Turbulence

Turbulent eddy dissipation rate is estimated using an algorithm developed by Sand (Sand et al. 1976), based on earlier work described in MacCready (1962). The basic approach is based on the spectral properties of homogeneous turbulence in the inertial subrange. Airspeed fluctuations also can be qualitatively correlated with turbulence characteristics. Sand (1976) gives an empirical correlation between airspeed fluctuations on few-seconds time scale and pilot-reported turbulence intensity in aircraft of the weight and speed class of the T-28: Light 2.5 7.5 m s-1; Moderate 7.5 12.5 m s-1; and Severe > 12.5 m s-1.

Figure 5.  Turbulent eddy dissipation rate observed during the entire flight on 29 June 2000.

MacCready, P.B., Jr., 1962: Turbulence measurements by sailplane. J. Geophys. Res., 67, 1041-1050.

Sand, W.R., 1976: Observations in hailstorms using the T-28 aircraft system. J. Appl. Meteor., 15, 641-650.

Sand, W.R., J.L. Halvorson and T.G. Kyle, 1976: Turbulence measurements inside thunderstorms used to determine diffusion characteristics for cloud. Proc. 2nd World Meteorological Organization Conference on Weather Modification, Boulder, CO, 539-545.