Characterizing atmospheric stability in complex terrain

Abstract

Characterizing atmospheric stability becomes challenging in heterogeneous, complex terrain. We use data from 47 meteorological towers associated with the Perdigão field campaign to recommend data-processing approaches and to assess the limitations of shorter or fewer towers. We quantify atmospheric stability according to the Obukhov length, the turbulence kinetic energy, and the turbulence dissipation rate using two decomposition periods, including consistent 10 min periods to match convention in the wind energy community and consistent 30 min periods to match convention in the atmospheric science community. We also demonstrate a methodology that can indicate the necessary number and location of towers to characterize atmospheric stability. We find that the 10 min Reynolds decomposition window underestimates turbulence patterns. Additionally, 10 m measurements do not provide reliable 100 m hub-height stability predictions. Holistically, this work addresses challenges in relying on sparse surface measurements.