The El Nino Theme Page is a comprehensive site from the National Oceanic and Atmospheric Administration (NOAA) covering the basics of El Nino, current updates, and related data. A link to Spanish language sites is also provided. According to the National Oceanic and Atmospheric Adminstration (NOAA), El Nino is "a disruption of the ocean-atmosphere system in the tropical Pacific having important...

Scientists have uncovered evidence of a long-term climate pattern in the North Pacific Ocean. Known as the Pacific Decadal Oscillation (PDO), this long-term ocean fluctuation waxes and wanes roughly every 20 to 30 years, and has been shown to have an important influence on salmon abundance. While the El Nino of the southern Pacific Ocean may appear for a year and then disappear, the PDO tends to...