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1

Soils as pacemakers and limiters of global silicate weathering  

NASA Astrophysics Data System (ADS)

The weathering and erosion processes that produce and destroy regolith are widely recognized to be positively correlated across diverse landscapes. However, conceptual and numerical models predict some limits to this relationship that remain largely untested. Using new global data compilations of soil production and weathering rates from cosmogenic nuclides and silicate weathering fluxes from global rivers, we show that the weathering-erosion relationship is capped by certain 'speed limits'. We estimate a soil production speed limit of between 320 to 450 t km-2 yr-1 and the associated weathering rate speed limit of roughly 150 t km-2 yr-1. These limits appear to be valid for a range of lithologies, and also extend to mountain belts, where soil cover is not continuous and erosion rates outpace soil production. We argue that the presence of soil and regolith is a requirement for high weathering fluxes from a landscape, and that rapidly eroding, active mountain belts are not the most efficient sites for weathering.

Dixon, Jean L.; von Blanckenburg, Friedhelm

2012-11-01

2

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.

Hilley, George E.; Porder, Stephen

2008-01-01

3

Global silicate weathering and CO 2 consumption rates deduced from the chemistry of large rivers  

Microsoft Academic Search

The main problem associated with the study of silicate weathering using river dissolved load is that the main control of solute chemistry is lithology and that all rivers are influenced by carbonate and evaporite weathering. In this paper, newly compiled data on the 60 largest rivers of the world are used to calculate the contribution of main lithologies, rain and

J. Gaillardet; B. Dupré; P. Louvat; C. J. Allègre

1999-01-01

4

Tectonic and climatic controls on silicate weathering  

Microsoft Academic Search

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

A. Joshua West; Albert Galy; Mike Bickle

2005-01-01

5

Natural Weathering Rates of Silicate Minerals  

Microsoft Academic Search

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 \\

A. F. White

2003-01-01

6

The geoengineering potential of artificially enhanced silicate weathering of olivine  

Microsoft Academic Search

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,

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

2010-01-01

7

Controlling The Global Weather  

Microsoft Academic Search

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

Ross N. Hoffman

2002-01-01

8

Direct effects of CO 2 and temperature on silicate weathering: Possible implications for climate control  

Microsoft Academic Search

A critical uncertainty in models of the global carbon cycle and climate is the combined effect of organic activity, temperature, and atmospheric CO 2 on silicate weathering. Here we present new dissolution rates of anorthite and augite which indicate that silicate weathering in organic-rich solutions is not directly affected by soil CO 2 but is very sensitive to temperature. Apparently

Patrick V. Brady; Susan A. Carroll

1994-01-01

9

Effects of temperature on silicate weathering: Solute fluxes and chemical weathering in a temperate rain forest watershed, Jamieson Creek, British Columbia  

Microsoft Academic Search

Chemical weathering of silicate minerals has long been known as a sink for atmospheric CO2, and feedbacks between weathering and climate are believed to affect global climate. While warmer temperatures are believed to increase rates of weathering, weathering in cool climates can be accelerated by increased mineral exposure due to mechanical weathering by ice. In this study, chemical weathering of

Benjamin F. Turner; Art F. White; Susan L. Brantley

2010-01-01

10

Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions?  

Microsoft Academic Search

CO2-consumption by chemical weathering of silicates and resulting silicate\\/carbonate weathering ratios influences the terrestrial lateral inorganic carbon flux to the ocean and long-term climate changes. However, little is known of the spatial extension of highly active weathering regions and their proportion of global CO2-consumption. As those regions may be of significant importance for global climate change, global CO2-consumption is calculated

Jens Hartmann; Nils Jansen; Hans H. Dürr; Stephan Kempe; Peter Köhler

2010-01-01

11

Global CO 2-consumption by chemical weathering: What is the contribution of highly active weathering regions?  

Microsoft Academic Search

CO2-consumption by chemical weathering of silicates and resulting silicate\\/carbonate weathering ratios influences long-term climate changes. However, little is known of the spatial extension of highly active weathering regions and their proportion of global CO2-consumption. As those regions may be of significant importance for global climate change, global CO2-consumption is calculated here at high resolution, to adequately represent them. In previous

Jens Hartmann; Nils Jansen; Hans H. Dürr; Stephan Kempe; Peter Köhler

2009-01-01

12

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

13

Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering, Reverse Weathering and Seawater Chemistry  

NASA Astrophysics Data System (ADS)

Weathering of continental rocks consumes CO2 and modulates cation fluxes to the ocean, playing a critical role in controlling both long-term seawater chemistry and climate. There are few archives of seawater chemistry that reveal shifts in global tectonic forces that connect Earth-Ocean-Climate processes. We present the first high-resolution 68 Myr record of Li isotopes in seawater (?7LiSW) reconstructed from planktonic forams. From the mid Paleocene (60Ma) to Holocene, ?7LiSW rose 9%, requiring large changes in continental weathering and seafloor reverse weathering fluxes. This scenario is consistent with increased tectonic uplift, more rapid continental denudation, increasingly incongruent continental weathering (lower weathering intensity), decreased dissolved-Li flux and rapid CO2 drawdown. The ?7LiSW today (31.0%, ?Li~1.5 Ma) reflects a balance between inputs of river dissolved Li (?7LiRiv~23%) and hydrothermal Li (?7LiHT~8.4%) and large fractionation (?SW-SED -15%) during removal of LiSW into marine authigenic clays (?7LiSED~16%). Thus a geologic record of ?7LiSW change, unlike 87/86SrSW, is sensitive to the large Li-isotope fractionation factors and to changes in silicate sources and sinks. ?7LiSW today is heavier than either upper continental crust (?7LiUCC =1.7%) or oceanic basalts (?7LiBasalt =3.4%) due to 6Li enrichment in the secondary clays formed during chemical weathering and to preferential 6Li-uptake during seafloor reverse weathering - the "push-me pull-you" systematics of ?7LiSW balance. The stepped increases in ?7LiSW accumulating to 9% over 60 Ma are coincident with major tectonic uplifts, large igneous province (LIP) eruptions, and global climate cooling events. With increased mountain building and changes in continental silicate weathering regimes over the Cenozoic, the isotopic signature of ?7LiRiv increased from 2% to 23%, and the dissolved Li river flux fell by 50%. This scenario requires that the total silicate-derived cation river flux to the ocean (dissolved plus clay-bound) increased, so that the uplift- and weathering-driven cooling of the climate shifted the global weathering pattern from transport limited to weathering limited, increasing secondary clay mineral formation. As a result of preferential retention of 6Li by secondary clays, ?7LiRiv became heavier, driving ?7LiSW to its current heavy value.

Misra, S.; Froelich, P. N.

2011-12-01

14

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.

15

Direct effects of CO[sub 2] and temperature on silicate weathering: Possible implications for climate control  

SciTech Connect

A critical uncertainty in models of the global carbon cycle and climate is the combined effect of organic activity, temperature, and atmospheric CO[sub 2] on silicate weathering. Here the authors present new dissolution rates of anorthite and augite which indicate that silicate weathering in organic-rich solutions is not directly affected by soil CO[sub 2] but is very sensitive to temperature. Apparently CO[sub 2] accelerates silicate weathering indirectly by fertilizing organic activity and the production of corrosive organic acids. The weathering dependencies highlight the ability of silicate weathering to act as a global thermostat and damp out climate change, when used as input in steady-state carbon cycle and climate models.

Brady, P.V. (Sandia National Laboratories, Albuquerque, NM (United States)); Carroll, S.A. (Lawrence Livermore National Lab., CA (United States))

1994-04-01

16

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.

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

2010-01-01

17

Direct measurement of the combined effects of lichen, rainfall, and temperature on silicate weathering  

SciTech Connect

A key uncertainty in models of the global carbonate-silicate cycle and long-term climate is the way that silicates weather under different climatologic conditions, and in the presence or absence of organic activity. Digital imaging of basalts in Hawaii resolves the coupling between temperature, rainfall, and weathering in the presence and absence of lichens. Activation energies for abiotic dissolution of plagioclase (23.1 {+-} 2.5 kcal/mol) and olivine (21.3 {+-} 2.7 kcal/mol) are similar to those measured in the laboratory, and are roughly double those measured from samples taken underneath lichen. Abiotic weathering rates appear to be proportional to rainfall. Dissolution of plagioclase and olivine underneath lichen is far more sensitive to rainfall.

Brady, P.V.; Dorn, R.I.; Brazel, A.J.; Clark, J.; Moore, R.B.; Glidewell, T.

1999-10-01

18

Coupling spatial geochemical and lithological information to distinguish silicate and non-silicate chemical weathering fluxes  

Microsoft Academic Search

Lithological maps have been proved to be a useful tool to evaluate regional and global matter fluxes from chemical weathering. However, lithological classes provide aggregated information of mineralogical, geochemical, sedimentary or diagenetic properties. Thus, using a limited number of lithological classes introduces by their definition a bias to the analysis of weathering fluxes, specifically in the case of multilithological catchments.

Jens Hartmann; Nils Moosdorf

2011-01-01

19

Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions?  

NASA Astrophysics Data System (ADS)

CO2-consumption by chemical weathering of silicates and resulting silicate/carbonate weathering ratios influences the terrestrial lateral inorganic carbon flux to the ocean and long-term climate changes. However, little is known of the spatial extension of highly active weathering regions and their proportion of global CO2-consumption. As those regions may be of significant importance for global climate change, global CO2-consumption is calculated here at high resolution, to adequately represent them. In previous studies global CO2-consumption is estimated using two different approaches: i) a reverse approach based on hydrochemical fluxes from large rivers and ii) a forward approach applying spatially explicit a function for CO2-consumption. The first approach results in an estimate without providing a spatial resolution for highly active regions and the second approach applied six lithological classes while including three sediment classes (shale, sandstone and carbonate rock) based at a 1° or 2° grid resolution. It remained uncertain, if the applied lithological classification schemes represent adequately CO2-consumption from sediments on a global scale (as well as liberation of other elements like phosphorus or silicon by chemical weatheirng). This is due to the large variability of sediment properties, their diagenetic history and the contribution from carbonates apparent in silicate dominated lithological classes. To address these issues, a CO2-consumption model, trained at high-resolution data, is applied here to a global vector based lithological map with 15 lithological classes. The calibration data were obtained from areas representing a wide range of weathering rates. Resulting global CO2-consumption by chemical weathering is similar to earlier estimates (237 Mt C a-1) but the proportion of silicate weathering is 63%, and thus larger than previous estimates (49 to 60%). The application of the enhanced lithological classification scheme reveals that it is important to distinguish among the various types of sedimentary rocks and their diagenetic history to evaluate the spatial distribution of rock weathering and thus lateral inorganic carbon fluxes. Results highlight the role of hotspots (>10 times global average weathering rates) and hyperactive areas (5 to 10 times global average rates). Only 9% of the global exorheic area is responsible for about 50% of CO2- consumption by chemical weathering (or if hotspots and hyperactive areas are considered: 3.4% of exorheic surface area corresponds to 28% of global CO2-consumption). The contribution of endorheic areas to the global CO2-consumption is with 3.7 Mt C a-1 only minor. A significant impact on the global CO2-consumption rate can be expected if identified highly active areas are affected by changes in the overall spatial patterns of the hydrological cycle due to ongoing global climate change. Specifically if comparing the Last Glacial Maximum with present conditions it is probable that also the global carbon cycle has been affected by those changes. It is expected that results will contribute to improve global carbon and global circulation models. In addition, recognizing chemical weathering rates and geochemical composition of certain lithological classes may be of value for studies focusing on biological aspects of the carbon cycles (e.g. studies needing information on the abundance of phosphorus or silica in the soil or aquatic system). Reference: Hartmann, J., Kempe, S, Dürr, H.H., Jansen, N. (2009) Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions?. Global and Planetary Change, 69, 185-194. doi:10.1016/j.gloplacha.2009.07.007

Hartmann, Jens; Jansen, Nils; Dürr, Hans H.; Kempe, Stephan; Köhler, Peter

2010-05-01

20

Global CO 2-consumption by chemical weathering: What is the contribution of highly active weathering regions?  

NASA Astrophysics Data System (ADS)

CO 2-consumption by chemical weathering of silicates and resulting silicate/carbonate weathering ratios influences long-term climate changes. However, little is known of the spatial extension of highly active weathering regions and their proportion of global CO 2-consumption. As those regions may be of significant importance for global climate change, global CO 2-consumption is calculated here at high resolution, to adequately represent them. In previous studies global CO 2-consumption is estimated using two different approaches: i) a reverse approach based on hydrochemical fluxes from large rivers and ii) a forward approach applying spatially explicit a function for CO 2-consumption. The first approach results in an estimate without providing a spatial resolution for highly active regions and the second approach applied six lithological classes while including three sediment classes (shale, sandstone and carbonate rock) based at a 1° or 2° grid resolution. It remained uncertain, if the applied lithological classification schemes represent adequately CO 2-consumption from sediments on a global scale. This is due to the large variability of sediment properties, their diagenetic history and the contribution from carbonates apparent in silicate dominated lithological classes. To address these issues, a CO 2-consumption model, trained at high-resolution data, is applied here to a global vector based lithological map with 15 lithological classes. The calibration data were obtained from areas representing a wide range of weathering rates. Resulting global CO 2-consumption by chemical weathering is similar to earlier estimates (237 Mt C a - 1 ) but the proportion of silicate weathering is 63%, and thus larger than previous estimates (49 to 60%). The application of the enhanced lithological classification scheme reveals that it is important to distinguish among the various types of sedimentary rocks and their diagenetic history to evaluate the spatial distribution of rock weathering. Results highlight the role of hotspots (> 10 times global average weathering rates) and hyperactive areas (5 to 10 times global average rates). Only 9% of the global exorheic area is responsible for about 50% of CO 2-consumption by chemical weathering (or if hotspots and hyperactive areas are considered: 3.4% of exorheic surface area corresponds to 28% of global CO 2-consumption). The contribution of endorheic areas to the global CO 2-consumption is with 3.7 Mt C a - 1 only minor. A significant impact on the global CO 2-consumption rate can be expected if identified highly active areas are affected by changes in the overall spatial patterns of the hydrological cycle due to ongoing global climate change. Specifically if comparing the Last Glacial Maximum with present conditions it is probable that also the global carbon cycle has been affected by those changes. It is expected that results will contribute to improve global carbon and global circulation models.

Hartmann, Jens; Jansen, Nils; Dürr, Hans H.; Kempe, Stephan; Köhler, Peter

2009-12-01

21

Global warming, bad weather, insurance losses and the global economy  

SciTech Connect

Global warming causes extremely bad weather in the near term. The impact on the insurance industry is described. Why global warming in the near term causes very bad weather is explained. The continuing trend of very bad weather and the future impact on the insurance industry is explored. How very bad weather can affect the global financial market is explained. Taking a historical view of the development of the modern economy, the authors describe in the near term the impact of global warming on the global economy. The long term impact of global warming on the global economy and the human race is explored. Opportunities presented by global warming are described.

Low, N.C. [UOB Life Assurance Ltd., Singapore (Singapore); Shen, S. [Global Warming International Center, Woodridge, IL (United States)

1996-09-01

22

Value of global weather sensors  

SciTech Connect

Long-range weather predictions have great scientific and economic potential, but require precise global observations. Small balloon transponders could serve as lagrangian trace particles to measure the vector wind, which is the primary input to long-range numerical forecasts. The wind field is difficult to measure; it is at present poorly sampled globally. Distance measuring equipment (DME) triangulation of signals from roughly a million transponders could sample it with sufficient accuracy to support {approximately} two week forecasts. Such forecasts would have great scientific and economic potential which is estimated below. DME uses small, low-power transmitters on each transponder to broadcast short, low-power messages that are detected by several small receivers and forwarded to the ground station for processing of position, velocity, and state information. Thus, the transponder is little more than a balloon with a small radio, which should only weigh a few grams and cost a few dollars.

Canavan, G.H.

1998-12-23

23

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

Microsoft Academic Search

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

M. Kakizawa; A. Yamasaki; Y. Yanagisawa

2001-01-01

24

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

NASA Astrophysics Data System (ADS)

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 geologic timescales. Natural landscapes have been reshaped into agricultural ones to meet food needs for growing world populations. These processes modify soil properties, alter hydrology, affect erosion, and consequently impact water-soil-rock interactions such as chemical weathering. Dissolved silica (DSi), Ca2+, Mg2+, NO3-, and total alkalinity were measured in water samples collected from five small (0.65 to 38.3 ha) gauged watersheds at the North Appalachian Experimental Watershed (NAEW) near Coshocton, Ohio, USA. The sampled watersheds in this unglaciated region include: a forested site (70+ yr stand), mixed agricultural use (corn, forest, pasture), an unimproved pasture, tilled corn, and a recently (<3 yr) converted no-till corn field. The first three watersheds had perennial streams, but the two corn watersheds only produced runoff during storms and snowmelt. For the perennial streams, total discharge was an important control of dissolved silicate transport. Median DSi yields (22.1-30.8 kg ha-1 a-1) were similar to the median of annual averages between 1979-2009 for the much larger Ohio-Tennessee River Basin (25.6 kg ha-1 a-1). Corn watersheds, which only had surface runoff, had substantially lower DSi yields (<5.3 kg ha-1 a-1) than the perennial-flow watersheds. The lack of contributions from Si-enriched groundwater largely explained their much lower DSi yields with respect to sites having baseflow. A significant positive correlation between the molar ratio of (Ca2+ + Mg2)/alkalinity to DSi in the tilled corn and the forested site suggested, however, that silicate minerals weathered as alkalinity was lost via enhanced nitrification resulting from fertilizer additions to the corn watershed and from leaf litter decomposition in the forest. This same relation was observed in the Ohio-Tennessee River Basin where dominant landuse types include both agricultural lands receiving nitrogenous fertilizers and forests. Greater gains in DSi with respect to alkalinity losses in the Ohio-Tennessee River Basin than in the NAEW sites suggested that soils derived from younger Pleistocene glacial-till may yield more DSi relative to nitrogenous fertilizer applications than the older NAEW soils. Because silicate weathering occurs via acids released from nitrification, CO2 consumption estimates based on the assumption that silicate weathers via carbonic-acid alone may be especially over-estimated in fertilized agricultural watersheds with little baseflow (i.e. 67% overestimated in the corn till watershed). CO2 consumption estimates based on silicate weathering may be as much as an average of 8% lower than estimates derived from carbonic acid weathering alone for the Ohio-Tennessee River Basin between 1979-2009.

Fortner, S. K.; Lyons, W. B.; Carey, A. E.; Shipitalo, M. J.; Welch, S. A.; Welch, K. A.

2011-09-01

25

Variation in silicate weathering across the Oligocene-Miocene boundary: evidence from lithium and neodymium isotopes  

NASA Astrophysics Data System (ADS)

Changes in global silicate weathering have a profound effect on the global carbon cycle and Earth's climate on multi-million year timescales. They may also be associated with short-term (<105 yrs) climatic aberrations: for example, temperature anomalies observed across the Oligocene-Miocene (O/M) boundary (~23 Ma) have been linked to changes in silicate rock exposure on Antarctica. To explore this idea further, we present trace element data along with lithium and neodymium isotope data measured in the carbonate tests of O/M-aged planktic foraminifera. These temporal records of the Li and Nd isotopic composition (?7Li and ?Nd) of seawater generated from deep-sea sediment core material (ODP Site 926, Ceara Rise) require large samples of mono-specific foraminifera (~20 mg). Therefore we first assess the geochemical utility of the large, abundant taxa, Dentoglobigerina venezuelana, for the purposes of ?7Li and ?Nd analysis. Three morphotypes of D. venezuelana are defined based on the morphology of the final chamber and aperture architecture. We find that the palaeoecology of these morphotypes based on their Mg/Ca, ?18O, and ?13C compositions is suitably similar to allow them to be grouped for the purpose of generating "sample-hungry" continental weathering records. Because the ?7Li and ?Nd of seawater are influenced by changes in continent-derived fluvial input to the oceans, records of seawater ?7Li and ?Nd have the potential to help constrain past changes in continental weathering. Li isotopes fractionate strongly during weathering processes, with ?7Li values becoming lower as weathering reactions tend towards completion. Nd sourced from ancient continental material typically possesses distinctively unradiogenic compositions (low ?Nd) relative to younger, mantle-derived sources. Finally, local vs. global signals of weathering input can be evaluated through utilisation of the differing oceanic residence times of Li (~1 Myrs) and Nd (~1 kyrs). To this end, we present a 4 Myr isotopic and trace element record for the O/M boundary, and we use these new data to better constrain the links between weathering and climate during this interval of significant climate change.

Stewart, J.; James, R. H.; Wilson, P. A.; Anand, P.; Edgar, K. M.

2011-12-01

26

Lithium isotope history of Cenozoic seawater: changes in silicate weathering and reverse weathering.  

PubMed

Weathering of uplifted continental rocks consumes carbon dioxide and transports cations to the oceans, thereby playing a critical role in controlling both seawater chemistry and climate. However, there are few archives of seawater chemical change that reveal shifts in global tectonic forces connecting Earth ocean-climate processes. We present a 68-million-year record of lithium isotopes in seawater (?(7)Li(SW)) reconstructed from planktonic foraminifera. From the Paleocene (60 million years ago) to the present, ?(7)Li(SW) rose by 9 per mil (‰), requiring large changes in continental weathering and seafloor reverse weathering that are consistent with increased tectonic uplift, more rapid continental denudation, increasingly incongruent continental weathering (lower chemical weathering intensity), and more rapid CO(2) drawdown. A 5‰ drop in ?(7)Li(SW) across the Cretaceous-Paleogene boundary cannot be produced by an impactor or by Deccan trap volcanism, suggesting large-scale continental denudation. PMID:22282473

Misra, Sambuddha; Froelich, Philip N

2012-01-26

27

Uncertainty in silicate mineral weathering rate estimates: source partitioning and policy implications  

NASA Astrophysics Data System (ADS)

Precise and accurate estimates of silicate mineral weathering rates are crucial when setting policy targets for long-term forest sustainability, critical load calculations and assessing consequences of proposed geo-engineering solutions to climate change. In this paper, we scrutinize 394 individual silicate mineral weathering estimates from 82 sites on three continents. We show that within-site differences of several hundred per cent arise when different methods are used to estimate weathering rates, mainly as a result of uncertainties related to input data rather than conceptually different views of the weathering process. While different methods tend to rank sites congruently from high to low weathering rates, large within-site differences in estimated weathering rate suggest that policies relying on quantitative estimates based upon a single method may have undesirable outcomes. We recommend the use of at least three independent estimates when making management decisions related to silicate mineral weathering rates.

Futter, M. N.; Klaminder, J.; Lucas, R. W.; Laudon, H.; Köhler, S. J.

2012-06-01

28

Silicate versus carbonate weathering in the Himalaya: a comparison of the Arun and Seti River watersheds  

Microsoft Academic Search

We studied the water chemistry of two large and geologically differing Himalayan watersheds in order to maximize the contrast between silicate versus carbonate weathering effects on river chemistry. Our previous research involved the Seti River of westernmost Nepal, geologically typical of many rivers in Nepal in draining mixed carbonate\\/silicate lithologies, including abundant carbonate rocks of the Lesser Himalayan Sequence. For

Jay Quade; Nathan English; Peter G DeCelles

2003-01-01

29

Carbonate versus silicate weathering in the Raikhot watershed within the High Himalayan Crystalline Series  

NASA Astrophysics Data System (ADS)

The major element and Sr isotope geochemistry of surface waters, bedrock, and river sands was investigated in the Raikhot watershed within the High Himalayan Crystalline Series (HHCS) in northern Pakistan. Mass-balance calculations of mineral-weathering contributions to the dissolved flux of ions from the watershed indicate that 82% of the HCO3- flux is derived from the weathering of carbonate minerals and only 18% is derived from silicate weathering, even though the bedrock is predominantly quartzofeldspathic gneiss and granite with only ˜1% carbonate in the watershed. This study demonstrates the importance of trace amounts of bedrock carbonate in controlling the water chemistry of glacial watersheds. We suggest that the flux of Sr with a high 87Sr/86Sr ratio in the major Himalayan rivers may be derived in large part from weathering of trace amounts of calcite within the largely silicate HHCS. Models that use the flux of radiogenic Sr from the Himalayas as a proxy for silicate weathering rates may, therefore, overestimate the amount of CO2 consumption due to silicate weathering in the Himalaya.

Blum, Joel D.; Gazis, Carey A.; Jacobson, Andrew D.; Page Chamberlain, C.

1998-05-01

30

Elastic collisions in ion irradiation experiments: A mechanism for space weathering of silicates  

Microsoft Academic Search

Ion irradiation experiments have been performed on silicates (bulk samples) rich of olivine, pyroxene, and serpentine to simulate the effects of space weathering induced on asteroids by solar wind ions. We have used different ions (H+, He+, Ar+, Ar2+) having different energies (from 60 to 400 keV) to weather the samples, probed by Raman spectroscopy and UV–vis–NIR reflectance spectroscopy. All

Rosario Brunetto; Giovanni Strazzulla

2005-01-01

31

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

Microsoft Academic Search

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

Roger G. Burns

1993-01-01

32

Control of Regional and Global Weather  

Microsoft Academic Search

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

Alexander Bolonkin

2007-01-01

33

The effect of land plants on weathering rates of silicate minerals  

Microsoft Academic Search

Land plants and their associated microbiota directly affect silicate mineral weathering in several ways: by generation of chelating ligands, by modifying pH through production of CO 2 or organic acids, and by altering the physical properties of a soil, particularly the exposed surface areas of minerals and the residence time of water. In laboratory experiments far from equilibrium, 1 mM

James I. Drever

1994-01-01

34

Global hydration kinetics of tricalcium silicate cement  

Microsoft Academic Search

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×)psi. For early times t

Frank Tzschichholz; Helene Zanni

2001-01-01

35

Bridging the gap between laboratory measurements and field estimations of silicate weathering using simple calculations  

Microsoft Academic Search

Weathering rates of silicate minerals observed in the laboratory are in general up to five orders of magnitude higher than\\u000a those inferred from field studies. Simple calculations show that even if the field conditions were fully simulated in standard\\u000a laboratory experiments, it would be impossible to measure the slow rates of mineral dissolution that are observed in the field.\\u000a As

Jiwchar Ganor; Peng Lu; Zuoping Zheng; Chen Zhu

2007-01-01

36

Silicate weathering in temperate forest soils: insights from a field experiment  

Microsoft Academic Search

Few studies of silicate mineral weathering have been conducted in carbonate-bearing temperate forest soils. With climate and\\u000a vegetation held constant, we compared soil mineralogy and major element chemistry of soil waters from a carbonate-free temperate\\u000a aspen forest site in the Cheboygan watershed, northern Michigan, with that from carbonate-containing soils from experimental\\u000a tree-growth chambers (low- vs. high- fertility). All soils were

E. L. Williams; L. M. Walter; T. C. W. Ku; K. K. Baptist; J. M. Budai; G. W. Kling

2007-01-01

37

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

38

Silicate weathering mechanisms determined using soil solutions held at high matric potential  

Microsoft Academic Search

We present evidence of surface-controlled and proton-promoted chemical weathering of primary silicates in a brown acidic soil (Vauxrenard, Rhône, France). We used aqueous silica (Si) in soil solutions held at high matric potential (180–1600 kPa), which are representative of solutions reacting with soil solids. Si concentration was well correlated with H+ concentration and to a lesser extent with dissolved organic

F. Gérard; J. Ranger; C. Ménétrier; P. Bonnaud

2003-01-01

39

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

40

Dynamics of natural system hillslope silicate weathering: coupling water transit time with REYs in solution  

NASA Astrophysics Data System (ADS)

Chemical weathering of silicates in the Critical Zone (CZ) breaks down bedrock primary minerals into soil secondary phase minerals. The chemical processes involved in silicate weathering contribute to forming subsurface flowpaths, mobilizing ecosystem sustaining nutrients, impacting stream water quality, buffering landscape acidification, and removing CO2 from the atmosphere. Coupling information about transit times of water through the CZ to fluxes of solutes in surface and soil pore waters can provide insights on chemical weathering dynamics. Larger transit times could allow a system to come closer to a state of equilibrium and thus release higher quantities of weathering derived solutes where shorter transit times might show lower solute concentrations and greater distance from geochemical equilibrium. We tested this hypothesis in the Marshall Gulch catchment of the Santa Catalina Mountains Critical Zone Observatory (SCMCZO) near Tucson, AZ. A fault line runs through the catchment separating schist from granite bedrock hillslopes. Using ?2H and ?18O isotope ratios, a comparison of transit times through schist and granite hillslopes at Marshall Gulch indicated that schist hillslopes have an order of magnitude larger transit time than granite hillslopes (AGU poster presented by Heidelbuchel et. al, 2008). We investigate the correlations between water transit times and chemical weathering patterns in the schist and granite hillslopes of Marshall Gulch via chemical information from surface and soil pore water samples using IC, ICP-MS, and TOC/TN analysis techniques. We incorporate solution fluxes of major and trace elements and constrain primary and secondary silicate mineral phases with rare earth element and yttrium (REY) solution fluxes for a geochemical mass balance model. Schist hillslopes exhibit greater variability in soil pore concentrations than for granite hillslopes for any given sampling day. Major and trace solute concentrations indicate greater weathering product release in the schist hillslopes compared to the granitic hillslopes. Rare earth element ratios of lanthanum to Praseodymium (La/Pr) and lanthanum to Ytterbium (La/Yb) indicate preferential release of La, the lighter rare earth element. Ratios of Yttrium to Holmium (Y/Ho) indicate strong fractionation with preferential release of the lower massed Y to solution. Cerium to Praseodymium (Ce/Pr) ratios indicate a preferential release of Ce for all samples, however is most pronounced for schist surface waters. While some scatter is seen particularly in the schist soil pore waters, Eu/Eu* ratios for all samples are near 0.4 and Gd/Gd* ratios are all close to 1.5. We suggest that concentrations of weathering products in solution indicate greater weathering activity in the schist hillslopes and that weathering patterns change over seasonal timescales and as function of antecedent moisture conditions.

Jardine, A. B.; Troch, P. A.; Chorover, J. D.; Rasmussen, C.; McIntosh, J. C.; Huxman, T. E.

