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1

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time-scales  

E-print Network

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time (received for review February 15, 2008) Global silicate weathering drives long-time-scale fluctuations in atmospheric CO2. While tectonics, climate, and rock-type influence silicate weathering, it is unclear how

Hilley, George

2

The effect of silicate weathering on global temperature and atmospheric CO2  

Microsoft Academic Search

Models of the carbon cycle, used to calculate atmospheric CO2 levels and mean global surface temperatures over geologic time, rely heavily on estimates of CO2 consumed by chemical weathering. Weathering of calcium and magnesium silicates is the primary sink for atmospheric CO2, yet alkali feldspar dissolution rates or data from carbonate aquifers have generally been used as model inputs instead.

Patrick V. Brady

1991-01-01

3

A framework for predicting global silicate weathering and CO2 drawdown rates over geologic time-scales  

PubMed Central

Global silicate weathering drives long-time-scale fluctuations in atmospheric CO2. While tectonics, climate, and rock-type influence silicate weathering, it is unclear how these factors combine to drive global rates. Here, we explore whether local erosion rates, GCM-derived dust fluxes, temperature, and water balance can capture global variation in silicate weathering. Our spatially explicit approach predicts 1.9–4.6 × 1013 mols of Si weathered globally per year, within a factor of 4–10 of estimates of global silicate fluxes derived from riverine measurements. Similarly, our watershed-based estimates are within a factor of 4–18 (mean of 5.3) of the silica fluxes measured in the world's ten largest rivers. Eighty percent of total global silicate weathering product traveling as dissolved load occurs within a narrow range (0.01–0.5 mm/year) of erosion rates. Assuming each mol of Mg or Ca reacts with 1 mol of CO2, 1.5–3.3 × 108 tons/year of CO2 is consumed by silicate weathering, consistent with previously published estimates. Approximately 50% of this drawdown occurs in the world's active mountain belts, emphasizing the importance of tectonic regulation of global climate over geologic timescales. PMID:18952842

Hilley, George E.; Porder, Stephen

2008-01-01

4

Hf and Nd isotopes in marine sediments: Constraints on global silicate weathering  

NASA Astrophysics Data System (ADS)

The combined use of Lu-Hf and Sm-Nd isotope systems potentially offers a unique perspective for investigating continental erosion, but little is known about whether, and to what extent, the Hf-Nd isotope composition of sediments is related to silicate weathering intensity. In this study, Hf and Nd elemental and isotope data are reported for marine muds, leached Fe-oxide fractions and zircon-rich turbidite sands collected off the Congo River mouth, and from other parts of the SE Atlantic Ocean. All studied samples from the Congo fan (muds, Fe-hydroxides, sands) exhibit indistinguishable Nd isotopic composition (? Nd ~ - 16), indicating that Fe-hydroxides leached from these sediments correspond to continental oxides precipitated within the Congo basin. In marked contrast, Hf isotope compositions for the same samples exhibit significant variations. Leached Fe-hydroxide fractions are characterized by ? Hf values (from - 1.1 to + 1.3) far more radiogenic than associated sediments (from - 7.1 to - 12.0) and turbidite sands (from - 27.2 to - 31.6). ? Hf values for Congo fan sediments correlate very well with Al/K (i.e. a well-known index for the intensity of chemical weathering in Central Africa). Taken together, these results indicate that (1) silicate weathering on continents leads to erosion products having very distinctive Hf isotope signatures, and (2) a direct relationship exists between ? Hf of secondary clay minerals and chemical weathering intensity. These results combined with data from the literature have global implications for understanding the Hf-Nd isotope variability in marine precipitates and sediments. Leached Fe-hydroxides from Congo fan sediments plot remarkably well on an extension of the 'seawater array' (i.e. the correlation defined by deep-sea Fe-Mn precipitates), providing additional support to the suggestion that the ocean Hf budget is dominated by continental inputs. Fine-grained sediments define a diffuse trend, between that for igneous rocks and the 'seawater array', which we refer to as the 'zircon-free sediment array' (? Hf = 0.91 ? Nd + 3.10). Finally, we show that the Hf-Nd arrays for seawater, unweathered igneous rocks, zircon-free and zircon-bearing sediments (? Hf = 1.80 ? Nd + 2.35) can all be reconciled, using Monte Carlo simulations, with a simple weathering model of the continental crust.

Bayon, G.; Burton, K. W.; Soulet, G.; Vigier, N.; Dennielou, B.; Etoubleau, J.; Ponzevera, E.; German, C. R.; Nesbitt, R. W.

2009-01-01

5

Silicate weathering in anoxic marine sediments  

NASA Astrophysics Data System (ADS)

Two sediment cores retrieved at the northern slope of Sakhalin Island, Sea of Okhotsk, were analyzed for biogenic opal, organic carbon, carbonate, sulfur, major element concentrations, mineral contents, and dissolved substances including nutrients, sulfate, methane, major cations, humic substances, and total alkalinity. Down-core trends in mineral abundance suggest that plagioclase feldspars and other reactive silicate phases (olivine, pyroxene, volcanic ash) are transformed into smectite in the methanogenic sediment sections. The element ratios Na/Al, Mg/Al, and Ca/Al in the solid phase decrease with sediment depth indicating a loss of mobile cations with depth and producing a significant down-core increase in the chemical index of alteration. Pore waters separated from the sediment cores are highly enriched in dissolved magnesium, total alkalinity, humic substances, and boron. The high contents of dissolved organic carbon in the deeper methanogenic sediment sections (50-150 mg dm-3) may promote the dissolution of silicate phases through complexation of Al3+ and other structure-building cations. A non-steady state transport-reaction model was developed and applied to evaluate the down-core trends observed in the solid and dissolved phases. Dissolved Mg and total alkalinity were used to track the in-situ rates of marine silicate weathering since thermodynamic equilibrium calculations showed that these tracers are not affected by ion exchange processes with sediment surfaces. The modeling showed that silicate weathering is limited to the deeper methanogenic sediment section whereas reverse weathering was the dominant process in the overlying surface sediments. Depth-integrated rates of marine silicate weathering in methanogenic sediments derived from the model (81.4-99.2 mmol CO2 m-2 year-1) are lower than the marine weathering rates calculated from the solid phase data (198-245 mmol CO2 m-2 year-1) suggesting a decrease in marine weathering over time. The production of CO2 through reverse weathering in surface sediments (4.22-15.0 mmol CO2 m-2 year-1) is about one order of magnitude smaller than the weathering-induced CO2 consumption in the underlying sediments. The evaluation of pore water data from other continental margin sites shows that silicate weathering is a common process in methanogenic sediments. The global rate of CO2 consumption through marine silicate weathering estimated here as 5-20 Tmol CO2 year-1 is as high as the global rate of continental silicate weathering.

Wallmann, K.; Aloisi, G.; Haeckel, M.; Tishchenko, P.; Pavlova, G.; Greinert, J.; Kutterolf, S.; Eisenhauer, A.

2008-06-01

6

Natural Weathering Rates of Silicate Minerals  

NASA Astrophysics Data System (ADS)

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

White, A. F.

2003-12-01

7

Chemical weathering rates of silicate-dominated lithological classes and associated liberation rates of phosphorus on the Japanese Archipelago—Implications for global scale analysis  

Microsoft Academic Search

Lithology is an important characteristic of the terrestrial surface, whose properties influence chemical weathering rates. Specifically non-silicate minerals may contribute significantly to the weathering derived fluxes from silicate-dominated lithological classes. The Japanese Archipelago consists of predominantly silicate-dominated lithologies with a high proportion of volcanics. However, the spatially explicit representation of chemical weathering rates remains difficult for such a large region,

Jens Hartmann; Nils Moosdorf

2011-01-01

8

Controlling The Global Weather.  

NASA Astrophysics Data System (ADS)

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 ethical questions. The nation that controls its own weather will perforce control the weather of other nations. Weather "wars" are conceivable. An international treaty may be required, limiting the use of weather control technology.

Hoffman, Ross N.

2002-02-01

9

Enhanced carbonate and silicate weathering accelerates recovery from fossil fuel CO2 perturbations  

Microsoft Academic Search

Increasing atmospheric CO2 and surface temperatures should increase carbonate and silicate weathering rates, directly via warming, and indirectly via the CO2 fertilization effect enhancing plant productivity. Enhanced weathering should in turn increase alkalinity input to the ocean and accelerate long-term CO2 uptake. We added silicate and carbonate weathering and carbonate sediments to an existing global carbon cycle and surface temperature

Timothy M. Lenton; Clare Britton

2006-01-01

10

Geochemistry of large river suspended sediments: Silicate weathering or recycling tracer?  

SciTech Connect

This study focuses on the major and trace element composition of suspended sediments transported by the world's largest rivers. Its main purpose is to answer the following question: is the degree of weathering of modern river-borne particles consistent with the estimated river dissolved loads derived from silicate weathering? In agreement with the well known mobility of elements during weathering of continental rocks, the authors confirm that river sediments are systematically depleted in Na, K, Ba with respect to the Upper Continental Crust. For each of these mobile elements, a systematics of weathering indexes of river-borne solids is attempted. A global consistency is found between all these indexes. Important variations in weathering intensities exist. A clear dependence of weathering intensities with climate is observed for the rivers draining mostly lowlands. However, no global correlation exists between weathering intensities and climatic or relief parameters because the trend observed for lowlands is obscured by rivers draining orogenic zones. An inverse correlation between weathering intensities and suspended sediment concentrations is observed showing that the regions having the highest rates of physical denudation produce the least weathered sediments. Finally, chemical and physical weathering are compared through the use of a simple steady state model. The authors show that the weathering intensities of large river suspended sediments can only be reconciled with the (silicate-derived) dissolved load or rivers, by admitting that most of the continental rocks submitted to weathering in large river basins have already suffered previous weathering cycles. A simple graphical method is proposed for calculating the proportion of sedimentary recycling in large river basins. Finally, even if orogenic zones produce weakly weathered sediments, the authors emphasize the fact that silicate chemical weathering rates (and hence CO{sub 2} consumption rates by silicate weathering) are greatly enhanced in mountains simply because the sediment yields in orogenic drainage basins are higher. Hence, the parameters that control chemical weathering rates would be those that control physical denudation rates.

Gaillardet, J.; Dupre, B.; Allegre, C.J.

1999-12-01

11

Silicate weathering and CO2 consumption within agricultural landscapes, the Ohio-Tennessee River Basin  

Technology Transfer Automated Retrieval System (TEKTRAN)

Myriad studies have shown the extent of human alteration to global biogeochemical cycles. Yet, there is only a limited understanding of the influence that humans have over silicate weathering fluxes; fluxes that have regulated atmospheric carbon dioxide concentrations and global climate over geologi...

12

The geoengineering potential of artificially enhanced silicate weathering of olivine  

NASA Astrophysics Data System (ADS)

Geoengineering is a proposed action to manipulate Earth's climate in order to counteract global warming from anthropogenic greenhouse gas emissions. We investigate in more detail the potential of a specific geoengineering technique, the carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification, because it influences the global climate via the carbon cycle. We here show the consequences of this technique for the chemistry of the surface ocean at rates necessary for geoengineering. We calculate that olivine dissolution has the potential to sequestrate up to one Pg C yr-1 directly, if olivine is distributed as fine powder over land areas of the humid tropics. The carbon sequestration potential is limited by the saturation concentration of silicic acid. In our calculations for the Amazon and Congo river catchments a maximum annual dissolution of 1.8 and 0.4 Pg of olivine seems possible, corresponding to the sequestration of 0.5 and 0.1 Pg C yr-1. Open water dissolution of fine grained olivine and an enhancement of the biological pump by the rising riverine input of silicic acid might increase our estimate of the carbon sequestration, but additional research is needed here. We finally calculate with a carbon cycle model the consequences of sequestration rates of 1 to 5 Pg C yr-1 for the 21st century by this technique. At maximum this technique would reduce global warming by 1 K and counteract ocean acidification by a rise in surface ocean pH by 0.1 in the year 2100.

Köhler, Peter; Hartmann, Jens; Wolf-Gladrow, Dieter A.

2010-05-01

13

Geoengineering potential of artificially enhanced silicate weathering of olivine.  

PubMed

Geoengineering is a proposed action to manipulate Earth's climate in order to counteract global warming from anthropogenic greenhouse gas emissions. We investigate the potential of a specific geoengineering technique, carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification, because it influences the global climate via the carbon cycle. If important details of the marine chemistry are taken into consideration, a new mass ratio of CO(2) sequestration per olivine dissolution of about 1 is achieved, 20% smaller than previously assumed. We calculate that this approach has the potential to sequestrate up to 1 Pg of C per year directly, if olivine is distributed as fine powder over land areas of the humid tropics, but this rate is limited by the saturation concentration of silicic acid. In our calculations for the Amazon and Congo river catchments, a maximum annual dissolution of 1.8 and 0.4 Pg of olivine seems possible, corresponding to the sequestration of 0.5 and 0.1 Pg of C per year, but these upper limit sequestration rates come at the environmental cost of pH values in the rivers rising to 8.2. Open water dissolution of fine-grained olivine and an enhancement of the biological pump by the rising riverine input of silicic acid might increase our estimate of the carbon sequestration, but additional research is needed here. We finally calculate with a carbon cycle model the consequences of sequestration rates of 1-5 Pg of C per year for the 21st century by this technique. PMID:21059941

Köhler, Peter; Hartmann, Jens; Wolf-Gladrow, Dieter A

2010-11-23

14

Geoengineering potential of artificially enhanced silicate weathering of olivine  

PubMed Central

Geoengineering is a proposed action to manipulate Earth’s climate in order to counteract global warming from anthropogenic greenhouse gas emissions. We investigate the potential of a specific geoengineering technique, carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification, because it influences the global climate via the carbon cycle. If important details of the marine chemistry are taken into consideration, a new mass ratio of CO2 sequestration per olivine dissolution of about 1 is achieved, 20% smaller than previously assumed. We calculate that this approach has the potential to sequestrate up to 1 Pg of C per year directly, if olivine is distributed as fine powder over land areas of the humid tropics, but this rate is limited by the saturation concentration of silicic acid. In our calculations for the Amazon and Congo river catchments, a maximum annual dissolution of 1.8 and 0.4 Pg of olivine seems possible, corresponding to the sequestration of 0.5 and 0.1 Pg of C per year, but these upper limit sequestration rates come at the environmental cost of pH values in the rivers rising to 8.2. Open water dissolution of fine-grained olivine and an enhancement of the biological pump by the rising riverine input of silicic acid might increase our estimate of the carbon sequestration, but additional research is needed here. We finally calculate with a carbon cycle model the consequences of sequestration rates of 1–5 Pg of C per year for the 21st century by this technique. PMID:21059941

Köhler, Peter; Hartmann, Jens; Wolf-Gladrow, Dieter A.

2010-01-01

15

Global Weather Patterns  

NSDL National Science Digital Library

This tutorial introduces students to global weather patterns and how they affect the kinds of trees and plants that grow in different latitudes of the Earth. The discussion covers the tropics and the lush rainforests that live there, temperate forests in the mid-latitudes, and boreal forests in the far north. There is also a description of how treeless areas occur in various climate zones (desert, tundra, savannah), and how plants adapt to low-water conditions in the desert. A quiz and glossary are included.

16

Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering  

PubMed Central

Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to ‘trenching’ of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO2 and climate history. PMID:22859556

Quirk, Joe; Beerling, David J.; Banwart, Steve A.; Kakonyi, Gabriella; Romero-Gonzalez, Maria E.; Leake, Jonathan R.

2012-01-01

17

Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering.  

PubMed

Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to 'trenching' of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO(2) and climate history. PMID:22859556

Quirk, Joe; Beerling, David J; Banwart, Steve A; Kakonyi, Gabriella; Romero-Gonzalez, Maria E; Leake, Jonathan R

2012-12-23

18

Grasslands, silicate weathering and diatoms: Cause and effect  

SciTech Connect

Diatoms are silica-limited, photosynthetic, single-celled eukaryotes that today occupy a wide variety of habitats both in freshwater and marine environments. Ultimately the silica they use is derived from the weathering of silicates on land. Although marine diatoms first appear in the Jurassic, the fossil record shows a remarkable correlation between the Mid-Miocene appearance of widespread grasslands and the drastic increase in diatom-rich deposits in freshwater, as well as in marine environments throughout the world. Grasses actively weather silicates, accumulating soluble silica into their leaves. Decomposing grasses release this soluble silica into the soil from whence it is transported into lakes and oceans and made available to diatoms. Grasses also probably increased chemical weathering, and hence the release of soluble silica, in previously weakly vegetated semi-arid areas. Increased weathering of silicates also led to cooler climates as evidenced by the Mid-Miocene [delta][sup 18]O record. The author suggests that the Tertiary expansion of grasslands is responsible for the explosive increase in diversity and abundance of diatoms in the oceans and freshwaters of the Mid-Miocene.

Johansson, A.K. (Columbia Univ., Palisades, NY (United States). Dept. of Geological Sciences)

1993-03-01

19

An Evaluation of Ethyl Silicate-Based Grouts for Weathered Silicate Stones  

NASA Astrophysics Data System (ADS)

Culturally significant monuments made of weathered siliceous stone often display sub-surface condition issues such as cracks and voids. These issues require grouts that are ideally compatible with the composition and properties of the substrate. Based on the successful application of ethyl silicates as consolidants in recent literature, this study examines possible formulation pathways for the development of a grout incorporating ethyl silicate. Tetraethylorthosilicate (TEOS), dibutyltin dilaurate (DBTL) as a catalyst, silicone oil (PDMS), various grades of ground quartz, sepiolite, and hollow glass spheres were used in differing concentrations to create samples. These were visually and physically assessed on workability, separation, shrinkage, cracking, strength, and flexibility. Quantitative analysis was performed on selected formulations using UV-Vis-NIR reflectance spectroscopy in coordination with a weight loss experiment to investigate kinetics, dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). Successful formulations tended to include oligomeric TEOS, crushed quartz of mixed grades, sepiolite powder, and PDMS, and show promise for future investigations.

Dolph, Brittany Helen

20

Tectonic and climatic controls on long-term silicate weathering in Asia since 5 Ma  

E-print Network

Tectonic and climatic controls on long-term silicate weathering in Asia since 5 Ma Shiming Wan,1 tectonic deforma- tion, climate, atmospheric CO2 concentrations and conti- nental weathering and erosion of paleo-climate and pCO2, the history of long- term silicate weathering in the Himalaya and Tibetan

Clift, Peter

21

Long-term Stability of Global Erosion Rates and1 Weathering during late Cenozoic Cooling2  

E-print Network

1 of 18 Long-term Stability of Global Erosion Rates and1 Weathering during late Cenozoic Cooling2 3 and is7 removed from the atmosphere by silicate rock weathering and organic carbon8 burial. This balance of continental11 rock weathering and erosion1,2 are superimposed on fluctuations in organic12 carbon burial3

Willenbring, Jeb F.

22

Silicate Mineral Weathering Reponses to Increasing Atmospheric CO2, Plants and Climate Evolution  

NASA Astrophysics Data System (ADS)

Mathematical modelling results of weathering processes in modern soils shed light on the role of land plants in weathering processes. Application to catchments in the boreal coniferous region of northern Europe demonstrates a stabilising biological feedback mechanism between hypothesised increasing atmospheric CO2 levels and silicate mineral weathering rates. The modelled feedback response agrees within a factor of 2 to that calculated by a weathering feedback function of the type generally used in global geochemical carbon cycle models of the Earth's Phanerozoic atmospheric CO2 history. Sensitivity analysis to model parameters indicate that the weathering feedback response is particularly sensitive to soil structure; its porosity, depth and water content. This suggests that the role of land plants to influence these soil characteristics are an important factor in the feedback to atmospheric CO2 levels. The model yields a relatively low sensitivity of soil pH to plant productivity. This is due to more rapid decomposition of dissolved organic carbon (DOC) under warmer conditions. Because DOC fluxes strongly influence the soil water proton balance and pH, this increased decomposition rate dampens the feedback between productivity and weathering. The conceptual model of linkages between biological, geochemical and hydrological processes is based on the influence of land plants and their associated soil microbial populations to influence the dynamics of nutrient elements in soil pore waters and the resulting impact of soil pore water composition on silicate mineral weathering rates. The translation to the mathematical description of these processes is through application of mass and flux balance from first principles. Sources and sinks for elements are based on stoichiometric mass balance equations that described coupled element transformations during biomass production and decomposition, microbial decomposition of dissolved organic carbon and element mass transfer from primary silicate minerals and formation of secondary oxide and clay mineral phases. Rapid, reversible transformations are described by thermodynamic mass action and slow, irreversible processes by kinetic mass action. This process-modelling approach to quantify the biological weathering feedback to atmospheric CO2 demonstrates the potential for a far-more mechanistic description of weathering feedback in simulations of the global geochemical carbon cycle.

Banwart, S. A.; Taylor, L.; Leake, J.; Beerling, D.

2009-04-01

23

Global ocean data for global weather and climate monitoring  

E-print Network

Jason-2 Global ocean data for global weather and climate monitoring #12;Global ocean data to meet of coupled ocean-atmosphere models used in climate research. Also, worldwide data sets are required importance for weather and climate. Currently, ocean altimetry satellites measure the height of the ocean

Stoffelen, Ad

24

Global hydration kinetics of tricalcium silicate cement  

NASA Astrophysics Data System (ADS)

We reconsider a number of measurements for the overall hydration kinetics of tricalcium silicate pastes having an initial water to cement weight ratio close to 0.5. We find that the time dependent ratio of hydrated and unhydrated silica mole numbers can be well characterized by two power laws in time, x/(1-x)~(t/t×)?. For early times tt× a parabolic behavior (?=1/2). The crossover time is estimated as t×~16 h. We interpret these results in terms of a global second-order rate equation indicating that (a) hydrates catalyze the hydration process for tt×, and (c) the value of the associated rate constant is of magnitude 6×10-7-7×10-6 l mol-1 s-1. We argue, by considering that the hydration process actually occurs via diffusion limited precipitation, that the exponents ?=5/2 and ?=1/2 directly indicate a preferentially platelike hydrate microstructure. This is essentially in agreement with experimental observations of cellular hydrate microstructures for this class of materials.

Tzschichholz, F.; Zanni, H.

2001-07-01

25

Space Weather and the Global Positioning System  

Microsoft Academic Search

The ability to monitor space weather in near-real time is required as our society becomes increasingly dependent on technological systems such as the Global Positioning System (GPS). Certain critical applications such as railway control, highway traffic management, emergency response, commercial aviation, and marine navigation require high-precision positioning. As a consequence, these applications require real-time knowledge of space weather effects. In

Anthea Coster; Attila Komjathy

2008-01-01

26

Control of Regional and Global Weather  

E-print Network

Author suggests and researches a new revolutionary idea for regional and global weather control. He offers to cover cities, bad regions of country, full country or a continent by a thin closed film with control clarity located at a top limit of the Earth troposphere (4 - 6 km). The film is supported at altitude by small additional atmospheric pressure and connected to ground by thin cables. It is known, the troposphere defines the Earth weather. Authors show this closed dome allows to do a full control of the weather in a given region (the day is always fine, the rain is only in night, no strong wind). The average Earth (white cloudy) reflectance equal 0.3 - 0.5. That means the Earth losses about 0.3 - 0.5 of a solar energy. The dome controls the clarity of film and converts the cold regions to subtropics and creates the hot deserts, desolate wildernesses to the prosperous regions with temperate climate. That is a realistic and the cheapest method of the weather control in the Earth at the current time. Key words: Global weather control, gigantic film dome, converting a cold region to subtropics, converting desolate wilderness to a prosperous region.

Alexander Bolonkin

2007-01-09

27

Global economic impacts of severe Space Weather.  

NASA Astrophysics Data System (ADS)

Coronal mass ejections (CMEs) strong enough to create electromagnetic effects at latitudes below the auroral oval are frequent events, and could have substantial impacts on electric power transmission and telecommunication grids. Modern society’s heavy reliance on these domestic and international networks increases our susceptibility to such a severe Space Weather event. Using a new high-resolution model of the global economy we simulate the economic impact of large CMEs for 3 different planetary orientations. We account for the economic impacts within the countries directly affected as well as the post-disaster economic shock in partner economies through international trade. For the CMEs modeled the total global economic impacts would range from US 380 billion to US 1 trillion. Of this total economic shock 50 % would be felt in countries outside the zone of direct impact, leading to a loss in global GDP of 0.1 - 1 %. A severe Space Weather event could lead to global economic damages of the same order as other weather disasters, climate change, and extreme financial crisis.

Schulte In Den Baeumen, Hagen; Cairns, Iver

28

Microbial control of silicate weathering in organic-rich ground water  

Microsoft Academic Search

An in situ microcosm study of the influence of surface-adhering bacteria on silicate diagenesis in a shallow petroleum-contaminated aquifer showed that minerals were colonized by indigenous bacteria and chemically weathered at a rate faster than theoretically predicted. Feldspar and quartz fragments were placed in anoxic, organic-rich ground water, left for 14 months, recovered, and compared to unreacted controls with scanning

F. K. Hiebert; P. C. Bennett

1992-01-01

29

Submarine weathering of silicate minerals and the extent of pore water freshening at active continental margins  

NASA Astrophysics Data System (ADS)

In order to investigate how submarine weathering processes may affect the water balance of sediments at convergent plate margins, six sediment cores were retrieved off Central Chile at water depth between ˜800 and 4000 m. The sediment solid phase was analyzed for its major element composition and the pore fluids were analyzed for dissolved sulfate, sulfide, total alkalinity, major cations, chloride, bromide, iodide, hydrocarbons as well as the carbon isotopic composition of methane. Because of negligible weathering on land, surface sediments off Central Chile are rich in reactive silicate minerals and have a bulk composition similar to volcanic rocks in the adjacent Andes. Deep-sourced fluxes of alkalinity, cations and chloride indicate that silicate minerals are subject to weathering in the forearc during burial. Comparison of deep-sourced signals with data from nearby Ocean Drilling Program Sites reveals two different types of weathering processes: In shallow (tens of meters), methanic sediments of slope basins with high organic carbon burial rates, reactive silicate minerals undergo incongruent dissolution through reaction with CO2 from methanogenesis. At greater burial depth (hundreds of meters), silicate weathering is dominated by authigenic smectite formation. This process is accompanied by uptake of water into the clay interlayers thus leading to elevated salinities in the surrounding pore water. Deep-seated smectite formation is more widespread than shallow silicate dissolution, as it is independent from the availability of CO2 from methanogenesis. Although solute transport is not focused enough to form cold seeps in the proper sense, tectonically induced, diffuse fluid flow transfers the deep-seated signal of smectite formation into the shallow sediments. The temperature-controlled conversion of smectite to illite is considered the most important dehydration process in marine forearc environments (depth of kilometers). However, in agreement with other studies at active margins (e.g. Aleutians, Cascadia, Nankai Trough) and despite ubiquitous evidence for smectite formation, little evidence for seafloor seepage of dehydration fluids could be found off Central Chile. We argue that the circular process of pore water uptake during smectite formation and release upon illitization implies a balanced freshwater budget and therefore a rather limited potential for net pore water freshening on a margin-wide scale. According to this rationale, pore water freshening at seafloor seeps preferentially occurs at lower latitudes (Central America, Barbados, Mediterranean Ridge) where terrestrial weathering is more intense thus leading to external (i.e. detrital) smectite and thus freshwater inputs to the subduction system.

Scholz, Florian; Hensen, Christian; Schmidt, Mark; Geersen, Jacob

2013-01-01

30

Rates and mechanisms of chemical weathering of ferromagnesium silicate minerals on Mars  

NASA Astrophysics Data System (ADS)

Ferric-bearing asemblages on Mars indicate that oxidative weathering of surface basalts has occurred during planetary evolution. In aqueous environments chemical weathering proceeded through stages of dissolution of Fe(2+)-bearing silicate and sulfide minerals, oxidation of dissolved Fe(2+) to Fe(3+) ions, and hydrolysis of dissolved Fe(3+) to insoluble ferric-bearing oxide, oxyhydride, and hydroxysulfate phases. Experimental data for terrestrial olivines and pyroxenes with compositions resembling assemblages in SNC meteorites are reviewed in order to determine when these ferrolysis reactions occurred on Mars and to estimate rates of chemical weathering of minerals in Martian surface rocks. Since low temperatures currently exist on Mars, dissolution rates of basaltic minerals are probably stoichiometric and extremely slow on the present-day Martian surface, but may have been much faster in the past, especially if acidic ground water and a more temperate climate prevailed.

Burns, Roger G.

1993-10-01

31

Temporal and spatial variation of surface reaction rates in porous media: Applications to silicate weathering  

NASA Astrophysics Data System (ADS)

Percolation theory provides a promising framework for modeling transport in heterogeneous porous media, including hydraulic and electrical conductivity, air permeability, gas diffusivity, and solute transport. Using percolation concepts (e.g., critical path analysis, fractal scaling of percolation clusters, and cluster statistics), we developed a physically-based model for predicting solute transport. Our model predicted spatial solute distributions as a function of time, and arrival time distributions as a function of system size. Our solute transport predictions gave good matches to a wide range of experiments. We now apply our solute transport model to silicate weathering. We assume that surface chemical reactions are at equilibrium at the scale of a single pore, but that at larger length scales, reactions are limited by transport of reactants or products. Using results from published field experiments, we find that the temporal and spatial dependence derived from solute velocity successfully predicts the measured time- and length-dependence of reaction rates and weathering of silicate minerals over a wide range of time and length scale. A similar analysis of lab experiments (uranium breakthrough curves measured in two short and long columns from the Hanford site) indicates that normalized reaction rate versus normalized time follow 2D invasion and 3D random percolation.

Ghanbarian, B.; Hunt, A. G.; Skinner, T. E.; Ewing, R. P.

2013-12-01

32

Investigating the Climate System: Weather- Global Awareness Tour  

NSDL National Science Digital Library

Through the scenario of planning concert locations for a "Global Awareness Tour", students will research, interpret, and explain general characteristics of weather in tropical regions. They will learn to use data from the Tropical Rainfall Measuring Mission (TRMM) satellite instruments to make observations on extreme weather situations, develop their Internet research skills, and enhance communication and presentation skills. This module is designed to be used at the end of a unit on weather. Students are expected to understand temperature, pressure, precipitation, clouds, winds, lightning, mid-latitude weather patterns, basic geography, and geographical influences on weather patterns. They should also be familiar with the TRMM satellite instruments and mission.

Passow, Michael

33

The fluvial geochemistry, contributions of silicate, carbonate and saline-alkaline components to chemical weathering flux and controlling parameters: Narmada River (Deccan Traps), India  

NASA Astrophysics Data System (ADS)

The Narmada River in India is the largest west-flowing river into the Arabian Sea, draining through the Deccan Traps, one of the largest flood basalt provinces in the world. The fluvial geochemical characteristics and chemical weathering rates (CWR) for the mainstream and its major tributaries were determined using a composite dataset, which includes four phases of seasonal field (spot) samples (during 2003 and 2004) and a decade-long (1990-2000) fortnight time series (multiannual) data. Here, we demonstrate the influence of minor lithologies (carbonates and saline-alkaline soils) on basaltic signature, as reflected in sudden increases of Ca 2+-Mg 2+ and Na + contents at many locations along the mainstream and in tributaries. Both spot and multiannual data corrected for non-geological contributions were used to calculate the CWR. The CWR for spot samples (CWR spot) vary between 25 and 63 ton km -2 year -1, showing a reasonable correspondence with the CWR estimated for multiannual data (CWR multi) at most study locations. The weathering rates of silicate ( SilWR), carbonate ( CarbWR) and evaporite ( Sal-AlkWR) have contributed ˜38-58, 28-45 and 8-23%, respectively to the CWR spot at different locations. The estimated SilWR (11-36 ton km -2 year -1) for the Narmada basin indicates that the previous studies on the North Deccan Rivers (Narmada-Tapti-Godavari) overestimated the silicate weathering rates and associated CO 2 consumption rates. The average annual CO 2 drawdown via silicate weathering calculated for the Narmada basin is ˜0.032 × 10 12 moles year -1, suggesting that chemical weathering of the entire Deccan Trap basalts consumes approximately 2% (˜0.24 × 10 12 moles) of the annual global CO 2 drawdown. The present study also evaluates the influence of meteorological parameters (runoff and temperature) and physical weathering rates (PWR) in controlling the CWR at annual scale across the basin. The CWR and the SilWR show significant correlation with runoff and PWR. On the basis of observed wide temporal variations in the CWR and their close association with runoff, temperature and physical erosion, we propose that the CWR in the Narmada basin strongly depend on meteorological variability. At most locations, the total denudation rates (TDR) are dominated by physical erosion, whereas chemical weathering constitutes only a small part (<10%). Thus, the CWR to PWR ratio for the Narmada basin can be compared with high relief small river watersheds of Taiwan and New Zealand (1-5%) and large Himalayan Rivers such as the Brahmaputra and the Ganges (8-9%).

Gupta, Harish; Chakrapani, Govind J.; Selvaraj, Kandasamy; Kao, Shuh-Ji

2011-02-01

34

Electrochemical Acceleration of Carbonate and Silicate Weathering for CO2 Mitigation  

NASA Astrophysics Data System (ADS)

Carbonate and many silicate minerals dissolve in strong acids, and such acids are commonly generated at the anode of a conventional saline water electrolysis cell. It was therefore reasoned that encasing such an anode with base minerals would lead to enhanced mineral dissolution and hence increased hydroxide (base) generation at the cathode, formed in course of splitting water, generating H2 and OH-. Subsequent exposue of the alkalized solution to CO2 (e.g., as in air) would lead to absorption of the CO2 and formation of stable dissolved or solid (bi)carbonates for carbon sequestration. Previously, it has been demonstrated that mineral carbonate encasement of a seawater electrolysis cell anode indeed generated basic solutions in excess of pH 9 that were subsequently neutralized via contact with air CO2, increasing the carbon content of the initial seawater by 30% (Rau, G.H. 2008. Environ Sci. Techol. 42, 8935-). To test such a weathering/CO2 capture scheme using silicate minerals, either powdered wollastonite or ultramafic rock standard (UM-4) was encased around the anode of an electrolysis cell composed of graphite electrodes and a 0.25M Na2SO4 electrolyte solution. After 0.5 to 1.5 hrs of electricity application (3.5Vdc, 5-10mA), the electrolyte pH rose to as much as 11.1 (initial and blank solution pH's <6.6). Subequent bubbling of these basic solutions with air lowered pH by at least 2 units and increased dissolve carbon content (primarily bicarbonate) by as much as 50X that of the blanks. While Ca2+ and Mg2+ concentrations were elevated, these were insufficient to balance the majority of the bicarbonate anions formed in solution. This suggests that in these experiments the silicate minerals acted as a neutralizer of the anolyte acid, H2SO4, forming mostly insoluble CaSO4 and MgSO4 at the anode. This then allowed NaOH normally produced at the cathode to accumulate in solution, in turn reacting with air CO2 to form NaHCO3. Longer electrolysis times and/or alternative electrolyte solutions might allow formation and precipitation of Ca or Mg carbonates. Such electrochemistry might ultimately provide a safe, efficient way to harness the planet's: i) large, off-peak or off-grid renewable electricity potential, ii) abundant basic minerals, and iii) vast natural brine electrolytes for large-scale air CO2 mitigation and carbon-negative H2 production.

Rau, G. H.; Carroll, S.

2011-12-01

35

Economic value of global weather measurements  

SciTech Connect

Global sensor networks could support increased activity in a number of economic sectors. Potential benefits and the predicted time scales required to realize them are estimated. Benefits are particular compelling for fundamental reasons for aviation, hotels and restaurants, natural disasters, construction, agriculture, and apparel. These benefits can be captured by simple logistic approximations.

Canavan, G.; Butterworth, J.

1999-02-19

36

The contribution of weathering of the main Alpine rivers on the global carbon cycle  

NASA Astrophysics Data System (ADS)

On geological time-scales the carbon fluxes from the solid Earth to the atmosphere mainly result from volcanism and metamorphic-decarbonation processes, whereas the carbon fluxes from atmosphere to solid Earth mainly depend on weathering of silicates and carbonates, biogenic precipitation and removal of CaCO3 in the oceans and volcanic gases - seawater interactions. Quantifying each contribution is critical. In this work, we estimate the atmospheric CO2 uptake by weathering in the Alps, using results of the study of the dissolved loads transported by 33 main Alpine rivers. The chemical composition of river water in unpolluted areas is a good indicator of surface weathering processes (Garrels and Mackenzie, 1971; Drever, 1982; Meybeck, 1984; Tardy, 1986; Berner and Berner, 1987; Probst et al., 1994). The dissolved load of streams originates from atmospheric input, pollution, evaporite dissolution, and weathering of carbonate and silicate rocks, and the application of mass balance calculations allows quantification of the different contributions. In this work, we applied the MEGA (Major Element Geochemical Approach) geochemical code (Amiotte Suchet, 1995; Amiotte Suchet and Probst, 1996) to the chemical compositions of the selected rivers in order to quantify the atmospheric CO2 consumed by weathering in Alpine region. The drainage basins of the main Alpine rivers were sampled near the basin outlets during dry and flood seasons. The application of the MEGA geochemical consisted in several steps. First, we subtracted the rain contribution in river waters knowing the X/Cl (X = Na, K, Mg, Ca) ratios of the rain. Next, we considered that all (Na+K) came from silicate weathering. The average molar ratio Rsil = (Na+K)/(Ca+Mg) for rivers draining silicate terrains was estimated from unpolluted French stream waters draining small monolithological basins (Meybeck, 1986; 1987). For the purpose, we prepared a simplified geo-lithological map of Alps according to the lithological classification of Meybeck (1986, 1987). Then for each basin we computed Rsil weighted average considering the surface and the mean precipitation for the surface area of each lithology. Lastly, we estimated the (Ca+Mg) originating from carbonate weathering as the remaining cations after silicate correction. Depending on time-scales of the phenomena (shorter than about 1 million year i.e., correlated to the short term carbon cycle, or longer than about 1 million years i.e., correlated to the long-term carbon cycle), we considered different equations for the quantification of the atmospheric CO2 consumed by weathering (Huh, 2010). The results show the net predominance of carbonate weathering on fixing atmospheric CO2 and that, considering the long-term carbon cycle, the amount of atmospheric CO2 uptake by weathering is about one order of magnitude lower than considering the short-term carbon cycle. Moreover, considering the short-term carbon cycle, the mean CO2 consumed by Alpine basins is of the same order of magnitude of the mean CO2 consumed by weathering by the 60 largest rivers of the world estimated by Gaillardet et al. (1999). References Amiotte-Suchet, P. "Cycle Du Carbone, Érosion Chimique Des Continents Et Transfert Vers Les Océans." Sci. Géol. Mém. Strasbourg 97 (1995): 156. Amiotte-Suchet, P., and J.-L. Probst. "Origins of dissolved inorganic carbon in the Garonne river waters: seasonal and interannual variations." Sci. Géologiques Bull. Strasbourg 49, no. 1-4 (1996): 101-126. Berner, E.K., and R.A. Berner. The Global Water Cycle. Geochemistry and Environment. Prentice Halle. Engelwood Cliffs, NJ, 1987. Drever, J.L. The Geochemistry of Natural Waters. Prentice Hall, 1982. Gaillardet, J., B. Dupré, P. Louvat, and C.J. Allègre. "Global Silicate Weathering and CO2 Consumption Rates Deduced from the Chemistry of Large Rivers." Chemical Geology 159 (1999): 3-30. Garrels, R.M., and F.T. Mackenzie. Evolution of Sedimentary Rocks. New York: W.W. Nortonand, 1971. Huh, Y. "Estimation of Atmospheric CO2 Uptake by Silicat

Donnini, Marco; Probst, Jean-Luc; Probst, Anne; Frondini, Francesco; Marchesini, Ivan; Guzzetti, Fausto

2013-04-01

37

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

PubMed Central

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

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

2012-01-01

38

Impact of derived global weather data on simulated crop yields.  

PubMed

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study's objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve as benchmarks to assess impact of climate change scenarios on crop productivity and land use change. Three GWDs (CRU, NCEP/DOE, and NASA POWER data) were evaluated for their ability to simulate Yp and Yw of rice in China, USA maize, and wheat in Germany. Simulations of Yp and Yw based on recorded daily data from well-maintained weather stations were taken as the control weather data (CWD). Agreement between simulations of Yp or Yw based on CWD and those based on GWD was poor with the latter having strong bias and large root mean square errors (RMSEs) that were 26-72% of absolute mean yield across locations and years. In contrast, simulated Yp or Yw using observed daily weather data from stations in the NOAA database combined with solar radiation from the NASA-POWER database were in much better agreement with Yp and Yw simulated with CWD (i.e. little bias and an RMSE of 12-19% of the absolute mean). We conclude that results from studies that rely on GWD to simulate agricultural productivity in current and future climates are highly uncertain. An alternative approach would impose a climate scenario on location-specific observed daily weather databases combined with an appropriate upscaling method. PMID:23801639

van Wart, Justin; Grassini, Patricio; Cassman, Kenneth G

2013-12-01

39

Impact of derived global weather data on simulated crop yields  

PubMed Central

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study's objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve as benchmarks to assess impact of climate change scenarios on crop productivity and land use change. Three GWDs (CRU, NCEP/DOE, and NASA POWER data) were evaluated for their ability to simulate Yp and Yw of rice in China, USA maize, and wheat in Germany. Simulations of Yp and Yw based on recorded daily data from well-maintained weather stations were taken as the control weather data (CWD). Agreement between simulations of Yp or Yw based on CWD and those based on GWD was poor with the latter having strong bias and large root mean square errors (RMSEs) that were 26–72% of absolute mean yield across locations and years. In contrast, simulated Yp or Yw using observed daily weather data from stations in the NOAA database combined with solar radiation from the NASA-POWER database were in much better agreement with Yp and Yw simulated with CWD (i.e. little bias and an RMSE of 12–19% of the absolute mean). We conclude that results from studies that rely on GWD to simulate agricultural productivity in current and future climates are highly uncertain. An alternative approach would impose a climate scenario on location-specific observed daily weather databases combined with an appropriate upscaling method. PMID:23801639

van Wart, Justin; Grassini, Patricio; Cassman, Kenneth G

2013-01-01

40

Entropy Shows that Global Warming Should Cause Increased Variability in the Weather  

E-print Network

Elementary physical reasoning seems to leave it inevitable that global warming would increase the variability of the weather. The first two terms in an approximation to the global entropy are used to show that global warming has increased the free energy available to drive the weather, and that the variance of the weather should increase correspondingly.

