provide the electrons at the beginning of the discharging, and then the excitated shielding gas element replaces the function of the metallic element. The electron density during the period of the arc ignition is calculated by the Stark-broadened lines of H?. Through the discussion with the repeatability in relaxation phenomenon, the statistical regularity in the arc ignition process is analyzed. The similar rules as above are observed through the comparison with the laser-assisted arc ignition experiments and the metal inert gas(MIG) arc ignition experiments. This research is helpful to further understanding on the generation mechanism of welding arc ignition and also has a certain academic and practical significance on enriching the welding physical theoretical foundation and improving the precise monitoring on automatic arc welding process.

  3. Neutron radiography and X-ray computed tomography for quantifying weathering and water uptake processes inside porous limestone used as building material

    SciTech Connect

    Dewanckele, J.; De Kock, T.; Fronteau, G.; Derluyn, H.; Vontobel, P.; Dierick, M.; Van Hoorebeke, L.; Jacobs, P.; Cnudde, V.

    2014-02-15

    Euville and Savonnières limestones were weathered by acid test and this resulted in the formation of a gypsum crust. In order to characterize the crystallization pattern and the evolution of the pore structure below the crust, a combination of high resolution X-ray computed tomography and SEM–EDS was used. A time lapse sequence of the changing pore structure in both stones was obtained and afterwards quantified by using image analysis. The difference in weathering of both stones by the same process could be explained by the underlying microstructure and texture. Because water and moisture play a crucial role in the weathering processes, water uptake in weathered and non-weathered samples was characterized based on neutron radiography. In this way the water uptake was both visualized and quantified in function of the height of the sample and in function of time. In general, the formation of a gypsum crust on limestone slows down the initial water uptake in the materials. - Highlights: • Time lapse sequence in 3D of changing pore structures inside limestone • A combination of X-ray CT, SEM and neutron radiography was used. • Quantification of water content in function of time, height and weathering • Characterization of weathering processes due to gypsum crystallization.

  4. On the Rust Products Formed on Weathering and Carbon Steels Exposed to Chloride in Dry-Wet Cyclical Processes

    NASA Astrophysics Data System (ADS)

    García, K. E.; Morales, A. L.; Barrero, C. A.; Greneche, J. M.

    2005-02-01

    The rust products formed on weathering and carbon steels exposed to dry-wet cyclical processes in different chloride-rich solutions are carefully examined by means of different techniques. Special emphasis is given to the methodology of analysis of the data using 300 K and 77 K Mössbauer spectrometry and X-ray diffraction. The rust that is loosely bound to the metal surface and that it is lost during the corrosion process, for both types of steel, was found to be composed of lepidocrocite, superparamagnetic goethite, hematite, and traces of akaganeite. On the other hand, the adherent rust, which is differentiated as scraped and hit according to the way it is obtained, from both steels was found to be composed of akaganeite, spinel phase, goethite exhibiting broad distribution of particle sizes and lepidocrocite. The relative abundances of rust components for both steels were very similar, suggesting similar corrosion processes. Mass loss measurements show that the corrosion rates increases with increasing the chloride concentration. The presence of large quantities of spinel phase and akaganeite are a consequence of a corrosion process under the influence of very high chloride concentrations. Our results are useful for assessing the behavior of weathering steels where the levels of chlorides are high or in contact with sea water.

  5. Tales of future weather

    NASA Astrophysics Data System (ADS)

    Hazeleger, W.; van den Hurk, B. J. J. M.; Min, E.; van Oldenborgh, G. J.; Petersen, A. C.; Stainforth, D. A.; Vasileiadou, E.; Smith, L. A.

    2015-02-01

    Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like.

  6. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

  7. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

  8. Bringing life to soil physical processes

    NASA Astrophysics Data System (ADS)

    Hallett, P. D.

    2013-12-01

    When Oklahoma's native prairie grass roots were replaced by corn, the greatest environmental (and social) disaster ever to hit America ensued. The soils lost structure, physical binding by roots was annihilated and when drought came the Great Dust Bowl commenced. This form of environmental disaster has repeated over history and although not always apparent, similar processes drive the degradation of seemingly productive farmland and forests. But just as negative impacts on biology are deleterious to soil physical properties, positive impacts could reverse these trends. In finding solutions to soil sustainability and food security, we should be able to exploit biological processes to improve soil physical properties. This talk will focus on a quantitative understanding of how biology changes soil physical behaviour. Like the Great Dust Bowl, it starts with reinforcement mechanisms by plant roots. We found that binding of soil by cereal (barley) roots within 5 weeks of planting can more than double soil shear strength, with greater plant density causing greater reinforcement. With time, however, the relative impact of root reinforcement diminishes due to root turnover and aging of the seedbed. From mechanical tests of individual roots, reasonable predictions of reinforcement by tree roots are possible with fibre bundle models. With herbaceous plants like cereals, however, the same parameters (root strength, stiffness, size and distribution) result in a poor prediction. We found that root type, root age and abiotic factors such as compaction and waterlogging affect mechanical behaviour, further complicating the understanding and prediction of root reinforcement. For soil physical stability, the interface between root and soil is an extremely important zone in terms of resistance of roots to pull-out and rhizosphere formation. Compounds analogous to root exudates have been found with rheological tests to initially decrease the shear stress where wet soils flow, but after decomposition of these exudates by microbes the shear stress increases. This suggests an initial dispersion, followed by aggregation of the soil, which explains the structural arrangement of soil particles in the rhizosphere observed by microscopy. Dispersion of soil minerals in the root zone is important to release bound nutrients from mineral surfaces. Using fracture mechanics we measured large impacts of biological exudates on the toughness and interparticle bond energy of soils. Now novel tests are being developed to quantify interparticle bonding by biological exudates on single and multiple particle contacts, including mechanical test specimens that can be inoculated with specific bacteria or fungi. This will allow for clay mineralogy, water potential and solution chemistry impacts on interparticle bonding to be quantified directly. Wettability experiments with the same samples measure hydrological properties such as contact angle. Basic information from these tests will help explain biological processes that drive soil structure formation and stabilisation, providing data for models of soil structure dynamics.

  9. Generation of abnormal trace element abundances in Antarctic eucrites by weathering processes

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Lindstrom, Marilyn M.

    1991-01-01

    Data were obtained on the trace- and major-element compositions of 16 Antarctic abnormal eucrites, many of which exhibiting positive (but sometimes negative) Ce anomalies, positive Eu anomalies, and low abundances of the remainder of the REEs. The results of data analysis suggest that the unusual REE patterns of abnormal Antarctic eucrites arise from weathering effects generated in or on the Antarctic ice. The suggested scenario involves the formation of melt water and its equilibration with the atmosphere, promoting the dissolution of REE-rich phosphates and the oxidation of Ce. As a result, tetravalent Ce is fractionated from the trivalent REE in solution.

  10. Rock Weathering and Damage

    NASA Astrophysics Data System (ADS)

    Hoke, G. D.; Turcotte, D. L.

    2001-12-01

    Weathering of rock surfaces is often associated with a surface dissolution process. Chemical interactions occur on grain boundaries where diffusion is the controlling process. A dissolution boundary layer (rind) develops adjacent to the weathering surface. We quantify the extent of dissolution by introducing a damage variable f; f = 0 for pristine rock and when f = f0, the rock disintegrates. We assume that the variations of the damage variable are given by the diffusion equation. We solve two problems. The first is for the structure of the transient dissolution boundary layer prior to surface disintegration. We find an incubation time ti before active weathering (disintegration) begins. The second is the solution for steady-state weathering with a constant weathering velocity vw. Our results are entirely consistent with weathering studies on Carrera marble gravestones in the United Kingdom.

  11. Weathering and damage

    NASA Astrophysics Data System (ADS)

    Hoke, Gregory D.; Turcotte, Donald L.

    2002-10-01

    Weathering of rock surfaces is often associated with a surface dissolution process. Chemical interactions occur on grain boundaries and diffusion is the controlling process. A dissolution boundary layer (rind) develops adjacent to the weathering surface. We quantify the extent of dissolution by introducing a damage variable f, f = 0 for pristine rock, and when f = f0 the rock disintegrates. We assume that the variations of the damage variable are given by the diffusion equation. We solve two problems. The first is for the structure of the transient dissolution boundary layer prior to surface disintegration. We find an incubation time ti before active weathering (disintegration) begins. The second is the solution for steady state weathering with a constant weathering velocity vw. Our results are entirely consistent with weathering studies on Carrera marble gravestones in the United Kingdom.

  12. Space Weathering in the Inner Solar System

    NASA Technical Reports Server (NTRS)

    Noble, Sarah K.

    2010-01-01

    "Space weathering" is the term given to the cumulative effects incurred by surfaces which are exposed to the harsh environment of space. Lunar sample studies over the last decade or so have produced a clear picture of space weathering processes in the lunar environment. By combining laboratory and remote spectra with microanalytical methods (scanning and transmission electron microscopy), we have begun to unravel the various processes (irradiation, micrometeorite bombardment, etc) that contribute to space weathering and the physical and optical consequences of those processes on the Moon. Using the understanding gleaned from lunar samples, it is possible to extrapolate weathering processes to other airless bodies from which we have not yet returned samples (i.e. Mercury, asteroids). Through experiments which simulate various components of weathering, the expected differences in environment (impact rate, distance from Sun, presence of a magnetic field, reduced or enhanced gravity, etc) and composition (particularly iron content) can be explored to understand how space weathering will manifest on a given body.

  13. Physical processes in collapse driven supernova

    SciTech Connect

    Mayle, R.W.

    1985-11-01

    A model of the supernova explosion is discussed. The method of neutrino transport is discussed, since the explosive mechanism depends on neutrino heating of the material behind the accretion shock. The core region of these exploding stars becomes unstable to convective motions during the supernova evolution. Convective mixing allows more neutrinos to escape from under the neutrinosphere, and thus increases the amount of heating by neutrinos. An approximate method of incorporating convection is described, and some results of including convection in a computer model is presented. Another phenomena is seen in computer simulations of supernova, oscillations in the neutrino luminosity and mass accretion rate onto the protoneutron star. The last topic discussed in this thesis describes the attempt to understand this oscillation by perturbation of the steady state solution to equations approximating the complex physical processes occurring in the late time supernova. 42 refs., 31 figs.

  14. Weathering in a Cup.

    ERIC Educational Resources Information Center

    Stadum, Carol J.

    1991-01-01

    Two easy student activities that demonstrate physical weathering by expansion are described. The first demonstrates ice wedging and the second root wedging. A list of the needed materials, procedure, and observations are included. (KR)

  15. Weather Forecasting for Radio Astronomy

    E-print Network

    Groppi, Christopher

    Weather Forecasting for Radio Astronomy Part I: The Mechanics and Physics Ronald J Maddalena August 1, 2008 #12;Outline Part I Background -- research inspirations and aspirations Vertical weather, .... Part II Results on refraction & air mass (with Jeff Paradis) Part III Results on opacity, weather

  16. A New Perspective on Surface Weather Maps

    ERIC Educational Resources Information Center

    Meyer, Steve

    2006-01-01

    A two-dimensional weather map is actually a physical representation of three-dimensional atmospheric conditions at a specific point in time. Abstract thinking is required to visualize this two-dimensional image in three-dimensional form. But once that visualization is accomplished, many of the meteorological concepts and processes conveyed by the…

  17. Physical Processes in Star-Gas Systems

    E-print Network

    R. Spurzem; P. Berczik; G. Hensler; Ch. Theis; P. Amaro-Seoane; M. Freitag; A. Just

    2004-03-12

    First we present a recently developed 3D chemodynamical code for galaxy evolution from the K**2 collaboration. It follows the evolution of all components of a galaxy such as dark matter, stars, molecular clouds and diffuse interstellar matter (ISM). Dark matter and stars are treated as collisionless N-body systems. The ISM is numerically described by a smoothed particle hydrodynamics (SPH) approach for the diffuse (hot) gas and a sticky particle scheme for the (cool) molecular clouds. Physical processs such as star formation, stellar death or condensation and evaporation processes of clouds interacting with the ISM are described locally. An example application of the model to a star forming dwarf galaxy will be shown for comparison with other codes. Secondly we will discuss new kinds of exotic chemodynamical processes, as they occur in dense gas-star systems in galactic nuclei, such as non-standard ``drag''-force interactions, destructive and gas producing stellar collisions. Their implementation in 1D dynamical models of galactic nuclei is presented. Future prospects to generalize these to 3D are work in progress and will be discussed.

  18. Factoring in weather variation to capture the influence of urban design and built environment on globally recommended levels of moderate to vigorous physical activity in children

    PubMed Central

    Katapally, Tarun Reddy; Muhajarine, Nazeem

    2015-01-01

    Objectives In curbing physical inactivity, as behavioural interventions directed at individuals have not produced a population-level change, an ecological perspective called active living research has gained prominence. However, active living research consistently underexplores the role played by a perennial phenomenon encompassing all other environmental exposures—variation in weather. After factoring in weather variation, this study investigated the influence of diverse environmental exposures (including urban design and built environment) on the accumulation of globally recommended moderate to vigorous physical activity levels (MVPA) in children. Design This cross-sectional observational study is part of an active living initiative set in the Canadian prairie city of Saskatoon. As part of this study, Saskatoon's neighbourhoods were classified based on urban street design into grid-pattern, fractured grid-pattern and curvilinear types of neighbourhoods. Moreover, diverse environmental exposures were measured including, neighbourhood built environment, and neighbourhood and household socioeconomic environment. Actical accelerometers were deployed between April and June 2010 (spring-summer) to derive MVPA of 331 10–14-year-old children in 25 1-week cycles. Each cycle of accelerometry was conducted on a different cohort of children within the total sample and matched with weather data obtained from Environment Canada. Multilevel modelling using Hierarchical Linear and Non-linear Modelling software was conducted by factoring in weather variation to depict the influence of diverse environmental exposures on the accumulation of recommended MVPA. Results Urban design, including diversity of destinations within neighbourhoods played a significant role in the accumulation of MVPA. After factoring in weather variation, it was observed that children living in neighbourhoods closer to the city centre (with higher diversity of destinations) were more likely to accumulate recommended MVPA. Conclusions The findings indicate that after factoring in weather variation, certain types of urban design are more likely to be associated with MVPA accumulation. PMID:26621516

  19. Thermodynamics of Irreversible Processes. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Levin, Michael; Gallucci, V. F.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module describes the application of irreversible thermodynamics to biology. It begins with…

  20. Weather impacts on space operations

    NASA Astrophysics Data System (ADS)

    Madura, J.; Boyd, B.; Bauman, W.; Wyse, N.; Adams, M.

    The efforts of the 45th Weather Squadron of the USAF to provide weather support to Patrick Air Force Base, Cape Canaveral Air Force Station, Eastern Range, and the Kennedy Space Center are discussed. Its weather support to space vehicles, particularly the Space Shuttle, includes resource protection, ground processing, launch, and Ferry Flight, as well as consultations to the Spaceflight Meteorology Group for landing forecasts. Attention is given to prelaunch processing weather, launch support weather, Shuttle launch commit criteria, and range safety weather restrictions. Upper level wind requirements are examined. The frequency of hourly surface observations with thunderstorms at the Shuttle landing facility, and lightning downtime at the Titan launch complexes are illustrated.

  1. Physical processes in EUV sources for microlithography

    NASA Astrophysics Data System (ADS)

    Banine, V. Y.; Koshelev, K. N.; Swinkels, G. H. P. M.

    2011-06-01

    The source is an integral part of an extreme ultraviolet lithography (EUVL) tool. Such a source, as well as the EUVL tool, has to fulfil very high demands both technical and cost oriented. The EUVL tool operates at a wavelength of 13.5 nm, which requires the following new developments. The light production mechanism changes from conventional lamps and lasers to relatively high-temperature emitting plasmas. The light transport, mainly refractive for deep ultraviolet (DUV), should be reflective for EUV. The source specifications as derived from the customer requirements on wafer throughput mean that the output EUV source power has to be hundreds of watts. This in its turn means that tens to hundreds of kilowatts of dissipated power has to be managed in a relatively small volume. In order to keep lithography costs as low as possible, the lifetime of the components should be as long as possible and at least of the order of thousands of hours. This poses a challenge for the sources, namely how to design and manufacture components robust enough to withstand the intense environment of high heat dissipation, flows of several keV ions as well as the atomic and particular debris within the source vessel. As with all lithography tools, the imaging requirements demand a narrow illumination bandwidth. Absorption of materials at EUV wavelengths is extreme with extinguishing lengths of the order of tens of nanometres, so the balance between high transmission and spectral purity requires careful engineering. All together, EUV lithography sources present technological challenges in various fields of physics such as plasma, optics and material science. These challenges are being tackled by the source manufacturers and investigated extensively in the research facilities around the world. An overview of the published results on the topic as well as the analyses of the physical processes behind the proposed solutions will be presented in this paper.

  2. Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events

    PubMed Central

    Algeo, T. J.

    1998-01-01

    The Devonian Period was characterized by major changes in both the terrestrial biosphere, e.g. the evolution of trees and seed plants and the appearance of multi-storied forests, and in the marine biosphere, e.g. an extended biotic crisis that decimated tropical marine benthos, especially the stromatoporoid-tabulate coral reef community. Teleconnections between these terrestrial and marine events are poorly understood, but a key may lie in the role of soils as a geochemical interface between the lithosphere and atmosphere/hydrosphere, and the role of land plants in mediating weathering processes at this interface. The effectiveness of terrestrial floras in weathering was significantly enhanced as a consequence of increases in the size and geographic extent of vascular land plants during the Devonian. In this regard, the most important palaeobotanical innovations were (1) arborescence (tree stature), which increased maximum depths of root penetration and rhizoturbation, and (2) the seed habit, which freed land plants from reproductive dependence on moist lowland habitats and allowed colonization of drier upland and primary successional areas. These developments resulted in a transient intensification of pedogenesis (soil formation) and to large increases in the thickness and areal extent of soils. Enhanced chemical weathering may have led to increased riverine nutrient fluxes that promoted development of eutrophic conditions in epicontinental seaways, resulting in algal blooms, widespread bottomwater anoxia, and high sedimentary organic carbon fluxes. Long-term effects included drawdown of atmospheric pCO2 and global cooling, leading to a brief Late Devonian glaciation, which set the stage for icehouse conditions during the Permo-Carboniferous. This model provides a framework for understanding links between early land plant evolution and coeval marine anoxic and biotic events, but further testing of Devonian terrestrial-marine teleconnections is needed.

  3. First look at RBSP Space Weather data

    NASA Astrophysics Data System (ADS)

    Weiss, M.; Mauk, B. H.; Fox, N. J.; Sotirelis, T.; Barnes, R. J.; Potter, M.

    2011-12-01

    NASA will launch two identical probes into the radiation belts to provide unprecedented insight into the physical processes and dynamics of near-Earth space. The RBSP mission in addition to the scientific data return, provides a 1kbps real-time space weather broadcast data in support of real time space weather modeling, forecast and prediction efforts. Networks of ground stations are being identified to downlink the space weather data. The RBSP instrument suites have selected space weather data to be broadcast from their collected space data on board the spacecraft, a subset from measurements based on information normally available to the instrument. The data subset includes particle fluxes at a variety of energies, and magnetic and electric field data. This selected space weather data is broadcast at all times through the primary spacecraft science downlink antennas when an observatory is not in a primary mission-related ground contact. The collected data will resolve important scientific issues and help researchers develop and improve various models for the radiation belts that can be used by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards. The near real-time data from RBSP will be available to monitor and analyze current environmental conditions, forecast natural environmental changes and support anomaly resolution. When RBSP launches in August 2012, the RBSP instruments will be generating and broadcasting real-time space weather data. These data are used for space weather forecasting. The space weather data will be available on the RBSP Science Data Portal at http://rbspsdp.jhuapl.edu/data.php and will provide access to the space weather data received from the RBSP real-time space weather broadcast. The near real-time data will be calibrated and displayed on the web as soon as possible. The CCMC will ingest the RBSP space weather data into real-time models. The raw space weather data will be permanently archived at APL. This presentation will provide a first look at RBSP space weather data products.

  4. The Stress Process in Physical Education

    ERIC Educational Resources Information Center

    Blankenship, Bonnie Tjeerdsma

    2007-01-01

    Negative stress in physical education can reduce a student's enjoyment of physical activity and destroy the individual's desire to be a lifelong mover. The purpose of this article is to explore the concept of stress in physical education. Stress is defined as a substantial imbalance between the demand of a situation and the individual's capability…

  5. Space Weathering of Rocks

    NASA Technical Reports Server (NTRS)

    Noble, Sarah

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

  6. Home Weatherization Visit

    ScienceCinema

    Chu, Steven

    2013-05-29

    Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

  7. World weather program

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A brief description of the Global Weather Experiment is presented. The world weather watch program plan is described and includes a global observing system, a global data processing system, a global telecommunication system, and a voluntary cooperation program. A summary of Federal Agency plans and programs to meet the challenges of international meteorology for the two year period, FY 1980-1981, is presented.

  8. Proton computed tomography from multiple physics processes

    NASA Astrophysics Data System (ADS)

    Bopp, C.; Colin, J.; Cussol, D.; Finck, Ch; Labalme, M.; Rousseau, M.; Brasse, D.

    2013-10-01

    Proton CT (pCT) nowadays aims at improving hadron therapy treatment planning by mapping the relative stopping power (RSP) of materials with respect to water. The RSP depends mainly on the electron density of the materials. The main information used is the energy of the protons. However, during a pCT acquisition, the spatial and angular deviation of each particle is recorded and the information about its transmission is implicitly available. The potential use of those observables in order to get information about the materials is being investigated. Monte Carlo simulations of protons sent into homogeneous materials were performed, and the influence of the chemical composition on the outputs was studied. A pCT acquisition of a head phantom scan was simulated. Brain lesions with the same electron density but different concentrations of oxygen were used to evaluate the different observables. Tomographic images from the different physics processes were reconstructed using a filtered back-projection algorithm. Preliminary results indicate that information is present in the reconstructed images of transmission and angular deviation that may help differentiate tissues. However, the statistical uncertainty on these observables generates further challenge in order to obtain an optimal reconstruction and extract the most pertinent information.

  9. Proton computed tomography from multiple physics processes.

    PubMed

    Bopp, C; Colin, J; Cussol, D; Finck, Ch; Labalme, M; Rousseau, M; Brasse, D

    2013-10-21

    Proton CT (pCT) nowadays aims at improving hadron therapy treatment planning by mapping the relative stopping power (RSP) of materials with respect to water. The RSP depends mainly on the electron density of the materials. The main information used is the energy of the protons. However, during a pCT acquisition, the spatial and angular deviation of each particle is recorded and the information about its transmission is implicitly available. The potential use of those observables in order to get information about the materials is being investigated. Monte Carlo simulations of protons sent into homogeneous materials were performed, and the influence of the chemical composition on the outputs was studied. A pCT acquisition of a head phantom scan was simulated. Brain lesions with the same electron density but different concentrations of oxygen were used to evaluate the different observables. Tomographic images from the different physics processes were reconstructed using a filtered back-projection algorithm. Preliminary results indicate that information is present in the reconstructed images of transmission and angular deviation that may help differentiate tissues. However, the statistical uncertainty on these observables generates further challenge in order to obtain an optimal reconstruction and extract the most pertinent information. PMID:24076769

  10. Statistical physics of media processes: Mediaphysics

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Dmitri V.; Mandel, Igor

    2007-04-01

    The processes of mass communications in complicated social or sociobiological systems such as marketing, economics, politics, animal populations, etc. as a subject for the special scientific subbranch-“mediaphysics”-are considered in its relation with sociophysics. A new statistical physics approach to analyze these phenomena is proposed. A keystone of the approach is an analysis of population distribution between two or many alternatives: brands, political affiliations, or opinions. Relative distances between a state of a “person's mind” and the alternatives are measures of propensity to buy (to affiliate, or to have a certain opinion). The distribution of population by those relative distances is time dependent and affected by external (economic, social, marketing, natural) and internal (influential propagation of opinions, “word of mouth”, etc.) factors, considered as fields. Specifically, the interaction and opinion-influence field can be generalized to incorporate important elements of Ising-spin-based sociophysical models and kinetic-equation ones. The distributions were described by a Schrödinger-type equation in terms of Green's functions. The developed approach has been applied to a real mass-media efficiency problem for a large company and generally demonstrated very good results despite low initial correlations of factors and the target variable.

  11. Evaluating the effects of terrestrial ecosystems, climate and carbon dioxide on weathering over geological time: a global-scale process-based approach

    PubMed Central

    Taylor, Lyla L.; Banwart, Steve A.; Valdes, Paul J.; Leake, Jonathan R.; Beerling, David J.

    2012-01-01

    Global weathering of calcium and magnesium silicate rocks provides the long-term sink for atmospheric carbon dioxide (CO2) on a timescale of millions of years by causing precipitation of calcium carbonates on the seafloor. Catchment-scale field studies consistently indicate that vegetation increases silicate rock weathering, but incorporating the effects of trees and fungal symbionts into geochemical carbon cycle models has relied upon simple empirical scaling functions. Here, we describe the development and application of a process-based approach to deriving quantitative estimates of weathering by plant roots, associated symbiotic mycorrhizal fungi and climate. Our approach accounts for the influence of terrestrial primary productivity via nutrient uptake on soil chemistry and mineral weathering, driven by simulations using a dynamic global vegetation model coupled to an ocean–atmosphere general circulation model of the Earth's climate. The strategy is successfully validated against observations of weathering in watersheds around the world, indicating that it may have some utility when extrapolated into the past. When applied to a suite of six global simulations from 215 to 50 Ma, we find significantly larger effects over the past 220 Myr relative to the present day. Vegetation and mycorrhizal fungi enhanced climate-driven weathering by a factor of up to 2. Overall, we demonstrate a more realistic process-based treatment of plant fungal–geosphere interactions at the global scale, which constitutes a first step towards developing ‘next-generation’ geochemical models. PMID:22232768

  12. Characterization and nultivariate analysis of physical properties of processing peaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterization of physical properties of fruits represents the first vital step to ensure optimal performance of fruit processing operations and is also a prerequisite in the development of new processing equipment. In this study, physical properties of engineering significance to processing of th...

  13. The influence of regional urbanization and abnormal weather conditions on the processes of human climatic adaptation on mountain resorts

    NASA Astrophysics Data System (ADS)

    Artamonova, M.; Golitsyn, G.; Senik, I.; Safronov, A.; Babyakin, A.; Efimenko, N.; Povolotskaya, N.; Topuriya, D.; Chalaya, E.

    2012-04-01

    This work is a further development in the study of weather pathogenic index (WPI) and negative influence of urbanization processes on the state of people's health with adaptation disorder. This problem is socially significant. According to the data of the WHO, in the world there are from 20 to 45% of healthy people and from 40 to 80% of people with chronic diseases who suffer from the raised meteosensitivity. As a result of our researches of meteosensitivity of people during their short-duration on mountain resorts there were used negative adaptive reactions (NAR) under 26 routine tests, stress-reactions under L.H. Garkavi's hemogram, vegetative indices, tests of neuro-vascular reactivity, signs of imbalance of vegetative and neurohumoral regulation according to the data of biorhythm fractal analysis and sudden aggravations of diseases (SAD) as an indicator of negative climatic and urbanization influence. In 2010-2011 the Caucasian mountain resorts were having long periods of climatic anomalies, strengthening of anthropogenic emissions and forest fires when record-breaking high waves of NAR and SAD were noticed. There have also been specified indices ranks of weather pathogenicity from results of comparison of health characteristics with indicators of synoptico-dynamic processes according to Weather Research and Forecasting model (WRF); air ionization N+, N-, N+/N- spectra of aerosol particles (the size from 500 to 20000 nanometers) and concentrations of chemically active gases (O3, NO, NO2, ), volatile phytoorganic substances in the surface atmosphere, bactericidal characteristics of vegetation by criterion ?2 (not above 0,05). It has allowed us to develop new physiological optimum borders, norm and pessimum, to classify emergency ecologo-weather situations, to develop a new techniques of their forecasting and prevention of meteopathic reactions with meteosensitive patients (Method of treatment and the early (emergency) and planned prevention meteopatic reactions in patients with coronary heart disease, hypertension stage I-II syndrome disadaptative using the transcranial mezo diencephalic modulation / L.I.Zherlitsina, N.V. Efimenko, N.P. Povolotskaya, I.I. Velikanov. the Patent for the invention No.2422128, RU (11) 2 422 128 (13) C1 from 6/27/2011; Bull.13). We have observed that such anthropogenic characteristics as accumulation of aerosol with the size of particles 500-5000 nanometers in the lower atmosphere in the quantity more than 60 particles/sm3 (getting to alveoli); decrease in quantity of negative ions (N-) lower than 200 ions/sm3, high coefficient of ions unipolarity (N+/N-) - more than 4-6; mass concentration of aerosol more than 150 mkg/m3 and other modules of the environment can act as limited markers for the forecast of dangerous NAR, SAD and taking of urgent radical preventive measures. These techniques of medical weather forecast and meteo prevention can be used in other mountain regions of the world. The studies were performed by support of the Program "Basic Sciences for Medicine" and RFBR project No.10-05-01014_a.

  14. Radiative torque alignment: Essential Physical Processes

    E-print Network

    Thiem Hoang; Alex Lazarian

    2007-10-22

    We study the physical processes that affect the alignment of grains subject to radiative torques (RATs). To describe the action of RATs, we use the analytical model (AMO) of RATs introduced in Paper I. We focus our discussion on the alignment by anisotropic radiation flux with respect to magnetic field, which defines the axis of grain Larmor precession. Such an alignment does not invoke paramagnetic dissipation (i.e. Davis-Greenstein mechanism), but, nevertheless, grains tend to be aligned with long axes perpendicular to the magnetic field. When we account for thermal fluctuations within grain material, we show that for grains, which are characterized by a triaxial ellipsoid of inertia, the zero-$J$ attractor point obtained in our earlier study develops into a low-$J$ attractor point. We study effects of stochastic gaseous bombardment and show that gaseous bombardment can drive grains from low-$J$ to high-$J$ attractor points in cases when the high-$J$ attractor points are present. As the alignment of grain axes with respect to angular momentum is higher for higher values of $J$, counter-intuitively, gaseous bombardment can increase the degree of grain alignment in respect to the magnetic field. We also study the effects of torques induced by H$_2$ formation and show that they can change the value of angular momentum at high-$J$ attractor point, but marginally affect the value of angular momentum at low-$J$ attractor points. We compare the AMO results with those obtained using the direct numerical calculations of RATs acting upon irregular grains and validate the use of the AMO for realistic situations of RAT alignment.

  15. Geochemical evidence of chemical and physical weathering of mine waste downriver from the New Idria Mercury Mine, San Benito County, California

    NASA Astrophysics Data System (ADS)

    Sharma, R. K.; Weinman, B.

    2014-12-01

    Soil, river bank, and sediment samples were collected from Panoache Creek's mine tailings and its drainages in the Mendota Pool area of California's Central Valley. The samples were collected in order to understand the transport mechanisms of mercury and other heavy metals from the abandoned New Idria Mercury Mine (NIMM) in San Banito County, CA. It is generally thought that materials weathered from the NIMM site flow down gradient into the San Carlos Creek, which then joins Silver Creek and Panoche Creek, before finally ending up in the Valley's Mendota pool and San Joaquin River (SJR). While we know that factors like geology, anthropogenic activities, and weathering can accelerate heavy metal accumulation at downgradient reaches (Chakravarty and Patgiri, 2009), it is unclear how this part of the SJR has responded to the mine's abandonment since the 1970s. To investigate how mercury and other heavy metals are weathering and being transported through this portion of the SJR drainage, gains and losses using "enrichment factors" (EF) were calculated and compared along a gradient downstream. Overall, EF of fine and bank sediments show Hg is being enriched and stored within bank sediments. For example, Hg in banks sediments are up to 5% enriched compared to the bed sediments. There is also an enrichment gain trending downstream, as sediments settling in the Mendota pool have comparatively higher EF for Hg (0.94 ppm to 6.91 ppm) relative to background concentrations. Along with other geochemical indices, which can be used to more highly resolve exactly how mine contaminants like Hg are chemically and physically being weathered, (i.e., Igeo, PLI, and CIA) the overall enrichment trend is interpreted to be the physical transport of erosion material during runoff events from the stream banks of SJR tributaries. This interpretation is also supported by depleted Sr and enriched Rb/Sr ratios, which further support physical transport as a dominating factor in contaminant enrichment along the banks of the catchment area. Combined with general trends of increasing Igeo, PLI values, and generally low CIA indices, results support Hg weathering predominantly being controlled by a combination of physical weathering, anthropogenic activities, and bank erosion, that lead to Hg mobilization and transport to downstream areas.

  16. Enabling Effective Space Weather and Climatology (SWaC) Capabilities: The NRC Decadal Survey in Solar and Space Physics

    NASA Astrophysics Data System (ADS)

    Baker, D. N.

    2012-12-01

    The U.S. very much needs long-term observations of the space weather environment and must support the development and application of coupled space weather models to protect critical societal infrastructure, including communication, navigation, and terrestrial weather satellites. As just one example, solar and space physicists partnering with power grid engineers have created the capability to model the effects of geomagnetically-induced currents on electricity transmission and distribution systems. This crucially important work has produced sophisticated software to assess the response of the electrical power system to geomagnetic storms, to assess the vulnerabilities, and to develop mitigation strategies. To fulfill the requirements for space weather presented in the June 2010 U.S. National Space Policy and envisioned in the 2010 National Space Weather Program Plan, we must develop a new approach. The National Research Council's 2013-2022 Decadal Survey presents a vision for renewed national commitment to a comprehensive program in Space Weather and Climatology, building on agency strengths. Enabling an effective SWaC capability will require action across multiple agencies. To coordinate the development of this plan, the National Space Weather Program should be re-chartered under the auspices of the National Science and Technology Council and include active participation from the Office of Science and Technology Policy and the Office of Management and Budget. The plan should take into account current agency efforts and capabilities, leverage the new capabilities and knowledge that will arise from implementation of the Decadal Survey, and develop additional monitoring capabilities and platforms specifically tailored to space weather monitoring and prediction.

  17. Wide variability in physical activity environments and weather-related outdoor play policies in child-care centers within a single county of Ohio

    PubMed Central

    Copeland, Kristen A; Sherman, Susan N; Khoury, Jane C; Foster, Karla E; Saelens, Brian E; Kalkwarf, Heidi J

    2011-01-01

    Objectives To examine the variability of physical activity environments and outdoor play-policies in child-care centers, and to determine if they are associated with center demographic characteristics Design Telephone survey—the Early Learning Environments Physical Activity and Nutrition Telephone Survey (ELEPhANTS) Setting Child-care centers in Hamilton County (Cincinnati area), Ohio, 2008–9. Participants Directors of all 185 licensed full-time child-care centers in Hamilton County. Outcome Measures Descriptive measures of center playground and indoor physical activity environments, and weather-related outdoor-play policies. Results 162 (88%) centers responded. Most (93%) centers reported an on-site playground, but only half reported their playgrounds as large, at least 1/3rd covered in shade, or having a variety of portable play equipment. Only half reported having a dedicated indoor gross-motor room where children could be active during inclement weather. Only 20% of centers allowed children to go outside in temperatures below 32°F, and 43% of centers reported allowing children outdoors during light rain. A higher percent of children receiving tuition-assistance was associated with lower quality physical activity facilities and stricter weather-related practices. National accreditation was associated with more physical-activity promoting practices. Conclusion We found considerable variability in the indoor and outdoor playground offerings among child-care centers, even within a single county of Ohio. Per center policy and limited inside options, children’s active opportunities are curtailed due to sub-freezing temperatures or light rain. Policy change and parent/teacher education may be needed to ensure children achieve ample opportunity for daily physical activity. PMID:21199969

  18. Biogenic catalysis in sulphide minerals' weathering processes and acid mine drainage genesis.

    PubMed

    Kušnierová, Mária; Praš?áková, Mária; Nowak, Anna K; Gorazda, Katarzyna; Wzorek, Zbigniew

    2014-01-01

    Bioleaching and biogenesis are the main outputs from a large group of environmental processes participating in the natural material cycle, used in raw materials processing. Bio-oxidation reactions are the main basis for bioleaching procedures, often participating in parallel leaching processes. During the leaching processes of polycomponent sulphide substrates, the factor of process selection also plays an important role, being in direct relation to the electric properties and galvanic effect occurring between the individual components of the leaching substrate. This work gives a summary of the results of a research focused on the possibilities of using biotechnological procedures for treatment of Slovak sulphide ores. The object of the research is extraction of valuable metals, undesirable admixtures and degradation of crystal lattice of sulphides for subsequent chemical leaching processing of precious metals. The results of experiments on the existence of biogenic processes in situ on waste dumps from exploitation containing residual sulphides are also presented. The processes result in acid mine drainage water generation. These waters are strongly mineralised (over 48 g/L) and of low pH; that is why they are very caustic. The arsenic content (2.558 mg/L) in outflowing waters from old mines is high and over the limits set by the law. PMID:24445359

  19. Soil mineralogy at the Mars Exploration Rover landing sites: An assessment of the competing roles of physical sorting and chemical weathering

    NASA Astrophysics Data System (ADS)

    McGlynn, Ian O.; Fedo, Christopher M.; McSween, Harry Y., Jr.

    2012-01-01

    Soils in Gusev Crater and Meridiani Planum derive primarily from a surface dominated by basalt. The modal mineralogy of primary (igneous) and secondary (alteration) phases in the soils is estimated using Mössbauer, MiniTES, and APXS spectra. Primary minerals include plagioclase, pyroxene, and olivine with less common apatite, magnetite, and chromite. Secondary phases are dominated by sulfates, and include nanophase oxides, chlorides, hematite, and are assumed to include amorphous silica and phyllosilicates. Most soil chemical compositions overlap with basalts indicating that despite the presence of a secondary component in the soils, they have not been significantly chemically weathered. We modeled the significance of olivine dissolution by acid-S by iteratively removing the molar FeOT + MgO component (olivine proxy) from the mean bulk compositions of the Gusev rock classes Adirondack, Algonquin, and Irvine until none remained. Regardless of modeling conditions, acid-S alteration cannot account for many soils in Gusev Crater that are either depleted or enriched in molar FeOT + MgO, although it is a process capable of explaining some soil compositions. Based on a rock and mineral mixing model, supports our hypothesis for soil formation that consists of surface comminution by impact gardening, followed by compositional modification by hydrodynamic sorting and admixing of secondary components, including phyllosilicates and sulfates. Such a physical process can produce the range of molar FeOT + MgO in soils by concentrating or depleting specific minerals. For example, dust and fine sands are enriched in molar FeOT + MgO relative to coarse sand, which suggests accumulation of more mafic phases in finer grain fractions.

  20. Probing new physics in rare charm processes

    SciTech Connect

    Hewett, J.L.

    1994-09-01

    The possibility of using the charm system to search for new physics is addressed. Phenomena such as D{sup 0} - {bar D}{sup 0} mixing and rare decays of charmed mesons are first examined in the Standard Model to test the present understanding and to serve as benchmarks for signals from new sources. The effects of new physics from various classes of non-standard dynamical models on D{sup 0} - {bar D}{sup 0} mixing are investigated.

  1. Mesoscale severe weather development under orographic influences

    NASA Astrophysics Data System (ADS)

    Reiter, Elmar R.; Bresch, James F.; Klitch, Marjorie A.; MacDonald, Bruce C.; Sheaffer, John D.

    1986-07-01

    Overall goals of this 3-year study are to: 1)examine the role of topography in the development of convective systems and 2) assess the orographic influences on cold season severe weather, such as blizzards, lee cyclogenesis, etc. Four approaches were taken to attain these goals: 1)Implementation of a field measurement program, 2) diagnostic studies of energy fluxes during various seasons, 3) numerical simulation of severe weather development, and 4) evaluation of model sensitivity ot various physical processes. Progress has been made on all four of these fronts in the first year.

  2. Space Weathering of Lunar Rocks

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2012-01-01

    All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

  3. Electrical Storm Simulation to Improve the Learning Physics Process

    ERIC Educational Resources Information Center

    Martínez Muñoz, Miriam; Jiménez Rodríguez, María Lourdes; Gutiérrez de Mesa, José Antonio

    2013-01-01

    This work is part of a research project whose main objective is to understand the impact that the use of Information and Communication Technology (ICT) has on the teaching and learning process on the subject of Physics. We will show that, with the use of a storm simulator, physics students improve their learning process on one hand they understand…

  4. A Probability Density for Modeling Unknown Physical Processes

    E-print Network

    Steven C. Gustafson; Adam C. Hillier

    2011-04-20

    This brief paper develops a probability density that models processes for which the physical mechanism is unknown. It has desirable properties which are not realized by densities derived from Gaussian process or other classic methods. In many areas of physics, such the analysis of chaotic phenomena, there is need for a density that has these properties.

  5. Enhancing Cloud Radiative Processes and Radiation Efficiency in the Advanced Research Weather Research and Forecasting (WRF) Model

    SciTech Connect

    Iacono, Michael J.

