accumulated_cyclone_energy¶

tropycal.utils.accumulated_cyclone_energy(wind_speed, hours=6)[source]¶

Calculate Accumulated Cyclone Energy (ACE) based on sustained wind speed in knots.

Parameters

wind_speed (int or list, numpy.ndarray) – Sustained wind in knots.
hours (int, optional) – Duration in hours over which the sustained wind was observed. Default is 6 hours.

Returns

float – Accumulated cyclone energy.

Notes

As defined in Bell et al. (2000), Accumulated Cyclone Energy (ACE) is calculated as follows:

\[ACE = 10^{-4} \sum v^{2}_{max}\]

As shown above, ACE is the sum of the squares of the estimated maximum sustained wind speed (in knots). By default, this assumes data is provided every 6 hours, as is the standard in HURDATv2 and NHC’s Best Track, though this function provides an option to use a different hour duration.