John Michael Williams

2001-02-21

41

Oceans Effect on Weather and Climate: Global Precipitation and Energy  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Ocean's Effect on Weather and Climate SciPack. It explores ocean circulation patterns and the effect oceans have on climate. Water in the oceans hold a lot of thermal energy (more than an equal amount of land). Throughout the ocean there is a global, interconnected circulation system that transfers this thermal energy across Earth. The shape of ocean basins and adjacent land masses influence the path of circulation. As ocean currents transfer thermal energy to various locations, the temperature of the atmosphere above the ocean is affected. For example, the condensation of water that has been evaporated from warm seas provides the energy for hurricanes and cyclones. When the pattern of thermal energy released into the atmosphere changes, global weather patterns are affected. An example of a large-scale change like this is the El Ni?o Southern Oscillation, which changes the pattern of thermal energy released into the atmosphere in the Pacific. Learning Outcomes:? Explain how the oceans might influence and affect local weather and climate, given a specific location (on the planet near the ocean) and the local ocean currents.? Describe the cause of hurricanes and explain why they usually occur within specific regions during certain times of the year.? Explain how changes in ocean temperatures (over a period of months) affect factors that influence weather patterns.? List the major variables that affect the transfer of energy through the ocean.

National Science Teachers Association (NSTA)

2007-03-28

42

Oceans Effect on Weather and Climate: Global Climate Patterns  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Ocean's Effect on Weather and Climate SciPack. It explores ocean circulation patterns and the effect oceans have on climate. Water in the oceans hold a lot of thermal energy (more than an equal amount of land). Throughout the ocean there is a global, interconnected circulation system that transfers this thermal energy across Earth. The shape of ocean basins and adjacent land masses influence the path of circulation. As ocean currents transfer thermal energy to various locations, the temperature of the atmosphere above the ocean is affected. For example, the condensation of water that has been evaporated from warm seas provides the energy for hurricanes and cyclones. When the pattern of thermal energy released into the atmosphere changes, global weather patterns are affected. An example of a large-scale change like this is the El Ni?o Southern Oscillation, which changes the pattern of thermal energy released into the atmosphere in the Pacific. Learning Outcomes:? Explain how the oceans might influence and affect local weather and climate, given a specific location (on the planet near the ocean) and the local ocean currents.? Describe the cause of hurricanes and explain why they usually occur within specific regions during certain times of the year.? Explain how changes in ocean temperatures (over a period of months) affect factors that influence weather patterns.? List the major variables that affect the transfer of energy through the ocean.

National Science Teachers Association (NSTA)

2007-03-28

43

Oceans Effect on Climate and Weather: Global Circulation Patterns  

NSDL National Science Digital Library

This Science Object explores ocean circulation patterns and the effect oceans have on climate. Water in the oceans hold a lot of thermal energy (more than an equal amount of land). Throughout the ocean there is a global, interconnected circulation system that transfers this thermal energy across Earth. The shape of ocean basins and adjacent land masses influence the path of circulation. As ocean currents transfer thermal energy to various locations, the temperature of the atmosphere above the ocean is affected. For example, the condensation of water that has been evaporated from warm seas provides the energy for hurricanes and cyclones. When the pattern of thermal energy released into the atmosphere changes, global weather patterns are affected. An example of a large-scale change like this is the El Ni?o Southern Oscillation, which changes the pattern of thermal energy released into the atmosphere in the Pacific. This Science Object is the third of four Science Objects in the Ocean's Effect on Weather and Climate SciPack. Learning Outcomes: ? Explain how the oceans might influence and affect local weather and climate, given a specific location (on the planet near the ocean) and the local ocean currents. ? Describe the cause of hurricanes and explain why they usually occur within specific regions during certain times of the year. ? Explain how changes in ocean temperatures (over a period of months) affect factors that influence weather patterns. ? List the major variables that affect the transfer of energy through the ocea

National Science Teachers Association (NSTA)

2007-03-28

44

Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values  

NASA Astrophysics Data System (ADS)

It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago.

Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

2015-01-01

45

Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values.  

PubMed

It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago. PMID:25583135

Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

2015-01-01

46

Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values  

PubMed Central

It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago. PMID:25583135

Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

2015-01-01

47

Atlas of the global distribution of atmospheric heating during the global weather experiment  

NASA Technical Reports Server (NTRS)

Global distributions of atmospheric heating for the annual cycle of the Global Weather Experiment are estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) Level 3b data set. Distributions of monthly, seasonally, and annually averaged heating are presented for isentropic and isobaric layers within the troposphere and for the troposphere as a whole. The distributions depict a large-scale structure of atmospheric heating that appears spatially and temporally consistent with known features of the global circulation and the seasonal evolution.

Schaack, Todd K.; Johnson, Donald R.

1991-01-01

48

Influence of weather and global warming in chloride ingress into concrete: a stochastic approach  

E-print Network

Influence of weather and global warming in chloride ingress into concrete: a stochastic approach E the influence of weather conditions and global warming on chloride ingress into concrete. The assessment including seasonal variations and global warming is also proposed in this work. Three scenarios of global

Paris-Sud XI, Université de

49

How severe space weather can disrupt global supply chains  

NASA Astrophysics Data System (ADS)

Coronal mass ejections (CMEs) strong enough to create electromagnetic effects at latitudes below the auroral oval are frequent events that could soon have substantial impacts on electrical grids. Modern society's heavy reliance on these domestic and international networks increases our susceptibility to such a severe space-weather event. Using a new high-resolution model of the global economy, we simulate the economic impact of strong CMEs for three different planetary orientations. We account for the economic impacts within the countries directly affected, as well as the post-disaster economic shock in partner economies linked by international trade. For a 1989 Quebec-like event, the global economic impacts would range from USD 2.4 to 3.4 trillion over a year. Of this total economic shock, about 50% would be felt in countries outside the zone of direct impact, leading to a loss in global Gross Domestic Product (GDP) of 3.9 to 5.6%. The global economic damage is of the same order as wars, extreme financial crisis and estimated for future climate change.

Schulte in den Bäumen, H.; Moran, D.; Lenzen, M.; Cairns, I.; Steenge, A.

2014-10-01

50

How severe Space Weather can disrupt global supply chains  

NASA Astrophysics Data System (ADS)

Coronal mass ejections (CMEs) strong enough to create electromagnetic effects at latitudes below the auroral oval are frequent events that could soon have substantial impacts on electrical grids. Modern society's heavy reliance on these domestic and international networks increases our susceptibility to such a severe space weather event. Using a new high-resolution model of the global economy we simulate the economic impact of strong CMEs for 3 different planetary orientations. We account for the economic impacts within the countries directly affected as well as the post-disaster economic shock in partner economies linked by international trade. For a 1989 Quebec-like event the global economic impacts would range from USD 2.4 to 3.4 trillion over a year. Of this total economic shock about 50% would be felt in countries outside the zone of direct impact, leading to a loss in global GDP of 3.9 to 5.6%. The global economic damages are of the same order as wars, extreme financial crisis and estimated for future climate change.

Schulte in den Bäumen, H.; Moran, D.; Lenzen, M.; Cairns, I.; Steenge, A.

2014-06-01

51

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.

Pamela Gore

1995-08-29

52

Shaken and Stirred: A Combined Reaction-Diffusion and Random Rate Model for the Temporal Evolution and Earthquake-induced Hydrodynamics of Silicate Mineral Weathering  

NASA Astrophysics Data System (ADS)

The time dependency of silicate mineral weathering has been explored in the literature in terms of processes and features that are intrinsic and extrinsic to the mineral [1]. However, although the advent of sophisticated reactive transport models has allowed for coupling increasingly complex reaction and transport processes [2,3], a simple and fundamental understanding of the temporal evolution of weathering is lacking. Here, we propose that a purely deterministic approach may not be sufficient given the inherent differences in reactivity over space and time. Therefore, we explore how a combined reaction-diffusion and random rate model - informed by a stochastic distribution of weathering rates K (T-1) - might be able to explain not only the temporal evolution but also the hydrodynamics of weathering during earthquakes; the latter being purportedly described by time-dependent property permeability (L2). Preliminary model results show that (1) an increase in dimensionless quantity ?rp, where ? is the diffusion length (L-1) and rp is the distance between pores (L), leads to a decrease in minimum reaction rate with time from the relation Kmin ? e-?rp/rp ; (2) at a given porosity, a time-dependent decrease in reactivity arises as permeability decreases due to decreasing pore size (and therefore increasing rp), which in turn may be related to the time-dependent feedback between dissolution and precipitation; (3) while permeability is lower in older soils, transient stresses as during earthquakes [4], may induce more efficient "declogging" of pores in these soils than in younger soils due to higher hydrodynamic viscous shear stress, thereby, resulting in a coseismic change in stream discharge Q; and (4) subsequent weathering beyond t~Kmin-1 exhibits a fall in rates, marking the cessation of logarithmic decay possibly due to dissolution-precipitation feedback. [1] White and Brantley (2003), Chem. Geol. 202, 479. [2] Lichtner P.C. (1996), Mineralogical Society of America, 1-81. [3] Maher K., Steefel C.I., White A.F. and Stonestrom D.A. (2009), Geochim. Cosmochim. Acta 73, 2804-2831. [4] Manga M., Beresnev I., Brodsky E. E., Elkhoury J. E., Elsworth D., Ingebritsen S. E., Mays D.C., and Wang C.Y. (2012), Rev. Geophys., 50, RG2004. (A) The evolution of reaction rates K(y-1) derived from published weathering rates as a first-order process. A similar scaling exponent was reported in the decay of marine organic carbon by Middelburg et al. (1993), K(t)=0.21t-0.99; and Rothman and Forney (2007) K(t)=0.23t-1. (B) Plot of global permeability (Gleeson et al. 2011) across a wide range of consolidated and loose hydrolithologies (different symbols) versus corresponding weathering rates from the reaction-diffusion model. Broken line approximates an inflection point (?log10 k -14.5 m2) based on the logistic curve fit (red line). Range of predicted reaction rates agree well with rates derived from the field.

Evaristo, J. A.; Willenbring, J.

2013-12-01

53

Carbon Dioxide Weathering Flux Since the Last Glacial Maximum to the Present, its Control of River Water Composition, and its Role in the Global Carbon Cycle  

NASA Astrophysics Data System (ADS)

A weathering potential ? = (net CO2 consumed)/(HCO3- produced) describes the consumption of CO2 in mineral weathering reactions. Based on the reaction stoichiometry, ? = 0.5 for pure carbonates and 1.0 for the crystalline silicate continental crust, with intermediate values for mixed- mineralogy rocks. Carbon dioxide is the main driver of mineral weathering reactions as an acid derived from the atmosphere and(or) remineralization of organic matter in soil, and it is supplemented by small, but perhaps regionally important, amounts of H2SO4 forming in the oxidation of pyrite. The projected anthropogenic emissions of SO2 to the atmosphere may provide H2SO4 to the continental surface at a rate that is 3 to 5 times greater than its natural production by the oxidation of sedimentary pyrite. The higher H2SO4 input may increase the main ionic concentrations in rivers by ~13%, without significantly affecting the CO2 weathering consumption. Sulfuric acid produces HCO3- or CO2 by reactions with the carbonates. In the global carbon cycle from the Last Glacial Maximum to the present, the CO2 uptake in the weathering layer is comparable to other major fluxes in the atmosphere-land-ocean system. The weathering layer thickness depends on the mineral dissolution rates, reactive mineral surface area, particle size, and rock porosity, not all of which are generally well known. In an average world river, the mass proportions of the main cations and anions differ from those in the weathering source consisting of the sediments and part of the continental crust, because of the differences in mineral solubilities and dissolution rates. A dissolution model of a weathering source (63 weight % average sediment and 37% upper continental crust) gives an average river water composition that agrees very well with the composition ranges of other investigators. This dissolution model gives an average CO2 consumption potential of ? = 0.72 and a sequence of relative stability or persistence in the weathering of the mineral constituents of the sedimentary carbonate, silicate, and evaporite rocks, and the crustal silicates. The calculated CO2 consumption is a weathering flux of 22×1012 mol C/yr, derived mainly from soil-atmosphere CO2 that forms by decomposition of soil organic matter. At the LGM, the consumption rate was smaller, ~13×1012 mol C/yr. Also smaller at the LGM are the computed inorganic and organic carbon transfer rates from land to the ocean, reflecting the lower temperature, smaller land surface area, and smaller phytomass and soil humus reservoirs.

Lerman, A.; Wu, L.; MacKenzie, F. T.

2006-12-01

54

Weather  

NSDL National Science Digital Library

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

Jennie, Miss

2009-10-22

55

Global Cooperation in the Science of Space Weather  

NASA Technical Reports Server (NTRS)

The international space science community had recognized the importance of space weather more than a decade ago, which resulted in a number of international collaborative activities such as the Climate and Weather of the Sun Earth System (CAWSES) by SCOSTEP and the International Space Weather Initiative (ISWI). The ISWI program is a continuation of the successful International Heliophysical Year (IHY) program. These programs have brought scientists together to tackle the scientific issues behind space weather. In addition to the vast array of space instruments, ground based instruments have been deployed, which not only filled voids in data coverage, but also inducted young scientists from developing countries into the scientific community. This paper presents a summary of CAWSES and ISWI activities that promote space weather science via complementary approaches in international scientific collaborations. capacity building. and public outreach.

Gopalswamy, Nat

2011-01-01

56

Silicate production and availability for mineral carbonation.  

PubMed

Atmospheric carbon dioxide sequestered as carbonates through the accelerated weathering of silicate minerals is proposed as a climate change mitigation technology with the potential to capture billions of tonnes of carbon per year. Although these materials can be mined expressly for carbonation, they are also produced by human activities (cement, iron and steel making, coal combustion, etc.). Despite their potential, there is poor global accounting of silicates produced in this way. This paper presents production estimates (by proxy) of various silicate materials including aggregate and mine waste, cement kiln dust, construction and demolition waste, iron and steel slag, and fuel ash. Approximately 7-17 billion tonnes are produced globally each year with an approximate annual sequestration potential of 190-332 million tonnes C. These estimates provide justification for additional research to accurately quantify the contemporary production of silicate minerals and to determine the location and carbon capture potential of historic material accumulations. PMID:21332128

Renforth, P; Washbourne, C-L; Taylder, J; Manning, D A C

2011-03-15

57

Atmospheric and oceanographic research review, 1978. [global weather, ocean/air interactions, and climate  

NASA Technical Reports Server (NTRS)

Research activities related to global weather, ocean/air interactions, and climate are reported. The global weather research is aimed at improving the assimilation of satellite-derived data in weather forecast models, developing analysis/forecast models that can more fully utilize satellite data, and developing new measures of forecast skill to properly assess the impact of satellite data on weather forecasting. The oceanographic research goal is to understand and model the processes that determine the general circulation of the oceans, focusing on those processes that affect sea surface temperature and oceanic heat storage, which are the oceanographic variables with the greatest influence on climate. The climate research objective is to support the development and effective utilization of space-acquired data systems in climate forecast models and to conduct sensitivity studies to determine the affect of lower boundary conditions on climate and predictability studies to determine which global climate features can be modeled either deterministically or statistically.

1978-01-01

58

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

59

Stormy Weather: 101 Solutions to Global Climate Change.  

ERIC Educational Resources Information Center

This document presents 101 solutions to global climate change. These solutions are actions that are well suited to every level of society. This book creates awareness about global climate change. The history of Earth and the greenhouse effect are discussed, and explanations and solutions to global climate change are provided including traveling…

Dauncey, Guy

60

Stable carbon isotopes in dissolved inorganic carbon: extraction and implications for quantifying the contributions from silicate and carbonate weathering in the Krishna River system during peak discharge.  

PubMed

We present a comparative study of two offline methods, a newly developed method and an existing one, for the measurement of the stable carbon isotopic composition (?(13)C) of dissolved inorganic carbon (DIC; ?(13)CDIC) in natural waters. The measured ?(13)CDIC values of different water samples, prepared from laboratory Na2CO3, ground and oceanic waters, and a laboratory carbonate isotope standard, are found to be accurate and reproducible to within 0.5 ‰\\ (1?). The extraction of CO2 from water samples by these methods does not require pre-treatment or sample poisoning and can be applied to a variety of natural waters to address carbon cycling in the hydrosphere. In addition, we present a simple method (based on a two-end-member mixing model) to estimate the silicate-weathering contribution to DIC in a river system by using the concentration of DIC and its ?(13)C. This approach is tested with data from the Krishna River system as a case study, thereby quantifying the contribution of silicate and carbonate weathering to DIC, particularly during peak discharge. PMID:24450598

Laskar, Amzad H; Gandhi, Naveen; Thirumalai, Kaustubh; Yadava, Madhusudan G; Ramesh, Rengaswamy; Mahajan, Ramakant R; Kumar, Dharmendra

2014-06-01

61

Water - The key to global change. [of weather and climate  

NASA Technical Reports Server (NTRS)

The role of water in processes of global change is discussed. The importance of water in global warming, the loss of biological diversity, the activity of the El Nino southern oscillation, and the melting of polar ice are examined. Plans for a mission to measure tropical rainfall using a two frequency radar, a visible/IR radiometer and a passive microwave radiometer are noted. The way in which global change is affected by changes in patterns of available water is considered.

Soffen, Gerald A.

1988-01-01

62

Seafloor weathering controls on atmospheric CO{sub 2} and global climate  

SciTech Connect

Alteration of surficial marine basalts at low temperatures (<40{degrees}C) is a potentially important sink for atmospheric CO{sub 2} over geologic time. Petrologic analyses, thermodynamic calculations, and experimental weathering results point to extensive Ca leaching and consumption of marine CO{sub 2} during alteration. Basalt weathering in seawater-like solutions is sensitive to temperature. The activation energy for initial basalt weathering in seawater is 41-65 U kJ mol{sup -1}. If seafloor weathering temperatures are set by deep ocean fluids under high fluid to rock ratios the feedback between weathering and atmospheric CO{sub 2} is indirect, but sizeable. If the bulk of seafloor weathering occurs in the presence of low-temperature hydrothermal fluids, the weathering feedback depends on the linkage between spreading rates and heat flow. In either case, the primary linkage between seafloor weathering and the global carbon cycle appears to be thermal as opposed to chemical. 81 refs., 4 figs., 2 tabs.

Brady, P.V. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States); Gislason, S.R. [Univ. of Iceland, Reykjavik (Iceland)] [Univ. of Iceland, Reykjavik (Iceland)

1997-03-01

63

Global markets and the differential effects of climate and weather on conflict  

NASA Astrophysics Data System (ADS)

Both climate and weather have been attributed historically as possible drivers for violence. Previous empirical studies have either focused on isolating local idiosyncratic weather variation or have conflated weather with spatially coherent climatic changes. This paper provides the first study of the differential impacts of climate and weather variation by employing methods developed in earlier work linking the El Nino Southern Oscillation (ENSO) with the onset of civil conflicts. By separating the effects of climate from local weather, we are able to test possible mechanisms by which atmospheric changes can cause violence. It is generally difficult to separate the effect of year-to-year climate variations from other global events that might drive conflict. We avoid this problem by examining the set of tropical countries that are strongly teleconnected to ENSO. For this region, the ENSO cycle parallels the common year-to-year pattern of violence. Using ENSO, we isolate the influence of climatic changes from other global determinants of violence and compare it with the effect of local weather variations. We find that while climate affects the onset of civil conflicts in teleconnected countries, local weather has no significant effect. Productivity overall as well as across major sectors is more affected by local weather than by climatic variation. This is particularly evident in the agricultural sector where total value and cereal yield decline much greater from a 1°C increase in local temperature than a 1°C increase in ENSO. However, when examining the effect on food prices, we find that ENSO is associated with a large and statistically significant increase in cereal prices but no effect from hotter local temperatures. Altogether, this evidence points toward the ability of global and regional commodity markets to insure against the effects of local weather variation and their limitations in containing losses from aggregate shocks such as El Nino events. We posit that conflict reacts to climate and not weather because climatic events trigger not only local agricultural losses but also increased food prices as a result of an aggregate decline in output. This is because in an open economy, idiosyncratic weather variation alone would not lead to higher prices. These results are informative in understanding the impacts of anthropogenic global change, which would yield variation exhibiting spatial coherence beyond the extent of existing markets.

Meng, K. C.; Hsiang, S. M.; Cane, M. A.

2011-12-01

64

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

65

Modeling extreme "Carrington-type" space weather events using three-dimensional global MHD simulations  

NASA Astrophysics Data System (ADS)

There is a growing concern over possible severe societal consequences related to adverse space weather impacts on man-made technological infrastructure. In the last two decades, significant progress has been made toward the first-principles modeling of space weather events, and three-dimensional (3-D) global magnetohydrodynamics (MHD) models have been at the forefront of this transition, thereby playing a critical role in advancing our understanding of space weather. However, the modeling of extreme space weather events is still a major challenge even for the modern global MHD models. In this study, we introduce a specially adapted University of Michigan 3-D global MHD model for simulating extreme space weather events with a Dst footprint comparable to the Carrington superstorm of September 1859 based on the estimate by Tsurutani et. al. (2003). Results are presented for a simulation run with "very extreme" constructed/idealized solar wind boundary conditions driving the magnetosphere. In particular, we describe the reaction of the magnetosphere-ionosphere system and the associated induced geoelectric field on the ground to such extreme driving conditions. The model setup is further tested using input data for an observed space weather event of Halloween storm October 2003 to verify the MHD model consistence and to draw additional guidance for future work. This extreme space weather MHD model setup is designed specifically for practical application to the modeling of extreme geomagnetically induced electric fields, which can drive large currents in ground-based conductor systems such as power transmission grids. Therefore, our ultimate goal is to explore the level of geoelectric fields that can be induced from an assumed storm of the reported magnitude, i.e., Dst˜=-1600 nT.

Ngwira, Chigomezyo M.; Pulkkinen, Antti; Kuznetsova, Maria M.; Glocer, Alex

2014-06-01

66

IS CHEMICAL INDEX OF ALTERATION (CIA) A RELIABLE PROXY FOR CHEMICAL WEATHERING IN GLOBAL DRAINAGE BASINS?  

E-print Network

IS CHEMICAL INDEX OF ALTERATION (CIA) A RELIABLE PROXY FOR CHEMICAL WEATHERING IN GLOBAL DRAINAGE Road, Shanghai 200092 China; Tel: 86-21-6598 9130; Fax: 86-21-6598 6278 ABSTRACT. The chemical as the most important carrier of terrigenous materials into the sea. The chemical index of alteration (CIA

Yang, Shouye

67

Development of a global fire weather database for 1980-2012  

NASA Astrophysics Data System (ADS)

The Canadian Fire Weather Index (FWI) System is the mostly widely used fire danger rating system in the world. We have developed a global database of daily, gridded FWI System calculations from 1980-2012. Input weather data were obtained from the NASA Modern Era Retrospective-Analysis for Research, and two different estimates of daily precipitation from rain gauges over land. FWI System Drought Code (DC) calculations from the gridded datasets were compared to calculations from individual weather station data for a representative set of stations in North, Central and South America, Europe, Russia, Southeast Asia and Australia. Agreement between gridded calculations and the station-based calculations tended to be most different over the tropics for strictly MERRA-based calculations. This dataset can be used for analyzing historical relationships between fire weather and fire activity at continental and global scales, in identifying large-scale atmosphere-ocean controls on fire weather, and calibration of FWI-based fire prediction models.

Field, R. D.; Spessa, A. C.; Aziz, N. A.; Camia, A.; Cantin, A.; Carr, R.; de Groot, W. J.; Dowdy, A. J.; Flannigan, M. D.; Manomaiphiboon, K.; Pappenberger, F.; Tanpipat, V.; Wang, X.

2014-10-01

68

44/40Ca and 87Sr/86Sr isotopes as tracers of silicate weathering in small catchments of the Massif Central, France  

NASA Astrophysics Data System (ADS)

We present calcium stable isotope and strontium radiogenic isotope data for soils and sediments developed on volcanic and igneous rocks forming small catchments in the Massif Central (France). Measurements of 44/40Ca isotope ratios (44/40Ca measured by the double spike method on TIMS and normalized to the value for seawater Ca in delta units) in rocks, sediments and soils from silicate catchments (e.g. granite and basalts) together with 87Sr/86Sr isotope ratios permit an examination of the relationships of these isotope systematics during weathering of silicate rocks. We have analysed the granite, weathered granite (arene) and saprolite, sediment and soil overlying the granite on one hand and the basanite, sediment and soil overlying the basanite on the other. The main bedrock in the volcanic zone (e.g. Allanche catchment) is 11 to 2.5 Ma basanite (nephelinitic to leucitic basalts) having SiO2 between 41-45 wt. %, Na2O + K2O <5%, modal or normative nepheline or leucite and a ground mass of clinopyroxene and plagioclase. Surrounding rocks are feldspathic basalts having SiO2 between 46-49 wt. %, Na2O + K2O <5%, normative nepheline, hyperstene and olivine, with plagioclase as the main crystalline phase. The granite massif (e.g. Margeride, 332 ± 12Ma) consists of light and dark facies as a result of the fractional crystallisation of a crustal magma in a sub-horizontal laccolith, with leucogranites dated at 298±2 Ma intruding this granite. The average mineral composition is 37% quartz, 30% oligoclase, 23% K-feldspar and 10% biotite (light facies) and 31% quartz, 30% andesine, 20% K-feldspar and 19% biotite (dark facies). Sr isotope ratios in the arene, sediment and soil diverge strongly from those in the granite bedrock and are positively correlated with Rb/Sr ratios. The 87Sr/86Sr and Rb/Sr ratios both increase from the whole rock to the arene, reflecting the weathering of low 87Sr/86Sr, low-Rb/Sr minerals such as plagioclase and apatite. Sediments collected on a river bank have 87Sr/86Sr ratios greater than that of the arene with values increasing in the sediment from the surface down to soil. The 87Sr/86Sr vs. Rb/Sr variation observed in the volcanic area likewise confirms the weathering of low 87Sr/86Sr, low Rb/Sr phases in the bedrock, and there is a linear increase in 87Sr/86Sr and Rb/Sr ratios from those in the sediment up to the values observed in the soils. In the volcanic area, the basanite bedrock has 44/40Ca = -0.94 ± 0.05‰ (n = 7), while the soils and sediments have 44/40Ca of -0.75 to -1.13‰ and -0.79 to -1.01‰, respectively. These results suggest that Ca isotopes are not strongly fractionated during weathering of the basalt. The granite whole-rock has 44/40Ca of -1.29‰, while the soil and sediments have 44/40Ca of -1.93 to -2.07‰ and -1.98 to -2.81‰, respectively, with values decreasing as the Ca content decreases. The 44/40Ca ratios of arene, soil and sediment are similar to or less than that of K- feldspar, reflecting complete loss of the relatively heavy Ca from plagioclase and apatite during weathering. Comparison of the 44/40Ca and 87Sr/86Sr ratios further revealed the role of mineralogical assemblage in sediments and soils, particularly for the lesser 44/40Ca - greater 87Sr/86Sr samples, when compared to the bedrock.

Négrel, Philippe; Guerrot, Catherine; Millot, Romain; Petelet-Giraud, Emmanuelle; Bullen, Thomas

2013-04-01

69

Global Muon Detector Network Used for Space Weather Applications  

NASA Astrophysics Data System (ADS)

In this work, we summarize the development and current status of the Global Muon Detector Network (GMDN). The GMDN started in 1992 with only two muon detectors. It has consisted of four detectors since the Kuwait-city muon hodoscope detector was installed in March 2006. The present network has a total of 60 directional channels with an improved coverage of the sunward Interplanetary Magnetic Field (IMF) orientation, making it possible to continuously monitor cosmic ray precursors of geomagnetic storms. The data analysis methods developed also permit precise calculation of the three dimensional cosmic ray anisotropy on an hourly basis free from the atmospheric temperature effect and analysis of the cosmic ray precursors free from the diurnal anisotropy of the cosmic ray intensity.

Rockenbach, M.; Dal Lago, A.; Schuch, N. J.; Munakata, K.; Kuwabara, T.; Oliveira, A. G.; Echer, E.; Braga, C. R.; Mendonça, R. R. S.; Kato, C.; Kozai, M.; Tokumaru, M.; Bieber, J. W.; Evenson, P.; Duldig, M. L.; Humble, J. E.; Al Jassar, H. K.; Sharma, M. M.; Sabbah, I.

2014-08-01

70

What's Up With the Weather? : NOVA and Frontline Examine the Truth About Global Warming  

NSDL National Science Digital Library

This site corresponds with the April 18, 2000 episode of Nova's "What's up with the Weather: the Truth About Global Warming." and is an in-depth look at the issue of global warming by NOVA and FRONTLINE. Numerous subjects are addressed, including the burning of fossil fuels, alternative energy sources including biomass energy, wind and solar power, alternative vehicles, and space-based solar power systems, the evidence for global warming in ice cores, and the threat of rising sea level. The differing views on global warming are presented, as is an interactive exercise meant to help the user determine the amount of CO2 produced from their daily activities. A section discussing frequently asked questions can be accessed, as well as a teachers guide for creating a class lesson discussing global warming.

71

System implementation for US Air Force Global Theater Weather Analysis and Prediction System (GTWAPS)  

SciTech Connect

The Global Theater Weather Analysis and Prediction System (GTWAPS) is intended to provide war fighters and decision makers with timely, accurate, and tailored meteorological and oceanographic (METOC) information to enhance effective employment of battlefield forces. Of critical importance to providing METOC theater information is the generation of meteorological parameters produced by numerical prediction models and application software at the Air Force Global Weather Central (AFGWC), Offutt Air Force Base, Nebraska. Ultimately, application-derived data will be produced by the regional Joint METOC Forecast Units and by the deployed teams within a theater. The USAF Air Staff contracted with Argonne National Laboratory (ANL) for assistance in defining a hardware and software solution using off-the-shelf technology that would give the USAF the flexibility of testing various meteorological models and the ability to use the system within their daily operational constraints.

Simunich, K.L.; Pinkerton, S.C.; Michalakes, J.G.; Christiansen, J.H.

1997-03-01

72

First report on Cretaceous paleoweathering rates in western Panthalassa: Evidence of global enhancement of continental weathering during OAE 2  

NASA Astrophysics Data System (ADS)

Mid-Cretaceous is characterized by intensified oceanic anoxia (Oceanic Anoxic Events: OAEs) that raised global deposition of organic black shales. Several models have been proposed to explain the cause of the OAEs in conjunction with Cretaceous global warmth, active volcanism, sea-level changes and others. For example, Weissert et al. (1998) proposed a mechanism called 'weathering hypothesis'. In this model, the cause of the OAEs is explained in a following chain reaction, (1) global warmth and increase in atmospheric CO2 enhanced weathering of continental crust, (2) enhanced land weathering led excessive influx of nutrients from continents to oceans, (3) eutrophication enhanced primary productivity, (4) the excessive primary producers consumed dissolved oceanic oxygen that finally led to the OAEs. Several studies, in fact, revealed a causal relation between enhanced weathering and OAEs in northern Tethys region. However, it is necessary to collect worldwide information to unravel the global response of weathering hypothesis as a cause of OAEs. For such reason, the present contribution conducted measurements of the degree of hinterland paleoweathering during OAEs in northern Japan, for the purpose to provide a first report on the relation between continental weathering and OAEs in open ocean, the western Panthalassa Ocean. Aptian to Campanian forearc basin mudstones (Yezo Group) were analyzed by XRF and the degree of hinterland weathering was evaluated by geochemical weathering index (W index; Ohta and Arai, 2007). The W values obtained for the Yezo Group are 30~50, which is equivalent to the W values of recent soils developed in temperate mid-latitude climate. The W values show a fluctuation pattern that is concordant with the Cretaceous paleotemperature changes. This match indicates that the change in paleotemperature governed the weathering rates of East Asian continental crust. In addition, hinterland weathering rates show instantaneous increase during the OAE intervals. Specifically, a clear positive excursion of W value is recorded in the OAE 2 horizon. High-resolution analysis revealed that increase in weathering rate slightly predates the OAE 2, c.a. 100 to 500 ka before the onset of anoxia. Therefore, our results are consistent with the weathering hypothesis in two aspects. As assumed in weathering hypothesis, enhanced hinterland weathering is linked with the OAEs and hinterland weathering precedes the onset of OAEs. Furthermore, our data suggests that, as well as in Tethys Ocean, enhanced hinterland paleoweathering during OAEs also occurred in the open Panathalassa Ocean. This indicates that enhanced hinterland weathering was a global and pervasive event causing OAEs.

Ohta, T.

2013-12-01

73

Global Weather States and Their Properties from Passive and Active Satellite Cloud Retrievals  

NASA Technical Reports Server (NTRS)

In this study, the authors apply a clustering algorithm to International Satellite Cloud Climatology Project (ISCCP) cloud optical thickness-cloud top pressure histograms in order to derive weather states (WSs) for the global domain. The cloud property distribution within each WS is examined and the geographical variability of each WS is mapped. Once the global WSs are derived, a combination of CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) vertical cloud structure retrievals is used to derive the vertical distribution of the cloud field within each WS. Finally, the dynamic environment and the radiative signature of the WSs are derived and their variability is examined. The cluster analysis produces a comprehensive description of global atmospheric conditions through the derivation of 11 WSs, each representing a distinct cloud structure characterized by the horizontal distribution of cloud optical depth and cloud top pressure. Matching those distinct WSs with cloud vertical profiles derived from CloudSat and CALIPSO retrievals shows that the ISCCP WSs exhibit unique distributions of vertical layering that correspond well to the horizontal structure of cloud properties. Matching the derived WSs with vertical velocity measurements shows a normal progression in dynamic regime when moving from the most convective to the least convective WS. Time trend analysis of the WSs shows a sharp increase of the fair-weather WS in the 1990s and a flattening of that increase in the 2000s. The fact that the fair-weather WS is the one with the lowest cloud radiative cooling capability implies that this behavior has contributed excess radiative warming to the global radiative budget during the 1990s.

Tselioudis, George; Rossow, William; Zhang, Yuanchong; Konsta, Dimitra

2013-01-01

74

Association of global weather changes with acute coronary syndromes: gaining insights from clinical trials data  

NASA Astrophysics Data System (ADS)

The aim of this study was to develop a method for the identification of global weather parameters and patient characteristics associated with a type of heart attack in which there is a sudden partial blockage of a coronary artery. This type of heart attack does not demonstrate an elevation of the ST segment on an electrocardiogram and is defined as a non-ST elevation acute coronary syndrome (NSTE-ACS). Data from the Global Summary of the Day database was linked with the enrollment and baseline data for a phase III international clinical trial in NSTE-ACS in four 48-h time periods covering the week prior to the clinical event that prompted enrollment in the study. Meteorological events were determined by standardizing the weather data from enrollment dates against an empirical distribution from the month prior. These meteorological events were then linked to the patients' geographic region, demographics and comorbidities to identify potential susceptible populations. After standardization, changes in temperature and humidity demonstrated an association with the enrollment event. Additionally there appeared to be an association with gender, region and a history of stroke. This methodology may provide a useful global insight into assessing the biometeorologic component of diseases from international data.

Bakal, Jeffrey A.; Ezekowitz, Justin A.; Westerhout, Cynthia M.; Boersma, Eric; Armstrong, Paul W.

2013-05-01

75

Bias corrections of global models for regional climate simulations of high-impact weather  

NASA Astrophysics Data System (ADS)

All global circulation models (GCMs) suffer from some form of bias, which when used as boundary conditions for regional climate models may impact the simulations, perhaps severely. Here we present a bias correction method that corrects the mean error in the GCM, but retains the six-hourly weather, longer-period climate-variability and climate change from the GCM. We utilize six different bias correction experiments; each correcting different bias components. The impact of the full bias correction and the individual components are examined in relation to tropical cyclones, precipitation and temperature. We show that correcting of all boundary data provides the greatest improvement.

Bruyère, Cindy L.; Done, James M.; Holland, Greg J.; Fredrick, Sherrie

2014-10-01

76

Long Range Weather Prediction III: Miniaturized Distributed Sensors for Global Atmospheric Measurements  

SciTech Connect

We continue consideration of ways-and-means for creating, in an evolutionary, ever-more-powerful manner, a continually-updated data-base of salient atmospheric properties sufficient for finite differenced integration-based, high-fidelity weather prediction over intervals of 2-3 weeks, leveraging the 10{sup 14} FLOPS digital computing systems now coming into existence. A constellation comprised of 10{sup 6}-10{sup 9} small atmospheric sampling systems--high-tech superpressure balloons carrying early 21st century semiconductor devices, drifting with the local winds over the meteorological spectrum of pressure-altitudes--that assays all portions of the troposphere and lower stratosphere remains the central feature of the proposed system. We suggest that these devices should be active-signaling, rather than passive-transponding, as we had previously proposed only for the ground- and aquatic-situated sensors of this system. Instead of periodic interrogation of the intra-atmospheric transponder population by a constellation of sophisticated small satellites in low Earth orbit, we now propose to retrieve information from the instrumented balloon constellation by existing satellite telephony systems, acting as cellular tower-nodes in a global cellular telephony system whose ''user-set'' is the atmospheric-sampling and surface-level monitoring constellations. We thereby leverage the huge investment in cellular (satellite) telephony and GPS technologies, with large technical and economic gains. This proposal minimizes sponsor forward commitment along its entire programmatic trajectory, and moreover may return data of weather-predictive value soon after field activities commence. We emphasize its high near-term value for making better mesoscale, relatively short-term weather predictions with computing-intensive means, and its great long-term utility in enhancing the meteorological basis for global change predictive studies. We again note that adverse impacts of weather involve continuing costs of the order of 1% of GDP, a large fraction of which could be retrieved if high-fidelity predictions of two weeks forward applicability were available. These {approx}$10{sup 2} B annual savings dwarf the <$1 B costs of operating a rational, long-range weather prediction system of the type proposed.

Teller, E; Leith, C; Canavan, G; Wood, L

2001-11-13

77

Proceedings of the First National Workshop on the Global Weather Experiment: Current Achievements and Future Directions, volume 2, part 2  

NASA Technical Reports Server (NTRS)

An assessment of the status of research using Global Weather Experiment (GWE) data and of the progress in meeting the objectives of the GWE, i.e., better knowledge and understanding of the atmosphere in order to provide more useful weather prediction services. Volume Two consists of a compilation of the papers presented during the workshop. These cover studies that addressed GWE research objectives and utilized GWE information. The titles in Part 2 of this volume include General Circulation Planetary Waves, Interhemispheric, Cross-Equatorial Exchange, Global Aspects of Monsoons, Midlatitude-Tropical Interactions During Monsoons, Stratosphere, Southern Hemisphere, Parameterization, Design of Observations, Oceanography, Future Possibilities, Research Gaps, with an Appendix.

1985-01-01

78

A comparison of water vapor derived from GPS occultations and global weather analyses  

NASA Astrophysics Data System (ADS)

Despite its fundamental importance in radiative transfer, atmospheric dynamics, and the hydrological cycle, atmospheric water is inadequately characterized particularly at a global scale. Occultation measurements from the Global Positioning System (GPS) should improve upon this situation. Individual occultations yield profiles of specific humidity accurate to 0.2 to 0.5 g/kg providing sensitive measurements of lower and middle tropospheric water vapor with global coverage in a unique, all-weather, limb-viewing geometry with several hundred meters to a kilometer vertical resolution. We have derived water vapor profiles from June 21 to July 4, 1995, using GPS occultation data combined with global temperature analyses from the European Center for Medium-Range Weather Forecasts (ECMWF) and reanalyses from the National Centers for Environmental Prediction (NCEP). The zonal mean structure of the profiles exhibits basic climatological features of tropospheric moisture. Specific humidity biases between the GPS results and the ECMWF global humidity analyses in the middle to upper troposphere are ˜0.1 g/kg or less. Occultation results below 6 km altitude are generally drier than those of ECMWF with the bias generally increasing toward warmer temperatures. Near the height of the trade wind inversion, the ECMWF analyses are significantly moister than the occultation results due to vertical smoothing and overextension of the boundary layer top in the analyses. Overall, the occultation results are drier than the NCEP reanalyses with a marked exception near the Intertropical Convergence Zone (ITCZ) where occultation results are wetter by more than 10%. The occultation results are significantly wetter near the ITCZ and drier in the subtropics than the classical moisture climatology of Peixoto and Oort. Similarities between the NCEP and the Peixoto and Oort near-ITCZ differences suggest that a common analysis/model problem may be responsible. The generally wetter Peixoto and Oort results in the subtropics are due in part to moist radiosonde biases. Discrepancies between these data sets are significant and limit our ability to resolve uncertainties in moisture control and feedbacks in a changing climate.

