---Companion data to Fahy and Maters et al. 2021 "Volcanic ash ice nucleation activity is variably reduced by aging in 
water and sulfuric acid: the effects of leaching, dissolution, and precipitation" in Environmental Science: Atmospheres---

Author: William Fahy

In this folder are the necessary data, files, and code to re-create the plots in the main text or supplement.

---Prerequisites---
For 'Freeze_Vector_Differences.py': Python 3, numpy, and pandas
For 'ICP_and_VAA analysis.ipynb': Python 3, Jupyter notebook, and packages noted in the file

---File descriptions---

IN spectra:
Folder containing all temperature-interpolated background-subtracted and averaged ice nucleation spectra. 
The mean, upper and lower confidence intervals, and standard deviations at each temperature are calculated
and reported for k, K, ns, nm, diffns, and diffnm (see Vali 2019 for more information on these variables), 
diffns and diffnm are the differential ice nucleation spectra of ns and nm respectively, as k is to K. Data 
files are named according to ash, treatment (A = H2SO4, W = H2O), and time where applicable.

Freeze_Vector_Differences.py:
File that calculates a 10th-order Chebyshev polynomial interpolation of an ice nucleation spectrum. The 
ice nucleation spectrum should be in a pandas dataframe with the temperature column called 'Temp' and the
variable of interest (k, K, ns, nm, diffns, diffnm) in a column with its respective names. Call freezeDiv
with two spectra and the "what" variable equal to one of the variables of interest to create a vector
representing the division of two spectra. Call freezeDiff to do the same representing the difference of two 
spectra. If either throws an error, try 'freezeDiffOld' instead. 

ICP_Data_Leachates.xlsx:
Excel file containing the ash leachate ICP measurements with calculated ratios as discussed in the manuscript.

Freeze_Vectors.csv and related:
.csv files containing the calculated IN vectors with ICP data for each IN spectrum. The 'divided' and 'subtracted'
files each have the original (non-aged) spectra divided and subtracted from the aged spectra, respectively.

ICP_and_VAA_analysis.ipynb:
Jupyter notebook containing code necessary to create heatmaps and permutation importance plots for an input
of either the divided or subtracted vectors as a .csv file. Required packages are imported in the first cell.


Please reach out to the authors of the associated manuscript if you have any additional questions.