Abstract The measured variations in the turbulent static pressure structure function Dpp(r) ${D}{pp}(r)$ with scale r $r$ in the roughness sublayer above a subarctic forest are empirically shown to exhibit exponents that are smaller than r4/3 ${r}^{4/3}$ predicted for the inertial subrange (ISR). Three hypotheses are offered to explain these deviations. The first is based on conventional intermittency correction to the averaged turbulent kinetic energy dissipation rate, the second is based on shearing introducing deviations from locally isotropic state that must be sensed by both velocity and pressure structure functions, and the third is based on large and inertial scale pressure interactions that persist at values of r $r$ within the resolvable ISR. The third hypothesis is shown to yield superior results, which allows a new formulation for Dpp(r) ${D}{pp}(r)$ to be derived that accommodates such finite interactions.

Read original article