2009-12-01

41

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

42

Silicate weathering rates and solute fluxes along an erosional gradient, Middle Fork of the Feather River, CA  

NASA Astrophysics Data System (ADS)

Over geologic timescales, the weathering of silicate rocks has helped to maintain a mostly habitable planet, and it is clear that understanding rates of chemical weathering is key to accurately interpreting past changes in climate and seawater chemistry. However, the mechanisms that drive changes in weathering rates through time are incompletely described. By more closely examining the interplay between variables which control weathering, including fluid residence time, dissolution kinetics, and thermodynamic constraints, we would like to gain a more detailed understanding of these mechanisms. For example, the rate of mineral dissolution is controlled by the flux of water, the availability of fresh mineral surfaces and the proximity to thermodynamic equilibrium between the dissolving and secondary phases-once the soil or ground water reaches equilibrium, increasing mineral availability would not result in an increase in solute flux. Thus, the residence time of water and the departure from thermodynamic equilibrium are anticipated to be important controls on weathering fluxes. To gain a better understanding of the relative importance of these variables, we have studied the chemical and physical composition of solids and waters from three soil-mantled hillslope transects with different erosion rates within a tributary basin of the Middle Fork Feather River, CA. Overall, lower water contents are found in areas with higher erosion rates, and at the high erosion rate transect the solute compositions suggest that water is mostly bypassing the saprolite layer. In the solute chemistry, there is a clear trend of increasing concentration with depth for non-biologically cycled weathering components (Na, Si, etc). Other elements, such as Ca, Mg, K and Al show elevated concentrations in the surface horizons due to strong biological cycling. Calculated mineral saturation indices show that deeper waters are saturated with respect to K-feldspar and kaolinite, and slightly undersaturated with respect to albite. In general, the solute concentrations at the base of the soil profiles are similar across the three different erosion rates, indicating that the waters have reacted to a similar extent on all three transects despite widely varying moisture content, infiltration fluxes, steepness, grain size and clay content in the soils. Total chemical denudation rates (based on solute fluxes) vary across the transects according to water fluxes. This detailed study of hillslopes with different erosion rates suggests that thermodynamic equilibrium, water residence time and water flux are likely important controls on global weathering rates, even in active tectonic environments.

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

2011-12-01

43

Silicate mineral weathering rate estimates: Are they precise enough to be useful when predicting the recovery of nutrient pools after harvesting?  

Microsoft Academic Search

Are current estimates of silicate minerals weathering rates precise enough to predict whether nutrient pools will recover after forest harvesting? Answering this question seems crucial for sustainable forestry practices on silicate dominated soils. In this paper, we synthesize estimated Ca and K weathering rates (derived using seven different approaches) from a forested area in northern Sweden (the Svartberget–Krycklan catchment) to

J. Klaminder; R. W. Lucas; M. N. Futter; K. H. Bishop; S. J. Köhler; G. Egnell; H. Laudon

2011-01-01

44

Isolation and characterization of silicate mineral-solubilizing Bacillus globisporus Q12 from the surfaces of weathered feldspar.  

PubMed

A silicate mineral-solubilizing bacterial strain Q12 was isolated from the surfaces of weathered feldspar and identified as Bacillus globisporus Q12 based on the 16S rDNA gene sequence analysis. Three silicate minerals (feldspar, muscovite, and biotite) were used to investigate potassium and silicon mobilization by strain Q12. In liquid cultures, the strain showed better growth on the biotite than on feldspar and muscovite. The biotite was the best potassium source for growth of the strain. Solubilization of potassium and silicon from the silicate minerals by the strain resulted mostly from the action of organic acids. Gluconic acid seemed to be the most active agent for the solubilization of the 3 silicate minerals. Gluconic and acetic acids were likely involved in the solubilization of feldspar. The strain could be acid or alkali and salt tolerant and temperature resistant. PMID:19096461

Sheng, Xia Fang; Zhao, Fei; He, Lin Yan; Qiu, Gang; Chen, Liang

2008-12-01

45

X-ray photoelectron studies of the mechanism of iron silicate dissolution during weathering  

NASA Astrophysics Data System (ADS)

Iron silicate minerals (bronzite, fayalite), exposed to aqueous dissolution in the laboratory for up to 60 days at room temperature and pH 1, 1.5, and 6, have been studied for evidence of changes in surface composition, using XPS, and these results compared with those obtained from solution chemical analysis. In the absence of dissolved O 2 or at low pH (1-1.5) dissolution proceeds congruently after the initial formation of a thin (<10 Å) protonated surface layer depleted in Fe relative to Si. This layer is unstable and does not grow with time as attested to by long term congruent dissolution and by the formation of an amorphous silica surficial breakdown product at pH 1 and 1.5. In bronzite the layer is also slightly depleted in Mg but much less than it is in Fe due to the preferential occupation by Fe +2 of more weakly bonded M 2 sites. The behavior of the layer is similar to that found earlier on iron-free pyroxene ( et al. , 1981); in other words, because of its thinness and instability it is not diffusion-inhibiting or protective toward dissolution. In the presence of dissolved O 2 , as would be the case in most weathering solutions, dissolution of bronzite and fayalite results in the formation of two surface layers whose compositions were deduced by measurements of XPS binding energies. The outer layer, consisting of hydrous ferric oxide, is readily removed by ultrasonic cleaning and, most likely, is not protective toward dissolution. The inner layer consists of Fe +3 in a protonated or hydroxylated silicate (Mg-silicate in the case of bronzite) matrix. This layer appears to impede dissolution over the time scale of the experiment as attested to by parabolic dissolution rates. However, the layer does not continue to grow on the time scale of weathering because ultrasonically cleaned soil grains ( and , 1982) exhibit surface compositions similar to those found in the present month-long laboratory experiments. In other words, a thick , highly altered, diffusion-inhibiting, protective surface layer does not form at the acidic pH of most soils.

Schott, Jacques; Berner, Robert A.

1983-12-01

46

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

47

Parameterisation of a global daily weather generator for terrestrial ecosystem modelling  

Microsoft Academic Search

Many global ecological models require globally-gridded daily weather data, but such data are not directly available from the current global network of weather stations. A method is described whereby a stochastic daily weather generator is parameterised to operate at the half-degree scale for the earth's terrestrial surface. The weather generator simulates 24 h shortwave irradiance, precipitation, maximum and minimum temperatures,

A. D Friend

1998-01-01

48

Weather  

NSDL National Science Digital Library

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

Lai, Ms.

2007-02-08

49

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

50

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

51

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

PubMed

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

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

2012-02-19

52

Boron and Lithium isotopic signatures in rivers as proxies of silicate weathering regimes : the example of the Mackenzie river system, Canada (Invited)  

NASA Astrophysics Data System (ADS)

Large river systems integrate the diversity of weathering and transport conditions as well as the bedrock composition. They provide a unique opportunity to unravel the parameters operating within the critical zone of the Earth globally. Here, we present B and Li isotopes data measured in both the complementary soluble and suspended phases in the Mackenzie river (Northeastern Canada), one of the world largest river the Mackenzie river basin. An interesting parallel can be made between these two isotopic systems: - Both elements are predominantly derived from the weathering of silicate minerals and are thus relatively less affected by lithology. - Both elements are considerably fractionated during water/rock interactions during which they partition between the solid and liquid phases. Their respective geochemical signature is then strongly dependent upon geomorphic features of the Basin (mountains, plains, shield area). - Both isotopic systems are greatly fractionated by a preferential release in solution of the heavy isotope, which considerably help investigating the nature and magnitude of the weathering and transport processes in action. - And finally, strong evidences indicate that local groundwaters may control their transfer through the basin and imprint their isotopic signature as well. Because, boron and lithium have very different chemical behaviors, in particular distinct surface properties, their respective isotopes behave distinctly under same reactive transport conditions. This feature results in the absence of correlation between this two isotopic systems despite their apparent similarities. Then the coupled investigation of the Li and B isotopes during chemical weathering adds strong constraints on the weathering regimes operating at large scale and clearly encourages the multi-isotopic tracing of the critical zone processes.

Gaillardet, J.; Millot, R.; Lemarchand, D.; Vigier, N.

2009-12-01

53

Long-term stability of global erosion rates and weathering during late-Cenozoic cooling  

Microsoft Academic Search

Over geologic timescales, CO2 is emitted from the Earth's interior and is removed from the atmosphere by silicate rock weathering and organic carbon burial. This balance is thought to have stabilized greenhouse conditions within a range that ensured habitable conditions. Changes in this balance have been attributed to changes in topographic relief, where varying rates of continental rock weathering and

Jane K. Willenbring; Friedhelm von Blanckenburg

2010-01-01

54

Can global warming make Indian monsoon weather less predictable?  

NASA Astrophysics Data System (ADS)

Reliable medium range prediction of monsoon weather is crucial for disaster preparedness. Weather in tropics, controlled by fast growing convective instabilities is, however, intrinsically less predictable than that in extra-tropics. Increased frequency and intensity of extreme rain events in the tropics in the backdrop of global warming has a potential for further decreasing the potential predictability of the tropical weather. Using nonlinear dynamical techniques on gridded daily rainfall data over India for 104 years (1901-2004), here we show that the deterministic predictability of monsoon weather over central India in the latest quarter of the period has indeed decreased significantly compared to that in the earlier three quarters. The decrease of initial error doubling time from approximately 3.0 days to 1.5 days is consistent with higher frequency of extreme events and increased potential instability of the atmosphere in the recent quarter. To overcome the increased difficulty in predicting monsoon weather, significant increase in efforts to improve models, observations and enhancement of computing power would be required.

Mani, Neena Joseph; Suhas, E.; Goswami, B. N.

2009-04-01

55

Effects of paleogeology, chemical weathering, and climate on the global geochemical cycle of carbon dioxide  

SciTech Connect

A new method of geologic reconstruction has been developed that determines areas of exposure for each epoch of the Phanerozoic. The paleogeologic maps reveal that the relative proportions of exposed rock types show few abrupt changes through Phanerozoic time, compared to the secular changes in areal extent of rock deposition. Chemical weathering of silicate minerals acts as a long-term transfer of CO{sub 2} from the atmosphere to carbonate sediments via river runoff. Thus, the roles of silicate and non-silicate rocks must be differentiated. Chemical records of streams draining monolithologic basins confirm that the relative weathering susceptibility of lithologies clearly favors carbonate over silicate rocks; surprisingly, among the silicates (clastic and igneous) there is no significant distinction. A survey of basalt catchments shows no correlation between temperature and weathering. Although a warm, wet climate promotes mineral weathering, this may be countered over time by soil shielding of bedrock-groundwater interactions. Mean annual runoff rates are 60% higher at {minus}100 my (using 4x current CO{sub 2}) from CCM simulations but, since Cretaceous land area is 30% smaller, total runoff changes very little. However, in a spatially distributed model of the Earth the annual bicarbonate flux of the Cretaceous (4x CO{sub 2}) is 59 {times} 10{sup 12}eq, compared to 39 {times} 10{sup 12}eq for the present-day. Net HCO{sub 3}{sup {minus}} flux from silicate weathering is 25% higher in the Cretaceous, because the distribution of silicate exposures coincides with regions of intense runoff. Thus, by adding spatial dimensions of runoff and geology to preexisting models, the balance of CO{sub 2} levels by silicate dissolution can be achieved without severe changes in either atmospheric chemistry or rock proportions.

Bluth, G.J.S.

1990-01-01

56

Negligible glacial-interglacial variation in continental chemical weathering rates  

Microsoft Academic Search

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

Gavin L. Foster; Derek Vance

2006-01-01

57

Building resilience of the Global Positioning System to space weather  

NASA Astrophysics Data System (ADS)

Almost every aspect of the global economy now depends on GPS. Worldwide, nations are working to create a robust Global Navigation Satellite System (GNSS), which will provide global positioning, navigation, and timing (PNT) services for applications such as aviation, electric power distribution, financial exchange, maritime navigation, and emergency management. The U.S. government is examining the vulnerabilities of GPS, and it is well known that space weather events, such as geomagnetic storms, contribute to errors in single-frequency GPS and are a significant factor for differential GPS. The GPS industry has lately begun to recognize that total electron content (TEC) signal delays, ionospheric scintillation, and solar radio bursts can also interfere with daily operations and that these threats grow with the approach of the next solar maximum, expected to occur in 2013. The key challenges raised by these circumstances are, first, to better understand the vulnerability of GPS technologies and services to space weather and, second, to develop policies that will build resilience and mitigate risk.

Fisher, Genene; Kunches, Joseph

2011-12-01

58

Weather and climate analyses using improved global water vapor observations  

NASA Astrophysics Data System (ADS)

The NASA Water Vapor Project (NVAP) dataset is a global (land and ocean) water vapor dataset created by merging multiple sources of atmospheric water vapor to form a global data base of total and layered precipitable water vapor. Under the NASA Making Earth Science Data Records for Research Environments (MEaSUREs) program, NVAP is being reprocessed and extended, increasing its 14-year coverage to include 22 years of data. The NVAP-MEaSUREs (NVAP-M) dataset is geared towards varied user needs, and biases in the original dataset caused by algorithm and input changes were removed. This is accomplished by relying on peer reviewed algorithms and producing the data in multiple “streams” to create products geared towards studies of both climate and weather. We briefly discuss the need for reprocessing and extension, steps taken to improve the product, and provide some early science results highlighting the improvements and potential scientific uses of NVAP-M.

Vonder Haar, Thomas H.; Bytheway, Janice L.; Forsythe, John M.

2012-08-01

59

Weather  

NSDL National Science Digital Library

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

Hyde, Mrs.

2007-02-08

60

Weather  

NSDL National Science Digital Library

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

Bullough, Ms.

2010-06-24

61

Weather  

NSDL National Science Digital Library

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

Stearns, Ms.

2008-10-25

62

Weather  

NSDL National Science Digital Library

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

Williams, Ms.

2005-10-25

63

Chemical denudation and silicate weathering in Himalayan glacier basins: Batura Glacier, Pakistan  

Microsoft Academic Search

The major ion, SiO2 and minor element contents of Batura Glacier meltwaters in the headwaters of the Indus Basin, Pakistan are examined. The data are used to examine the controls upon solute acquisition by runoff and to estimate solute yields. Solute yield calculations include estimation of the total and silicate-derived cationic denudation rates following the application of simple solute provenance

Andy Hodson; Phil Porter; Andy Lowe; Paul Mumford

2002-01-01

64

Behavior of Boron Isotopes During Chemical Weathering: a Global Approach  

NASA Astrophysics Data System (ADS)

Boron has two isotopes (10B and 11B) that fractionate largely during Earth surface processes. The major fractionating step takes place during low temperature water-rock interactions. Up to 20-30 \\permil difference in ? 11B units are shown to occur during the adsorption of boron onto surfaces or its precipitation into solids. Light boron has a much greater affinity for neoformed solids while the residual solution is enriched in heavy boron. For example, seawater has a boron isotopic composition of 40 \\permil, mainly due to the preferential removal of 10B during oceanic seafloor weathering, adsorption onto fluvial sediments and chemical weathering reactions occurring in soils. The high sensitivity of boron isotopes fractionation to water rock interactions make it a valuable tool to constrain chemical weathering processes. To have a global picture of the behavior of boron isotopes during chemical weathering of rocks at the surface of the continents, we analyzed the largest rivers for both the dissolved and suspended load. Dissolved boron isotopic compositions were published earlier ([Lemarchand et al., 2000]) and we here focus on the results for the suspended load and for the bottom sands. Boron clearly appears as a mobile element when its abundance in suspended sediments is normalized to upper continental material. Boron depletion in suspended solids is climate dependent, with higher depletion is warm climates. On average, more than 50 % of boron is transported to the ocean in a solid form. While the dissolved load of boron is clearly enriched in 11B (0 \\permil) with respect to the mean upper continental crust (-10 \\permil), isotopic composition of the suspended load of major rivers does not differ significantly from that of the continental crust. This result indicates that suspended material is not significantly fractionated with respect to the continental crust by chemical weathering processes or that the mass budget of boron partitioning between solids and water does not allow the residual solids to be significantly different from bedrock. This is supported by a Rayleigh distillation model. Our boron data, both in concentration and isotopic composition, give strong support to the idea that shale erosion is a major source of suspended sediments in large river system, making thus boron isotopes a good tracer of intra-continental recycling. Lemarchand et al., 2000, Nature, vol 408, pp 951-954.

Gaillardet, J.; Chetelat, B.

2004-12-01

65

Effects of paleogeology, chemical weathering, and climate on the global geochemical cycle of carbon dioxide  

Microsoft Academic Search

A new method of geologic reconstruction has been developed that determines areas of exposure for each epoch of the Phanerozoic. The paleogeologic maps reveal that the relative proportions of exposed rock types show few abrupt changes through Phanerozoic time, compared to the secular changes in areal extent of rock deposition. Chemical weathering of silicate minerals acts as a long-term transfer

Bluth; G. J. S

1990-01-01

66

Weathering  

NSDL National Science Digital Library

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

Gore, Pamela

1995-08-29

67

Weather  

NSDL National Science Digital Library

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

Tuttle, Rachelle

2005-10-25

68

Meteorological Parameters Derived from Space-Based Observing Systems, During the Global Weather Experiment and After.  

National Technical Information Service (NTIS)

Global coverage by geostationary and polar orbiting meteorological satellites during the Global Weather Experiment (GWE) for data collection from in situ platforms and remote sensing of the atmosphere and the earth's surface is reviewed. Quantitative data...

D. S. Johnson

1986-01-01

69

The reserve of weatherable primary silicates impacts the accumulation of biogenic silicon in volcanic ash soils  

Microsoft Academic Search

Banana plantlets (Musa acuminata cv Grande Naine) cultivated in hydroponics take up silicon proportionally to the concentration of Si in the nutrient solution\\u000a (0–1.66 mM Si). Here we study the Si status of banana plantlets grown under controlled greenhouse conditions on five soils\\u000a developed from andesitic volcanic ash, but differing in weathering stage. The mineralogical composition of soils was inferred\\u000a from

C. Henriet; N. De Jaeger; M. Dorel; S. Opfergelt; B. Delvaux

2008-01-01

70

Constraints on the Global-scale Chemical Weathering State of Mars From TES Results Based on Spectral Analysis of Chemically Weathered Basalts  

Microsoft Academic Search

On Earth, subaerially exposed basaltic rocks (from arid-to-tropical regions) develop weathering rinds and rock coatings that affect spectroscopic measurements of their natural surfaces. Similarly, basaltic rocks and basaltic soil particles on Mars may have rinds and coatings that are spectroscopically observable. Thermal emission spectroscopy, because it provides information about the composition and structure of silicate and non-silicate minerals and mineraloids,

J. R. Michalski; M. D. Kraft; T. G. Sharp; P. R. Christensen

2005-01-01

71

Weather.  

ERIC Educational Resources Information Center

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

Ruth, Amy, Ed.

1996-01-01

72

Weather  

NSDL National Science Digital Library

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

73

Seafloor weathering controls on atmospheric CO 2 and global climate  

Microsoft Academic Search

Alteration of surficial marine basalts at low temperatures (<40°C) is a potentially important sink for atmospheric CO2 over geologic time. Petrologic analyses, thermodynamic calculations, and experimental weathering results point to extensive Ca leaching and consumption of marine CO2 during alteration. Basalt weathering in seawater-like solutions is sensitive to temperature. The activation energy for initial basalt weathering in seawater is 41–65

Patrick V. Brady; Sigurdur R. Gíslason

1997-01-01

74

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

75

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

76

Reduction of forecast error for global numerical weather prediction by The Florida State University (FSU) Superensemble  

Microsoft Academic Search

The skill of the FSU Superensemble technique as applied to global numerical weather prediction is evaluated extensively in this paper. The global mass and motion fields for year 2000 and precipitation over the domain 55 S to 55 N for year 2001, as predicted by the Superensemble, the ensemble member models, and the mean of the ensemble members, are evaluated

R. S. Ross; T. N. Krishnamurti

2005-01-01

77

Reduction of forecast error for global numerical weather prediction by The Florida State University (FSU) Superensemble  

Microsoft Academic Search

Summary The skill of the FSU Superensemble technique as applied to global numerical weather prediction is evaluated extensively in this paper. The global mass and motion fields for year 2000 and precipitation over the domain 55?S to 55?N for year 2001, as predicted by the Superensemble, the ensemble member models, and the mean of the ensemble members, are evaluated by

R. S. Ross; T. N. Krishnamurti

2005-01-01

78

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

79

Terrestrial ecosystems and the global biogeochemical silica cycle  

Microsoft Academic Search

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

Daniel J. Conley

2002-01-01

80

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

Microsoft Academic Search

Reinforced concrete (RC) structures are subjected to environmental actions affecting their performance, serviceability and safety. Among these actions, chloride ingress leads to corrosion and has been recognized as a critical factor reducing service life of RC structures. This paper presents a stochastic approach to study the influence of weather conditions and global warming on chloride ingress into concrete. The assessment

E. Bastidas-Arteaga; A. Chateauneuf; M. Sánchez-Silva; Ph. Bressolette; F. Schoefs

2010-01-01

81

High Impact Weather Events in the Transition Seasons: Linked to Global Change?  

NASA Astrophysics Data System (ADS)

For over a decade the author has been involved in a call-in radio show concerning climate and weather issues. From among several common themes visited frequently in the context of the show is the question of whether or not a recent high impact weather event is (or is not) directly related to global warming/climate change. A plausible physical connection between global change and high impact, mid-latitude weather events in the transition seasons is suggested. The mechanism centers on an elevation of the subtropical tropopause that occurs either as a result of direct in-situ latent heating or as a result of outflow from upstream, organized tropical convection. When the subtropical tropopause is raised in proximity to the polar jet, an anomalously deep tropopause fold is steepened rapidly leading to an intensification of the juxtaposed subtropical and polar jet streams. The resulting "superjet" is shown to underlie a number of high impact, continental cyclones over a 50 year census. Several notable convective outbreaks also appear to originate from similar "superjets" including the deadly Tuscaloosa tornado outbreak of April 2011. It is suggested that the transition seasons are preferred times of year for such jet interactions and that the length of the transition seasons, so defined, may be extended in a warmer climate thus leading to a larger number of high impact, transition season weather events in the future.

Martin, J. E.

2011-12-01

82

Space Weather Activities at SERC for IHY: (1) Local Education, (2) Global Outreach and (3) Data Base Service (P61)  

Microsoft Academic Search

arnoldyuki@serc.kyushu-u.ac.jp The Space Environment Research Center (SERC), Kyushu University (KU), conducts everyday space weather ``now casting''. There are two main goals in this effort: (1) to train and educate KU students about the complexities of the Sun-Earth system so that they can become space weather forecasters in the future, (2) to globally disseminate space weather information from SERC as a

K. Yumoto

2006-01-01

83

Death and Death Rates Due to Extreme Weather Events: Global and U.S. Trends, 1900-2004  

Microsoft Academic Search

Despite the recent spate of deadly extreme weather events such as the 2003 European heat wave and the hurricanes of 2004 and 2005, aggregate mortality and mortality rates due to extreme weather events are generally lower today than they used to be. Globally, mortality and mortality rates have declined by 95 percent or more since the 1920s. The largest improvements

Indur M. Goklany

84

Pathways of calcrete development on weathered silicate rocks in Tamil Nadu, India: Mineralogy, chemistry and paleoenvironmental implications  

NASA Astrophysics Data System (ADS)

Poorly documented yet spectacularly thick and extensive outcrops of calcrete hardpan occur on gneiss in the semiarid region of Coimbatore, South India. The hardpan caps a series of residual plateaux forming the present-day continental divide and grades into large expanses of Vertisols. Characteristic calcrete and Vertisol profiles were logged along toposequences and sampled for macro- and micromorphological study, and for chemical and mineralogical composition. Strontium isotopic analyses revealed that the calcrete is derived from in situ weathering of Ca-bearing primary minerals of the saprolite, which is rich in ankerite, Ca-amphiboles and Ca-plagioclase. The macroscale analysis revealed a range of facies developed within the gneiss saprolite, but in terms of relative chronology the nodular hardpan has the longest history. Two evolutionary pathways leading to nodular hardpan formation have been established. The first occurs entirely within a vadose environment, whereas the second begins within a phreatic environment before continuing to develop in vadose conditions. The ability to identify and map these generic categories of calcrete constitutes a potential tool for reconstructing paleotopography and paleogroundwater levels. The bedrock-weathering-derived nodular hardpan is blanketed by a laminar facies that correlates with an eolian event with marine Sr signatures. This suggests influx of Ca dust from the Arabian Sea continental shelf during a Pleistocene sea-level low-stand. It defines an important benchmark in the chronology of the area and highlights the potential antiquity of the thick calcrete profiles.

Durand, N.; Gunnell, Y.; Curmi, P.; Ahmad, S. M.

2006-11-01

85

Developments of the Seamless Global-Regional Climate-Weather Model at NOAA/GFDL  

NASA Astrophysics Data System (ADS)

A "seamless" global-regional weather-climate modeling system is being developed at NOAA/Geophysical Fluid Dynamics Laboratory (GFDL). It will be built as a unified modeling system for all spatial and temporal scales of meteorological importance. The ultimate goal is to enable "cumulus parameterization-free" climate simulations at the global cloud resolving resolution (5-km or finer). The foundation of this unified modeling system is a non-hydrostatic extension of the "vertically Lagrangian" finite-volume dynamical core (Lin 2004) constructed on a general curvilinear coordinate system that can be of global or regional coverage with self- consistent nesting and adaptive mesh refinement capability. The self-consistent nesting/mesh refinement capability will be needed for climate change and tropical cyclone intensification studies before the computing capability permits true global cloud resolving. For the model to be able to "seamlessly" bridging the gap between "weather and climate", "regional and global" models, a flexible and efficient griding system on the sphere is a prerequisite. The current choice for the global grid is the quasi-uniform "Cubed Sphere". The primary focus of this talk will be on the algorithmic issues related to the development of the above and the followings: A domain flexible "dynamical core" using various cubed sphere grids (conformal, Gnomonic, and the hybrids). An important question to be answered is "which grid is best for what applications?" Hydrostatic and (optionally) non-hydrostatic dynamics with a terrain-following Lagrangian coordinate system. The novel feature here is the development of an "exact Riemann solver" to treat the vertically propagating sound waves without the CFL condition restriction. We have built a prototype of the seamless model that will be first tested in NOAA/GFDL's next coupled modeling system for climate change (IPCC5) at the very low end of the resolution (roughly at 200 km). Preliminary results will be shown if available.

Lin, S.

2006-12-01

86

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

PubMed

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. PMID:23010871

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

2012-07-19

87

Rare Earth Element Behavior During Incongruent Weathering and Varying Discharge Conditions in Silicate Dominated River Systems: The Australian Victorian Alps  

NASA Astrophysics Data System (ADS)

The distribution of rare earth elements (REE) and trace elements was measured by ICP-MS on fresh, slightly weathered and weathered granite and surface water samples from a network of 11 pristine rivers draining the Australian Victorian Alps during (i) high and (ii) low discharge conditions. River water REE concentrations are largely derived from atmospheric precipitation (rain, snow), as indicated by similar Chondrite normalized REE patterns (higher LREE over HREE; negative Ce anomalies, positive Eu anomalies) and similar total REE concentrations during both dry and wet seasons. Calculations based on the covariance between REE and Cl concentrations and oxygen and hydrogen isotopes indicate precipitation input coupled with subsequent evaporation may account for 30% o 100% of dissolved REE in stream waters. The dissolved contribution to the granitic substratum to stream water comes mainly from the transformation of plagioclase to smectite, kaolinite and gibbsite and minor apatite dissolution. However, since most REE of the regional granite are present in accessory minerals (titanite, zircon, etc.) they do not significantly contribute to the river REE pool. REE concentrations drop sharply downstream as a result of dilution and chemical attenuation. A trend of downstream enrichment of the heavier REE is due to selective partitioning of the lighter REE (as both free REE or REECO3 complexes) to hydrous oxides of suspended Al which, in turn, is controlled by a downstream increase of pH to values > 6.1 (for free REE) and > 7.3 (for REECO3 complexes). Although most circumneutral waters were supersaturated with REE phosphate compounds, precipitation of LnPO4 is not believed to have been a dominant process because the predicted phosphate fractionation pattern is inconsistent with the observed trends. Negative saturation indices of hydrous ferric oxides also militate against surface complexation onto goethite. Instead, REE attenuation most likely resulted from adsorption onto hydrous aluminium oxide. Seasonally, higher total REE concentrations during the dry season are due to longer residence time of water within rock fractures as well as high rainfall REE concentrations which, for the summer of 2007, might be related to organic carbon rich dust released after bushfires in the region. Lower pH values and low oxidation potentials at that time also contribute to raise REE concentrations through desorption.

Hagedorn, K. B.; Cartwright, I.

2008-12-01

88

Chemical weathering rates of a soil chronosequence on granitic alluvium: I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates  

USGS Publications Warehouse

Mineral weathering rates are determined for a series of soils ranging in age from 0.2-3000 Ky developed on alluvial terraces near Merced in the Central Valley of California. Mineralogical and elemental abundances exhibit time-dependent trends documenting the chemical evolution of granitic sand to residual kaolinite and quartz. Mineral losses with time occur in the order: hornblende > plagioclase > K-feldspar. Maximum volume decreases of >50% occur in the older soils. BET surface areas of the bulk soils increase with age, as do specific surface areas of aluminosilicate mineral fractions such as plagioclase, which increases from 0.4-1.5 m2 g-1 over 600 Ky. Quartz surface areas are lower and change less with time (0.11-0.23 m2 g-1). BET surface areas correspond to increasing external surface roughness (?? = 10-600) and relatively constant internal surface area (??? 1.3 m2 g-1). SEM observations confirm both surface pitting and development of internal porosity. A numerical model describes aluminosilicate dissolution rates as a function of changes in residual mineral abundance, grain size distributions, and mineral surface areas with time. A simple geometric treatment, assuming spherical grains and no surface roughness, predicts average dissolution rates (plagioclase, 10-17.4; K-feldspar, 10-17.8; and hornblende, 10-17.5 mol cm-1 s-1) that are constant with time and comparable to previous estimates of soil weathering. Average rates, based on BET surface area measurements and variable surface roughnesses, are much slower (plagioclase, 10-19.9; K-feldspar, 10-20.5; and hornblende 10-20.1 mol cm-2 s-1). Rates for individual soil horizons decrease by a factor of 101.5 over 3000 Ky indicating that the surface reactivities of minerals decrease as the physical surface areas increase. Rate constants based on BET estimates for the Merced soils are factors of 103-104 slower than reported experimental dissolution rates determined from freshly prepared silicates with low surface roughness (?? <10). This study demonstrates that the utility of experimental rate constants to predict weathering in soils is limited without consideration of variable surface areas and processes that control the evolution of surface reactivity with time.

White, A. F.; Blum, A. E.; Schulz, M. S.; Bullen, T. D.; Harden, J. W.; Peterson, M. L.

1996-01-01

89

The Irrotational and Rotational Kinetic Energy Balance in Isentropic Coordinates during the Global Weather Experiment Boreal Winter  

Microsoft Academic Search

Analysis of the irrotational and rotational kinetic energy balance employing isentropic transport equations was conducted for the Global Weather Experiment boreal winter (December 1978 to February 1979) using ECMWF Main IIIb data. The purpose of this research was to investigate the relation between the global distribution of heat sources and sinks, thermally forced isentropic mass circulations, and the maintenance of

Steven Richard Silberberg

1991-01-01

90

Recovery of Global Surface Weather Observations for Historical Reanalyses and International Users  

NASA Astrophysics Data System (ADS)

Third International Atmospheric Circulation Reconstructions Over the Earth Initiative Workshop: Reanalysis and Applications; Baltimore, Maryland, 3-5 November 2010 ; The third Atmospheric Circulation Reconstructions over the Earth (ACRE) workshop advanced the goals of the international ACRE initiative (http://www.met-acre.org/) to undertake and facilitate the recovery of instrumental terrestrial and marine global surface weather observations underpinning global weather reconstructions and reanalyses spanning the past 200-250 years (http://reanalyses.org). The workshop improved integration of the 35-40 ACRE-linked international scientific projects, institutions, and organizations working toward these ends. The meeting highlighted the broad array and international usage of ACRE-facilitated data sets and reanalysis: the International Surface Pressure Databank (ISPD; http://dss.ucar.edu/datasets/ds132.0/), the International Comprehensive Ocean-Atmosphere Data Set (http:/icoads.noaa.gov/ICOADS;), and the 20th Century Reanalysis (20CR; http://www.esrl.noaa.gov/psd/data/20thC_Rean/). The need for more data recovery for all regions of the globe during the nineteenth and early twentieth centuries was emphasized. Many regional efforts for such recovery are under way. The Arctic and maritime regions were highlighted as particular areas needing attention. As a result of the meeting, connections with existing projects were made and new efforts were started to address these needs.

