Eddy covariance
The eddy covariance (also known as eddy correlation and eddy flux) is a key atmospheric measurement technique to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The
Planetary boundary layer
In meteorology, the planetary boundary layer (PBL), also known as the atmospheric boundary layer (ABL) or peplosphere, is the lowest part of the atmosphere and its behaviour is directly influenced by
Roughness length
Roughness length is a parameter of some vertical wind profile equations that model the horizontal mean wind speed near the ground. In the log wind profile, it is equivalent to the height at which the
Bulk Richardson number
The Bulk Richardson Number (BRN) is an approximation of the . The BRN is a dimensionless ratio in meteorology related to the consumption of turbulence divided by the shear production (the generation o
Capping inversion
A capping inversion is an elevated inversion layer that caps a convective planetary boundary layer. The boundary layer is the part of the atmosphere which is closest to the ground. Normally, the sun h
Yamartino method
The Yamartino method is an algorithm for calculating an approximation of the standard deviation of wind direction during a single pass through the incoming data.
Remote sensing atmospheric boundary layer
Ground-based, flight-based, or satellite-based remote sensing instruments can be used to measure properties of the planetary boundary layer, including boundary layer height, aerosols and clouds. Satel
Ekman layer
The Ekman layer is the layer in a fluid where there is a force balance between pressure gradient force, Coriolis force and turbulent drag. It was first described by Vagn Walfrid Ekman. Ekman layers oc
Alpine planetary boundary layer
The alpine planetary boundary layer is the planetary boundary layer (PBL) associated with mountainous regions. Due to its high spatial and temporal variability, its behavior is more complex than over
Flux footprint
Flux footprint (also known as atmospheric flux footprint or footprint) is an upwind area where the atmospheric flux measured by an instrument is generated. Specifically, the term flux footprint descri
Low-latitude western boundary currents
Low-latitude western boundary currents (LLWBC) are western boundary currents located between the subtropical gyres, within 20° of the equator. They are important for closing the tropical circulation d
Von Kármán constant
In fluid dynamics, the von Kármán constant (or Kármán's constant), named for Theodore von Kármán, is a dimensionless constant involved in the logarithmic law describing the distribution of the longitu
Kelvin–Helmholtz instability
The Kelvin–Helmholtz instability (after Lord Kelvin and Hermann von Helmholtz) is a fluid instability that occurs when there is velocity shear in a single continuous fluid or a velocity difference acr
Valley exit jet
A valley exit jet is a strong, down-valley, elevated air current that emerges above the intersection of the valley and its adjacent plain. These winds frequently reach a maximum of 20 m/s (45 mph) at
Log wind profile
The log wind profile is a semi-empirical relationship commonly used to describe the vertical distribution of horizontal mean wind speeds within the lowest portion of the planetary boundary layer. The
Monin–Obukhov length
The Obukhov length is used to describe the effects of buoyancy on turbulent flows, particularly in the lower tenth of the atmospheric boundary layer. It was first defined by Alexander Obukhov in 1946.
Convective planetary boundary layer
The convective planetary boundary layer (CPBL), also known as the daytime planetary boundary layer (or simply convective boundary layer, CBL, when in context), is the part of the lower troposphere mos
Surface layer
The surface layer is the layer of a turbulent fluid most affected by interaction with a solid surface or the surface separating a gas and a liquid where the characteristics of the turbulence depend on
Wind profile power law
The wind profile power law is a relationship between the wind speeds at one height, and those at another.
Mixed layer
The oceanic or limnological mixed layer is a layer in which active turbulence has homogenized some range of depths. The surface mixed layer is a layer where this turbulence is generated by winds, surf