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Ingel, L. Kh. "Movement of heavy particles in tornadoes". Izvestiya, Atmospheric and Oceanic Physics 53, n.º 4 (julio de 2017): 413–18. http://dx.doi.org/10.1134/s0001433817040065.
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Wood, Vincent T., Rodger A. Brown y David C. Dowell. "Simulated WSR-88D Velocity and Reflectivity Signatures of Numerically Modeled Tornadoes". Journal of Atmospheric and Oceanic Technology 26, n.º 5 (1 de mayo de 2009): 876–93. http://dx.doi.org/10.1175/2008jtecha1181.1.
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Abstract Low-altitude radar reflectivity measurements of tornadoes sometimes reveal a donut-shaped signature (low-reflectivity eye surrounded by a high-reflectivity annulus) and at other times reveal a high-reflectivity knob associated with the tornado. The differences appear to be due to such factors as (i) the radar’s sampling resolution, (ii) the presence or absence of lofted debris and a low-reflectivity eye, (iii) whether measurements were made within the lowest few hundred meters where centrifuged hydrometeors and smaller debris particles were recycled back into the tornadic circulation, and (iv) the presence or absence of multiple vortices in the parent tornado. To explore the influences of some of these various factors on radar reflectivity and Doppler velocity signatures, a high-resolution tornado numerical model was used that incorporated the centrifuging of hydrometeors. A model reflectivity field was computed from the resulting concentration of hydrometeors. Then, the model reflectivity and velocity fields were scanned by a simulated Weather Surveillance Radar-1988 Doppler (WSR-88D) using both the legacy resolution and the new super-resolution sampling. Super-resolution reflectivity and Doppler velocity data are displayed at 0.5° instead of 1.0° azimuthal sampling intervals and reflectivity data are displayed at 0.25-km instead of 1.0-km range intervals. Since a mean Doppler velocity value is the reflectivity-weighted mean of the radial motion of all the radar scatterers within a radar beam, a nonuniform distribution of scatterers produces a different mean Doppler velocity value than does a uniform distribution of scatterers. Nonuniform reflectivities within the effective resolution volume of the radar beam can bias the indicated size and strength of the tornado’s core region within the radius of the peak tangential velocities. As shown in the simulation results, the Doppler-indicated radius of the peak wind underestimates the true radius and true peak tangential velocity when the effective beamwidth is less than the tornado’s core diameter and there is a weak-reflectivity eye at the center of the tornado. As the beam becomes significantly wider than the tornado’s core diameter with increasing range, the peaks of the Doppler velocity profiles continue to decrease in magnitude but overestimate the tornado’s true radius. With increasing range from the radar, the prominence of the weak-reflectivity eye at the center of the tornado is progressively lessened until it finally disappears. As to be expected, the Doppler velocity signatures and reflectivity eye signatures were more prominent and stronger with super-resolution sampling than those with legacy-resolution sampling.
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Ingel, L. Kh. "On the Nonlinear Dynamics of Massive Particles in Tornadoes". Technical Physics 65, n.º 6 (junio de 2020): 860–64. http://dx.doi.org/10.1134/s1063784220060122.
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Radovanovic, Milan, Bosko Milovanovic, Mila Pavlovic, Aleksandar Radivojevic y Milan Stevancevic. "The connection between solar wind charged particles and tornadoes: Case analysis". Nuclear Technology and Radiation Protection 28, n.º 1 (2013): 52–59. http://dx.doi.org/10.2298/ntrp1301052r.
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The temperature of charged particles coming from the Sun ranges from several hundred thousands to several millions ?C, in extreme cases. Theoretical possibilities of the hydrodynamic air mass seizing by charged particles, i. e. solar wind, are discussed in this paper. On one hand, they are characterized by extremely high temperatures, on the other, by the compression of cold air at an approximate altitude of 90 km towards the top of the cloud of the cyclone, they influence the phenomenon of extremely low temperatures. By using the Mann-Whitney U test we have tried to determine the potential link between certain indicators of solar activity and resulting disturbances in the atmosphere. Analyzed data refer to global daily values for the 2004-2010 period. Our results confirm the possibility of coupling between the charged particles and the vortex air mass movements, based on which a more detailed study of the appearance of a tornado near Sombor on May 12th, 2010, was carried out. It has also been proven that there are grounds for a causality between the sudden arrival of the solar wind charged particles, i. e. protons, and the appearance of a tornado. Based on the presented approach, elements for an entirely novel prediction model are given.
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Tanamachi, Robin L., Howard B. Bluestein, Stephen S. Moore y Robert P. Madding. "Infrared Thermal Imagery of Cloud Base in Tornadic Supercells". Journal of Atmospheric and Oceanic Technology 23, n.º 11 (1 de noviembre de 2006): 1445–61. http://dx.doi.org/10.1175/jtech1942.1.
