Estimation of Aviation Turbulence using High Vertical-Resolution Radiosonde Data and Comparison with In Situ Flight Data

The raw data of operational radiosonde with a temporal resolution of a second, corresponding to a vertical resolution of about 5 m, are invaluable resources for study of various atmospheric problems, such as gravity waves, atmospheric turbulence, tropopause structure, and atmospheric boundary layer. Among them, atmospheric turbulence in the free atmosphere has been estimated using these high vertical-resolution radiosonde data (HVRRD) based on a linear relationship between the Thorpe (1977) scale, which is the local overturning length scale estimated originally using the high vertical-resolution density profile in the ocean (also from potential temperature profile in the atmosphere), and the Ozmidov scale, which is the largest length scale of turbulence eddies in a stably stratified fluid. Although some uncertainties exist, values of the correlation coefficient between the Thorpe and Ozmidov scales that derived from recent observational and numerical modeling studies are generally consistent with each other. In the present study, we estimate the eddy dissipation rate in the free atmosphere using the HVRRD observed from 90 operational radiosonde stations in USA, which are available from SPARC data center (http://www.sparc-climate.org/data-center/data-access/us-radiosonde). The 1/3 power of eddy dissipation rate (EDR), which is the primary metric of aviation turbulence, is obtained, and the characteristics of radiosonde-derived EDR in horizontal and vertical directions are examined. Then, the results are compared with the EDR observed from in-situ flight data in USA for 6 months from October 2015 to March 2016. The potentials for utilizing the operational HVRRD in the research and forecasting of aviation turbulence will be discussed.