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1

Physical Processes in the Solar Interior: the Ultimate Sun-Weather Engine  

Microsoft Academic Search

The ultimate source of the magnetic fields that drive the Sun-Weather is located in the solar interior, where the dynamo mechanism (or mechanisms) operate. To model these processes, it is necessary to combine the tools of plasma physics (MHD) together with those of stellar structure and evolution, and large eddy simulations (LES) of the convective envelope. Because of the differences

S. Sofia

2004-01-01

2

Revisiting dirt cracking as a physical weathering process in warm deserts  

NASA Astrophysics Data System (ADS)

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

Dorn, Ronald I.

2011-12-01

3

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

4

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

Microsoft Academic Search

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

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

2004-01-01

5

Modelling the physical and chemical changes in roofing slate caused by weathering processes  

NASA Astrophysics Data System (ADS)

This research identifies the changes which takes place in roofing slate due to natural exposure and tries to replicate these changes experimentally. Traditional methods of testing, used by the British and other national standards, concentrate on the properties of unweathered samples and give no information on the relative durability of the different slates. Instead of concentrating on the initial properties, this research focuses on changes in the properties in order to assess durability. The effects of natural weathering were assessed by comparing old, used slates with new slates from the same or a similar source. The new slates were then weathered experimentally by repeated cycles of wetting and drying, and the increase in water absorbency compared with that observed in naturally weathering. Mineralogical differences due to both natural and experimental weathering were also measured using X-ray diffraction analysis. It was found that the effects of experimental weathering, using repeated cycles of wetting and drying, are similar to those observed in natural weathering. These include increased water absorbency and loss of crystallinity of the principal minerals. The greatest changes are found in those slates which are the most vulnerable to weathering, making it possible to identify poor quality slates.

Walsh, Joan Anne

2008-12-01

6

Quantification of physical weathering rates using thermodynamics  

Microsoft Academic Search

Physical weathering plays an important role in the global rock cycle in that it breaks up primary rock, thereby increasing the surface area for chemical weathering and providing the substrate for soil formation. We use a simple, thermodynamics based approach to quantify magnitudes of weathering, their spatial variation across climatic regions and their sensitivity to climatic change. Our approach is

F. Gans; S. Arens; S. J. Schymanski; A. Kleidon

2010-01-01

7

Soil Genesis and Development, Lesson 2 - Processes of Weathering  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

8

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

9

Weathering of the Oporto granite: geotechnical and physical properties  

Microsoft Academic Search

This paper characterizes the weathering products of the two-mica Oporto granite in terms of its mineralogical, chemical, geotechnical and physical properties. This information is used to identify a physical property that can be used as an index of the degree of weathering and to estimate other properties. In outcrop, the Oporto granite is always weathered and weathering profiles frequently exceed

A Begonha; M. A Sequeira Braga

2002-01-01

10

Weather  

NSDL National Science Digital Library

Meteorologists study the weather by recording and analyzing data. You can become an amateur meteorologist by building your own weather station and keeping a record of your measurements. After a while, you\\'ll notice the weather patterns that allow meteorologists to forecast the weather. Tasks: 1. As a group you will build a weather station outside. 2. Your group will build instruments to measure the weather. 3. Each person will record the data in personal weather journals. Process: 1.Since weather happens outside, you\\'ll need to make ...

Tuttle, Rachelle

2005-10-25

11

Weathering  

NSDL National Science Digital Library

This interactive Flash resource provides information regarding physical and chemical weathering at an introductory physical geology or Earth science level. It includes animations, diagrams, and supplementary information and is suitable for high school or undergraduate students.

Smoothstone; Mifflin, Houghton

12

Weather  

NSDL National Science Digital Library

This project will help you understand the weather and investigate weather interactively. What are the components of weather? How do you measure weather? Investigate the WeatherScholastic: Weather WatchWeatherWeather Center for Our 4th Grade ...

Lai, Ms.

2007-02-08

13

Application of a fluorescent technique to the study of the weathering process  

Microsoft Academic Search

Processes and rates of weathering in representative tuff obtained from a Green Tuff region were directly examined using a new fluorescent approach. This approach was developed to visualize microscopically the microcracks and micropores that contribute to deterioration. The following observations were made. Progression of tuff weathering is caused by a delicate balance between chemical alteration and physical disintegration. Weathering occurs

Takashi Nishiyama; Hiromu Kusuda

1996-01-01

14

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

15

Understanding Space Weather and the Physics Behind It  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

16

Weather  

NSDL National Science Digital Library

Learn all about the aspects of weather that effect us every day. Click here to see a weather forecast for anywhere in the world World Wide Weather Watch See what happens to weather when you change conditions at your house Weather Maker Weather Games ...

Hyde, Mrs.

2007-02-08

17

Weather  

NSDL National Science Digital Library

This lesson is written for fourth grade students. Students will explore weather and the effects it has on their lives. What is weather? video of what is weather Let's take a walk through the weather. Put on your hats and coats! Clouds Cloud Types Clouds - Dan's Wild Weather Page What to Wear? What to Wear? What to Drink? Weather Patterns and Climatic Regions ...

Bullough, Ms.

2010-06-24

18

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

19

Image processing for weather satellite cloud segmentation  

Microsoft Academic Search

Image segmentation of weather satellite imagery is an important first step in an automated weather forecasting system. Accurate cloud extraction is also important in the determination of solar radiative transfer in atmospheric research, where satellite observations are used as inputs to global climate models to predict climatic change. Most of the current cloud extraction algorithms tend to be quite complicated

I. J. H. Leung; J. E. Jordan

1995-01-01

20

Mechanical Weathering  

NSDL National Science Digital Library

This activity was designed to give students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Students discover that mechanical weathering is the process of breaking down bedrock into smaller fragments by physical as opposed to chemical means and that rock weathering, although it seems to occur slowly in human terms, is an extremely significant part of the rock cycle. They will learn that weathered rock materials are called sediments and are the structural basis for soils and can also be compacted into sedimentary rock. Students will realize that rock weathering rates vary widely depending on mineral content, texture, rock type, and climate and that differential weathering (varying weathering rates for two or more rock types in physical contact with each other) has given rise to some of the world's most breathtaking scenery.

21

Weather.  

ERIC Educational Resources Information Center

|This theme issue of "The Goldfinch" focuses on weather in Iowa and weather lore. The bulletin contains historical articles, fiction, activities, and maps. The table of contents lists: (1) "Wild Rosie's Map"; (2) "History Mystery"; (3) "Iowa's Weather History"; (4) "Weather Wonders"; (6) "Seasonal Jobs"; (7) "Fiction: Winter Courage"; (8) "Stayin'…

Ruth, Amy, Ed.

1996-01-01

22

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.

23

The relationship between physical and chemical weathering indices of granites around Seoul, Korea  

Microsoft Academic Search

In order to assess the relationship between chemical weathering indices and physical properties of granite, physical and chemical analyses were performed on both natural and artificially weathered granite samples from the Seoul area, where the pH of the rainfall occasionally drops to below 5. The results suggest that slake durability, uniaxial compressive strength, Ruxton ratio, Parker index, modified weathering potential

Sungsoo Kim; Hyeong-Dong Park

2003-01-01

24

Martian weathering processes: Terrestrial analog and theoretical modeling studies  

NASA Astrophysics Data System (ADS)

Understanding the role of water in the Martian near-surface, and its implications for possible habitable environments, is among the highest priorities of NASA's Mars Exploration Program. Characterization of alteration signatures in surface materials provides the best opportunity to assess the role of water on Mars. This dissertation investigates Martian alteration processes through analyses of Antarctic analogs and numerical modeling of mineral-fluid interactions. Analog work involved studying an Antarctic diabase, and associated soils, as Mars analogs to understand weathering processes in cold, dry environments. The soils are dominated by primary basaltic minerals, but also contain phyllosilicates, salts, iron oxides/oxyhydroxides, and zeolites. Soil clay minerals and zeolites, formed primarily during deuteric or hydrothermal alteration of the parent rock, were subsequently transferred to the soil by physical rock weathering. Authigenic soil iron oxides/oxyhydroxides and small amounts of poorly-ordered secondary silicates indicate some contributions from low-temperature aqueous weathering. Soil sulfates, which exhibit a sulfate- aerosol-derived mass-independent oxygen isotope signature, suggest contributions from acid aerosol-rock interactions. The complex alteration history of the Antarctic materials resulted in several similarities to Martian materials. The processes that affected the analogs, including deuteric/ hydrothermal clay formation, may be important in producing Martian surface materials. Theoretical modeling focused on investigating the alteration of Martian rocks under acidic conditions and using modeling results to interpret Martian observations. Kinetic modeling of the dissolution of plagioclase-pyroxene mineral mixtures under acidic conditions suggested that surfaces with high plagioclase/pyroxene, such as several northern regions, could have experienced some preferential dissolution of pyroxenes at a pH less than approximately 3-4. Modeling of the equilibrium secondary mineralogy produced by acidic, low- temperature weathering of potential Martian protoliths has been used to evaluate possible Martian mineral formation conditions. This modeling showed that silica-rich deposits, such as those in Gusev Crater, Mars, could form under low-temperature, low-pH (less than approximately 2) and high water/rock ratio conditions. High water/rock conditions could represent acid flow through rocks, discharge from an acid spring, and/or surface flows.

McAdam, Amy Catherine

2008-06-01

25

Physical weathering of marbles caused by anisotropic thermal expansion  

NASA Astrophysics Data System (ADS)

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

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

26

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

27

Effect of weathering on physical, mechanical and morphological properties of chemically modified wood materials  

Microsoft Academic Search

Physical, mechanical and morphological properties of chemically modified Acaciamangium and Acacia hybrid woods were investigated after weathering. The wood blocks prepared from Acaciamangium and Acacia hybrid, were treated with both propionic anhydride and succinic anhydride. Outdoor (natural) weathering was carried out for 1year, by exposing the samples to external environmental conditions. Chemical modification enhanced the weathering resistance of Acacia spp.

Irshad-ul-Haq Bhat; H. P. S. Abdul Khalil; Khairul B. Awang; I. O. Bakare; A. M. Issam

2010-01-01

28

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

29

Space weather risk  

Microsoft Academic Search

The importance of space weather to society is in a continuous increase since we are more and more dependent on reliable spaceborne and ground-based technological systems. Physical processes involved in space weather constitute a complicated chain from the Sun to the Earth's surface, so the management of space weather risks requires expertise in many disciplines of science and technology. In

Risto Pirjola; Kirsti Kauristie; Hanna Lappalainen; Ari Viljanen; Antti Pulkkinen

2005-01-01

30

The physical refining process  

Microsoft Academic Search

This paper deals with influences and optimizing of changing process conditions for physical refining of palm oil. These process\\u000a variables are temperature, pressure, residence time, fluid flow and stripping steam to oil ratio. These parameters influence\\u000a not only finished oil quality, oil yield, energy consumption and running costs, but also content and yield of natural stabilizers\\u000a like tocopherols or color

Hermann Stage

1985-01-01

31

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

32

Assessing the Effects of Weather Conditions on Physical Activity Participation Using Objective Measures  

PubMed Central

Habitual physical activity is an important determinant of health, yet many people are considered to be inactive. Identification of the obstacles to greater participation is necessary for the development of strategies to overcome those obstacles. The weather has been identified as a perceived barrier to participation in physical activity, but exactly which adverse weather conditions are most important, and the extent to which they contribute to decreases in physical activity have rarely been quantified in populations. In the past decade, a small number of studies have used publicly available databases to examine the quantitative effects of weather (e.g., temperature, precipitation, wind) on physical activity in children, adolescents and adults. This review examines our historical, qualitative versus emerging, quantitative understanding of how specific weather conditions affect a population’s activity.

Chan, Catherine B.; Ryan, Daniel A.

2009-01-01

33

wradlib - An Open Source Library for Weather Radar Data Processing  

NASA Astrophysics Data System (ADS)

Weather radar data is potentially useful in meteorology, hydrology, disaster prevention and mitigation. Its ability to provide information on precipitation with high spatial and temporal resolution over large areas makes it an invaluable tool for short term weather forecasting or flash flood forecasting. The indirect method of measuring the precipitation field, however, leads to a significant number of data artifacts, which usually must be removed or dealt with before the data can be used with acceptable quality. Data processing requires e.g. the transformation of measurements from polar to cartesian coordinates and from reflectivity to rainfall intensity, the composition of data from several radar sites in a common grid, clutter identification and removal, attenuation and VPR corrections, gauge adjustment and visualization. The complexity of these processing steps is a major obstacle for many potential users in science and practice. Adequate tools are available either only at significant costs with no access to the uncerlying source code, or they are incomplete, insufficiently documented and intransparent. The wradlib project has been initiated in order to lower the barrier for potential users of weather radar data in the geosciences and to provide a common platform for research on new algorithms. wradlib is an open source library for the full range of weather radar related processing algorithms, which is well documented and easy to use. The main parts of the library are currently implemented in the python programming language. Python is well known both for its ease of use as well as its ability to integrate code written in other programming languages like Fortran or C/C++. The well established Numpy and Scipy packages are used to provide decent performance for pure Python implementations of algorithms. We welcome contributions written in any computer language and will try to make them accessible from Python. We would like to present the current state of this library together with a few showcase examples.

Heistermann, M.; Pfaff, Th.; Jacobi, S.

2012-04-01

34

Linkages Between Physical Erosion and Chemical Weathering, Measured by Cosmogenic Nuclides and Geochemical Mass Balance  

Microsoft Academic Search

We have recently shown how rates of physical erosion and chemical weathering can be measured over 1,000- to 10,000-year time scales, using cosmogenic 10Be measurements coupled with the bulk elemental composition of regolith and its parent rock. We have used these methods to measure long-term rates of physical erosion and chemical weathering for 42 sites, encompassing widely varying climates and

C. S. Riebe; J. W. Kirchner; R. C. Finkel

2004-01-01

35

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

36

Process evaluation: Weatherization Residential Assistance Partnership (WRAP Program)  

SciTech Connect

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

Not Available

1990-10-01

37

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

SciTech Connect

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

Not Available

1990-10-01

38

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

39

Physics as Information Processing  

SciTech Connect

I review some recent advances in foundational research at Pavia QUIT group. The general idea is that there is only Quantum Theory without quantization rules, and the whole Physics - including space-time and relativity - is emergent from the quantum-information processing. And since Quantum Theory itself is axiomatized solely on informational principles, the whole Physics must be reformulated in information-theoretical terms: this is the It from bit of J. A. Wheeler.The review is divided into four parts: a) the informational axiomatization of Quantum Theory; b) how space-time and relativistic covariance emerge from quantum computation; c) what is the information-theoretical meaning of inertial mass and of ({h_bar}/2{pi}), and how the quantum field emerges; d) an observational consequence of the new quantum field theory: a mass-dependent refraction index of vacuum. I will conclude with the research lines that will follow in the immediate future.

D'Ariano, Giacomo Mauro [QUIT Group, Dipartimento di Fisica 'A. Volta', 27100 Pavia (Italy) and Istituto Nazionale di Fisica Nucleare, Gruppo IV, Sezione di Pavia (Italy)

2011-03-28

40

Physical weathering of marbles caused by anisotropic thermal expansion  

Microsoft Academic Search

Marbles as building stones as well as in their natural environments show complex weathering phenomena. The most important\\u000a damage scenario is based on the highly anisotropic thermal expansion coefficient ? of calcite, i.e. extreme expansion parallel and contraction normal to the crystallographic c-axis. Therefore, the rock fabric\\u000a and especially the lattice-preferred orientation (texture) of calcite and\\/or dolomite as the predominant

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

2000-01-01

41

Physical mechanisms of plant roots affecting weathering and leaching of loess soil  

Microsoft Academic Search

Plant roots have potential impacts on soil mineral weathering and leaching. Our objective is to understand the physical mechanisms\\u000a of plant roots affecting weathering and leaching of loess soil. Root densities were measured through the method of a large-size\\u000a dug profile, and transport fluxes of soil elements were determined using an undisturbed monolith soil infiltration device\\u000a on the hilly and

Yong Li; Qingwen Zhang; Guojiang Wan; Ronggui Huang; Hechun Piao; Lingyu Bai; Lu Li

2006-01-01

42

Distinctive space weathering on Vesta from regolith mixing processes  

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

43

Distinctive space weathering on Vesta from regolith mixing processes.  

PubMed

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

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

2012-11-01

44

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

45

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

2012-05-25

46

Relationship between objective measures of physical activity and weather: a longitudinal study  

PubMed Central

Background The weather may be a barrier to physical activity but objective assessment of this hypothesis is lacking. Therefore we evaluated the effect of temperature, rain or snow, and wind speed on the daily physical activity of adults. Methods This report contains data from 25 males (BMI (mean ± SD): 28.7 ± 3.83 kg/m2) and 177 females (BMI: 29.2 ± 5.92 kg/m2) enrolled in an intervention to increase physical activity. Steps/day of the participants was measured by pedometer. Weather data were obtained from Environment Canada. A total of 8,125 observations were included in a mixed linear model analysis. Results Significant weather related variables (at the 5% level) impacting steps/day included: seasonal effects related to the interaction between weekday and month; mean temperature, total rainfall, interactions between gender, BMI and total snow, interactions between maximum wind speed and BMI, and the amount of snow on the ground. The estimated magnitudes for the various effects were modest, ranging from ~1% to ~20%. Thus for an average individual taking ~10,000 steps/day, weather-dependent changes in physical activity could reach 2,000 steps/day. Conclusion We conclude that weather had modest effects on physical activity of participants in an intervention to increase their activity. It should be stressed that these effects may be different for less or more motivated people. With this in mind, we suggest that the effect of weather on physical activity in the general population needs to be objectively assessed to better understand the barrier it poses, especially as it relates to outdoor recreation or work activities.

Chan, Catherine B; Ryan, Daniel AJ; Tudor-Locke, Catrine

2006-01-01

47

Relationship between objective measures of physical activity and weather: a longitudinal study  

Microsoft Academic Search

: BACKGROUND: The weather may be a barrier to physical activity but objective assessment of this hypothesis is lacking. Therefore we evaluated the effect of temperature, rain or snow, and wind speed on the daily physical activity of adults. METHODS: This report contains data from 25 males (BMI (mean ± SD): 28.7 ± 3.83 kg\\/m2) and 177 females (BMI: 29.2

Catherine B Chan; Daniel AJ Ryan; Catrine Tudor-Locke

2006-01-01

48

Weathering processes in clayey sediments - on local to catchment scale  

NASA Astrophysics Data System (ADS)

In Denmark, postglacial weathering processes have introduced considerable changes in the inherited properties of the young sediments of Weichselian age. Over the last 12.000 years, oxidation and acidification are the main responsible processes for the changes that have taken place in water recharge areas. The distribution of nitrate has been shown to be closely related to the geochemical environment above the interface between the oxidized and reduced sediments and present in the oxic environment only. In the present study, the formation of oxidized geochemical environments was studied at different scales, from local to catchment scale, in areas dominated by clayey till. Sediment samples were collected in the field from surface and down to below the redox interface and described by color, redoximorphic features, and sediment type and analyzed for e.g., total amount of reduced compounds and reduced compounds (pyrite, ferrous iron, and organic matter). The results were used to describe the spatial development of oxidized environments and to identify the smallest possible scale at witch nitrate reduction in the subsurface can be assessed for Danish catchments.

Ernstsen, Vibeke

2013-04-01

49

The Effects of Daily Weather on Accelerometer-measured Physical Activity among Adults with Arthritis  

PubMed Central

Background This study analyzes Chicago-area weather effects on objectively measured physical activity over a three year period among a cohort of 241 participants in an on-going arthritis physical activity trial. Methods Uniaxial accelerometer counts and interview data were analyzed for up to six weekly study waves involving 4823 days of wear. The effects of temperature, rainfall, snowfall and daylight hours were analyzed after controlling for participant characteristics, day of the week, and daily accelerometer wear hours in a mixed effects linear regression model. Results Daylight hours, mean daily temperature <20 or ? 75 degrees and light or heavy rainfall (but not snowfall) were all significantly associated with lower physical activity after controlling for the significant effects of weekends, accelerometer wear hours, age, sex, type of arthritis, employment, Hispanic ethnicity, obesity, and SF36 physical and mental health scores. Conclusions The cumulative effects of weather are reflected in a 38.3% mean monthly difference in daily counts between November and June, reflecting over three additional hours of sedentary time. Physical activity promotion programs for older persons with chronic conditions need lifestyle physical activity plans adapted to weather extremes.

Feinglass, Joe; Lee, Julia; Dunlop, Dorothy; Song, Jing; Semanik, Pam; Chang, Rowland W.

2010-01-01

50

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

51

Transitioning From Space Physics Research to Space Weather Application at The Johns Hopkins University Applied Physics Laboratory (JHU/APL)  

NASA Astrophysics Data System (ADS)

The ability to monitor and predict our near-Earth space environment ("space weather") lags its sister discipline of terrestrial weather studies by years, in both observational and forecast capabilities. However, with current rapid progress in space physics research, and with current and near-future space environment sensors on research and operational satellites, the space weather operational community can reach new levels of maturity. A rapid transition of scientific research results into prototype operational products is especially important. This paper addresses the concept of rapid transition and presents examples carried out recently by scientists at JHU/APL, such as: OVATION (Oval Variation, Assessment, Tracking, Intensity and Online Nowcasting), and real-time geomagnetic activity nowcasting using observations from limited ground magnetometer stations. Several potential future application projects will be discussed as well; these space-environment products are designed to coincide with operationally significant events, such as communication outages or space object tracking.

Meng, C. I.

2003-12-01

52

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

53

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

54

Chemical and physical weathering in New Zealand’s Southern Alps monitored by bedload sediment major element composition  

Microsoft Academic Search

The Haast and Clutha rivers drain opposing flanks of New Zealand’s Southern Alps. Major element analyses of grain size fractions (2–1mm, 1mm–355?m, 355–63?m, and <63?m) from bedload sediments collected throughout the reach of each river suggest that weathering is strongly partitioned between the chemical weathering of carbonates and the physical weathering of silicates. Sand size fractions from both rivers are

Christopher Q. Kautz; Candace E. Martin

2007-01-01

55

Long-term rates of chemical weathering and physical erosion from cosmogenic nuclides and geochemical mass balance  

Microsoft Academic Search

Quantifying long-term rates of chemical weathering and physical erosion is important for understanding the long-term evolution of soils, landscapes, and Earth's climate. Here we describe how long-term chemical weathering rates can be measured for actively eroding landscapes using cosmogenic nuclides together with a geochemical mass balance of weathered soil and parent rock. We tested this approach in the Rio Icacos

Clifford S. Riebe; James W. Kirchner; Robert C. Finkel

2003-01-01

56

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

NASA Astrophysics Data System (ADS)

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

Thompson, Victoria

2012-01-01

57

Technical Note: An open source library for processing weather radar data (wradlib)  

NASA Astrophysics Data System (ADS)

The potential of weather radar observations for hydrological and meteorological research and applications is undisputed, particularly with increasing world-wide radar coverage. However, several barriers impede the use of weather radar data. These barriers are of both scientific and technical nature. The former refers to inherent measurement errors and artefacts, the latter to aspects such as reading specific data formats, geo-referencing, visualisation. The radar processing library wradlib is intended to lower these barriers by providing a free and open source tool for the most important steps in processing weather radar data for hydro-meteorological and hydrological applications. Moreover, the community-based development approach of wradlib allows scientists to share their knowledge about efficient processing algorithms and to make this knowledge available to the weather radar community in a transparent, structured and well-documented way.

