scholarly journals The occurrence of icing rain drops on powerlines

2018 ◽  
Author(s):  
Marija Orlović ◽  
◽  
Miloš Banjac
Keyword(s):  
Rain Drops

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

A laboratory and model investigation of secondary ice production during to supercooled drop collisions with ice surfaces 

2021 ◽  
Author(s):  
Paul Connolly ◽  
Rachel James ◽  
Vaughan Phillips
Keyword(s):  
Laboratory Data ◽  
Ice Formation ◽  
Atmospheric Sciences ◽  
Ice Particles ◽  
Cold Room ◽  
Mode 2 ◽  
Rain Drops ◽  
Break Up ◽  
Ice Surfaces ◽  
Ice Production

<p>This work presents new laboratory data investigating collisions between supercooled drops and ice particles as a source of secondary ice particles in natural clouds. Furthermore we present numerical model simulations to put the laboratory measurements into context.</p><p>Secondary ice particles form during the breakup of freezing drops due to so-called “spherical freezing” (or Mode 1), where an ice shell forms around the freezing drop. This process has been studied and observed for drops in free-fall in laboratory experiments since the 1960s, and also more recently by Lauber et al. (2018) with a high-speed camera. Aircraft field measurements (Lawson et al. 2015) and lab data (Kolomeychuk et al. 1975) suggest that such a process is dependent on the size of drops, with larger drops being more effective at producing secondary ice.  Collision induced break-up of rain drops has been well studied with pioneering investigations in the mid-1980s, and numerous modelling studies showing that it is responsible for observed trimodal rain drop size distributions in the atmosphere, which can be well approximated by an exponential distribution.</p><p> </p><p>In mixed-phase clouds we know that rain-drops can collide with more massive ice particles. This, depending on the type of collision, may lead to the break-up of the supercooled drop (e.g. as hinted by Latham and Warwicker, 1980), potentially stimulating secondary ice formation (Phillips et al. 2018 - non-spherical, Mode 2).  There is a dearth of laboratory data investigating this mechanism.  This mechanism is the focus of the presentation.</p><p>Here we present the results of recent experiments where we make use of the University of Manchester (UoM) cold room facility. The UoM cold room facility consists of 3 stacked cold rooms that can be cooled to temperatures below -55 degC. A new facility has been built to study secondary ice production via Mode 2 fragmentation. We generate supercooled drops at the top of the cold rooms and allow them to interact with different ice surfaces near the bottom. This interaction is filmed with a new camera setup.</p><p>Our latest results will be presented at the conference.</p><p>References</p><p>Kolomeychuk, R. J., D. C. McKay, and J. V. Iribarne. 1975. “The Fragmentation and Electrification of Freezing Drops.” <em>Journal of the Atmospheric Sciences</em> 32 (5): 974–79. https://doi.org/10.1175/1520-0469(1975)032<0974>2.0.CO;2.</p><p>Latham, J., and R. Warwicker. 1980. “Charge Transfer Accompanying the Splashing of Supercooled Raindrops on Hailstones.” Quarterly Journal of the Royal Meteorological Society 106 (449): 559–68. https://doi.org/10.1002/qj.49710644912.</p><p>Lauber, Annika, Alexei Kiselev, Thomas Pander, Patricia Handmann, and Thomas Leisner. 2018. “Secondary Ice Formation during Freezing of Levitated Droplets.” Journal of the Atmospheric Sciences 75 (8): 2815–26. https://doi.org/10.1175/JAS-D-18-0052.1.</p><p>Lawson, R. Paul, Sarah Woods, and Hugh Morrison. 2015. “The Microphysics of Ice and Precipitation Development in Tropical Cumulus Clouds.” Journal of the Atmospheric Sciences 72 (6): 2429–45. https://doi.org/10.1175/JAS-D-14-0274.1.</p><p> </p><p> </p>

scholarly journals A general database of hydrometeor single scattering properties at microwave and sub-millimetre wavelengths

2018 ◽  
Author(s):  
Patrick Eriksson ◽  
Robin Ekelund ◽  
Jana Mendrok ◽  
Manfred Brath ◽  
Oliver Lemke ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Single Scattering ◽  
Particle Orientation ◽  
Maximum Diameter ◽  
Particle Sizes ◽  
Orientation Data ◽  
Different Types ◽  
Rain Drops ◽  
Cloud Ice ◽  
Random Particle

