On the Surface Roughness Effects on − 1 ${-}1$ Spectral Scaling in Atmospheric Boundary Layer

Using field data from a coastal site, we explored the turbulence spectra of boundary layer flows over land and sea, focusing on the occurrence and characteristics of the $-1$ spectral scaling in the energy production region. Results reveal that the interaction of the flow with surface roughness is a critical factor influencing the extent of the $-1$ scaling. Flows over the sea under generally calm conditions consistently exhibited a robust $-1$ spectral scaling across times of day and seasons. In contrast, flows over land, encountering higher surface roughness and heterogeneity, display very limited $-1$ scaling. Inspection of turbulence intermittency showed sea winds with slightly higher intermittency, though both remain lower. Also, spectral normalization using the integral wave number provides a general trend in the spectra well across heights and flow conditions onto a general trend, highlighting the potential role of the integral scale in spectral behavior. These insights maybe instrumental for atmospheric modeling, wind energy systems, and pollutant dispersion.