Pacific Decadal Oscillation (PDO)

The Pacific Decadal Oscillation (PDO) is a long-term climate pattern involving fluctuations in sea surface temperatures in the North Pacific Ocean. It shifts between warm (positive) and cool (negative) phases roughly every 20 to 30 years. During a positive phase, the central and eastern North Pacific Ocean become warmer, affecting weather patterns, marine ecosystems, and fisheries. In the negative phase, these areas cool down. The PDO influences regional climates along the Pacific coast, impacting rainfall, temperature, and ocean conditions, and it interacts with other climate systems to shape long-term environmental trends.