UBF

class rojak.turbulence.diagnostic.UBF(u_wind: DataArray, v_wind: DataArray, geopotential: DataArray, vorticity: DataArray, jacobian: DataArray)

Bases: Diagnostic

Residual of the Unbalance Flow (UBF) Equation CAT diagnostic

The UBF diagnostic aims to forecast CAT due to gravity waves, it uses the residual of the non-linear divergence equation to identify regions where flow is unbalanced [Knox2016]. It is defined as,

\[\text{UBF} = | - \nabla^2 \Phi + 2 J(u,v) + f \zeta - \beta u|\]

where \(\nabla^{2}\) is the Laplacian, \(\Phi\) is the geopotential, \(J ()\) is the determinant of the Jacobian, \(f\) is the Coriolis parameter and \(\beta\) is the latitudinal derivative of the Coriolis parameter.

Parameters:

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

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

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

• vorticity (DataArray) – Vertical component of vorticity in m/s

• jacobian (DataArray) – Determinant of the Jacobian of the horizontal velocities

__init__(u_wind: DataArray, v_wind: DataArray, geopotential: DataArray, vorticity: DataArray, jacobian: DataArray) → None

Parameters:

• u_wind (DataArray)

• v_wind (DataArray)

• geopotential (DataArray)

• vorticity (DataArray)

• jacobian (DataArray)

Return type:

None

Methods

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

Attributes

computed_value
name