Allan, Rob; Compo, Gil; Carton, Jim

2011-05-01

91

Antarctic Weather  

NSDL National Science Digital Library

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

92

Development of an integrated chemical weather prediction system for environmental applications at meso to global scales: NMMB\\/BSC-CHEM  

Microsoft Academic Search

This contribution presents the ongoing developments of a new fully on-line chemical weather prediction system for meso to global scale applications. The modeling system consists of a mineral dust module and a gas-phase chemistry module coupled on-line to a unified global-regional atmospheric driver. This approach allows solving small scale processes and their interactions at local to global scales. Its unified

O. Jorba; C. Pérez; K. Karsten; Z. Janjic; D. Dabdub; J. M. Baldasano

2009-01-01

93

Basalt weathering across scales  

NASA Astrophysics Data System (ADS)

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

Navarre-Sitchler, Alexis; Brantley, Susan

2007-09-01

94

Evaluating a system of systems approach for integrated global weather, climate, and hazard monitoring  

NASA Astrophysics Data System (ADS)

Northrop Grumman Corporation (NGC) provides systems and technologies to ensure national security based on technologies - from undersea to outer space, and in cyberspace. With a heritage of developing and integrating science instruments on space platforms and airborne systems, NGC is conducting analysis of alternatives for a global observing system that integrates data collected from geostationary and polar-orbiting satellites with Unmanned Aerial System (UAS) platforms. This enhanced acquisition of environmental data will feed decision support systems such as the TouchTable ® to deliver improved decision making capabilities. Rapidly fusing and displaying multiple types of weather and ocean observations, imagery, and environmental data with geospatial data to create an integrated source of information for end users such as emergency managers and planners will deliver innovative solutions to improve disaster warning, mitigate disaster impacts, and reduce the loss of life and property. We present analysis of alternatives of combinations of sensor platforms that integrate space and airborne systems with ground and ocean observing sensors and form the basis for vertically integrated global observing systems with the capacity to improve measurements associated with hazard and climate-related uncertainties. The analyses include candidate sensors deployed on various configurations of satellites that include NPOESS, GOES R, and future configurations, augmented by UAS vehicles including Global Hawk, configured to deliver innovative environmental data collection capabilities over a range of environmental conditions, including severe hazards, such as hurricanes and extreme wildland fires. Resulting approaches are evaluated based on metrics that include their technical feasibility, capacity to be integrated with evolving Earth science models and relevant decision support tools, and life cycle costs.

Birk, Ronald; Baldauf, Brian; Ohlemacher, Rick; Andreoli, Leo

2008-08-01

95

High Temperature, Nanoscale Changes in Films Produced by Irradiation of Iron Bearing Silicates: Laboratory Simulations of Space Weathering in Hermean Environment  

NASA Astrophysics Data System (ADS)

Thin film on a silicon substrate was deposited by Ar-ion irradiation of the San Carlos olivine. This silicate film contains nanoinclusions of Fe, Cu, and Ni that increased in size when heated to 450°, relevant to Mercury.

Rout, S. S.; Stockhoff, T.; Moroz, L. V.; Hofsäss, H.; Dohmen, R.; Zhang, K.; Baither, D.; Schade, U.; Bischoff, A.; Hiesinger, H.

2012-03-01

96

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

2005-06-16

97

Impact of the Himalayan Orogeny on Global Climate  

NASA Astrophysics Data System (ADS)

The hypothesis that orogeny and the consequent uplift and erosion of continental crust cause global cooling by changing the feedback between temperature and silicate chemical weathering rate is longstanding but unresolved. Testing this hypothesis is frustrated by the difficulty of distinguishing the contributions of carbonate and silicate sources to riverine chemical fluxes and evaluating the long-term riverine chemical fluxes and their past variability. Interpretation of possible proxies for continental silicate weathering fluxes (e.g. Sr, Os, Li, Ca isotopic ratios) is complicated by variability in their source compositions and fractionations of the light stable isotopes. Potential CO2 degassing by decarbonation reactions during collisional orogens further complicates prediction of their climatic consequences. Calculation of the silicate-derived fluxes in the major rivers draining the Himalayas and Tibet implies that this region currently contributes between 16 and 33 of the global silicate weathering flux from 4.5 % of land area. Silicates are weathering at a factor of 3 to 10 faster in the Himalayan-Tibetan region than average continental crust. The impact of this increase in "weatherability" of the continental crust on global climate depends on climate sensitivity to atmospheric CO2, a much debated parameter. However this simple interpretation of global climate change over the Cenozoic is complicated by the seawater Sr-isotope curve which has been interpreted to imply a net increase in solid-earth CO2 degassing since 40 Ma. We have re-evaluated the relative inputs of radiogenic carbonate elevated in 87Sr/86Sr and silicates to Himalayan rivers by modelling time-series inputs to the rivers and analysing bedload carbonate and silicate minerals. We have also measured the chemical and isotopic fluxes carried by the Irrawaddy and Salween rivers and recalculated the impacts of silicate- and carbonate-derived Sr from the Himalayan-Tibetan orogen on oceanic 87Sr/86Sr ratios.

Bickle, M. J.

2011-12-01

98

Impact of nitrogenous fertilizers on carbonate dissolution in small agricultural catchments: Implications for weathering CO 2 uptake at regional and global scales  

NASA Astrophysics Data System (ADS)

The goal of this study was to highlight the occurrence of an additional proton-promoted weathering pathway of carbonate rocks in agricultural areas where N-fertilizers are extensively spread, and to estimate its consequences on riverine alkalinity and uptake of CO 2 by weathering. We surveyed 25 small streams in the calcareous molassic Gascogne area located in the Garonne river basin (south-western France) that drain cultivated or forested catchments for their major element compositions during different hydrologic periods. Among these catchments, the Hay and the Montoussé, two experimental catchments, were monitored on a weekly basis. Studies in the literature from other small carbonate catchments in Europe were dissected in the same way. In areas of intensive agriculture, the molar ratio (Ca + Mg)/HCO 3 in surface waters is significantly higher (0.7 on average) than in areas of low anthropogenic pressure (0.5). This corresponds to a decrease in riverine alkalinity, which can reach 80% during storm events. This relative loss of alkalinity correlates well with the NO3- content in surface waters. In cultivated areas, the contribution of atmospheric/soil CO 2 to the total riverine alkalinity (CO 2 ATM-SOIL/HCO 3) is less than 50% (expected value for carbonate basins), and it decreases when the nitrate concentration increases. This loss of alkalinity can be attributed to the substitution of carbonic acid (natural weathering pathway) by protons produced by nitrification of N-fertilizers (anthropogenic weathering pathway) occurring in soils during carbonate dissolution. As a consequence of these processes, the alkalinity over the last 30 years shows a decreasing trend in the Save river (one of the main Garonne river tributaries, draining an agricultural catchment), while the nitrate and calcium plus magnesium contents are increasing. We estimated that the contribution of atmospheric/soil CO 2 to riverine alkalinity decreased by about 7-17% on average for all the studied catchments. Using these values, the deficit of CO 2 uptake can be estimated as up to 0.22-0.53 and 12-29 Tg yr -1 CO 2 on a country scale (France) and a global scale, respectively. These losses represent up to 5.7-13.4% and only 1.6-3.8% of the total CO 2 flux naturally consumed by carbonate dissolution, for France and on a global scale, respectively. Nevertheless, this loss of alkalinity relative to the Ca + Mg content relates to carbonate weathering by protons from N-fertilizers nitrification, which is a net source of CO 2 for the atmosphere. This anthropogenic CO 2 source is not negligible since it could reach 6-15% of CO 2 uptake by natural silicate weathering and could consequently partly counterbalance this natural CO 2 sink. 1 Tg of carbon = 10 12 g of C = 0.083 10 12 mol of C.

Perrin, Anne-Sophie; Probst, Anne; Probst, Jean-Luc

2008-07-01

99

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

100

Weather One  

NSDL National Science Digital Library

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

Friend, Duane

101

Chemical weathering of silicate rocks in Aldan Shield and Baikal Uplift: insights from long-term seasonal measurements of solute fluxes in rivers  

Microsoft Academic Search

A reassessment of available information from the Russian Hydrological Survey on long-term seasonal measurements of water, suspended matter and dissolved major element discharges in ?30 small and large watersheds draining acid silicate rocks (granites, gneisses, quartzites, shales) of the Aldan Shield and Baikal Uplift was combined with new data on river water chemistry for three granitic watersheds in order to

E. A. Zakharova; O. S. Pokrovsky; B. Dupré; M. B. Zaslavskaya

2005-01-01

102

Global near-realtime monitoring of Tropical Cyclones Using Weather Satellites  

NASA Astrophysics Data System (ADS)

The Naval Research Laboratory maintains a satellite web portal that monitors global tropical cyclones in every basin on a continuing basis. The portal is used routinely by agencies around the world in forecasting operations and the issuance of warnings. Products from this site are widely redistributed and published frequently in journal articles, seasonal storm summaries, and ongoing World Wide Web discussions. Traditionally, weather satellite reconnaissance of tropical cyclones has depended on the interpretation of visible and infrared imagery. But such methods have limitations. Visible images are not available during the nighttime, and both kinds of imagery often fail to detect important structure, including storm eyes, which are vital for determining the strength and location of tropical systems. Thus, the portal supplements visible and infrared coverage with products from satellite microwave sensors. These sensors penetrate higher clouds to reveal important detail about low-level cloud and precipitation features. The first part of the talk will discuss how these various products can be used together for improved analysis. The second part of talk will present information about tropical cyclone structure. Surface winds from aircraft will be compared to features seen in passive microwave images. We see that low brightness temperature features on 85 GHz images often corresponding to wind maxima near the sea surface. We shall make some inferences about how the observation of specific structures in satellite images can help characterize the wind field when no aircraft data are available. Special attention will be paid to multiple eye walls apparent on satellite images. These are associated with very intense storms which undergo an evolutionary process not observed in weaker systems.

Lee, T.; Hawkins, J.; Turk, F.; Miller, S.; Sampson, C.; Kuciauskas, A.; Richardson, K.; Kent, J.

2006-12-01

103

Magnesium Silicate  

Microsoft Academic Search

A comprehensive profile of magnesium silicate with 80 references is reported. A full description including nomenclature, formulae, and appearance is included. Methods for magnesium silicate preparation including precipitation, hydrothermal precipitation, and mechanochemical dehydration are reviewed. Physical characteristics, compendia and non-compendia analytical methods, uses, stability and incompatibilities, biodegradability, toxicity, and substances related to magnesium silicate are also discussed.

Iyad Rashid; Nidal H. Daraghmeh; Mahmoud M. Al Omari; Babur Z. Chowdhry; Stephen A. Leharne; Hamdallah A. Hodali; Adnan A. Badwan

2011-01-01

104

Magnesium silicate.  

PubMed

A comprehensive profile of magnesium silicate with 80 references is reported. A full description including nomenclature, formulae, and appearance is included. Methods for magnesium silicate preparation including precipitation, hydrothermal precipitation, and mechanochemical dehydration are reviewed. Physical characteristics, compendia and non-compendia analytical methods, uses, stability and incompatibilities, biodegradability, toxicity, and substances related to magnesium silicate are also discussed. PMID:22469264

Rashid, Iyad; Daraghmeh, Nidal H; Al Omari, Mahmoud M; Chowdhry, Babur Z; Leharne, Stephen A; Hodali, Hamdallah A; Badwan, Adnan A

2011-06-23

105

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

106

Four-dimensional ensemble-variational data assimilation for global deterministic weather prediction  

NASA Astrophysics Data System (ADS)

The goal of this study is to evaluate a version of the ensemble-variational data assimilation approach (EnVar) for possible replacement of 4D-Var at Environment Canada for global deterministic weather prediction. This implementation of EnVar relies on 4-D ensemble covariances, obtained from an ensemble Kalman filter, that are combined in a vertically dependent weighted average with simple static covariances. Verification results are presented from a set of data assimilation experiments over two separate 6-week periods that used assimilated observations and model configuration very similar to the currently operational system. To help interpret the comparison of EnVar versus 4D-Var, additional experiments using 3D-Var and a version of EnVar with only 3-D ensemble covariances are also evaluated. To improve the rate of convergence for all approaches evaluated (including EnVar), an estimate of the cost function Hessian generated by the quasi-Newton minimization algorithm is cycled from one analysis to the next. Analyses from EnVar (with 4-D ensemble covariances) nearly always produce improved, and never degraded, forecasts when compared with 3D-Var. Comparisons with 4D-Var show that forecasts from EnVar analyses have either similar or better scores in the troposphere of the tropics and the winter extra-tropical region. However, in the summer extra-tropical region the medium-range forecasts from EnVar have either similar or worse scores than 4D-Var in the troposphere. In contrast, the 6 h forecasts from EnVar are significantly better than 4D-Var relative to radiosonde observations for both periods and in all regions. The use of 4-D versus 3-D ensemble covariances only results in small improvements in forecast quality. By contrast, the improvements from using 4D-Var versus 3D-Var are much larger. Measurement of the fit of the background and analyzed states to the observations suggests that EnVar and 4D-Var can both make better use of observations distributed over time than 3D-Var. In summary, the results from this study suggest that the EnVar approach is a viable alternative to 4D-Var, especially when the simplicity and computational efficiency of EnVar are considered. Additional research is required to understand the seasonal dependence of the difference in forecast quality between EnVar and 4D-Var in the extra-tropics.

Buehner, M.; Morneau, J.; Charette, C.

2013-09-01

107

Severe Space Weather Events: Global Geospace Responses to Powerful Solar Wind Drivers (Invited)  

NASA Astrophysics Data System (ADS)

Recent international space science programs have made a concerted effort to study activity on the Sun, the propagation of energy bursts from the Sun to near-Earth space, energy coupling into the magnetosphere, and its redistribution and deposition in the upper and middle atmosphere. Extreme solar, geomagnetic and solar wind conditions can be observed by a large international array of satellites and ground-based sensors. We discuss the types of space weather-related problems that have been identified in recent times and consider examples of space weather-induced spacecraft (and ground-based) anomalies and failures that affect both civilian and military systems. Special attention will be given to delineating the specific kinds of geospace responses that occur for different transient solar wind drivers. In this context, we discuss near-term plans to consolidate and integrate understanding as an important component of the community effort to propose technical and operational solutions to space weather problems. I will focus on new scientific advancement that is needed for successful space weather programs and will describe actions that can help assure a good future integrated space weather program.

Baker, D.

2009-12-01

108

GEM-AQ/EC, an on-line global multi-scale chemical weather modelling system: model development and evaluation of global aerosol climatology  

NASA Astrophysics Data System (ADS)

A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model - GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module) with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995-2004. The model was run for ten years from from 1995-2004 with re-analyzed meteorology on a global uniform 1° × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

Gong, S. L.; Lavoué, D.; Zhao, T. L.; Huang, P.; Kaminski, J. W.

2012-09-01

109

GEM-AQ/EC, an on-line global multiscale chemical weather modelling system: model development and evaluations of global aerosol climatology  

NASA Astrophysics Data System (ADS)

A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model - GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module) with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995-2004. The model was run for ten years from from 1995-2004 with re-analyzed meteorology on a global uniform 1 × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

Gong, S. L.; Lavoue, D.; Zhao, T. L.; Huang, P.; Kaminski, J. W.

2012-04-01

110

Formulation and results from ensemble forecasting using Multimodels for Hurricanes, Global Weather and Seasonal Climate  

Microsoft Academic Search

This paper carries a short review of a multimodel\\/multianalysis superensemble for weather and seasonal climate forecasts. This model was first developed by the authors in 1999 at Florida State University. This entails a large number of forecasts using these multimodels from past data sets, that is called a training phase of the superensemble. During this training phase statistical relation among

T. N. Krishnamurthi

2006-01-01

111

Research Review: Walter Orr Roberts on the Atmosphere, Global Pollution and Weather Modification  

ERIC Educational Resources Information Center

|Global Atmospheric Research Program is envisaged to study various aspects of the environment for the whole globe. Describes programs undertaken and the international problems involved in implementing results of such research on a global level. (PS)|

Jacobsen, Sally

1973-01-01

112

Developing a Global, Short-Term Fire Weather Forecasting Tool Using NWP Input Meteorology and Satellite Fire Data  

NASA Astrophysics Data System (ADS)

In order to meet the emerging need for better estimates of biomass burning emissions in air quality and climate models, a statistical model is developed to characterize the effect of a given set of meteorological conditions on the following day's fire activity, including ignition and spread potential. Preliminary tests are conducted within several spatial domains of the North American boreal forest by investigating a wide range of meteorological information, including operational fire weather forecasting indices, such as the Canadian Forest Fire Danger Rating System (CFFDRS). However, rather than using local noon surface station data, the six components of the CFFDRS are modified to use inputs from the North America Regional Reanalysis (NARR) and the Navy's Operational Global Atmospheric Prediction System Model (NOGAPS). The Initial Spread Index (ISI) and the Fire Weather Index (FWI) are shown to be the most relevant components of the CFFDRS for short-term changes in fire activity. However, both components are found to be highly sensitive to variations in relative humidity and wind speed input data. Several variables related to fire ignition from dry lighting, such as instability and the synoptic pattern, are also incorporated. Cases of fire ignition, growth, decay, and extinction are stratified using satellite fire observations from the Geostationary Operational Environmental Satellites (GOES) and the MODerate Resolution Imaging Spectroradiometer (MODIS) and compared to the available suite of meteorological information. These comparisons reveal that combinations of meteorological variables, such as the FWI, ISI, and additional indices developed for this study, produce the greatest separability between major fire growth and decay cases, which are defined by the observed change in fire counts and fire radiative power. This information is used to derive statistical relationships affecting the short-term changes in fire activity and subsequently applied to other spatial domains across North America, with the ultimate goal of producing a global, short-term fire weather forecasting tool.

Peterson, D. A.; Hyer, E. J.; Wang, J.

2011-12-01

113

Dynamic global patterns of nitrate, phosphate, silicate, and iron availability and phytoplankton community composition from remote sensing data  

Microsoft Academic Search

Satellites routinely provide frequent, large-scale, near-surface views of many oceanographic variables pertinent to plankton ecology, but nutrient fertility remains problematic. A recently derived set of nitrate (N), phosphate (P), and silicate (S) nutrient depletion temperatures (NDT) were subtracted from AVHRR-derived sea surface temperatures for March 1999 through June 2000 to determine eight categories of temporally varying N, P, and S

Daniel Kamykowski; Sara-Joan Zentara; John M. Morrison; Anne C. Switzer

2002-01-01

114

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 Fsil is 3.83 ± 0.12 × 105 mol/km2/a (upper limit), which is comparable with the Himalayan rivers at upper reaches. For carbonate weathering (Fcarb) 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 Fsil is 3.24 × 1005 mol/km2/a and Fcarb 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

115

THE POTENTIAL OF GLOBAL POSITIONING SYSTEM IN WEATHER AND ENVIRONMENTAL STUDIES  

Microsoft Academic Search

Malaysia is witnessing a rapid growth in the vicinity of urban cities with the construction of large engineering structures (e.g. towers, factories, high-rise condominiums, wide-span bridges and highways) to meet the requirement for the nation's economic growth, societal activities and the aspirations of its population. These manmade structures are, however, subject to deformation and structural displacement caused by severe weather

Mohd Hafiz Yahya; Samsung Lim; Chris Rizos

116

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

117

The global relocatable regional weather prediction model of the German Military Geophysical Office  

NASA Astrophysics Data System (ADS)

A regional numerical weather prediction system, consisting of an analysis scheme, a forecast model and a variety of interpretation, visualization and military application tools, named ‘BLM’ has been routinely operating at the German Military Geophysical Office (GMGO) since 1984. At that time, the grid domain was confined to Central Europe and parts of the North Atlantic, where a polar stereographic map projection was appropriate. Owing to increasing user demands, the system had to be made relocatable to provide numerical forecasts at any location of the globe. The relocatable version, called ‘RBL’, is still formulated on a stereographic plane, which is now defined using a rotated geographical system with an artificial north pole right in the middle of the domain. This approach is well known. However, most of the current numerical weather prediction systems are defined on a horizontal latitude-longitude grid, so that the equator in rotated coordinates runs through the centre of the forecast area. The main advantages of the horizontal coordinate transformation used by the ‘RBL’ are numerical stability for a large and economical time step, which enables the model to be run on a computer with limited power, and an invariant map factor all over the globe, which eases the interpretation of the model results for different locations.

Prenosil, Thomas; Amtmann, Richard; Derichs, Heinz

1999-06-01

118

Watching the World's Weather  

NASA Astrophysics Data System (ADS)

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

Burroughs, William James

1991-04-01

119

An assessment of European synoptic variability in Hadley Centre Global Environmental models based on an objective classification of weather regimes  

NASA Astrophysics Data System (ADS)

The frequency of occurrence of persistent synoptic-scale weather patterns over the European and North-East Atlantic regions is examined in a hierarchy of climate model simulations and compared to observational re-analysed data. A new objective method, employing pattern correlation techniques, has been constructed for classifying daily-mean mean-sea-level pressure and 500 hPa geopotential height fields with respect to a set of 29 European weather regime types, based on the widely known subjective Grosswetterlagen (GWL) system of the German Weather Service. The objective method is described and applied initially to ERA40 and NCEP re-analysis data. While the resulting daily Objective-GWL catalogue shows some systematic differences with respect to the subjectively-derived original GWL series, the method is shown to be sufficiently robust for application to climate model output. Ensemble runs from the most recent development of the Hadley Centre’s Global Environmental model, HadGEM1, in atmosphere-only, coupled and climate change scenario modes are analysed with regards to European synoptic variability. All simulations successfully exhibit a wide spread of GWL occurrences across all regime types, but some systematic differences in mean GWL frequencies are seen in spite of significant levels of interdecadal variability. These differences provide a basis for estimating local anomalies of surface temperature and precipitation over Europe, which would result from circulation changes alone, in each climate simulation. Comparison to observational re-analyses shows a clear and significant improvement in the simulation of realistic European synoptic variability with the development and resolution of the atmosphere-only models.

James, P. M.

2006-08-01

120

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

Microsoft Academic Search

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

E. R. Kursinski; G. A. Hajj

2000-01-01

121

Effects of climate on chemical weathering in watersheds  

USGS Publications Warehouse

Climatic effects on chemical weathering are evaluated by correlating variations in solute concentrations and fluxes with temperature, precipitation, runoff, and evapotranspiration (ET) for a worldwide distribution of sixty-eight watersheds underlain by granitoid rock types. Stream solute concentrations are strongly correlated with proportional ET loss, and evaporative concentration makes stream solute concentrations an inapprorpiate surrogate for chemical weathering. Chemical fluxes are unaffected by ET, and SiO2 and Na weathering fluxes exhibit systematic increases with precipitation, runoff, and temperature. However, warm and wet watersheds produce anomalously rapid weathering rates. A proposed model that provides an improved prediction of weathering rates over climatic extremes is the product of linear precipitation and Arrhenius temperature functions. The resulting apparent activation energies based on SiO2 and Na fluxes are 59.4 and 62.5 kJ.mol-1, respectively. The coupling between temperature and precipitation emphasizes the importance of tropical regions in global silicate weathering fluxes, and suggests it is not representative to use continental averages for temperature and precipitation in the weathering rate functions of global carbon cycling and climatic change models. Fluxes of K, Ca, and Mg exhibit no climatic correlation, implying that other processes, such as ion exchange, nutrient cycling, and variations in lithology, obscure any climatic signal. -from Authors

White, A. F.; Blum, A. E.

1995-01-01

122

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

Microsoft Academic Search

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

Harold Brooks

2008-01-01

123

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

124

Parallel, Adaptive-Mesh-Refinement MHD for Global Space-Weather Simulations  

Microsoft Academic Search

The first part of this paper reviews some issues representing major computational challenges for global MHD models of the space environment. These issues include mathematical formulation and discretization of the governing equations that ensure the proper jump conditions and propagation speeds, regions of relativistic Alfve´n speed, and controlling the divergence of the magnetic field. The second part of the paper

Kenneth G. Powell; Tamas I. Gombosi; Darren L. De Zeeuw; Aaron J. Ridley; Igor V. Sokolov; Quentin F. Stout; Ga´bor To´th

2003-01-01

125

Parallel, Adaptive-Mesh-Refinement MHD for Global Space-Weather Simulations  

Microsoft Academic Search

The first part of this paper reviews some issues representing major computational challenges for global MHD models of the space environment. These issues include mathematical formulation and discretization of the governing equations that ensure the proper jump conditions and propagation speeds, regions of relativistic Alfvén speed, and controlling the divergence of the magnetic field. The second part of the paper

Kenneth G. Powell; Tamas I. Gombosi; Darren L. de Zeeuw; Aaron J. Ridley; Igor V. Sokolov; Quentin F. Stout; Gábor Tóth

2003-01-01

126

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

127

Variational Assimilation of TMI Rain Type and Precipitation Retrievals into Global Numerical Weather Prediction  

Microsoft Academic Search

A One-dimensional Variational Method (1DVAR) was developed in the present study for the assimilation of convective and stratiform rain flags, and precipitation retrieved from TMI into a Japan Meteorological Agency (JMA) global NWP system. In order to simplify the observational operators of the 1DVAR, it was assumed that the rain flags (precipitation) were functions of total water content (divergence) alone.

Kazumasa AONASHI; Nobuo YAMAZAKI; Hirotaka KAMAHORI; Kiyotoshi TAKAHASHI; Fahua LIU; Kazuo YOSHIDA

2004-01-01

128

Thermal Expansion Calculation of Silicate Glasses at 210°C, Based on the Systematic Analysis of Global Databases  

SciTech Connect

Thermal expansion data for more than 5500 compositions of silicate glasses were analyzed statistically. These data were gathered from the scientific literature, summarized in SciGlass© 6.5, a new version of the well known glass property database and information system. The analysis resulted in a data reduction from 5500 glasses to a core of 900, where the majority of the published values is located within commercial glass composition ranges and obtained over the temperature range 20 to 500°C. A multiple regression model for the linear thermal expansivity at 210°C, including error formula and detailed application limits, was developed based on those 900 core data from over 100 publications. The accuracy of the model predictions is improved about twice compared to previous work because systematic errors from certain laboratories were investigated and corrected. The standard model error (precision) was 0.37 ppm/K, with R² = 0.985. The 95% confidence interval for individual predictions largely depends on the glass composition of interest and the composition uncertainty. The model is valid for commercial silicate glasses containing Na2O, CaO, Al2O3, K2O, MgO, B2O3, Li2O, BaO, ZrO2, TiO2, ZnO, PbO, SrO, Fe2O3, CeO2, fining agents, and coloring and de-coloring components. In addition, a special model for ultra-low expansion glasses in the system SiO2-TiO2 is presented. The calculations allow optimizing the time-temperature cooling schedule of glassware, the development of glass sealing materials, and the design of specialty glass products that are exposed to varying temperatures.

Fluegel, Alex

2010-10-01

129

Weather Girl Goes Rogue  

NSDL National Science Digital Library

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

Ram, Deep R.; Technologies, Institute F.

130

Direct measurement of the combined effects of lichen, rainfall, and temperature onsilicate weathering  

USGS Publications Warehouse

A key uncertainty in models of the global carbonate-silicate cycle and long-term climate is the way that silicates weather under different climatologic conditions, and in the presence or absence of organic activity. Digital imaging of basalts in Hawaii resolves the coupling between temperature, rainfall, and weathering in the presence and absence of lichens. Activation energies for abiotic dissolution of plagioclase (23.1 ?? 2.5 kcal/mol) and olivine (21.3 ?? 2.7 kcal/mol) are similar to those measured in the laboratory, and are roughly double those measured from samples taken underneath lichen. Abiotic weathering rates appear to be proportional to rainfall. Dissolution of plagioclase and olivine underneath lichen is far more sensitive to rainfall.

Brady, P. V.; Dorn, R. I.; Brazel, A. J.; Clark, J.; Moore, R. B.; Glidewell, T.

1999-01-01

131

Formulation and results from ensemble forecasting using Multimodels for Hurricanes, Global Weather and Seasonal Climate  

NASA Astrophysics Data System (ADS)

This paper carries a short review of a multimodel/multianalysis superensemble for weather and seasonal climate forecasts. This model was first developed by the authors in 1999 at Florida State University. This entails a large number of forecasts using these multimodels from past data sets, that is called a training phase of the superensemble. During this training phase statistical relation among the model forecasts and the observed fields is obtained using multiple regression methods. This training phase requires roughly 4 months of past daily forecasts for numerical weather prediction (NWP), approximately 6 years of past seasonal forecast and about 60 past hurricane/typhoon/tropical cyclone forecasts from each of the participating member models. The training phase is followed by a forecast phase where the member model forecasts (into the future) use the aforementioned statistics to construct multimodel superensemble forecasts. Our focus on NWP has been to examine the performance of the multimodel superensemble forecast against those of the member models, their ensemble mean and the bias removed ensemble means. We have noted an invariable much superior performance of the multimodel superensemble. We have noted that roughly a minimal number of 7 to 8 models are needed to carry out this exercise. We were also able to improve the database and the statistics of the training phase by rejecting poorer forecast days and optimizing the number of training days. The common metrics for forecast evaluation include root mean square error, anomaly correlation and equitable threat scores. Great impact on real time and experimental forecasts from the superensemble were noted for precipitation, sea level pressure, temperature and 500 hPa geopotential height fields. The improvements in forecasting heavy rains by the multimodel/multianalysis superensemble are found to provide useful guidance in flood events. In hurricane forecasts improvements in track position forecasts of the order of 100 to 250 km were noted in one to three day forecasts. Intensity forecast for hurricanes shows only a marginal improvement. The seasonal climate forecasts show a lower performance from the member models compared to climatology, the multimodel superensemble appears to have skill somewhat above that of climatology.

Krishnamurthi, T. N.