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Abstract During the spring seasons of 2003 and 2004, an infrared thermal camera was deployed in and around supercell thunderstorms in an attempt to retrieve the temperature at the cloud base of a mesocyclone prior to tornadogenesis. The motivation for this exercise was to obtain temperature information that might indicate the thermal structure, timing, and extent of the rear-flank downdraft (RFD) and possibly elucidate its relationship to tornadogenesis. An atmospheric transmissivity study was conducted to account for the effects of atmospheric transmission on the measured temperatures, and to determine an ideal range of distances from which infrared images of a wall cloud or a tornado could be safely captured while still retrieving accurate cloud temperatures. This range was found to be 1.5–3 km. Two case days are highlighted in which the infrared camera was deployed within 1.5–3 km of a tornado; the visible and infrared images are shown side by side for comparison. On the single occasion on which the tornadogenesis phase was captured, the infrared images show no strong horizontal temperature gradients. From the infrared images taken of tornadoes, it can be inferred that the infrared signal from the tornado consisted primarily of infrared emissions from lofted dust particles or cloud droplets, and that the infrared signal from the tornado condensation funnel was easily obscured by infrared emissions from lofted dust particles or intervening precipitation curtains. The deployment of the infrared camera near supercell thunderstorms and the analysis of the resulting images proved challenging. It is concluded that the infrared camera is a useful tool for measuring cloud-base temperature gradients provided that distance and viewing angle constraints are met and that the cloud base is unobscured by rain or other intervening infrared emission sources. When these restrictions were met, the infrared camera successfully retrieved horizontal temperature gradients along the cloud base and vertical temperature gradients (close to the moist adiabatic lapse rate) along the tornado funnel.
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Hollingshead, David. "Neko Case and the Molecular Turn". GLQ: A Journal of Lesbian and Gay Studies 25, n.º 4 (1 de octubre de 2019): 617–47. http://dx.doi.org/10.1215/10642684-7767809.
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Few contemporary artists channel the utopian impulses of the nonhuman turn with more creative energy than Neko Case. In her work, the untraceable movements of poisonous gases, the uncanny desires of tornadoes, and the recalcitrant withdrawal of subatomic particles envision an array of transits, elusions, and exit strategies so often denied to the subjects whose bodies, trajectories, and affective lives are policed by the regulatory cultural and institutional forces endemic to heteronormative biocapitalism, particularly poor and marginalized women. Drawing on recent scholarship in feminist new materialism as well as its critics, this essay considers the implications of these imaginings. On the one hand, the modes of agency that Case’s songs invoke frequently entail a circumvention or suppression of specific political interests, making them susceptible to antifeminist and settler-colonialist appropriations; on the other hand, her work potentially offers a vision of the political that refuses to take human action as the inevitable starting point for its theories of power and domination, an increasingly urgent task in an age of ecological catastrophe, when the lives of earth’s most vulnerable gendered and racialized subjects are irreducibly enmeshed in precarious planetary networks of biodependencies that include the actions of microbes, tornadoes, and atoms alike. In Case’s most original compositions, a reductionist materialism attendant to the agency of the nonhuman complements rather than forecloses an older materialist tradition insistent on antagonism between conflicting interest groups as the motor engine of history and the social.
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Friedrich, Katja, Stephanie Higgins, Forrest J. Masters y Carlos R. Lopez. "Articulating and Stationary PARSIVEL Disdrometer Measurements in Conditions with Strong Winds and Heavy Rainfall". Journal of Atmospheric and Oceanic Technology 30, n.º 9 (1 de septiembre de 2013): 2063–80. http://dx.doi.org/10.1175/jtech-d-12-00254.1.
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Abstract The influence of strong winds on the quality of optical Particle Size Velocity (PARSIVEL) disdrometer measurements is examined with data from Hurricane Ike in 2008 and from convective thunderstorms observed during the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) in 2010. This study investigates an artifact in particle size distribution (PSD) measurements that has been observed independently by six stationary PARSIVEL disdrometers. The artifact is characterized by a large number concentration of raindrops with large diameters (>5 mm) and unrealistic fall velocities (<1 m s−1). It is correlated with high wind speeds and is consistently observed by stationary disdrometers but is not observed by articulating disdrometers (instruments whose sampling area is rotated into the wind). The effects of strong winds are further examined with a tilting experiment, in which drops are dripped through the PARSIVEL sampling area while the instrument is tilted at various angles, suggesting that the artifact is caused by particles moving at an angle through the sampling area. Most of the time, this effect occurs when wind speed exceeds 20 m s−1, although it was also observed when wind speed was as low as 10 m s−1. An alternative quality control is tested in which raindrops are removed when their diameters exceed 8 mm and they divert from the fall velocity–diameter relationship. While the quality control does provide more realistic reflectivity values for the stationary disdrometers in strong winds, the number concentration is reduced compared to the observations with an articulating disdrometer.
