. Turbulence around small objects, and basic property of laminar flow in fluid dynamics On scales relevant to mesoscale and synoptic scale
Hodograph. Graphical examples
Ekman spiral. Graphical example one. Graphical example two.
Surface layer
Logarithmic wind profile. Graphical example with stability influence.
Turbulent stress
Surface wind stress. Note: The vertical derivative of wind stress is applied in numerical models to quantify PBL "friction"
Friction velocity
Roughness length. Typical range of values. Plot of values.
Eddy viscosity. Examples of K formulations: Figure one. Figure two.
Mixing length . Example of mixing length formulations .
Drag coefficient. Typical land values. Ocean values as a function of wind and sea state (current estimated ranges).
Gust factors (see Fig. 14)
WInd gusts in tropical cyclones
Video lectures
- The basics
- Turbulence basics
- Definition of the planetary boundary layer (PBL), also called the atmospheric boundary layer (ABL)
- Plot of key components of the PBL
- Stull's overview on the PBL
- Highlights from HH, Chapter 8
- Diurnal wind variation in the PBL. The nocturnal jet.
- Relevant definitions
Hodograph. Graphical examples
Ekman spiral. Graphical example one. Graphical example two.
Surface layer
Logarithmic wind profile. Graphical example with stability influence.
Turbulent stress
Surface wind stress. Note: The vertical derivative of wind stress is applied in numerical models to quantify PBL "friction"
Friction velocity
Roughness length. Typical range of values. Plot of values.
Eddy viscosity. Examples of K formulations: Figure one. Figure two.
Mixing length . Example of mixing length formulations .
Drag coefficient. Typical land values. Ocean values as a function of wind and sea state (current estimated ranges).
- Bulk formulas
- Other wind profile equations. Alternatives to the logarithmic wind profile. Rare document from Royal Netherlands Meteorological Institute, dated 1968.
- Dependence of wind profile power law on stability class.Table I gives Pasquill classes, and Table V is the main result.
- Values for Deacon wind profile parameter. Paper on Deacon wind profile parameters
- Online wind profile calculator, power law and log law
- Empirical conversions relating winds measurements from seconds up to one-hour
Gust factors (see Fig. 14)
WInd gusts in tropical cyclones
Video lectures