Go to the end to download the full example code
Use functions from
metpy.calc as well as pint’s unit support to perform calculations.
The code below uses example data from our test suite to calculate the hydrostatic thickness between the surface and 500-hPa level for the provided sounding data.
import pandas as pd from metpy.calc import (mixing_ratio_from_relative_humidity, relative_humidity_from_dewpoint, thickness_hydrostatic) from metpy.cbook import get_test_data from metpy.units import units
Upper air data can be obtained using the siphon package, but for this example we will use some of MetPy’s sample data.
# Set column names col_names = ['pressure', 'height', 'temperature', 'dewpoint', 'direction', 'speed'] # Read in test data using col_names df = pd.read_fwf(get_test_data('jan20_sounding.txt', as_file_obj=False), skiprows=5, usecols=[0, 1, 2, 3, 6, 7], names=col_names)
Drop any rows with all NaN values for T, Td, winds
Isolate pressure, temperature, and dewpoint and add units
p = df['pressure'].values * units.hPa T = df['temperature'].values * units.degC Td = df['dewpoint'].values * units.degC
Calculate the relative humidity to compute the mixing ratio
Calculate the thickness from the pressure, temperature, and mixing ratio for the layer from the surface pressure to 500-hPa
Total running time of the script: ( 0 minutes 0.015 seconds)