BrownIndex2#

class rojak.turbulence.diagnostic.BrownIndex2(u_wind: DataArray, v_wind: DataArray, geopotential: DataArray, brown_index_1: DataArray)[source]#

Bases: Diagnostic

Brown Index 2 CAT diagnostic

Brown Index 2 estimates the energy dissipation rate (EDR) of turbulence by using [Roach1970]’s conclusion that when considering the overall conservation of energy in a turbulent layer, the large scale deformation which maintain turbulence dissipate energy at a prescribed rate such that the Richardson number is limited to a constant value. It is defined in [Brown1973] as,

\[\begin{split}\varepsilon_{\text{brown}} = \begin{cases} \frac{1}{24} \frac{d\text{Ri}}{dt} S_{v}^{2} & \frac{d\text{Ri}}{dt} > 0 \\ 0 & \frac{d\text{Ri}}{dt} \leq 0 \end{cases}\end{split}\]

where \(\varepsilon\) is the EDR, \(\frac{d\text{Ri}}{dt}\) is the Richardson tendency index, and \(S_{v}\) is the vertical wind shear.

Parameters:

  • u_wind (DataArray) – Zonal wind speeds in m/s

  • v_wind (DataArray) – Meridional wind speeds in m/s

  • brown_index_1 (DataArray) – Computed value of the BrownIndex1 diagnostic

  • geopotential (DataArray) – Geopotential in m^2/s

__init__(u_wind: DataArray, v_wind: DataArray, geopotential: DataArray, brown_index_1: DataArray) → None[source]#
Parameters:
Return type:

None

Methods

__init__(u_wind, v_wind, geopotential, ...)

Attributes

computed_value

name