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

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 m as the distinction, exhibit significant difference between the measurement above 18m and 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.