What This Document Is
This is a focused section of course materials from ESPM C129 Biometeorology at UC Berkeley, delving into the complex interactions between wind, turbulence, and the Earth’s surface. Specifically, it concentrates on the dynamics within the surface boundary layer, particularly as influenced by vegetation. It builds upon foundational principles to explore how wind profiles are shaped by different types of landscapes. This material is part of a larger series examining the theory and principles of biometeorology.
Why This Document Matters
Students in biometeorology, environmental science, ecology, and related fields will find this resource valuable. It’s particularly useful when studying microclimate, atmospheric processes, and the exchange of energy and momentum between the land surface and the atmosphere. This section is ideal for those seeking a deeper understanding of how vegetation impacts wind patterns and turbulence, and how these factors influence ecological processes. It’s best used as a supplement to lectures and other course readings, providing a focused exploration of these key concepts.
Topics Covered
* Zero plane displacement and roughness length in relation to vegetation.
* The impact of atmospheric stability on wind profiles.
* Application of Monin-Obukhov theory to understand turbulent flow.
* The Richardson number and its role in stability assessments.
* Eddy exchange coefficients and their sensitivity to scalar influences.
* Characteristics of the roughness sublayer.
* Analysis of wind profile changes following vegetation removal.
* The Monin-Obukhov length scale and its significance.
* The ‘phi’ function and its behavior under varying thermal stratification.
What This Document Provides
* Detailed examination of wind behavior over tall vegetation.
* Discussion of established rules of thumb for estimating key parameters.
* References to foundational research in the field (e.g., Shaw & Pereira, Thom, Monteith & Unsworth).
* Visual representations and maps illustrating aerodynamic roughness length and zero plane displacement.
* Exploration of the relationship between thermal stratification and wind shear.
* A framework for understanding non-dimensional wind shear using the Monin-Obukhov similarity theory.
* Empirical data relating to the ‘phi’ function under stable and unstable atmospheric conditions.