2006-11-01

132

Rivers, chemical weathering and Earth's climate  

Microsoft Academic Search

We detail the results of recent studies describing and quantifying the large-scale chemical weathering of the main types of continental silicate rocks: granites and basalts. These studies aim at establishing chemical weathering laws for these two lithologies, describing the dependence of chemical weathering on environmental parameters, such as climate and mechanical erosion. As shown within this contribution, such mathematical laws

Bernard Dupré; Céline Dessert; Priscia Oliva; Yves Goddéris; Jérôme Viers; Louis François; Romain Millot; Jérôme Gaillardet

2003-01-01

133

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

NASA Astrophysics Data System (ADS)

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

Brooks, Harold

2008-07-01

134

Parallel, Adaptive-Mesh-Refinement MHD for Global Space-Weather Simulations  

NASA Astrophysics Data System (ADS)

The first part of this paper reviews some issues representing major computational challenges for global MHD models of the space environment. These issues include mathematical formulation and discretization of the governing equations that ensure the proper jump conditions and propagation speeds, regions of relativistic Alfvén speed, and controlling the divergence of the magnetic field. The second part of the paper concentrates on modern solution methods that have been developed by the aerodynamics, applied mathematics and DoE communities. Such methods have recently begun to be implemented in space-physics codes, which solve the governing equations for a compressible magnetized plasma. These techniques include high-resolution upwind schemes, block-based solution-adaptive grids and domain decomposition for parallelization. We describe the space physics MHD code developed at the University of Michigan, based on the developments listed above.

Powell, Kenneth G.; Gombosi, Tamas I.; de Zeeuw, Darren L.; Ridley, Aaron J.; Sokolov, Igor V.; Stout, Quentin F.; Tóth, Gábor

2003-09-01

135

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

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

136

Weather Cycles  

NASA Astrophysics Data System (ADS)

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

Burroughs, William James

2003-12-01

137

Impact of advanced infrared sounder radiancesin the french global numerical weather prediction ARPEGE model.  

NASA Astrophysics Data System (ADS)

The Atmospheric Infrared Sounder (AIRS) onboard Aqua and the Infrared Atmospheric Sounding Interferometer (IASI) onboard METOP belong to a new generation of advanced satellite sounding instruments. They provide information with spectral resolution far exceeding that of previous sounders (HIRS). The aim of this presentation is to describe the developments performed at Meteo-France to assimilate the IASI and AIRS radiances for clear and cloudy observation conditions, over sea and over land. Currently, 54 AIRS channels and 64 IASI channels are assimilated in operations, both in the global model ARPEGE 4D-Var and in the limited-area model ALADIN 3D-Var. They both provide information on temperature mainly from 50 hPa down to 650 hPa. Clouds are detected using the McNally and Watts (2003) method, which enables to have a cloud flag for each channel in a profile. Data are bias corrected with an adaptative variational method (namely VarBC), using geometric and flow-dependent predictors. In addition, 270 AIRS channels and 250 IASI channels are monitored. IASI data are assimilated both over sea and over land and sea-ice (specific subsets of channels are discarded over sea ice or over land), whereas AIRS data are only assimilated over open sea. Indeed, cloud affected radiances used to be rejected from the ARPEGE model (90% of total observations). The under-exploitation of these sounding instruments and the fact that sensitive regions (where forecast error can rapidly grow) are often cloudy, motivated our research efforts to assimilate AIRS and IASI cloudy radiances. The assimilation of AIRS radiances affected by low clouds inside the 4D-Var assimilation scheme has been implemented in the operational configuration. The approach is based on the use of cloud parameters, the cloud-top pressure and the net emissivity calculated offline by the cloud-characterization algorithm CO2-Slicing. These cloud parameters are then provided to the radiative transfer model RTTOV to simulate cloudy radiances from the background into the observation operator. Experiments assimilating AIRS cloud-affected radiances showed a significant positive impact on the forecast especially for long-term forecasts. The positive impact of the AIRS cloudy radiance assimilation had also been studied on a September 2006 meso-scale mediterranean cyclogenesis. In research mode, a great part of our work deals with the improvement of the data assimilation of IASI, especially for cloudy systems. The CO2-slicing approach used to assimilate AIRS cloudy radiances is currently extended and adapted to IASI data. The impact of the additional cloudy IASI radiances will be studied with global forecast scores and through impact studies on Atlantic storms of January 2009. The assimilation of IASI radiances is also extended to some water vapour channel and is currently evaluated. First results showed a positive impact on the forecasts.

Fourrie, N.; Pangaud, T.; Guidard, V.; Rabier, F.

2009-09-01

138

Chemical Weathering in the Eastern Himalaya: Geochemistry of Bhutanese Rivers  

NASA Astrophysics Data System (ADS)

Chemical weathering of Ca-Mg silicate minerals and subsequent marine carbonate precipitation is the fundamental sink for atmospheric CO2 in the long-term carbon cycle. Considerable effort has been made to examine Himalayan rivers and their relationship with weathering processes, in particular using mass balance estimates to quantify the weathering consumption of CO2 and the potential impact on global climate conditions. Weathering reactions produce alkalinity in rivers and thus dissolved load chemistry can be an effective means for assessing the total weathering budget of a watershed as well as for apportioning weathering fluxes between silicate and carbonate mineral sources. While weathering studies are abundant for the drainage basins of the Nepal and Indian Himalaya, they are lacking for Bhutan. Here we present new major element data for 35 rivers and streams across the Himalayan region of Bhutan. The rivers of Bhutan generally flow north to south through deeply incised gorges and are major tributaries to the Brahmaphutra. Within Bhutan, watersheds are largely underlain by the gneisses and metasediments of the High Himalayan Crystalline Series (HHC), with only the high reaches of the major streams flowing over the Tethyan Sedimentary Sequence (TSS) carbonates. Water samples were taken from all the major and most minor rivers at the end of the 2010 monsoon season (late August-September). Because of the strong seasonality of precipitation in Bhutan, these late-monsoon samples are taken to be reasonable first-order proxies for calculating annual dissolved load fluxes. The rivers are characterized by high calcium, with bicarbonate as the dominant anion, typical of carbonate weathering regimes. We note that in some cases, there is the strong influence of hot spring fluids in our stream samples, with 100-fold increases in downstream TDS. Initial analyses of our samples show that despite significant HHC dominated drainages, silicate alkalinity makes up on average 35% of the total alkalinity budget for the rivers of Bhutan, with a minimum of 5% and a maximum of 85%. This is comparable to other Himalayan streams with larger TSS influence to the west in Nepal, where carbonate weathering typically dominates stream dissolved loads.

Evans, M.; Petersen, C.

2011-12-01

139

Global Millimeter-Wave Precipitation Retrievals Trained With A Cloud-Resolving Numerical Weather-Prediction Model, Part II: Performance Evaluation  

Microsoft Academic Search

This paper evaluates the performance of the global precipitation rate retrieval algorithm for the Advanced Microwave Sounding Unit (AMSU) that was described in Part I of this paper. AMSU is in polar orbit on several National Ocean and Atmospheric Administration (NOAA) operational weather satellites. Predicted rms retrieval errors based on a 15-km resolution 0.5-1.0-mm\\/h MM5 truth were 0.88, 0.83, 1.13,

Chinnawat Surussavadee; David H. Staelin

2008-01-01

140

Friends of the Earth International Climate Change Briefing INDICATIONS OF CLIMATE CHANGE - RECENT EXTREME GLOBAL WEATHER EVENTS \\  

Microsoft Academic Search

th century record breaking temperatures and a run of extreme weather events rang the alarm bells. The trend is continuing into the 21 st century and this briefing catalogues some of the extreme weather events that have occurred during the last few months, along with signs in the environment that our climate is really changing.

WEATHER EXTREMES

141

Yellowstone Weather  

NSDL National Science Digital Library

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

Park, Yellowstone N.

142

The weathering and element fluxes from active volcanoes to the oceans: a Montserrat case study  

NASA Astrophysics Data System (ADS)

The eruptions of the Soufrière Hills volcano on Montserrat (Lesser Antilles) from 1995 to present have draped parts of the island in fresh volcaniclastic deposits. Volcanic islands such as Montserrat are an important component of global weathering fluxes, due to high relief and runoff and high chemical and physical weathering rates of fresh volcaniclastic material. We examine the impact of the recent volcanism on the geochemistry of pre-existing hydrological systems and demonstrate that the initial chemical weathering yield of fresh volcanic material is higher than that from older deposits within the Lesser Antilles arc. The silicate weathering may have consumed 1.3% of the early CO2 emissions from the Soufrière Hills volcano. In contrast, extinct volcanic edifices such as the Centre Hills in central Montserrat are a net sink for atmospheric CO2 due to continued elevated weathering rates relative to continental silicate rock weathering. The role of an arc volcano as a source or sink for atmospheric CO2 is therefore critically dependent on the stage it occupies in its life cycle, changing from a net source to a net sink as the eruptive activity wanes. While the onset of the eruption has had a profound effect on the groundwater around the Soufrière Hills center, the geochemistry of springs in the Centre Hills 5 km to the north appear unaffected by the recent volcanism. This has implications for the potential risk, or lack thereof, of contamination of potable water supplies for the island's inhabitants.

Jones, Morgan T.; Hembury, Deborah J.; Palmer, Martin R.; Tonge, Bill; Darling, W. George; Loughlin, Susan C.

2011-04-01

143

A ducting climatology derived from the European Centre for Medium-Range Weather Forecasts global analysis fields  

NASA Astrophysics Data System (ADS)

A global ducting climatology based on 6 years of European Centre for Medium-Range Weather Forecasts (ECMWF) data is presented. The ECMWF data have a resolution of 1.5°, 60 vertical levels, and a 6-hour daily frequency. Ducting probability, altitude, layer thickness, and magnitude are calculated for different seasons and universal times by analyzing the refractivity gradient with respect to altitude. Owing to the limited ECMWF vertical resolution, presented results are restricted to the lowest 2-2.5 km of the atmosphere. The climatology has mainly been generated for radio occultation data analysis, where ducting events found at higher altitudes are generally not affecting the signal acquisition. Since ducting is so much associated with boundary layer inversions and in the subtropics with cloud-topped boundary layers, this study can also be used as an inversion climatology. High ducting probabilities (?100%) are found off the west coasts of the Americas, Africa, and Australia in typical stratocumulus conditions. High probability is also observed over the Arabian Sea, with large seasonal variations. Polar nights lead to high ducting probabilities, especially visible over Antarctica but also over Greenland and Siberia. The daily cycle of the probabilities shows the impact of radiative cooling during the night over desert and tundra areas. Maximum mean ducting altitudes are found further off the west coasts. Land-based ducting events are generally near the surface. The mean ducting layer thickness is higher over the sea, with maximum thicknesses of up to 250 m. The mean magnitude of ducting is usually just below the critical gradient.

von Engeln, Axel; Teixeira, JoãO.

2004-09-01

144

Space Weather: Welcome, SEC  

NSDL National Science Digital Library

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

Spangler, Tim

2005-01-11

145

Chemical weathering rates along a steep climate gradient in the Idaho Batholith  

Microsoft Academic Search

Chemical weathering plays a major role in many Earth surface processes. It regulates rates of landscape evolution, supplies nutrients to soils and streams, and contributes to geochemical cycling. Over long timescales (> 1 Myr), chemical weathering of silicate minerals is the dominant sink for atmospheric carbon dioxide. If silicate chemical weathering rates increase with temperature (as theory and experiments suggest

K. L. Ferrier; J. W. Kirchner; R. C. Finkel

2006-01-01

146

Fair weather atmospheric electricity  

NASA Astrophysics Data System (ADS)

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

Harrison, R. G.

2011-06-01

147

On the Definition of El Niño and Associated Seasonal Average U.S. and Global Weather Anomalies  

NASA Astrophysics Data System (ADS)

A new NOAA definition of El Niño identifies a number of additional El Niño seasons beyond those conventionally agreed. These additional seasons are characterized by SST anomalies primarily in the western central equatorial Pacific. We show here that the seasonal weather anomalies over associated with these additional "Dateline" El Niño seasons are substantially different from those associated with conventional El Niño seasons. Although some regions have similar associated anomalies, most of the major regional anomalies are quite different. Treating the two as a single phenomenon yields weaker overall seasonal weather associations and does not take advantage of the stronger associations available when the two are treated separately.

Larkin, N.; Harrison, D.

2005-12-01

148

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.

149

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

150

A Hierarchical Bayesian model of wildfire in a Mediterranean biodiversity hotspot: Implications of weather variability and global circulation  

Microsoft Academic Search

In this study we combined an extensive database of observed wildfires with high-resolution meteorological data to build a novel spatially and temporally varying survival model to analyze fire regimes in the Mediterranean ecosystem in the Cape Floristic Region (CFR) of South Africa during the period 1980–2000. The model revealed an important influence of seasonally anomalous weather on fire probability, with

Adam M. Wilson; Andrew M. Latimer; John A. Silander Jr.; Alan E. Gelfand; Helen de Klerk

2010-01-01

151

On the Definition of El Niño and Associated Seasonal Average U.S. and Global Weather Anomalies  

Microsoft Academic Search

A new NOAA definition of El Niño identifies a number of additional El Niño seasons beyond those conventionally agreed. These additional seasons are characterized by SST anomalies primarily in the western central equatorial Pacific. We show here that the seasonal weather anomalies over associated with these additional \\

N. Larkin; D. Harrison

2005-01-01

152

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

153

Weather Forecasting  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

154

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

155

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

156

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

157

UM Weather  

NSDL National Science Digital Library

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

1994-01-01

158

Weather Predictions  

NSDL National Science Digital Library

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

Burr, Miss

2009-03-27

159

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

Microsoft Academic Search

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.

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

2012-01-01

160

The carbonate-silicate cycle and CO2/climate feedbacks on tidally locked terrestrial planets.  

PubMed

Atmospheric gaseous constituents play an important role in determining the surface temperatures and habitability of a planet. Using a global climate model and a parameterization of the carbonate-silicate cycle, we explored the effect of the location of the substellar point on the atmospheric CO(2) concentration and temperatures of a tidally locked terrestrial planet, using the present Earth continental distribution as an example. We found that the substellar point's location relative to the continents is an important factor in determining weathering and the equilibrium atmospheric CO(2) level. Placing the substellar point over the Atlantic Ocean results in an atmospheric CO(2) concentration of 7 ppmv and a global mean surface air temperature of 247 K, making ?30% of the planet's surface habitable, whereas placing it over the Pacific Ocean results in a CO(2) concentration of 60,311 ppmv and a global temperature of 282 K, making ?55% of the surface habitable. PMID:22775488

Edson, Adam R; Kasting, James F; Pollard, David; Lee, Sukyoung; Bannon, Peter R

2012-07-09

161

Atmospheric CO 2 consumption by chemical weathering in North America  

NASA Astrophysics Data System (ADS)

CO 2 consumption by chemical weathering is an integral part of the boundless carbon cycle, whose spatial patterns and controlling factors on continental scale are still not fully understood. A dataset of 338 river catchments throughout North America was used to empirically identify predictors of bicarbonate fluxes by chemical weathering and interpret the underlying controlling factors. Detailed analysis of major ion ratios enables distinction of the contributions of silicate and carbonate weathering and thus quantifying CO 2 consumption. Extrapolation of the identified empirical model equations to North America allows the analysis of the spatial patterns of the CO 2 consumption by chemical weathering. Runoff, lithology and land cover were identified as the major predictors of the riverine bicarbonate fluxes and the associated CO 2 consumption. Other influence factors, e.g. temperature, could not be established in the models. Of the distinguished land cover classes, artificial surfaces, dominated by urban areas, increase bicarbonate fluxes most, followed by shrubs, grasslands, managed lands, and forests. The extrapolation results in an average specific bicarbonate flux of 0.3 Mmol km -2 a -1 by chemical weathering in North America, of which 64% originates from atmospheric CO 2, and 36% from carbonate mineral dissolution. Chemical weathering in North America thus consumes 50 Mt atmospheric CO 2-C per year. About half of that originates from 10% of the area of North America. The estimated strength of individual predictors differs from previous studies. This highlights the need for a globally representative set of regionally calibrated models of CO 2 consumption by chemical weathering, which apply very detailed spatial data to resolve the heterogeneity of earth surface processes.

Moosdorf, Nils; Hartmann, Jens; Lauerwald, Ronny; Hagedorn, Benjamin; Kempe, Stephan

2011-12-01

162

Weather & Weather Maps. Teacher's Manual.  

ERIC Educational Resources Information Center

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

Metro, Peter M.; Green, Rachel E.

163

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

NASA Astrophysics Data System (ADS)

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

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

2008-06-01

164

The direction of fluid flow during contact metamorphism of siliceous carbonate rocks: new data for the Monzoni and Predazzo aureoles, northern Italy, and a global review  

Microsoft Academic Search

Periclase formed in siliceous dolomitic marbles during contact metamorphism in the Monzoni and Predazzo aureoles, the Dolomites, northern Italy, by infiltration of the carbonate rocks by chemically reactive, H2O-rich fluids at 500 bar and 565-710 °C. The spatial distribution of periclase and oxygen isotope compositions is consistent with reactive fluid flow that was primarily vertical and upward in both aureoles

John M. Ferry; Boswell A. Wing; Sarah C. Penniston-Dorland; Douglas Rumble

2002-01-01

165

Geochemistry of the Red River and Chang Jiang - Constraints on the Weathering Flux Associated with the Indo-Tibetan collision  

NASA Astrophysics Data System (ADS)

Red River and the headwaters of the Chang Jiang in western China and Vietnam are in the tectonically active part of the Himalayan-Tibetan orogeny. Riverine fluxes associated with weathering along these rivers contribute to the total weathering yield associated with the main collision. The riverine flux carried by Himalayan rivers is considered to be a significant fraction of continental weathering budgets globally. Interpreting the geochemistry of rivers in terms of lithology, weathering rates, tectonics and global climate implications pose a challenge and we therefore use a suite of geochemical tools, including but not limited to, major ion and trace element concentrations and analyses of various isotope systems namely Sr, Os, Li, U among others. Over 150 samples were obtained from pristine locations along these rivers during the summer and winter seasons spanning a period of 3 years. Major element chemistry along with some trace element analyses (Sr, Rb, Ba, Cs, U and Th) is comparable to that of the large rivers draining the Himalayan mountain belt. For example, Sr concentrations range from 0.2 to 7.0 uM for Red River and 0.07 to 13 uM for the Chang Jiang. Sr isotope analyses provide additional constraints on the source of the weathering flux (silicate v/s carbonate), which in turn provides constraints on interpretations of the global marine Sr isotope record, atmospheric CO2 drawdown and changing global climate.

Ellis, A.; Huh, Y.

2003-12-01

166

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

167

Weather Watchers  

NSDL National Science Digital Library

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

168

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.

169

Weather Talk  

NSDL National Science Digital Library

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

170

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

Microsoft Academic Search

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

Robert B. Weladji; Øystein Holand

2003-01-01

171

Severe Weather  

NSDL National Science Digital Library

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

Forde, Evan B.

2004-04-01

172

Global satellite millimeter-wave precipitation retrievals trained with a cloud-resolving numerical weather prediction model  

Microsoft Academic Search

This paper develops global retrieval algorithms for surface precipitation rate (mm\\/h), peak vertical wind (m\\/s), and water-paths (mm) for rainwater, snow, graupel, cloud water, cloud ice, and the sum of rainwater, snow, and graupel, for the Advanced Microwave Sounding Unit (AMSU) aboard the NOAA-15, -16, and -17 satellites. These retrieved products are expected to be available to researchers and operational

Chinnawat Surussavadee; David H. Staelin

2007-01-01

173

Dehydroxylated Clay Silicates on Mars: Riddles About the Martian Regolith Solved with Ferrian Saponites.  

National Technical Information Service (NTIS)

Clay silicates, resulting from the chemical weathering of volcanic glasses and basaltic rocks of Mars, are generally believed to be major constituents of the martian regolith and atmospheric dust. Because little attention has been given to the role, if an...

R. G. Burns

1992-01-01

174

Climate and Catastrophic Weather Events  

Microsoft Academic Search

The impacts of global climate change are conventionally discussed in terms of changes in temperature averaged over the year and over the globe. Much less emphasis has been placed on anticipated changes in weather variability. Of particular interest are extreme events such as windstorms, hurricanes, floods, droughts, hailstorms, tornadoes, etc. In the last decade, the number of catastrophic weather events

G. J. MacDonald

1999-01-01

175

The International Space Weather Initiative  

Microsoft Academic Search

The International Space Weather Initiative (ISWI) is an international program of scientific collaboration to understand the external drivers of space weather. One of the major thrusts of the ISWI is 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. Scientists from

Joseph Davila; Nat Gopalswamy

2010-01-01

176

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.

177

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

178

Weather Data  

NSDL National Science Digital Library

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

Harris, Ms.

2011-01-24

179

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

180

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

2003-04-18

181

Plant-induced weathering of a basaltic rock: experimental evidence  

Microsoft Academic Search

The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic

Philippe Hinsinger; Omar Neto Fernandes Barros; Marc F. Benedetti; Yves Noack; Gabriel Callot

2001-01-01

182

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

183

Strontium Isotopes, Basalt Weathering and Phanerozoic CO2  

NASA Astrophysics Data System (ADS)

Using a combined model for the strontium and carbon cycles that distinguishes the weathering of volcanic and non-volcanic silicate rocks, the weathering of younger and older carbonates, basalt-seawater reaction, and marine carbonate burial, the ratio of volcanic (mainly basalt) weathering to total silicate weathering is calculated as a function of time from the oceanic record of 87Sr/86Sr. The volcanic proportion is then used to modify the equations for calculating atmospheric CO2 in the GEOCARBSULF model by the addition of a new non- dimensional volcanic weathering factor. The effect of uplift and physical erosion on weathering is also modified by using only the distribution over time of the abundance of sandstones and shales, and not Sr isotopic data that had been used previously. Results indicate large variations in the volcanic proportion of silicates undergoing weathering over time and uniformly lower CO2 values than GEOCARBSULF for the early Paleozoic and for the Mesozoic with the degree of lowering depending upon the 87Sr/86Sr of nonvolcanics undergoing weathering and the ratio of the intrinsic weatherability of volcanics to nonvolcanics. An increased minimum in CO2 during the Late Ordovician is in agreement with the presence of a continental glaciation at that time, and, using intrinsic volcanic/non-volcanic weatherability = 10, variations of Jurassic and Cretaceous CO2 agree with the independent work of Fletcher et al (2007) based on liverwort delta 13C values.

Berner, R. A.

2007-12-01

184

Weather Forecasting  

NSDL National Science Digital Library

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

Twin Cities Public Television, Inc.

2005-01-01

185

Weather Instruments.  

ERIC Educational Resources Information Center

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

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

186

Effects of the January 16th-20th Solar Flares on the Fair Weather Global Electric Circuit.  

NASA Astrophysics Data System (ADS)

During the extremely active solar period from January 16th - 22nd, 2005, when several large X-class solar flares occurred, the MINIS (MINIature Spectrometer) balloon campaign had multiple payloads aloft in the stratosphere above Antarctica. Four MINIS balloons were launched from SANAE (South African National Antarctic Expedition) IV and measured DC electric fields, conductivity and x-ray flux. Increases in the conductivity and decreases in the vertical electric field magnitude were observed in conjunction with increases in particle flux seen by the balloon instruments as well as geospace satellites, reaffirming a direct connection between the solar activity and atmospheric electrodynamics. Additionally, a sustained (several hour) vertical field reversal was observed by one of the balloon instruments implying that a significant amount of positive charge was deposited below the balloon. This suggests that significant charge redistribution resulted from the solar flare and should be accounted for when describing the global electric circuit during active solar periods. By including rigidity cut-off estimates for the solar energetic particle (SEP) events based on ground based monitors we show that the reversal could have occurred over a significant portion of the globe.

Kokorowski, M.; Holzworth, R. H.; Bering, E. A.; Reddell, B. D.; McCarthy, M. P.; Bale, S.; Blake, J. B.; Collier, A. B.; Hughes, A. R.; Lay, E.; Lin, R. P.; Millan, R. M.; Moraal, H.; O'Brien, T. P.; Parks, G. K.; Pulupa, M.; Sample, J. G.; Smith, D.; Stoker, P.; Woodger, L.

2005-12-01

187

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

188

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

189

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

190

Space Weather  

NASA Astrophysics Data System (ADS)

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

Lanzerotti, L. J.

2005-05-01

191

Fluoroalkyleneether Silicate Copolymers.  

National Technical Information Service (NTIS)

Fluoroalkyleneether silicate copolymers are synthesized by the polycondensation of a bis-dimethylcarbinol containing a fluoroalkyleneether segment and bis-(dimethylamino) methylvinylsilane. The copolymers are useful in applications, e.g., as seals and sea...

R. E. Cochoy

1978-01-01

192

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

193

[Weather, climate and health].  

PubMed

The notion of complex influence of atmospheric conditions on modem human population, especially the relationship between weather, climate and human healths, has actuated the World Meteorological Organisation to commemorate the coming into force, on March 23, 1950, of the Convention of WMO and this year to celebrate this day by focusing on theme of current interest--"Weather, climate and health". In the light of this, the authors of this paper reveal the results of recent studies dealing with influence of sudden and short-term changes in weather and climate on human health, and future expected climate changes due to "greenhouse" effect, increase in global temperature and tropospheric ozone depletion, as well. Special attention is given to climate shifts due to ENSO (El Niño/Southern Oscillation) phenomenon because of its great impact on human society and epidemics of certain infectious diseases. The results of biometeorological studies dealing with complex influence of daily weather changes on incidence of certain diseases in Croatia have also been presented. In addition, the authors have stated their own view and opinion in regard to future biometeorlogical studies in Croatia in order to achieve better understanding of influence of climate and weather changes on human health, and help prevention of mortality and morbidity related to chronic noninfectious diseases. PMID:19658377

Bani?, M; Plesko, N; Plesko, S

194

Ensemble hydrological prediction-based real-time optimization of a multiobjective reservoir during flood season in a semiarid basin with global numerical weather predictions  

NASA Astrophysics Data System (ADS)

Future streamflow uncertainties hinder reservoir real-time operation, but the ensemble prediction technique is effective for reducing the uncertainties. This study aims to combine ensemble hydrological predictions with real-time multiobjective reservoir optimization during flood season. The ensemble prediction-based reservoir optimization system (EPROS) takes advantage of 8 day lead time global numerical weather predictions (NWPs) by the Japan Meteorological Agency (JMA). Thirty-member ensemble streamflows are generated through running the water and energy budget-based distributed hydrological model fed with 30-member perturbed quantitative precipitation forecasts (QPFs) and deterministic NWPs. The QPF perturbation amplitudes are calculated from the QPF intensity and location errors during previous 8 day periods. The reservoir objective function is established to minimize the maximum reservoir water level (reservoir and upstream safety), the downstream flood peak (downstream safety), and the difference between simulated reservoir end water level and target level (water use). The system is evaluated on the Fengman reservoir basin (semiarid), which often suffers from extreme floods in summer and serious droughts in spring. The results show the ensemble QPFs generated by EPROS are comparable to those for JMA by using probability-based measures. The streamflow forecast error is significantly reduced by employing the ensemble prediction approach. The system has demonstrated high efficiency in optimizing reservoir objectives for both normal and critical flood events. Fifty-member ensembles generate a wider streamflow and reservoir release range than 10-member ensembles, but the ensemble mean end water levels and releases are comparable. The system is easy to operate and thereby feasible for practical operations in various reservoir basins.

Wang, Fuxing; Wang, Lei; Zhou, Huicheng; Saavedra Valeriano, Oliver C.; Koike, Toshio; Li, Wenlong

2012-07-01

195

National Weather Service: Weather Education  

NSDL National Science Digital Library

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

196

Rates of consumption of atmospheric CO2 through the weathering of loess during the next 100 yr of climate change  

NASA Astrophysics Data System (ADS)

Quantifying how C fluxes will change in the future is a complex task for models because of the coupling between climate, hydrology, and biogeochemical reactions. Here we investigate how pedogenesis of the Peoria loess, which has been weathering for the last 13 kyr, will respond over the next 100 yr of climate change. Using a cascade of numerical models for climate (ARPEGE), vegetation (CARAIB) and weathering (WITCH) we explore the effect of an increase in CO2 of 315 ppmv (1950) to 700 ppmv (2100 projection). The increasing CO2 results in an increase in temperature along the entire transect. In contrast, drainage increases slightly for a focus pedon in the South but decreases strongly in the North. These two variables largely determine the behavior of weathering. In addition, although CO2 production rate increases in the soils in response to global warming, the rate of diffusion back to the atmosphere also increases, maintaining a roughly constant or even decreasing CO2 concentration in the soil gas phase. Our simulations predict that temperature increasing in the next 100 yr causes the weathering rates of the silicates to increase into the future. In contrast, the weathering rate of dolomite - which consumes most of the CO2-decreases due to its retrograde solubility in both end members (South and North) of the transect. We thus infer slower rates of advance of the dolomite reaction front into the subsurface, and faster rates of advance of the silicate reaction front. However, additional simulations for 9 pedons located along the North-South transect show that dolomite weathering will increase in the central part of the Mississippi Valley, owing to a maximum in the response of vertical drainage to the ongoing climate change. The carbonate reaction front can be likened to a terrestrial lysocline because it represents a depth interval over which carbonate dissolution rates increase drastically. However, in contrast to the lower pH and shallower lysocline expected in the oceans with increasing atmospheric CO2, we predict an acceleration of the lysocline deepening in soils in the central area of the Mississippi Valley, but a slowdown of its deepening in the Southern and Northern section. This result illustrates the complex behavior of carbonate weathering facing short term global climate change. Predicting the global response of terrestrial weathering to increased atmospheric CO2 and temperature in the future will mostly depend upon our ability to make precise assessments of which areas of the globe increase or decrease in precipitation and soil drainage.

Goddéris, Y.; Brantley, S. L.; François, L. M.; Schott, J.; Pollard, D.; Déqué, M.

2012-08-01

197

Chemical Weathering in the Amur River  

NASA Astrophysics Data System (ADS)

The Amur River is the fourth largest river (~1,855,000 km2) in north Eurasia which flow into the Pacific Ocean. It flows through 4 countries-the Russian Far East, northeast China, east Mongolia and a small territory of North Korea. Climatic and ecological conditions differ significantly from western intercontinental region to eastern coastal area. Southern part of the Amur basin is mostly lowland region with alluvial deposits and various rocks of sedimentary and magmatic origin. In the northern part, there are mountains with siliceous and carbonaceous sedimentary rocks, and permafrost plays an important role in river chemical discharge. We examined dissolved major element and Sr isotopic compositions of 19 summer samples in the middle reach of the Amur to better understand the relationship between chemical weathering, geology, and climate (with the aid of GlS). We found that the 87Sr/86Sr ratios fall a narrow the range of 0.709-0.712 and the TDS (total dissolved solids) is about 80 (40-180) mg/L. Kaolinite is the thermodynamically stable silicate mineral for most samples. We quantified chemical weathering rates using an inverse model: rain accounts for (2-14)% of the total cationic concentration, evaporites (3-19)%, carbonates (43-77)%, and silicates (14-32)%. Net CO2 consumption rate by silicate weathering in the Amur basin is in the range of (10-100) ×103 mol/km2/yr, and the value at the main channel above confluence with the Sungari tributary is ~10 ×103 mol/km2/yr. We tested correlations between the CO2 consumption rates by silicate weathering and various climatic (air temperature, precipitation, and runoff) and geologic (relief, slope, elevation) factors calculated using GIS. Stepwise regression using SPSS on the entire data set yielded best correlation (negative) with elevation (R2 = 0.6823, p = 0.0002).

