Novel approaches to estimating turbulent kinetic energy dissipation rate from low and moderate resolution velocity fluctuation time series

Abstract

Abstract. In this paper we propose two approaches to estimating the kinetic energy dissipation rate, based on the zero-crossing method by Sreenivasan et al. [J. Fluid Mech., 137, 1983]. The original formulation requires a good accuracy of the measured signal (down to the smallest dissipative scales). However, due to finite sampling frequency, as well as measurement errors, velocity time series obtained from airborne experiments are characterized by the presence of effective spectral cut-offs. In contrast to the original formulation the new approaches are suitable for use with signals originating from such experiments. The fittingness of the new approaches is tested using measurement data obtained during the Physics of Stratocumulus Top (POST) airborne research campaign.

Non-equilibrium dissipation scaling in atmospheric turbulence

“…Detailed analysis of this problem was presented in Ref. [11], where, additionally, methods based on the zero-crossing statistics and an iterative method (see [12]) were investigated. The conclusion which follows from those studies was that the method based on the second-order structure function (8) was less sensitive to smaller averaging window and performed better when the fitting range was moved towards smaller scales.…”

Coupled and decoupled stratocumulus-topped boundary layers: turbulence properties

“…Nevertheless, theoretical assumptions are often hardly satisfied in the atmosphere, e.g. considering complex stratification, and therefore estimation from moderateresolution (not directly resolving dissipative scales) measurements is challenging (Siebert et al, 2006b;Jen-La Plante et al, 2016;Wacławczyk et al, 2017Wacławczyk et al, , 2020. To account for possible anisotropy, was derived separately for longitudinal and vertical velocity fluctuations, following the methods of Siebert et al (2006b).…”