During SHEBA (the Surface Heat Budget of the Arctic Ocean experiment), we measured the momentum and sensible heat fluxes over sea ice with sonic anemometer/thermometers at five levels on a 20-meter tower. Nearby, with a laser-based scintillometer system operating over paths of 300 or 350 m, we measured the inner scale of turbulence l0 (read el_zero) and the refractive index structure parameter Cn2. From Cn2 and l0 it is possible to estimate path-averaged values of the momentum and sensible heat fluxes through Monin-Obukhov similarity theory.
We will compare these directly measured and scintillation-derived turbulent fluxes with two questions in mind. There are suggestions in the literature that the common Monin-Obukhov similarity functions for the dissipation rate of turbulent kinetic energy and for scalar dissipation rate are not the best ones to use for converting l0 and Cn2 to the momentum and sensible heat fluxes. We will investigate this controversy. Second, the literature also suggests that path-averaging instruments, like scintillometers, should yield meaningful fluxes in a fraction of the sampling time required for point measurements, with sonics for example. Since we have minute averages of l0 and Cn2, we will investigate this hypothesis, too.