Kursinski, E. R.; Hajj, G. A.

2001-01-01

79

142Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth.  

PubMed

New high-precision samarium-neodymium isotopic data for chondritic meteorites show that their 142Nd/144Nd ratio is 20 parts per million lower than that of most terrestrial rocks. This difference indicates that most (70 to 95%) of Earth's mantle is compositionally similar to the incompatible element-depleted source of mid-ocean ridge basalts, possibly as a result of a global differentiation 4.53 billion years ago (Ga), within 30 million years of Earth's formation. The complementary enriched reservoir has never been sampled and is probably located at the base of the mantle. These data influence models of Earth's compositional structure and require revision of the timing of global differentiation on Earth's Moon and Mars. PMID:15961629

Boyet, M; Carlson, R W

2005-07-22

80

Proceedings of the First National Workshop on the Global Weather Experiment: Current Achievements and Future Directions, volume 1  

NASA Technical Reports Server (NTRS)

A summary of the proceedings in which the most important findings stemming from the Global Weather Experiment (GWE) are highlighted, additional key results and recommendations are comered, and the presentations and discussion are summarized. Detailed achievements, unresolved problems, and recommendations are included.

1985-01-01

81

Improvement of the NVAP Global Water Vapor Data Set for Climate, Hydrological and Weather Studies  

NASA Astrophysics Data System (ADS)

The NASA Water Vapor Project (NVAP) dataset is an existing multisensor, global, daily climate data record of water vapor from 1988-2001. A variety of satellite retrievals of water vapor, both total column and layered, are blended together to create the dataset. NVAP has been valuable for a variety of studies of phenomena on different timescales. Examples include monsoons, the Madden-Julian Oscillation, and global effects of El Nino. The variety of NVAP users requires a dataset designed to meet the needs of a diverse group. Sample applications of the NVAP dataset for weather studies to interannual and decadal variability will be shown. A reanalysis and continuation of NVAP beyond 2001 has begun under the NASA MEaSURES program. Current efforts to continue NVAP beyond 2001 into the era of the NASA Aqua spacecraft will be described. The Aqua water vapor products from 2002 to the present are being used to understand the inputs to the NVAP reanalysis, which include SSM/I, TOVS, and AMSU and SSM/T-2. The overlap between these instruments and the Aqua spacecraft instruments will allow an understanding of the differences between these datasets, and guide a reanalysis of NVAP. In addition, the Aqua results will themselves be incorporated into the new NVAP dataset.

Forsythe, J. M.; Vonder Haar, T. H.; Bytheway, J.

2008-12-01

82

Global silicate mineralogy of the Moon from the Diviner lunar radiometer.  

PubMed

We obtained direct global measurements of the lunar surface using multispectral thermal emission mapping with the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment. Most lunar terrains have spectral signatures that are consistent with known lunar anorthosite and basalt compositions. However, the data have also revealed the presence of highly evolved, silica-rich lunar soils in kilometer-scale and larger exposures, expanded the compositional range of the anorthosites that dominate the lunar crust, and shown that pristine lunar mantle is not exposed at the lunar surface at the kilometer scale. Together, these observations provide compelling evidence that the Moon is a complex body that has experienced a diverse set of igneous processes. PMID:20847266

Greenhagen, Benjamin T; Lucey, Paul G; Wyatt, Michael B; Glotch, Timothy D; Allen, Carlton C; Arnold, Jessica A; Bandfield, Joshua L; Bowles, Neil E; Donaldson Hanna, Kerri L; Hayne, Paul O; Song, Eugenie; Thomas, Ian R; Paige, David A

2010-09-17

83

Space Solar Patrol data and changes in weather and climate, including global warming  

NASA Astrophysics Data System (ADS)

In this paper, the results obtained during the execution of several ISTC projects are presented. The general aim of these projects has been the study of global changes in the environment, connected with solar activity. A brief description of the optical apparatus of the Space Solar Patrol (SSP) developed and built in the framework of the ISTC projects 385, 385.2, 1523 and 2500 is given. The SSP is intended for permanent monitoring of spectra and absolute fluxes of soft x-ray and extreme ultraviolet (x-ray/EUV) radiation from the full disk of the Sun which ionizes the upper atmosphere of the Earth. Permanent solar monitoring in the main part of the ionizing radiation spectra 0.8-115 (119) nm does not exist. The apparatus of the SSP was developed in the years 1996-2005 with multiyear experience of developing such apparatus in S I Vavilov State Optical Institute. The basis of this apparatus is the use of unique detectors of ionizing radiation—open secondary electron multipliers, which are 'solar blind' to near UV, visible and IR radiation from the Sun, and new methodology of these solar spectroradiometric absolute measurements. The prospects are discussed of using the SSP data for the investigation and forecast of the influence of solar variability on the weather and climate including global warming and also on the biosphere including human beings (proposal 3878). This article was originally submitted for inclusion with the papers from the 9th International Symposium on Measurement Science and Intelligent Instruments (ISMTII-2009), published in the May 2010 issue.

Avakyan, S. V.; Baranova, L. A.; Leonov, N. B.; Savinov, E. P.; Voronin, N. A.

2010-08-01

84

Negligible glacial-interglacial variation in continental chemical weathering rates.  

PubMed

Chemical weathering of the continents is central to the regulation of atmospheric carbon dioxide concentrations, and hence global climate. On million-year timescales silicate weathering leads to the draw-down of carbon dioxide, and on millennial timescales chemical weathering affects the calcium carbonate saturation state of the oceans and hence their uptake of carbon dioxide. However, variations in chemical weathering rates over glacial-interglacial cycles remain uncertain. During glacial periods, cold and dry conditions reduce the rate of chemical weathering, but intense physical weathering and the exposure of carbonates on continental shelves due to low sea levels may increase this rate. Here we present high-resolution records of the lead isotope composition of ferromanganese crusts from the North Atlantic Ocean that cover the past 550,000 years. Combining these records with a simple quantitative model of changes in the lead isotope composition of the deep North Atlantic Ocean in response to chemical weathering, we find that chemical weathering rates were two to three times lower in the glaciated interior of the North Atlantic Region during glacial periods than during the intervening interglacial periods. This decrease roughly balances the increase in chemical weathering caused by the exposure of continental shelves, indicating that chemical weathering rates remained relatively constant on glacial-interglacial timescales. On timescales of more than a million years, however, we suggest that enhanced weathering of silicate glacial sediments during interglacial periods results in a net draw-down of atmospheric carbon dioxide, creating a positive feedback on global climate that, once initiated, promotes cooling and further glaciation. PMID:17167483

Foster, Gavin L; Vance, Derek

2006-12-14

85

Modeling the weather impact on aviation in a global air traffic model  

Microsoft Academic Search

Weather has a strong impact on aviation safety and efficiency. For a better understanding of that impact, especially of thunderstorms and similar other severe hazards, we pursued a modeling approach. We used the detailed simulation software (NAVSIM) of worldwide air traffic, developed by Rokitansky [Eurocontrol, 2005] and implemented a specific weather module. NAVSIM models each aircraft with its specific performance

S. Himmelsbach; T. Hauf; C. H. Rokitansky

2009-01-01

86

Arctic Sea Ice Hits Record Low--Extreme Weather to Come? Global warming to blame for highest observed decline, scientists say.  

E-print Network

" the previous record, set in 2007. The chief culprit? Global warming. The potential upshot? Longer and moreArctic Sea Ice Hits Record Low--Extreme Weather to Come? Global warming to blame for highest climate models to determine the extent to which global warming is responsible for the increasing shrinkage

South Bohemia, University of

87

Modeling the weather impact on aviation in a global air traffic model  

NASA Astrophysics Data System (ADS)

Weather has a strong impact on aviation safety and efficiency. For a better understanding of that impact, especially of thunderstorms and similar other severe hazards, we pursued a modeling approach. We used the detailed simulation software (NAVSIM) of worldwide air traffic, developed by Rokitansky [Eurocontrol, 2005] and implemented a specific weather module. NAVSIM models each aircraft with its specific performance characteristics separately along preplanned and prescribed routes. The specific weather module in its current version simulates a thunderstorm as an impenetrable 3D object, which forces an aircraft to circumvent the latter. We refer to that object in general terms as a weather object. The Cb-weather object, as a specific weather object, is a heuristic model of a real thunderstorm, with its characteristics based on actually observed satellite and precipitation radar data. It is comprised of an upper volume, mostly the anvil, and a bottom volume, the up- and downdrafts and the lower outflow area [Tafferner and Forster, 2009; Kober and Tafferner 2009; Zinner et al, 2008]. The Cb-weather object is already implemented in NAVSIM, other weather objects like icing and turbulence will follow. This combination of NAVSIM with a weather object allows a detailed investigation of situations where conflicts exist between planned flight routes and adverse weather. The first objective is to simulate the observed circum-navigation in NAVSIM. Real occurring routes will be compared with simulated ones. Once this has successfully completed, NAVSIM offers a platform to assess existing rules and develop more efficient strategies to cope with adverse weather. An overview will be given over the implementation status of weather objects within NAVSIM and first results will be presented. Cb-object data provision by A. Tafferner, C. Forster, T. Zinner, K. Kober, M. Hagen (DLR Oberpfaffenhofen) is greatly acknowledged. References: Eurocontrol, VDL Mode 2 Capacity Analysis through Simulations: WP3.B - NAVSIM Overview and Validation Results, Edition 1.2, 2005 Kober K. and A. Tafferner. Tracking and nowcasting of convective cells using remote sensing data from radar and satellite, Meteorologische Zeitschrift, 1 (No. 18), 75-84, 2009 Tafferner A. and C. Forster, Improvement of thunderstorm hazard information for pilots through a ground based weather information and management system, Eighth USA/Europe Air Traffic Management Research and Development Seminar (submitted), 2009 Zinner, T., H. Mannstein, A. Tafferner. Cb-TRAM: Tracking and monitoring severe convection from onset over rapid development to mature phase using multi-channel Meteosat-8 SEVIRI data, Meteorol. Atmos. Phys., 101, 191-210, 2008

Himmelsbach, S.; Hauf, T.; Rokitansky, C. H.

2009-09-01

88

Estimation of confidence intervals of global horizontal irradiance obtained from a weather prediction model  

NASA Astrophysics Data System (ADS)

Many photovoltaic (PV) systems have been installed in Japan after the introduction of the Feed-in-Tariff. For an energy management of electric power systems included many PV systems, the forecast of the PV power production are useful technology. Recently numerical weather predictions have been applied to forecast the PV power production while the forecasted values invariably have forecast errors for each modeling system. So, we must use the forecast data considering its error. In this study, we attempted to estimate confidence intervals for hourly forecasts of global horizontal irradiance (GHI) values obtained from a mesoscale model (MSM) de-veloped by the Japan Meteorological Agency. In the recent study, we found that the forecasted values of the GHI of the MSM have two systematical forecast errors; the first is that forecast values of the GHI are depended on the clearness indices, which are defined as the GHI values divided by the extraterrestrial solar irradiance. The second is that forecast errors have the seasonal variations; the overestimation of the GHI forecasts is found in winter while the underestimation of those is found in summer. The information of the errors of the hourly GHI forecasts, that is, confidence intervals of the forecasts, is of great significance for planning the energy management included a lot of PV systems by an electric company. On the PV systems, confidence intervals of the GHI forecasts are required for a pinpoint area or for a relatively large area control-ling the power system. For the relatively large area, a spatial-smoothing method of the GHI values is performed for both the observations and forecasts. The spatial-smoothing method caused the decline of confidence intervals of the hourly GHI forecasts on an extreme event of the GHI forecast (a case of large forecast error) over the relatively large area of the Tokyo electric company (approximately 68 % than for a pinpoint forecast). For more credible estimation of the confidence intervals, it is required to consider the location of the installed PV systems or its capacity over the region.

Ohtake, Hideaki; Gari da Silva Fonseca, Joao, Jr.; Takashima, Takumi; Oozeki, Takashi; Yamada, Yoshinori

2014-05-01

89

Estimation of weathering rates and CO2 drawdown based on solute load: Significance of granulites and gneisses dominated weathering in the Kaveri River basin, Southern India  

NASA Astrophysics Data System (ADS)

The solute load of the Kaveri River (South India) and its tributaries draining diverse Precambrian terrains during pre-monsoon and monsoon periods was determined. Using average annual flow, total drainage area and atmospheric input corrected major ion concentrations of these rivers chemical weathering rates, annual fluxes of different ionic species to the ocean and CO2 consumption rates were estimated. Bicarbonate is the most dominant ion (27-79% of anion budget) in all the river samples collected during monsoon period followed by Ca2+, whereas, in case of pre-monsoon water samples Na+ is the most dominant ion (in meq/l). Two approaches were adopted to estimate silicate and carbonate weathering rates in the drainage basin. At Musuri silicate weathering rate (SWR) is 9.44 ± 0.29 tons/km2/a and carbonate weathering rate (CWR) is 1.46 ± 0.16 tons/km2/a. More than 90% of the total ionic budget is derived from weathering of silicates in the Kaveri basin. CO2 consumption rate in the basin for silicate weathering FCO2sil is 3.83 ± 0.12 × 105 mol/km2/a (upper limit), which is comparable with the Himalayan rivers at upper reaches. For carbonate weathering (FCO2carb) CO2 consumption rate is 0.15 ± 0.03 × 105 mol/km2/a in the Kaveri basin. The lower limit of CO2 consumption rate corrected for H2SO4 during silicate and carbonate weathering is FCO2sil is 3.24 × 1005 mol/km2/a and FCO2carb 0.13 × 105 mol/km2/a respectively. CO2 sequestered due to silicate weathering in the Kaveri basin is 25.41 (±0.82) × 109 mol/a which represents 0.21 (±0.01)% of global CO2 drawdown. This may be due to tropical climatic condition, high rainfall during both SW and NE monsoon and predominance of silicate rocks in the Kaveri basin.

Pattanaik, J. K.; Balakrishnan, S.; Bhutani, R.; Singh, P.

2013-11-01

90

Diurnal variation of the global fair weather current from measurements at a Negev desert station in Israel  

NASA Astrophysics Data System (ADS)

The global electrical circuit (GEC) postulates a constant downward flowing current (Jz) equal to ~2 pA m-2 (Williams, 2009). We have been measuring the vertical fair-weather atmospheric electrical current from May 2011 continuously at the Wise astronomical observatory in the Negev desert, Israel. The instrument used is a modified version of the GDACCS design described by Bennet and Harrison (2008) which is capable of measuring the fair-weather current density with an accuracy of 0.4 pA m-2. The sensors are placed on a flat 1.5m x 1.5m concrete surface 150m away from the observatory. The signal is passed in a differential mode to the computer at the observatory, sampled at 250Hz by the data acquisition program (LabView) and saved to 1 minute files with a GPS time stamp every 1 second. The results show a clear daily pattern in the fluctuation of the fair weather vertical current Jz measured at the surface. The presence of airborne dust should reduce the conductivity (due to the attachment of small ions to aerosol particles). When analyzing the data with larger temporal resolution we note a strong correlation between the wind speed at the surface, the relative humidity and the Jz, suggesting the movement of space charge and rapid changes in the atmospheric conductivity. Additionally, we report initial indications for a response in Jz to the external forcing of geomagnetic conditions such as storms induced by solar flares, as evident from the correlation we find between Jz and Kp in solar quiescent and storm conditions. Bennett, A.J., Harrison, R.G. (2009), Evidence for global circuit current flow through water droplet layers. J. Atmos. Sol. Terr Phys. 71 (12), 1219-1221, doi:10.1016/j.jastp.2009.04.011. Williams, E. R. (2009), The global electrical circuit, Atmos. Res., 91, 2-4, doi:10.1016/j.atmosres.2008.05.018

Elhalel, G.; Yair, Y.; Price, C.; Halatzi, S.; Reuveni, Y.; Shtibelman, D.

2012-04-01

91

Proterozoic oxygen rise linked to shifting balance between seafloor and terrestrial weathering.  

PubMed

A shift toward higher atmospheric oxygen concentration during the late Proterozoic has been inferred from multiple indirect proxies and is seen by many as a prerequisite for the emergence of complex animal life. However, the mechanisms controlling the level of oxygen throughout the Proterozoic and its eventual rise remain uncertain. Here we use a simple biogeochemical model to show that the balance between long-term carbon removal fluxes via terrestrial silicate weathering and ocean crust alteration plays a key role in determining atmospheric oxygen concentration. This balance may be shifted by changes in terrestrial weatherability or in the generation rate of oceanic crust. As a result, the terrestrial chemical weathering flux may be permanently altered--contrasting with the conventional view that the global silicate weathering flux must adjust to equal the volcanic CO2 degassing flux. Changes in chemical weathering flux in turn alter the long-term supply of phosphorus to the ocean, and therefore the flux of organic carbon burial, which is the long-term source of atmospheric oxygen. Hence we propose that increasing solar luminosity and a decrease in seafloor spreading rate over 1,500-500 Ma drove a gradual shift from seafloor weathering to terrestrial weathering, and a corresponding steady rise in atmospheric oxygen. Furthermore, increased terrestrial weatherability during the late Neoproterozoic may explain low temperature, increases in ocean phosphate, ocean sulfate, and atmospheric oxygen concentration at this time. PMID:24927553

Mills, Benjamin; Lenton, Timothy M; Watson, Andrew J

2014-06-24

92

Proterozoic oxygen rise linked to shifting balance between seafloor and terrestrial weathering  

PubMed Central

A shift toward higher atmospheric oxygen concentration during the late Proterozoic has been inferred from multiple indirect proxies and is seen by many as a prerequisite for the emergence of complex animal life. However, the mechanisms controlling the level of oxygen throughout the Proterozoic and its eventual rise remain uncertain. Here we use a simple biogeochemical model to show that the balance between long-term carbon removal fluxes via terrestrial silicate weathering and ocean crust alteration plays a key role in determining atmospheric oxygen concentration. This balance may be shifted by changes in terrestrial weatherability or in the generation rate of oceanic crust. As a result, the terrestrial chemical weathering flux may be permanently altered—contrasting with the conventional view that the global silicate weathering flux must adjust to equal the volcanic CO2 degassing flux. Changes in chemical weathering flux in turn alter the long-term supply of phosphorus to the ocean, and therefore the flux of organic carbon burial, which is the long-term source of atmospheric oxygen. Hence we propose that increasing solar luminosity and a decrease in seafloor spreading rate over 1,500–500 Ma drove a gradual shift from seafloor weathering to terrestrial weathering, and a corresponding steady rise in atmospheric oxygen. Furthermore, increased terrestrial weatherability during the late Neoproterozoic may explain low temperature, increases in ocean phosphate, ocean sulfate, and atmospheric oxygen concentration at this time. PMID:24927553

Mills, Benjamin; Lenton, Timothy M.; Watson, Andrew J.

2014-01-01

93

NOAA Backgrounder: NOAA's Top Global Weather, Water and Climate Events of the 20th Century  

NSDL National Science Digital Library

Here's an interesting "greatest of the century list." Compiled by the National Oceanic and Atmospheric Administration (NOAA), this list details global storms and climate events most "noted for their atmospheric marvel or impact on human life."

1999-01-01

94

Global precipitation retrieval algorithm trained for SSMIS using a numerical weather prediction model: Design and evaluation  

E-print Network

This paper presents and evaluates a global precipitation retrieval algorithm for the Special Sensor Microwave Imager/Sounder (SSMIS). It is based on those developed earlier for the Advanced Microwave Sounding Unit (AMSU) ...

Surussavadee, Chinnawat

95

Rocks, Weathering, and Erosional Landscapes  

NSDL National Science Digital Library

Students will identify principal rock forming silicate minerals and distinguish their relative stability when exposed to weathering; identify sedimentary, igneous and metamorphic rocks and deduce the relative resistance based on mineral composition and texture;and finally relate erosional landscapes to the differential weathering and erosion of rocks of varying strengths. Designed for a geomorphology course

Hanson, Lindley

96

Investigating the Climate System: WEATHER. Global Awareness Tour. Problem-Based Classroom Modules  

ERIC Educational Resources Information Center

With support from National Aeronautics and Space Administration's (NASA's) Goddard Space Flight Center, Institute for Global Environmental Strategies (IGES) has developed educational materials that incorporate information and data from the Tropical Rainfall Measuring Mission (TRMM), a joint satellite mission between the United States and Japan.…

Passow, Michael J.

2003-01-01

97

Space Solar Patrol data and changes in weather and climate, including global warming  

Microsoft Academic Search

In this paper, the results obtained during the execution of several ISTC projects are presented. The general aim of these projects has been the study of global changes in the environment, connected with solar activity. A brief description of the optical apparatus of the Space Solar Patrol (SSP) developed and built in the framework of the ISTC projects 385, 385.2,

S. V. Avakyan; L. A. Baranova; N. B. Leonov; E. P. Savinov; N. A. Voronin

2010-01-01

98

The ocean is critical to the Earth's global systems, regulating weather and climate, the concentration of greenhouse gases in the atmosphere, the re-cycling  

E-print Network

Abstract The ocean is critical to the Earth's global systems, regulating weather and climate, Germany. His research is concerned with ocean and climate variability and change with particular emphasis resources. Through evaporation to cloud formation to rain, the ocean rejuvenates the Earth's drinking water

Johannesson, Henrik

99

Weathering and Secondary Minerals in the Martian Meteorite Shergotty  

NASA Technical Reports Server (NTRS)

The Shergotty martian meteorite contains weathering features and secondary minerals much like those in Nakhla, including secondary silicates, NaCl, and Ca-sulfate. It is likely that the weathering occurred on Mars.

Wentworth, Susan J.; Thomas-Keprta, Kathie L.; McKay, David S.

2000-01-01

100

Developing approaches to hindcast and earthcast climate controls on solute fluxes during shale weathering in the Critical Zone  

NASA Astrophysics Data System (ADS)

To quantify the anthropogenic and climatic controls on regolith formation and global weathering fluxes, it is critical to understand the evolution of weathering profiles and the consumption of CO2 associated with weathering. Using a cascade of global circulation, biota, and weathering models, Goddéris et al. (2010) hindcasted the evolution of weathering profiles over the last 10k years along a loess transect in the Mississippi Valley. After using the weathering code, WITCH, in this way to investigate the dissolution and precipitation of silicate and carbonate minerals in loess along the climosequence, Godderis et al. (2013) then used a similar cascade of models to project the response of weathering of the transect through 2100 - we call this forward projection an 'earthcast'. The effect of projected climate change on the weathering profile was largely dictated by increasing temperature (which slows the rate of advance of the dolomite reaction front but increases silicate weathering) and changes in drainage (variable along the transect). To a lesser extent, changes in soil CO2 affected weathering. The response of the dolomite reaction front acts like a terrestrial lysocline as it responds to changing CO2 and climate. Here, we embark on a similar study of shale weathering. Like the loess formations, shale has high surface area of silicates per unit volume, and can contain carbonate minerals. Shale also comprises 25% of the continental landmass. Specifically, to explore how climate evolution controls shale weathering we are beginning to compare soils along a shale climosequence transect that spans from Wales to Puerto Rico (Dere et al. in press)--i.e., like the loess north-south transect, a climosequence of pedons. For the shales, we will also explore the effects of climate variables by comparing soils on the north- and south-facing hillslopes of the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). The eventual goal is to utilize our understanding of the climatic controls on shale weathering profiles and solute chemistry from these explorations to 'earthcast' the next hundred years. We report our initial efforts to link the meteorological forcing from the North American Land Data Assimilation System (NLDAS-2), the fully-coupled land-surface Penn State Integrated Hydrologic Model (Flux-PIHM), and the geochemical box model WITCH. Our preliminary efforts show that WITCH can elucidate the controls on water and Mg weathering fluxes derived from clay weathering.

Sullivan, P. L.; Godderis, Y.; Shi, Y.; Schott, J.; Duffy, C.; Brantley, S. L.

2013-12-01

101

Electrochemical Acceleration of Chemical Weathering as an  

E-print Network

ocean acidification. Applicationofthistechnologymayinvolveneutralizingthealkaline solution the atmosphere that involves enhancing the solubility of CO2 in the ocean by a process equivalent to the natural silicate weathering reaction. HCl is electrochemically removed from the ocean and neutralized through

Schrag, Daniel

102

Global chemical weather forecasts for field campaign planning: predictions and observations of large-scale features during MINOS, CONTRACE, and INDOEX  

NASA Astrophysics Data System (ADS)

The first global tropospheric forecasts of O3 and its precursors have been used in the daily flight planning of field measurement campaigns. The 3-D chemistry-transport model MATCH-MPIC is driven by meteorological data from a weather center (NCEP) to produce daily 3-day forecasts of the global distributions of O3 and related gases, as well as regional CO tracers. This paper describes the forecast system and its use in three field campaigns, MINOS, CONTRACE and INDOEX. An overview is given of the forecasts by MATCH-MPIC and by three other chemical weather forecast models (EURAD, ECHAM, and FLEXPART), focusing on O3 and CO. Total CO and regional CO tracers were found to be the most valuable gases for flight planning, due to their relatively well-defined anthropogenic source regions and lifetimes of one to a few months. CO was in good agreement with the observations on nearly all the flights (generally r > 0.7, RMS < 20%). In every case in which the chemical weather forecasts were primarily responsible for the flight plans, the targeted features were observed. Two forecasted phenomena are discussed in detail: outflow from Asia observed in the Mediterranean upper troposphere during MINOS, and outflow from North America observed in the middle troposphere over northern Europe during CONTRACE. It is shown that although such pollution plumes occur repeatedly during the months around the campaigns, their frequency is sufficiently low (~10--30% of the time) that global chemical weather forecasts are important for enabling them to be observed during limited-duration field campaigns. The MATCH-MPIC chemical weather forecasts, including an interface for making customized figures from the output, are available for community use via http://www.mpch-mainz.mpg.de/~lawrence/forecasts.html .

Lawrence, M. G.; Rasch, P. J.; von Kuhlmann, R.; Williams, J.; Fischer, H.; de Reus, M.; Lelieveld, J.; Crutzen, P. J.; Schultz, M.; Stier, P.; Huntrieser, H.; Heland, J.; Stohl, A.; Forster, C.; Elbern, H.; Jakobs, H.; Dickerson, R. R.

2002-10-01

103

Weathering of glasses for solar applications  

Microsoft Academic Search

The weathering of several glasses being considered for solar applications has been studied by a number of surface characterization techniques including optical spectroscopy, optical and scanning electron microscopy, sputter-through Auger analysis, ESCA, SIMS, dye penetration testing, surface profile measurements and resonant nuclear reaction profiling. Significant weathering effects were observed only for the soda-lime-silicate glasses. For soda-lime-silicate glasses, the results indicate

J. E. Shelby; J. Vitko Jr.; C. G. Pantano

1980-01-01

104

The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.  

PubMed

On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. PMID:25211602

Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

2014-09-11

105

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

SciTech Connect

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

Steefell, C I

2003-02-01

106

Lithium isotope evidence for enhanced weathering during Oceanic Anoxic Event 2  

NASA Astrophysics Data System (ADS)

The Ocean Anoxic Event 2 (OAE2) about 93.5 million years ago was marked by high atmospheric CO2 concentration, rapid global warming and marine anoxia and euxinia. The event lasted for about 440,000 years and led to habitat loss and mass extinction. The marine anoxia is thought to be linked to enhanced biological productivity, but it is unclear what triggered the increased production and what allowed the subsequent rapid climate recovery. Here we use lithium isotope measurements from carbonates spanning the interval including OAE2 to assess the role of silicate weathering. We find the lightest values of the Li isotope ratio (?7Li) during OAE2, indicating high levels of weathering--and therefore atmospheric CO2 removal--which we attribute to an enhanced hydrological cycle. We use a geochemical model to simulate the evolution of ?7Li and the Ca, Sr and Os isotope tracers. Our simulations suggest a scenario in which the eruption of a large igneous province led to high atmospheric CO2 concentrations and rapid global warming, which initiated OAE2. The simulated warming was accompanied by a roughly 200,000 year pulse of accelerated weathering of mafic silicate rocks, which removed CO2 from the atmosphere. The weathering also delivered nutrients to the oceans that stimulated primary productivity. We suggest that this process, together with the burial of organic carbon, allowed the rapid recovery and stabilization from the greenhouse state.

Pogge von Strandmann, Philip A. E.; Jenkyns, Hugh C.; Woodfine, Richard G.

2013-08-01

107

Terrestrial ecosystems and the global biogeochemical silica cycle  

NASA Astrophysics Data System (ADS)

Most research on the global Si cycle has focused nearly exclusively on weathering or the oceanic Si cycle and has not explored the complexity of the terrestrial biogeochemical cycle. The global biogeochemical Si cycle is of great interest because of its impact on global CO2 concentrations through the combined processes of weathering of silicate minerals and transfer of CO2 from the atmosphere to the lithosphere. A sizable pool of Si is contained as accumulations of amorphous silica, or biogenic silica (BSi), in living tissues of growing plants, known as phytoliths, and, after decomposition of organic material, as remains in the soil. The annual fixation of phytolith silica ranges from 60-200 Tmol yr-1 and rivals that fixed in the oceanic biogeochemical cycle (240 Tmol yr-1). Internal recycling of the phytolith pool is intense with riverine fluxes of dissolved silicate to the oceans buffered by the terrestrial biogeochemical Si cycle, challenging the ability of weathering models to predict rates of weathering and consequently, changes in global climate. Consideration must be given to the influence of the terrestrial BSi pool on variations in the global biogeochemical Si cycle over geologic time and the influence man has had on modifying both the terrestrial and aquatic biogeochemical cycles.

Conley, Daniel J.

2002-12-01

108

Global chemical weather forecasts for field campaign planning: predictions and observations of large-scale features during MINOS, CONTRACE, and INDOEX  

NASA Astrophysics Data System (ADS)

The first global tropospheric forecasts of O3 and its precursors have been used in the daily flight planning of field measurement campaigns. The 3-D chemistry-transport model MATCH-MPIC is driven by meteorological data from a weather center (NCEP) to produce daily 3-day forecasts of the global distributions of O3 and related gases, as well as regional CO tracers. This paper describes the forecast system and its use in three field campaigns, MINOS, CONTRACE and INDOEX. An overview is given of the forecasts by MATCH-MPIC and by three other chemical weather forecast models (EURAD, ECHAM, and FLEXPART), focusing on O3 and CO. Total CO and regional CO tracers were found to be the most valuable gases for flight planning, due to their relatively well-defined anthropogenic source regions and lifetimes of one to a few months. CO was in good agreement with the observations on nearly all the flights (generally r > 0.7, and the relative RMS differences for the deviations from the means was less than 20%). In every case in which the chemical weather forecasts were primarily responsible for the flight plans, the targeted features were observed. Three forecasted phenomena are discussed in detail: outflow from Asia observed in the Mediterranean upper troposphere during MINOS, outflow from North America observed in the middle troposphere over northern Europe during CONTRACE, and the location of the "chemical ITCZ'' over the Indian Ocean during INDOEX. In particular it is shown that although intercontinental pollution plumes such as those observed during MINOS and CONTRACE occur repeatedly during the months around the campaigns, their frequency is sufficiently low (~10--30% of the time) that global chemical weather forecasts are important for enabling them to be observed during limited-duration field campaigns. The MATCH-MPIC chemical weather forecasts, including an interface for making customized figures from the output, are available for community use via http://www.mpch-mainz.mpg.de/~lawrence/forecasts.html.

Lawrence, M. G.; Rasch, P. J.; von Kuhlmann, R.; Williams, J.; Fischer, H.; de Reus, M.; Lelieveld, J.; Crutzen, P. J.; Schultz, M.; Stier, P.; Huntrieser, H.; Heland, J.; Stohl, A.; Forster, C.; Elbern, H.; Jakobs, H.; Dickerson, R. R.

2003-02-01

109

Differences Between Climate and Weather  

NSDL National Science Digital Library

In this activity, students collect weather data over several days or weeks, graph temperature data, and compare the temperature data collected with long-term climate averages from where they live. Understanding the difference between weather and climate and interpreting local weather data are important first steps to understanding larger-scale global climate changes.

Research, National C.

110

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

111

Weathering and weathering rates of natural stone  

NASA Astrophysics Data System (ADS)

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

Winkler, Erhard M.

1987-06-01

112

Air temperature-driven CO2 consumption by rock weathering at short timescales: Evidence from a Holocene lake sediment record  

NASA Astrophysics Data System (ADS)

The role that air temperature plays in the interaction between atmospheric CO2 levels and continental rock weathering at relatively short time scales is still a matter of debate. Laboratory studies reveal a strong dependence of mineral dissolution on temperature, but field comparisons among watersheds under different climate conditions often indicate correlations with other environmental factors. Using a paleolimnological approach, here we show that there has been an extremely good coupling between rock weathering, water alkalinity (CO2 consumption), and air temperature during the last 10,000 years at sub-millennial time scales in a small watershed of silicate bedrock and scarce vegetation. The calculation of apparent activation energy for the weathering reaction (as a means to describe the temperature dependence of the process) provides a value (Ea = 67 ± 7 kJ mol-1) that is comparable to those found for silicate rocks similar to those in the watershed in laboratory experiments and some field studies. Our results provide evidence that regulatory constraints between air temperature, atmospheric CO2 and silicate rock weathering can be fine-tuned at geological timescales and may not be negligible in the current context of global change.

Catalan, Jordi; Pla-Rabés, Sergi; García, Joan; Camarero, Lluís

2014-07-01

113

COST Action ES1206 : Advanced Global Navigation Satellite Systems Tropospheric Products for Monitoring Severe Weather Events and Climate (GNSS4SWEC)  

NASA Astrophysics Data System (ADS)

Global Navigation Satellite Systems (GNSS) have revolutionised positioning, navigation, and timing, becoming a common part of our everyday life. Aside from these well-known civilian and commercial applications, GNSS is now an established atmospheric observing system which can accurately sense water vapour, the most abundant greenhouse gas, accounting for 60-70% of atmospheric warming. Severe weather forecasting is challenging, in part due to the high temporal and spatial variation of atmospheric water vapour. Water vapour is under-sampled in the current meteorological and climate observing systems, obtaining and exploiting more high-quality humidity observations is essential to weather forecasting and climate monitoring. The new COST Action, ES1206, will address new and improved capabilities from con-current developments in both the GNSS and meteorological communities. For the first time, the synergy of the three GNSS systems (GPS, GLONASS and Galileo) will be used to develop new, advanced tropospheric products, exploiting the full potential of multi-GNSS water vapour estimates on a wide range of temporal and spatial scales, from real-time monitoring and forecasting of severe weather, to climate research. In addition the Action will promote the use of meteorological data in GNSS positioning, navigation, and timing services. The Action will stimulate knowledge transfer and data sharing throughout Europe.

Jones, Jonathan; Guerova, Guergana; Dousa, Jan; de Haan, Siebren; Bock, Olivier; Dick, Galina; Pottiaux, Eric; Pacione, Rosa

2014-05-01

114

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 — from old weather proverbs to modern forecasting equipment — and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

Integrated Teaching and Learning Program,

115

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.

116

Winter Weather  

NSDL National Science Digital Library

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

Mrs. Bellows

2009-09-28

117

Silicate volcanism on Io  

NASA Astrophysics Data System (ADS)

This paper is mainly concerned with the nature of volcanic eruptions on Io, taking into account questions regarding the presence of silicates or sulfur as principal component. Attention is given to the generation of silicate magma, the viscous dissipation in the melt zone, thermal anomalies at eruption sites, and Ionian volcanism. According to the information available about Io, it appears that its volcanism and hence its surface materials are dominantly silicic. Several percent of volatile materials such as sulfur, but also including sodium- and potassium-rich materials, may also be present. The volatile materials at the surface are continually vaporized and melted as a result of the high rates of silicate volcanism.

Carr, M. H.

1986-03-01

118

Rolling stones; fast weathering of olivine in shallow seas for cost-effective CO2 capture and mitigation of global warming and ocean acidification  

NASA Astrophysics Data System (ADS)

Human CO2 emissions may drive the Earth into a next greenhouse state. They can be mitigated by accelerating weathering of natural rock under the uptake of CO2. We disprove the paradigm that olivine weathering in nature would be a slow process, and show that it is not needed to mill olivine to very fine, 10 ?m-size grains in order to arrive at a complete dissolution within 1-2 year. In high-energy shallow marine environments olivine grains and reaction products on the grain surfaces, that otherwise would greatly retard the reaction, are abraded so that the chemical reaction is much accelerated. When kept in motion even large olivine grains rubbing and bumping against each other quickly produce fine clay- and silt-sized olivine particles that show a fast chemical reaction. Spreading of olivine in the world's 2% most energetic shelf seas can compensate a year's global CO2 emissions and counteract ocean acidification against a price well below that of carbon credits.

Schuiling, R. D.; de Boer, P. L.

2011-12-01

119

Controls on chemical weathering kinetics: Implications from modelling of stable isotope fractionations  

NASA Astrophysics Data System (ADS)

The kinetic controls on silicate chemical weathering rates are thought central to the feedback process that regulates global climate on geological time scales. However the nature and magnitude of these kinetic controls are controversial. In particular the importance of physical erosion rates is uncertain with some arguing that there is an upper limit on chemical weathering fluxes irrespective of physical erosion rates (e.g. Dixon and von Blackenburg, 2012). Others argue that it is the hydrology of catchments which determines flow path lengths and fluid residence times which are critical to chemical weathering fluxes (e.g. Maher, 2011). Understanding these physical controls is essential to predicting how chemical weathering fluxes will respond the key climatic controls. Chemical weathering fluxes are best estimated by the integrated riverine outputs from catchments as soil profiles may not integrate all the flow paths. However the interpretation of chemical weathering processes based solely on flux data is difficult, because of both the multiple processes acting and multiple phases dissolving that contribute to these fluxes. Fractionations of stable isotopes of the soluble elements including Li, Mg, Si and Ca should place additional constraints on chemical weathering processes. Here we use a simple reactive-transport model to interpret stable isotope fractionations. Although still a simplification of the natural system, this offers a much closer representation than simple batch and Rayleigh models. The isotopic fractionations are shown to be a function of the ratio of the amount of the element supplied by mineral dissolution to that lost to secondary mineral formation and the extent of reaction down the flow path. The modelling is used to interpret the evolution of dissolved Li, Mg and Si-isotope ratios in Ganges river system. The evolution of Si isotopic ratios in the rapidly eroding Himalayan catchments is distinct from that in the flood planes. Critically the extent of the isotopic fractionations is a measure of the approach of the system to chemical equilibrium, a key indicator of the temperature sensitivity of the chemical weathering rate and hence important to understanding the climate-weathering feedback. Dixon JL, & von Blanckenburg, F, (2012) Soils as pacemakers and limiters of global silicate weathering. Comptes Rendus Geoscience, 344:597-609. Maher, K (2011) The role of fluid residence time and topographic scales in determining chemical fluxes from landscapes. Earth and Planetary Science Letters, 312:48-58.

Bickle, M. J.; Tipper, E.; De La Rocha, C. L.; Galy, A.; Li, S.

2013-12-01

120

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.

121

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

122

Winter Weather  

MedlinePLUS

... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

123

Weather Odds  

NSDL National Science Digital Library

The Weather Odds site helps users learn about the odds of various weather happening at monthly and daily levels. The site relies on past climate data from thousands of locations and it's a fine resource. In the Quick Weather Data area, visitors can check out popular United States locations or use the search engine to breeze along to their preferred habitat. This version of Weather Odds is compatible with all operating systems.

2014-05-08

124

World Weather  

NSDL National Science Digital Library

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

Elias, Jaume S.

2014-02-20

125

Weathering of glasses for solar applications  

NASA Astrophysics Data System (ADS)

The weathering of several glasses being considered for solar applications has been studied by a number of surface characterization techniques including optical spectroscopy, optical and scanning electron microscopy, sputter-through Auger analysis, ESCA, SIMS, dye penetration testing, surface profile measurements and resonant nuclear reaction profiling. Significant weathering effects were observed only for the soda-lime-silicate glasses. For soda-lime-silicate glasses, the results indicate that the first stage of weathering is the formation of a low-density anti-reflection film on the glass surface. Growth of this film eventually results in spalling of the glass surface and severe degradation of the optical quality of the glass. Float glasses exhibit significantly better weathering resistance on their tin-rich surface than on the tin-poor surface.

Shelby, J. E.; Vitko, J., Jr.; Pantano, C. G.

1980-09-01

126

Predicting the Weather  

NSDL National Science Digital Library

This Topic in Depth explores the science behind predicting the weather. First, the United States Search and Rescue Task Force describe the basic tools and knowledge used to create weather forecasts (1). Students can find concise, clear explanations of weather, fronts and air masses, high and low pressure, precipitation, and water vapor and humidity as well. By performing the activities presented in the second website, fourth grade students can learn about weather instruments and data collection (2). This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Third, Edheads offers a Macromedia Flash Player enhanced interactive module allowing students to predict the weather by examining weather maps (3 ). Through this website, users can become familiar with the concepts of warm and cold fronts, wind direction and speed, air pressure, and humidity. The fourth website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather (4). Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Next, NOAA provides graphics for five forecast models: the ETA, the Global Forecast System (GFS), the Wave Watch III (WW3), the Nested Grid model (NGM), and the Rapid Update Cycle (RUC) (5). Outputs are available for North America, North Pacific, Western North Atlantic, and the Polar Ice Drift. Users can find links to detailed descriptions of the inputs and history of each model. Sixth, the British government's Met Office describes numerical modeling and its components (6). Students and educators can learn about the future in forecasting as well as educational opportunities with the Cooperative Program for Meteorology, Education, and Training (COMET).

