El Niño Causes Drastic Weather Patterns

Weather patterns are easy to observe. Conjectures formed upon stepping outside include (but are surely not limited to) “it’s hot!” or “it’s never going to cool down!”

While the observations come naturally, the explanations are slightly more detailed.

A driving factor in the abnormal atmospheric conditions, seemingly terrorizing those brave enough to partake in outside activities, is El Niño.

The National Oceanic Atmospheric Administration (NOAA) explains, “El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific [due to] an oscillation of the ocean-atmosphere system in the tropical Pacific, having important consequences for weather around the globe.”

Scientists can effectively describe El Niño but continue to theorize the root of its cause. NOAA continues, “In normal, non-El Niño conditions, the trade winds blow towards the west across the tropical Pacific. These winds pile up warm surface water in the west Pacific, so that the sea surface is about 1/2 meters higher at Indonesia than at Ecuador.”

In El Niño conditions, the trade winds ease up, allowing warmer water to flow east towards the Americas. This shifts the thermocline—the steep temperature gradient in the ocean where the top warm layer is typically thicker closer to Asia than America.

From there, NOAA continues, “Rainfall follows the warm water eastward, with associated flooding in Peru and drought in Indonesia and Australia… [This] results in large changes in the global atmospheric circulation, which in turn forces changes in weather conditions far removed from the tropical Pacific.”

Regarding typical patterns of the United States, El Niño influences conditions differently in different regions. Weather.com explains that El Niño causes cooler than average conditions for the Desert Southwest, Southern Plains, and the northern Gulf Coast, whereas it creates warmer conditions for the top layer of states from Washington to Maine. El Niño influences precipitation in the U.S. as well; drier conditions than average are present for the Northwest, Northern Rockies, Ohio River Valley, and Great Lakes. Wetter conditions are found in southern states from California to the Carolinas and up the Atlantic coast.

Citizens of California who are experiencing drought likely would disagree with these conditions. Weather.com says those are the “impacts that are typically expected, but they aren’t always the rules… No two El Niños are exactly alike. The intensity matters for impacts.”

Although each occurance brings new conditions, El Niño’s name is based on the conditions that it typically brings. NOAA explains, “El Niño was originally recognized by fisherman off the coast of South America as the appearance of unusually warm water in the Pacific ocean, occurring near the beginning of the year. El Niño means The Little Boy or Christ child in Spanish. This name was used for the tendency of the phenomenon to arrive around Christmas.”

Weather patterns are a part of our daily lives. Even though different patterns commence around us continuously, it remains a mystery as to how exactly they work. Billy Kessler, an oceanographer at the Pacific Marine Environmental Laboratory for NOAA explains, “We don’t initiate El Niño… While we can describe the collapse pretty well, we don’t seem to know what makes the system ready to collapse, or what exactly causes the opposing winds in the first place.”

Until more information is known, the best way to learn more about the natural world is to continue making observations about weather.