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Spineanu, F. y M. Vlad. "Field theoretical prediction of a property of the tropical cyclone". Nonlinear Processes in Geophysics Discussions 1, n.º 1 (20 de enero de 2014): 1–37. http://dx.doi.org/10.5194/npgd-1-1-2014.
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Abstract. The large scale atmospheric vortices (tropical cyclones, tornadoes) are complex physical systems combining thermodynamics and fluid-mechanical processes. The late phase of the evolution towards stationarity consists of the vorticity concentration, a well known tendency to self-organization , an universal property of the two-dimensional fluids. It may then be expected that the stationary state of the tropical cyclone has the same nature as the vortices of many other systems in nature: ideal (Euler) fluids, superconductors, Bose–Einsetin condensate, cosmic strings, etc. Indeed it was found that there is a description of the atmospheric vortex in terms of a classical field theory. It is compatible with the more conventional treatment based on conservation laws, but the field theoretical model reveals properties that are almost inaccessible to the conventional formulation: it identifies the stationary states as being close to self-duality. This is of highest importance: the self-duality is known to be the origin of all coherent structures known in natural systems. Therefore the field theoretical (FT) formulation finds that the cuasi-coherent form of the atmospheric vortex (tropical cyclone) at stationarity is an expression of this particular property. In the present work we examine a strong property of the tropical cyclone, which arises in the FT formulation in a natural way: the equality of the masses of the particles associated to the matter field and respectively to the gauge field in the FT model is translated into the equality between the maximum radial extension of the tropical cyclone and the Rossby radius. For the cases where the FT model is a good approximation we calculate characteristic quantities of the tropical cyclone and find good comparison with observational data.
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Kalmus, Peter, Brian H. Kahn, Sean W. Freeman y Susan C. van den Heever. "Trajectory-Enhanced AIRS Observations of Environmental Factors Driving Severe Convective Storms". Monthly Weather Review 147, n.º 5 (25 de abril de 2019): 1633–53. http://dx.doi.org/10.1175/mwr-d-18-0055.1.
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Abstract We investigate environmental factors of severe convective weather using temperature and moisture retrievals from the Atmospheric Infrared Sounder (AIRS) that lie along parcel trajectories traced from tornado, large hail, and severe wind producing events in the central United States. We create AIRS proximity soundings representative of the storm environment by calculating back trajectories from storm times and locations at levels throughout the troposphere, using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model forced with the 32-km North American Regional Reanalysis (NARR) and 12-km North American Mesoscale Forecast System (NAM12). The proximity soundings are calculated for severe weather events including tornadoes, hail ≥2 in. diameter, and wind gusts >65 mph (29 m s−1) specified in the NCEI Storm Events database. Box-and-whisker diagrams exhibit more realistic values of enhanced convective available potential energy (CAPE) and suppressed convective inhibition (CIN) relative to conventional “nearest neighbor” (NN) soundings; however, differences in lifting condensation level (LCL), level of free convection (LFC), and significant tornado parameter (STP) from the HYSPLIT-adjusted back traced soundings are more similar to NN soundings. This methodology should be extended to larger swaths of soundings, and to other operational infrared sounders, to characterize the large-scale environment in severe convective events.
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Nedostrelova, L., V. Chumachenko y V. Nedostrelov. "A study of the statistical characteristics of integrated energy transfers to the blocking process". Physical Geography and Geomorphology 89, n.º 1 (2018): 105–9. http://dx.doi.org/10.17721/phgg.2018.1.14.
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Thunderstorm is an atmospheric phenomenon that manifests itself in the form of electrical discharges in cumulonimbus clouds of lightning. Usually, lightning arise between the surfaces of the earth and the clouds. Sometimes electric flashes can go inside the cloud. At the same time on Earth there are about one and a half thousand thunderstorms, the average intensity of discharges is estimated at 46 zips per second. On the surface of the planet thunderstorms are distributed unevenly. Above the ocean thunderstorm is observed about ten times less than over continents. In the tropical and subtropical zone, about 78% of all bursts of lightning are concentrated. The maximum thunderstorm activity is in Central Africa. The intensity of thunderstorms follows the sun: the maximum of thunderstorms is observed in the summer (in medium latitudes) and in the afternoon. The minimum of registered thunderstorms falls on time before sunrise. Storm in Ukraine is constantly happening even in the winter months. They are especially dangerous in the steppe zone, the strikes of lightning strike all that, at least slightly rising above the grass or shrub. Lightning - an electrical discharge between the clouds or between the cloud and the earth. Inthe process of formation of rainfall in the cloud, the electrification of droplets or ice particles occurs. As a result of strong upward flow of air in the cloud, separate regions are formed, charged with different charges. When the intensity of the electric field in the cloud or between the lower charged region and the ground reaches a breakdown value, lightning arises. In such a weather, there are stormy clouds. As a rule, this event is accompanied by thunder, shower, hail and strong wind. The high density of settlements and agro-industrial facilities in the south of Ukraine, the intensity of air transportation at the international airport of Odessa and the construction of high-rise buildings require increased attention to prevent the devastating effects of natural hydrometeorological phenomena. One of the most dangerous HMAs for a society's life is a variety of convective phenomena, that is, showers, thunderstorms, hailstones, squalls, and tornadoes. They significantly affect the life, health and economic activity of man. For example, the defeat of people, aircraft with lightning, radio interference, interruptions in electrical supply - this is not a complete list of negative factors associated with thunderstorms. The purpose of the work was to study lightning activity at the Odessa airfield for 2013-2017 years. Daily observation of atmospheric phenomena was used as the source data for the study.