127

Cockpit weather information system  

NASA Technical Reports Server (NTRS)

Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

Tu, Jeffrey Chen-Yu (Inventor)

2000-01-01

128

Jerks as Guiding Influences on the Global Environment: Effects on the Solid Earth, Its Angular Momentum and Lithospheric Plate Motions, the Atmosphere, Weather, and Climate  

NASA Astrophysics Data System (ADS)

Jerks are thought to be the result of torques applied at the core-mantle boundary (CMB) caused by either of two possible processes, working together or separately: 1) Electromagnetic Induction and 2) Mechanical Slippage. In the first case, it is thought that electromagnetic energy slowly builds-up at the CMB, reaches some critical level, and is then suddenly released, causing a geomagneticly induced torque at the CMB due to the differential electrical conductivity between the lower mantle and the surface of the outer core. The second case is driven by stress and strain increases that buildup mechanical potential energy, which is released when a critical level is reached, thereby generating a torque at the CMB. Generally, a trigger is required to start the Jerk process in motion. In the electromagnetic case, it is suggested that energy from the Sun may supply the requisite energy buildup that is subsequently released by a magnetic storm trigger, for instance. In the case of mechanical slippage, bari-center motion among the Earth, Moon, and Sun, as well as tidal forces and mass redistributions through Earth's wobbles combine to provide the accumulated stress/strain buildup and subsequent trigger. The resulting fluid flow changes at the CMB result in geomagnetic field changes and Joule heating throughout the solid Earth, its oceans, and atmosphere. It is shown that the Global Temperature Anomaly (GTA), which is measured at Earth's surface, correlates with changes in the geomagnetic non-dipole moment, and thus with core fluid motions. This links Global Warming and weather with core processes, important examples being the 1930's Dust Bowl Era and the 1947 Impulse. The CMB torque also affects Earth's angular momentum. But it appears that magnetic storms can as well. As a consequence, the Jet Stream, atmospheric circulation patterns, and the Global Oscillation System (i.e., El-Nino/Southern-Oscillation, North Atlantic Oscillation, the Pacific Decade Oscillation, etc.) are modulated. These parameters in turn affect the weather and climate (e.g., the Dust Bowl Era, El Ninos, La Ninas, and hurricanes). The stress/strain within the Earth leads to Earth torsion, vibration, and mass redistribution, which leads to tectonic plate motion, seismicity, volcanism, and gravity waves, which drive atmospheric circulation and the teleconnection processes (i.e., a redistribution of magma beneath the plates) via surge tectonics. Various other connections among these processes and parameters will be discussed.

Quinn, J. M.; Leybourne, B. A.

2010-12-01

129

The role of nitrification in silicate hydrolysis in soils near Santa Cruz, CA  

NASA Astrophysics Data System (ADS)

In some ecosystems, nitrification (microbial conversion of ammonium to nitrate) may supplant carbonic acid as a source of acidity and drive silicate weathering. Recent studies have explored the impact that ammonium fertilizer addition to soils has on weathering of various mineral types (Pacheco et al. 2013) and demonstrated directly that ammonium addition to soils can increase carbonate weathering (Gandois et al. 2011). Some evidence points to a role for nitrification in silicate weathering at a series of coastal grassland terraces near Santa Cruz, CA. Weathering rates in these soils have been estimated using the byproducts of silicate hydrolysis (Cl--adjusted Na+ and other cations). If carbonic acid from dissolved CO2 is the source of acidity in silicate hydrolysis, bicarbonate should balance the cations produced during weathering. However, in the Santa Cruz soils nitrate is the dominant anion balancing cation concentrations. High concentrations of CO2 (>1%) at depths greater than 1m may provide additional support for nitrification-based silicate hydrolysis at Santa Cruz. We evaluate the role of nitrification in silicate weathering for soils from the Santa Cruz Marine Terrace Chronosequence using a column ammonium-addition experiment and a basic weathering model. The column experiment uses ammonium inputs in excess of natural inputs and measures weathering products in eluted fluids over time. The model incorporates more realistic estimates of ammonium input and explores whether the observed concentrations of cations, nitrate and CO2 seen at Santa Cruz can be explained by nitrification-driven acidity or if other inputs need to be considered. Gandois, L, Perrin, A-S, and Probst, A. 2011. Impact of nitrogenous fertiliser-induced proton release on cultivated soils with contrasting carbonate contents: A column experiment. Geochimica et Cosmochimica Acta 75 pp. 1185-1198. Pacheco, F, Landim, P, and Szocs, T. 2013. Anthropogenic impacts on mineral weathering: A statistical perspective. Applied Geochemistry 36 pp. 34-48.

Kyker-Snowman, E.; White, A.; Lawrence, C. R.; Schulz, M. S.

2013-12-01

130

Chemical weathering in a tropical watershed, Luquillo Mountains, Puerto Rico: I. Long-term versus short-term weathering fluxes  

USGS Publications Warehouse

The pristine Rio Icacos watershed in the Luquillo Mountains in eastern Puerto Rico has the fastest documented weathering rate of silicate rocks on the Earth's surface. A regolith propagation rate of 58 m Ma-1 calculated from iso-volumetric saprolite formation from quartz diorite, is comparable to the estimated denudation rate (25-50 Ma-1) but is an order of magnitude faster than the global average weathering rate (6 Ma-1). Weathering occurs in two distinct environments; plagioclase and hornblende react at the saprock interface and biotite and quartz weather in the overlying thick saprolitic regolith. These environments produce distinctly different water chemistries, with K, Mg, and Si increasing linearly with depth in saprolite porewaters and with stream waters dominated by Ca, Na, and Si. Such differences are atypical of less intense weathering in temperate watersheds. Porewater chemistry in the shallow regolith is controlled by closed-system recycling of inorganic nutrients such as K. Long-term elemental fluxes through the regolith (e.g., Si = 1.7 ?? 10-8 moles m-2 s-1) are calculated from mass losses based on changes in porosity and chemistry between the regolith and bedrock and from the age of the regolith surface (200 Ma). Mass losses attributed to solute fluxes are determined using a step-wise infiltration model which calculates mineral inputs to the shallow and deep saprolite porewaters and to stream water. Pressure heads decrease with depth in the shallow regolith (-2.03 m H2O m-1), indicating that both increasing capillary tension and graviometric potential control porewater infiltration. Interpolation of experimental hydraulic conductivities produces an infiltration rate of 1 m yr-1 at average field moisture saturation which is comparable with LiBr tracer tests and with base discharge from the watershed. Short term weathering fluxes calculated from solute chemistries and infiltration rates (e.g., Si = 1.4 ?? 10-8 moles m-2 s-1) are compared to watershed flux rates (e.g., Si = 2.7 ?? 10-8 moles m-2 s-1). Consistency between three independently determined sets of weathering fluxes imply that possible changes in precipitation, temperature, and vegetation over the last several hundred thousand years have not significantly impacted weathering rates in the Luquillo Mountains of Puerto Rico. This has important ramifications for tropical environments and global climate change. Copyright ?? 1998 Elsevier Science Ltd.

White, A.F.; Blum, A.E.; Schulz, M.S.; Vivit, D.V.; Stonestrom, D.A.; Larsen, M.; Murphy, S.F.; Eberl, D.

1998-01-01

131

Predicting Weather  

NSDL National Science Digital Library

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

2008-03-28

132

Weather Watch  

NSDL National Science Digital Library

The weather watch activity is designed to provide instruction on how to collect weather data from on-line databases. Following completion of this activity the user will be able to look up weather conditions for any city in North America, know what radar maps are used for and how to access them, and know how to access satellite images and make estimated guesses on cloud conditions for their area from them.

Hopson, R.

133

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.

134

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

135

MSATT Workshop on Chemical Weathering on Mars  

NASA Technical Reports Server (NTRS)

The topics covered with respect to chemical weathering on Mars include the following: Mars soil, mineralogy, spectroscopic analysis, clays, silicates, oxidation, iron oxides, water, chemical reactions, geochemistry, minerals, Mars atmosphere, atmospheric chemistry, salts, planetary evolution, volcanology, Mars volcanoes, regolith, surface reactions, Mars soil analogs, carbonates, meteorites, and reactivity.

Burns, Roger (editor); Banin, Amos (editor)

1992-01-01

136

Global climate change and reindeer: effects of winter weather on the autumn weight and growth of calves.  

PubMed

Reindeer/caribou (Rangifer tarandus), which constitute a biological resource of vital importance for the physical and cultural survival of Arctic residents, and inhabit extremely seasonal environments, have received little attention in the global change debate. We investigated how body weight and growth rate of reindeer calves were affected by large-scale climatic variability [measured by the North Atlantic Oscillation (NAO) winter index] and density in one population in central Norway. Body weights of calves in summer and early winter, as well as their growth rate (summer to early winter), were significantly influenced by density and the NAO index when cohorts were in utero. Males were heavier and had higher absolute growth than females, but there was no evidence that preweaning condition of male and female calves were influenced differently by the NAO winter index. Increasing NAO index had a negative effect on calves' body weight and growth rate. Increasing density significantly reduced body weight and growth rate of calves, and accentuated the effect of the NAO winter index. Winters with a higher NAO index are thus severe for reindeer calves in this area and their effects are associated with nutritional stress experienced by the dams during pregnancy or immediately after calving. Moreover, increased density may enhance intra-specific competition and limits food available at the individual level within cohorts. We conclude that if the current pattern of global warming continues, with greater change occurring in northern latitudes and during winter as is predicted, reduced body weight of reindeer calves may be a consequence in areas where winters with a high NAO index are severe. This will likely have an effect on the livelihood of many northern indigenous peoples, both economically and culturally. PMID:12707839

Weladji, Robert B; Holand, Øystein

2003-07-01

137

Oceans, Climate and Weather  

NSDL National Science Digital Library

What is the difference between weather and climate? What do the oceans have to do with them? Weather is the day-to-day state of the atmosphere and its short-term (minutes to weeks) variation. Climate is typically described by the regional patterns of seasonal temperature and precipitation over 30 years. The averages of annual temperature, rainfall, cloud cover, and depth of frost penetration are all typical climate-related statistics. The oceans influence the worlds climate by storing solar energy and distributing it around the planet through currents and atmospheric winds.This publication is all about developing your students understandings of earths oceans and the major effect they have on climate. Understanding and interpreting local weather data and understanding the relationship between weather and climate are important first steps to understanding larger-scale global climate changes. Activities that ask students to collect and analyze local weather data as well as analyze global data can be found in the Lessons and Activities section. Analyzing and interpreting data is a major focus of this publication. Numerous data sets can be found in the Sources for Real Data section. The Background Information section and the article Tomorrows Forecast will help reinforce your own content knowledge.

Lightle, Kimberly

2006-01-01

138

Wacky Weather  

ERIC Educational Resources Information Center

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

Sabarre, Amy; Gulino, Jacqueline

2013-01-01

139

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.

2012-06-26

140

Do disease cycles follow changes in weather? Researchers ponder global warming`s effect on the carriers of human illness  

SciTech Connect

Two years ago, Mother Nature one-upped an Institute of Medicine (IOM) committee big time. In 1991, the committee had wracked its collective brains to come up with a plausible epidemic scenario for a report on disease emergence. The team finally settled on a potential southern US outbreak of yellow fever, a well-known African viral disease carried by mosquitoes. The idea was realistic, if not particularly imaginative. Yellow fever is an old problem. Shortly after the report on microbe-induced epidemics was released, Mother Nature displayed tremendous creativity. In the spring of 1993, a mysterious virus began killing young people in the Southwest. The culprit turned out to be a previously unrecognized strain of hantavirus, which causes a deadly respiratory disease. Emerging from its natural host, the common deer mouse, the hantavirus strain affected at least 131 people. Half died. Today, emerging viruses have shocked the public and sent scientists searching for causes of epidemics and factors that determine how serious disease outbreaks might be be. One factor gaining attention climate. To learn how global warming might affect mosquitoes, mice and other microbe carriers, biologists are studying diseases within an environmental context. This article discusses the work in this area and some of the results, speculations, and future areas of interest.

Brown, K.S.

1996-07-01

141

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

142

Causal Electron Precipitation in Geospace Weather  

E-print Network

607080 18 Causal Electron Precipitation in Geospace Weather A Proposal submitted by Dartmouth;NSF: National Space Causal Electron Precipitation in Geospace Weather: W. Lotko, PI Weather Program and global characteristics of electron precipitation influence the magnetosphere-iono- sphere (MI

143

Using C and S isotopes to elucidate carbonic versus sulfuric acid reaction pathways during shale weathering in the Susquehanna Shale Hills Critical Zone Observatory  

NASA Astrophysics Data System (ADS)

Chemical weathering of silicate minerals via the carbonic acid reaction pathway regulates global climate on geological timescales. However, strong acids are also key dissolution agents that drive silicate and carbonate weathering. In order to assess the potentials of silicate weathering on CO2 consumption, it is crucial to separate carbonic acid versus sulfuric acid reaction pathways, and also to separate the contribution of stream-dissolved inorganic carbon (DIC) from silicate versus carbonate dissoution. Here we address these two questions using C and S isotopes at the well-studied Susquehanna Shale Hills Critical Zone Observatory (SSHO). In shallow soils of SSHO, clay dissolution dominates. Here soil waters are charaterized by low [DIC], which is controlled by equilibrium with soil pCO2. Carbonate minerals, in this Rose Hill Shale formation, are depleted in soils and have only been observed in few bedrock boreholes, i.e. at > 23m depth at ridges and > 2m depth under the valley. Indeed, some groundwaters have much higher [DIC], [Mg] and [Ca], presumably due to ankerite dissolution. Accompanied by the transition from silicate weathering in shallow soils to carbonate weathering below the water table, the source of sulfate shifts with depth from atmospheric deposition to pyrite dissolution. Apparently, the weathering fronts of ankerite and pyrite are at almost the same depth. The ?13CDIC values of these groundwaters indicate C mixing equally from ankerite and soil CO2, with only slight modification by the sulfuric acid pathway. Groundwater chemistry evolves to different extents with respect to ankerite saturation because the depths to ankerite weathering fronts vary due to heterogeneity of the Rose Hill shales and landscape position. Interestingly, groundwaters along the valley floor at the outlet of the first-order catchment are influenced by carbonate dissolution but also show S isotope signatures indicative of anthropogenic sulfate in wet precipitation. This provides another line of evidence that at least some of the carbonate we observe at shallow depths in the valley floor may be secondary. Indeed, C isotopes of some of the shallow carbonates differ from those in Rose Hill bedrock. Comparison between groundwater and soil water chemistry shows that at SSHO most DIC derives from the dissolution of carbonate minerals, i.e., primary ankerite or secondary carbonate. Sulfate derives almost entirely from atmospheric deposition in soil waters and some groundwater near the outlet; however, its source shifts to pyrite dissolution in groundwaters from ridges and headwater areas. Overall, in this catchment underlain by grey shale, the sulfuric acid pathway is insignicant due to the low pyrite content in comparison to ankerite or secondary carbonate.

Jin, L.; Ogrinc, N.; Yesavage, T.; Hasenmueller, E. A.; Ma, L.; Kaye, J. P.; Brantley, S. L.

2013-12-01

144

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

145

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

146

Chemical weathering and associated carbon-dioxide consumption in a tropical river basin (Swarna River), Southwestern India  

NASA Astrophysics Data System (ADS)

Chemical weathering in river basins forms the key process to study the global climate change on a long term scale due to its association with the carbon sequestration. Water samples from a west flowing tropical river (Swarna River) of Southern India were collected for a period of two years to study the chemical weathering process and to quantify the weathering and associated carbon-dioxide consumption rates in the river basin. In addition, the major ion chemistry of Swarna River is studied for the first time on a spatial and temporal (monthly) scale to decipher the factors (lithology, precipitation/ discharge, temperature, slope and physical weathering) controlling the chemical weathering process. Swarna River originates in Western Ghats at an altitude of 1100 m above mean sea level and flows westwards draining Peninsular Gneiss and Dharwar Schist to join the Arabian Sea near Udupi. The river basin receives annual rainfall of 4500 mm and experiences warm climate with average temperature of 30°C. Major ion composition and radiogenic strontium isotopic composition measured in the Swarna river water reflects the influence of silicate rocks in the basin. The river water chemistry is found to be least affected by anthropogenic impact; however, the effect of evaporation is observed on few samples during the peak dry season. The atmospheric inputs and carbonate contributions to the river water are corrected to estimate the silicate weathering rate (SWR) and the associated carbon-dioxide consumption rate (CCR) using local rainwater and bed rock composition respectively. The SWR and CCR in the Swarna river basin are estimated to be 46 tons/km2/yr and 4.4 x 10^5 mol/km2/yr respectively. This estimation is observed to be relatively higher than the recently reported SWR and CCR in the adjacent larger Nethravati river basin (Gurumurthy et al., 2012). The increased rate could be attributed to the relatively higher precipitation in the Swarna river basin than the lithological variation between the two basins. The weathering process is largely controlled by the higher run-off accompanied by warm temperature in the Swarna river basin. The intense silicate weathering is also supported by the highly radiogenic strontium isotope composition (87Sr/86Sr) ranging between 0.7195 and 0.7304 in the Swarna river water. The average 87Sr/86Sr = 0.7249 in the river water is found to be higher than the global river average. Keywords: Major ion, Radiogenic strontium isotope, Silicate weathering rate, Carbon-dioxide consumption rate, Tropical river, Southwestern India. Reference: Gurumurthy GP, Balakrishna K, Riotte J, Braun J-J, Audry S, Udayashankar HN, Manjunatha BR (2012), Controls on intense silicate weathering in a tropical river, southwestern India. Chemical Geology, 300-301, 61-69.

Muguli, T.; Gurumurthy, G. P.; Balakrishna, K.; Audry, S.; Riotte, J.; Braun, J.; Chadaga, M.; Shankar HN, U.

2013-12-01

147

Silicate emission in Orion  

E-print Network

We present mid-infrared spectro-imagery and high-resolution spectroscopy of the Orion bar and of a region in the Orion nebula. These observations have been obtained in the Guaranteed Time with the Circular Variable Filters of the ISO camera (CAM-CVF) and with the Short Wavelength Spectrometer (SWS), on board the European Infrared Space Observatory (ISO). Our data shows emission from amorphous silicate grains from the entire HII region and around the isolated O9.5V star Theta2 Ori A. The observed spectra can be reproduced by a mixture of interstellar silicate and carbon grains heated by the radiation of the hot stars present in the region. Crystalline silicates are also observed in the Orion nebula and suspected around Theta2 Ori A. They are probably of interstellar origin. The ionization structure and the distribution of the carriers of the Aromatic Infrared Bands (AIBs) are briefly discussed on the basis of the ISO observations.

D. Cesarsky; A. P. Jones; J. Lequeux; L. Verstraete

2000-02-14

148

Large-Scale Weather  

NSDL National Science Digital Library

In the previous chapter, we dealt with how the properties of air and water affected small-scale weather such as the formation of clouds, the formation of fog, and how comfortable you feel at different times of the year. In this chapter, we're going to go global, talking about major interactions between the Sun and Earth, the resulting effects on large air masses, and how these major interactions help us figure out what the weather's going to be tomorrow. As discussed earlier in the book, when science concepts are applied to the real world, things don't always work out exactly as expected. However, it is possible to get an overall picture of what's happening in large-scale weather.

Robertson, William C.

2005-01-01

149

Weatherizing America  

ScienceCinema

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

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

2013-05-29

150

Weatherizing America  

SciTech Connect

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

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

2009-01-01

151

Weather Creator  

NSDL National Science Digital Library

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

Kshumway

2009-09-28

152

Weathering Experiment  

NSDL National Science Digital Library

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

Stelling, Pete

153

Exploring Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday, February 1st: Look at the five-day forecast for Salt Lake City, Utah at Five day forecasts. The high temperature for the day will be in red and the low temperature will be in blue. Make sure you look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make ...

Miss Emily

2010-01-29

154

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

155

The effect of rock composition on cyanobacterial weathering of crystalline basalt and rhyolite.  

PubMed

The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-weathering is unknown. Cyanobacteria are known to be a ubiquitous surface taxon in volcanic rocks. In this study, we used a selection of fast and slow growing cyanobacterial species to compare microbial-mediated weathering of bulk crystalline rocks of basaltic and rhyolitic composition, under batch conditions. Cyanobacterial growth caused an increase in the pH of the medium and an acceleration of rock dissolution compared to the abiotic controls. For example, Anabaena cylindrica increased the linear release rate (R(i)(l)) of Ca, Mg, Si and K from the basalt by more than fivefold (5.21-12.48) and increased the pH of the medium by 1.9 units. Although A. cylindrica enhanced rhyolite weathering, the increase in R(i)(l) was less than threefold (2.04-2.97) and the pH increase was only 0.83 units. The R(i)(l) values obtained with A. cylindrica were at least ninefold greater with the basalt than the rhyolite, whereas in the abiotic controls, the difference was less than fivefold. Factors accounting for the slower rate of rhyolite weathering and lower biomass achieved are likely to include the higher content of quartz, which has a low rate of weathering and lower concentrations of bio-essential elements, such as, Ca, Fe and Mg, which are known to be important in controlling cyanobacterial growth. We show that at conditions where weathering is favoured, biota can enhance the difference between low and high Si-rock weathering. Our data show that cyanobacteria can play a significant role in enhancing rock weathering and likely have done since they evolved on the early Earth. PMID:22694082

Olsson-Francis, K; Simpson, A E; Wolff-Boenisch, D; Cockell, C S

2012-09-01

156

Calcium silicate insulation structure  

DOEpatents

An insulative structure including a powder-filled evacuated casing utilizes a quantity of finely divided synthetic calcium silicate having a relatively high surface area. The resultant structure-provides superior thermal insulating characteristics over a broad temperature range and is particularly well-suited as a panel for a refrigerator or freezer or the insulative barrier for a cooler or a insulated bottle.

Kollie, Thomas G. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

1995-01-01

157

Anorthite Weathering: Rates from Vertical Scanning Interferometry  

NASA Astrophysics Data System (ADS)

Feldspar weathering plays an important role in many environmental and engineering problems, including waste disposal, groundwater movement, and diagenesis. As the most abundant rock forming minerals in the Earth's crust, feldspar dissolution rates are especially important parameters in global flux models, as well as in smaller scale kinetic dissolution models. We present results based on the dissolution rates of anorthite measured during single-crystal, flow-through experiments at varying temperature and saturation state. The experiments are conducted in a 0.01M solution of sodium tetraborate with pH 9. Saturation states with respect to anorthite are controlled by adding known concentrations of aluminum chloride, calcium chloride, and sodium meta-silicate. Using vertical scanning interferometry we obtain absolute measurements of the rate of the mineral's surface normal retreat. From the molar volume of the mineral and the velocity of the surface normal retreat we calculate absolute rate constants. No external measurement of surface area is necessary. Each measurement by the interferometer produces up to 600,000 individual rate data. Statistical analyses of these data account for the heterogeneity of dissolution across the mineral surface and can provide an average dissolution rate constant that can be compared to bulk rates obtained from powder or weight loss experiments and with rates measured by AFM. Comparing data from various techniques is important for identifying the relationship between the varying rates obtained by the different methods, as well as to rates measured in the field.

Beig, M. S.; Luttge, A.

2001-12-01

158

Smooth Sailing for Weather Forecasting  

NASA Technical Reports Server (NTRS)

Through a cooperative venture with NASA's Stennis Space Center, WorldWinds, Inc., developed a unique weather and wave vector map using space-based radar satellite information and traditional weather observations. Called WorldWinds, the product provides accurate, near real-time, high-resolution weather forecasts. It was developed for commercial and scientific users. In addition to weather forecasting, the product's applications include maritime and terrestrial transportation, aviation operations, precision farming, offshore oil and gas operations, and coastal hazard response support. Target commercial markets include the operational maritime and aviation communities, oil and gas providers, and recreational yachting interests. Science applications include global long-term prediction and climate change, land-cover and land-use change, and natural hazard issues. Commercial airlines have expressed interest in the product, as it can provide forecasts over remote areas. WorldWinds, Inc., is currently providing its product to commercial weather outlets.

2002-01-01

159

Space Weather  

NSDL National Science Digital Library

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

2004-02-06

160

Wild Weather  

NSDL National Science Digital Library

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

161

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

162

Putting Weather into Weather Derivatives  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

163

Wacky Weather  

NSDL National Science Digital Library

This 5-lesson unit gives students practice in using calculating, graphing and modeling skills to analyze varoius aspects of weather. Students calculate fractions of a set of rainfall data, graph damage costs of selected hurricanes, and make Venn diagrams to compare droughts and hurricanes. Visuals and student handouts are provided.

Barbara Chichetti

2002-01-01

164

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.

165

Wonderful Weather  

NSDL National Science Digital Library

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

Mission Science Workshop

2013-01-01

166

Weather Stations  

NSDL National Science Digital Library

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

167

Tacoma Power Weatherization  

E-print Network

Tacoma Power Weatherization Specifications August 2009 KnowYourPower.com | #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition Page 2 #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition

168

Water Rock Interaction [WRI 14] Impact of rock weathering on the chemical composition of  

E-print Network

weathering and quantifying the inputs from each of several end-members (i.e silicate, carbonate, evaporite which, carbonate inputs dominate, evaporites often plays the second role, and silicate inputs may with evaporites domes. Groundwater recharge may occur to the east at the edge of the Massif Central, to the south

Paris-Sud XI, Université de

169

Seafloor weathering buffering climate: numerical experiments  

NASA Astrophysics Data System (ADS)

Continental silicate weathering is widely held to consume atmospheric CO2 at a rate controlled in part by temperature, resulting in a climate-weathering feedback [Walker et al., 1981]. It has been suggested that weathering of oceanic crust of warm mid-ocean ridge flanks also has a CO2 uptake rate that is controlled by climate [Sleep and Zahnle, 2001; Brady and Gislason, 1997]. Although this effect might not be significant on present-day Earth [Caldeira, 1995], seafloor weathering may be more pronounced during snowball states [Le Hir et al., 2008], during the Archean when seafloor spreading rates were faster [Sleep and Zahnle, 2001], and on waterworld planets [Abbot et al., 2012]. Previous studies of seafloor weathering have made significant contributions using qualitative, generally one-box, models, and the logical next step is to extend this work using a spatially resolved model. For example, experiments demonstrate that seafloor weathering reactions are temperature dependent, but it is not clear whether the deep ocean temperature affects the temperature at which the reactions occur, or if instead this temperature is set only by geothermal processes. Our goal is to develop a 2-D numerical model that can simulate hydrothermal circulation and resulting alteration of oceanic basalts, and can therefore address such questions. A model of diffusive and convective heat transfer in fluid-saturated porous media simulates hydrothermal circulation through porous oceanic basalt. Unsteady natural convection is solved for using a Darcy model of porous media flow that has been extensively benchmarked. Background hydrothermal circulation is coupled to mineral reaction kinetics of basaltic alteration and hydrothermal mineral precipitation. In order to quantify seafloor weathering as a climate-weathering feedback process, this model focuses on hydrothermal reactions that influence carbon uptake as well as ocean alkalinity: silicate rock dissolution, calcium and magnesium leaching reactions, carbonate precipitation, and clay formation.

Farahat, N. X.; Archer, D. E.; Abbot, D. S.

2013-12-01

170

Weathering of sulfides on Mars  

NASA Technical Reports Server (NTRS)

Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produce degradation products in the Martian regolith. By analogy and terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni, and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato-and hydroxo-complex ions and sols formed gossan above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite), and silica (opal). Underlying groundwater, now permafrost contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates, and phyllosilicates during dust storms on Mars.

Burns, Roger G.; Fisher, Duncan S.

1987-01-01

171

GATOR-GCMM: A global- through urban-scale air pollution and weather forecast model, 1. Model design and treatment of subgrid soil, vegetation, roads, rooftops, water, sea ice, and snow  

NASA Astrophysics Data System (ADS)

A model that treats nesting of gas, size- and composition-resolved aerosol, radiative, and meteorological parameters from the global through urban scales (<5-km grid spacing) was developed. The model treats multiple one-way-nested layers and multiple air quality and meteorological domains in each layer between the global and the urban scales. This latter feature allows forecast of air pollution and weather at several urban or regional sites during the same simulation. Regardless of the number of domains used during a single continuous simulation, the central memory required never exceeds 1.5 times and 2.1 times that of the largest domain for gas and gas/aerosol simulations, respectively. A submodule was developed for all domains to treat ground temperatures, latent heat fluxes, and sensible heat fluxes over subgrid soil types (with and without vegetation), water, sea ice, and urban areas. Urban areas are divided into road surfaces, rooftops, vegetation, and bare soil. Snow is treated over all surface types. The global-through-urban model is applied in a companion paper to study elevated ozone, ozone in national parks, and weather during a field campaign in northern and central California.

Jacobson, Mark Z.

2001-03-01

172

Can enhanced weathering remove carbon dioxide from the atmosphere to prevent climate change? (Invited)  

NASA Astrophysics Data System (ADS)

On long timescales, silicate weathering provides the ultimate sink for CO2 released by volcanic degassing and, because the rate of such weathering is temperature dependant, this sink is thought to respond to climate change to provide a strong negative feedback stabilising Earth's climate. An increase of global weathering rates is expected in response to anthropogenic warming and this increased weathering will ultimately (on the timescale of hundreds of thousands of years) serve to remove additional CO2 and return the climate system to lower temperatures. Some have proposed that accelerating this natural process by adding ground minerals to the land surface may help to prevent climate change. However, a major challenge in assessing such a proposal is the lack of experimental kinetic data for minerals added to the environment. Here we will present results from an experiment in which a forsterite rich olivine (Mg2SiO4) was added to the top of a soil column extracted from an agricultural field. A solution was passed through the columns over a period of 5 months and the drainage waters were collected and analysed. The greater flux of Mg measured eluting from the treated soil can be used to constrain the weathering rate of the olivine. A weathering rate can be determined by normalising the rate of magnesium flux to the surface area of olivine in the soil. By combining this information with a simple shrinking core model, we can estimate that an average particle size less than 1 ?m would be required in order for the olivine to completely dissolve in a year. Therefore, the energy requirements for enhanced weathering are large >2 GJ(electrical) per net tonne of CO2 sequestered, but it is at least comparable to direct air capture technologies. These preliminary results suggest limited carbon capture potential for enhanced weathering in temperate agricultural soils. However, some environments may be better suited (e.g. humid tropical agricultural soils) and additional experimental work is required to test these. This initial assessment does not include the plethora of other impacts that may be caused by enhanced weathering (ocean fertilisation, dust generation, soil carbon changes, K-feldspar fertilisation). More generally, terrestrial enhanced weathering is only one of a number of technologies that propose to add alkalinity to the surface ocean. The findings from this study will be presented in the context of this broader research field of ocean alkalinity modification.

Renforth, P.; Pogge von Strandmann, P.; Henderson, G. M.

2013-12-01

173

Weather Cycles  

NSDL National Science Digital Library

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

Mitchell, Mrs.

2010-09-23

174

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

175

Weather Observations  

NSDL National Science Digital Library

We will be observing the weather in our enviornment. Post your observations. Take a hike! Tell us what you see! Make sure and note the date/time/season. Take a walk in your neighboorhood- what signs show you the current season? Vacation? Make observations about the place you visited. Make obseravtions every week! Keep a journal about the changes you observe! Winter Storm ImageSeasonal ChangesAround the WorldSeasonsSeasons of the Year ...

sarahnp

2011-07-18

176

Weathering and the mobility of phosphorus in the catchments and forefields of the Rhône and Oberaar glaciers, central Switzerland: Implications for the global phosphorus cycle on glacial-interglacial timescales  

NASA Astrophysics Data System (ADS)

In this study we evaluate the dynamics of the biophile element phosphorus (P) in the catchment and proglacial areas of the Rhône and Oberaar glaciers (central Switzerland). We analysed erosion and dissolution rates of P-containing minerals in the subglacial environment by sampling water and suspended sediment in glacier outlets during three ablation and two accumulation seasons. We also quantified biogeochemical weathering rates of detrital P in proglacial sedimentary deposits using two chronosequences of samples of fresh, suspended, material obtained from the Oberaar and Rhône water outlets, Little-Ice-Age (LIA) moraines and Younger Dryas (YD) tills in each catchment. Subglacial P weathering is mainly a physical process and detrital P represents more than 99% of the precipitation-corrected total P denudation flux (234 and 540 kg km -2 yr -1 for the Rhône and Oberaar catchments, respectively). The calculated detrital P flux rates are three to almost five times higher than the world average flux. The precipitation-corrected soluble reactive P (SRP) flux corresponds to 1.88-1.99 kg km -2 yr -1 (Rhône) and 2.12-2.44 kg km -2 yr -1 (Oberaar), respectively. These fluxes are comparable to those of tropical rivers draining transport-limited, tectonically inactive weathering areas. In order to evaluate the efficiency of detrital P weathering in the Rhône and Oberaar proglacial areas, we systematically graded apatite grains extracted from the chronosequence in each catchment relative to weathering-induced changes in their surface morphologies (grades 1-4). Fresh apatite grains are heavily indented and dissolution rounded (grade 1). LIA grains from two 0-10 cm deep moraine samples show extensive dissolution etching, similar to surface grains from the YD profile (mean grades 2.7, 3.5 and 3.5, respectively). In these proglacial deposits, the weathering front deepens progressively as a function of time due to biocorrosion in the evolving acidic pedosphere , with mechanical indentations on grains acting as sites of preferential dissolution. We also measured iron-bound, organic and detrital P concentrations in the chronosequence and show that organic and iron-bound P has almost completely replaced detrital P in the top layers of the YD profiles. Detrital P weathering rates are calculated as 310 and 280 kg km -2 yr -1 for LIA moraines and 10 kg km -2 yr -1 for YD tills. During the first 300 years of glacial sediment exposure P dissolution rates are shown to be approximately 70 times higher than the mean global dissolved P flux from ice-free continents. After 11.6 kyr the flux is 2.5 times the global mean. These data strengthen the argument for substantial changes in the global dissolved P flux on glacial-interglacial timescales. A crude extrapolation from the data described here suggests that the global dissolved P flux may increase by 40-45% during the first few hundred years of a deglaciation phase.

Föllmi, Karl B.; Hosein, Rachel; Arn, Kaspar; Steinmann, Philipp

2009-04-01

177

21 CFR 172.410 - Calcium silicate.  

Code of Federal Regulations, 2011 CFR

...Drugs 3 2011-04-01 2011-04-01 false Calcium silicate. 172.410 Section 172.410 Food...HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium...

2011-04-01

178

21 CFR 172.410 - Calcium silicate.  

Code of Federal Regulations, 2013 CFR

...Drugs 3 2013-04-01 2013-04-01 false Calcium silicate. 172.410 Section 172.410 Food...HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium...

2013-04-01

179

21 CFR 172.410 - Calcium silicate.  

...Drugs 3 2014-04-01 2014-04-01 false Calcium silicate. 172.410 Section 172.410 Food...HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium...

2014-04-01

180

21 CFR 172.410 - Calcium silicate.  

Code of Federal Regulations, 2012 CFR

...Drugs 3 2012-04-01 2012-04-01 false Calcium silicate. 172.410 Section 172.410 Food...HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium...

2012-04-01

181

Mountain Weather  

NSDL National Science Digital Library

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

182

Interannual variability of Martian weather  

Microsoft Academic Search

Pressure, temperature, imaging, and wind data from the Mutch Memorial Station, the Viking lander located in Mars' subtropics, are used to demonstrate the existence of two disctinct regimes of northern hemisphere winter weather on Mars. One of these regime is characterized by one or more intense global dust storms in which the optical depth reaches about 5 over most of

C. B. Leovy; J. E. Tillman; W. R. Guest; J. Barnes

1985-01-01

183

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

184

Reconciling the elemental and Sr isotope composition of Himalayan weathering fluxes: insights from the carbonate geochemistry of stream waters  

Microsoft Academic Search

Determining the relative proportions of silicate vs. carbonate weathering in the Himalaya is important for understanding atmospheric CO2 consumption rates and the temporal evolution of seawater Sr. However, recent studies have shown that major element mass-balance equations attribute less CO2 consumption to silicate weathering than methods utilizing Ca\\/Sr and 87Sr\\/86Sr mixing equations. To investigate this problem, we compiled literature data

ANDREW D. JACOBSON; J OEL D. BLUM; LYNN M. WALTER

2002-01-01

185

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

186

Ion implantation in silicate glasses  

SciTech Connect

This review examines the effects of ion implantation on the physical properties of silicate glasses, the compositional modifications that can be brought about, and the use of metal implants to form colloidal nanosize particles for increasing the nonlinear refractive index.

Arnold, G.W.

1993-12-01

187

The Silicate Structures: Chalkboard Demonstration  

NSDL National Science Digital Library

Three-dimensional, magnetic representations of SiO tetrahedra and cations are manipulated on a chalkboard to create five basic silicate structures. Students are expected to complete a worksheet accompanying the exercise, which addresses silicate structures, bond types and strengths, physical properties (e.g. fracture, cleavage), Si:O ratio and introduction to vocabulary such as "felsic" and "mafic," and mineral formulae. The worksheet and chalkboard demonstration are designed to simplify silicate structures from complex ball-and-stick models typically used in textbook figures, and to grant students a visual, three-dimensional, manipulable, perspective on what tends to be a confusing concept. This exercise may be simplified or expanded to suit timeframe and the needs of the audience. Benefits of this approach include reinforcement of lecture concepts, broad appeal for a student group with multiple learning styles and degrees of knowledge, and strengthened understanding of the silicate structures.

Stevens, Liane

188

Final Report on the Safety Assessment of Aluminum Silicate, Calcium Silicate, Magnesium Aluminum  

E-print Network

Final Report on the Safety Assessment of Aluminum Silicate, Calcium Silicate, Magnesium Aluminum Sodium Silicate, Montmorillonite, Pyrophyllite, and Zeolite1 This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium

Ahmad, Sajjad

189

Understanding Weather  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the naturally-occurring greenhouse effect on Earth, and its connection to global warming. Students build model greenhouses to see how this process works. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

190

The mid-Cretaceous super plume, carbon dioxide, and global warming  

SciTech Connect

Carbon-dioxide releases associated with a mid-Cretaceous super plume and the emplacement of the Ontong-Java Plateau have been suggested as a principal cause of the mid-Cretaceous global warming. The authors developed a carbonate-silicate cycle model to quantify the possible climatic effects of these CO{sub 2} releases, utilizing four different formulations for the rate of silicate-rock weathering as a function of atmospheric CO{sub 2}. They find that CO{sub 2} emissions resulting from super-plume tectonics could have produced atmospheric CO{sub 2} levels from 3.7 to 14.7 times the modern pre-industrial value of 285 ppm. Based on the temperature sensitivity to CO{sub 2} increases used in the weathering-rate formulations, this would cause a global warming of from 2.8 to 7.7C over today's global mean temperature. Altered continental positions and higher sea level may have been contributed about 4.8C to mid-Cretaceous warming. Thus, the combined effects of paleogeographic changes and super-plume related CO{sub 2} emissions could be in the range of 7.6 to 12.5C, within the 6 to 14C range previously estimated for mid-Cretaceous warming. CO{sub 2} releases from oceanic plateaus alone are unlikely to have been directly responsible for more than 20% of the mid-Cretaceous increase in atmospheric CO{sub 2}.

Caldeira, K. (New York Univ., New York (United States)); Rampino, M.R. (New York Univ., New York (United States) NASA Goddard Inst. for Space Studies, New York, NY (United States))

1991-06-01

191

National Climatic Data Center's Extreme Weather and Climate Events  

NSDL National Science Digital Library

This National Climatic Data Center site offers observed data of worldwide extreme weather and climate events. Topic areas include: U.S. Hurricanes, Heavy Precipitation, Temperature Extremes, U.S.Tornadoes, Billion $$ Weather Disasters, 1991-2001 Weather Events, Global Climate Change, Historical Global Extremes, El Nino/La Nina, Satellite Images, Climate of 2000, U.S. Local Storm Reports, Climatic Data, and U.S. Radar Composites.

192

Yaquina Bay Weather & Tides  

E-print Network

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

Wright, Dawn Jeannine

193

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.

194

Vodcasting Space Weather  

NASA Astrophysics Data System (ADS)

The topic of space weather is the subject of a series of vodcasts (video podcasts) produced by MIT Haystack Observatory (Westford, MA) and Loch Ness Productions (Groton, MA). This paper discusses the production and distribution of the series via Webcast, Youtube, and other avenues. It also presents preliminary evaluation of the effectiveness and outreach of the project through feedback from both formal and information education venues. The vodcast series is linked to the NASA Living With a Star Targeted Research and Technology project award "Multi-Instrument Investigation of Inner-Magnetospheric/Ionosphere Disturbances.” It is being carried out by Principal Investigator Dr. John Foster, under the auspices of NASA Grant # NNX06AB86G. The research involves using ionospheric total electron content (TEC) observations to study the location, extent, and duration of perturbations within stormtime ionospheric electric fields at mid- to low latitudes. It combines ground-based global positioning system (GPS) TEC data, incoherent scatter radar measurements of the mid-latitude ionospheric state, and DMSP satellite observations to characterize conditions which lead to severe low-latitude ionospheric perturbations. Each vodcast episode covers a certain aspect of space weather and the research program.

