| 2005--2014 years Tarim basin in the tower and the surrounding 15 meteorological stations sandstorm data, according to the hinterland of the Taklimakan Desert sandstorm occurred tower surrounding the station in response to the number and scope of the division of the impact of the tower of the local and regional dust storms, the strength characteristics of the regional and local sandstorm duration, visibility, type, time, etc. characteristics. Then referring to July 2008--2014 December Taklimakan Desert atmospheric observation experiment station 80 m observation tower near surface observing systems data selected regional and local dust storms of 50 times the pre-analysis and continuous sandstorms coming in surface wind speed, barometric pressure, temperature variation, and 2012, three times the typical analysis of local and regional dust storms of dust storms and ground meteorological elements near ground wind speed, temperature, relative humidity profiles change characteristics, studies show that:(1) 10 a sandstorms 170 d higher than the average of the desert north and south edges 14 points, less than the Xiao Tong, where regional sandstorm 80 d, local sex sandstorm 90d; a regional sandstorm whether or visibility to the long duration of dust storms on the whole than the Bureau duration, low visibility; regional dust storms prevailing wind direction can be divided into five categories, but all kinds of storms exhibit regional sandstorm season uneven distribution; regional and local fluctuations in the growth of dust storms 10 a, regional dust storms occurred in the spring, local sex dust storms occurred in the summer, regional and inter-annual dust storms during the year are less than the coefficient of variation of the local dust storms, the day regional and local resistance is greater than the frequency of dust storms during the day at night. local dust storms mainly occurred in the afternoon, each regional sandstorm period can occur.(2) the regional and local dust storm before coming wind speed change is big, and there was a time of low wind speed, low regional sandstorm at 0, 4 m/s wind speed value and local sandstorms in low wind speed value 0-2 m/s; In the outbreak, the local sex sandstorm to 8 m/s, average wind speed value regional sandstorm average wind speed is greater than 6 m/s; In continuous phase, the local sex sandstorm average wind speed value in 8-12 m/s, average regional sand-dust storm in 8-11 m/s wind speed values, local sex sandstorm at 0, 4 m/s wind speed change value, regional sand-dust storm wind speed change value between 0-6 m/s. Regional and local dust storm occurred in the former temperature is higher, regional sandstorm is generally not more than 30 ℃, local sex sandstorm is not more than 40 ℃, is about to happen, regional sandstorm in 0-20 ℃, the increase or decrease amplitude local dust storm in 0-10 ℃; Continuous phase, regional and local dust storms continue to lower temperature, but the cooling effect is weak, increase or decrease amplitude are 0-10 ℃. before the regional and local dust storm occurred in high pressure, most regional sand-dust storm in 880-895 hpa, local dust storm in 880-890 hpa, regional sandstorm decompression range of 0-5 hpa, local sex sandstorm in 3-7 hpa, step-down amplitude and low pressure maintain for a long time; Continuous phase of regional and local sandstorms pressure rise, most regional sandstorm pressurization rate in 3-7 hpa, only a few in 7-12 hpa, most local sex sandstorm pressure rises in 1-3 hpa。three regional dust storms wind profile changes substantially similar, both in continuous sandstorms pick the fastest wind speed increases, and the maximum wind speed at 80 m. But whether the various weather phenomena on a larger gradient layer velocity profile at the end of a sandstorm wind profile slope greater than a sandstorm coming forward;(3) regional sandstorm sandstorm no local changes before the advent of the temperature profile rapid inversion layer thickness, local temperature of greater than storms, but not obvious weak inversion, which is made with regional sandstorms in the spring, and is leading to the invasion of cold air. Larger temperature difference between day and in regional sandstorm sandstorm continuation phase inversion disappeared, the temperature decreases with height, than the rapidly changing local gradient of sandstorms. regional sandstorm in various stages of relative humidity of greater than local storms, maximum 80 m above the top of the tower. Regional dust storms from high to low relative humidity continued slow increase in phase and amplitude variation of more than local dust storms, local dust storms at the end of a sandstorm substantially vertical humidity profile, no gradients... |
PDF Full Text Request