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Kogan, Abraham y Meir Kogan. "The Tornado Flow Configuration—An Effective Method for Screening of a Solar Reactor Window". Journal of Solar Energy Engineering 124, n.º 3 (1 de agosto de 2002): 206–14. http://dx.doi.org/10.1115/1.1487882.
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The working fluid in solar receivers, utilized for effecting chemical reactions, is usually flown through a sealed enclosure provided with a quartz window. When one of the reactants or products of reaction is a powder, care must be taken to prevent contact of the incandescent powder particles with the window, in order to obviate its destruction by overheating. Attempts made in the past to screen the window against particle deposition by a “curtain” of an auxiliary gas stream showed that very substantial flow rates of auxiliary gas (30—80% of the main stream flow rate) were necessary for perfect window screening. The heat absorbed by the auxiliary gas stream represented a major loss of energy. In an effort to reduce the auxiliary stream flow rate to a minimum, a certain flow pattern akin to the natural tornado phenomenon has recently been developed in our laboratory. It enabled effective reactor window screening by an auxiliary gas flow rate less than 5% of the main gas flow rate. The tornado effect is discussed and demonstrated by a smoke flow visualization technique.
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YOSHIMOTO, Takahiro. "Cross Sectional Particle Concentration of Laboratory Model Tornado". Journal of the Visualization Society of Japan 28-1, n.º 1 (2008): 413. http://dx.doi.org/10.3154/jvs.28.413.
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UENO, Yasutaka, Yuichi MURAI y Fujio YAMAMOTO. "Visualization of Fine Particle Behavior in Artificial Tornado". Journal of the Visualization Society of Japan 23, Supplement1 (2003): 57–58. http://dx.doi.org/10.3154/jvs.23.supplement1_57.
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kai, FENG, Hyun Jin PARK, Yuji TASAKA y Yuichi MURAI. "Micro Particles Aggregation and Motion in a Tornado-like Flow". Proceedings of Conference of Hokkaido Branch 2020.57 (2020): 33–34. http://dx.doi.org/10.1299/jsmehokkaido.2020.57.33.
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MURAI, Yuichi. "306 Two-phase dynamics of heavy particles captured by tornado core". Proceedings of Conference of Hokkaido Branch 2007.46 (2007): 79–80. http://dx.doi.org/10.1299/jsmehokkaido.2007.46.79.
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Tessendorf, Sarah A., L. Jay Miller, Kyle C. Wiens y Steven A. Rutledge. "The 29 June 2000 Supercell Observed during STEPS. Part I: Kinematics and Microphysics". Journal of the Atmospheric Sciences 62, n.º 12 (1 de diciembre de 2005): 4127–50. http://dx.doi.org/10.1175/jas3585.1.
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Abstract This is a two-part study that addresses the kinematic, microphysical, and electrical aspects of a severe storm that occurred in western Kansas on 29 June 2000 observed during the Severe Thunderstorm Electrification and Precipitation Study (STEPS) field campaign. In this first part, polarimetric and Doppler radar data are used along with a simple particle growth model to examine the evolution of the kinematic and microphysical properties of the storm from its earliest developing phase through its mature and dissipating phases. During its severe stage, the storm exhibited frequent positive cloud-to-ground lightning strikes, very large (∼5 cm) hail, and a tornado. Doppler-derived winds, radar reflectivity, and hydrometeor classifications from the polarimetric data over a nearly 4-h period are presented. It is shown that updraft velocity and vertical vorticity had to reach magnitudes of at least 10 m s−1 and 10−2 s−1 and occupy major portions of the storm before it could produce most of the observed severe storm characteristics. Furthermore, the establishment of cyclonic horizontal flow around the right flank of the updraft core was essential for hail production. Most of the largest hail grew from near millimeter-sized particles that originated in the mid- to upper-level stagnation region that resulted from obstacle-like flow of environmental air around the divergent outflow from the upper part of the updraft. These recycling embryonic particles descended around the right flank of the updraft core and reentered the updraft, intermingling with other smaller particles that had grown from cloud base along the main low-level updraft stream.