Collins Petersen, Carolyn; Erickson, P. J.; Needles, M.

2009-01-01

195

Supporting Weather Data  

NASA Technical Reports Server (NTRS)

Since its founding in 1992, Global Science & Technology, Inc. (GST), of Greenbelt, Maryland, has been developing technologies and providing services in support of NASA scientific research. GST specialties include scientific analysis, science data and information systems, data visualization, communications, networking and Web technologies, computer science, and software system engineering. As a longtime contractor to Goddard Space Flight Center s Earth Science Directorate, GST scientific, engineering, and information technology staff have extensive qualifications with the synthesis of satellite, in situ, and Earth science data for weather- and climate-related projects. GST s experience in this arena is end-to-end, from building satellite ground receiving systems and science data systems, to product generation and research and analysis.

2004-01-01

196

Comparative pathology of silicate pneumoconiosis.  

PubMed Central

A simple pneumoconiosis with lamellar birefringent crystals was observed in animals dying in the San Diego Zoo. We studied 100 autopsies from 11 mammalian and eight avian species. In mammals, mild pulmonary lesions comprised crystal-laden macrophages in alveoli and lymphatics. Interstitial fibrosis was present in 20% of cases. There were no nodules. In birds, dust retention produced large granulomas around tertiary bronchi without fibrosis. Mineralogic analysis using scanning and transmission electron microscopy showed most of the crystals to be silicates. Ninety percent were complex silicates, with aluminum-potassium silicates comprising 70% of the analyzed particles. Electron and x-ray diffraction showed the silicates to be muscovite mica and its hydrothermal degradation product, ie, illite clay. This mica was also present on filtration membranes of atmospheric air samples obtained from the San Diego Zoo. The amount of dust retention was related to the animal's age, anatomic or ecologic variances, and length of stay in the San Diego Zoo. Its semidesert atmosphere is rich in silicates, which are inhaled and deposited in the lungs. Similar mica-induced lesions are found in humans living in this region or the Southwest of the USA. This simple pneumoconiosis is likely to be widespread in human populations living in desert or semidesert climates. Images Figure 9 Figure 10 Figure 7 Figure 8 Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 PMID:223447

Brambilla, C.; Abraham, J.; Brambilla, E.; Benirschke, K.; Bloor, C.

1979-01-01

197

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.

198

GPS as a Weather Sensor  

NASA Astrophysics Data System (ADS)

Global Positioning System (GPS) stations are not just useful for studying how tectonic plates and glaciers surge or creep or how land deforms as magma runs below it. They also are rapidly becoming important sensors for monitoring the terrestrial water cycle (see "Using GPS to study the terrestrial water cycle," pages 505-506). What is more, they can help study and forecast weather, according to scientists who presented their work at AGU's 2013 Fall Meeting in San Francisco, Calif.

Kumar, Mohi

2013-12-01

199

Weather Camp 2012 "Weather and Climate All Around Us"  

E-print Network

Weather Camp 2012 "Weather and Climate All Around Us" Are you interested in the weather? Come to Weather Camp at UNL What is Weather Camp? For more information Weather camp is a week long day camp for students who will be 11-14 years old at the time of the camp Most of the activities at Weather Camp 2012

Farritor, Shane

200

Progress in space weather predictions and applications  

NASA Astrophysics Data System (ADS)

The methods of today's predictions of space weather and effects are so much more advanced and yesterday's statistical methods are now replaced by integrated knowledge-based neuro-computing models and MHD methods. Within the ESA Space Weather Programme Study a real-time forecast service has been developed for space weather and effects. This prototype is now being implemented for specific users. Today's applications are not only so many more but also so much more advanced and user-oriented. A scientist needs real-time predictions of a global index as input for an MHD model calculating the radiation dose for EVAs. A power company system operator needs a prediction of the local value of a geomagnetically induced current. A science tourist needs to know whether or not aurora will occur. Soon we might even be able to predict the tropospheric climate changes and weather caused by the space weather.

Lundstedt, H.

201

Progress in Space Weather Predictions and Applications  

NASA Astrophysics Data System (ADS)

The methods of today's predictions of space weather and effects are so much more advanced and yesterday's statistical methods are now being replaced by integrated knowledge-based neurocomputing and MHD methods. Within in the ESA Space Weather Programme Study a real-time forecast service has been developed of space weather and effects. This prototype is now being implemented for specific users. Today's applications are not only so many more but also so much more advanced and user-oriented. A scientist asks for a real-time predictions of a global index as input for a MHD model calculating the radiation dose for EVAs. A power system operator asks for a prediction of the local value of a geomagnetically induced current. A science tourist wants to know whether or not aurora will occur. Soon we might even be able to predict the tropospheric weather and climate changes from the variation of the space weather.

Lundstedt, H.

202

Pilot weather advisor  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

203

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

204

Tobermorite group of silicates (Tables)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume I4 'Inosilicates' of Volume 27 'Magnetic properties of non-metallic inorganic compounds based on transition elements' of Landolt-Börnstein - Group III Condensed Matter. It contains the data of the tobermorite group of silicates (Tables)

Burzo, E.

205

Tobermorite group of silicates (Figures)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume I4 'Inosilicates' of Volume 27 'Magnetic properties of non-metallic inorganic compounds based on transition elements' of Landolt-Börnstein - Group III Condensed Matter. It contains the data of the tobermorite group of silicates (Figures)

Burzo, E.

206

Tobermorite group of silicates (Text)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume I4 'Inosilicates' of Volume 27 'Magnetic properties of non-metallic inorganic compounds based on transition elements' of Landolt-Börnstein - Group III Condensed Matter. It contains the data of the tobermorite group of silicates (Text)

Burzo, E.

207

Laser processing of siliceous materials  

Microsoft Academic Search

Laser processing of siliceous materials becomes increasingly important. Analogous to the laser processing of conventional materials there are applications in the fields of cleaning, surface processing, cutting, etc. The present paper concerns the state of the art and new applications: (1) Laser cleaning of natural stone surfaces. The good disability allows restoration work to be carried out conveniently, as for

Michael Panzner; Andreas Lenk; Guenter R. Wiedemann; Jan Hauptmann; Hans J. Weiss; Thomas Ruemenapp; Lothar Morgenthal; Eckhard Beyer

2000-01-01

208

Solubility limits of silicate melts  

Microsoft Academic Search

A statistical mechanical model of silica melt is presented in which metal oxides are incorporated into the bonding network. In this approach a Flory-type lattice model for binary silicate melts is coupled with a set of chemical reactions that determine the extent of metal oxide incorporation into the silica network and regulate the distribution of nonbridging oxygens around a central

L. Rene Corrales; Keith D. Keefer

1997-01-01

209

Amended Silicated for Mercury Control  

SciTech Connect

Amended Silicates{trademark}, a powdered, noncarbon mercury-control sorbent, was tested at Duke Energy's Miami Fort Station, Unit 6 during the first quarter of 2006. Unit 6 is a 175-MW boiler with a cold-side electrostatic precipitator (ESP). The plant burns run-of-the-river eastern bituminous coal with typical ash contents ranging from 8-15% and sulfur contents from 1.6-2.6% on an as-received basis. The performance of the Amended Silicates sorbent was compared with that for powdered activated carbon (PAC). The trial began with a period of baseline monitoring during which no sorbent was injected. Sampling during this and subsequent periods indicated mercury capture by the native fly ash was less than 10%. After the baseline period, Amended Silicates sorbent was injected at several different ratios, followed by a 30-day trial at a fixed injection ratio of 5-6 lb/MMACF. After this period, PAC was injected to provide a comparison. Approximately 40% mercury control was achieved for both the Amended Silicates sorbent and PAC at injection ratios of 5-6 lbs/MMACF. Higher injection ratios did not achieve significantly increased removal. Similar removal efficiencies have been reported for PAC injection trials at other plants with cold-side ESPs, most notably for plants using medium to high sulfur coal. Sorbent injection did not detrimentally impact plant operations and testing confirmed that the use of Amended Silicates sorbent does not degrade fly ash quality (unlike PAC). The cost for mercury control using either PAC or Amended Silicates sorbent was estimated to be equivalent if fly ash sales are not a consideration. However, if the plant did sell fly ash, the effective cost for mercury control could more than double if those sales were no longer possible, due to lost by-product sales and additional cost for waste disposal. Accordingly, the use of Amended Silicates sorbent could reduce the overall cost of mercury control by 50% or more versus PAC for locations where fly ash is sold as a by-product.

James Butz; Thomas Broderick; Craig Turchi

2006-12-31

210

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather?  

E-print Network

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather? Come to Weather Camp at UNL! What is Weather Camp? For more information Weather camp is a week-long day camp for students who will be 11-14 years old at the time of the camp. Most of the activities at Weather Camp 2012

Farritor, Shane

211

Physical and chemical weathering. [of Martian surface and rocks  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

212

Owlie Skywarn's Weather Book  

NSDL National Science Digital Library

This is an online activity book from the National Weather Service that teaches about hazardous weather. The site also includes links to kids sites for the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Agency (NOAA).

Cris Garcia

2001-06-22

213

Favorite Demonstration: Differential Weathering  

NSDL National Science Digital Library

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

Francek, Mark

2002-10-01

214

High-latitude filtering in a global grid-point model using model normal modes. [Fourier filters for synoptic weather forecasting  

NASA Technical Reports Server (NTRS)

A normal modes expansion technique is applied to perform high latitude filtering in the GLAS fourth order global shallow water model with orography. The maximum permissible time step in the solution code is controlled by the frequency of the fastest propagating mode, which can be a gravity wave. Numerical methods are defined for filtering the data to identify the number of gravity modes to be included in the computations in order to obtain the appropriate zonal wavenumbers. The performances of the model with and without the filter, and with a time tendency and a prognostic field filter are tested with simulations of the Northern Hemisphere winter. The normal modes expansion technique is shown to leave the Rossby modes intact and permit 3-5 day predictions, a range not possible with the other high-latitude filters.

Takacs, L. L.; Kalnay, E.; Navon, I. M.

1985-01-01

215

The mid-Cretaceous super plume, carbon dioxide, and global warming  

NASA Technical Reports Server (NTRS)

Carbon-dioxide releases associated with a mid-Cretaceous super plume and the emplacement of the Ontong-Java Plateau have been suggested as a principal cause of the mid-Cretaceous global warming. A carbonate-silicate cycle model is developed to quantify the possible climatic effects of these CO2 releases, utilizing four different formulations for the rate of silicate-rock weathering as a function of atmospheric CO2. CO2 emissions resulting from super-plume tectonics could have produced atmospheric CO2 levels from 3.7 to 14.7 times the modern preindustrial value of 285 ppm. Based on the temperature sensitivity to CO2 increases used in the weathering-rate formulations, this would cause a global warming of from 2.8 to 7.7 C over today's glogal mean temperature. Altered continental positions and higher sea level may have been contributed about 4.8 C to mid-Cretaceous warming. Thus, the combined effects of paleogeographic changes and super-plume related CO2 emissions could be in the range of 7.6 to 12.5 C, within the 6 to 14 C range previously estimated for mid-Cretaceous warming. CO2 releases from oceanic plateaus alone are unlikely to have been directly responsible for more than 20 percent of the mid-Cretaceous increase in atmospheric CO2.

Caldeira, Ken; Rampino, Michael R.

1991-01-01

216

Weather and Road Management  

NSDL National Science Digital Library

Anticipating and dealing with weather and the hazards it creates is a real challenge for those in departments of transportation. This module gives road and highway managers a basic understanding of meteorology and weather hazards so that they can better interpret weather forecast information used to make road management decisions. The module also highlights web-based forecast products available from the National Weather Service that can help in the decision-making process.

Comet

2008-07-21

217

Weathering and Erosion  

NSDL National Science Digital Library

This unit provides an introduction for younger students to the concepts of weathering and erosion. Topics include types of weathering (physical versus chemical), rates of weathering, and weathering products (soil). The section on erosion explains the importance of water and gravity in the process, and discusses some of the more important erosional agents such as wind, water and ice, streams and glaciers. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

2010-09-07

218

Stormfax Weather Services  

NSDL National Science Digital Library

This site offers links to a variety of weather information, including national, international and local weather maps and forecasts, satellite and radar imagery, and severe weather warnings. There are also links to diverse resources such as fire maps, glacier inventories, snow depths, storm surges and tropical storms. There are reports and advisories about El Nino and La Nina. The site also has a glossary of weather terms and conversion charts for temperature, wind speed and atmospheric pressure.

2002-06-10

219

Web Weather for Kids  

NSDL National Science Digital Library

This set of resources for younger students includes activities and information on thunderstorms, tornadoes, hurricanes, blizzards and clouds: how they form, and how they impact our lives. There are games about clouds, stories about extreme weather events, and a set of activities in which students create simulations of various weather phenomena such as fog, clouds, tornadoes, and others. The 'Recipe for Weather' segment provides an overview of four atmospheric properties (temperature, pressure, volume, and density) which drive most weather phenomena.

220

Winter Weather Introduction  

E-print Network

Winter Weather Management #12;Introduction · Campus Facilities Staff · Other Campus Organizations #12;Purpose · Organize and coordinate the campus response to winter weather events to maintain campus for use by 7 AM. · Response will be modified depending upon forecast and current weather conditions. #12

Taylor, Jerry

221

Aviation weather services  

NASA Technical Reports Server (NTRS)

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

Sprinkle, C. H.

1983-01-01

222

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

223

Severe Weather Perceptions.  

ERIC Educational Resources Information Center

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

Abrams, Karol

224

Climate and Weather  

NSDL National Science Digital Library

This video discusses the differences between climate and weather by defining and presenting examples of each. When presenting examples of weather, the video focuses on severe events and how meteorologists predict and study the weather using measurement, satellites, and radar. The climate focus is primarily on an overview of climate zones.

Geographic, National

225

Hot Weather Tips  

MedlinePLUS

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

226

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.

Charles Burrows

227

Space Weathering on Icy Satellites in the Outer Solar System  

NASA Astrophysics Data System (ADS)

Space weathering produces well-known optical effects in silicate minerals in the inner Solar System, for example, on the Moon. Space weathering from solar wind and UV is expected to be weaker in the outer Solar System simply because intensities are lower. However, cosmic rays from inner to outer solar system would be similar to first order. Similarly with micrometeoroid bombardment. That, combined with the much higher volatility of icy surfaces means there is the potential for space weathering on icy outer Solar System surfaces to show optical effects. The Cassini spacecraft orbiting Saturn is providing evidence for space weathering on icy bodies. The Cassini VIMS instrument has spatially mapped satellite surfaces and the rings from .35-5 microns and the UVIS instrument from 0.1 to 0.2 microns. These data have sampled a complex mixing space between H2O ice and non-ice components and they show some common spectral properties. Similarly, spectra of the icy Galilean satellites and satellites in the Uranian system have some commonality in spectral properties with those in the Saturn system. The UV absorber is spectrally similar on many surfaces. VIMS has identified CO2, H2 and trace organics in varying abundances on Saturn's satellites. We postulate that through the spatial relationships of some of these compounds that they are created and destroyed through space weathering effects. For example, the trapped H2 and CO2 observed by VIMS in regions with high concentrations of dark material may in part be space weathering products from the destruction of H2O and organic molecules. The dark material, particularly on Iapetus which has the highest concentration in the Saturn system, is well matched by space-weathered silicates in the .4-2.6 micron range, and the spectral shapes closely match those of the most mature lunar soils, another indicator of space weathered material.

Clark, Roger N.; Perlman, Zachary; Pearson, Neil; Cruikshank, Dale P.

2014-11-01

228

External Resource: Weathering and Erosion  

NSDL National Science Digital Library

This activity includes background information about weathering, as well as simple demonstrations/activities to model how weather conditions contribute to weathering and erosion. Topics include: chemical weathering, dunes, erosion, floods, glaciers, physi

1900-01-01

229

A New Catalog of Silicate Carbon Stars  

NASA Astrophysics Data System (ADS)

A silicate carbon star is a carbon star which shows circumstellar silicate dust features. We collect a sample of 44 silicate carbon stars from the literature and investigate the validity of the classification. For some objects, it is uncertain whether the central star is a carbon star. We confirm that 29 objects are verified silicate carbon stars. We classify the confirmed objects into three subclasses based on the evolution phase of the central star. To investigate the effect of the chemical transition phase from O to C, we use the radiative transfer models for the detached silicate dust shells. The spectral energy distributions and the infrared two-color diagrams of the silicate carbon stars are compared with the theoretical model results. For the chemical transition model without considering the effect of a disk, we find that the life time of the silicate feature is about 50 to 400 years depending on the initial dust optical depth.

Kwon, Young-Joo; Suh, Kyung-Won

2014-08-01

230

Wet-Weather Pollution from Commonly-Used Building Materials  

E-print Network

Conference. Water Environment Federation. #12;2 SCRAPYARD RUNOFF (SOLUBLE FRACTION) 1.8 ­ 12Magnesium 8 ­ 200Calcium 0.1 ­ 6.7Zinc 0.1 ­ 0.3Lead 0.1 ­ 0.3Copper 0.05 ­ 0.35Phosphate Concentration (mg ·Gardner Wet-R-DriTM All Weather Plastic Roof Cement Petroleum Distillate Asphalt Silicate Mineral

Clark, Shirley E.

231

Characterization of Fungal Community Structure on a Weathered Pegmatitic Granite  

Microsoft Academic Search

This study exploited the contrasting major element chemistry of adjacent, physically separable crystals of framework and sheet\\u000a silicates in a pegmatitic granite to investigate the mineralogical influences of fungal community structure on mineral surfaces.\\u000a Large intact crystals of variably weathered muscovite, plagioclase, K-feldspar, and quartz were individually extracted, together\\u000a with whole-rock granite. Environmental scanning electron microscopy (ESEM) revealed a diversity

Deirdre B. Gleeson; Nicholas Clipson; Karrie Melville; Geoffrey M. Gadd; Frank P. McDermott

2005-01-01

232

Weather affects us  

NSDL National Science Digital Library

2nd grade weather unit. The students will learn how weather affects us in our daily lives Read and view the video on meteorologists Kid Meteorologist Learn about clouds - watch S'cool Clouds All About Clouds Do scholastic: weather watch and game Weather Read winter storms Interactive Weather Web Pages Read a reason for the season A Reason for the Season Read about precipitation Precipitation Read and view video on flooding Flood: Farming and Erosion Read about air pressure It's a Breeze: How Air Pressure Affects You Read about Hurricanes Hurricanes Do the activities and read ...

Kimmy

2009-11-09

233

Modifying Silicates for Better Dispersion in Nanocomposites  

NASA Technical Reports Server (NTRS)

An improved chemical modification has been developed to enhance the dispersion of layered silicate particles in the formulation of a polymer/silicate nanocomposite material. The modification involves, among other things, the co-exchange of an alkyl ammonium ion and a monoprotonated diamine with interlayer cations of the silicate. The net overall effects of the improved chemical modification are to improve processability of the nanocomposite and maximize the benefits of dispersing the silicate particles into the polymer. Some background discussion is necessary to give meaning to a description of this development. Polymer/silicate nanocomposites are also denoted polymer/clay composites because the silicate particles in them are typically derived from clay particles. Particles of clay comprise layers of silicate platelets separated by gaps called "galleries." The platelet thickness is 1 nm. The length varies from 30 nm to 1 m, depending on the silicate. In order to fully realize the benefits of polymer/silicate nanocomposites, it is necessary to ensure that the platelets become dispersed in the polymer matrices. Proper dispersion can impart physical and chemical properties that make nanocomposites attractive for a variety of applications. In order to achieve nanometer-level dispersion of a layered silicate into a polymer matrix, it is typically necessary to modify the interlayer silicate surfaces by attaching organic functional groups. This modification can be achieved easily by ion exchange between the interlayer metal cations found naturally in the silicate and protonated organic cations - typically protonated amines. Long-chain alkyl ammonium ions are commonly chosen as the ion-exchange materials because they effectively lower the surface energies of the silicates and ease the incorporation of organic monomers or polymers into the silicate galleries. This completes the background discussion. In the present improved modification of the interlayer silicate surfaces, the co-ion exchange strengthens the polymer/silicate interface and ensures irreversible separation of the silicate layers. One way in which it does this is to essentially tether one amine of each diamine molecule to a silicate surface, leaving the second amine free for reaction with monomers during the synthesis of a polymer. In addition, the incorporation of alkyl ammonium ions into the galleries at low concentration helps to keep low the melt viscosity of the oligomer formed during synthesis of the polymer and associated processing - a consideration that is particularly important in the case of a highly cross-linked, thermosetting polymer. Because of the chemical bonding between the surface-modifying amines and the monomers, even when the alkyl ammonium ions become degraded at high processing temperature, the silicate layers do not aggregate and, hence, nanometer-level dispersion is maintained.

Campbell, Sandi

2005-01-01

234

Silicate Dust in RS Ophiuchi  

NASA Astrophysics Data System (ADS)

We present Spitzer IRS spectra of the recurrent nova RS Ophiuchi obtained between 2006 and 2009. The data show emission lines due to HI, [Ne II], [Ne V], [Ne VI] and [O IV] and the well known silicate features at 10 ?m and 18 ?m, whose behaviour are reported here. The silicate features are variable in the period covered by the observations, appearing strongest in our 2007 data. Interestingly, the central wavelength of the 18 ?m band is shorter than observed in other symbiotic systems and other circumstellar environments, suggesting unusual grain properties in RS Oph. We report changes that have taken place in the dusty environment in RS Oph and investigate the properties of the dust grains.

Rushton, M. T.; Woodward, C. E.; Helton, L. A.; Gehrz, R. D.; Evans, A.; Kaminsky, B.; Pavlenko, Y. V.; Eyres, S. P. S.; Maxwell, M.

2014-12-01

235

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

236

Severe Weather 101: Winter Weather Basics  

MedlinePLUS

... Educators For Students For Everyone Severe Weather 101 Thunderstorms Basics Types Detection Forecasting FAQ Tornadoes Basics Types ... moisture. What we do: NSSL researchers studied winter thunderstorms and found that there is some evidence that ...

237

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.

238

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

239

Metal - Silicate Separation in a Deformation Regime: Implications for Early Differentiation Processes  

NASA Astrophysics Data System (ADS)

The segregation of metallic cores from silicate mantles is one of the earliest, and most important, differentiation process involved in the evolution of the Earth and other terrestrial planetary bodies. The physical segregation of Fe-rich metal from silicate imparted a strong geochemical signature on early silicate mantles due to the preferential incorporation of siderophile elements into the core. Reconciling our estimates of primary bulk silicate mantle with candidate planetary bulk compositions requires an understanding of the geochemical consequences of the different regimes in which core forming material may have been mobile. This includes not only the possible differentiation processes that occurred in the terrestrial planets, but also understanding the differentiation processes in the meteorite parent bodies. Although a magma ocean model is possible for efficient core formation, some scenarios call for segregation of the core from solid silicate and the geochemical consequences can be significantly different. Experimental studies are one way in which insight can be gained into the possible geochemical signatures of metal-silicate segregation. Deformation experiments in addition provide a dynamic component, which allows liquid metal to segregate from solid silicate. Starting materials are cored from a slab of the Kernouve fall which is composed of olivine, pyroxene, plagioclase, chromite and chlorapatite; Fe-Ni metal and sulfide form 20-25% of the sample. Experimental conditions are 1.0-1.4 GPa confining pressure with strain rates of 10-4/s to 10-6/s. Temperatures ranging from 900° C to 1050° C produce variable amounts of silicate melt and different mechanisms of metal segregation are observed. In experiments which are below the silicate solidus, mobility of FeS is extensive and deformation textures are cataclastic. Geochemical analyses shows that migration of Fe-S-Ni-O metal through fractures and along grain boundaries produces extensive modification to the solid silicate matrix, particularly at the slower strain rates. New Fe-rich olivine is produced by reaction between Fe and Mg-opx, whereas cpx and primary Mg-olivine become Fe-enriched. At moderate silicate melt fractions (below ~12.5 vol%), we observe preferential segregation of the silicate melt fraction from quench Fe-S, Fe(Ni) and occasionally, Fe-P, by deformation-induced pressure gradients. At the highest silicate melt fractions, metal is fully separated from the silicate melt rich portion of the samples. The silicate solidus is lower than expected and analyses show that silicate glass at 1000°C and 1050°C contains small amounts of Cl (0.01-0.09 wt%), S (0.03-0.07 wt%) and P (0.3 wt%). We suggest the presence of H2O. Chlorapatite, possibly in conjunction with the products of terrestrial weathering may represent a source of Cl, P and OH in the experiments. These results are also providing insight into differentiation processes in meteorite parent bodies which have undergone early differentiation. Different degrees of partial melting concomitant with deformation-enhanced separation of the silicate melt portion may be responsible for the formation of the parent bodies of acapulcoites and lodranites which formed from precursor chondrites. The experimental results contribute to our understanding of dynamic differentiation process, through which these different meteorite types may be linked, and to the formation of some of the earliest planetary compositions.

Rushmer, T.; Jones, J. H.; Gaetani, G.; Zanda, B.

2001-12-01

240

Space Weathering of Rocks  

NASA Technical Reports Server (NTRS)

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

Noble, Sarah

2011-01-01

241

Global Climate Change  

NSDL National Science Digital Library

Students learn how the greenhouse effect is related to global warming and how global warming impacts our planet, including global climate change. Extreme weather events, rising sea levels, and how we react to these changes are the main points of focus of this lesson.

2014-09-18

242

Sensitivity of building cooling loads to future weather predictions  

Microsoft Academic Search

The interaction and the relationship between global warming and thermal performance buildings are dynamic in nature. In order to model and understand this behaviour, different approaches, including that of keeping the weather variable unchanged, the morphing approach and the diurnal modelling method, have been used to project and generate future weather data. Among these approaches, various assumptions of change in

Lisa Guan

2011-01-01

243

Tales of future weather  

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

244

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.

Hydrometeorological Prediction Center

2011-01-01

245

Silicate absorption in heavily obscured galaxy nuclei  

E-print Network

Spectroscopy at 8-13 microns with T-ReCS on Gemini-S is presented for 3 galaxies with substantial silicate absorption features, NGC 3094, NGC 7172 and NGC 5506. In the galaxies with the deepest absorption bands, the silicate profile towards the nuclei is well represented by the emissivity function derived from the circumstellar emission from the red supergiant, mu Cephei which is also representative of the mid-infrared absorption in the diffuse interstellar medium in the Galaxy. There is spectral structure near 11.2 microns in NGC 3094 which may be due to a component of crystalline silicates. In NGC 5506, the depth of the silicate absorption increases from north to south across the nucleus, suggestive of a dusty structure on scales of 10s of parsecs. We discuss the profile of the silicate absorption band towards galaxy nuclei and the relationship between the 9.7 micron silicate and 3.4 micron hydrocarbon absorption bands.

P. F. Roche; C. Packham; D. K. Aitken; R. E. Mason

2006-10-19

246

Adsorption kinetics of silicic acid on akaganeite.  

PubMed

As part of a series of studies on the interaction between ferric ions and silicic acid in the hydrosphere, the adsorption of silicic acid on akaganeite was investigated kinetically at various pH values. The adsorption of silicic acid increased with increasing pH over an initial pH range of 4-11.5. In the kinetic experiment, the Cl(-) was released from akaganeite much faster than silicic acid was adsorbed. From this result, we concluded that chloride ions bound on the surface of akaganeite are released and Fe-OH or Fe-O(-) sites are formed, which then acts as an adsorption site for silicic acid. The uptake mechanism of silicic acid by akaganeite is significantly different from that by schwertmannite, despite the presence of the same tunnel structure. PMID:23538050

Naren, Gaowa; Ohashi, Hironori; Okaue, Yoshihiro; Yokoyama, Takushi

2013-06-01

247

International Collaboration in Space Weather Situational Awareness  

Microsoft Academic Search

Space weather is a global phenomena so interntional collaboration is necessary to maintain awareness of potentially dangerous conditions. The Regional Warning Centres (RWCs) of the International Space Environment Service were set up during the International Geophysical Year to alert the scientific community to conditions requiring special measurements. The information sharing continues to this day with URSIGRAM messages exchanged between RWCs

David Boteler; Larisa Trichtchenko; Donald Danskin

2010-01-01

248

Weather Changing Waves Chartered from Space  

NSDL National Science Digital Library

This article explains how the TOPEX/Poseidon satellite has been used to track large-scale ocean waves called Rossby waves. This new data indicates that the waves may move faster than previously thought, which may have implications for global weather forecasting. Links to related sites are provided.

249

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.

250

Winter weather activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...

Frankovic, Whitney

2009-09-28

251

RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

On August 23, 2012, NASA will launch two identical probes into the radiation belts to provide unprecedented insight into the physical processes and dynamics of near-Earth space. The RBSP mission in addition to the scientific data return, provides a 1Kbps real-time space weather broadcast data in support of real time space weather modeling, forecast and prediction efforts. Networks of ground stations have been identified to downlink the space weather data. The RBSP instrument suites have selected space weather data to be broadcast from their collected space data on board the spacecraft, a subset from measurements based on information normally available to the instrument. The data subset includes particle fluxes at a variety of energies, and magnetic and electric field data. This selected space weather data is broadcast at all times through the primary spacecraft science downlink antennas when an observatory is not in a primary mission-related ground contact. The collected data will resolve important scientific issues and help researchers develop and improve various models for the radiation belts that can be used by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards. The near real-time data from RBSP will be available to monitor and analyze current environmental conditions, forecast natural environmental changes and support anomaly resolution. The space weather data will be available on the RBSP Science Gateway at http://athena.jhuapl.edu/ and will provide access to the space weather data received from the RBSP real-time space weather broadcast. The near real-time data will be calibrated and displayed on the web as soon as possible. The CCMC will ingest the RBSP space weather data into real-time models. The raw space weather data will be permanently archived at APL. This presentation will provide a first look at RBSP space weather data products.

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

2012-12-01

252

Weather Radar Fundamentals  

NSDL National Science Digital Library

This 2-hour module presents the fundamental principles of Doppler weather radar operation and how to interpret common weather phenomena using radar imagery. This is accomplished via conceptual animations and many interactive radar examples in which the user can practice interpreting both radar reflectivity and radar velocity imagery. Although intended as an accelerated introduction to understanding and using basic Doppler weather radar products, the module can also serve as an excellent refresher for more experienced users.

COMET

2012-03-21

253

Everything Weather- Archived Data  

NSDL National Science Digital Library

Users can obtain current weather forecasts for their own areas by entering a ZIP code, or they can access a large archive of historic data on severe weather (tornadoes, hail, high winds, hurricanes). Materials presented in the archive include dates, times, and intensities of storms, a photo gallery, maps, radar and other satellite data, storm chaser reports, and links to other weather sites. Raw data can be found in several forms for teachers wishing to have unprocessed data to work with.

2001-01-01

254

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.

255

Cockpit weather information needs  

NASA Technical Reports Server (NTRS)

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 weather displays for the dispatcher, air traffic control (ATC), and pilot crew should also enhance the dialogue capabilities for reroute decisions. By utilizing a broadcast data link for surface observations, forecasts, radar summaries, lightning strikes, and weather alerts, onboard weather computing facilities construct graphical displays, historical weather displays, color textual displays, and other tools to assist the pilot crew. Since the weather data is continually being received and stored by the airborne system, the pilot crew has instantaneous access to the latest information. This information is color coded to distinguish degrees of category for surface observations, ceiling and visibilities, and ground radar summaries. Automatic weather monitoring and pilot crew alerting is accomplished by the airborne computing facilities. When a new weather information is received, the displays are instantaneously changed to reflect the new information. Also, when a new surface or special observation for the intended destination is received, the pilot crew is informed so that information can be studied at the pilot's discretion. The pilot crew is also immediately alerted when a severe weather notice, AIRMET or SIGMET, is received. The cockpit weather display shares a multicolor eight inch cathode ray tube and overlaid touch panel with a pilot crew data link interface. Touch sensitive buttons and areas are used for pilot selection of graphical and data link displays. Time critical ATC messages are presented in a small window that overlays other displays so that immediate pilot alerting and action can be taken. Predeparture and reroute clearances are displayed on the graphical weather system so pilot review of weather along the route can be accomplished prior to pilot acceptance of the clearance. An ongoing multiphase test series is planned for testing and modifying the graphical weather system. Preliminary data shows that the nine test subjects considered the graphical presentation to be much better than their current weather information source for situation awareness, flight safety, and reroute decision making.

Scanlon, Charles H.

1992-01-01

256

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

257

Pilot Weather Advisor System  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

258

Effect of silicate ions on electrode overvoltage  

NASA Technical Reports Server (NTRS)

The influence of the addition of a silicate to a caustic solution (KOH) is studied in order to determine the degree to which silicates inhibit the corrosion of chrysotile under conditions of electrolysis at working temperatures of 100 C and above. In an alkaline solution containing various silicate concentrations, current density was increased and electrode overvoltage was measured. Results show that silicate ion concentrations in the electrolyte increase with temperature without effecting electrochemical performance up to 115 C at 700 MA/sqcm. At this point the concentration is about 0.5 g Si/100 g KOH. Beyond this limit, electrolytic performance rapidly degenerates due to severe oxidation of the electrodes.

Gras, J. M.; Seite, C.

1979-01-01

259

MINERAL WEATHERING RATES FROM SMALL-PLOT EXPERIMENTS, WMP SITE, BEAR BROOKS, MAINE  

EPA Science Inventory

The pH-dependence of silicate mineral weathering rates was measured in small-plot experiments at the Bear Brooks Watershed Manipulation Project site in Maine, U.S.A. ix 2 m2 plots were acidified with solutions of HCL in deionized water at pH values of 2, 2.5, and 3. Acid applicat...

260

Mars surface weathering products and spectral analogs: Palagonites and synthetic iron minerals  

NASA Technical Reports Server (NTRS)

There are several hypotheses regarding the formation of Martian surface fines. These surface fines are thought to be products of weathering processes occurring on Mars. Four major weathering environments of igneous rocks on Mars have been proposed; (1) impact induced hydrothermal alterations; (2) subpermafrost igneous intrusion; (3) solid-gas surface reactions; and (4) subaerial igneous intrusion over permafrost. Although one or more of these processes may be important on the Martian surface, one factor in common for all these processes is the reaction of solid or molten basalt with water (solid, liquid, or gas). These proposed processes, with the exception of solid-gas surface reactions, are transient processes. The most likely product of transient hydrothermal processes are layer silicates, zeolites, hydrous iron oxides and palagonites. The long-term instability of hydrous clay minerals under present Martian conditions has been predicted; however, the persistence of such minerals due to slow kinetics of dehydration, or entrapment in permafrost, where the activity of water is high, can not be excluded. Anhydrous oxides of iron (e.g., hematite and maghemite) are thought to be stable under present Martian surface conditions. Oxidative weathering of sulfide minerals associated with Martian basalts has been proposed. Weathering of sulfide minerals leads to a potentially acidic permafrost and the formation of Fe(3) oxides and sulfates. Weathering of basalts under acidic conditions may lead to the formation of kaolinite through metastable halloysite and metahalloysite. Kaolinite, if present, is thought to be a thermodynamically stable phase at the Martian surface. Fine materials on Mars are important in that they influence the surface spectral properties; these fines are globally distributed on Mars by the dust storms and this fraction will have the highest surface area which should act as a sink for most of the absorbed volatiles near the surface of Mars. Therefore, the objectives of this study were to: (1) examine the fine fraction mineralogy of several palagonitic materials from Hawaii; and (2) compare spectral properties of palagonites and submicron sized synthetic iron oxides with the spectral properties of the Martian surface.

Golden, D. C.; Ming, D. W.; Morris, R. V.; Lauer, H. V., Jr.

1992-01-01

261

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

262

Chemical weathering inferred from riverine water chemistry in the lower Xijiang basin, South China.  

PubMed

Seasonal sampling was conducted on 13 sites involving the lower stem of the Xijiang river and its three tributaries to determine the spatial patterns of the riverine water chemistry and to quantify the chemical weathering rates of carbonate and silicate of the bedrock. Results indicate that the major ions in the Xijiang river system are dominated by Ca(2+) and HCO(3)(-) with a higher concentration of total dissolved solids, characteristic of the drainages developed on typical carbonate regions. Obvious spatial variations of major ion concentrations are found at various spatial scales, which are dominantly controlled by the lithology particularly carbonate distribution in the region. The four selected rivers show similar seasonal variations in major ions, with lower concentrations during the rainy season. Runoff is the first important factor for controlling the weathering rate in the basin, although increasing temperature and duration of water-rock interaction could make positive contributions to the enhancement of chemical weathering. The chemical weathering rates range from 52.6 to 73.7 t/km(2)/yr within the lower Xijiang basin and carbonate weathering is over one order of magnitude higher than that of silicates. CO(2) consumption rate by rock weathering is 2.0 x 10(11) mol/yr, of which more than 60% is contributed by carbonate weathering. The flux of CO(2) released to the atmosphere-ocean system by sulfuric acid-induced carbonate weathering is 1.1 x 10(5) mol/km(2)/yr, comparable with the CO(2) flux consumed by silicate weathering. PMID:20624634

Sun, Huiguo; Han, Jingtai; Li, Dong; Zhang, Shurong; Lu, Xixi

2010-09-15

263

Cloud information for FIRE from surface weather reports  

NASA Technical Reports Server (NTRS)

Surface weather observations of clouds were analyzed to obtain a global cloud climatology (Warren et al, 1986; 1988). The form of the synoptic weather code limits the types of cloud information which are available from these reports. Comparison of surface weather reports with instrumental observations during the FIRE field experiments can help to clarify the operational definitions which were made in the climatology because of the nature of the synoptic code. The long-term climatology from surface weather observations is also useful background for planning the location and timing of intensive field experiments.

Hahn, Carole J.; Warren, Stephen G.; London, Julius

1990-01-01

264

A Weathering Index for CK and R Chondrites  

NASA Technical Reports Server (NTRS)

We present a new weathering index (wi) for the metallic-Fe-Ni-poor chondrite groups (CK and R) based mainly on transmitted light observations of the modal abundance of crystalline material that is stained brown in thin sections: wi-0, <5 vol%; wi-1, 5-25 vol%; wi-2,25-50 vol%; wi-3,50- 75 vol%; wi-4, 75-95 vol%; wi-5, >95 vol%, wi-6, significant replacement of mafic silicates by phyllosilicates. Brown staining reflects mobilization of oxidized iron derived mainly from terrestrial weathering of Ni-bearing sulfide. With increasing degrees of terrestrial weathering of CK and R chondrites, the sulfide modal abundance decreases, and S, Se, and Ni become increasingly depleted. In addition, bulk Cl increases in Antarctic CK chondrites, probably due to contamination from airborne sea mist.

Rubin, Alan E.; Huber, Heinz

2006-01-01

265

GPU Computing in Space Weather Modeling  

NASA Astrophysics Data System (ADS)

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 that affect human life or health. In order to make the real- or faster than real-time numerical prediction of adverse space weather events and their influence on the geospace environment, high-performance computational models are required. The main objective in this article is to explore the application of programmable graphic processing units (GPUs) to the numerical space weather modeling for the study of solar wind background that is a crucial part in the numerical space weather modeling. GPU programming is realized for our Solar-Interplanetary-CESE MHD model (SIP-CESE MHD model) by numerically studying the solar corona/interplanetary solar wind. The global solar wind structures is obtained by the established GPU model with the magnetic field synoptic data as input. The simulated global structures for Carrington rotation 2060 agrees well with solar observations and solar wind measurements from spacecraft near the Earth. The model's implementation of the adaptive-mesh-refinement (AMR) and message passing interface (MPI) enables the full exploitation of the computing power in a heterogeneous CPU/GPU cluster and significantly improves the overall performance. Our initial tests with available hardware show speedups of roughly 5x compared to traditional software implementation. This work presents a novel application of GPU to the space weather study.

Feng, X.; Zhong, D.; Xiang, C.; Zhang, Y.

2013-04-01

266

What Is Space Weather?  

NSDL National Science Digital Library

This resource provides a brief overview of the phenomenon known as space weather, which happens when energetic particles emitted by the Sun impact the Earth's magnetosphere. Users can view images, video clips, and animations of auroras and other types of space weather. A set of links to related websites is also provided.

267

People and Weather.  

ERIC Educational Resources Information Center

Provides: (1) background information on ways weather influences human lives; (2) activities related to this topic; and (3) a ready-to-copy page with weather trivia. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

NatureScope, 1985

1985-01-01

268

Mild and Wild Weather.  

ERIC Educational Resources Information Center

Presents background information and six activities that focus on clouds, precipitation, and stormy weather. Each activity includes an objective, recommended age level(s), subject area(s), and instructional strategies. Also provided are two ready-to-copy pages (a coloring page on lightning and a list of weather riddles to solve). (JN)

NatureScope, 1985

1985-01-01

269

Sedimentary Rocks and Weathering  

NSDL National Science Digital Library

This site contains 42 questions on the topic of sedimentary rocks and weathering including clast sizes, depositional environments, and products of weathering. This is part of the Principles of Earth Science course at the University of South Dakota. Users select an answer and are provided immediate feedback.

Heaton, Timothy

270

Home Weatherization Visit  

ScienceCinema

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

Chu, Steven

2013-05-29

271

Designing a Weather Station  

ERIC Educational Resources Information Center

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

Roman, Harry T.