Heistermann, M.; Jacobi, S.; Pfaff, T.

2013-02-01

58

Physical limnological processes under ice  

Microsoft Academic Search

Penetration of solar radiation through ice and snow covering northern lakes produces a gravity current between regions with varying depths. This baroclinic current is a dominant physical process in winter because ice cover insulates lakes from the usual turbulence sources such as breaking surface waves and near-surface shear produced by the wind. The current forms a directed circulation from the

Bernard C. Kenney; T Slepukhina

1996-01-01

59

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

60

[Fiber emissions from weathered asbestos cement products. 2. Physical-chemical properties of liberated asbestos fibers].  

PubMed

It could be already shown that fibrous particulates can be emitted from weathered and corroded surfaces of asbestos-cement-(AC)-products and that these fibers increase the total ambient air concentration after having been dispersed in the atmosphere. In this investigation we studied the influence of the polluted atmosphere on physical and chemical properties of asbestos fibers in the corroded surface layer. It was found, that in a part of these asbestos fibers the magnesium was partly leached and that the fibers were strongly contaminated by deposited air pollutants. PMID:2547393

Spurny, K; Marfels, H; Boose, C; Weiss, G; Opiela, H; Wulbeck, F J

1989-06-01

61

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

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

Chemical and physical weathering in south Patagonian rivers: A combined Sr-U-Be isotope approach  

NASA Astrophysics Data System (ADS)

We investigated physical and chemical weathering in south Patagonia, encompassing both the tectonically active Andes with alpine glaciers and the quiescent seaboard plain with arid climate. Chemical denudation rates determined from riverine dissolved major elements were (0.07-5) × 105 tons year-1, and the long-term rates of CO2 consumption by alkaline earth silicates were (0.03-0.5) × 105 mol km-2 year-1, commensurate with the average global CO2 consumption rate (0.25 × 105 mol km-2 year-1). Unradiogenic strontium isotope ratios indicated that the source of silicate weathering was volcanic sedimentary cover. Basin average total denudation rates based on 10Be measured in active streambed sediments ranged from 0.009 to 0.6 mm year-1. Uranium series disequilibria suggested that there is significant redistribution of nuclides between the dissolved and suspended material. When applying the simultaneous gain and loss model to the U-series data of the suspended load, sediment residence times of 10-150 ky were obtained. Comparison of the dissolved load-based chemical denudation rate and 10Be-based total denudation rate revealed that some basins are dominated by chemical and some by physical denudation.

Lee, Borom; Han, Yeongcheol; Huh, Youngsook; Lundstrom, Craig; Siame, Lionel L.; Lee, Jong Ik; Park, Byong-Kwon; Aster Team

64

Radio Emission Processes as Tracers of Heliospheric Weather: An Ontological Approach  

Microsoft Academic Search

\\u000a The heliosphere is a complex physical system composed of a set of coupled plasma sub-systems typically in a state of marginal\\u000a stability. Hence a variety of perturbations can be triggered by instabilities occurring from large to small spatial and temporal\\u000a scales. This characterizes the heliospheric weather, i.e. the physical state of the heliosphere on short- to mid-timescale,\\u000a which is a

Mauro Messerotti

2011-01-01

65

AN URBAN WEATHER GENERATOR COUPLING BUILDING SIMULATIONS WITH A PHYSICALLY BASED URBAN MODEL  

Microsoft Academic Search

Building simulation programs predict the thermal performance of buildings under certain weather conditions. Weather information is usually taken from an available weather data file obtained from the closest meteorological station. However, the differences between the local urban climate and the conditions at the closest meteorological station can lead to inaccurate building simulation results. This paper presents an Urban Weather Generator

Bruno Bueno Unzeta; Leslie K. Norford; Rex Britter

66

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

NASA Astrophysics Data System (ADS)

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

Hill, Frank; Roth, Markus; Thompson, Michael

2013-04-01

67

A dynamically configurable system for operational processing of space weather data  

Microsoft Academic Search

Observations of space weather are based on the availability of various data collected by satellite or ground based instruments. In general, after reception these data have to be transferred into useful contexts and formats. Often there is a need to install processing chains to produce high level products by using information from different sources. Additionally, operational processing has to meet

A. Wehrenpfennig; N. Jakowski; J. Wickert

2001-01-01

68

Spectral evidence of size dependent space weathering processes on asteroid surfaces  

Microsoft Academic Search

Most compositional characterizations of the minor planets are derived from analysis of visible and near-infrared reflectance spectra. However, such spectra are derived from light which has only interacted with a very thin surface layer. Although regolith processes are assumed to mix all near-surface lithologic units into this layer, it has been proposed that space weathering processes can alter this surface

M. J. Gaffey; J. F. Bell; R. H. Brown; T. H. Burbine; J. L. Piatek; K. L. Reed; D. A. Chaky

1993-01-01

69

Activity Level, Activity Enjoyment, and Weather as Mediators of Physical Health Risks in Seasonal and Nonseasonal Depression  

Microsoft Academic Search

Research suggests that depression has negative consequences on physical health. One of the mechanisms driving this link may\\u000a be the decrease in physical activity characteristic of individuals before and during a depressive episode. However, the factors\\u000a that influence changes in physical activity across the seasons remain unclear. For instance, weather has been proposed to\\u000a play an important role in the

Sandra T. SigmonJanell; Janell G. Schartel; Nina E. Boulard; Geoffrey L. Thorpe

2010-01-01

70

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

PubMed Central

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.

Wolff, Dana; Fitzhugh, Eugene C.

2011-01-01

71

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

PubMed

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

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

72

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

73

Rock-weathering rates as functions of time  

USGS Publications Warehouse

The scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear. This assumption has been strengthened by studies that have calculated long-term average rates. However, little theoretical or empirical evidence exists to support linear rates for most chemical-weathering processes, with the exception of congruent dissolution processes. The few previous studies of rock-weathering rates that contain quantitative documentation of the relation between chemical weathering and time suggest that the rates of most weathering processes decrease with time. Recent studies of weathering rinds on basaltic and andesitic stones in glacial deposits in the western United States also clearly demonstrate that rock-weathering processes slow with time. Some weathering processes appear to conform to exponential functions of time, such as the square-root time function for hydration of volcanic glass, which conforms to the theoretical predictions of diffusion kinetics. However, weathering of mineralogically heterogeneous rocks involves complex physical and chemical processes that generally can be expressed only empirically, commonly by way of logarithmic time functions. Incongruent dissolution and other weathering processes produce residues, which are commonly used as measures of weathering. These residues appear to slow movement of water to unaltered material and impede chemical transport away from it. If weathering residues impede weathering processes then rates of weathering and rates of residue production are inversely proportional to some function of the residue thickness. This results in simple mathematical analogs for weathering that imply nonlinear time functions. The rate of weathering becomes constant only when an equilibrium thickness of the residue is reached. Because weathering residues are relatively stable chemically, and because physical removal of residues below the ground surface is slight, many weathering features require considerable time to reach constant rates of change. For weathering rinds on volcanic stones in the western United States, this time is at least 0.5 my. ?? 1981.

Colman, S. M.

1981-01-01

74

Effects Of Fungal-Mineral Interactions On Chemical Weathering And Denudation Processes - Observations From Experimental Ecosystems  

NASA Astrophysics Data System (ADS)

A mesoscale (`sandbox') lysimeter experiment was performed at Hubbard Brook Experimental Forest, New Hampshire, to study plant-growth influences on chemical weathering and chemical denudation. Weathering was estimated by mass balance for 5 and 15-year intervals, and denudation was monitored as the product of drainage flow and concentration for 20 years in large (7.5x7.5x1.5m) fully lined sandboxes a.) planted with red pine (Pinus resinosa Ait.), and b.) kept free of vascular vegetation. Mass-balance equations included base cations (Ca, Mg, and K) in precipitation inputs and drainage outputs, and changes of base cation contents in biomass and soil. Scanning Electron Microscopy (SEM) and Environmental-SEM studies of the coarse sandbox soils were used for detection of mycorrhizal fungal association with roots, fungal development and attachment features on mineral grain surfaces. In the non-vascular system chemical weathering and denudation fluxes did not change significantly during the monitored period, but denudation fluxes were 1.3-1.4 times higher than weathering fluxes. In the vascular ecosystem the chemical weathering flux was 3 and 1.8 times greater than the denudation flux over 5 and 15 years, respectively, but both rates decreased over time. In our experiment the pines retarded denudation and accelerated weathering relative to the nonvascular system, thereby increasing available nutrient pools. The SEM and ESEM studies indicated more weathering features (etch pits, cracks, wholes, channels, and secondary minerals) in the mineral surfaces of the vascular system associated with the mycorrhizal fungal hyphae. Profiles of base-cation concentrations in soil water suggest that hyphal-mineral surface attachment might also insulate cation uptake from bulk soil water and hydrologic loss. The sandbox study offers insight into short-term effects of ecosystems on global biogeochemical processes.

Balogh, Z.; Keller, C.; Dickinson, J.

2003-12-01

75

Urbanization impacts on severe weather dynamical processes and climatology  

Microsoft Academic Search

Rainfall changes are a complex manifestation of multi-scale processes that are influenced by both natural and anthropogenic activities. This dissertation focuses on understanding the relationship between rainfall climatology and urbanization. Even though there is a long-term increase in the rainfall amounts under a global warming background, the land use \\/ land cover change can also be an additional factor contributing

Ming Lei

2011-01-01

76

Using Numerical Weather Prediction Model Derived Tropospheric Slant Delays in GPS Processing: a Case Study  

Microsoft Academic Search

The troposphere is one of the most significant sources of error in precise GPS (Global Positioning System) positioning solutions nowadays. Uncertainties in troposphere estimation distort the height component especially. We have implemented the troposphere slant delays derived from a numerical weather prediction model to GPS processing. In this case study we calculated 24 vectors for 61 days, the length of

Maaria Nordman; Reima Eresmaa; Markku Poutanen; Heikki Järvinen; Hannu Koivula; Juha-Pekka Luntama

2007-01-01

77

Major ion chemistry and weathering processes in the Midyan Basin, northwestern Saudi Arabia.  

PubMed

Chemical characteristics of 72 groundwater samples collected from Midyan Basin have been studied to evaluate major ion chemistry together with the geochemical and weathering processes controlling the water composition. Water chemistry of the study area is mainly dominated by Na, Ca, SO4, and Cl. The molar ratios of (Ca?+?Mg)/total cations, (Na?+?K)/total cations, (Ca?+?Mg)/(Na?+?K), (Ca?+?Mg)/(HCO3?+?SO4), (Ca?+?Mg)/HCO3, and Na/Cl reveal that water chemistry of the Midyan Basin is controlled by evaporite dissolution (gypsum and/or anhydrite, and halite), silicate weathering, and minor contribution of carbonate weathering. The studied groundwater samples are largely undersaturated with respect to dolomite, gypsum, and anhydrite. These waters are capable of dissolving more of these minerals under suitable physicochemical conditions. PMID:23609922

Ghrefat, Habes A; Batayneh, Awni; Zaman, Haider; Zumlot, Taisser; Elawadi, Eslam; Nazzal, Yousef

2013-04-24

78

Effect of freeze–thaw and thermal shock weathering on the physical and mechanical properties of an andesite stone  

Microsoft Academic Search

Natural stones are exposed to physical weathering due to freeze–thaw (F–T) and thermal shock (TS) when they are used as pavement,\\u000a cladding and masonry material. In this study, the deterioration of andesite was investigated by determining the physical and\\u000a mechanical properties of andesite samples after each 10 cycles of F–T and TS up to 50 cycles. It was found that

Huseyin Yavuz

2011-01-01

79

Space weathering processes on airless bodies: Fe isotope fractionation in the lunar regolith  

Microsoft Academic Search

Nanophase Fe metal grains (np-Fe°) are a product of space weathering, formed by processes related to meteorite impacts, and solar-wind sputtering on airless planetary bodies, such as the Moon. Iron isotopes of lunar soils are fractionated during these processes, and the np-Fe° in the finest (<10 ?m), mature, size fractions of the soil become enriched in heavier isotopes by ?0.3‰

René A. Wiesli; Brian L. Beard; Lawrence A. Taylor; Clark M. Johnson

2003-01-01

80

Urbanization impacts on severe weather dynamical processes and climatology  

NASA Astrophysics Data System (ADS)

Rainfall changes are a complex manifestation of multi-scale processes that are influenced by both natural and anthropogenic activities. This dissertation focuses on understanding the relationship between rainfall climatology and urbanization. Even though there is a long-term increase in the rainfall amounts under a global warming background, the land use / land cover change can also be an additional factor contributing to regional climate change. This research study investigates the urbanization effect on rainfall at regional scales: (i) Multidecadal large scale: by investigating the eastern US urban rainfall climatology from 1958-2008; (ii) Decadal mesoscale summer-time thunderstorm climatology over central Indiana from 2000- 2009, and high resolution model studies for representative thunderstorms. For the multi-decadal rainfall climatology over eastern US, we examined the relationship between rainfall characteristics and urbanization by analyzing data from 4593 surface stations over the last 50 years (1958-2008), Parameter-elevation Regressions on Independent Slopes Model (PRISM) data in last two decades, North America Regional Reanalysis (NARR) winds, and a proxy for urbanization through gridded human population data. Results indicate that the summer monthly rainfall amount shows an increasing trend under the influence of urbanization changes. The frequency of heavy rainfall events shows a preferential positive bias towards urbanized regions. Most notably, consistent with case studies for individual cities, the frequency of rainfall amounts downwind of urban-rural boundaries shows a climatologically increasing trend. Analysis of heavy (top 2 percentile) and extreme (top 0.5 percentile) rainfall events indicates decreasing trends of heavy (top 10 percentile) rainfall event frequency and possible increasing trends of extreme rainfall event frequency over urban areas. Spatially the urbanization impact on rainfall was more pronounced in the North and the Central US with an increase in rainfall amounts, while the southern region showed mixed results. For the mesoscale thunderstorm climatology, we used both subjective and objective methods to analyze the summertime thunderstorm behavior over Indianapolis from 2000 to 2009. Results indicate that the intensity of thunderstorm is relatively lower over urban center and higher over upwind and downwind direction. Observations indicate that thunderstorm often split into smaller cells over the urban region and reintensify as larger, merged cells downwind. This splitting or morphology change in the thunderstorm characteristics was noted for nearly 30% of the daytime storms, with a bias for daytime cold fronts. Mesoscale model studies suggest that the urban-rural heterogeneity aids the formation of a mesoscale convergence zone which can alter the thunderstorm characteristics. Overall, this study highlights the important role of land use /land cover and urbanization for understanding the mesoscale rainfall changes as part of regional climate change.

Lei, Ming

81

Paleopedological reconstruction and quantitative analysis of weathering processes in the Southern Piedmont Province  

SciTech Connect

Soils and paleosols are commonly used to estimate ages of deposits and geomorphic surfaces, and to infer paleoenvironmental conditions during pedogenesis. Accurate interpretation of these and other parameters is currently limited, however, by considerable uncertainty in many fundamental areas of soils-geomorphic research. These include: (1) lack of accurate estimates of weathering rates for reliably-dated surfaces, (2) inability to quantitatively differentiate between the complex effects of climate vs. geomorphic age on weathering rates, processes, and pedogenic properties, and (3) difficulty in assessing which soil properties persist, alter, or become obliterated in the weathering environment as conditions change. In this paper, the authors discuss a method for assessing, on a regional basis, the quantitative relationships between climate, time, and weathering processes along a soil climosequence in the Southern Piedmont Province. Their approach involves sampling exclusively in areas of granitic plutons that exhibit a high degree of homogeneity with regard to total Fe content, bulk mineralogy, and absence of secondary phyllosilicates or sesquioxides. Independent age control is being established by [sup 10]Be dating, and analytical techniques include, in part, (1) geochemical speciation of soil solution and mineral equilibrium determination, (2) elemental analysis and mass balance calculations of elemental flux during pedogenesis, and (3) detailed analysis of Fe-oxide crystallinity, structure, and Al substitution using selective dissolution analysis, and both X-ray and differential X-ray diffraction.

Feldman, S.B.; Zelazny, L.W. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)); Pavich, M.J. (Geological Survey, Reston, VA (United States))

1992-01-01

82

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

83

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

84

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

85

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

86

Multi-PRI Signal Processing for the Terminal Doppler Weather Radar. Part I: Clutter Filtering  

Microsoft Academic Search

Multiple pulse repetition interval (multi-PRI) transmission is part of an adaptive signal transmission and processing algorithm being developed to aggressively combat range-velocity ambiguity in weather radars. In the past, operational use of multi-PRI pulse trains has been hampered due to the difficulty in clutter filtering. This paper presents finite impulse response clutter filter designs for multi-PRI signals with excel- lent

John Y. N. Cho; Edward S. Chornoboy

2005-01-01

87

Effects on Climate Records of Changes in National Weather Service Humidity Processing Procedures  

Microsoft Academic Search

The U.S. National Weather Service has recently corrected an error in radiosonde humidity data reduction algorithms, eliminated a sonde thats processing contained another error, and recently made a further change in the humidity data reduction algorithm. They also introduced new procedures for reporting humidity from radiosondes. These changes will affect the climate records of U.S. upper-air humidity. Because the changes

William P. Elliott; Rebecca J. Ross; Barry Schwartz

1998-01-01

88

Gravestone Weathering  

NSDL National Science Digital Library

In this activity (located on pages 9-14 of PDF), learners visit a cemetery to examine the distinguishing characteristics of rock weathering. After researching stone weathering and acid rain, learners apply their knowledge to collect data related to chemical decomposition and physical disintegration at a cemetery site. This detailed lesson guide includes tips for educators, pre/post activity suggestions, hands-outs, and background information.

Wiberg, Leanne; History, National M.

2000-01-01

89

Mechanics of Sheeting Joints and Spheroidal Weathering (Invited)  

Microsoft Academic Search

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

S. J. Martel

2010-01-01

90

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

91

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

92

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

National Technical Information Service (NTIS)

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 ...

D. Hood J. H. Barrett

2009-01-01

93

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

94

Comparison between physical variables acquired by a new multiparametric platform, ELFO, and data calculated by a three-dimensional hydrodynamic model in different weather conditions at Tiber River mouth (Latium coast, Italy)  

Microsoft Academic Search

The coastal ecosystem is characterized by high variability physical processes, which are strongly influenced by sudden changes in weather conditions. For this reason instruments able to collect data in a short time or mathematical models able to simulate the same phenomena from experimental data are basic. In this study in situ data are compared with data calculated by three-dimensional hydrodynamic

Simone Bonamano; Viviana Piermattei; Marco Marcelli; Maximo Peviani

2010-01-01

95

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

96

Why large-scale climate indices seem to predict ecological processes better than local weather.  

PubMed

Large-scale climatic indices such as the North Atlantic Oscillation are associated with population dynamics, variation in demographic rates and values of phenotypic traits in many species. Paradoxically, these large-scale indices can seem to be better predictors of ecological processes than local climate. Using detailed data from a population of Soay sheep, we show that high rainfall, high winds or low temperatures at any time during a 3-month period can cause mortality either immediately or lagged by a few days. Most measures of local climate used by ecologists fail to capture such complex associations between weather and ecological process, and this may help to explain why large-scale, seasonal indices of climate spanning several months can outperform local climatic factors. Furthermore, we show why an understanding of the mechanism by which climate influences population ecology is important. Through simulation we demonstrate that the timing of bad weather within a period of mortality can have an important modifying influence on intraspecific competition for food, revealing an interaction between climate and density dependence that the use of large-scale climatic indices or inappropriate local weather variables might obscure. PMID:15229599

Hallett, T B; Coulson, T; Pilkington, J G; Clutton-Brock, T H; Pemberton, J M; Grenfell, B T

2004-07-01

97

Physical Morphology and Quantitative Characterization of Chemical Changes of Weathered PVC/Pine Composites.  

National Technical Information Service (NTIS)

This study investigated weathering effects on polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on the color and structure that is attributed to the material composition. It is directed towards quantifying the main chemical modifi...

A. G. McDonald J. S. Fabiyi

2009-01-01

98

Post-processing rainfall forecasts from numerical weather prediction models for short-term streamflow forecasting  

NASA Astrophysics Data System (ADS)

Sub-daily ensemble rainfall forecasts that are bias free and reliably quantify forecast uncertainty are critical for flood and short-term ensemble streamflow forecasting. Post-processing of rainfall predictions from numerical weather prediction models is typically required to provide rainfall forecasts with these properties. In this paper, a new approach to generate ensemble rainfall forecasts by post-processing raw numerical weather prediction (NWP) rainfall predictions is introduced. The approach uses a simplified version of the Bayesian joint probability modelling approach to produce forecast probability distributions for individual locations and forecast lead times. Ensemble forecasts with appropriate spatial and temporal correlations are then generated by linking samples from the forecast probability distributions using the Schaake shuffle. The new approach is evaluated by applying it to post-process predictions from the ACCESS-R numerical weather prediction model at rain gauge locations in the Ovens catchment in southern Australia. The joint distribution of NWP predicted and observed rainfall is shown to be well described by the assumed log-sinh transformed bivariate normal distribution. Ensemble forecasts produced using the approach are shown to be more skilful than the raw NWP predictions both for individual forecast lead times and for cumulative totals throughout all forecast lead times. Skill increases result from the correction of not only the mean bias, but also biases conditional on the magnitude of the NWP rainfall prediction. The post-processed forecast ensembles are demonstrated to successfully discriminate between events and non-events for both small and large rainfall occurrences, and reliably quantify the forecast uncertainty. Future work will assess the efficacy of the post-processing method for a wider range of climatic conditions and also investigate the benefits of using post-processed rainfall forecasts for flood and short-term streamflow forecasting.

Robertson, D. E.; Shrestha, D. L.; Wang, Q. J.

2013-09-01

99

Residence time and physical processes in lakes  

Microsoft Academic Search

The residence time of a lake is highly dependent on internal physical processes in the water mass conditioning its hydrodynam- ics; early attempts to evaluate this physical parameter emphasize the complexity of the problem, which depends on very different natural phenomena with widespread synergies. The aim of this study is to analyse the agents involved in these processes and arrive

Walter AMBROSETTI; Luigi BARBANTI; Nicoletta SALA

2003-01-01

100

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

101

Project Weather and Water.  