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Wakimoto, Roger M., Nolan T. Atkins, Kelly M. Butler, Howard B. Bluestein, Kyle Thiem, Jeffrey Snyder y Jana Houser. "Photogrammetric Analysis of the 2013 El Reno Tornado Combined with Mobile X-Band Polarimetric Radar Data". Monthly Weather Review 143, n.º 7 (1 de julio de 2015): 2657–83. http://dx.doi.org/10.1175/mwr-d-15-0034.1.
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Abstract This study presents rapid-scanning X-band polarimetric radar data combined with photogrammetry of the El Reno tornado of 31 May 2013. The relationship between the hook echo, weak-echo hole (WEH), weak-echo column (WEC), and the rotational couplet with the visual characteristics of the tornado are shown. For the first time, cross-correlation coefficient (ρhv) and differential reflectivity (ZDR) data are included in the photogrammetric analyses. The tornado was accompanied by a large tornadic debris signature (TDS) with a diameter ~2 km wide during the analysis time. The center of the TDS was not collocated with the WEH and the rotational couplet. Instead, the TDS was displaced ~1 km to the north and within the weak-echo notch of the hook echo. A “debris overhang” was identified in vertical cross sections of the ρhv fields. The overhang was located in a weak-echo trench and a notch of high ρhv, consistent with the position of the tornado updraft. The updraft was hypothesized to be carrying small debris particles to heights that produced the overhang signature. A U-shaped band of high ρhv and ZDR was resolved in a vertical cross section and positioned at the periphery of the WEC during one of the analysis times. It was proposed that the band formed as a result of hydrometeors encircling the WEC while being surrounded on all sides by relatively hydrometeor-free air. The characteristics of the scatterers within the WEC were resolved and believed to be composed of a low concentration of very small, randomly oriented, debris particles, even in the presence of strong centrifuging, and a general absence of hydrometeors.
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Zhang, Wei y Partha P. Sarkar. "Near-ground tornado-like vortex structure resolved by particle image velocimetry (PIV)". Experiments in Fluids 52, n.º 2 (1 de diciembre de 2011): 479–93. http://dx.doi.org/10.1007/s00348-011-1229-5.
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Grants, I., D. Räbiger, T. Vogt, S. Eckert y G. Gerbeth. "Application of magnetically driven tornado-like vortex for stirring floating particles into liquid metal". Magnetohydrodynamics 51, n.º 3 (2015): 419–24. http://dx.doi.org/10.22364/mhd.51.3.2.
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Bodine, David J., Takashi Maruyama, Robert D. Palmer, Caleb J. Fulton, Howard B. Bluestein y David C. Lewellen. "Sensitivity of Tornado Dynamics to Soil Debris Loading". Journal of the Atmospheric Sciences 73, n.º 7 (27 de junio de 2016): 2783–801. http://dx.doi.org/10.1175/jas-d-15-0188.1.
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Abstract Past numerical simulation studies found that debris loading from sand-sized particles may substantially affect tornado dynamics, causing reductions in near-surface wind speeds up to 50%. To further examine debris loading effects, simulations are performed using a large-eddy simulation model with a two-way drag force coupling between air and sand. Simulations encompass a large range of surface debris fluxes that cause negligible to substantial impact on tornado dynamics for a high-swirl tornado vortex simulation. Simulations are considered for a specific case with a single vortex flow type (swirl ratio, intensity, and translation velocity) and a fixed set of debris and aerodynamic parameters. Thus, it is stressed that these findings apply to the specific flow and debris parameters herein and would likely vary for different flows or debris parameters. For this specific case, initial surface debris fluxes are varied over a factor of 16 384, and debris cloud mass varies by only 42% of this range because a negative feedback reduces near-surface horizontal velocities. Debris loading effects on the axisymmetric mean flow are evident when maximum debris loading exceeds 0.1 kg kg−1, but instantaneous maximum wind speed and TKE exhibit small changes at smaller debris loadings (greater than 0.01 kg kg−1). Initially, wind speeds are reduced in a shallow, near-surface layer, but the magnitude and depth of these changes increases with higher debris loading. At high debris loading, near-surface horizontal wind speeds are reduced by 30%–60% in the lowest 10 m AGL. In moderate and high debris loading scenarios, the number and intensity of subvortices also decrease close to the surface.
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Friedrich, Katja, Evan A. Kalina, Forrest J. Masters y Carlos R. Lopez. "Drop-Size Distributions in Thunderstorms Measured by Optical Disdrometers during VORTEX2". Monthly Weather Review 141, n.º 4 (1 de abril de 2013): 1182–203. http://dx.doi.org/10.1175/mwr-d-12-00116.1.
