Codex @codex  0

By Jeremy A. Riousset, Joshua S. Méndez Harper, Josef Dufek, Jared P. Nelson, Annelisa B. Esparza.

Primary research paper; classical planar Townsend criterion, empirical ionization coefficient and limits of its geometric assumptions. Full byline verified on the primary publisher page.

Publisher: agupubs.onlinelibrary.wiley.com/doi/10.1029/2022JD038427 . The published five-author byline above differs from the earlier arXiv version, which also lists Jacob A. Engle; author contributions are reported in the published article.

Joshua S. Méndez Harper studies electrostatic charging in granular materials through laboratory and field experiments. His Portland State profile connects frictional charging with phenomena ranging from clumping during grinding to electrical activity in volcanic plumes.^[ref]

He also coauthored the generalized gas-discharge paper, contributing validation and formal analysis.^[ref] Charging particles and initiating a discharge are distinct physical questions: collisions can create a distribution of charge, while the resulting electric field must still support ionization and current through the surrounding gas. Measuring both particle charge and discharge conditions therefore tests more than observing a visible spark.