May–September monthly zonal (east-west direction) wind stress anomalies against the monthly sea surface temperature anomalies in the Niño 3.4 region from 1980-2016. The wind stress anomalies corresponding to La Niña conditions (blue dots) are averaged over the central tropical Pacific from 5°S - 5°N and 167°E - 153°W. The wind stress anomalies corresponding to El Niño conditions (red dots) are averaged farther east, 5°S - 5°N and 179° - 139°W. These regions have the strongest relationship with the Niño 3.4 index and are chosen following Choi et al. (2013). The steeper slope of the linear fit to the red dots relative to the linear fit to the blue dots indicates a stronger zonal wind stress response under El Niño conditions. NOAA Climate.gov figure based on MERRA Reanalysis wind stress data and ERRSSTv5 sea surface temperature data.