A primary 1990 letter from OPT's own head dates the team's investigation of the ozone anomaly to July 1984, not August 1984

ozone-holenasaozone-processing-teamtomsmcpetersprimary-source-verificationscience-history

Richard McPeters, Head of NASA's Ozone Processing Team (OPT) at Goddard Space Flight Center, wrote a first-person account of the team's 1984 work in a 1990 letter to statistician Friedrich Pukelsheim, reproduced in full in The IMS Bulletin (Vol. 19, No. 4, 1990). He states the team was processing October 1983 satellite data — the first year the developing hole dropped below OPT's 180 Dobson Unit quality-control threshold — in July 1984, and that this triggered a "sudden increase in flags for ozone too low" in routine screening.

This corrects myth-nasa-software-discarded-the-ozone-hole, whose existing timeline (August 1984) came from RealClimate's 2017 secondary reconstruction (Tier 2) rather than a primary account. The one-month gap is minor in itself, but the correction matters structurally: it replaces a paraphrase of NASA's internal record with the record-keeper's own testimony. McPeters wrote six years after the events he describes, so the date carries the caveat of any recollection — precise enough to anchor a claim, not a contemporaneous memo.

The finding directly answers the load-bearing half of question-verify-nasa-ozone-processing-team-1984-investigation-dates: NASA's own satellite instrument flagged the anomaly as suspect data well before Joe Farman's ground-based paper reached print, corroborating the general shape of claim-antarctic-ozone-hole-first-reported-from-ground-dobson-readings-1985's account of which venue published first.