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1

Physical and chemical weathering  

NASA Astrophysics Data System (ADS)

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.

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

2

Weathering  

NSDL National Science Digital Library

This course handout covers the processes and effects of weathering. The purpose of this handout is to contrast weathering and erosion, contrast and discuss chemical and mechanical weathering, list the products resulting from the chemical weathering of igneous rocks, and list and discuss the factors that influence the type and rate of rock weathering. Many photographs accompany this summary which depict weathered landscapes. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-08-29

3

Space Weathering Processes on Mercury  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

4

Weather  

NSDL National Science Digital Library

Have you ever wondered how the weather man, or meteorolgist, on TV knows what to say about tomorrow\\'s weather? It\\'s because they have certain tools that they use that help them predict what the weather will be. Throughout this school year you are going to be making tools and predicting weather just like a meterorologist! Task You are going to be weather forcasters! You are going to record and track weather patterns throughout the year. You will also use weather tools to make predictions about the weather like real weather forecasters! The Process 1. First we need to learn a little bit about weather so ...

Williams, Ms.

2005-10-25

5

Physical weathering and modification of a rhyolitic hyaloclastite in Iceland  

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

6

The Chemical Weathering End Member of the Coupled Physical and Chemical Weathering System  

NASA Astrophysics Data System (ADS)

It is widely recognized that physical and chemical weathering processes are coupled. In natural systems erosion is constantly removing chemically weathered material making it difficult to decouple physical and chemical contributions. In order to understand these complicated systems it will be necessary to study end-member systems where processes that control chemical and physical weathering can be considered separately. We use 3 cm weathering rinds developed on basalt clasts within 125 ka fluvial terraces along the Pacific coast of Costa Rica as a proxy for saprolite development in the absence of physical weathering. This highly controlled system enables us to examine the weathering interface in detail. The weathering interface is comprised of thin reaction fronts where element concentrations vary from parent rock to rind concentrations. Electron microprobe data indicate a 2 mm thick reaction front of mobile elements (i.e., Ca and Na) at the interface and ~ 4 mm thick reaction fronts of less mobile elements (i.e., Si). These reaction fronts are 3 orders of magnitude narrower than those recognized at the bedrock-saprolite interface in landscape-scale studies. Iso-volumetric weathering of labradorite and augite has produced a rind of gibbsite and iron oxide. This transition is accompanied by a pronounced change in porosity from <1% in the core to 50% in the rind. Petrographic and SEM images reveal labradorite dissolution coreward of the rind/core interface producing secondary porosity and increased permeability into the core. Reactive transport modeling allows simulation of rind development using appropriate values of diffusion, mineral surface area, and reaction rate. A controlling feature appears to be porosity of the basalt clast which controls both diffusion of reactants and products into and away from the weathering front. Initial reaction-diffusion simulations were based on the assumption of constant porosity so as to understand important controls on the thickness of the reaction front and the rate at which it advances. Results indicate that the initial rate of rind advancement is a mix of interface- and transport-control. However, once a dissolution front is established, the long-term rate of rind advancement becomes transport-limited and shows the parabolic time dependence characteristic of diffusion processes. Field data, however, indicate that rind advance rates are constant through time, suggesting that more complicated transport within the rind simple diffusion. One possibility is that the increase in rind porosity allows for flow through the rind, thus causing the fixed concentration boundary condition to migrate coreward along with the weathering front. Such a mechanism could result in linear rather than parabolic rind advance rate with time. Diffusion rates and mineral surface area were varied to match initial rind advance rates to 2.4x10-4 mm/year calculated from field data. Effective diffusion coefficients for dissolved aqueous species ranged from 0.51x10-5 cm2/sec to 8.57x10-5 cm2/sec for Fe3+ and H+, respectively. Initial rind advance rate (2.1x10-4 mm/yr) and reaction front thickness (2 mm) were closest to observed values when formation factor, labradorite surface area, and augite surface area were 6.7E-5, 1500 m2/m3, and 500 m2/m3, respectively. Further modeling is ongoing to investigate how porosity changes affect transport within the weathering rind and rind advance rate. These modeling efforts will help clarify the coupling of physical and chemical processes at the reaction front.

Navarre, A. K.; Steefel, C. I.; Sak, P. B.; Brantley, S. L.

2004-12-01

7

Analysis of a Sandstorm Weather Process.  

National Technical Information Service (NTIS)

The favorable synoptic situation and climate background for a sandstorm process, which occurred in the period from the 9th to the 16th of April 1988, has been studied through analyzing weather maps, meteorological elements, satellite cloud pictures and sa...

D. Yang X. Ji

1993-01-01

8

Weather  

NSDL National Science Digital Library

You will learn how to describe and observe changes in weather patterns by completing the following activities. The students will record and report changes in weather on their data sheet. The Process: Read the information on How Air Pressure Affects You. In this article you will see the term barometer. Write its definition. Now look over Weather Facts. Now go to Investigate Climate Conditions and use the weather maker to observe the effects of certain changes. Answer the questions: How much of a change in temperature is needed to make it ...

Lauren, Ms.

2010-11-17

9

Olivine Weathering: Abiotic Versus Biotic Processes as Possible Biosignatures  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

10

Physical mechanisms of solar variability influence on weather and climate  

NASA Astrophysics Data System (ADS)

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.

Avakyan, Sergei

2010-05-01

11

Data processing techniques for airport surveillance radar weather sensing  

Microsoft Academic Search

Discusses data processing techniques that can provide high quality, automated weather information using the FAA's existing Airport Surveillance Radars (ASR-9). The cost of modifying the ASR-9 is significantly less than that for deployment of the dedicated terminal Doppler weather radar. These techniques have been implemented on a prototype ASR-9 weather surveillance processor (WSP) and have been tested operationally at the

Mark E. Weber; Richard L. Delanoy; E. S. Chornoboy

1995-01-01

12

Weather  

NSDL National Science Digital Library

This is a first grade weather unit. SEASONS Fall Winter Build a Snowman Spring Summer What things determine and effect the weather? Cloud Precipitation Sunshine Temperature Visibility Wind Direction Wind Force WEATHER VIDEOS Tornado Hurricane Hail Lightning FUN AND GAMES Dress the Bear for the Weather The Great Weather Race Game Weather coloring books for kids ...

Stearns, Ms.

2008-10-25

13

Weather  

NSDL National Science Digital Library

The National Oceanic and Atmospheric Administration (NOAA) provides these two Websites on weather. The first site serves as a major hub for information related to weather, with links to primary data sources, forecasts, maps, images (such as the latest satellite imagery for North America), and a wealth of other data, including space weather. Researchers will also find links to national weather research centers and other related agencies.

14

Weather  

NSDL National Science Digital Library

What are the different types of weather? In this project you will compare different types of weather by drawing pictures and making it into a flip book. First you will begin by learning about the different types of weather. Read about each topic. Then get together with your partner and draw a picture of each type of weather. 1. Thunder storm Thunder storm Thunder storm Kids 2. Lightning Lightning Lightning picture 3. Tornado Tornadoes Tornado Kids 4. ...

Jennie, Miss

2009-10-22

15

Improving the physics models in the Space Weather Modeling Framework  

NASA Astrophysics Data System (ADS)

The success of physics based space weather forecasting depends on several factors: we need sufficient amount and quality of timely observational data, we have to understand the physics of the Sun-Earth system well enough, we need sophisticated computational models, and the models have to run faster than real time on the available computational resources. This presentation will focus on a single ingredient, the recent improvements of the mathematical and numerical models in the Space Weather Modeling Framework. We have developed a new physics based CME initiation code using flux emergence from the convection zone solving the equations of radiative magnetohydrodynamics (MHD). Our new lower corona and solar corona models use electron heat conduction, Alfven wave heating, and boundary conditions based on solar tomography. We can obtain a physically consistent solar wind model from the surface of the Sun all the way to the L1 point without artificially changing the polytropic index. The global magnetosphere model can now solve the multi-ion MHD equations and take into account the oxygen outflow from the polar wind model. We have also added the options of solving for Hall MHD and anisotropic pressure. Several new inner magnetosphere models have been added to the framework: CRCM, HEIDI and RAM-SCB. These new models resolve the pitch angle distribution of the trapped particles. The upper atmosphere model GITM has been improved by including a self-consistent equatorial electrodynamics and the effects of solar flares. This presentation will very briefly describe the developments and highlight some results obtained with the improved and new models.

Toth, G.; Fang, F.; Frazin, R. A.; Gombosi, T. I.; Ilie, R.; Liemohn, M. W.; Manchester, W. B.; Meng, X.; Pawlowski, D. J.; Ridley, A. J.; Sokolov, I.; van der Holst, B.; Vichare, G.; Yigit, E.; Yu, Y.; Buzulukova, N.; Fok, M. H.; Glocer, A.; Jordanova, V. K.; Welling, D. T.; Zaharia, S. G.

2010-12-01

16

Weather.  

ERIC Educational Resources Information Center

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)

Web Feet K-8, 2000

2000-01-01

17

Weathering  

Microsoft Academic Search

In the natural environment, weathering and breakdown of stone is an accepted part of long-term landscape development but the\\u000a same acceptance of change and deterioration is not extended to stone used in construction especially when such deterioration\\u000a affects historically and\\/or culturally important structures. The value of an integrative approach to improve understanding\\u000a of weathering and failure of building stone is

P. A. Warke; J. McKinley; B. J. Smith

18

Space weather  

NASA Astrophysics Data System (ADS)

Space weather is caused by conditions on the Sun and in the solar wind, the magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can affect human life or health. It affects man-made systems such as satellite electronics, terrestrial power grids and radio communications. This paper provides an overview of how space weather arises in the solar terrestrial system and how physical processes are able to cause space weather effects. We also discuss European perspectives and activities geared towards the possible initiation of a European Space Weather programme.

Glover, Alexi; Daly, Eamonn; Hilgers, Alain; Berghmans, David

2002-05-01

19

Synoptic observations of space weather processes in the inner magnetosphere  

Microsoft Academic Search

Space weather in the magnetosphere is driven by coronal mass ejections and other solar wind disturbances. The magnetosphere has, in turn, a remarkable capability of further processing the energy and plasma coming from the solar wind. One way of determining the severeness of magnetic storms is to estimate the strength of the westward ring current carried by ions at energies

H. Koskinen

2002-01-01

20

Lithium isotopes as a probe of weathering processes: Orinoco River  

NASA Astrophysics Data System (ADS)

Lithium isotopes have the potential to be effective tracers of weathering processes due to their large relative mass difference and therefore fractionation. In this study an attempt is made to fill a major gap in the knowledge of Li isotope fractionation during continental weathering and of the mechanisms involved. Finally the relationship between the suspended and dissolved material is made on a basin-wide scale. The Orinoco basin provides a clear contrast in reaction-limited and transport-limited weathering regimes that has already been documented by a comprehensive study on its fluvial geochemistry (Edmond et al., Geochim. Cosmochim. Acta 60 (1996) 2949-2976; Edmond et al., Geochim. Cosmochim. Acta 59 (1995) 3301-3325). Conspicuous in our new results is the difference in ?6Li of the dissolved load between the Andean (-30 to -22‰) and Shield (-22 to -7‰) tributaries, while the ?6Li of the suspended load is similar between the two. To a first approximation, during superficial weathering in high-relief, tectonically active terrains the dissolved load is high in Li and isotopically heavy (more negative ?6Li), whereas in stable Shield regions the concentrations are low and isotopically light in proportion to the increasing degree of weathering.

Huh, Youngsook; Chan, Lui-Heung; Edmond, John M.

2001-12-01

21

Stealth CMEs: A Challenge for Solar Physics and Space Weather  

NASA Astrophysics Data System (ADS)

It is commonly believed that coronal mass ejections (CMEs) are a primary driver of intense disturbances in the inner heliosphere. Although many of these CMEs are associated with clear solar transient phenomena such as flares, there have been a number of events without unambiguous solar origin, presenting a significant challenge not only for solar physics research, but also for space weather forecasts. For example, nearly 20% of major geomagnetic storms in solar cycle 23 that involved the interplanetary counterparts of CMEs (i.e., ICMEs) did not leave compelling signatures in EUV or X-ray images. We now tend to consider such orphan CMEs to be 'stealth' CMEs as first identified in data from the Solar Terrestrial Relations Observatory (STEREO) during last solar minimum. In the meantime the sensitivity of coronal observations has been tremendously improved as the Solar Dynamics Observatory (SDO) was launched in February 2010; SDO carries the Atmospheric Imaging Assembly (AIA), which provides high-cadence, full-disk images in a broad temperature range as sampled in EUV wavelengths. In principle, AIA should allow us to trace the origin of every Earth-directed CME observed as a limb event by the coronagraphs (COR-1, COR-2, HI-1 and HI-2) on STEREO. In reality, however, we have at least a handful of ICMEs whose origin may not clearly be tracked down to the low corona. Some of them were indeed geo-effective, further complicated by other factors including co-rotating interaction regions (CIRs). Here we give a survey of these events, discussing AIA and STEREO observations of their onsets and propagations in reference to their in-situ manifestations. We list key questions that should be answered by observational and modeling work in order to get more solid understanding of the origin of geomagnetic storms.

Nitta, N.; Srivastava, N.

2013-12-01

22

Physical mechanisms of solar variability influence on weather and climate  

Microsoft Academic Search

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;

Sergei Avakyan

2010-01-01

23

Weather  

NSDL National Science Digital Library

In the project you will learn about thunderstorms and tornadoes and play a weather matching game. What exactly are thunderstorms and tornadoes? Use your T- chart to explain some facts about a thunderstorm and a tornado as we review each. T-Chart Begin by reviewing what a thunderstorm is and how they form. Thunderstorm information What is a thunderstorm? What are thunderstorms most likely to occur? What causes thunder? Next review what a tornado ...

Caitlin, Ms.

2009-10-21

24

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

NASA Astrophysics Data System (ADS)

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.

Moldwin, Mark

2012-08-01

25

Chemical and Physical Weathering Field and Lab Experiment: Development and Testing of Hypotheses  

NSDL National Science Digital Library

The primary purpose of this exercise is to learn about chemical and/or physical weathering rates and processes via a self-designed experiment. A second, but important, goal of this exercise is to introduce students to all aspects of the scientific process via a mini-research experience. As such, the instructions for the exercise are somewhat open-ended and specific outcomes can vary widely depending on the focus of each student working group. This exercise is presented in two parts (chemical and physical weathering). Students break into groups that focus on one type of weathering and then share results with the other working groups at the termination of the project period. First, students use geologic and topographic maps to create hypotheses concerning the nature (composition, grain size distribution, sorting, shape, etc.) of sediments that will be found at several pre-determined field locations. They then design an experiment or data collection protocol to test their hypotheses using samples collected from the field (alternately, students could be given samples to work with). Students are responsible (with guidance when needed) for all aspects of the experiment and often must learn to adapt field and analytical data collection techniques throughout the project period. The exercise culminates in a scientific paper that is rigorously edited by the instructor and a presentation to other student working groups in the classroom. A discussion of 'lessons learned' can be very valuable at this time as results must be presented in a larger context (does this 'fit' with what you learn in your textbook?).

Greer, Lisa

26

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

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

27

Anvil Forecast Tool in the Advanced Weather Interactive Processing System  

NASA Technical Reports Server (NTRS)

Meteorologists from the 45th Weather Squadron (45 WS) and National Weather Service 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) was tasked to create a graphical overlay tool for the Meteorological Interactive Data Display System (MIDDS) that indicates the threat of thunderstorm anvil clouds, using either observed or model forecast winds as input. The tool creates a graphic depicting the potential location of thunderstorm anvils one, two, and three hours into the future. The locations are based on the average of the upper level observed or forecasted winds. The graphic includes 10 and 20 n mi standoff circles centered at the location of interest, as well as one-, two-, and three-hour arcs in the upwind direction. The arcs extend outward across a 30 sector width based on a previous AMU study that determined thunderstorm anvils move in a direction plus or minus 15 of the upper-level wind direction. The AMU was then tasked to transition the tool to the Advanced Weather Interactive Processing System (AWIPS). SMG later requested the tool be updated to provide more flexibility and quicker access to model data. This presentation describes the work performed by the AMU to transition the tool into AWIPS, as well as the subsequent improvements made to the tool.

Barrett, Joe H., III; Hood, Doris

2009-01-01

28

Evidence of Space Weathering Processes Across the Surface of Vesta  

NASA Astrophysics Data System (ADS)

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).

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

2011-12-01

29

Evidence of Space Weathering Processes Across the Surface of Vesta  

NASA Technical Reports Server (NTRS)

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).

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

30

Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes  

USGS Publications Warehouse

Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute fluxes (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. Mass-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute mass-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.

Jones, B. F.; Herman, J. S.

2008-01-01

31

Physical Processes in Stellar Interiors  

NASA Technical Reports Server (NTRS)

The author set himself three fundamental tasks: (1) To show how modern atomic and nuclear physics can contribute to the description of processes in stellar interiors. (2) To present the fundamentals of the methods for calculating physical processes taking place at temperatures of millions of degrees. (3) To provide the required minimum of information on problems of atomic and nuclear physics to astrophysicists, and on astronomical problems to physicists. The book is divided into four parts, the Introduction, the Theory of Stationary Processes, the Applications of the Theory of Stationary Processes and the Theory of Non-Stationary Processes.

Frank-Kamenetskii, D. A.

1962-01-01

32

Interactions of physical, chemical, and biological weather calling for an integrated approach to assessment, forecasting, and communication of air quality.  

PubMed

This article reviews interactions and health impacts of physical, chemical, and biological weather. Interactions and synergistic effects between the three types of weather call for integrated assessment, forecasting, and communication of air quality. Today's air quality legislation falls short of addressing air quality degradation by biological weather, despite increasing evidence for the feasibility of both mitigation and adaptation policy options. In comparison with the existing capabilities for physical and chemical weather, the monitoring of biological weather is lacking stable operational agreements and resources. Furthermore, integrated effects of physical, chemical, and biological weather suggest a critical review of air quality management practices. Additional research is required to improve the coupled modeling of physical, chemical, and biological weather as well as the assessment and communication of integrated air quality. Findings from several recent COST Actions underline the importance of an increased dialog between scientists from the fields of meteorology, air quality, aerobiology, health, and policy makers. PMID:22627871

Klein, Thomas; Kukkonen, Jaakko; Dahl, Aslög; Bossioli, Elissavet; Baklanov, Alexander; Vik, Aasmund Fahre; Agnew, Paul; Karatzas, Kostas D; Sofiev, Mikhail

2012-12-01

33

Physical Mechanisms of Extra Area Effects from Weather Modification.  

National Technical Information Service (NTIS)

The physical mechanisms which could have produced extra area effects downwind of the Climax I and II wintertime orographic cloud seeding experiments were investigated. The two most probable mechanisms identified, namely, artificial nuclei transport and ic...

G. J. Mulvey

1977-01-01

34

Weathering processes implied from analysis of small Martian avalanche chutes  

NASA Technical Reports Server (NTRS)

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.

Sullivan, R.

1992-01-01

35

Space Weather  

NASA Astrophysics Data System (ADS)

Following James Van Allen's discovery of Earth's radiation belts (1958), it was immediately recognized that the space environment would be hostile to the communications satellites that had been envision by Arthur Clark (1945) and John Pierce (1955). Van Allen's discovery set off a burst of "space weather" research and engineering that continues to today, paralleling "space weather" research that had, prior to 1958, been directed toward understanding environment effects on cable and early wireless communications, electric power distribution, and pipelines. Van Allen's discovery also meant that the flight of humans above the sensible atmosphere would be fraught with more peril than mere weightlessness. This Van Allen lecture will discuss the space weather considerations that arose from Van Allen's discovery as well as space weather effects that occur from numerous other physical processes in the complex sun-heliosphere-magnetosphere environmental system.

Lanzerotti, L. J.

2005-05-01

36

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

NASA Technical Reports Server (NTRS)

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.

Cooper, John F.

2006-01-01

37

wradlib - an Open Source Library for Weather Radar Data Processing  

NASA Astrophysics Data System (ADS)

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.

Pfaff, Thomas; Heistermann, Maik; Jacobi, Stephan

2014-05-01

38

Weathering Experiment  

NSDL National Science Digital Library

After discussing weathering and erosion in class, students are asked to do a small amount of research on different types of chemical weathering, physical weathering, and erosion processes (mostly out of their textbook). Outside of class students then dirty at least four similar dishes with the same type, thickness and aerial extent of food, preferably baked on to ensure maximum stick. One dish is set aside as a control (no weathering or erosion will occur for that dish). For each of the remaining three dishes, students devise an experiment that mimics some sort of chemical weathering, physical weathering, or erosion process (freeze/thaw, sand abrasion, oxidation, etc.). Prior to the experiments, the thickness of food is measured. Experiments are timed, and at the end of the experiment each plate is turned over to determine how much which method removed the greatest aerial extent of food. Experimental results are compared to the control plate to determine the actual effectiveness. Erosion/weathering rates are determined by dividing the thickness of food removed by the experimental time. Students then calculate how long it would take to remove a pile of food the size of the Geology building (assume a 50 m radius sphere), and to remove an amount of food equivalent to the depth of the Grand Canyon. Students then compare these results to rock erosion and weathering rates, performing similar calculations using these "real" rates (see the full project description for details). Photos of each step and the scientists are encouraged in their 2-3 page writeup.

Stelling, Pete

39

Reconstruction of space weather physical parameters on 400-year scale  

Microsoft Academic Search

The main goal of this paper is to get physically informative comprehensive data about dynamics of the solar magnetic field,\\u000a geomagnetic field, and interplanetary magnetic field over large time scales. The total sunspot magnetic flux, aa and IDV indices of geomagnetic activity, the IMF strength, the dipole-octopole index of the large-scale magnetic field of\\u000a the Sun, and the open magnetic

Yu. A. Nagovitsyn; E. V. Miletsky; V. G. Ivanov; S. A. Guseva

2008-01-01

40

Anvil Tool in the Advanced Weather Interactive Processing System  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

41

Interstellar Dust: Physical Processes  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

42

Computer Animations of Physical Processes  

NSDL National Science Digital Library

This site contains various applets and animations of physical processes, demonstrating various ideas in waves, optics, mechanics, and thermodynamics. The site also contains information on the theory behind diffraction gratings, and a simulator for ballistic projectiles.

2011-02-02

43

PHYSICAL-BASED DOWNSCALING INCLUDING CHARACTERISTICS OF URBAN WEATHER  

NASA Astrophysics Data System (ADS)

CReSiBUC consists of CReSS and SiBUC. This model is able to consider land surface conditions in detail. Especially, the characteristics of urban conditions such as artificial heat and geometry of building height can be considered. In this study, the effect of the physical-based downscaling is investigated by using CReSiBUC. Simulations are carried out around Tokyo Metropolitan Area during 5 summer seasons (from 2003 to 2007). Temperatures at 3 a.m. and Temperatures at 3 p.m. are investigated. It is found that outputs of CReSiBUC are more accurate than temperatures of MANAL. This result suggests the importance of considering urban conditions in detail.

Fujii, Takahiro; Tanaka, Kenji; Souma, Kazuyoshi; Kojiiri, Toshiharu

44

Spring Break-Weathering Homework  

NSDL National Science Digital Library

Students are asked to photograph something that shows either physical or chemical weathering. They must be in the photograph for purposes of scale. They must then write up their description of the weathering feature and explain the actual weathering processes. This assignment can also be expanded to include mass wasting and mass wasting prevention.

Farthing, Dori

45

Weather Modification: Finding Common Ground  

Microsoft Academic Search

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

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

2005-01-01

46

A reactive transport perspective on the links between physical erosion rates, fluid flow and chemical weathering rates  

NASA Astrophysics Data System (ADS)

Chemical weathering rates are theoretically governed by the balance between the time that fluid spends in contact with the rock, or the fluid transit time, and the time required to reach chemical equilibrium. Physical erosion is expected to be the first order control on the chemical equilibrium timescale because the supply of fresh mineral increases the rate of approach to chemical equilibrium. In weathering environments where fluid transit times are long relative to the equilibrium timescale, chemical weathering rates should increase with increasing water flux (or runoff) because the concentration of weathering products is always fixed by chemical equilibrium. By extension, short fluid transit times and/or long chemical equilibrium times result in lower concentrations and a plateau in chemical weathering rates with increasing runoff. To assess the relationship between physical erosion and equilibrium time scales, we analyzed soil water, stream and gas compositions across multiple seasons along three hillslope transects in the Feather River Basin, California, with varying erosion rates but identical lithology, vegetation and climate. We use the depth gradients in solute profiles and mineral saturation states to assess the equilibrium length scales (the depth over which fluids reach chemical equilibrium), which can then be compared to the equilibrium and transit time scales based on water fluxes measured by chloride mass balance. Calculated equilibrium length scales increase from an average of 30-40 cm at high erosion rate transect, to 80 to 100 cm at lower erosion rates. At high erosion rates, the fluids reach chemical equilibrium in the soil zone, and there is little driving force for chemical weathering in the saprolite. At lower erosion rates, the equilibrium length scale extends into the saprolite, while minimal weathering occurs in the soil zone because of passivation of mineral surfaces by secondary minerals. Liquid saturation also increases with decreasing erosion rate—this may favor biological activity that further enhances weathering in the saprolite resulting in the high CO2 levels (ca. 2 to 5%) in the saprolite at low erosion rates. Across all three transects, chemical weathering rates are limited by the rate of fluid flow and not the rate of mineral supply: average infiltration rates are highest at the higher erosion rate transect, resulting in higher rates of chemical denudation. Thermodynamic limitation of chemical weathering rates is consistent with the streamwater concentrations, which show minimal variation with discharge (i.e. chemostatic behavior). A substantial reservoir of immobile solute, which is observed here to increase with increasing erosion rate, appears to play an important role in facilitating thermodynamic limitation. Collectively, these results support the theoretical model for solute production described above, and emphasize the importance of considering the thermodynamic limitations on chemical weathering rates that are set by the physical process of erosion and fluid flow.

Maher, K.; Kouba, C. M.; Rosen, V. B.; Weinman, B. A.; Yoo, K.; Mudd, S. M.

2012-12-01

47

Anvil Tool in the Advanced Weather Interactive Processing System.  

National Technical Information Service (NTIS)

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 an...

J. Barrett J. Keen W. Bauman

2007-01-01

48

Modeling the Effects of Weathering Processes on Uranium-series Comminution Ages  

NASA Astrophysics Data System (ADS)

Determining the ages of detrital sediments is important for understanding the geomorphic processes in which the sediment particles participate. The uranium-series comminution age method can be used to directly date fine-grained Quaternary detrital sediments to obtain the elapsed time since particle formation (termed the comminution age), which is the sum of sediment transport & storage times and the depositional age. The method is based on the time-dependent alpha recoil loss of 234U from detrital grains due to energetic decay of the 238U parent, resulting in a measurable (234U/238U) decrease relative to secular equilibrium after grains are reduced below a critical size of ~50 microns diameter. Based on the existing comminution age model of time-dependent changes in the (234U/238U) activity ratio due solely to alpha recoil from sediment grains with a constant recoil loss parameter f? (related to grain size and surface area), ideal sediments for comminution age dating are fresh sediments that have experienced minimal alteration subsequent to particle formation. However, many sediments and soils of potential geomorphic interest are composed of grains that have undergone chemical and/or physical weathering after reduction below the critical grain size threshold. We present models designed to understand how weathering-related processes alter the (234U/238U) ratio of detrital grains. The aim is to improve the accuracy of the comminution ages determined from measured sediment (234U/238U) ratios, and extend the applicability of the dating method to a broader range of sediment types. Weathering-related scenarios explored are: addition of secondary minerals to the primary detrital fraction, incorporating preferential aqueous leaching of 234U as a possible additional mechanism for 234U loss, dissolution of the primary mineral phases, and physical abrasion and fracturing of the grains.

Lee, V. E.; Huber, C.; Henderson, G. M.

2010-12-01

49

Interplay between physical movements of soils and mineral grains and chemical weathering  

NASA Astrophysics Data System (ADS)

Most soil biogeochemistry studies treat the soils and their inorganic and organic constituents as physically immobile. Those soil materials, however, are in perpetual motion due to the conversion of bedrock to soils, colluvial transport, and vertical mixing by various biophysical perturbations of the soils. Subsequently, a soil is continuously replaced by the materials from the neighboring soils and the underlying parent material, while its individual horizons are gradually mixed with the materials in the neighboring horizons. The movements of bulk soil materials are ultimately driven by moving individual mineral grains. While rarely appreciated, these physical movements of soil's mineral components operate in the presence of strong vertical and topographic gradients of the rates of mineral dissolution and leaching. The result is that the physical movement of soil constituents affects chemical weathering. The fluxes of soil materials (via physical movements and solute fluxes) in and out of a soil system defined by a researcher determine the time length that the materials reside in the system. The residence time, together with the system-specific rates of chemical weathering, determine the degree of weathering of the materials within the system. This presentation provides a new mathematical framework to consistently quantify the residence times of minerals, individual soil horizons, soil profiles, and an entire soil within a watershed boundary. Soil age, which is equivalent of the time length since the cessation of erosion or deposition on level grounds, becomes a special case of the residence time. The model is combined with empirical data to quantitatively illustrate the impacts that the physical motion of soil constituents have on the rates of chemical weathering. The data are drawn from ongoing field and laboratory studies focusing on the impact of river incision, colluvial flux, bioturbation, and agricultural tillage on the vertical and lateral variation of elemental composition within the soils.

Yoo, K.

2007-12-01

50

Weathering Animation  

NSDL National Science Digital Library

Weathering is the term that describes all the processes that break down rocks in the environment near the Earth's surface. This module will help you to understand two weathering processes: mechanical and chemical.

2002-01-01

51

The Colorado Student Space Weather Experiment : A CubeSat for Space Physics  

NASA Astrophysics Data System (ADS)

Energetic particles, electrons and protons either directly associated with solar flares or trapped in the terrestrial radiation belt, have a profound space weather impact. A National Science Foundation supported 3U CubeSat mission with a single instrument, Relativistic Electrons and Proton Telescope integrated little experiment (REPTile), is proposed to address fundamental scientific questions relating to these high energy particles. Of key importance are the relation-ship between solar flares and energetic particles and the acceleration and loss mechanism of outer radiation belt electrons. REPTile, operating in a highly inclined low earth orbit, will measure differential fluxes of relativistic electrons in the energy range of 0.5-3.5 MeV and pro-tons in 10-40 MeV. The Colorado Student Space Weather Experiment cubesat will be designed, integrated and testing by students at the University of Colorado under the oversight of pro-fessional engineers with the Laboratory of Atmospheric and Space Physics who have extensive space hardware experience. Our design philosophy is to use commercially off the shelf (COTS) parts where available and only engage in detailed designed where COTS parts cannot meet the system needs. The top level science requirements for the mission have driven the system and subsystem level performance requirements and the specific design choices such as a passive magnetic attitude system and instrument design. In this paper we will present details of the CSSWE design and management approach. Specifically we will discuss the top level science requirements for the mission and show that these measurements are novel and will address open questions in the scientific community. The overall system architecture resulting from a flow-down of these requirements will be presented with a focus on the novel aspects of the system including the instrument design. Finally we will discuss how this project is organized and man-aged as part of the Department of Aerospace Engineering graduate projects course sequence along with the integration of professional engineers in the program. It is often underappreciated that the management of a student project, given the transient nature of the students in the program, is more challenging than many of the technical aspects. We will discuss our process to managing this project risk along with our pedagological philosophy for student learning and its relationship to a small satellite program.

