Relations Between the El Niño-Southern Oscillation and River Flow in Oregon and Nothern California

The El Niño-Southern Oscillation (ENSO) is one of the most prominent climate phenomena as it is responsible for many changes in weather patterns around the world. ENSO is generally believed to have different effects on the southwestern and northwestern United States. However, Effects of ENSO on Oregon and northern California are more ambiguous as they lie in a transitional area between the southwestern and northwestern regions. We explored possible quadratic or linear relations between the strength of ENSO and precipitation and streamflow in eight basins: Upper Klamath Lake, Upper and Lower Rogue, North and South Umpqua, Sprague, and Williamson in southern Oregon and Upper Sacramento in California. Linear and quadratic correlations between ENSO and streamflow were statistically significant shown by low p-values, but no correlation coefficient exceeded -0.062. Linear correlation coefficients of near 0 indicate that the relation is most likely not linear. When the data was plotted, it further confirmed the lack of correlation as there was a great spread in the range of the data. Furthermore, extreme El Niño values (>2) tended to be associated with a slight increase in precipitation values. This could be indicative of new expectations for ENSO behavior at the extremes.