    2015-03-09

    The objective of this research has been to evaluate and implement enhancements to the computational performance of the RRTMG radiative transfer option in the Advanced Research version of the Weather Research and Forecasting (WRF) model. Efficiency is as essential as accuracy for effective numerical weather prediction, and radiative transfer is a relatively time-consuming component of dynamical models, taking up to 30-50 percent of the total model simulation time. To address this concern, this research has implemented and tested a version of RRTMG that utilizes graphics processing unit (GPU) technology (hereinafter RRTMGPU) to greatly improve its computational performance; thereby permitting either more frequent simulation of radiative effects or other model enhancements. During the early stages of this project the development of RRTMGPU was completed at AER under separate NASA funding to accelerate the code for use in the Goddard Space Flight Center (GSFC) Goddard Earth Observing System GEOS-5 global model. It should be noted that this final report describes results related to the funded portion of the originally proposed work concerning the acceleration of RRTMG with GPUs in WRF. As a k-distribution model, RRTMG is especially well suited to this modification due to its relatively large internal pseudo-spectral (g-point) dimension that, when combined with the horizontal grid vector in the dynamical model, can take great advantage of the GPU capability. Thorough testing under several model configurations has been performed to ensure that RRTMGPU improves WRF model run time while having no significant impact on calculated radiative fluxes and heating rates or on dynamical model fields relative to the RRTMG radiation. The RRTMGPU codes have been provided to NCAR for possible application to the next public release of the WRF forecast model.

  6. DOE Workshop; Pan-Gass Conference on the Representation of Atmospheric Processes in Weather and Climate Models

    SciTech Connect

    Morrison, PI Hugh

    2012-09-21

    This is the first meeting of the whole new GEWEX (Global Energy and Water Cycle Experiment) Atmospheric System Study (GASS) project that has been formed from the merger of the GEWEX Cloud System Study (GCSS) Project and the GEWEX Atmospheric Boundary Layer Studies (GABLS). As such, this meeting will play a major role in energizing GEWEX work in the area of atmospheric parameterizations of clouds, convection, stable boundary layers, and aerosol-cloud interactions for the numerical models used for weather and climate projections at both global and regional scales. The representation of these processes in models is crucial to GEWEX goals of improved prediction of the energy and water cycles at both weather and climate timescales. This proposal seeks funds to be used to cover incidental and travel expenses for U.S.-based graduate students and early career scientists (i.e., within 5 years of receiving their highest degree). We anticipate using DOE funding to support 5-10 people. We will advertise the availability of these funds by providing a box to check for interested participants on the online workshop registration form. We will also send a note to our participants' mailing lists reminding them that the funds are available and asking senior scientists to encourage their more junior colleagues to participate. All meeting participants are encouraged to submit abstracts for oral or poster presentations. The science organizing committee (see below) will base funding decisions on the relevance and quality of these abstracts, with preference given to under-represented populations (especially women and minorities) and to early career scientists being actively mentored at the meeting (e.g. students or postdocs attending the meeting with their advisor).

  7. Verifying the learning process in physics

    NASA Astrophysics Data System (ADS)

    Tartaglia, A.; Tresso, E.

    2001-05-01

    This paper describes an automated evaluation system for the learning of general physics. The system whose name is Test on Line (ToL) is based on a question bank from which an appropriate software generates individual multi-issue questionnaires to be submitted through the Web. ToL has been extensively tested over three years and is presently in use for basic physics courses at the Engineering Faculties of the Turin Politecnico. The results of the experimentation and use are presented and discussed. Accumulating data allows for an optimization of the internal partitions of the question bank and of the selection criteria for generating of the questionnaires. The instrument proved to be useful and reliable and could become the core of an agreed common standard for physics education at university level.

  8. Logically Central, Physically Distributed Control in a Process Runtime Environment

    E-print Network

    Massachusetts at Amherst, University of

    Logically Central, Physically Distributed Control in a Process Runtime Environment Aaron G. Cass of a broad class of process definition languages. Keywords Process, Workflow, Distribution, Static Analysis@cs.umass.edu ABSTRACT An effective process definition language must be powerful, yet clear. It must also have well

  9. Process Physics From Quantum Foam to General Relativity

    E-print Network

    Cahill, R T

    2002-01-01

    Progress in the new information-theoretic process physics is reported in which the link to the phenomenology of general relativity is made. In process physics the fundamental assumption is that reality is to be modelled as self-organising semantic (or internal or relational) information using a self-referentially limited neural network model. Previous progress in process physics included the demonstration that space and quantum physics are emergent and unified, with time a distinct non-geometric process, that quantum phenomena are caused by fractal topological defects embedded in and forming a growing three-dimensional fractal process-space, which is essentially a quantum foam. Other features of the emergent physics were: quantum field theory with emergent flavour and confined colour, limited causality and the Born quantum measurement metarule, inertia, time-dilation effects, gravity and the equivalence principle, a growing universe with a cosmological constant, black holes and event horizons, and the emergen...

  10. TIME SERIES ANALYSIS OF REMOTELY-SENSED TIR EMISSION: linking anomalies to physical processes

    NASA Astrophysics Data System (ADS)

    Pavlidou, E.; van der Meijde, M.; Hecker, C.; van der Werff, H.; Ettema, J.

    2013-12-01

    In the last 15 years, remote sensing has been evaluated for detecting thermal anomalies as precursor to earthquakes. Important issues that need yet to be tackled include definition of: (a) thermal anomaly, taking into account weather conditions, observation settings and ';natural' variability caused by background sources (b) the length of observations required for this purpose; and (c) the location of detected anomalies, which should be physically related to the tectonic activity. To determine whether thermal anomalies are statistical noise, mere meteorological conditions, or actual earthquake-related phenomena, we apply a novel approach. We use brightness temperature (top-of-atmosphere) data from thermal infrared imagery acquired at a hypertemporal (sub-hourly) interval, from geostationary weather satellites over multiple years. The length of the time series allows for analysis of meteorological effects (diurnal, seasonal or annual trends) and background variability, through the application of a combined spatial and temporal filter to distinguish extreme occurrences from trends. The definition of potential anomalies is based on statistical techniques, taking into account published (geo)physical characteristics of earthquake related thermal anomalies. We use synthetic data to test the performance of the proposed detection method and track potential factors affecting the results. Subsequently, we apply the method on original data from Iran and Turkey, in quiescent and earthquake-struck periods alike. We present our findings with main focus to assess resulting anomalies in relation to physical processes thereby considering: (a) meteorological effects, (b) the geographical, geological and environmental settings, and (c) physically realistic distances and potential physical relations with the activity of causative faults.

  11. Hydrologic regulation of chemical weathering and the geologic carbon cycle.

    PubMed

    Maher, K; Chamberlain, C P

    2014-03-28

    Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks that operates over million-year time scales. To explain variations in the strength of the weathering feedback, we present a model for silicate weathering that regulates climatic and tectonic forcing through hydrologic processes and imposes a thermodynamic limit on weathering fluxes, based on the physical and chemical properties of river basins. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to the situation today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts, even in the absence of appreciable changes in CO2 degassing rates. PMID:24625927

  12. Atomic physics and radiation processes in plasmas

    NASA Astrophysics Data System (ADS)

    Itoh, K.; Salzmann, D.; Takabe, H.; Kato, T.

    1993-08-01

    It is pointed out that atomic and molecular (A/M) processes play important roles in divertor plasmas but the problems related to these processes are not yet studied quantitatively. Recently new subjects related to A/M processes such as plasma-vapor interaction during plasma disruption are presented. This is a brief summary of our discussions. Our recent results of the calculations for the line emissions of carbon atoms in edge plasmas are also included.

  13. CHEMICAL AND PHYSICAL PROCESS AND MECHANISM MODELING

    EPA Science Inventory

    The goal of this task is to develop and test chemical and physical mechanisms for use in the chemical transport models of EPA's Models-3. The target model for this research is the Community Multiscale Air Quality (CMAQ) model. These mechanisms include gas and aqueous phase ph...

  14. NATURAL ARSENIC CONTAMINATION OF HOLOCENE ALLUVIAL AQUIFERS BY LINKED TECTONIC, WEATHERING, AND MICROBIAL PROCESSES

    EPA Science Inventory

    Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of...

  15. Extrapolation of space weathering processes to other small solar system bodies

    NASA Technical Reports Server (NTRS)

    Gaffey, M. J.

    1993-01-01

    A diverse range of processes were invoked as the dominant factor or as important contributory factors in the modification of the optical surface and regolith of the moon. These include impact vitrification by large and small projectiles, solar wind implantation and the reduction of oxidized iron during energetic events, sputtering and crystal lattice damage by energetic cosmic rays, shock metamorphism of minerals, mixing of diverse lithologies by impacts, and contamination by external materials. These processes are also potentially important on the rocky surfaces of other small solar system bodies. For icy bodies, several additional processes are also possible, including formation of complex organic compounds from methane and ammonia-bearing ices by ultraviolet irradiation and the condensation of vapor species to form frost layers in the polar or cooler regions of objects at appropriate heliocentric distances. The lunar case, even when completely understood, will not extend in a simple linear fashion to other small rocky objects, nor will the optical surfaces of those objects all be affected to the same degree by each process. The major factors that will control the relative efficacy of a possible mechanism include the efficiency of ejecta retention and the degree to which the regolith materials experience multiple events (primarily a function of body size, escape velocity, and impactor velocities); the mean duration of typical regolith particle exposure at the optical surface and within reach of the micrometeorite, cosmic ray, solar wind, or UV fluxes (a function of the rate and scale of regolith mixing, production, and removal processes); the incident flux of solar (low energy) cosmic rays, solar wind, or UV radiation (inverse square of heliocentric distance) or of galactic (high energy) cosmic rays (slowly increasing flux with heliocentric distance); and the compositional and mineralogical nature of the surface being affected. In general, those processes that depend upon either the retention of impact ejecta or on the presence of multigenerational regoliths should be substantially less effective on smaller bodies with lower escape velocities. However, there are important exceptions to this generalization. For example, a process that involves the hypervelocity impact of small particles into a fine-grained regolith may be able to effectively retain highly shocked or melted material due to the nature of shock wave propagation in such a heterogeneous material.

  16. Getting Middle-School Students up and Moving: What's the Role of School and Neighborhood Environments...and the Weather: Studying the Effect of Neighborhood and School Environments on Youth Physical Activity Levels. Program Results

    ERIC Educational Resources Information Center

    Nakashian, Mary

    2008-01-01

    Researchers at the Harvard Prevention Research Center at Harvard University School of Public Health examined how physical and social environments of schools and neighborhoods shape routine physical activities of students attending 10 middle schools in the Boston area. They also analyzed the effect of weather conditions on student physical

  17. Turbulence and Fluid Flow: Perspectives. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Simpson, James R.

    This module is part of a series on Physical Processes in Terrestrial and Aquatic Ecosystems. The materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process.…

  18. AN overview of the FLYSAFE datalink solution for the exchange of weather information: supporting aircrew decision making processes.

    NASA Astrophysics Data System (ADS)

    Mirza, A.; Drouin, A.

    2009-09-01

    FLYSAFE is an Integrated Project of the 6th framework of the European Commission with the aim to improve flight safety through the development of an avionics solution the Next Generation Integrated Surveillance System (NGISS), which is supported by a ground based network of Weather Information Management Systems (WIMS) and access points in the form of the Ground Weather Processor (GWP). The NGISS provides information to the flight crew on the three major external hazards for aviation: weather, air traffic and terrain. The NGISS has the capability of displaying data about all three hazards on a single display screen, facilitating rapid appreciation of the situation by the flight crew. Weather Information Management Systems (WIMS) were developed to provide the NGISS and the flight crew with weather related information on in-flight icing, thunderstorms and clear-air turbulence. These products are generated on the ground from observations and model forecasts. WIMS will supply relevant information on three different scales: global, regional and local (over airport Terminal Manoeuvring Area). The Ground Weather Processor is a client-server architecture that utilises open source components, which include a geospatial database and web feature services. The GWP stores Weather Objects generated by the WIMS. An aviation user can retrieve on-demand all Weather Objects that intersect the volume of space that is of interest to them. The Weather Objects are fused with in-situ observation data and can be used by the flight management system to propose a route to avoid the hazard. In addition they can be used to display the current hazardous weather to the Flight Crew thereby raising their awareness. Within the FLYSAFE program, around 120 hours of flight trials were performed during February 2008 and August 2008. Two aircraft were involved each with separate objectives: - to assess FLYSAFE's innovative solutions for the data-link, on-board data-fusion and data-display and data-updates during flight; - to evaluate the new weather information management systems (in-flight icing and thunderstorms) using in-situ measurements recorded on-board the test aircraft. In this presentation we will focus on the data link solution to uplink the Weather Objects to the NGISS. As part of the solution, a brief description is given on how grid data created by the WIMS are transformed to Weather Objects; which describe the weather hazard and are formatted using the Geospatial Mark-up Language.

  19. Brazilian Space Weather Program

    NASA Astrophysics Data System (ADS)

    Padilha, Antonio; Takahashi, Hisao; de Paula, Eurico; Sawant, Hanumant; de Campos Velho, Haroldo; Vitorello, Icaro; Costa, Joaquim; Souza, Jonas; Cecatto, José; Mendes, Odim; Gonzalez Alarcon, Walter Demétrio

    A space weather program is being initiated at the Brazilian National Institute for Space Research (INPE) to study events from their initiation on the sun to their impacts on the earth, including their effects on space-based and ground-based technological systems. The program is built on existing capabilities at INPE, which include scientists with a long tradition and excellence in the observation, analysis and modeling of solar and solar-terrestrial phenomena and an array of geophysical instruments that spans all over the Brazilian territory from the north to south of the magnetic dip equator. Available sensors include solar radio frequency receivers and telescopes, optical instruments and solar imagers, GNSS receivers, ionosondes, radars, allsky imagers, magnetometers and cosmic ray detectors. In the equatorial region, ionosphere and thermosphere constitute a coupled system with electrodynamical and plasma physical processes being responsible for a variety of peculiar phenomena. The most important of them are the equatorial electrojet current system and its instabilities, the equatorial ionization anomaly, and the plasma instabilities/irregularities of the night-time ionosphere (associated with the plasma bubble events). In addition, space weather events modify the equatorial ionosphere in a complex and up to now unpredictable manner. Consequently, a main focus of the program will be on monitoring the low, middle and upper atmosphere phenomena and developing a predictive model of the equatorial ionosphere through data assimilation, that could help to mitigate against the deleterious effects on radio communications and navigation systems. The technological, economic and social importance of such activities was recognized by the Brazilian government and a proposal for funding was approved for the period 2008-2011. New ground instruments will be installed during this period allowing us to extend our current capability to provide space weather observations, accurate forecasts of space weather conditions, and timely hazard alert warnings. The program is expected to be fully operational for the peak activity of the next solar maximum, but for its future growth and development it is essential to have a wide network of international collaborations.

  20. Extreme Weather: Understanding the Science of Hurricanes, Tornadoes, Floods, Heat Waves, Snow Storms, Global Warming and Other Atmospheric Disturbances

    NASA Astrophysics Data System (ADS)

    Brooks, Harold

    2008-07-01

    Extreme weather is of importance because of the threats it makes to life and property. At the same time, extreme weather is a great fascination for meteorologists as well as for the general public. The conditions and processes that lead to extreme weather-although governed by the same physical principles as ``ordinary'' weather-frequently are far from the average state of the atmosphere. Thus, explaining them in simple terms can be difficult. This book represents an effort to explain the development of extreme weather to the public.

  1. Foundations of Physical Theory, I: Force and Energy. Physical Processes in Terrestrial and Aquatic Ecosystems, Fundamentals.

    ERIC Educational Resources Information Center

    Pearson, Nolan E.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module is one of two units on the foundations of physical theory and the…

  2. Zeolite Formation and Weathering Processes Within the Martian Regolith: An Antarctic Analog

    NASA Technical Reports Server (NTRS)

    Gibson, E. K.; McKay, D. S.; Wentworth, S. J.; Socki, R. A.

    2003-01-01

    As more information is obtained about the nature of the surface compositions and processes operating on Mars, it is clear that significant erosional and depositional features are present on the surface. Apparent aqueous or other fluid activity on Mars has produced many of the erosional and outflow features observed. Evidence of aqueous activity on Mars has been reported by earlier studies. Gooding and colleagues championed the cause of pre-terrestrial aqueous alteration processes recorded in Martian meteorites. Oxygen isotope studies on Martian meteorites by Karlsson et al. and Romenek et al. gave evidence for two separate water reservoirs on Mars. The oxygen isotopic compositions of the host silicate minerals was different from the oxygen isotopic composition of the secondary alteration products within the SNC meteorites. This implied that the oxygen associated with fluids which produced the secondary alteration was from volatiles which were possibly added to the planetary inventory after formation of the primary silicates from which the SNC s were formed. The source of the oxygen may have been from a cometary or volatile-rich veneer added to the planet in its first 600 million years.

  3. Genesis of karren in Kentucky Lake, Tennessee: Interaction of geologic structure, weathering processes, and bioerosion

    SciTech Connect

    Gibson, M.A.; Smith, W.L. )

    1993-03-01

    While karst features formed along marine coastlines are commonly reported, shoreline karst features produced within lacustrine systems have received little attention. The shoreline of Bond Island'' in Kentucky Lake has evolved a distinctive karren geomorphology not recognized elsewhere in the lake. The karren consist of well-developed clint and grike topography, trench formation, solution pits, flutes, and runnels, and pit and tunnel development. Two processes are responsible for the karren. First, freshwater dissolution and wave action on structurally fractured Decatur Limestone (Silurian) mechanically and chemically weaken the entire exposed surface. Second, a seasonal cycle of winter freeze-thaw and frost wedging followed by spring bioerosion overprints the first set of processes. Bioerosion by chemical dissolution involving a complex association of predominantly chironomids, algae, fungi, and bryozoa results in preferential dissolution along joints, stylolites, and bedding planes to form shallow spindle-shaped solution pits over the entire surface and sides of the karren. The solution pits average 1 cm length by 0.4 cm depth densely covering rock surfaces. This study suggests that seasonal bioerosion may constitute a more important geomorphic factor in lacustrine systems than previously recognized.

  4. Weather Instruments.

    ERIC Educational Resources Information Center

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities to measure various weather phenomena. Directions for constructing a weather station are included. Instruments including rain gauges, thermometers, wind vanes, wind speed devices, humidity devices, barometers, atmospheric observations, a dustfall jar, sticky-tape can, detection of gases in the air, and pH of…

  5. Wacky Weather

    ERIC Educational Resources Information Center

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  6. The use of imprecise processing to improve accuracy in weather and climate prediction

    SciTech Connect

    Düben, Peter D.; McNamara, Hugh; Palmer, T.N.

    2014-08-15

    The use of stochastic processing hardware and low precision arithmetic in atmospheric models is investigated. Stochastic processors allow hardware-induced faults in calculations, sacrificing bit-reproducibility and precision in exchange for improvements in performance and potentially accuracy of forecasts, due to a reduction in power consumption that could allow higher resolution. A similar trade-off is achieved using low precision arithmetic, with improvements in computation and communication speed and savings in storage and memory requirements. As high-performance computing becomes more massively parallel and power intensive, these two approaches may be important stepping stones in the pursuit of global cloud-resolving atmospheric modelling. The impact of both hardware induced faults and low precision arithmetic is tested using the Lorenz '96 model and the dynamical core of a global atmosphere model. In the Lorenz '96 model there is a natural scale separation; the spectral discretisation used in the dynamical core also allows large and small scale dynamics to be treated separately within the code. Such scale separation allows the impact of lower-accuracy arithmetic to be restricted to components close to the truncation scales and hence close to the necessarily inexact parametrised representations of unresolved processes. By contrast, the larger scales are calculated using high precision deterministic arithmetic. Hardware faults from stochastic processors are emulated using a bit-flip model with different fault rates. Our simulations show that both approaches to inexact calculations do not substantially affect the large scale behaviour, provided they are restricted to act only on smaller scales. By contrast, results from the Lorenz '96 simulations are superior when small scales are calculated on an emulated stochastic processor than when those small scales are parametrised. This suggests that inexact calculations at the small scale could reduce computation and power costs without adversely affecting the quality of the simulations. This would allow higher resolution models to be run at the same computational cost.

  7. Study on the Fog Weather Process Ionic Species Concentration Variation of The Fog Water in Beijing

    NASA Astrophysics Data System (ADS)

    Jiang, Y. H.; Wang, Q.; Xu, X. B.; Wang, Z. X.

    2010-07-01

    To study the formation mechanism as well as the urban fog pollution in Beijing, a heavy fog with horizontal visibility under 100 meters was observed in the Beijing Observatory which locates in the south suburb (39°56'N, 116°17'E)during 11-12 Dec 2006.The synoptic system and fog water ionic species concentration are analyzed. It has demonstrated that the observed fog process is an advection-radiation fog with a deep layer more than 150 meters and a low visibility less than 100 meters. The formation and development stage of the heavy fog event accompany with an air pollution index V(APIV). Comparing with 1999 Beijing's fog water sample, the PH rises, electric conductivity rate descents, the anion’s concentration has decreased generally, but the cation’s risen. The chemistrical composition, ion component and concentration of the fog water has improved obviously. Studies have shown that Beijing’s city government has taken measures to reduce the heavy fog’s frequency and fog water’s pollution in recent years.

  8. Nonequilibrium statistical physics applied to biophysical cellular processes 

    E-print Network

    Sugden, Kate E. P.

    2010-01-01

    The methods of statistical physics are increasingly being employed in a range of interdisciplinary areas. In particular, aspects of complex biological processes have been elucidated by bringing the problems down to the ...

  9. Properties, Processes & Change Alternative Representations: Spectral, Physical , Thematic

    E-print Network

    Small, Christopher

    Properties, Processes & Change Alternative Representations: Spectral, Physical , Thematic - Is the result valid across spatial scales? Can it be aggregated? Change Detection - Can change be interpreted Band2 Thematic Image Classification - Statistical · Image pixel samples of known composition define

  10. Urban weather generator user interface development : towards a usable tool for integrating urban heat island effect within urban design process

    E-print Network

    Nakano, Aiko

    2015-01-01

    Urban Weather Generator (UWG) is the urban design simulation tool that provides climate-specific advice for cityscape geometry and land use to assist the development of energy-efficient cities that are also thermally ...

  11. Distributed System of Processing of Data of Physical Experiments

    NASA Astrophysics Data System (ADS)

    Nazarov, A. A.; Moiseev, A. N.

    2014-11-01

    Complication of physical experiments and increasing volumes of experimental data necessitate the application of supercomputer and distributed computing systems for data processing. Design and development of such systems, their mathematical modeling, and investigation of their characteristics and functional capabilities is an urgent scientific and practical problem. In the present work, the characteristics of operation of such distributed system of processing of data of physical experiments are investigated using the apparatus of theory of queuing networks.

  12. Fourth National Aeronautics and Space Administration Weather and Climate Program Science Review

    NASA Technical Reports Server (NTRS)

    Kreins, E. R. (editor)

    1979-01-01

    The NASA Weather and Climate Program has two major thrusts. The first involves the development of experimental and prototype operational satellite systems, sensors, and space facilities for monitoring and understanding the atmosphere. The second thrust involves basic scientific investigation aimed at studying the physical and chemical processes which control weather and climate. This fourth science review concentrated on the scientific research rather than the hardware development aspect of the program. These proceedings contain 65 papers covering the three general areas: severe storms and local weather research, global weather, and climate.

  13. Process Physics: From Quantum Foam to General Relativity

    E-print Network

    Reginald T. Cahill

    2002-03-05

    Progress in the new information-theoretic process physics is reported in which the link to the phenomenology of general relativity is made. In process physics the fundamental assumption is that reality is to be modelled as self-organising semantic (or internal or relational) information using a self-referentially limited neural network model. Previous progress in process physics included the demonstration that space and quantum physics are emergent and unified, with time a distinct non-geometric process, that quantum phenomena are caused by fractal topological defects embedded in and forming a growing three-dimensional fractal process-space, which is essentially a quantum foam. Other features of the emergent physics were: quantum field theory with emergent flavour and confined colour, limited causality and the Born quantum measurement metarule, inertia, time-dilation effects, gravity and the equivalence principle, a growing universe with a cosmological constant, black holes and event horizons, and the emergence of classicality. Here general relativity and the technical language of general covariance is seen not to be fundamental but a phenomenological construct, arising as an amalgam of two distinct phenomena: the `gravitational' characteristics of the emergent quantum foam for which `matter' acts as a sink, and the classical `spacetime' measurement protocol, but with the later violated by quantum measurement processes. Quantum gravity, as manifested in the emergent Quantum Homotopic Field Theory of the process-space or quantum foam, is logically prior to the emergence of the general relativity phenomenology, and cannot be derived from it.

  14. Waste glass weathering

    SciTech Connect

    Bates, J.K.; Buck, E.C.

    1993-12-31

    The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass.

  15. Physical Processes in the MAGO/MFT Systems

    SciTech Connect

    Garanin, Sergey F; Reinovsky, Robert E.

    2015-03-23

    The Monograph is devoted to theoretical discussion of the physical effects, which are most significant for the alternative approach to the problem of controlled thermonuclear fusion (CTF): the MAGO/MTF approach. The book includes the description of the approach, its difference from the major CTF systems—magnetic confinement and inertial confinement systems. General physical methods of the processes simulation in this approach are considered, including plasma transport phenomena and radiation, and the theory of transverse collisionless shock waves, the surface discharges theory, important for such kind of research. Different flows and magneto-hydrodynamic plasma instabilities occurring in the frames of this approach are also considered. In virtue of the general physical essence of the considered phenomena the presented results are applicable to a wide range of plasma physics and hydrodynamics processes. The book is intended for the plasma physics and hydrodynamics specialists, post-graduate students, and senior students-physicists.

  16. Rainy Weather Science.

    ERIC Educational Resources Information Center

    Reynolds, Karen

    1996-01-01

    Presents ideas on the use of rainy weather for activities in the earth, life, and physical sciences. Topics include formation and collision of raindrops, amount and distribution of rain, shedding of water by plants, mapping puddles and potholes, rainbow formation, stalking storms online, lightning, and comparing particles in the air before and…

  17. Weatherizing America

    ScienceCinema

    Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony;

    2013-05-29

    As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

  18. Weatherizing America

    SciTech Connect

    Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony;

    2009-01-01

    As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

  19. Social Media: Space Weather #SpaceWeather

    E-print Network

    on the Power Grid Space Weather and the Aurora Borealis What are Solar Flares? What are Coronal Mass Social Media: Space Weather #SpaceWeather Please help the NWS spread these important safety build a WeatherReady Nation. New Space Weather Safety Page What is Space Weather and What

  20. Process Evaluation Results from the HEALTHY Physical Education Intervention

    ERIC Educational Resources Information Center

    Hall, William J.; Zeveloff, Abigail; Steckler, Allan; Schneider, Margaret; Thompson, Deborah; Pham, Trang; Volpe, Stella L.; Hindes, Katie; Sleigh, Adriana; McMurray, Robert G.

    2012-01-01

    Process evaluation is an assessment of the implementation of an intervention. A process evaluation component was embedded in the HEALTHY study, a primary prevention trial for Type 2 diabetes implemented over 3 years in 21 middle schools across the United States. The HEALTHY physical education (PE) intervention aimed at maximizing student…

  1. Process evaluation results from the HEALTHY physical education intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Process evaluation is an assessment of the implementation of an intervention. A process evaluation component was embedded in the HEALTHY study, a primary prevention trial for Type 2 diabetes implemented over 3 years in 21 middle schools across the United States. The HEALTHY physical education (PE) i...

  2. Logically Central, Physically Distributed Control in a Process Runtime Environment

    E-print Network

    Lerner, Barbara Staudt

    Logically Central, Physically Distributed Control in a Process Runtime Environment Aaron G. Cass Barbara Staudt Lerner Eric K. McCall Leon J. Osterweil Alexander Wise Department of Computer Science.umass.edu ABSTRACT An effective process definition language must be powerful, yet clear. It must also have well

  3. Rb Sr and K Ar systems of biotite in surface environments regulated by weathering processes with implications for isotopic dating and hydrological cycles of Sr isotopes

    NASA Astrophysics Data System (ADS)

    Jeong, Gi Young; Cheong, Chang-Sik; Kim, Jeongmin

    2006-09-01

    Biotite is widely used for Rb-Sr and K-Ar isotopic dating and influences Sr isotope geochemistry of hydrological regimes. The isotopic system of biotite behaves diversely in response to surface weathering; i.e. the complete preservation of original Rb-Sr and K-Ar isotopic ages or dramatic reduction. In this study, we have explored the relation between the behavior of isotopic systems and complex weathering processes of biotites in the weathering profiles distributed on the Mesozoic granitoids in South Korea. In the lower parts of the profiles, biotite in the early stages of weathering was transformed into either oxidized biotite or hydrobiotite, with a mass release of 87Sr and 40Ar forced by the rapid oxidation of ferrous iron. During the transformation to oxidized biotite, 87Sr and 40Ar were preferentially released relative to Rb and K, respectively, via solid-state diffusion through the biotite lattice, resulting in a drastic reduction of original isotopic age. The reduction of Rb-Sr age was greater than that of K-Ar age because K was preferentially released over Rb whereas 87Sr and 40Ar were released proportionally to each other. However, during the transformation of biotite to hydrobiotite (i.e., to regularly interstratified biotite-vermiculite), 87Sr, Rb, 40Ar, and K were completely retained in the alternating biotite interlayer, and thus the original isotopic age can be preserved. In the upper parts of the profiles, where iron oxidation was almost completed, 87Sr, Rb, 40Ar, and K were gradually and proportionally released, with no further significant change in isotopic age during the gradual transformation of the early-formed oxidized biotite into hydrobiotite and vermiculite or during their final decomposition to kaolinite. The ratios and amounts of isotopes released from weathered biotites are dependent upon the degree of iron oxidation and the pathways of mineralogical transformation. Regional and local variations in isotopic systems affected by particular weathering processes should be considered when dating biotite or biotite-bearing rocks in weathering environments, modeling the transfer of Sr isotopes to hydrologic regimes, and tracking the provenance of sediments.

  4. The Sun and Space Weather

    NASA Astrophysics Data System (ADS)

    Hanslmeier, Arnold

    2007-06-01

    This second edition is a great enhancement of literature which will help the reader get deeper into the specific topics. There are new sections included such as space weather data sources and examples, new satellite missions, and the latest results. At the end a comprehensive index is given which will allow the reader to quickly find his topics of interest. The Sun and Space weather are two rapidly evolving topics. The importance of the Sun for the Earth, life on Earth, climate and weather processes was recognized long ago by the ancients. Now, for the first time there is a continuous surveillance of solar activity at nearly all wavelengths. These data can be used to improve our understanding of the complex Sun-Earth interaction. The first chapters of the book deal with the Sun as a star and its activity phenomena as well as its activity cycle in order to understand the complex physics of the Sun-Earth system. The reader will see that there are many phenomena but still no definite explanations and models exist for many of them. Other topics are the influences on the Earth's atmosphere, long and short term climate variations. The last chapters discuss the protection against enhanced radiation environment in view of upcoming manned missions to the Moon and Mars, and the threat from space debris, asteroids and meteoroids. Since the field is quite interdisciplinary, the book will be of interest to scientists working in different fields such as solar physics, geophysics, and space physics. Link: http://www.springer.com/west/home/generic/search/results?SGWID=4-40109-22-173699408-0

  5. Ontology of physics for biology: representing physical dependencies as a basis for biological processes

    PubMed Central

    2013-01-01

    Background In prior work, we presented the Ontology of Physics for Biology (OPB) as a computational ontology for use in the annotation and representations of biophysical knowledge encoded in repositories of physics-based biosimulation models. We introduced OPB:Physical entity and OPB:Physical property classes that extend available spatiotemporal representations of physical entities and processes to explicitly represent the thermodynamics and dynamics of physiological processes. Our utilitarian, long-term aim is to develop computational tools for creating and querying formalized physiological knowledge for use by multiscale “physiome” projects such as the EU’s Virtual Physiological Human (VPH) and NIH’s Virtual Physiological Rat (VPR). Results Here we describe the OPB:Physical dependency taxonomy of classes that represent of the laws of classical physics that are the “rules” by which physical properties of physical entities change during occurrences of physical processes. For example, the fluid analog of Ohm’s law (as for electric currents) is used to describe how a blood flow rate depends on a blood pressure gradient. Hooke’s law (as in elastic deformations of springs) is used to describe how an increase in vascular volume increases blood pressure. We classify such dependencies according to the flow, transformation, and storage of thermodynamic energy that occurs during processes governed by the dependencies. Conclusions We have developed the OPB and annotation methods to represent the meaning—the biophysical semantics—of the mathematical statements of physiological analysis and the biophysical content of models and datasets. Here we describe and discuss our approach to an ontological representation of physical laws (as dependencies) and properties as encoded for the mathematical analysis of biophysical processes. PMID:24295137

  6. Snowslip Mountain Weather Station, MT

    USGS Multimedia Gallery

    USGS Physical Scientist Erich Peitzsch sets up a weather station on Snowslip Mountain in Glacier National Park.  It provides meteorological data for avalanche forecasting and research, including wind speed and direction, air temperature, relative humidity, and net radiation measurements....

  7. Physics-based signal processing algorithms for micromachined cantilever arrays

    DOEpatents

    Candy, James V; Clague, David S; Lee, Christopher L; Rudd, Robert E; Burnham, Alan K; Tringe, Joseph W

    2013-11-19

    A method of using physics-based signal processing algorithms for micromachined cantilever arrays. The methods utilize deflection of a micromachined cantilever that represents the chemical, biological, or physical element being detected. One embodiment of the method comprises the steps of modeling the deflection of the micromachined cantilever producing a deflection model, sensing the deflection of the micromachined cantilever and producing a signal representing the deflection, and comparing the signal representing the deflection with the deflection model.

  8. Heat Transfer Processes for the Thermal Energy Balance of Organisms. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Stevenson, R. D.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module describes heat transfer processes involved in the exchange of heat…

  9. TESTING SOLIDS SETTING APPARATUSES FOR DESIGN AND OPERATION OF WET-WEATHER FLOW SOLIDS-LIQUID SEPARATION PROCESSES

    EPA Science Inventory

    This study was a side-by-side comparison of two settling evaluation methods: one traditional and one new. The project investigated whether these column tests were capable of capturing or representing the rapidly settling particles present in wet-weather flows (WWF). The report r...

  10. Weathering, Soil Production, and Erosion Across Climatic and Tectonic Gradients

    NASA Astrophysics Data System (ADS)

    Norton, K. P.; Larsen, I. J.

    2014-12-01

    Weathering is one of the fundamental processes that sustain life on our planet. Physical weathering breaks down rock for soil production and chemical weathering is thought to operate as the ultimate long-term negative feedback on atmospheric CO2 concentrations. There remains, however, uncertainty as to the relationship between chemical and physical weathering at very fast rates. If chemical weathering becomes kinetically limited at rapid erosion rates, as has been shown in a number of locations around the globe, then the fastest erosion rates will be associated with reduced chemical weathering. This has led to a debate as to whether tectonically active mountain ranges or rolling plains are the main source of CO2 drawdown through silicate weathering. At the heart of this debate is the dearth of chemical weathering data at fast erosion rates. New cosmogenic nuclide-derived denudation rates from the West Coast of the New Zealand Southern Alps are among the fastest in the world and are linearly correlated with chemical weathering rates. The associated soil production rates reach an order of magnitude faster than previous estimates and far exceed the suggested maximum soil production rate. This suggests that very fast weathering and soil production is possible in such active landscapes and extreme climates. We investigate the controls on these rapid rates with a climate-driven soil production model. At the most basic level, soil production requires chemical weathering of primary minerals to secondary minerals. We apply soil production models with both exponential and hump-shaped dependencies on soil thickness. Mean annual temperature and precipitation are incorporated in the form of a modified Arrhenius equation that controls the maximum soil production rate. When applied to the Southern Alps, the model predicts very rapid soil production that matches the magnitude of the cosmogenic nuclide-derived rates. High annual precipitation in the Southern Alps supports rapid soil generation through increased chemical weathering rates and extensive vegetation cover. When applied more broadly, the climate-dependent soil production model suggests that actively eroding mountain belts may display a linear relationship between weathering and erosion in strongly orographic settings, such as in New Zealand's Southern Alps.

  11. Weathering processes and the composition of inorganic material transported through the orinoco river system, Venezuela and Colombia

    USGS Publications Warehouse

    Stallard, R.F.; Koehnken, L.; Johnsson, M.J.

    1991-01-01

    The composition of river-borne material in the Orinoco River system is related primarily to erosion regime, which in turn is related to tectonic setting; especially notable is the contrast between material derived from tectonically active mountain belts and that from stable cratonic regions. For a particular morpho-tectonic region, the compositional suites of suspended sediment, bed material, overback deposits, and dissolved phases are fairly uniform are are typically distinct from whose of other regions. For each region, a consistent set of chemical weathering reactions can be formulated to explain the composition of dissolved and solid loads. In developing these formulations, erosion on slopes and storage of solids in soils and alluvial sediments are important considerations. Compositionally verymature sediment is derived from areas of thick soils where erosion is transport limited and from areas where sediments are stored for extended periods of time in alluvial deposits. Compositionally immature sediments are derived from tectonically active mountain belts where erosion is weathering limited. Weathering-limited erosion also is important in the elevated parts of the Guayana Shield within areas of sleep topography. Compared to the mountain belts, sediments derived from elevated parts of the Shield are more mature. A greater degree of chemical weathering seems to be needed to erode the rock types typical of the Shield. The major-element chemistry and mineral composition of sediment delivered by the Orinoco River to the ocean are controlled by rivers that have their headwaters in mountain belts and cross the Llanos, a region of alluvial plains within the foreland basin. The composition of sediments in rivers that drain the Shield seems to be established primarily at the site of soil formation, whereas for rivers that drain the mountain belts, additional weathering occurs during s episodes of storage on alluvial plains as sediments are transported across the Llanos to the main stem of the Orinoco. After mixing into the main stem, there seems to be little subsequent alteration of sediment. ?? 1991.

  12. Improved solar irradiance forecast with Weather Research and Forecasting model: A Sensitivity test of shallow cumulus clouds to the turbulence process

    NASA Astrophysics Data System (ADS)

    Kim, C. K.; Betterton, E. A.; Leuthold, M.; Holmgren, W.; Cronin, A.

    2014-12-01

    Accurate forecasts of solar irradiance are required for electric utilities to economically integrate substantial amounts of solar power into their power generation portfolios. A common failing of numerical weather models is the prediction of shallow cumulus clouds which are generally difficult to be resolved due to complicated processes in the planetary boundary layer. The present study carried out the sensitivity test of turbulence parameterization for better predicting solar irradiance during the shallow cumulus events near the state of Arizona by using the Weather Research and Forecasting model. The results from the simulations show that increasing the exchange coefficient leads to enhanced vertical mixing and a deeper mixed layer. At the top of mixed layer, an adiabatically ascending air parcel achieved the water vapour saturation and finally shallow cumulus is generated. A detailed analysis will be discussed in the upcoming conference.

  13. Weathering effects on the structure and reactivity of US coals: Final report, July 15, 1984-July 14, 1987. [Many data

    SciTech Connect

    Meuzelaar, H.L.C.; Hill, G.R.; Yun, Yongseung; Jakab, E.; Windig, W.; Urban, D.; Yon, Kyung Yol; Oestreich, J.; East, J.

    1987-01-01

    This report covers the work performed from July 1984 to July 1987 under the project entitled ''Weathering Effects on Structure and Reactivity of US Coals'' (grant number FG22-84PC70798). The main objectives of the study were to investigate the structural changes in coal during the weathering process as well as to develop a simple, reliable weathering index, which can monitor indirectly the weathering-induced changes in physical and chemical properties. Although there have been numerous publications on structure and reactivity of coal, most data reported in the literature thus far have been obtained on coal samples of uncertain weathering status and therefore need to be interpreted with great caution. Weathering has a profound effect on many important coal properties such as heating value, caking characteristics, acidity, flotability and reactivity in liquefaction, combustion and gasification processes. The objective of developing a weathering index is to predict these coal property changes due to weathering without resorting to real-time measurements or pilot plant runs. This report is comprised of four main chapters: I. Structural Changes due to Weathering; II. Material Balance in Weathering Process; III. Development of a Reliable Weathering Index; and IV. Proposed Weathering Mechanisms. A battery of sophisticated analytical tools and techniques was employed during this study. Pyrolysis mass spectrometry in time-integrated, as well as in time-resolved modes with computer-aided data analysis techniques (such as factor and discriminant analysis), gas chromatography, thermogravimetry/mass spectrometry and solvent extraction were used for determining the role of oxygen during the weathering process. Pyrolysis mass spectrometry, Free Swelling Index and a novel slurry pH technique were employed as weathering indicators. 170 refs.

