4.11.1.2. refractiveIndex.ice

refractive.ice module.

Copyright (C) 2017 - 2018 Davide Ori dori@uni-koeln.de Institute for Geophysics and Meteorology - University of Cologne

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

This module provides a list of ice refractive index models to compute the dielectric properties of ice according to the requested frequency and temeperatures. The module can be also used as a standalone python script.

Example

The python script is callable as

$ python ice.py Temperature Frequency

and returns the complex refractive index of ice at the requested Temperature [Kelvin] and Frequency [Hz]

Notes

It is possible to call the functions implemented in this module using nd-arrays. The function arguments must either have exactly the same shape allowing element-wise application of the functions or one of the two must be a scalar which will be spread across the nd computations

Temperature should be provided in Kelvin and frequency in Hz The specific called algorithm check for arguments values to be within the limits of validity of the dielectric model and raises ValueError in case they are not respected

4.11.1.2.1. Module Contents

4.11.1.2.1.1. Functions

iwabuchi_yang_2011(temperature, frequency)

Ice complex relative dielectric constant according to Iwabuchi (2011)

warren_brandt_2008(frequency)

Ice complex relative dielectric constant according to Warren (2008)

matzler_2006(temperature, frequency, checkTemperature=True)

Ice complex relative dielectric constant according to Matzler (2006)

eps(temperature, frequency, model='Matzler_2006', matzlerCheckTemperature=True)

Ice complex relative dielectric constant according to the requested model

n(temperature, frequency, model='Matzler_2006', matzlerCheckTemperature=True)

Ice complex refractive index according to the requested model

4.11.1.2.1.2. Attributes

module_path

warren_ice_table

warren_ice_table

warren_ice_table

warren_ice_eps

warren_ice_interpolated

iwabuchi_ice_table

name

iwabuchi_ice_interp_real

iwabuchi_ice_interp_imag

module_path[source]
warren_ice_table[source]
warren_ice_table[source]
warren_ice_table[source]
warren_ice_eps[source]
warren_ice_interpolated[source]
iwabuchi_ice_table[source]
name = f[source]
iwabuchi_ice_interp_real[source]
iwabuchi_ice_interp_imag[source]
iwabuchi_yang_2011(temperature, frequency)[source]

Ice complex relative dielectric constant according to Iwabuchi (2011) ‘Temperature dependence of ice optical constants: Implications for simulating the single-scattering properties of cold ice clouds’ J. Quant. Spec. Rad. Tran. 112, 2520-2525

The model is valid for temperature ranging from 160 to 270 K. Frequency/wavelength range of validity is [150 MHz/2 meters; 44 nanometers]

Source of the table is the additional material published along with the paper

Parameters
  • temperature (float) – nd array of temperature [Kelvin] which will be ignored

  • frequency (float) – nd array of frequency [Hz]

Returns

Relative dielectric constant of ice at the requested frequency and temperature

Return type

nd - complex

Raises

ValueError – If a negative frequency or temperature is passed as an argument

warren_brandt_2008(frequency)[source]

Ice complex relative dielectric constant according to Warren (2008) ‘Optical constants of ice from the ultraviolet to the microwave: A revised compilation.’ J. Geophys. Res., 113, D14220, doi:10.1029/2007JD009744 which updates and corrects Warren, S. G. (1984), ‘Optical constants of ice from the ultraviolet to the microwave’, Appl. Opt., 23, 1206–1225.

The model is valid for temperature = 266 K, thus this parameter is dropped Source of the tables https://atmos.washington.edu/ice_optical_constants/

Parameters

frequency (float) – nd array of frequency [Hz]

Returns

Relative dielectric constant of ice at the requested frequency and temperature

Return type

nd - complex

Raises

ValueError – If a negative frequency or temperature is passed as an argument

matzler_2006(temperature, frequency, checkTemperature=True)[source]

Ice complex relative dielectric constant according to Matzler (2006) “Thermal Microwave Radiation: application to remote sensing, Chapter 5, pp 456-460”

Parameters
  • temperature (float) – nd array of temperature [Kelvin]

  • frequency (float) – nd array of frequency [Hz]

  • checkTemperature (bool) – check temperature range for Matzler (2006) (default True)

Returns

Relative dielectric constant of ice at the requested frequency and temperature

Return type

nd - complex

Raises

ValueError – If a negative frequency or temperature is passed as an argument

eps(temperature, frequency, model='Matzler_2006', matzlerCheckTemperature=True)[source]

Ice complex relative dielectric constant according to the requested model

Parameters
  • temperature (float) – nd array of temperature [Kelvin]

  • frequency (float) – nd array of frequency [Hz]

  • model (string) – dielectric model name default to Matzler (2006)

  • matzlerCheckTemperature (bool) – check temperature range for Matzler (2006) (default True)

Returns

Relative dielectric constant of ice at the requested frequency and temperature

Return type

nd - complex

Raises

ValueError – If a negative frequency or temperature is passed as an argument

n(temperature, frequency, model='Matzler_2006', matzlerCheckTemperature=True)[source]

Ice complex refractive index according to the requested model

Parameters
  • temperature (float) – nd array of temperature [Kelvin]

  • frequency (float) – nd array of frequency [Hz]

  • model (string) – dielectric model name default to Matzler (2006)

  • matzlerCheckTemperature (bool) – check temperature range for Matzler (2006) (default True)

Returns

Refractive index of ice at the requested frequency and temperature

Return type

nd - complex

Raises

ValueError – If a negative frequency or temperature is passed as an argument