Use of the Inertial Dissipation Method for Calculating Turbulent Fluxes from Low-Level Airborne Measurements

Abstract

Airborne measurements are currently used for computing turbulence fluxes of heat and momentum. The method generally used is the eddy correlation technique, which requires sophisticated equipments to calculate the absolute velocities of the air. We used the well-known inertial dissipation method to calculate the turbulent fluxes of heat and momentum from low-level airborne measurements This only requires knowledge of inertial subrange characteristics of velocity and scalars. The method was validated by comparing dissipation fluxes with those computed by the eddy correlation method. The agreement between the two is very good, particularly for heat fluxes. Last, it is shown how the turbulent kinetic energy dissipation rate can be easily calculated, using a single measurement (the attack angle by example), and therefore how turbulent fluxes can be simply calculated from low level airborne measurements.