cape_cin

metpy.calc.cape_cin(pressure, temperature, dewpt, parcel_profile, which_lfc='bottom', which_el='top')[source]

Calculate CAPE and CIN.

Calculate the convective available potential energy (CAPE) and convective inhibition (CIN) of a given upper air profile and parcel path. CIN is integrated between the surface and LFC, CAPE is integrated between the LFC and EL (or top of sounding). Intersection points of the measured temperature profile and parcel profile are logarithmically interpolated.

Parameters

  • pressure (pint.Quantity) – The atmospheric pressure level(s) of interest, in order from highest to lowest pressure.

  • temperature (pint.Quantity) – The atmospheric temperature corresponding to pressure.

  • dewpt (pint.Quantity) – The atmospheric dewpoint corresponding to pressure.

  • parcel_profile (pint.Quantity) – The temperature profile of the parcel.

  • which_lfc (str) – Choose which LFC to integrate from. Valid options are ‘top’, ‘bottom’, ‘wide’, and ‘most_cape’. Default is ‘bottom’.

  • which_el (str) – Choose which EL to integrate to. Valid options are ‘top’, ‘bottom’, ‘wide’, and ‘most_cape’. Default is ‘top’.

Returns

  • pint.Quantity – Convective Available Potential Energy (CAPE).

  • pint.Quantity – Convective INhibition (CIN).

Notes

Formula adopted from [Hobbs1977].

\[\text{CAPE} = -R_d \int_{LFC}^{EL} (T_{parcel} - T_{env}) d\text{ln}(p)\]
\[\text{CIN} = -R_d \int_{SFC}^{LFC} (T_{parcel} - T_{env}) d\text{ln}(p)\]

  • \(CAPE\) Convective available potential energy

  • \(CIN\) Convective inhibition

  • \(LFC\) Pressure of the level of free convection

  • \(EL\) Pressure of the equilibrium level

  • \(SFC\) Level of the surface or beginning of parcel path

  • \(R_d\) Gas constant

  • \(g\) Gravitational acceleration

  • \(T_{parcel}\) Parcel temperature

  • \(T_{env}\) Environment temperature

  • \(p\) Atmospheric pressure

See also

lfc(), el()