The NOAA/NCEI ENSO SST Indicators Guide cites the Relative Oceanic Niño Index (RONI) as a comparison tool for El Niño and La Niña events.
Notes on verification
Confirmed by primary NOAA/PMEL source text and corroborated by multiple independent NOAA/NWS/CPC documents describing RONI's official role in ENSO monitoring. [tier=unverified indep_score=0.5 clusters=1 claim_tier=notable] [kind-backfill 2026-09-15: kind=attributed eligibility=high] [harvest 2026-09-24: +4 source(s) on new hosts; tier unverified->gold indep=0.94 clusters=5]
Sources
- El Niño Today | El Nino Theme Page - A comprehensive Resource (seed:science_and_space)
- https://bmcnoldy.earth.miami.edu/tropics/roni/ (corroboration)
- https://weather.gov/media/notification/pdf_2026/pns26-05_Relative_ONI.pdf (corroboration)
- https://journals.ametsoc.org/view/journals/clim/37/4/JCLI-D-23-0406.1.xml (corroboration)
- https://www.drought.gov/news/new-noaa-el-nino-southern-oscillation-index-supports-drought-early-warning-2026-03-11 (corroboration)
- https://www.climate.us/news-features/understanding-climate/climate-variability-relative-oceanic-nino-index (corroboration)