What is the Pacific Decadal Oscillation?

The PDO is a long-term (10-20 year) oscillation of the Pacific Ocean. During a warm (positive) phase, warm waters are brought in the Eastern Pacific Ocean and along the coast of North America and cool nutrient-rich waters in the western Pacific Ocean. During a cool (negative) phase the Eastern Pacific Ocean becomes cooler and the Western Pacific Ocean becomes warmer.

What are we looking at?

The plot tracks the conditions in the Pacific Ocean. When the value of the time series is positive, the warm phase of the PDO, and when the value is negative, the cool phase of the PDO is present. The plot tracks the conditions in the Pacific Ocean, when the value of the time series is positive (red shading), El Niño conditions are present, and when the value is negative (blue shading), La Niña conditions are present.

Why do we care?

The PDO has impacts on fisheries and on weather: causing heavy rains or droughts in America, Asia and Australia. Also, by impacting sea level, it can cause changes in coastal impacts.

Reference: Hamlington et al., 2019

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