2012-01-01

272

Weather Fundamentals: Wind. [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) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

1998

273

Weather Fundamentals: Clouds. [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) discusses how clouds form, the different types of clouds, and the important role they play in…

1998

274

Uncertain weather, uncertain climate  

E-print Network

of the Speckled Band" "Good-morning, madam," said Holmes cheerily. "My name is Sherlock Holmes. #12;222b Baker sit on the left-hand side of the driver." #12;Holmes' calculation D. Nychka Uncertain weather Maximize over vehicle #12;D. Nychka Uncertain weather, uncertain climate 8 Holmes' conclusion ­ the highest

Nychka, Douglas

275

Modulation of Late Cretaceous and Cenozoic climate by variable drawdown of atmospheric pCO2 from weathering of basaltic provinces on continents drifting through the equatorial humid belt  

NASA Astrophysics Data System (ADS)

The small reservoir of carbon dioxide in the atmosphere (pCO2) that modulates climate through the greenhouse effect reflects a delicate balance between large fluxes of sources and sinks. The major long-term source of CO2 is global outgassing from sea-floor spreading, subduction, hotspot activity, and metamorphism; the ultimate sink is through weathering of continental silicates and deposition of carbonates. Most carbon cycle models are driven by changes in the source flux scaled to variable rates of ocean floor production, but ocean floor production may not be distinguishable from being steady since 180 Ma. We evaluate potential changes in sources and sinks of CO2 for the past 120 Ma in a paleogeographic context. Our new calculations show that decarbonation of pelagic sediments by Tethyan subduction contributed only modestly to generally high pCO2 levels from the Late Cretaceous until the early Eocene, and thus shutdown of this CO2 source with the collision of India and Asia at the early Eocene climate optimum at around 50 Ma was inadequate to account for the large and prolonged decrease in pCO2 that eventually allowed the growth of significant Antarctic ice sheets by around 34 Ma. Instead, variation in area of continental basalt terranes in the equatorial humid belt (5° S-5° N) seems to be a dominant factor controlling how much CO2 is retained in the atmosphere via the silicate weathering feedback. The arrival of the highly weatherable Deccan Traps in the equatorial humid belt at around 50 Ma was decisive in initiating the long-term slide to lower atmospheric pCO2, which was pushed further down by the emplacement of the 30 Ma Ethiopian Traps near the equator and the southerly tectonic extrusion of SE Asia, an arc terrane that presently is estimated to account for 1/4 of CO2 consumption from all basaltic provinces that account for ~1/3 of the total CO2 consumption by continental silicate weathering (Dessert et al., 2003). A negative climate-feedback mechanism that (usually) inhibits the complete collapse of atmospheric pCO2 is the accelerating formation of thick cation-deficient soils that retard chemical weathering of the underlying bedrock. Nevertheless, equatorial climate seems to be relatively insensitive to pCO2 greenhouse forcing and thus with availability of some rejuvenating relief as in arc terranes or thick basaltic provinces, silicate weathering in this venue is not subject to a strong negative feedback, providing an avenue for ice ages. The safety valve that prevents excessive atmospheric pCO2 levels is the triggering of silicate weathering of continental areas and basaltic provinces in the temperate humid belt. Excess organic carbon burial seems to have played a negligible role in atmospheric pCO2 over the Late Cretaceous and Cenozoic.

Kent, D. V.; Muttoni, G.

2013-03-01

276

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2011-04-01

277

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2010-04-01

278

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2011-04-01

279

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2010-04-01

280

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2012-04-01

281

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2013-04-01

282

21 CFR 582.2122 - Aluminum calcium silicate.  

...2014-04-01 2014-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2014-04-01

283

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2012-04-01

284

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2013-04-01

285

21 CFR 182.2122 - Aluminum calcium silicate.  

...2014-04-01 2014-04-01 false Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2014-04-01

286

40 CFR 721.9513 - Modified magnesium silicate polymer (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Modified magnesium silicate polymer (generic). 721...Substances § 721.9513 Modified magnesium silicate polymer (generic). ...substance identified generically as modified magnesium silicate polymer (PMN...

2012-07-01

287

40 CFR 721.9513 - Modified magnesium silicate polymer (generic).  

...2014-07-01 2014-07-01 false Modified magnesium silicate polymer (generic). 721...Substances § 721.9513 Modified magnesium silicate polymer (generic). ...substance identified generically as modified magnesium silicate polymer (PMN...

2014-07-01

288

40 CFR 721.9513 - Modified magnesium silicate polymer (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Modified magnesium silicate polymer (generic). 721...Substances § 721.9513 Modified magnesium silicate polymer (generic). ...substance identified generically as modified magnesium silicate polymer (PMN...

2013-07-01

289

Global Warming  

NSDL National Science Digital Library

Use the links below to complete your research. The Heat Over Global Warming God and Global Warming Robert Redford: Business Warming Up to Environment Emission Impossible? Senator Stepping Up on Climate Control Interview: Bill McKibben Climate Change and the Media Senate Hearings Five Questions with Environmental Writer Tom Philpott Home Grown Oil, Politics Bribes E2: Energy The Greens Online NewsHour: The Global Warming Debate NewsHour Extra: Global Warming Linked to Humans NewsHour Extra: Global Warming Fears Lead to Ratification of the Kyoto Protocol Frontline: Doubters of Global Warming Journey to Planet Earth: The State of the Planet: Global Warming What s Up With the Weather? Some of the below resources were found in the book Global Warming : Opposing Viewpoints (available in the MRC) The Heritage Foundation - Global Warming Rainforest Alliance Doing a global warming search in this website will result in a list of various articles Sierra Club - homepage eLibrary (Proquest) is now available through the

Ms. Schultz

2007-12-03

290

Estimation of the annual yield of organic carbon released from carbonates and shales by chemical weathering  

E-print Network

weathering Christian Di-Giovannia, Jean Robert Disnarb and Jean Jacques Macairea a Lab. de Géologie des matter yield induced by chemical weathering of carbonates and shales, considering their global surface carbonate rocks and shales weathering in major world watersheds, published by numerous authors. The results

Paris-Sud XI, Université de

291

Online coupled chemical weather forecasting based on HIRLAM - overview and prospective of Enviro-HIRLAM  

Microsoft Academic Search

Chemical weather is a field of increasing popularity and several institutes, such as Environment Canada and NOAA, currently forecast both chemical and meteorological weather. Following a definition (Lawrence et al., 2005), chemical weather may be given as local, regional and global distributions of trace gases and aerosols with corresponding variability ranging from minutes to days. Two modeling paradigms exist for

Ulrik Smith Korsholm; Alexander Baklanov; Allan Gross; Alexander Mahura; Bent Hansen Sass; Eigil Kaas

2008-01-01

292

Identifying the crystal graveyards remaining after large silicic eruptions  

NASA Astrophysics Data System (ADS)

The formation of crystal-poor high-silica rhyolite via extraction of interstitial melt from an upper crustal mush predicts the complementary formation of large amounts of (typically unerupted) silicic cumulates. However, identification of these cumulates remains controversial. One hindrance to our ability to identify them is a lack of clear predictions for complementary chemical signatures between extracted melts and their residues. To address this discrepancy, we present a generalized geochemical model tracking the evolution of trace elements in a magma reservoir concurrently experiencing crystallization and extraction of interstitial melt. Our method uses a numerical solution rather than analytical, thereby allowing for various dependencies between crystallinity, partition coefficients for variably compatible and/or incompatible elements, and melt extraction efficiency. Results reveal unambiguous fractionation signatures for the extracted melts, while those signatures are muted for their cumulate counterparts. Our model is first applied to a well-constrained example (Searchlight pluton, USA), and provides a good fit to geochemical data. We then extrapolate our results to understanding the relationship between volcanic and plutonic silicic suites on a global scale. Utilizing the NAVDAT database to identify crystal accumulation or depletion signatures for each suite, we suggest that many large granitoids are indeed silicic cumulates, although their crystal accumulation signature is expected to be subtle.

Gelman, Sarah E.; Deering, Chad D.; Bachmann, Olivier; Huber, Christian; Gutiérrez, Francisco J.

2014-10-01

293

The speciation of water in silicate melts  

Microsoft Academic Search

Previous models of water solubility in silicate melts generally assume essentially complete reaction of water molecules to hydroxyl groups. In this paper a new model is proposed that is based on the hypothesis that the observed concentrations of molecular water and hydroxyl groups in hydrous silicate glasses reflect those of the melts from which they were quenched. The new model

Edward Stolper

1982-01-01

294

Environmental Education Tips: Weather Activities.  

ERIC Educational Resources Information Center

Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

Brainard, Audrey H.

1989-01-01

295

Oceans Effect on Weather and Climate  

NSDL National Science Digital Library

The Ocean's Effect on Weather and Climate SciPack explores concepts related to Earth's weather and climate. The focus is on Standards and Benchmarks related to weather and climate, the water cycle, climate change, and the role of solar energy and its affect on the atmosphere and oceans. The unique role oceans play in defining Earth's weather and climate patterns is also specifically addressed. In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Ocean's Effect on Weather and Climate: Global Climate Patterns? Explain why the temperature of the ocean does not generally fluctuate as dramatically as the temperature of the land.? Describe the relationship between density of liquids and gases and their temperature.? Explain how a difference in density of different layers/portions of a fluid will cause internal currents (rising and falling of the fluid).? Explain the cause of predictable wind patterns along the coastal regions of large land masses.? Describe how the Coriolis Effect helps determine the direction of movement of air and water currents.? List the major variables that affect the transfer of energy through the atmosphere.? Provide an example showing how the transfer of energy affects weather and climate.? Explain how convection relates to weather, including its role in the development of circulation patterns. Ocean's Effect on Weather and Climate: Global Precipitation and Energy? Outline the basic steps in the water cycle in terms of density, energy of the water, and the relative molecular arrangement and motion in each phase.? Describe how energy is transferred to the atmosphere by heating from the ocean and by the evaporation of water and its subsequent condensation. ? Identify the Sun as the energy source that drives atmospheric circulation and the movement of masses of air and water from one place on Earth to another (via convection).? Llist sources for the water cycle and identify the largest source.? Explain the relationship between water, temperature, the amount of water evaporated into the atmosphere (and subsequently condensed), and the energy of the atmosphere at or near the location of evaporation.Ocean's Effect on Weather and Climate: Global Circulation Patterns? Explain how the oceans might influence and affect local weather and climate, given a specific location (on the planet near the ocean) and the local ocean currents.? Describe the cause of hurricanes and explain why they usually occur within specific regions during certain times of the year.? Explain how changes in ocean temperatures (over a period of months) affect factors that influence weather patterns.? List the major variables that affect the transfer of energy through the ocean.Ocean's Effect on Weather and Climate: Changing Climate? Explain the role that phenomena such as volcanic eruptions or asteroid impact play in changing climate.? Describe the type of atmospheric conditions and weather related data that can be obtained from ice core and deep-sea sediment records.? Describe how a small change in the content of oceans and atmosphere (such as a rise in carbon dioxide levels) can have significant impacts on global climate.? Describe human activity that has an affect on climate.

National Science Teachers Association (NSTA)

2007-03-28

296

Northern latitude chemical weathering rates: clues from the Mackenzie River Basin, Canada  

NASA Astrophysics Data System (ADS)

The main scope of this study is to investigate parameters controlling chemical weathering rates for a large river system submitted to subarctic climate. More than 110 river water samples from the Mackenzie River system (northern Canada) have been sampled and analyzed for major and trace elements and Sr isotopic ratios in the dissolved phase. The three main morphological units are reflected in water chemistry. Rivers from the Canadian Shield are very dilute, dominated by silicate weathering (Millot et al., 2002), whereas the rivers of the Rocky and Mackenzie Mountains as well as the rivers of the sedimentary Interior Platform are dominated by carbonate weathering and are SO 4 rich. Compared to the rivers of the Mackenzie and Rocky Mountains, the rivers of the interior plains are organic, silica, and Na rich and constitute the dominant input term to the Mackenzie River mainstream. Rivers of the Canadian Shield area do not significantly contribute to the Mackenzie River system. Using elemental ratios and Sr isotopic ratios, a mathematical inversion procedure is presented that distinguishes between solutes derived from silicate weathering and solutes derived from carbonate weathering. Carbonate weathering rates are mostly controlled by runoff, which is higher in the mountainous part of the Mackenzie basin. These rates are comparable to the carbonate weathering rates of warmer areas of the world. It is possible that part of the carbonate weathering is controlled by sulfide oxidative weathering, but its extent remains difficult to assess. Conversely to what was stated by Edmond and Huh (1997), overall silicate weathering rates in the Mackenzie basin are low, ranging from 0.13 to 4.3 tons/km 2/yr (Na + K + Ca + Mg), and confirm the negative action of temperature on silicate weathering rates for river basins in cold climates. In contrast to what has been observed in other large river systems such as the Amazon and Ganges Rivers, silicate weathering rates appear 3 to 4 times more elevated in the plains than in the mountainous headwaters. This contradicts the "Raymo hypothesis" (Raymo and Ruddiman, 1992). Isotopic characterization of suspended material clearly shows that the higher weathering rates reported for the plains are not due to the weathering of fine sediments produced in the mountains (e.g., by glaciers) and deposited in the plains. Rather, the relatively high chemical denudation rates in the plains are attributed to lithology (uncompacted shales), high mechanical denudation, and the abundance of soil organic matter derived from incomplete degradation and promoting crystal lattice degradation by element complexation. The three- to fourfold factor of chemical weathering enhancement between the plains and mountains is similar to the fourfold factor of enhancement found by Moulton et al. (2000) between unvegetated and vegetated watershed. This study confirms the negative action of temperature on silicate weathering for cold climate but shows that additional factors, such as organic matter, associated with northern watersheds are able to counteract the effect of temperature. This acceleration by a factor of 4 in the plains is equivalent to a 6°C increase in temperature.

Millot, Romain; Gaillardet, J. érôme; Dupré, Bernard; Allègre, Claude Jean

2003-04-01

297

Global Predictions  

E-print Network

above 500 will institute a burn ban. The index uses weather station estimates of temperature and Doppler radar-based precipitation estimates to produce geographic information systems (GIS) maps. The KBDI maps are one of more than 15 map products... created every day by the lab and used by the forest service, county commissioners and others. Using computer technology and satellites, the lab currently focuses on three core spatial technologies? GIS, global positioning systems (GPS) and remote...

Swyden, Courtney

2006-01-01

298

Space Weather Now  

NSDL National Science Digital Library

The NOAA Space Weather Now website provides non-technical information and an assortment of images detailing current space weather. Visitors can find summaries describing auroras, plots of current auroral ovals on the poles, and viewing information for the Northern and Southern Hemispheres. The Real-Time Solar Wind Pages furnish dynamic plots of data, geomagnetic activity test product information, and resources about the four instruments used to collect data on geomagnetic storms. The website features Space Weather Scales to help the public understand the severity of environmental disturbances due to geomagnetic storms, solar radiation storms, and radio blackouts. Visitors can find the latest news, alerts, advisory bulletins, and much more.

299

Weather Observing Fundamentals  

NSDL National Science Digital Library

"Weather Observing Fundamentals" provides guidance for U.S. Navy Aerographer's Mates, Quartermasters, and civilian observers tasked with taking and reporting routine, special, and synoptic observations. Although the focus of this lesson is on shipboard observations, much of the content applies to land-based observing and reporting as well. The lesson details standard procedures for taking accurate weather observations and for encoding those observations on COMNAVMETOCCOM Report 3141/3. Exercises throughout the lesson and four weather identification drills at the end provide learners with opportunities to practice and build their skills. The lesson covers a large amount of content. You may wish to work through the material in multiple sessions.

2014-09-14

300

World Weather Information Service  

NSDL National Science Digital Library

The World Meteorological Organization Web site offers the World Weather Information Service page. Here, visitors will find official weather forecasts and climatological information for selected cities worldwide. Users choose a particular continent and country, and are then presented with a list of various cities they can get information on. This includes the date and time of the current forecast, minimum and maximum temperatures for that day, a general cloud description, and a monthly review of various data for that city. If for nothing else, the site does a good job of providing a very straightforward and easy way to find weather information from hundreds of cities around the globe.

301

Weather Map Assignment  

NSDL National Science Digital Library

I gave this assignment so that students could relate real-time weather changes to mid-latitude cyclones and air mass movement. Basically, by the time I assigned the project, we have discussed all the necessary weather phenomena and this project gives the students a way to apply what we have discussed to "reality" by explaining why the weather occurred the way it did over a short time period. It also provides me with a way to assess how well they are able to tie all the major concepts together, which is one of the goals of the course.

Brueseke, Matt

302

Weather and Climate  

NSDL National Science Digital Library

This unit introduces younger students to the concepts of weather and climate. Topics include the structure of the atmosphere, the definitions of weather and climate, and temperature and how it is measured. There are also discussions of heat transfers (radiation, conduction, convection), air pressure, wind, and the Coriolis effect. Other topics include types of storms, larger-scale weather systems such as pressure systems and fronts, and factors (insolation, land-sea breezes, orographic effect) that influence the climate in a given region. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

303

Extreme Weather Sourcebook 2001  

NSDL National Science Digital Library

Originally reviewed in the February 26, 1999 Scout Report, the latest version of the National Center for Atmospheric Research (NCAR) Extreme Weather Sourcebook offers easy access to updated data on the economic damage from hurricanes, floods, and tornadoes in the United States and its territories. Time spans for each type of extreme weather vary, with hurricane data covering 1900-99, tornadoes 1950-99, floods 1955-1999, and lightning 1959-1994; however, all damage data are reported in constant 1999 dollars to simplify comparisons. The data are offered by weather event and state by rank or alphabetically.

2001-01-01

304

WeatherTracker  

NSDL National Science Digital Library

WeatherTracker is the ideal desktop application for anyone who always wants to know what the weather outside is like. The temperature, barometric pressure, humidity, winds, and current conditions can be displayed in three different formats, updated hourly for North American Cities. The local forecasts, climate data and near shore marine forecasts can be displayed in other windows and are available for select North American cities. Other cities are limited to temperature and current conditions. WeatherTracker is shareware with a fee of $20.00.

305

GEOSS interoperability for Weather, Ocean and Water  

NASA Astrophysics Data System (ADS)

"Understanding the Earth system — its weather, climate, oceans, atmosphere, water, land, geodynamics, natural resources, ecosystems, and natural and human-induced hazards — is crucial to enhancing human health, safety and welfare, alleviating human suffering including poverty, protecting the global environment, reducing disaster losses, and achieving sustainable development. Observations of the Earth system constitute critical input for advancing this understanding." With this in mind, the Group on Earth Observations (GEO) started implementing the Global Earth Observation System of Systems (GEOSS). GEOWOW, short for "GEOSS interoperability for Weather, Ocean and Water", is supporting this objective. GEOWOW's main challenge is to improve Earth observation data discovery, accessibility and exploitability, and to evolve GEOSS in terms of interoperability, standardization and functionality. One of the main goals behind the GEOWOW project is to demonstrate the value of the TIGGE archive in interdisciplinary applications, providing a vast amount of useful and easily accessible information to the users through the GEO Common Infrastructure (GCI). GEOWOW aims at developing funcionalities that will allow easy discovery, access and use of TIGGE archive data and of in-situ observations, e.g. from the Global Runoff Data Centre (GRDC), to support applications such as river discharge forecasting.TIGGE (THORPEX Interactive Grand Global Ensemble) is a key component of THORPEX: a World Weather Research Programme to accelerate the improvements in the accuracy of 1-day to 2 week high-impact weather forecasts for the benefit of humanity. The TIGGE archive consists of ensemble weather forecast data from ten global NWP centres, starting from October 2006, which has been made available for scientific research. The TIGGE archive has been used to analyse hydro-meteorological forecasts of flooding in Europe as well as in China. In general the analysis has been favourable in terms of forecast skill and concluded that the use of a multi-model forecast is beneficial. Long term analysis of individual centres, such as the European Centre for Medium-Range Weather Forecasts (ECMWF), has been conducted in the past. However, no long term and large scale study has been performed so far with inclusion of different global numerical models. Here we present some initial results from such a study.

Richardson, David; Nyenhuis, Michael; Zsoter, Ervin; Pappenberger, Florian

2013-04-01

306

Chemical Weathering, Atmospheric CO2, and Climate  

NASA Astrophysics Data System (ADS)

There has been considerable controversy concerning the role of chemical weathering in the regulation of the atmospheric partial pressure of carbon dioxide, and thus the strength of the greenhouse effect and global climate. Arguments center on the sensitivity of chemical weathering to climatic factors, especially temperature. Laboratory studies reveal a strong dependence of mineral dissolution on temperature, but the expression of this dependence in the field is often obscured by other environmental factors that co-vary with temperature. In the field, the clearest correlation is between chemical erosion rates and runoff, indicating an important dependence on the intensity of the hydrological cycle. Numerical models and interpretation of the geologic record reveal that chemical weathering has played a substantial role in both maintaining climatic stability over the eons as well as driving climatic swings in response to tectonic and paleogeographic factors.

Kump, Lee R.; Brantley, Susan L.; Arthur, Michael A.

307

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

-Ready Nation Flooding Winter Weather Safety www.weather.gov · Flooding is possible due to snowmelt, ice jams and coastal storms such as Nor'easters. · Ice jams are common during the winter. · As ice moves downstream www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

308

Weathering of Martian Evaporites  

NASA Technical Reports Server (NTRS)

Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

2001-01-01

309

Weathering in a Cup.  

ERIC Educational Resources Information Center

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

Stadum, Carol J.

1991-01-01

310

Waste glass weathering  

SciTech Connect

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

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

1993-12-31

311

Biological and Organic Chemical Decomposition of Silicates. Chapter 7.2  

NASA Technical Reports Server (NTRS)

The weathering of silicate rocks and minerals, an important concern of geologists and geochemists for many years, traditionally has been approached from strictly physical and chemical points of view. Biological effects were either unrecognized, ignored, or were mentioned in passing to account for such phenomena as the accumulation of organic matter in sediments or the generation of reducing environments. A major exception occurred in soil science where agricultural scientists, studying the factors important in the development of soils and their ability to nourish and sustain various crops, laid the foundation for much of what is known of the biological breakdown of silicate rocks and minerals. The advent of the space age accelerated the realization that many environmental problems and geo- chemical processes on Earth can only be understood in terms of ecosystems. This in turn, spurred renewed interest and activity among modem biologists, geologists and soil scientists attempting to unravel the intimate relations between biology and the weathering of silicate rocks and minerals of the earth surface.

Silverman, M. P.

1979-01-01

312

TypoWeather  

NSDL National Science Digital Library

The TypoWeather application is a great way to stay on top of the latest weather conditions. This handy device presents users with a five day outlook and an hourly breakdown that is updated based on data from the National Meteorological Service. Visitors can customize their layout to include alerts about certain meteorological conditions, such as wind patterns, humidity, and more. This version is compatible with all operating systems.

2014-03-13

313

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based unit has been created for use by students in the elementary grades to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, students develop a basic understanding of how weather can be described in measurable quantities. The lesson plans have been designed to allow teachers to select the ones which fit into their curriculum, and to allow for flexibility in implementation.

2011-01-01

314

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

315

Weathering and Erosion  

NSDL National Science Digital Library

In this multi-station lab, learners conduct a series of experiments to explore the processes and effects of weathering and erosion. Using the results from these explorations, learners design and conduct an experiment comparing the rate of erosion in different biomes. Use this activity to teach weathering and erosion, and also to illustrate how scientists often use the results of one experiment to inspire another. This activity is intended to be conducted over multiple meetings.

Whitfield, Lise

2010-01-01

316

Extreme Weather Sourcebook: Tornadoes  

NSDL National Science Digital Library

The Extreme Weather Sourcebook is a database maintained by the Societal Impacts Program (SIP) at NCAR of statistics on extreme weather events. The Sourcebook is intended as a resource for researchers, policy makers, the media, and the general public, among other users. This page from the Sourcebook showcases data on tornado damages as total losses for the years 1950-2009 in the United States.

University Consortium for Atmospheric Research (UCAR)

317

Space Weather Needs of an Evolving Customer Base (Invited)  

NASA Astrophysics Data System (ADS)

Great progress has been made in raising the global awareness of space weather and the associated impacts on Earth and our technological systems. However, significant gaps still exist in providing comprehensive and easily understood space weather information, products, and services to the diverse and growing customer base. As technologies, such as Global Navigation Satellite Systems (GNSS), have become more ingrained in applications and fields of work that previously did not rely on systems sensitive to space weather, the customer base has grown substantially. Furthermore, the causes and effects of space weather can be difficult to interpret without a detailed understanding of the scientific underpinnings. In response to this change, space weather service providers must address this evolution by both improving services and by representing space weather information and impacts in ways that are meaningful to each facet of this diverse customer base. The NOAA Space Weather Prediction Center (SWPC) must work with users, spanning precision agriculture, emergency management, power grid operators and beyond, to both identify unmet space weather service requirements and to ensure information and decision support services are provided in meaningful and more easily understood forms.

Rutledge, B.; Viereck, R. A.; Onsager, T. G.

2013-12-01

318

Alkali Silicate Vehicle Forms Durable, Fireproof Paint  

NASA Technical Reports Server (NTRS)

The problem: To develop a paint for use on satellites or space vehicles that exhibits high resistance to cracking, peeling, or flaking when subjected to a wide range of temperatures. Organic coatings will partially meet the required specifications but have the inherent disadvantage of combustibility. Alkali-silicate binders, used in some industrial coatings and adhesives, show evidence of forming a fireproof paint, but the problem of high surface-tension, a characteristic of alkali silicates, has not been resolved. The solution: Use of a suitable non-ionic wetting agent combined with a paint incorporating alkali silicate as the binder.

Schutt, John B.; Seindenberg, Benjamin

1964-01-01

319

Utilization of Live Localized Weather Information for Sustainable Agriculture  

NASA Astrophysics Data System (ADS)

Authors: Jim Anderson VP, Global Network and Business Development WeatherBug® Professional Jeremy Usher Managing Director, Europe WeatherBug® Professional Localized, real-time weather information is vital for day-to-day agronomic management of all crops. The challenge for agriculture is twofold in that local and timely weather data is not often available for producers and farmers, and it is not integrated into decision-support tools they require. Many of the traditional sources of weather information are not sufficient for agricultural applications because of the long distances between weather stations, meaning the data is not always applicable for on-farm decision making processes. The second constraint with traditional weather information is the timeliness of the data. Most delivery systems are designed on a one-hour time step, whereas many decisions in agriculture are based on minute-by-minute weather conditions. This is especially true for decisions surrounding chemical and fertilizer application and frost events. This presentation will outline how the creation of an agricultural mesonet (weather network) can enable producers and farmers with live, local weather information from weather stations installed in farm/field locations. The live weather information collected from each weather station is integrated into a web-enabled decision support tool, supporting numerous on-farm agronomic activities such as pest management, or dealing with heavy rainfall and frost events. Agronomic models can be used to assess the potential of disease pressure, enhance the farmer's abilities to time pesticide applications, or assess conditions contributing to yield and quality fluctuations. Farmers and industry stakeholders may also view quality-assured historical weather variables at any location. This serves as a record-management tool for viewing previously uncharted agronomic weather events in graph or table form. This set of weather tools is unique and provides a significant enhancement to the agronomic decision-support process. Direct benefits to growers can take the form of increased yield and grade potential, as well as savings in money and time. Pest management strategies become more efficient due to timely and localized disease and pest modelling, and increased efficacy of pest and weed control. Examples from the Canadian Wheat Board (CWB) WeatherFarm weather network will be utilized to illustrate the processes, decision tools and benefits to producers and farmers.

Anderson, J.; Usher, J.

2010-09-01

320

Iron isotopic fractionation during continental weathering  

SciTech Connect

The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01

321

2012 Severe Weather Awareness Guide  

E-print Network

Florida's 2012 Severe Weather Awareness Guide 2012 Severe Weather Awareness Guide F L O R I D A D I of Emergency Management #12;Florida's Severe Weather Awareness Guide 2 Florida is affected by many natural. That is why I am proud to present the 2012 Severe Weather Awareness Guide. By reading this guide you can learn

Meyers, Steven D.

322

Detection of solar wind-produced water in irradiated rims on silicate minerals  

PubMed Central

The solar wind (SW), composed of predominantly ?1-keV H+ ions, produces amorphous rims up to ?150 nm thick on the surfaces of minerals exposed in space. Silicates with amorphous rims are observed on interplanetary dust particles and on lunar and asteroid soil regolith grains. Implanted H+ may react with oxygen in the minerals to form trace amounts of hydroxyl (?OH) and/or water (H2O). Previous studies have detected hydroxyl in lunar soils, but its chemical state, physical location in the soils, and source(s) are debated. If ?OH or H2O is generated in rims on silicate grains, there are important implications for the origins of water in the solar system and other astrophysical environments. By exploiting the high spatial resolution of transmission electron microscopy and valence electron energy-loss spectroscopy, we detect water sealed in vesicles within amorphous rims produced by SW irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Our findings establish that water is a byproduct of SW space weathering. We conclude, on the basis of the pervasiveness of the SW and silicate materials, that the production of radiolytic SW water on airless bodies is a ubiquitous process throughout the solar system. PMID:24449869

Bradley, John P.; Ishii, Hope A.; Gillis-Davis, Jeffrey J.; Ciston, James; Nielsen, Michael H.; Bechtel, Hans A.; Martin, Michael C.

2014-01-01

323

Detection of solar wind-produced water in irradiated rims on silicate minerals.  

PubMed

The solar wind (SW), composed of predominantly ?1-keV H(+) ions, produces amorphous rims up to ?150 nm thick on the surfaces of minerals exposed in space. Silicates with amorphous rims are observed on interplanetary dust particles and on lunar and asteroid soil regolith grains. Implanted H(+) may react with oxygen in the minerals to form trace amounts of hydroxyl (-OH) and/or water (H2O). Previous studies have detected hydroxyl in lunar soils, but its chemical state, physical location in the soils, and source(s) are debated. If -OH or H2O is generated in rims on silicate grains, there are important implications for the origins of water in the solar system and other astrophysical environments. By exploiting the high spatial resolution of transmission electron microscopy and valence electron energy-loss spectroscopy, we detect water sealed in vesicles within amorphous rims produced by SW irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Our findings establish that water is a byproduct of SW space weathering. We conclude, on the basis of the pervasiveness of the SW and silicate materials, that the production of radiolytic SW water on airless bodies is a ubiquitous process throughout the solar system. PMID:24449869

Bradley, John P; Ishii, Hope A; Gillis-Davis, Jeffrey J; Ciston, James; Nielsen, Michael H; Bechtel, Hans A; Martin, Michael C

2014-02-01

324

Rates of oxidative weathering on the surface of Mars  

NASA Technical Reports Server (NTRS)

Implicit in the mnemonic 'MSATT' (Mars surface and atmosphere through time) is that rates of surface processes on Mars through time should be investigated, including studies of the kinetics and mechanism of oxidative weathering reactions occurring in the Martian regolith. Such measurements are described. Two major elements analyzed in the Viking Lander XRF experiment that are most vulnerable to atmospheric oxidation are iron and sulfur. Originally, they occurred as Fe(2+)-bearing silicate and sulfide minerals in basaltic rocks on the surface of Mars. However, chemical weathering reactions through time have produced ferric- and sulfate-bearing assemblages now visible in the Martian regolith. Such observations raise several question about: (1) when the oxidative weathering reactions took place on Mars; (2) whether or not the oxidized regolith is a fossilized remnant of past weathering processes; (3) deducting chemical interactions of the ancient Martian atmosphere with its surface from surviving phases; (4) possible weathering reactions still occurring in the frozen regolith; and (5) the kinetics and mechanism of past and present-day oxidative reactions on Mars. These questions may be addressed experimentally by studying reaction rates of dissolution and oxidation of basaltic minerals, and by identifying reaction products forming on the mineral surfaces. Results for the oxidation of pyrrhotite and dissolved ferrous iron are reported.

Burns, Roger G.

1992-01-01

325

2011 Space Weather Workshop to Be Held in April  

NASA Astrophysics Data System (ADS)

The annual Space Weather Workshop will be held in Boulder, Colo., 26-29 April 2011. The workshop will bring customers, forecasters, commercial service providers, researchers, and government agencies together in a lively dialogue about space weather. The workshop will include 4 days of plenary sessions on a variety of topics, with poster sessions focusing on the Sun, interplanetary space, the magnetosphere, and the ionosphere. The conference will address the remarkably diverse impacts of space weather on today's technology. Highlights on this year's agenda will include presentations on space weather impacts on the Global Positioning System (GPS), the Solar Terrestrial Relations Observatory's (STEREO) mission milestone of a 360° view of the Sun, the latest from NASA's Solar Dynamics Observatory (SDO), and space weather impacts on emergency response by the Federal Emergency Management Agency (FEMA). Additionally, the vulnerabilities of satellites and the power grid to space weather will be addressed. Additional highlights will include the Commercial Space Weather Interest Group's (CSWIG) roundtable session and a presentation from the Office of the Federal Coordinator for Meteorology (OFCM). The CSWIG roundtable session on the growth of the space weather enterprise will feature distinguished panelists. As always, lively interaction between the audience and the panel is anticipated. The OFCM will present the National Space Weather Program's new strategic plan.

Peltzer, Thomas

2011-04-01

326

Micro Weather Stations for Mars  

NASA Technical Reports Server (NTRS)

A global network of weather stations will be needed to characterize the near-surface environment on Mars. Here, we review the scientific and measurement objectives of this network. We also show how these objectives can be met within the cost-constrained Mars Surveyor Program by augmenting the Mars Pathfinder-derived landers with large numbers of very small (less than 5 liter), low-mass (less than 5 kg), low-power, low-cost Mini-meteorological stations. Each station would include instruments for measuring atmospheric. pressures, temperatures, wind velocities, humidity, and airborne dust abundance. They would also include a data handling, telemetry, power, atmospheric entry, and deployment systems in a rugged package capable of direct entry and a high-impact landing. In this paper, we describe these systems and summarize the data-taking strategies and data volumes needed to achieve the surface meteorology objectives for Mars.

Crisp, David; Kaiser, William J.; VanZandt, Thomas R.; Hoenk, Michael E.; Tillman, James E.

1995-01-01

327

MARINE WEATHER BROADCASTS 9.1. General. The National Weather Service and the Department of Homeland Security's  

E-print Network

) global search and rescue plan. 9.2. Global Maritime Distress and Safety System (GMDSS). The goals-to-shore (rescue coordination center) based. GMDSS provides for automatic distress alerting and locating, weather forecasts and warnings, search and rescue notices, and similar information to ships. It has been

328

Silicate Liquid Immiscibility in Young Impact Glasses  

NASA Astrophysics Data System (ADS)

Emulsion textures have rarely been described from impact melts. Here, we present and compare several examples of silicate emulsions in impact melts and show that liquid immiscibility may play an important role in the formation of impact melts.

Hamann, C.; Hecht, L.; Schultze, D.; Ebert, M.; Reimold, W. U.; Wirth, R.

2014-09-01

329

Siliceous microfossil extraction from altered Monterey rocks  

SciTech Connect

Samples of altered Monterey rocks of differing lithologies were processed by various methods to develop new techniques for extracting siliceous microfossils. The preliminary use of thin sections made from the same rocks reduced the number of probable samples (samples worth further processing) by about one-third. Most of the siliceous microfossils contained in altered Monterey rocks appear to be highly recrystallized and are extremely fragile; however, some contained silicified and silica-infilled radiolarians and planktonic and benthonic foraminifera, which are very tough. In general the most useful techniques were gently hydrochloric acid, hydrogen peroxide, formic acid, monosodium glutamate, and regular siliceous microfossil extraction techniques. Unsuccessful techniques and a new siliceous microfossil flotation technique are also documented.

Nelson, C.O.; Casey, R.E.

1986-04-01

330

The significance of mid-latitude rivers for weathering rates and chemical fluxes: Evidence from northern Xinjiang rivers  

NASA Astrophysics Data System (ADS)

SummaryRivers draining the sedimentary platform of northern Xinjiang (the center of Asian continent) are characterized by low discharge under a temperate and arid climate. The influence of rock mineralogy, climate, relief and human activity on natural water composition and export as a result of weathering is a major scientific concern both at the local and the global scale. While comprehensive work on the controlling mechanism of chemical weathering has been less carried out in the sedimentary platform of northern Xinjiang. Thus, the effects of climate and rock weathering on the inorganic hydrogeochemical processes are not well quantified at this climatic extreme. To remedy this lack a comprehensive survey has been carried out of the geochemistry of the large, pristine rivers in northern Xinjiang, the Erlqis, Yili, Wulungu, Jingou and numerous lesser streams which has not experienced the pervasive effects of glaciation and subsequent anthropogenic impacts. The scale of the terrain sampled, in terms of area, is comparable to that of the Huanghe and includes a diverse range of geologic and climatic environments. In this paper the chemical fluxes from the stable sedimentary basin of the northern Xinjiang platform will be presented and compared to published results from analogous terrains in the monsoon basins of China and world. Overall, the fluvial geochemistry of northern Xinjiang in westerly climate is similar to that of the Chinese rivers (Huanghe and Yangtze) in the East-Asian monsoon Climate, both in property-property relationships and concentration magnitudes. The range in the chemical signatures of the various tributaries is large; this reflects that lithology exerts the dominant influence in determining the weathering yield from the sedimentary terrains rather than the weathering environment. The effect of different rock weathering ranges from rivers dominated by aluminosilicate weathering, mainly of granites, sandstones and shales, to those bearing the signatures of dissolution of carbonates and evaporites and of continental playa deposits. Carbonates are the general predominant lithology undergoing dissolution particularly within the lesser arid areas. The pCO2 in the study rivers is out of equilibrium with respect to atmospheric pCO2, about up to ˜20 times supersaturated relative to the atmosphere but not to such an extent as the Amazon in the floodplain. A roughly positive relationship is observed between solute concentrations and the drought index (DI) for natural waters in the region, indicating a coupled mountain-basin climate has a direct effect. The relative contributions of end-member solute sources to the total dissolved cations from each watershed have been quantitatively estimated using dissolved load balance models, showing the results as evaporite dissolution > carbonate weathering > silicate weathering > atmospheric input for the whole catchment. The areal total dissolved fluxes range from 0.05 to 2.53 × 106 mol/km2/yr, 0.02-2.09 × 106 mol/km2/yr and 0.01-1.04 × 106 mol/km2/yr in the Yili, Zhungarer and Erlqis, respectively, comparable to those of Chinese and Siberia rivers draining sedimentary platforms, even though they are in drastically different climatic regimes. In general, the fluxes from rivers in sedimentary basins are comparable to those from orogenic zones, but are much higher than in the shield regions. The CO2 consumption by aluminosilicate weathering (0.2-284 × 103 mol/km2/yr) is much smaller than in active orogenic belts (19-1750 × 103 mol/km2/yr in similar latitudes and 143-1000 × 103 mol/km2/yr in the tropical basins), but comparable to those of the Chinese (7-106 × 103 mol/km2/yr) and Siberia (16-112 × 103 mol/km2/yr) rivers.

Zhu, Bingqi; Yu, Jingjie; Qin, Xiaoguang; Rioual, Patrick; Liu, Ziting; Zhang, YiChi; Jiang, Fengqing; Mu, Yan; Li, Hongwei; Ren, Xiaozong; Xiong, Heigang

2013-04-01

331

Sunlight and the Earth : Climate and Weather  

NSDL National Science Digital Library

These web pages trace the processes involved in the suns impact on weather. This is an exploration of the importance of radiation and reflection of light, both visible and infra-red, and the greenhouse effect. Convection and the role of water vapor are also considered. Global-scale air flows are described, explaining why wind in the continental US usually blows from the west, while near the equator it comes from the east.

David P. Stern

2004-09-22

332

Peroxide-assisted syntheses of metal silicates  

SciTech Connect

Peroxide-containing intermediates have played pivotal roles in new synthesis of several magnesium silicates including olivine, forsterite, transition metal-doped forsterite, and enstatite. The involvement of a little-known hydroperoxide of magnesium will be discussed. Elaboration of the synthesis methodology has produced layered silicates such as the fluoro-mica, potassium fluorophlogopite, and a fluoro-talc that has a higher level of substitution of hydroxide by fluoride than any previously reported.

Burlitch, J.M. [Cornell Univ., Ithaca, NY (United States)

1993-12-31

333

Sepiolite and palygorskite group of silicates  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume I5? `Phyllosilicates - Part ?' of Volume 27 `Magnetic properties of non-metallic inorganic compounds based on transition elements` of Landolt-Börnstein - Group III `Condensed Matter'. It presents silicates belonging to the sepiolite and palygorskite group of silicates, discussing their crystal structures, lattice parameters, nuclear gamma resonance (NGR), nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) data, electrical properties and dielectric behavior, and optical properties.

Burzo, E.

334

Laser processing of siliceous materials  

NASA Astrophysics Data System (ADS)

Laser processing of siliceous materials becomes increasingly important. Analogous to the laser processing of conventional materials there are applications in the fields of cleaning, surface processing, cutting, etc. The present paper concerns the state of the art and new applications: (1) Laser cleaning of natural stone surfaces. The good disability allows restoration work to be carried out conveniently, as for example the complete removal of crusts or the removal to such degree that moisture is not trapped beneath. (2) Non-slip finish of polished natural stone surfaces: The excellent focusing of laser beams on spots as small as 100 micrometer and below can be exploited to produce macroscopically invisible structures on the surfaces of different materials. This permits microscopically small craters and lentil shaped depressions to be generated on the stone surface. Therefore it is possible to provide a non-slip finish to polished natural stone surfaces without noticeably impairing the gloss. (3) Concrete cutting: In Europe, and particularly in Germany, there is a growing demand for redevelopment of concrete apartment buildings, involving the removal of non-bearing walls and the cutting of openings. The temporal relocation of residents due to the noise and moisture from the use of diamond tools could be avoided by applying a laser cutting technology. With a 3 kW-Nd-YAG-laser, 70 mm concrete can be cut with rates up to 25 mm/min.

