Recently, a large part of the United States witnessed heavy rain, strong winds and severe thunderstorms due to a type of storm known as an atmospheric river.
What Are Atmospheric Rivers?
- Definition: Narrow, fast-moving bands of moisture in the atmosphere — essentially “rivers in the sky” — that transport vast amounts of water vapor.
- Size: Typically 400–600 km wide, and over 1,600 km long.
- Function: While they are a vital part of the Earth’s water cycle (contributing to rainfall and snowpack), they can also cause severe weather events when they hit land.
- Distribution: Although atmospheric rivers occur all over the world, they are most common in the mid-latitudes.
- One famous example: The Pineapple Express (brings moisture from around Hawaii to North America).
- The recent atmospheric river over the U.S. was not the Pineapple Express, as it originated in the Caribbean, per AccuWeather meteorologist Tom Kines.
Impacts of Atmospheric Rivers
- Severe Weather:
- Heavy rainfall
- Cyclone-force winds
- Flooding and mudslides
- Increased wave height along coasts
- Produces significant levels of snow
- Damage Potential: They can produce hurricane-like conditions and cause significant loss of life, infrastructure damage, and economic disruption.
Link to Climate Change
- Rising Global Temperatures:
- Warmer air holds more moisture: 7% more water vapor per 1°C rise in temperature.
- Leads to heavier, longer, and more frequent precipitation events.
- This enhances the intensity of atmospheric rivers, increasing their potential to cause extreme flooding and landslide risks globally.
(Sources: IE & NOAA)