Palo, Scott; Li, Xinlin; Gerhardt, David; Turner, Drew; Hoxie, V.; Kohnert, Rick; Batiste, Susan

52

Rock weathering processes and landform development in the Sør Rondane Mountains, Antarctica  

NASA Astrophysics Data System (ADS)

Field observations of weathering processes and the related landforms, combined with laboratory analyses of weathering products, permit a synthetic evaluation of Late Cenozoic weathering environments in the Sør Rondane Mountains, Antarctica, an arid upland characterized by low temperatures and strong winds. Rates and character of weathering depend mainly on moisture availability and the bedrock geology. Under the humid weathering regime that occurs only locally around the margin of the present sheet, frequent diurnal freeze-thaw cycles in summer cause relatively rapid rock fragmentation. Most of the mountains are situated in the arid weathering regime, under which rock breakdown is very slow unless the rock contains plenty of salts. Salt weathering becomes more intensive and extensive with exposure age, as a result of salt accumulation in rock, eventually producing soils as small as fine-silt size. Lack of clay mineralization even in weathered rocks having been exposed above the ice sheet prior to 4 Ma ago indicates that hydrolysis or carbonation of rock minerals has been insignificant during the past 4 Ma. The final products of weathering are due mainly to salt action and reflect the parent lithology. Resistant fine-grained granite forms strongly oxidized tors carved with tafoni, or fields of mushroom-like boulders overlying the fractured bedrock. Less resistant rocks, like biotite gneiss and amphibolite, produce stone pavements underlain by saline, silty soils up to 30-40 cm thick, the thickness of which corresponds to the maximum thaw depth.

Matsuoka, Norikazu

1995-07-01

53

Physical limits on information processing  

NASA Astrophysics Data System (ADS)

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.

Hsu, Stephen D. H.

2006-09-01

54

Weathering and Erosion  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses weather conditions and their contribution to weathering and erosion. Students learn to explain the process of physical and chemical weathering. They also learn to compare and contrast erosion resulting from wind, ice and water. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

55

Processing of Indian Doppler Weather Radar data for mesoscale applications  

NASA Astrophysics Data System (ADS)

This paper demonstrates the usefulness of Indian Doppler Weather Radar (DWR) data for nowcasting applications, and assimilation into a mesoscale Numerical Weather Prediction (NWP) model. Warning Decision Support System Integrated Information (WDSS-II) developed by National Severe Storm Laboratory (NSSL) and Advanced Regional Prediction System (ARPS) developed at the Centre for Analysis and Prediction, University of Oklahoma are used for this purpose. The study reveals that the WDSS-II software is capable of detecting and removing anomalous propagation echoes from the Indian DWR data. The software can be used to track storm cells and mesocyclones through successive scans. Radar reflectivity mosaics are created for a land-falling tropical cyclone—Khaimuk of 14 November 2008 over the Bay of Bengal using observations from three DWR stations, namely, Visakhapatnam, Machilipatnam and Chennai. Assimilation of the quality-controlled radar data (DWR, Chennai) of the WDSS-II software in a very high-resolution NWP model (ARPS) has a positive impact for improving mesoscale prediction. This has been demonstrated for a land-falling tropical cyclone Nisha of 27 November 2008 of Tamil Nadu coast. This paper also discusses the optimum scan strategy and networking considerations. This work illustrates an important step of transforming research to operation.

Roy Bhowmik, S. K.; Sen Roy, Soma; Srivastava, Kuldeep; Mukhopadhay, B.; Thampi, S. B.; Reddy, Y. K.; Singh, Hari; Venkateswarlu, S.; Adhikary, Sourav

2011-03-01

56

Modeling land-surface processes and land-atmosphere interactions in the community weather and regional climate WRF model (Invited)  

NASA Astrophysics Data System (ADS)

The Weather Research and Forecasting (WRF) model has been widely used with high-resolution configuration in the weather and regional climate communities, and hence demands its land-surface models to treat not only fast-response processes, such as plant evapotranspiration that are important for numerical weather prediction but also slow-evolving processes such as snow hydrology and interactions between surface soil water and deep aquifer. Correctly representing urbanization, which has been traditionally ignored in coarse-resolution modeling, is critical for applying WRF to air quality and public health research. To meet these demands, numerous efforts have been undertaken to improve land-surface models (LSM) in WRF, including the recent implementation of the Noah-MP (Noah Multiple-Physics). Noah-MP uses multiple options for key sub-grid land-atmosphere interaction processes (Niu et al., 2011; Yang et al., 2011), and contains a separate vegetation canopy representing within- and under-canopy radiation and turbulent processes, a multilayer physically-based snow model, and a photosynthesis canopy resistance parameterization with a dynamic vegetation model. This paper will focus on the interactions between fast and slow land processes through: 1) a benchmarking of the Noah-MP performance, in comparison to five widely-used land-surface models, in simulating and diagnosing snow evolution for complex terrain forested regions, and 2) the effects of interactions between shallow and deep aquifers on regional weather and climate. Moreover, we will provide an overview of recent improvements of the integrated WRF-Urban modeling system, especially its hydrological enhancements that takes into account the effects of lawn irrigation, urban oasis, evaporation from pavements, anthropogenic moisture sources, and a green-roof parameterization.

Chen, F.; Barlage, M. J.

2013-12-01

57

K-Ar and 40Ar/39Ar Geochronology of Weathering Processes  

NASA Astrophysics Data System (ADS)

Recent developments in the application of K-Ar and 40Ar/39Ar dating of continental weathering process demonstrate the method's suitability for dating minerals present in weathering profiles. Alunite-group sulfates and hollandite-group manganese oxides, which often precipitate through weathering reactions, were first analyzed by the K-Ar method 30 years ago. Recently these minerals were shown to be suitable to 40Ar/39Ar geochronology, despite their fine-grained habits. The bulk nature of the K-Ar technique and the complex mineral assemblages in weathering profiles restrict K-Ar dating of weathering processes. The single-crystal approach possible with the 40Ar/39Ar method allows the study of weathering profiles where alunite- and hollandite-group minerals occur as minor phases. Step-heating analysis possible with the 40Ar/39Ar method provides information about the Ar and K retention histories, the presence of hypogene contaminants, and possible 39Ar recoil during sample irradiation. Fully automated, modern 40Ar/39Ar systems enable analysis of several samples, providing a comprehensive weathering database. These results are useful in the study of continental paleoclimates and the geochemical, geomorphological, and tectonic histories of an area.

Vasconcelos, P. M.

58

Physical-chemical weathering of petroleum hydrocarbons from the Ixtoc I blowout: chemical measurements and a weathering model  

Microsoft Academic Search

Detailed chemical measurements of the saturated and aromatic hydrocarbon composition of surface oil\\/mousse, surface microlayer, and water column samples were coupled to attempts to model the chemical weathering of oil from the Ixtoc I blowout. Such a modeling effort, rooted firmly in analytical measurements on samples for an actual major spill, has been attempted here for the first time. The

Paul D. Boehm; David L. Fiest; Donald Mackay; Sally Paterson

1982-01-01

59

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)

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.

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

2014-05-01

60

Physical and chemical weathering rates and CO 2 consumption in a tropical lateritic environment: the upper Niger basin  

Microsoft Academic Search

The chemical composition of Niger river water measured bimonthly at Bamako (Mali) during the period 1990–1992 provides an estimate of present weathering rates in the upper Niger basin. The dominant weathering process is kaolinite formation (`monosiallitization'). However, seasonal variations promote gibbsite formation in the rainy season (September) and smectite development in the dry season (May). The results show that lateritic

Jean-Loup Boeglin; Jean-Luc Probst

1998-01-01

61

SEVAN particle-detector network for Solar Physics and Space Weather research  

NASA Astrophysics Data System (ADS)

A network of detectors called SEVAN (Space Environmental Viewing and Analysis Network) is planned in the framework of the International Heliophysical Year (IHY), to improve fundamental research of the Solar accelerators and Space Weather conditions. The network will detect changing fluxes of the most of species secondary cosmic rays at different altitudes, latitudes and altitudes those constituting powerful integrated device in exploration of solar modulation effects. Surface particle detectors measure time series of secondary particles born in cascades originated in the atmosphere by nuclear interactions of the "primary" protons and nuclei accelerated in galaxy. During violent solar explosions sometimes additional particles, accelerated at sun's environments, are added to this "background" flux. If solar particles are energetic enough they also will generate secondary particles reaching earth surface. Therefore, registration of changing time series of secondary particles shed light on the high-energy particle acceleration mechanisms by solar flares and Coronal Mass Ejection driven shocks. Network of particle detectors located at middle-to-low latitudes is sensitive to the highest energy solar particles. The enigma of particle acceleration in supernovae remnants, super-massive black holes, clusters of galaxies can be researched using particle beams accelerated by sun and detected at earth. The shock acceleration is a universal process responsible for the same physical process (particle acceleration) on the different scales. Time series of intensities of high energy particles can also provide highly cost-effective information on the key characteristics of the disturbances of interplanetary magnetic field. Recent results on of the detection of the extreme solar events (2003, 2005) by the monitors of the Aragats Space-Environmental Center (ASEC) illustrate wide possibilities opening with introduction of new particle detectors measuring neutron, electron and muon fluxes with inherent correlations. One of the major advantages of multi-particle detectors is probing of the different populations of the primary cosmic rays, initiated particle cascades in terrestrial atmosphere. With basic detector of SEVAN network we are measuring fluxes of neutrons and gammas, of low energy charged component and high energy muons. This diversity of information obtained from SEVAN network located mostly at low and middle latitudes will give possibility to estimate the energy spectra of the highest energy SCR. SEVAN network will be sensitive to very weak fluxes of SCR above 10 GeV, very poorly explored highest energy region. First modules of SEVAN network are in operation in Armenia, in 2008 SEVAN modules were installed in Croatia and Bulgaria, in 2009 we plan to install new SEVAN modules in Slovakia and India.

Chilingarian, A.

2009-04-01

62

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...

63

Experimental simulations of the physical weathering of a rhyolitic glaciovolcanic glass  

NASA Astrophysics Data System (ADS)

Hyaloclastites are a common eruption product formed during subglacial eruptions. These glassy materials are often found in periglacial environments and they are highly abundant in the environments in Iceland and on planet Mars. Physical weathering results therefore primarily from freeze-thaw cycles and abrasion during aeolian transport. We studied various facets of the mechanical modification of these materials using a fresh rhyolitic hyaloclastite from the Bláhnúkur edifice in Torfajökull (Iceland). Experiments were set up to simulate the environmental conditions during freeze-thaw cycles. Physico-mechanical properties were measured for understanding scale effects from freezing of water inside pores and tensile strengths from volumetric expansion of ice. Fracturing was found to occur primarily by crystallisation inside larger vesicles and interparticle pore spaces, whereas surface pores only marginally contributed to superficial crack propagation. Experimental simulations of aeolian abrasion consisted of tumbling sand-sized particles for 15 weeks (equivalent to transport distances of >500 km) in rotating drums. Compared to the effects of ice-induced weathering, abrasion only leads to marginal textural alterations. Larger, centimetre-sized components in glassy breccias are therefore considered to be most susceptible to the destructive effects of periglacial environments and contribute the most to the formation of new sandy textures.

de Vet, Sebastiaan; Mittelmeijer-Hazeleger, Marjo; Braakhekke, Jochem; Cammeraat, Erik

2013-04-01

64

Performance of a high-rate sedimentation process for combined sewerage treatment in wet weather  

Microsoft Academic Search

A novel high-rate sedimentation process has been developed for directly treating combined sewer overflows (CSOs). This was done using a test facility at an actual wastewater treatment plant in Tokyo. Pilot test results, carried out 13 times, from December 2002 to July 2003 in wet weather, suggested that the process was suitable for treatment of CSOs. The performance of the

K. Suzuki; T. Fujihashi; S. Kosanda; H. Hinum; R. Hat

65

Space Weather data processing and Science Gateway for the Van Allen Probes  

NASA Astrophysics Data System (ADS)

A near real-time data processing pipeline for the Space Weather broadcast data from the Van Allen Probes is presented. The Van Allen Probes broadcasts a sub-set of the science data in real-time when not downlinking the principal science data. This broadcast is received by several ground stations and relayed to APL in near real time to be ingested into the space weather processing pipeline. This pipeline processes the available level zero space weather data into higher level science data products. These products are made available to the public via the Van Allen Probes Science Gateway website (http://athena.jhuapl.edu). The website acts as pivotal point though which all other instrument SOC's can be accessed. Several other data products (e.g KP/DST indices) and tools (e.g orbit calculator) are made also available to the general public.

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

2013-12-01

66

Physical and chemical weathering in modern and Permian proximal fluvial systems  

NASA Astrophysics Data System (ADS)

Chapter 1 Inferring paleoclimate from ancient fluvial strata can be challenging, and conflicting interpretations for a given system are common in the literature. This research uses a combination of physical and chemical weathering signals in an attempt to better define the paleoclimatic interpretations for the proximal Cutler Formation near Gateway, Colorado (Chapter 3) and the Post Oak Conglomerate in the Wichita Mountains, Oklahoma (Chapter 4), both Permian units. Chapter 4 includes a comparison of weathering signals from modern sediments in the Wichita Mountains. A methodology for pretreatment techniques used for grain-size analysis was evaluated during the course of the research and is the topic of Chapter 2. This dissertation is organized as three stand-alone manuscripts and a brief summary of each is presented below. Chapter 2 Pretreatment drying of mud-sized sediment (<63 im) resulted in clayrich (>39%) samples exhibiting more sensitivity to drying techniques than clay-poor (<39%) samples. This demonstrates an influence of the drying technique on the granulometric results. Employing freeze drying for sample drying yielded the most consistent results. However, for samples with <39% clay-sized material, all drying techniques are equally effective, and no apparent need exists for the extra effort (and expense) that accompanies freeze drying. Chapter 3 Scanning Electron Microscopy is a useful tool in the study of quartz grain microtextures. Microtextures on quartz grains from the proximal Cutler Formation near Gateway, CO were documented for the presence/absence of 18 distinct microtextures. Averaging of presence/absence data for the samples provided a means to use more quantitative techniques than previously employed for SEM microtextural analysis. These continuous quantitative variables were utilized for non-metric multidimensional scaling, a purely quantitative technique that does not rely on initial assumptions of what environments produce specific microtextures. Chapter 4 The Post Oak Conglomerate was deposited in a climate much wetter than the modern climate of the Wichita Mountains today. Significant amounts of clay, high percentages of Al2O3 in the mud fraction, spheroidal weathering, thick weathering rinds, and hyperconcentrated flood flow deposits are prominent in the Post Oak conglomerate and lacking in the modern Blue Beaver Creek sediment. When compared to other modern climates, the Post Oak Conglomerate fits best with a tropical climate. The climate of the region for the Early Permian is commonly interpreted to be arid. However; these results suggest a brief time period of wet conditions in the Wichita Mountains prior to the onset of the aridity documented in younger Permian units of the area.

Keiser, Leslie Jo

67

Processing and Interpretation of Alternately Polarised Weather Radar Echoes.  

National Technical Information Service (NTIS)

Processing methods to derive polarimetric measurables differential phase constant K sub DP, and the correlation coefficient between horizontally and vertically polarized echoes, rho HV(o) simultaneously with Doppler velocity from an alternating sequence o...

D. S. Zrnic N. Balakrishnan M. Sachidananda

1988-01-01

68

Physical Fitness and the Stress Process  

ERIC Educational Resources Information Center

In the current paper we focus on the role of physical fitness in the life stress process for both psychological and physical well-being. The major research question posed in the current study is: Does physical fitness deter distress in a model containing the major components of the life stress process? That is, do individuals who exercise show…

Ensel, Walter M.; Lin, Nan

2004-01-01

69

The relationships between weather-related factors and daily outdoor physical activity counts on an urban greenway.  

PubMed

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

Wolff, Dana; Fitzhugh, Eugene C

2011-02-01

70

RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

On August 23, 2012, 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 have been 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. The space weather data will be available on the RBSP Science Gateway at http://athena.jhuapl.edu/ 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.

Weiss, M.; Fox, N. J.; Mauk, B. H.; Barnes, R. J.; Potter, M.; Romeo, G.; Smith, D.

2012-12-01

71

Chemical weathering processes in the Yalong River draining the eastern Tibetan Plateau, China  

NASA Astrophysics Data System (ADS)

To better understand chemical weathering and controlling processes in the Yalong River of the eastern Tibetan Plateau, this study presents major ion concentrations and stable isotopes of the dissolved loads. The isotopic compositions (?13C-DIC, ?34S and ?18O-SO4) of the dissolved loads are very useful to quantify solute sources and define the carbon budget related with chemical weathering in riverine systems. The isotopic composition of sulphate demonstrates that most of the sulphate is derived from sulphide oxidation, particularly in the upper reach of the Yalong River. The correlations between ?13C-DIC, water chemistry and isotopes of sulphate, suggest that the carbon dynamics are mainly affected by carbonate weathering by sulphuric acid and equilibration processes. Approximately 13% of the dissolved inorganic carbon in the Yalong River originates from carbonate weathering by strong acid. The CO2 consumption rates are estimated to be 2.8 × 105 mol/km2/yr and 0.9 × 105 mol/km2/yr via carbonate and silicate weathering in the Yalong River, respectively. In this study, the influence of sulphide oxidation and metamorphic CO2 on the carbon budget is estimated for the Yalong River draining the eastern Tibetan Plateau.

Li, Si-Liang; Chetelat, Benjamin; Yue, Fujun; Zhao, Zhiqi; Liu, Cong-Qiang

2014-07-01

72

Working Process Development For Weathering Degree Mapping Of Stone Monument Using Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

Most stone monuments have been weathered on the field with exposure of rain and wind during hundreds or thousands years. Reflectance spectroscopy can be applied to assess weathering degree of those stone monuments composed of granite which is the most general material of stone monument in Korea. Weathering degree was analyzed by using reflected and transmitted electromagnetic energy based on the theory of reflectance spectroscopy on the surface of rock to identify rock forming minerals using their diagnostic spectral absorption features. This method could be used as an improved nondestructive assessment method compared with conventional subjective and qualitative assessment methods. We tested feasibility of this technique for actual granite stone monuments. Granite is generally composed of quartz, feldspars and micas. Feldspars are changed to clay minerals such as kaolinite and illite after weathering process. Biotite of mica produce iron oxides which induce color changes on surface of rocks. The experiments were conducted using field spectrometer FieldSpec®3 of ASD Inc. and the range of measurement was form 350µm to 2500µm wavelength. Spectral reflectance of weathering products at each measuring point was processed by removing delineated convex hull from raw reflectance curves to exclude background effects and to extract quantitative absorption depths which indicate relative distribution degree of weathering products. We produced deterioration map on the surface of the monument by interpolating absorption depth values of each point with consideration of spatial distribution of measurements. For facilitation of practical uses a chain of working process of this method was designed using whole experimental processes.

Hyun, C.; Park, H.

2008-12-01

73

Comparison of rate of physical and chemical decomposition of rocks in weathering by wetting-drying and wetting-freezing-drying cycles  

NASA Astrophysics Data System (ADS)

The type and amount of weathering is determined by a complex combination of physico-chemical properties of the material and climatic conditions. Different materials respond differently in the same environments, but also the same materials can respond in different ways to the same processes in different environments. Weathering processes are often acting simultaneously at one site and it is sometimes hard to determine the exact weathering process that resulted in a certain weathering product. Rock characteristics, alternation of wetting and drying cycles and presence of joints and fissures are crucial for weathering processes. However, there is a big difference in the material response to precipitation depending on whether or not it is followed by freezing when more deterioration occurs. In order to study in detail the behaviour of different rocks under moisture and temperature regimes, weathering experiments with multiple cycles were carried out. The aim of these experiments was to obtain data about dynamics of decomposition of rocks under controlled laboratory conditions. Six rocks were selected for the weathering experiments due to their geological setting in mountain regions and their physico-chemical and mineralogical characteristics: red and grey sandstone (Germany), red sandstone (Serbia), tuffaceous rock (Island), gabbro (Serbia), and dunite (Germany). Samples of each of these rocks were examined in two separate experimental sets. First set consisted of 10 identical cycles that included 4 steps: raining, freezing, thawing and drying. After each step, sample mass was measured. Second set also had 10 cycles, but consisted of two steps: raining and drying. Leachate was collected after each cycle during both sets and volume, pH and conductivity was measured. Contents of Ca, K, Mg, Si, Al and Fe were determined in collected leachate after cycles 1, 5 and 10. Leachate characteristics were similar in both experimental sets. Volume, conductivity and pH of leachate were constant throughout all cycles. Furthermore, the concentrations of analyzed elements in the leachate were low throughout both sets of the experiment. As expected, freezing of samples did not show significant influence on concentration of tested elements in the leachate. However, the rate of mass loss differentiated samples from two experimental sets. Mass loss in samples submitted to freezing was constantly increasing with the number of cycles for all tested rocks. According to mass loss, dunite was most quickly deteriorating from all tested rocks during both experimental sets. Dunite lost about twice as much mass when frozen then when rained on. Both red sandstones behaved similarly to dunite. On the contrary, mass loss in grey sandstone, tuffaceous rock and gabbro during raining was <1%, but increased 4 times with freezing. Rock characteristics crucial for weathering are mineralogical composition and physico-mechanical characteristics. Obtained results indicate that the physical weathering processes are important in all tested rocks. Furthermore, they indicate that the rate of physical weathering during rainfall is not an indication of deterioration that will occur during freezing. Key words: weathering experiment, raining, freezing, rocks

Vezmar, T.; Kasanin-Grubin, M.; Kuhn, N. J.; Milovanovic, D.

2012-04-01

74

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

Microsoft Academic Search

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

P. Stelling; S. Wuotila; M. Giuliani

2006-01-01

75

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

Microsoft Academic Search

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

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

2010-01-01

76

Kinetic Processes in Solar Physics  

NASA Astrophysics Data System (ADS)

Non-maxwellian particle distributions seem to occur commonly in the collisionless conditions of the corona and solar wind. The most extreme examples accompany the events of solar flares, when we find ions on occasions attaining energies in the 10 GeV range. In the denser atmosphere, temperature scale lengths comparable to mean free paths will induce strongly non-maxwellian distributions. Even when there is no direct evidence for their presence, we must expect these to be present in low density plasmas. How do we account for these distributions? What roles must they play in energy transport, in equilibrium and stability, in the interpretation of diagnostics? We first review some textbook ideas on the situations that demand kinetic descriptions, and the extent to which this can be achieved via moment descriptions. We next consider some key problems in solar physics: thermal conductivity in steep temperature gradients; energy release and particle acceleration in solar flares; the origin of non-maxwellian velocity distributions in the solar wind; coherent radio emission. In each case we try to characterise the problem in a general way, then discuss some recent advances in understanding. We conclude with some comments on the implications of such distributions in situations where their presence is at first not recognised.

MacKinnon, A.

2008-09-01

77

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

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

78

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

NASA Technical Reports Server (NTRS)

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.

Barrett, Joe H., III; Hood, Doris

2009-01-01

79

Automatic processing, quality assurance and serving of real-time weather data  

NASA Astrophysics Data System (ADS)

Recent advances in technology have produced a significant increase in the availability of free sensor data over the Internet. With affordable weather monitoring stations now available to individual meteorology enthusiasts, a reservoir of real time data such as temperature, rainfall and wind speed can now be obtained for most of the world. Despite the abundance of available data, the production of usable information about the weather in individual local neighbourhoods requires complex processing that poses several challenges. This paper discusses a collection of technologies and applications that harvest, refine and process this data, culminating in information that has been tailored toward the user. In this instance, this allows a user to make direct queries about the weather at any location, even when this is not directly instrumented, using interpolation methods provided by the INTAMAP project. A simplified example illustrates how the INTAMAP web processing service can be employed as part of a quality control procedure to estimate the bias and residual variance of user contributed temperature observations, using a reference standard based on temperature observations with carefully controlled quality. We also consider how the uncertainty introduced by the interpolation can be communicated to the user of the system, using UncertML, a developing standard for uncertainty representation.

Williams, Matthew; Cornford, Dan; Bastin, Lucy; Jones, Richard; Parker, Stephen

2011-03-01

80

Human information processing during physical exercise  

Microsoft Academic Search

This study was designed to investigate how conditions of physical exercise affect human information processing. Sixteen subjects performed two information processing tasks (perception and decision) during two exercise conditions (endurance vs interval protocols) and during two control conditions (rest vs minimal load protocols). The control conditions required subjects either to perform the information processing tasks under resting conditions or while

FRED G. W. C. PAAS; JOS J. ADAM

1991-01-01

81

Adaptive contrast enhancement involving CNN-based processing for foggy weather conditions & non-uniform lighting conditions  

Microsoft Academic Search

Adaptive image processing in the context of Ad- vanced Driver Assistance Systems (ADAS) is a crucial issue because bad weather conditions lead to poor vision. In a foggy weather, image contrast and visibility are low due to the presence of airlight that is generated by scattering light, which in turn is caused by fog particles. Since vision based ADAS are

Christopher Schwarzlmuller; Fadi Al Machot; Alireza Fasih; Kyandoghere Kyamakya

2011-01-01

82

WHEAT KERNEL PHYSICAL PROPERTIES AND MILLING PROCESS  

Microsoft Academic Search

A b s t r a c t . Studies concerning the relations between wheat kernel physical properties and milling properties have been carried out since the beginning of the cereal processing industry. The aim of the present work was to show the application of the most important physical properties of wheat for the evaluation of wheat technological qua lity,

Dariusz Dziki; Janusz Laskowski

83

Scattering processes in atomic physics, nuclear physics, and cosmology  

NASA Astrophysics Data System (ADS)

The universal way to probe a physical system is to scatter a particle or radiation off the system. The results of the scattering are governed by the interaction Hamiltonian of the physical system and scattered probe. An object of the investigation can be a hydrogen atom immersed in a laser field, heavy nucleus exposed to a flux of neutrons, or space-time metric perturbed by the stress-energy tensor of neutrino flux in the early Universe. This universality of scattering process designates the Scattering Matrix, defined as the unitary matrix of the overlapping in and out collision states, as the central tool in theoretical physics. In this Thesis we present our results in atomic physics, nuclear physics, and cosmology. In these branches of theoretical physics the key element that unifies all of them is the scattering matrix. Additionally, within the scope of Thesis we present underlying ideas responsible for the unification of various physical systems. Within atomic physics problems, namely the axial anomaly contribution to parity nonconservation in atoms, and two-photon resonant transition in a hydrogen atom, it was the scattering matrix which led to the Landau-Yang theorem, playing the central role in these problems. In scattering problems of cosmology and quantum optics we developed and implemented mathematical tools that allowed us to get a new point of view on the subject. Finally, in nuclear physics we were able to take advantage of the target complexity in the process of neutron scattering which led to the formulation of a new resonance width distribution for an open quantum system.

Shchedrin, Gavriil

84

Iron weathering products in a CO 2 + (H 2O or H 2O 2) atmosphere: Implications for weathering processes on the surface of Mars  

NASA Astrophysics Data System (ADS)

Various iron-bearing primary phases and rocks have been weathered experimentally to simulate possible present and past weathering processes occurring on Mars. We used magnetite, monoclinic and hexagonal pyrrhotites, and metallic iron as it is suggested that meteoritic input to the martian surface may account for an important source of reduced iron. The phases were weathered in two different atmospheres: one composed of CO 2 + H 2O, to model the present and primary martian atmosphere, and a CO 2 + H 2O + H 2O 2 atmosphere to simulate the effect of strong oxidizing agents. Experiments were conducted at room temperature and a pressure of 0.75 atm. Magnetite is the only stable phase in the experiments and is thus likely to be released on the surface of Mars from primary rocks during weathering processes. Siderite, elemental sulfur, ferrous sulfates and ferric (oxy)hydroxides (goethite and lepidocrocite) are the main products in a water-bearing atmosphere, depending on the substrate. In the peroxide atmosphere, weathering products are dominated by ferric sulfates and goethite. A kinetic model was then developed for iron weathering in a water atmosphere, using the shrinking core model (SCM). This model includes competition between chemical reaction and diffusion of reactants through porous layers of secondary products. The results indicate that for short time scales, the mechanism is dominated by a chemical reaction with second order kinetics ( k = 7.75 × 10 -5 g -1/h), whereas for longer time scales, the mechanism is diffusion-controlled (De A = 2.71 × 10 -10 m 2/h). The results indicate that a primary CO 2- and H 2O-rich atmosphere should favour sulfur, ferrous phases such as siderite or Fe 2+-sulfates, associated with ferric (oxy)hydroxides (goethite and lepidocrocite). Further evolution to more oxidizing conditions may have forced these precursors to evolve into ferric sulfates and goethite/hematite.

Chevrier, V.; Mathé, P.-E.; Rochette, P.; Grauby, O.; Bourrié, G.; Trolard, F.

2006-08-01

85

Cockpit Weather Information Needs.  

National Technical Information Service (NTIS)

The primary objective is to develop an advanced pilot weather interface for the flight deck and to measure its utilization and effectiveness in pilot reroute decision processes, weather situation awareness, and weather monitoring. Identical graphical weat...

C. H. Scanlon

1992-01-01

86

External Resource: Mechanical Weathering  

NSDL National Science Digital Library

A student activity with teacher's sheet, to give the students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Mechanical weathering is the process of breaking down bedroc

1900-01-01

87

Biological processes and links to the physics  

NASA Astrophysics Data System (ADS)

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.

Hinrichsen, Hans-Harald

2009-10-01

88

Weathering processes as predisposing factors of the landscape evolution along plutono-metamorphic profiles of the Sila Massif, Calabria, southern Italy  

NASA Astrophysics Data System (ADS)

This work is aimed to join interdisciplinary research topics of weathering profile stages on plutonic (granitoid) and metamorphic (gneissic) rocks related to tectonic and landscape evolution of the western Sila Grande Massif (southern Italy). The grain-size of the studied samples is related to the parent rocks in response to physical and chemical weathering processes. Weathering processes produce an unconsolidated rock characterized by sand-gravel grain-size fraction for the granitoid rocks and by sand-silt grain-size fraction for the gneissic rocks. Chemical and mineralogical analyses confirm the granulometric observations. The difference between granitoid and gneissic rocks are mainly related to a higher content of quartz and feldspars for the first one rock type, whereas the second rock type shows higher content of neoformed clay minerals as well expandable phases. The main mineralogical changes concern the partial transformation of biotite and the partial destruction of feldspars, associated with the neoformation of secondary minerals (clay minerals and Fe-oxides) during the most advanced weathering stage; these processes also produce a substitution of the original rock fabric. All these petrological, chemical and mineralogical observations associated to microfractures and morphological variations occur on both plutonic and metamorphic original rocks and, thereby, affect the surrounding landscape processes. Generally, the granitoid profiles are regular and simple, characterized by gradual variation in the degree of weathering from bottom to top; where granitoid rocks show strong morphologies characterized by high relief energy and steep slopes, earth and debris slides, soil slips and earth flow can occur especially when fresher granitoids is near the surface and is covered by organic debris, colluvium, or soil. The gneissic profiles are characterized by structural complexity may be related to several factors such as presence of faults, high state of fracturing and the compositional heterogeneity of the gneiss. These profile characteristics are strongly related to the tectonic setting of the studied area. In particular, many fractured zone associated to fault planes and completely degraded rocks associated to thrust planes have been observed along the cutslope studied, where physical and chemical weathering produce argillified levels. These profile features represents a predisposing factor to the development of mass movements such as deep landslide (e.g., rock slide) and DSGSD (Deep Seated Gravitational Slope Deformation) in the fresher rocks. The weathering puzzle resulting from this preliminary study, based on the reconstruction of the weathering profiles in the plutonic and metamorphic rocks will help to evaluate the landslides susceptibility and hazard assessment in homogeneous geological context.

