suspect it's mostly what joe said but yeah, wouldn't be surprised if dust is helping a lil
https://www.sciencedirect.com/science/article/abs/pii/S016980952300025X
https://www.technologyreview.com/2010/03/30/205017/how-sandstorms-generate-spectacular-lightning-displays/
https://ui.adsabs.harvard.edu/abs/2018AGUFMAE34A..23Y/abstract