Abstract. A main limitation today in simulations and inversions of microwave observations of ice hydrometeors (cloud ice, snow, hail ...) is the lack of data describing the interaction between electromagnetic waves and the particles. To improve the situation, the development of a comprehensive dataset of such "scattering properties" has been started. The database aims at giving a broad coverage in both frequency (1 to 886 GHz) and temperature (190 to 270 K), to support both passive and active current and planned measurements, and to provide data corresponding to the full Stokes vector. This first version of the database is restricted to totally random particle orientation. Data for 34 particle sets, i.e. habits, have been generated. About 17 of the habits can be classified as single crystals, three habits can be seen as heavily rimed particles, and remaining habits are aggregates of different types, representing e.g. snow and hail. The particle sizes considered vary between the habits, but a maximum diameter of 10 and 20 mm are typical values for the largest single crystal and aggregate particles, respectively, and the number of sizes per habit is at least 30. Particles containing liquid water are also inside the scope of the database, but this phase of water is so far only represented by a liquid sphere habit. The database is built upon the netCDF4 file format. Interfaces to browse, extract and convert data for selected radiative transfer models are provided in Matlab and Python. The database and associated tools are publically available from Zenedo (https://doi.org/10.5281/zenodo.1175572 and https://doi.org/10.5281/zenodo.1175588, respectively). Planned extensions include non-spherical rain drops, melting particles and a second orientation case that can be denoted as azimuthally random.

scholarly journals The theoretical approaches for calculation of the vertical effective pressure of drop impact of artificial rain on soil and hard surface

2016 ◽  
Vol 1 ◽  
pp. 16-20
Author(s):  
Bryl S.V. ◽  
Zverkov M.S.
Keyword(s):  
Solid Surface ◽  
Land Reclamation ◽  
Effective Pressure ◽  
Pressure Drops ◽  
Impact Performance ◽  
Theoretical Approaches ◽  
Rain Drops ◽  
Artificial Rain ◽  
Newton’S Laws ◽  
The Impact

The article considers the problem of calculating the vertical effective pressure drops of artificial rain on soil and hard surfaces. It is noted that the problem of determining the effective vertical pressure p of rain drops on soil although it is difficult, however, has a solution using Newton’s laws. This issue V.V. Slastenin, G. and A.P. Isaev, V.M. Moskovkin and V.F. gahs, etc., and N scientists. Erowyn S. , M.B. Lebedev, V.I., Gorodnichev, etc. proposed different approaches for determining the pressure p in terms of land reclamation (artificial irrigation). These issues dealt with and foreign researchers. Selected according to, according to the authors, the most suitable for the study of impact of the drops of artificial rain with the help of the patented device, and also to compare the obtained results with those of researchers dealing with the drip of erosion and determining the impact performance characteristics of droplets on a solid surface.

« Rain drops on roses and whiskers on kittens »

Vacarme ◽  
2016 ◽  
Vol 76 (3) ◽  
pp. 45
Author(s):  
Cyril Lecerf Maulpoix
Keyword(s):  
Rain Drops

Shading effect of rain drops in ship free space laser communication

2014 ◽  
Vol 22 (10) ◽  
pp. 2652-2658
Author(s):  
汪亭玉 WANG Ting-yu ◽  
陈家璧 CHEN Jia-bi
Keyword(s):  
Free Space ◽  
Laser Communication ◽  
Shading Effect ◽  
Rain Drops

scholarly journals Field Determination of the Specific Input Characteristics to Calculate the Value of C Factor of Time-variable Crops for the Revised Universal Soil Loss Equation (RUSLE)

2013 ◽  
Vol 1 (No. 1) ◽  
pp. 10-15 ◽  
Author(s):  
Jakubíková Alena ◽  
Tippl Miloslav Janeček and Martin
Keyword(s):  
Soil Loss ◽  
Canopy Cover ◽  
Agricultural Crops ◽  
Growth Phases ◽  
Specific Input ◽  
Rain Drops ◽  
Basic Characteristics ◽  
Runoff And Soil Loss ◽  
Fall Height

To determine specific characteristics necessary for the computation of the C factor in RUSLE for timevariable crops, measurements were carried out in fields with selected agricultural crops grown by conventional practices. Sloping plots on an experimental area in Třebsin locality and farm fields were used to measure surface runoff and soil loss by erosion in conditions of natural and simulated rainfall. Basic characteristics to compute the C factor were determined in the particular growth phases of selected crops – sunflower, flax, poppy and rape. Effective root mass, canopy cover and fall height of rain drops were measured.

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