Non-stationary Boundary Layers

L. Mahrt, Elie Bou-Zeid

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


The literature includes a wide variety of definitions or perceptions of non-stationarity. Non-stationarity can be expressed in terms of turbulence statistics or variability of the forcing of the turbulence such as time changes of the wind vector, the horizontal pressure gradient, or the surface heat flux. Our survey emphasizes the development of non-equilibrium turbulence caused by non-stationary forcing. The degree of non-equilibrium of the turbulence is most reliably evaluated following the local flow rather than using the more available fixed-point measurements. We survey methods to eliminate non-stationary records or partially filter out the non-stationarity. We also summarize issues with parametrization of the non-stationarity. Non-stationarity over the sea can be complex due to time-dependent wave state and surface roughness. The impact of non-stationarity is generally less understood in the stable boundary layer compared to the unstable boundary layer.

Original languageEnglish (US)
Pages (from-to)189-204
Number of pages16
JournalBoundary-Layer Meteorology
Issue number2-3
StatePublished - Dec 1 2020
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Atmospheric Science


  • Equilibrium turbulence
  • Non-stationarity
  • Spectral gap
  • Submeso
  • Turbulence adjustment


Dive into the research topics of 'Non-stationary Boundary Layers'. Together they form a unique fingerprint.

Cite this