  14. Weather Forecasting Systems and Methods

    NASA Technical Reports Server (NTRS)

    Mecikalski, John (Inventor); MacKenzie, Wayne M., Jr. (Inventor); Walker, John Robert (Inventor)

    2014-01-01

    A weather forecasting system has weather forecasting logic that receives raw image data from a satellite. The raw image data has values indicative of light and radiance data from the Earth as measured by the satellite, and the weather forecasting logic processes such data to identify cumulus clouds within the satellite images. For each identified cumulus cloud, the weather forecasting logic applies interest field tests to determine a score indicating the likelihood of the cumulus cloud forming precipitation and/or lightning in the future within a certain time period. Based on such scores, the weather forecasting logic predicts in which geographic regions the identified cumulus clouds will produce precipitation and/or lighting within during the time period. Such predictions may then be used to provide a weather map thereby providing users with a graphical illustration of the areas predicted to be affected by precipitation within the time period.

  15. The s Process: Nuclear Physics, Stellar Models, Observations

    E-print Network

    Kaeppeler, Franz; Bisterzo, Sara; Aoki, Wako

    2010-01-01

    Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar system material. Depending on stellar mass and metallicity the resulting s-abundance patterns exhibit characteristic features, which provide comprehensive information for our understanding of the stellar life cycle and for the chemical evolution of galaxies. The rapidly growing body of detailed abundance observations, in particular for AGB and post-AGB stars, for objects in binary systems, and for the very faint metal-poor population represents exciting challenges and constraints for stellar model calculations. Based on updated and improved nuclear physics data for the s-process reaction network, current models are aiming at ab initio solution for the stellar physics related to convection and mixing processes. Progress in the intimately related areas of observations, nuclear...

  16. Exploring clouds, weather, climate, and modeling using bilingual content and activities from the Windows to the Universe program and the Center for Multiscale Modeling of Atmospheric Processes

    NASA Astrophysics Data System (ADS)

    Foster, S. Q.; Johnson, R. M.; Randall, D.; Denning, S.; Russell, R.; Gardiner, L.; Hatheway, B.; Genyuk, J.; Bergman, J.

    2008-12-01

    The need for improving the representation of cloud processes in climate models has been one of the most important limitations of the reliability of climate-change simulations. Now in its third year, the National Science Foundation-funded Center for Multi-scale Modeling of Atmospheric Processes (CMMAP) at Colorado State University is addressing this problem through a revolutionary new approach to representing cloud processes on their native scales, including the cloud-scale interaction processes that are active in cloud systems. CMMAP has set ambitious education and human-resource goals to share basic information about the atmosphere, clouds, weather, climate, and modeling with diverse K-12 and public audiences through its affiliation with the Windows to the Universe (W2U) program at University Corporation for Atmospheric Research (UCAR). W2U web pages are written at three levels in English and Spanish. This information targets learners at all levels, educators, and families who seek to understand and share resources and information about the nature of weather and the climate system, and career role models from related research fields. This resource can also be helpful to educators who are building bridges in the classroom between the sciences, the arts, and literacy. Visitors to the W2U's CMMAP web portal can access a beautiful new clouds image gallery; information about each cloud type and the atmospheric processes that produce them; a Clouds in Art interactive; collections of weather-themed poetry, art, and myths; links to games and puzzles for children; and extensive classroom- ready resources and activities for K-12 teachers. Biographies of CMMAP scientists and graduate students are featured. Basic science concepts important to understanding the atmosphere, such as condensation, atmosphere pressure, lapse rate, and more have been developed, as well as 'microworlds' that enable students to interact with experimental tools while building fundamental knowledge. These resources can be accessed online at no cost by the entire atmospheric science K-12 and informal science education community.

  17. Transpiration and Leaf Temperature. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Gates, David M.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This report introduces two models of the thermal energy budget of a leaf. Typical values for…

  18. Pressure and Buoyancy in Aquatic Ecosystems. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Cowan, Christina E.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module explores some of the characteristics of aquatic organisms which can be…

  19. Light and Sound: Evolutionary Aspects. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Roseman, Leonard D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module is concerned with the exchange of energy between an organism and its environment in…

  20. Fluid Dynamics Applied to Streams. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Cowan, Christina E.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module deals specifically with concepts that are basic to fluid flow and…

  1. Biological Production in Lakes. Physical Processes in Terrestrial and Aquatic Ecosystems, Ecological Processes.

    ERIC Educational Resources Information Center

    Walters, R. A.; Carey, G. F.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Primary production in aquatic ecosystems is carried out by phytoplankton, microscopic plants…

  2. Effective Physical Processes and Active Information in Quantum Computing

    E-print Network

    Ignazio Licata

    2007-10-23

    The recent debate on hypercomputation has arisen new questions both on the computational abilities of quantum systems and the Church-Turing Thesis role in Physics. We propose here the idea of "effective physical process" as the essentially physical notion of computation. By using the Bohm and Hiley active information concept we analyze the differences between the standard form (quantum gates) and the non-standard one (adiabatic and morphogenetic) of Quantum Computing, and we point out how its Super-Turing potentialities derive from an incomputable information source in accordance with Bell's constraints. On condition that we give up the formal concept of "universality", the possibility to realize quantum oracles is reachable. In this way computation is led back to the logic of physical world.

  3. Physics/Astronomy 442 High Energy Astrophysics and Radiative Processes

    E-print Network

    Gustafsson, Torgny

    Physics/Astronomy 442 High Energy Astrophysics and Radiative Processes Fall 2009 Dr. Tad Pryor 302W. High energy astrophysics is a very active area of astronomy today, with at least eight orbiting Press (undergraduate-level survey of x-ray astronomy; out of print and somewhat out of date, though

  4. Physical characteristics of diblock polyacetylene copolymers: processability-conductivity correlation

    SciTech Connect

    Aldissi, M.; Hou, M.; Farrell, J.

    1986-01-01

    The physical properties of polyacetylene diblock copolymers containing polystyrene (PS) or polyisoprene (PI) blocks of various compositions are studied using electron spin resonance, resonance Raman scattering, and room temperature conductivity measurements. This study is performed to investigate the processability-conductivity correlation in these materials and their viability as conducting systems.

  5. Physics Course on Information Processing in the Nervous System

    ERIC Educational Resources Information Center

    Horwitz, Barry

    1974-01-01

    Discusses the nature and structure of an interdisciplinary course with emphasis on the problem of how the nervous system receives, processes, and transmits information. Included is a description of the course teaching to junior and senior physics and biology majors. (CC)

  6. PHYSICAL PROCESSES GOVERNING ELECTRIC CURRENTS IN A HALL THRUSTER

    E-print Network

    Carlos III de Madrid, Universidad

    PHYSICAL PROCESSES GOVERNING ELECTRIC CURRENTS IN A HALL THRUSTER R. Santos and E. Ahedo E.T.S. Ingenieros Aeron´auticos, Universidad Polit´ecnica de Madrid, Madrid, Spain ABSTRACT The discharge current and the ion current in the plume of a Hall thruster are generally known from experiments. The difference

  7. Pilot based frameworks for Weather Research Forecasting

    NASA Astrophysics Data System (ADS)

    Ganapathi, Dinesh Prasanth

    The Weather Research Forecasting (WRF) domain consists of complex workflows that demand the use of Distributed Computing Infrastructure (DCI). Weather forecasting requires that weather researchers use different set of initial conditions and one or a combination of physics models on the same set of input data. For these type of simulations an ensemble based computing approach becomes imperative. Most DCIs have local job-schedulers that have no smart way of dealing with the execution of an ensemble type of computational problem as the job-schedulers are built to cater to the bare essentials of resource allocation. This means the weather scientists have to submit multiple jobs to the job-scheduler. In this dissertation we use Pilot-Job based tools to decouple work-load submission and resource allocation therefore streamlining the complex workflows in Weather Research and Forecasting domain and reduce their overall time to completion. We also achieve location independent job execution, data movement, placement and processing. Next, we create the necessary enablers to run an ensemble of tasks bearing the capability to run on multiple heterogeneous distributed computing resources there by creating the opportunity to minimize the overall time consumed in running the models. Our experiments show that the tools developed exhibit very good, strong and weak scaling characteristics. These results bear the potential to change the way weather researchers are submitting traditional WRF jobs to the DCIs by giving them a powerful weapon in their arsenal that can exploit the combined power of various heterogeneous DCIs that could otherwise be difficult to harness owing to interoperability issues.

  8. Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists

    NASA Astrophysics Data System (ADS)

    Koskinen, H. E.

    2008-12-01

    Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

  9. Physics-based model for electro-chemical process

    SciTech Connect

    Zhang, Jinsuo

    2013-07-01

    Considering the kinetics of electrochemical reactions and mass transfer at the surface and near-surface of the electrode, a physics-based separation model for separating actinides from fission products in an electro-refiner is developed. The model, taking into account the physical, chemical and electrochemical processes at the electrode surface, can be applied to study electrorefining kinetics. One of the methods used for validation has been to apply the developed model to the computation of the cyclic voltammetry process of PuCl{sub 3} and UCl{sub 3} at a solid electrode in molten KCl-LiCl. The computed results appear to be similar to experimental measures. The separation model can be applied to predict materials flows under normal and abnormal operation conditions. Parametric studies can be conducted based on the model to identify the most important factors that affect the electrorefining processes.

  10. Results from the Second Forum on the Future Role of the Human in the Forecast Process. Part II: Cognitive Psychological Aspects of Expert Weather Forecasters

    E-print Network

    Schultz, David

    : Cognitive Psychological Aspects of Expert Weather Forecasters NEIL A. STUART* NOAA/National Weather Service of Applied Research Associates, Fairborn, Ohio In Preparation for Submission to Forecasters Forum, Weather and Forecasting 30 June 2006 Corresponding author address: Neil A. Stuart, National Weather Service, 10009 General

  11. Weather from the Stratosphere?

    NASA Technical Reports Server (NTRS)

    Baldwin, Mark P.; Thompson, David W. J.; Shuckburgh, Emily F.; Norton, Warwick A.; Gillett, Nathan P.

    2006-01-01

    Is the stratosphere, the atmospheric layer between about 10 and 50 km, important for predicting changes in weather and climate? The traditional view is that the stratosphere is a passive recipient of energy and waves from weather systems in the underlying troposphere, but recent evidence suggests otherwise. At a workshop in Whistler, British Columbia (1), scientists met to discuss how the stratosphere responds to forcing from below, initiating feedback processes that in turn alter weather patterns in the troposphere. The lowest layer of the atmosphere, the troposphere, is highly dynamic and rich in water vapor, clouds, and weather. The stratosphere above it is less dense and less turbulent (see the figure). Variability in the stratosphere is dominated by hemispheric-scale changes in airflow on time scales of a week to several months. Occasionally, however, stratospheric air flow changes dramatically within just a day or two, with large-scale jumps in temperature of 20 K or more. The troposphere influences the stratosphere mainly through atmospheric waves that propagate upward. Recent evidence shows that the stratosphere organizes this chaotic wave forcing from below to create long-lived changes in the stratospheric circulation. These stratospheric changes can feed back to affect weather and climate in the troposphere.

  12. Process description and evaluation of Canadian Physical Activity Guidelines development

    PubMed Central

    2010-01-01

    Background This paper describes the process used to arrive at recommended physical activity guidelines for Canadian school-aged children and youth (5-17 years), adults (18-64 years) and older adults (?65 years). Methods The Canadian Society for Exercise Physiology (CSEP) Physical Activity Measurement and Guidelines (PAMG) Steering Committee used the Appraisal of Guidelines for Research Evaluation (AGREE II) Instrument to inform the guideline development process. Fourteen background papers and five systematic reviews were completed. Systematic review authors appraised and synthesized the data, and proposed specific recommendations at an international consensus conference of invited experts and key stakeholders. Independently, an international panel of experts interpreted the evidence from the systematic reviews and developed recommendations following attendance at the Consensus Conference. Results Using the AGREE II instrument as a guide, specific foci for each of the guidelines were defined and systematic review methodology was used to synthesize the evidence base. The expert panel, CSEP PAMG Steering Committee and methodological consultants reviewed the systematic reviews and Consensus Statement. The expert panel achieved consensus on the level of evidence informing the physical activity guidelines and developed a separate document outlining key recommendations, interpretation of the evidence and justification of each recommendation. Conclusion The CSEP and Public Health Agency of Canada followed a rigorous process to examine the evidence informing potential revisions to existing physical activity guidelines for Canadians. It is believed that this is the first physical activity guideline development process in the world to be guided and assessed by AGREE II and AMSTAR instruments. PMID:20459786

  13. Weather control

    SciTech Connect

    Leepson, M.

    1980-09-05

    Weather modification, the intentional altering of atmospheric conditions to suit the purposes of humankind, has five basic forms: (1) fog dissipation; (2) rain and snow enhancement; (3) hail suppression; (4) lightning suppression; and (5) the abatement of severe storms such as hurricanes and tornadoes. The dissipation of fog and the seeding of clouds with dry ice or silver iodide to produce rain are the most successful weather modification techniques. Both are used extensively and with varying degrees of success in the United States and around the world. Cloud seeding, though, is not effective in easing the harshness of a drought, such as the one that hit the Southwest, Midwest and Great Plains this summer.

  14. Twelve testable hypotheses on the geobiology of weathering.

    PubMed

    Brantley, S L; Megonigal, J P; Scatena, F N; Balogh-Brunstad, Z; Barnes, R T; Bruns, M A; Van Cappellen, P; Dontsova, K; Hartnett, H E; Hartshorn, A S; Heimsath, A; Herndon, E; Jin, L; Keller, C K; Leake, J R; McDowell, W H; Meinzer, F C; Mozdzer, T J; Petsch, S; Pett-Ridge, J; Pregitzer, K S; Raymond, P A; Riebe, C S; Shumaker, K; Sutton-Grier, A; Walter, R; Yoo, K

    2011-03-01

    Critical Zone (CZ) research investigates the chemical, physical, and biological processes that modulate the Earth's surface. Here, we advance 12 hypotheses that must be tested to improve our understanding of the CZ: (1) Solar-to-chemical conversion of energy by plants regulates flows of carbon, water, and nutrients through plant-microbe soil networks, thereby controlling the location and extent of biological weathering. (2) Biological stoichiometry drives changes in mineral stoichiometry and distribution through weathering. (3) On landscapes experiencing little erosion, biology drives weathering during initial succession, whereas weathering drives biology over the long term. (4) In eroding landscapes, weathering-front advance at depth is coupled to surface denudation via biotic processes. (5) Biology shapes the topography of the Critical Zone. (6) The impact of climate forcing on denudation rates in natural systems can be predicted from models incorporating biogeochemical reaction rates and geomorphological transport laws. (7) Rising global temperatures will increase carbon losses from the Critical Zone. (8) Rising atmospheric P(CO2) will increase rates and extents of mineral weathering in soils. (9) Riverine solute fluxes will respond to changes in climate primarily due to changes in water fluxes and secondarily through changes in biologically mediated weathering. (10) Land use change will impact Critical Zone processes and exports more than climate change. (11) In many severely altered settings, restoration of hydrological processes is possible in decades or less, whereas restoration of biodiversity and biogeochemical processes requires longer timescales. (12) Biogeochemical properties impart thresholds or tipping points beyond which rapid and irreversible losses of ecosystem health, function, and services can occur. PMID:21231992

  15. Assessing processes in uncertain, complex physical phenomena and manufacturing

    SciTech Connect

    Booker, J. M.; Kerscher, W. J. III; Smith, R. E.

    2002-01-01

    PREDICT (Performance and Reliability Evaluation with Diverse Information Combination and Tracking) is a set of structured quantitative approaches for the evaluation of system performance based on multiple information sources. The methodology integrates diverse types and sources of information, and their associated uncertainties, to develop full distributions for performance metrics, such as reliability. The successful application of PREDICT has involved system performance assessment in automotive product development, aging nuclear weapons, and fatigued turbine jet engines. In each of these applications, complex physical, mechanical and materials processes affect performance, safety and reliability assessments. Processes also include the physical actions taken during manufacturing, quality control, inspections, assembly, etc. and the steps involved in product design, development and certification. In this paper, we will examine the various types of processes involved in the decision making leading to production in an automotive system reliability example. Analysis of these processes includes not only understanding their impact on performance and reliability, but also the uncertainties associated with them. The automotive example demonstrates some of the tools used in tackling the complex problem of understanding processes. While some tools and methods exist for understanding processes (man made and natural) and the uncertainties associated with them, many of the complex issues discussed are open for continued research efforts.

  16. Mountain weather and climate

    SciTech Connect

    Barry, R.G.

    1992-01-01

    Mountain environments are reaching the world environmental agenda of concern. The first edition of this book provided a well organized set of principles on how weather and climate processes operate in mountain environments; it was and remains the major reference on the subject. This second edition remains in the original format but adds new material, including updates and increased bibliography and stressing the importance of the temporal dimension of mountain climates and the potential sensitivity of these environments to global change processes.

  17. University of Arkansas Libraries Inclement Weather Policy

    E-print Network

    Capogna, Luca

    University of Arkansas Libraries Inclement Weather Policy Decision Process for Closing the Libraries The general University policy regarding inclement weather is that the University must continue certain operations despite bad weather, but that the obligation to provide services to students must

  18. Being qua becoming: Aristotle's "Metaphysics", quantum physics, and Process Philosophy

    NASA Astrophysics Data System (ADS)

    Johnson, David Kelley

    In Aristotle's First Philosophy, science and philosophy were partners, but with the rise of empiricism, went their separate ways. Metaphysics combined the rational and irrational (i.e. final cause/unmoved mover) elements of existence to equate being with substance, postulating prime matter as pure potential that was actuated by form to create everything. Modern science reveres pure reason and postulates its theory of being by a rigorous scientific methodology. The Standard Model defines matter as energy formed into fundamental particles via forces contained in fields. Science has proved Aristotle's universe wrong in many ways, but as physics delves deeper into the quantum world, empiricism is reaching its limits concerning fundamental questions of existence. To achieve its avowed mission of explaining existence completely, physics must reunite with philosophy in a metascience modeled on the First Philosophy of Aristotle. One theory of being that integrates quantum physics and metaphysics is Process Philosophy.

  19. Remote sensing of atmospheric particulates: Technological innovation and physical limitations in applications to short-range weather prediction

    NASA Technical Reports Server (NTRS)

    Curran, R. J.; Kropfil, R.; Hallett, J.

    1984-01-01

    Techniques for remote sensing of particles, from cloud droplet to hailstone size, using optical and microwave frequencies are reviewed. The inherent variability of atmospheric particulates is examined to delineate conditions when the signal can give information to be effectively utilized in a forecasting context. The physical limitations resulting from the phase, size, orientation and concentration variability of the particulates are assessed.

  20. Reconstructing chemical weathering, physical erosion and monsoon intensity since 25 Ma in the northern South China Sea: A review of competing proxies

    NASA Astrophysics Data System (ADS)

    Clift, Peter D.; Wan, Shiming; Blusztajn, Jerzy

    2014-03-01

    Reconstructing the changing strength of the East Asian summer monsoon has been controversial because different proxies, many being indirect measures of rainfall, tell contrasting stories about how this has varied over long periods of geologic time. Here we present new Sr isotope, grain-size and clastic flux data and synthesize existing proxies to reconstruct changing chemical erosion in the northern South China Sea since the Oligocene, using the links between weathering rates and monsoon strength established in younger sediments as a way to infer intensity. Chemical proxies such as K/Rb, K/Al and the Chemical Index of Alteration (CIA), together with clay proxies like kaolinite/(illite + chlorite) show a steady decline in alteration after a sharp fall following a maximum at the Mid Miocene Climatic Optimum (MMCO; 15.5-17.2 Ma), probably as a result of cooling global temperatures. In contrast, physical erosion proxies, including bulk Ti/Ca and clastic mass accumulation rates (MAR), show peaks at 21-23 Ma, ~ 19 Ma and 15.5-17.2 Ma, implying faster run-off in the absence of drainage capture. Rates increase again, likely driven by slightly increased run-off after 13 Ma, but decrease after 8 Ma, which is identified as a period of summer monsoon weakening. Sr isotope composition correlates with hematite/goethite and the spectral proxy CRAT to show stronger weathering linked to more monsoonal seasonality. These proxies argue for a strengthening of the East Asian Monsoon after 22-23 Ma, followed by an extended period of monsoon maximum between 18 and 10 Ma, then weakening. There is some suggestion that the summer monsoon may have strengthened since 3-4 Ma after reaching a minimum in the Pliocene.

  1. Major ion chemistry of the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    SciTech Connect

    Sarin, M.M.; Krishnaswami, S.; Dilli, K.; Somayajulu, B.L.K. ); Moore, W.S. )

    1989-05-01

    The Ganga-Brahmaputra, one of the worlds's largest river systems, is first in terms of sediment transport and fourth in terms of water discharge. A detailed and systematic study of the major ion chemistry of these rivers and their tributaries, as well as the clay mineral composition of the bed sediments has been conducted. The chemistry of the highland rivers are all dominated by carbonate weathering; (Ca + Mg) and HCO{sub 3} account for about 80% of the cations and anions. In the lowland rivers, HCO{sub 3} excess over (Ca + Mg) and a relatively high contribution of (Na + K) to the total cations indicate that silicate weathering and/or contributions from alkaline/saline soils and ground waters could be important sources of major ions to these waters. The chemistry of the Ganga and the Yamuna in the lower reaches is by and large dictated by the chemistry of their tributaries and their mixing proportions. The highland rivers weather acidic rocks, whereas the others flow initially through basic effusives. The Ganga-Brahmaputra river system transports about 130 million tons of dissolved salts to the Bay of Bengal, which is nearly 3% of the global river flux to the oceans. The chemical denudation rates for the Ganga and the Brahmaputra basins are about 72 and 105 tons{center dot}km{sup {minus}2}{center dot}yr{sup {minus}1}, respectively, which are factors of 2 to 3 higher than the global average. The high denudation rate, particularly in the Brahmaputra, is attributable to high relief and heavy rainfall.

  2. Geochemical and Isotopic (Sr, U) Tracing of Weathering Processes Controlling the Recent Geochemical Evolution of Soil Solutions in the Strengbach Catchment (Vosges, France)

    NASA Astrophysics Data System (ADS)

    Chabaux, F. J.; Prunier, J.; Pierret, M.; Stille, P.

    2012-12-01

    The characterization of the present-day weathering processes controlling the chemical composition of waters and soils in natural ecosystems is an important issue to predict and to model the response of ecosystems to recent environmental changes. It is proposed here to highlight the interest of a multi-tracer geochemical approach combining measurement of major and trace element concentrations along with U and Sr isotopic ratios to progress in this topic. This approach has been applied to the small granitic Strengbah Catchment, located in the Vosges Mountain (France), used and equipped as a hydro-geochemical observatory since 1986 (Observatoire Hydro-Géochimique de l'Environnement; http://ohge.u-strasbg.fr). This study includes the analysis of major and trace element concentrations and (U-Sr) isotope ratios in soil solutions collected within two soil profiles located on two experimental plots of this watershed, as well as the analysis of soil samples and vegetation samples from these two plots The depth variation of elemental concentration of soil solutions confirms the important influence of the vegetation cycling on the budget of Ca, K, Rb and Sr, whereas Mg and Si budget in soil solutions are quasi exclusively controlled by weathering processes. Variation of Sr, and U isotopic ratios with depth also demonstrates that the sources and biogeochemical processes controlling the Sr budget of soil solutions is different in the uppermost soil horizons and in the deeper ones, and clearly influence by the vegetation cycling.

  3. Significant impacts of radiation physics in the Weather Research and Forecasting model on the precipitation and dynamics of the West African Monsoon

    NASA Astrophysics Data System (ADS)

    Li, R.; Jin, J.; Wang, S.-Y.; Gillies, R. R.

    2015-03-01

    Precipitation from the West African Monsoon (WAM) provides food security and supports the economy in the region. As a consequence of the intrinsic complexities of the WAM's evolution, accurate simulations of the WAM and its precipitation regime, through the application of regional climate models, are challenging. We used the coupled Weather Research and Forecasting (WRF) and Community Land Model (CLM) to explore impacts of radiation physics on the precipitation and dynamics of the WAM. Our results indicate that the radiation physics schemes not only produce biases in radiation fluxes impacting radiative forcing, but more importantly, result in large bias in precipitation of the WAM. Furthermore, the different radiation schemes led to variations in the meridional gradient of surface temperature between the north that is the Sahara desert and the south Guinean coastline. Climate diagnostics indicated that the changes in the meridional gradient of surface temperature affect the position and strength of the African Easterly Jet as well as the low-level monsoonal inflow from the Gulf of Guinea. The net result was that each radiation scheme produced differences in the WAM precipitation regime both spatially and in intensity. Such considerable variances in the WAM precipitation regime and dynamics, resulting from radiation representations, likely have strong feedbacks within the climate system and so have inferences when it comes to aspects of predicted climate change both for the region and globally.

  4. Physical activity across the curriculum: year one process evaluation results

    PubMed Central

    Gibson, Cheryl A; Smith, Bryan K; DuBose, Katrina D; Greene, J Leon; Bailey, Bruce W; Williams, Shannon L; Ryan, Joseph J; Schmelzle, Kristin H; Washburn, Richard A; Sullivan, Debra K; Mayo, Matthew S; Donnelly, Joseph E

    2008-01-01

    Background Physical Activity Across the Curriculum (PAAC) is a 3-year elementary school-based intervention to determine if increased amounts of moderate intensity physical activity performed in the classroom will diminish gains in body mass index (BMI). It is a cluster-randomized, controlled trial, involving 4905 children (2505 intervention, 2400 control). Methods We collected both qualitative and quantitative process evaluation data from 24 schools (14 intervention and 10 control), which included tracking teacher training issues, challenges and barriers to effective implementation of PAAC lessons, initial and continual use of program specified activities, and potential competing factors, which might contaminate or lessen program effects. Results Overall teacher attendance at training sessions showed exceptional reach. Teachers incorporated active lessons on most days, resulting in significantly greater student physical activity levels compared to controls (p < 0.0001). Enjoyment ratings for classroom-based lessons were also higher for intervention students. Competing factors, which might influence program results, were not carried out at intervention or control schools or were judged to be minimal. Conclusion In the first year of the PAAC intervention, process evaluation results were instrumental in identifying successes and challenges faced by teachers when trying to modify existing academic lessons to incorporate physical activity. PMID:18606013

  5. Contaminants from Cretaceous Black Shale Part 1: Natural weathering processes controlling contaminant cycling in Mancos Shale, southwestern United States, with emphasis on salinity and selenium

    USGS Publications Warehouse

    Tuttle, Michele L.W.; Fahy, Juli W.; Elliott, John G.; Grauch, Richard I.; Stillings, Lisa L.

    2013-01-01

    Soils derived from black shale can accumulate high concentrations of elements of environmental concern, especially in regions with semiarid to arid climates. One such region is the Colorado River basin in the southwestern United States where contaminants pose a threat to agriculture, municipal water supplies, endangered aquatic species, and water-quality commitments to Mexico. Exposures of Cretaceous Mancos Shale (MS) in the upper basin are a major contributor of salinity and selenium in the Colorado River. Here, we examine the roles of geology, climate, and alluviation on contaminant cycling (emphasis on salinity and Se) during weathering of MS in a Colorado River tributary watershed. Stage I (incipient weathering) began perhaps as long ago as 20 ka when lowering of groundwater resulted in oxidation of pyrite and organic matter. This process formed gypsum and soluble organic matter that persist in the unsaturated, weathered shale today. Enrichment of Se observed in laterally persistent ferric oxide layers likely is due to selenite adsorption onto the oxides that formed during fluctuating redox conditions at the water table. Stage II weathering (pedogenesis) is marked by a significant decrease in bulk density and increase in porosity as shale disaggregates to soil. Rainfall dissolves calcite and thenardite (Na2SO4) at the surface, infiltrates to about 1 m, and precipitates gypsum during evaporation. Gypsum formation (estimated 390 kg m?2) enriches soil moisture in Na and residual SO4. Transpiration of this moisture to the surface or exposure of subsurface soil (slumping) produces more thenardite. Most Se remains in the soil as selenite adsorbed to ferric oxides, however, some oxidizes to selenate and, during wetter conditions is transported with soil moisture to depths below 3 m. Coupled with little rainfall, relatively insoluble gypsum, and the translocation of soluble Se downward, MS landscapes will be a significant nonpoint source of salinity and Se to the Colorado River well into the future. Other trace elements weathering from MS that are often of environmental concern include U and Mo, which mimic Se in their behavior; As, Co, Cr, Cu, Ni, and Pb, which show little redistribution; and Cd, Sb, V, and Zn, which accumulate in Stage I shale, but are lost to varying degrees from upper soil intervals. None of these trace elements have been reported previously as contaminants in the study area.

  6. Honeycomb Weathering of Limestone Formations

    USGS Multimedia Gallery

    Honeycomb weathering of sandstone located on the shores of Puget Sound occurs when expanding salt crystals break fragments of rock, creating a small hole that becomes larger as the process repeats itself over time....

  7. The physical basis of explosion and blast injury processes.

    PubMed

    Proud, W G

    2013-03-01

    Energetic materials are widely used in civilian and military applications, such as quarrying and mining, flares, and in munitions. Recent conflicts have involved the widespread use of improvised explosive devices to attack military, civilians and infrastructure. This article gives a basic overview of explosive technology and the underlying physical processes that produce the injuries encountered. In particular aspects relevant to primary and secondary injuries are discussed. PMID:23631318

  8. Physical process first law and caustic avoidance for Rindler horizon

    E-print Network

    Srijit Bhattacharjee; Sudipta Sarkar

    2014-12-03

    We study the perturbation induced by a slowly rotating massive object as it passes through a Rindler horizon. It is shown that the passage of this object can be approximately modeled as Delta\\,function type tidal distortions hitting the horizon. Further, following the analysis presented by Amsel, Marolf and Virmani related to the issue of the validity of physical process first law, we establish a condition on the size of the object so that this law holds for the Rindler horizon.

  9. Urgency of evolution-process congruent thinking in physics

    NASA Astrophysics Data System (ADS)

    Roychoudhuri, Chandrasekhar

    2015-09-01

    It is now generally recognized that physics has not been contributing anything conceptually fundamentally new beyond the century old Relativity and 90 years old Quantum Mechanics [1-4]. We have also started recognizing that there is an increasing rate of species extinction all over the world, especially since the last century [5]; and we are beginning to understand that the related problems are being steadily accelerated by human behavior to conquer nature, rather than understanding nature as is and living within its system logics [6,7]. We are beginning to appreciate that our long-term sustainability as a species literally depends upon proactively learning to nurture the entire bio-diversity [8-10]. Thus, humans must consciously become evolution process congruent thinkers. The evolutionary biologists have been crying out loud for us to listen [5,6, 8-10]. Social scientists, political scientists, economic scientists [13] have started chiming in to become consilient thinkers [6] for re-constructing sustainable societies. But, the path to consilient thinking requires us to recognize and accept a common vision based thinking process, which functionally serves as a uniting platform. I am articulating that platform as the "evolution process congruent thinking" (EPCT). Do physicists have any obligation to co-opt this EPCT? Is there any immediate and/or long-term gain for them? This paper argues affirmatively that co-opting EPCT is the best way to re-anchor physics back to reality ontology and develop newer and deeper understanding of natural phenomena based on understanding of the diverse interaction processes going on in nature. Physics is mature enough to acknowledge that all of our theories are "work in progress". This is a good time to start iteratively re-evaluating and re-structuring all the foundational postulates behind all the working theories. This will also consistently energize all the follow-on generation of physicists to keep on fully utilizing their evolution-given enquiring minds without being afraid by the prevailing culture of "publish-or-perish", requiring them to stay within the bounds of the prevailing theories as the final ones. Current physics thinking has been successfully driven by Measurable Data Modeling Epistemology (MDM-E); which is basically curve-fitting without demanding to understand the actual physical processes nature is carrying out. I am proposing to add an iterative repertoire, Interaction Process mapping Epistemology (IPM-E) over and above successful MDM-E. This will facilitate the physicists to become conceptual reverse engineers of nature. The gap between physicists and engineers will start melting down and our collective sustainability will be re-assured as successful engineers of nature.

  10. Social Media: Space Weather #SpaceWeather

    E-print Network

    Weather Check out this video on how space weather impacts communications: https://youtu.be/7vFGTl_Cp6I://www.swpc.noaa.gov/impacts/spaceweatherandgpssystems #SpaceWeather Check out this video on how space weather impacts GPS: https

  11. UNH Sport Club Weather Guidelines Cold Weather*

    E-print Network

    1 UNH Sport Club Weather Guidelines Cold Weather* *All temperatures are with wind during the cold weather months. Be sure to provide plenty of opportunities for re: Modify activity to limit exposure to weather and allow more frequent chances to re

  12. Integrated Research and Education in Solar Physics, Space Weather, and Energetic Charged Particles at the University of Arizona

    NASA Astrophysics Data System (ADS)

    Giacalone, J.

    2011-12-01

    I will discuss how a NSF Early-Career Award led to a new emphasis in solar physics at the University of Arizona (UA) that has enabled new opportunities for scientific research in this area, but has also led to new education and public-outreach initiatives. I will discuss the approach used to integrate education with research, emphasizing the importance of the prestige of the CAREER award itself. A particular highlight from this project was a summer school in solar physics that was held for four consecutive years from 2006-2009 aimed at beginning graduate students, but also had a number of advanced undergraduates as well. The award was also used to support workshops for local-area middle-school teachers on topics germane to solar physics that could be instituted in their respective school's curricula. The award also subsidized a number of graduate students and postdoctoral researchers at the UA promoting their career development. While the focus of this presentation will be on the educational and public-outreach aspects of this project, it is important emphasize that this project had a strong research component. The UA is a major research university and the award was instrumental in the development of the principal investigator's career, both in terms of obtaining tenure and promotion to full professor, and also to put him in a good position to secure extramural funding. Therefore, I will also discuss some key research highlights from this project as well.

  13. Effects of physical erosion on chemical denudation rates: A numerical modeling study of soil-mantled hillslopes

    E-print Network

    Kirchner, James W.

    2008 Editor: R.W. Carlson Keywords: chemical weathering physical erosion denudation cosmogenic nuclides Many biogeochemical and Earth surface processes depend critically on chemical weathering. The immediate products of chemical weathering are present as solutes and secondary minerals in groundwater, soils

  14. Public Awareness of Space Weather

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis J.

    2009-08-01

    As society increasingly relies on space-based infrastructure for communication and national security, there is a growing need to improve public awareness of the risks space weather poses. The National Space Weather Program (NSWP) should consider this need as it develops new strategic plans. The 2006 “Report of the Assessment Committee for the National Space Weather Program” (http://www.ofcm.gov/r24/fcm-r24.htm) continues to guide this important national program, which aims to improve space weather forecasting services and reduce technological vulnerabilities. NSWP, under the auspices of the Office of the Federal Coordinator for Meteorology (OFCM), is coordinated by the NSWP Council, which consists of eight federal agencies. This council, through its Committee for Space Weather, is in the process of formulating new Strategic and Implementation plans for the NSWP using recommendations from the Assessment Committee.

  15. Physical Processes of Poloidal Flux Injection in CMEs

    NASA Astrophysics Data System (ADS)

    Chen, James

    2011-05-01

    The erupting flux rope (EFR) model of CMEs has been extensively tested against CME dynamics observed by SOHO and STEREO, demonstrating good agreement between model results and data: the best-fit solutions can reproduce observed CME trajectories from the Sun to 1 AU to within 1-2% of the data, and such solutions yield the poloidal flux injection function whose temporal profiles closely match those of the associated soft X-ray flare emissions. This provides evidence that the flux injection function captures the underlying physical connection between CME acceleration and flare energy release [1]. This mathematical function admits two distinct physical interpretations. In this talk, the physical processes that can contribute to poloidal flux injection are discussed, one involving flux of subphotospheric source and the other of coronal source. Recently, Schuck [2] and earlier, Forbes [3] argued that there is insufficient Poynting flux observable through the photosphere to support the subphotospheric flux injection hypothesis. These calculations, however, impose ad hoc large-scale coherent horizontal fields in the photosphere and do not have any subphotospheric source of flux or any equations of motion describing an ``injection'' process from a source through a medium. That is, these arguments contain no flux injection mechanism that they purport to ``falsify'' and no physical properties of the convection zone. Physically relevant signatures of subphotospheric flux injection are discussed. [1] Chen, J., and Kunkel, V. 2010, ApJ, 717, 1105. [2] Schuck, P. W. 2010, 714, 68. [3] Forbes, T. G. 2001, Eos Trans. AGU, 82(20), SH41C-03.

  16. Major ion chemistry of the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Sarin, M. M.; Krishnaswami, S.; Dilli, K.; Somayajulu, B. L. K.; Moore, W. S.

    1989-05-01

    The Ganga-Brahmaputra, one of the world's largest river systems, is first in terms of sediment transport and fourth in terms of water discharge. A detailed and systematic study of the major ion chemistry of these rivers and their tributaries, as well as the clay mineral composition of the bed sediments has been conducted. The chemistry of the highland rivers (upper reaches of the Ganga, the Yamuna, the Brahmaputra, the Gandak and the Ghaghra) are all dominated by carbonate weathering; (Ca + Mg) and HCO 3 account for about 80% of the cations and anions. In the lowland rivers (the Chambal, the Betwa and the Ken), HCO 3 excess over (Ca + Mg) and a relatively high contribution of (Na + K) to the total cations indicate that silicate weathering and/or contributions from alkaline/saline soils and groundwaters could be important sources of major ions to these waters. The chemistry of the Ganga and the Yamuna in the lower reaches is by and large dictated by the chemistry of their tributaries and their mixing proportions. Illite is the dominant clay mineral (about 80%) in the bedload sediments of the highland rivers. Kaolinite and chlorite together constitute the remaining 20% of the clays. In the Chambal, Betwa and Ken, smectite accounts for about 80% of the clays. This difference in the clay mineral composition of the bed sediments is a reflection of the differences in the geology of their drainage basins. The highland rivers weather acidic rocks, whereas the others flow initially through basic effusives. The Ganga-Brahmaputra river system transports about 130 million tons of dissolved salts to the Bay of Bengal, which is nearly 3% of the global river flux to the oceans. The chemical denudation rates for the Ganga and the Brahmaputra basins are about 72 and 105 tons· km -· yr -1, respectively, which are factors of 2 to 3 higher than the global average. The high denudation rate, particularly in the Brahmaputra, is attributable to high relief and heavy rainfall.

  17. Health physics aspects of processing EBR-I coolant

    SciTech Connect

    Burke, L.L.; Thalgott, J.O.; Poston, J.W. Jr.

    1998-12-31

    The sodium-potassium reactor coolant removed from the Experimental Breeder Reactor Number One after a partial reactor core meltdown had been stored at the Idaho National Engineering and Environmental Laboratory for 40 years. The State of Idaho considered this waste the most hazardous waste stored in the state and required its processing. The reactor coolant was processed in three phases. The first phase converted the alkali metal into a liquid sodium-potassium hydroxide. The second phase converted this caustic to a liquid sodium-potassium carbonate. The third phase solidified the sodium-potassium carbonate into a form acceptable for land disposal. Health physics aspects and dose received during each phase of the processing are discussed.

  18. Adaptive Numerical Algorithms in Space Weather Modeling

    NASA Technical Reports Server (NTRS)

    Toth, Gabor; vanderHolst, Bart; Sokolov, Igor V.; DeZeeuw, Darren; Gombosi, Tamas I.; Fang, Fang; Manchester, Ward B.; Meng, Xing; Nakib, Dalal; Powell, Kenneth G.; Stout, Quentin F.; Glocer, Alex; Ma, Ying-Juan; Opher, Merav

    2010-01-01

    Space weather describes the various processes in the Sun-Earth system that present danger to human health and technology. The goal of space weather forecasting is to provide an opportunity to mitigate these negative effects. Physics-based space weather modeling is characterized by disparate temporal and spatial scales as well as by different physics in different domains. A multi-physics system can be modeled by a software framework comprising of several components. Each component corresponds to a physics domain, and each component is represented by one or more numerical models. The publicly available Space Weather Modeling Framework (SWMF) can execute and couple together several components distributed over a parallel machine in a flexible and efficient manner. The framework also allows resolving disparate spatial and temporal scales with independent spatial and temporal discretizations in the various models. Several of the computationally most expensive domains of the framework are modeled by the Block-Adaptive Tree Solar wind Roe Upwind Scheme (BATS-R-US) code that can solve various forms of the magnetohydrodynamics (MHD) equations, including Hall, semi-relativistic, multi-species and multi-fluid MHD, anisotropic pressure, radiative transport and heat conduction. Modeling disparate scales within BATS-R-US is achieved by a block-adaptive mesh both in Cartesian and generalized coordinates. Most recently we have created a new core for BATS-R-US: the Block-Adaptive Tree Library (BATL) that provides a general toolkit for creating, load balancing and message passing in a 1, 2 or 3 dimensional block-adaptive grid. We describe the algorithms of BATL and demonstrate its efficiency and scaling properties for various problems. BATS-R-US uses several time-integration schemes to address multiple time-scales: explicit time stepping with fixed or local time steps, partially steady-state evolution, point-implicit, semi-implicit, explicit/implicit, and fully implicit numerical schemes. Depending on the application, we find that different time stepping methods are optimal. Several of the time integration schemes exploit the block-based granularity of the grid structure. The framework and the adaptive algorithms enable physics based space weather modeling and even forecasting.

