Figure 7
From: The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960–2006
Annual measure of ENSO status, 1960–2006. The index of ENSO is the sea surface temperature (SST) averaged by month over the east-central tropical Pacific region called "Niño 3.4" (5°N – 5°S, 120–170°W) [21]. The thick line represents ENSO_Avg, which is simply the average of the SST anomaly (°C) in the region over the 12 months of the year. The thin line represents ENSO_Dom, which is the average SST during only the months having the ENSO state (La Niña, neutral, or El Niño) that existed for the greatest number of consecutive months during the given year. A first-order categorization of the ENSO status of each year, listed in the caption of Fig.1, is based on whether the weighted average of 1/3 × (ENSO_Dom) + 2/3 × (ENSO_Avg), is above 0.85°C (El Niño), or below -0.85°C (La Niña).