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Abstract When studying the influence of microphysics on the near-surface buoyancy tendency in convective thunderstorms, in situ measurements of microphysics near the surface are essential and those are currently not provided by most weather radars. In this study, the deployment of mobile microphysical probes in convective thunderstorms during the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) is examined. Microphysical probes consist of an optical Ott Particle Size and Velocity (PARSIVEL) disdrometer that measures particle size and fall velocity distributions and a surface observation station that measures wind, temperature, and humidity. The mobile probe deployment allows for targeted observations within various areas of the storm and coordinated observations with ground-based mobile radars. Quality control schemes necessary for providing reliable observations in severe environments with strong winds and high rainfall rates and particle discrimination schemes for distinguishing between hail, rain, and graupel are discussed. It is demonstrated how raindrop-size distributions for selected cases can be applied to study size-sorting and microphysical processes. The study revealed that the raindrop-size distribution changes rapidly in time and space in convective thunderstorms. Graupel, hailstones, and large raindrops were primarily observed close to the updraft region of thunderstorms in the forward- and rear-flank downdrafts and in the reflectivity hook appendage. Close to the updraft, large raindrops were usually accompanied by an increase in small-sized raindrops, which mainly occurred when the wind speed and standard deviation of the wind speed increased. This increase in small drops could be an indicator of raindrop breakup.
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Pandey, Amit y Verma R.K. "Nutritional composition, Taxonomical and phytoremediation status of Duckweed (Wolffia): Review". Annals of Plant Sciences 7, n.º 1 (23 de julio de 2018): 1928. http://dx.doi.org/10.21746/aps.2018.7.1.13.
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Wolffia are the crucial in decline of a flowering plant having tiny, rootless spheres in 1 mm length (or less). Wolffia is commonly known as Watermeal because it look like small particles over the water. 5 species of Wolffia are found in Western United States, while 11 species all over world. Being taken from pond to pond on the feet of water fowl (tucked neatly under the ducks' bodies during flight), might describe the distribution of few Wolffia species. In the South eastern part of US, there are evidence of Wolffia plant being taken from tornado, and they had been reported in the water of melted hailstones. Our review were focus on the Nutritional aspects, Taxonomy, Phytoremediation of heavy metal and uses of different species of Wolffia plant.
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Bockeria, L. A., A. Yu Gorodkov, A. V. Agafonov, S. T. Zhorzholiani, G. I. Kiknadze, A. A. Mironov y E. A. Talygin. "The use of smoothed particles approach in realistic mathematical model of intracardiac blood flow: Simulation of a self-organizing tornado-like flow". Human Physiology 43, n.º 2 (marzo de 2017): 213–21. http://dx.doi.org/10.1134/s0362119717020049.
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GRANTS, I., C. ZHANG, S. ECKERT y G. GERBETH. "Experimental observation of swirl accumulation in a magnetically driven flow". Journal of Fluid Mechanics 616 (10 de diciembre de 2008): 135–52. http://dx.doi.org/10.1017/s0022112008003650.
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Independent poloidal and azimuthal body forces are induced in a liquid metal cylinder by travelling and rotating magnetic fields of different frequencies, respectively. The bulk axial and azimuthal velocities are measured by the ultrasound Doppler method. Particle image velocimetry is used to observe the upper free surface velocity distribution. The transition from the poloidal to the azimuthal body force governed regime occurs at a fixed ratio of the respective force magnitude of around 100. This transition is marked by the formation of a concentrated vortex revealing several similarities to intense atmospheric vortices. The vortex structure is controlled by a relatively weak azimuthal force while the maximum speed of the swirl is mainly governed by the poloidal one. Under a certain force ratio the average axial velocity changes its direction in the vortex core, resembling the subsidence in an eye of a tropical cyclone or a large tornado. Multiple moving vortices encircle the vortex core in this regime.
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Firas, Basim Ismail, Kee Wei Yeo y Fazreen Ahmad Fuzi Noor. "Intelligent Prediction of Clinker Formation Condition for Steam Boiler Tubes Using Artificial Neural Network". MATEC Web of Conferences 255 (2019): 06007. http://dx.doi.org/10.1051/matecconf/201925506007.
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Ash, as one of the by-product of combustion either accumulates onto boiler tubes as slag or is collected by electrostatic precipitators attached to the backend of the boiler. Flue gas will transport these ash particles either to the inner surfaces of the boiler or to the dust collecting facilities at the backend of the boiler. Sintered ash deposits formed in the radiant section of the boiler are known as clinkers and they contribute to a wide variety of problems to the boiler. Preventative measures to combat clinker formation is in dire need to the energy sector. In this study, a prediction model using real plan data was developed for detection of clinker formation conditions. Several variations of Artificial Neural Networks were tried and test, with emphasis given on the feed-forward neural network, cascade neural network and recurrent neural network. In addition, sensitivity analysis was also conducted to determine the influence of random input variables to their respective response variables. The Tornado Diagram is selected as the method to determine the most influential parameter for clinker formation. It is expected that the Recurrent Neural Network prediction model and the identified most influential input parameter for clinker formation will assist operators in decision making for the maintenance of boilers.