  19. Weathering crusts on peridotite

    NASA Astrophysics Data System (ADS)

    Bucher, Kurt; Stober, Ingrid; Müller-Sigmund, Hiltrud

    2015-05-01

    Chemical weathering of dark-green massive peridotite, including partly serpentinized peridotite, produces a distinct and remarkable brown weathering rind when exposed to the atmosphere long enough. The structure and mineral composition of crusts on rocks from the Ronda peridotite, Spain, have been studied in some detail. The generic overall weathering reaction serpentinized peridotite + rainwater = weathering rind + runoff water describes the crust-forming process. This hydration reaction depends on water supply from the outcrop surface to the reaction front separating green peridotite from the brown crust. The reaction pauses after drying and resumes at the front after wetting. The overall net reaction transforms olivine to serpentine in a volume-conserving replacement reaction. The crust formation can be viewed as secondary serpentinization of peridotite that has been strongly altered by primary hydrothermal serpentinization. The reaction stoichiometry of the crust-related serpentinization is preserved and reflected by the composition of runoff waters in the peridotite massif. The brown color of the rind is caused by amorphous Fe(III) hydroxide, a side product from the oxidation of Fe(II) released by the dissolution of fayalite component in olivine.

  20. Building a Weather-Ready Nation Winter Weather Safety

    E-print Network

    Building a Weather-Ready Nation Winter Weather Safety NOAA/NWS Winter Weather Safety Seasonal Campaign www.weather.gov #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

  1. Guidelines for Automatic Data Processing Physical Security and Risk Management. Federal Information Processing Standards Publication 31.

    ERIC Educational Resources Information Center

    National Bureau of Standards (DOC), Washington, DC.

    These guidelines provide a handbook for use by federal organizations in structuring physical security and risk management programs for their automatic data processing facilities. This publication discusses security analysis, natural disasters, supporting utilities, system reliability, procedural measures and controls, off-site facilities,…

  2. GEM: Statistical weather forecasting procedure

    NASA Technical Reports Server (NTRS)

    Miller, R. G.

    1983-01-01

    The objective of the Generalized Exponential Markov (GEM) Program was to develop a weather forecast guidance system that would: predict between 0 to 6 hours all elements in the airways observations; respond instantly to the latest observed conditions of the surface weather; process these observations at local sites on minicomputing equipment; exceed the accuracy of current persistence predictions at the shortest prediction of one hour and beyond; exceed the accuracy of current forecast model output statistics inside eight hours; and be capable of making predictions at one location for all locations where weather information is available.

  3. Reconnaissance of Field Sites for the Study of Chemical Weathering on the Guayana Shield, South America

    SciTech Connect

    Steefell, C I

    2003-02-01

    Despite the fact that chemical weathering of silicate rocks plays an important role in the draw-down of CO{sub 2} over geologic time scales (Berner and Berner, 1996), the overall controls on the rate of chemical weathering are still not completely understood. Lacking a mechanistic understanding of these controls, it remains difficult to evaluate a hypothesis such as that presented by Raymo and Ruddiman (1992), who suggested that enhanced weathering and CO{sub 2} draw-down resulting from the uplift of the Himalayas contributed to global cooling during the Cenozoic. At an even more fundamental level, the three to four order of magnitude discrepancy between laboratory and field weathering rates is still unresolved (White et al., 1996). There is as yet no comprehensive, mechanistic model for silicate chemical weathering that considers the coupled effects of precipitation, vadose zone flow, and chemical reactions. The absence of robust process models for silicate weathering and the failure to resolve some of these important questions may in fact be related-the controls on the overall rates of weathering cannot be understood without considering the weathering environment as one in which multiple, time-dependent chemical and physical processes are coupled (Malmstrom, 2000). Once chemical weathering is understood at a mechanistic process level, the important controls on chemical weathering (physical erosion, temperature, precipitation) can be folded into larger scale models tracking the global carbon cycle. Our goal in this study was to carry out the preliminary work needed to establish a field research site for chemical weathering om the Cuayana Shield in South America. The Guayana Shield is a Precambrian province greater than 1.5 billion years old covering portions of Venezuela, Guyana (the country), Surinam, French Guiana, and Brazil (Figure 1). More important than the age of the rocks themselves, however, is the age of the erosion surface developed on the Shield, with estimates ranging as old as 65 million years. Preserved mostly in highlands, this very old erosion surface represents an end-member site where physical erosion has been significantly slower than the rate of chemical weathering. Much of the Shield is also noteworthy for the fact that chemical weathering is still occurring today, thus offering the chance to study a system in which a present day weathering regime is accompanied by an integrated weathering record over millions of years (Soler and Lasaga, 2000). If rates of chemical weathering can be determined for this very old weathering system where physical erosion is minor, they can then be compared with rates determined from sites with similar annual temperatures and rainfall, but much higher physical erosion rates. Comparative studies of this kind can provide a parameterization of chemical weathering rates as a function of physical erosion and tectonic uplift that can be used in global models for the carbon cycle.

  4. The r-process nucleosynthesis: Nuclear physics challenges

    SciTech Connect

    Goriely, S.

    2012-10-20

    About half of the nuclei heavier than iron observed in nature are produced by the socalled rapid neutron capture process, or r-process, of nucleosynthesis. The identification of the astrophysics site and the specific conditions in which the r-process takes place remains, however, one of the still-unsolved mysteries of modern astrophysics. Another underlying difficulty associated with our understanding of the r-process concerns the uncertainties in the predictions of nuclear properties for the few thousands exotic neutron-rich nuclei involved and for which essentially no experimental data exist. The present contribution emphasizes some important future challenges faced by nuclear physics in this problem, particularly in the determination of the nuclear structure properties of exotic neutron-rich nuclei as well as their radiative neutron capture rates and their fission probabilities. These quantities are particularly relevant to determine the composition of the matter resulting from the r-process. Their impact on the r-abundance distribution resulting from the decompression of neutron star matter is discussed.

  5. Upconversion luminescent nanoparticles in physical sensing and in monitoring physical processes in biological samples

    NASA Astrophysics Data System (ADS)

    González-Béjar, María; Pérez-Prieto, Julia

    2015-12-01

    The most frequently used strategy for sensing is based on the emission variation of a photoactive system and it can be classified as chemical or physical depending on its response to either a chemical or a physical stimulus. There are a large number of luminescent nanomaterials that respond to chemical species, but comparatively, with the exception of temperature sensing, to date there are few examples showing the capacity of photoactive nanosystems responsive to physical stimuli, such as magnetic and electric fields, high radiation energy, tension/pressure, viscosity, etc, and very few of them comprise upconversion nanoparticles (UCNPs). These nanomaterials consist of an inorganic matrix doped with rare earth (RE) ions and can be advantageously used in sensing due to their unique optical features: near-infrared excitation, anti-Stokes emission, multiplexed emissions that span over a broad range (i.e. from the UV to NIR region depending on the nature of the RE ions), narrow emission bands, long emission lifetimes, high photostability, and non-photoblinking, among others. In this review we focus on the advances in the application of the luminescence of UCNPs for sensing environmental physical changes and for tracking physical processes in living systems.

  6. Weather information network including graphical display

    NASA Technical Reports Server (NTRS)

    Leger, Daniel R. (Inventor); Burdon, David (Inventor); Son, Robert S. (Inventor); Martin, Kevin D. (Inventor); Harrison, John (Inventor); Hughes, Keith R. (Inventor)

    2006-01-01

    An apparatus for providing weather information onboard an aircraft includes a processor unit and a graphical user interface. The processor unit processes weather information after it is received onboard the aircraft from a ground-based source, and the graphical user interface provides a graphical presentation of the weather information to a user onboard the aircraft. Preferably, the graphical user interface includes one or more user-selectable options for graphically displaying at least one of convection information, turbulence information, icing information, weather satellite information, SIGMET information, significant weather prognosis information, and winds aloft information.

  7. Linking Weathering, Rock Moisture Dynamics, Geochemistry, Runoff, Vegetation and Atmospheric Processes through the Critical Zone: Graduate Student led Research at the Eel River Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Dietrich, W. E.

    2014-12-01

    In the Eel River Critical Zone Observatory lies Rivendell, a heavily-instrumented steep forested hillslope underlain by nearly vertically dipping argillite interbedded with sandstone. Under this convex hillslope lies "Zb", the transition to fresh bedrock, which varies from less than 6 m below the surface near the channel to 20 m at the divide. Rempe and Dietrich (2014, PNAS) show that the Zb profile can be predicted from the assumption that weathering occurs when drainage is induced in the uplifting fresh bedrock under hillslopes by lateral head gradients driven by channel incision at the hillslope boundary. Infiltrating winter precipitation is impeded at the lower conductivity boundary at Zb, generating perched groundwater that dynamically pulses water laterally to the channel, controlling stream runoff. Below the soil and above the water table lies an unsaturated zone through which all recharge to the perched groundwater (and thus all runoff to channels) occurs. It is this zone and the waters in them that profoundly affect critical zone processes. In our seasonally dry environment, the first rains penetrate past the soil and moisten the underlying weathered bedrock (Salve et al., 2012, WRR). It takes about 200 to 400 mm of cumulative rain, however, before the underlying groundwater rises significantly. Oshun et al (in review) show that by this cumulative rainfall the average of the wide-ranging isotopic signature of rain reaches a nearly constant average annual value. Consequently, the recharging perched groundwater shows only minor temporal isotopic variation. Kim et al, (2014, GCA) find that the winter high-flow groundwater chemistry is controlled by relatively fast-reacting cation exchange processes, likely occurring in transit in the unsaturated zone. Oshun also demonstrates that the Douglas fir rely on this rock moisture as a water source, while the broadleaf trees (oaks and madrone) use mostly soil moisture. Link et al (2014 WRR) show that Doug fir declines in transpiration rate significantly compared to the madrone during summer high water stress periods, with may induce feedbacks from the forest to atmospheric temperature and humidity. Collectively these studies spotlight the seasonally dynamic unsaturated zone in the weathered bedrock beneath the soil as key to understanding critical zone processes.

  8. Insight into the Physical and Dynamical Processes that Control Rapid Increases in Total Flash Rate

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Carey, Lawrence D.; Schultz, Elise V.; Blakeslee, Richard J.; Goodman, Steven J.

    2015-01-01

    Rapid increases in total lightning (also termed "lightning jumps") have been observed for many decades. Lightning jumps have been well correlated to severe and hazardous weather occurrence. The main focus of lightning jump work has been on the development of lightning algorithms to be used in real-time assessment of storm intensity. However, in these studies it is typically assumed that the updraft "increases" without direct measurements of the vertical motion, or specification of which updraft characteristic actually increases (e.g., average speed, maximum speed, or convective updraft volume). Therefore, an end-to-end physical and dynamical basis for coupling rapid increases in total flash rate to increases in updraft speed and volume must be understood in order to ultimately relate lightning occurrence to severe storm metrics. Herein, we use polarimetric, multi-Doppler, and lightning mapping array measurements to provide physical context as to why rapid increases in total lightning are closely tied to severe and hazardous weather.

  9. Hot Weather Tips

    MedlinePLUS

    HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  10. Weather Prediction Models

    NASA Astrophysics Data System (ADS)

    Bacmeister, Julio T.

    Awareness of weather and concern about weather in the proximate future certainly must have accompanied the emergence of human self-consciousness. Although weather is a basic idea in human existence, it is difficult to define precisely.

  11. Weather in the News.

    ERIC Educational Resources Information Center

    Markle, Sandra

    1989-01-01

    A discussion of TV weather forecasting introduces this article which features several hands-on science activities involving observing, researching, and experimenting with the weather. A reproducible worksheet on the reliability of weather forecasts is included. (IAH)

  12. Forecasting the Weather.

    ERIC Educational Resources Information Center

    Bollinger, Richard

    1984-01-01

    Presents a computer program which predicts the weather based on student input of such weather data as wind direction and barometric pressure. Also provides procedures for several hands-on, weather-related activities. (JN)

  13. Physical anthropology: the search for general processes and principles.

    PubMed

    Lasker, G W

    1970-02-01

    Physical anthropology consists of two interdependent types of study: (1) the biological history of man and (2) general biological processes in man (such as mechanisms of evolution and growth). Popular interest may focus on the former, the fascinating story of the origin of man and of specific people, but the latter affords physical anthropology potential practical value in respect to medicine, dentistry, public health, and population policy. The study of general processes is the study of human beings in particular situations, not for what we can learn about these particular populations but for the sake of generalization about mankind anywhere in comparable situations. This is, of course, the purpose of experimental science in general, but in anthropology the method is usually comparative. Long ago the study of the growth of the two sexes and of children in different countries was started on a comparative basis as was the study of the so-called secular change in adult stature. By 1911 Franz Boas had compared the changes in stature and head form of children of several different immigrant groups in the United States. There have since been comparative studies of the amount and distribution of body fat (but not yet adequate comparative measurements of the relation of tissue components to diet and to diseases). Demographic patterns, inbreeding, outbreeding, and their effects are other general problems. The Human Adaptability Project of the International Biological Program promises studies of human response to heat, cold, altitude, and other conditions on a wide international basis. If supported, these could turn physical anthropology's search in a useful direction. The functional biology of people of even out-of-the-way communities will be compared with each other. These studies can yield general statements concerning human response to types of ecological situation including such sociocultural conditions as those of hunting-gathering tribes and urban slums. PMID:19681215

  14. Framework for Understanding Lenr Processes, Using Conventional Condensed Matter Physics

    NASA Astrophysics Data System (ADS)

    Chubb, Scott R.

    2006-02-01

    Conventional condensed matter physics provides a unifying framework for understanding low-energy nuclear reactions (LENRs) in solids. In the paper, standard many-body physics techniques are used to illustrate this fact. Specifically, the paper shows that formally the theories by Schwinger, Hagelstein, and Chubb and Chubb (C&C), all can be related to a common set of equations, associated with reaction rate and energy transfer, through a standard many-body physics procedure (R-matrix theory). In each case, particular forms of coherence are used that implicitly provide a mechanism for understanding how LENRs can proceed without the emission of high-energy particles. In addition, additional ideas, associated with Conventional Condensed Matter physics, are used to extend the earlier ion band state (IBS) model by C&C. The general model clarifies the origin of coherent processes that initiate LENRs, through the onset of ion conduction that can occur through ionic fluctuations in nanoscale crystals. In the case of PdDx, these fluctuations begin to occur as x ? 1 in sub-lattice structures with characteristic dimensions of 60 nm. The resulting LENRs are triggered by the polarization between injected d's and electrons (immediately above the Fermi energy) that takes place in finite-size PdD crystals. During the prolonged charging of PdDx, the applied, external electric field induces these fluctuations through a form of Zener tunneling that mimics the kind of tunneling, predicted by Zener, that is responsible for possible conduction (referred to as Zener-electric breakdown) in insulators. But because the fluctuations are ionic, and they occur in PdD, nano-scale structures, a more appropriate characterization is Zener-ionic breakdown in nano-crystalline PdD. Using the underlying dynamics, it is possible to relate triggering times that are required for the initiation of the effect, to crystal size and externally applied fields.

  15. CLARA: A Contemporary Approach to Physics Data Processing

    SciTech Connect

    V Gyurjyan, D Abbott, J Carbonneau, G Gilfoyle, D Heddle, G Heyes, S Paul, C Timmer, D Weygand, E Wolin

    2011-12-01

    In traditional physics data processing (PDP) systems, data location is static and is accessed by analysis applications. In comparison, CLARA (CLAS12 Reconstruction and Analysis framework) is an environment where data processing algorithms filter continuously flowing data. In CLARA's domain of loosely coupled services, data is not stored, but rather flows from one service to another, mutating constantly along the way. Agents, performing event processing, can then subscribe to particular data/events at any stage of the data transformation, and make intricate decisions (e.g. particle ID) by correlating events from multiple, parallel data streams and/or services. This paper presents a PDP application development framework based on service oriented and event driven architectures. This system allows users to design (Java, C++, and Python languages are supported) and deploy data processing services, as well as dynamically compose PDP applications using available services. The PDP service bus provides a layer on top of a distributed pub-sub middleware implementation, which allows complex service composition and integration without writing code. Examples of service creation and deployment, along with the CLAS12 track reconstruction application design will be presented.

  16. Physics students' approaches to learning and cognitive processes in solving physics problems

    NASA Astrophysics Data System (ADS)

    Bouchard, Josee

    This study examined traditional instruction and problem-based learning (PBL) approaches to teaching and the extent to which they foster the development of desirable cognitive processes, including metacognition, critical thinking, physical intuition, and problem solving among undergraduate physics students. The study also examined students' approaches to learning and their perceived role as physics students. The research took place in the context of advanced courses of electromagnetism at a Canadian research university. The cognitive science, expertise, physics and science education, instructional psychology, and discourse processes literature provided the framework and background to conceptualize and structure this study. A within-stage mixed-model design was used and a number of instruments, including a survey, observation grids, and problem sets were developed specifically for this study. A special one-week long problem-based learning (PBL) intervention was also designed. Interviews with the instructors participating in the study provided complementary data. Findings include evidence that students in general engage in metacognitive processes in the organization of their personal study time. However, this potential, including the development of other cognitive processes, might not be stimulated as much as it could in the traditional lecture instructional context. The PBL approach was deemed as more empowering for the students. An unexpected finding came from the realisation that a simple exposure to a structured exercise of problem-solving (pre-test) was sufficient to produce superior planning and solving strategies on a second exposure (post-test) even for the students who had not been exposed to any special treatment. Maturation was ruled out as a potential threat to the validity of this finding. Another promising finding appears to be that the problem-based learning (PBL) intervention tends to foster the development of cognitive competencies, particularly physical intuition, even if it was only implemented for a short period of time. Other findings relate to the nature of the cognitive actions and activities that the students engage in when learning to solve electromagnetism problems in a PBL environment for the first time and the tutoring actions that guide students in this context.

  17. Deciphering the weathering processes using environmental mineralogy and geochemistry: Towards an integrated model of laterite and podzol genesis in the Upper Amazon Basin

    NASA Astrophysics Data System (ADS)

    Fritsch, Emmanuel; Balan, Etienne; Régina Do Nascimento, Nadia; Allard, Thierry; Bardy, Marion; Bueno, Guilherme; Derenne, Sylvie; Melfi, Adolpho José; Calas, Georges

    2011-02-01

    This article reports major results from collaborative research between France and Brazil on soil and water systems, carried out in the Upper Amazon Basin. It reveals the weathering processes acting in the partly inundated, low elevation plateaus of the Basin, mostly covered by evergreen forest. Our findings are based on geochemical data and mineral spectroscopy that probe the crystal chemistry of Fe and Al in mineral phases (mainly kaolinite, Al- and Fe-(hydr)oxides) of tropical soils (laterites). These techniques reveal crystal alterations in mineral populations of different ages and changes of metal speciation associated with mineral or organic phases. These results provide an integrated model of soil formation and changes (from laterites to podzols) in distinct hydrological compartments of the Amazon landscapes and under altered water regimes.

  18. Experimental Approaches to Space Weathering

    NASA Astrophysics Data System (ADS)

    Allen, C. C.; Morris, R. V.; McKay, D. S.

    1996-03-01

    The process of space weathering in lunar soil (maturation) includes the combined effects of micrometeorite impacts and solar wind interactions. Impacts melt small volumes of soil containing solar wind hydrogen and carbon. The melt quenches rapidly to agglutinitic glass in a strongly reducing environment. Glass formation under these conditions causes reduction of Fe2+ in the glass to nanophase (~4-33 nm) iron metal (np-Fe0). Space weathering also produces distinct changes in the reflectance spectra of lunar soils. With increasing maturity overall soil albedo is reduced, spectral contrast is diminished, and the continuum slope is increased. We are attempting to duplicate the effects of space weathering in the laboratory using hydrogen reduction at subsolidus temperatures. Alterations induced in the mineralogical and optical properties of 17 lunar soils resemble changes caused by natural space weathering.

  19. Measurement of physical properties of coal liquids under process conditions

    SciTech Connect

    Oswald, G.E.; Youngblood, E.L.; Hightower, J.R.; Cochran, H.D.

    1980-01-01

    Instrumentation has been developed for measurement of physical properties (viscosity and density) of coal liquids and slurries under conditions typical of those found in coal liquefaction processes such as SRC, H-Coal, and EDS. The instruments are being operated in a flow system designed for slurry rates up to 1 g/s at 810 K and 31 MPa pressure. A capillary tube viscometer and a Norcross falling ring viscometer are used for viscosity measurement. Thus far rheograms (shear rate vs shear stress diagrams) have been determined for 35 wt % Illinois No. 6 coal (-170 mesh) in SRC-I recycle solvent at 13.9 MPa (2000 psig) for the temperature range of 400 to 700 K. A commercially available gamma radiation absorption instrument has been modified for the operating conditions required and is being used for density measurements. Instruments for measurement of thermal conductivity and heat capacity of coal liquids have been designed for future installation in the facility.

  20. Framework for Understanding LENR Processes, Using Ordinary Condensed Matter Physics

    NASA Astrophysics Data System (ADS)

    Chubb, Scott

    2005-03-01

    As I have emphasizedootnotetextS.R. Chubb, Proc. ICCF10 (in press). Also, http://www.lenr-canr.org/acrobat/ChubbSRnutsandbol.pdf http://www.lenr-canr.org/acrobat/ChubbSRnutsandbol.pdf, S.R. Chubb, Trans. Amer. Nuc. Soc. 88 , 618 (2003)., in discussions of Low Energy Nuclear Reactions(LENRs), mainstream many-body physics ideas have been largely ignored. A key point is that in condensed matter, delocalized, wave-like effects can allow large amounts of momentum to be transferred instantly to distant locations, without any particular particle (or particles) acquiring high velocity through a Broken Gauge Symmetry. Explicit features in the electronic structure explain how this can occur^1 in finite size PdD crystals, with real boundaries. The essential physics^1 can be related to standard many-body techniquesootnotetextBurke,P.G. and K.A. Berrington, Atomic and Molecular Processes:an R matrix Approach (Bristol: IOP Publishing, 1993).. In the paper, I examine this relationship, the relationship of the theory^1 to other LENR theories, and the importance of certain features (for example, boundaries^1) that are not included in the other LENR theories.

  1. Solar variability, weather, and climate

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Advances in the understanding of possible effects of solar variations on weather and climate are most likely to emerge by addressing the subject in terms of fundamental physical principles of atmospheric sciences and solar-terrestrial physis. The limits of variability of solar inputs to the atmosphere and the depth in the atmosphere to which these variations have significant effects are determined.

  2. Role of the subgrid-scale physical processes in supermodelling

    NASA Astrophysics Data System (ADS)

    Yano, J.

    2011-12-01

    The basic ides of supermodelling is in overcoming deficits of existing models by combining them together to improve our ability of climate simulations and prediction. However, in order to exploit this method better, we have to pay special attention to the common defects of the current climate models. Representation of subgrid-scale physical processes is such a particular example. . The present talk presents the author's point of view on representation of subgrid-scale processes in the above general question in mind. The focus of the talk will be on interplay between traditional parameterizations and recently proposed superparameterization (also often called "multiscale modelling"), but it also covers the issues of downscaling as well as possibilities of introducing mesh-refinement approaches into the context of subgrid-scale modelling. The author's main perspective is that the subgrid-scale parameterization should not be considered as a distinguished approach in contrast to explicit (more direct) modelling, such as superparameterization, but a hierarchy of modelling approaches should be constructed by taking various intermediate approaches. The mass-flux convection parameterization is taken as an example in order to make this point. It will be shown that at the most basic level, the mass-flux parameterization is equivalent to a finite-volume numerical approach, though various additional approximations and hypotheses must be introduced in order to arrive at a classical mass-flux parameterization. At the mathematical level, the multiresolution analysis based on wavelet provides a basic source of inspirations for developing this general perspective. From this perspective, the issue of parameterization is considered as "compression" of a full explicit model in the same sense as the wavelet can be used for the image compression. This perspective also leads to a concept of compression of physics. Compression of cloud microphysics would be the most urgent issue considering its vast complexity as well as its crucial importance in climate feedbacks.

  3. NASA's Advancements in Space-Based Spectrometry Lead to Improvements in Weather Prediction and Understanding of Climate Processes

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Iredell, Lena

    2010-01-01

    AIRS (Atmospheric Infra-Red Sounder), was launched, in conjunction with AMSU-A (Advanced Microwave Sounding Unit-A) on the NASA polar orbiting research satellite EOS (Earth Observing System) Aqua satellite in May 2002 as a next generation atmospheric sounding system. Atmospheric sounders provide information primarily about the vertical distribution of atmospheric temperature and water vapor distribution. This is achieved by measuring outgoing radiation in discrete channels (spectral intervals) which are sensitive primarily to variations of these geophysical parameters. The primary objectives of AIRS/AMSU were to utilize such information in order to improve the skill of numerical weather prediction as well as to measure climate variability and trends. AIRS is a multi-detector array grating spectrometer with 2378 channels covering the spectral range 650/cm (15 microns) to 2660/cm (3.6 microns) with a resolving power (i/a i) of roughly 1200 where a i is the spectral channel bandpass. Atmospheric temperature profile can be determined from channel observations taken within the 15 micron (the long-wave CO2 absorption band) and within the 4.2 micron (the short-wave CO2 absorption band). Radiances in these (and all other) spectral intervals in the infrared are also sensitive to the presence of clouds in the instrument?s field of view (FOV), which are present about 95% of the time. AIRS was designed so as to allow for the ability to produce accurate Quality Controlled atmospheric soundings under most cloud conditions. This was achieved by having 1) extremely low channel noise values in the shortwave portion of the spectrum and 2) a very flat spatial response function within a channel?s FOV. IASI, the high spectral resolution IR interferometer flying on the European METOP satellite, does not contain either of these important characteristics. The AIRS instrument was also designed to be extremely stabile with regard to its spectral radiometric characteristics, which is critical with regard to the ability to measure accurate long term trends.

  4. Electrochemical Acceleration of Chemical Weathering as an

    E-print Network

    Schrag, Daniel

    formations (e.g., oil and gas fields (5), coal beds (6), and saline aquifers (7)); injecting CO2.Whereasthenaturalsilicate weathering process is effected primarily by carbonic acid, the engineered process accelerates the weathering kinetics to industrial rates by replacing this weak acid with HCl. In the thermodynamic limit

  5. Physical processes effecting the baryonic matter content of the Universe

    NASA Astrophysics Data System (ADS)

    Panayotova, Mariana

    2015-01-01

    We have discussed physical processes effecting the generation of the matter content of the Universe. First we have studied the processes effecting Big Bang Nucleosynthesis during which the chemical content of the baryonic component of the Universe was produced. We have provided detail numerical analysis of the BBN production of ^4He, Y_p, in the presence of ?_e ? ?_s neutrino oscillations, effective after electron neutrino decoupling. We have accounted for all known effects of neutrino oscillations on cosmological nucleosyntesis. We have obtained cosmological bounds corresponding to ? Y_p/Y_p= 5.2 % in correspondance with the recently found higher uncertainty in ^4He. Iso-helium contours for ? Y_p/Y_p > 5% and population of the ?_s state ? N_s = 0; 0.5; 0.7; 0.9, both for resonant and non-resonant oscillations have been calculated. Next we have studied the processes effecting the formation of the baryon content of the Universe. We have investigated a baryogenesis model based on Affleck and Dine baryogenesis scenario, Scalar Field Condensate (SFC) baryogenesis model. We have provided precise numerical analysis of the SFC baryogenesis model numerically accounting for the particle creation processes by the time varying scalar field. We have numerically obtained the dependence of the field and baryon charge evolution and their final values on the model's parameters, namely: the gauge coupling constant ?, the Hubble constant during inflation H_I, the mass of the field m and the self coupling constants ?_i. We have found the range of the model parameters for which a baryon asymmetry value close to the observed one can be generated.

  6. Space Weather Modeling at the Community Coordinated Modeling Center

    NASA Technical Reports Server (NTRS)

    Hesse M.

    2005-01-01

    The Community Coordinated Modeling Center (CCMC) is a multi-agency partnership, which aims at the creation of next generation space weather models. The goal of the CCMC is to support the research and developmental work necessary to substantially increase the present-day modeling capability for space weather purposes, and to provide models for transition to the rapid prototyping centers at the space weather forecast centers. This goal requires dose collaborations with and substantial involvement of the research community. The physical regions to be addressed by CCMC-related activities range from the solar atmosphere to the Earth's upper atmosphere. The CCMC is an integral part of the National Space Weather Program Implementation Plan, of NASA's Living With a Star (LWS) initiative, and of the Department of Defense Space Weather Transition Plan. CCMC includes a facility at NASA Goddard Space Flight Center, as well as distributed computing facilities provided by the US Air Force. CCMC also provides, to the research community, access to state-of-the-art space research models. In this paper we will provide updates on CCMC status, on current plans, research and development accomplishments and goals, and on the model testing and validation process undertaken as part of the CCMC mandate. Special emphasis will be on solar and heliospheric models currently residing at CCMC, and on plans for validation and verification.

  7. Space Weather Modeling Services at the Community Coordinated Modeling Center

    NASA Technical Reports Server (NTRS)

    Hesse, Michael

    2006-01-01

    The Community Coordinated Modeling Center (CCMC) is a multi-agency partnership, which aims at the creation of next generation space weather models. The goal of the CCMC is to support the research and developmental work necessary to substantially increase the present-day modeling capability for space weather purposes, and to provide models for transition to the Rapid Prototyping Centers at the space weather forecast centers. This goal requires close collaborations with and substantial involvement of the research community. The physical regions to be addressed by CCMC-related activities range from the solar atmosphere to the Earth's upper atmosphere. The CCMC is an integral part of the National Space Weather Program Implementation Plan, of NASA's Living With a Star (LWS) initiative, and of the Department of Defense Space Weather Transition Plan. CCMC includes a facility at NASA Goddard Space Flight Center. CCMC also provides, to the research community, access to state-of-the-art space research models. In this paper we will provide a description of the current CCMC status, discuss current plans, research and development accomplishments and goals, and describe the model testing and validation process undertaken as part of the CCMC mandate. Special emphasis will be on solar and heliospheric models currently residing at CCMC, and on plans for validation and verification.

  8. Indirect consequences of extreme weather and climate events and their associations with physical health in coastal Bangladesh: a cross-sectional study

    PubMed Central

    Beier, Dominik; Brzoska, Patrick; Khan, Mobarak Hossain

    2015-01-01

    Background Bangladesh is one of the countries in the world which is most prone to natural disasters. The overall situation is expected to worsen, since extreme weather and climate events (EWCE) are likely to increase in both frequency and intensity. Indirect consequences caused in the events’ aftermath widen the range of possible adverse health outcomes. Objective To assess the association of indirect consequences of EWCE and physical health. Design We used recent cross-sectional self-reported data from 16 coastal villages in Bangladesh. A total of 980 households were surveyed using a structured questionnaire. The outcome of physical health was categorized into three groups, reflecting the severity of reported diseases by the respective source of treatment as a proxy variable (hospital/clinic for severe disease, other source/no treatment for moderate disease, and no disease). The final statistical analysis was conducted using multinomial logistic regression. Results Severe diseases were significantly associated with drinking water from open sources [odds ratio (OR): 4.26, 95% confidence interval (CI): 2.25–8.09] and tube wells (OR: 2.39, 95% CI: 1.43–4.01), moderate harm by river erosion (OR: 6.24, 95% CI: 2.76–14.11), food scarcity (OR: 1.98, 95% CI: 1.16–3.40), and the perception of increased employment problems (OR: 2.19, 95% CI: 1.18–4.07). Moderate diseases were significantly associated with moderate harm by river erosion (OR: 2.65, 95% CI: 1.28–5.48) and fully experienced food scarcity (OR: 1.75, 95% CI: 1.16–2.63). For both categories, women and the elderly had higher chances for diseases. Conclusions Indirect consequences of EWCE were found to be associated with adverse health outcomes. Basic needs such as drinking water, food production, and employment opportunities are particularly likely to become threatened by EWCE and, thus, may lead to a higher likelihood of ill-health. Intervention strategies should concentrate on protection and provision of basic needs such as safe drinking water and food in the aftermath of an event. PMID:26477878

  9. Mercury's Weather-Beaten Surface: An Examination of the Relevant Processes Through Comparisons and Contrasts with the Moon and Asteroids

    NASA Astrophysics Data System (ADS)

    Domingue, D. L.; Schirver, D.; Trávní?ek, P. M.; Helbert, J.

    2015-11-01

    We examine global color properties of Mercury and their correlations to the predicted trends due to particle bombardment and thermal processing. Color ratio and spectral slope analyzes are interpreted relative to lunar and asteroid studies.

  10. Geomorphology's role in the study of weathering of cultural stone

    NASA Astrophysics Data System (ADS)

    Pope, Gregory A.; Meierding, Thomas C.; Paradise, Thomas R.

    2002-10-01

    Great monumental places—Petra, Giza, Angkor, Stonehenge, Tikal, Macchu Picchu, Rapa Nui, to name a few—are links to our cultural past. They evoke a sense of wonderment for their aesthetic fascination if not for their seeming permanence over both cultural and physical landscapes. However, as with natural landforms, human constructs are subject to weathering and erosion. Indeed, many of our cultural resources suffer from serious deterioration, some natural, some enhanced by human impact. Groups from the United Nations to local civic and tourism assemblies are deeply interested in maintaining and preserving such cultural resources, from simple rock art to great temples. Geomorphologists trained in interacting systems, process and response to thresholds, rates of change over time, and spatial variation of weathering processes and effects are able to offer insight into how deterioration occurs and what can be done to ameliorate the impact. Review of recent literature and case studies presented here demonstrate methodological and theoretical advances that have resulted from the study of cultural stone weathering. Because the stone was carved at a known date to a "baseline" or zero-datum level, some of the simplest methods (e.g., assessing surface weathering features or measuring surface recession in the field) provide useful data on weathering rates and processes. Such data are difficult or impossible to obtain in "natural" settings. Cultural stone weathering studies demonstrate the importance of biotic and saline weathering agents and the significance of weathering factors such as exposure (microclimate) and human impact. More sophisticated methods confirm these observations, but also reveal discrepancies between field and laboratory studies. This brings up two important caveats for conservators and geomorphologists. For the conservator, are laboratory and natural setting studies really analogous and useful for assessing stone damage? For the geomorphologist, does cultural stone data have any real relevance to the natural environment? These are questions for future research and debate. In any event, cultural stone weathering studies have been productive for both geomorphologists and conservators. Continued collaboration and communication between the geomorphic, historic preservation, archaeological, and engineering research communities are encouraged.

  11. Weather satellite activity mixed

    NASA Astrophysics Data System (ADS)

    On August 21 at 7:15 P.M. EDT, controllers lost contact with the NOAA-13 weather satellite due to a power system failure aboard the craft. Almost simultaneously, however, representatives of U.S. and European agencies signed an agreement promising mutual cooperation and backup of one another's geostationary weather satellites, effective when both agencies have systems in place, expected in 1995.The newest in a series of polar-orbiting weather satellites, NOAA-13 was launched on August 9 from Vandenburg Air Force Base, Calif., to monitor the Earth's ocean and atmosphere, collecting data for direct transmission to users around the world and to central data-processing centers. According to officials at NASA and the National Oceanographic and Atmospheric Administration, the spacecraft showed steadily decreasing battery voltages and currents during ground passes after 3:45 EDT on August 21, although output from the solar panels remained normal. Charles E. Thienel, NASA Goddard Space Flight Center, Greenbelt, Md., stated that these circumstances indicate a failure in the circuitry between the solar arrays and the batteries.

  12. Teaching Weather Concepts.

    ERIC Educational Resources Information Center

    Sebastian, Glenn R.

    Ten exercises based on the weather map provided in the national newspaper "U.S.A. Today" are used to teach intermediate grade students about weather. An overview describes the history of "U.S.A. Today," the format of the newspaper's weather map, and the map's suitability for teaching weather concepts. Specific exercises, which are briefly…

  13. Weather in Your Life.

    ERIC Educational Resources Information Center

    Kannegieter, Sandy; Wirkler, Linda

    Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

  14. Yaquina Bay Weather & Tides

    E-print Network

    Wright, Dawn Jeannine

    Yaquina Bay Weather & Tides Clay Creech Phil Barbour #12;HMSC Weather Station #12;Temp-Humidity Sensor at Library #12;http://weather.hmsc.oregonstate.edu #12;#12;#12;#12;#12;#12;Archived Data is Available every 15 mins. #12;#12;A pyranometer measures solar radiation #12;#12;National Weather Service

  15. Weather Derivative Valuation

    NASA Astrophysics Data System (ADS)

    Jewson, Stephen; Brix, Anders

    2005-04-01

    Weather Derivative Valuation is the first book to cover all the meteorological, statistical, financial and mathematical issues that arise in the pricing and risk management of weather derivatives. There are chapters on meteorological data and data cleaning, the modelling and pricing of single weather derivatives, the modelling and valuation of portfolios, the use of weather and seasonal forecasts in the pricing of weather derivatives, arbitrage pricing for weather derivatives, risk management, and the modelling of temperature, wind and precipitation. Specific issues covered in detail include the analysis of uncertainty in weather derivative pricing, time-series modelling of daily temperatures, the creation and use of probabilistic meteorological forecasts and the derivation of the weather derivative version of the Black-Scholes equation of mathematical finance. Written by consultants who work within the weather derivative industry, this book is packed with practical information and theoretical insight into the world of weather derivative pricing.

  16. Enhanced Weather Radar (EWxR) System

    NASA Technical Reports Server (NTRS)

    Kronfeld, Kevin M. (Technical Monitor)

    2003-01-01

    An airborne weather radar system, the Enhanced Weather Radar (EWxR), with enhanced on-board weather radar data processing was developed and tested. The system features additional weather data that is uplinked from ground-based sources, specialized data processing, and limited automatic radar control to search for hazardous weather. National Weather Service (NWS) ground-based Next Generation Radar (NEXRAD) information is used by the EWxR system to augment the on-board weather radar information. The system will simultaneously display NEXRAD and on-board weather radar information in a split-view format. The on-board weather radar includes an automated or hands-free storm-finding feature that optimizes the radar returns by automatically adjusting the tilt and range settings for the current altitude above the terrain and searches for storm cells near the atmospheric 0-degree isotherm. A rule-based decision aid was developed to automatically characterize cells as hazardous, possibly-hazardous, or non-hazardous based upon attributes of that cell. Cell attributes are determined based on data from the on-board radar and from ground-based radars. A flight path impact prediction algorithm was developed to help pilots to avoid hazardous weather along their flight plan and their mission. During development the system was tested on the NASA B757 aircraft and final tests were conducted on the Rockwell Collins Sabreliner.

  17. Flight Deck Weather Avoidance Decision Support: Implementation and Evaluation

    NASA Technical Reports Server (NTRS)

    Wu, Shu-Chieh; Luna, Rocio; Johnson, Walter W.

    2013-01-01

    Weather related disruptions account for seventy percent of the delays in the National Airspace System (NAS). A key component in the weather plan of the Next Generation of Air Transportation System (NextGen) is to assimilate observed weather information and probabilistic forecasts into the decision process of flight crews and air traffic controllers. In this research we explore supporting flight crew weather decision making through the development of a flight deck predicted weather display system that utilizes weather predictions generated by ground-based radar. This system integrates and presents this weather information, together with in-flight trajectory modification tools, within a cockpit display of traffic information (CDTI) prototype. that the CDTI features 2D and perspective 3D visualization models of weather. The weather forecast products that we implemented were the Corridor Integrated Weather System (CIWS) and the Convective Weather Avoidance Model (CWAM), both developed by MIT Lincoln Lab. We evaluated the use of CIWS and CWAM for flight deck weather avoidance in two part-task experiments. Experiment 1 compared pilots' en route weather avoidance performance in four weather information conditions that differed in the type and amount of predicted forecast (CIWS current weather only, CIWS current and historical weather, CIWS current and forecast weather, CIWS current and forecast weather and CWAM predictions). Experiment 2 compared the use of perspective 3D and 21/2D presentations of weather for flight deck weather avoidance. Results showed that pilots could take advantage of longer range predicted weather forecasts in performing en route weather avoidance but more research will be needed to determine what combinations of information are optimal and how best to present them.

