Home >> Science & Nature >> Nature

Oceanic Phenomenons That Affect Weather

The Earth's oceans are actually a single vast body of water. This water is always circulating, moving salt water from warm parts of the Earth to cold and back again. Ocean currents and water temperature affect weather around the world. The ocean helps create blizzards, hurricanes and tropical storms. It even helps cause drought.

El Nino
- El Nino is a phenomenon in which the water in the Pacific Ocean near the equator is warmer than usual. This happens when easterly trade winds are less active. Once the water warms up, it affects weather throughout the world. Heavy rains cause flooding in Peru. Indonesia and Australia have droughts in wet areas. The western portion of South America and the southwestern portion of the United States experience heavier rainfall during El Nino. Northwestern North America becomes warmer; southeastern North America is cooler and wetter. El Nino happens every 3 to 5 years and can last 1 to 2 years.
La Nina
- La Nina is El Nino's opposite ocean phenomenon. The mechanics of the two phenomena are roughly the same, except La Nina presents with cooler temperatures in the tropical Pacific Ocean rather than warmer. Weather and rainfall patterns that La Nina causes tend to be the opposite of El Nino's. Regions that are cooler during El Nino are hotter during La Nina. Regions that are wetter during El Nino are dryer during La Nina.
Pacific Decadal Oscillations
- Pacific Decadal Oscillation, or PDO, is similar to El Nino and La Nina in the weather patterns it produces. PDO lasts 20 to 30 years. During those years, Pacific Ocean surface temperatures are either colder or warmer than normal, particularly in the north. Cold Pacific Decadal Oscillation mimics the weather patterns of El Nina, while warm PDOs mimic El Nino. When cold PDOs happen, they worsen the weather patterns of El Nina and weaken those of El Nino. Adversely, when warm PDOs occur, they worsen El Nino weather and weaken El Nina weather.
Ocean Effect Snow
- Ocean effect snow occurs when ocean water is warm and surface air is cold. This phenomenon takes place when cold air blows into regions where the ocean is still warm. Ocean effect snow typically happens over the coast of New England when cold air comes in from the north. The air and the ocean interact in such a way that snowstorms develop over the ocean, sometimes producing snowfall over coastal regions.

Nature