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Zhang, Yunji, Fuqing Zhang y David J. Stensrud. "Assimilating All-Sky Infrared Radiances from GOES-16 ABI Using an Ensemble Kalman Filter for Convection-Allowing Severe Thunderstorms Prediction". Monthly Weather Review 146, n.º 10 (21 de septiembre de 2018): 3363–81. http://dx.doi.org/10.1175/mwr-d-18-0062.1.
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Abstract This article presents the first practice of assimilating real-world all-sky GOES-16 ABI infrared brightness temperature (BT) observations using an ensemble-based data assimilation system coupled with the Weather Research and Forecasting (WRF) Model at a convection-allowing (1 km) horizontal resolution, focusing on the tornadic thunderstorm event across Wyoming and Nebraska on 12 June 2017. It is found that spurious clouds created before observed convection initiation are rapidly removed, and the analysis and forecasts of thunderstorms are significantly improved, when all-sky BT observations are assimilated with the adaptive observation error inflation (AOEI) and adaptive background error inflation (ABEI) techniques. Better forecasts of the timing and location of convection initiation can be achieved after only 30 min of assimilating BT observations; both deterministic and probabilistic WRF forecasts of midlevel mesocyclones and low-level vortices, started from the final analysis with 100 min of BT assimilation, closely coincide with the tornado reports. These improvements result not only from the effective suppression of spurious clouds, but also from the better estimations of hydrometeors owing to the frequent assimilation of all-sky BT observations that yield a more accurate analysis of the storm. Results show that BT observations generally have a greater impact on ice particles than liquid water species, which might provide guidance on how to better constrain modeled clouds using these spaceborne observations.
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Vershigora, Valery. "Climate Solutions based on advanced scientific discoveries of Allatra physics". Open Physics 14, n.º 1 (1 de enero de 2016): 140–44. http://dx.doi.org/10.1515/phys-2016-0014.
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AbstractGlobal climate change is one of the most important international problems of the 21st century. The overall rapid increase in the dynamics of cataclysms, which have been observed in recent decades, is particularly alarming. Howdo modern scientists predict the occurrence of certain events? In meteorology, unusually powerful cumulonimbus clouds are one of the main conditions for the emergence of a tornado. The former, in their turn, are formed during the invasion of cold air on the overheated land surface. The satellite captures the cloud front, and, based on these pictures, scientists make assumptions about the possibility of occurrence of the respective natural phenomena. In fact, mankind visually observes and draws conclusions about the consequences of the physical phenomena which have already taken place in the invisible world, so the conclusions of scientists are assumptions by their nature, rather than precise knowledge of the causes of theorigin of these phenomena in the physics of microcosm. The latest research in the field of the particle physics and neutrino astrophysics, which was conducted by a working team of scientists of ALLATRA International Public Movement (hereinafter ALLATRA SCIENCE group)allatra-science.org, last accessed 10 April 2016., offers increased opportunities for advanced fundamental and applied research in climatic engineering.
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Crook, Sarah D., Timothy C. W. Lau y Richard M. Kelso. "Three-dimensional flow within shallow, narrow cavities". Journal of Fluid Mechanics 735 (28 de octubre de 2013): 587–612. http://dx.doi.org/10.1017/jfm.2013.519.
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AbstractThe three-dimensional structure of incompressible flow in a narrow, open rectangular cavity in a flat plate was investigated with a focus on the flow topology of the time-averaged flow. The ratio of cavity length (in the direction of the flow) to width to depth was $l{: }w{: }d= 6{: }2{: }1$. Experimental surface pressure data (in air) and particle image velocimetry data (in water) were obtained at low speed with free-stream Reynolds numbers of ${\mathit{Re}}_{l} = 3. 4\times 1{0}^{5} $ in air and ${\mathit{Re}}_{l} = 4. 3\times 1{0}^{4} $ in water. The experimental results show that the three-dimensional cavity flow is of the ‘open’ type, with an overall flow structure that bears some similarity to the structure observed in nominally two-dimensional cavities, but with a high degree of three-dimensionality both in the flow near the walls and in the unsteady behaviour. The defining features of an open-type cavity flow include a shear layer that traverses the entire cavity opening ultimately impinging on the back surface of the cavity, and a large recirculation zone within the cavity itself. Other flow features that have been identified in the current study include two vortices at the back of the cavity, of which one is barely visible, a weak vortex at the front of the cavity, and a pair of counter-rotating streamwise vortices along the sides of the cavity near the cavity opening. These vortices are generally symmetric about the cavity centre-plane. However, the discovery of a single tornado vortex, located near the cavity centreline at the front of the cavity, indicated that the flow within the cavity is asymmetric. It is postulated that the observed asymmetry in the time-averaged flow field is due to the asymmetry in the instantaneous flow field, which switches between two extremes at large time scales.
