Turbulence in the Strongly Heterogeneous Near-Surface Boundary Layer over Patchy Snow

• DOI: 10.1007/s10546-023-00856-4
• Publication Date: 2024-01-22T09:02:18Z
• Authors: Michael Haugeneder; Michael Lehning; Ivana Stiperski; Dylan Reynolds; Rebecca Mott
• Keywords: Surface layer; Snow field

Abstract The near-surface boundary layer above patchy snow cover in mountainous terrain is characterized by a highly complex interplay of various flows on multiple scales. In this study, we present data from comprehensive field campaign that period 21 days the ablation season an alpine valley, continuous until complete melt out. We recorded eddy covariance at different heights and investigated spectral decompositions. topographic setting led to categorisation into up down valley flows, with Föhn event middle observation period. Our findings reveal fraction major driver for structure dynamics atmospheric adjacent surface. With bare ground emerging, stable internal layers (SIBL) developed over snow. As coverage decreased, depth SIBL decreased below 1 m spectra air temperature variance showed transition towards turbulent time scales, which were caused intermittent advection shallow plumes warm could also be observed visually high spatio-temporal resolution measurements using thermal infrared camera. While only affected lowest measurement level 0.3 m, 2 3 indicate distribution size and, thus, turbulence structure, did not distinctly change height.