Identifying the Causes of Pyrocumulonimbus (PyroCb)

Understand

A first causal discovery analysis from observational data of pyroCb (storm clouds generated from extreme wildfires) is presented.

• Invariant Causal Prediction was used to develop tools to understand the causal drivers of pyroCb formation.
• This includes a conditional independence test for testing $Y$ conditionally independent of $E$ given $X$ for binary variable $Y$ and multivariate, continuous variables $X$ and $E$, and a greedy-ICP search algorithm that relies on fewer conditional independence tests to obtain a smaller more manageable set of causal predictors.
• With these tools, we identified a subset of seven causal predictors which are plausible when contrasted with domain knowledge: surface sensible heat flux, relative humidity at $850$ hPa, a component of wind at $250$ hPa, $13.3$ micro-meters, thermal emissions, convective available potential energy, and altitude.