ERIC Educational Resources Information Center

Introduces Project Weather and Water with the goal of developing and testing ideas of how to implement weather topics and water physics in an integrated way. Discusses teacher preparation, implementation, and evaluation of this project. (ASK)

Hansen, Pal J. Kirkeby

2000-01-01

102

Reconfigurable data acquisition system for weather radar applications  

Microsoft Academic Search

Tornado, hazardous weather and flood detection radars demand high-throughput, high-speed data acquisition and processing. Weather-processing systems need to be capable of implementing powerful signal processing algorithms on the raw data collected by the radars. Following processing, data is distributed to the end-user in real-time for timely and accurate detection of imminent weather disasters. Since physical accessibility to such systems is

Rishi Khasgiwale; Luko Krnan; Atchuthan Perinkulam; Russell Tessier

2005-01-01

103

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

104

Characterization of an Antarctic Mars Analog Soil and Implications for Martian Weathering Processes  

NASA Astrophysics Data System (ADS)

Terrestrial analogs can be used to gain insight into potential martian weathering processes and the role of water in the near-surface environment. We are investigating the mineralogy and chemical properties of a fine size fraction of a soil weathered from the Ferrar Dolerite. The soil was collected near Lewis Cliff in the Transantarctic Mountains. The Ferrar exhibits mineralogical similarities to martian basaltic lithologies, as represented by the shergottites [Harvey, 2001]. Production of fines from this parent rock in the cold, arid Antarctic makes the fines a promising Mars analog material. The analog soil fines have been studied with SEM/EDS, IR spectroscopy, XRD, TEM, and Mössbauer spectroscopy. XRD-derived semi-quantitative mineral abundances reveal that the Antarctic fines contain ~30% primary phases (plagioclase feldspar, pyroxenes, a small amount of quartz) and ~70% secondary phases (clays and clay-like mineraloids, zeolites, and ~50% calcium sulfates). The fines' thermal IR spectrum revealed silicate, bound water and sulfate features, consistent with the XRD-derived mineralogy. The significant amount of secondary phases present indicate that even in the Earth's coldest, driest environment, there is enough water and energy to weather some primary minerals. Atmospheric sulfate aerosols may have been important in producing the fines' abundant sulfate salts. Oxygen isotope studies of Antarctic Dry Valleys sulfates have revealed a ?17O anomaly, which suggests the sulfates are not just from sea salt (?17O =0) but also from atmospheric oxidation of gaseous sulfur compounds (e.g. marine biogenic dimethylsulfide) [e.g. Bao et al., 2000]. The anomaly implies that atmospheric sulfur aerosols interact with rocks and soils in Antarctica, similar to the acid fog model for martian weathering [e.g. Banin et al. 1997]. We have obtained an average ?17O value of +1.67±0.05‰ for the sulfates in the Antarctic fines being investigated here. This indicates that, in this Lewis Cliff soil as well, some of the sulfate in sulfate salts was contributed from atmospheric sources. Also, several clay-like aggregate particles examined contain sulfur. Iron oxides and clays in soils can absorb sulfate anions [e.g. Parfitt and Smart, 1978]. TEM work has revealed that many particles are clays or clay-like mineraloids, which exhibit a range of crystallinity and stacking disorder, or aggregates of these. While some particles were well crystalline clays or amorphous secondary products, most clay-like particles exhibited short-range order. Also, gypsum, primary minerals and particles in which secondary minerals are associated with primary minerals were observed. The presence of particles consisting of clay minerals and mineraloids of varying crystallinity and layer orientation, or aggregates of these, indicates that the Antarctic environment does not preclude significant chemical weathering, but it is consistent with limited water availability. Using the diverse dataset produced by applying multiple techniques, the characteristics of the fines support the hypothesis that chemical weathering products were produced by interaction of acidic aerosols with soils and rocks. Additional alteration by small amounts of water (e.g. thin water films) is also a likely contributor to the weathering process.

McAdam, A. C.; Leshin, L. A.; Sharp, T. G.; Harvey, R. P.; Farquhar, J.

2005-12-01

105

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

106

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

107

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

108

Novel natural and anthropogenic physical mechanisms of weather and climate changes  

Microsoft Academic Search

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

Nikolai Voronin; Sergei Avakyan

2010-01-01

109

Phytoplankton Blooms and Coastal Physical Processes.  

National Technical Information Service (NTIS)

The overall goal of our study was to gain understanding of the modes by which the physics of coastal regions couple with biological processes to create mesoscale enhancements of phytoplankton production. We attempted to identify the influence of various t...

D. M. Anderson

1993-01-01

110

Impact of Physical Processes on Maritime Frontogenesis.  

National Technical Information Service (NTIS)

A hydrostatic primitive equation model initialized in a highly baroclinically unstable state was used to simulate maritime cyclogenesis and frontogenesis. In order to identify boundary layer physical processes important in maritime frontogenesis, several ...

W. T. Thompson

1994-01-01

111

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

Microsoft Academic Search

Extreme weather is of importance because of the threats it makes to life and property. At the same time, extreme weather is a great fascination for meteorologists as well as for the general public. The conditions and processes that lead to extreme weather-although governed by the same physical principles as ``ordinary'' weather-frequently are far from the average state of the

Harold Brooks

2008-01-01

112

Post processing rainfall forecasts from numerical weather prediction models for short term streamflow forecasting  

NASA Astrophysics Data System (ADS)

Sub-daily ensemble rainfall forecasts that are bias free and reliably quantify forecast uncertainty are critical for flood and short-term ensemble streamflow forecasting. Post processing of rainfall predictions from numerical weather prediction models is typically required to provide rainfall forecasts with these properties. In this paper, a new approach to generate ensemble rainfall forecasts by post processing raw NWP rainfall predictions is introduced. The approach uses a simplified version of the Bayesian joint probability modelling approach to produce forecast probability distributions for individual locations and forecast periods. Ensemble forecasts with appropriate spatial and temporal correlations are then generated by linking samples from the forecast probability distributions using the Schaake shuffle. The new approach is evaluated by applying it to post process predictions from the ACCESS-R numerical weather prediction model at rain gauge locations in the Ovens catchment in southern Australia. The joint distribution of NWP predicted and observed rainfall is shown to be well described by the assumed log-sinh transformed multivariate normal distribution. Ensemble forecasts produced using the approach are shown to be more skilful than the raw NWP predictions both for individual forecast periods and for cumulative totals throughout the forecast periods. Skill increases result from the correction of not only the mean bias, but also biases conditional on the magnitude of the NWP rainfall prediction. The post processed forecast ensembles are demonstrated to successfully discriminate between events and non-events for both small and large rainfall occurrences, and reliably quantify the forecast uncertainty. Future work will assess the efficacy of the post processing method for a wider range of climatic conditions and also investigate the benefits of using post processed rainfall forecast for flood and short term streamflow forecasting.

Robertson, D. E.; Shrestha, D. L.; Wang, Q. J.

2013-05-01

113

A practical example of Moving Target Detection (MTD) processing for an air traffic control radar with weather channel  

Microsoft Academic Search

Air Traffic Control (ATC) radar processing of the Moving Target Detector (MTD) type is described. It comprises an independent processing channel called weather channel, which supplies meteorological data. The MTD processing technique is aimed at improving the detection of useful targets in the midst of clutter. The algorithms employed are detailed, as well as the performance to be expected, in

Christine Bruno

1986-01-01

114

Slope processes in weathered volcaniclastic deposits within the city of Naples: The Camaldoli Hill case  

NASA Astrophysics Data System (ADS)

We describe the slope processes acting on Camaldoli Hill, the main volcanic feature of the Neapolitan area whose geological evolution and setting have been reconstructed. The backbone of the hill includes the remnants of two partially superposed tuff cones, lying between the Campanian Ignimbrite (CI) and the Neapolitan Yellow Tuff (NYT). This sequence is mantled by pyroclastic, anthropogenic and epiclastic deposits, with abrupt thickness and facies variations. The structural setting of the hill mainly results from several phases of reactivation of the CI caldera faults which were active until about 9.5 ka. Deformation younger than 15 ka is evidenced by landslide deposits, caused by slope instability from volcano-tectonism, and by a high-angle erosional unconformity, formed in response to a base-level lowering. A stratigraphic analysis of the reworked deposits at the foot of the slopes allowed us to define both depositional mechanisms and sedimentation rates. The results of combined volcanological, geomorphological and engineering-geological studies permitted us to constrain and quantify past geological processes and hypothesis about the future evolution of the hill. Present-day slope processes on Camaldoli Hill are largely controlled by the presence of weathered and reworked deposits, whose nature and thickness have been analysed and mapped in detail. Four main kinds of slope processes have been recognized: falls and toppling failures from NYT; small-scale slides in the weathered and pedogenized loose cover; mixed events, represented by slides evolving to hyperconcentrated flows, mud flows and debris flows; and areal and linear erosion. Consequently, a high number of mass movements not previously documented have been mapped. At the same time, an insight into the sedimentation rate due to the overall slope processes, covering a time-span of about 5 ka, was given. Some final considerations regarding landslide hazard are presented in the context of the most suitable remedial works.

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

2007-06-01

115

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

116

Water quality mapping and assessment, and weathering processes of selected aflaj in Oman.  

PubMed

There are more than 4,000 falaj (singular of a peculiar dug channel) distributed in different regions in Oman. The chemical characteristics of the water in 42 falaj were studied to evaluate the major ion chemistry; geochemical processes controlling water composition; and suitability of water for drinking, domestic, and irrigation uses. GIS-based maps indicate that the spatial distribution of chemical properties and concentrations vary within the same region and the different regions as well. The molar ratios of (Ca + Mg)/Total cations, (Na + K)/Total cations, (Ca + Mg)/(Na + K), (Ca + Mg)/(HCO? + SO?), and Na/Cl reveal that the water chemistry of the majority of aflaj are dominated by carbonate weathering and evaporite dissolution, with minor contribution of silicate weathering. The concentrations of most of the elements were less than the permissible limits of Omani standards and WHO guidelines for drinking water and domestic use and do not generally pose any health and environmental problems. Some aflaj in ASH Sharqiyah and Muscat regions can be used for irrigation with slight to severe restriction because of the high levels of electrical conductivity, total dissolved solids, chloride, and sodium absorption ratio. PMID:21210214

Ghrefat, Habes Ahmad; Jamarh, Ahmad; Al-Futaisi, Ahmed; Al-Abri, Badr

2011-01-06

117

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

118

Physical conditions for the r-process  

SciTech Connect

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

Wanajo, S.; Tachibana, T.; Goriely, S. [Technische Universitaet Muenchen, Excellence Cluster Universe, Boltzmannstr. 2, D-85748 Garching and Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Senior High School of Waseda University, Nerima, Tokyo 177-0044 (Japan); Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium)

2012-11-12

119

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

120

Sandstone weathering processes damaging prehistoric rock paintings at the Albarracin Cultural Park, NE Spain  

NASA Astrophysics Data System (ADS)

The rock paintings in cliff-foot caves of the Albarracin Cultural Park are known as some of the most important evidences of the Levantine prehistoric art of Spain (8000 3000 BP). The paintings are on sandstone (Buntsandstein facies) of Triasic age, which may develop intense weathering. The analysis of the variables controlling the weathering indicate that salt and wetting-drying weathering are responsible for granular disintegration and flaking, which lead to rock painting deterioration.

Benito, G.; Machado, M. J.; Sancho, C.

1993-09-01

121

Analyzing the Role of Biofilm in Weathering Processes in the Rhizosphere with Various Microscopic Techniques  

NASA Astrophysics Data System (ADS)

Biofilm is thought to have a significant role in biological weathering of minerals in the rhizosphere (root systems). The goal of our study is to examine the characteristics of rhizospheric biofilms under a range of base cation limitations and determine the best microscopic techniques to analyze the biofilm-microbe-fungus-mineral interface. We hypothesized that tree-fungus-bacteria association increases biofilm formation under severe base cation limitations that enhance mineral weathering rate and improve potassium and calcium retention and transport to the trees. Our hypothesis was tested in samples from a growth column experiment. Red pine (Pinus resinosa) trees were grown in leach tubes in quartz sand amended with 1 wt% biotite and anorthite. Half of the trees were inoculated with Suillus tomentosus and a group of soil bacteria, and the other half were left without microbial inoculation. Columns without any biology added served as controls. Calcium and potassium were supplied in irrigation water in 0, 30, 60 and 100% of an amount for healthy tree growth and the concentration of all other nutrients stayed constant in all solutions. After four weeks, the columns were destructively sampled and the root systems were analyzed by various microscopic techniques such as helium ion microscopy (HeIM), scanning electron microscopy (SEM) coupled with focused ion beam (FIB) and energy dispersive x-ray spectroscopy (EDS), cryo-SEM, and high resolution transmission electron microscopy (TEM) also coupled with EDS. These techniques were employed to collect the most information about the biofilm-microbe-fungus-mineral interface. The HeIM uses a beam of helium ions to produce 3-D high resolution images with greater depth of field than SEM and produces detailed surface topography results. The SEM coupled with EDS gives detailed chemical distribution of elements on a surface topography. The SEM coupled with FIB produces a cross-section of the analyzed material and allows a view inside of the sample. It also allows preparing a thin section of a selected area, which could be transferred to the TEM for correlative imaging and analyses providing high resolution structural and chemical information of the biofilm-microbe-fungus-mineral interface. Using cryo-SEM complements the above results with preserving the specimen in its real, hydrated state that allows the characterization of the original topography and cross-section. The combinations of these state-of-the-art techniques shed new light on the characteristics of biofilm-microbe-fungus-mineral interface and provide information about weathering processes, rates, and base cation immobilization in soils.

Niedziela, S.; Greenberg, K. A.; Dohnalkova, A.; Arey, B.; Balogh-Brunstad, Z.

2011-12-01

122

Process of Physical Fitness Standards Development.  

National Technical Information Service (NTIS)

This State-of-the-Art Report (SOAR) documents the methods, processes, and issues that are involved with the development of physical fitness standards with special reference to the military. There has been a long-standing interest in standards for individu...

B. Palmer S. Constable

2000-01-01

123

Statistical physics of media processes: Mediaphysics  

Microsoft Academic Search

The processes of mass communications in complicated social or sociobiological systems such as marketing, economics, politics, animal populations, etc. as a subject for the special scientific subbranch—“mediaphysics”—are considered in its relation with sociophysics. A new statistical physics approach to analyze these phenomena is proposed. A keystone of the approach is an analysis of population distribution between two or many alternatives:

Dmitri V. Kuznetsov; Igor Mandel

2007-01-01

124

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

125

Yellowstone Weather  

NSDL National Science Digital Library

Yellowstone National Park's high altitude and mountainous terrain makes weather prediction very difficult. This website provides seasonal weather information, average temperature and precipitation data, links to weather forecasts, and other weather links.

Park, Yellowstone N.

126

Day Length and Weather Effects on Children's Physical Activity and Participation in Play, Sports, and Active Travel  

PubMed Central

Background Children in primary school are more physically active in the spring/summer. Little is known about the relative contributions of day length and weather, however, or about the underlying behavioral mediators. Methods 325 British children aged 8 to 11 wore accelerometers as an objective measure of physical activity, measured in terms of mean activity counts. Children simultaneously completed diaries in which we identified episodes of out-of-home play, structured sports, and active travel. Our main exposure measures were day length, temperature, rainfall, cloud cover, and wind speed. Results Overall physical activity was higher on long days (? 14 hours daylight), but there was no difference between short (< 9.5 hours) and medium days (10.2–12.6 hours). The effect of long day length was largest between 5 PM and 8 PM, and persisted after adjusting for rainfall, cloud cover, and wind. Up to half this effect was explained by a greater duration and intensity of out-of-home play on long days; structured sports and active travel were less affected by day length. Conclusions At least above a certain threshold, longer afternoon/evening daylight may have a causal role in increasing child physical activity. This strengthens the public health arguments for daylight saving measures such as those recently under consideration in Britain.

Goodman, Anna; Paskins, James; Mackett, Roger

2013-01-01

127

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

128

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

129

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

130

Isotopic tracers of chemical weathering and consequences for marine geochemical budgets  

Microsoft Academic Search

The mechanical breakdown of rock by physical weathering exerts a significant control on chemical weathering rates because it produces surface area. During periods of icehouse conditions on Earth, the grinding of rock by glacial processes should lead to faster chemical weathering of the continents, perhaps particularly during periods of pronounced climatic variability, like the Quaternary. Evidence is reviewed here for

D. Vance

2011-01-01

131

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

132

Commercializing Space Weather using GAIM  

NASA Astrophysics Data System (ADS)

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

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

133

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

134

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

Microsoft Academic Search

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

K. Yoo

2007-01-01

135

River dissolved and solid loads in the Lesser Antilles: New insight into basalt weathering processes  

Microsoft Academic Search

We present here the first available estimations of chemical weathering and associated atmospheric CO2 consumption rates as well as mechanical erosion rate for the Lesser Antilles. The chemical weathering (100–120 t\\/km2\\/year) and CO2 consumption (1.1–1.4×106 mol\\/km2\\/year) rates are calculated after subtraction of the atmospheric and hydrothermal inputs in the chemical composition of the river dissolved loads. These rates thus reflect

Sétareh Rad; Pascale Louvat; Caroline Gorge; Jérôme Gaillardet; Claude Jean Allègre

2006-01-01

136

Free electron laser physical process code (FELPPC)  

SciTech Connect

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

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

1995-02-01

137

Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization  

Microsoft Academic Search

In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol

Ghaleb N. Salaita; Frank M. S. Ma; Trudy C. Parker; Gar B. Hoflund

2008-01-01

138

Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization  

NASA Astrophysics Data System (ADS)

In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol (PEG) products including PEG PLUS™, PEG 8000 solutions and Compound 20M in varying concentrations. All contained the wood preservative chromated copper arsenate (CCA). One sample was treated with a CCA solution only. The treatments were carried out at 20 °C and 150 psig for 1/2 h after exposure to vacuum (28 mmHg) for 15 min. Simulated weathering was achieved in an Atlas 65-W Weather-Ometer for 2000 h with both light and dark periods and rain. The temperature ranged from 23 °C during the dark cycle to 35 °C during the light cycle. With weathering the XPS O/C ratios increase due to oxidation of the surface. Exposure to UV light results in bond breakage and reaction with oxygen in the presence of air to form organic functional groups such as ?, ?, C dbnd O and/or O-C-O. These oxidized products can protect the underlying wood from deterioration if they are insoluble in water and remain on the surface as a protective coating. If soluble, rain washes the compounds away and assists in the degradation. Correlated changes are observed in the XPS O/C ratios, the high-resolution XPS C 1s spectra, the SEM micrographs and physical measurements including thickness alteration, weight loss, and discoloration by yellowing or whitening of the weathered wood. The PEG treatments are effective in protecting wood with the 2% PEG PLUS treatment providing the best weathering behavior similar to that of the CCA treatment. The WR and water treatments yield the poorest weathering properties.

Salaita, Ghaleb N.; Ma, Frank M. S.; Parker, Trudy C.; Hoflund, Gar B.

2008-04-01

139

Studying the Space Weather Features of the High-Latitude Ionosphere by Using a Physics-Based Data Assimilation Model and Observational Data from Ground Magnetometer Arrays  

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. Presently, most of the space-weather models use limited observations and/or indices to define a set of empirical drivers for physical models to move forward in time. Since the empirical drivers have a "climatological" nature and there are significant physical inconsistencies among various empirical drivers due to independent statistical analysis of different observational data, the specifications of high-latitude space environment from these space weather models cannot truthfully reflect the weather features. In fact, unrealistic small- and large-scale structures could be produced in the specifications and forecasts from these models. We developed a data assimilation model for the high-latitude ionospheric plasma dynamics and electrodynamics to overcome these hurdles. With a set of physical models and an ensemble Kalman filter, the data assimilation model can determine the self-consistent structures of the high-latitude convection electric field, ionospheric conductivity, and the key drivers associated with these quantities by ingesting data from multiple observations. These ingested data include 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. As a result, the assimilation model can capture the small- and large-scale plasma structures and sharp electrodynamic boundaries, thus, can provide a more accurate picture of the high-latitude space weather. In this presentation, we will first briefly describe the data-assimilation model of high-latitude electrodynamics and its strengths over the other space-weather models. Then we will present the space weather features produced by the model for quiet and storm periods constrained by the data from ground magnetometer arrays. This will demonstrate the dynamic variability of the high-latitude ionosphere. Finally, we will present high-resolution ionospheric modeling results of the time-evolution and spatial features of the high-latitude plasma structures to further demonstrate the model's capability in producing the space weather features in the high-latitude ionosphere. These results will illuminate the importance of real-time data availability and data assimilation models for accurate specification and forecasting of space weather.

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

2011-12-01

140

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

141

Thermal Weathering on Airless Planetary Surfaces  

Microsoft Academic Search

All airless planetary surfaces in our Solar System appear to be covered by a regolith layer. There are several general processes that could form such a regolith layer, including the rain of impactors on the surface, mass wasting, sublimation degradation, and physical weathering by thermal changes. Several of these processes have been well studied on icy satellites [e.g. Moore et

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

2009-01-01

142

Multi-PRI Signal Processing for the Terminal Doppler Weather Radar. Part II: Range–Velocity Ambiguity Mitigation  

Microsoft Academic Search

Multiple pulse-repetition interval (multi-PRI) transmission is part of an adaptive signal transmission and processing algorithm being developed to combat range-velocity (RV) ambiguity for the Terminal Doppler Weather Radar (TDWR). In Part I of this two-part paper, an adaptive clutter filtering procedure that yields low biases in the moments estimates was presented. In this part, algorithms for simultaneously providing range-overlay protection

John Y. N. Cho

2005-01-01

143

Impact of weathering on the geomechanical properties of rocks along thermal–metamorphic contact belts and morpho-evolutionary processes: The deep-seated gravitational slope deformations of Mt. Granieri–Salincriti (Calabria– Italy)  

Microsoft Academic Search

Numerous Deep-Seated Gravitational Slope Deformations (DSGSDs) occur throughout Italy, that originate from particular tectono-stratigraphic settings, relief, seismicity, deglaciation, as well as from intense and deep processes of chemico-physical weathering of crystalline–metamorphic rocks. These DSGSDs are particularly widespread in the Calabrian mountains. This study is focused on the Mt. Granieri–Salincriti slope, on the Ionian side of the Serre Massif, where granites

A. Pellegrino; A. Prestininzi

2007-01-01

144

Advances in Doppler Weather Radar Observing Methods and Data Processing Techniques.  

National Technical Information Service (NTIS)

A continuing objective of the Navy-sponsored, Doppler radar studies has been to develop the operational utility of the radar, both as a weather research tool and as an observing instrument useful for specialized, short-term forecasting. To fill this role ...