Perri, Francesco; Borrelli, Luigi; Muto, Francesco; Gullà, Giovanni; Critelli, Salvatore; Conforti, Massimo; Filomena, Luciana; Rago, Valeria

2013-04-01

89

A new CO 2 disposal process via artificial weathering of calcium silicate accelerated by acetic acid  

Microsoft Academic Search

A new disposal process for anthropogenic CO2 via an artificially accelerated weathering reaction is proposed to counteract global warming. The process is essentially composed of the following two steps:(1)CaSiO3+2CH3COOH?Ca2++2CH3COO?+H2O+SiO2(2)Ca2++2CH3COO?+CO2+H2O?CaCO3?+2CH3COOHStep (1) is the extraction of calcium ions by acetic acid from calcium silicate, for example, wollastonite rocks. Step (2) is the deposition of calcium carbonate from the solution of calcium ions

M. Kakizawa; A. Yamasaki; Y. Yanagisawa

2001-01-01

90

Multi Physics Modelling of the Electrodeposition Process  

Microsoft Academic Search

This paper describes ongoing research into the development of multi-physics models of the electrodeposition process. This is part of the collaborative project - MEMSA (modelling the electrodeposition process for microsystems applications) - between the universities of Greenwich and Heriott-Watt, and our industrial partners: Merlin Circuits and Raytheon Systems. The aim of this research is to build numerical models that can

M. Hughes; C. Bailey; K. McManus

2007-01-01

91

Ultramafic rock weathering and slope erosion processes in a South West Pacific tropical environment  

NASA Astrophysics Data System (ADS)

Weathering and erosion processes are investigated using electrical resistivity tomography (ERT) imaging and the quantification of geomorphic patterns at the edges of a lateritic plateau overlying ultramafic rocks in the north western region of the main island of New Caledonia (Southwest Pacific). The obtained ERT images document the structure and long-term evolution of the regolith, while source area parameters such as area ( A) local slope above channel head (tan ?) and longitudinal river profiles allow the characterization of contrasting geomorphic patterns around the plateau. The geo-electrical profiles show a succession of hard rock protrusions and weathering troughs, whose depth varies greatly. The area-slope relationship allows the distinction between saprolite- and ferricrete-mantled source areas. The former could result from a regolith erosion process by shallow landslides; the latter from a secondary ferruginization process of reworked lateritic debris. The deepest troughs underlie saprolite-mantled source areas above channel heads, which are characterized by a low permeability saprolite, relatively high slope gradient, and lower area/slope ratios. Such source areas generate fairly high runoff, sustaining rivers and creeks with relatively high erosion power. The ferricrete-mantled source areas are characterized by higher permeability and area/slope ratios, leading to lower runoff and less erosion but further chemical rock weathering. The ferricrete of those source areas acts as a protective hardcover against mechanical erosion of the underlying regolith. This ferricrete reworks, at least partly, allochtonous lateritic materials inherited from a previous disaggregated ferricrete that suggests past erosion processes driven by hydro-climatic condition changes.

Beauvais, Anicet; Parisot, Jean-Claude; Savin, Cécile

2007-01-01

92

Local topography of Mars and its relationship to surface weathering processes  

NASA Technical Reports Server (NTRS)

There is a growing body of evidence in favor of the importance of aqueous sedimentary processes on Mars. It is important to understand the role that surface weathering processes have played in the development of the present morphology of the Martian surface. Such an understanding is important not only for its relevance to the study of volatile sources and sinks on Mars through time, but also for its relevance to Martian geologic and tectonic history. Starting in the fall of this year, the Mars Observer Laser Altimeter will begin sending back to Earth data on the topography of Mars that is of a higher quality than most of the topography data available for the Earth. This data will be invaluable, not only for understanding global and large-scale regional processes and landforms on Mars, but also for the study of local and smaller-scale regional processes and landforms. Digital topography is an important part of geologic and geomorphic studies, useful in distinguishing between different lithologies and between different types of weathering. Digital topography data may be used to study a wide variety of local and regional-scale landforms, including valleys, sand dunes, lava flows, landslides, and slopes. Topography data are also essential to the analysis of spectral response patterns, especially in areas of high topographic relief. Geomorphic classification can be significantly improved by the addition of topographic information.

Schaefer, M. W.

1993-01-01

93

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

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

94

SEVAN particle-detector network for Solar Physics and Space Weather research  

Microsoft Academic Search

A network of detectors called SEVAN (Space Environmental Viewing and Analysis Network) is planned in the framework of the International Heliophysical Year (IHY), to improve fundamental research of the Solar accelerators and Space Weather conditions. The network will detect changing fluxes of the most of species secondary cosmic rays at different altitudes, latitudes and altitudes those constituting powerful integrated device

A. Chilingarian; Ch. Angelov; K. Arakelyan; T. Arsov; K. Avakyan; S. Chilingaryan; A. Hovhannisyan; G. Hovsepyan; D. Hrzina; T. Hovhannisyan; D. Maricic; A. Nishev; A. Tchorbadjieff; I. Kalapov; T. Karapetyan; L. Kozliner; B. Mailyan; A. Reymers; I. Romstajn; D. Rosa; J. Stamenov; S. Tserunyan; A. Yeghikyan

2009-01-01

95

The Colorado Student Space Weather Experiment : A CubeSat for Space Physics  

Microsoft Academic Search

Energetic particles, electrons and protons either directly associated with solar flares or trapped in the terrestrial radiation belt, have a profound space weather impact. A National Science Foundation supported 3U CubeSat mission with a single instrument, Relativistic Electrons and Proton Telescope integrated little experiment (REPTile), is proposed to address fundamental scientific questions relating to these high energy particles. Of key

Scott Palo; Xinlin Li; David Gerhardt; Drew Turner; V. Hoxie; Rick Kohnert; Susan Batiste

2010-01-01

96

Post Processing Numerical Weather Prediction Model Rainfall Forecasts for Use in Ensemble Streamflow Forecasting in Australia  

NASA Astrophysics Data System (ADS)

Through the water information research and development alliance (WIRADA) project, CSIRO is conducting research to improve flood and short-term streamflow forecasting services delivered by the Australian Bureau of Meteorology. WIRADA aims to build and test systems to generate ensemble flood and short-term streamflow forecasts with lead times of up to 10 days by integrating rainfall forecasts from Numerical Weather Prediction (NWP) models and hydrological modelling. Here we present an overview of the latest progress towards developing this system. Rainfall during the forecast period is a major source of uncertainty in streamflow forecasting. Ensemble rainfall forecasts are used in streamflow forecasting to characterise the rainfall uncertainty. In Australia, NWP models provide forecasts of rainfall and other weather conditions for lead times of up to 10 days. However, rainfall forecasts from Australian NWP models are deterministic and often contain systematic errors. We use a simplified Bayesian joint probability (BJP) method to post-process rainfall forecasts from the latest generation of Australian NWP models. The BJP method generates reliable and skilful ensemble rainfall forecasts. The post-processed rainfall ensembles are then used to force a semi-distributed conceptual rainfall runoff model to produce ensemble streamflow forecasts. The performance of the ensemble streamflow forecasts is evaluated on a number of Australian catchments and the benefits of using post processed rainfall forecasts are demonstrated.

Shrestha, D. L.; Robertson, D.; Bennett, J.; Ward, P.; Wang, Q. J.

2012-12-01

97

Geochemical balance of lateritization processes and climatic signatures in weathering profiles overlain by ferricretes in Central Africa  

NASA Astrophysics Data System (ADS)

A simple geochemical balance of lateritization processes governing the development of several tens of meters of weathering profiles overlain by ferricretes is estimated on the basis of detailed mineralogical and geochemical data. The lateritic weathering mantle of the "Haut-Mbomou" area in Central Africa is composed of different weathering layers described from the base to the top of vertical profiles as a saprolite, a mottled clay layer, a soft nodular layer, a soft ferricrete, and a ferricrete in which kaolinite, gibbsite, goethite, and hematite occur in various quantities. Incongruent dissolution of kaolinite leads to the formation of gibbsite in the upper saprolite, whereas the hematite does not clearly replace the kaolinite according to an epigene process in the upper ferruginous layers of the profiles. Instead, that kaolinite is also transformed into gibbsite according to an incongruent dissolution under hydrated and reducing conditions induced by a relatively humid climatic pattern. The respective relations of the silica, iron, and aluminum balances and the Al substitution rate of the hematite on the one hand, and of RHG [RHG = 100 (hematite/hematite + goethite)] and the kaolinite on the other hand, to the consumption or the release of protons H + permit differentiation of aggrading ferruginization and degradation processes operating in the different lateritic weathering profiles. The Al substitution rate of the Fe-oxyhydroxides varies according to the nature of lateritization processes, e.g., saprolitic weathering and aggrading ferruginization vs. degradation. The observations and results indicate that the ferruginization process of the weathering materials of parent rocks is not a simple ongoing process as often thought. This suggests that the actual lateritic weathering mantle of the Haut-Mbomou area may result from different stages of weathering and erosion during climatic changes.

Beauvais, Anicet

1999-12-01

98

Favorite Demonstration: Differential Weathering  

NSDL National Science Digital Library

In this inquiry-based demonstration, the consumption of a Baby Ruth candy bar is used to nurture students' interest in chemical and physical weathering. In addition, two other concepts can be illustrated: the difference between weathering and erosion and

Francek, Mark

2002-10-01

99

Places and Processes: Physical Processes in Shaping Places  

NSDL National Science Digital Library

In this lesson, students analyze the roles of climate, tectonic and other physical processes in shaping places by selecting two states and explaining the processes that may have shaped their current environments. Although it focuses on places in the United States, this lesson can easily be adapted to other regions of the world.

2001-01-01

100

Physical Processes in H II Regions.  

National Technical Information Service (NTIS)

The effects of various physical processes on the structure of H II regions are investigated on the basis of simple dynamical considerations. The parts of an H II region in ionization and thermal equilibrium are considered to have a uniform density, and th...

R. M. Hjellming

1965-01-01

101

Polymer processing: the physics of stretching chains  

Microsoft Academic Search

Recent developments in the physical understanding and the achievement of high chain extension in polymeric material which could lead to significant advances in existing and new areas of polymer processing technology are described. Solid-state deformation and melt and solution orientation are outlined

M. R. Mackley

1978-01-01

102

Space plasma physics: I - Stationary processes  

NASA Technical Reports Server (NTRS)

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.

Hasegawa, Akira; Sato, Tetsuya

1989-01-01

103

Stochastic Process Models in Device Physics.  

National Technical Information Service (NTIS)

The aim of this project was to undertake a statistical study of Monte Carlo methods in device physics using tools from the modern theory of probability and stochastic processes. The Monte Carlo approach has been used to obtain numerical estimates of param...

F. M. Hoppe

1989-01-01

104

Boston University Physics Applets: Cyclic Processes  

NSDL National Science Digital Library

This web page is an interactive physics simulation on cyclic processes. The user can put an engine through four steps, returning it to its original conditions. The work done by the engine is graphed after each step, showing the net work done. This is part of a collection of similar simulation-based student activities.

Duffy, Andrew

2008-08-01

105

Studying the space weather variability of the high-latitude ionosphere by using a physics-based data assimilation model  

NASA Astrophysics Data System (ADS)

The high-latitude ionosphere is a very dynamic region in the solar-terrestrial environment. Frequent disturbances in the region can adversely affect numerous military and civilian technologies. Accurate specifications and forecasts of the high-latitude electrodynamic and plasma structures have fundamental space weather importance for enabling mitigation of adverse effects. We developed a data assimilation model for the high-latitude ionosphere. The model consists of a set of first-principle physical models and an ensemble Kalman filter and assimilates the real-time (or rear real-time) observational measurements. Presently, the model can ingest the magnetic perturbation from the ground-based magnetometers in the high-latitude regions, magnetic measurements of IRIDIUM satellites, SuperDARN line-of-sight velocity, and in-situ drift velocity measured by DMSP satellites. In this presentation, we will show the preliminary results of a systematic study of the space weather variability of the electrodynamic and plasma structures in the high-latitude ionosphere by using our data assimilation model. The study covers the periods of various seasons and geomagnetic conditions. With these results, we would demonstrate the dynamic nature of the high-latitude ionosphere and elucidate the importance of the data assimilation technique for accurate specification and forecasting of space weather.

Zhu, L.; Schunk, R. W.; Scherliess, L.; Eccles, J. V.; Sojka, J. J.

2012-12-01

106

Some topics on geochemistry of weathering: a review.  

PubMed

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

Formoso, Milton L L

2006-12-01

107

Soil biotic processes remain remarkably stable after 100-year extreme weather events in experimental grassland and heath  

Microsoft Academic Search

Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests\\u000a that extreme weather events pose threats to ecosystem functioning, particularly to nutrient cycling and biomass production.\\u000a These ecosystem functions depend strongly on below-ground biotic processes, including the activity and interactions among\\u000a plants, soil fauna, and micro-organisms. Here, experimental grassland and heath communities

Juergen Kreyling; Carl Beierkuhnlein; Michael Elmer; Karin Pritsch; Monica Radovski; Michael Schloter; Jens Wöllecke; Anke Jentsch

2008-01-01

108

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is a set of computer-based learning modules that teach students about meteorology from the point of view of learning how to forecast the weather. The modules were designed as the primary teaching resource for a seminar course on weather forecasting at the introductory college level (originally METR 151, later ATMO 151) and can also be used in the laboratory component of an introductory atmospheric science course. The modules assume no prior meteorological knowledge. In addition to text and graphics, the modules include interactive questions and answers designed to reinforce student learning. The module topics are: 1. How to Access Weather Data, 2. How to Read Hourly Weather Observations, 3. The National Collegiate Weather Forecasting Contest, 4. Radiation and the Diurnal Heating Cycle, 5. Factors Affecting Temperature: Clouds and Moisture, 6. Factors Affecting Temperature: Wind and Mixing, 7. Air Masses and Fronts, 8. Forces in the Atmosphere, 9. Air Pressure, Temperature, and Height, 10. Winds and Pressure, 11. The Forecasting Process, 12. Sounding Diagrams, 13. Upper Air Maps, 14. Satellite Imagery, 15. Radar Imagery, 16. Numerical Weather Prediction, 17. NWS Forecast Models, 18. Sources of Model Error, 19. Sea Breezes, Land Breezes, and Coastal Fronts, 20. Soundings, Clouds, and Convection, 21. Snow Forecasting.

Nielsen-Gammon, John

1996-09-01

109

Real-time storm detection and weather forecast activation through data mining and events processing  

Microsoft Academic Search

Each year across the United States, destructive weather events disrupt transportation and commerce, resulting in both loss of lives and property. Mitigating the impacts of such severe events requires innovative new software tools and cyberinfrastructure through which scientists can monitor data for specific weather events and launch focused modeling computations for prediction and forecasts of these evolving weather events. Bringing

Xiang Li; Beth Plale; Nithya N. Vijayakumar; Rahul Ramachandran; Sara J. Graves; Helen Conover

2008-01-01

110

Challenges of Representing Land-Surface Processes in Weather and Climate Models over the Tropics: Examples over the Indian Subcontinent  

Microsoft Academic Search

Land-surface processes are an important driver for weather and climate systems over the tropics and particularly the Indian subcontinent. Realistic representation of land- surface processes over the Indian region will help accurate simulations of environmen- tal processes at micro, meso, and regional climate scale. However, in order to achieve these potential benefits, it is necessary to develop a strategy through

DEV DUTTA S. NIYOGI; ROGER PIELKE SR; KIRAN ALAPATY; JOSEPH EASTMAN; TEDDY HOLT; U. C. MOHANTY; SETHU RAMAN; T. K. ROY; Y. K. XUE

111

Tires, Worms and Weathering: Investigating the Role of Earthworm Processes in Urban Soils Receiving Roadway Derived Contaminants  

NASA Astrophysics Data System (ADS)

Increased development around urban centers has altered the biogeochemistry of near surface systems. One major impact of development has been an increase in the availability of potentially toxic trace metals in soils and surface waters. A primary source of trace metals to near surface environments in urban systems is roadway runoff and dust. The potential hazard that roadway runoff and dust pose to biota is not well understood and is an area of extensive investigation in the multi-disciplinary field of environmental biogeochemistry. Because earthworms ingest, transport, process and excrete large amounts of soil on a daily basis, earthworms can have a profound impact on soil chemistry and the bioavailability of potentially toxic trace metals. Therefore, it is important to investigate how earthworms are affecting the distribution and bioavailability of potentially toxic metals in the soils that they re-work. Results from a set of mesocosm experiments using the native endogeic earthworm species Eisenoides loennbergi and soils from the Red Run watershed in Baltimore County, MD, exhibit evidence of the physical and chemical earthworm weathering processes over time periods as short as 3 week. The target element for this experiment was Zn which is highly enriched in roadway dust. In this study, 200 g of soil was amended with roadway dust. The total mass of Zn introduced was 20 mg making the target concentration 159 ppm. Six replicates were prepared with leaf litter added as a food source. Ten earthworms were then introduced into the soils. Two duplicate batches were then held at constant moisture (70%) and temperature (16 degrees C) for three weeks. An additional four were let run for six weeks. Control samples for both time periods show no change in either total Zn or extractable (1 M MgCl2) Zn concentration. The amended samples however, display evidence of extensive mixing and an increase in the extractable Zn that can be attributed to earthworm weathering processes. The results from this initial experimental work suggest that there is an important physical component to trace metal fate and transport in urban soils that is earthworm dominated and that earthworm processing can alter the extractable fraction of roadway dust.

Carroll, W.; Lev, S. M.; Szlavecz, K.; Landa, E. R.; Casey, R.; Snodgrass, J. W.

2006-05-01

112

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

113

SEVAN particle-detector network located at Middle-Low latitudes for Solar Physics and Space Weather research  

NASA Astrophysics Data System (ADS)

A network of middle to low latitude particle detectors called SEVAN (Space Environmental Viewing and Analysis Network) is planned in the framework of the International Heliophysical Year (IHY), to improve fundamental research of the Solar accelerators and Space Weather conditions. The network will detect changing fluxes of secondary cosmic rays at different altitudes, latitudes and altitudes those constituting powerful integrated device in exploration of solar modulation effects. Surface particle detectors measure time series of secondary particles born in cascades originated in the atmosphere by nuclear interactions of the "primary" protons and nuclei accelerated in galaxy. During violent solar explosions additional particles, accelerated at sun's environments, can add to this "background" flux. If solar particles are energetic enough they also will generate secondary particles reaching earth surface. Therefore, registration of changing time series of secondary particles shed light on the high-energy particle acceleration mechanisms by solar flares and Coronal Mass Ejection driven shocks. Network of particle detectors located at middle-to-low latitudes is sensitive to the highest energy solar particles. The enigma of particle acceleration in supernovae remnants, super-massive black holes, clusters of galaxies can be researched using particle beams accelerated by sun and detected at earth. The shock acceleration is a universal process responsible for the same physical process (particle acceleration) on the different scales. Time series of intensities of high energy particles can also provide highly cost-effective information on the key characteristics of the disturbances of interplanetary magnetic field. Recent results on of the detection of the extreme solar events (2003, 2005) by the monitors of the Aragats Space-Environmental Center (ASEC) illustrate wide possibilities opening with introduction of new particle detectors measuring neutron, electron and muon fluxes simultaneously. One of the major advantages of multi-particle detectors is probing of the different populations of the primary cosmic rays. With basic detector of SEVAN network we are measuring fluxes of neutrons and gammas, of low energy charged component and high energy muons. This diversity of information obtained from SEVAN network located mostly at low and middle latitudes will give possibility to estimate the energy spectra of the highest energy Solar Cosmic Rays (SCR). SEVAN network will be sensitive to very weak fluxes of SCR above 10 GeV, very poorly explored with worldwide network of neutron monitors . First modules of SEVAN network are in operation in Armenia, in 2008 we plan to install additional modules in Croatia, Bulgaria and India, in 2009 in Costa Rica, Indonesia and Slovakia.

Chilingarian, Ashot

114

A novel process for recovering rare earth from weathered black earth  

SciTech Connect

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.

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

2000-02-01

115

Putting Weather into Weather Derivatives  

NASA Astrophysics Data System (ADS)

Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

Smith, L. A.; Smith, L. A.

2001-12-01

116

Physical processes during development of lightning flashes  

Microsoft Academic Search

The objective of this paper is to review our present understanding of the physical processes in lightning flashes during their development within or outside a cloud, following lightning initiation. This represents the ‘big picture’ of lightning development, in the scale of the cloud dimensions themselves. Since the acceptance of the bi-directional, zero-net-charge leader concept, significant changes have occurred in our

Vladislav Mazur

2002-01-01

117

Chemical Alteration of Soils on Earth as a Function of Precipitation: Insights Into Weathering Processes Relevant to Mars  

NASA Astrophysics Data System (ADS)

Soils lie at the interface of the atmosphere and lithosphere, and the rates of chemical and physical processes that form them hinge on the availability of water. Here we quantify the effect of these processes on soil volume and mass in different rainfall regimes. We then use the results of this synthesis to compare with the growing chemical dataset for soils on Mars in order to identify moisture regimes on Earth that may provide crude analogues for past Martian weathering conditions. In this synthesis, the rates of elemental gains/losses, and corresponding volumetric changes, were compared for soils in nine soil chronosequences (sequences of soils of differing ages) - sequences formed in climates ranging from ~1 to ~4500 mm mean annual precipitation (MAP). Total elemental chemistry of soils and parent materials were determined via XRF, ICP-MS, and/or ICP-OES, and the absolute elemental gains or losses (and volume changes) were determined by normalizing data to an immobile index element. For the chronosequences examined, the initial stages of soil formation (103^ to 104^ yr), regardless of climate, generally show volumetric expansion due to (1) reduction in bulk density by biological/physical turbation, (2) addition of organic matter, (3) accumulation of water during clay mineral synthesis, and/or (4) accumulation of atmospheric salts and dust. Despite large differences in parent materials (basalt, sandstone, granitic alluvium), there was a systematic relationship between long-term (105^ to 106^ yr) volumetric change and rainfall, with an approximate cross-over point between net expansion (and accumulation of atmospheric solutes and dust) and net collapse (net losses of Si, Al, and alkaline earths and alkali metals) between approximately 20 and 100 mm MAP. Recently published geochemical data of soils at Gusev Crater (Gellert et al. 2004. Science 305:829), when normalized to Ti, show apparent net losses of Si and Al that range between 5 and 50% of values relative to adjacent rocks. However the chemical impact of globally distributed dust on Mars greatly affects the interpretation of these apparent elemental losses. From the available soil data, no Earth-based soil geochemical signature perfectly matches the reported Martian data, though arid soils in the Atacama Desert and elsewhere exhibit certain similarities (losses of Si, Al and gains of S). For both Earth and Mars, an understanding of the chemical signature of atmospherically derived elements is critical for calculating accurate measures of chemical weathering in soils.

Amundson, R.; Chadwick, O.; Ewing, S.; Sutter, B.; Owen, J.; McKay, C.

2004-12-01

118

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

119

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

NASA Astrophysics Data System (ADS)

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.

Ashley, James Warren

2011-09-01

120

Process-based evaluation of stochastic physics schemes  

NASA Astrophysics Data System (ADS)

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.

Sanchez, Claudio; Williams, Keith

2014-05-01

121

Physics of a random biological process  

NASA Astrophysics Data System (ADS)

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.

Canessa, E.; Calmetta, A.

1994-07-01

122

Novel natural and anthropogenic physical mechanisms of weather and climate changes  

NASA Astrophysics Data System (ADS)

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.

Voronin, Nikolai; Avakyan, Sergei

2010-05-01

123

Chemical and mineralogical weathering rates and processes in an upland granitic till catchment in Scotland  

Microsoft Academic Search

Weathering in an upland granitic till catchment receiving an intermediate level of acidic deposition has been studied by chemical and mineralogical analyses of soil profiles and chemical analysis of precipitation and streamwater. Long-term weathering rates for base cations calculated from analyses of soil profile horizons using Zr as an internal, immobile, index element are similar for alpine podzols and peaty

D. C. Bain; A. Mellor; M. J. Wilson; D. M. L. Duthie

1994-01-01

124

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)

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.

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

125

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)

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.

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

126

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

NASA Astrophysics Data System (ADS)

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.

Mushkin, Amit; Sagy, Amir; Trabelci, Eran

2013-04-01

127

Glacial effects on weathering processes: New insights from the elemental and lithium isotopic composition of West Greenland rivers  

Microsoft Academic Search

Greenland is by far the dominant source of glacial runoff to the oceans but the controls on the chemical and isotopic composition of this runoff are poorly known. To better constrain glacial effects on weathering processes, we have conducted elemental and lithium isotope analyses of glacial and non-glacial rivers in gneiss catchments in West Greenland. The glacial rivers have high

Josh Wimpenny; Rachael H. James; Kevin W. Burton; Abdelmouhcine Gannoun; Fatima Mokadem; Sigurður R. Gíslason

2010-01-01

128

A robust vehicle detecting and tracking system for wet weather conditions using the IMAP-VISION image processing board  

Microsoft Academic Search

We present a robust vehicle detecting and tracking system for highway scenes of both dry and wet weather conditions taken from a forward-looking vehicle mounted camera. The system comprises the potential vehicle search, vehicle validation, and vehicle tracking processes. In order to overcome reduced visibility conditions, image normalization is performed automatically according to input image contrast and a weak edge

Sholin Kyo; Takuya Koga; Kazuyuki Sakurai; S. Okazaki

1999-01-01

129

Observations of Mesoscale and Microscale Space Weather Processes on the Canadian ASSIOPE Enhanced Polar Outflow Probe (e-POP)  

Microsoft Academic Search

CASSIOPE is a Canadian small satellite scheduled for launch in late 2007 into a polar orbit 300 times 1500 km 80 r inclination The scientific objective of its Enhanced Polar Outflow Probe e-POP payload is to make observations of mesoscale and microscale space weather processes in the topside polar ionosphere at the highest-possible resolution specifically to study the microscale characteristics

A. W. Yau; H. G. James

2006-01-01

130

Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal - a review  

Microsoft Academic Search

Rapid turnover of organic matter leads to a low efficiency of organic fertilizers applied to increase and sequester C in soils of the humid tropics. Charcoal was reported to be responsible for high soil organic matter contents and soil fertility of anthropogenic soils (Terra Preta) found in central Amazonia. Therefore, we reviewed the available information about the physical and chemical

Bruno Glaser; Johannes Lehmann; Wolfgang Zech

2002-01-01

131

Physical processes in EUV sources for microlithography  

NASA Astrophysics Data System (ADS)

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.

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

2011-06-01

132

The Stress Process in Physical Education  

ERIC Educational Resources Information Center

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…

Blankenship, Bonnie Tjeerdsma

2007-01-01

133

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

134

Stellar Evolution Physics, Volume 1: Physical Processes in Stellar Interiors  

NASA Astrophysics Data System (ADS)

This volumes describes the microscopic physics operating in stars and demonstrates how stars respond to the operation of this physics from formation through hydrogen-burning phases, up to the onset of helium burning. Intended for beginning graduate students and senior undergraduates with a good background in physics and mathematics, it describes with many numerical examples and illustrations the intricate interplay between the microscopic physics and the macroscopic responses of the stars. Considerable attention is paid to how numerical solutions are obtained. The volume examines the gravitationally contracting phases which carry a star from formation to the core hydrogen-burning main sequence, through the main sequence phase, through shell hydrogen-burning phases as a red giant, up to the onset of core helium burning. Particular emphasis is placed on the gravothermal responses of stars to nuclear transformations in the interior , energy loss by photons from the surface, and energy loss by neutrinos from the interior, responses which express the very essence of stellar evolution.

Iben, Icko, Jr.

135

Multi-isotopic approach to assess the role of soil weathering processes on rivers draining a basaltic catchment  

NASA Astrophysics Data System (ADS)

Continental weathering not only plays a pivotal role for the long-term climate and CO2 regulation, it also sustains the biosphere by providing nutrients. During weathering, stable isotopes of Si, Mg and Li are fractionated, directly impacting river signatures. In a monolithological catchment, isotopic variations in rivers would rather be related to pedogenic processes such as mineral dissolution, sequestration in secondary minerals via neoformation or adsorption, and plant uptake. However, separating inorganic from biologically driven isotopic fractionation remains complex, owing the tight coupling of biology and weathering. Applying stable isotope techniques, such as Mg, can potentially provide information about those processes that control the Mg budget during weathering reactions. Existing Mg-isotope data obtained from different soils point to a contrasting picture however. Soils derived from gneissic bedrock (India) were shown to display heavier isotopic signatures relative to the bedrock, and associated fluids were enriched in light Mg isotopes, suggesting that weathering discriminates against light Mg isotopes (Tipper et al 2006). By contrast, Icelandic rivers were found to display a large range of Mg isotopic variations both lighter and heavier relative to the parental basalt, and few measured soils were shown to be isotopically lighter than basalt (Pogge von Strandmann et al 2008), suggesting isotope fractionation pattern similar to those found for other light stable isotope systems of Li and Si (e.g. Huh et al 2004; Ziegler et al 2005). This present study aims at a detailed approach to investigate the Mg isotope fractionation in Icelandic soils (Borgarfjordur catchment), in order to elucidate the potential impact of soil weathering on riverine Mg isotopic compositions. On the long run, Mg data will be complemented by Si and Li isotope measurements in order to provide a better constraint on the influence of inorganic versus biological fractionation in a natural system. The combination of these three isotope systems will contribute to a better understanding of weathering derived fluxes to rivers and hence oceans. Huh et al. (2004) Geochem. Geophys. Geosyst. 5, Q09002. Pogge von Strandmann et al. (2008) Earth Planet. Sci. Letts. 276, 187-197. Tipper et al. (2006) Earth Planet. Sci. Letts. 247, 267-279. Ziegler et al. (2005) Geochim. Cosmochim. Acta 69, 4597-4610.

Opfergelt, S.; Georg, R. B.; Burton, K.; Gislason, S. R.; Sigfusson, B.; Halliday, A. N.

2009-12-01

136

Proton computed tomography from multiple physics processes  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

137

Weather Forecasting  

NSDL National Science Digital Library

This activity is designed to give students an understanding of how to forecast weather and how to use weather reports for their personal benefit. They will be able to tell what weather is, read weather instruments, understand basic cloud formations in relation to the weather, and make forecasts for two days in advance.

138

The Effects of Chemical Weathering on Thermal-Infrared Spectral Data and Models: Implications for Aqueous Processes on the Martian Surface  

NASA Astrophysics Data System (ADS)

Chemical and mineralogical data from Mars shows that the surface has been chemically weathered on local to regional scales. Chemical trends and the types of chemical weathering products present on the surface and their abundances can elucidate information about past aqueous processes. Thermal-infrared (TIR) data and their respective models are essential for interpreting Martian mineralogy and geologic history. However, previous studies have shown that chemical weathering and the precipitation of fine-grained secondary silicates can adversely affect the accuracy of TIR spectral models. Furthermore, spectral libraries used to identify minerals on the Martian surface lack some important weathering products, including poorly-crystalline aluminosilicates like allophane, thus eliminating their identification in TIR spectral models. It is essential to accurately interpret TIR spectral data from chemically weathered surfaces to understand the evolution of aqueous processes on Mars. Laboratory experiments were performed to improve interpretations of TIR data from weathered surfaces. To test the accuracy of deriving chemistry of weathered rocks from TIR spectroscopy, chemistry was derived from TIR models of weathered basalts from Baynton, Australia and compared to actual weathering rind chemistry. To determine how specific secondary silicates affect the TIR spectroscopy of weathered basalts, mixtures of basaltic minerals and small amounts of secondary silicates were modeled. Poorly-crystalline aluminosilicates were synthesized and their TIR spectra were added to spectral libraries. Regional Thermal Emission Spectrometer (TES) data were modeled using libraries containing these poorly-crystalline aluminosilicates to test for their presence on the Mars. Chemistry derived from models of weathered Baynton basalts is not accurate, but broad chemical weathering trends can be interpreted from the data. TIR models of mineral mixtures show that small amounts of crystalline and amorphous silicate weathering products (2.5-5 wt.%) can be detected in TIR models and can adversely affect modeled plagioclase abundances. Poorly-crystalline aluminosilicates are identified in Northern Acidalia, Solis Planum, and Meridiani. Previous studies have suggested that acid sulfate weathering was the dominant surface alteration process for the past 3.5 billion years; however, the identification of allophane indicates that alteration at near-neutral pH occurred on regional scales and that acid sulfate weathering is not the only weathering process on Mars.

