Over the course of this winter, California has been hit by a number of record-breaking rains. As the state reported one of its wettest winters, researchers detected their cause. And this is atmospheric rivers, a strange weather phenomenon.
Atmospheric rivers are a narrow filament or corridor of concentrated moisture. They form and reside in the Earth’s atmosphere. These filaments are capable of holding significantly high quantities of water.
Reportedly, they are capable of holding a water quantity 15 times higher than what flows through the Mississippi.
According to specialists, atmospheric rivers are more than just ‘rain’. They are a unique and quite strange weather phenomenon. This event is responsible for carrying most of the horizontal water vapors outside of the tropics.
The atmospheric river filaments can stretch up to 250 – 370 miles wide. And they have already been connected to some extreme weather reports. For example, they were linked to all of the seven floods on the Russian River in California. These took place in between 1996 and 2007. Atmospheric rivers are also believed to have played a role in the ‘Snowmageddon’. This latter took place in 2010 and blanketed the East Coast.
Atmospheric rivers are famous for causing highly wet events. But they may also be very windy ones. Just recently, a team of scientists released a new study on the phenomenon. And they discovered that atmospheric rivers are not just very wet, they are also very windy.
Research on the matter was led by Duane Waliser. He is an atmospheric scientist, part of the NASA Jet Propulsion Lab. Study results were released earlier this week. They were published in the Nature Geoscience journal.
Available online since February 20th, the study paper was titled as follows. “Extreme winds and precipitation during landfall of atmospheric rivers”.
Waliser, together with his team, determined the following. Massive atmospheric rivers are behind almost 75 percent of all the extreme rainfall and wind events. And this is applicable for all over the world’s coasts. They are also the cause of about half of the strongest wind gusts. All that have been recorded over these last two decades.
Massive atmospheric rivers were also linked to most of the extreme snow and rain events to have hit the United States. More exactly, its Western parts. Almost 65 percent of all such events can be linked to this strange weather phenomenon.
Monday’s storm, the one to have hit Northern California, was also traced back to an atmospheric river. And they may also be the reason behind up to 80 percent of all the state’s major floods.
Last month, various California countries called in a state of emergency. The decision came based on the devastating storms that keep hitting them. Such storms have also been linked to atmospheric rivers.
And they come with their very bad parts. But also the slightly good ones. California’s 5-years drought dropped significantly following the storms. In just a week, the drought fell and is now affecting less than a quarter of California.
But the atmospheric rivers determined weather phenomenon don’t seem to be slowing down. California officials issued a flood warning that affects around 14 million people. And this alert will probably remain in place for at least another day.
According to research, on average, scientists register about 5 to 7 atmospheric rivers per year. In contrast, this winter alone saw some 10 or even more such events. As such, most declared this to have been “a very active winter”.
And according to Waliser, atmospheric rivers can come with two high-impact events. One is the risk of flooding hazards. And the other are its potential high impact extremes and winds. These were seen to cause hazardous conditions.
Such winds can have twice the speeds of an average storm. They are strong enough to topple even a sequoia. Last month, a 1,000-years old Californian tree, the great Pioneer Cabin Tree, fell down.
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