Particle X Climate

Idea path

Week of 28 September

One nominated paper, three approved ideas, and research directions. Grant-agnostic — no call names.

Chosen paper

Stratospheric ozone projections under sulfur-based stratospheric aerosol injection: Insights from the multi-model G6-1.5K-SAI experiment

Bednarz et al. (2026), ACP — picked by Mrs. Lantern alone, after shortlist pass ×3.

https://doi.org/10.5194/acp-26-12751-2026

Path that ran: Mrs. Vanguard emailed 6 papers → Mrs. Lantern shortlist of 3 (Bednarz, Perny, Lee reframed) → The Devil pass ×3 → Mrs. Lantern picked Bednarz → up to 3 ideas + one research-directions write-up → The Devil document review pass.

Ideas

Scientific hooks: what questions are worth chasing.

Idea 1 — author documented

Why does UKESM dry the stratosphere under subtropical SO₂ SAI when CESM and MIROC moisten it? Bednarz lists four candidate processes beyond cold-point warming and asks for follow-up; this idea is that UKESM attribution.

Idea 2 — author documented

Why does UKESM lose NH mid-latitude ozone under G6-1.5K-SAI while other models do not? Bednarz already shows chemistry is only part of it (WITH_HET / NO_HET); this idea digs into residual circulation versus mixing.

Idea 3 — mostly inferred; pass with teeth

Can that same chemistry-vs-transport habit transfer to high-burden volcanic cases, and later to solid-particle SAI only if GLOMAP/UKCA is ready? Not claimed by Bednarz; fences stay hard.

Research directions

How those hooks could become actual UKESM work.

Direction A, from Idea 1

Take Bednarz’s four candidate processes for UKESM’s dry stratosphere under G6-1.5K-SAI and rank which ones matter in the model — using budgets and diagnostics already available, not a new multi-model campaign.

Direction B, from Idea 2

Use the existing WITH_HET / NO_HET UKESM pair to split how much of the NH mid-latitude ozone drop is chemistry vs transport, and whether residual circulation or mixing is doing more of the transport work.

Direction C, from Idea 3 — mostly inferred

Reuse that chemistry-vs-transport mindset on high-burden volcanic / Hunga-class cases first; solid-particle SAI only after a written GLOMAP/UKCA readiness check — and never as a soft rewrite of Idea 1 or 2.

The Devil’s fences that must hold: do not soften Idea 3’s inferred tags; do not claim Bednarz studied solid particles; do not re-bridge Lee’s Arctic residual to material via lifetime/R_eff.

Joint note from Mrs. Lantern and The Devil. Mrs. Lantern maps the questions Bednarz left open. The Devil maps where overclaim would land. Between them: three hooks, one readiness gate, and a fence that still has teeth in it.

Mrs. Vanguard