Parameterizing Turbulent Exchange at a Snow-Covered Surface

• Main Authors: Edgar L Andreas, P. Ola, G. Persson, Rachel E. Jordan, Thomas W. Horst, Peter S. Guest, Andrey A. Grachev, Christopher, W. Fairall
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: bulk flux algorithm; friction velocity; Monin-Obukhov similarity; roughness length of snow; SHEBA experiment; turbulence measurements; winter sea ice; Arctic; Arctic Ocean; Sea ice; Surface Heat Budget of the Arctic Ocean
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.595.5730; http://www.easternsnow.org/proceedings/2008/andreas_et_al.pdf

During the experiment to study the Surface Heat Budget of the Arctic Ocean (SHEBA), our multiple micrometeorological sites yielded over 10,000 hours of turbulent surface flux measurements during the polar winter. These measurements are relevant to the Eastern Snow Conference because polar sea ice is an ideal site for observing the fundamental processes that control turbulent exchange between the atmosphere and snow-covered surfaces. Each SHEBA site was on a horizontal surface (i.e., snow-covered sea ice) that was uniform and had no topographic variations for hundreds of kilometers in all directions. Consequently, density-driven flows that can confound measurements over land surfaces did not occur. Moreover, diurnal forcing was often weak or nonexistent; mesoscale and synoptic-scale disturbances with 1–4 day time scales were the primary mode of temporal variability. Consequently, our measurements were often in quasi-stationary conditions. We describe our eddy-covariance measurements of the surface fluxes of momentum and sensible and latent heat and how we develop parameterizations for these fluxes. Our approach relies on Monin-Obukhov similarity theory, which, in turn, requires that we evaluate the