Rampe, Elizabeth Barger

139

Deep weathering and alteration in granites - a product of coupled processes  

Microsoft Academic Search

Weathering and alternation in granite has a deep inpact on both geotechnical properties of the rock as well as of the rock mass. In a granite rock mass, the discontinuity pattern together with joint cohesion and friction plays a major role in tunnel construction and road cut slopes. These pheneomena and their cou-pling could be exclusively studied at the Königshainer

K. Thuro; M. Scholz

2004-01-01

140

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

Microsoft Academic Search

article i nfo Carbonates capping Neoproterozoic glacial deposits contain peculiar sedimentological features and geochemical anomalies ascribed to extraordinary environmental conditions in the snowball Earth aftermath. It is commonly assumed that post-snowball climate dominated by CO2 partial pressures several hundred times greater than modern levels, would be characterized by extreme temperatures, a vigorous hydrological cycle, and associated high continental weathering rates.

Guillaume Le Hir; Yannick Donnadieu; Yves Goddéris; Raymond T. Pierrehumbert; Galen P. Halverson; Mélina Macouin; Anne Nédélec; Gilles Ramstein

2008-01-01

141

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

Microsoft Academic Search

Carbonates capping Neoproterozoic glacial deposits contain peculiar sedimentological features and geochemical anomalies ascribed to extraordinary environmental conditions in the snowball Earth aftermath. It is commonly assumed that post-snowball climate dominated by CO2 partial pressures several hundred times greater than modern levels, would be characterized by extreme temperatures, a vigorous hydrological cycle, and associated high continental weathering rates. However, the climate

Guillaume Le Hir; Yannick Donnadieu; Yves Goddéris; Raymond T. Pierrehumbert; Galen P. Halverson; Mélina Macouin; Anne Nédélec; Gilles Ramstein

2009-01-01

142

Contrasting Li and Mg isotope behaviour in small Alpine rivers: tracing seasonal changes in weathering processes (Invited)  

NASA Astrophysics Data System (ADS)

Seasonal changes in river chemistry offer the potential to assess how weathering processes respond to changing meteorological parameters and ultimately how chemical weathering might respond to climatic parameters. A key observation with time-series data on river waters is that variations in elemental concentrations (typically less than an order of magnitude) are damped compared to variations in discharge (up to several orders of magnitude). This behavior is referred to as chemostatic. However, both radiogenic and stable isotope ratios of the solutes show significant, systematic temporal variations than indicate that there is not a chemostasis in the elemental release of solutes during dissolution. Here we discuss systematic seasonal variations in lithium and magnesium isotope ratios (the 7Li/6Li 26Mg/24Mg ratio expressed as delta7Li and delta26Mg in per mil units) in stream waters from a mono-lithological granitic, weathering-limited, first order catchment from the Swiss Alps (Damma glacier). Rain, ground, and pore-waters, in addition to plants, rocks, mineral separates and soil are also reported. Whilst the concentration response of Li and Mg in the river waters is attenuated compared to the large changes in discharge that occur over an annual cycle the systematic trends in both the Mg and Li isotope data imply that either the source of the Li and Mg changes in a systematic manner, or that the process by which Mg and Li are released into solution changes as a function of discharge. In the first order the Mg and Li isotope data appear to show similar trends. However, when examined in more detail, it is difficult to reconcile the data by one pair of fractionation factors for Li and Mg. This provides an additional constraint on how weathering processes vary over a seasonal cycle, and perhaps indications an incomplete equilibrium or kinetic limitation to weathering. The reasons behind these trends will be discussed in the context of the apparent chemostatic behavior of solute concentrations. Such isotopic observations provide significant insight into how solutes can apparently keep pace with order of magnitude variations in discharge, one of the key reasons why runoff is frequently identified as being a key variable in weathering fluxes.

Tipper, E.; Hindshaw, R. S.; Bourdon, B.; Lemarchand, E.

2013-12-01

143

Chemistry of uranium, thorium, and radium isotopes in the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal  

Microsoft Academic Search

Rivers are the major pathways for the transport of weathered materials from the land to the oceans. The geochemical studies on river waters provide an insight into the weathering processes that control the distribution of elements in dissolved and particulate phases and their fluxes to the estuaries. Consequently, a detailed and systematic study of the major ion composition and radionuclide

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

1990-01-01

144

Weather Watch  

ERIC Educational Resources Information Center

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)

Bratt, Herschell Marvin

1973-01-01

145

Probing new physics in rare charm processes  

SciTech Connect

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.

Hewett, J.L.

1994-09-01

146

Physical and Chemical Changes in the Digestion Process  

NSDL National Science Digital Library

This lesson demonstrates how students can determine the cause and effect relationship in the digestion process. Students will be able to determine where chemical and physical changes occur in the digestion process and support their findings from an informational text. This lesson provides students with an opportunity to apply their knowledge of physical and chemical changes in matter to the process of digestion.

Clark, Monica

2012-09-16

147

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

148

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

NASA Technical Reports Server (NTRS)

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.

Barrett, Joe H., III

2008-01-01

149

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

NASA Astrophysics Data System (ADS)

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.

Baker, D. N.

2012-12-01

150

Weather Basics  

NSDL National Science Digital Library

Students are introduced to the basics of the Earth's weather. Concepts include fundamental causes of common weather phenomena such as temperature changes, wind, clouds, rain and snow. The different factors that affect the weather and the instruments that measure weather data are also addressed.

Integrated Teaching And Learning Program

151

Weather Forecasting  

NSDL National Science Digital Library

Students consider how weather forecasting plays an important part in their daily lives. They learn about the history of weather forecasting â from old weather proverbs to modern forecasting equipment â and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

Integrated Teaching And Learning Program

152

Severe Weather  

NSDL National Science Digital Library

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, flash floods, lightning, and tornadoes.

Forde, Evan B.

2004-04-01

153

Severe Weather  

ERIC Educational Resources Information Center

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…

Forde, Evan B.

2004-01-01

154

Severe Weather  

ERIC Educational Resources Information Center

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,…

Forde, Evan B.

2004-01-01

155

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...

156

Computer Animations of Physical Processes: Thermodynamics  

NSDL National Science Digital Library

This item is a set of eight animations relating to heat and thermodynamics. Topics include Brownian motion, Maxwell distribution, molecular structures, and behavior of gas molecules subjected to heating and cooling. Each image is accompanied by conceptual explanations and calculations. Most also link to videos which more fully explore the phenomena. This item is part of a larger collection of physics animations and simulations.

2007-02-07

157

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

158

Severe Weather  

NSDL National Science Digital Library

Meteorologists disagree as to what constitutes severe weather. However, most concur that thunderstorms, tornadoes, and hurricanes, all considered to be "convective" weather, fit the definition of severe weather, which is a weather condition likely to cause hardship. This science guide will explore each of the three weather phenomena. By virtue of their locations, most students are familiar with at least one of the three severe weather events. Students who tour the web sites will have an opportunity to make connections between the familiar and the perhaps less understood weather events.

National Science Teachers Association (NSTA)

2005-04-01

159

Avalanche Weather Forecasting  

NSDL National Science Digital Library

Avalanches form through the interaction of snowpack, terrain, and weather, the latter being the focus of this module. The module begins with basic information about avalanches, highlighting weather's role in their development. The rest of the module teaches weather forecasters how to make an avalanche weather forecast, that is, one in which key weather parameters are evaluated for their impact on avalanche potential. The forecasts are used primarily by avalanche forecasters, who integrate them with other information to determine when to issue avalanche hazard warnings. The module contains five cases that let users apply the avalanche weather forecast process to different combinations of snowpack, terrain, and weather conditions. It is a companion to the COMET module "Snowpack and Its Assessment," which describes snowpack development and various assessment techniques.

Linder, Dave

2011-01-01

160

Garments, Outer (Wet Weather).  

National Technical Information Service (NTIS)

The report describes a method for evaluation of wet weather clothing operational and functional performance characteristics. Identifies supporting tests, facilities, and equipment required. Provides procedures for preoperational inspection, physical chara...

R. Rush

1972-01-01

161

Winter Weather  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Bellows, Mrs.

2009-09-28

162

Weathering of Minerals  

NSDL National Science Digital Library

Students determine the % change in mass of mineral samples that have been placed in a rock tumbler. They graph the relationship between the hardness of the mineral and the % change in mass. They then consider why some of the mineral samples do not conform the the relationship they graphed. They investigate the physical properties of the outliers and consider how the physical properties contributed to the rate of weathering, and what kind of weathering occured in the rock tumbler.

Van Norden, Wendy

163

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

NASA Astrophysics Data System (ADS)

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.

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

2005-02-01

164

Common physical processes in natural and artificially triggered lightning  

Microsoft Academic Search

Common physical processes are identified in various types of natural and artificially triggered lightning flashes, both in summer and winter storms. By applying an electrostatic model of bidirectional, uncharged and monopolar, charged leaders, the main physical principles are defined for interpretation of common lightning processes. These principles focus on lightning initiation, charger on the leader, the leader's electrical potential, the

Vladislav Mazur; Lothar H. Ruhnke

1993-01-01

165

What similar physical processes occur on both Earth and Mars?  

NSDL National Science Digital Library

This NASA Module investigation compares and contrasts physical processes that occur on Both Earth and Mars. Students are given unidentified images of Earth and Mars. Their task is to arrange the images into pairs that show evidence of similar physical processes. Then they identify each image as one of Earth or of Mars by comparing and contrasting physical features that they observe in the image pairs. It includes teacher background materials and an answer key where appropriate.

2002-05-26

166

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

NASA Astrophysics Data System (ADS)

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.

Mittlefehldt, D. W.; Lindstrom, M. M.

1991-01-01

167

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

ERIC Educational Resources Information Center

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…

Pearson, Nolan E.

168

A New Perspective on Surface Weather Maps  

ERIC Educational Resources Information Center

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…

Meyer, Steve

2006-01-01

169

Proposed Initiative Would Study Earth's Weathering Engine  

Microsoft Academic Search

At the Earth's surface, a complex suite of chemical, biological, and physical processes combines to create the engine that transforms bedrock into soil (Figure 1). Earth's weathering engine provides nutrients to nourish ecosystems and human society, mediates the transport of toxic components within the biosphere, creates water flow paths that carve and weaken bedrock, and contributes to the evolution of

Suzanne P. Anderson; Joel Blum; Susan L. Brantley; Oliver Chadwick; Jon Chorover; Louis A. Derry; James I. Drever; Janet G. Hering; James W. Kirchner; Lee R. Kump; Daniel Richter; Art F. White

2004-01-01

170

WWW - Wonderful Web Weather  

NSDL National Science Digital Library

This is a web quest for students to research weather forecasting using the Internet. Students work in groups to study how accurate weather forecasts are by tracking the weather for 3 days in several locations. Using graphs students then compare how each location scored in accuracy and present their findings to the class. This site contains links for students to use for more background information, a process for the students to follow, and evaluation rubrics for the student-produced graphs and presentation.

Parrish, Jason

171

OpenWeather: a peer-to-peer weather data transmission protocol  

Microsoft Academic Search

The study of the weather is performed using instruments termed weather stations. These weather stations are distributed around the world, collecting the data from the different phenomena. Several weather organizations have been deploying thousands of these instruments, creating big networks to collect weather data. These instruments are collecting the weather data and delivering it for later processing in the collections

Adrian Yanes

2011-01-01

172

Physical Modeling of Hydrologic Processes in South Central Texas  

NASA Astrophysics Data System (ADS)

Flood magnitude and recurrence modeling and analysis play an important role in water resources planning, management, and permitting. In both urban and rural situations, flood analysis is important to flood plain mapping and the development of best management practices for both environmental and engineering concerns. The majority of annual precipitation in South Texas results from extreme, large storm events, which produce flash floods (the number one cause of weather-related deaths in Texas). Surface geology such as such as Edward out crop faulting zone at Balcones escarpment has different properties than the classified soil; affect the soil parameters such as infiltration or hydraulic conductivity. This result in a very high infiltration and channel loss as a recharge component to the Edward aquifer from the surface runoff and rivers that are crossing the recharge zone, such as Nueces, San Antonio, Guadalupe and Colorado Rivers. Water quality is another issue in hydrological modeling, specifically in south central Texas. Water quality assessment is another issue on hydrological modeling in south central Texas. SWAT Soil and water assessment tool model is used for water quality assessment in San Antonio River basin since the rainfall runoff simulation is a necessity to derive the surface water quality process especially in the streams. With the advances in the Geographical information system (GIS) and instant precipitation products such as next generation radar (NEXRAD) and data acquisition for these products, the accuracy of the hydrological models has improved. Different hydrological models were used to evaluate the surface water and other hydrological cycle components in different watersheds in south central Texas through different events and their different causes and effects in these watersheds. Some of them are semi distributed and lumped models such as Soil and Water Assessment Tool (SWAT), Hydrologic Modeling System (HEC-HMS) and physically based distributed model Girded Surface Subsurface Hydrologic Assessment GSSHA taking the advances of GIS, NEXRAD product, remote sensing and other product such as gridded land use and soil map to achieve the highest accuracy of these models.

El Hassan, A.; Sharif, H.; Xie, H.; Terrance, J.; Mcclelland, J.

2012-04-01

173

Space Weathering in the Inner Solar System  

NASA Technical Reports Server (NTRS)

"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.

Noble, Sarah K.

2010-01-01

174

The impact of precipitation physical processes on the polarimetric radar variables  

NASA Astrophysics Data System (ADS)

The ongoing upgrade of the National Weather Service WSR-88D radar network to polarimetric capabilities, as well as similar upgrades worldwide, will soon provide a wealth of data and information regarding storm precipitation physics. Fully understanding how a variety of microphysical processes are revealed in polarimetric data is necessary for the best use of these new data by operational and research meteorologists. The focus of this study is to quantify a number of these precipitation physics "fingerprints" in the polarimetric radar variables by using a synthesis of explicit microphysical modeling, electromagnetic scattering calculations, thought experiments, and polarimetric radar observations. The complete set of polarimetric variables available from linearly-orthogonal dual-polarization radars are derived from basic electromagnetic scattering principles. A detailed physical description of these variables is then provided for applications in precipitation and other atmospheric scatterers, as is a summary of common data artifacts. The impact of various precipitation physical processes on these radar variables is then quantified. Using explicit microphysical models, scattering calculations, observations, and thought experiments, the microphysical fingerprints are determined and quantified for raindrop thermal conduction, raindrop size sorting by sedimentation, updrafts, and vertical wind shear, evaporation of raindrops, coalescence of raindrops, and freezing of raindrops in deep convective storm updrafts. A catalogue of the qualitative fingerprints of a number of precipitation processes is summarized.

Kumjian, Matthew Robert

175

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

176

Fractional calculus and some intermediate physical processes  

Microsoft Academic Search

One of the main applications of the fractional calculus (integration and differentiation of arbitrary (fractional) order) is the modeling of the intermediate processes [J. Frac. Calculus 7 (1995) 89; Int. J. Theo. Phys. 35(2) (1996) 311; R. Gorenflo, R. Rutman, Fachbereich Mathematik Reprint No. A-28\\/94 (1994); F. Mainardi, Proc. 14th IMACS World Congr., vol. 1, 1994, p. 329; Chaos Soliton

Ahmed M. A. El-Sayed; Fatma M. Gaafar

2003-01-01

177

Device Physics of Solution Processable Solar Cells  

Microsoft Academic Search

This Ph.D work reports the studies of photovoltaic devices produced by solution processable methods. Two material systems are of interest: one is based on organic semiconductors, and another on organic\\/inorganic hybrid composites. Specifically, organic photovoltaic (OPV) devices are made using photoactive materials consisted of a ?-conjugated polymer [Poly(3-hexylthiophene), or P3HT] and fullerene derivative [phenyl-C60-butric acid methyl ester, or PCBM] in

Jason Erik Lewis

2011-01-01

178

SEVAN particle-detector network located at Middle-Low latitudes for Solar Physics and Space Weather research  

Microsoft Academic Search

A network of middle to low latitude particle detectors called SEVAN (Space Environmental Viewing and Analysis Network) is planned in the framework of the International Heliophysical Year (IHY), to improve fundamental research of the Solar accelerators and Space Weather conditions. The network will detect changing fluxes of secondary cosmic rays at different altitudes, latitudes and altitudes those constituting powerful integrated

Ashot Chilingarian

2008-01-01

179

Physical processes at high field strengths  

SciTech Connect

Measurements of the radiation produced by the high field interaction with the rare gases have revealed the presence of both copious harmonic production and fluorescence. The highest harmonic observed was the seventeenth (14.6 rm) in Ne, the shortest wavelength ever produced by that means. Strong fluorescence was seen in Ar, Kr, and Xe with the shortest wavelengths observed being below 10 nm. Furthermore, radiation from inner-shell excited configurations in Xe, specifically the 4d/sup 9/5s5p ..-->.. 4d/sup 10/5s manifold at approx. 17.7 nm, was detected. The behaviors of the rare gases with respect to multiquantum ionization, harmonic production, and fluorescence were found to be correlated so that the materials fell into two groups, He and Ne in one and Ar, Kr, and Xe in the other. These experimental findings, in alliance with other studies on inner-shell decay processes, give evidence for a role of atomic correlations in a direct nonlinear process of inner-shell excitation. It is expected that an understanding of these high-field processes will enable the generation of stimulated emission in the x-ray range. 59 refs., 6 figs., 5 tabs.

Rhodes, C.K.

1986-01-01

180

Bioremediation of a weathered and a recently oil-contaminated soils from Brazil: a comparison study  

Microsoft Academic Search

The facility with which hydrocarbons can be removed from soils varies inversely with aging of soil samples as a result of weathering. Weathering refers to the result of biological, chemical and physical processes that can affect the type of hydrocarbons that remain in a soil. These processes enhance the sorption of hydrophobic organic contaminants (HOCs) to the soil matrix, decreasing

P. V. O. Trindade; L. G. Sobral; A. C. L. Rizzo; S. G. F. Leite; A. U. Soriano

2005-01-01

181

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

ERIC Educational Resources Information Center

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.…

Simpson, James R.

182

Weather Forecasting  

NSDL National Science Digital Library

This website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather. Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Once you have a firm grasp on the science of weather forecasting, be sure to check out the other sections of this site, which include: "ice and snow," "our changing climate," "the water cycle," and "powerful storms."

2008-03-27

183

Weather Talk  

NSDL National Science Digital Library

Weather Talk is a primer on weather and naval meteorology. It provides a brief overview of major weather elements and is presented in a non-mathematical way, so that the reader will have a better understanding of the basic mechanisms of weather and use it to their advantage and safety in planning and carrying out their own activities. The site explains temperature, wind, pressure, atmospheric moisture, air masses and fronts, thunderstorms, tornadoes, hurricanes, and climatology.

184

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

PubMed Central

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.

Algeo, T. J.

1998-01-01

185

Alteration processes in volcanic soils and identification of exobiologically important weathering products on Mars using remote sensing  

NASA Astrophysics Data System (ADS)

Determining the mineralogy of the Martian surface material provides information about the past and present environments on Mars which are an integral aspect of whether or not Mars was suitable for the origin of life. Mineral identification on Mars will most likely be achieved through visible-infrared remote sensing in combination with other analyses on landed missions. Therefore, understanding the visible and infrared spectral properties of terrestrial samples formed via processes similar to those thought to have occurred on Mars is essential to this effort and will facilitate site selection for future exobiology missions to Mars. Visible to infrared reflectance spectra are presented here for the fine-grained fractions of altered tephra/lava from the Haleakala summit basin on Maui, the Tarawera volcanic complex on the northern island of New Zealand, and the Greek Santorini island group. These samples exhibit a range of chemical and mineralogical compositions, where the primary minerals typically include plagioclase, pyroxene, hematite, and magnetite. The kind and abundance of weathering products varied substantially for these three sites due, in part, to the climate and weathering environment. The moist environments at Santorini and Tarawera are more consistent with postulated past environments on Mars, while the dry climate at the top of Haleakala is more consistent with the current Martian environment. Weathering of these tephra is evaluated by assessing changes in the leachable and immobile elements, and through detection of phyllosilicates and iron oxide/oxyhydroxide minerals. Identifying regions on Mars where phyllosilicates and many kinds of iron oxides/oxyhydroxides are present would imply the presence of water during alteration of the surface material. Tephra samples altered in the vicinity of cinder cones and steam vents contain higher abundances of phyllosilicates, iron oxides, and sulfates and may be interesting sites for exobiology.

Bishop, Janice L.; Fröschl, Heinz; Mancinelli, Rocco L.

1998-12-01

186

Weathering patterns in high-latitude regolith  

NASA Astrophysics Data System (ADS)

Large areas distributed on the Earth's surface are covered by regolith, an unconsolidated heterogeneous material overlying bedrock. In high-latitude areas, most of the land surface has been reworked and eroded by both glacial and fluvial processes, leaving only remnants of formerly extensive regolith covers. In an effort to further the understanding of weathering patterns and processes in old regolith covers, a comprehensive study of localities spread across Norway was carried out. On the basis of the distribution of minerals and elements within regolith, as well as its internal structure and geomorphologic setting, we ascertained that it was formed in situ and originated in pre-Quaternary times. There are similarities between the study sites with respect to regolith thickness, zonation, and composition. The Chemical Index of Alteration (CIA) and the Weathering Index of Parker (WIP) suggests that the degree of chemical weathering in the regolith is advanced compared to the parental bedrock with a maximum change of over 80%, which indicates a substantial increase in the proportion of secondary versus primary minerals. Mineral analysis identified kaolinite and gibbsite, which are considered indicative of advanced weathering and therefore support this observation. On the basis of statistical relationships between different grain size fractions (<125 ?m), we observed a consistent pattern, which revealed that physical weathering becomes progressively less important in the production of grains smaller than 32 ?m. On the basis of this finding, we infer that chemical weathering progressively dominates the production of fine silt, very fine silt, and clay, whereas physical weathering primarily controls the production of grain size fractions larger than 32 ?m. This particular pattern is suggested to be an intrinsic feature in the formation of weathered high-latitude regolith.

StrøMsøE, JøRund Raukleiv; Paasche, Øyvind

2011-09-01

187

Weathering patterns in high latitude regolith  

NASA Astrophysics Data System (ADS)

Large areas distributed on the Earth's surface are covered by regolith, an unconsolidated heterogeneous material overlying bedrock. In high latitude areas, most of the land surface has been reworked and eroded by both glacial and fluvial processes, leaving only remnants of formerly extensive regolith covers. In an effort to further the understanding of weathering patterns and processes in old regolith covers, a comprehensive study of localities spread across Norway was carried out. Based on the distribution of minerals and elements within regolith, as well as its internal structure and geomorphologic setting, we ascertained that it was formed in situ and originated in pre-Quaternary times. There are similarities between the study sites with respect to regolith thickness, zonation, and composition. The Chemical Index of Alteration (CIA) and the Weathering Index of Parker (WIP) suggests that the degree of chemical weathering in the regolith is advanced compared to the parental bedrock with a maximum change of over 80%, which indicates a substantial increase in the proportion of secondary versus primary minerals. Mineral analysis identified kaolinite and gibbsite, which are considered indicative of advanced weathering and therefore support this observation. On the basis of statistical relationships between different grain size fractions (<125 ?m), we observed a consistent pattern, which revealed that physical weathering becomes progressively less important in the production of grains smaller than 32 ?m. Based on this finding, we infer that chemical weathering progressively dominates the production of fine silt, very fine silt, and clay, whereas physical weathering primarily controls the production of grain size fractions larger than 32 ?m. This particular pattern is suggested to be an intrinsic feature in the formation of weathered high latitude regolith.

Stromsoe, J.; Paasche, O.

2011-12-01

188

Space Weathering of Rocks  

NASA Technical Reports Server (NTRS)

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.

Noble, Sarah

2011-01-01

189

Antarctic Weather  

NSDL National Science Digital Library

Visitors to this site can read a discussion about the weather in Anarctica, including why it is so cold, how weather observations are conducted there, and what role the continent plays in the global weather system. Links to related topics, a wind chill calculator, and a Fahrenheit-Celsius-Kelvin temperature converter are also provided.

190

Development of a Zinc Physical Vapor Deposition Process.  

National Technical Information Service (NTIS)

The technology for continuous zinc physical vapor deposition on steel strips on a industrial basis has been developed. This process is the first of its type in the world. The development process of this new coating process is given in this paper as follow...

M. Maeda A. Morita H. Furukawa K. Waki Y. Shimozato

1984-01-01

191

First look at RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

192

Combined physical/microbial process for coal beneficiation.  

National Technical Information Service (NTIS)

A combined physical/microbial process for the removal of pyritic sulfur from coal was demonstrated in a 200 L aerated trough slurry reactor. The reactor was divided into six sections, each of which acted as both a physical separator and a bioreactor. Sett...

K. S. Noah A. W. Glenn C. J. Stevens N. B. McAtee M. E. McIlwain

1993-01-01

193

A combined physical\\/microbial process for coal beneficiation  

Microsoft Academic Search

A combined physical\\/microbial process for the removal of pyritic sulfur from coal was demonstrated in a 200 L aerated trough slurry reactor. The reactor was divided into six sections, each of which acted as both a physical separator and a bioreactor. Settled solids from sections 2 through 6 were recycled to section 1 which acted as a rougher. The objective

K. S. Noah; A. W. Glenn; C. J. Stevens; N. B. McAtee; M. E. McIlwain; G. F. Andrews

1993-01-01

194

Home Weatherization Visit  

ScienceCinema

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.

195

Home Weatherization Visit  

ScienceCinema

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.

Chu, Steven

2013-05-29

196

Erosion and Weathering  

NSDL National Science Digital Library

Weathering and erosion work together as natural forces, removing and transporting material. Sediments, the by-products of these processes, are subsequently deposited to produce characteristic landforms such as dunes, deltas, and glacial moraines. This slide show presents images of landforms that result from erosion and weathering, as well as measures designed to mitigate their unwanted effects.

197

World Weather  

NSDL National Science Digital Library

What's going on in the world of weather? Are there storms around Sri Lanka? What about the snows of Kilimanjaro? These can be pressing questions, indeed, and the World Weather app is a great way to stay in touch with weather patterns around the globe. Users will find that they can just type in a city name to see the current weather and also zoom around the globe as they see fit. It's a remarkable addition to the world of existing weather tracking apps and is compatible with all operating systems.

Elias, Jaume S.

2014-02-20

198

Weather Watcher  

NSDL National Science Digital Library

As spring progresses, weather conditions can continue to fluctuate dramatically, something that may foil vacation plans or other outings. Keeping that in mind, visitors may do well to download the Weather Watcher application created by Mike Singer. With this application, users may automatically retrieve the current weather conditions, look through hourly forecasts, keep abreast of severe weather alerts, and take a look at weather maps for almost any city world-wide. This application is compatible with all systems running Windows 98 and above.

Singer, Mike

199

Can we use the processes of physics to guide physics instruction?  

Microsoft Academic Search

Abstract Educational studies indicate that students accept all knowledge as “facts,” without understanding how it was constructed. This paper describes one of the ways in which physics knowledge is constructed and organized by physicists, and suggests how toreplicate these construction processes and this organization in physics,instruction. It offers a way,to help students learn physics through answering,the question “what is it

E. Etkina

200

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

201

Fair weather atmospheric electricity  

NASA Astrophysics Data System (ADS)

Not long after Franklin's iconic studies, an atmospheric electric field was discovered in "fair weather" regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

Harrison, R. G.

2011-06-01

202

Process Evaluation Results from the HEALTHY Physical Education Intervention  

ERIC Educational Resources Information Center

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…

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

203

An integrated biochemical and physical model for the composting process  

Microsoft Academic Search

A dynamic model for the composting process has been developed, which integrates several biochemical and physical processes. Different microbial populations (mesophilic and thermophilic bacteria, actinomycetes and fungi) have been considered, each specialized in certain types of polymeric substrates (carbohydrates, proteins, lipids, hemicellulose, cellulose and lignin) and their hydrolysis products. Heat and mass transfer between the three phases of the system

Francina Sole-Mauri; Josep Illa; Albert Magrí; Francesc X. Prenafeta-Boldú; Xavier Flotats

2007-01-01

204

Physical Properties and Processing of Asteroid Regoliths and Interiors  

Microsoft Academic Search

Four aspects of the physical properties and processing of asteroid regoliths and interiors are examined: (1) impact cratering, (2) thermal cycling, (3) electrostatic processing, and (4) asteroid densities. These aspects contribute to understanding the production, emplacement, redistribution, segregation, disruption, loss, and overall state of regoliths on asteroids. Impact cratering (Chapter 2) is considered through a study of the scaling characteristics

Pascal Clayton-Clyde Lee

1997-01-01

205

Physical model for the laser induced forward transfer process  

NASA Astrophysics Data System (ADS)

This paper presents a numerical model which describes the underlying physical processes during laser induced forward transfer. The laser induced forward transfer uses a pulsed laser to transfer thin layers from a transparent support to a substrate. The model predicts the threshold energies Eth as well as the blow-off time tblow, thus allowing a profound physical understanding of the transfer process. The good agreement of simulated with measured Eth and tblow of thin nickel layers demonstrates the accuracy of the model. The model shows that gasification of the soda-lime glass support is the main driving force of the transfer process.

Röder, Tobias C.; Köhler, Jürgen R.

2012-02-01

206

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

PubMed

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

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

2014-01-01

207

Weather Instruments  

NSDL National Science Digital Library

This Topic in Depth discusses the variety of instruments used to collect climate and weather data. The first two websites provide simple introductions to the many weather instruments. Bethune Academy's Weather Center (1) discusses the functions of psychrometers, anemometers, weather balloons, thermometers, and barometers. The Illinois State Water Survey (2) furnishes many images of various instruments that collect data daily for legal issues, farmers, educators, students, and researchers. The third website (3), created by the Center for Improving Engineering and Science Education (CIESE), provides a classroom activity to educate users on how to build and use weather instruments. By the end of the group project, students should know all about wind vanes, rain gauges, anemometers, and thermometers. Next, the Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes (4). Students can learn about the wind, air pressure, moisture, and temperature. At the fifth website, the Tyson Research Center at Washington University describes the devices it uses in its research (5). At the various links, users can find out the center's many projects that utilize meteorological data such as acid rain monitoring. The sixth website, a pdf document created by Dr. John Guyton at the Mississippi State University Extension Service, provides guidance to teachers about the education of weather patterns and instruments (6). Users can find helpful information on pressure systems, humidity, cloud patterns, and much more. Next, the University of Richmond discusses the tools meteorologists use to learn about the weather (7). While providing materials about the basic tools discussed in the other websites, this site also offers information about weather satellites, radar, and computer models. After discovering the many weather instruments, users can learn about weather data output and analysis at the Next Generation Weather Lab website (8). This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States.

208

Predicting Weather  

NSDL National Science Digital Library

By performing the activities presented in this website, fourth grade students can learn about weather instruments and data collection. This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Each activity presented here includes both objectives and assessment techniques for the lesson. Sixteen different activity suggestions provide students and teachers with ample opportunities to explore weather in the classroom.

2008-03-28

209

Weather Experiments  

NSDL National Science Digital Library

Looking for fun ways to learn about weather? Weather Wiz Kids has 39 fun weather related experiments for you to try. These experiments can be done in the classroom with your friends or even at home! Some of the experiments on the site include: tornado in a bottle, make lightning, make it rain, cloud in a bottle, what's in the wind, the Doppler Effect, and baking soda volcano.

2010-01-01

210

Accelerated Weathering of Rocks.  

National Technical Information Service (NTIS)

The project concerns correlation between weathering indices obtained from samples of one type of sedimentary rock (graywacke) and those obtained after laboratory agency tests of the same rocks. Study is made of the process of natural alteration in three s...

