geocat.comp.gradient._arc_lon_wgs84(lon, lat)#

The arc length calculation for the wgs84 ellipsoid at a longitude uses a taylor series from.

\[arclon = lon \cdot \cos(lat) \cdot \sqrt{a^2 \cdot \cos(lat)^2+b^2 \cdot \sin(lat)^2}\]

This returns the distance from the Greenwich Meridian to a given latitude This is accurate to within floating point error.


This doesn’t need to be a taylor series, though the taylor series is faster and a needed step for the _arc_lat_wgs84 function to avoid the elliptic integral


gradients (list of numpy.ndarray, list of xarray.DataArray) – Longitudinal arc from Prime Meridian calculated using th WGS84 geoid.

See also

Related NCL Functions: grad_latlon_cfd, gradsf, gradsg