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Published in Anna M. Doro-on, Handbook of Systems Engineering and Risk Management in Control Systems, Communication, Space Technology, Missile, Security and Defense Operations, 2023
Weather modification is a man-made alteration of atmospheric conditions on local or regional capacities as clouds, snow, fog, rain, hail, lightning, thunderstorms, tornadoes, hurricanes, and cyclones. For the past several years scientists have been attempting to disrupt incoming hurricanes or tropical cyclones. Recently, China employed rockets to deliver its silver iodide to the sky to create artificial snow. For the residents of Beijing, those armaments deliver all the headaches that go along with big snowstorms: traffic problems, flight delays, cancelled classes, and various transportation issues (Dillow 2009). While the government of China claims the seeding is for the good of the country, that claim is about as dubious as the practice of seeding itself. In 2005, a snow melting agent killed 10,000 trees in Beijing, and experts worry it could be eroding the city’s infrastructure (Dillow 2009). In 2008, China attempted to stop rain for the 2008 Olympics by utilizing 30 airplanes, 4000 rocket launchers, and 7000 anti-aircraft guns. Cloud seeding is a relatively well-known practice that involves shooting various substances into clouds, such as silver iodide, salts, and dry ice, that bring on the formation of larger raindrops, triggering a downpour (Demick 2008). But Chinese scientists believe they have perfected a technique that reduces the size of the raindrops, delaying the rain until the clouds move on (Demick 2008). Scientist working for the Abu Dhabi government created more than 50 rainstorms in Al Ain in July and August 2010, during the peak of the emirate’s summer months (Leigh 2011). The rains are part of a secret of $11 million project, reportedly commissioned by HH Sheikh Khalifa bin Zayed Al Nahyan, president of the UAE, which used ionizers to generate storms (Leigh 2011). The fake storms went so far as to produce hail, wind gales, and even lightning, baffling residents (Leigh 2011).
Sources and demand for water
Published in Amithirigala Widhanelage Jayawardena, Fluid Mechanics, Hydraulics, Hydrology and Water Resources for Civil Engineers, 2021
Amithirigala Widhanelage Jayawardena
Cloud seeding is a method of weather modification. It is done by introducing a seeding agent to a cloud. It may be carried out by deploying the seeding agent from above or inside the cloud, from below the cloud and allowing it to disperse naturally by updrafts or thermals, or by ground-based generators for low-hanging cold clouds in mountainous areas. The most widely used purpose is to increase precipitation.
Atmospheric Effects
Published in Wayne T. Davis, Joshua S. Fu, Thad Godish, Air Quality, 2021
Wayne T. Davis, Joshua S. Fu, Thad Godish
Pollutants may also affect precipitation in cold cloud processes by influencing the concentration of freezing nuclei. Because atmospheric levels of freezing nuclei are frequently low, the addition of freezing nuclei in the form of pollution particles may enhance precipitation under cold cloud conditions. An application of this principle is cloud seeding with silver iodide crystals.
Study of ice nucleation on silver iodide surface with defects
Published in Molecular Physics, 2019
Rohit Goswami, Atanu K. Metya, S. V. Shevkunov, Jayant K. Singh
Among all the ice-nucleating agents, silver iodide (AgI) is widely used as cloud seeding agents because of its efficacious ice-nucleating ability [43]. Owing to this efficiency, diverse experimental and theoretical studies [29,44] have been devoted to the ice nucleation on AgI surface. Zielke et al. [38] observed that silver exposed AgI surface accelerated ice nucleation while iodide exposed surface hindered the process. Water condensation studies over β-AgI surface with defects in the form of rectangular towers [45] and pyramids [46,47] showed greater thermodynamic stability of condensate over the surface. The increased stability at the early stage of nucleation was reported to be a function of the shape and size of the nanostructure [45]. Similar condensation study over AgI surface with disordered structure observed an increase in absorption ability [48] and rupture of the hydrogen bond between molecules due to defects [46,48]. However, the influence of defective AgI surface on the liquid to solid transition mechanism of water has not been probed using molecular dynamics (MD). Recent studies have reported enhanced ice nucleation efficiency for systems with surface defects in the form of steps, cavities, and crevices [27]. The nucleation rate has been reported to increase for surface geometries which favour the formation of topological defects in ice lattice structures [49].