L. Aires-Barros

1977-01-01

211

Observe the effects of mechanical weathering  

NSDL National Science Digital Library

In this interactive Earth science resource, students are first presented with six photographs, each featuring a different mechanical weathering event in which rock is broken down. Examples of the events include road damage due to ice heaving and the expansion of cracks in rocks due to tree growth. Students are instructed to click on each labeled image to see an enlarged version of it. In the enlarged view, brief text, often accompanied by visual cues such as arrows, explains the physical weathering process shown. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

212

Physical activity across the curriculum: year one process evaluation results  

Microsoft Academic Search

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

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

2008-01-01

213

Uranium and thorium isotopes in the rivers of the Amazonian basin: hydrology and weathering processes  

NASA Astrophysics Data System (ADS)

Two expeditions (October 1989 and May 1992) were carried out to two points of the main Amazon River channel and four tributaries. The Solimões and Madeira rivers, taking their origin in the Andes, are whitewater rivers. The Negro River is a typical acid, blackwater river. The Trombetas River flows through bauxite-rich areas, and is characterized by low concentrations of dissolved humic substances. The 238U, 234U, 232Th and 230Th activities were recorded from dissolved, suspended particulate phases and river bank sediments. The latter were analysed for their 226Ra, 228Ra and 210Pb contents, and also subjected to leaching with 0·2 M hydroxylamine-hydrochloride solution to determine the concentrations of radionuclides bound to amorphous Fe hydroxides and Mn oxides and hydroxides.The dissolved U average concentration in the Amazon system is ten times lower than the mean world river concentration. The uranium concentration observed at Óbidos in the lower Amazon (0·095 µg L-1), where the U content in the river bank sediments and suspended matter is lowest, suggests U release from the solid phase during river transport. About 485 t of U are transported annually to the Amazon delta area in dissolved form, and 1943 t bound to suspended particulate matter.Total U and Th concentrations in the river bank sediments ranged from 1·59 to 7·14 µg g-1 and from 6·74 to 32 µg g-1, respectively. The highest concentrations were observed in the Trombetas River. The proportion extracted by means of the hydroxylamine solution (HL) was relatively high for U in the Trombetas river bank sediment (31%) and for Th in the Solimões sediment (30%).1, but were <1 in the Negro River (at Manaus). The activity ratios of dissolved U correlate with pH and also with the U activity ratios in the river bank sediment hydroxylamine extracts. As expected, the 1 in the Trombetas and Negro rivers. Such ratios probably result from the binding of dissolved uranium to solid sediment.weathering rate of rocks in the Amazon system, which was estimated to be 2·7 cm 1000 year

Marques, Aguinaldo N., Jr.; Al-Gharib, Iyad; Bernat, Michel; Fernex, François

2003-01-01

214

Analysis of weather patterns associated with air quality degradation and potential health impacts  

EPA Science Inventory

Emissions from anthropogenic and natural sources into the atmosphere are determined in large measure by prevailing weather conditions through complex physical, dynamical and chemical processes. Air pollution episodes are characterized by degradation in air quality as reflected by...

215

Delaminations Induced by Weathering in Wood and Wood-Based Composites Panels  

Microsoft Academic Search

\\u000a The term “weathering” (Feist 1982) defines any of the physical, mechanical or chemical process by which wood or wood based\\u000a products undergo slow degradation induced by the weather (sunlight, wind, precipitations, diurnal and seasonal changes in\\u000a relative humidity, atmospheric pollution, etc). Knowledge about weathering durability comes from practical experiences of\\u000a end-users, from field tests and from standardized laboratory tests. The

Voichita Bucur

216

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

SciTech Connect

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).

Morrison, PI Hugh

2012-09-21

217

Wind Turbine Clutter mitigation for weather radar by Adaptive Spectrum Processing  

Microsoft Academic Search

Wind Turbine Clutter (WTC) is the radar clutter caused by strong backscatter from large wind turbines within the radar vicinity. Due to the rotation of the rotor blades, the Doppler spectrum of WTC varies from scan to scan. This time-varying radar signature results in the failure of classic ground clutter filter techniques. The Adaptive Spectrum Processing (ASP) algorithm proposed in

Fanxing Kong; Yan Zhang; Robert Palmer

2012-01-01

218

Space Weathering of Lunar Rocks  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

219

JOINT DRY/WET WEATHER TREATMENT OF MUNICIPAL WASTEWATER AT CLATSKANIE, OREGON  

EPA Science Inventory

This report describes the two year plant scale evaluation of physical and biological processes used for joint treatment of dry weather and storm generated sanitary sewer flow. The project was conducted in Clatskanie, OR at the City's new joint dry/wet weather sewage treatment pla...

220

Weather Forecasting  

NSDL National Science Digital Library

This activity (on page 2 of the PDF) is a full inquiry investigation into meteorology and forecasting. Learners will research weather folklore, specifically looking for old-fashioned ways of predicting the weather. Then, they'll record observations of these predictors along with readings from their own homemade barometer, graphing the correct predictions for analysis. Relates to linked video, DragonflyTV: Forecasting.

Twin Cities Public Television, Inc.

2005-01-01

221

Space Weather  

NASA Technical Reports Server (NTRS)

This video provides a narrated exploration of the history and affects of space weather. It includes information the earth's magnetic field, solar radiation, magnetic storms, and how solar winds affect electronics on earth, with specific information on how space weather affects space exploration in the future.

Gallagher, Dennis L.

2010-01-01

222

Weather Instruments.  

ERIC Educational Resources Information Center

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…

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

223

Weathering processes in the Rio Icacos and Rio Mameyes watersheds in Eastern Puerto Rico: Chapter I in Water quality and landscape processes of four watersheds in eastern Puerto Rico  

USGS Publications Warehouse

Streams draining watersheds of the two dominant lithologies (quartz diorite and volcaniclastic rock) in the Luquillo Experimental Forest of eastern Puerto Rico have very high fluxes of bedrock weathering products. The Río Blanco quartz diorite in the Icacos watershed and the Fajardo volcaniclastic rocks in the Mameyes watershed have some of the fastest documented rates of chemical weathering of siliceous rocks in the world. Rapid weathering produces thick, highly leached saprolites in both watersheds that lie just below the soil and largely isolate subsurface biogeochemical and hydrologic processes from those in the soil. The quartz diorite bedrock in the Icacos watershed weathers spheroidally, leaving large, relatively unweathered corestones that are enveloped by slightly weathered rock layers called rindlets. The rindlets wrap around the corestones like an onionskin. Within the corestones, biotite oxidation is thought to induce the spheroidal fracturing that leads to development of rindlets; plagioclase in the rindlets dissolves, creating additional pore spaces. Near the rindlet-saprolite interface, the remaining plagioclase dissolves, hornblende dissolves to completion, and precipitation of kaolinite, gibbsite, and goethite becomes pervasive. In the saprolite, biotite weathers to kaolinite and quartz begins to dissolve. In the soil layer, both quartz and kaolinite dissolve. The volcaniclastic bedrock of the Mameyes watershed weathers even faster than the quartz diorite bedrock of the Icacos watershed, leaving thicker saprolites that are devoid of all primary minerals except quartz. The quartz content of volcaniclastic bedrock may help to control watershed geomorphology; high-quartz rocks form thick saprolites that blanket ridges. Hydrologic flow paths within the weathering profiles vary with total fluid flux, and they influence the chemistry of streams. Under low-flow conditions, the Río Icacos and its tributaries are fed by rainfall and by groundwater from the fracture zones; during storm events, intense rainfall rapidly raises stream levels and water is flushed through the soil as shallow flow. As a result, weathering constituents that shed into streamwaters are dominated by rindlet-zone weathering processes during base flow and by soil weathering processes during stormflow. The upper reaches of the Mameyes watershed are characterized by regolith more than 35 meters thick in places that contains highly fractured rock embedded in its matrix. Weathering contributions to stream chemistry at base flow are predicted to be more spatially variable in the Mameyes watershed than in the Icacos watershed owing to the more complex subsurface weathering profile of the volcaniclastic bedrocks of the Mameyes watershed.

Buss, Heather L.; White, Arthur F.

2012-01-01

224

Hydrologic regulation of chemical weathering and the geologic carbon cycle.  

PubMed

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

Maher, K; Chamberlain, C P

2014-03-28

225

Brazilian Space Weather Program  

NASA Astrophysics Data System (ADS)

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.

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

226

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

NASA Astrophysics Data System (ADS)

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.

Mirza, A.; Drouin, A.

2009-09-01

227

Slope processes in weathered volcaniclastic rocks of the Camaldoli hill (Naples, Italy): Geomorphologic and Engineering-Geological aspects  

NASA Astrophysics Data System (ADS)

Following the geological study performed by Orsi et al. (this session), the main results of a geomorphologic and engineering-geological investigation of the stability conditions of the Camaldoli hill (urban area of Naples) are here presented. The Camaldoli hill, the highest peak of the Phlegraean Fields caldera (452 m asl), is characterized by relief energy of a few hundreds of meters, and by high slope gradients, which frequently reach the verticality. Low-order, structurally controlled channels drain the hillslopes; the development of stepped longitudinal profiles in the channels is related to the alternance of rocks and soils. The geological framework of the hill represent a further factor predisposing to mass movements and soil erosion. The Camaldoli hill is in fact characterized, as already highlighted by Orsi et al., by a basal sequence of jointed weak tuffs, overlain by some tens of metres of loose, unconsolidated pyroclastic terrains, ranging in age from about 12.000 and 4.000 yrs. BP. The latter deposits are generally weathered in their upper layers, as a consequence of interaction with decay agents and of past slope instabilities. Present-day morphodynamics of the hill is ruled by the occurrence of a variety of slope processes. Shallow landslides involve the weathered portion of the youngest pyroclastic products, showing features typical of slides or falls. Such events, which usually start in the upper reaches of the slope, may undergo different evolution, essentially controlled by the local slope morphology: (i) low-mobility soil slides-debris flows on open slopes; (ii) slides/falls evolving to hyperconcentrated flows along channels. The first processes have been seldom observed on open slopes, while the transition from slides/falls to hyperconcentrated flows along channels seems much more diffuse in the study area. The flows are generally fed, under intense to extreme rainfall events, by the re-mobilization of pre-existing landslide debris. The upper tuff formations (namely, the Neapolitan Yellow Tuff) are involved in falls and topple failures, which can detach volumes up to some tens of cubic metres, frequently reaching the lowest sectors of the slope, close to, if not within, the urbanized area. Eventually, accelerated soil erosion plays a major role in the open slopes, where evidences of sheet, rills and gullies have been surveyed. Joining the contribution of volcanologists and engineering-geologists, a tentative evaluation of the volumes susceptible to be mobilized by instability processes acting on the surficial, weathered cover of the loose pyroclastics was performed, adopting different methodologies. The so obtained results are compared and discussed in the paper: overall, they provide evidence of a widespread proneness to slope instability, which in turn may result into a serious threat to the diffuse settlements and infrastructures located at the Camaldoli’s foothill.

Calcaterra, D.; Coppin, D.; Palma, B.; Parise, M.; Orsi, G.; de Vita, S.; di Vito, M. A.

2003-04-01

228

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

SciTech Connect

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.

Gibson, M.A.; Smith, W.L. (Univ. of Tennessee, Martin, TN (United States))

1993-03-01

229

Theoretical model of space weather impact on GPS ionospheric delay  

Microsoft Academic Search

Space weather is a common name for the group of physical and chemical processes taking place in the vast space between the Sun and the Earth. Caused primarily by the solar activity, those processes create a flow of materia and energy. When directed to the Earth and its surroundings, this flow disrupts magnetic and ionospheric conditions, affecting numerous technical systems

Tomislav Kos; Renato Filjar; Ivan Markezic

2007-01-01

230

Modeling chemical and physical processes of wood and biomass pyrolysis  

Microsoft Academic Search

This review reports the state of the art in modeling chemical and physical processes of wood and biomass pyrolysis. Chemical kinetics are critically discussed in relation to primary reactions, described by one- and multi-component (or one- and multi-stage) mechanisms, and secondary reactions of tar cracking and polymerization. A mention is also made of distributed activation energy models and detailed mechanisms

Colomba Di Blasi

2008-01-01

231

Estuarine Physical Processes Research: Some Recent Studies and Progress  

Microsoft Academic Search

The literature on estuarine physical studies is vast, diverse and contains many valuable case studies in addition to pure, process-based research. This essay is an attempt to summarize both some of the more recent studies that have been undertaken during the last several years, as well as some of the trends in research direction and progress that they represent. The

R. J. Uncles

2002-01-01

232

Gendering Processes in the Field of Physical Education  

ERIC Educational Resources Information Center

In Finnish secondary schools, girls and boys are taught physical education (PE) in separate groups. A male teacher normally teaches the boys and a female teacher teaches the girls. Focusing on PE teachers' comments in two different ethnographic studies of seventh graders (13-14-year-olds), we examine the processes that reproduce or challenge the…

Berg, Paivi; Lahelma, Elina

2010-01-01

233

A laboratory of image processing and holography for physics students  

Microsoft Academic Search

In the Physics degree in Spain the students have a mandatory course in Fundamentals of Optics as well as an Optics Laboratory course. With these two courses the students receive a general background of optics. There are also some optional courses on Optics in the last years of the degree. One of them is a course on Optical Image Processing

M. J. Yzuel; J. C. Escalera; A. Lizana; M. Espínola; J. Campos

234

Chemical/Physical and Biological Treatment of Wool Processing Wastes.  

National Technical Information Service (NTIS)

Elevated temperature acid-cracking combined with pilot activated sludge and solids. The chemical/physical system consisted of a hot acid-cracking process to reduce the grease content in the influent to the biological system. The biological system consiste...

L. T. Hatch R. E. Sharpin W. T. Wirtanen

1974-01-01

235

The use of imprecise processing to improve accuracy in weather & climate prediction  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

236

Building and Using Coupled Models for the Space Weather System: Lessons Learned  

NASA Astrophysics Data System (ADS)

Numerical modeling of the space weather system is at an exciting juncture, in some ways similar to that of terrestrial weather modeling in the 1950s [e.g., Siscoe, 2006, 2007]. Improved scientific understanding of the physical processes underlying space weather, combined with advancing computational capabilities, is making physics-based modeling of the Sun-Earth system increasingly useful not only for scientific research but also for important aspects of operational space weather forecasting. As a result, both researchers and forecasters want to make use of space weather models that are developed by others. Furthermore, given the complexity of the Sun-Earth system, coupling models of various parts of the system is an attractive way to simulate the system as a whole. To do this well requires collaborations among experts in the various components of the space weather system on both scientific and computational issues.

Quinn, Jack; Hughes, Jeffrey; Baker, Daniel N.; Linker, Jon; Lyon, John; Solomon, Stanley C.; Wiltberger, Michael

2009-05-01

237

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

NASA Astrophysics Data System (ADS)

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.

Koskinen, H. E.

2008-12-01

238

Planetary Weather  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the weather conditions on other planets. After learning more about weather patterns, students research the weather on a given planet and create a visual display of the conditions there. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

239

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

ERIC Educational Resources Information Center

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…

Stevenson, R. D.

240

Extreme Value and Record Statistics in Heavy-Tailed Processes with Long-Range Memory: Application to Space Weather  

NASA Astrophysics Data System (ADS)

Extreme events are of large interest in many fields of research because of their typically devastating effects on society and their scientific complexities. The latter is particularly true if the underlying dynamics does not lead to independent extreme events as often observed in natural systems. Here, we focus on this case and consider stationary stochastic processes that are characterized by long-range memory and heavy-tailed distributions, often called fractional Lévy noise and associated with the Noah and Joseph effect introduced by Mandelbrot. We show that while the size distribution of extreme events is not affected by the long-range memory in the asymptotic limit and remains a Fréchet distribution, there are strong finite-size effects if the memory leads to persistence in the underlying dynamics. Strong persistence also gives rise to significant modifications of the records' statistics. Moreover, we show that this persistence is also present in the extreme events, which allows one to make a time-dependent hazard assessment of future extreme events based on events observed in the past. We show that this has direct applications in the field of space weather. Specifically, we discuss this for the solar power influx into the magnetosphere described by Akasofu's ? parameter.

Schumann, A.; Moloney, N.; Davidsen, J.

2011-12-01

241

Major ion chemistry, weathering processes and water quality assessment in upper catchment of Damodar River basin, India  

NASA Astrophysics Data System (ADS)

The chemical characteristics of surface, groundwater and mine water of the upper catchment of the Damodar River basin were studied to evaluate the major ion chemistry, geochemical processes controlling water composition and suitability of water for domestic, industrial and irrigation uses. Water samples from ponds, lakes, rivers, reservoirs and groundwater were collected and analysed for pH, EC, TDS, F, Cl, HCO3, SO4, NO3, Ca, Mg, Na and K. In general, Ca, Na, Mg, HCO3 and Cl dominate, except in samples from mining areas which have higher concentration of SO4. Water chemistry of the area reflects continental weathering, aided by mining and other anthropogenic impacts. Limiting groundwater use for domestic purposes are contents of TDS, F, Cl, SO4, NO3 and TH that exceed the desirable limits in water collected from mining and urban areas. The calculated values of SAR, RSC and %Na indicate good to permissible use of water for irrigation. High salinity, %Na, Mg-hazard and RSC values at some sites limit use for agricultural purposes.

Singh, Abhay Kumar; Mondal, G. C.; Kumar, Suresh; Singh, T. B.; Tewary, B. K.; Sinha, A.

2008-04-01

242

Glacial effects on weathering processes: New insights from the elemental and lithium isotopic composition of West Greenland rivers  

NASA Astrophysics Data System (ADS)

Greenland is by far the dominant source of glacial runoff to the oceans but the controls on the chemical and isotopic composition of this runoff are poorly known. To better constrain glacial effects on weathering processes, we have conducted elemental and lithium isotope analyses of glacial and non-glacial rivers in gneiss catchments in West Greenland. The glacial rivers have high total suspended solids (0.5 g l - 1 ) and low total dissolved solids (12 ?Scm - 1 ) relative to the non-glacial rivers, and they contain a higher proportion of dissolved Ca 2+ and K + because of subglacial, preferential, weathering of trace carbonates and biotite. The glacial rivers also have high SO 42- because of the oxidation of trace sulphides under the ice. Both glacial and non-glacial rivers have high ?7Li (respectively, ˜ 26‰ and ˜ 30‰) relative to the rocks from which the Li is derived (˜ 8‰). Saturation state modelling suggests that this is due to the formation of Fe-oxyhydroxides in the non-glacial rivers, with preferential uptake of 6Li during inner sphere sorption of Li + on the Fe-oxyhydroxide surface. Glacial rivers, however, are undersaturated with respect to clay minerals and Fe-oxyhydroxides. Nevertheless, leaching of suspended sediments indicates that ˜ 65% of the Li in these sediments is associated with Fe-oxyhydroxide phases, and the ?7Li value of this Li is low, ˜ 5‰. These results suggest that these Fe-oxyhydroxides formed under the ice, as a product of sulphide oxidation, with preferential uptake of 6Li onto the mineral surface. Solubilisation of Li from these Fe-oxyhydroxide phases is unlikely to represent a significant flux of Li to the oceans. Moreover, because the difference between the ?7Li values of glacial vs non-glacial rivers is small, glaciation has not had a significant impact on the Li isotopic composition of the riverine flux delivered to the oceans in the past, even at the height of the last deglaciation.

Wimpenny, Josh; James, Rachael H.; Burton, Kevin W.; Gannoun, Abdelmouhcine; Mokadem, Fatima; Gíslason, Sigurður R.

2010-02-01

243

Weatherizing America  

ScienceCinema

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.

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

2013-05-29

244

Weather One  

NSDL National Science Digital Library

This website contains summaries and lessons about various aspects of weather. This includes the seasons, types of clouds, air, winds, global warming, hurricanes, tornadoes and lightning. Worksheets are provided to accompany the lesson themes.

Friend, Duane

245

Weather Watchers  

NSDL National Science Digital Library

In this month-long interdisciplinary project students collect weather data, determine the best visual representation for displaying it, and discuss the patterns and implications of their findings. This resource includes extension and assessment suggestions and guiding questions.

2014-01-01

246

Weatherizing America  

ScienceCinema

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.

247

Weatherizing America  

SciTech Connect

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.

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

2009-01-01

248

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

ERIC Educational Resources Information Center

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…

Cowan, Christina E.

249

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

ERIC Educational Resources Information Center

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…

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

250

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

ERIC Educational Resources Information Center

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…

Roseman, Leonard D.

251

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

ERIC Educational Resources Information Center

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…

Cowan, Christina E.

252

Weather Creator  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What can you do to make it rain or even snow? 4. Does it always snow when ...

Kshumway

2009-09-28

253

Weather Maps  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades K-5. It focuses on basic information about the weather and how different weather maps depict conditions. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

254

Space Weather Basics, 2nd Edition  

NSDL National Science Digital Library

This module presents an overview of space weather processes, their impacts on Earth and human activities, and the technologies used for forecasting space weather events. The module goal is to provide NWS forecasters a basic understanding of space weather and the operations of NOAA's Space Weather Prediction Center (SWPC). It will be of interest to a general audience as well.

Abshire, Wendy

2012-01-01

255

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

NASA Astrophysics Data System (ADS)

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.

Johnson, David Kelley

256

Characterizing englacial and subglacial weathering processes in a silicate-carbonate system at Robertson Glacier, Canada: Combining field measurements and remote sensing  

NASA Astrophysics Data System (ADS)

Geologic weathering processes in cold environments, especially processes acting on subglacial and englacial sediments and rocks, are not well characterized due to the difficulty of accessing these environments. However, subglacial and englacial weathering of geologic materials contributes to the solute flux in meltwater and provides a potential source of energy to chemotrophic microbes, and is thus an important component to understand. In this study, we characterize the weathering products present in a glaciated silicate-carbonate system using infrared spectroscopy, x-ray diffraction, and geochemical analyses. We use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data to determine whether glacial weathering products can be detected from remotely detected infrared spectra. The major goals of the project are to quantify weathering inputs to the glacial energy budget, and to link in situ sampling with remote sensing capabilities. Robertson Glacier, Alberta, Canada (115°20'W, 50°44'N) provides an excellent field site for this technique as it is accessible, and its retreating stage allows sampling of fresh subglacial and englacial sediments. This site is also of great significance to microbiology studies due to the recent detection of methanogens in the local subglacial till. Samples of glacially altered rock and sediments were collected on a downstream transect of the glacier in September 2011. Infrared laboratory spectroscopy and x-ray diffraction were used to determine the composition and abundance of minerals present. Infrared imagery of the region was collected at the time of sampling with the ASTER satellite instrument. Geochemical data were also collected at each location, and ice and water samples were analyzed for major and minor elements. pH values decreased in the downstream direction, and Ca+2 and SO4-2 in solution increased downstream. This is initially consistent with earlier studies of similar systems; however, the majority of the observed changes in concentrations seem to occur immediately at the supraglacial-subglacial interface. Change in concentrations decreases downstream of the glacier terminus. Our initial conclusion is that the majority of the weathering seems to be occurring at the ice-rock interface rather than in the outwash stream. Initial results from both laboratory and ASTER data indicate the presence of weathering products. A general trend of decreasing carbonate abundances with elevation (i.e. residence time in ice) is observed, which is consistent with the increasing Ca+2 ion concentrations towards the terminus. More mineralogical work, such as thin section analyses, is ongoing in order to refine the types of weathering products present in the system.

Rutledge, A. M.; Christensen, P. R.

2012-12-01

257

Physical activity across the curriculum: year one process evaluation results  

PubMed Central

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.

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

258

A combined physical/microbial process for coal beneficiation  

SciTech Connect

A combined physical/microbial process for the removal of pyritic sulfur from coal was demonstrated in a 200 L aerated trough slurry reactor. The reactor was divided into six sections, each of which acted as both a physical separator and a bioreactor. Settled solids from sections 2 through 6 were recycled to section 1 which acted as a rougher. The objective was physical removal of the larger pyritic inclusions, which would take many days to biodegrade, and biodegradation of the micropyrite, which is difficult to remove physically. The process was operated continuously for 8 months, treating two Illinois No. 6 coals (4 months each). Reduction of 90% in-pyritic sulfur with 90% energy recovery and 35% ash removal was obtained for a low pyrite Monterey coal at a 5 day coal retention time and 20% (w/w) slurry concentration. Increased coal loading reduced performance apparently due to losses of sulfur oxidizing bacteria. A low pyrite Consol coal gave 63--77% pyrite reduction with 23--30% ash removal and 77--90% heating value recovery. Product coal pyritic sulfur analysis indicated no differences between treatments of Consol coal. This suggests that the coal residence time could be further reduced and the slurry concentration increased in future work.

Noah, K.S.; Glenn, A.W.; Stevens, C.J.; McAtee, N.B.; McIlwain, M.E.; Andrews, G.F.

1993-11-01

259

CLARA: A Contemporary Approach to Physics Data Processing  

NASA Astrophysics Data System (ADS)

CLARA (CLAS12 Reconstruction and Analysis framework) is CLAS12 physics data processing (PDP) application development framework based on a service oriented architecture (SOA). This framework allows users to design and deploy data processing services as well as dynamically compose PDP applications using available services. Services can be written in Java, C++, and Python languages. The PDP service bus provides a layer on top of a distributed pub-sub middleware implementation. This allows complex service composition and integration without writing a code. We believe that by deviating from the traditional self contained, monolithic PDP application models we can improve maintenance, scalability and quality of physics data analysis. The SOA approach also helps us to separate a specific service programmer from a PDP application designer. Examples of service creation and deployment, along with the CLAS12 track reconstruction application design are presented.

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

2011-12-01

260

Geography and Physical Processes of the Circumpolar World  

NSDL National Science Digital Library

This module provides a brief introduction to the physical features and processes of the Arctic region and the significant factors that influence them, which include: the climate, including very low winter temperatures, relatively high summer temperatures, and the subsequent freeze-thaw cycle; the long-term glaciation cycle; and the presence or absence of water and the dynamics and influence thereof, both as liquid and ice, on the northern landscape. A review of map reading skills is also included.

261

Fusing signatures of different physical processes in muon tomography  

Microsoft Academic Search

We explored the cosmic ray flux attenuation, the induction of electro-magnetic showers, and muonic X-rays as a means to radiograph small scale objects. We are reporting on the value of the signatures provided by these physical processes to the muon tomography. The results of the related experiments and the Monte-Carlo calculations that we performed are discussed. Based on our data

A. V. Klimenko; C. L. Morris; W. C. Priedhorsky; K. N. Borozdin; L. J. Schultz

2005-01-01

262

Influence of different natural physical fields on biological processes  

NASA Astrophysics Data System (ADS)

In space flight conditions gravity, magnetic, and electrical fields as well as ionizing radiation change both in size, and in direction. This causes disruptions in the conduct of some physical processes, chemical reactions, and metabolism in living organisms. In these conditions organisms of different phylogenetic level change their metabolic reactions undergo changes such as disturbances in ionic exchange both in lower and in higher plants, changes in cell morphology for example, gyrosity in Proteus ( Proteus vulgaris), spatial disorientation in coleoptiles of Wheat ( Triticum aestivum) and Pea ( Pisum sativum) seedlings, mutational changes in Crepis ( Crepis capillaris) and Arabidopsis ( Arabidopsis thaliana) seedling. It has been found that even in the absence of gravity, gravireceptors determining spatial orientation in higher plants under terrestrial conditions are formed in the course of ontogenesis. Under weightlessness this system does not function and spatial orientation is determined by the light flux gradient or by the action of some other factors. Peculiarities of the formation of the gravireceptor apparatus in higher plants, amphibians, fish, and birds under space flight conditions have been observed. It has been found that the system in which responses were accompanied by phase transition have proven to be gravity-sensitive under microgravity conditions. Such reactions include also the process of photosynthesis which is the main energy production process in plants. In view of the established effects of microgravity and different natural physical fields on biological processes, it has been shown that these processes change due to the absence of initially rigid determination. The established biological effect of physical fields influence on biological processes in organisms is the starting point for elucidating the role of gravity and evolutionary development of various organisms on Earth.

Mashinsky, A. L.

2001-01-01

263

Influence of different natural physical fields on biological processes.  

PubMed

In space flight conditions gravity, magnetic, and electrical fields as well as ionizing radiation change both in size, and in direction. This causes disruptions in the conduct of some physical processes, chemical reactions, and metabolism in living organisms. In these conditions organisms of different phylogenetic level change their metabolic reactions undergo changes such as disturbances in ionic exchange both in lower and in higher plants, changes in cell morphology for example, gyrosity in Proteus (Proteus vulgaris), spatial disorientation in coleoptiles of Wheat (Triticum aestivum) and Pea (Pisum sativum) seedlings, mutational changes in Crepis (Crepis capillaris) and Arabidopsis (Arabidopsis thaliana) seedling. It has been found that even in the absence of gravity, gravireceptors determining spatial orientation in higher plants under terrestrial conditions are formed in the course of ontogenesis. Under weightlessness this system does not function and spatial orientation is determined by the light flux gradient or by the action of some other factors. Peculiarities of the formation of the gravireceptor apparatus in higher plants, amphibians, fish, and birds under space flight conditions have been observed. It has been found that the system in which responses were accompanied by phase transition have proven to be gravity-sensitive under microgravity conditions. Such reactions include also the process of photosynthesis which is the main energy production process in plants. In view of the established effects of microgravity and different natural physical fields on biological processes, it has been shown that these processes change due to the absence of initially rigid determination. The established biological effect of physical fields influence on biological processes in organisms is the starting point for elucidating the role of gravity and evolutionary development of various organisms on Earth. PMID:11803963

Mashinsky, A L

2001-01-01

264

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

NASA Technical Reports Server (NTRS)

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.

Kreins, E. R. (editor)

1979-01-01

265

Mechanics of Sheeting Joints and Spheroidal Weathering (Invited)  

NASA Astrophysics Data System (ADS)

Physical weathering in low-porosity materials, like most crystalline rocks, commonly involves fracture, which increases the surface area that can be accessed by reactive chemicals. Chemical reactions on these surfaces can in turn affect the course of further fracturing. Physical and chemical weathering thus commonly go hand in hand, although one process can dominate the other. Two common products of physical weathering are sheeting joints and spheroidal weathering. Both involve fracturing parallel or subparallel to a nearby surface, but they are distinctly different in several ways. Sheeting joints can achieve dimensions of a couple of hundred meters, typically have radii of curvature of 100m - 1000m, and are bounded on one side by the topographic surface. As the distance from the topographic surface increases, the spacing between sheeting joints generally increases and they become less curved. Neither chemical weathering nor grain-scale effects appear to be consequential in the formation of sheeting joints. In contrast, for spheroidal weathering the individual fractures are roughly grain-sized, form in “shells” with radii of curvature of about 1m, and are bounded on all sides by pre-existing bedrock fractures. As the distance from the bounding surfaces increases, the spacing between fractures generally stays about the same but the “shells” defined by the fractures become more curved. Both chemical weathering and grain-scale cracking accompany spheroidal weathering. The processes of sheeting joint formation and spheroidal weathering have been approached from the perspective of a complete boundary value problem in continuum mechanics, where several factors generally are needed to predict the physical failure of a rock mass, including: (a) the shape of a rock body; (b) the stresses acting on its surface, (c) the body forces within it, and (d) the equations of equilibrium; and (e) the constitutive laws for the material. In the cases of sheeting joint formation and spheroidal weathering, a simpler approach that depends on only four factors can be used to provide insight into the fracture process: (a) the shape of a rock body; (b) the stress distribution parallel to its surface, (c) the body forces within it, and (d) a single equation of equilibrium. This approach indicates that in both cases high compressive stresses parallel to convex bounding surfaces contribute fundamentally to the formation of the fractures. In at least some cases involving sheeting joints, the origin of these stresses is likely to be tectonic. In the case of spheroidal weathering, the compressive stresses are likely to arise from chemical alteration of grains.

Martel, S. J.

2010-12-01

266

Physical Processes of Poloidal Flux Injection in CMEs  

NASA Astrophysics Data System (ADS)

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.

