Calculate TC Ventilation Index using python.
TC Ventilation Index was proposed in Tang and Emanuel(2012b).
From the expression of the ventilation index, we need to calculate three parts:
Vertical Wind Shear
The bulk environmental vertical wind shear between 850 and 200 hPa.
Entropy Deficit
The (nondimensional) entropy deficit, expression is Equation(2) in Tang and Emanuel(2012b).
Potential Intensity
The potential intensity of a TC is a theoretical upper bound on the maximum wind speed considering the local thermodynamic profile and gradient wind balance.
The potential intensity is calculated by Equation(3) from Bister and Emanuel (2002) under pseudoadia-batic assumptions.
Here, I calculate the three parts separately and save them as three .nc files, then put them together to get the ventilation index.