C. C. Easterbrook

1971-01-01

145

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

146

Salt-induced alveolar weathering of rhyolite tuff on a building: causes and processes  

Microsoft Academic Search

Studies of stone texture and spatial distribution of soluble salts were carried out at the historical façade of the church of St. Kunigunden in Rochlitz in order to explain the occurrence of alveolar weathering on the building stone, a local rhyolithe tuff. The rhyolithe tuff contains lapilli inclusions with porosities and water uptake quite different to those of the stone

Heiner Siedel

147

Paleopedological reconstruction and quantitative analysis of weathering processes in the Southern Piedmont Province  

Microsoft Academic Search

Soils and paleosols are commonly used to estimate ages of deposits and geomorphic surfaces, and to infer paleoenvironmental conditions during pedogenesis. Accurate interpretation of these and other parameters is currently limited, however, by considerable uncertainty in many fundamental areas of soils-geomorphic research. These include: (1) lack of accurate estimates of weathering rates for reliably-dated surfaces, (2) inability to quantitatively differentiate

S. B. Feldman; L. W. Zelazny; M. J. Pavich

1992-01-01

148

Investigation of pyrite-weathering processes in the vadose zone using optical oxygen sensors  

Microsoft Academic Search

Pyrite weathering in the unsaturated zone of overburden material was investigated in column experiments. Optodes were used to monitor changes in oxygen concentrations. Oxygen recharge in the vadose zone and effects of secondary reactions were investigated. Oxygen transport limits thickness and the rate of the depyritisation. The overburden material (thickness 0.6 m, initial pyrite content 1.2 wt%) was depyritised within

H. Hecht; M. Kölling

2002-01-01

149

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

150

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

151

Physical processes in collapse driven supernova  

SciTech Connect

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

Mayle, R.W.

1985-11-01

152

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

153

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

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 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

155

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

156

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…

Forde, Evan B.

2004-01-01

157

SWIFF: Space weather integrated forecasting framework  

NASA Astrophysics Data System (ADS)

SWIFF is a project funded by the Seventh Framework Programme of the European Commission to study the mathematical-physics models that form the basis for space weather forecasting. The phenomena of space weather span a tremendous scale of densities and temperature with scales ranging 10 orders of magnitude in space and time. Additionally even in local regions there are concurrent processes developing at the electron, ion and global scales strongly interacting with each other. The fundamental challenge in modelling space weather is the need to address multiple physics and multiple scales. Here we present our approach to take existing expertise in fluid and kinetic models to produce an integrated mathematical approach and software infrastructure that allows fluid and kinetic processes to be modelled together. SWIFF aims also at using this new infrastructure to model specific coupled processes at the Solar Corona, in the interplanetary space and in the interaction at the Earth magnetosphere.

Lapenta, Giovanni; Pierrard, Viviane; Keppens, Rony; Markidis, Stefano; Poedts, Stefaan; Šebek, Ond?ej; Trávní?ek, Pavel M.; Henri, Pierre; Califano, Francesco; Pegoraro, Francesco; Faganello, Matteo; Olshevsky, Vyacheslav; Restante, Anna Lisa; Nordlund, Åke; Trier Frederiksen, Jacob; Mackay, Duncan H.; Parnell, Clare E.; Bemporad, Alessandro; Susino, Roberto; Borremans, Kris

2013-02-01

158

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

PubMed

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

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

2012-11-19

159

UM Weather  

NSDL National Science Digital Library

Sponsored by The Weather Underground at the University of Michigan at Ann Arbor, UM Weather bills itself as the "Internet's premier source of weather information." The site offers several general audience tools such as the Fast Forecast for any city in the US, ski weather, and weather cams. But, it also provides access to over two dozen weather software packages, a new computer model forecasts page, and most impressively a list of close to 400 other weather related Web sites. Professionals and researchers will appreciate the non-technical feel of the site and the valuable information they can procure from it.

1994-01-01

160

Weather Predictions  

NSDL National Science Digital Library

Students will use the internet to learn about weather and play games enhancing their knowledge and interest. Using the knowledge they learned students will write out their prediction of their next 5 days of weather. Intro Task Resources Evaluation Conclusion Teacher Guide Intro Look at the current weather forecast-Click here Current Weather-CNN Task Search for information about what causes different kinds of weather and what instruments people use to predict weather. What is a person called who predicts weather? Resources Resource 1 Resource 2 Resource 3 Resource 4 Resource 5 Resource 6 Evaluation Rubric Conclusion After researching, create your ...

Burr, Miss

2009-03-27

161

Weather & Weather Maps. Teacher's Manual.  

ERIC Educational Resources Information Center

This guide is intended to provide an opportunity for students to work with weather symbols used for reporting weather. Also included are exercises in location of United States cities by latitude and longitude, measurement of distances in miles and kilometers, and prediction of weather associated with various types of weather fronts. (RE)

Metro, Peter M.; Green, Rachel E.

162

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

163

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

NASA Astrophysics Data System (ADS)

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 but potentially high magnitude events or ‘exceptional’ factors (for example, lime rendering, severe frost events, fire). The impact of complex histories on the decay pathways of historic sandstone is not clearly understood, but this paper seeks to improve that understanding through the use of a laboratory ‘process combination’ study. Blocks of quartz sandstone (Peakmoor, from NW England) were divided into subsets that experienced different histories (lime rendering and removal, fire and freeze-thaw cycles in isolation and combination) that reflected the event timeline of a real medieval sandstone monument in NE Ireland, Bonamargy Friary (McCabe et al. 2006b). These subsets were then subject to salt weathering cycles using a 10% salt solution of NaCl and MgSO4 that represents the ‘every-day’ stress environment of, for example, sandstone structures in coastal, or polluted urban, location. Block response to salt weathering was monitored by collecting, drying and weighing the debris that was released as blocks were immersed in the salt solution at the beginning of each cycle. The results illustrate the complexity of the stone decay system, showing that seemingly small variations in stress history can produce divergent response to salt weathering cycles. Applied to real-world historic sandstone structures, this concept may help to explain the spatial and temporal variability of sandstone response to background environmental factors on a single façade, and encourage conservators to include the role of stress inheritance when selecting and implementing conservation strategies.

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

2007-03-01

164

Humps and hollows: basalt weathering in low-latitude mountains  

NASA Astrophysics Data System (ADS)

Physical, chemical and biological weathering processes are significant contributors to landscape development in mountain blocks worldwide, and over long time scales, but the interplay between different weathering processes is uncertain. Jurassic-age basalt lava flows underlie the Drakensberg mountain range of eastern Lesotho, southern Africa (summits 3200-3400 m asl), and weathered bedrock is commonly exposed on flat plateau surfaces. Subaerial weathering throughout the Quaternary and Holocene has resulted in a range of weathering forms, some of which exploit pre-existing cooling fractures within the basalts, and some of which are independent of geological control. These forms include pseudokarst-style potholes, karren and other microforms. The geometry, chemistry of water contained within the potholes, seasonal presence of ice, sediment and organic residues all suggest that physical, chemical and biological weathering processes are significant at different times and in different ways in subaerial weathering. Moreover, it is also likely that these process-types show pronounced seasonal variability that means that the interplay between different processes is subtle. Aggregated rates of land surface denudation or geomorphic development of single landforms therefore hide this subtle interplay between different processes. Changes in mountain summit soil depth (through soil erosion), ecosystems and climate will change this balance between different processes, and will operate over different spatial and temporal scales.

Knight, Jasper; Grab, Stefan

2013-04-01

165

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

166

Proton computed tomography from multiple physics processes.  

PubMed

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

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

2013-09-27

167

Statistical physics of media processes: Mediaphysics  

NASA Astrophysics Data System (ADS)

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

Kuznetsov, Dmitri V.; Mandel, Igor

2007-04-01

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

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

170

Impacts of natural weathering on the transformation/neoformation processes in landfilled MSWI bottom ash: a geoenvironmental perspective.  

PubMed

Natural weathering processes are significant mechanisms that noticeably affect the fundamental nature of incineration ash residues. To provide a greater understanding of these processes, a MSWI (mono)landfill site in the north east of the US was selected as the target for systematic investigation of the natural weathering of bottom ash residues. Samples of various ages were collected from locations A (1 yr), B (10 yrs), C (13-14 yrs) and D (20 yrs) of the landfill in 2009. We investigated the phase transformation of the collected bottom ash particles, neoformation processes as well as the behavior and distribution of certain heavy metals (Cu, Pb, Zn, Ni, and Cr) in the neoformed phases using optical microscopy, SEM-EDX, and bulk examinations. Key findings: at the preliminary stage, the waste metallic particles (Al, Fe, and Cu) and unstable minerals such as lime, portlandite, ettringite and hydrocalumite convert to oxide and hydroxide (hydrate) phases, calcite, alumina gel and gypsum. At the intermediate stage, the decomposition of melt products including magnetite spinels and metallic inclusions is triggered due to the partial dissolution of the melt glass. At the longer time horizon it is possible to track the breakdown of the glass phase, the extensive formation of calcite and anhydrite, Al-hydrates and more stable Fe-hydrates all through the older ash deposits. Among the dominant secondary phases, we propose the following order based on their direct metal uptake capacity: Fe-hydrates>Al-hydrates>calcite. Calcite was found to be the least effective phase for the direct sorption of heavy metals. Based on overall findings, a model is proposed that demonstrates the general trend of ash weathering in the landfill. PMID:21873042

Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Wei, Yunmei; Gardner, Kevin H; Musselman, Craig N

2011-08-27

171

The Space Weather Reanalysis  

NASA Astrophysics Data System (ADS)

The objective of this project is to generate a complete 11 year space weather representation using physically consistent data-driven space weather models. The project will create a consistent, integrated historical record of the near Earth space environment by coupling observational data from space environmental monitoring systems archived at NGDC with data-driven, physically based numerical models. The resulting product will be an enhanced look at the space environment on consistent grids, time resolution, coordinate systems and containing key fields allowing an interested user to quickly and easily incorporate the impact of the near-Earth space climate in environmentally sensitive models. Currently there are no easily accessible long term climate archives available for the space-weather environment. Just as with terrestrial weather it is crucial to understand both daily weather forecasts as well as long term climate changes, so this project will demonstrate the ability to generate a meaningful and physically derived space weather climatology. The results of this project strongly support the DOD's Environmental Scenario Generator (ESG) project. The ESG project provides tools for intellegent data mining, classification and event detection which could be applied to a historical space-weather database. The two projects together provide a suite of tools for the user interested in modeling the effect of the near-earth space environment. We will present results and methodologies developed during the first two years of effort in the project.

Kihn, E. A.; Ridley, A. J.; Zhizhin, M.

2002-12-01

172

Weather Watchers  

NSDL National Science Digital Library

In this lesson, students learn how meteorologists measure the weather by examining some online, real-time data resources and collaborating to create an in-class weather station that tracks local weather patterns for one week. Students compare this information to weather patterns in two other locations. After completing this lesson, students should be able to explain ways that meteorologists measure and predict weather and use the Internet to research information about weather conditions in various locations in the United States, including their hometown. Students will also collaborate on creating some weather-measurement instruments and keep a weather journal for one week. This site provides an overview of the lesson, detailed procedures for the teacher, including a list of research sites, and an organizational path for students.

173

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.

174

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.

175

Waste glass weathering  

Microsoft Academic Search

The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared

J. K. Bates; E. C. Buck

1993-01-01

176

Physical Processes in Electromagnetic Shock Tubes.  

National Technical Information Service (NTIS)

The monograph deals with experimental research into the physical properties of plasma behind powerful shock waves arising during a powerful impulse discharge. The results are presented of experimental studies of the structure of the luminosity front in el...

Y. V. Makarov E. K. Chekalin

1970-01-01

177

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

178

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. The National Weather Service (NWS)--which is part of NOAA and its parent agency, the Department of Commerce--is charged with the critical responsibility of observing and reporting the weather and with issuing forecasts and warnings of weather and floods in the interest of national safety and economy. Through a massive network of weather-monitoring and reporting stations around the globe, including land, sea, air, and space-borne instruments, NWS scientists constantly assimilate all of the reliable weather data available. Much of this data are then used in numerical computer models of the atmosphere that help to accurately describe and interpret current conditions and produce the best possible forecasts of future weather.

Forde, Evan B.

2004-04-01

179

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

ERIC Educational Resources Information Center

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

Nakashian, Mary

2008-01-01

180

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

PubMed

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. PMID:11542259

Bishop, J L; Froschl, H; Mancinelli, R L

1998-12-25

181

Space Weather: Where Is The Beef?  

NASA Astrophysics Data System (ADS)

Space weather has become a highly fashionable topic in solar-terrestrial physics. It is perhaps the best tool to popularise the field and it has contributed significantly to the dialogue between solar, magnetospheric, and ionospheric scientist, and also to mu- tual understanding between science and engineering communities. While these are laudable achievements, it is important for the integrity of scientific space weather re- search to recognise the central open questions in the physics of space weather and the progress toward solving them. We still lack sufficient understanding of the solar physics to be able to tell in advance when and where a solar eruption will take place and whether it will turn to a geoeffective event. There is much to do to understand ac- celeration of solar energetic particles and propagation of solar mass ejecta toward the Earth. After more than 40 years of research scientific discussion of energy and plasma transfer through the magnetopause still deals mostly with qualitative issues and the rapid acceleration processes in the magnetosphere are not yet explained in a satisfac- tory way. Also the coupling to the ionosphere and from there to the strong induction effects on ground is another complex of research problems. For space weather science the beef is in the investigation of these and related topics, not in marketing half-useful space weather products to hesitant customers.

Koskinen, H. E. J.

182

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

183

Bell Labs - Physical Sciences - Silicon Processing Introduction  

NSDL National Science Digital Library

This website includes a description of silicon processing from Bell Laboratories. Silicon chips are prepared by an elaborate sequence of processing steps applied to a silicon wafer. Keywords: Patterning, implantation, oxidation, metallization, photoresist

2012-12-20

184

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

185

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

PubMed

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

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

2012-02-19

186

Impact of bacterial and fungal processes on 14C-hexadecane mineralisation in weathered hydrocarbon contaminated soil.  

PubMed

In this study, the impact of bacterial and fungal processes on (14)C-hexadecane mineralisation was investigated in weathered hydrocarbon contaminated soil. The extent of (14)C-hexadecane mineralisation varied depending on the bioremediation strategy employed. Under enhanced natural attenuation conditions, (14)C-hexadecane mineralisation after 98 days was 8.5 ± 3.7% compared to <1.2% without nitrogen and phosphorus additions. (14)C-hexadecane mineralisation was further enhanced through Tween 80 amendments (28.9 ± 2.4%) which also promoted the growth of a Phanerochaete chyrsosporium fungal mat. Although fungal growth in weathered hydrocarbon contaminated soil could be promoted through supplementing additional carbon sources (Tween 80, sawdust, compost, pea straw), fungal (14)C-hexadecane mineralisation was negligible when sodium azide was added to soil microcosms to inhibit bacterial activity. In contrast, when fungal activity was inhibited through nystatin additions, (14)C-hexadecane mineralisation ranged from 6.5 ± 0.2 to 35.8 ± 3.8% after 98 days depending on the supplied amendment. Bacteria inhibition with sodium azide resulted in a reduction in bacterial diversity (33-37%) compared to microcosms supplemented with nystatin or microcosms without inhibitory supplements. However, alkB bacterial groups were undetected in sodium azide supplemented microcosms, highlighting the important role of this bacterial group in (14)C-hexadecane mineralisation. PMID:22154183

Adetutu, Eric M; Ball, Andy S; Weber, John; Aleer, Samuel; Dandie, Catherine E; Juhasz, Albert L

2011-12-07

187

Weathering of rocks induced by lichen colonization — a review  

Microsoft Academic Search

The evidence presented by numerous investigations of the interface between lichens and their rock substrates strongly suggests that the weathering of minerals can be accelerated by the growth of at least some lichen species. The effects of lichens on their mineral substrates can be attributed to both physical and chemical processes. The physical effects are reflected by the mechanical disruption

Jie Chen; Hans-Peter Blume; Lothar Beyer

2000-01-01

188

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

189

Using Forecasting to Teach Weather Science  

NASA Astrophysics Data System (ADS)

Weather affects our lives and hence, is a popular topic in daily conversations and in the media. Therefore, it is not only important to teach weather, but is also a good idea to use 'weather' as a topic in science teaching. Science education has two main objectives: to acquire scientific concepts and methods. Weather forecasting is an adequate theme to teach scientific methods because it is dependent on observation. However, it is not easy to forecast weather using only temporal observation. We need to know the tendency of 'weather change' via consecutive and/or continuous weather observation. Students will acquire scientific-observation skills through weather observation. Data-processing skills would be enhanced through a weather-forecasting contest. A contest should be announced within 5 days of school events, such as a school excursion and field day. Students submit their own weather forecast by gathering weather information through the internet, news paper and so on. A weather-forecasting contest compels the student to observe the weather more often. We currently have some different weather forecasts. For example, American weather-related companies such as ACCU weather and Weather Channel provide weather forecast for the many locations all over the world. Comparing these weather forecasting with actual weather, participants such as students could evaluate the differences between forecasted and actual temperatures. Participants will judge the best weather forecast based on the magnitude of the difference. Also, participants evaluate the 'hitting ratio' of each weather forecast. Students can learn elementary statistics by comparing various weather forecasts. We have developed our weather web-site that provides our own weather forecasting and observation. Students acquire science skills using our weather web-site. We will report our lessen plans and explain our weather web-site.

Tsubota, Y.; Takahashi, T.

2009-09-01

190

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.

191

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

192

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

193

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.

194

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

195

Weather Data  

NSDL National Science Digital Library

The listed websites are recommended safe kid friendly sites that may be used when gathering data for the at home data project. Use the websites listed to learn more about daily weather patterns in different cities around the world. After you have collected and organized your data, create a graph representing the different weather patterns in that city. Use this site to record the daily high temperature for your assigned city. The Weather Channel Use this ...

Harris, Ms.

2011-01-24

196

Impact of weathering on the geomechanical properties of rocks along thermal metamorphic contact belts and morpho-evolutionary processes: The deep-seated gravitational slope deformations of Mt. Granieri Salincriti (Calabria Italy)  

NASA Astrophysics Data System (ADS)

Numerous Deep-Seated Gravitational Slope Deformations (DSGSDs) occur throughout Italy, that originate from particular tectono-stratigraphic settings, relief, seismicity, deglaciation, as well as from intense and deep processes of chemico-physical weathering of crystalline metamorphic rocks. These DSGSDs are particularly widespread in the Calabrian mountains. This study is focused on the Mt. Granieri Salincriti slope, on the Ionian side of the Serre Massif, where granites and granodiorites (Stilo Unit, Palaeozoic) are in contact with metamorphites through a thermal metamorphic aureole. This setting generates deep geochemical processes, inducing intense chemical weathering. These processes are mainly due to the interaction between groundwater and the sulphides that are contained in the local pegmatitic hydrothermal intrusions, especially along the thermal metamorphic contact belt. The Mt. Granieri Salincriti slope has an important DSGSD, which is associated with many active and/or quiescent landslides. Among these landslides, the Salincriti rock avalanche-debris flow (about 2 M m3) represents the paroxysmal and terminal stage of the deep creep deformations of Mt. Granieri, typifying a geological setting that is common in the Calabrian Arc. This multi-disciplinary study assessed the weathering susceptibility of the local crystalline metamorphic rocks, especially those lying along thermal metamorphic contact belts, by characterising the weathering horizons and the spatial distribution of weathering in the rock mass. The study was also aimed at identifying the relations between weathering, above all deep geochemical processes, effects on rocks and slope morphodynamics. The methodology was based on detailed geological data, geological engineering surveys, geomorphology and surface hydrogeology analyses, as well as physico-mechanical laboratory tests. These investigations, supported by a monitoring program, led to the development of an engineering geological model of the slope. Geological character (attributed to a thermal metamorphic contact belt), geomorphological evidence and geomechanical elements elucidated the interactions between deep geochemical processes and weak belts in the investigated rocks, as well as the critical role that these interactions play in the evolution of deep-seated creep deformations and associated shallow landslides.

Pellegrino, A.; Prestininzi, A.

2007-06-01

197

Mesoscale severe weather development under orographic influences  

NASA Astrophysics Data System (ADS)

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

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

1986-07-01

198

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

199

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...

200

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

Microsoft Academic Search

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

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

2004-01-01

201

Rock-weathering by lichens in Antarctic: patterns and mechanisms  

Microsoft Academic Search

Saxicolous species of lichens are able to induce and accelerate weathering of their rock substrate, and effects of lichens\\u000a on substrate can be attributed to both physical and chemical causes. This paper is focused on biotic weathering actions of\\u000a epilithic and endolithic species on the different rock types (sandstones and volcanogenic rocks) in Antarctica. The patterns,\\u000a mechanisms, processes and neoformations

Chen Jie; Hans-Peter Blume

2002-01-01

202

The Weathering Behavior of Heavy Metals in Ore Processing Residues (Mansfeld Region, Germany)  

Microsoft Academic Search

.   One of the ore processing residues in the Mansfeld region of Germany is a flue dust, which was scrubbed out of the smelter\\u000a process gases by spraying water into the hot gas stream. During the many years of ore processing, the resulting fine-grained\\u000a sludge was washed into ponds for storage. These sludge deposits were covered by water and thus

M. Schubert; P. Morgenstern; R. Wennrich; K. Freyer; H. Weiss

2003-01-01

203

The influence of weathering processes on riverine magnesium isotopes in a basaltic terrain  

NASA Astrophysics Data System (ADS)

This study presents major-, trace-element and Mg isotope data for the dissolved load and suspended particulates of Icelandic rivers draining dominantly basaltic catchments, including both glacier-fed and direct-runoff rivers. These samples provide the opportunity to understand the behaviour of Mg isotopes during chemical weathering, where variations due to lithology are not extant. Given the significant role of Mg in the carbon cycle, such variations may provide important information on the regulation of Earth's climate. Hydrothermal waters, groundwater, precipitation (glacial ice), basalt glass, olivine and representative soils have also been analysed. The dissolved load shows a wide range of ?26Mg compositions, compared to the parent basaltic glass ( ?26Mg = - 0.29‰), ranging from - 0.96 to + 0.64‰, while precipitation and hydrothermal waters possess ?26Mg values of - 0.83‰ and + 0.85‰, respectively, with lower Mg concentrations than the dissolved load. Biomass activity in vegetation and organic material in soils and rivers (colloids) appear to have little effect on the Mg isotope compositions. Rather, the data suggest that Mg elemental and isotopic variations are largely controlled by the formation and stability of secondary phases in response to differing hydrological conditions. In some samples seawater, in the form of direct precipitation or glacial runoff, also appears to be an important source of Mg. Glacier-fed rivers, groundwaters, and some direct-runoff rivers, with a high pH, have higher ?26Mg than basalt, which is most likely due to the incorporation of light Mg isotopes in secondary minerals. In contrast, those direct-runoff rivers which have a relatively low pH, have low ?26Mg (relative to basalt), consistent with preferential incorporation of heavy Mg isotopes into secondary phases, although it is not possible to rule out some contribution from precipitation. Riverine suspended particulates are depleted in mobile elements, and have ?26Mg compositions values both higher and lower than unweathered basalt. In the glacier-fed and direct-runoff rivers where the ?26Mg of the dissolved phase is heavy, due to the formation of secondary phases, the suspended load is light, because it contains more of those phases. The opposite is true for the remainder of the direct-runoff rivers which have low pH. This could be due to dissolution of secondary minerals, enriched in light Mg, which are unstable at low pH, or the formation of new secondary phases.