Chen, James

2011-05-01

267

Sandstone weathering: a century of research and innovation  

NASA Astrophysics Data System (ADS)

A review of sandstone weathering research, particularly in the past 100 years, reveals a trajectory of enquiry from early description and classification of features, to development of process-based explanations, to decreasing scales of investigation, and a disparity between understanding of process(es) and explanations of the genesis of sandstone weathering features. Developments in expositions on mesoscale weathering features on sandstone surfaces are discussed, demonstrating a range of approaches to weathering phenomena—field-based and laboratory-based—that must be linked to provide an explanation of observed features on a landform scale. Throughout the twentieth century, a thematic chronology highlights certain trends in research: description of forms, often in arid and semi-arid environments; single process-form models; an emphasis on experimentation; difficulties in measuring weathering rates; and a persistent emphasis on physical causes of breakdown. A new research agenda is promoted in which biodeterioration and chemical processes gain parity, a holistic approach based on conceptual modeling of weathering systems gains prominence, and scale issues are addressed more rigorously.

Turkington, Alice V.; Paradise, Thomas R.

2005-04-01

268

Space Weather  

NASA Astrophysics Data System (ADS)

This volume provides a comprehensive overview of our current observational knowledge, theoretical understanding, and numerical capability with regard to the phenomena known as space weather. Space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems, and can endanger human life or health. The rapid advance in these technologies has provided us with unprecedented capability and convenience, and we have come to rely on them more and more. Technology has reduced society's risk to many kinds of natural disasters, but through its own vulnerability, it has actually increased society's risk to space weather. 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.

Song, Paul; Singer, Howard J.; Siscoe, George L.

269

Delicious Differential Weathering  

NSDL National Science Digital Library

Students are asked to place a Baby Ruth candy bar in their mouths but are asked not to bite it. Once they have sucked off all the chocolate and caramel the students are given permission to bite the peanuts. After lecturing on the differences between chemical and physical weathering students are asked to list the order of ingredients they tasted. Each group is given a sample of granite. Students are asked to list three visible minerals in the granite. Relate the minerals of the granite (hornblende, feldspar, and quartz) to the ingredients of the candy bar. Explain Bowen's reaction series and how different minerals will weather first and how climate will affect weathering rates.

Gorte, Mary

270

Process evaluation results from the HEALTHY physical education intervention  

PubMed Central

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 engagement in moderate-to-vigorous physical activity through delivery of structured lesson plans by PE teachers. Process evaluation data collected via class observations and interventionist interviews assessed fidelity, dose delivered, implementor participation, dose received and barriers. Process evaluation results indicate a high level of fidelity in implementing HEALTHY PE activities and offering 225 min of PE every 10 school days. Concerning dose delivered, students were active for approximately 33 min of class, representing an average of 61% of the class time. Results also indicate that PE teachers were generally engaged in implementing the HEALTHY PE curriculum. Data on dose received showed that students were highly engaged with the PE intervention; however, student misbehavior was the most common barrier observed during classes. Other barriers included teacher disengagement, large classes, limited gym space and poor classroom management. Findings suggest that the PE intervention was generally implemented and received as intended despite several barriers.

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

271

Wild Weather  

NSDL National Science Digital Library

In this online, interactive module, students learn about severe weather (thunderstorms, hurricanes, tornadoes, and blizzards) and the key features for each type of "wild weather" using satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

272

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is one of several online guides produced by the Weather World 2010 project at the University of Illinois. These guides use multimedia technology and the dynamic capabilities of the web to incorporate text, colorful diagrams, animations, computer simulations, audio, and video to introduce topics and concepts in the atmospheric sciences. This module introduces forecast methods and the numerous factors one must consider when attempting to make an accurate forecast. Sections include forecasting methods for different scenarios, surface features affecting forecasting, forecasting temperatures for day and night, and factors for forecasting precipitation.

2010-01-01

273

Weather One  

NSDL National Science Digital Library

From the University of Illinois Extension comes the Weather One instructional Web site for kids. The lesson consists of six pages that cover various weather related topics including seasons, clouds, the atmosphere, wind, global warming, and storms. Each page describes the particular subject, provides related photographs, and contains several activities that reinforce the learning. For example, the clouds page shows how kids can make a cloud and create a collage out of simple material found around the house. The effective organization and clean look of the site will surely make it easy for students to follow and enjoy.

1969-12-31

274

Space Weather  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on Space Weather and the terms scientists use to describe the everchanging conditions in space. Explosions on the Sun create storms of radiation, fluctuating magnetic fields, and swarms of energetic particles. These phenomena travel outward through the Solar System with the solar wind. Upon arrival at Earth, they interact in complex ways with Earth's magnetic field, creating Earth's radiation belts and the Aurora. Some space weather storms can damage satellites, disable electric power grids, and disrupt cell phone communications systems. This site provides images, activities, and interesting facts about all of these events.

2004-02-06

275

Weather Activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. Why does the wind blow? 2. When winds are blowing, how can you get them to stop? 3. What happens when the temperature is the same? 4. What happens when there is high relative humidity? 5. What ...

missy.jones@gmail.com

2009-09-28

276

Major and trace element abundances, and strontium isotopes in the Nyong basin rivers (Cameroon): constraints on chemical weathering processes and elements transport mechanisms in humid tropical environments  

Microsoft Academic Search

This paper aims to improve our understanding of chemical weathering processes and element transport mechanisms in the humid tropical environments. We studied the Nyong River basin (27,800 km2) located on the northwestern part (Ntem Complex) of the Congo craton (central Africa). The dissolved concentrations (i.e., <0.20 ?m) of major and trace elements, dissolved organic carbon (DOC) and the 87Sr\\/86Sr ratios

Jérôme Viers; Bernard Dupré; Jean-Jacques Braun; Samuel Deberdt; Bernard Angeletti; Jules Ndam Ngoupayou; Annie Michard

2000-01-01

277

Compact effector optics for processing in limited physical access situations  

NASA Astrophysics Data System (ADS)

A major advantage of fiber-optic beam delivery in laser materials processing is the ability to guide the laser power to the location where it is needed, leaving the laser itself remote and protected from the process. This is of special importance if the processing is to be performed in a hazardous environment. Particular problems are faced by the nuclear industry where weld repair and surface treatment work are required inside radioactive installations. By use of fiber beam delivery, only part of the delivery system and effector optics become contaminated, but the expensive laser system does not. However, in many cases the region where repair is required is not only radioactive but has only limited physical access, e.g., inside tubes or into corners, which prevents use of standard effector optics. We present a new design to deal with such constraints of a 2-mm outer diameter employing a hollow waveguide and gas shielding. This design is optically characterized and its performance assessed in welding and surface treatment applications. The potential of this compact effector optics in limited physical access situations is clearly demonstrated.

Kuhn, Andreas; Fox, Mahlen D. T.; French, Paul W.; Hettrick, Simon; Hand, Duncan P.; Shi, Yi-Wei; Matsuura, Yuji; Miyagi, Mitsunobu; Watkins, Kenneth G.; Ireland, Clive L. M.; Jones, Julian D. C.

2003-09-01

278

Weather Stations  

NSDL National Science Digital Library

This is a series of seven brief activities about Jupiter's atmosphere and weather. Learners will look at Jupiter's distinct banded appearance, violent storms, and clouds of many different colors. The activities are part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

279

Wonderful Weather  

NSDL National Science Digital Library

In this activity, learners conduct three experiments to examine temperature, the different stages of the water cycle, and how convection creates wind. These activities can be used individually or as a group for a lesson on weather. Note: boiling water is required for this activity; adult supervision required.

Workshop, Mission S.

2013-01-01

280

Today's Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and contains an online exploration of weather maps. Students use current maps to learn about and locate different features such as low-pressure areas and fronts. They then explore how these are related to severe storms.

281

Weather Wordsearch  

NSDL National Science Digital Library

Find the 12 weather related words in this word search brought to you by the Southeast Regional Climate Center (SERCC). When you finish finding all 12 words, hit the restart button to re-scramble the letters and start all over again!

2007-01-01

282

On the persistence of 'weathering'  

NASA Astrophysics Data System (ADS)

The term 'weathering' has been in use for a very long time but it has come to mean different things to different people and hence, as scientific short-hand, it no longer functions. Here we question the tenets underpinning the most common usage of the term and note that the climate-process linkage implicit to the term is often missing and amounts to misdirection. Rather than climate as the primary driver behind specific weathering processes, it is argued that rock properties constitute the dominant control. Further, a case is made for reconsideration of our present bipartite (mechanical/chemical) division of weathering processes and of the weathering processes currently deemed to be 'those that occur'. As process studies become evermore reductionist in nature, so the functionality of the term comes more and more into question. The linkage between process and landform, the scaling-up attribute, is seen as a current weakness and one that will become more confusing as reductionist approaches continue. As a 'way forward' it is suggested that weathering, stripped of specific preconceived notions of specific processes, be envisaged as a function of energy transfer and be investigated in that light. Identification of new processes as well as restructuring of known processes, particularly when considering weathering on other planets, is a potential outcome of such an approach. With a process foundation rooted in energy transfer, 'rock decay' provides a better umbrella term and liberates researchers from the inescapable conceptual baggage implicit to the term 'weathering'.

Hall, Kevin; Thorn, Colin; Sumner, Paul

2012-05-01

283

The Weather Doctor  

NSDL National Science Digital Library

Published by Spectrum Educational Enterprises, The Weather Doctor Web site is maintained by meteorologist Keith Heidorn. Visitors to the site will find everything from the joys of weather watching, to making rain, to weather history, to much more. Coming from someone who clearly enjoys what they do, this site explores unique aspects of weather including weather people, weather history, and weather and arts.

Heidorn, Keith.

2002-01-01

284

Preliminary observations on the impact of complex stress histories on sandstone response to salt weathering: laboratory simulations of process combinations  

Microsoft Academic Search

Historic sandstone structures carry an inheritance, or a `memory', of past stresses that the stone has undergone since its placement in a façade. This inheritance, which conditions present day performance, may be made up of long-term exposure to a combination of low magnitude background environmental factors (for example, salt weathering, temperature and moisture cycling) and, superimposed upon these, less frequent

S. McCabe; B. J. Smith; P. A. Warke

2007-01-01

285

57 Fe Mössbauer spectroscopy studies of chondritic meteorites from the Atacama Desert, Chile: Implications for weathering processes  

NASA Astrophysics Data System (ADS)

Some terrestrial areas have climatic and geomorphologic features that favor the preservation, and therefore, accumulation of meteorites. The Atacama Desert in Chile is among the most important of such areas, known as dense collection areas. This desert is the driest on Earth, one of the most arid, uninhabitable locals with semi-arid, arid and hyper-arid conditions. The meteorites studied here were collected from within the dense collection area of San Juan at the Central Depression and Coastal Range of Atacama Desert. 57Fe Mössbauer spectroscopy was used for quantitative analysis of the degree of weathering of the meteorites, through the determination of the proportions of the various Fe-bearing phases and in particular the amount of oxidized iron in the terrestrial alteration products. The abundance of ferric ions in weathered chondrites can be related to specific precursor compositions and to the level of terrestrial weathering. The aim of the study was the identification, quantification and differentiation of the weathering products in the ordinary chondrites found in the San Juan area of Atacama Desert.

Munayco, P.; Munayco, J.; Valenzuela, M.; Rochette, P.; Gattacceca, J.; Scorzelli, R. B.

2014-01-01

286

Spring Deposits on Mars: Physical Processes from Terrestrial Analogs  

NASA Technical Reports Server (NTRS)

An important first step in the current Mars exploration strategy is the detection of sites where there is evidence for past or present near-surface water on Mars. This study evaluates the large-scale morphology of spring deposits and the physical processes of their formation, growth, and evolution in terms that relate to (1) their identification in image data, (2) their formation, evolution, and preservation in the environment of Mars, and (3) their potential as sites of long-term or late stage shallow groundwater emergence at the surface of Mars.

Crumpler, L. S.

2003-01-01

287

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

NASA Astrophysics Data System (ADS)

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.

Bouchard, Josee

288

Space Weather and Management of Environmental Risks and Hazards  

NASA Astrophysics Data System (ADS)

"Space Weather" is defined as electromagnetic and particle conditions in the space environment that can disturb space-borne and ground-based technological systems (e.g. satellite operation, telecommunication, aviation, electric power transmission) and even endanger human health. Thus, space weather is of great importance to the society since people are dependent on reliable operation of modern technology, interruptions of which may lead to large economical and other losses. Physical processes involved in space weather constitute a complicated chain from the Sun to the Earth's surface. Thus, a full understanding of space weather and the risks it produces requires expertise in many different disciplines of science and technology. Space weather is a new subject among the natural risks and hazards which threaten the society and its infrastructure (although the first observations of ground effects of space weather were already made about 150 years ago). Monitoring systems for the management of other risks, such as floods, forest fires, etc., and for security are, to a great extent, based on satellite observations. Spacecraft and the communication between satellites and the ground are vulnerable to space weather. Thus, besides being a direct risk to technological systems, space weather may also be indirectly adverse to risk management. These two aspects of space weather are considered in a proposal to be submitted to EU's Sixth Framework Programme under the "Aeronautics and Space" priority in the "Global Monitoring for Environment and Security (GMES) / Risk Management" area in March 2004. The proposal coordinated by the Finnish Meteorological Institute with five to ten participating institutes is called SW-RISK ("Space Weather - Risk Indices from Scientific Know-how").

Pirjola, R.; Kauristie, K.; Lappalainen, H.

289

The r-process nucleosynthesis: Nuclear physics challenges  

SciTech Connect

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.

Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

2012-10-20

290

Solar physics applications of computer graphics and image processing  

NASA Technical Reports Server (NTRS)

Computer graphics devices coupled with computers and carefully developed software provide new opportunities to achieve insight into the geometry and time evolution of scalar, vector, and tensor fields and to extract more information quickly and cheaply from the same image data. Two or more different fields which overlay in space can be calculated from the data (and the physics), then displayed from any perspective, and compared visually. The maximum regions of one field can be compared with the gradients of another. Time changing fields can also be compared. Images can be added, subtracted, transformed, noise filtered, frequency filtered, contrast enhanced, color coded, enlarged, compressed, parameterized, and histogrammed, in whole or section by section. Today it is possible to process multiple digital images to reveal spatial and temporal correlations and cross correlations. Data from different observatories taken at different times can be processed, interpolated, and transformed to a common coordinate system.

Altschuler, M. D.

1985-01-01

291

Computational modeling of physical processes during laser ablation  

SciTech Connect

A combined theoretical and experimental effort to model various physical processes during laser ablation of solids (silicon) using a variety of computational techniques is described. Currently the focus of the modeling is on the following areas: (a) rapid transformations through the liquid and vapor phases under possibly nonequilibrium thermodynamic conditions induced by laser-solid interactions, (b) breakdown of the vapor into a plasma in the early stages of ablation through both electronic and photoionization processes, (c) hydrodynamic behavior of the vapor/plasma during and after ablation, and (d) effects of initial conditions in the vapor, in particular, the nature of the initial velocity distribution, on the characteristics of subsequent vapor expansion. Results from the modeling are compared with experimental observations where possible.

Liu, C.L.; Leboeuf, J.N.; Wood, R.F.; Geohegan, D.B.; Donato, J.M.; Chen, K.R.; Puretzky, A.A.

1994-09-01

292

Simplified electronic signal processing in the small nuclear physics laboratory  

NASA Astrophysics Data System (ADS)

Small nuclear physics laboratories of all kinds traditionally have processed the signals from radiation detectors with a variety of discrete NIM- or CAMAC-based electronic modules. The logic signals associated with signal processing are often passed through gate generators, coincidence modules, fan-in/fan-out modules, delay units, counters, and other assorted logic modules. These multi-component systems generate gates for acquisition systems, gates for specific linear electronics modules (ADCs and TDCs), or measure count rates and dead times. This can involve a significant number of individual modules each of which can be quite costly and each of which provides only limited functions. We describe here an upgrade to our acquisition system where all the needed logic functions are performed in just a single unit: a Universal Logic Module based on a Field Programmable Gate Array (FPGA) from JTEC Corporation. This module also contains flash memory that holds three separate configurations allowing for rapid changes from one electronics configuration to a different one. Both CAMAC and VME versions of the unit are available. The system described here is just one example of the huge variety of functionality that can be programmed into this single module. It can accommodate very complicated circuits and is easily reprogrammed. In the small nuclear physics laboratory the Universal Logic Module can save cost when upgrading systems and reduce the number of instances where one has an insufficient number of channels of a particular function.

DeYoung, P. A.; Peaslee, G. F.

2005-10-01

293

NOAA Weather Radio Hourly Weather Roundup Formatter.  

National Technical Information Service (NTIS)

The National Weather Service (NWS) is planning to replace the aging National Oceanic and Atmospheric Administration (NOAA) Weather Radio (NWR) as part of its modernization program. The Office of Meteorology (OM) selected the Hourly Weather Roundup (HWR) t...

G. F. Battel G. A. Kokolis J. E. Calkins

1994-01-01

294

Weather Watchers  

NSDL National Science Digital Library

Students are introduced to some essential meteorology concepts so they more fully understand the impact of meteorological activity on air pollution control and prevention. First, they develop an understanding of the magnitude and importance of air pressure. Next, they build a simple aneroid barometer to understand how air pressure information is related to weather prediction. Then, students explore the concept of relative humidity and its connection to weather prediction. Finally, students learn about air convection currents and temperature inversions. In an associated literacy activity, students learn how scientific terms are formed using Latin and Greek roots, prefixes and suffixes, and are introduced to the role played by metaphor in language development. Note: Some of these activities can be conducted simultaneously with the air quality activity (What Color Is Your Air Today?) of Air Pollution unit, Lesson 1.

Integrated Teaching And Learning Program

295

Weather Cycles  

NSDL National Science Digital Library

We are professionals in the teaching profession. We designed this project for children ranging from 4th grade to 6th grade. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. YOU WILL NEED: Paper with copied questions, Overhead projector and Students broken up into groups of 3. Form groups of three. Have each group explore the following simulation: Weather Maker Simulator Have students use the simulation to answer the following questions on paper. They should be discussing the questions in their groups. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

Mitchell, Mrs.

2010-09-23

296

Physics-based processing for terahertz reflection spectroscopy and imaging  

NASA Astrophysics Data System (ADS)

The spectra obtained from Terahertz (THz) reflection imaging can be distorted by scattering from rough interfaces, layers, and granular inclusions. Since the facets of the object being imaged are not generally aligned normal to the THz beam, the received signal is produced from diffuse scattering, which can be appreciably lower in signal strength than specular returns. These challenges can be addressed with advanced signal processing approaches based upon the coherent and incoherent combination of returns from multiple sensors and frequencies. This paper presents two examples of physics-based processing strategies applied to THz imaging spectroscopy. The first method is based on synthetic aperture processing of a 2D sensor array to provide variable depth focused images of buried inclusions (a ball bearing embedded in polyethylene sample). The second method uses correlation processing to coherently combine multiple sensors and multiple frequencies to extract material signatures from measurements of THz scattering from rough interfaces. Results for both methods show an increase in performance relative to conventional imaging or spectroscopy approaches.

Zurk, L. M.; Henry, S. C.; Schecklman, S.; Duncan, D. D.

2010-11-01

297

Weathering Corruption  

Microsoft Academic Search

Could bad weather be responsible for U.S. corruption? Natural disasters create resource windfalls in the states they strike by triggering federally provided natural-disaster relief. By increasing the benefit of fraudulent appropriation and creating new opportunities for such theft, disaster-relief windfalls may also increase corruption. We investigate this hypothesis by exploring the effect of disaster relief provided by the Federal Emergency

2008-01-01

298

Shedding Light on the Weather  

Microsoft Academic Search

Virtually all methods in image processing and computer vision, for removing weather effects from images, as- sume single scattering of light by particles in the atmo- sphere. In reality, multiple scattering effects are signif- icant. A common manifestation of multiple scattering is the appearance of glows around light sources in bad weather. Modeling multiple scattering is critical to un- derstanding

Srinivasa G. Narasimhan; Shree K. Nayar

2003-01-01

299

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

ERIC Educational Resources Information Center

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,…

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

300

Preliminary observations on the impact of complex stress histories on sandstone response to salt weathering: laboratory simulations of process combinations  

Microsoft Academic Search

Historic sandstone structures carry an inheritance, or a ‘memory’, of past stresses that the stone has undergone since its\\u000a placement in a façade. This inheritance, which conditions present day performance, may be made up of long-term exposure to\\u000a a combination of low magnitude background environmental factors (for example, salt weathering, temperature and moisture cycling)\\u000a and, superimposed upon these, less frequent

S. McCabe; B. J. Smith; P. A. Warke

2007-01-01

301

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)

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.

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

2008-12-01

302

Linking Weather and Climate  

NASA Astrophysics Data System (ADS)

This presentation provides an overview major phenomena and mechanisms linking weather and climate variations, with a focus on a subset of major, recurrent phenomena that impact extratropical wintertime weather and climate variations over the Pacific-North American region. While progress in advancing understanding has been impressive, research has also illuminated areas where significant future gains are possible. Emerging thrusts in international and national research priorities suggest that over time artificial distinctions will be removed between "weather" and "climate", as we begin to achieve a more unified understanding of phenomena and processes that bridge time scales. We discuss these research thrusts, which are likely to serve as increasingly vital components of an overall research strategy in earth system science.

Dole, R.

2006-05-01

303

Stacking of blocks by chimpanzees: developmental processes and physical understanding.  

PubMed

The stacking-block task has been used to assess cognitive development in both humans and chimpanzees. The present study reports three aspects of stacking behavior in chimpanzees: spontaneous development, acquisition process following training, and physical understanding assessed through a cylindrical-block task. Over 3 years of longitudinal observation of block manipulation, one of three infant chimpanzees spontaneously started to stack up cubic blocks at the age of 2 years and 7 months. The other two infants began stacking up blocks at 3 years and 1 month, although only after the introduction of training by a human tester who rewarded stacking behavior. Cylindrical blocks were then introduced to assess physical understanding in object-object combinations in three infant (aged 3-4) and three adult chimpanzees. The flat surfaces of cylinders are suitable for stacking, while the rounded surface is not. Block manipulation was described using sequential codes and analyzed focusing on failure, cause, and solution in the task. Three of the six subjects (one infant and two adults) stacked up cylindrical blocks efficiently: frequently changing the cylinders' orientation without contacting the round side to other blocks. Rich experience in stacking cubes may facilitate subjects' stacking of novel, cylindrical shapes from the beginning. The other three subjects were less efficient in stacking cylinders and used variable strategies to achieve the goal. Nevertheless, they began to learn the effective way of stacking over the course of testing, after about 15 sessions (75 trials). PMID:16909233

Hayashi, Misato

2007-04-01

304

Developing Tutorials for Advanced Physics Students: Processes and Lessons Learned  

NSDL National Science Digital Library

When education researchers describe newly developed curricular materials, they typically concentrate on the research base behind their design, and the efficacy of the final products, but do not highlight the initial stages of creating the actual materials. With the aim of providing useful information for faculty engaged in similar projects, we describe here our development of a set of in-class tutorials for advanced undergraduate electrodynamics students, and discuss factors that influenced their initial design and refinement. Among the obstacles to be overcome was the investigation of student difficulties within the short time frame of our project, and devising ways for students to engage in meaningful activities on advanced-level topics within a single 50-minute class period. We argue for a process that leverages faculty experience and classroom observations, and present several guidelines for tutorial development and implementation in upper-division physics classrooms.

Baily, Charles; Dubson, Michael; Pollock, Steven J.

2014-01-06

305

Weather Science Hotlist  

NSDL National Science Digital Library

The Franklin Institute Online offers the metadata Web site Weather Science Hotlist. The page contains dozens of links organized into ten topics that include Online Exhibits, Weather Right Now, Background Information, Severe Weather, El Nino/ La Nina, Historical Weather, Career Connections, Activities, Atmosphere, and Weather Forecasting. A great source for anyone looking for online weather information.

2008-04-11

306

Influence of chemical weathering and aging of iron oxides on the potential iron solubility of Saharan dust during simulated atmospheric processing  

NASA Astrophysics Data System (ADS)

The flux of bioavailable Fe from mineral dust to the surface ocean is controlled not only by the processes in the atmosphere but also by the nature and source of the dust. In this study, we investigated how the nature of Fe minerals in the dust affects its potential Fe solubility (Fepsol) employing traditional and modern geochemical, mineralogical, and microscopic techniques. The chemical and mineralogical compositions, particularly Fe mineralogy, in soil samples as dust precursors collected from North African dust source regions were determined. The Fepsol was measured after 3 days of contact with sulfuric acid at pH 2 to simulate acid processes in the atmosphere. Fepsol of the soil dust samples were compared with calculated predictions of Fepsol based on the amount of individual Fe-bearing minerals present in the samples and Fe solubilities of corresponding standard minerals. The calculated Fepsol deviated significantly from the measured Fepsol of the soil dust samples. We attributed this to the variability in properties of Fe minerals (e.g., size of Fe oxides and heterogeneity of chemical compositions of clay minerals) in soil dusts in comparison to the standard minerals. There were, however, clear relationships between the degree of chemical weathering of North African soils and Fepsol. The Parker index and ratio of ascorbate plus dithionite Fe to total Fe ((FeA+FeD)/FeT) are positively and negatively correlated with Fepsol, respectively. In addition, the ratio of FeA/(FeA+FeD), which decreases with aging of the Fe oxides, was found to be positively correlated with Fepsol in the soil dusts. Overall, our results indicate that there is a significant regional variability in the chemical and Fe mineralogical compositions of dusts across North African sources, as a result of the differences in chemical weathering and aging of Fe oxides. Furthermore, the indices for these weathering processes can provide an estimate of the fraction of Fe which can be solubilized if acid processed in the atmosphere.

Shi, Zongbo; Krom, Michael D.; Bonneville, Steeve; Baker, Alex R.; Bristow, Charlie; Drake, Nick; Mann, Graham; Carslaw, Ken; McQuaid, James B.; Jickells, Tim; Benning, Liane G.

2011-06-01

307

Physical processes controlling ice concentrations in synoptically forced, midlatitude cirrus  

NASA Astrophysics Data System (ADS)

Numerical simulations and airborne measurements are used to evaluate the impact of physical processes on synoptically forced, midlatitude cirrus ice concentrations. The agreement within a factor of 2 between ice concentrations measured with independent techniques (replicators and optical imaging probes) provides confidence in the accuracy of the in situ measurements. We use a computationally efficient modeling approach that incorporates the key cirrus physical processes, such that thousands of cloud cases can be simulated and the model results can be statistically compared with observations. One-dimensional simulations with detailed treatments of cloud microphysical processes are driven by temperatures and vertical winds extracted from meteorological analyses. Small-scale temperature and vertical wind perturbations associated with mesoscale waves are superimposed on the analysis fields. We find that in simulations with only homogeneous freezing nucleation, ice concentration statistics are very sensitive to the specified mesoscale wave vertical wind perturbations. With the frequency distribution of vertical winds adjusted to agree with aircraft observations, we obtain good agreement between the simulated and observed ice concentration frequency distributions. Both the observations and simulations indicate that relatively high ice concentrations (?1000 L-1) occur rarely in these clouds (less than 1% of the time). Simulations including both homogeneous and heterogeneous nucleation indicate that even with moderate concentrations of ice nuclei (20 L-1), heterogeneous nucleation is an important ice production process, particularly for relatively low ice concentrations and warm temperatures. With enhanced ice nuclei concentrations (100 L-1), heterogeneous nucleation dominates ice production in the model. We find that it is critically important to include the impact of sedimentation on the evolution of ice concentrations when comparing model results with observations. Ice crystal collection efficiencies are poorly constrained at low temperatures, and we find that aggregation can significantly reduce ice concentrations. Sensitivity tests indicate that neither the agreement between observed and simulated ice crystal statistics nor the sensitivities indicated by the simulations are significantly affected by model assumptions such as the time periods simulated, geographic domain covered, trajectory paths calculated, or ice crystal habit assumed.

Jensen, E. J.; Lawson, R. P.; Bergman, J. W.; Pfister, L.; Bui, T. P.; Schmitt, C. G.

2013-06-01

308

The Rhetoric of Physics: AN Ethnography of the Research and Writing Processes in a Physics Laboratory.  

NASA Astrophysics Data System (ADS)

This dissertation explores the extent to which rhetoric plays a role in the research and writing processes of physicists. It seeks to join the on-going conversation in the rhetoric of inquiry about the ways in which rhetorical forces shape all knowledge systems. Based on data collected during a six-month ethnography in a thin films laboratory, this study argues that these physicists use rhetoric in all stages of the knowledge creation process. After following the experimental process through all its stages from the inception of an experiment through to publication, this study maps out the types of heuristic devices employed by the physicists as they analyzed, interpreted, and presented their research data in a persuasive scientific article. In light of the insights gained from studying the dynamic interactions between physicists, this dissertation also comments on the theoretical and philosophical debates under discussion in the rhetoric of inquiry and the rhetoric of science. It examines current theories of language (as expressed by rhetoricians, critical theorists, and the physicists in this laboratory) to explore the relationship between reality and language, the role that rhetoric plays in knowledge creation in physics, and the ways in which reality and knowledge may be socially constructed. It concludes that these physicists use rhetorical invention strategies to interpret and present their data. It also argues that scientific knowledge is subject to rhetorical forces because it deals with contingent affairs--phenomena about which scientists advance propositions which appear to be true but about which there is no way to gain absolute certainty or truth. Finally, it concludes that rhetoric both is and is not epistemic in the physics research studied here, and it argues that instead of asking "Is rhetoric epistemic?" perhaps we might shift our attention to inquiring "When is rhetoric epistemic?".

Graves, Heather Ann Brodie

1992-01-01

309

Weather Tamers  

NSDL National Science Digital Library

Problem-based learning experiences that extend at least two weeks provide an opportunity for students to investigate a real-world problem while learning science content and skills in an exciting way. Meteorology provides a wealth of problems students can investigate while learning specific science concepts and skills found frequently in middle level national and state curricula standards. The hands-on activity described in this article helps students learn about the science behind weather events by planning, constructing, and testing models of cities exposed to a series of simulated hurricanes and tornado conditions.

Sterling, Donna R.; Frazier, Wendy M.

2007-03-01

310

Mountain Weather  

NSDL National Science Digital Library

Mountains can be awe-inspiring both for the vistas they provide and for the weather events and long-term climate systems they support. This interactive feature illustrates how a moisture-laden air mass interacts with a mountain slope to produce characteristic patterns of precipitation over the mountain and surrounding areas. Viewers can see how clouds and precipitation form as the air mass ascends the windward side of the peak, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air. A background essay and list of discussion questions supplement the interactive feature.

311

Weather Photography  

NSDL National Science Digital Library

Ph.D. student Harald Edens describes himself as a "photographer of lightning, clouds, atmospheric optical phenomena and astronomy". His Web site entitled Weather Photography proves this by providing a stunning collection of photographs and movies of atmospheric optics, lightning, clouds, and astronomy. The author describes how the photographs were taken, what equipment was used, and even discusses many of the phenomenon being observed such as mirages and halos. An added bonus of this very interesting site is that the author generously allows free personal use of the photographs.

2000-01-01

312

Weather Activities  

NSDL National Science Digital Library

This entertaining, interactive website is the perfect tool to educate users about the basics of weather forecasting and reporting. The two educational modules, created by EdHeads, each contain three levels and are designed for grades four through nine. While discovering how to predict a three-day forecast, students learn about warm and cold fronts, wind direction and speed, high and low pressure systems, isobars, and humidity. Teachers can find a helpful guide discussing how best to use the site as well as providing an overview of science standards, lesson plans, and pre- and post-tests for students.

313

Destructive Weather  

NSDL National Science Digital Library

What are the effects of different types of destructive weather? Learn All About Hurricanes Record on your chart 3 things that you learned. Watch a Hurricane Video These are the devastating Effects of Hurricanes Learn All About Tornadoes Record on your chart 3 things that you learned. Watch a Tornado Video These are the devastating Effects of tornadoes Learn All About Thunderstorms Record on your chart 3 things that you learned. These are the devastating Effects of thunderstorms Follow these important tips To keep safe. ...

Alizabethirwin

2010-11-03

314

Mountain weather and climate  

SciTech Connect

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.

Barry, R.G.