Moon, S.; Huh, Y.

2006-12-01

198

Space Weather  

NASA Astrophysics Data System (ADS)

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

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

199

Unisys Weather  

NSDL National Science Digital Library

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

200

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

201

Impact of nitrogenous fertilizers on carbonate dissolution in small agricultural catchments: Implications for weathering CO 2 uptake at regional and global scales  

Microsoft Academic Search

The goal of this study was to highlight the occurrence of an additional proton-promoted weathering pathway of carbonate rocks in agricultural areas where N-fertilizers are extensively spread, and to estimate its consequences on riverine alkalinity and uptake of CO2 by weathering. We surveyed 25 small streams in the calcareous molassic Gascogne area located in the Garonne river basin (south-western France)

Anne-Sophie Perrin; Anne Probst; Jean-Luc Probst

2008-01-01

202

The Weather Doctor  

NSDL National Science Digital Library

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

Heidorn, Keith.

2002-01-01

203

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.

204

Weather control  

Microsoft Academic Search

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

Leepson

1980-01-01

205

Adhesion of Hydrated Silicate Films.  

National Technical Information Service (NTIS)

We used fracture mechanics test techniques to measure the adhesive bond energy formed between hydrated silica glass surfaces and silicate species deposited from solution. In the case of silicate surfaces hydrated in room temperature water vapor, intermole...

T. A. Michalske K. D. Keefer

1988-01-01

206

Selective Weathering of Shocked Minerals and Chondritic Enrichment of the Martian Fines.  

National Technical Information Service (NTIS)

In a recent paper, Boslough and Cygan reported the observation of shock-enhanced chemical weathering kinetics of three silicate minerals. Based on the experimental data and on those of Tyburczy and Ahrens for enhanced dehydration kinetics of shocked serpe...

M. B. Boslough

1987-01-01

207

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

NASA Astrophysics Data System (ADS)

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

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

208

Does mineral surface area affect chemical weathering rates?  

NASA Astrophysics Data System (ADS)

Iceland is a basaltic volcanic island representative of the high relief, volcanic and tectonic active islands that contribute over 45% of river suspended material to the oceans worldwide (Milliman and Syvitski, 1992). These islands have enormous mechanical and chemical weathering rates due to the combined effects of high relief, high runoff, the presence of glaciers and easily weathered volcanic rocks, and a lack of sedimentary traps. In total, Iceland delivers 0.7% of the worldwide river suspended matter flux to the ocean, which is approximately one fourth that of Africa (Tómasson, 1990). River suspended matter from volcanic islands is highly reactive in seawater and might play an important role in the global carbon cycle (Gislason et al., 2006). Thus it is important to define and understand the mechanical and chemical weathering rates of these islands. Experimental dissolution experiments performed in the laboratory suggest that chemical weathering rates should be proportional to rock-water interfacial surface area. This hypothesis is tested in the present study through a study of the chemical composition of suspended material collected from rivers located in Northeast Iceland. These rivers were selected for this study because their catchments essentially monolithic, consisting of uniform compositioned and aged basalts. Gaillardet (1999) described weathering intensities of the worlds river systems to be from 1 (low weathering intensity) to 25 (high weathering intensity). These indexes were calculated to be from 1.8 to 3.2 in rivers in NE-Iceland (Eiriksdottir et al., 2008). The surface area of sediments is inversely proportional to particle size; smaller particles have larger specific surface areas. As a result, smaller particles should weather faster. This trend is confirmed by the measured compositions of analyzed suspended material. The concentration of insoluble elements (Zr, Fe, Cu, Ni, Y) is found to increase in the suspended material, whereas the concentration of soluble elements (Na, Ca, Ba, V) decrease with decreasing particle size in samples collected from various catchments. References. Eiriksdottir E.S., Louvat P., Gislason S.R., Óskarsson N., Hardardóttir J., 2008. Temporal variation of chemical and mechanical weathering in NE Iceland: Evaluation of a steady-state model of erosion. EPSL 272, 78-88 Gaillardet, J., Dupré, B., Allegre, C.J., Négrel, P., 1999b. Geochemistry of large river suspended sediments: silicate weathering or recycling tracer? Geochim. Cosmochim. Acta 63, 4037-4051. Gislason, S.R., Oelkers, E.H., Snorrason, Á., 2006. Role of river-suspended material in the global carbon cycle. Geology 34, 49-52. Milliman, J.D., Syvitski, J.P.M., 1992. Geomorphic/tectonic control of sediment discharge to the ocean: the importance of small mountainous rivers. J. Geol. 100, 525-544. Tómasson, H., 1990. Suspended material in Icelandic rivers. In: Guttormur, S. (Ed.), Vatnid og Landid. Orkustofnun, Reykjavik, pp. 169-174.

Salome Eiriksdottir, Eydis; Reynir Gislason, Sigurdur; Oelkers, Eric H.

2010-05-01

209

Capped Mesoporous Silicates.  

National Technical Information Service (NTIS)

The invention provides an article comprising, a mesoporous silicate matrix, such as a particle, having one or more pores; and one or more releasable caps obstructing one or more of the pores. The articles are useful as delivery vehicles for encapsulated a...

C. Y. Lai D. M. Jeftinija S. Jeftinija V. S. Y. Lin

2004-01-01

210

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

211

The Daily Martian Weather Report  

NSDL National Science Digital Library

This site from the Mars Global Surveyor Radio Science Team features the results of a detailed study of the Martian atmosphere in the form of a daily weather report and precise atmospheric measurements for the planet Mars. Atmospheric temperature and pressure profiles which have been archived with NASA's Planetary Data System are also available on this site. These profiles illustrate the vertical structure of the atmosphere of Mars. The site also includes links to many images of Martian atmospheric and weather phenomena (with captions) from the Mars Global Surveyor Mars Orbiter Camera (MGS MOC), the Imager for Mars Pathfinder (IMP) and the Hubble Space Telescope.

Team, Mars G.; University, Stanford

212

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

213

Reply to the comments on [open quotes]Weathering, plants, and the long-term carbon cycle[close quotes  

Microsoft Academic Search

Some lichens can and do promote the weathering of their substrates. The authors' sole interest for purposes of carbon-cycle modeling is the degree of that enhancement for calcium and magnesium silicates relative to both abiotic chemical weathering due to water-rock interaction and the weathering that occurs beneath higher plants. The work by Jackson and Keller (1970) had offered the most

M. F. Cochran; R. A. Berner

1993-01-01

214

Chemical weathering in the Three Rivers region of Eastern Tibet  

NASA Astrophysics Data System (ADS)

Three large rivers - the Chang Jiang (Yangtze), Mekong (Lancang Jiang) and Salween (Nu Jiang) - originate in eastern Tibet and run in close parallel over 300 km near the eastern Himalayan syntaxis. Seventy-four river water samples were collected mostly during the summer season from 1999 to 2004. Their major element compositions vary widely, with total dissolved solids (TDS) ranging from 31 to 3037 mg/l, reflecting the complex geologic makeup of the vast drainage basins. The major ion distribution of the main channel samples primarily reflects the weathering of carbonates. Evaporite dissolution prevails in the headwater samples of the Chang Jiang in the Tibetan Plateau interior, as evidenced by the high TDS (928 and 3037 mg/l) and the Na-Cl dominant major element composition. Local tributary samples of the Mekong and Salween, draining the Lincang Batholith and the Tengchong Volcano, show distinctive silicate weathering signatures. We used five reservoirs - rain, halite, sulfate, carbonate, and silicate - in a forward model to calculate the contribution from silicate weathering to the total dissolved load and to estimate the consumption rate of atmospheric CO 2 by silicate weathering. Carbonate weathering accounts for about 50% of the total cationic charge (TZ +) in the samples of the Mekong and the Salween exiting the Tibetan Plateau. In the "exit" sample of the Chang Jiang, 45% of TZ + is from halite dissolution inherited from the extreme headwater tributaries in the interior of the plateau, and carbonates contribute only 26% to the TZ +. The net rate of CO 2 consumption by silicate weathering is (103-121) × 10 3 mol km -2 year -1, lower than the rivers draining the Himalayan front. GIS-based analyses indicate that runoff and relief can explain 52% of the spread in the rate of atmospheric CO 2 drawdown by silicate weathering, but other climatic (temperature, precipitation, potential evapotranspiration) and geomorphic (elevation, slope) factors also show collinearity. Only qualitative conclusions can be drawn for the significance of lithology due to lack of digitized lithologic information. The effect of the peculiar drainage pattern due to tectonic forcing is not readily apparent in the major element composition or in increased chemical weathering rates. The 87Sr/ 86Sr ratios and the silicate weathering rates are in general lower in the Three Rivers than in the rivers draining the Himalayan front.

Noh, Hyonjeong; Huh, Youngsook; Qin, Jianhua; Ellis, Andre

2009-04-01

215

Aviation weather radar  

Microsoft Academic Search

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

D. H. Turnbull

1995-01-01

216

Weather Science Hotlist  

NSDL National Science Digital Library

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

1969-12-31

217

GLOBAL CHANGE RESEARCH NEWS #33: PUBLICATION OF RESEARCH AGENDA FROM UNITED STATES - CANADA SYMPOSIUM ON NORTH AMERICAN CLIMATE CHANGE AND WEATHER EXTREMES  

EPA Science Inventory

A three-day workshop on climate variability and change and extreme weather events in North America was held in October 1999 in Atlanta, Georgia. The workshop was a bi-national effort conducted under the auspices of a United States - Canada agreement fostering cooperation on activ...

218

Instruments and Methods Monitoring ice-capped active Volc´ an Villarrica, southern Chile, using terrestrial photography combined with automatic weather stations and global positioning systems  

Microsoft Academic Search

Volcan Villarrica (39 ? 25? 12?? S, 71 ? 56? 27?? W; 2847 m a.s.l.) is an active ice-capped volcano located in the Chilean lake district. The surface energy balance and glacier frontal variations have been monitored for several years, using automatic weather stations and satellite imagery. In recent field campaigns, surface topography was measured using Javad GPS receivers. Daily

Javier G. CORRIPIO; Ben BROCK; Jorge CLAVERO; Jens WENDT

219

Solubility and availability to sugarcane ( Saccharum Spp.) of two silicate materials  

Microsoft Academic Search

Silicate materials, dicalcium orthosilicate (Ca2SiO4), calcium metasilicate (CaSiO3), and mini-granulated CaSiO3, were incorporated into three highly weathered, low-Si soils. The mixtures were moistened to field moisture-holding capacity and incubated in plastic bags for 60 days at approximately 25°C, after which Si was extracted. Application rates of silicate materials were 0, 460, 920, and 1380 mg Si per kg soil. Two

O. A. Medina-Gonzales; R. L. Fox; R. P. Bosshart

1988-01-01

220

Chemical weathering, river geochemistry and atmospheric carbon fluxes from volcanic and ultramafic regions on Luzon Island, the Philippines  

NASA Astrophysics Data System (ADS)

We investigated rates of chemical weathering of volcanic and ophiolitic rocks on Luzon Island, the Philippines. Luzon has a tropical climate and is volcanically and tectonically very active, all factors that should enhance chemical weathering. Seventy-five rivers and streams (10 draining ophiolites, 65 draining volcanic bedrock) and two volcanic hot springs were sampled and analyzed for major elements, alkalinity and 87Sr/ 86Sr. Cationic fluxes from the volcanic basins are dominated by Ca 2+ and Mg 2+ and dissolved silica concentrations are high (500-1900 ?M). Silica concentrations in streams draining ophiolites are lower (400-900 ?M), and the cationic charge is mostly Mg 2+. The areally weighted average CO 2 export flux from our study area is 3.89 ± 0.21 × 10 6 mol/km 2/yr, or 5.99 ± 0.64 × 10 6 mol/km 2/yr from ophiolites and 3.58 ± 0.23 × 10 6 mol/km 2/yr from volcanic areas (uncertainty given as ±1 standard error, s.e.). This is ˜6-10 times higher than the current best estimate of areally averaged global CO 2 export by basalt chemical weathering and ˜2-3 times higher than the current best estimate of CO 2 export by basalt chemical weathering in the tropics. Extrapolating our findings to all tropical arcs, we estimate that around one tenth of all atmospheric carbon exported via silicate weathering to the oceans annually is processed in these environments, which amount to ˜1% of the global exorheic drainage area. Chemical weathering of volcanic terranes in the tropics appears to make a disproportionately large impact on the long-term carbon cycle.

Schopka, H. H.; Derry, L. A.; Arcilla, C. A.

2011-02-01

221

Commercializing Space Weather using GAIM  

NASA Astrophysics Data System (ADS)

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

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

222

Lithium as a Silicate Weathering Proxy: Problems and Perspectives  

Microsoft Academic Search

The lithium concentration of the dissolved load from the Lena River, together with major element chemistry and GIS-based area\\u000a and runoff data demonstrate the importance of evaporites in controlling dissolved Li in river waters. Eighty-four percent\\u000a of the Li in the dissolved load of upper Lena tributaries comes from evaporites in these drainage basins. Altogether, at least\\u000a ~20% of the

Junyeon Yoon

2010-01-01

223

Destructive Weather  

NSDL National Science Digital Library

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

Alizabethirwin

2010-11-03

224

Weather Tamers  

NSDL National Science Digital Library

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

Sterling, Donna R.; Frazier, Wendy M.

2007-03-01

225

Image processing for weather satellite cloud segmentation  

Microsoft Academic Search

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

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

1995-01-01

226

Investigating Weather and Climate with Google Earth  

NSDL National Science Digital Library

In this activity, students use Google Earth to explore global temperature changes during a recent 50 - 58 year period. They also explore, analyze, and interpret climate patterns of 13 different cities, and analyze differences between weather and climate patterns.

University, Environmental L.

227

Identification of rock weathering and environmental control in arid catchments (northern Xinjiang) of Central Asia  

NASA Astrophysics Data System (ADS)

Chemical weathering is an integral part of the earth surface processes, whose spatial patterns and controlling factors on continental scale are still not fully understood. Highlands of the Asian continent have been shown having some of the highest observed rates of chemical weathering yet reported. However, the paucity of river gauge data in many of these terrains has limited determination of chemical weathering budget in a continental scale. A dataset of three large watersheds throughout northern Xinjiang in Central Asia is used to empirically identify chemical weathering regimes and interpret the underlying controlling factors. Detailed analysis of major ion ratios and a forward model of mass budget procedure are presented to distinguish the relative significances and contributions of silicate, carbonate weathering and evaporite dissolution. The analytical results show that carbonic acid is the most important weathering agent to the studied watersheds. Silicate weathering contributes, on average, ˜17.8% (molar basis) of total cations on a basin wide scale with an order of Zhungarer > Erlqis > Yili, indicating that silicate weathering, however, does not seem to be intense in the study basins. Evaporite dissolution, carbonate weathering and precipitation input contribute 43.6%, 29.7% and 8.9% of the total dissolved cations on average for the whole catchment, respectively. The three main morphological and hydrological units are reflected in water chemistry. Rivers from the montane areas (recharge area) of the three watersheds are very dilute, dominated by carbonate and silicate weathering, whereas the rivers of piedmont areas as well as the rivers of the sedimentary platform (runoff area) are dominated by carbonate weathering, and rivers of desert plain in the central Zhungarer basin (discharge area) are dominated by evaporite dissolution and are SO4 rich. This spatial pattern indicates that, beside lithology, runoff conditions have significant role on the regional chemical weathering regimes. Chemical weathering processes in the areas appear to be significantly climate controlled, displaying a tight correlation with runoff and aridity. Carbonate weathering are mostly influenced by runoff, which is higher in the mountainous part of the studied basins. The identification of chemical weathering regimes from our study confirmed the weathering potential and complexity of temperate watersheds in arid environment and that additional studies of these terrains are warranted. However, because the dominant weathering reactions in the sedimentary platform of northern Xinjiang are of carbonates and evaporites rather than silicate minerals, and the climatic factors have important role on the rock weathering regimes, we think that weathering at the arid temperate drainage system (Central Asia) is maybe not an important long-term sink for atmospheric CO2, if the future climate has no great change.

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

2013-04-01

228

Pedogenesis and weathering rates of a Histic Andosol in Iceland: Field and experimental soil solution study  

Microsoft Academic Search

It is important to study the rate determining processes of chemical weathering and soil formation in volcanic islands since a significant part of the carbon fixed by chemical weathering of silicates on Earth is fixed at the surface of volcanic islands. These soils are fertile and much of the river suspended matter delivered to the ocean stems from these islands.

Bergur Sigfusson; Sigurdur R. Gislason; Graeme I. Paton

2008-01-01

229

Mesocosm-Scale Experimental Quantification of Plant-Fungi Associations on Carbon Fluxes and Mineral Weathering  

Microsoft Academic Search

The rise of land plants in the Paleozoic is classically implicated as driving lower atmospheric CO2 levels through enhanced weathering of Ca and Mg bearing silicate minerals. However, this view overlooks the fact that plants coevolved with associated mycorrhizal fungi over this time, with many of the weathering processes usually ascribed to plants actually being driven by the combined activities

M. Y. Andrews; B. Palmer; J. R. Leake; S. A. Banwart; D. J. Beerling

2009-01-01

230

Chemical weathering in a tropical watershed, Luquillo Mountains, Puerto Rico III: quartz dissolution rates  

Microsoft Academic Search

The paucity of weathering rates for quartz in the natural environment stems both from the slow rate at which quartz dissolves and the difficulty in differentiating solute Si contributed by quartz from that derived from other silicate minerals. This study, a first effort in quantifying natural rates of quartz dissolution, takes advantage of extremely rapid tropical weathering, simple regolith mineralogy,

Marjorie S Schulz; Art F White

1999-01-01

231

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

232

Chemical Weathering and the Viking Biology Experiments on Mars  

Microsoft Academic Search

The activity observed by the three Viking lander life detection experiments is reviewed, and the active agents are characterized. It is proposed that the activity in all three experiments may have been caused by a single active agent in the Martian soil, resulting from contemporary chemical weathering of mafic silicates by low-temperature frost and adsorbed H20. Earlier laboratory studies indicated

Robert L. Huguenin

1982-01-01

233

Globalization  

Microsoft Academic Search

Globalization--the integration of the world economy--has ebbed and flowed over the twentieth century. This paper surveys the varying flows of goods, people, and capital around the world. It asks also about the flow of information across national boundaries and the flows of all these various commodities and factors within countries. Goods, people, and capital flowed easily in much, but not

Peter Temin

1999-01-01

234

Dissolution of pyroxenes and amphiboles during weathering.  

PubMed

Augite, hypersthene, diopside, and hornblende all undergo dissolution during weathering by means of the formation, growth, and coalescence of distinctive, parallel, lens-shaped etch pits. Similar etch features can be produced if these minerals are treated in the laboratory with concentrated hydrofluoric acid plus hydrochloric acid. These pits most likely form at dislocation outcrops, and their shape and orientation are controlled primarily by the crystallography of the underlying mineral. The results are similar to those found for soil feldspars and suggest that silicate weathering, in general, takes place by selective etching and not by general attack of the surface with consequent rounding as necessiated by bulk diffusion-type weathering theories. PMID:17776857

Berner, R A; Sjöberg, E L; Velbel, M A; Krom, M D

1980-03-14

235

Deep chemical weathering in a rapidly eroding mountain belt, Taiwan  

Microsoft Academic Search

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

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

2009-01-01

236

The Topographic Control of Chemical Weathering in Hillslope Soils  

Microsoft Academic Search

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

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

2004-01-01

237

Effects of Weathering on Basaltic Rocks and Their Thermal Emission Spectra: Implications for Evaluating Mars Mineralogy and Weathering  

NASA Astrophysics Data System (ADS)

Thermal emission spectroscopy has provided crucial information about the mineralogical composition of the Martian surface. Portions of that surface may be chemically weathered, and it is, therefore, important that the influence of chemical weathering on thermal infrared observations be recognized and understood. To this end, we have examined a suite of weathered rocks collected from the Columbia River Basalt Group. Weathering causes distinct changes to the thermal emissivity spectra of these basalts, which will be discussed in detail by J. R. Michalski et al. (this meeting). Here, we document physical and mineralogical features of weathering rinds to understand how weathering affects infrared spectra. Chemical weathering of basalts forms microcracks, dissolves primary minerals, and produces secondary phases. In the rocks examined, the relative abundance of primary minerals is the same in the weathering rind and corresponding unweathered rock. This is true even for olivine, the least stable phase in the rocks studied. Thus, preferential dissolution is not a controlling factor in the observed spectral changes. Microcracks form by expansion and dissolution and represent <20 vol% of the weathering rinds studied. While they potentially act as blackbody cavities, they probably influence emissivity spectra more by acting as sites where secondary phases form. Because the cracks are generally a few micrometers in width, the secondary phases filling them are optically thin, which may produce nonlinearity in spectral mixing of mineral phases, complicating spectral modeling. Secondary phases are Si-Al-rich and strongly influence the Si-O stretching region of infrared spectra. Dissolution of silica from primary phases and its precipitation in microcracks are the principle factors controlling changes in emissivity spectra in weathered rocks. These changes can lead to inaccurate relative abundances of primary phases derived from deconvolution modeling of weathered rocks. Also, the secondary silicates are generally amorphous to poorly crystalline, and deconvolution modeling misinterprets these materials as silicate glasses and clay minerals. The exact effects weathering exerts on emissivity spectra and subsequent modeling results will depend on what secondary silicates form, particularly how much silica is present, which will in turn depend on the conditions of weathering. However, the basic scenario of crack formation and mineralogical redistribution of silica should hold for a wide range of weathering conditions, and similar effects are expected for weathered Martian surfaces.

Kraft, M. D.; Michalski, J. R.; Sharp, T. G.

2005-12-01

238

Forecasting the Weather.  

ERIC Educational Resources Information Center

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

Bollinger, Richard

1984-01-01

239

Weather Prediction Models  

NASA Astrophysics Data System (ADS)

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

Bacmeister, Julio T.

240

Cockpit Weather Information Needs.  

National Technical Information Service (NTIS)

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

C. H. Scanlon

1992-01-01

241

National Weather Service  

MedlinePLUS

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

242

What's the Weather?  

NSDL National Science Digital Library

In this lesson, students use daily observations, videos, and activities to learn about meteorology and the changing nature of weather. Students also identify weather events that are commonly reported in the news and discuss how weather affects lives.

Foundation, Wgbh E.

2009-07-21

243

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

244

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

245

A Century of Monitoring Weather and Crops: The Weekly Weather and Crop Bulletin.  

NASA Astrophysics Data System (ADS)

Publication of a national weekly weather summary called the Weekly Weather Chronicle began in 1872. This summary was the precursor of today's Weekly Weather and Crop Bulletin (WWCB), a publication that reports global weather and climate conditions relevant to agricultural interests, as well as current national activities and assessments of crop and livestock conditions. The WWCB is produced by the Joint Agricultural Weather Facility (JAWF), a world agricultural weather information center located in the U.S. Department of Agriculture (USDA) headquarters in Washington, D.C., and jointly staffed by units of the National Oceanic and Atmospheric Administration's Climats. Analysis Center and USDA's World Agricultural Outlook Board and National Agricultural Statistics Service. Besides featuring charts and tables (e.g., temperature and precipitation maps and crop progress and condition tables), the WWCB contains summaries and special stories highlighting significant weather events affecting agriculture, such as droughts, torrential rains, floods, unusual warmth, heat waves, severe freezes, heavy snowfall, blizzards, damaging storms, and hurricanes.

Heddinghaus, Thomas R.; Le Comte, Douglas M.

1992-02-01

246

Stardust silicates from primitive meteorites  

Microsoft Academic Search

Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the planets of the Solar System formed, but no presolar silicates

Kazuhide Nagashima; Alexander N. Krot; Hisayoshi Yurimoto

2004-01-01

247

Industry and Government Officials Meet for Space Weather Summit  

NASA Astrophysics Data System (ADS)

Commercial airlines, electric power grids, cell phones, handheld Global Positioning Systems: Although the Sun is less active due to solar minimum, the number and types of situations and technologies that can benefit from up-to-date space weather information are growing. To address this, the second annual summit of the Commercial Space Weather Interest Group (CSWIG) and the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC) was held on 1 May 2008 during Space Weather Workshop (SWW), in Boulder, Colo.

Intriligator, Devrie S.

2008-10-01

248

The Behaviour of Uranium and Lithium Isotopes During Basalt Weathering and Erosion  

NASA Astrophysics Data System (ADS)

Basalt weathering rates are higher than for many other silicate rocks, and thus exert a strong control on atmospheric CO2 [1]. Moreover, variations in weathering in response to climatic or tectonic change will inevitably affect chemical fluxes to the oceans. Li isotopes potentially provide key information on weathering rates, but their behaviour in the riverine and estuarine environment remains poorly constrained. While U-series nuclides can give information on both the weathering process and the timescale over which it occurs, comparison of both U and Li provides some insight into the processes which govern the geochemical cycles of each element. This study presents new U and Li isotope data for rivers draining basalt terrains in Iceland and Sao Miguel (Azores). Both of these islands are essentially monolithologic, but have different climatic regimes, and variations in river chemistry are linked to differences in the weathering environment, rather than to rock type. River waters from Iceland were taken from both a large catchment in the west of the island, an associated estuary, and from glacial rivers in the south. The U concentration in the rivers ranges from 0.2 to 20 ng/l, and rises from 3 ng/l to almost 3 ?g/l in the estuary, showing conservative behaviour in the mixing zone. Li concentrations range from 0.02 to 1.05 ?g/l in the rivers, and rise to 160 ?g/l in the estuary. Li also behaves conservatively in the mixing zone. For the Azores U and Li river concentrations range from 3 to 212 ng/l and from 0.09 to 3.5 ?g/l, respectively. Highest concentrations are linked to hydrothermal input. Uranium activity ratios (234U/238U) range from 1.13 to 2.14 in Iceland, and from 1.02 to 1.92 in the Azores, showing that silicate weathering can yield a large range of values (down to 1, which is secular equilibrium). Lowest U concentrations typically correspond to highest activity ratios, especially in glacial rivers. The behaviour of U in the catchment shows mixing between the inputs of glaciers, groundwater and hydrothermal water. The 234U/238U ratios in the colloidal fractions are closer to secular equilibrium than their host waters, indicating that these isotopes do not partition equally between the dissolved and colloidal phases. Li isotope values for rivers in Iceland range from 10 to 33 ‰, with low values due to hydrothermal input and high values stemming from superficial weathering in glacial rivers, indicating significant fractionation during weathering of the source basalts. These results indicate that although both elements behave conservatively in the mixing zone, the isotope signal to the oceans may be significantly modified by the weathering environment, in particular the balance of physical/chemical weathering and for U the presence of a colloidal phase. [1] Dessert, C. et al., 2001. Erosion of Deccan Traps determined by river geochemistry: impact on the global climate and the Sr-87/Sr-86 ratio of seawater. EPSL, 188(3-4): 459-474. [2] Riotte, J. et al., 2003. Uranium colloidal transport and origin of the U-234-U-238 fractionation in surface waters: new insights from Mount Cameroon. Chem Geol, 202(3-4): 365-381.

Pogge von Strandmann, P. A.; Burton, K. W.; James, R. H.; van Calsteren, P.; Gislason, S.

2005-12-01

249

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.

250

Weather in Your Life.  

ERIC Educational Resources Information Center

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

Kannegieter, Sandy; Wirkler, Linda

251

Cosmic Rays and Space Weather  

NASA Astrophysics Data System (ADS)

In this review-paper we consider following problems. 1. Cosmic rays (CR) as element of space weather 1.1. Influence of CR on the Earth's atmosphere and global climate change 1.2. Radia-tion hazard from galactic CR 1.3. Radiation hazard from solar CR 1.4. Radiation hazard from energetic particle precipitation from radiation belts 2. CR as tool for space weather forecasting 2.1. Forecasting of the part of global climate change caused by CR intensity variations 2.2. Forecasting of radiation hazard for aircrafts and spacecrafts caused by variations of galactic CR intensity 2.3. Forecasting of the radiation hazard from solar CR events by using on-line one-min ground neutron monitors network and satellite data 2.4. Forecasting of great magnetic storms hazard by using on-line one hour CR intensity data from ground based world-wide network of neutron monitors and muon telescopes 3. CR, space weather, and satellite anomalies 4. CR, space weather, and people health

Dorman, Lev

252

Fate of silicate minerals in a peat bog  

SciTech Connect

An investigation of silicate weathering in a Minnesota mire indicates that quartz and aluminosilicates rapidly dissolve in anoxic, organic-rich, neutral-pH environments. Vertical profiles of pH, disolved silicon, and major cations were obtained at a raised bog and a spring fen and compared. Profiles of readily extractable silicon, diatom abundance, ash mineralogy, and silicate surface texture were determined from peat cores collected at each site. In the bog, normally a recharge mound, dissolved silicon increases with depth as pH increases, exceeding the background silicon concentration by a factor of two. Silicate grain surfaces, including quartz, are chemically etched at this location, despite being in contact with pore water at neutral pH with dissolved silicon well above the equilibrium solubility of quartz. The increasing silica concentrations at circum-neutral pH are consistent with a system where silicate solubility is influenced by silica-organic-acid complexes. Silica-organic-acid complexes therefore may be the cause of the almost complete absence of diatoms in decomposed peat and contribute to the formation of silica-depleted underclays commonly found beneath coal.

Bennett, P.C. (Univ. of Texas, Austin (USA)); Siegel, D.I.; Hill, B.M. (Syracuse Univ., NY (USA)); Glaser, P.H. (Univ. of Minnesota, Minneapolis (USA))

1991-04-01

253

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

254

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

PubMed

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. We developed a carbonate-silicate cycle model 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. We find that CO2 emissions resulting from super-plume tectonics could have produced atmospheric CO2 levels from 3.7 to 14.7 times the modern pre-industrial 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 degrees C over today's global mean temperature. Altered continental positions and higher sea level may have been contributed about 4.8 degrees 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 degrees C, within the 6 to 14 degrees 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% of the mid-Cretaceous increase in atmospheric CO2. PMID:11539811

Caldeira, K; Rampino, M R

1991-06-01

255

Weather Derivative Valuation  

NASA Astrophysics Data System (ADS)

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

Jewson, Stephen; Brix, Anders

2005-04-01

256

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.

