storm_relative_helicity¶
-
metpy.calc.
storm_relative_helicity
(u, v, heights, depth, bottom=<Quantity(0, 'meter')>, storm_u=<Quantity(0.0, 'meter / second')>, storm_v=<Quantity(0.0, 'meter / second')>)[source]¶ Calculate storm relative helicity.
Calculates storm relatively helicity following [Markowski2010] 230-231.
\[\int\limits_0^d (\bar v - c) \cdot \bar\omega_{h} \,dz\]This is applied to the data from a hodograph with the following summation:
\[\sum_{n = 1}^{N-1} [(u_{n+1} - c_{x})(v_{n} - c_{y}) - (u_{n} - c_{x})(v_{n+1} - c_{y})]\]- Parameters
u (array-like) – u component winds
v (array-like) – v component winds
heights (array-like) – atmospheric heights, will be converted to AGL
depth (number) – depth of the layer
bottom (number) – height of layer bottom AGL (default is surface)
storm_u (number) – u component of storm motion (default is 0 m/s)
storm_v (number) – v component of storm motion (default is 0 m/s)
- Returns
pint.Quantity – positive storm-relative helicity
pint.Quantity – negative storm-relative helicity
pint.Quantity – total storm-relative helicity