Environment

Atmospheric Rivers

Everything to know about Atmospheric rivers.

By NOAA – http://blogs.discovermagazine.com/imageo/2014/12/11/pineapple-express-drenches-california-easing-worst-drought-1200-years/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=37318031

By: Kaleb Fuard, Journalist

Atmospheric rivers get their name because they are like rivers in the sky. They are long, narrow regions in the atmosphere but they come in many shapes and sizes. They’re about 250 to 375 miles wide and are able to be over 1,000 miles long. Atmospheric rivers are airborne corridors of water vapor that flow from Earth’s tropics to higher altitudes. The size and strength of an atmospheric river can vary greatly but the average atmospheric river can carry the same amount of water vapor about the same as the average flow of water at the mouth of the Mississippi River. Very strong atmospheric rivers, however, can transport up to even 15 times that. Once the atmospheric river makes landfall, this water vapor often gets released in the form of rain or snow. Atmospheric rivers can cause extreme rainfall and flooding by stalling over watersheds that are vulnerable to flooding. A well-known atmospheric river is called the “Pineapple Express,” and it is a strong atmospheric river. It is able to bring moisture from the tropics near Hawaii to the US West Coast. This is what is responsible for California’s climate changing. The introduced way of measuring the severity of Atmospheric rivers is called the AR(Atmospheric River) Scale. The AR scale ranges from AR 1, the weakest Atmospheric river, to AR 5, the strongest Atmospheric river. Atmospheric rivers can be hazardous and/or beneficial. AR 1 is primarily beneficial, AR 2 is mostly beneficial but also hazardous, AR 3 is a balance of beneficial and hazardous, AR 4 is mostly hazardous but also beneficial, and AR 5 is primarily hazardous. The reason they can be beneficial as well is because they “can steer much needed water to parched lands.”