257

Fire Weather and Land Degradation  

Microsoft Academic Search

Recent years have witnessed a global increase in more intense, widespread and frequent fires that threaten human security\\u000a and ecosystems and contribute to green house gas emissions which result in climate change with feed-backs on both fire patterns\\u000a and land degradation. The interplay between fire weather-risk and land degradation is complex and involves several non linear\\u000a inter-actions that influence trends

Opha Pauline Dube

258

Development and initial application of the global-through-urban weather research and forecasting model with chemistry (GU-WRF/Chem)  

NASA Astrophysics Data System (ADS)

A unified model framework with online-coupled meteorology and chemistry and consistent model treatments across spatial scales is required to realistically simulate chemistry-aerosol-cloud-radiation-precipitation-climate interactions. In this work, a global-through-urban WRF/Chem model (i.e., GU-WRF/Chem) has been developed to provide such a unified model framework to simulate these important interactions across a wide range of spatial scales while reducing uncertainties from the use of offline-coupled model systems with inconsistent model treatments. Evaluation against available observations shows that GU-WRF/Chem is capable of reproducing observations with comparable or superior fidelity than existing mesoscale models. The net effect of atmospheric aerosols is to decrease shortwave and longwave radiation, NO2photolysis rate, near-surface temperature, wind speed at 10-m, planetary boundary layer height, and precipitation as well as to increase relative humidity at 2-m, aerosol optical depths, column cloud condensation nuclei, cloud optical thickness, and cloud droplet number concentrations at all scales. As expected, such feedbacks also change the abundance and lifetimes of chemical species through changing radiation, atmospheric stability, and the rates of many meteorologically-dependent chemical and microphysical processes. The use of higher resolutions in progressively nested domains from the global to local scale notably improves the model performance of some model predictions (especially for chemical predictions) and also captures spatial variability of aerosol feedbacks that cannot be simulated at a coarser grid resolution. Simulated aerosol, radiation, and cloud properties exhibit small-to-high sensitivity to various nucleation and aerosol activation parameterizations. Representing one of the few unified global-through-urban models, GU-WRF/Chem can be applied to simulate air quality and its interactions with meteorology and climate and to quantify the impact of global change on urban/regional air quality across various spatial scales.

Zhang, Yang; Karamchandani, Prakash; Glotfelty, Timothy; Streets, David G.; Grell, Georg; Nenes, Athanasios; Yu, Fangqun; Bennartz, Ralf

2012-10-01

259

Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.  

PubMed

This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers <5 microm were not classified as to their carcinogenicity to humans. Likewise, Clinoptilolite, Phillipsite, Mordenite, Nonfibrous Japanese Zeolite, and synthetic Zeolites were not classified as to their carcinogenicity to humans. These ingredients are not significantly toxic in oral acute or short-term oral or parenteral toxicity studies in animals. Inhalation toxicity, however, is readily demonstrated in animals. Particle size, fibrogenicity, concentration, and mineral composition had the greatest effect on toxicity. Larger particle size and longer and wider fibers cause more adverse effects. Magnesium Aluminum Silicate was a weak primary skin irritant in rabbits and had no cumulative skin irritation in guinea pigs. No gross effects were reported in any of these studies. Sodium Magnesium Silicate had no primary skin irritation in rabbits and had no cumulative skin irritation in guinea pigs. Hectorite was nonirritating to the skin of rabbits in a Draize primary skin irritation study. Magnesium Aluminum Silicate and Sodium Magnesium Silicate caused minimal eye irritation in a Draize eye irritation test. Bentonite caused severe iritis after injection into the anterior chamber of the eyes of rabbits and when injected intralamellarly, widespread corneal infiltrates and retrocorneal membranes were recorded. In a primary eye irritation study in rabbits, Hectorite was moderately irritating without washing and practically nonirritating to the eye with a washout. Rats tolerated a single dose of Zeolite A without any adverse reaction in the eye. Calcium Silicate had no discernible effect on nidation or on maternal or fetal survival in rabbits. Magnesium Aluminum Silicate had neither a teratogenic nor adverse effects on the mouse fetus. Female rats receiving a 20% Kaolin diet exhibited maternal anemia but no significant reduction in birth weight of the pups was recorded. Type A Zeolite produced no adverse effects on the dam, embryo, or fetus in either rats or rabbits at any dose level. Clinoptilolite had no effect on female rat reproductive performance. These ingredients were not genotoxic in the Ames bacterial test system. In primary hepatocyte cultures, the addition of Attapulgite had no significant unscheduled DNA synthesis. Attapulgite did cause significant increases in unscheduled DNA synthesis in rat pleural mesothelial cells, but no significant increase in sister chromosome exchanges were seen. Zeolite particles (<10 microm) produced statistically significant increase in the percentage of aberrant metaphases in human peripheral blood lymphocytes and cells collected by peritoneal lavage from exposed mice. Topical application of Magnesium Aluminum Silicate to human skin daily for 1 week produced no adverse effects. Occupational exposure to mineral dusts has been studied extensively. Fibrosis and pneumoconiosis have been documented in workers involved in the mining and processing of Aluminum Silicate, Calcium Silicate, Zirconium Silicate, Fuller's Earth, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite. The Cosmetic Ingre

Elmore, Amy R

2003-01-01

260

Interpreting a Weathered Mars: Investigating the Effects of Weathering on Spectroscopic Observations Through Laboratory Study  

NASA Astrophysics Data System (ADS)

Infrared spectroscopy is a critical tool for Martian mineralogy. Because it is crucial to evaluate the history of water on Mars, mineralogical study of weathering and alteration is among the most important topics of Mars spectroscopy. The state of alteration of the Martian surface is evaluated by the presence or absence of alteration phases and their overall abundance. Interpretations of Martian weathering processes are based on the types of alteration products, the mineral assemblages, and derived chemistry. The spectroscopy of alteration minerals has been studied in detail for decades; however, detecting and identifying alteration products from remotely- sensed spectra of natural surfaces is complicated by microtextural mixing of rock-forming minerals, alteration products, and void space. We are investigating the effects that low-temperature weathering has on spectral observations in order to facilitate interpretation of spectroscopic data of Martian surfaces that may be weathered. Our approach has been to characterize the infrared spectra, mineral assemblages, and textures of weathering rinds and rock coatings formed on volcanic rocks in a variety of environments. This approach enables us to witness the spectral variability that results from weathering and tie it to differences in texture or mineralogical composition. More importantly, by examining numerous rinds and coatings, we can determine what effects are common to broader weathering phenomena. For instance, basalt weathering typically leads to systematic changes in silicate vibrational absorptions that can hamper spectral modeling techniques used to assess Martian data. In addition, weathered surfaces may show little evidence of hydrated minerals in near-infrared data. Another important component of our research is the use of controlled laboratory experiments designed to simplify, yet emulate, important attributes of the naturally weathered surfaces, in order to better constrain the spectral effects of weathering. Based on our findings regarding weathering mineral detectability, assertions that Mars has lacked aqueous weathering in its latter history may be incorrect. Rather, we suggest that volumetrically small amounts of high-silica weathering products formed in aqueous environments at middle and high latitudes and that this is consistent with spectroscopic observations of Mars.

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

2007-12-01

261

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

262

Analysis of a Sheet Silicate.  

ERIC Educational Resources Information Center

|Describes a student project in analytical chemistry using sheet silicates. Provides specific information regarding the use of phlogopite in an experiment to analyze samples for silicon, aluminum, magnesium, iron, potassium, and fluoride. (CS)|

Adams, J. M.; Evans, S.

1980-01-01

263

Splitting Aluminosilicates with Silicate Bacteria.  

National Technical Information Service (NTIS)

An experiment was conducted to demonstrate the ability of silicate bacteria to break down the aluminosilicate nucleus in soils and the subsequent liberation of potassium. The equipment and procedures used in the experiment are described along with the res...

M. I. Ternovskaya R. N. Blagodyr V. G. Aleksandrov

1973-01-01

264

Adhesion of hydrated silicate films  

SciTech Connect

We used fracture mechanics test techniques to measure the adhesive bond energy formed between hydrated silica glass surfaces and silicate species deposited from solution. In the case of silicate surfaces hydrated in room temperature water vapor, intermolecular bonding between hydrated surfaces can be attributed to either hydrogen bonding interactions between adsorbed water molecules (0.15 Jm/sup 2/) or electrostatic bonds formed between adsorbed cations and anionic-nonbridging surface oxygen groups (2.0 Jm/sup 2/). The bonding interaction observed at room temperature depends upon the glass surface composition and the degree of surface hydration. When hydrated silicate solution species are added to the interface and heat treated, adhesion energies as large as the cohesive energy of silica glass can be obtained with heat treatments as low as 200/degree/C. The adhesion of the silicate interfacial film produced by the addition of solution species is greatest for silicate precursors showing a low degree of molecular crosslinking. In addition, the presence of alkali in the silicate solution greatly enhances interface adhesion for heat treatments below 200/degree/C. 9 refs., 10 figs.

Michalske, T.A.; Keefer, K.D.

1988-01-01

265

THE BIOCOMPATIBILITY OF MESOPOROUS SILICATES  

PubMed Central

Micro- and nano- mesoporous silicate particles are considered potential drug delivery systems because of their ordered pore structures, large surface areas and the ease with which they can be chemically modified. However, few cytotoxicity or biocompatibility studies have been reported, especially when silicates are administered in the quantities necessary to deliver low-potency drugs. The biocompatibility of mesoporous silicates of particle sizes ~ 150 nm, ~ 800 nm and ~ 4 µm and pore sizes of 3 nm, 7 nm and 16 nm respectively are examined here. In vitro, mesoporous silicates showed a significant degree of toxicity at high concentrations with mesothelial cells. Following subcutaneous injection of silicates in rats, the amount of residual material decreased progressively over three months, with good biocompatibility on histology at all time points. In contrast, intra peritoneal and intra venous injections in mice resulted in death or euthanasia. No toxicity was seen with subcutaneous injection of the same particles in mice. Microscopic analysis of the lung tissue of the mice indicates that death may be due to thrombosis. Although local tissue reaction to mesoporous silicates was benign, they caused severe systemic toxicity. This toxicity could be mitigated by modification of the materials.

Hudson, Sarah; Padera, Robert F.; Langer, Robert; Kohane, Daniel S.

2008-01-01

266

Edheads: Weather Activities  

NSDL National Science Digital Library

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

2010-01-01

267

Space Weather FX  

NSDL National Science Digital Library

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

268

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

269

Internet Weather Links: Weather and Weather Related Lesson Plans  

NSDL National Science Digital Library

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

1996-01-01

270

Air Weather Service Weather-Modification Program.  

National Technical Information Service (NTIS)

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

H. S. Appleman

1968-01-01

271

Palagonite-like Alteration Products on the Earth and Mars 2: Secondary Mineralogy of Crystalline Basalts Weathered Under Semi-Arid Conditions  

NASA Astrophysics Data System (ADS)

In weathering rinds of crystalline basalts, we find poorly crystalline secondary silicates, similar to palagonites. Small volumes of these products cause rinds to have "glassy" thermal-IR spectra. Similar spectral surfaces on Mars may be altered.

Kraft, M. D.; Michalski, J. R.; Sharp, T. G.

2005-03-01

272

Hiding Silicates in Saturn's Rings  

NASA Astrophysics Data System (ADS)

A series of numerical simulations are presented that look at the impact of replacing some of the ice particles in Saturn's rings with silicate particles. All particles are modeled as perfect spheres with no tangential friction. Collisions and particle self-gravity are considered and regions in both the A and B rings have been explored. The particles that represent silicates are given a density of 3 g/cm3 while the icy particles have a density of 0.5 g/cm3. Simulations were done using particles of a single size as well as size distributions and parameters were picked to roughly match measured surface densities. The primary conclusion of this work is that silicate material is well hidden from observations as it collapses down to form core-like structures in the ephemeral gravity wakes. When 4% of the particles are silicates, less than 1% of the reflected light is reflected from the silicate bodies. The light reflected from silicates preferentially comes from particles that are not currently in gravity wakes. Higher percentages of high density material can also be very effectively hidden. Hence, direct observation of spectra does not serve as a strong bound on ring composition. However, having even 4% silicate material does change the pitch angle and structure of gravity wakes and this might serve as an indirect diagnostic of the presence of higher density material. This is especially relevant in the A ring where gravity wake pitch angle affects the azimuthal brightness asymmetry. This work supported by NASA PG&G.

Lewis, Mark C.; Stewart, G. R.

2009-09-01

273

Project Weather and Water.  

ERIC Educational Resources Information Center

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

Hansen, Pal J. Kirkeby

2000-01-01

274

Hot Weather Tips  

MedlinePLUS

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

275

On Observing the Weather  

NSDL National Science Digital Library

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

Crane, Peter

2004-05-01

276

Introduction to Weather  

NSDL National Science Digital Library

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

2010-01-01

277

A Milestone in Commercial Space Weather: USTAR Center for Space Weather  

NASA Astrophysics Data System (ADS)

As of 2009, Utah State University (USU) hosts a new organization to develop commercial space weather applications using funding that has been provided by the State of Utah’s Utah Science Technology and Research (USTAR) initiative. The USTAR Center for Space Weather (UCSW) is located on the USU campus in Logan, Utah and is developing innovative applications for mitigating adverse space weather effects in technological systems. Space weather’s effects upon the near-Earth environment are due to dynamic changes in the Sun’s photons, particles, and fields. Of the space environment domains that are affected by space weather, the ionosphere is the key region that affects communication and navigation systems. The UCSW has developed products for users of systems that are affected by space weather-driven ionospheric changes. For example, on September 1, 2009 USCW released, in conjunction with Space Environment Technologies, the world’s first real-time space weather via an iPhone app. Space WX displays the real-time, current global ionosphere total electron content along with its space weather drivers; it is available through the Apple iTunes store and is used around the planet. The Global Assimilation of Ionospheric Measurements (GAIM) system is now being run operationally in real-time at UCSW with the continuous ingestion of hundreds of global data streams to dramatically improve the ionosphere’s characterization. We discuss not only funding and technical advances that have led to current products but also describe the direction for UCSW that includes partnering opportunities for moving commercial space weather into fully automated specification and forecasting over the next half decade.

Tobiska, W.; Schunk, R. W.; Sojka, J. J.; Thompson, D. C.; Scherliess, L.; Zhu, L.; Gardner, L. C.

2009-12-01

278

Extreme Weather on Earth  

NSDL National Science Digital Library

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

Mika, Anna; Education, National G.

279

Weather Maps in Motion  

NSDL National Science Digital Library

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

Burrows, Charles

280

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

281

Doppler weather radar  

Microsoft Academic Search

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

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

1979-01-01

282

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

283

Severe Weather Primer  

NSDL National Science Digital Library

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

Laboratory, National S.

2010-04-24

284

Weather and Climate Basics  

NSDL National Science Digital Library

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

2008-01-01

285

American Weather Stories.  

ERIC Educational Resources Information Center

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

Hughes, Patrick

286

Space weather risk  

Microsoft Academic Search

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

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

2005-01-01

287

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

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

1979-01-01

288

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

Microsoft Academic Search

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

Christopher Q. Kautz; Candace E. Martin

2007-01-01

289

Chemical weathering in Malay Peninsula and North Borneo: Clay mineralogy and element geochemistry of river surface sediments  

Microsoft Academic Search

Weathering products of silicate rocks are particularly useful for evaluating the continental chemical weathering on the Earth’s\\u000a surface and its mechanism. Clay mineralogy and major-element geochemistry of surface sediment samples collected in major rivers\\u000a of Malay Peninsula and North Borneo in the tropical Southeast Asian region are used to study the present chemical weathering\\u000a process and its controlling factors of

Hao Wang; ZhiFei Liu; Edlic Sathiamurthy; Christophe Colin; JianRu Li; YuLong Zhao

2011-01-01

290

Hydrochemical and Isotopic Constraints on the Temporal and Spatial Variability of Chemical Weathering and CO2 Fluxes: An Example From the Australian Victorian Alps  

NASA Astrophysics Data System (ADS)

Water from a network of 11 pristine rivers draining the Australian Victorian Alps was collected at different locations during (i) high discharge (June 2006) and (ii) low discharge (February 2007) conditions and was analyzed for dissolved major ions, ?2H and ?18O, and ?34S of dissolved sulphate. River water chemistry implies that solutes are largely derived from precipitation and chemical weathering of silicate lithologies. Cl/Br ratios as low as 30 molar suggest that rivers have not dissolved halite, however, higher salinity (?100 mmol/L) winter samples have intermediate Cl/Br ratios (600 to 2000 molar) that are attributed to minor halite dissolution at the onset of the rainy season. Subsequent mixing of river water homogenizes ratios and evaporation is the dominant process that increases downstream salinities. Oxygen and Hydrogen isotopes also indicate that mixing and evaporation have occurred. Despite the lack of carbonate outcrops in the study area and uniform negative calcite saturation indices, the dissolution of hydrothermal calcite may account for up to 67% of the total dissolved cations, generating up to 92% of all dissolved Ca and Mg. The sulphur isotope data (16 to 20°CDT) indicates that the dissolved SO4 is derived predominantly from atmospheric deposition and minor gypsum weathering and not from bacterial reduction of FeS. This militates against sulphuric acid weathering in Victorian rivers. Si/(Na* + K*) ratios suggest that silicate weathering is dominated by the transformation of plagioclase (An40) to smectite and, to a lesser extend, the production of kaolinite. In total, chemical weathering consumes 17.6 x 106 (summer) to 71.59 x 106(winter) mol/km2/yr CO2, with the highest values in rivers draining the basement outcrops rather than sedimentary rocks. This range is at the upper end of the global scale and shows that the predominance of fresh silicate lithologies exerts the main control on higher CO2 fluxes; temperature and runoff, in turn, are crucial variables for the inter- seasonal variability in this region. Data on discharge and major ion chemistry, measured in regular intervals between 1977 and 1990, support this; however, the timing of absolute maxima of Si/(Na* + K*) and CO2 flux peaks do not coincide. We suggest that the combination of dissolution of diatoms that precipitated under low flow- and high temperature conditions in the tributaries and Na-adsorption by suspended clay particles, that were probably redistributed locally after bushfires and/or duststorms during drought periods in the early 1980's, as mechanisms to spontaneously elevate Si/(Na* + K*) ratios and, when coupled with irregular discharge fluctuations, explain deviations from seasonal CO2 fluxes.

Hagedorn, B.; Cartwright, I.

2007-12-01

291

Fabulous Weather Day  

NSDL National Science Digital Library

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

Marshall, Candice; Mogil, H. M.

2007-01-01

292

Effect of silicate anion distribution in sodium silicate solution on silicate conversion coatings of hot-dip galvanized steels  

Microsoft Academic Search

Silicate conversion coatings are prepared by immersing hot-dip galvanized (HDG) steel sheets in sodium silicate solutions with 5wt.% SiO2 and SiO2:Na2O molar ratio in the range of 1.00 to 4.00. The coating with better corrosion resistance is usually obtained in silicate solution with higher molar ratio (3.00–4.00). In this article, the distribution of types of silicate anion in solutions is

Mei-rong Yuan; Jin-tang Lu; Gang Kong; Chun-shan Che

2011-01-01

293

The effect of temperature on experimental and natural chemical weathering rates of granitoid rocks  

USGS Publications Warehouse

The effects of climatic temperature variations (5-35??C) on chemical weathering are investigated both experimentally using flow-through columns containing fresh and weathered granitoid rocks and for natural granitoid weathering in watersheds based on annual solute discharge. Although experimental Na and Si effluent concentrations are significantly higher in the fresh relative to the weathered granitoids, the proportional increases in concentration with increasing temperature are similar. Si and Na exhibit comparable average apparent activation energies (E(a)) of 56 and 61 kJ/mol, respectively, which are similar to those reported for experimental feldspar dissolution measured over larger temperature ranges. A coupled temperature-precipitation model, using an expanded database for solute discharge fluxes from a global distribution of 86 granitoid watersheds, produces an apparent activation energy for Si (51 kJ/mol), which is also comparable to those derived from the experimental study. This correlation reinforces evidence that temperature does significantly impact natural silicate weathering rates. Effluent K concentrations in the column study are elevated with respect to other cations compared to watershed discharge due to the rapid oxidation/dissolution of biotite. K concentrations are less sensitive to temperature, resulting in a lower average E(a) value (27 kJ/mol) indicative of K loss from lower energy interlayer sites in biotite. At lower temperatures, initial cation release from biotite is significantly faster than cation release from plagioclase. This agrees with reported higher K/Na ratios in cold glacial watersheds relative to warmer temperate environments. Increased release of less radiogenic Sr from plagioclase relative to biotite at increasing temperature produces corresponding decreases in 87Sr/86Sr ratios in the column effluents. A simple mixing calculation using effluent K/Na ratios, Sr concentrations and 87Sr/86Sr ratios for biotite and plagioclase approximates stoichiometric cation ratios from biotite/plagioclase dissolution at warmer temperatures (35??C), but progressively overestimates the relative proportion of biotite with decreasing temperature. Ca, Mg, and Sr concentrations closely correlate, exhibit no consistent trends with temperature, and are controlled by trace amounts of calcite or exchange within weathered biotite. The inability of the watershed model to differentiate a climate signal for such species correlates with the lower temperature dependence observed in the experimental studies.

White, A. F.; Blum, A. E.; Bullen, T. D.; Vivit, D. V.; Schulz, M.; Fitzpatrick, J.

1999-01-01

294

hydrochemistry of the Andeans and sub-andeans Amazon basins - Weathering and CO2 consumption rates.  

NASA Astrophysics Data System (ADS)

Measuring mountain weathering rates, estimating their role on C cycle and identifying the parameters which control them are key to better constrain the knowledge of the continental-ocean-atmosphere interactions over geological timescale. The Andes, in contrast to the Himalaya, have received poor attention in terms of chemical weathering. Several authors have worked on the Amazon river basin, but it is difficult to assess the role of the Andes (10% of the surface area of the Amazon river basin) by only sampling the Amazon at mouth or sampling its largest tributaries. As shown by earlier works, the Upper-Amazon basins are the main matter source of the Amazon basin. The studied area participates at more than 70% of the Amazon weathering rates while it contributes to the total discharge on 30% for 27% of the total area. The studied area is comprised between latitude 0°47'N and 20°28'S and between longitude 79°36'W and 58°45'W and can be divided in three major hydrosystems (the Napo river at North, the Maranon-Ucayali rivers on the central part and the upper Madeira at south) which can be separated on Andes and sub-Andes parts. This work presents the results of the HYBAM research program (present-day hydro-geodynamics of the Amazon Basin) on the upper Amazon basin. The concentration of major elements was analyzed on a monthly basis, sampling at 26 gauging stations which include the Andean basins of the Amazon River and a part of the downstream catchment domain. The objectives of this work are i) calculate the major elements fluxes and their spatial distribution, ii) estimate the present-day rate of rock weathering, as well as the flux of atmospheric/soil CO2 consumption from total rock and silicate weathering, and iii) constrain the major environmental factor which controls the dissolved matter production using unique high temporal and spatial resolution data sampling. The main difficulty of studying large river geochemistry is to separate the main sources of the dissolved matter. Studying the temporal dynamic exportation of each element and their main associations helps to better constrain the main matter origin per sub basins and to identify the main processes of production. Variability of runoff rates and lithology between the 3 hydrosystems mainly explain the intersystem weathering rates variability. o The convergence of high runoff rates and main volcanic lithology on Napo basin implies a high weathering rate compared to other basins of the studied area and the main world basins. o Due to the high presence of evaporites and carbonates rocks, the Maranon and Ucayali hydrosystems controls more than 60% of the Amazon hydrochemistry. o Sandstone lithology and low runoff rates on Upper Madeira basins imply a poor contribution of this basin on Amazon dissolved load. Sub-andean plains basins can take place a major role on weathering balance. On the carbonates basins of Maranon Ucayali the subandes catchments contributes to more than 40% to the dissolved load of the hydrosystem. It can reflect the importance of the weathering of sediments exported from Andes or/and the importance of the upper plain weathering rate. The role of environmental parameters, which control those processes, can be partly constrained over the studied area and are compared to other world results. Those results give new keys to better understand the role of major orogenese zones on global weathering processes and its effect on C cycle.

Moquet, Jean-Sébastien; Crave, Alain; Viers, Jérome; Guyot, Jean-Loup; Lagane, Christelle; Sven Lavado Casimiro, Waldo; Pombosa, Rodrigo; Noriega, Luis; Chavary, Eduardo

2010-05-01

295

Avalanche Weather Forecasting  

NSDL National Science Digital Library

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

Linder, Dave

2011-01-01

296

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

297

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

298

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

299

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.

300

Geo-neutrinos, Mantle Circulation and Silicate Earth  

Microsoft Academic Search

In preparation to the experimental results which will be available in the future, we consider geo-neutrino production in greater detail than in [F. Mantovani et al., arXiv:hep-ph\\/0309013], putting the basis for a more refined model. We study geo-neutrino production for different models of matter circulation and composition in the mantle. By using global mass balance for the Bulk Silicate Earth,

Gianni Fiorentini; Marcello Lissia; Fabio Mantovani; Riccardo Vannucci

2004-01-01

301

Battery components employing a silicate binder  

SciTech Connect

A battery component structure employing inorganic-silicate binders. In some embodiments, casting or coating of components may be performed using aqueous slurries of silicates and electrode materials or separator materials.

Delnick, Frank M. (Albuquerque, NM); Reinhardt, Frederick W. (Albuquerque, NM); Odinek, Judy G. (Rio Rancho, NM)

2011-05-24

302

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

303

Iron-Magnesium Silicate Bioweathering on Earth (and Mars?)  

NASA Astrophysics Data System (ADS)

We examined the common, iron-magnesium silicate minerals olivine and pyroxene in basalt and in mantle rocks to determine if they exhibit textures similar to bioweathering textures found in glass. Our results show that weathering in olivine may occur as long, narrow tunnels (1-3 µm in diameter and up to 100 µm long) and as larger irregular galleries, both of which have distinctive characteristics consistent with biological activity. These weathering textures are associated with clay mineral by-products and nucleic acids. We also examined olivine and pyroxene in martian meteorites, some of which experienced preterrestrial aqueous alteration. Some olivines and pyroxenes in the martian meteorite Nakhla were found to contain tunnels that are similar in size and shape to tunnels in terrestrial iron-magnesium silicates that contain nucleic acids. Though the tunnels found in Nakhla are similar to the biosignatures found in terrestrial minerals, their presence cannot be used to prove that the martian alteration features had a biogenic origin. The abundance and wide distribution of olivine and pyroxene on Earth and in the Solar System make bioweathering features in these minerals potentially important new biosignatures that may play a significant role in evaluating whether life ever existed on Mars.

Fisk, M. R.; Popa, R.; Mason, O. U.; Storrie-Lombardi, M. C.; Vicenzi, E. P.

2006-03-01

304

Iron-magnesium silicate bioweathering on Earth (and Mars?).  

PubMed

We examined the common, iron-magnesium silicate minerals olivine and pyroxene in basalt and in mantle rocks to determine if they exhibit textures similar to bioweathering textures found in glass. Our results show that weathering in olivine may occur as long, narrow tunnels (1-3 microm in diameter and up to 100 microm long) and as larger irregular galleries, both of which have distinctive characteristics consistent with biological activity. These weathering textures are associated with clay mineral by-products and nucleic acids. We also examined olivine and pyroxene in martian meteorites, some of which experienced preterrestrial aqueous alteration. Some olivines and pyroxenes in the martian meteorite Nakhla were found to contain tunnels that are similar in size and shape to tunnels in terrestrial iron-magnesium silicates that contain nucleic acids. Though the tunnels found in Nakhla are similar to the biosignatures found in terrestrial minerals, their presence cannot be used to prove that the martian alteration features had a biogenic origin. The abundance and wide distribution of olivine and pyroxene on Earth and in the Solar System make bioweathering features in these minerals potentially important new biosignatures that may play a significant role in evaluating whether life ever existed on Mars. PMID:16551226

Fisk, M R; Popa, R; Mason, O U; Storrie-Lombardi, M C; Vicenzi, E P

2006-02-01

305

Chemical weathering in the Krishna Basin and Western Ghats of the Deccan Traps, India: Rates of basalt weathering and their controls  

Microsoft Academic Search

Rates of chemical and silicate weathering of the Deccan Trap basalts, India, have been determined through major ion measurements in the headwaters of the Krishna and the Bhima rivers, their tributaries, and the west flowing streams of the Western Ghats, all of which flow almost entirely through the Deccan basalts.Samples (n = 63) for this study were collected from 23

A. Das; S. Krishnaswami; M. M. Sarin; K. Pande

2005-01-01

306

Iron Isotope Fractionation in Artic Weathering Environments  

NASA Astrophysics Data System (ADS)

While our current knowledge of Fe isotope systematics in rivers is still limited, Fe isotopes provide a new approach to important questions concerning Fe sources, Fe speciation and its bioavailability in the hydrological cycles. Here, we investigated several Arctic rivers for elemental and Fe-isotopic composition with specific emphasis on silicate weathering and organic C content in order to provide new insights into the delivery of trace nutrients, such as Fe, that are important for the biological productivity of the Arctic Ocean. Without such characterization of the present state of the system, future changes in the response of these river systems to global change cannot be properly evaluated. Our Fe isotope systematics results in Siberian rivers, include (1) a time-series of water samples from large rivers (Ob and Lena) focusing on the peak flow that has not yet been investigated despite its critical importance for annual budgets; (2) the colloidal fractions (1 kDa to 0.45 ?m) of rivers and their estuaries in the White Sea, including the Severnaya Dvina River to assess the influence of Fe-rich colloids flocculation on the Fe isotopic composition of the estuarine waters. Dissolved iron fractions (<0.22 ?m) in large rivers have restricted ?56Fe values, with the Ob River varying from -0.29 to 0.01‰, averaging -0.11‰ (n= 20) and the Lena River varying from -0.24 to -0.01‰, averaging -0.11‰ (n=15). These values are slightly lower than bulk silicate earth values (defined at 0.09‰ relative to IRMM-14) and do not display any relationships with ice break-up on the rivers. In contrast, dissolved iron fractions in the Severnaya Dvina River and its tributaries yield more positive ?56Fe values, with values ranging from -0.09 to up to 0.64‰, averaging 0.2‰ (n=19). Small swamp rivers from the South White Sea coast reveal an even higher spread of dissolved ?56Fe values, from -1.1 to +0.8‰ with some clear variations among the various colloidal fractions (1 kDa-10 kDa - 100 kDa). These results, together with the high Fe and DOC concentrations in the water samples, suggest that Fe-redox cycling in soil aquifer, as well as the formation of organic-rich colloids, may impart specific Fe-isotope signatures in dissolved Fe reaching the Artic Ocean. Recent studies (e.g. Fantle and De Paolo, 2004 and Bergquist and Boyle, 2006) have demonstrated that rivers present an isotopically light Fe source to the oceans. Our study further suggests that ?56Fe composition of Artic rivers is not unique and depending on Fe speciation in organo- mineral colloids and their origin, may be characterized by more positive and negative ?56Fe values relative to the crust than previously reported.

Rouxel, O. J.; Escoube, R.; Pokrovsky, O. S.; Wisch, M.; Miller, C.

2008-12-01

307

A stochastic daily weather generator for skewed data  

NASA Astrophysics Data System (ADS)

To simulate multivariate daily time series (minimum and maximum temperatures, global radiation, wind speed, and precipitation intensity), we propose a weather state approach with a multivariate closed skew-normal generator, WACS-Gen, that is able to accurately reproduce the statistical properties of these five variables. Our weather generator construction takes advantage of two elements. We first extend the classical wet and dry days dichotomy used in most past weather generators to the definition of multiple weather states using clustering techniques. The transitions among weather states are modeled by a first-order Markov chain. Second, the vector of our five daily variables of interest is sampled, conditionally on these weather states, from a closed skew-normal distribution. This class of distribution allows us to handle nonsymmetric behaviors. Our method is applied to the 20 years of daily weather measurements from Colmar, France. This example illustrates the advantages of our approach, especially improving the simulation of radiation and wind distributions.