  18. Physical Education Resources, Class Management, and Student Physical Activity Levels: A Structure-Process-Outcome Approach to Evaluating Physical Education Effectiveness

    ERIC Educational Resources Information Center

    Bevans, Katherine B.; Fitzpatrick, Leslie-Anne; Sanchez, Betty M.; Riley, Anne W.; Forrest, Christopher

    2010-01-01

    Background: This study was conducted to empirically evaluate specific human, curricular, and material resources that maximize student opportunities for physical activity during physical education (PE) class time. A structure-process-outcome model was proposed to identify the resources that influence the frequency of PE and intensity of physical

  19. S. Lovejoy McGill, Montreal The weather and

    E-print Network

    Lovejoy, Shaun

    S. Lovejoy McGill, Montreal The weather and climate as problems in physics: scale invariance and multifractals McGill April 13, 2012 #12;The Weather and Climate Emergent Laws and Multifractal Cascades SHAUN LOVEJOY and DANIEL SCHERTZER (in press, Oct. 2012) Required reading for this course #12;The Weather 3 #12

  20. Questa Baseline and Pre-mining Ground-Water Quality Investigation, 7. A Pictorial Record of Chemical Weathering, Erosional Processes, and Potential Debris-flow Hazards in Scar Areas Developed on Hydrothermally Altered Rocks

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Ludington, Steve; Vincent, Kirk R.; Verplanck, Philip L.; Caine, Jonathan S.; Livo, K. Eric

    2009-01-01

    Erosional scar areas developed along the lower Red River basin, New Mexico, reveal a complex natural history of mineralizing processes, rapid chemical weathering, and intense physical erosion during periodic outbursts of destructive, storm-induced runoff events. The scar areas are prominent erosional features with craggy headwalls and steep, denuded slopes. The largest scar areas, including, from east to west, Hottentot Creek, Straight Creek, Hansen Creek, Lower Hansen Creek, Sulfur Gulch, and Goat Hill Gulch, head along high east-west trending ridges that form the northern and southern boundaries of the lower Red River basin. Smaller, topographically lower scar areas are developed on ridge noses in the inner Red River valley. Several of the natural scar areas have been modified substantially as a result of large-scale open-pit and underground mining at the Questa Mine; for example, much of the Sulfur Gulch scar was removed by open pit mining, and several scars are now partially or completely covered by mine waste dumps.

  1. Improved in Situ Space Weather Data Services from the NOAA National Geophysical Data Center

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. V.; Denig, W. F.; Green, J. C.; Lotoaniu, T. M.; McGuire, R. E.; Redmon, R. J.; Rowland, W. F.; Turner, D. L.; Weigel, R. S.; Wilkinson, D. C.

    2014-12-01

    The international space weather enterprise relies heavily on in situ plasma, particle and magnetic field measurements from U. S. weather satellites. This year marks the 40th anniversary of the launch of the first U. S. geostationary weather satellite (SMS-1), which carried the direct ancestor of the current GOES Space Environment Monitor (SEM) suite. The GOES space weather observations support the issuance of real-time alerts by the NOAA Space Weather Prediction Center (SWPC). The publicly-available archive of space weather observations at the NOAA National Geophysical Data Center (NGDC) includes NOAA geostationary observations since 1974 and POES/MetOp and Air Force DMSP polar-orbiting observations since 1978 and 1982, respectively. This archive supports the retrospective aspect of the space weather enterprise, which includes model development and anomaly resolution efforts. Over the last several years, NGDC has made a concerted effort to improve its data services in cooperation with the broader space weather community. These improvements include (1) taking over the processing of existing products, (2) creating science-quality versions of existing products, (3) developing new products, (4) improving the distribution of these products, and (5) validating products via on-orbit cross-comparisons. Complementing this retrospective role, NGDC is also responsible for the next-generation GOES-R space weather instrument science and is working as part of the GOES-R calibration/validation group to ensure that these new instruments and their products meet NOAA's requirements. This presentation will survey NGDC's efforts in each of these areas, including (1) POES/MetOp SEM-2 fluxes and radiation belt indices, (2) GOES fluxes with data quality flags and error bars, (3) in situ products from GOES-R(S,T,U), (4) cooperative distribution efforts with the NASA Space Physics Data Facility (SPDF) and the Space Physics Environmental Data Analysis System (SPEDAS), and (5) inter-calibrations of solar energetic proton fluxes and of magnetospheric electron fluxes.

  2. Building a Weather-Ready Nation Fall Weather Safety

    E-print Network

    Building a Weather-Ready Nation Fall Weather Safety www.weather.gov/safety Wildfire ­ Drought ­ Hurricanes ­ Wind ­ Early Season Winter ­ Flood #12;Building a Weather-Ready Nation Wildfire Safety smoking materials. weather.gov/wildfire www.weather.gov/safety #12;Building a Weather-Ready Nation

  3. Physical Abuse, Cognitive and Emotional Processes, and Aggressive/Disruptive Behavior Problems

    ERIC Educational Resources Information Center

    Teisl, Michael; Cicchetti, Dante

    2008-01-01

    Cognitive and emotional processes were examined in maltreated children with a history of physical abuse (n = 76), children with a history of maltreatment other than physical abuse (i.e., sexual abuse, physical neglect, and emotional maltreatment; n = 91), and a group of non-maltreated comparison children (N = 100). Physical abuse was associated…

  4. Weathering processes in superficial deposits (regolith) and their influence on pedogenesis: A case study in the Swiss Jura Mountains

    NASA Astrophysics Data System (ADS)

    Martignier, Loraine; Verrecchia, Eric P.

    2013-05-01

    The last glacial period left a mantle of freshly reworked sediments covering the European landscape. Glacial, periglacial, fluvio-glacial, and aeolian dynamics enhanced transportation and mixing of materials, generating new superficial deposits in which Holocene soils developed. These assorted surface sediments often differed from the underlying bedrock in their lithological composition and texture, and were delimited by lithological discontinuities. In the Swiss Jura Mountains, the Mesozoic limestone bedrocks are covered by various superficial deposits (moraines, cover-beds, loess deposits, cryoclasts, etc.), which reduce or even suppress the influence of limestone on present-day soil development. In this context, soils and their underlying bedrock no longer present a genetic continuity. The nature and relationships between these deposits is studied within a toposequence of soils, in terms of their mineralogical and geochemical compositions. Three main superficial deposits (limestone bedrock clasts, loess, and non-carbonate moraine), are used as reference materials in order to characterize the complex mixing of sediments through the toposequence. Soils with limestone clasts undergo decarbonation and decalcification processes. Iron-rich Alpine loess deposits, composed of fine silicate particles, enhance brunification process in soils. A non-carbonate Alpine moraine displays the most acidic conditions within the toposequence due to enhanced leaching (clay and ions) processes. Consequently, the reworked surface sediments (including limestone cryoclasts, moraines, and cover-beds) have a prevailing influence on pedogenesis compared to the hard underlying bedrock.

  5. The quiet revolution of numerical weather prediction.

    PubMed

    Bauer, Peter; Thorpe, Alan; Brunet, Gilbert

    2015-09-01

    Advances in numerical weather prediction represent a quiet revolution because they have resulted from a steady accumulation of scientific knowledge and technological advances over many years that, with only a few exceptions, have not been associated with the aura of fundamental physics breakthroughs. Nonetheless, the impact of numerical weather prediction is among the greatest of any area of physical science. As a computational problem, global weather prediction is comparable to the simulation of the human brain and of the evolution of the early Universe, and it is performed every day at major operational centres across the world. PMID:26333465

  6. The quiet revolution of numerical weather prediction

    NASA Astrophysics Data System (ADS)

    Bauer, Peter; Thorpe, Alan; Brunet, Gilbert

    2015-09-01

    Advances in numerical weather prediction represent a quiet revolution because they have resulted from a steady accumulation of scientific knowledge and technological advances over many years that, with only a few exceptions, have not been associated with the aura of fundamental physics breakthroughs. Nonetheless, the impact of numerical weather prediction is among the greatest of any area of physical science. As a computational problem, global weather prediction is comparable to the simulation of the human brain and of the evolution of the early Universe, and it is performed every day at major operational centres across the world.

  7. Carbonate Beaches: A Balance Between Biological and Physical Processes

    NASA Astrophysics Data System (ADS)

    Nairn, R.; Risk, M.

    2004-12-01

    Carbonate beaches are a unique example of the interaction between biological processes, creating the sediments, and physical processes, moving and often removing the sediments. On the sediment supply side, carbonate sediments are born, not made. They exist in dynamic equilibrium between production and destruction. Following the creation of carbonate sediment in coral reef and lagoon environments, the sediments are moved shoreward to the beach, transport along the shore and sometimes, eventually lost offshore, often as the result of tropical storms. Comprehensive studies of the balance between the supply and loss of carbonate sediments and beach dynamics have been completed for the islands of Mauritius and Barbados. Field studies and remote sensing (Compact Airborne Spectrometry Imaging) have been applied to develop carbonate sediment production rates for a range of reef and lagoon conditions. Using GIS, these production rates have been integrated to determine sediment supply rates for different segments of the coastline. 1-D and 2-D models of waves, hydrodynamics, sediment transport and morphodynamics were set-up and tested against observed beach response to storm events or a sequence of storm events. These complex deterministic models are not suitable for application over periods of decades. However, it was possible to characterize storm events by the extent of sand loss, and relate this to key descriptive factors for groups of storm events, thereby encapsulating the erosion response. A long-term predictive tool for evaluating beach erosion and accretion response, over a period of several decades, was developed by combining the supply rates for carbonate sediment and the encapsulated representation of the loss rates through physical processes. The ability of this predictive tool was successfully tested against observed long term beach evolution along sections of the coast in Barbados and Mauritius using air photo analysis in GIS for shoreline change over periods of 40 years. The long-term predictive tool for carbonate beach evolution provided valuable support to developing coastal zone management policy and actions to preserve the beaches in their natural form, minimizing the need for artificial nourishment of the beaches. Many models of sediment movement on shorelines are derived from clastic examples, and fit carbonate coastlines only with difficulty. We have combined field surveys of benthic biota, estimates of sediment production from skeletal growth and bioerosion, and sediment destruction by comminution and dissolution with dynamic models of sediment movement in the littoral zone, achieving improved understanding of coastal processes of erosion and deposition. Mauritius is fringed by shallow lagoons, often with luxuriant stands of Acropora. The offshore region is exhumed Pleistocene-all the sediment on the beaches comes from the lagoons. From surveys of coral cover, and estimates of sediment production from reef, sand and hardground areas, we produced dynamic models that faithfully hindcast shoreline dynamics for decades, and allowed identification of regions especially vulnerable to erosion. On the south coast of Barbados, one of the main issues in stabilising and rehabilitation the coastline is the balance between sediment from longshore drift and local sources. By identifying localised areas of characteristic sediment-producers (e.g., the foraminiferan Homotrema rubrum, the green alga Halimeda), we were able to determine the balance between proximal and distal sediment sources. The resulting model hindcasts the coastline through all the major hurricanes of the past 30 years.

  8. Evidence of Space Weathering in Regolith Breccias II: Asteroidal Regolith Breccias

    NASA Technical Reports Server (NTRS)

    Noble, Sarah K.; Keller, Lindsay P.; Pieters, Carle M.

    2011-01-01

    Space weathering products, such as agglutinates and nanophaase iron-bearing rims are easily preserved through lithifcation in lunar regolith breccias, thus such products, if produced, should be preserved in asteroidal regotith breccias as well. A study of representative regolith breecia meteorites, Fayetteville (H4) and Kapoeta (howardite), was undertaken to search for physical evidence of space weathering on asteroids. Amorphous or npFe(sup 0)-bearing rim cannot be positively identified in Fayetteville, although possible glass rims were found. Extensive friction melt was discovered in the meteorite that is difficult to differentiate from weathered materials. Several melt products, including spherules and agglutinates, as well as one irradiated rim and one possible npFe(sup 0)-bearing rim were identified in Kapoeta. The existence of these products suggests that lunar-like space weathering processes are, or have been, active on asteroids.

  9. Thermal Weathering on Airless Planetary Surfaces

    NASA Astrophysics Data System (ADS)

    Pochat, N. G.; Vance, S.; Collins, G. C.

    2009-12-01

    All airless planetary surfaces in our Solar System appear to be covered by a regolith layer. There are several general processes that could form such a regolith layer, including the rain of impactors on the surface, mass wasting, sublimation degradation, and physical weathering by thermal changes. Several of these processes have been well studied on icy satellites [e.g. Moore et al. 1999]. Weathering of craters and regolith generation on airless bodies are presumed to result from micrometeorite impacts. For instance, one could look at examples of smooth terrain on the moon and try to explain smooth terrain on Callisto by small impacts, but the crater density is well below equilibrium. This led Moore et al. (1999) to state, “…some other process is dominating its surface layer.” The question is: what process could this be? Moore et al. (1999) argue that sublimation and deposition is a dominant weathering process occurring on Callisto, but it may not be the only regolith-generating process. Vance et al. (2007) adapted a thermal expansion anisotropy and mismatch driven fracturing model for a matrix of square grains. Recently we have been looking at the stress at grain boundaries in this model. This stress term is dependent on the grain size and rate of temperature change at the surface of the body. The question we are trying to answer is whether the stress generated at grain boundaries during diurnal heating and cooling is enough to generate and propagate fractures in the surface material. We started by developing a one dimensional finite difference thermal model for the near-surface environment on an airless body, insulated on the bottom boundary and driven by insolation and radiation to space on the surface. We also assumed that density was constant with depth. The program can take the different parameters for each body (e.g. the bolometric albedo and distance from the sun) and calculate the temperature change at any depth over a diurnal cycle at any latitude. Ice is a simple material to consider in models of thermal weathering. We have developed a thermal model for airless planetary surfaces in our Solar System. By linking this thermal model to the grain boundary stress model, we are able to place limits on the smallest grain size that permits thermal weathering, and the depth to which cracking will occur on different icy bodies in our solar system. For instance, we found that cracking can occur on the surfaces of Ganymede and Callisto for grain sizes > 0.5 microns. Thermal weathering may be an important process contributing to regolith generation on airless planetary surfaces. This near-surface process may help to speed up other processes like mass wasting and sublimation degradation. We will present maps of susceptibility to thermal cracking for airless planetary surfaces in our solar system at the meeting and compare to what is known about the regolith. References: Moore et al. (1999) Icarus 140, p. 294-312; Vance et al. (2007) Astrobiology 7, p. 987-1005.

  10. Biogeochemical weathering under ice: Size matters J. L. Wadham,1

    E-print Network

    Priscu, John C.

    is a critical control on the balance of chemical weathering processes and that microbial activity is ubiquitous of chemical weathering dynamics provides important information on subglacial biodiversity and global; Tranter et al., 2005]. These chemical weathering processes may be critical to their survival through

  11. Germaniumsilicon fractionation in a tropical, granitic weathering environment

    E-print Network

    Derry, Louis A.

    . All rights reserved. 1. INTRODUCTION Chemical weathering is a fundamental process at the earth-based studies of chemical weathering typically involve elemental/ionic mass balance (Garrels and Mackenzie, 1967 the development of germanium­silicon ratios as a tracer of chemical weathering processes and the biogeo- chemical

  12. Pilot weather advisor

    NASA Technical Reports Server (NTRS)

    Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

    1992-01-01

    The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

  13. The problems of solar-terrestrial coupling and new processes introduced to the physics of the ionosphere from the physics of atomic collisions

    NASA Astrophysics Data System (ADS)

    Avakyan, Sergei

    2010-05-01

    Further progress in research of solar-terrestrial coupling requires better understanding of solar variability influence on the ionosphere. The most powerful manifestations of solar variability are solar flares and geomagnetic storms. During a flare EUV/X-ray irradiations are completely absorbed in the ionosphere producing SID. During geomagnetic storms precipitations of electrons with energy of several keV (and to a lesser extent protons precipitations) from radiation belts and geomagnetosphere produce additional ionization and low latitude auroras. Considering the physics of ionosphere during the last several decades we have been taking into account three novel processes well known in the physics of atomic collisions. These are Auger effect [S. V. Avakyan, The consideration of Auger processes in the upper atmosphere of Earth. In Abstracts of paper presented at the Tenth scien. and techn. Conf. of young specialists of S.I. Vavilov State Optical Institute, 1974, 29-31.], multiple photoionization of upper, valence shell [S.V. Avakyan, The source of O++ ions in the upper atmosphere, 1979, Cosmic Res, 17, 942 - 943] and Rydberg excitation of all the components of upper atmosphere [S.V. Avakyan, The new factor in the physics of solar - terrestrial relations - Rydberg atomic and molecules states. Conf. on Physics of solar-terrestrial relationships, 1994, Almaty, 3 - 5]. In the present paper the results of bringing these new processes in the ionospheric physics are discussed and also its possible role in the physics of solar-terrestrial coupling is considered. Involving these processes to the model estimations allowed us for the first time to come to the following important conclusions: - Auger electrons play the determinant role at the formation of energy spectrum of photoelectrons and secondary auroral electrons at the range above 150 eV; - double photoionization of the outer shell of the oxygen atom (by a single photon) plays a dominant role in the formation of ionospheric doubly charged positive ions, and Auger effect mainly determines the formation of double- and triple charged ions in the low ionosphere of planets and also comets; - transitions in the Rydberg excited ionospheric atoms and molecules play the main role in generation of new type of upper atmospheric emission - microwave characteristic radiation. The ionospheric O++ ions fill the magnetosphere after geomagnetic storms. These ions scatter the solar radiation in one of the most intense lines with a wavelength of 30.4 nm (He+) and also in the 50.7-, 70.3-, 83.3-83.5-nm lines in geocorona to the nocturnal side, giving rise to additional ionization and optical excitation in the F-region. The first calculations of the excitation rate of Rydberg states by photoelectrons and by auroral electrons (including Auger electrons) were carried out. It was shown that such process can generate the microwave ionospheric radioemission. Such emissions were observed during solar flares and in auroras. We suggest that Rydberg microwave radioemissions which take place during ionospheric disturbances produced by the solar flares and geomagnetic storms can be considered as an agent of influence of solar-geomagnetic activity on the biosphere and also as a factor of Sun-weather-climate links All these results obtained experimental confirmation in space investigations and in some ground-based measurements carried out with radiophysical and optical methods. The new processes which we introduced to the physics of upper atmosphere and ionosphere are now widely used in the ionospheric science for interpretation of spacecraft measurement data (the spacecrafts ISIS, GEOS-1, IMAGE, the satellites DE-1,-B, EXOS-D (AKEBOHO), FAST, Intercosmos-19, -24, -25, the orbital stations "Salut", "Mir"). There is a Russian patent on the method of remote registration of radioactive atmospheric clouds and nuclear weapon tests over the atmosphere by means of optical fluorescence which is based on Auger processes.

  14. Chemical weathering and CO? consumption in the Lower Mekong River.

    PubMed

    Li, Siyue; Lu, X X; Bush, Richard T

    2014-02-15

    Data on river water quality from 42 monitoring stations in the Lower Mekong Basin obtained during the period 1972-1996 was used to relate solute fluxes with controlling factors such as chemical weathering processes. The total dissolved solid (TDS) concentration of the Lower Mekong varied from 53 mg/L to 198 mg/L, and the median (114 mg/L) was compared to the world spatial median value (127 mg/L). Total cationic exchange capacity (Tz(+)) ranged from 729 to 2,607 ?molc/L, and the mean (1,572 ?molc/L) was 1.4 times higher than the world discharge-weighted average. Calcium and bicarbonate dominated the annual ionic composition, accounting for ~70% of the solute load that equalled 41.2×10(9)kg/y. TDS and major elements varied seasonally and in a predictable way with river runoff. The chemical weathering rate of 37.7t/(km(2)y), with respective carbonate and silicate weathering rates of 27.5t/(km(2) y) (13.8mm/ky) and 10.2t/(km(2) y) (3.8mm/ky), was 1.5 times higher than the global average. The CO2 consumption rate was estimated at 191×10(3)molCO2/(km(2)y) for silicate weathering, and 286×10(3)molCO2/(km(2)y) by carbonate weathering. In total, the Mekong basin consumed 228×10(9)molCO2/y and 152×10(9)molCO2/y by the combined weathering of carbonate and silicate, constituting 1.85% of the global CO2 consumption by carbonate weathering and 1.75% by silicates. This is marginally higher than its contribution to global water discharge ~1.3% and much higher than (more than three-fold) its contribution to world land surface area. Remarkable CO2 consumed by chemical weathering (380×10(9)mol/y) was similar in magnitude to dissolved inorganic carbon as HCO3(-) (370×10(9)mol/y) exported by the Mekong to the South China Sea. In this landscape, atmospheric CO2 consumption by rock chemical weathering represents an important carbon sink with runoff and physical erosion controlling chemical erosion. PMID:24291559

  15. Effective Physical Functioning: A Precondition for the Helping Process

    ERIC Educational Resources Information Center

    Collingwood, Thomas R.

    1976-01-01

    Within the human resource development model, physical fitness is viewed as a key factor of counselor functioning. A review of the literature reveals that fitness is related to several physical, intellectual, and emotional factors that have a bearing on counselor and client functioning. Implications for training counselors on fitness are explored.…

  16. National Weather Service

    MedlinePLUS

    ... Tornadoes Space Weather Sun (Ultraviolet Radiation) Safety Campaigns Wind Drought Winter Weather Fog INFORMATION Owlie's Kids Page ... Advisory For Rough Bar Small Craft Advisory Brisk Wind Advisory Wind Advisory Frost Advisory Beach Hazards Statement ...

  17. Winter Weather: Frostbite

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... related health problems. More Information: Hypothermia Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  18. Winter Weather: Hypothermia

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... be successfully resuscitated. More Information: Frostbite Disasters & Severe Weather ... Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  19. Winter Weather: Indoor Safety

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Outdoor Safety Winter PSAs and Podcasts Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  20. Winter Weather Emergencies

    MedlinePLUS

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

  1. Asteroids: Does Space Weathering Matter?

    NASA Technical Reports Server (NTRS)

    Gaffey, Michael J.

    2001-01-01

    The interpretive calibrations and methodologies used to extract mineralogy from asteroidal spectra appear to remain valid until the space weathering process is advanced to a degree which appears to be rare or absent on asteroid surfaces. Additional information is contained in the original extended abstract.

  2. Intelligent weather agent for aircraft severe weather avoidance 

    E-print Network

    Bokadia, Sangeeta

    2002-01-01

    avoidance capability has increased. In this thesis, an intelligent weather agent is developed for general aviation aircraft. Using a radar image from an onboard weather radar, the intelligent weather agent determines the safest path around severe weather...

  3. Optimal assimilation for ionospheric weather Theoretical aspect

    NASA Astrophysics Data System (ADS)

    Guo, Jian-Shan; Shang, She-Ping; Shi, Jiankui; Zhang, Manlian; Luo, Xigui; Zheng, Hong

    2003-04-01

    Observation, specification and prediction of ionospheric weather are the key scientific pursuits of space physicists, which largely based on an optimal assimilation system. The optimal assimilation system, or commonly called data assimilation system, consists of dynamic process, observation system and optimal estimation procedure. We attempt to give a complete framework in this paper under which the data assimilation procedure carries through. We discuss some crucial issues of data assimilation as follows: modeling a dynamic system for ionospheric weather; state estimation for static or steady system in sense of optimization and likelihood; state and its uncertainty estimation for dynamic process. Meanwhile we also discuss briefly the observability of an observation system; system parameter identification. Some data assimilation procedures existed at present are reviewed in the framework of this paper. As an example, a second order dynamic system is discussed in more detail to illustrate the specific optimal assimilation procedure, ranging from modeling the system, state and its uncertainty calculation, to the quantitatively integration of dynamic law, measurement to significantly reduce the estimation error. The analysis shows that the optimal assimilation model, with mathematical core of optimal estimation, differs from the theoretical, empirical and semi-empirical models in assimilating measured data, being constrained by physical law and being optimized respectively. The data assimilation technique, due to its optimization and integration feature, could obtain better accurate results than those obtained by dynamic process, measurement or their statistical analysis alone. The model based on optimal assimilation meets well with the criterion of the model or algorithm assessment by ‘space weather metrics’. More attention for optimal assimilation procedure creation should be paid to transition matrix finding, which is usually not easy for practical space weather system. High performance computing hardware and software studies should be promoted further so as to meet the requirement of large storage and extensive computation in the optimal estimation. The discussion in this paper is appropriate for the static or steady state or transition process of dynamic system. Many phenomena in space environment are unstable and chaos. So space environment study should include and integrate these two branches of learning.

  4. Vertical structure and physical processes of the Madden-Julian oscillation: Linking hindcast fidelity to simulated diabatic heating and moistening

    NASA Astrophysics Data System (ADS)

    Klingaman, Nicholas P.; Woolnough, Steven J.; Jiang, Xianan; Waliser, Duane; Xavier, Prince K.; Petch, Jon; Caian, Mihaela; Hannay, Cecile; Kim, Daehyun; Ma, Hsi-Yen; Merryfield, William J.; Miyakawa, Tomoki; Pritchard, Mike; Ridout, James A.; Roehrig, Romain; Shindo, Eiki; Vitart, Frederic; Wang, Hailan; Cavanaugh, Nicholas R.; Mapes, Brian E.; Shelly, Ann; Zhang, Guang J.

    2015-05-01

    Many theories for the Madden-Julian oscillation (MJO) focus on diabatic processes, particularly the evolution of vertical heating and moistening. Poor MJO performance in weather and climate models is often blamed on biases in these processes and their interactions with the large-scale circulation. We introduce one of the three components of a model evaluation project, which aims to connect MJO fidelity in models to their representations of several physical processes, focusing on diabatic heating and moistening. This component consists of 20 day hindcasts, initialized daily during two MJO events in winter 2009-2010. The 13 models exhibit a range of skill: several have accurate forecasts to 20 days lead, while others perform similarly to statistical models (8-11 days). Models that maintain the observed MJO amplitude accurately predict propagation, but not vice versa. We find no link between hindcast fidelity and the precipitation-moisture relationship, in contrast to other recent studies. There is also no relationship between models' performance and the evolution of their diabatic heating profiles with rain rate. A more robust association emerges between models' fidelity and net moistening: the highest-skill models show a clear transition from low-level moistening for light rainfall to midlevel moistening at moderate rainfall and upper level moistening for heavy rainfall. The midlevel moistening, arising from both dynamics and physics, may be most important. Accurately representing many processes may be necessary but not sufficient for capturing the MJO, which suggests that models fail to predict the MJO for a broad range of reasons and limits the possibility of finding a panacea.

  5. Hot Weather Tips

    MedlinePLUS

    ... FCA - A A + A You are here Home HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  6. American Weather Stories.

    ERIC Educational Resources Information Center

    Hughes, Patrick

    Weather has shaped United States' culture, national character and folklore; at times it has changed the course of history. The seven accounts compiled in this publication highlight some of the nation's weather experiences from the hurricanes that threatened Christopher Columbus to the peculiar run of bad weather that has plagued American…

  7. Weather Fundamentals: Meteorology. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  8. Severe Weather Perceptions.

    ERIC Educational Resources Information Center

    Abrams, Karol

    Severe weather is an element of nature that cannot be controlled. Therefore, it is important that the general public be aware of severe weather and know how to react quickly and appropriately in a weather emergency. This study, done in the community surrounding the Southern Illinois University at Carbondale, was conducted to compile and analyze…

  9. Aviation weather services

    NASA Technical Reports Server (NTRS)

    Sprinkle, C. H.

    1983-01-01

    The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

  10. Building a Weather-Ready Nation Winter Weather Safety

    E-print Network

    Building a Weather-Ready Nation Winter Weather Safety Snow & Ice ­ Blizzards ­ Freezing Rain & Sleet ­ Cold Temperatures ­ Wind ­ Flooding ­ Fog www.weather.gov/safety #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety · Snow & Ice · Blizzards · Freezing Rain & Sleet

  11. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots are likely to avoid. The automated system periodically updates forecasts and reassesses rerouting decisions in order to account for changing weather predictions. The main objectives are to reroute flights to avoid convective weather regions and determine the resulting complexity due to rerouting. The eventual goal is to control and reduce complexity while rerouting flights during the 20 minute - 2 hour planning period. A three-hour simulation is conducted using 4800 flights in the national airspace. The study compares several metrics against a baseline scenario using the same traffic and weather but with rerouting disabled. The results show that rerouting can have a negative impact on congestion in some sectors, as expected. The rerouting system provides accurate measurements of the resulting complexity in the congested sectors. Furthermore, although rerouting is performed only in the 20-minute - 2-hour range, it results in a 30% reduction in encounters with nowcast weather polygons (100% being the ideal for perfectly predictable and accurate weather). In the simulations, rerouting was performed for the 20-minute - 2-hour flight time horizon, and for the en-route segment of air traffic. The implementation uses CWAM, a set of polygons that represent probabilities of pilot deviation around weather. The algorithms were implemented in a software-based air traffic simulation system. Initial results of the system's performance and effectiveness were encouraging. Simulation results showed that when flights were rerouted in the 20-minute - 2-hour flight time horizon of air traffic, there were fewer weather encounters in the first 20 minutes than for flights that were not rerouted. Some preliminary results were also obtained that showed that rerouting will also increase complexity. More simulations will be conducted in order to report conclusive results on the effects of rerouting on complexity. Thus, the use of the 20-minute - 2-hour flight time horizon weather avoidance teniques performed in the simulation is expected to provide benefits for short-term weather avoidan

  12. Process reconstruction: From unphysical to physical maps via maximum likelihood

    SciTech Connect

    Ziman, Mario; Plesch, Martin; Stelmachovic, Peter; Buzek, Vladimir

    2005-08-15

    We show that the method of maximum likelihood (MML) provides us with an efficient scheme for the reconstruction of quantum channels from incomplete measurement data. By construction this scheme always results in estimations of channels that are completely positive. Using this property we use the MML for a derivation of physical approximations of unphysical operations. In particular, we analyze the optimal approximation of the universal NOT gate as well as the physical approximation of a quantum nonlinear polarization rotation.

  13. Space Weathering in the Mercurian Environment

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Pieters, C. M.

    2001-01-01

    Space weathering processes are known to be important on the Moon. These processes both create the lunar regolith and alter its optical properties. Like the Moon, Mercury has no atmosphere to protect it from the harsh space environment and therefore it is expected that it will also incur the effects of space weathering. However, there are many important differences between the environments of Mercury and the Moon. These environmental differences will almost certainly affect the weathering processes and the products of those processes. It should be possible to observe the effects of these differences in Vis (visible)/NIR (near infrared) spectra of the type expected to be returned by MESSENGER. More importantly, understanding these weathering processes and their consequences is essential for evaluating the spectral data returned from MESSENGER and other missions in order to determine the mineralogy and the Fe content of the Mercurian surface. Additional information is contained in the original extended abstract.

  14. Animal Thermoregulation and the Operative Environmental (Equivalent) Temperature. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Process.

    ERIC Educational Resources Information Center

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Thermoregulation is defined as the ability of an organism to modify its body temperature. This…

  15. Heat Balance of a Sheep in the Sun. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    ERIC Educational Resources Information Center

    Hatheway, W. H.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Specifically, this module develops a method for calculating the exchange of heat between an…

  16. Physical and chemical controls on the critical zone

    USGS Publications Warehouse

    Anderson, S.P.; Von Blanckenburg, F.; White, A.F.

    2007-01-01

    Geochemists have long recognized a correlation between rates of physical denudation and chemical weathering. What underlies this correlation? The Critical Zone can be considered as a feed-through reactor. Downward advance of the weathering front brings unweathered rock into the reactor. Fluids are supplied through precipitation. The reactor is stirred at the top by biological and physical processes. The balance between advance of the weathering front by mechanical and chemical processes and mass loss by denudation fixes the thickness of the Critical Zone reactor. The internal structure of this reactor is controlled by physical processes that create surface area, determine flow paths, and set the residence time of material in the Critical Zone. All of these impact chemical weathering flux.

  17. Natural Weathering Rates of Silicate Minerals

    NASA Astrophysics Data System (ADS)

    White, A. F.

    2003-12-01

    Silicates constitute more than 90% of the rocks exposed at Earth's land surface (Garrels and Mackenzie, 1971). Most primary minerals comprising these rocks are thermodynamically unstable at surface pressure/temperature conditions and are therefore susceptible to chemical weathering. Such weathering has long been of interest in the natural sciences. Hartt (1853) correctly attributed chemical weathering to "the efficacy of water containing carbonic acid in promoting the decomposition of igneous rocks." Antecedent to the recent interest in the role of vegetation on chemical weathering, Belt (1874) observed that the most intense weathering of rocks in tropical Nicaragua was confined to forested regions. He attributed this effect to "the percolation through rocks of rain water charged with a little acid from decomposing vegetation." Chamberlin (1899) proposed that the enhanced rates of chemical weathering associated with major mountain building episodes in Earth's history resulted in a drawdown of atmospheric CO2 that led to periods of global cooling. Many of the major characteristics of chemical weathering had been described when Merrill (1906) published the groundbreaking volume Rocks, Rock Weathering, and Soils.The major advances since that time, particularly during the last several decades, have centered on understanding the fundamental chemical, hydrologic, and biologic processes that control weathering and in establishing quantitative weathering rates. This research has been driven by the importance of chemical weathering to a number environmentally and economically important issues. Undoubtedly, the most significant aspect of chemical weathering is the breakdown of rocks to form soils, a process that makes life possible on the surface of the Earth. The availability of many soil macronutrients such as magnesium, calcium, potassium, and PO4 is directly related to the rate at which primary minerals weather. Often such nutrient balances are upset by anthropogenic activities. For example, Huntington et al. (2000) show that extensive timber harvesting in the southeastern forests of the United States, which are underlain by intensely weathered saprolites, produces net calcium exports that exceed inputs from weathering, thus creating a long-term regional problem in forest management.The role of chemical weathering has long been recognized in economic geology. Tropical bauxites, which account for most of world's aluminum ores, are typical examples of residual concentration of silicate rocks by chemical weathering over long time periods (Samma, 1986). Weathering of ultramafic silicates such as peridotites forms residual lateritic deposits that contain significant deposits of nickel and cobalt. Ores generated by chemical mobilization include uranium deposits that are produced by weathering of granitic rocks under oxic conditions and subsequent concentration by sorption and precipitation ( Misra, 2000).Over the last several decades, estimating rates of silicate weathering has become important in addressing new environmental issues. Acidification of soils, rivers, and lakes has become a major concern in many parts of North America and Europe. Areas at particular risk are uplands where silicate bedrock, resistant to chemical weathering, is overlain by thin organic-rich soils (Driscoll et al., 1989). Although atmospheric deposition is the most important factor in watershed acidification, land use practices, such as conifer reforestation, also create acidification problems ( Farley and Werritty, 1989). In such environments, silicate hydrolysis reactions are the principal buffer against acidification. As pointed out by Drever and Clow (1995), a reasonable environmental objective is to decrease the inputs of acidity such that they are equal to or less than the rate of neutralization by weathering in sensitive watersheds.The intensive interest in past and present global climate change has renewed efforts to understand quantitatively feedback mechanisms between climate and chemical weathering. On timescales longer than

  18. Dissolution of Olivine, Siderite, and Basalt at 80 Deg C in 0.1 M H2SO4 in a Flow Through Process: Insights into Acidic Weathering on Mars

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, D. W.; Hausrath, E. M.; Morris, R. V.; Niles, P. B.; Achilles, C. N.; Ross, D. K.; Cooper, B. L.; Gonzalex, C. P.; Mertzman, S. A.

    2012-01-01

    The occurrence of jarosite, other sulfates (e.g., Mg-and Ca-sulfates), and hematite along with silicic-lastic materials in outcrops of sedimentary materials at Meridiani Planum (MP) and detection of silica rich deposits in Gusev crater, Mars, are strong indicators of local acidic aqueous processes [1,2,3,4,5]. The formation of sediments at Meridiani Planum may have involved the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [6,7]. Also, our previous work on acid weathering of basaltic materials in a closed hydro-thermal system was focused on the mineralogy of the acid weathering products including the formation of jarosite and gray hematite spherules [8,9,10]. The object of this re-search is to extend our earlier qualitative work on acidic weathering of rocks to determine acidic dissolution rates of Mars analog basaltic materials at 80 C using a flow-thru reactor. We also characterized residual phases, including poorly crystalline or amorphous phases and precipitates, that remained after the treatments of olivine, siderite, and basalt which represent likely MP source rocks. This study is a stepping stone for a future simulation of the formation of MP rocks under a range of T and P.

  19. UNCORRECTEDPROOF 1 Toward process-

    E-print Network

    Mudd, Simon Marius

    formation Land forms Modeling Physical weathering Chemical weathering 10 We present a mathematical model in (1) scaling chemical weathering reactions from mineral grains to pedons to soil catenas, 19 (2) understanding the emergence of geochemical soil catenas, and (3) coupling physical and chemical 20 weathering

  20. Physica A 369 (2006) 185200 Statistical physics of active processes in cells

    E-print Network

    Jülicher, Frank

    2006-01-01

    motility, muscle contraction and active processes that take place inside cells such as cell divisionPhysica A 369 (2006) 185­200 Statistical physics of active processes in cells Frank Ju¨ licher Max general physical features of motor proteins that generate forces in the cell cytoskeleton. In integrated

  1. Role of Wavelets in the Physical and Statistical Modelling of Complex Geological Processes

    E-print Network

    Erlebacher, Gordon

    Role of Wavelets in the Physical and Statistical Modelling of Complex Geological Processes D. A wavelets, physical modelling, statistical modelling, geological processes 1 Introduction Today Carolina State University, Raleigh, NC. E-mail: fuentes@stat.ncsu.edu 1 #12;2 D. A. YUEN ET AL. involving

  2. A Library Manager's Guide to the Physical Processing of Nonprint Materials. The Greenwood Library Management Collection.

    ERIC Educational Resources Information Center

    Driessen, Karen C.; Smyth, Shelia A.

    The librarian is presented with a foundation for decision making as it relates to the physical processing of nonprint materials, and with a demonstration of how these decisions move from theoretical to practical physical processing issues. Such issues include packaging and repackaging; treating accompanying materials; labeling; preparing…

  3. Spatial patterns and controls of soil chemical weathering rates along a transient hillslope

    USGS Publications Warehouse

    Yoo, K.; Mudd, S.M.; Sanderman, J.; Amundson, Ronald; Blum, A.

    2009-01-01

    Hillslopes have been intensively studied by both geomorphologists and soil scientists. Whereas geomorphologists have focused on the physical soil production and transport on hillslopes, soil scientists have been concerned with the topographic variation of soil geochemical properties. We combined these differing approaches and quantified soil chemical weathering rates along a grass covered hillslope in Coastal California. The hillslope is comprised of both erosional and depositional sections. In the upper eroding section, soil production is balanced by physical erosion and chemical weathering. The hillslope then transitions to a depositional slope where soil accumulates due to a historical reduction of channel incision at the hillslope's base. Measurements of hillslope morphology and soil thickness were combined with the elemental composition of the soil and saprolite, and interpreted through a process-based model that accounts for both chemical weathering and sediment transport. Chemical weathering of the minerals as they moved downslope via sediment transport imparted spatial variation in the geochemical properties of the soil. Inverse modeling of the field and laboratory data revealed that the long-term soil chemical weathering rates peak at 5 g m- 2 yr- 1 at the downslope end of the eroding section and decrease to 1.5 g m- 2 yr- 1 within the depositional section. In the eroding section, soil chemical weathering rates appear to be primarily controlled by the rate of mineral supply via colluvial input from upslope. In the depositional slope, geochemical equilibrium between soil water and minerals appeared to limit the chemical weathering rate. Soil chemical weathering was responsible for removing 6% of the soil production in the eroding section and 5% of colluvial influx in the depositional slope. These were among the lowest weathering rates reported for actively eroding watersheds, which was attributed to the parent material with low amount of weatherable minerals and intense coating of the primary minerals by secondary clay and iron oxides. We showed that both the morphologic disequilibrium of the hillslope and the spatial heterogeneity of soil properties are due to spatial variations in the physical and chemical processes that removed mass from the soil. ?? 2009 Elsevier B.V.

  4. Weatherization and Intergovernmental Program - Weatherization Assistance Program

    SciTech Connect

    2010-06-01

    The U.S. Department of Energy’s (DOE) Weatherization Assistance Program reduces energy costs for low-income households by increasing the energy efficiency of their homes, while ensuring their health and safety.

  5. Integrating Physical and Chemical Alteration Mechanisms of Soil Formation on Mars from the Mars Exploration Rovers

    NASA Astrophysics Data System (ADS)

    McGlynn, I. O.; McSween, H. Y.; Fedo, C. M.

    2011-03-01

    Models of soil formation by chemical weathering must also incorporate physical processes including impact gardening and aeolian transport to remove and concentrate olivine and explain the compositional scatter of soils along the olivine-feldspar join.

  6. Simulation of Forming Process as an Educational Tool Using Physical Modeling

    ERIC Educational Resources Information Center

    Abdullah, A. B.; Muda, M. R.; Samad, Z.

    2008-01-01

    Metal forming process simulation requires a very high cost including the cost for dies, machine and material and tight process control since the process involve very huge pressure. A physical modeling technique is developed and initiates a new era of educational tool of simulating the process effectively. Several publications and findings have…

  7. Physical processes of quartz amorphization due to friction

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Muto, J.; Nagahama, H.; Miura, T.; Arakawa, I.; Shimizu, I.

