parcel_profile_with_lcl#

metpy.calc.parcel_profile_with_lcl(pressure, temperature, dewpoint)#

Calculate the profile a parcel takes through the atmosphere.

The parcel starts at temperature, and dewpoint, lifted up dry adiabatically to the LCL, and then moist adiabatically from there. pressure specifies the pressure levels for the profile. This function returns a profile that includes the LCL.

Parameters:

pressure (pint.Quantity) – Atmospheric pressure level(s) of interest. This array must be from high to low pressure.
temperature (pint.Quantity) – Atmospheric temperature at the levels in pressure. The first entry should be at the same level as the first pressure data point.
dewpoint (pint.Quantity) – Atmospheric dewpoint at the levels in pressure. The first entry should be at the same level as the first pressure data point.

Returns:

pressure (pint.Quantity) – The parcel profile pressures, which includes the specified levels and the LCL
ambient_temperature (pint.Quantity) – Atmospheric temperature values, including the value interpolated to the LCL level
ambient_dew_point (pint.Quantity) – Atmospheric dewpoint values, including the value interpolated to the LCL level
profile_temperature (pint.Quantity) – The parcel profile temperatures at all of the levels in the returned pressures array, including the LCL

Examples

>>> from metpy.calc import dewpoint_from_relative_humidity, parcel_profile_with_lcl
>>> from metpy.units import units
>>> # pressure
>>> p = [1008., 1000., 950., 900., 850., 800., 750., 700., 650., 600.,
...      550., 500., 450., 400., 350., 300., 250., 200.,
...      175., 150., 125., 100., 80., 70., 60., 50.,
...      40., 30., 25., 20.] * units.hPa
>>> # temperature
>>> T = [29.3, 28.1, 23.5, 20.9, 18.4, 15.9, 13.1, 10.1, 6.7, 3.1,
...      -0.5, -4.5, -9.0, -14.8, -21.5, -29.7, -40.0, -52.4,
...      -59.2, -66.5, -74.1, -78.5, -76.0, -71.6, -66.7, -61.3,
...      -56.3, -51.7, -50.7, -47.5] * units.degC
>>> # relative humidity
>>> rh = [.85, .65, .36, .39, .82, .72, .75, .86, .65, .22, .52,
...       .66, .64, .20, .05, .75, .76, .45, .25, .48, .76, .88,
...       .56, .88, .39, .67, .15, .04, .94, .35] * units.dimensionless
>>> # calculate dewpoint
>>> Td = dewpoint_from_relative_humidity(T, rh)
>>> # computer parcel temperature
>>> Td = dewpoint_from_relative_humidity(T, rh)
>>> p_wLCL, T_wLCL, Td_wLCL, prof_wLCL = parcel_profile_with_lcl(p, T, Td)
>>> print(f'Shape of original pressure array: {p.shape}')
Shape of original pressure array: (30,)
>>> print(f'Shape of pressure array from function: {p_wLCL.shape}')
Shape of pressure array from function: (31,)
>>> print(p == p_wLCL)
False