brunt_vaisala_frequency

metpy.calc.brunt_vaisala_frequency(height, potential_temperature, vertical_dim=0)

Calculate the Brunt-Vaisala frequency.

This function will calculate the Brunt-Vaisala frequency as follows:

$$N={\left(\frac{g}{\theta }\frac{d\theta }{dz}\right)}^{\frac{1}{2}}$$

This formula based off of Equations 3.75 and 3.77 in [Hobbs2006].

This function is a wrapper for brunt_vaisala_frequency_squared that filters out negative (unstable) quantities and takes the square root.

Parameters

• height (xarray.DataArray or pint.Quantity) – Atmospheric (geopotential) height

• potential_temperature (xarray.DataArray or pint.Quantity) – Atmospheric potential temperature

• vertical_dim (int, optional) – The axis corresponding to vertical in the potential temperature array, defaults to 0, unless height and potential_temperature given as xarray.DataArray, in which case it is automatically determined from the coordinate metadata.

Returns

pint.Quantity or xarray.DataArray – Brunt-Vaisala frequency. Given as pint.Quantity, unless both height and potential_temperature arguments are given as xarray.DataArray, in which case will be xarray.DataArray.

Changed in version 1.0: Renamed heights, axis parameters to height, vertical_dim

See also

brunt_vaisala_frequency_squared, brunt_vaisala_period, potential_temperature

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