equivalent_potential_temperature¶
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metpy.calc.
equivalent_potential_temperature
(pressure, temperature, dewpoint)[source]¶ Calculate equivalent potential temperature.
This calculation must be given an air parcel’s pressure, temperature, and dewpoint. The implementation uses the formula outlined in [Bolton1980]:
First, the LCL temperature is calculated:
\[T_{L}=\frac{1}{\frac{1}{T_{D}-56}+\frac{ln(T_{K}/T_{D})}{800}}+56\]Which is then used to calculate the potential temperature at the LCL:
\[\theta_{DL}=T_{K}\left(\frac{1000}{p-e}\right)^k \left(\frac{T_{K}}{T_{L}}\right)^{.28r}\]Both of these are used to calculate the final equivalent potential temperature:
\[\theta_{E}=\theta_{DL}\exp\left[\left(\frac{3036.}{T_{L}} -1.78\right)*r(1+.448r)\right]\]Parameters: - pressure (pint.Quantity) – Total atmospheric pressure
- temperature (pint.Quantity) – Temperature of parcel
- dewpoint (pint.Quantity) – Dewpoint of parcel
Returns: pint.Quantity – The equivalent potential temperature of the parcel
Notes
[Bolton1980] formula for Theta-e is used, since according to [DaviesJones2009] it is the most accurate non-iterative formulation available.