4/3/2023 0 Comments Farming simulator 14![]() For example, Lin used a 3D sub-cloud idealized simulation to reproduce the microbursts and found that the simulation could capture the key features that were observed in real downburst events. As the downburst events are small in spatial scale and short in temporal scale, high resolution simulations are a useful tool for related studies. Of these, to understand their formation mechanisms and to explore their three-dimensional (3D) structures are of particular importance. ĭue to their high frequency and strong destructive power, the downbursts have been a hot research topic for decades. Moreover, the disastrously strong winds associated with downbursts often caused considerable damages to crops, trees, houses, and transmission line towers, resulting in serious casualties and property losses, Of these, damages to the power facilities were usually more serious as in addition to affecting local regions, downbursts could also affect other regions through causing an interruption to the power supply. Up to 442 people were killed in this accident. On 1 June 2015, a cruise ship named “Dongfangzhixing” encountered a downburst in the Jianli (Hubei Province) section of the Yangtze River and capsized instantaneously. For example, on 24 June 1975, when a Boeing aircraft was about to land at Kennedy Airport in New York, it encountered a downburst and crashed rapidly, resulting in 113 deaths and 11 injuries. Downburst has a significant impact on the aviation and the shipping industry. According to the horizontal scale, Fujita classified the downbursts into two types: the downbursts over horizontal spatial scales ≤4 km are referred to as microbursts, and those events with horizontal spatial scales >4 km are termed macrobursts. The kinetic energy budget analyses denote that, for the region surrounding the location where the tower toppling appeared, the work done by the strong pressure gradient force between the high-pressure closed center (corresponding to intense descending motions) and the low-pressure closed center (corresponding to strong latent heat release) dominated the rapid wind enhancement.Īccording to the definition from the American Meteorological Society (AMS), the downburst is defined as an area of strong (usually >17.2 m s −1), often damaging, winds produced by one or more convective downdrafts. These air particles experienced notable descending processes, during which most of the air particles decreased notably in their potential temperature, while they increased significantly in their specific humidity. Backward trajectory analysis indicates that the air particles that came from the middle troposphere west of the key region (~61.2% in proportion) were crucial for producing the strong winds of the downburst event. The downburst-associated convection was deep (from surface to 200 hPa) in the near surface layer, it was mainly associated with positive geopotential height and negative temperature deviations, whereas, at higher levels, it was mainly associated with negative geopotential height and positive temperature deviations. It was found that a southwest–northeast-orientated, eastward moving strong squall line was the parent convection system for the downburst event. By using the Weather Research and Forecasting (WRF) model version 4.4, key features of the downburst event were reproduced reasonably based on which, we explored the evolutionary mechanisms and the three-dimensional structures of the strong winds associated with the downburst event. ![]() On, a series of severe convection occurred in middle and eastern China, during which six 500-kilovolt transmission line towers in Zhejiang were toppled down by a downburst event, resulting in a large range of power outages. ![]() The downburst events have been a research focus for decades, as their associated disastrously strong winds pose a great threat to aviation, the shipping industry, agriculture, and the power industry. ![]()
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