Niño3.4 SST anomaly index (Zoom: last 2 years). “In the full series case, monthly averages are shown by the plus signs, three-month running mean filtered index values are shown by the shaded regions. In the “last 2 years” case, weekly averages are shown by the plus signs and the monthly average values are shown by the shaded regions”. Source and details: stateoftheocean.osmc.noaa.gov.
Southern Oscillation Index (SOI). (a, b) SOI based on sea level pressure (SLP) inTahiti (TAH) and Darwin (DAR). (c, d) Equatorial SOI based on Indonesia (INDO) and Eastern Pacific (PAC) SLP. Source and details: NOAA Climate Prediction Center.