ecape

ecape is a simple module that contains an entraining CAPE, or ECAPE, calculation described by Peters et al. [PCM+23]. Additionally, Peters [Pet23] -provided MatLab scripts serve as a reference and test verification data. The module leans heavily on MetPy [May et al. [MAM+23]] for meteorological calculations.

Package published via Hatch.

Installation & Use

To use ecape, install it with pip:

pip install ecape

See the examples page.

from ecape.calc import calc_ecape
...
ecape = calc_ecape(height, pressure, temperature, specific_humidity, u_wind, v_wind)

Source

https://github.com/citylikeamradio/ecape

Contact

Questions, comments, and feedback are certainly welcome. This project is a personal exercise in learning how to publish packages to Github & PyPI, so excuse the excessive documentation for one function 😄.

Future Work

  • add support for other water content variables

  • if useful, incorporate into MetPy

  • provide cli .nc, .csv, & aws support

Disclaimer

There is a ~10% difference in ECAPE between calc_ecape and Peters’ published matlab scripts. This is primarily due to a difference in calculated CAPE. The tests describe other sources of error (~1%).

Since:
  • the methods here are within ~1% of Peters’ calculations when CAPE is equivalent in the sample data

  • Peters et. al. specifically mention MetPy for determining CAPE

  • MetPy is a reliable, open-source, and frequently used meteorological calculation package

MetPy’s CAPE calculations were chosen for ease of readability and implementation.

If users prefer their own CAPE calculations, use the manual_cape parameter to override this decision!

References

[MAM+23]

Ryan M. May, Sean C. Arms, Patrick Marsh, Eric Bruning, John R. Leeman, Kevin Goebbert, Jonathan E. Thielen, Zachary S Bruick, and M. Drew. Camron. Metpy: a Python package for meteorological data. 2023. URL: Unidata/MetPy, doi:10.5065/D6WW7G29.

[PCM+23]

John M. Peters, Daniel R. Chavas, Hugh Morrison, Chun-Yian Su, and Brice E. Coffer. An analytic formula for entraining cape in mid-latitude storm environments. 2023. arXiv:2301.04712.