VULCAN

Photochemical kinetics for exoplanetary atmospheres, a fast and easy-to-use python code. This distribution of VULCAN contains a number of performance and usability improvements.

More information can be found on the documentation pages:

• installation guide
• usage guide
• contributing guide

The theory papers of VULCAN can be found here:

• Tsai et al. 2021 (with photochemistry)
• Tsai et al. 2017 (without photochemistry).

Quick Demo

Let's dive in and see chemical kinetics in action!

First, go to the fastchem_vulcan/ folder to compile FastChem by running

make

After compilation has finished, go back to the main directory of VULCAN and run

python vulcan.py

You should see the default model starts running with real-time plotting. This will take about 10-15 minutes to complete depending on your comuputer.

Now you may want to try a different T-P input, changing the elemental abundances or vertical mixing. All these settings are set in config.py. For example, find and edit

const_Kzz = 1.E7

and

C_H = 6.0618E-4

for a weaker vertical mixing (K_zz) and carbon rich (C/O=1) run. Set use_live_plot = False if you wish to switch off the real-time plotting (why whould you though?). More detailed instruction can be found in the following sections. Have fun!

The object in this config.py file can be edited at runtime and passed around as a variable.

Reading Output Files

Run plot_vulcan.py within plot_py

python plot_vulcan.py [vulcan output] [species] [plot name] [-h (for plotting height)]

will read vulcan output (.vul files) can plot the species profiles. Species should be sepreated by commas without space. Plot is in pressure by diffcult and can be changed to height by adding "-h".