The Comparative Study Of Calculating Turbulence Parameters Based On Thorpe Analysis Method And The Vertical Velocity Fluctuation Method

On the basis of the high resolution wind and temperature data observed by the ra-diosound on the Kexue 1 scientific observation ship during SCSMEX (South China Sea Monsoon Experiment) in 1998(May 5-25; June 5-25), the turbulence parameters(kinetic energy dissipation rate ? and turbulence diffusivity K) in the troposphere and lower strato-sphere(TLS) are derived using the following two methods:Thorpe analysis and the vertical velocity fluctuation method. The results from the two methods exhibit similarities in terms of the vertical structure and magnitudes of ? and K. In the respect of vertical structure, ? and K are relatively large above 10 km and below the tropopause(about 17-18 km), no matter the averaged results are on a monthly or daily basis. By contrast, they are relatively small above the tropopause; The magnitudes of ? and K calculated using the two methods are both in the range of 10-6-10-2 m2s-3 for ? and 0-10 m2s-1 for K. The differences of the results from the two methods are that the turbulence parameters calculated by the vertical velocity fluctuation method are smaller than those by Thorpe analysis; In the respect of peak value, the peak value of ? is at about 15 km according to Thorpe analysis, but at about 17 km according to the vertical velocity fluctuation method, but the peak values of K derived using the two methods are both at about 15 km; In the respect of range of application, considering of the case of stable atmospheric structure, the two methods are feasible in the resolution of 10 m. But we should better use the vertical velocity fluctuation method to calculate the turbulence parameters when the resolution value is greater than 10 m. when the resolution value is smaller than 10 m, Thorpe analysis is more appropriate.Because the data observation time is short during SCSMEX, we can't further study the monthly variation, the seasonal variation and the annual variation of the turbulence parameters. On the basis of the high resolution data observed by the radiosound on the site of Santa Teresa, New Mexico(31.9°N253.3°E) from 2008 to 2011, the turbulence parameters are derived using Thorpe analysis. And we further study the monthly variation, the seasonal variation and the annual variation of the turbulence parameters. We find that:1, The peak values of the turbulence parameters are higher in summer than others, generally at about 10-15 km, but lower in winter at about 7-12 km.2?The maximum values of the turbulence parameters appear in summmer, especially larger in near surface about 2 km.3?Regardless of the season average or the annual average, the variation of turbulence parameters between the different years is not obvious, the overall trend is decreased with increasing altitude. But the Orders of magnitude of the minimum values of ? and K are respectively -4 and-1.