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 "cells": [
  {
   "cell_type": "markdown",
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   "source": [
    "# Specifying Aerosol"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "import matplotlib.pyplot as plt\n",
    "import numpy as np\n",
    "import sasktran as sk"
   ]
  },
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   "source": [
    "SASKTRAN supports Mie scattering aerosol particles.  The core of this functionality is contained within the :py:class:`MieAerosol <sasktran.MieAerosol>` optical property.  The :py:class:`MieAerosol <sasktran.MieAerosol>` class assumes a log-normal particle size distribution of stratospheric aerosols for a given species such as \"ice\", \"H2SO4\", or \"water\".  To create the :py:class:`MieAerosol <sasktran.MieAerosol>` optical property we first have to specify the parameters of the log-normal particle size distribution as a function of altitude"
   ]
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  {
   "cell_type": "code",
   "execution_count": null,
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   "outputs": [],
   "source": [
    "particle_size_dist = sk.ClimatologyUserDefined(altitudes=[0, 100000],\n",
    "                                               values={'SKCLIMATOLOGY_LOGNORMAL_MODEWIDTH': [1.6, 1.6],\n",
    "                                                       'SKCLIMATOLOGY_LOGNORMAL_MODERADIUS_MICRONS': [0.08, 0.08]})"
   ]
  },
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   "source": [
    "Here we have created a particle size distribution which is constant as a function of altitude, with a mode width of 1.6 and a mode radius of 0.08 microns.  We can now create the optical property,"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "aerosol_optprop = sk.MieAerosol(particlesize_climatology=particle_size_dist, species='H2SO4')"
   ]
  },
  {
   "cell_type": "raw",
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   "source": [
    "And calculate the cross section as a function of wavelength.  In our case the aerosol cross section should be the same independent of location/time, so we can include any parameters we want."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
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   "outputs": [],
   "source": [
    "wavel = np.linspace(300, 1000, 100)\n",
    "\n",
    "aerosol_xs = aerosol_optprop.calculate_cross_sections(sk.MSIS90(),\n",
    "                                                      latitude=0,\n",
    "                                                      longitude=0,\n",
    "                                                      mjd=54372,\n",
    "                                                      altitude=10000,\n",
    "                                                      wavelengths=wavel)\n",
    "\n",
    "plt.plot(aerosol_xs.wavelengths, aerosol_xs.total)\n",
    "plt.ylabel('Cross Section [/cm$^2$]')\n",
    "plt.xlabel('Wavelength [nm]');"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "raw_mimetype": "text/restructuredtext"
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   "source": [
    "To include aerosol in a radiative transfer calculation we also need to create a climatology.  To create a user defined aerosol climatology we can do"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "aerosol_clim = sk.ClimatologyUserDefined(altitudes=[0, 100000],\n",
    "                                        values={'SKCLIMATOLOGY_AEROSOL_CM3': [1, 1]})\n",
    "\n",
    "aerosol_species = sk.Species(aerosol_optprop, aerosol_clim)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "raw_mimetype": "text/restructuredtext"
   },
   "source": [
    "Which creates a constant values aerosol climatology and the corresponding :py:class:`Species <sasktran.Species>` object.  This object can then be added to SASKTRAN the same way as any other species."
   ]
  },
  {
   "cell_type": "raw",
   "metadata": {
    "raw_mimetype": "text/restructuredtext"
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   "source": [
    "GloSSAC Climatology\n",
    "-------------------\n",
    "For quick additions of a realistic stratospheric aerosol profile the easiest thing to use is the :py:class:`SpeciesAerosolGloSSAC <sasktran.SpeciesAerosolGloSSAC>` object, which implements the GloSSAC climatology available here https://eosweb.larc.nasa.gov/project/glossac/glossac. "
   ]
  }
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