Pogge von Strandmann, Philip A. E.; Burton, Kevin W.; James, Rachael H.; van Calsteren, Peter; Gislason, Sigurður R.; Sigfússon, Bergur

2008-11-01

204

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

205

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.

206

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

207

Process Ontology from Whitehead to Quantum Physics  

Microsoft Academic Search

Although Alfred North Whitehead probably did not know of the new quantum theory of Heisenberg, Schrodinger and Dirac, there seem to be deep similarities between his idea of the process and the ideas of quantum theory. Both Whitehead's metaphysics and quantum theory are theories of observations: The realities which quantum theory deals with are certain observations by scientists who use

Joachim Klose

2007-01-01

208

Multiplicative stochastic processes in statistical physics  

Microsoft Academic Search

For a large class of nonlinear stochastic processes with pure multiplicative fluctuations the corresponding time-dependent Fokker-Planck equation is solved exactly by means of analytic methods. We obtain a universal eigenvalue spectrum and the corresponding set of eigenfunctions.

A. Schenzle; H. Brand

1979-01-01

209

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.

210

Modelling the physical and chemical changes in roofing slate caused by weathering processes  

Microsoft Academic Search

This research identifies the changes which takes place in roofing slate due to natural exposure and tries to replicate these changes experimentally. Traditional methods of testing, used by the British and other national standards, concentrate on the properties of unweathered samples and give no information on the relative durability of the different slates. Instead of concentrating on the initial properties,

Joan Anne Walsh

2008-01-01

211

Modelling the physical and chemical changes in roofing slate caused by weathering processes  

Microsoft Academic Search

This research identifies the changes which takes place in roofing slate due to\\u000a natural exposure and tries to replicate these changes experimentally. Traditional methods\\u000a of testing, used by the British and other national standards, concentrate on the properties\\u000a of unweathered samples and give no information on the relative durability of the different\\u000a slates. Instead of concentrating on the initial properties,

Joan Anne Walsh

2008-01-01

212

The 2007 Space Weather Workshop  

NASA Astrophysics Data System (ADS)

The applications of space weather information are changing rapidly. New operating procedures at electric power facilities now take geomagnetic activity into account; the next-generation air transportation system could rely heavily on GPS navigation, which is susceptible to ionospheric disturbances; and satellite design, operation, and human space flight all demand accurate specification and prediction of space radiation. Our ability to meet these needs is improving. Our increased knowledge of the underlying physical processes in the solar-terrestrial environment, our improving numerical models, and new targeted data sources are enhancing our ability to specify and predict the important conditions in space.

Onsager, Terrance; Zwickl, Ron

2007-02-01

213

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

214

Quantum Speed Limit for Physical Processes  

NASA Astrophysics Data System (ADS)

The evaluation of the minimal evolution time between two distinguishable states of a system is important for assessing the maximal speed of quantum computers and communication channels. Lower bounds for this minimal time have been proposed for unitary dynamics. Here we show that it is possible to extend this concept to nonunitary processes, using an attainable lower bound that is connected to the quantum Fisher information for time estimation. This result is used to delimit the minimal evolution time for typical noisy channels.

Taddei, M. M.; Escher, B. M.; Davidovich, L.; de Matos Filho, R. L.

2013-02-01

215

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

216

Multiplicative stochastic processes in statistical physics  

Microsoft Academic Search

For a large class of nonlinear stochastic processes with pure multiplicative fluctuations the corresponding time-dependent Fokker-Planck-equation is solved exactly by analytic methods. A universal eigenvalue spectrum and the corresponding set of eigenfunctions are obtained in closed form. The eigenvalue spectrum consists of a discrete as well as a continuous part. To emphasize the significance of the model proposed for the

A. Schenzle; H. Brand

1979-01-01

217

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

218

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

219

Coupling physical processes in simulations of chemically reactive flows  

Microsoft Academic Search

The exact way the processes are coupled depends on the individual properties of the different algorithms used and the regimes in which the competing physical processes interact. In particular, we have found that the best form of the coupling to use varies according to whether the convection is treated by an implicit or explicit approach. Other processes may be done

E. S. Oran; J. P. Boris; K. Kailasanath; G. Patnaik

1989-01-01

220

Coupling physical processes in simulations of chemically reactive flows  

Microsoft Academic Search

The exact way the processes are coupled depends on the individual properties of the different algorithms used and the regimes in which the competing physical processes interact. In particular, we have found that the best form of the coupling to use varies according to whether the convection is treated by an implicit or explicit approach. Other processes may be done

E. Oran; J. Boris; K. Kailasanath; G. Patnaik

221

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

222

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

223

ERP differences between processing of physical characteristics and personality attributes  

PubMed Central

Background Limited data from behavioral and brain-imaging studies indicate that personality traits and physical characteristics are processed differently by the brain. Additionally, electrophysiological results of studies comparing the processing of positive and negative words have produced mixed results. It is therefore not clear how physical and personality attributes with emotional valence (i.e., positive and negative valence) are processed. Thus, this study aimed to examine the neural activity associated with words describing personality traits and physical characteristics with positive or negative emotional valence using Event Related Potentials (ERPs). Methods A sample of 15 healthy adults (7 men, 8 women) participated in a computerized word categorization task. Participants were asked to categorize visual word stimuli as physical characteristics or personality traits, while ERPs were recorded synchronously. Results Behavioral reaction times to negative physical stimuli were shorter compared to negative personality words, however reaction times did not significantly differ for positive stimuli. Electrophysiological results showed that personality stimuli elicited larger P2 and LPC (Late Positive Component) amplitudes compared to physical stimuli, regardless of negative or positive valence. Moreover, negative as compared with positive stimuli elicited larger P2 and LPC amplitudes. Conclusion Personality and physical stimuli were processed differently regardless of positive or negative valence. These findings suggest that personality traits and physical characteristics are differentially classified and are associated with different motivational significance.

2012-01-01

224

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

NASA Astrophysics Data System (ADS)

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

Brooks, Harold

2008-07-01

225

Operational, regional-scale, chemical weather forecasting models in Europe  

Microsoft Academic Search

Numerical models that combine weather forecasting and atmospheric chemistry are here referred to as chemical weather forecasting models. Eighteen operational chemical weather forecasting models on regional and continental scales in Europe are described and compared in this article. Topics discussed in this article include how weather forecasting and atmospheric chemistry models are integrated into chemical weather forecasting systems, how physical

J. Kukkonen; T. Balk; D. M. Schultz; A. Baklanov; T. Klein; A. I. Miranda; A. Monteiro; M. Hirtl; V. Tarvainen; M. Boy; V.-H. Peuch; A. Poupkou; I. Kioutsioukis; S. Finardi; M. Sofiev; R. Sokhi; K. Lehtinen; K. Karatzas; M. Astitha; G. Kallos; M. Schaap; E. Reimer; H. Jakobs; K. Eben

2011-01-01

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

Two-Photon Physics in Hadronic Processes  

SciTech Connect

Two-photon exchange contributions to elastic electron-scattering are reviewed. The apparent discrepancy in the extraction of elastic nucleon form factors between unpolarized Rosenbluth and polarization transfer experiments is discussed, as well as the understanding of this puzzle in terms of two-photon exchange corrections. Calculations of such corrections both within partonic and hadronic frameworks are reviewed. In view of recent spin-dependent electron scattering data, the relation of the two-photon exchange process to the hyperfine splitting in hydrogen is critically examined. The imaginary part of the two-photon exchange amplitude as can be accessed from the beam normal spin asymmetry in elastic electron-nucleon scattering is reviewed. Further extensions and open issues in this field are outlined.

Carl Carlson; Marc Vanderhaeghen

2007-11-01

228

Rates of Chemical Weathering  

NSDL National Science Digital Library

In this activity, students will investigate the weathering of rocks by chemical processes. They will use effervescent cleansing tablets as a model for rock, and vary surface area, temperature, and acidity to see how rapidly the "rock" dissolves. This investigation will help them understand three of the factors that affect the rate of chemical weathering and develop better understanding of how to design controlled experiments by exploring only one experimental variable at a time.

Passow, Michael

229

Simplified modeling of solar process heating systems using stochastic weather input  

Microsoft Academic Search

A model has been developed which accurately predicts solar district heating and industrial process heating collection performance on a daily basis. The model is system specific with no storage and constant load return temperature. This model was tested for its statistical significance and found to be highly significant. Performance data to construct the model were generated through numerous TRNSYS runs.

Boardman

1986-01-01

230

Slope processes in weathered volcaniclastic deposits within the city of Naples: The Camaldoli Hill case  

Microsoft Academic Search

We describe the slope processes acting on Camaldoli Hill, the main volcanic feature of the Neapolitan area whose geological evolution and setting have been reconstructed. The backbone of the hill includes the remnants of two partially superposed tuff cones, lying between the Campanian Ignimbrite (CI) and the Neapolitan Yellow Tuff (NYT). This sequence is mantled by pyroclastic, anthropogenic and epiclastic

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

2007-01-01

231

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

232

Overlooked sedimentary particles from tropical weathering environments  

Microsoft Academic Search

Two varieties of sedimentary particles that are common in tropical weathering environments have remained largely overlooked by sedimentary petrologists. Alterites are grains that have been so thoroughly altered by chemical weathering processes that identification of the precursor grain is impossible. They consist of secondary weathering products such as clays, zeolites, and iron sesquioxides, as well as incompletely weathered remains of

Mark J. Johnson

1990-01-01

233

Comparison between physical variables acquired by a new multiparametric platform, ELFO, and data calculated by a three-dimensional hydrodynamic model in different weather conditions at Tiber River mouth (Latium coast, Italy)  

NASA Astrophysics Data System (ADS)

The coastal ecosystem is characterized by high variability physical processes, which are strongly influenced by sudden changes in weather conditions. For this reason instruments able to collect data in a short time or mathematical models able to simulate the same phenomena from experimental data are basic. In this study in situ data are compared with data calculated by three-dimensional hydrodynamic model. The multiparametric platform was developed ad hoc by Laboratory of Experimental Oceanology and Marine Ecology (DECOS, Tuscia University) for coastal monitoring by small vessels (ELFO), and integrates temperature, conductivity, dissolved oxygen and suspended solids measures with bio-optical measures like fluorescence, photosynthetic efficiency and PAR. The hydrodynamic model is the three-dimensional coastal hydrodynamic DELFT3D-FLOW simulating processes of temperature and salinity diffusion and the transport of suspended sediment (cohesive and non cohesive) in the water column. This study analyses the area at mouth of Tiber river investigated by two surveys wiht different weather conditions. Data collected during the first survey were used to calibrate the DELFT3D-FLOW model which computational domain extends from the Argentario headland to Capo Anzio. A microscale wind field (resolution of about 7 km), provided by the atmospheric model COSMO-ME (developed by CNMCA of Aeronautica Militare, Italy), was used to reproduce the hydrodynamic field and the distribution of the physical variables of the whole period. In this way the data calculated by the model can be compared with those collected in situ during the second survey. Moreover dynamic phenomena existed between the two monitoring periods can be investigated.

Bonamano, Simone; Piermattei, Viviana; Marcelli, Marco; Peviani, Maximo

2010-05-01

234

Physical processes in the ROFI regime  

NASA Astrophysics Data System (ADS)

The distinctive feature of all ROFI (Regions Of Freshwater Influence) systems is the input of significant amounts of buoyancy as freshwater from river sources. If the spatial scale is unrestricted by coastal topography and stirring is weak, this input tends to drive a coast-parallel flow in which the Coriolis force constrains a wedge of low density water against the coastal boundary. Without frictional effects, this flow is subject to baroclinic instability which induces large meanders and eddies in the flow but in, many ROFIs, the tidal flow induces frictional effects which stabilise the density driven flow. In the absence of the effects of rotation and stirring, the buoyancy input tends to induce stratification through an estuarine circulation in the direction of the gradient. When stirring is applied, by the action of wind, waves or tidal flow, the density current is suppressed but is rapidly re-established when stirring ceases, as in the Linden-Simpson (1988) laboratory tank experiments. In real ROFI systems, a combination of all these processes operates so that the structure of the water column and the flow is the result of a competition between the stratifying influence of buoyancy input and the net stirring effect of the wind, waves and the tides. This competition is more difficult to analyse than the heating-stirring competition, because freshwater buoyancy input is not spatially uniform but enters at discrete sources along the coast and its subsequent spreading has to be determined. While the springs-neaps cycle in tidal stirring imposes a regular fortnightly modulation on vertical mixing, the influence of the wind is irregular and depends, not just on the magnitude of the stress, but also on the direction in which it acts. In some exposed shallow water situations there may also be significant stirring due to waves generated by non-local winds. ROFI systems are further complicated by the action of tidal straining in which differential advection, due to vertical shear in the tide, interacts with the density gradient to generate fluctuations in vertical stability at the tidal frequency which, in some cases, are of sufficient amplitude to switch the water column between stable stratification and vertical density homogeneity each tidal cycle. This straining along with the other ROFI processes have been incorporated into a series of 1-D models to provide a more objective test of the hypotheses about the mechanisms involved. Comparison of model hindcasts with observations indicate that we now have a first-order understanding of the complex behaviour of ROFIs. On a global scale it is clear that ROFIs represent an important component of the shelf-sea environment of particular concern in relation to the impact of pollutant discharges. To date, most studies of ROFI's have concentrated on systems in temperate latitudes but attention needs to be focused on the very extensive ROFIs in tropical regions where most of the world's river discharge enters the ocean. In monsoonal regions, these inputs exhibit strong seasonal modulation which may, in competition with tidal stirring, result in an annual cycle of stratification and the formation of fronts.

Simpson, J. H.

1997-08-01

235

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

236

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

237

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

238

Weather service upgrade too costly?  

NASA Astrophysics Data System (ADS)

America needs timely and accurate weather forecasting, said Ernest F. Hollings (D-S.C.), chairman of the Senate Committee on Commerce, Science, and Transportation on National Ocean Policy. Calling the existing warning and forecast system dangerously obsolete, Hollings said that new technology “should dramatically improve the accuracy and timeliness of weather predictions,” as we face the new challenge of bringing the National Weather Service into the 21st century. Hollings' committee heard testimony to consider the modernization of the NWS and pending legislation (S98, S916) on June 18.Major components of the Weather Service Modernization program, according to John A. Knauss, administrator of the National Oceanic and Atmospheric Administration, are the Next Generation Weather Radar (NEXRAD), a new generation of Geostationary Operational Environmental Satellites (GOES-NEXT), the Automated Surface Observing System (ASOS), and the Advanced Weather Interactive Processing System (AWIA). The best defense against severe weather—early warnings—is probably hampered by outdated equipment, he added.

Bush, Susan

239

Carbonate Beaches: A Balance Between Biological and Physical Processes  

Microsoft Academic Search

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

R. Nairn; M. Risk

2004-01-01

240

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

241

Physical Maturation and Information-Processing Speed in Middle Childhood.  

ERIC Educational Resources Information Center

Examined association of individual differences in physical maturation with information-processing speed among 9- and 10-year olds. Found that early maturers were faster than late matureres, although this maturity effect was primarily the result of a significant effect for boys. The early maturers' faster processing times may be specific to boys or…

Eaton, Warren O.; Ritchot, Kathryn F. M.

1995-01-01

242

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

243

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

244

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

245

Weathering of Oil at Sea.  

National Technical Information Service (NTIS)

A study was conducted to trace the fate of petroleum products discharged in the marine environment and to determine the magnitude of the more important weathering variables on the physical and chemical changes which occur. Six carefully selected oils, fou...

J. W. Frankenfeld

1973-01-01

246

Prototype Cold Weather Face Mask.  

National Technical Information Service (NTIS)

An improved cold weather face mask has been developed which should provide protection from cold, wind, blowing snow, and frostbite in environments to -65F and 35 mph wind velocities. The mask provides physical compatibility with military clothing and equi...

D. Mangelsdorf M. Goldberg R. Colman S. Tobey

1971-01-01

247

National Weather Service: Weather Education  

NSDL National Science Digital Library

The National Weather Service's Office of Climate, Water, and Weather Services has a strong outreach component. This "Education" page offers a range of materials for educators and young people which includes lesson plans, brochures, satellite image collections and career information for the fields of meteorology and climatology. The site doesn't have a search engine, but visitors can scroll through eight topical sections, including "Classroom Materials", "Careers in Weather", and "Graphics, Photos, Images". Science teachers won't want to miss the "Classroom Materials", as they can find materials on the "One Sky, Many Voices" project designed to bring together meteorology projects from around the United States together in a collaborative learning environment. Moving on, the "Graphics, Photos, Images" area contains a range of lightning photos and satellite images organized into categories like "Ocean Events", "Severe Weather", and "Tropical Cyclones".

248

Space Weather Applications and Spacecraft Anomalies  

NASA Astrophysics Data System (ADS)

The first priority for the use of space weather information for improving spacecraft performance is in the diagnosis of anomalies so that designs and procedures may be optimised to limit their occurrence. The association of certain spacecraft anomalies with the space environment is well established on the basis of statistical correlations with space weather indicators. However, the global indicators commonly used are frequently only an indirect measure of the aspects of the environment that causes the anomaly. Better diagnosis of anomalies should be possible by processing raw data to extract physically relevant parameters. Spacecraft operators can rapidly diagnose anomalies and even anticipate or avoid them if provided with now-casts and short-term forecasts of relevant hazard indicators. This is the goal of space weather applications like GEOSHAFT, part of ESA's network of space weather prototype services. The space weather indices currently available need to be supplemented by data that is more directly related to the way the space environment interacts with electronic equipment, e.g. for the outer belt, charging current is preferred to electron flux; and for solar particle events LET is preferred to energy. Instruments such as Merlin are focussed on collecting data which will aid anomaly diagnosis.

Rodgers, D.; Dyer, C.; Clucas, S.; Hunter, K.; Ryden, K.

249

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

250

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

251

Terrestrial Weathering of Ordinary Chondrites in Nature and Continuing During Laboratory Storage and Processing: Implications for Sample Integrity  

NASA Astrophysics Data System (ADS)

Terrestrial weathering has affected OC finds, samples of OC falls exposed in hot-deserts before recovery, and OC falls recovered promptly and curated promptly after recovery. Similar phenomena must be anticipated in planning for returned samples.

Velbel, M. A.

2013-09-01

252

Process description and evaluation of Canadian Physical Activity Guidelines development  

Microsoft Academic Search

BACKGROUND: This paper describes the process used to arrive at recommended physical activity guidelines for Canadian school-aged children and youth (5-17 years), adults (18-64 years) and older adults (?65 years). METHODS: The Canadian Society for Exercise Physiology (CSEP) Physical Activity Measurement and Guidelines (PAMG) Steering Committee used the Appraisal of Guidelines for Research Evaluation (AGREE II) Instrument to inform the

Mark S Tremblay; Michelle E Kho; Andrea C Tricco; Mary Duggan

2010-01-01

253

Physical and chemical characterization of bioaerosols - Implications for nucleation processes  

NASA Astrophysics Data System (ADS)

The importance of organic compounds in the oxidative capacity of the atmosphere, and as cloud condensation and ice-forming nuclei, has been recognized for several decades. Organic compounds comprise a significant fraction of the suspended matter mass, leading to local (e.g. toxicity, health hazards) and global (e.g. climate change) impacts. The state of knowledge of the physical chemistry of organic aerosols has increased during the last few decades. However, due to their complex chemistry and the multifaceted processes in which they are involved, the importance of organic aerosols, particularly bioaerosols, in driving physical and chemical atmospheric processes is still very uncertain and poorly understood. Factors such as solubility, surface tension, chemical impurities, volatility, morphology, contact angle, deliquescence, wettability, and the oxidation process are pivotal in the understanding of the activation processes of cloud droplets, and their chemical structures, solubilities and even the molecular configuration of the microbial outer membrane, all impact ice and cloud nucleation processes in the atmosphere. The aim of this review paper is to assess the current state of knowledge regarding chemical and physical characterization of bioaerosols with a focus on those properties important in nucleation processes. We herein discuss the potential importance (or lack thereof) of physical and chemical properties of bioaerosols and illustrate how the knowledge of these properties can be employed to study nucleation processes using a modeling exercise. We also outline a list of major uncertainties due to a lack of understanding of the processes involved or lack of available data. We will also discuss key issues of atmospheric significance deserving future physical chemistry research in the fields of bioaerosol characterization and microphysics, as well as bioaerosol modeling. These fundamental questions are to be addressed prior to any definite conclusions on the potential significance of the role of bioaerosols on physico-chemical atmospheric processes and that of climate.

Ariya, P. A.; Sun, J.; Eltouny, N. A.; Hudson, E. D.; Hayes, C. T.; Kos, G.

254

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

255

Process description and evaluation of Canadian Physical Activity Guidelines development  

PubMed Central

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

2010-01-01

256

The vp-process: critical nuclear physics and astrophysical implications  

NASA Astrophysics Data System (ADS)

The neutrino-p-process is thought to occur in the innermost proton-rich layers ejected in core-collapse supernovae. The importance of the vp-process lies in the fact that it may contribute to the abundances of elements above Nickel and possibly the light p-nuclei. The reaction path of the vp-process lies in a region where nuclear masses are partly unknown and all involved reaction rates are based on theoretical predictions. Detailed studies of the vp-process nucleosynthesis and its uncertainty due to the nuclear physics are presented, with a focus on the reaction path at and above 56Ni. The vp-process path is found to be mainly determined by nuclear structure and thus is trajectory independent. Critical nuclear physics input are identified and the impact of uncertainties on the resulting nucleosynthesis is discussed.

Fröhlich, Carla

2012-12-01

257

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.

258

Invasibility of grassland and heath communities exposed to extreme weather eventsadditive effects of diversity resistance and fluctuating physical environment  

Microsoft Academic Search

Understanding the resistance of plant communities to invasion is urgent in times of changes in the physical environment due to climate change and changes in the resident communities due to biodiversity loss. Here, we test the interaction between repeated drought or heavy rainfall events and functional diversity of grassland and heath communities on invasibility, measured as the number of plant

Juergen Kreyling; Carl Beierkuhnlein; Laura Ellis; Anke Jentsch

2008-01-01

259

Unisys Weather  

NSDL National Science Digital Library

The Unisys weather website offers a host of weather analyses and forecasts. In the Analyses link, visitors can find satellite images as well as surface, upper air, and radar images. Visitors can learn the intricacies of Unisys's many forecast models such as the Nested Grid Model (NGM), Aviation Model, and the Rapid Update Cycle (RUC) Model. Users can find archived hurricane data for the Atlantic, the Eastern Pacific, and the Western Pacific. The site also furnishes archived surface maps, infrared satellite images, upper air charts, and sea surface temperature (SST) plots.