Panzner, Michael; Lenk, Andreas; Wiedemann, Guenter R.; Hauptmann, Jan; Weiss, Hans J.; Ruemenapp, Thomas; Morgenthal, Lothar; Beyer, Eckhard

2000-08-01

335

Interpreting the 10 micron Astronomical Silicate Feature  

NASA Astrophysics Data System (ADS)

10micron spectra of silicate dust in the diffuse medium towards Cyg OB2 no. 12 and towards field and embedded objects in the Taurus Molecular Cloud (TMC) were obtained with CGS3 at the United Kingdom Infrared Telescope (UKIRT). Cold molecular-cloud silicates are sampled in quiescent lines of sight towards the field stars Taurus-Elias 16 and Elias 13, whilst observations of the embedded young stellar objects HL Tau, Taurus-Elias 7 (Haro6-10) and Elias 18 also include emission from heated dust. To obtain the foreground silicate absorption profiles, featureless continua are estimated using smoothed astronomical and laboratory silicate emissivities. TMC field stars and Cyg OB2 no. 12 are modelled as photospheres reddened by foreground continuum and silicate extinction. Dust emission in the non-photospheric continua of HL Tau and Elias 7 (Haro6-10) is distinguished from foreground silicate absorption using a 10micron disk model, based on the IR-submm model of T Tauri stars by Adams, Lada & Shu (1988), with terms added to represent the foreground continuum and silicate extinction. The absorption profiles of HL Tau and Elias 7 are similar to that of the field star Elias 16. Fitted temperature indices of 0.43 (HL Tau) and 0.33 (Elias 7) agree with Boss' (1996) theoretical models of the 200-300K region, but are lower than those of IR-submm disks (0.5-0.61; Mannings & Emerson 1994); the modelled 10micron emission of HL Tau is optically thin, that of Elias 7 is optically thick. A preliminary arcsecond-resolution determination of the 10micron emissivity near ?1 Ori D in the Trapezium region of Orion and a range of emission temperatures (225-310K) are derived from observations by T. L. Hayward; this Ney-Allen emissivity is 0.6micron narrower than the Trapezium emissivity obtained by Forrest et al. (1975) with a large aperture. Published interstellar grain models, elemental abundances and laboratory studies of Solar System silicates (IDPs, GEMS and meteorites), the 10micron spectra of comets, interstellar silicates, synthetic silicates and terrestrial minerals, and the effects of laboratory processing on the 10micron spectra of crystalline and amorphous silicates are reviewed to provide insight into the mineralogy of interstellar silicate dust. The wavelengths of the peaks of the 10micron silicate profiles decrease between circumstellar, diffuse medium and molecular-cloud environments, indicating (after Gürtler & Henning 1986) that the amorphous pyroxene content of initially olivine-rich interstellar dust increases with time. This is accompanied by an increase in the FWHM of the features which indicates an increase in grain size and/or an increasing fraction of chemically-varied crystalline pyroxene. Fine structure in the Cyg OB2 no. 12, Elias 16, Elias 7, HL Tau profiles indicate that hydrated layer silicates similar to terrestrial serpentines, clays and talc may be a ubiquitous component of interstellar dust. At 10microns the narrow bands of mixed crystalline pyroxenes blend, making their identification difficult. Since no fine structure is observed near 11.2microns, the fraction of crystalline olivine is small. In geology direct olivine-plus-SiO2 to pyroxene reactions occur only at high pressure within the terrestrial mantle. Therefore the fraction of amorphous pyroxene is probably increased by the hydration of Mg-rich olivine to form a serpentine-like hydrated silicate, which is subsequently annealed to form a mixture of amorphous pyroxene and olivine. Terrestrial and laboratory olivine samples are readily converted to serpentine in the presence of water, and (after extended annealing) the first crystalline band to appear is the 11.2micron olivine feature frequently observed in cometary spectra.

Bowey, Janet E.

1998-11-01

336

Space Weather Workshop 2010 to Be Held in April  

NASA Astrophysics Data System (ADS)

The annual Space Weather Workshop will be held in Boulder, Colo., 27-30 April 2010. The workshop will bring customers, forecasters, commercial service providers, researchers, and government agencies together in a lively dialogue about space weather. The workshop will include 4 days of plenary sessions on a variety of topics, with poster sessions focusing on the Sun, interplanetary space, the magnetosphere, and the ionosphere. The conference will address the remarkably diverse impacts of space weather on today's technology. Highlights on this year's agenda include ionospheric storms and their impacts on the Global Navigation Satellite System (GNSS), an update on NASA's recently launched Solar Dynamics Observatory (SDO), and new space weather-related activities in the Federal Emergency Management Agency (FEMA). Also this year, the Commercial Space Weather Interest Group will feature a presentation by former NOAA administrator, Vice Admiral Conrad Lautenbacher, U.S. Navy (Ret.).

Peltzer, Thomas

2010-03-01

337

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

338

Geochemistry of Daihai Lake sediments, Inner Mongolia, north China: Implications for provenance, sedimentary sorting, and catchment weathering  

Microsoft Academic Search

To advance the understanding of sediment distribution, catchment weathering, hydraulic sorting, and sediment provenance in a tectonically stable basin, the geochemistry of surface sediment samples from Daihai Lake in north China is presented. Mud bulk sediments were analyzed for 10 major and 30 trace elements, organic carbon, and nitrogen and for 87Sr\\/86Sr ratios in silicate fraction (acid insoluble, AI) and

Zhangdong Jin; Fuchun Li; Junji Cao; Sumin Wang; Jimin Yu

2006-01-01

339

Diversity history of Cenozoic marine siliceous plankton  

NASA Astrophysics Data System (ADS)

Marine planktonic diatoms and polycystine radiolarians, both with shells of opaline silica, make up a large part of the deep-sea sediment fossil record. Diatom export of organic material to the deep ocean and sediments strongly affects the global carbon cycle; while both groups compete for, and are regulated by the availability of, dissolved silica derived from global weathering. Diatoms and radiolarians also both have a relatively (compared to foraminifera or coccolithophores) complex biogeography, with diverse, endemic polar and tropical assemblages. Changes in past diatom and radiolarian diversity can be used to understand how the ocean's biologic pump has evolved, how co-evolution between groups occurs, and how nutrient availability controls evolutionary change. Lazarus et al. (2014) recently showed that diatom diversity increased by a factor of ca 3.5X over the Cenozoic, with a temporary peak in the latest Eocene, a late Oligocene-early Miocene low interval, very strong diversification in the late Miocene-early Pliocene, and minor decline in the late Pliocene-Recent. Only Phanerozoic scale radiolarian diversity estimates have been available until now, and these are strongly biased by sample size. We employed similar data (NSB database) and methods (1 my bins, 'sqs' subsampling, outlier removal using Pacman trims) as Lazarus et al. (2014) to calculate, for the first time, a detailed estimate of radiolarian diversity history, and origination and extinction rates over the last 50 my, the period for which sufficient NSB data is available. Radiolarian diversity increases almost monotonically by a factor of 5, with relatively rapid increases in the mid Eocene (high relative origination) and early Miocene (due to low extinction rates), and a moderate decline in the Plio-Pleistocene due to high extinction rates. Combined high rates of both extinction and origination, with little diversity change, are seen at the Eocene-Oligocene boundary. Most of these events can be related to changing global paleoceanographic conditions. Radiolarians show a major decrease in Cenozoic silica usage, apparently due to the rise of diatoms and consequent reduction of surface water silica concentrations (Lazarus et al. 2009). This inference based on diatom diversity has been confirmed (Renaudie et al., this meeting) with new estimates showing Cenozoic increasing rates of global diatom silica deposition. Our new radiolarian results show this did not negatively impact radiolarian diversity. Presumably increasing diversity from increasing faunal provinciality dominated Cenozoic radiolarian diversity dynamics, similar to the diversity controls on diatoms (Lazarus et al. 2014). Lazarus et al. (2009). PNAS 106:9333-9338. Lazarus et al. (2014). PLOS One (in press).

Lazarus, David; Renaudie, Johan

2014-05-01

340

Weather Station Model  

NSDL National Science Digital Library

This lesson instructs students on how to read station models, the symbols used on weather maps to show data (temperature, wind speed and direction, barometeric pressure, etc.) for a given reporting station. It includes a diagram of a station model, an explanation of the data conveyed by the numbers and symbols, and a table of definitions for the graphic symbols used with models. There is also a set of interactive station models students can use for practice at interpretation, and an interactive exercise in which students use real-time weather data to interpret models.

341

Reading Weather Maps  

NSDL National Science Digital Library

From the University of Illinois at Urbana-Champaign's Department of Atmospheric Sciences comes the Reading Weather Maps Web site. Visitors learn how to convert their local time to the standard used by all meteorologists; to tell the difference between Kelvin, Celsius, and Fahrenheit temperatures; and how to read maps with weather data collected on and above the Earth's surface. For example, wind bards, which are flag-like symbols that indicate wind direction and wind speed, always point in the direction the wind is blowing "from." Other interesting facts, descriptions, and illustrations are available on the site.

1969-12-31

342

Weather and Climate  

NSDL National Science Digital Library

This background chapter reviews the basic principles of meteorology that educators need to guide inquiry activities in the classroom. Topics include structure of the atmosphere, Coriolis effect, water cycle, greenhouse effect, cyclones, anticyclones, and jet streams. This is chapter 2 of Meteorology: An Educator's Resource for Inquiry-Based Learning for Grades 5-9. The guide includes a discussion of learning science, the use of inquiry in the classroom, instructions for making simple weather instruments, and more than 20 weather investigations ranging from teacher-centered to guided and open inquiry investigations.

343

Weather and Health  

NSDL National Science Digital Library

This course will help meteorologists and others broaden their understanding of the impacts of weather and climate on public health, including the impacts of heat waves and cold temperatures, winter storms and thunderstorms, flooding, drought, poor air quality, tornadoes, hurricanes, wildfire, UV radiation, and others. This course is directed to broadcast meteorologists, in particular, who play a critical role in the community by helping the public to protect against weather-related health threats and by promoting good health. The course also describes the public health communication system, providing information about reliable public health services, tools, and resources.

Comet

2008-11-25

344

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based module uses hands-on activities and real-time data investigations to allow students in the elementary grades to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, the students will develop a basic understanding of how weather can be described in measurable quantities, such as temperature, wind and precipitation. The lesson plans which make up this module have been designed to allow teachers to select the ones which fit into their curriculum to allow for flexibility in implementation

2003-01-01

345

The Silicate\\/non-silicate distribution of metals in fly ash and its effect on solubility  

Microsoft Academic Search

In a study at DOE's National Energy Technology Laboratory, 32 Class F fly ash samples from pulverized coal (PC) power plants were dissolved in concentrated nitric acid and in hydrofluoric acid to estimate the distribution of metals in non-silicate and silicate matrices. Nineteen cations occurred to some extent in both phases. Using a column leaching method, the release of the

Ann G. Kim; George Kazonich

2004-01-01

346

Space Weather affects on Air Transportation  

NASA Astrophysics Data System (ADS)

In Europe, legislation requires the airline industry to monitor the occupational exposure of aircrew to cosmic radiation. However, there are other significant impacts of space weather phenomena on the technological systems used for day-to-day operations which need to be considered by the airlines. These were highlighted by the disruption caused to the industry by the period of significant solar activity in late October and early November 2003. Next generation aircraft will utilize increasingly complex avionics as well as expanding the performance envelopes. These and future generation platforms will require the development of a new air-space management infrastructure with improved position accuracy (for route navigation and landing in bad weather) and reduced separation minima in order to cope with the expected growth in air travel. Similarly, greater reliance will be placed upon satellites for command, control, communication and information (C3I) of the operation. However, to maximize effectiveness of this globally interoperable C3I and ensure seamless fusion of all components for a safe operation will require a greater understanding of the space weather affects, their risks with increasing technology, and the inclusion of space weather information into the operation. This paper will review space weather effects on air transport and the increasing risks for future operations cause by them. We will examine how well the effects can be predicted, some of the tools that can be used and the practicalities of using such predictions in an operational scenario. Initial results from the SOARS ESA Space Weather Pilot Project will also be discussed,

Jones, J. B. L.; Bentley, R. D.; Dyer, C.; Shaw, A.

347

Weatherization Works: An interim report of the National Weatherization Evaluation  

SciTech Connect

The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

1993-11-01

348

Rainy Weather Science.  

ERIC Educational Resources Information Center

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

Reynolds, Karen

1996-01-01

349

Weathering and mass wasting  

NSDL National Science Digital Library

This class exercise is an opportunity for students to apply textbook information about weathering and mass wasting to local and nationally-recognized surface features, such as Stone Mountain (GA), Half Dome (CA), and others. It also serves as an introduction to the use of Google Earth as an analytical tool for calculating distances, slopes, and evaluating landforms. Designed for a geomorphology course

Clayton, Jordan

350

Microbial Weathering of Olivine  

NASA Technical Reports Server (NTRS)

Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature. Additional information is contained in the original extended abstract.

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

2002-01-01

351

Weathering the Double Whammy.  

ERIC Educational Resources Information Center

Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the institution's…

Wellman, Jane V.

2002-01-01

352

Rocks and Weathering  

NSDL National Science Digital Library

Sedimentary, igneous and metamorphic rocks, weathering, erosion and transport, and the rock cycle are explained in this resource for students through written content, interactive content, audio, video and games. A multiple choice test is included. Students may score their tests and the correct responses will be given.

353

Gulf of Maine: Weather  

NSDL National Science Digital Library

Lessons and activities from the Gulf of Maine Research Institute (formerly Gulf of Maine Aquarium), focused on hurricanes, El Nino, fog, and volcanic eruptions. Emphasis on important hurricanes of the past. Resources include lessons, guides for simple experiments, and a student weather network. Downloadable materials and additional webpages also provided.

2010-08-04

354

Weather and emotional state  

Microsoft Academic Search

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

Z. Spasova

2010-01-01

355

Weather Stations: Storms  

NSDL National Science Digital Library

In this activity, learners test how cornstarch and glitter in water move when disturbed. Learners compare their observations with videos of Jupiter's and Earth's storm movements. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

Institute, Lunar A.; Nasa

2011-01-01

356

Blogging About the Weather  

NSDL National Science Digital Library

Since the majority of the content standards related to weather focus on forecasting, elementary students often spend a lot of time studying cloud types, fronts, storms, and using a barometer to read air pressure. Although this allows students to "do" scie

Kyle Evans

2010-04-01

357

Weather and the Sky  

NSDL National Science Digital Library

This self-contained module on weather and objects in the sky includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Houghton Mifflin Science

358

Sunspots and Space Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and is an online investigation for students in how sunspots impact space weather between the Sun and Earth. Students research solar maximum and minimum as well as recent sunspot numbers to determine a connection between the numbers and solar activity. This page is accompanied by a page of websites for further resources.

359

METEOROLOGICAL Weather and Forecasting  

E-print Network

AMERICAN METEOROLOGICAL SOCIETY Weather and Forecasting EARLY ONLINE RELEASE This is a preliminary it is available. © 2010 American Meteorological Society #12;Generated using version 3.0 of the official AMS LATEX template Multidisciplinary Analysis of an Unusual Tornado: Meteorology,1 Climatology, and the Communication

360

Weather, Climate, and You.  

ERIC Educational Resources Information Center

Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

Blai, Boris, Jr.

361

Uncertain weather, uncertain climate  

E-print Network

Adventure of the Speckled Band" "Good-morning, madam," said Holmes cheerily. "My name is Sherlock Holmes, and then only when you sit on the left-hand side of the driver." #12;Holmes' calculation D. Nychka Uncertain of vehicle Maximize over vehicle #12;D. Nychka Uncertain weather, uncertain climate 8 Holmes' conclusion

Nychka, Douglas

362

Space Weather Action Center  

NSDL National Science Digital Library

The Space Weather Action Center is a computer-based activity that allows students to track, from their classroom, the development and progress of solar storms. The activity incorporates online NASA data and addresses national education standards in science, technology and math. Students rotate through four space weather learning stations and are challenged to answer the following questions: Do sunspot regions exist today that could be a source of solar storms?; Have radio signals been recorded today from a flare or coronal mass ejection that could affect Earth?; Has there been a measurable disturbance in the Earth's magnetic field?; and Have auroras been seen within the last 24 hours because of a solar storm? A setup guide is provided to show how to create a Space Weather Action Center in the classroom, including recommendations, diagrams, and the necessary list of materials. The instructional guide features background and evaluation materials, alignments to national standards, extension activities, and instructions on how to read, analyze and record space weather data.

363

Weather and Flight Testing  

NASA Technical Reports Server (NTRS)

This viewgraph document reviews some of the weather hazards involved with flight testing. Some of the hazards reviewed are: turbulence, icing, thunderstorms and winds and windshear. Maps, pictures, satellite pictures of the meteorological phenomena and graphs are included. Also included are pictures of damaged aircraft.

Wiley, Scott

2007-01-01

364

Phosphorus Equilibria Among Mafic Silicate Phases  

NASA Technical Reports Server (NTRS)

Phosphorus incorporation in major rock-forming silicate minerals has the following implications: (1) Reactions between phosphorus-hosting major silicates and accessory phosphates, which are also major trace element carriers, may control the stability of the latter and thus may affect the amount of phosphorus and other trace elements released to the coexisting melt or fluid phase. (2) Less of a phosphate mineral is needed to account for the bulk phosphorus of planetaty mantles. (3) During partial melting of mantle mineral assemblages or equilibrium fractional crystallization of basaltic magmas, and in the absence or prior to saturation with a phosphate mineral, silicate melts may become enriched in phosphorus, especially in the geochemically important low melt fraction regime, Although the small differences in the ionic radii of IVp5+, IVSi4+, and IV Al3+ makes phosphoms incorporation into crystalline silicates perhaps unsurprising, isostructural silicate and phosphate crystalline solids do not readily form solutions, e.g., (Fe, Mg)2SiO4 vs. LiMgPO4, SiO)2 VS. AlPO4. Nonetheless, there are reports of, poorly characterized silico-phosphate phases in angrites , 2-4 wt% P2O5 in olivine and pyroxene grains in pallasites and reduced terestrial basalts which are little understood but potentially useful, and up to 17 wt% P2O5 in olivine from ancient slags. However, such enrichments are rare and only underscore the likelihood of phosphoms incorporation in silicate minerals. The mechanisms that allow phosphorus to enter major rock-forming silicate minerals (e.g., Oliv, Px, Gt) remain little understood and the relevant data base is limited. Nonetheless, old and new high-pressure (5-10 GPa) experimental data suggest that P2O5 wt% decreases from silica-poor to silica-rich compositions or from orthosilicate to chain silicate structures (garnet > olivine > orthopyroxene) which implies that phosphorus incorporation in silicates is perhaps more structure-than site-specific. The data also indicate that DXVliQP2O5 decrease in the same order, but DOVLiQP2O5 and DOpx/LiQP205 are likely constant, respectively equal to 0.08(3) and 0.007(4), in contrast, DG1ILiQP205 increases from 0.15(3) to 0.36(10) as garnet becomes majoritic, thus silica-enriched, and may also depend on liquid composition (SiO2, P2O5 and Na2O wt%).

Berlin, Jana; Xirouchakis, Dimitris

2002-01-01

365

Biotic enhancement of weathering, atmospheric oxygen and carbon dioxide in the Neoproterozoic  

NASA Astrophysics Data System (ADS)

It has been suggested that biological colonization of the land surface began in the Neoproterozoic 1000-544 million years ago (Ma). We hypothesize that this colonization involved selective weathering of P from rocks, as well as an amplification of overall weathering rates. We show that two recent models, despite differences in the feedback mechanisms represented, predict that an increase in the weathering flux of P to the ocean would have caused a rise in atmospheric O2 in the Neoproterozoic. This in turn may have provided a necessary condition for the evolution of animals with hard skeletons seen in the 'Cambrian explosion'. Increased weathering of silicate rocks would also have caused a decline in atmospheric CO2, which could have been a causal factor in the Neoproterozoic glaciations.

Lenton, Timothy M.; Watson, Andrew J.

2004-03-01

366

When winter weather disrupts work.  

PubMed

Paul Beevers, of the BVA's legal helpline, explains the implications for employers of travel disruption resulting from bad weather and offers a few pointers on dealing with exceptional weather conditions. PMID:25556140

2015-01-01

367

External Resource: Erosion and Weathering  

NSDL National Science Digital Library

This is a Teachers' Domain photo essay with images that depict surface features on Earth that result from weathering and erosion, as well as measures designed to mitigate their unwanted effects. Topics: weathering, erosion, sediments, dunes, deltas, glaci

1900-01-01

368

Briefing highlights space weather risks to GPS  

NASA Astrophysics Data System (ADS)

Solar storms, which are expected to increase as the Sun nears the most active phase of the solar cycle, can disrupt a variety of technologies on which society relies. Speakers at a 22 June briefing on Capitol Hill in Washington, D. C., focused on how space weather can affect the Global Positioning System (GPS), which is used in a wide range of industries, including commercial air travel, agriculture, national security, and emergency response. Rocky Stone, chief technical pilot for United Airlines, noted that GPS allows more aircraft to be in airspace, saves fuel, and helps aircraft move safely on runways. “Improvements in space weather forecasting need to be pursued,” he said. Precision GPS has also “changed the whole nature of farming,” said Ron Hatch, Director of Navigation Systems, NavCom Technology/John Deere. GPS makes it possible for tractors to be driven in the most efficient paths and for fertilizer and water to be applied precisely to the areas that most need them. Space weather-induced degradation of GPS signals can cause significant loss to farms that rely on GPS. Elizabeth Zimmerman, Deputy Associate Administrator for the Office of Response and Recovery at the Federal Emergency Management Agency (FEMA), described how FEMA relies on GPS for disaster recovery. The agency is developing an operations plan for dealing with space weather, she said.

Tretkoff, Ernie

2011-07-01

369

International Collaboration in Space Weather Situational Awareness  

NASA Astrophysics Data System (ADS)

Space weather is a global phenomena so interntional collaboration is necessary to maintain awareness of potentially dangerous conditions. The Regional Warning Centres (RWCs) of the International Space Environment Service were set up during the International Geophysical Year to alert the scientific community to conditions requiring special measurements. The information sharing continues to this day with URSIGRAM messages exchanged between RWCs to help them produce space weather forecasts. Venturing into space, especially with manned missions, created a need to know about the space environment and particularly radiation dangers to man in space. Responding to this need led to the creation of a network of stations around the world to provide continuous monitoring of solar activity. Solar wind monitoring is now provided by the ACE satellite, operated by one country, but involving international collaborators to bring the information down in real time. Disturbances in the Earth's magnetic field are monitored by many magnetic observatories that are collaborating through INTERMAGNET to provide reliable data. Space weather produces effects on the ionosphere that can interfere with a variety of systems: the International GNSS Service provides information about effects on positioning systems, and the International Space Environment Service is providing information about iono-spheric absorption, particularly for trans-polar airline operations. The increasing availability of internet access, even at remote locations, is making it easier to obtain the raw information. The challenge now is how to integrate that information to provide effective international situational awareness of space weather.

Boteler, David; Trichtchenko, Larisa; Danskin, Donald

370

Space Weather Impacts on Aviation  

NSDL National Science Digital Library

Space Weather Impacts on Aviation examines the effects of solar flares, coronal mass ejections, and other solar phenomena on aviation operations. The module builds on background science knowledge taught in the course prerequisite, Space Weather Basics, 2nd Edition. The content gives aviation forecasters and others an overview of the information and products available from NOAA's Space Weather Prediction Center and provides practice interpreting and using those products for decision support during space weather events.

Comet

2012-06-12

371

Real-Time Weather Data  

NSDL National Science Digital Library

This website provides real-time and forecast weather maps and data for the United States. The Satellite section contains satellite weather images from the GOES 8 and GOES 10 satellites, the Radar section contains radar weather images from NEXRAD radars, the Surface Data section contains plots of various weather conditions (temperatures, winds, pressure, precipitation), and the Upper Air section plots winds and temperatures across the United States.

372

International Space Weather Initiative (ISWI)  

NASA Technical Reports Server (NTRS)

The International Heliophysical Year (IHY), an international program of scientific collaboration to understand the external drivers of planetary environments, has come to an end. The IHY was a major international event of great interest to the member States, which involved the deployment of new instrumentation, new observations from the ground and in space, and an education component. We propose to continue the highly successful collaboration between the heliophysics science community and the United Nations Basic Space Science (UNBSS) program. One of the major thrust of the IHY was to deploy arrays of small instruments such as magnetometers, radio antennas, GPS receivers, all-sky cameras, particle detectors, etc. around the world to provide global measurements of heliospheric phenomena. The United Nations Basic Space Science Initiative (UNBSSI) played a major role in this effort. Scientific teams were organized through UNBSS, which consisted of a lead scientist who provided the instruments or fabrication plans for instruments in the array. As a result of the this program, scientists from UNBSS member states now participate in the instrument operation, data collection, analysis, and publication of scientific results, working at the forefront of science research. As part of this project, support for local scientists, facilities and data acquisition is provided by the host nation. In addition, support at the Government level is provided for local scientists to participate. Building on momentum of the IHY, we propose to continue the highly successful collaboration with the UNBSS program to continue the study of universal processes in the solar system that affect the interplanetary and terrestrial environments, and to continue to coordinate the deployment and operation of new and existing instrument arrays aimed at understanding the impacts of Space Weather on Earth and the near-Earth environment. Toward this end, we propose a new program, the International Space Weather Initiative (ISWI).

Davila, Joseph; Gopalswamy, Nathanial; Thompson, Barbara

2010-01-01

373

International Space Weather Initiative (ISWI)  

NASA Technical Reports Server (NTRS)

The International Heliophysical Year (IHY), an international program of scientific collaboration to understand the external drivers of planetary environments, has come to an end. The IHY was a major international event of great interest to the member States, which involved the deployment of new instrumentation, new observations from the ground and in space, and an education component. We propose to continue the highly successful collaboration between the heliophysics science community and the United Nations Basic Space Science (UNBSS) program. One of the major thrust of the IHY was to deploy arrays of small instruments such as magnetometers, radio antennas, GPS receivers, all-sky cameras, particle detectors, etc. around the world to provide global measurements of heliospheric phenomena. The United Nations Basic Space Science Initiative (UNBSSI) played a major role in this effort. Scientific teams were organized through UNBSS, which consisted of a lead scientist who provided the instruments or fabrication plans for instruments in the array. As a result of the this program, scientists from UNBSS member states now participate in the instrument operation, data collection, analysis, and publication of scientific results, working at the forefront of science research. As part of this project, support for local scientists, facilities and data acquisition is provided by the host nation. In addition, support at the Government level is provided for local scientists to participate. Building on momentum of the IHY, we propose to continue the highly successful collaboration with the UNBSS program to continue the study of universal processes in the solar system that affect the interplanetary and terrestrial environments, and to continue to coordinate the deployment and operation of new and existing instrument arrays aimed at understanding the impacts of Space Weather on Earth and the near-Earth environment. Toward this end, we propose a new program, the International Space Weather Initiative (ISWI).

Davila, Joseph M.; Gopalswamy, Nat; Thompson, Barbara

2009-01-01

374

Road Weather and Transportation Systems  

E-print Network

Road Weather and Transportation Systems Rhonda Young, P.E., PhD Associate Professor Dept. of Civil & Arch. Engineering Portland State University April 18, 2014 #12;Engineering Perspective of Road Weather · How does weather impact transportation systems? · As engineers, is there anything we can do

Bertini, Robert L.

375

Spring Break-Weathering Homework  

NSDL National Science Digital Library

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

Farthing, Dori

376

Weather Forecasting for Radio Astronomy  

E-print Network

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

Groppi, Christopher

377

Science Sampler: Clever with weather  

NSDL National Science Digital Library

In eighth-grade Earth science at Louisville Middle School in Louisville, Colorado, students learn how large-scale weather patterns such as the jet stream and weather fronts interact to generate local weather conditions. The authors have developed a modeli

David Crowder

2011-02-01

378

Weather Fundamentals: Climate & Seasons. [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), describes weather patterns and cycles around the globe. The various types of climates around…

1998

379

Sulfide mineralization: Its role in chemical weathering of Mars  

NASA Technical Reports Server (NTRS)

Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produced degradation products in the Martian regolith. By analogy with terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato- and hydroxo-complex ions and sols formed gossans above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite) and silica (opal). Underlying groundwater, now permafrost, contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, etc., which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates and phyllosilicates during dust storms on Mars.

Burns, Roger G.

1988-01-01

380

A record of Late Quaternary continental weathering in the sediment of the Caspian Sea: evidence from U-Th, Sr isotopes, trace element and palynological data  

NASA Astrophysics Data System (ADS)

This study presents combined mineralogical, chemical, isotopic (87Sr/86Sr and U-Th disequilibria series) and palynological analyses on bulk sediments and on distinct mineral phases (carbonates and clays) from a 10-m-long core drilled in the southern Caspian Sea and containing a Late Pleistocene and Early Holocene record. The data allowed identifying 1) the main variations in sedimentation, 2) the processes causing these variations, 3) the modification of erosion vs weathering, and 4) the influence of climatic and/or Caspian Sea level changes in the region since the Late Pleistocene. The chemical and mineralogical results allowed the division of the sedimentary sequence into three main units and a transition zone. The lower unit (unit U1) primarily consists of silicate and carbonate-rich detritus. Sedimentation characteristics, including observation of detritus in secular equilibrium, are relatively constant within this unit and reflect mechanical erosion in a cold climate. Unit U1 probably corresponds to a glacial period when the vegetation cover was sparse and wind and river transport of pollen were strong. Subsequently, global increase in temperatures has greatly modified the sedimentation in the Caspian Sea south basin. Biogenic sedimentation is higher in units U2 and U3, and detrital inputs varied from unit U1. Variations in detrital input are likely to be caused by decreasing aeolian contribution and by relative changes in river volumes and origins. The study of the bulk sediments, clays and carbonates reflects an increase in chemical weathering since about 10 14C ka BP ago (base of unit U2), in line with an increase in the vegetation cover. Our results suggest an evolution of continental weathering conditions in the catchment area of the Caspian Sea, from dominantly mechanical/physical erosion during the cold period to a continuous increase in weathering since the Lateglacial period, as climate improved, which illustrates the strong relation between climate, vegetation cover and weathering processes. This paper also highlights how the U-Th disequilibrium series proxy, combined with other geochemical and palynological studies, could be a useful tool to record and constrain the modification of weathering regime in response to climatic and environmental changes at regional scale.

Pierret, M. C.; Chabaux, F.; Leroy, S. A. G.; Causse, C.

2012-09-01

381

Ca isotopes, chemical weathering, and geomorphic controls on long-term climate  

Microsoft Academic Search

Calcium isotope geochemistry (delta44Ca) offers a unique opportunity to directly quantify proportions of riverine Ca originating from silicate versus carbonate weathering, which is essential for understanding how geomorphic processes affecting landscape evolution, such as tectonic uplift and glaciation, influence the long-term cycling of atmospheric CO2. We measured the elemental and delta44Ca chemistry of river and rock samples from the New

J. Moore; A. D. Jacobson; C. E. Holmden; D. Craw

2009-01-01

382

Climate of Eccentric Terrestrial Planets with Carbonate-Silicate Geochemical Cycle  

NASA Astrophysics Data System (ADS)

Recent discovery of extrasolar planets indicates that some of them have much higher eccentricity than the planets in the solar system. Here, we investigate the climate of such eccentric terrestrial planets with oceans and carbonate-silicate geochemical cycles. We find that the climate of the planets are dependent on the annual mean insolation as shown in previous works. We also find that the planets orbiting slightly further from our Sun than the Earth are globally ice-covered even if the carbonate-silicate geochemical cycle works under the same CO2 degassing rate as on the present Earth. However, when the CO2 degassing rate is higher, the planets avoid being globally ice-covered owing to the high level.

Kadoya, Shintaro; Tajika, Eiichi; Watanabe, Yoshiyasu

2014-04-01

383

Seasonal Extreme Weather Forecasts  

NSDL National Science Digital Library

Forecasts for UK winter gales and severe gales, North Atlantic and US landfalling hurricanes, Northwest Pacific and Far East landfalling typhoons, Southwest Pacific and Australian landfalling cyclones, and US Cooling Degree Days are available at this site from the Benfield Greig Hazard Research Centre at University College, London. Forecast summaries, descriptions of forecasting methodology, and graphics of historical and predicted events through time are presented in .pdf format for each weather subcategory. This site also tells users when the next predictions are to be released and has links to press releases and other extreme weather Websites. This is a good site for those interested in methods of climatology or those who want to prepare for that next big typhoon.

384

Weather Stations: Winds  

NSDL National Science Digital Library

In this activity, learners use a toaster to generate wind and compare the appliance's heat source to Jupiter's own hot interior. Learners discover that convection drives wind on Jupiter and on Earth. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth. For safety reasons, this activity should be facilitated by an adult or used as a demonstration only.

Institute, Lunar A.; Nasa

2011-01-01

385

National Weather Service Glossary  

NSDL National Science Digital Library

This glossary contains information on more than 2000 terms, phrases and abbreviations used by the National Weather Service (NWS). Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years; the glossary will aid users in better understanding NWS products. The glossary is searchable by keyword or browsable by letter of the alphabet.

386

Space Weathering of Lunar Rocks  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

387

Fracture characteristics in weathered granites  

NASA Astrophysics Data System (ADS)

The variability of weathered materials is an important factor in the geotechnical characterization of rock for engineering purposes. Most engineering rock mass classifications include weathering schemes that separate the weathering profile into zones or grades that depend upon the engineering and geological properties of the rock. Many geotechnical characteristics, including weathering, are controlled by the density and arrangement of fractures within the rock, but the relationships between fracture patterns and weathering grades are typically not addressed. Fracture characteristics were investigated in 13 exposures in five study areas in weathered granite in eastern Asia. All weathering grades were present, but never in the same exposure. Two approaches were used to evaluate the field data: (1) joint spacings were tabulated and examined within each weathering grade (tabulated classification); and (2) each exposure was classified according to the dominant weathering grade (visual classification). Mean and median joint spacings and joint spacing frequency distributions were analyzed and compared statistically for each approach. The box fractal dimensions for joint spacing were calculated for exposures classified visually in each weathering grade. Three-dimensional models of fresh and weathered granite were also generated and sampled for comparison to the field data. Mean joint spacing is usually 25% or more closer in weathered granite than it is in fresh granite, and the difference between the mean spacings for weathered granite and fresh granite tend to be statistically significant. There are no significant differences between any distribution medians. The joint spacing distributions for weathered granite and fresh granite are also not statistically significantly different, and there are no significant differences among the joint spacing frequency distributions for the different grades of weathered granite. Fractal analysis of joint spacings, however, suggests spacing characteristics of fresh and slightly weathered (SW) granite are very different from those in moderately, highly, and completely weathered granite, and sampling of three-dimensional models for weathered and fresh granite supports this. In an engineering context, this suggests that joint spacing relationships in the various grades of weathered granite can be treated as the same regardless of weathering grade and that joint patterns in fresh granite must be evaluated separately. This knowledge could result in significant time and cost savings in the geotechnical characterization of these materials.

Ehlen, Judy

1999-12-01

388

Kazakhstan Space Weather Initiative  

NASA Astrophysics Data System (ADS)

Kazakhstan experimental complex is a center of experimental study of space weather. This complex is situated near Almaty, Kazakhstan and includes experimental setup for registration of cosmic ray intensity (neutron monitor) at altitude of 3340 m above sea level, geomagnetic observatory and setup for registration of solar flux density with frequency of 1 and 3 GHz with 1 second time resolution. Results of space environment monitoring in real time are accessible via Internet. This experimental information is used for space weather investigations and different cosmic ray effects. Almaty mountain cosmic ray station is one of the most suitable and sensitive stations for investigation and forecasting of the dangerous situations for satellites; for this reason Almaty cosmic ray station is included in the world-wide neutron monitor network for the real-time monitoring of the space weather conditions and European Database NMDB (www.nmdb.eu). All data are represented on the web-site of the Institute of Ionosphere (www.ionos.kz) in real time. Since July, 2006 the space environment prediction laboratory represents the forecast of geomagnetic activity every day on the same site (www.ionos.kz/?q=en/node/21).

Kryakunova, Olga

2012-07-01

389

Europium-doped yttrium silicate nanophosphors prepared by flame synthesis  

E-print Network

Europium-doped yttrium silicate nanophosphors prepared by flame synthesis Xiao Qin a,*, Yiguang Ju; accepted 7 November 2006 Available online 22 December 2006 Abstract Europium-doped yttrium silicate (Y2SiO5

Bernhard, Stefan

390

Optical absorption and ionization of silicate glasses Leonid B. Glebov  

E-print Network

Optical absorption and ionization of silicate glasses Leonid B. Glebov School of Optics and hydroxyl), and induced (color centers) absorption of multicomponent silicate glasses in UV, visible and near JR spectral regions are described. Parasitic effects influencing absorption measurements

Glebov, Leon

391

Mechanisms of primary mineral weathering inferred from B isotopes  

NASA Astrophysics Data System (ADS)

Silicate weathered minerals result from a combination of dissolution/precipitation or transformation reactions. Despite their chemical and isotopic compositions as well as their mineralogy record the physico-chemical conditions of their formation and history, the determination of the current state of weathering in soils still remains very challenging. The main difficulties come from a difficult access to the mineral sites actually active during primary mineral transformation and from non-stoichiometric release of site-forming cations. To better characterize how minerals record the conditions of their formation, we coupled analyses of mineralogy with major elements and boron isotopes in a series of primary minerals (biotite, muscovite, K-feldspar and plagioclase) associated in varying amount with their replacement phases (vermiculite, kaolinite, illite…). The minerals are sampled along an acid Alocrisoil profile developed on granitic bedrock from the Breuil-Chenue forest (France). Previous studies have demonstrated that boron occupies different minerals sites (tetrahedron in substitution of Si, or interfoliar sites possibly in direct contact with the surrounding fluid, Williams et al. 2001, Muttik et al. 2011, Voinot et al., in prep.). Voinot et al. (in prep.) have also demonstrated that boron isotopes are very sensitive to silicate transformation or dissolution reactions. In deeper soil layers (100 to 130 cm), kaolinite is found in biotite mineral habitus. Examination of the boron isotopes distribution in those weathered agglomerates points to a boron depletion and a rapid isotopic equilibration with the surrounding soil solution as kaolinite fraction increases. The same - but magnified - trend is observed during shallow weathering mechanisms (20 to 30 cm) of fine particles of biotite (< 200 µm). By contrast, coarse biotite minerals (> 200 µm) evolve to a vermiculite-like product that tends to be enriched in boron (up to three times the initial biotite concentration) but share a common isotopic composition with kaolinite revealing an equilibrium with the solution. Plagioclases dissolve very early in the deepest horizon with a high degree of in-situ kaolinite reprecipitation in their mineral habitus. Here again, the isotopic composition reflect exchange with the soil solution. Muscovite shows no particular weathering mechanism other than dissolution, but isotope shift toward the soil solution value tends to indicate that the reacting boron is mainly located in easy accessible mineral interlayer sites. K-feldspar samples remained unchanged either mineralogically or isotopically. These results suggest an apparent duality between phyllosilicates which are mainly involved in transformation reactions with rapid isotopic equilibration with the surrounding soil solution, whilst tectosilicates show mainly dissolution reactions without evidence of isotopic exchange with the fluid. Depending on their nature, the secondary phases that replace the weathered primary minerals will also play a major role in the boron cycle in soils.

Voinot, A.; Turpault, M.-P.; Chabaux, F.; Lemarchand, D.

2012-04-01

392

Space Weather and Management of Environmental Risks and Hazards  

NASA Astrophysics Data System (ADS)

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

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

393

Abiotic Versus Biotic Weathering Of Olivine As Possible Biosignatures  

NASA Technical Reports Server (NTRS)

We are investigating the weathering of silicate minerals by both purely inorganic, and biologically mediated processes using field-emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectroscopy (EDS). By resolving surface textures and chemical compositions of weathered surfaces at the sub-micron scale we hope to be able to distinguish abiotic from biotic weathering processes and so establish a new biosignature applicable to the study of astromaterials including but not limited to the Martian meteorites. Sterilized olivine grains (San Carlos, Arizona) no more than 1-2 mm in their longest dimension were optically assayed to be uniform in color and free of inclusions were selected as weathering subjects. Prior to all experiments surface morphologies and Fe/Mg ratios were determined for each grain using FE-SEM and EDS. Experiments were divided into two categories abiotic and biotic and were compared with "naturally" weathered samples. For the preliminary experiments, two trials (open and closed to the ambient laboratory environment) were performed under abiotic conditions, and three trials under biotic conditions (control, day 1 and day 2). The open system abiotic trials used sterile grains heated at 98 C and 200 C for both 24 and 48 hours in 1L double distilled de-ionized water. The closed system abiotic trials were conducted under the same conditions but in a sealed two layer steel/Teflon "bomb" apparatus. The biotic trials used sterile grains mounted in a flow-through device attached to a wellhead on the Columbia River aquifer. Several discolored, altered, grains were selected to document "natural" weathering surface textures for comparison with the experimental samples. Preliminary results indicate there are qualitative differences in weathered surface textures among all the designed experiments. The olivine grains in abiotic trials displayed etching, pitting, denticulate margins, dissolution and clay formation. The scale of the features ranged from tens to a few microns with textures that remained relatively sharp and were crystallographically controlled. These results were comparable to that observed in the "naturally" weathered comparison/reference grains. Chemical analysis by EDS indicates these textures correlated with the relative loss of Mg and Fe cations by diffusional processes. In contrast the biotic results indicated changes in the etching patterns on the scale of hundreds of nm, which are neither sharp nor crystallographically controlled (nanoetching). Organisms, organic debris and/or extracellular polymeric substances (biofilm) were often in close proximity or direct contact with the nanoetching. While there are many poorly constrained variables in natural weathering experiments to contend with, such as the time scale, the chemistry of the fluids and degree of biologic participation, some preliminary observations can be made: (1) certain distinct surface textures appear correlated with the specific processes giving rise to these textures; (2) the process of diffusing cations can produce many similar styles of surface textural changes; and (3) the main difference between abiotic and biotically produced weathering is the scale (microns versus nanometers) and the style (crystallographically versus noncrystallographically controlled) of the textural features. Further investigation into nanosize scale surface textures should attempt to quantify both textures and chemical changes of the role of microorganisms in the weathering of silicates. Additional experiments addressing nanoscale textures of shock features for comparison with the current data set.

