thickness_hydrostatic_from_relative_humidity#

metpy.calc.thickness_hydrostatic_from_relative_humidity(pressure, temperature, relative_humidity, bottom=None, depth=None)[source]#

Calculate the thickness of a layer given pressure, temperature and relative humidity.

Similar to thickness_hydrostatic, this thickness calculation uses the pressure, temperature, and relative humidity profiles via the hypsometric equation with virtual temperature adjustment

\[Z_2 - Z_1 = -\frac{R_d}{g} \int_{p_1}^{p_2} T_v d\ln p,\]

which is based off of Equation 3.24 in [Hobbs2006]. Virtual temperature is calculated from the profiles of temperature and relative humidity.

This assumes a hydrostatic atmosphere.

Layer bottom and depth specified in pressure.

Parameters:

pressure (pint.Quantity) – Atmospheric pressure profile
temperature (pint.Quantity) – Atmospheric temperature profile
relative_humidity (pint.Quantity) – Atmospheric relative humidity profile. The relative humidity is expressed as a unitless ratio in the range [0, 1]. Can also pass a percentage if proper units are attached.
bottom (pint.Quantity, optional) – The bottom of the layer in pressure. Defaults to the first observation.
depth (pint.Quantity, optional) – The depth of the layer in hPa. Defaults to the full profile if bottom is not given, and 100 hPa if bottom is given.

Returns:

pint.Quantity – The thickness of the layer in meters

Examples

>>> from metpy.calc import thickness_hydrostatic_from_relative_humidity
>>> 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
>>> ip1000_500 = (p <= 1000 * units.hPa) & (p >= 500 * 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
>>> # compute hydrostatic thickness from RH
>>> thickness_hydrostatic_from_relative_humidity(p[ip1000_500],
...                                              T[ip1000_500],
...                                              rh[ip1000_500])
<Quantity(5781.13913, 'meter')>