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Giant cloud condensation nuclei (GCCN)-based cloud seeding which uses 1-10 µm-sized hygroscopic powder has been known to be an effective warm-cloud seeding material, especially compared to hygroscopic flares in a rain enhancement weather modification operation. This is because it is able to produce 3 times the number of GCCN compared to that from flare-based seeding. The resulting GCCN would then accelerate collision and coalescence process within the clouds, which then result in higher precipitation events. However, one of the main challenges in preparing and utilizing this material is its tendency to coagulate in a room temperature and high humidity environment. Understanding and controlling this property is a major consideration in the use of this material in a weather modification operation. Further, there are not many literatures that discusses degradation behavior from this type of seeding material. I n this research, we have prepared and identified a 10:1 mixture of NaCl powder mixed with Cab-o-Sil anti-caking agent as a potential GCCN seeding material. We use a combination of frequent mechanical mixing, cross-beater (CB) milling and jet mill micronization to produce GCCN powders with the 1-10 µm size distribution. In order to understand and investigate seeding material degradation under such environmental condition, we performed weekly particle size (PSA), mass flow rate and angle of repose analysis to two batches of sample kept under two different conditions, one in a controlled room environment and another in a high humidity, room temperature environment, for a period of 4 weeks. We readily found that after 4 weeks, the mean and D90 particle size changes of the controlled sample are relatively small compared to changes in both parameters in an uncontrolled sample. While after the same period, the uncontrolled sample's flow rate is slightly larger compared to the controlled sample, with both sample's angle of repose showing small or insignificant changes compared to the beginning of experiment. We then conclude that although the 1-10 µm hygroscopic seeding material experiences large changes in particle sizes under a room temperature environment, the material flow characteristics in terms of flow rate and angle of repose does not change significantly. [ABSTRACT FROM AUTHOR]

Cloud seeding materials for weather modification used today have been around for many decades. This paper is working to design a new cloud seeding material with optimal properties to ensure water vapor condensation occurred effectively and maximize the rainfall achieved by using nanotechnology. The nanotechnology changed the surface of the material to make it more reactive at a lower relative humidity so the water can be absorbed easily and increase the probability of forming water droplets. Due to this reason the present research is focused on the developing sodium chloride (NaCl) nanoparticles fabrication using silica (SiO2) as a coating and anticaking material and then investigated the effect on the particle size reduction of sodium chloride. In this study we have successfully developed and identified sodium chloride (NaCl) nanoparticles fabrication as a potential new cloud seeding material. By using jet milling method for particle size reduction and varied SiO2 percentage (wt%) in the mixture and the cycling number of jet milling parameters has resulted NaCl/SiO2 submicron particles size distribution. Measurement on the jet milling results by a particle size analyzer (PSA) instrument showed that material with 3% SiO2 (wt%) addition and 3 (three) times jet milling cycling were found to contain NaCl/SiO2 mixture with less than 100 nm size distribution [ABSTRACT FROM AUTHOR]

Despite the increase of rainfall globally with the climate change, the large rivers are drying out. Less water in the river means less water supply to the cities and agricultural land, and indeed need more water for the dry soil for the farm. Eventually there is a need for more water than available. Cloud seeding has become one of the appealing methods across the globe for countries to accomplish the need of water. The cost involved in cloud seeding is gigantic. The implementation of cloud seeding with the 3D Printed Sounding Rocket can reduce ample amount of cost. This can also be used concurrently for agricultural surveying, in supplementary can help in research field on farm. Cloud seeding is enhancing the natural precipitation in clouds with the help of seeding agent, i.e., dry ice and silver iodide. Silver iodide is used for its similar molecular structure with water. 3D Printed Sounding Rocket is built with biodegradable material, PLA (Poly Lactic Acid), which contribute in reducing average cost of the cloud seeding process. On the basis of the experiment, the thrust requirement for 50 kg of rocket would be around 4521.3 N. Rocket travelling range is up to 48 to 145Km and carries payload of 10 to 100Kg as per the capability of designed rocket. Being first in India to evolve cloud seeding process with complete 3D Printed Sounding Rocket can have a great impact on Indian Economy. [ABSTRACT FROM AUTHOR]