260

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

261

The r-Process Elements: Physics, Origin, and RIA  

NASA Astrophysics Data System (ADS)

Approximately half of the heavy elements with A>70 are made via rapid neutron capture, the r-process. The conditions required for this process have been examined in terms of the parameters for adiabatic expansion from high temperature and density. There have been many developments regarding core-collapse supernova and neutron star merger models of the r-process. Meteoritic data and observations of metal-poor stars have demonstrated the diversity of r-process sources. Stellar observations have also found some regularity in r-process abundance patterns and large dispersions in r-process abundances at low metallicities. This talk will summarize the recent results from parametric studies, astrophysical models, and observational studies of the r-process. The interplay between nuclear physics and astrophysics will be emphasized. Possible measurements crucial to r-process studies will be discussed in connection with rare isotope accelerator facilities such as RIA .

Qian, Yong-Zhong

2003-10-01

262

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

263

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

264

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

NASA Astrophysics Data System (ADS)

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

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

2006-09-01

265

Space weather: science and effects  

NASA Astrophysics Data System (ADS)

From the point-of-view of somebody standing outside on a cold winter night looking up at a clear cloudless sky, the space environment seems to be of a peaceful and stable nature. Instead, the opposite is found to be true. In fact the space environment is very dynamic on all spatial and temporal scales, and in some circumstances may have unexpected and hazardous effects on technology and humans both in space and on Earth. In fact the space environment seems to have a weather all of its own - its own “space weather”. Our Sun is definitely the driver of our local space weather. Space weather is an interdisciplinary subject covering a vast number of technological, scientific, economic and environmental issues. It is an application-oriented discipline which addresses the needs of “space weather product” users. It can be truly said that space weather affects everybody, either directly or indirectly. The aim of this paper is to give an overview of what space weather encompasses, emphasizing how solar-terrestrial physics is applied to space weather. Examples of “space weather product” users will be given highlighting those products that we as a civilization are most dependent on.

Crosby, Norma B.

2009-03-01

266

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

NASA Astrophysics Data System (ADS)

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

Giacalone, J.

2011-12-01

267

Selexol, Allied Chemical Corp. 's physical absorption process  

Microsoft Academic Search

Selexol (Allied Chemical Corp's Physical Absorption Process) basically has a 9:1 selectivity for hydrogen sulfide over carbon dioxide, which can be enhanced by well-known process engineering techniques such as recycling, limiting solvent rates, etc. A Selexol plant has been operating since 1970 for Mobil A.G. in which feed gas composition is 9Vertical Bar3< hydrogen sulfide and 9Vertical Bar3< carbon dioxide

Valentine

1978-01-01

268

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.

269

Weather control  

Microsoft Academic Search

Weather modification, the intentional altering of atmospheric conditions to suit the purposes of humankind, has five basic forms: (1) fog dissipation; (2) rain and snow enhancement; (3) hail suppression; (4) lightning suppression; and (5) the abatement of severe storms such as hurricanes and tornadoes. The dissipation of fog and the seeding of clouds with dry ice or silver iodide to

Leepson

1980-01-01

270

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

271

Physical characteristics of diblock polyacetylene copolymers: processability-conductivity correlation  

SciTech Connect

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

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

1986-01-01

272

Physical Process Time and Space Scales Related to River Restoration  

Microsoft Academic Search

River restoration studies need to consider stream dynamics, evolution, rates of adjustment, and relative effects of various human disturbances. The history of stream channel adjustment typically needs to be investigated over a time scale of decades to centuries to include the time before human disturbance. An investigation of historical change will help with understanding the processes of physical change, how

T. Randle; J. Boutry

2005-01-01

273

Physical Properties of Spent Liquor from Chemical Pulping Processes.  

National Technical Information Service (NTIS)

The aim of this work has been to collect information from the literature about the physical properties of spent liquor from chemical pulping processes and to prepare a summary, based on this information, with the aid of which the calculation of a given ph...

J. G. Salin

1984-01-01

274

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

275

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.

276

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.

277

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.

278

Transpiration and Leaf Temperature. 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 report introduces two models of the thermal energy budget of a leaf. Typical values for…

Gates, David M.

279

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

280

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.

2013-02-01

281

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

SciTech Connect

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

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

1987-01-01

282

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

283

Weather Cycles  

NASA Astrophysics Data System (ADS)

This completely updated edition explores in detail the unresolved debate on the existence of weather cycles. It provides a different perspective on one of the most difficult questions in the current global warming debate: how much of the recent temperature rise can be attributed to natural causes? The book examines the complex analysis required to assess the evidence for cycles with a minimum of mathematics. First Edition Hb (1992): 0-521-38178-9 First Edition Pb (1995): 0-521-47869-3

Burroughs, William James

2003-12-01

284

How Physicists Made Stable Lévy Processes Physically Plausible  

NASA Astrophysics Data System (ADS)

Stable Lévy processes have very interesting properties for describing the complex behaviour of non-equilibrium dissipative systems such as turbulence, anomalous diffusion or financial markets. However, although these processes better fit the empirical data, some of their statistical properties can raise several theoretical problems in empirical applications because they generate infinite variables. Econophysicists have developed statistical solutions to make these processes physically plausible. This paper presents a review of these analytical solutions (truncations) for stable Lévy processes and how econophysicists transformed them into data-driven processes. The evolution of these analytical solutions is presented as a progressive research programme provided by (econo)physicists for theoretical problems encountered in financial economics in the 1960s and the 1970s.

Schinckus, Christophe

2013-08-01

285

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

286

Aviation weather radar  

Microsoft Academic Search

The Federal Aviation Administration has established three ground-based weather radar programs. The terminal Doppler weather radar (TDWR) and weather system processor (WSP) provide wind shear detection capability for air traffic controllers in the terminal area. These systems also reduce weather related delays. The next generation weather radar (NEXRAD) is used by the FAA to improve safety and reduce weather related

D. H. Turnbull

1995-01-01

287

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.

1969-12-31

288

Basalt weathering across scales  

NASA Astrophysics Data System (ADS)

Weathering of silicate minerals impacts many geological and ecological processes. For example, the weathering of basalt contributes significantly to consumption of atmospheric carbon dioxide (CO 2) and must be included in global calculations of such consumption over geological timeframes. Here we compare weathering advance rates for basalt ( wD?), where D and ? indicate the scale at which the rate is determined and surface area measured, respectively, from the laboratory to the watershed scales. Data collected at the laboratory, weathering rind, soil profile and watershed scales show that weathering advance rate of basalt is a fractal property that can be described by a fractal dimension ( dr ? 2.3). By combining the fractal description of rates with an Arrhenius relationship for basalt weathering, we derive the following equation to predict weathering advance rates at any spatial scale from weathering advance rates measured at the BET scale: wD?=k(e. Here, k0 is the pre-exponential factor (1.29 × 10 7 mm 3 mm - 2 yr - 1 ), Ea is the activation energy (70 kj mol - 1 ), and a is a spatial constant related to the scale of measurement of BET surface area (10 - 7 mm). The term, (, is the roughness. The roughness fractal dimension can be conceptualized as a factor related to both the thickness of the reaction front and the specific surface area within the reaction front. However, the above equation can also be written in terms of a surface fractal dimension and the hypothetical average grain radius. These fractal dimensions provide insight into reaction front geometry and should vary with lithology. Once the surface area discrepancy has been accounted for using this method, we find a one to two order of magnitude range in weathering advance rates measured at any scale or temperature that can be attributed to factors such as changes in erosional regime, parent lithology, mechanism, climate, composition of reacting fluid, and biological activity. Our scaled equation, when used to predict global basalt CO 2 consumption based upon global lithologic maps, yields an uptake flux (1.75 × 1013 mol CO 2 yr - 1 ) within the predicted error of fluxes estimated based upon riverine measurements.

Navarre-Sitchler, Alexis; Brantley, Susan

2007-09-01

289

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.

290

Substorm Physical Process in the Near-Earth Plasma Sheet  

Microsoft Academic Search

The physical processes of substorm onset and subsequent current disruption in the near-Earth plasma sheet observed by AMPTE\\/CCE are presented. Toward the end of growth phase (approximately 2 minutes before the substorm onset) a low frequency instability with a wave period of 50-75 sec is excited and grows exponentially to a large amplitude with delta B \\/ B >= 0.3

C. Z. Cheng; A. T. Y. Lui

1998-01-01

291

Quantum Processes and Dynamic Networks in Physical and Biological Systems.  

NASA Astrophysics Data System (ADS)

Quantum theory since its earliest formulations in the Copenhagen Interpretation has been difficult to integrate with general relativity and with classical Newtonian physics. There has been traditionally a regard for quantum phenomena as being a limiting case for a natural order that is fundamentally classical except for microscopic extrema where quantum mechanics must be applied, more as a mathematical reconciliation rather than as a description and explanation. Macroscopic sciences including the study of biological neural networks, cellular energy transports and the broad field of non-linear and chaotic systems point to a quantum dimension extending across all scales of measurement and encompassing all of Nature as a fundamentally quantum universe. Theory and observation lead to a number of hypotheses all of which point to dynamic, evolving networks of fundamental or elementary processes as the underlying logico-physical structure (manifestation) in Nature and a strongly quantized dimension to macroscalar processes such as are found in biological, ecological and social systems. The fundamental thesis advanced and presented herein is that quantum phenomena may be the direct consequence of a universe built not from objects and substance but from interacting, interdependent processes collectively operating as sets and networks, giving rise to systems that on microcosmic or macroscopic scales function wholistically and organically, exhibiting non-locality and other non -classical phenomena. The argument is made that such effects as non-locality are not aberrations or departures from the norm but ordinary consequences of the process-network dynamics of Nature. Quantum processes are taken to be the fundamental action-events within Nature; rather than being the exception quantum theory is the rule. The argument is also presented that the study of quantum physics could benefit from the study of selective higher-scale complex systems, such as neural processes in the brain, by virtue of mathematical and computational models that may be transferred from the macroscopic domain to the microscopic. A consequence of this multi-faceted thesis is that there may be mature analytical tools and techniques that have heretofore not been adequately recognized for their value to quantum physics. These may include adaptations of neural networks, cellular automata, chaotic attractors, and parallel processing systems. Conceptual and practical architectures are presented for the development of software and hardware environments to employ massively parallel computing for the modeling of large populations of dynamic processes.

Dudziak, Martin Joseph

292

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

293

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

294

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

295

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

296

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

SciTech Connect

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 abundances in the dissolved and suspended phases of the Ganga-Brahmaputra rivers was undertaken during 1982-83. We present here data on the dissolved uranium and radium isotopes in these river waters and on some of the U-Th decay series nuclides in the suspended sediments. Prior to this work, Bhat and Krishnaswami (1969) have reported the downstream and seasonal variations in the concentration of dissolved uranium and radium isotopes in the Ganga main stream. The primary objective of our study is to identify the parameters controlling the supply of uranium and radium isotopes to these river waters during weathering, and to determine their fluxes to the estuaries. The results presented in this paper represent the most comprehensive data set on uranium and radium isotopes yet published for a major river system.

Sarin, M.M.; Krishnaswami, S.; Somayajulu, B.L.K. (Physical Research Laboratory, Ahmedabad (India)); Moore, W.S. (Univ. of South Carolina, Columbia (USA))

1990-05-01

297

Twelve testable hypotheses on the geobiology of weathering.  

PubMed

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

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

2011-01-14

298

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

299

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

300

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

301

Space Weather - Sun Earth Relations  

NASA Astrophysics Data System (ADS)

Sun, a star of spectral type G2 is the main source of energy to the Earth. Being close to the Earth, Sun produces a resolvable disk of great detail, which is not possible for other stars. Solar flares and coronal mass ejections are the enigmatic phenomena that occur in the solar atmosphere and regularly bombard the Earth's environment in addition to the solar wind. Thus it becomes important for us not only to understand these physical processes of the Sun, but in addition how these activities affect the Earth and it's surrounding. Thus a branch of study called "Space Weather" had emerged in the recent past, which connects the Sun Earth rela-tions. This paper details about the solar activity and associated energetic phenomena that occur in the atmosphere of the Sun and their influence on the Earth.

Raman, K. Sundara

2011-03-01

302

Physical process first law for bifurcate Killing horizons  

SciTech Connect

The physical process version of the first law for black holes states that the passage of energy and angular momentum through the horizon results in a change in area ({kappa}/8{pi}){delta}A={delta}E-{omega}{delta}J, so long as this passage is quasistationary. A similar physical process first law can be derived for any bifurcate Killing horizon in any spacetime dimension d{>=}3 using much the same argument. However, to make this law nontrivial, one must show that sufficiently quasistationary processes do in fact occur. In particular, one must show that processes exist for which the shear and expansion remain small, and in which no new generators are added to the horizon. Thorne, MacDonald, and Price considered related issues when an object falls across a d=4 black hole horizon. By generalizing their argument to arbitrary d{>=}3 and to any bifurcate Killing horizon, we derive a condition under which these effects are controlled and the first law applies. In particular, by providing a nontrivial first law for Rindler horizons, our work completes the parallel between the mechanics of such horizons and those of black holes for d{>=}3. We also comment on the situation for d=2.

Amsel, Aaron J.; Marolf, Donald; Virmani, Amitabh [Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106 (United States)

2008-01-15

303

Process evaluation results from the HEALTHY physical education intervention.  

PubMed

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. PMID:22156231

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

2011-12-08

304

Physics as quantum information processing: Quantum fields as quantum automata  

NASA Astrophysics Data System (ADS)

Can we reduce Quantum Field Theory (QFT) to a quantum computation? Can physics be simulated by a quantum computer? Do we believe that a quantum field is ultimately made of a numerable set of quantum systems that are unitarily interacting? A positive answer to these questions corresponds to substituting QFT with a theory of quantum cellular automata (QCA), and the present work is examining this hypothesis. These investigations are part of a large research program on a quantum-digitalization of physics, with Quantum Theory as a special theory of information, and Physics as emergent from the same quantum-information processing. A QCA-based QFT has tremendous potential advantages compared to QFT, being quantum ab-initio and free from the problems plaguing QFT due to the continuum hypothesis. Here I will show how dynamics emerges from the quantum processing, how the QCA can reproduce the Dirac-field phenomenology at large scales, and the kind of departures from QFT that that should be expected at a Planckscale discreteness. I will introduce the notions of linear field quantum automaton and local-matrix quantum automaton, in terms of which I will provide the solution to the Feynman's problem about the possibility of simulating a Fermi field with a quantum computer.

D'Ariano, Giacomo Mauro

2012-03-01

305

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

Microsoft Academic Search

Many biogeochemical and Earth surface processes depend critically on chemical weathering. The immediate products of chemical weathering are present as solutes and secondary minerals in groundwater, soils, and streams, and form the nutritional foundation for terrestrial biogeochemistry. Chemical weathering also contributes to physical erosion by weakening bedrock and producing easily erodible regolith, and as the primary long-term sink for atmospheric

Ken L. Ferrier; James W. Kirchner

2008-01-01

306

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

307

Public Awareness of Space Weather  

NASA Astrophysics Data System (ADS)

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

Lanzerotti, Louis J.

2009-08-01

308

Public Awareness of Space Weather  

NASA Astrophysics Data System (ADS)

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

Lanzerotti, Louis J.

2009-08-01

309

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

SciTech Connect

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

Sarin, M.M.; Krishnaswami, S.; Dilli, K.; Somayajulu, B.L.K. (Physical Research Laboratory, Ahmedabad (India)); Moore, W.S. (Univ. of South Carolina (USA))

1989-05-01

310

GEM-AQ, an on-line global multiscale chemical weather system: model description and evaluation of gas phase chemistry processes  

NASA Astrophysics Data System (ADS)

Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale model. The integrated model, GEM-AQ, has been developed as a platform to investigate chemical weather at scales from global to urban. The model was exercised for five years (2001-2005) to evaluate its ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide on the global scale. The model results presented are compared with observations from satellites, aircraft measurement campaigns and balloon sondes.

Kaminski, J. W.; Neary, L.; Struzewska, J.; McConnell, J. C.; Lupu, A.; Jarosz, J.; Toyota, K.; Gong, S. L.; Côté, J.; Liu, X.; Chance, K.; Richter, A.

2007-10-01

311

PVD by electron-beam processes. [Physical vapor deposition  

SciTech Connect

Physical vapor deposition by electron beam evaporation has been used to produce coatings and resistive elements. A new technique in electron beam evaporation is hot hollow cathode evaporation. Some of the differences between electron beam evaporation and sputtering are listed, as are the process parameters and coating properties which must be correlated. Properties of Be films are correlated with substrate temperature. Hot hollow cathode evaporation of Ag is used to illustrate the effects of substrate bias voltage on coating properties. Finally, some of the applications of electron beam evaporation and the materials used are tabulated. (DLC)

K

1982-01-01

312

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

313

3D physical modeling for patterning process development  

NASA Astrophysics Data System (ADS)

In this paper we will demonstrate how a 3D physical patterning model can act as a forensic tool for OPC and ground-rule development. We discuss examples where the 2D modeling shows no issues in printing gate lines but 3D modeling shows severe resist loss in the middle. In absence of corrective measure, there is a high likelihood of line discontinuity post etch. Such early insight into process limitations of prospective ground rules can be invaluable for early technology development. We will also demonstrate how the root cause of broken poly-line after etch could be traced to resist necking in the region of STI step with the help of 3D models. We discuss different cases of metal and contact layouts where 3D modeling gives an early insight in to technology limitations. In addition such a 3D physical model could be used for early resist evaluation and selection for required ground-rule challenges, which can substantially reduce the cycle time for process development.

Sarma, Chandra; Abdo, Amr; Bailey, Todd; Conley, Will; Dunn, Derren; Marokkey, Sajan; Talbi, Mohamed

2010-03-01

314

Terminal Doppler weather radar  

Microsoft Academic Search

The terminal Doppler weather radar (TDWR) system, now under development, will provide automatic detection of microbursts and low-level wind shear. This paper discusses the TDWR performance parameters and describes its structural elements, including the antenna subsystem, the transmitter, the receiver\\/exciter, the digital signal processor, and the radar product generator\\/remote monitoring subsystem. Attention is also given to the processes of the

M. Michelson; W. W. Shrader; J. G. Wieler

1990-01-01

315

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.

316

CLARA: A Contemporary Approach to Physics Data Processing  

SciTech Connect

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

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

2011-12-01

317

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

318

Weather Prediction Models  

NASA Astrophysics Data System (ADS)

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

Bacmeister, Julio T.

319

National Weather Service  

MedlinePLUS

... CURRENT CONDITIONS Radar Climate Monitoring River Levels Observed Precipitation Surface Weather Upper Air Marine and Buoy Reports ... Weather Current Outlook Maps Drought Fire Weather Fronts/Precipitation Maps Current Graphical Forecast Maps Rivers Marine Offshore ...

320

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. Students also identify weather events that are commonly reported in the news and discuss how weather affects lives.

Foundation, Wgbh E.

2009-07-21

321

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

322

Laboratory simulations of space weathering and impact heating of planetary surfaces: the TEM studies.  

NASA Astrophysics Data System (ADS)

Space weathering (SW) is alteration of optical and physical properties of the surface layers of airless solar system bodies due to exogenic processes such as micrometeorite bombardment and interaction with solar wind plasma. Understanding the nature of physical/chemical alteration produced by the SW processes is crucial to derive reliable mineralogical information from remote sensing data. Although natural space weathered samples collected from the surface of the Moon are available for study, the SW of other targets in different environments may produce different effects. Therefore, laboratory simulation experiments on various analogue materials and detailed characterisation of the produced effects are important.

Rout, S. S.; Moroz, L. V.; Baither, D.; van der Bogert, C. H.; Bischoff, A.

2008-09-01

323

The Role of Atomic Physics in Understanding Physical Processes in High Energy Astrophysics  

NASA Astrophysics Data System (ADS)

X-ray grating spectra from Chandra and XMM-Newton have provided new insights into many of the physical processes present in astrophysical sources. For example, (i) shocks produced by magnetic accretion onto stellar surfaces cool as the material flows down, with density and temperature diagnostics providing tests of the accretion models; (ii) many active galactic nuclei (AGN) produce winds or outflows, detectable through X-ray absorption; (iii) active cool stars have coronal pressures several orders of magnitude larger than found on the Sun. The diagnostics used to determine temperatures, densities, elemental abundances, ionization states, and opacities require extremely accurate atomic data. At the same time, we must have a fairly complete database in order to ensure that the diagnostics are not blended or otherwise compromised. The best spectra are from bright objects with long exposures (days), but the information contained allows us to infer the location(s) of the emitting and absorbing plasmas and understand the physical properties. We will give examples to illustrate the role of atomic physics in our analyses of such spectra and the quality of data required.

Brickhouse, Nancy S.

2007-08-01

324

The Role of Atomic Physics in Understanding Physical Processes in High Energy Astrophysics  

SciTech Connect

X-ray grating spectra from Chandra and XMM-Newton have provided new insights into many of the physical processes present in astrophysical sources. For example (i) shocks produced by magnetic accretion onto stellar surfaces cool as the material flows down, with density and temperature diagnostics providing tests of the accretion models; (ii) many active galactic nuclei (AGN) produce winds or outflows, detectable through X-ray absorption; (iii) active cool stars have coronal pressures several orders of magnitude larger than found on the Sun.The diagnostics used to determine temperatures, densities, elemental abundances, ionization states, and opacities require extremely accurate atomic data. At the same time, we must have a fairly complete database in order to ensure that the diagnostics are not blended or otherwise compromised. The best spectra are from bright objects with long exposures (days), but the information contained allows us to infer the location(s) of the emitting and absorbing plasmas and understand the physical properties. We will give examples to illustrate the role of atomic physics in our analyses of such spectra and the quality of data required.

Brickhouse, Nancy S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS 15, Cambridge, MA 02138 (United States)

2007-08-02

325

Corrosion processes of physical vapor deposition-coated metallic implants.  

PubMed

Protecting metallic implants from the harsh environment of physiological fluids is essential to guaranteeing successful long-term use in a patient's body. Chemical degradation may lead to the failure of an implant device in two different ways. First, metal ions may cause inflammatory reactions in the tissues surrounding the implant and, in extreme cases, these reactions may inflict acute pain on the patient and lead to loosening of the device. Therefore, increasing wear strength is beneficial to the performance of the metallic implant. Second, localized corrosion processes contribute to the nucleation of fatigue cracks, and corrosion fatigue is the main reason for the mechanical failure of metallic implants. Common biomedical alloys such as stainless steel, cobalt-chrome alloys, and titanium alloys are prone to at least one of these problems. Vapor-deposited hard coatings act directly to improve corrosion, wear, and fatigue resistances of metallic materials. The effectiveness of the corrosion protection is strongly related to the structure of the physical vapor deposition layer. The aim of this paper is to present a comprehensive review of the correlation between the structure of physical vapor deposition layers and the corrosion properties of metallic implants. PMID:20565379

Antunes, Renato Altobelli; de Oliveira, Mara Cristina Lopes

2009-01-01

326

Tectonic and climatic controls on silicate weathering  

Microsoft Academic Search

Understanding the controls on chemical weathering, especially of silicate minerals, remains a major challenge, despite its importance in controlling the evolution of the Earth's surface. In particular, it has proved hard to distinguish the temperature sensitivity of silicate weathering rates from other factors. Here we present a new compilation of chemical and physical erosion rates in small catchments and show

A. Joshua West; Albert Galy; Mike Bickle

2005-01-01

327

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

ERIC Educational Resources Information Center

|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

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

2010-01-01

328

Role of the subgrid-scale physical processes in supermodelling  

NASA Astrophysics Data System (ADS)

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

Yano, J.