Longazo, Teresa G.; Wentworth, Susan J.; Clemett, Simon J.; Southam, Gordon; McKay, David S.

2001-01-01

394

Subarctic weathering of mineral wastes provides a sink for atmospheric CO(2).  

PubMed

The mineral waste from some mines has the capacity to trap and store CO(2) within secondary carbonate minerals via the process of silicate weathering. Nesquehonite [MgCO(3)·3H(2)O] forms by weathering of Mg-silicate minerals in kimberlitic mine tailings at the Diavik Diamond Mine, Northwest Territories, Canada. Less abundant Na- and Ca-carbonate minerals precipitate from sewage treatment effluent deposited in the tailings storage facility. Radiocarbon and stable carbon and oxygen isotopes are used to assess the ability of mine tailings to trap and store modern CO(2) within these minerals in the arid, subarctic climate at Diavik. Stable isotopic data cannot always uniquely identify the source of carbon stored within minerals in this setting; however, radiocarbon isotopic data provide a reliable quantitative estimate for sequestration of modern carbon. At least 89% of the carbon trapped within secondary carbonate minerals at Diavik is derived from a modern source, either by direct uptake of atmospheric CO(2) or indirect uptake though the biosphere. Silicate weathering at Diavik is trapping 102-114 g C/m(2)/y within nesquehonite, which corresponds to a 2 orders of magnitude increase over the background rate of CO(2) uptake predicted from arctic and subarctic river catchment data. PMID:21854037

Wilson, Siobhan A; Dipple, Gregory M; Power, Ian M; Barker, Shaun L L; Fallon, Stewart J; Southam, Gordon

2011-09-15

395

Receivers Gather Data for Climate, Weather Prediction  

NASA Technical Reports Server (NTRS)

Signals from global positioning system (GPS) satellites are now being used for more than just location and navigation information. By looking at the radio waves from GPS satellites, a technology developed at NASA s Jet Propulsion Laboratory (JPL) not only precisely calculates its position, but can also use a technique known as radio occultation to help scientists study the Earth s atmosphere and gravity field to improve weather forecasts, monitor climate change, and enhance space weather research. The University Corporation for Atmospheric Research (UCAR), a nonprofit group of universities in Boulder, Colorado, compares radio occultation to the appearance of a pencil when viewed though a glass of water. The water molecules change the path of visible light waves so that the pencil appears bent, just like molecules in the air bend GPS radio signals as they pass through (or are occulted by) the atmosphere. Through measurements of the amount of bending in the signals, scientists can construct detailed images of the ionosphere (the energetic upper part of the atmosphere) and also gather information about atmospheric density, pressure, temperature, and moisture. Once collected, this data can be input into weather forecasting and climate models for weather prediction and climate studies. Traditionally, such information is obtained through the use of weather balloons. In 1998, JPL started developing a new class of GPS space science receivers, called Black Jack, that could take precise measurements of how GPS signals are distorted or delayed along their way to the receiver. By 2006, the first demonstration of a GPS radio occultation constellation was launched through a collaboration among Taiwan s National Science Council and National Space Organization, the U.S. National Science Foundation, NASA, the National Oceanic and Atmospheric Administration (NOAA), and other Federal entities. Called the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), JPL was responsible for designing COSMIC s primary instrument - based on its revolutionary Black Jack receiver.

2012-01-01

396

Green Bank Weather Dana S. Balser  

E-print Network

Green Bank Weather Dana S. Balser #12;Weather Resources 1. Weather Stations 2. Weather Forecasts (NOAA/Maddalena) 3. Pyrgeometer 4. 86 GHz Tipping Radiometer 5. 12 GHz Interferometer #12;Weather Parameters 1 May 2004 to 1 March 2007 speedwindousInstantaneV :Hz)(12StationWeather e

Balser, Dana S.

397

Extreme water-related weather events and waterborne disease.  

PubMed

Global climate change is expected to affect the frequency, intensity and duration of extreme water-related weather events such as excessive precipitation, floods, and drought. We conducted a systematic review to examine waterborne outbreaks following such events and explored their distribution between the different types of extreme water-related weather events. Four medical and meteorological databases (Medline, Embase, GeoRef, PubMed) and a global electronic reporting system (ProMED) were searched, from 1910 to 2010. Eighty-seven waterborne outbreaks involving extreme water-related weather events were identified and included, alongside 235 ProMED reports. Heavy rainfall and flooding were the most common events preceding outbreaks associated with extreme weather and were reported in 55·2% and 52·9% of accounts, respectively. The most common pathogens reported in these outbreaks were Vibrio spp. (21·6%) and Leptospira spp. (12·7%). Outbreaks following extreme water-related weather events were often the result of contamination of the drinking-water supply (53·7%). Differences in reporting of outbreaks were seen between the scientific literature and ProMED. Extreme water-related weather events represent a risk to public health in both developed and developing countries, but impact will be disproportionate and likely to compound existing health disparities. PMID:22877498

Cann, K F; Thomas, D Rh; Salmon, R L; Wyn-Jones, A P; Kay, D

2013-04-01

398

Structure, properties and applications of phenyl-modified silicate films  

Microsoft Academic Search

Organically modified silicate films prepared by sol-gel techniques have been studied. The silicate structure has been modified by phenyl radicals. The films were prepared by cohydrolysis in various proportions of tetraethyloxysilane and phenyl triethoxysilane or diphenyl diethylhexyloxy diethoxydisiloxane. It is shown that phenyl radicals introduced into the silicate network reduce cross-linking in polymer structure, their density and hydroxyl contents. These

Konstantin A. Vorotilov; Vladimir A. Vasiljev; Michael V. Sobolevsky; Natalia I. Afanasyeva

1996-01-01

399

Olivine Weathering in Soil, and Its Effects on Growth and Nutrient Uptake in Ryegrass (Lolium perenne L.): A Pot Experiment  

PubMed Central

Mineral carbonation of basic silicate minerals regulates atmospheric CO2 on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO2 sequestration (‘enhanced weathering’). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha?1. Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha?1 (14.8% of dose, OLIV1) to 2240 kg ha?1 (1.1%, OLIV4). This corresponds to gross CO2 sequestration of 290 to 2690 kg ha?1 (29 103 to 269 103 kg km?2.) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the ‘enhanced weathering’ concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop. PMID:22912685

ten Berge, Hein F. M.; van der Meer, Hugo G.; Steenhuizen, Johan W.; Goedhart, Paul W.; Knops, Pol; Verhagen, Jan

2012-01-01

400

Inorganic Plant Nutrients: Nitrogen, Phosphorus, Silicate Introduction  

E-print Network

. The biogeochemical cycle of nitrogen is further complicated by the different forms in which nitrogen can occurLab 3: Inorganic Plant Nutrients: Nitrogen, Phosphorus, Silicate Introduction Compounds of nitrogen processes. Concentrations of nitrogen and phosphorus, on the other hand, are highly dynamic because they may

Jochem, Frank J.

401

Dynamic Fatigue of a Titanium Silicate Glass  

NASA Technical Reports Server (NTRS)

A dynamic fatigue study was performed on a Titanium Silicate Glass in order to assess its susceptibility to delayed failure. Fracture mechanics techniques were used to analyze the results for the purpose of making lifetime predictions for optical elements made from this material. The material has reasonably good resistance (N=23 to stress corrosion in ambient conditions).

Tucker, Dennis S.; Nettles, Alan T.; Cagle, Holly A.; Smith, W. Scott (Technical Monitor)

2002-01-01

402

Thermoset polymer-layered silicic acid nanocomposites  

NASA Astrophysics Data System (ADS)

Nanocomposites are formed when phase mixing occurs on a nanometer length scale. Due to the improved phase morphology and interfacial properties, nanocomposites exhibit mechanical properties superior to conventional composites. Toyota researchers first demonstrated that organoclay could be exfoliated in a nylon-6 matrix to greatly improve the thermal and mechanical properties of the polymer, which has resulted in a practical application in the automobile industry. A great deal of research has been conducted on organic-inorganic hybrid composites in which smectite clays are used as reinforcement agents. However, little work has been devoted to derivatives of other layered inorganic solids. In the present work, the first examples of organic polymer-layered silicic acid nanocomposites have been prepared by formation of a cured epoxy polymer network in the presence of organo cation exchange forms of magadiite. The exfoliation of silicate nanolayers in the epoxy matrix was achieved by in-situ intragallery polymerization during the thermosetting process. In general, the tensile properties, solvent resistance, barrier properties and chemical stability of the polymer matrix are greatly improved by the embedded silicate nanolayers when the matrix is flexible (sub-ambient Tg). The improvement of properties are dependent on the silicate loading, the degree of nanolayer separation and interfacial properties. Interestingly, the exfoliation also affects the polymer elasticity in a favorable way. The mechanism leading to nanocomposite formation is proposed. One exfoliated epoxy-magadiite nanocomposite/composition possessed unique transparent optical properties. The exfoliation chemistry was successfully extended to the other members of the layered silicic acid family. A new approach also was developed to prepare thermoset epoxy polymer-layered silicate nanocomposites in which curing agents can be directly intercalated into the intragallery without the need for alkylammonium ions on the exchange sites. This new development has resulted in a greater improvement in the overall properties of thermoset polymer-clay nanocomposites. The exfoliation chemistry was extended further to other thermoset silicone polymer systems. The new polysiloxane-layered silicic acid nanocomposites were prepared with promising mechanical properties. Some fundamental chemistry and physics issues regarding nanocomposite formation were elucidated by this research work, particularly with regard to the relationship of microstructure and interfacial factors to the mechanical properties of the nanocomposites.

Wang, Zhen

403

Visualizing weather with synthetic high-dynamic range images  

NASA Astrophysics Data System (ADS)

The appearance of the sky has a fundamental effect on the way human beings perceive an environment. This paper presents a method to compute synthetic high-dynamic-range fisheye images from weather parameter data sets. These images can then be used in global-illumination systems (e. g. Radiance) to define the lighting conditions at an arbitrary weather state. Applications of this technology can be found in flight simulators and in architectural visualization. The method combines artificial neural networks and principal component analysis to associate the appearance of the sky with the state of a weather parameter vector. A model is trained with examples of sky images and weather data from a period of seven months. This model is then used to generate artificial sky images corresponding to a specific weather parameter vector. This is a novel method which contrary to many previous methods is able to synthesize a sky image which varies with the current weather state. The results show that, although it is not possible to represent the cloud details, it is possible to distinguish between different weather states.

Olsson, Bjorn; Ynnerman, Anders; Lenz, Reiner

2004-06-01

404

Grain Growth and Silicates in Dense Clouds  

NASA Technical Reports Server (NTRS)

Interstellar silicates are likely to be a part of all grains responsible for visual extinction (Av) in the diffuse interstellar medium (ISM) and dense clouds. A correlation between Av and the depth of the 9.7 micron silicate feature (measured as optical depth, tau(9.7)) is expected if the dust species are well 'mixed. In the di&se ISM, such a correlation is observed for lines of sight in the solar neighborhood. A previous study of the silicate absorption feature in the Taurus dark cloud showed a tendency for the correlation to break down at high Av (Whittet et al. 1988, MNRAS, 233,321), but the scatter was large. We have acquired Spitzer Infrared Spectrograph data of several lines of sight in the IC 5 146, Barnard 68, Chameleon I and Serpens dense clouds. Our data set spans an Av range between 2 and 35 magnitudes. All lines of sight show the 9.7 micron silicate feature. The Serpens data appear to follow the diffuse ISM correlation line whereas the data for the other clouds show a non-linear correlation between the depth of the silicate feature relative to Av, much like the trend observed in the Taurus data. In fact, it appears that for visual extinctions greater than about 10 mag, tau(9.7) begins to level off. This decrease in the growth of the depth of the 9.7 micron feature with increasing Av could indicate the effects of grain growth in dense clouds. In this poster, we explore the possibility that grain growth causes an increase in opacity (Av) without causing a corresponding increase in tau(9.7).

Pendeleton, Yvonne J.; Chiar, J. E.; Ennico, K.; Boogert, A.; Greene, T.; Knez, C.; Lada, C.; Roellig, T.; Tielens, A.; Werner, M.; Whittet, D.

2006-01-01

405

Severe Weather Forecast Decision Aid  

NASA Technical Reports Server (NTRS)

This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

Bauman, William H., III; Wheeler, Mark M.; Short, David A.

2005-01-01

406

Carbonate-Silicate Cycle Models of the Long-Term Carbon Cycle, Carbonate Accumulation in the Oceans, and Climate  

Microsoft Academic Search

Several models of the long-term carbon cycle, incorporating models of the carbonate-silicate cycle, were developed and utilized to investigate issues relating to global climate and the causes and consequences of changes in calcium carbonate accumulation in the oceans. Model results indicate that the marked mid-Cretaceous (120 Ma) global warming could be explained by increased rates of release of carbon dioxide

Kenneth George Caldeira

1991-01-01

407

Urban climate, weather and sustainability  

NASA Astrophysics Data System (ADS)

As concentrated areas of human activities, urban areas and urbanization are key drivers of global environmental change and pose a challenge to the achievement of sustainability. One of the key goals of sustainable development is to separate increases in non-renewable resource use (particularly fossil fuels) from economic growth. This is to be accomplished by modifying individual practices, encouraging technological innovation and redesigning systems of production and consumption. Settlements represent a scale at which significant advances on each of these can be made and where there is an existing management structure. However, urban areas currently consume a disproportionate share of the Earth's resources and urbanization has modified local climate and weather significantly, usually to the detriment of urban dwellers. There is now a lengthy history of urban climate study that links existing settlement form to climatic consequences yet, there is little evidence that climate information is incorporated into urban designs or that the climatic impact of different plans is considered. Consequently, opportunities for planning sustainable urban forms that are suitable to local climates and promote energy conservation and healthy atmospheres are not taken and much effort is later expended in `fixing' problems that emerge. This paper will outline the links between urban climate and sustainability, identify gaps in our urban climate knowledge and discuss the opportunities and barriers to the application of this knowledge to urban design and planning.

Mills, Gerald

408

Regional climate of hazardous convective weather through high-resolution dynamical downscaling  

Microsoft Academic Search

We explore the use of high-resolution dynamical downscaling as a means to simulate the regional climatology and variability of hazardous convective-scale weather. Our basic approach differs from a traditional regional climate model application in that it involves a sequence of daily integrations. We use the weather research and forecasting (WRF) model, with global reanalysis data as initial and boundary conditions.

Robert J. Trapp; Eric D. Robinson; Michael E. Baldwin; Noah S. Diffenbaugh; Benjamin R. J. Schwedler

2011-01-01

409

Regional climate of hazardous convective weather through high-resolution dynamical downscaling  

Microsoft Academic Search

We explore the use of high-resolution dynamical downscaling as a means to simulate the regional climatology and variability of hazardous convective-scale weather. Our basic approach differs from a traditional regional climate model application in that it involves a sequence of daily integrations. We use the weather research and forecasting (WRF) model, with global reanalysis data as initial and boundary conditions.

Robert J. Trapp; Eric D. Robinson; Michael E. Baldwin; Noah S. Diffenbaugh; Benjamin R. J. Schwedler

2010-01-01

410

GBS data mapper: modeling worldwide availability of Ka-band links using ITU weather data  

Microsoft Academic Search

In support of SPAWAR PMW 176 (Navy SATCOM Program Office), we have developed GDM, the Global Broadcast Service (GBS) data mapper. GDM is comprised of a raster-based modeling core, a simple geographic display tool, a comprehensive set of ITU-based weather and RF propagation models, and a substantial set of weather and mapping databases. The model develops expected link margins for

Gerry Fitzgerald; Greg Bostrom

1999-01-01

411

Operational evapotranspiration mapping using remote sensing and weather datasets: A new parameterization for the SSEB approach  

Technology Transfer Automated Retrieval System (TEKTRAN)

The increasing availability of multi-scale remotely sensed data and global weather datasets is allowing the estimation of evapotranspiration (ET) at multiple scales. We present a simple but robust method that uses remotely sensed thermal data and model-assimilated weather fields to produce ET for th...

412

he Cooperative Observer Program is a unique partnership between the National Weather Service  

E-print Network

sites support local weather, climate and flood forecasts, data from 1,221 of them also contribute the extent of climate change from local to global scales. In addition, data collected by weather observers help local officials make long-term planning decisions about water resources and are used by a variety

413

Weather Regimes and Preferred Transition Three-Level Quasi-Geostrophic Model  

E-print Network

;Abstract Multiple flow regimes are reexamined in a global, three-level, quasi-geostrophic model of large-scale persistent and recurrent flow patterns, also called weather regimes. Weather regimes can (RNA), the North Atlantic Oscillation (NAO), and the Arctic Oscillation (AO). The positive and negative

Ghil, Michael

414

Finding Space Weather Events  

NSDL National Science Digital Library

This is an activity about searching online data archives for solar wind events. Learners will find at least three episodes of increased solar wind activity impacting Earth using direct measurements of solar wind velocity and density. Then, they will characterize each events by its rise time, the time it takes for the solar wind speed to rise from normal levels to the peak speed of the event, and the percentage increase in solar wind velocity. This is Activity 11 of the Space Weather Forecast curriculum.

415

Weather Stations: Phase Change  

NSDL National Science Digital Library

In this activity, learners observe the water cycle in action! Water vapor in a tumbler condenses on chilled aluminum foil — producing the liquid form of water familiar to us as rain and dew. Learners discuss how Jupiter's lack of a surface simplifies its water cycle. Learners then consider the roles ammonia and ammonia compounds play in Jupiter's more complicated atmosphere. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

2014-07-11

416

Weather Forecasting Aid  

NASA Technical Reports Server (NTRS)

Weather forecasters are usually very precise in reporting such conditions as temperature, wind velocity and humidity. They also provide exact information on barometric pressure at a given moment, and whether the barometer is "rising" or "falling"- but not how rapidly or how slowly it is rising or falling. Until now, there has not been available an instrument which measures precisely the current rate of change of barometric pressure. A meteorological instrument called a barograph traces the historical ups and downs of barometric pressure and plots a rising or falling curve, but, updated every three hours, it is only momentarily accurate at each updating.

1979-01-01

417

The Global Circuit.  

ERIC Educational Resources Information Center

Discusses the nature of and research related to a theory explaining the earth's electric budget. The theory suggests a global electric circuit completed by a positive current flowing up into thunderstorm clouds, from clouds to ionosphere, distributed around the globe, and down to earth through the lower atmosphere in fair-weather regions. (JN)

Lansford, Henry

1983-01-01

418

Land-surface influences on weather and climate  

NASA Technical Reports Server (NTRS)

Land-surface influences on weather and climate are reviewed. The interrelationship of vegetation, evapotranspiration, atmospheric circulation, and climate is discussed. Global precipitation, soil moisture, the seasonal water cycle, heat transfer, and atmospheric temperature are among the parameters considered in the context of a general biosphere model.

Baer, F.; Mintz, Y.

1984-01-01

419

Multimodel Ensemble Forecasts for Weather and Seasonal Climate  

Microsoft Academic Search

In this paper the performance of a multimodel ensemble forecast analysis that shows superior forecast skills is illustrated and compared to all individual models used. The model comparisons include global weather, hurricane track and intensity forecasts, and seasonal climate simulations. The performance improvements are completely attributed to the collective information of all models used in the statistical algorithm.The proposed concept

T. N. Krishnamurti; C. M. Kishtawal; Zhan Zhang; Timothy Larow; David Bachiochi; Eric Williford; Sulochana Gadgil; Sajani Surendran

2000-01-01

420

The formation of residual pedogenic clays by limestone weathering  

SciTech Connect

The weathering of carbonate rocks and formation of residual soils differs markedly from processes associated with formation of soils on other rock types. Soils derived from non-carbonate rocks, for example, will invariably produce a weathered product whose volume significantly exceeds that of the original parent rock (because of the formation of less dense, hydrated silicates and oxyhydroxides); the weathering of carbonate rocks, however, produces an infinitely smaller volume of residual weathering products because the soil must originate from the small amount of insoluble residue present in the parent limestone. Further, because limestones are often deposited in a quiet (low energy) shelf environment, or adjacent to land areas where a minimal supply of clastic debris is available, the minerals that are involved in the formation of residual soils are largely authigenic in origin. The Yucatan Peninsula of Mexico is an ideal site to observe these processes and all stages of soil development on limestones are present. Emergence of the region began in the Middle Tertiary and, because surface streams are wholly lacking in the northern peninsula, the soils that are now present do not include any detrital, clastic components. Examination of the insoluble residues of limestones shows that the source materials for the soils consisted of authigenic talc, chlorite, palygorskite, smectite, and mixed layer clays. Subaerial weathering of these limestones initially results in release of the trace amount of clays and formation of poorly crystalline, 10 angstrom halloysite (plus amorphous oxyhydroxides of iron and aluminum); as the profiles thicken and mature, halloysite is slowly transformed to well crystallized kaolinite and goethite, lepidocrocite, and boehmite may also appear. The stage of development of the soils was noted to be closely related with the geomorphic maturity of the region, and the thickest profiles were associated with areas of mature cone karst.

Carr, M.B.; Isphording, W.C.; O'Hearn, S.M.; Kusion, J.E. (Univ. of South Alabama, Mobile, AL (United States). Dept. of Geology-Geography)

1992-01-01

421

Make Your Own Weather Station  

NSDL National Science Digital Library

In this OLogy activity, kids learn about climate and atmospheric conditions by making their own weather station. The activity begins with an overview that explains that weather happens in the atmosphere, where conditions are always changing. Students are given step-by-step, illustrated directions to make a wind vane, a rain gauge and a barometer. The activity includes a printable Weather Chart and wind vane cutouts.

422

Science Sampler: Weathering database technology  

NSDL National Science Digital Library

Collecting weather data is a traditional part of a meteorology unit at the middle level, but making connections between the data and weather conditions can be a challenge for students. One way to help students make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which readings are associated with certain types of weather.

Robert Snyder

2005-02-01

423

Weathering of rock 'Ginger'  

NASA Technical Reports Server (NTRS)

One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

1997-01-01

424

The nanostructure of calcium silicate hydrate  

NASA Astrophysics Data System (ADS)

The nanostructure of C-S-H, the principle binding phase of hydrated cements in concrete, is examined through classical and spectroscopic methods such as solubility, 29Si MAS NMR, inelastic neutron scattering (INS), and small-angle neutron scattering (SANS). A more comprehensive understanding of the nanostructure is proposed. The central finding of this thesis is that variations in Ca/Si ratio, silicate structure, and Ca-OH content of C-S-H are systematically related to previously undiscovered variations in solubility in the CaO-SiO2-H 2O system at room temperature. These relationships show how C-S-H resembles disordered forms of the calcium silicate hydrate minerals 1.4-nm tobermorite [Ca5Si6O16(OH)2·8H 2O] and jennite [Ca9(Si6O18)(OH) 6·8H2O]. For example, in solids lacking Ca-OH groups, the structure resembles a purely tobermorite-like structure, which, when equilibrated in aqueous solutions saturated in Ca(OH)2, has a Ca/Si ratio of 1.5 and a minimum mean silicate chain length of 2; with increasing Ca-OH contents, the structure becomes increasingly jennite-like while showing higher Ca/Si ratios and higher mean chain lengths at saturation in Ca(OH)2. These relationships appear to reconcile the broad variations in the literature. 29Si NMR on concrete specimens aged 43--96 years show that the mean silicate chain length of C-S-H gel ultimately converges to a value of 5. With supporting evidence from chemical analysis and from high Ca-OH contents measured by INS, it is concluded that C-S-H gel formed in Ca3SiO5 pastes eventually equilibrates to a purely jennite-like structure. A Ca/Si ratio of 1.2 in C-S-H gel marks the composition at which Ca-OH groups are eliminated (or introduced) and below which spontaneous silicate polymerization occurs. Leaching studies on cement pastes show that when C-S-H is decalcified below Ca/Si ˜ 1.2, the induced silicate polymerization occurring in situ leads to macroscopic polymerization shrinkage. Cement pastes blended with high contents of mineral additions may be more susceptible to this mechanism. SANS measurements on leached Ca3SiO5 and cement pastes show dramatic variations in surface area with Ca/Si ratio. These variations are attributed to transformations between low- and high-density morphologies of C-S-H.

Chen, Jeffrey J.

425

Space Weathering: An Ultraviolet Indicator  

NASA Technical Reports Server (NTRS)

We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

Hendrix, A. R.; Vilas, F.

2004-01-01

426

Space Weathering: An Ultraviolet Indicator  

NASA Technical Reports Server (NTRS)

We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

Hendrix, A. R.; Vilas, F.

2003-01-01

427

AWE: Aviation Weather Data Visualization  

NASA Technical Reports Server (NTRS)

The two official sources for aviation weather reports both require the pilot to mentally visualize the provided information. In contrast, our system, Aviation Weather Environment (AWE) presents aviation specific weather available to pilots in an easy to visualize form. We start with a computer-generated textual briefing for a specific area. We map this briefing onto a grid specific to the pilot's route that includes only information relevant to his flight route that includes only information relevant to his flight as defined by route, altitude, true airspeed, and proposed departure time. By modifying various parameters, the pilot can use AWE as a planning tool as well as a weather briefing tool.

Spirkovska, Lilly; Lodha, Suresh K.

2001-01-01

428

Global spatial distribution of natural riverine silica inputs to the coastal zone  

NASA Astrophysics Data System (ADS)

Silica, SiO2, in dissolved (DSi) and particulate (PSi) form, is both a major product of continental weathering as well as an essential nutrient in terrestrial and aquatic systems. Here we present estimates of the spatial distribution of riverine silica fluxes under natural conditions, i.e. without human influence, to ~140 segments of the global coastal zone. Focussing on the construction of the DSi budget, natural DSi concentration is multiplied with discharge of rivers for each segment for documented basins and segments. Segments with no documentation available are estimated using clustered information based mainly on considerations of local lithology, climate, and lake retention. We approximate fluxes of particulate silica in various forms (PSi) from fluxes of suspended matter, calculated from existing models. Results have been established for silica fluxes, concentrations and yields for drainage basins of the different continents, oceans basins as well as coastal segment basins. For the continental surfaces actually draining into the oceans (exorheic regions, representing 114.7 M km2), 371 M t y-1 of DSi and 8835 M t y-1 of PSi are transported, corresponding to a mean concentration of 9.5 mg l-1 and 226 mg l-1, and to a mean yield of 3.3 t km-2 y-1 and 77 t km-2 y-1, respectively. DSi yields exceeding 6.6 t km-2 y-1, i.e. >2× the global average, represent 17.4% of the global continental ice-free exorheic area but correspond to 56.0% of DSi fluxes. Pacific catchments hold most of the hyper-active areas (>5× global average), suggesting a close connection between tectonic activity and DSi fluxes resulting from silicate weathering. The macro-filters of regional and marginal seas intercept 33% and 46% of the total dissolved and particulate silica fluxes.

Dürr, H. H.; Meybeck, M.; Hartmann, J.; Laruelle, G. G.; Roubeix, V.

2009-01-01

429

Worldwide distribution of continental rock lithology: Implications for the atmospheric\\/soil CO2 uptake by continental weathering and alkalinity river transport to the oceans  

Microsoft Academic Search

The silicate rock weathering followed by the formation of carbonate rocks in the ocean, transfers CO2 from the atmosphere to the lithosphere. This CO2 uptake plays a major role in the regulation of atmospheric CO2 concentrations at the geologic timescale and is mainly controlled by the chemical properties of rocks. This leads us to develop the first world lithological map

Philippe Amiotte Suchet; Jean-Luc Probst; Wolfgang Ludwig

2003-01-01

430

The silicate component of Martian dust  

NASA Astrophysics Data System (ADS)

Absorption features in telescopic reflectance spectra of Mars obtained during 1978, and absorption features in Mariner 7 and Mariner 9 spectra, are analyzed which are assigned to structural hydroxyl within a strongly hydrogen-bonded acidic material suggested to be a silicate. Deduced fundamentals indicate that the Si-O(b)-Si bond angle may be approximately linear, and that the estimated Si-O(b) bridge length may be about 1.61 A. Viking compositional data indicate that Mg(2+), rather than Ca(2+) may be the dominant cation in the Martian material. The results suggest that the silicate component of the dust may be an incipient hydrolysis product of olivine-rich ultramafic or mafic material, involving a process that resulted in minimum loss of mobile cations and that maintained the high O/Si ratio of the starting material.

Huguenin, R. L.

1987-04-01

431

Crystalline-amorphous transition in silicate perovskites  

Microsoft Academic Search

CaSiO3 and MgSiO3 perovskites are known to undergo solid-state crystal to amorphous transitions near ambient pressure when decompressed from their high-pressure stability fields. In order to elucidate the mechanistic aspects of this transition we have performed detailed molecular-dynamics simulations and lattice-dynamical calculations on model silicate perovskite systems using empirical rigid-ion pair potentials. In the simulations at low temperatures, the model

Mahin Hemmati; Andrew Chizmeshya; George H. Wolf; Peter H. Poole; Jun Shao; C. Austen Angell

1995-01-01

432

Conductimetric determination of decomposition of silicate melts  

NASA Technical Reports Server (NTRS)

A description of a procedure is given to detect decomposition of silicate systems in the liquid state by conductivity measurements. Onset of decomposition can be determined from the temperature curves of resistances measured on two pairs of electrodes, one above the other. Degree of decomposition can be estimated from temperature and concentration dependency of conductivity of phase boundaries. This procedure was tested with systems PbO-B2O3 and PbO-B2O3-SiO2.

Kroeger, C.; Lieck, K.

1986-01-01

433

SILICATE EVOLUTION IN BROWN DWARF DISKS  

SciTech Connect

We present a compositional analysis of the 10 {mu}m silicate spectra for brown dwarf disks in the Taurus and Upper Scorpius (UppSco) star-forming regions, using archival Spitzer/Infrared Spectrograph observations. A variety in the silicate features is observed, ranging from a narrow profile with a peak at 9.8 {mu}m, to nearly flat, low-contrast features. For most objects, we find nearly equal fractions for the large-grain and crystalline mass fractions, indicating both processes to be active in these disks. The median crystalline mass fraction for the Taurus brown dwarfs is found to be 20%, a factor of {approx}2 higher than the median reported for the higher mass stars in Taurus. The large-grain mass fractions are found to increase with an increasing strength in the X-ray emission, while the opposite trend is observed for the crystalline mass fractions. A small 5% of the Taurus brown dwarfs are still found to be dominated by pristine interstellar medium-like dust, with an amorphous submicron grain mass fraction of {approx}87%. For 15% of the objects, we find a negligible large-grain mass fraction, but a >60% small amorphous silicate fraction. These may be the cases where substantial grain growth and dust sedimentation have occurred in the disks, resulting in a high fraction of amorphous submicron grains in the disk surface. Among the UppSco brown dwarfs, only usd161939 has a signal-to-noise ratio high enough to properly model its silicate spectrum. We find a 74% small amorphous grain and a {approx}26% crystalline mass fraction for this object.

Riaz, B. [Instituto de Astrofisica de Canarias, E38205 La Laguna, Tenerife (Spain)], E-mail: basmah@iac.es

2009-08-10

434

Drawdown of atmospheric CO2 by gray shale weathering: insights from carbon, sulphur, and oxygen isotope systematics in the Susquehanna Shale Hills Critical Zone Observatory  

NASA Astrophysics Data System (ADS)

Shales, covering 25% of land surface, are an important lithology in linking the CO2 drawdown and continental silicate weathering on the global scale. In this study, we aim to evaluate the potentials of shale weathering to consume CO2 by investigating the elemental chemistry as well as stable isotopes (C, S and O) along the water flow paths in the well-studied Susquehanna Shale Hills Critical Zone Observatory (SSHO). We also try to determine the potentials of releasing CO2 by quantifying the relative importance of sulfuric acid in carbonate dissolution and the decomposition rates of ancient organic matter. At SSHO, shallow soils are dominated by clay dissolution, and soil waters are low in dissolved inorganic carbon (DIC) concentrations controlled by equilibrium with soil pCO2. Here CO2 is produced primarily by oxidative decomposition of soil organic matter, and its concentrations vary seasonally and spatially. Ankerite, present in the Rose Hills bedrock, is depleted in soils and only remains at greater depths. Weathering of ankerite contributes to much higher concentrations of DIC and divalent cations (Ca and Mg) in groundwaters, but groundwater chemistry evolves to different extents with respect to ankerite saturation because the depths to ankerite weathering fronts vary due to heterogeneity of the Rose Hill shales and landscape position. Consistently, the ?13CDIC ratios of these groundwaters are indicative of mixing between DIC from ankerite and soil CO2 endmembers. Hydrologically, the first-order stream is contributed by different proportions of groundwater and shallow soil waters as observed by major elemental chemistry, [DIC] and ?13CDIC ratio of stream waters. In addition to reacting with carbonic acid , shale can also react with sulfuric acid. The strong acidity derives from oxidative dissolution of pyrite at SSHO. Similar to ankerite, pyrite, at trace levels, is depleted from soils and is only present close to the ankerite weathering front at depth. Additionally, Pennsylvania receives high rates of acid deposition, loading significant amounts of sulfuric acid at the land surface. Thus at SSHO, the dissolution of the carbonate mineral ankerite by sulfuric acid may release CO2, instead of consuming CO2, and may be important in the mass balance of inorganic carbon. We collected preliminary S/O isotope data to evalute the sources of sulfuric acid and quantify its involvement in shale weathering. The global inventory of organic carbon in sedimentary rocks such as shales is greater than all the other surface reservoirs combined. Although most of the ancient organic matter is relatively refractory, it may still be altered at Earth's surface, which is important in the atmospheric CO2 and O2 levels on global scales. Our ongoing investigation is also focused on the degradation rates of this ancient organic matter during shale weathering and its contribution to CO2 mass balance using C isotope analyses.

Jin, L.; Ogrinc, N.; Yesavage, T.; Kaye, J. P.; Brantley, S. L.

2012-12-01

435

The role of disseminated calcite in the chemical weathering of granitoid rocks  

USGS Publications Warehouse

Accessory calcite, present at concentrations between 300 and 3000 mg kg-1, occurs in fresh granitoid rocks sampled from the Merced watershed in Yosemite National Park, CA, USA; Loch Vale in Rocky Mountain National Park CO USA; the Panola watershed, GA USA; and the Rio Icacos, Puerto Rico. Calcite occurs as fillings in microfractures, as disseminated grains within the silicate matrix, and as replacement of calcic cores in plagioclase. Flow-through column experiments, using de-ionized water saturated with 0.05 atm. CO2, produced effluents from the fresh granitoid rocks that were dominated by Ca and bicarbonate and thermodynamically saturated with calcite. During reactions up to 1.7 yr, calcite dissolution progressively decreased and was superceded by steady state dissolution of silicates, principally biotite. Mass balance calculations indicate that most calcite had been removed during this time and accounted for 57-98% of the total Ca released from these rocks. Experimental effluents from surfically weathered granitoids from the same watersheds were consistently dominated by silicate dissolution. The lack of excess Ca and alkalinity indicated that calcite had been previously removed by natural weathering. The extent of Ca enrichment in watershed discharge fluxes corresponds to the amounts of calcite exposed in granitoid rocks. High Ca/Na ratios relative to plagioclase stoichiometries indicate excess Ca in the Yosemite, Loch Vale, and other alpine watersheds in the Sierra Nevada and Rocky Mountains of the western United States. This Ca enrichment correlates with strong preferential weathering of calcite relative to plagioclase in exfoliated granitoids in glaciated terrains. In contrast, Ca/Na flux ratios are comparable to or less than the Ca/Na ratios for plagioclase in the subtropical Panola and tropical Rio Icacos watersheds, in which deeply weathered regoliths exhibit concurrent losses of calcite and much larger masses of plagioclase during transport-limited weathering. These results indicate that the weathering of accessory calcite may strongly influence Ca and alkalinity fluxes from silicate rocks during and following periods of glaciation and tectonism but is much less important for older stable geomorphic surfaces.

White, A.F.; Bullen, T.D.; Vivit, D.V.; Schulz, M.S.; Clow, D.W.

1999-01-01

436

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

NASA Technical Reports Server (NTRS)

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

Kreins, E. R. (editor)

1979-01-01

437

Premixed calcium silicate cement for endodontic applications  

PubMed Central

Calcium silicate-based materials (also called MTA) are increasingly being used in endodontic applications. However, the handling properties of MTA are not optimal when it comes to injectability and cohesion. Premixing the cements using glycerol avoids these issues. However, there is a lack of data on the effect of common cement variables on important properties of premixed cements for endodontic applications. In this study, the effects of liquid-to-powder ratio, amount of radiopacifier and amount of calcium sulfate (added to control the setting time) were screened using a statistical model. In the second part of the study, the liquid-to-powder ratio was optimized for cements containing three different amounts of radiopacifier. Finally, the effect of using glycerol rather than water was evaluated in terms of radiopacity. The setting time was found to increase with the amount of radiopacifier when the liquid-to-powder ratio was fixed. This was likely due to the higher density of the radiopacifier in comparison to the calcium silicate, which gave a higher liquid-to-powder ratio in terms of volume. Using glycerol rather than water to mix the cements led to a decrease in radiopacity of the cement. In conclusion, we were able to produce premixed calcium silicate cements with acceptable properties for use in endodontic applications. PMID:23507729

Persson, Cecilia; Engqvist, Håkan

2011-01-01

438

National Severe Storms Laboratory's Weather Room  

NSDL National Science Digital Library

This educational website from NOAA has: facts on tornadoes, hurricanes, lightning and thunderstorms; lessons on weather symbols, maps and systems; an extensive list of weather and climate resources for teachers; information on careers in weather; and a list of weather links including weather data. Additionally, the site includes all the latest meteorological research including tornado genesis and lightning.

2010-08-06

439

How Do Meteorologists Forecast the Weather?  

NSDL National Science Digital Library

This is a lesson that I developed where students learn how meteorologists predict the weather. Students will use surface weather maps, radar, satellite, and weather models from the National Weather Service to assess the current state of the weather and make a prediction.

David Faysash

2012-07-30

440

Space Weather Action Center  

NSDL National Science Digital Library

This is a revised "Tracking a Solar Storm-Student Observation Network" with a new format and Web site. The Space Weather Action Center (SWAC) allows students to use near real time data and track a solar storm. By following the basic steps in the Instructional Guide students can access, analyze and record NASA satellite and observatory data. There is a downloadable 'step-by-step' Educator's Setup Guide where you will find a variety of recommendations and diagrams detailing how to construct a fully functional SWAC while keeping potential limitations on space and technology in mind. Flip charts provide the step by step data use and there are also instructions for using green screen technology.

2009-01-01

441

Severe Weather: Hurricanes  

NSDL National Science Digital Library

Severe Weather: Hurricanes is part of an on-line series of modules entitled Exploring the Environment. Emphasizing an integrated approach to environmental Earth Science education through problem-based learning, this module asks student groups to track an actual (past) hurricane. Background information explains how hurricanes occur, how they are named, and the Saffir-Simpson Intensity Scale. Activities train groups on how to track hurricanes. Once they are given an actual hurricane to track, students must determine the speed of its movement and where it will come ashore. There are extension activities, a glossary of terms, teacher resources, a reference for the problem-based learning model, and links to additional resources.

442

The Weather Calculator  

NSDL National Science Digital Library

This collection of resources, provided by the National Weather Service Forecast Office for the El Paso area, allows users to be their own meteorologists. For example, armed with data such as current temperature, humidity, and windspeed, users may calculate the heat index or wind chill. Using the resources on this page, and providing basic meteorological data such as temperature, air pressure, and dew point, users can calculate such things as the vapor pressure, maxing ratio, or density altitude. This site also provides unit conversion calculators, allowing users to convert temperatures, air pressures, and wind speeds into various units. For some of the conversions, this site presumes its users to have an understanding of meteorological terms and to be able to read basic meteorological instruments.

1969-12-31

443

Micro Weather Station  

NASA Technical Reports Server (NTRS)

Improved in situ meteorological measurements in the troposphere and stratosphere are needed for studies of weather and climate, both as a primary data source and as validation for remote sensing instruments. Following the initial development and successful flight validation of the surface acoustic wave (SAW) hygrometer, the micro weather stati