1992-01-01

315

Compensation for Lithography Induced Process Variations during Physical Design  

NASA Astrophysics Data System (ADS)

This dissertation addresses the challenge of designing robust integrated circuits in the deep sub micron regime in the presence of lithography process variability. By extending and combining existing process and circuit analysis techniques, flexible software frameworks are developed to provide detailed studies of circuit performance in the presence of lithography variations such as focus and exposure. Applications of these software frameworks to select circuits demonstrate the electrical impact of these variations and provide insight into variability aware compact models that capture the process dependent circuit behavior. These variability aware timing models abstract lithography variability from the process level to the circuit level and are used to estimate path level circuit performance with high accuracy with very little overhead in runtime. The Interconnect Variability Characterization (IVC) framework maps lithography induced geometrical variations at the interconnect level to electrical delay variations. This framework is applied to one dimensional repeater circuits patterned with both 90nm single patterning and 32nm double patterning technologies, under the presence of focus, exposure, and overlay variability. Studies indicate that single and double patterning layouts generally exhibit small variations in delay (between 1--3%) due to self compensating RC effects associated with dense layouts and overlay errors for layouts without self-compensating RC effects. The delay response of each double patterned interconnect structure is fit with a second order polynomial model with focus, exposure, and misalignment parameters with 12 coefficients and residuals of less than 0.1ps. The IVC framework is also applied to a repeater circuit with cascaded interconnect structures to emulate more complex layout scenarios, and it is observed that the variations on each segment average out to reduce the overall delay variation. The Standard Cell Variability Characterization (SCVC) framework advances existing layout-level lithography aware circuit analysis by extending it to cell-level applications utilizing a physically accurate approach that integrates process simulation, compact transistor models, and circuit simulation to characterize electrical cell behavior. This framework is applied to combinational and sequential cells in the Nangate 45nm Open Cell Library, and the timing response of these cells to lithography focus and exposure variations demonstrate Bossung like behavior. This behavior permits the process parameter dependent response to be captured in a nine term variability aware compact model based on Bossung fitting equations. For a two input NAND gate, the variability aware compact model captures the simulated response to an accuracy of 0.3%. The SCVC framework is also applied to investigate advanced process effects including misalignment and layout proximity. The abstraction of process variability from the layout level to the cell level opens up an entire new realm of circuit analysis and optimization and provides a foundation for path level variability analysis without the computationally expensive costs associated with joint process and circuit simulation. The SCVC framework is used with slight modification to illustrate the speedup and accuracy tradeoffs of using compact models. With variability aware compact models, the process dependent performance of a three stage logic circuit can be estimated to an accuracy of 0.7% with a speedup of over 50,000. Path level variability analysis also provides an accurate estimate (within 1%) of ring oscillator period in well under a second. Another significant advantage of variability aware compact models is that they can be easily incorporated into existing design methodologies for design optimization. This is demonstrated by applying cell swapping on a logic circuit to reduce the overall delay variability along a circuit path. By including these variability aware compact models in cell characterization libraries, design metrics such as circuit timing, power, area, and delay var

Chin, Eric Yiow-Bing

316

Next Generation Weather Radar (NEXRAD)/Air Route Surveillance Radar (ARSR) Operational Comparison.  

National Technical Information Service (NTIS)

The National Weather Service (NWS), Federal Aviation Administration (FAA), and Department of Defense are in the process of fielding the Next Generation Weather Radars (NEXRAD). These doppler weather radars, also known as Weather Surveillance Radar (WSR)-8...

B. Dunbar J. Mittelman

1993-01-01

317

Next Generation Weather Radar (NEXRAD)/Air Route Surveillance Radar (ARSR) Operational Comparison.  

National Technical Information Service (NTIS)

The National Weather Service (NWS), Federal Aviation Administration (FAA), and Department of Defense are in the process of fielding the Next Generation Weather Radars (NEXRAD). These doppler weather radars, also known as Weather Surveillance Radar (WSR)88...

B. Dunbar J. Mittelman

1993-01-01

318

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

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.

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

2013-01-01

319

Physical processes in grid control gas discharge device Tacitron  

NASA Astrophysics Data System (ADS)

Physical processes in grid control gas discharge device Tacitron Arefjev A.S., Vereschagin N.M., Kruglov S. A. Radioengineering Academy, Ryazan, Russia Nowdays pulsed power units is getting widely used for cleaning biogas and water. Their parameters and dimension defines by the current commutator, which is used as a switch for interrupting the current in the circuit. Experimental investigations have been carried out to find out the propeties of the one type of the current commutator - the so-called tacitron. It has specific construction of the control grid ,which enables to control the moment of the discharge plasma distinguish and consequently a tacitron has ability to distinguish the discharge, e.i. to interrupt the current, flowing through the device. The grid of a tacitron is constructed of small-mesh metal. The dimension of the small-mesh cell must be compare with Debay radius at the proper discharge conditions. It is stipulated by the fact that if the dimensions of the grid cell are compare with Debay radius then ionic sheaths on the negative electrode as if 'overlap' each other. Then if to supply the controlling impulse to the grid of the tacitron one can ensure interrupting the current through the tacitron. Thus a tacitron is full controlling discharge current commutator. There has been performed experimental investigation of the process of the current interruption.(distinguishing of the gas discharge), taking place in the discharge space between the anode and the cathode of the tacitron. The outcomes of experiments show that the process of the distinguishing may be divided on 4 stages, which differ one from another by elementary processes, going on there : - delay of the distinguishing of the discharge; - so-called 'slow ' stage; - decay of plasma inside the anode - grid gap; - decay of plasma inside the cathode - grid gap. The whole duration of the process of the discharge distinguishing equals mostly the second and the third stages together. The duration of all stages of the distinguishing depends on: - pressure of the gas; - magnitude of the interrupting current (the concentration of electrons and ions in the discharge space); - magnitude of the voltage on the anode and grid; - sort of the filling gas - type of the load. According to the results of the investigation some recomendations on the operating of the tacitron in pulse power units were done.

Arefiev, Alexander; Vereschagin, Nicolay; Kruglov, Sergey

2003-10-01

320

Contrast Restoration of Weather Degraded Images  

Microsoft Academic Search

Images of outdoor scenes captured in bad weather suffer from poor contrast. Under bad weather conditions, the light reaching a camera is severely scattered by the atmosphere. The resulting decay in contrast varies across the scene and is exponential in the depths of scene points. Therefore, traditional space invariant image processing techniques are not sufficient to remove weather effects from

Srinivasa G. Narasimhan; Shree K. Nayar

2003-01-01

321

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....

2010-08-16

322

Linking stochastic sediment transport to physical processes (Invited)  

NASA Astrophysics Data System (ADS)

Intermittent transport is the rule rather than the exception in sedimentary systems. Avalanching dynamics in granular flows is known to produce stochastic transport fluctuations over a wide range of scales - for example, the well known power-law distributions of landslide magnitudes. Similar stochastic dynamics can occur in multi-phase flows, e.g., bedload transport in rivers. A generalized theoretical framework for understanding stochastic transport is lacking. A pragmatic alternative is the stochastic processes approach: using (fractional) advection-diffusion equations, conditioned with measured statistics from a real system, to make future predictions about transport. Linking the macroscopic statistics described by such models to the microscopic physics of sediment transport will require a new statistical mechanics approach. We propose to begin by delineating generic categories of transport mechanics - universality classes - and determining their statistical signatures through theory and experiment. A first separation may be drawn between periodic and aperiodic transport fluctuations. Periodic transport fluctuations have been observed in both sand piles and river delta experiments, and appear to arise under conditions of a well-defined transport threshold (e.g., an angle of repose) and limited dissipation. Under these conditions, inertia overwhelms system heterogeneity and gives rise to periodic oscillations having a characteristic magnitude. Aperiodic transport fluctuations often imply a strong control of system heterogeneity, and/or significant dissipation or friction capable of “breaking up” sediment pulses. For example, varying soil properties give rise to a range of critical failure slopes for landslides. Transitions in the dominant transport process from small to large time or space scales are expected to result in transitions in scaling. Bedload transport is super-diffusive at short timescales because of correlated motion due to particle momentum. At long timescales, however, particles spend more time at rest than they do in motion and, dispersion of grains becomes sub-diffusive. In this talk we will outline the origins of thresholds, correlations and rest periods that arise in sediment transport, and their expected macroscopic scaling. We synthesize recent experiments to show how length and time scales imparted by the physical system can force a transition in transport statistics.

Jerolmack, D. J.; Martin, R.; Paola, C.; Reitz, M. D.; Schumer, R.

2010-12-01

323

Terrestrial weathering of ordinary chondrites in nature and continuing during laboratory storage and processing: Review and implications for Hayabusa sample integrity  

NASA Astrophysics Data System (ADS)

Abstract- The Hayabusa mission recently returned the first samples from an ordinary chondrite (OC) parent body. Olivine, low-Ca pyroxene, and kamacite compositions fall within the known ranges of minerals from LL4 to LL6 chondrites. Hayabusa samples are being processed and stored in a pure N2 atmosphere. However, during recovery, prior to receiving, and during preliminary examination, some Hayabusa samples were briefly exposed to terrestrial atmosphere. Some of the minerals already identified in the Hayabusa samples (olivine, sulfides) are known to be among the most vulnerable to weathering reactions in moist, oxidizing terrestrial environments. Oxidation of Fe in metal, sulfides, and ferrous silicates is ubiquitous in naturally weathered OC finds, in samples of falls subjected to even a few decades of weathering before recovery, and in OC falls recovered and curated promptly after recovery. All prerecovery oxidation, hydrolysis, hydration, and product-forming phenomena documented to affect OC finds have been documented to continue in OC samples in curatorial and laboratory settings, producing mineralogical and textural effects at scales easily discernable by electron microscopy, on timescales of decades. Hayabusa samples will be exposed to similar terrestrial conditions at times throughout sample processing, allocation, and examination. Maximizing the science yield from these important samples requires thorough understanding of how LL chondrite minerals like those in the Hayabusa samples react with terrestrial moisture and oxidants in support of proper planning for maintaining Hayabusa sample integrity after allocation, and for proper anticipation of the effects of inevitable exposure to Earth's atmosphere during storage and examination in terrestrial analytical laboratories.

Velbel, Michael A.

2014-02-01

324

Application of Multi-Physical Model to Process Solution in Electromagnetic Field Technique  

Microsoft Academic Search

Since the actual on-line process in steel making plant consists of a kind of the combined multi-physical phenomena, multi-physical model taken into account of each physical phenomenon as a numerical calculation model is has been developed. The multi-physical model taken into account of electromagnetic field, fluid dynam- ics, heat transfer, solidification, steel quality and process control expresses the real process

Keisuke FUJISAKI; Ryu HIRAYAMA; Kiyoshi WAJIMA

2004-01-01

325

Adaptive numerical algorithms in space weather modeling  

NASA Astrophysics Data System (ADS)

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 relevant physics in different domains. A multi-physics system can be modeled by a software framework comprising 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 Solarwind Roe-type Upwind Scheme (BATS-R-US) code that can solve various forms of the magnetohydrodynamic (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 short-term forecasting.

Tóth, Gábor; van der Holst, Bart; Sokolov, Igor V.; De Zeeuw, Darren L.; Gombosi, Tamas I.; Fang, Fang; Manchester, Ward B.; Meng, Xing; Najib, Dalal; Powell, Kenneth G.; Stout, Quentin F.; Glocer, Alex; Ma, Ying-Juan; Opher, Merav

2012-02-01

326

Influence of Model Physics on NWP Forecasts  

NSDL National Science Digital Library

This module describes model parameterizations of sub-surface, boundary-layer,and free atmospheric processes, such as surface snow processes, soil characteristics, vegetation, evapotranspiration, PBL processes and parameterizations, and trace gases, and their interaction with the radiative transfer process. It specifically addresses how models treat these physical processes and how they can influence forecasts of sensible weather elements.

Spangler, Tim

1999-11-24

327

Influence of Model Physics on NWP Forecasts  

NSDL National Science Digital Library

This module describes model parameterizations of sub-surface, boundary-layer,and free atmospheric processes, such as surface snow processes, soil characteristics, vegetation, evapotranspiration, PBL processes and parameterizations, and trace gases, and their interaction with the radiative transfer process. It specifically addresses how models treat these physical processes and how they can influence forecasts of sensible weather elements.

2007-07-17

328

Carbonate Beaches: A Balance Between Biological and Physical Processes  

NASA Astrophysics Data System (ADS)

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.

Nairn, R.; Risk, M.

2004-12-01

329

Convection in the Physical Vapor Transport Process. Part 2; Thermosolutal  

NASA Technical Reports Server (NTRS)

We consider the effect of an inert gas on the diffusive-convective physical vapor transport process. We investigate the case when the temperature gradient is stabilizing and the concentration gradient is destabilizing for a wide parametric range. When an inert gas is present, the thermal and solutal convection oppose each other. The solutal field is destabilizing while the thermal field and the advective-diffusive flux stabilize the flow field. When the pressure of the inert component is increased, the stabilizing effect of the advective-diffusive flux is decreased. The intensity of convection as well as the oscillatory transient time increases. Below, the critical Rayleigh number, the nonlinear dynamics of the flow field show an oscillatory approach to steady state. For parametric values in the neighborhood of the critical Rayleigh number, the flow field undergoes a chaotic transient which settles to a periodic state. The asymptotic state of the flow field shows that growth and amalgamation of cells yields an overturning motion which results in an asymmetric cellular structure. The low gravity environment yields the stabilizing advective-diffusive flow which results in uniform temperature and concentration gradients near the crystal interface.

Duval, Walter M. B.

1994-01-01

330

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

ERIC Educational Resources Information Center

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…

Teisl, Michael; Cicchetti, Dante

2008-01-01

331

The Weather Dude  

NSDL National Science Digital Library

The Weather Dude is a weather education Web site offered by meteorologist Nick Walker of The Weather Channel. For kids, the site offers a great online textbook entitled Weather Basics, which explains everything from precipitation to the seasons, using simple text and fun graphics. Other fun things for kids include weather songs, questions and quizzes, weather proverbs, and more. Teachers are also provided with helpful resources such as weather activity sheets and printable blank maps, as well as many other links to weather forecasts and information that will help make teaching about weather fun.

Walker, Nick.

2002-01-01

332

Physical processes and hydrological structures related to the Bay of Biscay anchovy  

Microsoft Academic Search

SUMMARY: Knowledge of the fundamental physical processes governing hydrological structures is necessary for a better understanding of complex physical - biological interactions. In this review attention is focused on spatial and temporal scales of physical processes and hydrological structures related to the life cycle of anchovy (Engraulis encrasicolus, L.) and poten- tially affecting the population dynamics in the Bay of

CONSTANTIN KOUTSIKOPOULOS; BERNARD LE CANN

333

Role of Experiments in Physics Instruction - A Process Approach  

Microsoft Academic Search

This paper describes an approach to classroom experiments that serves roles closer to that in the practice of physics. We propose that in the history of physics most ``classical'' experiments fall into one of three groups: observational experiments, testing theoretical model experiments, or application experiments.

E. Etkina; A. van Heuvelen; D. T. Brookes; D. Mills

2002-01-01

334

Atmospherics\\/Weather Works: A Spatialized Meteorological Data Sonification Project  

Microsoft Academic Search

Atmospherics\\/Weather Works is a performance, installation and distributed software project for the sonification of storms and other meteorological events, generated directly from data produced by a highly detailed and physically accurate simulation of the weather.

Andrea Polli

2005-01-01

335

Forecasting the Weather.  

ERIC Educational Resources Information Center

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)

Bollinger, Richard

1984-01-01

336

National Weather Service  

MedlinePLUS

HOME FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long ... LOADING... Menu ? ACTIVE ALERTS ? FORECAST MAPS ? RADAR ? RIVERS, LAKES, RAINFALL ? AIR QUALITY ? SATELLITE ? PAST WEATHER ? Local forecast ...

337

GEM: Statistical weather forecasting procedure  

NASA Technical Reports Server (NTRS)

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.

Miller, R. G.

1983-01-01

338

Predicting Weather and Understanding Weather Systems  

NSDL National Science Digital Library

The assignment requires students to observe the weather map in the newspaper for four consecutive days. On the first day they are instructed to choose a location somewhere in the country. The will record the weather conditions there and observe any weather systems that exist elsewhere in the country. They then make predictions of how they expect weather in their location to change over the subsequent three days.

Grandy, Carla

339

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

SciTech Connect

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.

Steefell, C I

2003-02-01

340

FAWN: Florida Automated Weather Network  

NSDL National Science Digital Library

The Florida Automated Weather Network (FAWN) provides up-to-date weather information through a system of automated weather stations distributed throughout the State of Florida. Research scientists at the University of Florida work closely with extension agents to monitor the FAWN system and make sure it provides fast, reliable, and convenient access. Overall, there are four parts to the FAWN system: collecting data, transmitting it to the collection site, processing the data, and redistributing it to the end user. FAWN database servers maintained by IFAS Information Technologies receive weather data about the date and time of collection, the air temperature, soil temperature, relative humidity, dewpoint, rainfall, wind direction, wind speed, and radiation from remote stations every 15 minutes. The information is processed and made available almost instantaneously through several different search methods accessible through FAWN web server, as well as an interactive voice-response system.

341

Physics of Green Energy & Fundamentals of Nuclear Processes  

NASA Astrophysics Data System (ADS)

This poster presents topics in outline form of two courses offered by the physics department at Springfield Technical Community College, Springfield MA. These are both four credit, three hour laboratory, transferable courses that fulfill science distribution requirement.

McCarthy, Margaret E.

2011-11-01

342

Palmer Automatic Weather Station  

NSF Publications Database

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

343

Photocatalytic activity of titanium dioxide nanoparticle coatings applied on autoclaved aerated concrete: effect of weathering on coating physical characteristics and gaseous toluene removal.  

PubMed

Autoclaved aerated concrete has been coated by TiO(2) nanoparticles through a dip-coating (DC) and a novel vacuum saturation (VS) method to investigate the weathering resistance and gaseous toluene removal potential of both coating types. The effect of intensive weathering - corresponding to a period of about 25 years - on the coating characteristics was studied in terms of TiO(2) content, coating thickness and color changes. Toluene removal was investigated in a lab-scale flow-through photoreactor at 24°C and 52% relative humidity, and results obtained immediately after application of the coatings and after two weathering stages were compared. Weathering of the DC and VS coated samples resulted into a decrease of the coating layer thickness of more than 98%, confirmed by a decline in TiO(2) content by more than 99% and 93%, respectively. Surprisingly, toluene removal efficiencies before and after weathering kept constant at about 95% for both coating types, corresponding to an elimination rate of 60-70 mg/(m(2)h) at an initial toluene concentration of 15 ppm(v) and a gas residence time of 3 min. Increasing the toluene load by applying higher toluene inlet concentrations (up to 35 ppm(v)) and lower gas residence times (1 min) did decrease the toluene removal efficiency to 32-41%, but elimination rates increased up to 214 mg/(m(2)h), being a factor of 1.6-4.5 times higher than reported in recent work. PMID:22226715

Maury-Ramirez, Anibal; Demeestere, Kristof; De Belie, Nele

2012-04-15

344

On the relationship between learning strategy and feedback processing in the weather prediction task--Evidence from event-related potentials.  

PubMed

Previous work has shown that both declarative and non-declarative strategies can be engaged in probabilistic classification learning. With respect to the neural correlates of these strategies, earlier studies have focused on the classification process itself. In the present experiment, we asked whether the feedback for classification performance is processed differently by declarative and non-declarative learners. We recorded event-related potentials (ERPs) while participants performed a modified version of the weather prediction task, a well-known probabilistic classification learning task. ERP analysis focused on two ERP components typically associated with feedback processing, the feedback-related negativity (FRN) and the P300. FRN amplitude was not affected by learning strategy. The P300, however, was more pronounced in declarative learners, particularly at frontal electrode site Fz. In addition, P300 topography was different in declarative learners, with amplitude differences between negative and positive feedback being more pronounced over the frontal than the parietal cortex. Differences in feedback processing between groups were still seen after declarative learners had switched to a non-declarative strategy in later phases of the task. Our findings provide evidence for different neural mechanisms of feedback processing in declarative and non-declarative learning. This difference emerges at later stages of feedback processing, after the typical time window of the FRN. PMID:23347964

Rustemeier, Martina; Schwabe, Lars; Bellebaum, Christian

2013-03-01

345

Weather information network including graphical display  

NASA Technical Reports Server (NTRS)

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.

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

346

Exploratory Observations of Physical Processes in the upper Sulu Sea  

NASA Astrophysics Data System (ADS)

The Sulu Sea extends roughly 600 km in all directions, is up to 5 km deep, and is connected to the Pacific Ocean, but only via surrounding seas through several straits of varying width and depth. The Dipolog Strait between the Philippine islands of Mindanao and Negros connects the Sulu to the Bohol Sea. Straits between the islands of Panay, Palawan and Borneo connect the Sulu to the South China Sea. Straits between Borneo and Mindanao connect the Sulu to the Sulawesi Sea. External interactions with the Sulu Sea include strait currents, monsoon wind stress, tides and internal waves propagating into the sea from the perimeter. Mooring observations indicate large intraseasonal signals in currents through the Dipolog Strait and the Cuyo East Passage, west of Panay. Known impacts on the Sulu thus have timescales ranging from a day to a year. Currents through the boundary straits reverse direction with depth and so have a complex interaction with the Sulu Sea. To explore physical processes in the Sulu Sea, four in situ surveys were conducted between June 2007 and March 2009 during the Philippines Straits Dynamics Experiment (PhilEx). Observations collected include current from hull-mounted Doppler sonar and temperature, salinity, dissolved oxygen and fluorescence from station casts and underway surface measurements. Horizontal shear dominates the surface current pattern. The shear’s horizontal scales are small compared to the Sulu Sea’s dimensions. The surface water also has significant density fronts at scales similar to the horizontal shear. This horizontal structure is described by viewing observed properties on maps and as a function of along-track position. Horizontal structure is quantified by computing basic statistics along-track and through spectral and wavelet analysis. A topic investigated is the relative role of boundary strait current variability and wind forcing in generating the observed horizontal shear and density fronts. When currents directed into the Sulu are stronger, more energy could be available for eddies in the sea and these eddies could have sizes related to strait dimensions. Sulu Sea water is traced to sources in boundary straits. One example is relatively warm and fresh surface water which appears to come from the Balabac Strait between Palawan and Borneo. A broader horizontal picture of the Sulu Sea is established by using remote sensing and numerical model output.

Martin, J. P.; Gordon, A. L.

2010-12-01

347

Magnesium isotope fractionation between brucite [Mg(OH)2] and Mg aqueous species: Implications for silicate weathering and biogeochemical processes  

NASA Astrophysics Data System (ADS)

Brucite, with its octahedral structure, has a lattice configuration that is similar to the Mg-bearing octahedral layers in phyllosilicates. Understanding stable Mg isotope fractionation between brucite and aqueous solution therefore bears on interpretation of Mg isotope data in natural weathering systems. In this study, we experimentally determined Mg isotope fractionation between brucite and two Mg aqueous species, the free Mg aquo ion ([Mg(OH2)6]2+) and EDTA-bonded Mg (Mg-EDTA2-). Results from recrystallization and brucite synthesis experiments suggest mild preferential partitioning of light Mg isotopes into brucite compared to Mg aquo ions at low temperatures, where measured ?Mgbrucite-Mg26 fractionation increased from ca. -0.3‰ at 7?°C, to ca. -0.2‰ at 22?°C, to ca. 0‰ at 40?°C. MgO hydrolysis experiments in EDTA-bearing solutions suggest that the ?Mgbrucite-Mg-EDTA26 fractionation is ?+2.0‰ at 22?°C, indicating that light Mg isotopes strongly partition into Mg-EDTA complex relative to brucite, as well as relative to Mg aquo ions. Magnesium atoms in brucite, Mg aquo ions, and Mg-EDTA complexes are all octahedrally coordinated, and the measured Mg isotope fractionations correlate with average bond lengths for Mg. Aqueous Mg ions have the shortest bond length among the three phases, and enrich heavy Mg isotopes relative to brucite and Mg-EDTA. In contrast, Mg-EDTA has the longest average bond length for Mg, and enriches light Mg isotopes relative to Mg aquo ions and brucite; the relatively long Mg-EDTA bond suggests that organically bound Mg may commonly have low 26Mg/24Mg ratios, which may explain proposed "vital" effects for stable Mg isotopes. Such relations between bond length and Mg isotope fractionation could be extended to other phyllosilicates such as serpentine- and clay-group minerals where Mg is also octahedrally coordinated.

Li, Weiqiang; Beard, Brian L.; Li, Chengxiang; Johnson, Clark M.

2014-05-01

348

Solar variability, weather, and climate  

NASA Technical Reports Server (NTRS)

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.

1982-01-01

349

Space Weathering on Airless Bodies  

NASA Astrophysics Data System (ADS)

Space weathering refers to an array of processes that measurably alter the character of surfaces that are exposed to the space environment with time. Important observations and constraints come from integration of ground truth sample information and remotely sensed data for the surface. Currently, such combined sample and remote data are available for the Moon, a few near-Earth asteroids (NEAs), and Vesta. Although common processes exist on every planetary body visited, the character of surface alteration by space weathering on airless bodies is very dependent on the particular space environment and the geology and composition of the host. For the Moon, lunar samples have provided a direct link between exposure to the space environment and the development and accumulation of nanophase reduced iron (npFe^0) on soil grains [1]. The optical properties of npFe^0 are well defined experimentally [2]. The resulting effects on lunar materials include reduction of diagnostic absorption bands, prominence of a red-sloped near-infrared (NIR) continuum, and lower albedo [3]. For Eros and Hyabusa, two NEAs visited by spacecraft, similar, but less pronounced optical effects are observed [4]. The in situ Eros measurements and returned Hyabusa samples confirm both bodies are ordinary chondritic in composition despite the optical alteration of their surface [5]. The main-belt proto-planet Vesta has long been associated with HED basaltic achondrite meteorites [6]. Data from Dawn reveal an anti-correlation between mineral band strength and albedo often observed around fresh craters. However, no association is seen with NIR continuum slope implying little development of significant npFe^0 [7]. Several physical and compositional reasons that hinder npFe^0 creation on Vesta are now recognized; alteration processes are instead more linked with dispersal of opaques and regolith mixing processes [7, 8]. Space weathering and evolution of the optical properties of regolith on airless bodies include the following general principles: A. Accumulation of nanophase opaque coatings on regolith grains with time is a common process and involves solar wind bombardment and/or micrometeoroid vaporization. This may be more dominant in the inner solar system. B. Although recent impacts often produce local heterogeneity at a crater, repeated impact mixing by smaller events results in apparent surficial homogenization over time. There is a suggestion that regolith mixing may be dominant for low-gravity regimes. Common related products involve impact darkening that creates and disperses micron-scale opaques [9] that darken but do not 'redden' the surface. C. Surface gravity and electrostatic forces strongly affect the development and retention of space weathering products. These are currently poorly quantified but steady-state processes appear to provide regional uniformity. References: 1. Keller & McKay, GCA, 1997; Taylor et al., JGR, 2001; 2010; Noble et al., MaPS, 2001. 2. Sasaki et al., Nature, 2001; Noble et al., Icarus, 2007. 3 Pieters et al., MaPS, 2000; Hapke JGR, 2001. 4. Clark et al., MaPS, 2001; Binzel et al., MaPS, 2001; Hiroi et al., Nature, 2006. 5. Trombke et al., Science, 2000; Nakamura et al., Science, 2011. 6. McCord et al., Science, 1970; De Sanctis et al., Science, 2012. 7. Pieters et al., Nature in press, 2012. 8. McCord et al., Nature in press; Reddy et al., Icarus, submitted. 9. Britt & Pieters, GCA, 1994.

Pieters, C. M.; Blewett, D. T.; Hiroi, T.; Marchi, S.; McFadden, L. A.; Noble, S. K.; De Sanctis, M. C.; Taylor, L. A.; Reddy, V.

2012-12-01

350

Localized Weathering: Implications for Theoretical and Applied Studies  

Microsoft Academic Search

In situ quantification of localized weathering processes on basalt flows in New Mexico and Hawaii demonstrates that small-area factors can be more important than other more readily observable factors. Further, it demonstrates that the factorial concept of the Pope Boundary-Layer weathering model is partially solvable, that organic weathering can accentuate glass weathering (with implications for climate models and storage of

Steven J. Gordon; Ronald I. Dorn

2005-01-01

351

Clarification Concepts for Treating Peak Wet-Weather Wastewater Flows  

Microsoft Academic Search

Clarification can be an effective process for treating wet weather flows. The effectiveness of clarification in removing pollutants will depend on the characteristics of the suspended solids in wet weather. Suspended solids in wet weather flows can be significantly different from the suspended solids in dry weather flows. Hence determination of organic content, particle size distributions, and most importantly settling

Roderick Reardon

2005-01-01

352

Heterogeneous distribution of nanophase aluminosilicate weathering products: Interpreting Martian weathering  

NASA Astrophysics Data System (ADS)

Nanocrystalline alteration products form in a range of soil and regolith weathering environments on Earth. In some weathering systems, poorly crystalline aluminosilicates such as allophane are distributed heterogeneously, as a function of depth in a vertical weathering profile or as a function of micro-environmental factors. Both of these factors can be important for understanding weathering processes on Earth and are particularly important to consider when interpreting allophane on Mars. Chemical and mineralogical measurements of Mars could be confounded by a vertical heterogeneity common to many weathering systems, because what is observed at the surface by spacecraft may not be representative of the complete weathering system. Appropriate caution should be taken to compare surface measurements of Mars to terrestrial weathering environments that examine soil columns. Also, nanocrystalline aluminosilicates are known to form coatings on regolith particles and rock fragments and can be compositionally distinct from weathering products formed in the greater regolith matrix. These types of coatings are particularly important to consider for interpreting remotely sensed spectral measurements because fragmented rocks, from sand to boulders, comprise much of the relatively dust-free surfaces of Mars. Due to their strong influence on spectral observations, coatings could be strongly detectable by thermal infrared spectroscopy relative to coexisting, weakly aggregated fine-grained weathering products, resulting in the oversampling of coatings. Consequently, detected nanocrystalline aluminosilicates phases may not represent the overall weathering system. As an example of these influences, we will consider the high-silica material(s) detected in Mars northern plains. Although there are several models for how this material formed, if it formed by in situ regolith weathering then the high-silica material was precipitated from dissolved regolith materials. Evidence for extensive cryoturbation in the northern plains indicates that subsurface materials have been brought to the surface, thus any vertical compositional heterogeneity resulting from weathering may have been subsequently homogenized. However, small-scale compositional heterogeneities could persist. Although high-silica material may coat particulates that comprise much of the surface, it may only represent only a micro-environment of the subsurface weathering. For example, although we suggest that the northern plains contain a silica-rich allophanic phase, weathering may also have produced more aluminous phases that are undetected in spectra because they do not form coatings. In addition, we will consider the possibility that Martian weathering produces poorly crystalline aluminosilicate phases that are structurally different from true allophane. We will report on the thermal infrared spectral difference between these phases. The details of Martian weathering processes that can be inferred from detection of allophane are limited by how well vertical and micro-environmental heterogeneities are understood and compensated for, for which input from the terrestrial weathering and soil science communities is essential.

Kraft, M. D.; Sharp, T. G.; Rampe, E. B.

2011-12-01

353

Bioremediation of a weathered and a recently oil-contaminated soils from Brazil: a comparison study.  

