{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Advanced Aerosols in Eclipse Geometry\n", "\n", "As of POSEIDON v1.3.1. we have included support in emission geometries (direct emission, reflection, thermal scattering) for two new beta features: \n", "\n", "1. Overlapping clouds \n", "- When POSEIDON v1.2 was released, emission and reflection geometries could only handle one aerosol species.\n", "- With POSEIDON v1.3.1, the code now can handle as many aerosol species as needed by computing the weighted scattering properties for each pressure layer in the atmosphere (including those in regions where more than one aerosol is present).\n", "- Models with multiple clouds can be useful for atmospheres where multiple different aerosol layers are expected to form and overlap (i.e. brown dwarfs which have $\\rm{Fe}$, $\\rm{Mg_2 SiO_4}$, and $\\rm{MgSiO_3}$ layers)\n", "- Average w and g are generated in emission_Toon and reflection_Toon (in emission.py) via: \n", "\n", "\n", "$$\n", "\\bar{\\omega} = \\frac{\\Delta\\tau_{Ray}}{\\Delta\\tau_{tot}} \\; + \\frac{\\sum_{i}\\Delta\\tau_{Mie}^i \\; \\omega_{Mie}^i}{\\Delta\\tau_{tot}}\n", "$$\n", "\n", "$$\n", "\\bar{g} = \\frac{\\sum_i\\omega_{Mie}^i \\; \\Delta\\tau_{Mie}^i \\; g_{Mie}^i}{\\Delta\\tau_{Ray} + \\sum_i\\omega_{Mie}^i \\; \\Delta\\tau_{Mie}^i} \n", "$$\n", "\n", "2. Patchy 2D clouds\n", "- POSEIDON v1.2 included 1D + 1D patchy Mie clouds. This involved computing two spectra (one clear and one cloudy) and then taking the weighted sum of the two spectra. \n", "- POSEIDON v1.3.1 now has support for patchy Mie clouds up to two aerosol species. This will compute a 1D + 1D + 1D + 1D weighted spectra where the models are Both Clouds + Cloud 1 + Cloud 2 + Clear.\n", "- This can be useful for brown dwarfs which can have clear sectors, $\\rm{Fe}$ deck sectors, and $\\rm{Fe}$ + $\\rm{MgSiO_3}$ sectors. \n", "\n", "Below, we will show off the above features with HD 189733b emission (with thermal scattering) and reflection, including both $\\rm{SiO_2}$ and $\\rm{MgSiO_3}$ clouds overlapping. " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "