easyclimate.core.geowind¶

Geostrophic Wind

Functions¶

`calc_geostrophic_wind`(→ xarray.DataArray)	Calculate the geostrophic wind.
`calc_geostrophic_wind_vorticity`(→ xarray.DataArray)	Calculate the geostrophic vorticity.

Module Contents¶

easyclimate.core.geowind.calc_geostrophic_wind(z_data: xarray.DataArray, lon_dim: str = 'lon', lat_dim: str = 'lat', omega: float = 7.292e-05, g: float = 9.8, R: float = 6371200.0) → xarray.DataArray¶

Calculate the geostrophic wind.

\[u_g = - \frac{g}{f} \frac{\partial H}{\partial y}\]

\[v_g = \frac{g}{f} \frac{\partial H}{\partial x}\]

Parameters¶

z_data: xarray.DataArray.: Atmospheric geopotential height.
lon_dim: str, default: lon.: Longitude coordinate dimension name. By default extracting is applied over the lon dimension.
lat_dim: str, default: lat.: Latitude coordinate dimension name. By default extracting is applied over the lat dimension.
omega: float, default: 7.292e-5.: The angular speed of the earth.
g: float, default: 9.8.: The acceleration of gravity.
R: float, default: 6370000.: Radius of the Earth.

Returns¶

The geostrophic wind term. (xarray.DataArray).

easyclimate.core.geowind.calc_geostrophic_wind_vorticity(z_data: xarray.DataArray, lon_dim: str = 'lon', lat_dim: str = 'lat', spherical_coord: bool = True, omega: float = 7.292e-05, g: float = 9.8, R: float = 6371200.0, cyclic_boundary_setting: Literal['nan', 'cyclic', 'cyclic+diff', 'diff'] = 'nan', method: Literal['raw', 'ncl', 'rust'] = 'ncl') → xarray.DataArray¶

Calculate the geostrophic vorticity.

Rectangular coordinates

\[\zeta_g = \frac{\partial v_g}{\partial x} - \frac{\partial u_g}{\partial y}\]

Spherical coordinates

\[\zeta_g = \frac{\partial v_g}{\partial x} - \frac{\partial u_g}{\partial y} + \frac{u_g}{R} \tan \varphi\]

Parameters¶

z_data: xarray.DataArray.

Atmospheric geopotential height.

lon_dim: str, default: lon.

Longitude coordinate dimension name. By default extracting is applied over the lon dimension.

lat_dim: str, default: lat.

Latitude coordinate dimension name. By default extracting is applied over the lat dimension.

spherical_coord: bool, default: True.

Whether or not to compute the horizontal Laplace term in spherical coordinates.

omega: float, default: 7.292e-5.

The angular speed of the earth.

g: float, default: 9.8.

The acceleration of gravity.

R: float, default: 6370000.

Radius of the Earth.

cyclic_boundary_setting: {“nan”, “cyclic”, “cyclic+diff”, “diff”}, default: nan.

A scalar integer equal to the boundary condition option:

nan: Boundary points are set to the missing value.
cyclic: The u and v arrays are cyclic in longitude. (The arrays should NOT include the cyclic point.) The upper and lower boundaries will be set to missing.
cyclic+diff: Boundary points are estimated using one-sided difference schemes normal to the boundary.
diff: The u and v arrays are cyclic in longitude. (The arrays should NOT include the cyclic points.) The upper and lower boundaries are estimated using a one-sided difference scheme normal to the boundary.

Note

The parameter is applicable only when method = ncl or method = rust.

method: {“raw”, “ncl”, rust}, default: ncl.

The method to calculate horizontal divergence term. Optional values are raw, ncl or rust.

Returns¶

The geostrophic vorticity term. (xarray.DataArray).