Flecher, C.; Naveau, P.; Allard, D.; Brisson, N.

2010-07-01

308

Weather and Atmosphere  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

309

Fallout fractionation in silicate soils  

Microsoft Academic Search

The existing models for testing radiochemical fractionation in nuclear weapon debris are discussed and compared. A method which extends the existing theory for the case of surface bursts over silicate soils is developed and validated with weapons test data. There is evidence that fission product absorption by soil and weapon debris is diffusion controlled. There is also evidence that there

1985-01-01

310

Core formation in silicate bodies  

Microsoft Academic Search

Differentiation of a body into a metallic core and silicate mantle occurs most efficiently if temperatures are high enough to allow at least the metal to melt [1], and is enhanced if matrix deformation occurs [2]. Elevated temperatures may occur due to either decay of short-lived radio-isotopes, or gravitational energy release during accretion [3]. For bodies smaller than the Moon,

F. Nimmo; D. P. O'Brien; T. Kleine

2008-01-01

311

Mineralogy of Natural Basalt Weathering Rinds With Application to Thermal Emission Spectra of Mars  

NASA Astrophysics Data System (ADS)

Mineralogy of Natural Basalt Weathering Rinds With Application to Thermal Emission Spectra of Mars M.D. Kraft, J.R. Michalski, T.G. Sharp, (and P.R. Christensen?) Chemically weathered rocks have been suggested to cover a significant portion of the Martian surface based on orbiter observations, and rocks investigated by the Mars Exploration Rover at the Gusev landing site show evidence of chemical alteration and weathering rinds. To understand remote mineralogical and chemical measurements of altered rock surfaces, whether in situ or from orbit, it is important to understand the general characteristics of weathering rinds (e.g., secondary mineralogy and microstructure in rinds) and how these characteristics affect remote observations. We are investigating a suite of weathered rocks of the Columbia River Basalt Group (CRBG) to identify chemical, mineralogical, and micro-structural changes associated with weathering and determine how these changes influence thermal emission measurements. Preliminary work shows that thermal emission spectra of weathered surfaces can vary substantially from spectra of fresh rocks despite rather low degrees of alteration in weathered surfaces. In rocks studied thus far, the predominant difference between the unweathered rock and weathering rind is an increase in porosity in the rind due to dissolution and/or volume expansion, causing a substantial increase in the volume density of micron-scale cracks. Mineralogical differences are imparted in the rind by the (partial) infilling of cracks by secondary materials that are Si, Al, and Fe-rich. A previous investigation by Colman (1982) showed that secondary silicates in basalt weathering rinds were dominantly X-ray amorphous. High-resolution secondary electron imaging of crack-filling products reveals spheroid-shaped materials, 10s of nm in diameter, which are consistent with short-range order allophane. We are currently performing additional analyses using XRD and TEM to constrain the mineralogy of secondary phases in CRGB weathering rinds, including the crystallinity of secondary silicates. Assessing chemical weathering on Mars may rely largely on the ability to detect and constrain the mineralogy of short-range order silicates, which may be the dominant Martian weathering products. Thermal emission spectroscopic data of Mars, with the detailed understanding that we intend to provide with this study, provides a unique and excellent means of constraining the nature of silicate weathering on Mars.

Kraft, M. D.; Michalski, J. R.; Sharp, T. G.; Christensen, P. R.

2004-12-01

312

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

313

Marangoni effect in metal-silicate self separation  

NASA Astrophysics Data System (ADS)

High pressure experiments of metal silicate mixture display a tendency for the molten metal phase to percolate through the solid silicate matrix toward the coolest regions of the sample. This simple observation carries important implications for processes leading to formation of planetary cores and present day core-mantle interactions. For the percolation to work, two ingredients are necessary, the classical wetting condition and a driving force to compact the silicate matrix. In laboratory scale experiments, gravity is negligible and the only available driving force is the interfacial tension, and in particular its temperature dependence, the Marangoni effect. We developed a physical model to treat numerically this problem within the framework of the compaction two-phase theory proposed by Bercovici, Ricard et al. Experimental results can be used to tune several of the unknown parameters in the numerical model and to test the theory. Both models and experiments show that interfacial tension can trigger metal silicate differentiation at the local scale, even in small planetesimals before gravity can act, and help global scale core formation. In addition, at the bottom of the mantle, the large temperature gradient can help core material to percolate upward. This process is much faster than the time scale for changes in the mantle and a steady state calculation gives the height in the mantle reached by the metal. The implications in terms of core-mantle electromagnetic interactions will be considered.

Labrosse, Stephane; Terasaki, Hidenori; Ricard, Yanick

2010-05-01

314

Death and Death Rates Due to Extreme Weather Events  

Microsoft Academic Search

Abstract Despite the recent spate of deadly extreme weather events such as the 2003 European heat wave and the hurricanes of 2004 and 2005, aggregate mortality and mortality rates due to extreme weather events are generally lower today than they used to be. Globally, mortality and mortality rates have declined by 95 percent or more since the 1920s. The largest

Indur M. Goklany; Third Floor; Bedford Chambers

315

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

316

A stochastic daily weather generator for skewed data  

Microsoft Academic Search

To simulate multivariate daily time series (minimum and maximum temperatures, global radiation, wind speed, and precipitation intensity), we propose a weather state approach with a multivariate closed skew-normal generator, WACS-Gen, that is able to accurately reproduce the statistical properties of these five variables. Our weather generator construction takes advantage of two elements. We first extend the classical wet and dry

C. Flecher; P. Naveau; D. Allard; N. Brisson

2010-01-01

317

Earth weather and climate control: can space technology contribute?  

Microsoft Academic Search

With ongoing progress in space technology, questions of its potential for the modification of weather and climate phenomena (often summarized by the term ‘geoengineering’) ranging from small-scale severe weather events to mitigation of effects caused by global climate change and ozone depletion have become popular. This paper reviews the current state of scientifically based studies in this context and attempts

Peter Bauer; Wolfgang Seboldt; Michael Klimke

1999-01-01

318

Projected Changes in Extreme Weather and Climate Events in Europe  

Microsoft Academic Search

Extreme weather and climate events have wide ranging impacts on society as well as on biophysical systems. That society, on occasions, is unable to cope with extreme weather and climate events is concerning, especially as increases in the frequency and intensity of certain events are predicted by some global climate change projections. Extreme events come in many different shapes and

Glenn McGregor; Christopher Ferro; David Stephenson

319

A decade of weather extremes  

NASA Astrophysics Data System (ADS)

The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme -- notably heatwaves, but also precipitation extremes -- there is now strong evidence linking specific events or an increase in their numbers to the human influence on climate. For other types of extreme, such as storms, the available evidence is less conclusive, but based on observed trends and basic physical concepts it is nevertheless plausible to expect an increase.

Coumou, Dim; Rahmstorf, Stefan

2012-07-01

320

NOAA Daily Weather Maps  

NSDL National Science Digital Library

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

Center, Hydrometeorological P.

2011-01-01

321

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. However, 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 although decarbonation of pelagic sediments in Tethyan subduction likely contributed to generally high pCO2 levels from the Late Cretaceous until the Early Eocene, shutdown of Tethyan subduction with 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 basaltic provinces in the equatorial humid belt (5° S-5° N) seems to be the dominant control on 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 sporadic 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. Increase in Mg/Ca ratio of seawater over the Cenozoic may be due to weathering input from continental basaltic provinces.

Kent, D. V.; Muttoni, G.

2012-09-01

322

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.

323

Fire Weather Technology for Fire Agrometeorology Operations  

Microsoft Academic Search

Even as the magnitude of wildfire problems increases globally, United Nations agencies are acting to mitigate the risk of wildfire disasters to members. Fire management organizations worldwide may vary considerably in operational scope, depending on the number and type of resources an organization manages. In any case, good fire weather information is vital. This paper describes an approach for introducing

Francis M. Fujioka

324

Portrait of Global Aerosols  

NASA Website

High-resolution global atmospheric modeling run on the Discover supercomputer at the NASA Center for Climate Simulation at Goddard Space Flight Center, Greenbelt, Md., provides a unique tool to study the role of weather in Earth's climate system. ...

325

Space Weather Media Viewer  

NSDL National Science Digital Library

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

2011-01-01

326

Plymouth State Weather Center  

NSDL National Science Digital Library

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

327

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.

328

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.

329

Weather and Climate Data  

NSDL National Science Digital Library

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

330

Heavy ion bombardment of silicates and nitrides  

Microsoft Academic Search

Several silicates, including ?-quartz, zirconium silicate, thorium silicate, LiAlSiO, a silicate glass and several nitrides, ? and ? Si3N4, AlN, ZrN as well as Si2N2O and ThO2, have been irradiated by 10-10 Krypton(3MeV)ions\\/m The damaged powders of original particle size less than 5 ?m, have been examined by x-ray diffraction and electron microscope methods. The silicates and Si2N2O become non-crystalline

L. Cartz; F. G. Karioris; R. A. Fournelle

1981-01-01

331

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

332

Effects of ionization on silicate glasses. [Silicate glasses  

SciTech Connect

This evaluation of radiation effects in silicate glasses caused by ionization is based on our own investigations, on material collected in our files (reports, articles, and notes), and on a computer literature search through recent issues of Physics Abstracts and Chemical Abstracts (and the apparently pertinent references which appeared). Some of our recent results, available heretofore only in internal correspondence, are presented in some detail. It is concluded that research into the behavior of silicate glasses generally will be required before the specific effects in the radioactive waste storage glasses can be properly understood and evaluated. Two particular neglected areas of investigation are targeted for immediate concern: a kinetic analysis of annealing data and the acquisition of data on effects of irradiation at controlled elevated temperatures.

Primak, W.

1982-02-01

333

Biogenic silicate accumulation in sediments, Jiazhou Bay  

NASA Astrophysics Data System (ADS)

It has been widely recognized that low silicate content in seawater is a major limiting factor to phytoplankton primary production in Jiaozhou Bay. However the reason of Si-limitation remains poorly understood. In the present study we measured the biogenic silicate content and discussed the accumulation of silicate in Jiaozhou Bay sediment. The results show that the biogenic silica content in the sediment of the Jiaozhou Bay is obviously much higher than those in the Yellow Sea and the Bohai Sea. The Bsi:TN ratios and BSi:16P ratios in the sediment are>1 and the OC:BSi ratio in sediment is lower than these of Redfield ratio (106?16), indicating that the decomposition rate of OC is much higher than that for BSi in similar conditions. Therefore, the majority of the biogenic silicate was buried and thus did not participate in silicate recycling. Silicate accumulation in sediment may explain why Si limits the phytoplankton growth in the Jiaozhou Bay. Comparing the flux of biogenic silicate from sediments with primary production rate, it can be concluded that only 15.5% of biogenic silicate is hydrolyzed during the journey from surface to bottom in seawater, thus approximate 84.5% of biogenic silicate could reach the bottom. The silicate releasing rate from the sediment to seawater is considerably lower than that of sedimentation of biogenic silicate, indicating silicate accumulation in sediment too. In a word, the silicate accumulation in sediment is the key reason of silicate limiting to phytoplankton growth in Jiaozhou Bay.

Li, Xuegang; Song, Jinming; Dai, Jicui; Yuan, Huamao; Li, Ning; Li, Fengye; Sun, Song

2006-09-01

334

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

335

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

SciTech Connect

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

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

1989-05-01

336

Comparison of The Christiansen Feature Position and Lunar Iron: Evidence for Space Weathering Effects  

Microsoft Academic Search

Diviner's three channels near 8-microns characterize an infrared emissivity maximum called the Christiansen Feature (CF) which is has been established as compositional indicator in laboratory experiments. Laboratory measurements show that the CF is related to silicate polymerization and occurs at shorter wavelengths for feldspathic minerals and longer wavelengths for mafic minerals. Laboratory experiments regarding the effect of space weathering on

P. G. Lucey; D. A. Paige; B. T. Greenhagen; C. Allen; J. L. Bandfield; N. Bowles; K. Hanna; T. D. Glotch; I. R. Thomas; M. B. Wyatt

2009-01-01

337

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...

338

On Observing the Weather  

ERIC Educational Resources Information Center

|Rain, sun, snow, sleet, wind... the weather affects everyone in some way every day, and observing weather is a terrific activity to attune children to the natural world. It is also a great way for children to practice skills in gathering and recording information and to learn how to use simple tools in a standardized fashion. What better way to…

Crane, Peter

2004-01-01

339

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

340

On Observing the Weather  

ERIC Educational Resources Information Center

Rain, sun, snow, sleet, wind... the weather affects everyone in some way every day, and observing weather is a terrific activity to attune children to the natural world. It is also a great way for children to practice skills in gathering and recording information and to learn how to use simple tools in a standardized fashion. What better way to…

Crane, Peter

2004-01-01

341

Weathering Database Technology  

ERIC Educational Resources Information Center

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

Snyder, Robert

2005-01-01

342

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…

1998

343

The Home Weather Station.  

ERIC Educational Resources Information Center

Described is how an amateur weather observer measures and records temperature and precipitation at a well-equipped, backyard weather station. Directions for building an instrument shelter and a description of the instruments needed for measuring temperature and precipitation are included. (KR)

Steinke, Steven D.

1991-01-01

344

Advanced Aviation Weather Forecasts  

Microsoft Academic Search

n The U.S. air transportation system faces a continuously growing gap between the demand for air transportation and the capacity to meet that demand. Two key obstacles to bridging this gap are traffic delays due to en route severe- weather conditions and airport weather conditions. Lincoln Laboratory has been addressing these traffic delays and related safety problems under the Federal

Marilyn M. Wolfson; David A. Clark

2006-01-01

345

Teacher's Weather Sourcebook.  

ERIC Educational Resources Information Center

|This book is a teaching resource for the study of weather-related phenomena. A "weather unit" is often incorporated into school study because of its importance to our daily lives and because of its potential to cut across disciplinary content. This book consists of two parts. Part I covers the major topics of atmospheric science such as the…

Konvicka, Tom

346

Fabulous Weather Day  

ERIC Educational Resources Information Center

|Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

Marshall, Candice; Mogil, H. Michael

2007-01-01

347

The Home Weather Station.  

ERIC Educational Resources Information Center

|Described is how an amateur weather observer measures and records temperature and precipitation at a well-equipped, backyard weather station. Directions for building an instrument shelter and a description of the instruments needed for measuring temperature and precipitation are included. (KR)|

Steinke, Steven D.

1991-01-01

348

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.

349

Northwest Weather Watch  

NSDL National Science Digital Library

This educational module is designed to teach students about predicting weather. This includes a series of activites about clouds, moisture, air and rain for students to complete. There are curriculum connections to art, writing and math as well as links for more resources and live weather data.

Palewicz, Sue; Scurlock, Marianne; Edmon, Harry

350

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

351

Weather and Individual Happiness  

Microsoft Academic Search

This paper investigates the influence of weather on happiness. While previous studies have examined climatic influence by comparing the well-being of people living in different regions, this paper focuses on how daily changes in weather affect individuals living in a single location. Our data set consists of 516 days of data on 75 students from Osaka University. Daily information on

Yoshiro Tsutsui

2011-01-01

352

Waste glass weathering  

Microsoft Academic Search

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

J. K. Bates; E. C. Buck

1993-01-01

353

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

354

Fabulous Weather Day  

ERIC Educational Resources Information Center

Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

Marshall, Candice; Mogil, H. Michael

2007-01-01

355

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

356

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

2010-07-10

357

Insensitivity of weathering behavior to planetary land fraction and effect on habitability  

NASA Astrophysics Data System (ADS)

It is likely that an increasing number of terrestrial planets of unknown water content will soon be discovered in the habitable zone of their stars. Planetary surface land fraction may, however, influence the functioning of the silicate weathering feedback, which buffers planetary surface climate against changes in stellar luminosity over a star's lifetime. It is therefore worthwhile to consider the effect of land fraction on the planetary carbon cycle and weathering behavior in a general sense. Here a low-order model of weathering and climate is developed that includes both continental silicate weathering and seafloor weathering. This model can be used to gain an intuitive sense of the behavior of terrestrial planets with different land fractions in the habitable zone of main-sequence stars as their star's insolation changes with time. It is found that, as long as seafloor weathering is independent of surface temperature, there can be no weathering feedback on a waterworld. This means that the tenure of a waterworld in the habitable zone (before it undergoes a moist greenhouse) is likely to be much shorter than that of a planet with some land fraction. The silicate weathering feedback, however, is effective even at very low land fractions. A planet with a land fraction of 0.01 should remain in the habitable zone nearly as long as a planet with a land fraction of 0.3. Finally, by comparing the timescale for water loss to space to the weathering timescale, it is found that it is possible for a waterworld to draw down atmospheric CO2 quickly enough as a moist greenhouse is in progress to prevent complete loss of all water. This would imply that waterworlds in the habitable zone of main sequence stars can go through a moist greenhouse stage and end up as planets like Earth with only partial ocean coverage and a habitable climate.

Abbot, D. S.; Archer, D.; Pierrehumbert, R. T.; Ciesla, F. J.; Bean, J. L.

2012-04-01

358

Space Weather and the Earth's Climate  

NASA Astrophysics Data System (ADS)

Space Weather is a multi-disciplinary subject covering many technological, scientific, environmental and economical topics and the aim of this paper is to give a global overview of what this encompasses. Defining the various Space Weather induced effects (technological and biological) should have the potential Space Weather User in mind. Phenomena that can induce these effects are for the most part natural, but can also be man-made. Tools using models to explain the dynamical space environment and its effects incorporating real-time data are essential for any Space Weather forecasting center. This involves international interactions between different fields and the many world-wide Space Weather initiatives that have been initiated show indeed how much emphasis is being placed on this at present. Defining the physical relation of the Earth's changing climate with various long-term changes in the space environment may provide clues to the short-term changes that one wants to predict both on the weather in space and on Earth.

Crosby, Norma B.

2001-05-01

359

Silicates of the rare earths  

Microsoft Academic Search

of Silicate Chemistry, we have plotted phase diagrams for binary systems of silica with oxides of lanthanum, samarium, ga0olinium, dysprosium, yttrium, erbium, and ytterbium. The investigations showed similarities in the structure of these systems: the existence of three types of compounds - the oxyorthosilicates (Ln~O[SiO4] or Ln20 s ?9 sin2), the orthosilicates (Ln4[SiO4]s or 2Ln20 s ?9 3SIO2), the diorthosilicates

F. Ya. Galakhov; N. A. Toropov

1962-01-01

360

Scholastic: Weather Watch  

NSDL National Science Digital Library

The Weather Watch series of online projects investigates seasonal weather phenomena. Students discover the scientific explanations for these events, and use tools and resources for enhanced research. The Hurricanes project allows students to monitor patterns and plot the progression of hurricanes. The Winter Storms project contains an interactive weather maker allowing students to create different weather patterns by changing factors. A winter storm timeline provides stories of the harshest blizzards that have occurred in the U.S. The Weather Reporters project includes a selection of hands-on science experiments for classroom participation, leading up to sharing results online with students worldwide. Each project provides assessment tools and lesson plan suggestions for educators. Links are provided for additional resources.

361

Introdution of China Weather TV and its work on climate change  

Microsoft Academic Search

A. Introduction of China Weather TV China Weather TV is the exclusive meteorological channel in China which broadcasting 24 hours each day. Nowadays, climate change becomes the global hot issue. As the professional meteorological channel, China Weather TV focuses on the education and public awareness on climate change. It not only makes news reports to let the public know the

R. Li

2007-01-01

362

Geochemical Fluxes and Weathering on High Standing Islands: Taranaki and Manawatu-Wanganui Regions, New Zealand  

NASA Astrophysics Data System (ADS)

Sediment fluxes from high standing oceanic islands (HSIs) such as New Zealand are some of the highest known. Recent geochemical work has suggested that along with their extremely high physical weathering yields, many New Zealand watersheds also have very high chemical weathering yields. In New Zealand, the magnitude of both the physical and chemical weathering yields is related to the lithology of the watershed. Most of the previous work on this topic has been undertaken in Southern Alps watersheds of schist and greywacke and in East Cape watersheds of semi-consolidated marine sediments and greywacke. We recently sampled North Island watersheds in the Taranaki and Manawatu-Wanganui regions which have been subjected to volcanism since the Miocene. We sampled watersheds that contain both volcanic and sedimentary rocks. A series of water and sediment samples was collected and analyzed for major, minor and trace elements. This was done to quantify the weathering intensities in the watersheds and to establish the relationship between physical and chemical weathering yields in volcanic lithologies. Our results reveal distinct chemical signatures for the different regions. Waters draining the Taranaki region volcanics are significantly enriched in Si and K+ and depleted in Ca2+, Sr2+, and HCO3- compared to waters draining the Manawatu-Wanganui region volcanics, which also traverse expanses of sedimentary siltstones and mudstones. The Ca2+, Sr2+, and HCO3- depletions may reflect the relative absence of CaCO3 in the Taranaki region watersheds. In addition, sediment samples from the Taranaki region show significant enrichment in Ti, Al, Ca, Fe, Mn, Mg, Ca, and P and depletion in Si and Rb compared to those of the Manawatu-Wanganui region. From total dissolved solids concentrations and annual volumetric water discharge, we calculate chemical weathering yields of 60-238 tons km-2a-1. These weathering yields fall within the middle to upper range of those previously documented for the Southern Alps (93-480 tons km-2 a-1) and East Cape (62-400 tons km-2 a-1). Calculated silicate weathering yields of 12-33.6 tons km-2 a-1) and CO2 consumption of 852-2390 x 103 moles km-2 a-1) for the rivers draining the Taranaki volcanic region are higher than those previously reported for watersheds hosted in sedimentary and metamorphosed rock terrains on HSIs. CO2 consumption is found to be within the range previously measured for the basaltic terrains of the Deccan Traps (580-2450 x103 moles km-2 a-1) and Reunion Island (1300-4400 x103 moles km-2 a-1). Our calculated chemical weathering yields demonstrate the importance of HSIs, particularly those with volcanic terrains, when considering global geochemical fluxes.

Goldsmith, S. T.; Carey, A. E.; Lyons, W. B.; Hicks, D. M.

2005-12-01

363

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

364

Analysis of Preflight Weather Briefings.  

National Technical Information Service (NTIS)

Weather is often cited as a factor in general aviation (GA) accidents and mishaps. The type of weather information requested from, or provided by, automated flight service station (AFSS) specialists is dependent on weather conditions at the time the prefl...

A. M. Hendrix O. V. Prinzo R. Hendrix

2007-01-01

365

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

366

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

367

Paleosol at the Archean—Proterozoic contact in NW India revisited: Evidence for oxidizing conditions during paleo-weathering?  

NASA Astrophysics Data System (ADS)

A number of fine-grained sericite bearing pelitic, schistose lithologies occur along the Archean (Banded Gneiss Complex)-Proterozoic (Aravalli Supergroup) contact (APC) in the Udaipur valley in NW Indian craton. These Al-rich lithologies (subsequently metamorphosed) have been described as ‘paleosols’, developed over a 3.3 Ga old Archean gneissic basement and are overlain by Paleoproterozoic Aravalli quartzite. The paleosol was developed between 2.5 and 2.1, coincident with the globally recognized Great Oxidation Event (GOE). In previous studies these paleosol sections were interpreted to have developed under reducing environment, however, the finding of a ‘ferricrete’ zone in the upper part of Tulsi Namla section (east of Udaipur) during the present study (in addition to earlier reported lithologies) has led to an alternative suggestion of oxygen-rich conditions during paleosol development. The Tulsi Namla paleosol section shows all the features characteristic of a complete paleosol section described from other Archean cratons. The paleosol includes sericite schist with kyanite as the prevalent Al-silicate in the lower part of profile while chloritoid and Fe-oxides typify the Fe-rich upper part. Alumina has remained immobile during the weathering process while Fe and Mn show a decrease in the lower part of the section and an abrupt rise in the upper part, in the ferricrete zone. The field and geochemical data indicate that the Tulsi Namla section is an in situ weathering profile and at least the upper part shows evidence of oxidizing conditions.

Pandit, Manoj K.; de Wall, Helga; Chauhan, Narendra K.

2008-06-01

368

The Space Weather Reanalysis  

NASA Astrophysics Data System (ADS)

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

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

2002-12-01

369

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

370

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

371

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.

372

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

373

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.

374

SWIFF: Space weather integrated forecasting framework  

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

375

Barium in the Yamuna River System in the Himalaya: Sources, fluxes, and its behavior during weathering and transport  

NASA Astrophysics Data System (ADS)

Systematic measurements of Ba in waters and bed sediments of the Yamuna and many of its tributaries in the Himalaya (Yamuna River System) have been carried out. Dissolved Ba in the Yamuna River System (YRS) ranges from 17 to 871 nM. Streams near the source region draining predominantly granites/gneisses have lower abundance of Ba, <100 nM compared with those in the lower reaches. These data, coupled with those available for major ion composition of these rivers and their sediments, have been used to determine the contributions of silicates and carbonates, the two major lithologies in the drainage basin, to dissolved Ba in YRS. In YRS, dissolved Ba shows significant covariations with Na*, Si, Ca, and Mg. Using Na* as an index, it is estimated that silicates are an important source of Ba to many of the rivers; in a few streams in the lower reaches, however, they account for only <20% of measured Ba. Carbonate weathering, which dominates the major ion composition of YRS rivers, contributes on average ˜30% of dissolved Ba. Together, silicates and carbonates roughly balance measured Ba in many of the rivers, whereas in a few streams, Ba contributions from additional sources are needed to balance the budget. Prospective sources include organic matter/phosphorites. Plot of 1/Ba versus 87Sr/86Sr shows a two-component mixing trend, one with low Ba-high 87Sr/86Sr (silicates) and the other with high Ba-low 87Sr/86Sr (carbonates, phosphorites). Ba also shows significant positive correlation with dissolved Re and SO4. A likely explanation for the Ba-Re-SO4 association is that they are supplied from organic matter/phosphorites/carbonates assemblages through H2SO4 weathering. In YRS bed sediments, Ba shows significant correlation with K and Al. Ba/Na and Ba/Sr in these sediments are higher than those in granites of the Higher Himalaya. These observations can be explained in terms of (1) differential release of these elements during weathering, Ba being less mobile because of its association with weathering resistant minerals or (2) "nonconservative" behavior of Ba in rivers resulting in its removal from dissolved to particulate phases. Either way, these results indicate that Ba is less mobile relative to Na and Sr. Dissolved Ba flux from the YRS basin is ˜5 times more than that from the Ganga headwaters, a result consistent with higher physical and chemical erosion in the YRS basin. The Yamuna and the Ganga together transport ˜5.4 × 106 mol yr-1 of Ba out of the Himalaya, which is ˜10% of the dissolved Ba flux from the Ganga at Bangladesh, roughly the same as their contribution to water discharge. The rate of Ba mobilization in the Yamuna and the Ganga basins in the Himalaya is a factor of ˜2 higher than the global average.

Dalai, Tarun K.; Krishnaswami, S.; Sarin, M. M.

2002-12-01

376

How does weather change?  

NSDL National Science Digital Library

This activity is a field investigation where students gather temperature and weather data in the a.m and p.m. and develop a new, experimental question to predict temperature over the course of the year.

Susan Anderson, Taylors Falls Elementary, Taylors Falls, MN based on an activity from Houghton Mifflin Science Grade 2 Weather Patterns, p. D6.

377

The Weather Calculator  

NSDL National Science Digital Library

This set of conversion tools helps convert units and values for weather data, including temperature, moisture, atmospheric pressure, wind, and other parameters. Formulas are also provided for the conversions.

378

Tombstone Weathering Lab  

NSDL National Science Digital Library

Students work in groups in a cemetery to collect a quantitative and a qualitative measure of the extent of weathering of tombstones and their ages. The data are shared between all students, graphed as scatter plots, and the rate of weathering is estimated. Students write about and then discuss the results, the difference between the quantitative and qualitative measures, and speculate on factors in addition to time that may be important for weathering rate. The exercise ends with each students writing a hypothesis about a factor that influences weathering rate and describing a research project that could test that hypothesis. This activity is aimed at developing an understanding of the scatter in "real data", allowing for practice of team work, and hypothesis generation and testing. Designed for a geomorphology course Has minimal/no quantitative component

Anders, Alison

379

Weather and Climate.  

National Technical Information Service (NTIS)

Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human lo...

1975-01-01

380

Winter Weather FAQs  

MedlinePLUS

... lower your body temperature. What is the best clothing for cold weather? Adults and children should wear: ... coat and shoes several layers of loose-fitting clothing Be sure the outer layer of your clothing ...

381

Weatherization Materials Handbook.  

National Technical Information Service (NTIS)

This handbook provides information on purchasing weatherization products, and is intended for use by Community Action Agencies and other community-based organizations in their energy conservation programs. Product information is given for insulation, stor...

1979-01-01

382

Experimentation with Weather Control.  

National Technical Information Service (NTIS)

Contents: Brief historical sketch (woes of citizens as a source of inspiration for, and a cause of difficulties in, weather control experimentation); Three consecutive hail-prevention experiments in Switzerland. Reports of the U.S. National Academy of Sci...

J. Neyman

1967-01-01

383

Winter Weather Emergencies  

MedlinePLUS

... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. You should have a disaster plan. Being prepared can help reduce fear, anxiety and losses. Centers for Disease Control and Prevention

384

Mapping Weather Severity Zones.  

National Technical Information Service (NTIS)

The goals of this project were to develop a methodology to map winter severity from a winter maintenance perspective, and to create electronic maps and associated geospatial data depicting winter weather severity across the country. Work performed under t...

J. J. Mewes

2011-01-01

385

Decreased water flowing from a forest amended with calcium silicate  

PubMed Central

Acid deposition during the 20th century caused widespread depletion of available soil calcium (Ca) throughout much of the industrialized world. To better understand how forest ecosystems respond to changes in a component of acidification stress, an 11.8-ha watershed was amended with wollastonite, a calcium silicate mineral, to restore available soil Ca to preindustrial levels through natural weathering. An unexpected outcome of the Ca amendment was a change in watershed hydrology; annual evapotranspiration increased by 25%, 18%, and 19%, respectively, for the 3 y following treatment before returning to pretreatment levels. During this period, the watershed retained Ca from the wollastonite, indicating a watershed-scale fertilization effect on transpiration. That response is unique in being a measured manipulation of watershed runoff attributable to fertilization, a response of similar magnitude to effects of deforestation. Our results suggest that past and future changes in available soil Ca concentrations have important and previously unrecognized implications for the water cycle.

Green, Mark B.; Bailey, Amey S.; Bailey, Scott W.; Battles, John J.; Campbell, John L.; Driscoll, Charles T.; Fahey, Timothy J.; Lepine, Lucie C.; Likens, Gene E.; Ollinger, Scott V.; Schaberg, Paul G.

2013-01-01

386

Decreased water flowing from a forest amended with calcium silicate.  