2011-12-01

329

A Query Processing Approach Based on Queuing Model for Cyber-Physical Systems  

Microsoft Academic Search

Cyber-Physical Systems (CPS) are integrations of computation with physical processes, and applications of CPS will appear in a wide variety of fields. As part of CPS, sensor networks can observe a physical system by acquiring data and processing queries. In this paper, a query processing approach based on a queuing model is proposed for a mass of periodic queries and

Fangfang Li; Dejun Yue; Chuanwen Li

2010-01-01

330

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

331

Growing up Fast: Stress Exposure and Subjective “Weathering” in Emerging Adulthood?  

Microsoft Academic Search

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

Holly Foster; John Hagan; Jeanne Brooks-Gunn

2008-01-01

332

Processing device and method for structure data representing a physical structure  

US Patent & Trademark Office Database

A processing device and a method for processing structure data representing a physical structure are disclosed to obtain information about physical properties of the physical structure faster and with high quality and accuracy. The processing device for processing structure data representing a physical structure comprises an obtainer module for obtaining structure data representing a physical structure; a parts defining module for subdividing said structure data into at least two parts including a connection part and a material part; a meshing module for generating a mesh model approximating said physical structure by transforming said connection part and said material part into mesh elements having different sizes, wherein the mesh element sizes of said connection part are smaller than the mesh element sizes of said material part; and a processing module for processing said mesh model to estimate physical properties of said physical structure.

Patnala; Manoj Kumar (Warren, MI)

2013-03-19

333

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.

334

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

335

Controlling The Global Weather  

Microsoft Academic Search

the weather controller is extremely complex, the existence of the required technology is plausible in the time range of several decades.While the concept of controlling the weather has often appeared in science fiction literature, this statement of the problem provides a scientific basis and a system architecture to actually implement global weather control. Large-scale weather control raises important legal and

Ross N. Hoffman

2002-01-01

336

Spin wave processes in ferrite-film structures: physics and devices for microwave signal processing  

Microsoft Academic Search

Physics of spin wave processes in thin ferrite-film structures as a basis for novel device applications is briefly reviewed. Two types of novel microwave spin-wave devices, namely, nonlinear spin-wave phase shifter and nonlinear spin-wave interferometer are described. Experimentally measured and theoretically calculated operating characteristics for these devices are presented. It is shown that a good agreement exists between experimental and

B. A. Kalinikos; A. B. Ustinov

2005-01-01

337

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

338

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

2011-12-21

339

Weather Derivative Valuation  

NASA Astrophysics Data System (ADS)

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

Jewson, Stephen; Brix, Anders

2005-04-01

340

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.

341

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.

342

Modeling convective-stratiform precipitation processes on a Mei-Yu front with the Weather Research and Forecasting model: Comparison with observations and sensitivity to cloud microphysics parameterizations  

NASA Astrophysics Data System (ADS)

Deep convective-scale simulations of the linear mesoscale convective systems (MCSs) formed on a Mei-Yu front over the Huai River basin in China on 7-8 July 2007 were conducted using the Advanced Research Weather Research and Forecasting model to investigate impacts of cloud microphysics parameterizations on simulated convective-stratiform precipitation processes. Eight simulations were performed with identical configurations, except for differences in the cloud microphysics parameterizations. Measurements from rain gauges, ground-based weather radars, and the Tropical Rainfall Measuring Mission satellite Precipitation Radar were used to quantitatively evaluate the model results. While all of the simulations largely capture the observed large-scale characteristics of the precipitation event, notable differences among the simulations are found in the morphology and evolution of the MCSs at mesoscale and cloud scale. Significant influences on the coupling between dynamical and microphysical processes at the resolved deep convective scale by the various microphysical parameterizations are evident. On the one hand, the different microphysical schemes produce not only substantial differences in intensity of convective precipitation but also distinguishable vertical distributions of latent heating and condensate loading in the deep convective regions, which in turn results in significant differences in the vertical distributions of vertical air velocity and in the heights and strength of detrainment from deep convective regions. Consequently, detrainment of hydrometeors and positively buoyant air from the deep convective regions to the stratiform regions is significantly different, which impacts the formation and growth of ice-phase hydrometeors at the upper levels and thus surface rainfall rates in the stratiform regions. On the other hand, prediction of rain size distribution significantly impacts the simulated rain evaporation rates and mass-weighted rain fall speeds, and hence rain flux. Improper determination of the intercept parameter of rain size distribution can result in unrealistic features in the morphology of the storm and can have substantial impacts on precipitation distribution and evolution.

Luo, Yali; Wang, Yanjie; Wang, Hongyan; Zheng, Yongjun; Morrison, Hugh

2010-09-01

343

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

344

Physical and Chemical Properties of Sol-Gel Processing.  

NASA Astrophysics Data System (ADS)

Sol-gel processing is known as a novel technique to synthesize glasses using liquid chemicals. Hydrolysis reaction can basically determine a polymeric structure resulting in glasses of different properties. The hydrolysis reaction of tetramethyl orthosilicate, TMOS, is investigated at pHs of 4.9, 6.0, 7.5 of water, and with the chemical additives: formamide, acetone, methanol acetonitrile, and dioxane. The chemical additives are used for a solvation effect, and the water of different pHs is used as a catalyst. The experiment has been completed as a function of time, and at pressures from 1 to 2 kilobars. The rate constant is determined using Raman spectroscopy. The roles of viscosity, pressure induced mobility, concentration of hydronium and hydroxyl ions, volumes of activations, dipole moment, dielectric constant, and hydrogen bonds are discussed. After hydrolysis and polymerization, gelation occurs. The Positronium Decay Technique is also used to measure pore sizes of the silica gels. The results are compared with the BET method. The gels of pores larger than 50 A are used to synthesize titanium and boron doped gels and to characterize their physical properties. Infrared spectroscopy is used to identify Si-O-Ti and Si-O-B bonds.

Hoang, Geun Chang

345

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

NASA Astrophysics Data System (ADS)

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

Avakyan, Sergei

2010-05-01

346

Terminal Doppler weather radar  

NASA Astrophysics Data System (ADS)

The terminal Doppler weather radar (TDWR) system, now under development, will provide automatic detection of microbursts and low-level wind shear. This paper discusses the TDWR performance parameters and describes its structural elements, including the antenna subsystem, the transmitter, the receiver/exciter, the digital signal processor, and the radar product generator/remote monitoring subsystem. Attention is also given to the processes of the base data formation, point target removal, signal-to-noise thresholding, and velocity de-aliasing and to the TDWR algorithms and displays. A schematic diagram of the TDWR system is presented.

Michelson, M.; Shrader, W. W.; Wieler, J. G.

1990-02-01

347

GEM-AQ, an on-line global multiscale chemical weather modelling system: model description and evaluation of gas phase chemistry processes  

NASA Astrophysics Data System (ADS)

Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale weather prediction model. The integrated model, GEM-AQ, was developed as a platform to investigate chemical weather at scales from global to urban. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module with 5 aerosols types. All tracers are advected using the semi-Lagrangian scheme native to GEM. The vertical transport includes parameterized subgrid-scale turbulence and large scale deep convection. Dry deposition is included as a flux boundary condition in the vertical diffusion equation. Wet deposition of gas-phase species is treated in a simplified way, and only below-cloud scavenging is considered. The emissions used include yearly-averaged anthropogenic, and monthly-averaged biogenic, ocean, soil, and biomass burning emission fluxes, as well as NOx from lightning. In order to evaluate the ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide, the model was run for a period of five years (2001 2005) on a global uniform 1.5°×1.5° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. Model results were compared with observations from satellites, aircraft measurement campaigns and balloon sondes. We find that GEM-AQ is able to capture the spatial details of the chemical fields in the middle and lower troposphere. The modelled ozone consistently shows good agreement with observations, except over tropical oceans. The comparison of carbon monoxide and nitrogen dioxide with satellite measurements emphasizes the need for more accurate, year-specific emissions fluxes for biomass burning and anthropogenic sources. Other species also compare well with available observations.

Kaminski, J. W.; Neary, L.; Struzewska, J.; McConnell, J. C.; Lupu, A.; Jarosz, J.; Toyota, K.; Gong, S. L.; Côté, J.; Liu, X.; Chance, K.; Richter, A.

2008-06-01

348

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

349

Space Weather FX  

NSDL National Science Digital Library

Space Weather FX is a vodcast (video podcast) series that explores the science of space weather and how it can impact our every day lives. Episodes include Space Weather and its Effects, Connecting the Sun and Earth, When Space Weather Attacks, Stratospheric Sudden Warming, A Tour of Haystack's Radars, GPS and Space Weather, It Came from the Sun, and The Big Picture. The site also contain links to space weather information and educational materials. The episodes will run on one of four free video players.

350

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

351

Internet Weather Links: Weather and Weather Related Lesson Plans  

NSDL National Science Digital Library

The Internet Weather Links is a collection of lesson plans provided by the Utah Education Network's Weather Report Web site. The activities are organized by grade level from kindergarten to fourth grade and include such topics as Sunny Colors, Weather in a Box, Changes Due to Freezing, and Geological Features. Each lesson is well organized with explanations of its objectives, intended learning outcomes, and instructional procedures. Downloadable documents, related links, extensions to the lesson, and even rating systems for teachers are also provided, making it a great resource especially for use with younger students.

1996-01-01

352

Physical processes and sedimentation on a broad, shallow bank  

NASA Astrophysics Data System (ADS)

An integrated study of the meteorology, physical oceanography, sedimentationand coastal morphology on the broad, shallow Miskito Bank off the eastern coast of Nicaragua has uncovered systematic interrelationships between driving forces. Bank geometry and sedimentologic environments on the Bank. Extremely high rainfall results from an interaction between meteorological processes over the Bank and topographic effects along the coast. Both acoustic and radio sounding of the lower atmosphere have documented the feedback between convective plumes, inversion layers and the incessant rainfall, which brings three times more freshwater and 15 times more sediment down to a unit length of coast than on the U.S. Atlantic shore. The resultant brackish, turbid coastal water moves as a highly organized band of water parallel to the coast. Seaward of this coastal boundary layer, offshore water from the Caribbean Current rides up on the Bank and provides an environment ideal for carbonate production. A zone of fine-grained terrigenous sediment underlying the coastal boundary current merges abruptly into a smooth carbonate plain covering most of the surface of the Bank. These central Bank carbonates are composed primarily of the disintegration products of prolific calcareous green algae. A trend of high relief, luxuriant coral reef growth is aligned along the steep dropoff at the Bank edge, a zone of observed upwelling of cooler and saltier basin water. A threefold southerly increase in wave energy at the shoreline due to the decreasing width of the shallow shelf results in wave-dominated coastal morphologies in the south compared to fluvial domination in the north and a systematic change from straight, linear bars and beaches in the north to rhythmic topography in the south.

Murray, S. P.; Hsu, S. A.; Roberts, H. H.; Owens, E. H.; Crout, R. L.

1982-02-01

353

Air Weather Service Weather-Modification Program.  

National Technical Information Service (NTIS)

The Air Weather Service has recently inaugurated a program to field test those weather-modification techniques within the scientific state-of-the-art and of potential value to the Air Force in order to bring them to a state of operational readiness. The f...

H. S. Appleman

1968-01-01

354

Thermal Weathering on Airless Planetary Surfaces  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

355

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

356

Phytoplankton Diversity in Relation to Coastal Physical Processes.  

National Technical Information Service (NTIS)

This study describes and interprets phytoplankton distributions across the Texas-Louisiana shelf, detailing relationships among the major phytoplankton groups, including diatoms (Bacillariophyceae). Phytoplankton distributions will be related to physical ...

P. S. Bontempi D. A. Wiesenburg

1997-01-01

357

Hot Weather Tips  

MedlinePLUS

Home > Newsletters > Connections newsletter - Archives > Spring 2003 > HOT Weather Tips E-mail to a Friend Printable Version ©Family Caregiver Alliance We all suffer in hot weather. However, for elderly and disabled ...

358

On Observing the Weather  

NSDL National Science Digital Library

In this article, Mount Washington Observatory meteorologist Tim Markle shares the ins and outs of his daily weather-observing routine and offers insights on making weather observations at home or at school.

Crane, Peter

2004-05-01

359

Deep chemical weathering in a rapidly eroding mountain belt, Taiwan  

Microsoft Academic Search

Chemical weathering constitutes a principal component of the carbon cycle and a long-term control on global climate. River chemistry offers integrated information on weathering processes and their location within a river basin and its substrate. As such, it combines the contributions moderated by surface processes including erosion, sediment production and soil formation with weathering fluxes from deeper levels in the

D. Calmels; A. Galy; M. J. Bickle; N. Hovius; M.-C. Chen; H. Chapman

2009-01-01

360

Introduction to Weather  

NSDL National Science Digital Library

This resource provides an overview of weather, the day-to-day changes in temperature, air pressure, moisture, wind, cloudiness, rainfall and sunshine. Links embedded in the text provide access to descriptions of cloud types and to information on weather hazards such as fog, hurricanes, thunderstorms, and tornadoes. Other topics include meteorology, weather measurements, and weather mapping. Materials are also provided on the water cycle and its elements, such as evaporation, uplift and cooling of air, dew point, condensation, and precipitation.

2010-01-01

361

Integration of geochemical mass balance with sediment transport to calculate rates of soil chemical weathering and transport on hillslopes  

Microsoft Academic Search

We developed a process-oriented hillslope soil mass balance model that integrates chemical and physical processes within hillslope soils. The model explicitly factors that soil chemical weathering at any hillslope position is related to the flux of soil eroded from upslope as well as soil production from underlying bedrock. The model was merged with measurements of soil elemental chemistry and cosmogenic

Kyungsoo Yoo; Ronald Amundson; Arjun M. Heimsath; William E. Dietrich; George H. Brimhall

2007-01-01

362

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

363

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

364

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

365

Extreme Weather on Earth  

NSDL National Science Digital Library

In this activity, students utilize a set of photographs and a 30 minute video on weather to investigate extreme weather events. They are posed with a series of questions that ask them to identify conditions predictive of these events, and record them on a worksheet. Climate and weather concepts defined.

Mika, Anna; Education, National G.

366

Weather Maps in Motion  

NSDL National Science Digital Library

In this activity, students learn to interpret current weather maps. They will observe weather map loop animations on the internet, learn the concept of Zulu time (Universal Time Coordinated, UTC) and visualize the movement of fronts and air masses. They will then analyze a specific weather station model, generate a meteogram from their observations, and answer a set of questions about their observations.

Burrows, Charles

367

Weather Fundamentals: Meteorology. [Videotape].  

ERIC Educational Resources Information Center

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

1998

368

Doppler weather radar  

Microsoft Academic Search

The Doppler weather radar and its signals are examined from elementary considerations to show the origin and development of useful weather echo properties such as signal-to-noise ratio (SNR), range correlation, signal statistics, etc. We present a form of the weather radar equation which explicitly shows the echo power loss due to finite receiver bandwidth and how it is related to

RICHARD J. DOVIAK; DUSAN S. ZRNIC; DALE S. SIRMANS

1979-01-01

369

Weather Fundamentals: Meteorology. [Videotape].  

ERIC Educational Resources Information Center

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

1998

370

Severe Weather Primer  

NSDL National Science Digital Library

The severe weather primer from the National Severe Storms Laboratory of the NOAA provides text and graphic explanations of how severe weather phenomena form. Basics on thunderstorms, tornadoes, floods, hail, lightning, winter weather, and winds are provided in a question-oriented format including answers to frequently asked questions.

Laboratory, National S.

2010-04-24

371

Weather Girl Goes Rogue  

NSDL National Science Digital Library

This humorous video suggests what might happen if a weather forecaster reported the weather in the context of climate change. There is a sharp contrast between the anchor focusing on short-term local concerns and the weather forecaster describing what is happening on a long-term global basis.

Ram, Deep R.; Technologies, Institute F.

372

Weather and Climate Basics  

NSDL National Science Digital Library

This primer from the National Center for Atmospheric Research (NCAR) defines weather and climate, and explains related concepts such as the atmosphere, natural hazards, rising sea level, and modeling. Users explore how dynamic forces within the atmosphere change our weather and climate. They learn what causes weather events and climate change and how NCAR scientists are exploring our atmosphere through scientific research.

2008-01-01

373

American Weather Stories.  

ERIC Educational Resources Information Center

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

Hughes, Patrick

374

Space weather: European Space Agency perspectives  

NASA Astrophysics Data System (ADS)

Spacecraft and payloads have become steadily more sophisticated and therefore more susceptible to space weather effects. ESA has long been active in applying models and tools to the problems associated with such effects on its spacecraft. In parallel, ESA and European agencies have built a highly successful solar-terrestrial physics capability. ESA is now investigating the marriage of these technological and scientific capabilities to address perceived user needs for space weather products and services. Two major ESA-sponsored studies are laying the groundwork for a possible operational European space weather service. The wide-ranging activities of ESA in the Space Weather/Space Environment domain are summarized and recent important examples of space weather concerns given.

Daly, E. J.; Hilgers, A.

375

Physical and chemical controls on the critical zone  

USGS Publications Warehouse

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

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

2007-01-01

376

Physical Sciences and Processes of Inquiry: A Critique of CHEM, CBA and PSSC  

ERIC Educational Resources Information Center

|The author sees the physical sciences as processes of inquiry and proceeds to analyze and criticize CHEM Study, CBA, and PSSC physics in terms of their views of inquiry and of the sciences. A discussion of some desirable features for a high school program in physical science is included. Bibliography. (LC)|

Diederich, Mary E.

1969-01-01

377

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...

2009-04-01

378

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

379

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

Code of Federal Regulations, 2013 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...

2013-04-01

380

Fabulous Weather Day  

NSDL National Science Digital Library

Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. After studying weather for three months, we celebrate what we have learned and stretch our thinking further into the weather world around us! Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in their understanding of how the weather works and how it can affect their lives. Our unit focused on guiding students to formulate explanations about animals based on scientific evidence.

Marshall, Candice; Mogil, H. M.

2007-01-01

381

The simulation of pressurized water reactor NPP physical process  

Microsoft Academic Search

The simulations of pressurized water reactor (PWR) nuclear power plant (NPP) is a very important domain in the society of nuclear power, and there are several problems with the current PWR-NPP simulations. First, the current physical modeling of PWR is over-simplified which can bring convenience of implementation, while severe inaccuracy is prone to be incurred at some critical situation. Second,

W. A. Ping; Xi Shi; Jie Zhao; Dichen Liu; Yaowen Wu; Qingsheng Lei; D. C. Zhi

2009-01-01

382

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

383

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

384

Process for using preferential physical solvents for selective processing of hydrocarbon gas streams  

SciTech Connect

This patent describes a process for the removal of hydrocarbon gas liquids, comprising hydrocarbons heavier than methane, from a hydrocarbon gas stream, wherein a need exists for recovering to any selected degree and at extremely high recoveries a selected hydrocarbon component and heavier hydrocarbons. The hydrocarbons are within the group consisting of ethane, propane, butane, and pentane without the need simultaneously to recover hydrocarbons lighter than the selected hydrocarbon component from the hydrocarbon gas stream, The improvement of selectively extracting the hydrocarbon gas liquids from the hydrocarbon gas stream with a preferential physical solvent is described here. The method provides selective capability for recovery according to the selected degree of (a) ethane in amounts ranging from 2-98%, (b) propane in amounts ranging from 2-99%, (c) butane in amounts ranging from 2-100%, or (d) pentanes and higher molecular weight hydrocarbons in amounts ranging up to 100%.

Mehra, Y.R.

1986-10-14

385

The lithium, boron and strontium isotopic systematics of groundwaters from an arid aquifer system: Implications for recharge and weathering processes  

NASA Astrophysics Data System (ADS)

Saline groundwaters are common to inland Australia, but their hydrochemical evolution and origin remain largely unknown. The saline groundwaters in the alluvial aquifers of the Darling River have previously been found to exhibit broad similarity in traditional hydrochemical and isotopic tracers. By contrast, in this study the trace element isotopes (?7Li, ?11B and 87Sr/86Sr) have illuminated more complex hydrogeochemical processes in the same aquifer system. This paper reports the first ever set of ?7Li values in any groundwater system in Australia. They varied from +5.8 to +16.2 with an average value of +9.7‰ (n = 19) in the alluvial aquifers of the Darling River catchment. The ?11B values were all higher than seawater and close to some of the highest ?11B values ever reported in the literature for a groundwater system (+44.4 to +53.9; average: +48.8, n = 17). The 87Sr/86Sr ratios ranged from 0.708 to 0.713, with an average value of 0.709 (n = 19). The differing signatures in these trace element isotope values, highlighted by discovery of the deeper older groundwater system with heavier Li isotope values and higher 87Sr/86Sr, is an important finding of this research. Simple mixing models between river water and saline groundwater cannot explain the observed variation in trace element isotopes. Hydrochemical evolution was found to be dependent on proximity to the Darling River and depth. Varying degrees of Li and B isotopic fractionation during water-sediment interaction were interpreted to account for the evolution of the saline groundwaters. The measurement of these trace element isotopes has permitted delineation of groundwater end-members that would have otherwise not been identified; in their absence an inaccurate interpretation of the hydrochemical evolution of these saline groundwaters would have been made. This study highlights the importance of a multi-tracer approach, which includes trace element isotopes, in resolving complex geochemical processes in groundwater in semi-arid to arid zone environments.

Meredith, Karina; Moriguti, Takuya; Tomascak, Paul; Hollins, Suzanne; Nakamura, Eizo

2013-07-01

386

The assessment of weathering stages in granites using an EC\\/pH meter  

Microsoft Academic Search

The weathering of granite encompasses a wide range extending from slightly weathered rock to saprolite to soil. Although many different methods are available for quantifying the amount of chemical or physical weathering in granites, dissolution rate as a method for estimating the degree of chemical weathering in these rocks was not thoroughly investigated. This study sought to identify a method

Anestoria Shalkowski; Yoshinori Kodama; Shigenori Nakano

2009-01-01

387

Beyond the Weather Chart: Weathering New Experiences.  

ERIC Educational Resources Information Center

Describes an early childhood educator's approach to teaching children about rain, rainbows, clouds, precipitation, the sun, air, and wind. Recommends ways to organize study topics and describes experiments that can help children better understand the different elements of weather. (MOK)

Huffman, Amy Bruno

1996-01-01

388

Beyond the Weather Chart: Weathering New Experiences.  

ERIC Educational Resources Information Center

|Describes an early childhood educator's approach to teaching children about rain, rainbows, clouds, precipitation, the sun, air, and wind. Recommends ways to organize study topics and describes experiments that can help children better understand the different elements of weather. (MOK)|

Huffman, Amy Bruno

1996-01-01

389

National Weather Service- Severe Weather Awareness  

NSDL National Science Digital Library

This website provides access to information designed to protect and prepare individuals from severe weather. Materials presented here include forecasts for aviation and marine interests and the general public, maps, statistical data, educational materials, publications, and links to related sites.