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Izhovkina, N. I., S. N. Artekha, N. S. Erokhin y L. A. Mikhailovskaya. "Influence of Cosmic Ray Invasions and Aerosol Plasma on Powerful Atmospheric Vortices". Physical Science International Journal, 16 de septiembre de 2019, 1–13. http://dx.doi.org/10.9734/psij/2019/v23i230152.
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The Earth’s atmosphere is affected by various ionizing sources. The maximum ionization of atmospheric particles by cosmic rays corresponds to the altitude of formation of tropospheric clouds. In the high-latitude troposphere for the region of the geomagnetic polar cap, in the winter period, the excitation of local cyclonic structures are observed which are accompanied with ice storms, with invasions into middle and subtropical latitudes. The time of excitation of such cyclones is about a day that is comparable with the time of excitation of tornadoes, which are generated at low latitudes. Localization of polar cyclones is not accidental. The region of the polar cap is connected with geomagnetic field lines extended into the tail of the Earth’s magnetosphere. This area is open for the penetration of cosmic rays. The ionization of aerosols in the stratosphere and the upper troposphere by precipitating particles of cosmic rays enhances the vortex activity of the atmosphere. The important role of the aerosol impurity is manifested in the generation of plasma vortices and in the accumulation of energy and mass in the atmosphere by vortices during condensation of moisture. Due to the cascade character of the ionization process, the influence of cosmic radiation turns out to be non-linear and increases with increasing pollution of the atmosphere. Aperiodic electrostatic perturbations, which play a remarkable role in the genesis of vortices, are stochastically excited in plasma inhomogeneities. During the interaction of plasma vortices and Rossby vortices, a large-scale vortex structure is formed and grows.
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Ozalp, Nesrin y Anoop Kanjirakat. "A Computational Fluid Dynamics Study on the Effect of Carbon Particle Seeding for the Improvement of Solar Reactor Performance". Journal of Heat Transfer 132, n.º 12 (22 de septiembre de 2010). http://dx.doi.org/10.1115/1.4002173.
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This study focuses on a technique, referred to as “solar cracking” of natural gas for the coproduction of hydrogen and carbon as byproduct with zero emission footprint. Seeding a solar reactor with micron-sized carbon particles increases the conversion efficiency drastically due to the radiation absorbed by the carbon particles and additional nucleation sites formed by carbon particles for heterogeneous decomposition reaction. The present study numerically tries to investigate the above fact by tracking carbon particles in a Lagrangian framework. The results on the effect of particle loading, particle emissivity, injection point location, and effect of using different window screening gases on a flow and temperature distribution inside a confined tornado flow reactor are presented.
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Motome, Yuiko, Yoshiya Akiyama y Hiroyuki Murao. "Evaluation of Radiation Effects on Residents Living Around the NSRR Under External Hazards". Journal of Nuclear Engineering and Radiation Science 6, n.º 2 (3 de febrero de 2020). http://dx.doi.org/10.1115/1.4045075.
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Abstract The nuclear safety research reactor (NSRR) is a research reactor of training research isotopes general atomics—annular core pulse reactor (TRIGA-ACPR) type, located in the Nuclear Science Research Institute (NSRI). The NSRR facility has been utilized for fuel irradiation experiments to study the behaviors of nuclear fuels under reactivity-initiated accident (RIA) conditions. Under the new regulation standards, which was established after the Fukushima Daiichi accident, research reactors are regulated based on the risk of the facilities. The graded approach is introduced in the regulation. To apply the graded approach, the radiation effects on residents living around the NSRR under the external hazards were evaluated, and the level of the risk of the NSRR facility was investigated. This paper summarizes the result of the evaluation in the case where the safety functions are lost due to a tornado, an earthquake followed by a tsunami. There is fuel in the reactor core, fresh fuel storage, and spent fuel storage. As the effects from reactor core, we evaluate the external exposure to radiation and exposure from the release of fission products assuming that loss of function to shut down the reactor, break of cladding tubes, loss of reactor pool water, and collapse of the reactor building. As the effects from fresh fuel storage, we evaluate the internal exposure assuming that the fresh fuel particles released into the air because of breaking into pieces. In addition, we evaluate the critical safety assuming that the critical safety shapes of the fresh fuel storage are lost. As the effects from spent fuel storage, we evaluate the critical safety assuming that the critical safety shapes of the spent fuel storage are lost. All in all, the risk is confirmed to be relatively low, since the effective dose on the residents is found to be below 5 mSv per event due to the loss of the safety functions caused by the tornado, earthquake, and the accompanying tsunami.