PubMed

Acid deposition during the 20th century caused widespread depletion of available soil calcium (Ca) throughout much of the industrialized world. To better understand how forest ecosystems respond to changes in a component of acidification stress, an 11.8-ha watershed was amended with wollastonite, a calcium silicate mineral, to restore available soil Ca to preindustrial levels through natural weathering. An unexpected outcome of the Ca amendment was a change in watershed hydrology; annual evapotranspiration increased by 25%, 18%, and 19%, respectively, for the 3 y following treatment before returning to pretreatment levels. During this period, the watershed retained Ca from the wollastonite, indicating a watershed-scale fertilization effect on transpiration. That response is unique in being a measured manipulation of watershed runoff attributable to fertilization, a response of similar magnitude to effects of deforestation. Our results suggest that past and future changes in available soil Ca concentrations have important and previously unrecognized implications for the water cycle. PMID:23530239

Green, Mark B; Bailey, Amey S; Bailey, Scott W; Battles, John J; Campbell, John L; Driscoll, Charles T; Fahey, Timothy J; Lepine, Lucie C; Likens, Gene E; Ollinger, Scott V; Schaberg, Paul G

2013-03-25

387

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

388

Predicting Seasonal Weather  

NSDL National Science Digital Library

Large-scale weather patterns which occur in various locations around the Earth play a significant part in controlling the weather on a seasonal time scale. A National Science Foundation (NSF)-funded collaborative research effort between Atmospheric and Environmental Research, Inc. (AER), and the Massachusetts Institute of Technology (MIT) has led to a new understanding of the relationship between fall snow cover and winter climate variability. This research has led to the development of a new seasonal forecast model.

389

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)

390

An Ocean of Weather  

NSDL National Science Digital Library

In this lesson, students will investigate the close relationship between the ocean and the atmosphere to determine the extent the ocean affects the Earth's weather in the South Atlantic Bight region. As they study this relationship, students will learn that the ocean and atmosphere work together as a system. They will experiment to find out that heat transfer from the ocean is a cause of much of Earth's weather and will make and explain an ocean water cycle.

391

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

Code of Federal Regulations, 2013 CFR

... false Modified magnesium silicate polymer (generic). 721.9513 Section 721...721.9513 Modified magnesium silicate polymer (generic). (a) Chemical substance...generically as modified magnesium silicate polymer (PMN P-98-604) is subject to...

2013-07-01

392

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

393

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

394

Space Weather Applications and Spacecraft Anomalies  

NASA Astrophysics Data System (ADS)

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

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

395

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

396

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

397

The space-weather enterprise: past, present, and future  

NASA Astrophysics Data System (ADS)

Space-weather impacts society in diverse ways. Societies' responses have been correspondingly diverse. Taken together these responses constitute a space weather ``enterprise'', which has developed over time and continues to develop. Technological systems that space-weather affects have grown from isolated telegraph systems in the 1840s to ocean and continent-spanning cable communications systems, from a generator electrifying a few city blocks in the 1880s to continent-spanning networks of high-tension lines, from wireless telegraphy in the 1890s to globe-spanning communication by radio and satellites. To have a name for the global totality of technological systems that are vulnerable to space weather, I suggest calling it the cyberelectrosphere. When the cyberelectrosphere was young, scientists who study space weather, engineers who design systems that space weather affects, and operators of such systems - the personnel behind the space-weather enterprise - were relatively isolated. The space-weather enterprise was correspondingly incoherent. Now that the cyberelectrosphere has become pervasive and indispensable to most segments of society, the space weather enterprise has become systematic and coherent. At present it has achieved considerable momentum, but it has barely begun to realize the level of effectiveness to which it can aspire, as evidenced by achievements of a corresponding but more mature enterprise in meteorology, a field which provides useful lessons. The space-weather enterprise will enter a new phase after it matures roughly to where the tropospheric weather enterprise is now. Then it will become indispensable for humankind's further global networking through technology and for humankind's further utilization of and expansion into space.

Siscoe, G.

2000-09-01

398

The use of Meteonorm weather generator for climate change studies  

Microsoft Academic Search

The global climatological database Meteonorm (www.meteonorm.com) is widely used as meteorological input for simulation of solar applications and buildings. It's a combination of a climate database, a spatial interpolation tool and a stochastic weather generator. Like this typical years with hourly or minute time resolution can be calculated for any site. The input of Meteonorm for global radiation is the

J. Remund; S. C. Müller; C. Schilter; B. Rihm

2010-01-01

399

Initial effects of vegetation on Hawaiian basalt weathering rates  

SciTech Connect

Weathering of Ca and Mg silicates on land and ensuing precipitation and burial of Ca and Mg carbonates in marine sediments is the principal sink for carbon dioxide from the atmosphere/ocean system on geologic time scales. Model calculations of ancient atmospheric CO[sub 2] partial pressure depend strongly on the authors assumptions about the enhancement of silicate weathering rates first by primitive terrestrial biota, then by the appearance and evolution of the vascular plants. Aa and pahoehoe basalts were collected from Mauna Loa and Kilauea volcanoes on the island of Hawaii. Flows ranged in age (one year to several thousand years) and in ambient climate. Where possible, each flow was sampled beneath a suite of current plant covers: none, lichens, and higher plants. Rocks were embedded in epoxy to preserve the plant-rock interface, then sectioned and subjected to electron probe microanalysis. During initial weathering, vascular plants appeared to promote congruent dissolution of minerals (particularly olivine and Ca-rich plagioclase) and glass near the surfaces of underlying basalts. In the neighborhood of roots, primary cracks widened with time into networks of open channels. This effect was observed prior to the formation of measurable leached zones in exterior grains and prior to the appearance of secondary minerals. As a result, initial mass loss from young, plant-covered basalts appeared to be up to one or more orders of magnitude greater than from bare-rock controls. Despite earlier reports of substantial enhancement of Hawaiian basalt weathering rates by the lichen Stereocaulon vulcani, weathering observed beneath this lichen was comparable to that of unvegetated rocks.

Cochran, M.F.; Berner, R.A. (Yale Univ., New Haven, CT (United States))

1992-01-01

400

Weather Science, Weather Research: History of Their Problems and Findings from Documents during Three Thousand Years.  

National Technical Information Service (NTIS)

Contents: The prescientific era. Perception of weather; Establishment of the science of weather. Recording the weather in numbers; Extension of the science of weather. Representation of weather: climatic charts and weather charts; Meteorology up to the be...

K. Schneider-Carius

1975-01-01

401

Titan: Callisto With Weather?  

NASA Astrophysics Data System (ADS)

Instead of being endogenically active, Titan's interior may be cold and dead. Those landforms on Titan that are unambiguously identifiable can all be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). At the scale of available imaging data, the surface is dominated by vast dune ergs and by fluvial erosion, transportation, and deposition. The sparse distribution of recognizable impact craters (themselves exogenic) is consistent with the presence of aeolian and fluvial activity sufficient to cover and or erode smaller craters, leaving only large ones. Previous suggestions of endogenically produced landforms have been, without exception, inconclusively identified. Features suggested to be cryovolcanic flows may be debris flows and other mass movements, facilitated by hydrocarbon-fluidized unconsolidated materials. Ganesa Macula has been suggested as a putative cryovolcanic dome, but it may simply be an impact structure that contains radar-dark dune or mass-wasted materials. Mountains, which are heavily modified by fluvial and mass wasting processes, could have formed as the scarps of large impact features and/or by slow contraction due to global cooling and freezing of an internal ammonia-water ocean, rather than by endogenically powered orogeny. A cold and inactive interior is consistent with an internal ammonia-water ocean, which has a peritectic temperature of 173K, easily obtained in Titan by radioactive decay alone in the absence of tidal heating. Titan's orbital eccentricity should have damped if its interior is warm and dissipative; instead, its high eccentricity can be ancient if the interior is assumed to be cold and non-dissipative. Indeed, it has been suggested that Titan may be non-hydrostatic, consistent with a thick ice shell and a cold and rigid interior. We suggest that the satellite most akin to Titan may be Callisto. Like Callisto, which may have formed relatively slowly in the outer circumjovian accretion disk, Titan might have accreted relatively cold. Without being in a forced resonance, Titan's interior may have never undergone significant tidal heating. Analogous to Callisto's tenuous CO2 atmosphere, believed to be generated by sublimation of interior ices, interior clathrated methane within Titan may slowly diffuse outward from the cold interior, rather than the atmosphere being replenished by cryovolcanism. The hypothesis that Titan is "Callisto with weather" -- with geological processes that are principally exogenic -- can be tested through geophysical and thermal modeling, and by modeling the evolution of landscapes that are shaped by exogenic processes alone.

Moore, J. M.; Pappalardo, R. T.

2008-12-01

402

Diffusion of Water in Silicate Melts  

Microsoft Academic Search

Diffusion of water in silicate melts and glasses has significant impact on both high temperature igneous and low temperature alteration processes. Water diffusivity in silicates is complicated by its strong, complex dependence on composition, including water content, which has been used to infer molecular level mechanisms of water diffusion. Very little has been done on mafic melts, but such studies

S. Newman; E. Persikov; E. Stolper; P. Bukhtiyarov; Y. Zhang

2005-01-01

403

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

404

Martian Weathering Environments of the Amazonian Indicated by Correlated Morphologic and Spectral Observation in Acidalia Planitia  

NASA Astrophysics Data System (ADS)

While much attention has been given to chemical alteration and the state of water on early Mars, it remains important to understand aqueous processes throughout Martian history, including the recent geologic past. It has been suggested that the Amazonian was marked primarily by anhydrous, oxidative weathering because Amazonian surfaces, such as the northern plains, lack hydration features in near-infrared spectra [1]. But high-silica materials (Surface Type 2, ST2) discovered by the Thermal Emission Spectrometer [2] that occur in the northern plains attest to aqueous alteration of silicate minerals. The questions are when did this occur and by what process? ST2 correlates spatially with outflow sediments and high-silica materials may have formed in large amounts of water related to outflow flooding events of the late Hesperian [3,4]. ST2 also may correspond to global ice-rich mantles, indicating formation in icy environments related to geologically recent climate fluctuations [3]. Can these very different mechanisms and environments be discerned? In a global study of TES spectra, Rogers et al. (2007) [5] found significant spectral differences between ST2 surfaces in northern and southern Acidalia Planitia that occur near 40-50° N. Several geomorphic transitions occur across latitudes, and many of these are directly or potentially related to Amazonian periglacial activity and occur in the 40-50° N range. This potential link between composition and periglacial morphology needs further exploration. We examined this relationship from 40-50° N in Acidalia Planitia, using Thermal Emission Imaging System (THEMIS) multispectral data to measure the local spectral properties of the surface. We identified a boundary between two surface spectral types that match closely the spectra of north and south Acidalia derived by Rogers et al. [2007]. This boundary is diffuse, occurring between 47-48° N in our study region in western Acidalia, and correlates with observed morphologic and thermophysical differences. Close examination of those surfaces with High Resolution Imaging Science Experiment (HiRISE) images shows that the area north of the boundary is a modified version of the southern surface, subdued and overprinted by periglacial polygonal ground. Thus, we think that ground ice has modified the surface morphology and, furthermore, that periglacial processing also modified the silicate composition of the northern surface materials. Weathering that created the northern Acidalia composition involved ground ice, and was likely similar to weathering in Antarctic soils, in which silica is mobilized by thin water films and deposited as gels [6]. By this mechanism, aqueous weathering on Mars has probably persisted into, and throughout, the Amazonian. References: [1] Bibring et al. (2006) Science, 312, 400-404. [2] Bandfield et al. (2000) Science, 287, 1626-1630. [3] Wyatt et al. (2004) Geology, 32, 645-648. [4] Tanaka et al. (2005) USGS Sci. Invest. Map 2888. [5] Rogers et al. (2007) J. Geophys. Res.,112, E02004. [6] Ugolini and Anderson (1973), Soil Sci., 105, 461-470.

Kraft, M. D.; Rogers, D.; Fergason, R. L.; Michalski, J. R.; Sharp, T. G.

2009-12-01

405

Weather and The Water Cycle  

NSDL National Science Digital Library

Students will be able to do activities dealing with weather and water cycles. Learn what makes weather wet and wild, forcast and predict weather. Webweather For Kids Learn about tornadoes and hurricanes. Kidstorm Learn about the water cycles. water Cycles Now click on the following link: Interactive weather maker 1. How much change in temperature is needed to make it snow? On the right side of the page click on Weather Detective Web Quest. Follow the ...

Merritt, Mrs.

2005-10-15

406

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

407

Astrobiological relevance of phenols and their silicates  

NASA Astrophysics Data System (ADS)

We have prepared solid silicates of various phenols and have studied them by the IR (infra-red) spectroscopy. Phenols are organic compounds that are important in biology. Only very recently phenols have been synthesized in prebiotic manner. They are formed under the hydrothermal conditions and also under the simulated conditions of the interstellar space. Solid phenol silicates, which we have prepared, are ideally suited for the preservation of phenols on prebiotic Earth and in space, and for their transportation in space. The reflectance IR spectra of phenol silicates were taken and are currently being analyzed. Our goal is to determine if phenols are entombed, covalently bound, or both, in respect to the silicate matrix. We have also prepared fluorescent phenol silicates.

Kolb, Vera M.; Liesch, Patrick J.

2008-08-01

408

Comparison of The Christiansen Feature Position and Lunar Iron: Evidence for Space Weathering Effects  

NASA Astrophysics Data System (ADS)

Diviner’s three channels near 8-microns characterize an infrared emissivity maximum called the Christiansen Feature (CF) which is has been established as compositional indicator in laboratory experiments. Laboratory measurements show that the CF is related to silicate polymerization and occurs at shorter wavelengths for feldspathic minerals and longer wavelengths for mafic minerals. Laboratory experiments regarding the effect of space weathering on this feature have not been conclusive. The Diviner Lunar Radiometer Experiment data begin to illustrate these effects. Because the hosts of iron in lunar materials are the mafic minerals pyroxene and olivine (with the rare ilmenite-rich maria being the chief exception), the CF wavelength position, roughly proportional to mafic mineral abundance, should correlate with iron abundance. Deviations from this correlation will be due to variations in mineral chemistry, olivine-pyroxene ratio, and possibly, space weathering effects. Using Clementine-derived global FeO estimates, calibrated to Lunar Prospector gamma-ray spectrometer iron data, we regressed iron on a global CF map with 12 km spatial resolution. The residuals of the difference between the FeO based CF prediction and the CF measurements show differences we attribute to rock and soil composition, but also, in the highlands, the effects of space weathering. The residual image (CF predicted from FeO, minus CF measured by Diviner) correlates reasonably well with optical maturity derived from visible and near-IR measurements. Using laboratory soils, optical maturity has been shown to be a reliable maturity indicator. Large fresh craters, including Tycho and Jackson, as well as a host of lesser craters, that show bright ray patterns but are not compositionally distinct from the background, show both CF and optical maturity anomalies. Specifically, fresh highland craters show shorter wavelength CF positions than mature highland background The origin of the CF dependence upon soil maturity is not known. Optical maturity is dominated by the abundance of nanophase iron that causes darkening, reddening, and loss of spectral contrast with space exposure. It is not clear how the CF, being a wavelength position parameter, could be affected by nanophase iron. However, soil maturity includes a host of other effects including prodigious production of glass, grain size evolution, and implantation of solar wind gases. At the 12km scale at which we are measuring there could also be macroscopic, but sub-pixel effects as well, such as variations in the rock-soil ratio. Further investigation of the Diviner data and supporting laboratory measurements will be used to understand this phenomenon.

Lucey, P. G.; Paige, D. A.; Greenhagen, B. T.; Allen, C.; Bandfield, J. L.; Bowles, N.; Hanna, K.; Glotch, T. D.; Thomas, I. R.; Wyatt, M. B.

2009-12-01

409

Slow advance of the weathering front during deep, supply-limited saprolite formation in the tropical Highlands of Sri Lanka  

NASA Astrophysics Data System (ADS)

Silicate weathering - initiated by major mineralogical transformations at the base of ten meters of clay-rich saprolite - generates the exceptionally low weathering flux found in streams draining the crystalline rocks of the mountainous and humid tropical Highlands of Sri Lanka. This conclusion is reached from a thorough investigation of the mineralogical, chemical, and Sr isotope compositions of samples within a regolith profile extending >10 m from surface soil through the weathering front in charnockite bedrock (a high-grade metamorphic rock), corestones formed at the weathering front, as well as from the chemical composition of the dissolved loads in nearby streams. Weatherable minerals and soluble elements are fully depleted at the top of the profile, showing that the system is supply-limited, such that weathering fluxes are controlled directly by the supply of fresh minerals. We determine the weathering rates using two independent means: (1) in situ-produced cosmogenic nuclides in surface soil and creek sediments in the close vicinity of the regolith combined with immobile element mass balance across the regolith and (2) river dissolved loads. Silicate weathering rates determined from both approaches range from 16 to 36 t km-2 y-1, corresponding to a weathering front advance rate of 6-14 mm ky-1. These rates agree across the 101 to 104 y time scales over which our rate metrics integrate, suggesting that the weathering system operates at steady state. Within error these rates are furthermore compatible with those obtained by modeling the advance rate of the weathering front from chemical gradients and mineral dissolution rates. The silicate weathering flux out of the weathering profile, measured on small creeks, amounts to 84% of the profile's export flux; the remaining 16% is contributed by non-silicate, atmospheric-derived input. The silicate weathering flux, as measured by dissolved loads in large catchments, amounts to ca. 50% of the total dissolved flux; the remainder being contributed by dust, rain, and weathering of local marble bands. Spheroidal weathering is the key processes of converting the fresh bedrock into saprolite at the weathering front. The mineralogical composition of weathering rinds shows that the sequence of mineral decomposition is: pyroxene; plagioclase; biotite; K-feldspar. Observable biotite alteration does not appear to initiate spheroidal weathering within corestones; therefore, we infer that other processes than biotite oxidation, like pyroxene oxidation, clay formation from pyroxene and plagioclase decomposition, the development of secondary porosity by plagioclase dissolution, or even microbiologic processes at depth enable the coupling between slow advance of the weathering front and slow erosion at the surface. The comparison to tectonically more active tropical landscapes lets us conclude that the combination of hard rock with tightly interlocked mineral grains and slow erosion in the absence of tectonically-induced landscape rejuvenation lead to these exceptionally low weathering rates.

Hewawasam, Tilak; von Blanckenburg, Friedhelm; Bouchez, Julien; Dixon, Jean L.; Schuessler, Jan A.; Maekeler, Ricarda

410

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

411

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

412

Extreme Weather Sourcebook  

NSDL National Science Digital Library

This report presents a summary of damage caused by hurricanes, floods, tornadoes, lightning, hail, thunderstorms, and windstorms in the United States and its territories. Information was collected from as far back as 1900 (for hurricanes) and as recently as 1999 (for most categories). For each weather category, there is statistical information on monetary damages (in millions of dollars), sorted by rank and by alphabetic listing. There is also a summary table for composite damage from tornadoes, hurricanes, and floods; tables and graphs for damage and casualties caused by lightning; and summary information for other types of extreme weather (hail, thunderstorms, winter storms). Links are provided to information on data sources and methodology and on the societal impacts of weather.

413

Mesoporous Silicate Materials in Sensing  

PubMed Central

Mesoporous silicas, especially those exhibiting ordered pore systems and uniform pore diameters, have shown great potential for sensing applications in recent years. Morphological control grants them versatility in the method of deployment whether as bulk powders, monoliths, thin films, or embedded in coatings. High surface areas and pore sizes greater than 2 nm make them effective as adsorbent coatings for humidity sensors. The pore networks also provide the potential for immobilization of enzymes within the materials. Functionalization of materials by silane grafting or through co-condensation of silicate precursors can be used to provide mesoporous materials with a variety of fluorescent probes as well as surface properties that aid in selective detection of specific analytes. This review will illustrate how mesoporous silicas have been applied to sensing changes in relative humidity, changes in pH, metal cations, toxic industrial compounds, volatile organic compounds, small molecules and ions, nitroenergetic compounds, and biologically relevant molecules.

Melde, Brian J.; Johnson, Brandy J.; Charles, Paul T.

2008-01-01

414

Wisconsin Weather Stories  

NSDL National Science Digital Library

University of Wisconsin meteorologists and folklorists along with Wisconsin teachers created this website to offer classroom materials "that integrate earth science, social studies, language arts, and math." Students can learn about severe weather and the importance of forecasting by listening to and reading people's accounts. Each lesson contains benchmarks and standards for grades four, eight, and twelve; as well as many fun activities. The website features a concise glossary and many links where teachers can discover more resources. Visitors who remember the weather discussed, such as the Ice Bowl of 1967, can find out how to submit their accounts to the website.

415

Indigenous Weather Knowledge  

NSDL National Science Digital Library

Produced by the Commonwealth Bureau of Meteorology, this Web site exhibits seasonal weather calendars created by Indigenous people thousands of years ago. The site first discusses the Aboriginal people in Australia and their methods for dealing with past climate changes. Studying the calendars, users will notice that Indigenous people dealt with climate on a local scale and recognized a varying number of seasons. For comparison, the site presents the Bureau of Meteorology's Temperature and Rainfall Graphs and climate group classification maps. Because it is still in the early stages of development, users should revisit this site to learn more about Aboriginal knowledge of weather and climate.

416

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

417

Space weather in Japan  

NASA Astrophysics Data System (ADS)

In Japan, Communications Research Laboratory engages in operational space environment information service as National Forecasting Center and Regional Warning Center of ISES. Data of local observation and data collected via internet from domestic and foreign institute are used for daily operational forecast. Fundamental research on space weather issue has been carried out at several institutes and university, including STE Laboratory and NASDA. In this presentation, overview of current space weather forecast operation and system for information outreach in Japan will be presented. Current and future observation program from ground-base and space will be also briefly reviewed.

Akioka, M.

418

Space weather in Japan  

NASA Astrophysics Data System (ADS)

In Japan, Communications Research Laboratory engages in operational space environment information services as National Forecasting Center and Regional Warning Center of ISES. Data from local observations and data collected via internet from domestic and foreign institutes are used for the daily operational forecast. Fundamental research on space weather issues has been carried out at several institutes and universities, including STE Laboratory and NASDA. In this presentation, an overview of current space weather forecast operations and a system for information outreach in Japan will be presented. Current and future observation programs from ground-base and space will be also briefly reviewed.

Akioka, M.; Ishibashi, H.; Kikuchi, T.; Sagawa, E.; Nagatsuma, T.

419

Space Weather Action Center  

NSDL National Science Digital Library

In this interdisciplinary activity, learners create a Space Weather Action Center (SWAC) to monitor solar storms and develop real SWAC news reports. Learners work in teams to first investigate sunspot regions, storm signals, a magnetosphere, and auroras and share their research with their peers. Then, learners assemble an instructional flip chart, data collection clipboards/notebook, and display board for their SWAC. Learners conclude the activity by writing their own weather reports, which can be filmed or broadcast if equipment is available. Once learners create a SWAC, solar storm research and reporting can become an ongoing activity.

Nasa

2013-07-30

420

Olympian weather forecasting  

NASA Astrophysics Data System (ADS)

A unique public-private partnership will provide detailed weather information at the 2002 Winter Olympics in Utah, 8-24 February About 50 meteorologists with the National Weather Service (NWS) and several private groups will work in the background to provide accurate forecasts.This is the first time that U.S. government and private meteorologists will share forecasting responsibilities for the Olympics, according to the Salt Lake Organizing Committee for the Olympic Games. The partnership includes meteorologists with the University of Utah and KSL-TV in Salt Lake City.

Showstack, Randy

421

Weather and The Seasons  

NSDL National Science Digital Library

This project will allow students to see the different weather conditions that are apart of the different seasons. It will also help students to identify the characterisitics that go along with each of the different seasons, For example, what weather conditions are present in each season and how we dress for each season. With a partner watch the video: Observing Clouds On piece of paper write your answers to the following questions: 1). What types of changes in the clouds did you observe? 2). What do you think caused the changes in the clouds? (Ex: teperature, morning to night, etc) Next, with your partner, please watch the second video: Observing Precipitation On ...

Maxwell, Ms.

2012-02-07

422

Weather Depot 1.21  

NSDL National Science Digital Library

As a quote commonly misattributed to Mark Twain goes, "Everyone talks about the weather, but no one does a thing about it." This little program from the folks at Weather Depot won't allow users to modify weather conditions, but it will let users customize their own weather planner (with hourly and daily updates), view regional radar, and view a map of current temperatures around the United States. Additionally, users may look up current road conditions, and view weather Web cams. Weather Depot 1.21 is compatible with all systems running Windows 98 and higher.

423

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.

424

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

425

Carbon fluxes, pCO 2 and substrate weathering in a large northern river basin, Canada: carbon isotope perspectives  

Microsoft Academic Search

Isotopic composition of dissolved inorganic carbon (?13CDIC) in the Ottawa River basin is about ?8 and ?16‰ for lowland carbonate and upland silicate tributaries, respectively. This suggests that (1) the source of DIC to the Ottawa River is soil respiration and carbonate weathering, (2) exchange with the atmosphere is unidirectional or volumetrically unimportant, and (3) in-river respiration and photosynthesis are

Kevin Telmer; Jan Veizer

1999-01-01

426

Downscaling Extended Weather Forecasts for Hydrologic Prediction  

SciTech Connect

Weather and climate forecasts are critical inputs to hydrologic forecasting systems. The National Center for Environmental Prediction (NCEP) issues 8-15 days outlook daily for the U.S. based on the Medium Range Forecast (MRF) model, which is a global model applied at about 2? spatial resolution. Because of the relatively coarse spatial resolution, weather forecasts produced by the MRF model cannot be applied directly to hydrologic forecasting models that require high spatial resolution to represent land surface hydrology. A mesoscale atmospheric model was used to dynamically downscale the 1-8 day extended global weather forecasts to test the feasibility of hydrologic forecasting through this model nesting approach. Atmospheric conditions of each 8-day forecast during the period 1990-2000 were used to provide initial and boundary conditions for the mesoscale model to produce an 8-day atmospheric forecast for the western U.S. at 30 km spatial resolution. To examine the impact of initialization of the land surface state on forecast skill, two sets of simulations were performed with the land surface state initialized based on the global forecasts versus land surface conditions from a continuous mesoscale simulation driven by the NCEP reanalysis. Comparison of the skill of the global and downscaled precipitation forecasts in the western U.S. showed higher skill for the downscaled forecasts at all precipitation thresholds and increasingly larger differences at the larger thresholds. Analyses of the surface temperature forecasts show that the mesoscale forecasts generally reduced the root-mean-square error by about 1.5 C compared to the global forecasts, because of the much better resolved topography at 30 km spatial resolution. In addition, initialization of the land surface states has large impacts on the temperature forecasts, but not the precipitation forecasts. The improvements in forecast skill using downscaling could be potentially significant for improving hydrologic forecasts for managing river basins.

Leung, Lai-Yung R.; Qian, Yun

2005-03-01

427

Optical and microhardness measurement of lead silicate  

NASA Astrophysics Data System (ADS)

Lead silicate glasses, PbO-SiO2, are interesting because these glasses exhibit thermal, optical, and mechanical properties different than other silicate glasses, and they form a thermally and chemically stable glass over a wide composition range. They are also interesting as PbO acts as glass modifier and as glass former depending on the concentration. In the present work we have prepared lead silicate glasses (xPbO-(1-x).SiO2) by melt quenching. We measured UV absorbance, Vickers hardness, and glass transition for these samples. It is found that band gap is proportional to glass transition.

Jogad, Rashmi M.; Kumar, Rakesh; Krishna, P. S. R.; Jogad, M. S.; Kothiyal, G. P.; Mathad, R. D.

2013-02-01

428

A Mechanism of Crystallization of Cometary Silicates  

NASA Astrophysics Data System (ADS)

We propose a mechanism of crystallization of cometary silicate grains on the basis of the Greenberg model of cometary dust which is composed of a silicate core an organic mantle and an outermost icy mantle. The crystallization mechanism we propose is due to energy release by polymerization of the organic mantle when the grains are released from a cometary nucleus and heated by solar radiation. We formulate the crystallization mechanism and calculate the degree of crystallization of the silicate core. We show the results of the calculations of the crystallization degree for plausible values of the physical parameters and of the infrared emission spectra.

Yamamoto, Tetsuo; Chigai, Takeshi

2005-01-01

429

Brazilian Space Weather Program  

Microsoft Academic Search

A space weather program is being initiated at the Brazilian National Institute for Space Research (INPE) to study events from their initiation on the sun to their impacts on the earth, including their effects on space-based and ground-based technological systems. The program is built on existing capabilities at INPE, which include scientists with a long tradition and excellence in the

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

2008-01-01

430

What Makes the Weather?  

ERIC Educational Resources Information Center

Provides (1) background information showing how the sun, earth, air, and water work together to create weather; (2) six activities on this topic; and (3) a ready-to-copy coloring page on the water cycle. 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

431

Dress for the Weather  

ERIC Educational Resources Information Center

"If someone were traveling to our area for the first time during this time of year, what would you tell them to bring to wear? Why?" This question was used to engage students in a guided-inquiry unit about how climate differs from weather. In this lesson, students explored local and national data sets to give "travelers" advice when preparing for…

Glen, Nicole J.; Smetana, Lara K.

2010-01-01

432

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…

Blai, Boris, Jr.

433

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.

434

Weather Specialist (AFSC 25120).  

ERIC Educational Resources Information Center

This correspondence course is designed for self-study to help military personnel to attain the rating of weather specialist. The course is organized in three volumes. The first volume, containing seven chapters, covers background knowledge, meteorology, and climatology. In the second volume, which also contains seven chapters, surface…

Air Univ., Gunter AFS, Ala. Extension Course Inst.

435

Palaeoclimate: Weathering away warmth  

NASA Astrophysics Data System (ADS)

At the end of the Eocene epoch, permanent ice cover developed over Antarctica as the Earth began to cool from greenhouse warmth. Sediment records off the Antarctic coast show spikes in weathering rate at the onset of ice growth that may indicate synchronous consumption of atmospheric carbon dioxide.

Haley, Brian A.

2013-02-01

436

Dress for the Weather  

NSDL National Science Digital Library

"If someone were traveling to our area for the first time during this time of year, what would you tell them to bring to wear? Why?" This question was used to engage students in a guided-inquiry unit about how climate differs from weather. In this lesson,

Smetana, Lara K.; Glen, Nicole J.

2010-04-01

437

Winds, Weather, and Deserts  

NSDL National Science Digital Library

This site contains 17 questions on the topic of wind and weathering, which covers the Coriolis Effect and wind characteristics. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit an answer and are provided immediate verification.

Heaton, Timothy

438

Weather and Health  

NSDL National Science Digital Library

Funded by the National Environmental Education Foundation (NEEF), 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, ultraviolet radiation, and other phenomena.

2008-01-01

439

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

Evans, Kyle; Frazier, Wendy

2010-04-01

440

Weather and Agriculture  

NSDL National Science Digital Library

In this lesson plan students will research, discuss, and write reports on the relationship between climate and agriculture. They will pretend that they have just purchased farms in specific parts of the United States and will investigate the weather and climate of that region in order to maximize the chances that their farms will succeed.

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