戈壁地区近地面折射率结构常数统计特性分析

Statistical characteristics on near-surface refractive index structure parameter in Gobi area

利用温度脉动仪对大气折射率结构常数进行测量,通过在铁塔上不同测量高度架设温度脉动仪,对戈壁地区近地面层开展长期连续测量。从各测量高度折射率结构常数的累积概率、偏度与峰度、季节变化、高度经验关系等四个方面对大量实验数据统计分析,结果表明:测量地区大气折射率结构常数白天和夜间的累积概率以18m为区别界限,表现出明显的不同;所有测量高度折射率结构常数的概率分布均表现出右偏、平峰特性;季节变化对低层折射率结构常数的影响更为明显;测量地区折射率结构常数随高度变化的经验公式表明,白天折射率结构常数随高度递减接近"-2/3"指数,夜间折射率结构常数的高度变化则是表现出层次性,低层折射率结构常数随高度递减接近"-0.16"指数,而高层变化则接近"-1.05"指数。

By using the micro-thermal meters at different heights of a tower in Gobi area,refractive index structure parameters were continuously measured in the atmospheric surface layer for a long time.A statistical analysis on large numbers of experimental data on cumulative probability,skewness and kurtosis,seasonal variation,and empirical formula of refractive index structure parameter dependence on height is provided.The obtained results show that the cumulative probabilities in the measured area during day and night with 18 mas the distinction,exhibit significant difference between the measurement above 18 mand the measurement under 18 m.The probability distribution of refractive index structure parameter at all heights show a right skewed,flat peak characteristics.Seasonal variation have more obvious influence on the refractive index structure parameter of lower levels.Empirical formula in measured area on refractive index structure parameter by day shows optical turbulence strength decreases with a＂-2/3＂exponent altitude dependence.Whereas refractive index structure parameter of empirical formula at night shows levels,and optical turbulence of lower levels decreases with a ＂-0.16＂exponent altitude dependence,while the higher change with height close to the＂-1.05＂.