Non-renewable resources are being depleted at a faster rate and consequently can cause a strong asymmetry in marginalized cities and towns, a resource as vital as water is a gift of nature that is not valued as it deserves, and the lack of it can be a high-risk factor causing serious economic, social, and health problems (UNHCR 2019). That is why the research objective is to design an industrial application model for the capture of atmospheric water, focused especially on agribusinesses in Mexico City. The design of the model is based on the models of Cloud Seeding (Super and Heimbach 1983) and Fog Trapping (Bautista et al. 2018), applying the analytical mechanics model (Zayas 2019). The main contribution of this research is that the proposal of this model supports the fulfillment of three Sustainable Development Goals of the 2030 Agenda: SDG 2. Zero Hunger; SDG 6. Clean Water and Sanitation and SDG 9. Responsible Consumption and Production. [ABSTRACT FROM AUTHOR]

The generation and occurrence of surface runoff from a slope is driven by many factors, such as the slope gradient, the physical properties and current state of the soil, the type and density of the vegetation cover, and the intensity and duration of rainfall events. Within the study experiments with a rainfall simulator were focused on an analysis of the impact of a changing slope gradient on the generation of surface runoff and the amount of eroded soil material. The experiments were conducted in laboratory conditions on a disturbed soil sample, which was exposed to 12-minute continuous and discontinuous simulated rainfalls with a given intensity of 5 mm/min. In the case of the discontinuous rainfall, the impact of the interruption on the amount of the surface runoff generated as well as on the course of the soil moisture values within the irrigated area was investigated every 3 minutes. The experiment also investigated the relationship between the time after which the surface runoff occurred and the slope gradient of the irrigated area, when various values of the slope gradient were used. Apart from the volume of the surface runoff generated, the weight of the eroded soil material and the ratio between the volumes of infiltrated water and the surface runoff were also calculated. The results of the rainfall simulator experiment confirmed the key role the antecedent soil moisture and the slope gradient of the area investigated have in the generation of surface runoff, especially in its volume and the time after which the surface runoff occurs. The results obtained during the laboratory experiment are an important complement to the terrain measurements and could be used together to better understand the processes involved in the generation of surface runoff and sediment transport. [ABSTRACT FROM AUTHOR]

Studies to date have shown that in western and southern Iasi county hail events presents the highest incidence. In these areas are the most important vineyards of the county, some of them internationally renowned (Cotnari, Bucium Copou etc.). In the past five years, the damage caused by storms accompanied by hail in Iasi county exceed 10 million euros. Unit for Combating Hail Moldova 1 Iasi help reduce these losses in Cotnari vineyard region. Since 2014 this unit acts by 5 Local Launching Points and protects 30,000 hectares of farmland. In this paper is presented a study case that points out the hailstorm that took place on the 9th of July 2012, phenomenon which caused considerable damage to crops and setelments. In the unprotected area, the hailstone reached the size of almost 5 centimeters in diameter and caused damage to a significant area, affecting vineyards and vegetable farming. A detailed analysis of this phenomenon and the damages caused by it demonstrates that the intervention with the anti-hail rockets had an efficiency of over 70% in the protected area. [ABSTRACT FROM AUTHOR]

The failure mode of fine-grain debris flow is investigated by using self-designed flume model device. Artificial rainfall is applied onto grain slopes in a flume model. Full-field displacement contour of fine-grain rainfallinduced debris flow during failure process is analyzed by using Digital Photogrammetry Deformation Measurement (GEODOG). The studies indicate that the particle movement of fine grains' experimental results respectively concentrated on the anterior and rear of sand slope of debris flow. The pore water pressure test results show that in the fine grain sample it is higher than it in coarse sand. [ABSTRACT FROM AUTHOR]

The hydrological assessment of the modified precipitation by the idealized cloud seeding experiment has been investigated using the Weather Research Forecast-Chemistry (WRF-CHEM) model and a hydrological model, SWAT. Simulation of the cloud seeding cases are conducted under the cloud seeding scenarios with aerosol/chemistry modules and emission data. The hydrological assessment for these variations in precipitation due to the cloud seeding was analyzed by the SWAT model. According to the analysis of WRF-CHEM model, the cloud seeding scenario showed more amounts of accumulated precipitation than those of control run with no aerosol/chemistry modules during winter season. According to the analysis of SWAT, this enhancement of precipitation could influence the increase of water resources through the increase of soil water and snow melt in next spring and summer season. [ABSTRACT FROM AUTHOR]

Concurrent measurements of aerosol physical and chemical properties, cloud condensation nuclei (CCN), and in-situ cloud droplet concentration were carried out during the fourth Pallas Cloud Experiment (PaCE) at Pallas-Sodankyla¨ GAW station, in northern Finland in autumn of 2012. Analysis of aerosol particle and cloud droplet properties will be presented in the conference. [ABSTRACT FROM AUTHOR]