PubMed

The facility with which hydrocarbons can be removed from soils varies inversely with aging of soil samples as a result of weathering. Weathering refers to the result of biological, chemical and physical processes that can affect the type of hydrocarbons that remain in a soil. These processes enhance the sorption of hydrophobic organic contaminants (HOCs) to the soil matrix, decreasing the rate and extent of biodegradation. Additionally, pollutant compounds in high concentrations can more easily affect the microbial population of a recently contaminated soil than in a weathered one, leading to inhibition of the biodegradation process. The present work aimed at comparing the biodegradation efficiencies obtained in a recently oil-contaminated soil (spiked one) from Brazil and an weathered one, contaminated for four years, after the application of bioaugmentation and biostimulation techniques. Both soils were contaminated with 5.4% of total petroleum hydrocarbons (TPHs) and the highest biodegradation efficiency (7.4%) was reached for the weathered contaminated soil. It could be concluded that the low biodegradation efficiencies reached for all conditions tested reflect the treatment difficulty of a weathered soil contaminated with a high crude oil concentration. Moreover, both soils (weathered and recently contaminated) submitted to bioaugmentation and biostimulation techniques presented biodegradation efficiencies approximately twice as higher as the ones without the aforementioned treatment (natural attenuation). PMID:15620743

Trindade, P V O; Sobral, L G; Rizzo, A C L; Leite, S G F; Soriano, A U

2005-01-01

354

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

NASA Technical Reports Server (NTRS)

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.

Susskind, Joel; Iredell, Lena

2010-01-01

355

Transpose AMIP: a process oriented climate model evaluation and intercomparison using model weather forecasts and field campaign observations  

NASA Astrophysics Data System (ADS)

Transpose AMIP is a WGNE intercomparison of weather forecasts made by climate models, with the goal of exposing parameterization errors. The approach allows direct comparison of parameterized variables such as clouds, precipitation, and radiative flues with observations from field programs. During the early period of the forecasts, the parameterization calculations are based on a resolved model state which is close to the observed atmosphere instead of one which is in a model balance. Thus the parameterization errors can be identified. We compare global models from the the Numerical Prediction Division, Japan Meteorological Agency; the National Center for Atmospheric Research; the Geophysical Fluid Dynamics Laboratory; the Experimental Climate Prediction Center, Scripps Institute of Oceanography; and the Climate Model Development and Evaluation group of the Met Office Hadley Centre. We consider the parameterization behaviors in the atmospheric column at the ARM Southern Great Plains site during summer 1997 and spring 2000 IOPs for five-day forecasts initialized from ERA-40 data. ARM observations and the ARM variational analysis are used for verification. We will show that the models exhibit a wide range of behaviors in the parameterization tendencies, which lead to different dynamical responses, balances, and errors. In summer, some models dry the lower troposphere compared to ARM data while others moisten it, and still others produce only modest changes. However, those modest changes arise from a balance between parameterization and dynamical tendency errors as calculated against the ARM estimates. One model shows large 0-24 hour parameterization errors which produce an erroneous state after 1 day. However, for days 2-5 the parameterization errors are relatively small, and the state errors remain relatively unchanged from the day 1 values. The parameterizations produce the correct forcing after day 1 but they calculate it from the wrong state. We speculate that this is a result of tuning for the climate. In contrast, other models show relatively constant state errors from day 1 to day 3, with the parameterization and dynamics errors balancing after day 1 to yield relatively constant state errors. The 0-24 hr rainfall varies greatly between models, one rains heavily almost every day, another rains very little, and still another is in between and captures the episodic nature of the rain fairly well. However, for each model the 24-48 hr rainfall is very different from the 0-24 hour values. This arises because after day one the model states no longer match the atmosphere. Other aspects of the development of the errors will be discussed, in particular the diurnal phasing of the errors, and the response of the dynamics to the parameterizations.

Williamson, D.; Nakagawa, M.; Klein, S.; Earnshaw, P.; Nunes, A.; Roads, J.

2009-04-01

356

Physical modeling of failure process of the excavation in horizontal strata based on IR thermography  

Microsoft Academic Search

In order to capture the mechanism of roadway instability in deep mines, a new approach of Physically Finite Elemental Slab Assemblage (PFESA) is proposed in order to construct a large-scale physical model simulating the geologically horizontal strata. We carried out physical modeling on the deformation and failure processes of roadways subjected to a plane loading scheme. Our laboratory tests were

Man-chao HE; Wei-li GONG; De-jian LI; Hui-ming ZHAI

2009-01-01

357

Graphing in Physics: Processes and Sources of Error in Tertiary Entrance Examinations in Western Australia  

ERIC Educational Resources Information Center

Interpretation and construction of graphs are central to the study of physics and to performance in physics. In this paper, I explore the interpretation and construction processes called upon in questions with a graphical component, in Western Australian Physics Tertiary Entrance Examinations. In addition, I list errors made by students as…

Forster, Patricia A.

2004-01-01

358

Processes Underlying Children's Adjustment in Families Characterized by Physical Aggression.  

ERIC Educational Resources Information Center

The hypothesis that physical aggression in the family affects children's adjustment through both observational learning/modeling and through its impact on parenting was tested, via LISREL, using data from a sample of Canadian children (N=11,221). Results showed observational learning and disrupted parenting provide reasonable explanations of…

Onyskiw, Judee; Hayduk, Leslie A.

2001-01-01

359

Modeling and control of physical processes using proper orthogonal decomposition  

Microsoft Academic Search

The proper orthogonal decomposition (POD) technique (or the Karhunan Loève procedure) has been used to obtain low-dimensional dynamical models of many applications in engineering and science. In principle, the idea is to start with an ensemble of data, called snapshots, collected from an experiment or a numerical procedure of a physical system. The POD technique is then used to produce

Hung V. Ly; Hien T. Tran

2001-01-01

360

Physical processes of quartz amorphization due to friction  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

361

WeatherNet  

NSDL National Science Digital Library

WeatherNet, brought to us by The Weather Underground at University of Michigan, aims to be the premier site of weather links on the Internet. Besides the topical tropical storm page, you can view Accu-Weathers graphics including Nexrad imagery, satellite photos, surface maps, and forecast maps.

1998-01-01

362

Teaching Weather Concepts.  

ERIC Educational Resources Information Center

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…

Sebastian, Glenn R.

363

Backyard Weather Station  

NSDL National Science Digital Library

Students use their senses to describe what the weather is doing and predict what it might do next. After gaining a basic understanding of weather patterns, students act as state park engineers and design/build "backyard weather stations" to gather data to make actual weather forecasts.

Integrated Teaching And Learning Program

364

Future Weather Station  

NSDL National Science Digital Library

In this activity students build dioramas of futuristic weather stations to demonstrate their knowledge of weather forecasting. They will work in groups to research modern forecasting equipment and techniques, and then build a weather station that will do something we cannot do at present (such as stopping tornadoes). They will present their dioramas and then discuss the pros and cons of controlling the weather.

365

Weather in Your Life.  

ERIC Educational Resources Information Center

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…

Kannegieter, Sandy; Wirkler, Linda

366

24 CFR 200.857 - Administrative process for scoring and ranking the physical condition of multifamily housing...  

...Administrative process for scoring and ranking the physical condition of multifamily housing properties...GENERAL INTRODUCTION TO FHA PROGRAMS Physical Condition of Multifamily Properties...Administrative process for scoring and ranking the physical condition of multifamily housing...

2014-04-01

367

24 CFR 200.857 - Administrative process for scoring and ranking the physical condition of multifamily housing...  

Code of Federal Regulations, 2012 CFR

...Administrative process for scoring and ranking the physical condition of multifamily housing properties...GENERAL INTRODUCTION TO FHA PROGRAMS Physical Condition of Multifamily Properties...Administrative process for scoring and ranking the physical condition of multifamily housing...

2012-04-01

368

24 CFR 200.857 - Administrative process for scoring and ranking the physical condition of multifamily housing...  

Code of Federal Regulations, 2011 CFR

...Administrative process for scoring and ranking the physical condition of multifamily housing properties...GENERAL INTRODUCTION TO FHA PROGRAMS Physical Condition of Multifamily Properties...Administrative process for scoring and ranking the physical condition of multifamily housing...

2011-04-01

369

24 CFR 200.857 - Administrative process for scoring and ranking the physical condition of multifamily housing...  

Code of Federal Regulations, 2010 CFR

...Administrative process for scoring and ranking the physical condition of multifamily housing properties...GENERAL INTRODUCTION TO FHA PROGRAMS Physical Condition of Multifamily Properties...Administrative process for scoring and ranking the physical condition of multifamily housing...

2010-04-01

370

Space Weather  

NASA Video Gallery

This lesson explores the origins, processes and risks associated with solar radiation including how it travels through the solar system, affects the Earthâ??s magnetosphere and poses a threat to as...

371

Factors Affecting the Earth's Weather  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses factors affecting the weather on Earth. Students learn about solar radiation, wind circulation, precipitation, and biomes that result from weather patterns. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

372

Weather Modification—a Scenario for the Future.  

NASA Astrophysics Data System (ADS)

The ever-increasing severe economic damage imposed on national and world wide economies by severe weather, the need for sufficient and safe water resources for an increasing world population, and the threat of adverse climate change led to this critical assessment of the state-of-the-art of weather modification (WM) and to a proposal of a road map for the future.Special attention is given to rain enhancement because it is further developed than snowpack augmentation, hail suppression, tornado and hurricane modification, and other weather-related disaster control ideas. The question of what makes a rain enhancement experiment acceptable to the scientific community is answered by the World Meteorological Organization's (WMO) criteria, which address statistical evaluation, the measurement of rain, the understanding of nature's precipitation processes with the underlying physics and dynamics of clouds and cloud systems, and the transferability of experiment design. These criteria are no longer specific enough or satisfactory and will have to be reconsidered.An actual WM experiment also involves a variety of techniques and technologies, aspects that need to be complemented by numerical modeling of clouds and cloud responses to seeding. Modeling also allows assessment of the extra-area effects, that is, detrimental effects of precipitation on adjacent areas. Assimilation models may be giving better estimates of the rain at the ground because they can integrate restricted information from radar and rain gauges with mesoscale meteorological and remote sensing, as well as hydrological, data. However, massive improvements in computer capacity are required to handle these problems.Weather modification has been progressing very slowly in the past because of the enormity of the problem and the fact that the precipitation process is far from being understood. Considering that rain increases are attempted within a range of 10% 20%, the lack of knowledge at corresponding accuracy is particularly evident in the fields of cloud physics, cloud and cloud systems dynamics, weather forecasting, numerical modeling, and measuring technology.Benefits of new intensive studies of precipitation processes will not be limited to WM; they are also vital to improving weather forecasting and climate change modeling. There is one additional aspect of WM; WM can also be used to test newly developed precipitation physics and models by studying if the clouds react to seeding in the predicted manner.This article is a wake-up call to put more intellectual and financial resources into the exploration and modification of the precipitation processes in all their forms. All these points lead to the suggestion of an outline of a national precipitation research and weather modification program.

List, Roland

2004-01-01

373

[On the issue of optimization of adaptation process to new environment taking into consideration climate and weather conditions].  

PubMed

There are revealed the features in the registration of newly diagnosed morbidity in cases in the organized team out of number of persons constantly living in the conditions of Baltic Sea (Kaliningrad region), as well as in those coming from other parts of the Russian Federation. This stipulates the elaboration of measures for prevention of disadaptational shifts in the organism related with adaptational processes as well as the process of acclimatization. PMID:24749283

2014-01-01

374

Deeply weathered basement rocks in Norway  

NASA Astrophysics Data System (ADS)

Recent studies show that, in addition to tectonic processes, surface processes have also had a profound impact on the topography of Norway. This is especially obvious for the northernmost part of the Nordland county and for western Norway, where the current immature Alpine-type topography cannot be easily explained by tectonic processes only. Erosion of the sedimentary succession also does not seem sufficient to explain the observed relief. Common remnants of deeply weathered basement rocks, however, indicate a history of deep alteration and later erosion of the bedrock, which needs to be considered as another important factor in the development of the topographic relief. Most of the sites with deeply weathered basement exhibit a clay-poor grussy type of weathering, which is generally considered to be of relatively young age (Plio-/Pleistocene) and thought to represent an intermediate stage of weathering. Unfortunately, small amounts or complete absence of clay minerals in these weathering products precluded the accurate dating of this weathered material. Scandinavia was exposed to a large range of glaciations and the once extensive sedimentary successions have been almost entirely eroded, which impedes a minimum age estimate of the weathering profile. Although several sites preserving remnants of deep weathering can still be observed onshore Norway, they are all covered by Quaternary overburden and the age of the regolith remains thus unconstrained and a matter of debate. The only exception is a small Mesozoic basin on Andøya, northern Norway, where weathered and clay-poor saprolite was found underlying Jurassic and Cretaceous sedimentary rocks. Over the last few years the Geological Survey of Norway (NGU) has mapped and investigated deep weathering onshore Norway to better understand weathering processes and to constrain the age of the weathering remnants. The combined interpretation of geophysical, mineralogical and geochemical data, together with recent observations from the Norwegian shelf, where grussy type of weathered bedrock was found buried under Mesozoic sediments, leads to the conclusion that coarse-grained, clay-poor saprolite does not necessarily indicate a young age of weathering but could in fact be of Early Mesozoic age or even older. The Late Jurassic to Early Cretaceous faults in the Lofoten-Vesterålen area are for instance little affected by weathering processes. With the goal to refine our understanding of the complex weathering processes and to constrain them in time, the NGU is establishing a new K-Ar laboratory for the dating and characterization of illite grown authigenically in the saprolites. It is expected that the data generated therein will contribute new quantitative constraints to the long-lasting debate as to the age of weathering processes in Scandinavia.

Bönner, Marco; Knies, Jochen; Fredin, Ola; Olesen, Odleiv; Viola, Giulio

2014-05-01

375

Australian Severe Weather  

NSDL National Science Digital Library

The Australian Severe Weather Web site is maintained by self proclaimed severe weather enthusiasts Michael Bath and Jimmy Deguara. Other weatherphobes will fully appreciate what the authors have assembled. Everything from weather images, storm news, tropical cyclone data, bush fire and wild fire information, weather observation techniques, and even video clips and Web cam links. Although these other items make the site well rounded, the extensive amount of categorized weather pictures (which are quite extraordinary) are reason enough to visit.

376

What's the Weather?  

NSDL National Science Digital Library

In this lesson, students use daily observations, videos, and activities to learn about meteorology and the changing nature of weather. They will also identify weather events that are commonly reported in the news and discuss how weather affects lives. They should understand that weather can change daily and weather patterns change over the seasons, and that it has characteristics that can be measured and predicted. Suggestions for an optional field trip are also provided.

2005-01-01

377

Modeling and Control of Physical Processes using Proper Orthogonal Decomposition  

Microsoft Academic Search

Proper orthogonal decomposition (POD) technique (or the Karhunan Lo`eve procedure)has been used to obtain low dimensional dynamical models of many applications in engineeringand science. In principle, the idea is to start with an ensemble of data, calledsnapshots, collected from an experiment or a numerical procedure of a physical system. ThePOD technique is then used to produce a set of basis

Hung V. Ly; Hien T. Tran

1999-01-01

378

Organic Materials in Optoelectronic Applications: Physical Processes and Active Devices  

Microsoft Academic Search

We are a new group at MIT. We study physical properties of organic thin films, structures, and devices. Our fundamental findings are applied to the development of optoelectroni c, electronic, and photonic organic devices of nano -scale thickness, including visible LEDs, lasers, solar cells, photodetectors, transistors, flexible and transparent optoelectronics. In addition to working on small-molecular-weight van-der-Waals-bonded organic thin films,

Vladimir Bulovic; Seth Coe; Conor Madigan; Debbie Mascaro

379

Space Weather Modeling Services at the Community Coordinated Modeling Center  

NASA Technical Reports Server (NTRS)

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.

Hesse, Michael

2006-01-01

380

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

ERIC Educational Resources Information Center

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…

Hatheway, W. H.

381

Health physics monitoring at the Defense Waste Processing Facility  

SciTech Connect

Remote radiation monitoring has been designed into the Vitrification portion of the Defense Waste Processing Facility (DWPF) at the Savannah River Site in South Carolina. Local alarms and remote readings are provided for area radiation levels, door alarms, airborne radioactivity, effluent air activity and liquid (process system) activity.

Hogue, M.G.; Priester, H.P.

1994-06-01

382

Influence of aerosols on weather conditions  

NASA Astrophysics Data System (ADS)

The accurate numerical weather prediction demands the better understanding and detailed representation of aerosol effects in the atmosphere. The presence of various types of aerosols as well as other chemical components in the atmosphere causes different effects on weather, climate and still keeps many unresolved aspects. Non-linear interactions between weather phenomena, in particular, precipitation and aerosols need to be additionally highlighted. To investigate features of the atmosphere sensitivity to aerosols the high resolution limited area model Harmonie (Hirlam Aladin Regional/Meso-scale Operational NWP In Europe) was used. The Harmonie is extensively developing weather forecast modeling system, in which the convection-permitting physics substantially promotes to the near-realistic representation of the aerosol effects complexity. Numerical experiments with modifications in aerosol concentrations were performed over the Finland domain. The direct effect of aerosols associates with changes in both radiation processes and precipitation formation. The presence of aerosols increases cloud drop concentration and reduces the effective drop size. A high density of nuclei population initializes coalescence growth, accelerates precipitation formation, increases cloud lifetime and lags precipitation. Since aerosols disperse and absorb the radiation they have a direct effect on the albedo, which depends on the aerosol type. The land aerosols increase the albedo mainly in the lower atmospheric layers. Higher up, the effect of land aerosols on the shortwave radiation coming down toward the surface is diminished in comparison with aerosols of the marine origin. The high concentrations of continental aerosols lead to changes in the precipitation rate, while sea aerosols mainly cause the displacement in time of the precipitation event.

Palamarchuk, Iuliia; Stepanenko, Sergiy; Ivanov, Sergiy; Ruban, Igor; Pavlova, Hanna

2014-05-01

383

Terrestrial Weathering Effects on Meteoritic Organics  

NASA Astrophysics Data System (ADS)

It is now well established for meteorites which fall in hot deserts that weathering brings about a readjustment of extra-terrestrial minerals. Assemblages which had achieved a level of equilibrium on the meteorite parent body now become unstable when exposed to new chemical and physical conditions[1] with FeO and Fe2+ minerals converting to Fe3+ species. Ash and Pillinger[2] have suggested that meteoritic organic matter may also become degraded in desert environments but this is less well substantiated and the processes involved far from clear. To investigate the effects of weathering on meteorite organics, five Saharan carbon-rich chondrites were studied by Mossbauer spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). Experimental conditions are given elsewhere. The samples chosen were El Djouf (CR), Acfer 186 and 187 (both CR, undoubtably related to one another and probably El Djouf, even though the latter was found some 500km away), Acfer 182 an anomalous chondrite (possibly in the CR clan) and Acfer 202 (a C03) . Table 1 shows the relative amounts (%) of iron containing assemblages in four of the meteorites analysed as determined by Mossbauer spectroscopy. El Djouf is substantially weathered with Acfer 187 and Acfer 182 perhaps less so but more weathered than Acfer 202. Fig 1 shows the pyrograms of four of the meteorites analyzed. El Djouf, Acfer 182 and Acfer 186 (=Acfer 187) yield very few discrete organic compounds. However Py-GCMS of unweathered CRs frequently detects a variety of organic fragments. Therefore it seems reasonable to suggest that, in the two CRs at least, macromolecular material has been present but has been degraded by weathering. Such a conclusion agrees well with the results from Mossbauer spectroscopy which indicate extensive oxidation in the CR meteorites. Acfer 202 clearly contains a number of organic components almost exclusively without oxygen, indicating that the macromolecule in Acfer 202 has escaped significant terrestrial oxidation. Again this is consistent with our Mossbauer results which show that Acfer 202 contains predominantly ferrous iron indicative of low levels of terrestrial oxidation. At face value we would argue that Acfer 202 is a relatively fresh carbonaceous chondrite worthy of detailed organic study. Clearly the above samples represent almost end-member cases where terrestrial weathering has either destroyed or has yet to affect the organic material present. Perhaps the most valuable information would come from a sample where oxidation of the macromolecule is at an intermediate stage. References: [1] Bland P. A. et al. (1995) LPS XXVI, 39. [2] Ash R. D. and Pillinger C. T. (1995) Meteoritics, 30, 85-92.

Sephton, M. A.; Bland, P. A.; Gilmour, I.; Pillinger, C. T.

1995-09-01

384

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

Microsoft Academic Search

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

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

2004-01-01

385

Characterisation of recharge processes and groundwater flow mechanisms in weathered-fractured granites of Hyderabad (India) using isotopes  

Microsoft Academic Search

In order to address the problem of realistic assessment of groundwater potential and its sustainability, it is vital to study the recharge processes and mechanism of groundwater flow in fractured hard rocks, where inhomogeneties and discontinuities have a dominant role to play. Wide variations in chloride, ?18O and 14C concentrations of the studied groundwaters observed in space and time could

B. S. Sukhija; D. V. Reddy; P. Nagabhushanam; S. K. Bhattacharya; R. A. Jani; Devender Kumar

2006-01-01

386

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

PubMed Central

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.

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

2011-01-01

387

Extractability of protein in physically processed rice bran  

Microsoft Academic Search

Commercially obtained defatted (DF), full-fat stabilized (FFS), and full-fat unstabilized (FFU) rice bran were processed by\\u000a colloid milling and homogenization to affect bran breakdown and extraction of rice protein. Relative to unprocessed samples,\\u000a there were moderate to slight increases in the amount of protein extracted from the various fractions of processed bran. Colloid\\u000a milling and homogenizing slightly influenced the distribution

Alfred K. Anderson; Harmeet S. Guraya

2001-01-01

388

Enhanced Weather Radar (EWxR) System  

NASA Technical Reports Server (NTRS)

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.

Kronfeld, Kevin M. (Technical Monitor)

2003-01-01

389

s-process nucleosynthesis-nuclear physics and the classical model  

Microsoft Academic Search

Among the various processes responsible for the formation of the heavy elements in stars, the slow neutron capture process (s-process) is distinguished by the fact that it involves mostly stable isotopes. Therefore, the relevant nuclear physics data can be determined by experiments. With this rather reliable data basis, s-process nucleosynthesis offers an important testground of models for the late stages

F. Kappeler; H. Beer; K. Wisshak

1989-01-01

390

Major ion chemistry, weathering processes and water quality assessment in upper catchment of Damodar River basin, India  

Microsoft Academic Search

The chemical characteristics of surface, groundwater and mine water of the upper catchment of the Damodar River basin were\\u000a studied to evaluate the major ion chemistry, geochemical processes controlling water composition and suitability of water\\u000a for domestic, industrial and irrigation uses. Water samples from ponds, lakes, rivers, reservoirs and groundwater were collected\\u000a and analysed for pH, EC, TDS, F, Cl,

Abhay Kumar Singh; G. C. Mondal; Suresh Kumar; T. B. Singh; B. K. Tewary; A. Sinha

2008-01-01

391

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

NASA Astrophysics Data System (ADS)

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.

Martignier, Loraine; Verrecchia, Eric P.

2013-05-01

392

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

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.

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

2009-01-01

393

Earth Observation Services Weather Imaging  

NASA Technical Reports Server (NTRS)

Microprocessor-based systems for processing satellite data offer mariners real-time images of weather systems, day and night, of large areas or allow them to zoom in on a few square miles. Systems West markets these commercial image processing systems, which have significantly decreased the cost of satellite weather stations. The company was assisted by the EOCAP program, which provides government co-funding to encourage private investment in, and to broaden the use of, NASA-developed technology for analyzing information about Earth and ocean resources.

1992-01-01

394

CyberRadar: A Regression Analysis Approach to the Identification of Cyber-Physical Mappings in Process Control Systems  

Microsoft Academic Search

One of the attack requirements for maximizing physical dam- age to digitally controlled infrastructures is the identification of a mapping between program variables in a compromised control system and physical parameters related to physical processes or physical equipment. A cyber-physical mapping is quite critical from the offensive perspective as physical parameters are affected via modification of the associated program variables.

Julian L. Rrushi; Kyoung-Don Kang

395

Multi-scale description of a Sahelian synoptic weather system representative of the West African monsoon  

Microsoft Academic Search

A reference case of a Sahelian weather system observed during the Hydrological Atmospheric Pilot Experiment, HAPEX-SAHEL, in August 1992, is described from a seasonal viewpoint as well as from synoptic and convective system viewpoints. It is shown that the case-study is representative of the climatology at all these scales and presents many interacting scales and physical processes. At intraseasonal scale,

J. L. Redelsperger; A. Diongue; A. Diedhiou; J. P. Ceron; M. Diop; J. F. Gueremy; J. P. Lafore

2002-01-01

396

Interactive Weather Information Network  

NSDL National Science Digital Library

Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.

2002-01-01

397

Edheads: Weather Activities  

NSDL National Science Digital Library

This great interactive resource allows you multiple opportunities to explore weather related concepts. After clicking start, you will learn how to report and predict the weather at the underground W.H.E.D weather caves! Each activity has three different levels, and each level is harder than the one before it. This resource also includes a teacher's guide (with pre- and post- tests) and links to additional weather related resources. These include a weather glossary, a Fahrenheit to Celsius & Celsius to Fahrenheit converter, and a link that provides information about interesting people in the weather field.

2010-01-01

398

Pilot weather advisor  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

399

Weather and Precipitation  

NSDL National Science Digital Library

How are different types of weather common in our everyday life? How can we use what we know about weather to go about everyday activities? First, use the Weather Chart to write down what you learn from each website. Then, go to Weather Information Website #1 and click on "What's the Weather?" to dress the bear for the day. Make sure you write it down on your graphic organizer. Next, go to Weather Information Website #3 and explore at least 5(clouds, thunderstorms, winter storms, etc.) of ...

Jones, Ms.

2012-04-12

400

The Weather Man  

NSDL National Science Digital Library

This project is designed to let you be "The Weather Man" and control the weather through simulation, and hands on experience, followed by guided questioning and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. How does humility play a role in weather? How does more or less change weather? 2. What is water vapor? Where does it come from? 3. What happens when the weather drops below zero degrees? ...

Grasser, Mrs. E.

2012-09-27

401

Processes in karst systems, physics, chemistry, and geology  

SciTech Connect

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.

Dreybrodt, W.

1988-01-01

402

An introduction to physical phenomena in arc welding processes  

Microsoft Academic Search

As is well known, arc discharges have been applied to various processes such as welding, cutting, spray coating, melting and refining. Unlike electrodeless discharge methods such as high frequency discharge of inductive coupling type (eg. RF discharge), arc discharge is a polarized discharge in which the arc is generated between the positive and negative electrodes. Accordingly, when the arc discharge

M. Tanaka

2004-01-01

403

Speaking and Speaking Education as Physical Process in Turkish Education  

ERIC Educational Resources Information Center

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…

Kurudayioglu, Mehmet

2011-01-01

404

Weather Modification A Theoretician's Viewpoint.  

NASA Astrophysics Data System (ADS)

Early progress in weather modification is attributed to a healthy interaction between theory and experiment. During the 1970s, a divergence of approaches took place. A "theoretical/experimental" approach, exemplified by the Cascade Project, focused on testing scientific hypotheses; an "observational/experimental" approach, exemplified by the Colorado River Basin Pilot Project, sought to enhance understanding of the seeding process through more detailed observations.The theoretical/experimental school soon came to focus almost exclusively on natural cloud processes, leaving the field of weather modification nearly devoid of a theoretical component. It is suggested that this theoretical component is necessary to revitalize the field of weather modification.Key questions are addressed. These include 1) identification of clouds that are amenable to seeding; 2) glaciogenic versus hygroscopic seeding; 3) optimizing critical seeding variables, such as seed particle concentration for glaciogenic seeding and seed particle size for hygroscopic seeding; and 4) seeding for hail suppression.

Young, Kenneth C.

1996-11-01

405

Investigating the relation of thermodynamic processes to local budgets Investigating the relation of thermodynamic processes to local budgets in a mesoscale weather prediction model  

Microsoft Academic Search

Recent models apply the non-hydrostatic compressible equations and include various physical parameterizations. On the one hand, such models are able to resolve flow structures on a very wide range of spatial and temporal scales. On the other hand, their complexity makes it difficult to evaluate and later on to improve the model. One usually verifies the model with meteorological data

R. Petrik; A. Gassmann; H. Schlünzen

2009-01-01

406

Control of physical properties on solid surface via laser processing  

SciTech Connect

In a safety operation of a nuclear power plant, vapor conditions such as a droplet or liquid membrane toward a solid surface of a heat exchanger and reactor vessel is important. In the present study, focusing on the droplet, the wettability on solid surface and surface free energy of solid are evaluated. In addition, wettability on a metal plate fabricated by laser processing is also considered for the nuclear engineering application.

Yonemoto, Yukihiro; Nishimura, Akihiko [Applied Laser Technology Institute, Japan Atomic Energy Agency, 65-20 Kizaki, Tsuruga, Fukui (Japan)

2012-07-11

407

Spin physics in polarised Drell-Yan processes at COMPASS  

NASA Astrophysics Data System (ADS)

The Drell-Yan process can be used to access Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs), such as Boer-Mulders function, Sivers function and Transversity functions, providing complementary informations to what is known from Semi Inclusive Deep Inelastic Scattering (SIDIS) data. The COMPASS experiment offers the possibility to extract TMD PDFs from Drell-Yan data, using its spectrometer and its unique transversely polarisable target.

Takekawa, S.; Compass Collaboration

408

Control of physical properties on solid surface via laser processing  

NASA Astrophysics Data System (ADS)

In a safety operation of a nuclear power plant, vapor conditions such as a droplet or liquid membrane toward a solid surface of a heat exchanger and reactor vessel is important. In the present study, focusing on the droplet, the wettability on solid surface and surface free energy of solid are evaluated. In addition, wettability on a metal plate fabricated by laser processing is also considered for the nuclear engineering application.

Yonemoto, Yukihiro; Nishimura, Akihiko

2012-07-01

409

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

410

A graphical weather system design for the NASA transport systems research vehicle B-737  

NASA Technical Reports Server (NTRS)

A graphical weather system was designed for testing in the NASA Transport Systems Research Vehicle B-737 airplane and simulator. The purpose of these tests was to measure the impact of graphical weather products on aircrew decision processes, weather situation awareness, reroute clearances, workload, and weather monitoring. The flight crew graphical weather interface is described along with integration of the weather system with the flight navigation system, and data link transmission methods for sending weather data to the airplane.

Scanlon, Charles H.

1992-01-01

411

Prescribing effective human problem solving processes: Problem description in physics  

NSDL National Science Digital Library

A theoretical model specifying the underlying knowledge and procedures whereby human subjects can generate effective initial descriptions of scientific problems was formulated. The model is prescriptive since it does not necessarily try to simulate the behavior of actual experts nor assume that their performance is optimal. The model, elaborated in the domain of mechanics, specifies explicit procedures for redescribing problems in terms of a relevant knowledge base. To test the model, carefully controlled experiments were devised where human subjects were induced to act in accordance with alternative models and where their resulting performance was observed in detail. Such experiments, carried out with undergraduate physics students, showed that the proposed model is sufficient to generate excellent problem descriptions, that these markedly improve subsequent problem solutions, and that most components of the model are indeed necessary for good performance. Detailed data analysis also showed how the model predictably prevents the occurrence of many common errors. Such a validated model of effective problem description provides a useful basis for teaching students improved scientific problem-solving skills.

Heller, Joan I.; Reif, Frederick

2006-06-09

412

Physical processes affecting the sedimentary environments of Long Island Sound  

USGS Publications Warehouse

A modeling study was undertaken to simulate the bottom tidal-, wave-, and wind-driven currents in Long Island Sound in order to provide a general physical oceanographic framework for understanding the characteristics and distribution of seafloor sedimentary environments. Tidal currents are important in the funnel-shaped eastern part of the Sound, where a strong gradient of tidal-current speed was found. This current gradient parallels the general westward progression of sedimentary environments from erosion or non-deposition, through bedload transport and sediment sorting, to fine-grained deposition. Wave-driven currents, meanwhile, appear to be important along the shallow margins of the basin, explaining the occurrence of relatively coarse sediments in regions where tidal currents alone are not strong enough to move sediment. Finally, westerly wind events are shown to locally enhance bottom currents along the axial depression of the sound, providing a possible explanation for the relatively coarse sediments found in the depression despite tide- and wave-induced currents below the threshold of sediment movement. The strong correlation between the near-bottom current intensity based on