    2011-12-01

    Solid state amorphization of minerals occurs in indentations, in shock experiments, and in high pressure metamorphic quartz rock. A production of amorphous material is also reported in experimentally created silicate gouges (Yund et al., 1990), and in San Andreas Fault core samples (Janssen et al., 2010). Rotary-shear friction experiments of quartz rocks imply dynamic weakening at seismic rates (Di Toro et al., 2004). These experiments have suggested that weakening is caused by formation and thixotropic behavior of a silica gel layer which comprises of very fine particles of hydrated amorphous silica on fault gouges (Goldsby & Tullis, 2002; Hayashi & Tsutsumi, 2010). Therefore, physical processes of amorphization are important to better understand weakening of quartz bearing rocks. In this study, we conducted a pin-on-disk friction experiment to investigate details of quartz amorphization (Muto et al, 2007). Disks were made of single crystals of synthetic and Brazilian quartz. The normal load F and sliding velocity V were ranged from 0.01 N to 1 N and from 0.01 m/s to 2.6 m/s, respectively. The friction was conducted using quartz and diamond pins (curvature radii of 0.2 ~ 3 mm) to large displacements (> 1000 m) under controlled atmosphere. We analyzed experiment samples by Raman spectroscopy and FT-IR. Raman spectroscopy (excitation wavelength 532.1 nm) provides lattice vibration modes, and was used to investigate the degree of amorphization of samples. Raman spectra of friction tracks on the disk show clear bands at wavenumbers of 126, 204, 356, 394, and 464 cm-1, characteristic of intact ?-quartz. Remarkably, in experiments using diamond pins (F = 0.8 N, normal stress ?r calculated by contact area = 293 ~ 440 MPa, V = 0.12 ~ 0.23 m/s), the bands at 204 and 464 cm-1 gradually broaden to reveal shoulders on the higher-wavenumber sides of these peaks. Especially, two distinguished peaks at 490 and 515 cm-1 and a weak broad peak at 606 cm-1 appear sporadically on the track after the slip distance of 43 m. The bands at 490 and 606 cm-1 can be assigned to the symmetric stretching of four-membered Si-O ring (D1 band) and planar three-membered Si-O ring (D2 band) in amorphous silica, respectively. The peak at 515 cm-1 corresponds to the strongest coesite A1 mode arising from four-membered Si-O ring structure. On the other hand, the bands at 464 cm-1 broaden to reveal a shoulder adjacent to the main peak in experiments using quartz pins (F = 1 N, ?r = 1 MPa, V = 0.01 ~ 2.6 m/s) after a large displacement (>1000m). These results indicate that quartz change intermediate range structure of SiO2 network during friction, and four or three-membered Si-O rings gradually increase in six-membered quartz. The results of FT-IR analyses on friction tracks showed a broad peak at 3000 -3600 cm-1 which indicates the -OH symmetric stretching band of molecular H2O. It shows that hydration of quartz on friction tracks occur due to friction. The results of Raman spectroscopy and FT-IR imply that Si-O-Si bridging of strained rings preferentially react with water to form hydrated amorphous silica layer on friction surfaces, which is likely to occur weakening.

  8. Effect of Reprocessing and Accelerated Weathering on Impact-Modified Recycled Blend

    NASA Astrophysics Data System (ADS)

    Ramesh, V.; Mohanty, Smita; Biswal, Manoranjan; Nayak, Sanjay K.

    2015-11-01

    Recovery of recycled polycarbonate, acrylonitrile butadiene styrene, high-impact polystyrene, and its blends from waste electrical and electronic equipment plastics products properties were enhanced by the addition of virgin polycarbonate and impact modifier. The optimized blend formulation was processed through five cycles, at processing temperature, 220-240 °C and accelerated weathering up to 700 h. Moreover, the effect of reprocessing and accelerated weathering in the physical properties of the modified blends was investigated by mechanical, thermal, rheological, and morphological studies. The results show that in each reprocessing cycle, the tensile strength and impact strength decreased significantly and the similar behavior has been observed from accelerated weathering. Subsequently, the viscosity decreases and this decrease becomes the effect of thermal and photo-oxidative degradation. This can be correlated with FTIR analysis.

  9. Basalt weathering in an Arctic Mars-analog site

    NASA Astrophysics Data System (ADS)

    Yesavage, Tiffany; Thompson, Aaron; Hausrath, Elisabeth M.; Brantley, Susan L.

    2015-07-01

    The martian surface has undergone chemical and physical weathering in the past, and these processes may continue intermittently today. To explore whether martian rocks are likely to retain features indicative of weathering, we investigated how basaltic material weathers on Earth. Specifically, we investigated weathering of a Quaternary-aged basaltic flow at the Sverrefjell volcano in Svalbard, above the Arctic Circle. This flow weathered since deglaciation under cold, dry (<400 mm/yr) conditions. We analyzed a ?75-cm core of regolith for chemical loss and then characterized the mineralogical and morphological properties using electron microscopy (EM), X-ray diffraction (XRD), infrared (IR) spectroscopy and selective chemical dissolution. In addition, we ran colloidal dispersion, wetting/drying, and freeze/thaw experiments. In the regolith, we observed concentrations of short-range ordered (SRO) phases similar to those observed in warmer, wetter volcanic ash soils. IR and EM analyses of the clay-sized fraction were consistent with allophane as the predominant secondary phase. Selective chemical extractions targeting SRO phases indicated lower Al/Si ratios than those observed in volcanic soils reported in warmer localities, which we attribute to Si-rich allophane and/or abundant Si-rich rock coatings. The oxic circumneutral-pH colloidal dispersion experiments mobilized Al, Fe and Ti primarily as 260-415 nm particles and Ca, Mg and Na as solutes. Si was lost both in the colloidal and dissolved forms. Dispersed colloids likely contain allophane and ferrihydrite. Under anoxic conditions, dissolution of Fe oxide cements also released fines. The experiments help to explain elemental loss from the clay-sized regolith fraction at Svalbard: observed depletions in Ca, K, Mg and Na were likely due to solute loss, while particle-reactive Al, Fe, Si and Ti were mostly retained. Wetting/drying was observed to be as effective as freeze/thaw in driving material loss. It is thus possible that cyclic adsorption of water onto basaltic rocks in this dry climate may result in high physical spalling rates that in turn promote chemical leaching. Many observations at Sverrefjell are similar to inferences from Mars: the presence of SRO phases, Si-rich coatings, and/or Si-rich allophane, as well as the persistence of olivine. Given these similarities, it is inferred that Sverrefjell volcano is a good analog for martian weathering and that other processes operating at Sverrefjell may also have occurred on Mars, including Na leaching, surface spalling, and precipitation of Si-rich layers. Such processes could have occurred on Mars wherever basalts were exposed to water at circumneutral pH for thousands to tens of thousands of years.

  10. The effects of age and physical health on processing speed in HIV.

    PubMed

    Van Dyk, Kathleen; Golub, Sarit A; Porter, James B; Robin, Kevin J; Kowalczyk, William J; Tomassilli, Julia C; Ly, Jenny J; Foldi, Nancy S

    2015-10-01

    The impact of age and physical health on processing speed was investigated in 42 non-demented HIV+ individuals ranging in age from 30 to 75. We used the Medical Outcomes Study-HIV Healthy Survey (MOS-HIV) to measure self-reported physical health, neuropsychological tests to measure psychomotor and cognitive processing speed (Delis-Kaplan Executive Function System Trail Making Test, Grooved Pegboard Test, letter and category fluency), and a test of the foreperiod effect to measure reaction time under increasing attentional load. Results indicated that aging and worse physical health each independently contributed to slowing on different processing speed measures, while the interaction between aging and physical health did not contribute to processing speed. These findings highlight the importance of considering physical health separately from age when measuring cognitive function in HIV+ adults. PMID:26468908

  11. Effect of degree of weathering on dynamic properties of residual soils

    SciTech Connect

    Macari, E.J.; Loyos, L. Jr.

    1996-12-01

    The process of soil formation in the tropics is quite different than that of more temperate regions. The weathering processes tend to be intensified by the warm and humid climates that are prevalent in tropical regions. Chemical weathering processes that dominate in these regions, such as decomposition and dissolution, are fairly well understood phenomena. However, the effect this weathering has on the physical, mechanical, and dynamic properties of the rock/soil is not fully understood. This paper presents some laboratory test results and correlations that indicate behavioral trends to be caused by the effects that weathering has on a residual soil from the western coast of Puerto Rico. The study focuses on the dynamic shear modulus G and material damping ratio D of both natural (undisturbed) and remolded samples, for low- to mid-level amplitudes of vibration. The understanding of these effects will allow for a better prediction of phenomena such as soil amplification that may trigger landslides in such soil formations. This study was accomplished with the aid of a computerized resonant column device. Correlations and empirical formulations are presented that demonstrate the effects that the degree of weathering has on the dynamic properties of these residual soils for undisturbed and remolded samples.

  12. Adaptive, maladaptive, mediational, and bidirectional processes of relational and physical aggression, relational and physical victimization, and peer liking.

    PubMed

    Kawabata, Yoshito; Tseng, Wan-Ling; Crick, Nicki R

    2014-01-01

    A three-wave longitudinal study among ethnically diverse preadolescents (N?=?597 at Time 1, ages 9-11) was conducted to examine adaptive, maladaptive, mediational, and bidirectional processes of relational and physical aggression, victimization, and peer liking indexed by peer acceptance and friendships. A series of nested structural equation models tested the hypothesized links among these peer-domain factors. It was hypothesized that (1) relational aggression trails both adaptive and maladaptive processes, linking to more peer victimization and more peer liking, whereas physical aggression is maladaptive, resulting in more peer victimization and less peer liking; (2) physical and relational victimization is maladaptive, relating to more aggression and less peer liking; (3) peer liking may be the social context that promotes relational aggression (not physical aggression), whereas peer liking may protect against peer victimization, regardless of its type; and (4) peer liking mediates the link between forms of aggression and forms of peer victimization. Results showed that higher levels of peer liking predicted relative increases in relational aggression (not physical aggression), which in turn led to more peer liking. On the other hand, more peer liking was predictive of relative decreases in relational aggression and relational victimization in transition to the next grade (i.e., fifth grade). In addition, relational victimization predicted relative increases in relational aggression and relative decreases in peer liking. Similarly, physical aggression was consistently and concurrently associated more physical victimization and was marginally predictive of relative increases in physical victimization in transition to the next grade. More peer liking predicted relative decreases in physical victimization, which resulted in lower levels of peer liking. The directionality and magnitude of these paths did not differ between boys and girls. PMID:24318459

  13. International Polar Year (IPY) Student Traineeships: Investigation of the impact of western arctic volcanic eruption on weather and climate

    E-print Network

    Moelders, Nicole

    volcanic eruption on weather and climate Nicole Mölders, UA faculty member, PI NOAA Goals: Serve Society. This project is complete. Primary objectives of the project Large volcanic eruptions have been shown to alter large-scale dynamical and physical processes, which impact climate regionally and globally. Alaska has

  14. Time delayed processes in physics, biophysics and archaeology

    E-print Network

    Magdalena Anna Pelc

    2007-05-31

    The motion of particles, where the particles: electrons, ions in microtubules or migrated peoples can be described as the superposition of diffusion and ordered waves. In this paper it is shown that the master equation for transport processes can be formulated as the time delayed hyperbolic partial equation. The equation describes the processes with memory. For characteristic times shorter than the relaxation time the master equation is the generalized Klein - Gordon equation. Key words: hyperbolic transport, microtubules, heat waves, Neolithic migration

  15. Weathering: methods and techniques to measure

    NASA Astrophysics Data System (ADS)

    Lopez-Arce, P.; Zornoza-Indart, A.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    Surface recession takes place when weathered material is removed from the rocks. In order to know how fast does weathering and erosion occur, a review of several methods, analyses and destructive and non-destructive techniques to measure weathering of rocks caused by physico-chemical changes that occur in bedrocks due to salt crystallization, freezing-thaw, thermal shock, influence of water, wind, temperature or any type of environmental agent leading to weathering processes and development of soils, in-situ in the field or through experimental works in the laboratory are addressed. From micro-scale to macro-scale, from the surface down to more in depth, several case studies on in-situ monitoring of quantification of decay on soils and rocks from natural landscapes (mountains, cliffs, caves, etc) or from urban environment (foundations or facades of buildings, retaining walls, etc) or laboratory experimental works, such as artificial accelerated ageing tests (a.a.e.e.) or durability tests -in which one or more than one weathering agents are selected to assess the material behaviour in time and in a cyclic way- performed on specimens of these materials are summarised. Discoloration, structural alteration, precipitation of weathering products (mass transfer), and surface recession (mass loss) are all products of weathering processes. Destructive (SEM-EDX, optical microscopy, mercury intrusion porosimetry, drilling resistance measurement, flexural and compression strength) and Non-destructive (spectrophotocolorimetry, 3D optical surface roughness, Schmidt hammer rebound tester, ultrasound velocity propagation, Nuclear Magnetic Resonance NMR, X ray computed micro-tomography or CT-scan, geo-radar differential global positioning systems) techniques and characterization analyses (e.g. water absorption, permeability, open porosity or porosity accessible to water) to assess their morphological, physico-chemical, mechanical and hydric weathering; consolidation products or methods to stop or to slow down their weathering or durability and stability of soils and rocks are also topics where the methods and techniques deal with the quantification of weathering. Cultural stone weathering studies contribute substantially to the knowledge of weathering rates revealing the importance of specific weathering agents and weathering factors.

  16. Weather and climate

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

  17. Setups for Weathering Tests 

    E-print Network

    Unknown

    2011-08-17

    quickly transform into a raindrop heavy enough to fall to the ground. Texas has a rather extensive weather modifica- tion program. ? The first statewide program, the Colorado River Municipal Water District, is one of the oldest weather modification... programs in the world. Established in 1971 to generate runoff into Lake Thomas and E.V. Spence Reservoir on the Colorado River, this program covers 2.6 million acres between Lubbock and Midland. ? The West Texas Weather Modification Association...

  18. Pilot Weather Advisor System

    NASA Technical Reports Server (NTRS)

    Lindamood, Glenn; Martzaklis, Konstantinos Gus; Hoffler, Keith; Hill, Damon; Mehrotra, Sudhir C.; White, E. Richard; Fisher, Bruce D.; Crabill, Norman L.; Tucholski, Allen D.

    2006-01-01

    The Pilot Weather Advisor (PWA) system is an automated satellite radio-broadcasting system that provides nearly real-time weather data to pilots of aircraft in flight anywhere in the continental United States. The system was designed to enhance safety in two distinct ways: First, the automated receipt of information would relieve the pilot of the time-consuming and distracting task of obtaining weather information via voice communication with ground stations. Second, the presentation of the information would be centered around a map format, thereby making the spatial and temporal relationships in the surrounding weather situation much easier to understand

  19. Weather assessment and forecasting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Data management program activities centered around the analyses of selected far-term Office of Applications (OA) objectives, with the intent of determining if significant data-related problems would be encountered and if so what alternative solutions would be possible. Three far-term (1985 and beyond) OA objectives selected for analyses as having potential significant data problems were large-scale weather forecasting, local weather and severe storms forecasting, and global marine weather forecasting. An overview of general weather forecasting activities and their implications upon the ground based data system is provided. Selected topics were specifically oriented to the use of satellites.

  20. A Model for Formation of Dust, Soil and Rock Coatings on Mars: Physical and Chemical Processes on the Martian Surface

    NASA Technical Reports Server (NTRS)

    Bishop, Janice; Murchie, Scott L.; Pieters, Carle M.; Zent, Aaron P.

    2001-01-01

    This model is one of many possible scenarios to explain the generation of the current surface material on Mars using chemical, magnetic and spectroscopic data From Mars and geologic analogs from terrestrial sites. One basic premise of this model is that the dust/soil units are not derived exclusively from local rocks, but are rather a product of global, and possibly remote, weathering processes. Another assumption in this model is that there are physical and chemical interactions of the atmospheric dust particles and that these two processes create distinctly different results on the surface. Physical processes distribute dust particles on rocks and drift units, forming physically-aggregated layers; these are reversible processes. Chemical reactions of the dust/soil particles create alteration rinds on rock surfaces and cohesive, crusted surface units between rocks, both of which are relatively permanent materials. According to this model the dominant components of the dust/soil particles are derived from alteration of volcanic ash and tephra, and contain primarily nanophase and poorly crystalline ferric oxides/oxyhydroxide phases as well as silicates. These phases are the alteration products that formed in a low moisture environment. These dust/soil particles also contain a smaller amount of material that was exposed to more water and contains crystalline ferric oxides/oxyhydroxides, sulfates and clay silicates. These components could have formed through hydrothermal alteration at steam vents or fumeroles, thermal fluids, or through evaporite deposits. Wet/dry cycling experiments are presented here on mixtures containing poorly crystalline and crystalline ferric oxides/oxyhydroxides, sulfates and silicates that range in size from nanophase to 1-2 pm diameter particles. Cemented products of these soil mixtures are formed in these experiments and variation in the surface texture was observed for samples containing smectites, non-hydrated silicates or sulfates. Reflectance spectra were measured of the initial particulate mixtures, the cemented products and ground versions of the cemented material. The spectral contrast in the visible/near-infrared and mid-infrared regions is significantly reduced for the cemented material compared to the initial soil, and somewhat reduced for the ground, cemented soil compared to the initial soil. The results of this study suggest that diurnal and seasonal cycling on Mars will have a profound effect on the texture and spectral properties of the dust/soil particles on the surface. The model developed in this study provides an explanation for the generation of cemented or crusted soil units and rock coatings on Mars and may explain albedo variations on the surface observed near large rocks or crater rims.

  1. Nuclear Physics Data Relevant to r-Process Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Kratz, K.-L.; Ostrowski, A. N.; Pfeiffer, B.

    2005-05-01

    The production of about half of the heavy elements in nature occurs via the r-process, i.e., a combination of rapid neutron captures, inverse photodisintegrations, and slower ?-decays, ?-delayed processes as well as fission and possibly interactions with neutrino fluxes. A correct understanding and modelling of this nucleosynthesis process requires the knowledge of nuclear properties far from stability and a detailed description of the astrophysical environments. Experiments at radioactive ion beam facilities have played a pioneering role in exploring the characteristics of nuclear structure in terms of masses and ?-decay properties. Initial examinations paid attention to short-lived ``waiting-point'' nuclei with magic neutron numbers related to the location and height of the solar-system r-process abundance peaks, while more recent activities, mainly in the 132Sn region, focus on the evolution of shell effects as a function of isospin. In this context, shape transitions and the erosion of the classical shell gaps with possible occurrence of new magic numbers play an important role. Consequences of improved theoretical and experimental nuclear data on calculations of the r-process matter flow will be presented, and the applicability of the long-lived actinides 232Th and 238U as cosmo-chronometers will be discussed.

  2. Towards a National Space Weather Predictive Capability

    NASA Astrophysics Data System (ADS)

    Fox, N. J.; Lindstrom, K. L.; Ryschkewitsch, M. G.; Anderson, B. J.; Gjerloev, J. W.; Merkin, V. G.; Kelly, M. A.; Miller, E. S.; Sitnov, M. I.; Ukhorskiy, A. Y.; Erlandson, R. E.; Barnes, R. J.; Paxton, L. J.; Sotirelis, T.; Stephens, G.; Comberiate, J.

    2014-12-01

    National needs in the area of space weather informational and predictive tools are growing rapidly. Adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socio-economic losses and impacts on our security. Future space exploration and most modern human endeavors will require major advances in physical understanding and improved transition of space research to operations. At present, only a small fraction of the latest research and development results from NASA, NOAA, NSF and DoD investments are being used to improve space weather forecasting and to develop operational tools. The power of modern research and space weather model development needs to be better utilized to enable comprehensive, timely, and accurate operational space weather tools. The mere production of space weather information is not sufficient to address the needs of those who are affected by space weather. A coordinated effort is required to support research-to-applications transition efforts and to develop the tools required those who rely on this information. In this presentation we will review datasets, tools and models that have resulted from research by scientists at JHU/APL, and examine how they could be applied to support space weather applications in coordination with other community assets and capabilities.

  3. Growing Up Fast: Stress Exposure and Subjective "Weathering" in Emerging Adulthood

    ERIC Educational Resources Information Center

    Foster, Holly; Hagan, John; Brooks-Gunn, Jeanne

    2008-01-01

    We examine "subjective weathering" among females entering adulthood, using three waves of a national study. Subjective weathering is a social psychological component of aging that is associated with "physical weathering" previously observed in research on physical health. We examine the influence of stressors from childhood and adolescence on…

  4. Role of Wavelets in the Physical and Statistical Modelling of Complex Geological Processes

    E-print Network

    Vasilyev, Oleg V.

    Role of Wavelets in the Physical and Statistical Modelling of Complex Geological Processes D. A modelling, statistical modelling, geological processes 1. Introduction Today, there is an ongoing explosion massive amounts of data has precipitated an urgent need for novel tools to process data more efficiently

  5. A Model of the Creative Process Based on Quantum Physics and Vedic Science.

    ERIC Educational Resources Information Center

    Rose, Laura Hall

    1988-01-01

    Using tenets from Vedic science and quantum physics, this model of the creative process suggests that the unified field of creation is pure consciousness, and that the development of the creative process within individuals mirrors the creative process within the universe. Rational and supra-rational creative thinking techniques are also described.…

  6. Perceptual and processing differences between physical and dichorhinic odor mixtures.

    PubMed

    Schütze, M; Negoias, S; Olsson, M J; Hummel, T

    2014-01-31

    Perceptual integration of sensory input from our two nostrils has received little attention in comparison to lateralized inputs for vision and hearing. Here, we investigated whether a binary odor mixture of eugenol and l-carvone (smells of cloves and caraway) would be perceived differently if presented as a mixture in one nostril (physical mixture), vs. the same two odorants in separate nostrils (dichorhinic mixture). In parallel, we investigated whether the different types of presentation resulted in differences in olfactory event-related potentials (OERP). Psychophysical ratings showed that the dichorhinic mixtures were perceived as more intense than the physical mixtures. A tendency for shift in perceived quality was also observed. In line with these perceptual changes, the OERP showed a shift in latencies and amplitudes for early (more "sensory") peaks P1 and N1 whereas no significant differences were observed for the later (more "cognitive") peak P2. The results altogether suggest that the peripheral level is a site of interaction between odorants. Both psychophysical ratings and, for the first time, electrophysiological measurements converge on this conclusion. PMID:24240030

  7. Coupled model of physical and biological processes affecting maize pollination

    NASA Astrophysics Data System (ADS)

    Arritt, R.; Westgate, M.; Riese, J.; Falk, M.; Takle, E.

    2003-04-01

    Controversy over the use of genetically modified (GM) crops has led to increased interest in evaluating and controlling the potential for inadvertent outcrossing in open-pollinated crops such as maize. In response to this problem we have developed a Lagrangian model of pollen dispersion as a component of a coupled end-to-end (anther to ear) physical-biological model of maize pollination. The Lagrangian method is adopted because of its generality and flexibility: first, the method readily accommodates flow fields of arbitrary complexity; second, each element of the material being transported can be identified by its source, time of release, or other properties of interest. The latter allows pollen viability to be estimated as a function of such factors as travel time, temperature, and relative humidity, so that the physical effects of airflow and turbulence on pollen dispersion can be considered together with the biological aspects of pollen release and viability. Predicted dispersion of pollen compares well both to observations and to results from a simpler Gaussian plume model. Ability of the Lagrangian model to handle complex air flows is demonstrated by application to pollen dispersion in the vicinity of an agricultural shelter belt. We also show results indicating that pollen viability can be quantified by an "aging function" that accounts for temperature, humidity, and time of exposure.

  8. Processes in karst systems, physics, chemistry, and geology

    SciTech Connect

    Dreybrodt, W.

    1988-01-01

    Dreybrodt deals quantitatively with many of the chemical and hydrological processes involved in the formation of karst systems. The book is divided into 3 major parts. The first part develops the basic chemical and fluid-flow principles needed in modeling karst systems. The second part investigates the experimental kinetics of calcite dissolution and precipitation and applies the resulting kinetic laws to the modeling of these processes in systems both open and closed to carbon dioxide. The last part of the book includes a qualitative examination of karst systems, quantitative modeling of the development of karst features, and an examination and modeling of the growth of spelotherms in caves.

  9. Process dominance shift in solute chemistry as revealed by long-term high-frequency water chemistry observations of groundwater flowing through weathered argillite underlying a steep forested hillslope

    NASA Astrophysics Data System (ADS)

    Kim, Hyojin; Bishop, James K. B.; Dietrich, William E.; Fung, Inez Y.

    2014-09-01

    Significant solute flux from the weathered bedrock zone - which underlies soils and saprolite - has been suggested by many studies. However, controlling processes for the hydrochemistry dynamics in this zone are poorly understood. This work reports the first results from a four-year (2009-2012) high-frequency (1-3 day) monitoring of major solutes (Ca, Mg, Na, K and Si) in the perched, dynamic groundwater in a 4000 m2 zero-order basin located at the Angelo Coast Range Reserve, Northern California. Groundwater samples were autonomously collected at three wells (downslope, mid-slope, and upslope) aligned with the axis of the drainage. Rain and throughfall samples, profiles of well headspace pCO2, vertical profiles and time series of groundwater temperature, and contemporaneous data from an extensive hydrologic and climate sensor network provided the framework for data analysis. All runoff at this soil-mantled site occurs by vertical unsaturated flow through a 5-25 m thick weathered argillite and then by lateral flows to the adjacent channel as groundwater perched over fresher bedrock. Driven by strongly seasonal rainfall, over each of the four years of observations, the hydrochemistry of the groundwater at each well repeats an annual cycle, which can be explained by two end-member processes. The first end-member process, which dominates during the winter high-flow season in mid- and upslope areas, is CO2 enhanced cation exchange reaction in the vadose zone in the more shallow conductive weathered bedrock. This process rapidly increases the cation concentrations of the infiltrated rainwater, which is responsible for the lowest cation concentration of groundwater. The second-end member process occurs in the deeper perched groundwater and either dominates year-round (at the downslope well) or becomes progressively dominant during low flow season at the two upper slope wells. This process is the equilibrium reaction with minerals such as calcite and clay minerals, but not with primary minerals, suggesting the critical role of the residence time of the water. Collectively, our measurements reveal that the hydrochemistry dynamics of the groundwater in the weathered bedrock zone is governed by two end-member processes whose dominance varies with critical zone structure, the relative importance of vadose versus groundwater zone processes, and thus with the seasonal variation of the chemistry of recharge and runoff.

  10. Reviews Book: Marie Curie and Her Daughters Resource: Cumulus Equipment: Alpha Particle Scattering Apparatus Equipment: 3D Magnetic Tube Equipment: National Grid Transmission Model Book: Einstein's Physics Equipment: Barton's Pendulums Equipment: Weather Station Web Watch

    NASA Astrophysics Data System (ADS)

    2013-09-01

    WE RECOMMEND Marie Curie and Her Daughters An insightful study of a resilient and ingenious family and their achievements Cumulus Simple to install and operate and with obvious teaching applications, this weather station 'donationware' is as easy to recommend as it is to use Alpha Particle Scattering Apparatus Good design and construction make for good results National Grid Transmission Model Despite its expense, this resource offers excellent value Einstein's Physics A vivid, accurate, compelling and rigorous treatment, but requiring an investment of time and thought WORTH A LOOK 3D Magnetic Tube Magnetic fields in three dimensions at a low cost Barton's Pendulums A neat, well-made and handy variant, but not a replacement for the more traditional version Weather Station Though not as robust or substantial as hoped for, this can be put to good use with the right software WEB WATCH An online experiment and worksheet are useful for teaching motor efficiency, a glance at CERN, and NASA's interesting information on the alpha-magnetic spectrometer and climate change

  11. Speaking and Speaking Education as Physical Process in Turkish Education

    ERIC Educational Resources Information Center

    Kurudayioglu, Mehmet

    2011-01-01

    Speaking is sending the message which is desired to be transferred to another one with vocal organs and produced by complicated operations in the brain. Speaking, which is a complicated process, is the most common and important means of communication among people. Speaking, which has essential place both individually and socially, affects success…

  12. Processing and physical properties of chia-oat hydrocolloids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chia-oat dry blended composites and their processed hydrocolloids containing omega-3 and omega-6 fatty acids from chia along with soluble ß-glucan from three oat products were developed and studied. Chia’s omega-3 fatty acids and soluble ß-glucan from oat products are recognized for preventing heart...

  13. The weathering of stones due to dissolution

    NASA Astrophysics Data System (ADS)

    Hoke, G.; Turcotte, D.

    2003-04-01

    We hypothesize that the weathering of building stones can be attributed to surface dissolution processes. We assume that chemical interactions occur on grain boundaries and that diffusion is the controlling process. A dissolution boundary layer (rind) develops adjacent to the weathering surface. We quantify the extent of dissolution by introducing a damage variable f, f = 0 for pristine rock, and when f = f0 the rock disintegrates. We assume that the variations of the damage variable are given by the diffusion equation. We solve two problems. The first is for the structure of the transient dissolution boundary layer prior to surface disintegration. We find an incubation time ti before active weathering (disintegration) begins. The second is the solution for steady state weathering with a constant weathering velocity vw. Our results are entirely consistent with weathering studies on Carrera marble gravestones in the United Kingdom. Typical incubation times are 20--30 yr and typical steady-state weathering velocities 5--10 ?m yr-1.

  14. Weather and emotional state

    NASA Astrophysics Data System (ADS)

    Spasova, Z.

    2010-09-01

    Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions, while those who are emotionally unstable have a stronger dependence to the impacts of the weather.

  15. Dynamics and materials physics of fault rupture and glacial processes

    NASA Astrophysics Data System (ADS)

    Platt, John Daniel

    This thesis focuses on two main topics, the physics governing how faults rapidly weaken during an earthquake and the thermal and mechanical structure of ice stream shear margins. The common theme linking these two projects is the desire to understand how the complicated interactions between stress and temperature control deformation and failure. All of the problems in this thesis are attacked using a combination of analytic and numerical methods, and the interplay between these two approaches provides a powerful way to understand the different physical balances that dominate in different regimes. We also use aspects of materials science to understand how the often complicated rheologies are controlled by underlying physical phenomena such as melting, phase transitions, diffusion, and dislocation motion. With regards to fault mechanics, we begin by showing how co-seismic weakening mechanisms driven by elevated pore fluid pressures lead to micron-scale strain localization during an earthquake. We solve for the localized zone thickness for a range of fault temperatures, test these predictions using numerical simulations, and show how the onset of localization accelerates fault weakening. Next we present the first solutions to account for thermal decomposition reactions during a dynamic rupture, showing that the activation of thermal decomposition may lead to a larger slip duration and total slip. Finally we present a new set of experiments studying flash heating of serpentinite, highlighting the dependence of friction on normal stress and the presence of gouge, and producing the first model to explain the hysteresis commonly observed in flash heating experiments. With regards to ice stream shear margins, we begin by extending the work of Perol and Rice [2011] to study the formation of temperate ice in shear margins, and quantify the total melt that may be generated within the shear margins. We conclude by investigating how the presence of such a channel alters the stress on and strength of the undeforming bed in the shear margin, showing that the transition from a deforming to an undeforming bed across a channel is stable when the water flux in the channel exceeds a critical value.

  16. 2007 Weather and Aeolian Sand-Transport Data from the Colorado River Corridor, Grand Canyon, Arizona

    USGS Publications Warehouse

    Draut, Amy E.; Andrews, Timothy; Fairley, Helen C.; Brown, Christopher R.

    2009-01-01

    Weather data constitute an integral part of ecosystem monitoring in the Colorado River corridor and are particularly valuable for understanding processes of landscape change that contribute to the stability of archeological sites. Data collected in 2007 are reported from nine weather stations in the Colorado River corridor through Grand Canyon, Ariz. The stations were deployed in February and March 2007 to measure wind speed and direction, rainfall, air temperature, relative humidity, and barometric pressure. Sand traps near each weather station collect windblown sand, from which daily aeolian sand-transport rates are calculated. The data reported here were collected as part of an ongoing study to test and evaluate methods for quantifying processes that affect the physical integrity of archeological sites along the river corridor; as such, these data can be used to identify rainfall events capable of causing gully incision and to predict likely transport pathways for aeolian sand, two landscape processes integral to the preservation of archeological sites. Weather data also have widespread applications to other studies of physical, cultural, and biological resources in Grand Canyon. Aeolian sand-transport data reported here, collected in the year before the March 2008 High-Flow Experiment (HFE) at Glen Canyon Dam, represent baseline data against which the effects of the 2008 HFE on windblown sand will be compared in future reports.

  17. Relativity Based on Physical Processes Rather Than Space-Time

    NASA Astrophysics Data System (ADS)

    Giese, Albrecht

    2013-09-01

    Physicists' understanding of relativity and the way it is handled is at present dominated by the interpretation of Albert Einstein, who related relativity to specific properties of space and time. The principal alternative to Einstein's interpretation is based on a concept proposed by Hendrik A. Lorentz, which uses knowledge of classical physics to explain relativistic phenomena. In this paper, we will show that on the one hand the Lorentz-based interpretation provides a simpler mathematical way of arriving at the known results for both Special and General Relativity. On the other hand, it is able to solve problems which have remained open to this day. Furthermore, a particle model will be presented, based on Lorentzian relativity, which explains the origin of mass without the use of the Higgs mechanism, based on the finiteness of the speed of light, and which provides the classical results for particle properties that are currently only accessible through quantum mechanics.

  18. Physical Education Resources, Class Management, and Student Physical Activity Levels: A Structure-Process-Outcome Approach to Evaluating Physical Education Effectiveness

    PubMed Central

    Bevans, Katherine B.; Fitzpatrick, Leslie-Anne; Sanchez, Betty M.; Riley, Anne W.; Forrest, Christopher

    2011-01-01

    BACKGROUND This study was conducted to empirically evaluate specific human, curricular, and material resources that maximize student opportunities for physical activity during physical education (PE) class time. A structure-process-outcome model was proposed to identify the resources that influence the frequency of PE and intensity of physical activity during PE. The proportion of class time devoted to management was evaluated as a potential mediator of the relations between resource availability and student activity levels. METHODS Data for this cross-sectional study were collected from interviews conducted with 46 physical educators and the systematic observation of 184 PE sessions in 34 schools. Regression analyses were conducted to test for the main effects of resource availability and the mediating role of class management. RESULTS Students who attended schools with a low student-to-physical educator ratio had more PE time and engaged in higher levels of physical activity during class time. Access to adequate PE equipment and facilities was positively associated with student activity levels. The availability of a greater number of physical educators per student was found to impact student activity levels by reducing the amount of session time devoted to class management. CONCLUSION The identification of structure and process predictors of student activity levels in PE will support the allocation of resources and encourage instructional practices that best support increased student activity levels in the most cost-effective way possible. Implications for PE policies and programs are discussed. PMID:21087253

  19. Applications of the First Law to Ecological Systems. Physical Processes in Terrestrial and Aquatic Ecosystems, Thermodynamics.

    ERIC Educational Resources Information Center

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This report describes concepts presented in another module called "The First Law of…

  20. The First Law of Thermodynamics for Ecosystems. Physical Processes in Terrestrial and Aquatic Ecosystems, Thermodynamics.

    ERIC Educational Resources Information Center

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module and a comparison module are concerned with elementary concepts of thermodynamics as…

  1. Calculus - Differentiation. Physical Processes in Terrestrial and Aquatic Ecosystems, Applied Mathematics.

    ERIC Educational Resources Information Center

    Hertzberg, Richard C.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module is used to introduce the biology student to differential calculus, a…

  2. Weather and Culture.

    ERIC Educational Resources Information Center

    Contemporary Learning Center, Houston, TX.

    This document is a minicourse on the interaction of weather, environment, and culture. It is designed for the high school student to read and self-administer. Performance objectives, enabling activities, and postassessment questions are given for each of eight modules. The modules are: (1) Basic Facts About Your Weather Known As Rain, (2) The…

  3. Designing a Weather Station

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  4. Tracking Weather Satellites.

    ERIC Educational Resources Information Center

    Martin, Helen E.

    1996-01-01

    Describes the use of weather satellites in providing an exciting, cohesive framework for students learning Earth and space science and in providing a hands-on approach to technology in the classroom. Discusses the history of weather satellites and classroom satellite tracking. (JRH)

  5. Weathering Database Technology

    ERIC Educational Resources Information Center

    Snyder, Robert

    2005-01-01

    Collecting weather data is a traditional part of a meteorology unit at the middle level. However, making connections between the data and weather conditions can be a challenge. One way to make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which…

  6. Weather Cardboard Carpentry

    ERIC Educational Resources Information Center

    DeBruin, Jerome E.

    1977-01-01

    Included are instructions and diagrams for building weather instruments (wind vane, Celsius temperature scale, and anemometer) from simple tools and Tri-Wall, a triple-thick corrugated cardboard. Ordering sources for Tri-Wall are listed. Additional weather instruments that can be constructed are suggested. (CS)

  7. Weathering warming in Colorado

    SciTech Connect

    Gillis, A.M.

    1996-03-01

    This article describes the results of a field experiment heating patches of a subalpine meadow in the Rocky Mountains to determine what will weather and what will weather under projected global warming. The problems with actually measuring the feedback is discussed, along with the changes which come as the meadow is heated.

  8. People and Weather.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Provides: (1) background information on ways weather influences human lives; (2) activities related to this topic; and (3) a ready-to-copy page with weather trivia. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

  9. Teacher's Weather Sourcebook.

    ERIC Educational Resources Information Center

    Konvicka, Tom

    This book is a teaching resource for the study of weather-related phenomena. A "weather unit" is often incorporated into school study because of its importance to our daily lives and because of its potential to cut across disciplinary content. This book consists of two parts. Part I covers the major topics of atmospheric science such as the modern…

  10. Mild and Wild Weather.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Presents background information and six activities that focus on clouds, precipitation, and stormy weather. Each activity includes an objective, recommended age level(s), subject area(s), and instructional strategies. Also provided are two ready-to-copy pages (a coloring page on lightning and a list of weather riddles to solve). (JN)

  11. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  12. Weather Fundamentals: Wind. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

  13. Exercising in Cold Weather

    MedlinePLUS

    ... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

  14. On Observing the Weather

    ERIC Educational Resources Information Center

    Crane, Peter

    2004-01-01

    Rain, sun, snow, sleet, wind... the weather affects everyone in some way every day, and observing weather is a terrific activity to attune children to the natural world. It is also a great way for children to practice skills in gathering and recording information and to learn how to use simple tools in a standardized fashion. What better way to…

  15. Fabulous Weather Day

    ERIC Educational Resources Information Center

    Marshall, Candice; Mogil, H. Michael

    2007-01-01

    Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

  16. Weatherizing a Structure.

    ERIC Educational Resources Information Center

    Metz, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with weatherizing a structure. Its objective is for the student to be able to analyze factors related to specific structures that indicate need for weatherizing activities and to determine steps to correct defects in structures that…

  17. Weather in stellar atmosphere revealed by the dynamics of mercury clouds in

    E-print Network

    Loss, Daniel

    LETTERS Weather in stellar atmosphere revealed by the dynamics of mercury clouds in Andromedae , and may have the same underlying physics as the weather patterns on terrestrial and giant planets. Since

  18. Highlights of Space Weather Services/Capabilities at NASA/GSFC Space Weather Center

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Zheng, Yihua; Hesse, Michael; Kuznetsova, Maria; Pulkkinen, Antti; Taktakishvili, Aleksandre; Mays, Leila; Chulaki, Anna; Lee, Hyesook

    2012-01-01

    The importance of space weather has been recognized world-wide. Our society depends increasingly on technological infrastructure, including the power grid as well as satellites used for communication and navigation. Such technologies, however, are vulnerable to space weather effects caused by the Sun's variability. NASA GSFC's Space Weather Center (SWC) (http://science.gsfc.nasa.gov//674/swx services/swx services.html) has developed space weather products/capabilities/services that not only respond to NASA's needs but also address broader interests by leveraging the latest scientific research results and state-of-the-art models hosted at the Community Coordinated Modeling Center (CCMC: http://ccmc.gsfc.nasa.gov). By combining forefront space weather science and models, employing an innovative and configurable dissemination system (iSWA.gsfc.nasa.gov), taking advantage of scientific expertise both in-house and from the broader community as well as fostering and actively participating in multilateral collaborations both nationally and internationally, NASA/GSFC space weather Center, as a sibling organization to CCMC, is poised to address NASA's space weather needs (and needs of various partners) and to help enhancing space weather forecasting capabilities collaboratively. With a large number of state-of-the-art physics-based models running in real-time covering the whole space weather domain, it offers predictive capabilities and a comprehensive view of space weather events throughout the solar system. In this paper, we will provide some highlights of our service products/capabilities. In particular, we will take the 23 January and the 27 January space weather events as examples to illustrate how we can use the iSWA system to track them in the interplanetary space and forecast their impacts.

