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What are atmospheric river and why do floods occur?

Atmospheric Rivers are storms that look like rivers in the skies. They can produce massive amounts of rainfall, cause flooding and mudslides, and even result in death and property damage.

This article explains how they are formed, their size, and possible impacts.

WHAT IS A ATMOSPHERIC RIVE?

This weather system is present all over the globe. The weather system begins when tropical oceans are carried to land by a jetstream. As air rises it cools down and condenses resulting in snow or rain. According to NASA, they form most often in oceans at mid-latitudes, between 30 and 60 degrees north or south.

The trail can be hundreds of miles long.

How do atmospheric rivers cause flooding?

The majority of atmospheric rivers are weak, and they do not cause any damage. They can even provide rain or snow when needed. According to the National Oceanic and Atmospheric Administration, atmospheric rivers can carry as much as 15 times more volume than the Mississippi River.

Such storms in drought-stricken California have caused mudslides and toppled poles. They also replenished depleted reservoirs while reducing the risk of fires by moistening the parched vegetation.

A "Pineapple Express", an atmospheric river, hit California in 2019. Water vapor near Hawaii caused rain, mudslides and forced drivers to swim in order to save their lives. Homes also began sliding downhill.

In 2021, a atmospheric river dumped two days' worth of rain in British Columbia, causing deadly floods and land slides, destroying communities, and cutting off access to Canada's biggest port.

How will climate change impact atmospheric rivers?

Scientists say that climate change will cause atmospheric rivers to grow and become more destructive. They are the same ones that have flooded British Columbia and California in recent years.

According to the American Meteorological Society, columns in the atmosphere that are hundreds of miles long transport water vapor from tropical regions to temperate areas in quantities more than twice as large as the Amazon River. According to a research paper published in 2018, atmospheric rivers are expected to decrease by 10%, but increase in size and length, and transport more water. It could be difficult to manage water supply as atmospheric rivers that are beneficial for water supplies will become less frequent and stronger ones more dangerous.

(source: Reuters)