El Nino-Southern Oscillation

**Definition:** El Nino-Southern Oscillation or ENSO is a cycle of extreme alternating warm El Niño and cold La Nina events which is the dominant year-to-year climate pattern on Earth. Both terms refer to large-scale changes in sea-surface temperature across the eastern tropical Pacific. ENSO is associated with a heightened risk of certain vector-borne diseases. (From http://www.elnino.noaa.gov/lanina_new_faq.html, accessed 5/12/2020)

**Tree numbers:** - G16.500.275.071.387