  19. A Analysis of the Development of Weather Concepts

    NASA Astrophysics Data System (ADS)

    Mroz, Paul John

    Weather information in all forms is poorly understood and often misinterpreted by the general public. Weather literacy is necessary for everyone if critical weather messages, designed to save lives and protect property, are to be effective. The purpose of this study was to seek content and causal evidence for a developmental concept of Weather Information Processing that was consistent with Piagetian Cognitive Stages of Development. Three ordinal Content Stages Of Weather Information Processing (phenomena, process and mechanism) and three ordinal Causal Explanation Stages Of Weather Information Processing (non-real, natural, and scientifically valid abstract ideas) were explored for their relationship with Piaget's Pre-Operational, Concrete and Formal Stages of Development. One hundred and fifty -five elementary and secondary school students from two school districts were administered a written Piagetian exam. Commonly available television weather programs were categorized, randomly assigned and viewed by 42 randomly selected students who were administered three Piagetian tasks. Students were clinically interviewed for the level of content information and causal explanations (reasoning). Results indicated that content information and causal reasoning of students to televised weather information is significantly related (p <.01) to age, and Piagetian Cognitive Stages of Development. Two Piagetian logic operations (seriation and correlation) were established as significantly different (p <.05) when related to age. These findings support a developmental concept of Weather Information Processing and have implications for teaching and presenting weather information to the public.

  20. Physical-chemical treatment of tar-sand processing wastewater

    SciTech Connect

    King, P.H.

    1982-07-01

    This final report for Phase I summarizes work done to determine the ability of several coagulants to contribute significantly in the treatment of selected tar sand wastewaters. The coagulation process must be considered as one possible step in a treatment scheme to reduce pollutants in these wastewaters and lead to a water quality acceptable for reuse or disposal. Two wastewaters were provided by the Laramie Energy Technology Center (LETC). The primary emphasis in this study was focused on a representative steam flooding wastewater designated in the report as TARSAND 1S. The coagulation study in which treatment of this wastewater was the prime goal is described in full detail in the thesis entitled Chemical Coagulation of Steam Flooding Tar Sand Wastewaters. This thesis, written by Mr. Omar Akad, is included as Appendix A in this report. A representative combustion wastewater, designated as TARSAND 2C, was also provided by LETC. This wastewater was characteristically low in suspended solids and after initial screening experiments were conducted, it was concluded that coagulation was relatively ineffective in the treatment of TARSAND 2C. Hence, efforts were concentrated on the parametric evaluation of coagulation of TARSAND 1S. The objectives for the research conducted under Phase I were: (1) to compare the effectiveness of lime, alum, ferric chloride and representative synthetic organic polymers in reducing suspended solids and total organic carbon (TOC) from TARSAND 1S wastewater; (2) to determine the effects of pH, coagulant aids, and mixing conditions on the coagulation process; (3) to determine the relative volume of sludge produced from each selected coagulation process.

  1. Removing Weather Effects from Monochrome Images Srinivasa G. Narasimhan and Shree K. Nayar

    E-print Network

    Narasimhan, Srinivasa G.

    Removing Weather Effects from Monochrome Images Srinivasa G. Narasimhan and Shree K. Nayar}@cs.columbia.edu Abstract Images of outdoor scenes captured in bad weather suffer from poor contrast. Under bad weather space invariant image processing techniques are not sufficient to remove weather effects from images

  2. Phytoplankton photoadaptation related to some frontal physical processes

    NASA Astrophysics Data System (ADS)

    Claustre, H.; Kerhervé, P.; Marty, J.-C.; Prieur, L.

    1994-08-01

    Using phytoplankton pigments as biomarkers, we studied light adaptation of phytoplankton communities in a geostrophic front and the surrounding area by (i) onboard kinetic experiments and (ii) detailed analyses of the vertical profiles of a selected photoadaptive index. Kinetic experiments, in which populations were subjected to a sudden light shift (from high to low irradiances and vice versa), clearly demonstrated that frontal phytoplankton populations, especially diatoms (fucoxanthin) are less affected by light shifts than the populations of the adjacent oligotrophic zones. Kinetic experiments also showed that the ratio diadinoxanthin/Chl. a, positively correlated with light intensity, is a useful index to characterize and identify certain time scales of photoadaptation in microalgae. The rate of change of this index was estimated around 0.5 h -1, with significantly higher values for the frontal communities compared to the adjacent area. The rate of variation of this ratio, deduced from in situ measurements, is however one order of magnitude lower than the rate obtained from kinetic experiments. These two approaches allowed us (i) to compare different populations and (ii) to define an upper limit of the adaptation rates. Typical in situ profiles of the diadinoxanthin/Chl. a ratio showed obvious day-night variations. Relative anomalies in these profiles were interpretated in terms of "light histories" of phytoplankton communities and compared with potential causal physical motions (diffusion or advection).

  3. Solar and Space Physics PhD Production and Job Availability: Implications for the Future of the Space Weather Research Workforce

    NASA Astrophysics Data System (ADS)

    Moldwin, M.; Morrow, C. A.; Moldwin, L. A.; Torrence, J.

    2012-12-01

    To assess the state-of-health of the field of Solar and Space Physics an analysis of the number of Ph.D.s produced and number of Job Postings each year was done for the decade 2001-2010. To determine the number of Ph.D's produced in the field, the University of Michigan Ph.D. Dissertation Archive (Proquest) was queried for Solar and Space Physics dissertations produced in North America. The field generated about 30 Ph.D. per year from 2001 to 2006, but then saw the number increase to 50 to 70 per year for the rest of the decade. Only 14 institutions account for the majority of Solar and Space Physics PhDs. To estimate the number of jobs available each year in the field, a compilation of the job advertisements listed in the American Astronomical Society's Solar Physics Division (SPD) and the American Geophysical Union's Space Physics and Aeronomy (SPA) electronic newsletters was done. The positions were sorted into four types (Faculty, Post-doctoral Researcher, and Scientist/Researcher or Staff), institution type (academic, government lab, or industry) and if the position was located inside or outside the United States. Overall worldwide, 943 Solar and Space Physics positions were advertised over the decade. Of this total, 52% were for positions outside the US. Within Solar Physics, 44% of the positions were in the US, while in Space Physics 57% of the positions were for US institutions. The annual average for positions in the US were 26.9 for Solar Physics and 31.5 for Space Physics though there is much variability year-to-year particularly in Solar Physics positions outside the US. A disconcerting trend is a decline in job advertisements in the last two years for Solar Physics positions and between 2009 and 2010 for Space Physics positions. For both communities within the US in 2010, the total job ads reached their lowest levels in the decade (14), approximately half the decadal average number of job advertisements.

  4. Weather based risks and insurances for crop production in Belgium

    NASA Astrophysics Data System (ADS)

    Gobin, Anne

    2014-05-01

    Extreme weather events such as late frosts, droughts, heat waves and rain storms can have devastating effects on cropping systems. Damages due to extreme events are strongly dependent on crop type, crop stage, soil type and soil conditions. The perspective of rising risk-exposure is exacerbated further by limited aid received for agricultural damage, an overall reduction of direct income support to farmers and projected intensification of weather extremes with climate change. According to both the agriculture and finance sectors, a risk assessment of extreme weather events and their impact on cropping systems is needed. The impact of extreme weather events particularly during the sensitive periods of the farming calendar requires a modelling approach to capture the mixture of non-linear interactions between the crop, its environment and the occurrence of the meteorological event. The risk of soil moisture deficit increases towards harvesting, such that drought stress occurs in spring and summer. Conversely, waterlogging occurs mostly during early spring and autumn. Risks of temperature stress appear during winter and spring for chilling and during summer for heat. Since crop development is driven by thermal time and photoperiod, the regional crop model REGCROP (Gobin, 2010) enabled to examine the likely frequency, magnitude and impacts of frost, drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages. The risk profiles were subsequently confronted with yields, yield losses and insurance claims for different crops. Physically based crop models such as REGCROP assist in understanding the links between different factors causing crop damage as demonstrated for cropping systems in Belgium. Extreme weather events have already precipitated contraction of insurance coverage in some markets (e.g. hail insurance), and the process can be expected to continue if the losses or damages from such events increase in the future. Climate change will stress this further and impacts on crop growth are expected to be twofold, owing to the sensitive stages occurring earlier during the growing season and to the changes in return period of extreme weather events. Though average yields have risen continuously due to technological advances, there is no evidence that relative tolerance to adverse weather events has improved. The research is funded by the Belgian Science Policy Organisation (Belspo) under contract nr SD/RI/03A.

  5. Processing of speech signals for physical and sensory disabilities.

    PubMed Central

    Levitt, H

    1995-01-01

    Assistive technology involving voice communication is used primarily by people who are deaf, hard of hearing, or who have speech and/or language disabilities. It is also used to a lesser extent by people with visual or motor disabilities. A very wide range of devices has been developed for people with hearing loss. These devices can be categorized not only by the modality of stimulation [i.e., auditory, visual, tactile, or direct electrical stimulation of the auditory nerve (auditory-neural)] but also in terms of the degree of speech processing that is used. At least four such categories can be distinguished: assistive devices (a) that are not designed specifically for speech, (b) that take the average characteristics of speech into account, (c) that process articulatory or phonetic characteristics of speech, and (d) that embody some degree of automatic speech recognition. Assistive devices for people with speech and/or language disabilities typically involve some form of speech synthesis or symbol generation for severe forms of language disability. Speech synthesis is also used in text-to-speech systems for sightless persons. Other applications of assistive technology involving voice communication include voice control of wheelchairs and other devices for people with mobility disabilities. Images Fig. 4 PMID:7479816

  6. Physical Processes for Driving Ionospheric Outflows in Global Simulations

    NASA Technical Reports Server (NTRS)

    Moore, Thomas Earle; Strangeway, Robert J.

    2009-01-01

    We review and assess the importance of processes thought to drive ionospheric outflows, linking them as appropriate to the solar wind and interplanetary magnetic field, and to the spatial and temporal distribution of their magnetospheric internal responses. These begin with the diffuse effects of photoionization and thermal equilibrium of the ionospheric topside, enhancing Jeans' escape, with ambipolar diffusion and acceleration. Auroral outflows begin with dayside reconnexion and resultant field-aligned currents and driven convection. These produce plasmaspheric plumes, collisional heating and wave-particle interactions, centrifugal acceleration, and auroral acceleration by parallel electric fields, including enhanced ambipolar fields from electron heating by precipitating particles. Observations and simulations show that solar wind energy dissipation into the atmosphere is concentrated by the geomagnetic field into auroral regions with an amplification factor of 10-100, enhancing heavy species plasma and gas escape from gravity, and providing more current carrying capacity. Internal plasmas thus enable electromagnetic driving via coupling to the plasma, neutral gas and by extension, the entire body " We assess the Importance of each of these processes in terms of local escape flux production as well as global outflow, and suggest methods for their implementation within multispecies global simulation codes. We complete 'he survey with an assessment of outstanding obstacles to this objective.

  7. Winter Weather Frequently Asked Questions

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Weather Information on Specific Types of Emergencies Winter Weather Frequently Asked Questions Language: English Español (Spanish) Recommend ...

  8. Food Safety for Warmer Weather

    MedlinePLUS

    ... Fight Off Food Poisoning Food Safety for Warmer Weather In warm-weather months, who doesn’t love to get outside ... to keep foods safe to eat during warmer weather. If you’re eating or preparing foods outside, ...

  9. Environmental Education Tips: Weather Activities.

    ERIC Educational Resources Information Center

    Brainard, Audrey H.

    1989-01-01

    Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

  10. Alternative Processes for Water Reclamation and Solid Waste Processing in a Physical/chemical Bioregenerative Life Support System

    NASA Technical Reports Server (NTRS)

    Rogers, Tom D.

    1990-01-01

    Viewgraphs on alternative processes for water reclamation and solid waste processing in a physical/chemical-bioregenerative life support system are presented. The main objective is to focus attention on emerging influences of secondary factors (i.e., waste composition, type and level of chemical contaminants, and effects of microorganisms, primarily bacteria) and to constructively address these issues by discussing approaches which attack them in a direct manner.

  11. Introduction of a pyramid guiding process for general musculoskeletal physical rehabilitation.

    PubMed

    Stark, Timothy W

    2006-01-01

    Successful instruction of a complicated subject as Physical Rehabilitation demands organization. To understand principles and processes of such a field demands a hierarchy of steps to achieve the intended outcome. This paper is intended to be an introduction to a proposed pyramid scheme of general physical rehabilitation principles. The purpose of the pyramid scheme is to allow for a greater understanding for the student and patient. As the respected Food Guide Pyramid accomplishes, the student will further appreciate and apply supported physical rehabilitation principles and the patient will understand that there is a progressive method to their functional healing process. PMID:16759396

  12. Coupling chemical weathering with soil production across soil-mantled landscapes

    USGS Publications Warehouse

    Burke, B.C.; Heimsath, A.M.; White, A.F.

    2007-01-01

    Soil-covered upland landscapes constitute a critical part of the habitable world. Our understanding of how they evolve as a function of different climatic, tectonic and geological regimes is important across a wide range of disciplines and depends, in part, on understanding the links between chemical and physical weathering processes. Extensive previous work has shown that soil production rates decrease with increasing soil column thickness, but chemical weathering rates were not measured. Here we examine a granitic, soil-mantled hillslope at Point Reyes, California, where soil production rates were determined using in situ produced cosmogenic nuclides (10Be and 26Al), and we quantify the extent as well as the rates of chemical weathering of the saprolite from beneath soil from across the landscape. We collected saprolite samples from the base of soil pits and analysed them for abrasion pH as well as for major and trace elements by X-ray fluorescence spectroscopy, and for clay mineralogy by X-ray diffraction spectroscopy. Our results show for the first time that chemical weathering rates decrease with increasing soil thickness and account for 13 to 51 per cent of total denudation. We also show that spatial variation in chemical weathering appears to be topographically controlled: weathering rate decreases with slope across the divergent ridge and increases with upslope contributing area in the convergent swale. Furthermore, to determine the best measure for the extent of saprolite weathering, we compared four different chemical weathering indices - the Vogt ratio, the chemical index of alteration (CIA), Parker's index, and the silicon-aluminium ratio - with saprolite pH. Measurements of the CIA were the most closely correlated with saprolite pH, showing that weathering intensity decreases linearly with an increase in saprolite pH from 4.7 to almost 7. Data presented here are among the first to couple directly rates of soil production and chemical weathering with how topography is likely to control weathering at a hillslope scale. Copyright ?? 2006 John Wiley & Sons, Ltd.

  13. Searching for deep understanding : implementing a mechanical engineering design process in K9-K12 physics classrooms to identify and improve levels of physics intuition and content

    E-print Network

    Williams, John Alejandro

    2010-01-01

    This experiment tested the level of Physics content knowledge of various K9-K12 Physics students in a local Boston high school by having them implement a mechanical engineering design process to solve open-ended design ...

  14. Educating Emergency Managers About Weather -Related Hazards

    NASA Astrophysics Data System (ADS)

    Spangler, T. C.; Johnson, V.

    2006-12-01

    The most common crises that emergency managers face are those related to hazardous weather - snowstorms, floods, hurricanes, heat waves, tornadoes, etc. However, man-made disasters, such as accidental releases of hazardous substances or terrorist acts, also often have a weather component. For example, after the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, emergency managers were concerned that thunderstorms in the area might cause the building to collapse, putting rescuers in further danger. Training emergency managers to recognize the importance of weather in disaster planning and response has been a small but important focus of the COMET Program's educational development effort. Topics addressed in COMET training modules that are pertinent to emergency management include fire weather, hurricanes, flood events, and air contaminant dispersion. Additionally, the module entitled Anticipating Hazardous Weather and Community Risk provides an overview of basic meteorological processes, describes a broad range of weather phenomenon, and then addresses what forecast products are available to emergency managers to assess a threat to their community. In many of the modules, learners are presented with scenarios that give them the opportunity to practice decision-making in hazardous weather situations. We will demonstrate some of those scenarios and discuss how training can be used to model good emergency management skills. We will discuss ways to communicate with the emergency management community and provide examples of how distance learning can be used to educate and train emergency managers.

  15. Weathering Grade Classification of Granite Stone Monument Using Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hyun, C.; Roh, T.; Choi, M.; Park, H.

    2009-05-01

    Stone monument has been placed in field and exposed to rain and wind. This outdoor environment and air pollution induced weathering of stone monument. Weathering grade classification is necessary to manage and conserve stone monuments. Visual interpretation by geologist and laboratory experiments using specimens fallen off from the monument to avoid damage on the monument have been applied to classify weathering grade conventionally. Rocks and minerals absorb some particular wavelength ranges of electromagnetic energy by electronic process and vibrational process of composing elements and these phenomena produce intrinsic diagnostic spectral reflectance curve. Non-destructive technique for weathering degree assessment measures those diagnostic absorption features of weathering products and converts the depths of features related to abundance of the materials to relative weathering degree. We selected granite outcrop to apply conventional six folded weathering grade classification method using Schmidt hammer rebound teste. The correlations between Schmidt hammer rebound values and absorption depths of iron oxides such as ferric oxide in the vicinity of 0.9 micrometer wavelength and clay minerals such as illite and kaolinite in the vicinity of 2.2 micrometer wavelength, representative weathering products of granite, were analyzed. The Schmidt hammer rebound value decreased according to increase of absorption depths induced from those weathering products. Weathering grade classification on the granite stone monument was conducted by using absorption depths of weathering products This research is supported from National Research Institute of Cultural Heritage and we appreciate for this.

  16. Solar structure and terrestrial weather

    NASA Technical Reports Server (NTRS)

    Wilcox, J. M.

    1976-01-01

    The possibility that solar activity has discernible effects on terrestrial weather is considered. Research involving correlation of weather conditions with solar and geomagnetic activity is discussed.

  17. Coal weathering studies

    SciTech Connect

    Alvarez, R.; Barriocanal, C.; Casal, M.D.; Diez, M.A.; Gonzalez, A.I.; Pis, J.J.; Canga, C.S.

    1996-12-31

    Weathering studies were carried out on coal/blend piles stored in the open yard at the INCAR facilities. Firstly, a typical and complex coal blend used by the Spanish Steel Company, ENSIDESA, prepared and ground at industrial scale, was stored. Several methods have been applied for detecting weathering in coals, Gieseler maximum fluidity being the most sensitive indicator of the loss of thermoplastic properties. Carbonization tests were carried out in a semi-industrial and a movable-wall ovens available at the INCAR Coking Test Plant. In addition to the measurements of internal gas pressure and cooling pressure, laboratory tests to measure expansion/contraction behavior of coals were performed. There is a clear decrease in internal gas pressure with weathering, measured in the semi-industrial oven. A decrease in wall pressure after two months of weathering followed by a period of stabilization lasting practically ten months were observed. As regards coke quality, no significant changes were produced over a storing period of ten months, but after this date impairment was observed. The behavior of selected individual coals stored without grinding, which are components of the blend, was rather different. Some coals showed a maximum wall pressure through the weathering period. Coke quality improved with some coals and was impaired with others due to weathering. It should be pointed out that slight weathering improved coke quality not only in high-volatile and fluid coals but also in medium-volatile coals.

  18. Application of green IT for physics data processing at INCDTIM

    NASA Astrophysics Data System (ADS)

    Farcas, Felix; Trusca, Radu; Albert, Stefan; Szabo, Izabella; Popeneciu, Gabriel

    2012-02-01

    Green IT is the next generation technology used in all datacenter around the world. Its benefit is of economic and financial interest. The new technologies are energy efficient, reduce cost and avoid potential disruptions to the existing infrastructure. The most important problem appears at the cooling systems which are the most important in the functionality of a datacenter. Green IT used in Grid Network will benefit the environment and is the next phase in computer infrastructure that will fundamentally change the way we think about and use computing power. At the National Institute for Research and Development of Isotopic and Molecular Technologies Cluj-Napoca (INCDTIM) we have implemented such kind of technology and its support helped us in processing multiple data in different domains, which brought INCDTIM on the major Grid domain with the RO-14-ITIM Grid site. In this paper we present benefits that the new technology brought us and the result obtained in the last year after the implementation of the new green technology.

  19. Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Seal, R.R., II; Meier, A.L.; Jackson, J.C.

    2003-01-01

    Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

  20. Modeling High-Impact Weather and Climate: Lessons From a Tropical Cyclone Perspective

    SciTech Connect

    Done, James; Holland, Greg; Bruyere, Cindy; Leung, Lai-Yung R.; Suzuki-Parker, Asuka

    2012-06-01

    Although the societal impact of a weather event increases with the rarity of the event, our current ability to assess extreme events and their impacts is limited by not only rarity but also by current model fidelity and a lack of understanding of the underlying physical processes. This challenge is driving fresh approaches to assess high-impact weather and climate. Recent lessons learned in modeling high-impact weather and climate are presented using the case of tropical cyclones as an illustrative example. Through examples using the Nested Regional Climate Model to dynamically downscale large-scale climate data the need to treat bias in the driving data is illustrated. Domain size, location, and resolution are also shown to be critical and should be guided by the need to: include relevant regional climate physical processes; resolve key impact parameters; and to accurately simulate the response to changes in external forcing. The notion of sufficient model resolution is introduced together with the added value in combining dynamical and statistical assessments to fill out the parent distribution of high-impact parameters. Finally, through the example of a tropical cyclone damage index, direct impact assessments are presented as powerful tools that distill complex datasets into concise statements on likely impact, and as highly effective communication devices. Capsule: "Combining dynamical modeling of high-impact weather using traditional regional climate models with statistical techniques allows for comprehensive sampling of the full distribution, uncertainty estimation, direct assessment of impacts, and increased confidence in future changes."

  1. Effect of weathering on mobilization of biochar particles and bacterial removal in a stormwater biofilter.

    PubMed

    Mohanty, Sanjay K; Boehm, Alexandria B

    2015-11-15

    To improve bacterial removal, a traditional stormwater biofilter can be augmented with biochar, but it is unknown whether bacterial removal remains consistent as the biochar weathers during intermittent exposure to stormwater under dry-wet and freeze-thaw cycles. To examine the effect of weathering on bacterial removal capacity of biochar, we subjected biochar-augmented sand filters (or simplified biofilters) to multiple freeze-thaw or dry-wet cycles for a month and then compared their bacterial removal capacity with the removal capacity of unweathered biofilters. To isolate the effect of physical and chemical weathering processes from that of biological processes, the biofilters were operated without any developed biofilm. Biochar particles were mobilized during intermittent infiltration of stormwater, but the mobilization depended on temperature and antecedent conditions. During stormwater infiltration without intermediate drying, exposure to natural organic matter (NOM) in the stormwater decreased the bacterial removal capacity of biochar, partly due to exhaustion of attachment sites by NOM adsorption. In contrast, exposure to the same amount of NOM during stormwater infiltration with intermediate drying resulted in higher bacterial removal. This result suggests that dry-wet cycles may enhance recovery of the previously exhausted attachment sites, possibly due to diffusion of NOM from biochar surfaces into intraparticle pores during intermediate drying periods. Overall, these results indicate that physical weathering has net positive effect on bacterial removal by biochar-augmented biofilters. PMID:26320722

  2. Understanding the Interplay Between Neighborhood Structural Factors, Social Processes, and Alcohol Outlets on Child Physical Abuse.

    PubMed

    Freisthler, Bridget; Maguire-Jack, Kathryn

    2015-11-01

    This article seeks to understand the relative influence of neighborhood structural characteristics (e.g., disadvantage) and social processes (e.g., interactions between residents) on child physical abuse. Using multilevel modeling in a sample of 3,023 parents in 194 zip codes, structural characteristics of factor scores representing residential stability and foreign-born Latino males were negatively related to child physical abuse. High proportions of naturalized and Asian/Pacific Islander families were positively related to the frequency of physical abuse. Higher levels of neighborhood social disorder were related to more frequent physical abuse, while higher levels of collective efficacy were related to less frequent physical abuse. Programs designed to alleviate disorder and increase neighborly interactions may be effective at reducing physical abuse. By understanding the relative importance of the demographic characteristics of neighborhoods and the actions and interactions of residents within the neighborhoods, policy and practice can be tailored more effectively to prevent maltreatment. PMID:26251328

  3. Combined physical and biogeochemical processes control the mobility of arsenic in rivers of the Atacama desert, Northern Chile

    NASA Astrophysics Data System (ADS)

    Packman, A.; Gaillard, J.; Pasten, P.; Pizarro, G.; Alsina, M.; Vega, A.; Florenzano, A.; MacDonald, L.; Chen, C.

    2008-12-01

    Many watersheds are contaminated by arsenic (As) derived from natural weathering of earth-surface minerals. Some of the highest naturally occurring As concentrations in surface waters occur in the Atacama desert, Chile. Arsenic enters the Rio Loa and Rio Lluta watersheds from hydrothermal sources in the high Altiplano, producing substantial dissolved and particulate-phase As throughout both river systems. Further, occasional floods related to the ENSO cycle have produced substantial pulses of sediment-laden, As-rich water. Nonetheless, water scarcity in this extremely arid region causes the resident population to rely on these river systems for water supply, and this has historically led to substantial public health effects from chronic As exposure. Despite the scientific and practical significance of As in the rivers of northern Chile, little information is available on the processes that control As dynamics in these systems. Recently we have investigated the distribution and speciation of As in the Rio Loa and Rio Lluta river networks using a variety of new measurement methodologies in an attempt to understand how the interplay of physical and biogeochemical processes regulates As migration through these systems. The unusual chemistry associated with these volcanic, hyper-arid watersheds appears to make As more mobile in these systems than in other types of As-contaminated rivers, favoring rapid remobilization during high-flow events. Further, As transport is largely conservative under low-flow conditions, and its concentration is primarily regulated by dilution from uncontaminated sources and concentration due to the very high rates of evaporation that occur during downstream transport.

  4. Executive Functions in Learning Processes: Do They Benefit from Physical Activity?

    ERIC Educational Resources Information Center

    Barenberg, Jonathan; Berse, Timo; Dutke, Stephan

    2011-01-01

    As executive functions play an essential role in learning processes, approaches capable of enhancing executive functioning are of particular interest to educational psychology. Recently, the hypothesis has been advanced that executive functioning may benefit from changes in neurobiological processes induced by physical activity. The present…

  5. Overland erosion of uranium-mill-tailings impoundments: physical processes and computational methods

    SciTech Connect

    Walters, M.H.

    1983-03-01

    The surface runoff and erosional processes of watersheds caused by rainfall-runoff are reviewed. Soil properties, topography, and rainstorm distribution are discussed with respect to their effects on soil erosion. The effects of climate and vegetation are briefly presented. Regression models and physical process simulation models are reviewed.

  6. Physical Review Letters (at press) Edge-mediated dislocation processes in carbon nano-onions?

    E-print Network

    Dumitrica,Traian

    Physical Review Letters (at press) Edge-mediated dislocation processes in carbon nano-onions? E graphite [7] accommodated in an icosahedral nano-onion. In the planar case, Fig. 1(a), the disloca- tion and rationalize dislocation processes in nano-onions. Our experiments were conducted inside a high reso- lution

  7. Improved gas metal arc welding multi-physics process model and

    E-print Network

    Grujicic, Mica

    Improved gas metal arc welding multi-physics process model and its application to MIL A46100 armor-grade steel butt-welds M. Grujicic, J.S. Snipes, R. Galgalikar, S. Ramaswami and R. Yavari Department for the conventional gas metal arc welding (GMAW) joining process has been improved with respect to its predictive

  8. Physical processes involved in strip electrode welding using the method of slatted splicing

    SciTech Connect

    Bushma, V. O.

    2010-12-15

    Physical processes that take place in a strip electrode during welding using the slatted splicing technique are considered. Flowing of the welding current in the electrode is shown to be the key process which determines electrode heating and melting. Technological receipts are proposed that allow obtaining high-quality welds by the method of slatted splicing.

  9. Mathematical modeling of physical processes in inorganic chemistry

    SciTech Connect

    Chiu, H.L.

    1988-01-01

    The first part deals with the rapid calculation of steady-state concentration profiles in contactors using the Purex Process. Most of the computer codes simulating the reprocessing of spent nuclear fuel generate the steady-state properties by calculating the transient behavior of the contactors. In this study, the author simulates the steady-state concentration profiles directly without first generating the transient behavior. Two computer codes are developed, PUMA (Plutonium-Uranium-Matrix-Algorithm) and PUNE (Plutonium-Uranium-Non-Equilibrium). The first one simulates the steady-state concentration profiles under conditions of equilibrium mass transfer. The second one accounts for deviations from mass transfer equilibrium. The second part of this dissertation shows how to use the classical trajectory method to study the equilibrium and saddle-point geometries of MX{sub n} (n = 2-7) molecules. Two nuclear potential functions that have the property of invariance to the operations of the permutation group of nuclei in molecules of the general formula MX{sub n} are described. Such potential functions allow equivalent isomers to have equal energies so that various statistical mechanical properties can be simply determined. The first function contains two center interactions between pairs of peripheral atoms and its defined by V(r) = 1/2{Sigma}{sub {alpha}}k{triangle}r{sub {alpha}{mu}}{sup 2} + {Sigma}{sub {alpha}< {beta}} QR{sub {alpha}{beta}}{sup {minus}n} (n = 1,2...). The second function contains two and three center interactions and is defined by V({Theta}) = 1/2{Sigma}{sub {alpha}}K{triangle}{sub {alpha}{mu}}{sup 2} + 1/2{Sigma}{sub {alpha}<{beta}}Qr{sub 0}{sup 2} ({Theta}{sub {alpha}{mu}{beta}} - {pi}){sup 2}.

  10. Take a Tumble: Weathering and Erosion Using a Rock Tumbler

    ERIC Educational Resources Information Center

    Coffey, Patrick; Mattox, Steve

    2006-01-01

    Weathering--the physical and chemical breakdown of geologic materials--and erosion--the transport of materials by wind, water, or ice--can be subtle, yet powerful forces. For example, shale, a rock made of mud-sized particles, is by far the most common sedimentary rock, a testament to the ability of weathering and erosion to take a rock and reduce…

  11. Statistics-related and reliability-physics-related failure processes in electronics devices and products

    NASA Astrophysics Data System (ADS)

    Suhir, E.

    2014-05-01

    The well known and widely used experimental reliability "passport" of a mass manufactured electronic or a photonic product — the bathtub curve — reflects the combined contribution of the statistics-related and reliability-physics (physics-of-failure)-related processes. When time progresses, the first process results in a decreasing failure rate, while the second process associated with the material aging and degradation leads to an increased failure rate. An attempt has been made in this analysis to assess the level of the reliability physics-related aging process from the available bathtub curve (diagram). It is assumed that the products of interest underwent the burn-in testing and therefore the obtained bathtub curve does not contain the infant mortality portion. It has been also assumed that the two random processes in question are statistically independent, and that the failure rate of the physical process can be obtained by deducting the theoretically assessed statistical failure rate from the bathtub curve ordinates. In the carried out numerical example, the Raleigh distribution for the statistical failure rate was used, for the sake of a relatively simple illustration. The developed methodology can be used in reliability physics evaluations, when there is a need to better understand the roles of the statistics-related and reliability-physics-related irreversible random processes in reliability evaluations. The future work should include investigations on how powerful and flexible methods and approaches of the statistical mechanics can be effectively employed, in addition to reliability physics techniques, to model the operational reliability of electronic and photonic products.

  12. Scheme of splitting with respect to physical processes for a model of heat and moisture transfer

    NASA Astrophysics Data System (ADS)

    Amirkhanov, I. V.; Pavluš, M.; Puzynina, T. P.; Puzynin, I. V.; Sarhadov, I.; Vabishchevich, P. N.

    2015-05-01

    A difference scheme of splitting with respect to physical processes for a model of heat and moisture transfer is proposed. The model involves three physical processes—heat, liquid and saturated vapor transfer in the porous material. The density of saturated vapor and the transfer coefficients of liquid and vapor moistures depend on the temperature. At the same time, the heat capacity and conductivity of the porous material depend on moisture. On the basis of the proposed scheme of the model, a numerical simulation of the heat and moisture transfer for a drying process has been performed.

  13. Lithium isotope history of Cenozoic seawater: changes in silicate weathering and reverse weathering.

    PubMed

    Misra, Sambuddha; Froelich, Philip N

    2012-02-17

    Weathering of uplifted continental rocks consumes carbon dioxide and transports cations to the oceans, thereby playing a critical role in controlling both seawater chemistry and climate. However, there are few archives of seawater chemical change that reveal shifts in global tectonic forces connecting Earth ocean-climate processes. We present a 68-million-year record of lithium isotopes in seawater (?(7)Li(SW)) reconstructed from planktonic foraminifera. From the Paleocene (60 million years ago) to the present, ?(7)Li(SW) rose by 9 per mil (‰), requiring large changes in continental weathering and seafloor reverse weathering that are consistent with increased tectonic uplift, more rapid continental denudation, increasingly incongruent continental weathering (lower chemical weathering intensity), and more rapid CO(2) drawdown. A 5‰ drop in ?(7)Li(SW) across the Cretaceous-Paleogene boundary cannot be produced by an impactor or by Deccan trap volcanism, suggesting large-scale continental denudation. PMID:22282473

  14. Operational Space Weather in USAF Education

    NASA Astrophysics Data System (ADS)

    Smithtro, C.; Quigley, S.

    2006-12-01

    Most education programs offering space weather courses are understandably and traditionally heavily weighted with theoretical space physics that is the basis for most of what is researched and modeled. While understanding the theory is a good and necessary grounding for anyone working the field of space weather, few military or commercial jobs employ such theory in real-time operations. The operations sites/centers are much more geared toward use of applied theory-resultant models, tools and products. To ensure its operations centers personnel, commanders, real-time system operators and other customers affected by the space environment are educated on available and soon-to-be operational space weather models and products, the USAF has developed applicable course/lecture material taught at various institutions to include the Air Force Institute of Technology (AFIT) and the Joint Weather Training Complex (335th/TRS/OUA). Less frequent training of operational space weather is available via other venues that will be discussed, and associated course material is also being developed for potential use at the National Security Space Institute (NSSI). This presentation provides an overview of the programs, locations, courses and material developed and/or taught by or for USAF personnel dealing with operational space weather. It also provides general information on student research project results that may be used in operational support, along with observations regarding logistical and professional benefits of teaching such non-theoretical/non-traditional material.

  15. Physical Processes in the Vicinity of a Supermassive Black Hole

    NASA Astrophysics Data System (ADS)

    Do, Tuan

    2010-08-01

    The Galactic center offers us an opportunity to study the environment around a supermassive black hole at a level of detail not possible in other galactic nuclei. This potential has been greatly expanded by the implementation of laser guide star adaptive optics and integral field spectroscopy on large ground-based telescopes. This thesis takes advantage of these technologies to address the nature of the variable near-infrared emission from the black hole as well as test theories of the equilibrium configuration of a star cluster with a supermassive black hole at its center. First, we present the results of near-infrared (2 and 3 micron) monitoring of Sgr A*-IR with 1 min time sampling. Sgr A*-IR was observed continuously for up to three hours on each of seven nights, between 2005 July and 2007 August. Sgr A*-IR is detectable at all times and is continuously variable, with a median observed 2 micron flux density of 0.192 mJy, corresponding to 16.3 magnitude at K^'. These observations allow us to investigate Nyquist sampled periods ranging from about 2 minutes to an hour. Using Monte Carlo simulations, we find that the variability of Sgr A* in this data set is consistent with models based on correlated noise with power spectra having frequency dependent power law slopes between 2.0 to 3.0, consistent with those reported for AGN light curves. Of particular interest are periods of ˜ 20 min, corresponding to a quasi-periodic signal claimed based upon previous near-infrared observations and interpreted as the orbit of a `hot spot' at or near the last stable orbit of a spinning black hole. We find no significant periodicity at any time scale probed in these new observations for periodic signals. This study is sensitive to periodic signals with amplitudes greater than 20% of the maximum amplitude of the underlying red noise component for light curves with duration greater than ˜ 2 hours at a 98% confidence limit. Second, we report on the structure of the nuclear star cluster in the innermost 0.16 pc of the Galaxy as measured by the number density profile of late-type giants. Using laser guide star adaptive optics in conjunction with the integral field spectrograph, OSIRIS, at the Keck II telescope, we are able to differentiate between the older, late-type (˜ 1 Gyr) stars, which are presumed to be dynamically relaxed, and the unrelaxed young (˜ 6 Myr) population. This distinction is crucial for testing models of stellar cusp formation in the vicinity of a black hole, as the models assume that the cusp stars are in dynamical equilibrium in the black hole potential. In the survey region, we classified 77 stars as early-type 79 stars as late-type. We find that contamination from young stars is significant, with more than twice as many young stars as old stars in our sensitivity range (K' < 15.5) within the central arcsecond. Based on the late-type stars alone, the surface stellar number density profile, ?(R) ? R(-?) , is flat, with ? = -0.26±0.24. Monte Carlo simulations of the possible de-projected volume density profile, n(r) ? r^{-?}, show that ? is less than 1.0 at the 99.7 % confidence level. These results are consistent with the nuclear star cluster having no cusp, with a core profile that is significantly flatter than predicted by most cusp formation theories, and even allows for the presence of a central hole in the stellar distribution. Of the possible dynamical interactions that can lead to the depletion of the red giants observable in this survey - stellar collisions, mass segregation from stellar remnants, or a recent merger event - mass segregation is the only one that can be ruled out as the dominant depletion mechanism. The degeneracy in the true distribution of stars cannot be broken with number counts alone, but we show how the addition of kinematic measurements can remov! e the degeneracy. Resolving the physical origin of the lack of a stellar cusp will have important implications for black hole growth models and inferences on the presence of a black hole based upon stellar distributions.

  16. NOAA's National Weather Service Building a Weather-Ready Nation

    E-print Network

    NOAA's National Weather Service Building a Weather-Ready Nation For more information, please visit: www.noaa.gov and www.nws.noaa.gov NOAA's National Weather Service (NWS) is the Nation's official source for weather and water data, forecasts, and warnings. From information accessed on your smartphone

  17. PREFACE: First International Workshop on Nonequilibrium Processes in Plasma Physics and Studies of Environment

    NASA Astrophysics Data System (ADS)

    Petrovi?, Z. Lj; Malovi?, G.; Tasi?, M.; Nikitovi?, Ž.

    2007-06-01

    This volume is a collection of papers associated with a series of invited lectures presented at the First Workshop on Nonequilibrium processes in Plasma Physics and studies of Environment that was held at Mt Kopaonik in August 2006. The workshop originated as a part of the FP6 COE 026328 which had the basic aim of promoting centers of excellence in Western Balkan countries, to facilitate dissemination of their results and to help them establish themselves in the broader arena of European and international science. So the best way to achieve all those goals was to prepare a workshop associated with the local conference SPIG (Symposium on Physics of Ionized Gases) where the participants could attend sessions in which the host Laboratory presented progress reports and papers and thereby gain a full perspective of our results. At the same time this allowed participants in the COE the opportunity to compare their results with the results of external speakers and to gain new perspectives and knowledge. The program of the workshop was augmented by inviting some of our colleagues who visited the COE in recent years or have an active collaboration with a participating member. In that respect this volume is not only a proceedings of the workshop but a collection of papers related to the topic of the workshop: Non-equilibrium phenomena in plasmas and in the science of our environment. The idea is to offer review articles either summarizing a broader area of published or about to be published work or to give overviews showing preliminary results of the works in progress. The refereeing of the papers consisted of two parts, first in selection of the invitees and second in checking the submitted manuscripts. The papers were refereed to the standard of the Journal. As the program of the COE covers a wide area of topics from application of plasmas in nano- electronics to monitoring and removal of pollutants in the atmosphere, so the program of the workshop covered an even broader range of topics with the common thread of non- equilibrium phenomena playing a major part in the basic physics and also in the technological applications. The universal symbol of non-equilibrium phenomena is Maxwell's demon and it was selected, as designed by Professor Rastko ?iri? (of Belgrade's University for Fine Arts), to be the symbol of the conference. In plasma physics, the field is usually divided between equilibrium and non-equilibrium plasmas. The advantage of studying plasmas in thermal equilibrium is that they may be described by universal laws, such as Saha and Boltzmann equations. The only problem is that, apart from the very early stages in the development of the universe, such plasmas do not exist, although there are plasmas that come very close and at least satisfy the thermal laws locally. Non-equilibrium plasmas have laws unique to each situation and studies of their idiosyncrasies continue to provide a lot of food for thought for scientists, possibilities for applications and job opportunities. Or as Tolstoy wrote, `Happy families are all alike; every unhappy family is unhappy in its own way?'. So, while making analogy of the non-equilibrium with the lack of happiness may sound discouraging, the scientists who try to observe these phenomena (like psychologists in the case of families) have plenty to study and are, therefore, likely to be happy. At the same time non-equilibrium phenomena in plasmas and in the atmosphere are extremely important. A fact we should be aware of every time we use an integrated circuit manufactured after the late 1970s or whenever weather changes, wind blows and pollution is carried in from some distant locations. This volume starts with a paper by D Batani (Milano, Italy) on shock waves, an example of plasmas that may be locally thermal but display very strong gradients, M Pinheiro (Lisboa, Portugal) contributed an article on anomalous diffusion in magnetized plasmas, a problem that has been addressed in the literature from many different standpoints. A special case of non-equilibrium is that of non-neutral plasm

  18. Weathering of Martian Evaporites

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

    2001-01-01

    Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

  19. Cold Weather Pet Safety

    MedlinePLUS

    ... as huskies and other dogs bred for colder climates, are more tolerant of cold weather; but no ... the winter to generate enough body heat and energy to keep them warm – talk to your veterinarian ...

