Scientific Reading: How the Equatorial Pacific Ocean Influences Global Weather Patterns

Arab Weather - The Pacific Ocean is the largest ocean in the world, covering a large part of the Earth's surface. The tropical part of the Pacific Ocean plays a fundamental role in regulating global weather patterns, affecting climate and weather around the world. Changes in ocean surface temperatures in this region lead to major changes in weather patterns, the effects of which extend to different continents.

Main influences of the tropical Pacific Ocean

Weather experts at the Arab Weather Center said that the tropical part of the Pacific Ocean is where the El Niño and La Niña phenomena occur, and they are two of the most important weather phenomena that affect global weather patterns.

El Niño: This phenomenon occurs when sea surface temperatures are abnormally high in the eastern part of the tropical Pacific Ocean. This phenomenon leads to a major disruption in weather patterns, causing warm and dry winters in some areas such as North America, and very wet winters in other areas such as Southeast Asia and Australia.

La Niña: Occurs when sea surface temperatures are abnormally low in the same region. This phenomenon leads to weather patterns opposite to those that occur during El Niño, causing cold, wet winters in some areas such as North America, and dry winters in other areas such as Southeast Asia.

Impact on global air currents

Temperatures in the tropical Pacific Ocean greatly influence the regulation of global air currents, particularly the jet stream in the Northern Hemisphere. During an El Niño, the jet stream shifts more southward, leading to changes in weather patterns including an increased likelihood of severe storms on the west coast of North America. Conversely, a La Niña causes the jet stream to shift northward, bringing cold, dry weather to certain parts of the world.

Impact on the global hydrological cycle

Changes in sea surface temperatures in the tropical Pacific Ocean significantly affect the global hydrological cycle (the hydrological cycle, also known as the water cycle, is the continuous process by which water moves across the Earth's surface and between the oceans, atmosphere, and land). El Niño increases evaporation into the ocean, leading to increased precipitation in areas such as South America and Southeast Asia. In contrast, La Niña reduces evaporation and precipitation in these areas and increases them in others.

Impact on hurricane season

The tropical Pacific Ocean greatly influences the hurricane seasons in both the Pacific and Atlantic Oceans. During an El Niño, sea surface temperatures increase in the Pacific, leading to increased hurricane activity in the Pacific and decreased hurricane activity in the Atlantic. In contrast, a La Niña increases hurricane activity in the Atlantic and decreases hurricane activity in the Pacific.

Southern Oscillation

Experts at the Arab Weather Center said that the Southern Oscillation is an integral part of the El Niño and La Niña phenomena and refers to changes in air pressure between the Indian and Pacific Oceans. This oscillation directly affects the distribution of winds and atmospheric pressure over the Pacific Ocean, leading to changes in ocean currents and the atmosphere that in turn affect the global climate.

Positive Southern Oscillation: Usually associated with El Niño, atmospheric pressure decreases in the eastern Pacific Ocean and increases in the west, enhancing the eastward flow of warm water and increasing the effect of El Niño.

Negative Southern Oscillation: Associated with La Niña, atmospheric pressure rises in the eastern Pacific Ocean and falls in the west, causing an increase in the flow of cold water from the depths towards the surface in the eastern Pacific Ocean, thus strengthening the effect of La Niña.

God knows best.

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