IGRA2 Upper Air Data Request

This example shows how to use siphon’s simplewebswervice support to create a query to the Integrated Global Radiosonde Archive version 2.

from datetime import datetime

from siphon.simplewebservice.igra2 import IGRAUpperAir

Create a datetime object for the sounding and string of the station identifier.

date = datetime(2014, 9, 10, 0)
station = 'USM00070026'

Make the request. IGRAUpperAir returns a dataframe containing the sounding data and a dataframe with station metadata from the sounding header.

df, header = IGRAUpperAir.request_data(date, station)

Inspect data columns in the dataframe.

print(df.columns)

# Inspect metadata from the data headers
print(header.columns)

Index(['lvltyp1', 'lvltyp2', 'etime', 'pressure', 'pflag', 'height', 'zflag',
       'temperature', 'tflag', 'relative_humidity', 'direction', 'speed',
       'date', 'u_wind', 'v_wind', 'dewpoint'],
      dtype='object')
Index(['site_id', 'year', 'month', 'day', 'hour', 'release_time',
       'number_levels', 'pressure_source_code', 'non_pressure_source_code',
       'latitude', 'longitude', 'date'],
      dtype='object')

Pull out a specific column of data.

print(df['pressure'])
print(header['latitude'])

0      1020.95
1      1018.16
2      1003.21
3      1000.00
4       983.95
        ...
226        NaN
227        NaN
228        NaN
229        NaN
230        NaN
Name: pressure, Length: 231, dtype: float64
0    71.2889
Name: latitude, dtype: float64

Units are stored in a dictionary with the variable name as the key in the units attribute of the dataframe.

print(df.units)
print(header.units)

{'etime': 'second', 'pressure': 'hPa', 'height': 'meter', 'temperature': 'degC', 'dewpoint': 'degC', 'direction': 'degrees', 'speed': 'meter / second', 'u_wind': 'meter / second', 'v_wind': 'meter / second'}
{'release_time': 'second', 'latitude': 'degrees', 'longitude': 'degrees'}

print(df.units['pressure'])

hPa

Multiple records can be extracted simultaneously:

date = [datetime(2014, 9, 10, 0), datetime(2015, 9, 10, 12)]
station = 'USM00070026'
df, header = IGRAUpperAir.request_data(date, station)

print(df.head())
print(header.head())

   lvltyp1  lvltyp2  etime  pressure  ...       date  u_wind  v_wind  dewpoint
0        2        1      0   1020.95  ... 2014-09-10    -6.0    -3.9      -1.0
1        2        0      5   1018.16  ... 2014-09-10    -6.3    -3.1      -2.5
2        2        0     32   1003.21  ... 2014-09-10    -7.5    -0.1      -2.8
3        1        0     38   1000.00  ... 2014-09-10    -7.7    -0.3      -2.9
4        2        0     69    983.95  ... 2014-09-10    -9.0    -1.9      -3.1

[5 rows x 16 columns]
       site_id  year  month  ...  latitude  longitude                date
0  USM00070026  2014      9  ...   71.2889  -156.7833 2014-09-10 00:00:00
1  USM00070026  2014      9  ...   71.2889  -156.7833 2014-09-10 12:00:00
2  USM00070026  2014      9  ...   71.2889  -156.7833 2014-09-11 00:00:00
3  USM00070026  2014      9  ...   71.2889  -156.7833 2014-09-11 12:00:00
4  USM00070026  2014      9  ...   71.2889  -156.7833 2014-09-12 00:00:00

[5 rows x 12 columns]

IGRA2-Derived data can be accessed using the keyword derived=True. This data has much more information in the headers.

df, header = IGRAUpperAir.request_data(date, station, derived=True)

Inspect data columns in the dataframe.

print(df.columns)
print(header.columns)

Index(['pressure', 'reported_height', 'calculated_height', 'temperature',
       'temperature_gradient', 'potential_temperature',
       'potential_temperature_gradient', 'virtual_temperature',
       'virtual_potential_temperature', 'vapor_pressure',
       'saturation_vapor_pressure', 'reported_relative_humidity',
       'calculated_relative_humidity', 'relative_humidity_gradient', 'u_wind',
       'u_wind_gradient', 'v_wind', 'v_wind_gradient', 'refractive_index',
       'date'],
      dtype='object')
Index(['site_id', 'year', 'month', 'day', 'hour', 'release_time',
       'number_levels', 'precipitable_water', 'inv_pressure', 'inv_height',
       'inv_strength', 'mixed_layer_pressure', 'mixed_layer_height',
       'freezing_point_pressure', 'freezing_point_height', 'lcl_pressure',
       'lcl_height', 'lfc_pressure', 'lfc_height', 'lnb_pressure',
       'lnb_height', 'lifted_index', 'showalter_index', 'k_index',
       'total_totals_index', 'cape', 'convective_inhibition', 'date'],
      dtype='object')