  20. Interpreting Weather Maps.

    ERIC Educational Resources Information Center

    Smith, P. Sean; Ford, Brent A.

    1994-01-01

    Presents a brief introduction of our atmosphere, a guide to reading and interpreting weather maps, and a set of activities to facilitate teachers in helping to enhance student understanding of the Earth's atmosphere. (ZWH)

  1. Neighborhood Weatherization, Houston 

    E-print Network

    Fowler, M.

    2011-01-01

    . Referrals http://www.click2houston.com/video/24501979/index.html 2010 CLEAResult. All rights reserved. Milestone Celebration 2010 CLEAResult. All rights reserved. 10,000 Homes Weatherized 2010 CLEAResult. All rights reserved. CATEE...

  2. Process monitoring using automatic physical measurement based on electrical and physical variability analysis

    NASA Astrophysics Data System (ADS)

    Shauly, Eitan N.; Levi, Shimon; Schwarzband, Ishai; Adan, Ofer; Latinsky, Sergey

    2015-04-01

    A fully automated silicon-based methodology for systematic analysis of electrical features is shown. The system was developed for process monitoring and electrical variability reduction. A mapping step was created by dedicated structures such as static-random-access-memory (SRAM) array or standard cell library, or by using a simple design rule checking run-set. The resulting database was then used as an input for choosing locations for critical dimension scanning electron microscope images and for specific layout parameter extraction then was input to SPICE compact modeling simulation. Based on the experimental data, we identified two items that must be checked and monitored using the method described here: transistor's sensitivity to the distance between the poly end cap and edge of active area (AA) due to AA rounding, and SRAM leakage due to a too close N-well to P-well. Based on this example, for process monitoring and variability analyses, we extensively used this method to analyze transistor gates having different shapes. In addition, analysis for a large area of high density standard cell library was done. Another set of monitoring focused on a high density SRAM array is also presented. These examples provided information on the poly and AA layers, using transistor parameters such as leakage current and drive current. We successfully define "robust" and "less-robust" transistor configurations included in the library and identified unsymmetrical transistors in the SRAM bit-cells. These data were compared to data extracted from the same devices at the end of the line. Another set of analyses was done to samples after Cu M1 etch. Process monitoring information on M1 enclosed contact was extracted based on contact resistance as a feedback. Guidelines for the optimal M1 space for different layout configurations were also extracted. All these data showed the successful in-field implementation of our methodology as a useful process monitoring method.

  3. Summary of the NASA/MSFC FY-79 Severe Storm and Local Weather research review. [cloud physics, atmospheric electricity, and mesoscale/storm dynamics reserach

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Significant acomplishments, current focus of work, plans for FY-80, and recommendations for new research are outlined for 36 research projects proposed for technical monitoring by the Atmospheric Sciences Division at Marshall Space Flight Center. Topics of the investigations, which were reviewed at a two-day meeting, relate to cloud physics, atmospheric electricity, and mesoscale/storm dynamics.

  4. Effect of weathering transformations of coal combustion residuals on trace element mobility in view of the environmental safety and sustainability of their disposal and use. I. Hydrogeochemical processes controlling pH and phase stability.

    PubMed

    Stefaniak, Sebastian; Miszczak, Ewa; Szczepa?ska-Plewa, Jadwiga; Twardowska, Irena

    2015-06-01

    Coal combustion residuals (CCRs) are one of the most abundant high-volume waste materials disposed in impoundments worldwide. Some methods of CCR recycling, e.g. their use as structural fill for low lying areas or as soil amendment, also expose this material to atmospheric conditions. Combustion processes result in concentration of trace elements in CCRs at about an order of magnitude compared to coal. In order to assess an effect of long-term weathering transformations of CCRs on trace element binding/release, a study has been carried out. It is based on the chemical composition of real pore solutions extracted from the most abundant primary alkaline Class F bituminous CCRs, 0 to >40 years old, sampled from the surface layer and vertical profiles at four different impoundments. In this part of the study, results of a hydrogeochemical simulation of the saturation state of real pore solutions with respect to mineral phases of CCRs with use of the PHREEQC program, related to actual pH values reflecting the full cycle of weathering transformations, have been discussed. This study is the first geochemical proof of the general trend towards a progressive acidification up to pH < 4 of primary alkaline CCRs due to release of protons during internal processes of formation of gibbsite and aluminosilicate minerals, buffered by carbonates at the alkaline - near-neutral stages, and followed by parallel dissolution and buffering by aluminosilicates at pH < 7 after carbonate depletion, to the level up to pH?3.5-4.0. The intrinsic geochemical changes have resulted in the different susceptibility of trace elements to release and associated changes in risk to the environment at consecutive stages of weathering. PMID:25841194

  5. Seafloor weathering buffering climate: numerical experiments

    NASA Astrophysics Data System (ADS)

    Farahat, N. X.; Archer, D. E.; Abbot, D. S.

    2013-12-01

    Continental silicate weathering is widely held to consume atmospheric CO2 at a rate controlled in part by temperature, resulting in a climate-weathering feedback [Walker et al., 1981]. It has been suggested that weathering of oceanic crust of warm mid-ocean ridge flanks also has a CO2 uptake rate that is controlled by climate [Sleep and Zahnle, 2001; Brady and Gislason, 1997]. Although this effect might not be significant on present-day Earth [Caldeira, 1995], seafloor weathering may be more pronounced during snowball states [Le Hir et al., 2008], during the Archean when seafloor spreading rates were faster [Sleep and Zahnle, 2001], and on waterworld planets [Abbot et al., 2012]. Previous studies of seafloor weathering have made significant contributions using qualitative, generally one-box, models, and the logical next step is to extend this work using a spatially resolved model. For example, experiments demonstrate that seafloor weathering reactions are temperature dependent, but it is not clear whether the deep ocean temperature affects the temperature at which the reactions occur, or if instead this temperature is set only by geothermal processes. Our goal is to develop a 2-D numerical model that can simulate hydrothermal circulation and resulting alteration of oceanic basalts, and can therefore address such questions. A model of diffusive and convective heat transfer in fluid-saturated porous media simulates hydrothermal circulation through porous oceanic basalt. Unsteady natural convection is solved for using a Darcy model of porous media flow that has been extensively benchmarked. Background hydrothermal circulation is coupled to mineral reaction kinetics of basaltic alteration and hydrothermal mineral precipitation. In order to quantify seafloor weathering as a climate-weathering feedback process, this model focuses on hydrothermal reactions that influence carbon uptake as well as ocean alkalinity: silicate rock dissolution, calcium and magnesium leaching reactions, carbonate precipitation, and clay formation.

  6. Cockpit weather information system

    NASA Technical Reports Server (NTRS)

    Tu, Jeffrey Chen-Yu (Inventor)

    2000-01-01

    Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

  7. Sediment and process water characterization in support of 300 Area North Process Pond physical soil washing test

    SciTech Connect

    Field, J.G.

    1994-02-18

    The sediments in the 300 Area North Process Pond are being considered for clean-up using soil washing processes. Prior to site clean-up several preliminary pilot-scale physical washing campaigns were performed by Westinghouse Hanford Company (WHC) staff in the summer of 1993. WHC used equipment that was obtained from the US Environmental Protection Agency. Specific details are found in the 300-FF-1 Physical Separations CERCLA Treatability Test Plan. Physical soil washing includes separation and proper containment of the contaminant-rich fines and residual liquid effluent and release of the coarse ``clean`` fraction, should it meet minimum performance levels for residual contaminant concentration to the site being cleaned. A goal of the demonstration is to concentrate the contaminants into {le}10% of the soil volume excavated and, therefore, to release {ge}90% of the soil back to the site as clean soil. To support interpretation of the WHC soil washing treatability study, PNL performed some sediment and process water characterization on samples taken during three major and one small campaign. This report documents particle-size distributions in various field washed piles, and chemical and gama emitting radionuclide contents as a function of particle-size distribution for the field washed sediments and contents in the spent process water. All of the particle fractions were separated by wet sieving, but two field samples were also subjected to dry sieving and attrition scrubbing followed by wet sieving.

  8. Perspectives of weather and sensitivities to heat: Social media applications for cultural climatology

    NASA Astrophysics Data System (ADS)

    Austin, Bradley J.

    This dissertation explores the cultural significance and physical perception of heat evident in a corpus of Twitter messages collected for six cities across the US over a seven-week period following historic heat events in the summer of 2012. Through a mixed-methods analysis of what weather means and how it feels, emergent conceptual tools are put forth that seek to envisage weather and society as co-productive, and sometimes indistinguishable, elements in a broader ecological process of world formation. Following a review of concepts from literature on everyday interactions with weather, the dissertation proceeds with two analytical chapters. The first analysis is textual and focuses on 'weather typing' as a discursive practice that works to produce abstract spaces with, of, and for weather through the conceptual distancing of the environment from the body. These practices are considered constitutive of situated perspectives of weather, many of which show a latent influence of heat, be it in the form of shared bodily energy or as an ambient environmental factor. The second analysis quantitatively explores emotional and physiological sensitivities to heat through transforming textual indicators into metrics that can be meaningfully tracked over time alongside biometeorological constructs, particularly with apparent temperature. Each analysis is intended to open the study of weather to multiple lines of inquiry across different scales while remaining rooted in empirical observation. The conclusion of the dissertation is left open as a discussion on further uses of these concepts and analytical strategies in hopes that they may find uses in different contexts, with different data sources, and through a variety of theoretical lenses.

  9. Comparison of characteristics of aerosol during rainy weather and cold air-dust weather in Guangzhou in late March 2012

    NASA Astrophysics Data System (ADS)

    Chen, Huizhong; Wu, Dui; Yu, Jianzhen

    2015-03-01

    Using the data on aerosol observed hourly by Marga ADI 2080 and Grimm 180, we compared the characteristics of aerosol during rainy weather and cold air-dust weather in Guangzhou in late March 2012. The mass concentration of aerosol appeared distinct between the two weather processes. During rainy weather, the mass concentration of PM and total water-soluble components decreased obviously. During cold air-dust weather, the cleaning effect of cold air occurred much more suddenly and about a half day earlier than the dust effect. As a result, the mass concentration of PM and total water-soluble components first dropped dramatically to a below-normal level and then rose gradually to an above-normal level. The ratio of PM2.5/PM10 and PM1/PM10 decreased, suggesting that dust-storm weather mainly brought in coarse particles. The proportion of Ca2+ in the total water-soluble components significantly increased to as high as 50 % because of the effect of dust weather. We further analysed the ionic equilibrium during rainy and cold air-dust weather, and compared it with that during hazy weather during the same period. The aerosol during rainy weather was slightly acidic, whereas that during hazy weather and cold air-dust weather was obviously alkaline, with that during cold air-dust weather being significantly more alkaline. Most of the anions, including SO4 2- and NO3 -, were neutralised by NH4 + during rainy and hazy weather, and by Ca2+ during cold air-dust weather.

  10. Physical abrasion of mafic minerals and basalt grains: application to Martian aeolian deposits

    USGS Publications Warehouse

    Cornwall, Carin; Bandfield, Joshua L.; Titus, Timothy N.; Schreiber, B. C.; Montgomery, D.R.

    2015-01-01

    Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. Mature terrestrial sands are dominated by quartz, which is abundant in source lithologies on Earth and is physically and chemically stable under a wide range of conditions. Immature sands, such as those rich in feldspars or mafic minerals, are composed of grains that are easily physically weathered and highly susceptible to chemical weathering. On Mars, which is predominately mafic in composition, terrestrial standards of sediment maturity are not applicable. In addition, the martian climate today is cold, dry and sediments are likely to be heavily influenced by physical weathering rather than chemical weathering. Due to these large differences in weathering processes and composition, martian sediments require an alternate maturity index. Abrason tests have been conducted on a variety of mafic materials and results suggest that mature martian sediments may be composed of well sorted, well rounded, spherical basalt grains. In addition, any volcanic glass present is likely to persist in a mechanical weathering environment while chemically altered products are likely to be winnowed away. A modified sediment maturity index is proposed that can be used in future studies to constrain sediment source, paleoclimate, mechanisms for sediment production, and surface evolution. This maturity index may also provide details about erosional and sediment transport systems and preservation processes of layered deposits.

  11. Physical abrasion of mafic minerals and basalt grains: Application to martian aeolian deposits

    NASA Astrophysics Data System (ADS)

    Cornwall, C.; Bandfield, J. L.; Titus, T. N.; Schreiber, B. C.; Montgomery, D. R.

    2015-08-01

    Sediment maturity, or the mineralogical and physical characterization of sedimentary deposits, has been used to identify sediment sources, transport medium and distance, weathering processes, and paleoenvironments on Earth. Mature terrestrial sands are dominated by quartz, which is abundant in source lithologies on Earth and is physically and chemically stable under a wide range of conditions. Immature sands, such as those rich in feldspars or mafic minerals, are composed of grains that are easily physically weathered and highly susceptible to chemical weathering. On Mars, which is predominately mafic in composition, terrestrial standards of sediment maturity are not applicable. In addition, the martian climate today is cold and dry and sediments are likely to be heavily influenced by physical weathering rather than chemical weathering. Due to these large differences in weathering processes and composition, martian sediments require an alternate maturity index. This paper reports the results of abrasion tests conducted on a variety of mafic materials and results suggest that mature martian sediments may be composed of well sorted, well rounded, spherical polycrystalline materials, such as basalt. Volcanic glass is also likely to persist in a mechanical weathering environment while more fragile and chemically altered products are likely to be winnowed away. A modified sediment maturity index is proposed that can be used in future studies to constrain sediment source, paleoclimate, mechanisms for sediment production, and surface evolution. This maturity index may also provide insights into erosional and sediment transport systems and preservation processes of layered deposits.

  12. Iron isotopic fractionation during continental weathering

    SciTech Connect

    Fantle, Matthew S.; DePaolo, Donald J.

    2003-10-01

    The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

  13. Hazardous Weather Plan Support Document

    E-print Network

    Huang, Haiying

    StormReady Hazardous Weather Plan Support Document Annex A Warning #12;ii Ver. 3.0 05/2014 RECORD OF CHANGES StormReady Hazardous Weather Plan Support Document 12 to Annex A Warning Change # Date of Change. REPORTING DAMAGE TO THE NATIONAL WEATHER SERVICE.....................6 VIII. GLOSSARY OF WEATHER TERMS

  14. Cave development by frost weathering

    NASA Astrophysics Data System (ADS)

    Oberender, Pauline; Plan, Lukas

    2015-01-01

    This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50 m and entrances can be more than 100 m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2 m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5 g/month of debris could be collected, but a few 100 g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

  15. Mapping the regolith: Deep weathering and its impact for the Norwegian landscape

    NASA Astrophysics Data System (ADS)

    Brönner, Marco; Olesen, Odleiv

    2013-04-01

    Different epochs of glaciations onshore Norway eroded and removed almost entirely the overlying sedimentary successions. The preglacial landscape is consequently masked by glacial erosion and the landscape as it is today might reflect the impact of deep weathering. The numerous sounds and islands along the Norwegian coast could to a large extend be conditioned by exhumation and erosion of weathered basement. Onshore Norway and in wells on the Norwegian continental shelf quite a few examples of deeply weathered and fractured basement are observed. A couple of hundred meters deep saprolites in narrow fracture zones were for example observed on the mainland of south-eastern Norway. Furthermore along the Norwegian coast several places like Lista, Karmøy, Vågsøy and at the Lofoten-Vesterålen archipelago, are well known for significant amounts of deeply weathered basement. A comprehensive mapping of these remains of weathering gives valuable indications if and to what extend the today's Norwegian landscape can be the product of glacial erosion of not only sedimentary rocks, but also thick packages of soft, deep weathered basement. New high quality aeromagnetic data were acquired along the Norwegian coast over the last years by the Geological survey of Norway as part of a crustal onshore-offshore project (COOP) and were applied for systematic mapping of deep weathering in conjunction with reprocessed data by using the AMAGER (AeroMAgnetic and GEomorphological Relations) method. Onshore Norway the AMAGER method was successfully applied in SE Norway (Olesen et al. 2007) and comprises a correlation of morphological depressions and magnetic lows. The method is based on the not necessarily but for Norway common observation that saprolite shows a noticeable reduced magnetization compared to the parent material and is moreover easily erodible. Relative magnetic lows correlating with topographic depressions in eroded and exposed basement landscapes are hitherto likely to indicate the location and distribution of deep weathering. Offshore, on the Norwegian shelf the AMAGER method is not easily applicable due to possible sedimentary coverage. But folded and fractured basement and the alteration of basement rocks by weathering processes, however, cause noticeable characteristics of the rock's physical parameters, which are also likely to be detected by marine geophysical methods. From onshore-offshore high-resolution aeromagnetic data we correlated noticeable onshore deep weathering/fractured basement lineaments with magnetic features offshore and 2D seismic data were finally used to confirm the character of the interpreted magnetic features.

  16. A proposal for a unified process to improve probabilistic ground snow loads in the United States using SNODAS modeled weather station data

    NASA Astrophysics Data System (ADS)

    DePaolo, Michael Robert

    Snow loads govern roof design in many parts of the United States. These loads are largely prescribed by the American Society of Civil Engineers ASCE 7 Standard for minimum design loads. Where ASCE 7 does not specify snow loads due to extreme local variability, such as in the West, many state jurisdictions have developed individual roof snow load documents and maps. However, among the western states border discrepancies and a general lack of uniformity in the methodology for developing such loads indicates a need for a unified approach. This paper proposes a methodology to develop ground snow loads for the western United States, the application of which is illustrated for the state of Colorado. An innovative approach is taken which utilizes a hydrological snowpack model, Snow Data Assimilation System (SNODAS), developed by NOAA. This model provides estimates of ground snow depth and snow water content, easily convertible into loads, at 588 SNODAS weather stations in Colorado. The methodology proposed here then incorporates statistical techniques such as principal component analysis (PCA) and multivariate cluster analyses to regionalize the SNODAS stations by key shared properties. Several types of cluster analyses are evaluated including agglomerative hierarchical clustering (AHC), k-means, and a PCA-based method. Using various statistical and practical measures of quality, a step-wise hybrid method combining both AHC and k-means techniques is found to be the most statistically sound and robust clustering method. A relationship is then developed between ground snow depths and ground snow loads for each cluster of SNODAS weather stations. This paper proposes the following additional steps. A database of National Weather Service CO-OP stations with snow depth only measurements is gathered for the state of interest. The 50-year ground snow depths are extrapolated by testing the goodness-of-fit of several probability distributions. The ground snow depth-load relationships for each cluster produced by the hybrid method are then coupled with these 50-year ground snow depths to produce 50-year ground snow loads. Finally, these ground snow loads are mapped in GIS software using a Kriging geostatistical interpolation method to create continuous snow load isolines.

  17. Revision Vodcast Influence on Assessment Scores and Study Processes in Secondary Physics

    NASA Astrophysics Data System (ADS)

    Marencik, Joseph J.

    A quasi-experimental switching replications design with matched participants was employed to determine the influence of revision vodcasts, or video podcasts, on students' assessment scores and study processes in secondary physics. This study satisfied a need for quantitative results in the area of vodcast influence on students' learning processes. Thirty-eight physics students in an urban Ohio public high school participated in the study. The students in one Physics class were paired with students in another Physics class through the matching characteristics of current student cumulative test score mean and baseline study process as measured by the Study Process Questionnaire (SPQ). Students in both classes were given identical pedagogic treatment and access to traditional revision tools except for the supplemental revision vodcasts given to the experimental group. After students in the experimental group viewed the revision vodcast for a particular topic, the assessment scores of the students in the experimental group were compared to the assessment scores of the control group through the direct-difference, D, test to determine any difference between the assessment score means of each group. The SPQ was given at the beginning of the experiment and after each physics assessment. The direct-difference method was again used to determine any difference between the SPQ deep approach scores of each group. The SPQ was also used to determine any correlative effects between study process and revision vodcast use on students' assessment scores through descriptive statistics and an analysis of variance (ANOVA) test. Analysis indicated that revision vodcast use significantly increased students' assessment scores (p<.05), but did not significantly influence students' deep approach to studying ( p>.05). There were no significant correlative effects of revision vodcast use and study processes on students' assessment scores (p>.05). This study offers educators the empirical support to devote the necessary effort, time, and resources into developing successful revision vodcasts at the secondary physics level.

  18. Utilization of Live Localized Weather Information for Sustainable Agriculture

    NASA Astrophysics Data System (ADS)

    Anderson, J.; Usher, J.

    2010-09-01

    Authors: Jim Anderson VP, Global Network and Business Development WeatherBug® Professional Jeremy Usher Managing Director, Europe WeatherBug® Professional Localized, real-time weather information is vital for day-to-day agronomic management of all crops. The challenge for agriculture is twofold in that local and timely weather data is not often available for producers and farmers, and it is not integrated into decision-support tools they require. Many of the traditional sources of weather information are not sufficient for agricultural applications because of the long distances between weather stations, meaning the data is not always applicable for on-farm decision making processes. The second constraint with traditional weather information is the timeliness of the data. Most delivery systems are designed on a one-hour time step, whereas many decisions in agriculture are based on minute-by-minute weather conditions. This is especially true for decisions surrounding chemical and fertilizer application and frost events. This presentation will outline how the creation of an agricultural mesonet (weather network) can enable producers and farmers with live, local weather information from weather stations installed in farm/field locations. The live weather information collected from each weather station is integrated into a web-enabled decision support tool, supporting numerous on-farm agronomic activities such as pest management, or dealing with heavy rainfall and frost events. Agronomic models can be used to assess the potential of disease pressure, enhance the farmer's abilities to time pesticide applications, or assess conditions contributing to yield and quality fluctuations. Farmers and industry stakeholders may also view quality-assured historical weather variables at any location. This serves as a record-management tool for viewing previously uncharted agronomic weather events in graph or table form. This set of weather tools is unique and provides a significant enhancement to the agronomic decision-support process. Direct benefits to growers can take the form of increased yield and grade potential, as well as savings in money and time. Pest management strategies become more efficient due to timely and localized disease and pest modelling, and increased efficacy of pest and weed control. Examples from the Canadian Wheat Board (CWB) WeatherFarm weather network will be utilized to illustrate the processes, decision tools and benefits to producers and farmers.

  19. Integrating remote sensing data with WRF for improved simulations of oasis effects on local weather processes over an arid region in northwestern China

    NASA Astrophysics Data System (ADS)

    Wen, X.; Dong, W.; Liao, X.; Lu, S.; Jin, J.

    2012-12-01

    Land use/cover types derived by satellite remote sensing data from the Earth Observing System Moderate Resolution Imaging Spectroradiometer (MODIS) were used to replace the U.S. Survey (USGS) data in the Weather Research and Forecasting (WRF) model. Simulations in this study were further improved by modifying the initial fields of WRF with soil temperature and moisture observations, because these two variables are important to producing "cold-wet island" effects. These improvements enabled the WRF model to reproduce the observed "cold and wet island" effects of the oasis.; Location and landscape map of the Jinta oasis. Jinta oasis is an inverse triangle situated between 98°39?E and 99°08?E and 39°56?N and 40°17?N in the north-central Heihe River Basin in northwestern China (Fig. 1). The average annual total precipitation is about 59.5 mm and the annual potential evapotranspiration is about 2538.6 mm (Meng et al. 2009). The total area is about 1652 km2. Jinta oasis is a typical irrigated area in arid northwestern China. It has an undulating topography and varies in elevation by only 80 m. ; In the field, there were 4 automatic weather stations (AWSs) and 1 oasis meteorological tower station in the vegetated areas, and 1 Gobi meteorological tower station was located in the nonvegetated area. The four AWSs were at 2 m height, and the two tower stations were at 4 heights (1.8, 5.8, 13, and 18.9 m). This figure shows the comparison of land use/vegetation maps between the default (USGS) and modified MODIS data for the 1 km-resolution domain. Most of the oasis is irrigated cropland, with grassland decreasing rapidly in the interior and outer edges of the Jinta oasis and degrading to desert (Fig. 2b). With population growth, more and more grassland is used to plant crops, which results in the reduction of shrubland and grassland.

  20. Physical Ion Sputtering At Glancing Angles As A Novel IC De-processing Technique

    SciTech Connect

    Vyatkin, A. F.; Zinenko, V. I.

    2011-01-07

    Failure analysis (de-processing) techniques are becoming more and more important in tackling integrated circuits (IC) process-related problems. Particularly, failure analysis of ICs requires opening and de-layering a chip in a layer by layer mode in order to find hidden defects. Selective chemical etching, reactive ion etching, plasma etching and chemical mechanical polishing or a combination of these techniques are traditionally used for de-processing of IC. In this work a novel technique which is physical ion sputtering at glancing incidence angles allowing precise information about possible reasons of IC failures occurring at different steps of IC processing is proposed.

  1. A combined physical/microbial process for the beneficiation of coal

    SciTech Connect

    Andrews, G.F.; Stevens, C.J.; Noah, K.S.; McIlwain, M.E.

    1993-09-01

    A large-laboratory scale physical/microbial process was demonstrated for the removal of pyritic sulfur from coal. The process took place in an aerated-trough slurry reactor with a total slurry volume of 150 L. The reactor was divided into six sections, each of which acted as a physical separator and a bioreactor. The process objective was to physically remove the larger pyritic inclusions and to biodegrade the small inclusions (micropyrite). The process was continuously operated for 120 days, treating approximately 1 ton of Illinois {number_sign}6 coal. Ninety percent pyrite removal was achieved at a 20% slurry concentration and a reactor residence time of 5 days. Additional research should be performed to find the optimum values for reactor residence time, slurry concentration, and process hydraulic residence time (or recycle ratio). Finding these optimum values will enable a process to be developed that will maximize the amount of coal that can be processed per unit reactor volume per unit time with the desired level of pyritic sulfur removal.

  2. Physical Processes and Real-Time Chemical Measurement of the Insect Olfactory Environment

    PubMed Central

    Abrell, Leif; Hildebrand, John G.

    2009-01-01

    Odor-mediated insect navigation in airborne chemical plumes is vital to many ecological interactions, including mate finding, flower nectaring, and host locating (where disease transmission or herbivory may begin). After emission, volatile chemicals become rapidly mixed and diluted through physical processes that create a dynamic olfactory environment. This review examines those physical processes and some of the analytical technologies available to characterize those behavior-inducing chemical signals at temporal scales equivalent to the olfactory processing in insects. In particular, we focus on two areas of research that together may further our understanding of olfactory signal dynamics and its processing and perception by insects. First, measurement of physical atmospheric processes in the field can provide insight into the spatiotemporal dynamics of the odor signal available to insects. Field measurements in turn permit aspects of the physical environment to be simulated in the laboratory, thereby allowing careful investigation into the links between odor signal dynamics and insect behavior. Second, emerging analytical technologies with high recording frequencies and field-friendly inlet systems may offer new opportunities to characterize natural odors at spatiotemporal scales relevant to insect perception and behavior. Characterization of the chemical signal environment allows the determination of when and where olfactory-mediated behaviors may control ecological interactions. Finally, we argue that coupling of these two research areas will foster increased understanding of the physicochemical environment and enable researchers to determine how olfactory environments shape insect behaviors and sensory systems. PMID:18548311

  3. Entropy Shows that Global Warming Should Cause Increased Variability in the Weather

    E-print Network

    John Michael Williams

    2001-02-21

    Elementary physical reasoning seems to leave it inevitable that global warming would increase the variability of the weather. The first two terms in an approximation to the global entropy are used to show that global warming has increased the free energy available to drive the weather, and that the variance of the weather should increase correspondingly.

  4. Sharp decrease in long-term chemical weathering rates along an altitudinal transect

    E-print Network

    Kirchner, James W.

    Sharp decrease in long-term chemical weathering rates along an altitudinal transect§ Cli¡ord S long-term rates of chemical weathering and physical erosion across a steep climatic gradient analyses indicate that, relative to the parent rock, soils are less intensively weathered with increasing

  5. Field Guide to Rock Weathering. Earth Science Curriculum Project Pamphlet Series PS-1.

    ERIC Educational Resources Information Center

    Boyer, Robert E.

    Highlighted are the effects of weathering through field investigations of the environment, both natural rocks, and the urban environment's pavements, buildings, and cemeteries. Both physical weathering and chemical weathering are discussed. Questions are presented for post-field trip discussion. References and a glossary are provided. (Author/RE)

  6. Impacts of two best management practices on Pb weathering and leachability in shooting range soils

    E-print Network

    Ma, Lena

    physical and chemical weathering of Pb bullets/shot leads to Pb accumulation in shooting range soils, whileImpacts of two best management practices on Pb weathering and leachability in shooting range soils Environmental Protection Agency on Pb weather- ing and leachability in shooting range soils. The two BMPs

  7. Holocene evolution in weathering and erosion patterns in the Pearl River delta

    E-print Network

    Clift, Peter

    . Keywords: physical erosion; chemical weathering; human settlement; proxies; landscape; Pearl river basinHolocene evolution in weathering and erosion patterns in the Pearl River delta Dengke Hu School London, London, UK [1] Sediments in the Pearl River delta have the potential to record the weathering

  8. The Tale of the Weather Worm Joe Szabo, John Aycock, Randal Acton, and Jorg Denzinger

    E-print Network

    Denzinger, Jörg

    The Tale of the Weather Worm Joe Szabo, John Aycock, Randal Acton, and J¨org Denzinger Department soft- ware. We introduce the idea of weather worms, worms that can automat- ically identify abnormal of a physical terrorist attack. Defenses against weather worms require serious examination of policy

  9. Hybrid models for the simulation of microstructural evolution influenced by coupled, multiple physical processes.

    SciTech Connect

    Tikare, Veena; Hernandez-Rivera, Efrain; Madison, Jonathan D.; Holm, Elizabeth Ann; Patterson, Burton R.; Homer, Eric R.

    2013-09-01

    Most materials microstructural evolution processes progress with multiple processes occurring simultaneously. In this work, we have concentrated on the processes that are active in nuclear materials, in particular, nuclear fuels. These processes are coarsening, nucleation, differential diffusion, phase transformation, radiation-induced defect formation and swelling, often with temperature gradients present. All these couple and contribute to evolution that is unique to nuclear fuels and materials. Hybrid model that combines elements from the Potts Monte Carlo, phase-field models and others have been developed to address these multiple physical processes. These models are described and applied to several processes in this report. An important feature of the models developed are that they are coded as applications within SPPARKS, a Sandiadeveloped framework for simulation at the mesoscale of microstructural evolution processes by kinetic Monte Carlo methods. This makes these codes readily accessible and adaptable for future applications.

  10. New weather index

    NASA Astrophysics Data System (ADS)

    Scientists at the National Oceanic and Atmospheric Administration (NOAA) and the University of Delaware have refined the wind-chill factor, a common measurement of weather discomfort, into a new misery register called the weather stress index. In addition to the mix of temperature and wind speed data used to calculate wind chill, the recipe for the index adds two new ingredients—humidity and a dash of benchmark statistics—to estimate human reaction to weather conditions. NOAA says that the weather stress index estimates human reaction to weather conditions and that the reaction depends on variations from the ‘normal’ conditions in the locality involved.Discomfort criteria for New Orleans, La., and Bismarck, N.D., for example, differ drastically. According to NOAA, when it's the middle of winter and it's -10°C with a relative humidity of 80% and 24 km/h winds, persons in New Orleans would be highly stressed while those in Bismarck wouldn't bat an eye.

  11. Probability for Weather and Climate

    NASA Astrophysics Data System (ADS)

    Smith, L. A.

    2013-12-01

    Over the last 60 years, the availability of large-scale electronic computers has stimulated rapid and significant advances both in meteorology and in our understanding of the Earth System as a whole. The speed of these advances was due, in large part, to the sudden ability to explore nonlinear systems of equations. The computer allows the meteorologist to carry a physical argument to its conclusion; the time scales of weather phenomena then allow the refinement of physical theory, numerical approximation or both in light of new observations. Prior to this extension, as Charney noted, the practicing meteorologist could ignore the results of theory with good conscience. Today, neither the practicing meteorologist nor the practicing climatologist can do so, but to what extent, and in what contexts, should they place the insights of theory above quantitative simulation? And in what circumstances can one confidently estimate the probability of events in the world from model-based simulations? Despite solid advances of theory and insight made possible by the computer, the fidelity of our models of climate differs in kind from the fidelity of models of weather. While all prediction is extrapolation in time, weather resembles interpolation in state space, while climate change is fundamentally an extrapolation. The trichotomy of simulation, observation and theory which has proven essential in meteorology will remain incomplete in climate science. Operationally, the roles of probability, indeed the kinds of probability one has access too, are different in operational weather forecasting and climate services. Significant barriers to forming probability forecasts (which can be used rationally as probabilities) are identified. Monte Carlo ensembles can explore sensitivity, diversity, and (sometimes) the likely impact of measurement uncertainty and structural model error. The aims of different ensemble strategies, and fundamental differences in ensemble design to support of decision making versus advance science, are noted. It is argued that, just as no point forecast is complete without an estimate of its accuracy, no model-based probability forecast is complete without an estimate of its own irrelevance. The same nonlinearities that made the electronic computer so valuable links the selection and assimilation of observations, the formation of ensembles, the evolution of models, the casting of model simulations back into observables, and the presentation of this information to those who use it to take action or to advance science. Timescales of interest exceed the lifetime of a climate model and the career of a climate scientist, disarming the trichotomy that lead to swift advances in weather forecasting. Providing credible, informative climate services is a more difficult task. In this context, the value of comparing the forecasts of simulation models not only with each other but also with the performance of simple empirical models, whenever possible, is stressed. The credibility of meteorology is based on its ability to forecast and explain the weather. The credibility of climatology will always be based on flimsier stuff. Solid insights of climate science may be obscured if the severe limits on our ability to see the details of the future even probabilistically are not communicated clearly.

  12. Space Weather Prediction with Exascale Computing

    E-print Network

    Lapenta, Giovanni

    2011-01-01

    Space weather refers to conditions on the Sun, in the interplanetary space and in the Earth space environment that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health. Adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socioeconomic losses. The conditions in space are also linked to the Earth climate. The activity of the Sun affects the total amount of heat and light reaching the Earth and the amount of cosmic rays arriving in the atmosphere, a phenomenon linked with the amount of cloud cover and precipitation. Given these great impacts on society, space weather is attracting a growing attention and is the subject of international efforts worldwide. We focus here on the steps necessary for achieving a true physics-based ability to predict the arrival and consequences of major space weather storms....

  13. [Effects of combined use of therapeutic physical factors on early postoperative adhesion process in experiment].

    PubMed

    Gobedzhishvili, V K; Lavreshin, P M; Ovchrenko, L M

    2006-01-01

    Experimental adhesion process in the abdominal cavity was provoked in 36 guinea-pigs by autoimmune injury of the abdomen. The adhesions were exposed to impulse magnetic field and low-intensive infra-red laser radiation. The effects of the latter modalities on adhesion in early postoperative period, further use of lidase electrophoresis and ultrasound were studied. A combined action of various physical factors changes adhesion process: limits adhesion and visceral deformity, makes adhesions elastic. PMID:16862884

  14. Basic physical and chemical processes in space radiation effects on polymers

    NASA Technical Reports Server (NTRS)

    Kamaratos, E.; Wilson, J. W.; Chang, C. K.; Xu, Y. J.

    1982-01-01

    The effects of space ionizing radiation on polymers is investigated in terms of operative physical and chemical processes. A useful model of charged particle impact with a polymer was designed. Principle paths of molecular relaxation were identified and energy handling processes were considered. The focus of the study was on energy absorption and the immediately following events. Further study of the radiation degradation of polymers is suggested.

  15. GEOLOGY | Volume 43 | Number 5 | www.gsapubs.org 1 Human impact overwhelms long-term climate control of weathering

    E-print Network

    Clift, Peter

    , and terrigenous flux, indicative of strong chemical weathering and physical erosion during the mid-Holocene warm that precipitation and temperature controlled both physical erosion and chemical weathering intensity before 1800 cal control of weathering and erosion in southwest China Shiming Wan1 *, Samuel Toucanne2 , Peter D. Clift3

  16. Goddard Laboratory for Atmospheric Sciences physical retrieval system for remote determination of weather and climate parameter from HIRS2 and MSU observations

    NASA Technical Reports Server (NTRS)

    Susskind, J.

    1984-01-01

    At the Goddard Laboratory for Atmospheric Sciences (GLAS) a physically based satellite temperature sounding retrieval system, involving the simultaneous analysis of HIRS2 and MSU sounding data, was developed for determining atmospheric and surface conditions which are consistent with the observed radiances. In addition to determining accurate atmospheric temperature profiles even in the presence of cloud contamination, the system provides global estimates of day and night sea or land surface temperatures, snow and ice cover, and parameters related to cloud cover. Details of the system are described elsewhere. A brief overview of the system is presented, as well as recent improvements and previously unpublished results, relating to the sea-surface intercomparison workshop, the diurnal variation of ground temperatures, and forecast impact tests.

  17. Geochemistry of large river suspended sediments: Silicate weathering or recycling tracer?

    SciTech Connect

    Gaillardet, J.; Dupre, B.; Allegre, C.J.

    1999-12-01

    This study focuses on the major and trace element composition of suspended sediments transported by the world's largest rivers. Its main purpose is to answer the following question: is the degree of weathering of modern river-borne particles consistent with the estimated river dissolved loads derived from silicate weathering? In agreement with the well known mobility of elements during weathering of continental rocks, the authors confirm that river sediments are systematically depleted in Na, K, Ba with respect to the Upper Continental Crust. For each of these mobile elements, a systematics of weathering indexes of river-borne solids is attempted. A global consistency is found between all these indexes. Important variations in weathering intensities exist. A clear dependence of weathering intensities with climate is observed for the rivers draining mostly lowlands. However, no global correlation exists between weathering intensities and climatic or relief parameters because the trend observed for lowlands is obscured by rivers draining orogenic zones. An inverse correlation between weathering intensities and suspended sediment concentrations is observed showing that the regions having the highest rates of physical denudation produce the least weathered sediments. Finally, chemical and physical weathering are compared through the use of a simple steady state model. The authors show that the weathering intensities of large river suspended sediments can only be reconciled with the (silicate-derived) dissolved load or rivers, by admitting that most of the continental rocks submitted to weathering in large river basins have already suffered previous weathering cycles. A simple graphical method is proposed for calculating the proportion of sedimentary recycling in large river basins. Finally, even if orogenic zones produce weakly weathered sediments, the authors emphasize the fact that silicate chemical weathering rates (and hence CO{sub 2} consumption rates by silicate weathering) are greatly enhanced in mountains simply because the sediment yields in orogenic drainage basins are higher. Hence, the parameters that control chemical weathering rates would be those that control physical denudation rates.

  18. What will be the weather like tomorrow?

    NASA Astrophysics Data System (ADS)

    Christelle, Guilloux

    2014-05-01

    Since June 2010, our school is part of the network '"météo à l'école'": it hosts an autonomous weather station, approved by Météo France , which measures continuously the temperature and precipitation. The data is transmitted by a GSM module to a computer server. After its validation by Météo France, it is send online every day on a public accessible website : http://www.edumeteo.org/ The MPS Education ( Scientific Methods and Practices) in junior high school classes (one hour and half per week throughout the school year ) makes full use of data from the networks '"météo à l'école'" data and Météo France. Three scientific disciplines :; Mathematics, Life and Earth Sciences, Physical Sciences and Chemistry are part of a schedule defined after consultation and educational coherence to enable students to: - Discovering and understanding the operation of the sensors station, weather satellites ... - Operating satellite images, studying of the atmosphere and weather phenomena (formation of a storm, for example) - Operating collected data (networks 'météo à l'école' and Météo France) to identify climatic differences between regions, seasons, and their effects on living beings (study of the greenhouse effect and climate warming among others). The ultimate goal is to discover used tools and data to produce a weather forecast. We work for these purposes with the Cité de l'Espace in Toulouse (weather Pole) and the head forecaster Meteo France Merignac.

  19. are exploring planet Earth is the part of earth science dealing with the physical processes and

    E-print Network

    Brückl, Ewald

    GeoKids are exploring planet Earth Geophysics is the part of earth science dealing of the children provides a good basis for effective learning. The reflection on selected themes of earth sciences with the physical processes and characteristics of the Earth and its environment. Volcanism, earthquakes

  20. CHEMISTRY AND PHYSICAL PROPERTIES OF MELT PROCESSED- AND SOLUTION-CROSS LINKED CORN ZEIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn zein was cross linked with glutaraldehyde (GDA) and with glacial acetic acid (HAc) as catalyst with the objective to enhance the mechanical properties of poured films which were compared with the physical properties of compression molded tensile bars from melt processed zein with GDA. A reacti...