N_CT
Cold-tongue ENSO index (Ren–Jin)
N3 − αN4 with α = 2/5 when N3·N4 > 0, else 0 (30-day means). — Ren & Jin 2011, Geophys. Res. Lett. 38, L04704, doi:10.1029/2010GL046031
DATA THROUGH 2026-11-07 · UPDATED 2026-11-08 11:26 UTC
N3 − αN4 with α = 2/5 when N3·N4 > 0, else 0 (30-day means). — Ren & Jin 2011, Geophys. Res. Lett. 38, L04704, doi:10.1029/2010GL046031