390

Morphologic Evidence for Mechanical and Chemical Weathering of Three New Iron-Nickel Meteorites on Mars --- Process Insights for Meridiani Planum  

Microsoft Academic Search

We describe the morphology of three new iron-nickel meteorites found by the Opportunity spacecraft on Mars, and provide preliminary results and their implications for an assessment of weathering features identified.

J. W. Ashley; M. P. Golombek; C. Schröder; I. Fleischer; T. J. McCoy; P. R. Christensen; T. J. Parker

2010-01-01

391

Spatial relationships of salt distribution and related physical changes of underlying rocks on naturally weathered sandstone exposures (Bohemian Switzerland National Park, Czech Republic)  

Microsoft Academic Search

Efflorescence, case hardening, and granular disintegration represent common weathering features of Upper Cretaceous quartz\\u000a sandstones exposed in the Bohemian Switzerland National Park (NW Bohemia, Czech Republic). Salt species (sulphates: gypsum\\u000a (CaSO42H2O), potassium alum (KAl(SO4)212H2O), tschermigite (NH4Al(SO4)212H2O), alunite (K(Al3(SO4)2(OH)6), and alunogen (Al2(SO4)317H2O), minor nitrates: nitrammite (NH4NO3)) determined by X-ray diffraction exhibit vertical and geographic zoning. More soluble salts (chlorides, nitrates, tschermigite)

R. P?ikryl; L. Melounová; Z. Va?ilová; Z. Weishauptová

2007-01-01

392

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

Microsoft Academic Search

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

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

2011-01-01

393

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

394

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

NASA Astrophysics Data System (ADS)

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

2013-09-01

395

Introduction to statistical physics of media processes: Mediaphysics  

Microsoft Academic Search

Processes of mass communications in complicated social or sociobiological systems such as marketing, economics, politics, animal populations, etc. as a subject for the special scientific discipline - \\

Dmitri V. Kuznetsov; Igor Mandel

2005-01-01

396

Comprehensive study of the weathered condition of welded tuff from a historic stone bridge in Kagoshima, Japan  

Microsoft Academic Search

This paper deals with the problematic weathering of a 150 year old historic stone bridge made of welded tuff. The weathered condition of the structurally important arch stone from the bridge is studied comprehensively by physical, chemical, and mechanical methods. As a result of this study, a physical weathering degree index (PWD), a chemical weathering degree index (CWD) and related

T. Esaki; K. Jiang

2000-01-01

397

Comprehensive study of the weathered condition of welded tuff from a historic stone bridge in Kagoshima, Japan  

Microsoft Academic Search

This paper deals with the problematic weathering of a 150year old historic stone bridge made of welded tuff. The weathered condition of the structurally important arch stone from the bridge is studied comprehensively by physical, chemical, and mechanical methods. As a result of this study, a physical weathering degree index (PWD), a chemical weathering degree index (CWD) and related experimental

T. Esaki; K. Jiang

2000-01-01

398

Validation Of Space Weather Products  

NASA Astrophysics Data System (ADS)

One of the key questions asked about a new Space Weather product is: how good is it? To address this question, the Air Force Research Laboratory Space Vehicles Di- rectorate is undertaking to verify as necessary and perform validations of several ex- isting Space Weather models and application products. The models and applications to be validated include: the Parameterized Real-time Ionospheric Specification Model (PRISM), for specific input and ground-truth data types, and map products showing regional Space Weather effects on satellite communication, HF communication, and satellite-based navigation systems. The AFRL approach to this validation and verifi- cation (VnV) process consists of several steps, each of which may be performed at first in a hands-on or expert-intensive mode, but with a goal of software enhance- ment/automation to improve the process and productivity of the studies. In general, empirical data is used both as input to drive the model or application to be validated, and as ground-truth against which the output of the model/application is compared via a systematic process that extracts comparable parameters and generates quantifi- able performance metrics. In the current effort, it is expected that software tools will be developed that will enable a user to simply fill in a configuration file to execute a validation. The file would allow the user to stipulate which data to use, the setup conditions, the number of runs, and the analysis programs to execute. A mature tool would be designed to be modular and portable so as to enhance its potential for future use. The goals of this effort are to define processes for VnV of each Space Weather product, perform validation by exploiting automation, (thereby facilitating additional production validation), and support the ultimate capability of real-time metrics and confidence factors for Space Weather products. Approaches, data and procedures for various products will be described.

Bishop, G.; Decker, D.; Sexton, E.; Doherty, P.; de La Beaujardiere, O.; Bullett, T.; Quigley, S.; Groves, K.

399

Validation of Space Weather Products  

NASA Astrophysics Data System (ADS)

One of the key questions asked about a new Space Weather product is: "how good is it?" To address this question, the Air Force Research Laboratory Space Vehicles Directorate is undertaking to verify as necessary and perform validations of several existing Space Weather models and application products. The models and applications to be validated include: the Parameterized Real-time Ionospheric Specification Model (PRISM), for specific input and ground-truth data types, and map products showing regional Space Weather effects on satellite communication, HF communication, and satellite-based navigation systems. AFRL's approach to this validation and verification (VnV) process consists of several steps, each of which may be performed at first in a hands-on or expert-intensive mode, but with a goal of software enhancement/automation to improve the process and productivity of the studies. In general, empirical data is used both as input to drive the model or application to be validated, and as `ground-truth' against which the output of the model/application is compared via a systematic process that extracts comparable parameters and generates quantifiable performance metrics. In the current effort, it is expected that software tools will be developed that will enable a user to simply fill in a configuration file to execute a validation. The file would allow the user to stipulate which data to use, the setup conditions, the number of runs, and the analysis programs to execute. A mature tool would be designed to be modular and portable so as to enhance its potential for future use. The goals of this effort are to define processes for VnV of each Space Weather product, perform validation by exploiting automation, (thereby facilitating additional `production validation'), and support the ultimate capability of real-time metrics and confidence factors for Space Weather products. Approaches, data and procedures for various products will be described.

Bishop, G.; Decker, D.; Sexton, E.; Doherty, P.; de la Beaujardiere, O.; Bullett, T.; Quigley, S.; Groves, K.

2002-05-01

400

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

401

Logically Central, Physically Distributed Control in a Process Runtime Environment  

Microsoft Academic Search

An effective process definition language must be powerful, yet clear. It must also have well defined semantics to support powerful and definitive analysis. End users require that a runtime interpreter for the language faithfully implement the semantics used in analysis of process definitions, and that the interpreter be efficient and scalable. In addition to all of the above, the language,

Aaron G. Cass; Barbara Staudt Lerner; Eric K. McCall; Leon J. Osterweil; Alexander Wise

1999-01-01

402

Weather and Atmosphere  

NSDL National Science Digital Library

In this unit, students learn the basics about weather and the atmosphere. They investigate materials engineering as it applies to weather and the choices available to us for clothing to counteract the effects of weather. Students have the opportunity to design and analyze combinations of materials for use in specific weather conditions. In the next lesson, students also are introduced to air masses and weather forecasting instrumentation and how engineers work to improve these instruments for atmospheric measurements on Earth and in space. Then, students learn the distinguishing features of the four main types of weather fronts that accompany high and low pressure air masses and how those fronts are depicted on a weather map. During this specific lesson, students learn different ways that engineers help with storm prediction, analysis and protection. In the final lesson, students consider how weather forecasting plays an important part in their daily lives by learning about the history of weather forecasting and how improvements in weather technology have saved lives by providing advance warning of natural disasters.

Integrated Teaching And Learning Program

403

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

404

History of surface weather observations in the United States  

Microsoft Academic Search

In this paper, the history of surface weather observations in the United States is reviewed. Local weather observations were first documented in the 17th Century along the East Coast. For many years, the progression of a weather observation from an initial reading to dissemination remained a slow and laborious process. The number of observers remained small and unorganized until agencies

Christopher A. Fiebrich

2009-01-01

405

A New Conceptual Model for Understanding Geographical Variations in Weathering  

Microsoft Academic Search

The prevailing theory used to explain geographical variability in weathering is based on visual correlations with climatic regions. For instance, mechanical weathering is assumed to predominate in warm and cold deserts. Yet this visual perspective fails to account for a diversity and quantity of data at the mineral-atmosphere-hydrosphere-biosphere interface where weathering processes actually occur. To address these discrepancies, a new

Gregory A. Pope; Ronald I. Dorn; John C. Dixon

1995-01-01

406

The Topographic Control of Chemical Weathering in Hillslope Soils  

Microsoft Academic Search

Chemical weathering drives biogeochemical cycles from local to global scales, and has the power to regulate the earth's climate on geological time scales. However, little is known of the spatial variation in weathering on hillslopes, and the mechanisms behind those variations. This study addresses the topographic control on soil chemical weathering on convex uplands. We developed a process-based mass balance

K. Yoo; R. Amundson; A. M. Heimsath; W. E. Dietrich; G. H. Brimhall

2004-01-01

407

Nuclear Physics Issues of r-Process Nucleosynthesis  

SciTech Connect

Nucleosynthesis theory predicts that about half of the chemical elements above iron are formed in explosive stellar scenarios by the r-process, i.e. a combination of rapid neutron captures, inverse photodisintegrations, and slower {beta}-decays, {beta}-delayed processes, as well as fission and possibly interactions with neutrinos. A correct modelling of this process, therefore, requires the knowledge of nuclear properties very far from stability and a detailed description of the astrophysical environments. With respect to nuclear data, after an initial period of measuring classical 'waiting-point' nuclei with magic neutron numbers, recent investigations have paid special attention to shape transitions and the erosion of classical shell gaps with possible occurrence of new magic numbers. The status of experimental and theoretical nuclear data on masses and {beta}-decay properties will be briefly reviewed, and consequences on the overall r-process matter flow up to the cosmochronometers 232Th and 238U will be discussed.

Kratz, K.-L. [Institut fuer Kernchemie, Universitaet Mainz (Germany); HGF Virtual Institute for Nuclear Structure and Astrophysics, Mainz (Germany); Institute for Structure and nuclear Astrophysics, University of Notre Dame (United States)

2006-03-13

408

NOAA Daily Weather Maps  

NSDL National Science Digital Library

The charts on this website are the principal charts of the former Weather Bureau publication, "Daily Weather Map." They are the Surface Weather Map, the 500-Millibar Height Contours chart, the Highest and Lowest Temperatures chart, and the Precipitation Areas and Amounts chart. For each day, simple charts are arranged on a single page. These charts are the surface analysis of pressure and fronts, color shading, in ten degree intervals,of maximum and minimum temperature, 500-Millibar height contours, and color shaded 24-hour total precipitation. These charts act as links to their respective Daily Weather Map charts. All charts are derived from the operational weather maps prepared at the National Centers for Environmental Prediction, Hydrometeorological Prediction Center, National Weather Service.

Center, Hydrometeorological P.

2011-01-01

409

Watching the World's Weather  

NASA Astrophysics Data System (ADS)

At a time of growing concern about the impact of pollution on the global climate, weather satellites will play an increasingly crucial role in monitoring how changes such as the ozone hole and global warming will affect the world's climate. The complexities of the global weather machine on every scale are attractively revealed through spectacular images of satellite photography. Anyone interested in how the weather satellite works now and in the future should buy this book.

Burroughs, William James

1991-04-01

410

Space Weather Media Viewer  

NSDL National Science Digital Library

This is version 3 of the space Weather Media Viewer, created to work with the space Weather Action Center to see near-real time data and to provide additional images and resources available for educational use. It features easy downloads that can also be added to news reports and space weather reports. It was designed for ease in adding any media (videos, images) data.

2011-01-01

411

Plymouth State Weather Center  

NSDL National Science Digital Library

The Plymouth State Weather Center offers the latest observations and forecasts for the United States and Southern Canada. By simply selecting a state, individuals can find data on the temperature, wind direction and speed, cloud cover, and other weather information for stations throughout the selected region. The website provides a state forecast as well. The map on the homepage allows users to observe the overall weather patterns throughout the continental United States and Southern Canada.

412

National Weather Service  

NSDL National Science Digital Library

Sick and tired of the heat? Feel like it will never end? Then check out the National Weather Service's (NWS) Heat Wave, a site devoted to the extreme weather that is crippling the south. The NWS provides information on the heat index, heat's affect on the body, and how to beat the heat. For those who want an up-to-the-minute look at the weather, the site links to current conditions, forecasts, and watches and warnings.

413

Space Weather: Welcome, SEC  

NSDL National Science Digital Library

This video presentation welcomes the Space Environment Center (SEC) to the National Weather Service (NWS) as an operational entity of the National Centers for Environmental Prediction (NCEP) family. Describing the ways in which space weather affects global communications and power resources, it demonstrates the importance of space weather forecasting as a part of the NWS family of services. With the inclusion of SEC, the NWS now provides environmental understanding from the sun to the sea.

Spangler, Tim

2005-01-11

414

Backyard Weather Stations  

NSDL National Science Digital Library

Learn how to build your own backyard weather station with complete directions provided by FamilyEducation.com's Web site, Backyard Weather Stations. The site shows exactly what you'll need and how to build the necessary components (e.g., rain gauge and barometer), as well as how to keep records of the data collected. Parents and teachers will enjoy watching the kids "learn the basics of scientific observation and record-keeping while satisfying their natural curiosity about weather."

Randall, Dennis.

415

Weather and Climate Data  

NSDL National Science Digital Library

The Weather and Climate Data site for the Center for Ocean-Land-Atmosphere Studies (COLA) contains analyses of current conditions and the state of the atmosphere; weather forecasts; metropolitan quick-look weather summaries and meteograms; short-term climate outlooks for temperature, precipitation and soil moisture; El Nino forecasts for understanding the ocean-atmosphere system; and maximum potential hurricane intensity maps showing potential minimum pressure and potential maximum winds for the oceans.

416

Nuclear Physics Data Relevant to r-Process Nucleosynthesis  

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

417

Constraining the North Pacific carbon sink: biological and physical processes  

NASA Astrophysics Data System (ADS)

The transition zone region of the North Pacific is a notably large sink for atmospheric carbon dioxide on a mean annual basis, though seasonally the region varies between strong wintertime uptake and weak summertime outgassing. Because the direction of air-sea carbon flux is effectively set by the sea surface pCO2, we seek to identify and quantify those processes most responsible for its variability in this region. While changes in temperature, salinity, dissolved inorganic carbon, and alkalinity are all factors that impact sea surface pCO2 on a seasonal basis, on a mean annual basis the region must be maintained as a sink by processes that remove carbon from surface waters: biological drawdown as well as the result of advection/mixing. In this work we constrain the quantitative contribution of each of these processes throughout an annual cycle. The least constrained of these processes is the biological pump, which we estimate in two independent ways: bottom-up, using satellite data-based primary productivity models coupled with export estimates from literature; and top-down, by determining what the biological pump would need to be to maintain the observed sea surface pCO2 values in the region, given our estimates of all the other regulatory processes.

Ayers, J.; Lozier, M.

2010-12-01

418

Winter Storm (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. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? 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 ...

Miller, Aubree

2009-09-28

419

Observing Space Weather towards building Predictive Capabilities  

NASA Astrophysics Data System (ADS)

Simultaneous data from multi-point space missions operating in the Sun-Earth system in conjunction with dedicated ground- based networks have facilitated major steps towards the quantification of space weather processes, better understandings of their impacts on the various high level systems of modern societal infrastructure and fundamental developments in space weather forecasting. Through the EU FP7 program and the ESA Space Situational Awareness (SSA) program several dedicated space weather projects and studies have currently been initiated, such as the AFFECTS (Advanced Forecast For Ensuring Communications Through Space), aiming in establishing prototype space weather services, instruments and missions as precursors of a future space weather operational system. This presentation provides an overview of the ongoing European activities, upcoming challenges and opportunities for international collaborations.

Bothmer, Volker

2012-07-01

420

Evaluation of artificially-weathered standard fuel oil toxicity by marine invertebrate embryogenesis bioassays.  

PubMed

wWeathering of petroleum spilled in the marine environment may not only change its physical and chemical properties but also its effects on the marine ecosystem. The objective of this study was to evaluate the toxicity of the water-accommodated fraction (WAF) obtained from a standard fuel oil following an environmentally realistic simulated weathering process for a period of 80 d. Experimental flasks with 40 g L(-1) of fuel oil were incubated at 18°C with a 14 h light:10 h dark photoperiod and a photosynthetically active radiation (PAR) intensity of 70 ?E m(-2) s(-1). Samples were taken at four weathering periods: 24 h, 7, 21 and 80 d. WAF toxicity was tested using the sea urchin (Paracentrotus lividus) and mussel (Mytilus galloprovincialis) embryo-larval bioassays and the aromatic hydrocarbons levels (AH) in the WAF were measured by gas chromatography/mass spectrometry. In contrast with the classic assumption of toxicity decrease with oil weathering, the present study shows a progressive increase in WAF toxicity with weathering, being the EC(50) after 80d eightfold lower than the EC(50) at day 1, whereas AH concentration slightly decreased. In the long term, inoculation of WAF with bacteria from a hydrocarbon chronically-polluted harbor slightly reduced toxicity. The differences in toxicity between fresh and weathered fuels could not be explained on the basis of the total AH content and the formation of oxidized derivatives is suggested to explain this toxicity increase. PMID:23022168

Bellas, Juan; Saco-Álvarez, Liliana; Nieto, Óscar; Bayona, Josep María; Albaigés, Joan; Beiras, Ricardo

2012-09-27

421

Fractionation of the noble metals by physical processes  

Microsoft Academic Search

During partial melting in the earth’s mantle, the noble metals become fractionated. Os, Ir, Ru, and Rh tend to remain in the mantle residue whereas Pt, Pd, and Re behave mildly incompatible and are sequestered to the silicate melt. There is consensus that sulfide plays a role in the fractionation process; the major noble metal repository in the mantle is

Chris Ballhaus; Conny Bockrath; Cora Wohlgemuth-Ueberwasser; Vera Laurenz; Jasper Berndt

2006-01-01

422

FROM THE CURRENT LITERATURE: Hydrodynamic cumulative processes in plasma physics  

NASA Astrophysics Data System (ADS)

This review is devoted to cumulative hydrodynamic processes in a plasma and to the possibility of using them for controlled thermonuclear fusion. The cumulation of convergent shock waves and the mechanisms of their limitation are discussed in greatest detail. Results are presented of study of non-one-dimensional cumulative shock waves, which had practically not yielded to analysis until recently.

Sokolov, Ivan V.

1990-11-01

423

Wet agglomeration of powders: from physics toward process optimization  

Microsoft Academic Search

A general method to optimize a wet powder agglomeration process for achieving desired properties of granulated products is suggested. The different states of a wet powder are characterized by a cohesion function, i.e. the evolution of the torque of the stirred system as a function of the moisture content. Two different types of agglomeration behaviours are shown: Stepwise Growing Behaviour

Alexandre Goldszal; Jacques Bousquet

2001-01-01

424

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

425

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

ERIC Educational Resources Information Center

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

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

2008-01-01

426

Weathering: methods and techniques to measure  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

427

Cosmochemical implications of the physical processing of cometary nuclei  

SciTech Connect

Comets are not necessarily pristine nebular and interstellar material, despite a common perception to that effect. Alteration processes may occur during comet formation in the outer planet region, during their dispersal to or residence within the Oort cloud, and after their return to the planetary region. Processes that may have significantly modified cometary nuclei include heating, impacts, and irradiation. Possible consequences include phase changes in ices, hydration reactions in silicates, synthesis of organic compounds, collisional disruption and re-accretion, shock and irradiation effects in minerals and ices, cosmogenic nuclide formation, redistribution or loss of volatiles, and formation of a refractory veneer. A model of cometary nuclei that emerges from these considerations provides a framework for understanding observations of comets and future samples.

McSween, H.Y. Jr. (Univ. of Tennessee, Knoxville (USA)); Weissman, P.R. (Jet Propulsion Laboratory, Pasadena, CA (USA))

1989-12-01

428

Weather and emotional state  

NASA Astrophysics Data System (ADS)

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

Spasova, Z.

2010-09-01

429

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

430

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

431

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

432

Effect of degree of weathering on dynamic properties of residual soils  

SciTech Connect

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

Macari, E.J.; Loyos, L. Jr. [Georgia Inst. of Technology, Atlanta, GA (United States)

1996-12-01

433

McRunjob: A High Energy Physics Workflow Planner for Grid Production Processing  

Microsoft Academic Search

McRunjob is a powerful grid workflow manager used to manage the generation of large numbers of production processing jobs in High Energy Physics. In use at both the DZero and CMS experiments, McRunjob has been used to manage large Monte Carlo production processing since 1999 and is being extended to uses in regular production processing for analysis and reconstruction. Described

Gregory E. Graham; David Evans; Iain Bertram

2003-01-01

434

Rallying the Troops: A Four-Step Guide to Preparing a Residency Program for Short-Term Weather Emergencies  

Microsoft Academic Search

Background: Weather emergencies present a multifaceted challenge to residents and residency programs. Both the individual trainee and program may be pushed to the limits of physical and mental strain, potentially jeopardizing core competencies of patient care and professionalism. Although daunting, the task of preparing for these events should be a methodical process integrated into every residency training program. Summary: The

Grant V. Chow; Jennifer Hayashi; Glenn A. Hirsch; Colleen Christmas

2011-01-01

435

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

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 used to introduce the biology student to differential calculus, a…

Hertzberg, Richard C.

436

Physical modeling and analysis of rain and clouds by anisotropic scaling multiplicative processes  

Microsoft Academic Search

We argue that the basic properties of rain and cloud fields (particularly their scaling and intermittency) are best understood in terms of coupled (anisotropic and scaling) cascade processes. We show how such cascades provide a framework not only for theoretically and empirically investigating these fields, but also for constructing physically based stochastic models. This physical basis is provided by cascade

Daniel Schertzer; Shaun Lovejoy

1987-01-01

437

Programmer's Guide for FFORM. Physical Processes in Terrestrial and Aquatic Ecosystems, Computer Programs and Graphics Capabilities.  

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. FFORM is a portable format-free input subroutine package written in ANSI Fortran IV…

Anderson, Lougenia; Gales, Larry

438

Estimation of physical parameters for dynamic processes with application to an industrial robot  

Microsoft Academic Search

The unknown parameters of physical laws which govern the dynamics of processes can be gained from measured input and output signals in a two step procedure. First the parameters of differential equations are estimated and then the physical parameters are calculated based on algebraic relations. After considering the model structures a suitable parameter estimation method for continuous time signals is

R. ISERMANN

1992-01-01

439

Programmer's Guide for FFORM. Physical Processes in Terrestrial and Aquatic Ecosystems, Computer Programs and Graphics Capabilities.  

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. FFORM is a portable format-free input subroutine package written in ANSI Fortran IV…

Anderson, Lougenia; Gales, Larry

440

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

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 report describes concepts presented in another module called "The First Law of…

Stevenson, R. D.