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Snapshot of an atmospheric river simulated landfall along the west coast of North America on February 11, 2020. Gray tones indicate water vapor. The colors indicate the intensity of precipitation from blue (light rain) to green (very heavy rain). credit: Department of Energy Office of Science, Energy Exascale Earth System Model (E3SM) Project.
atmospheric rivers There are large, narrow sections of Earth’s atmosphere that transport moisture from Earth’s tropics to the poles near the equator. On average, there are four to five active atmospheric rivers on Earth at any given time. They transport huge amounts of moisture. Each carries an equivalent of liquid water flowing through the mouth of the Amazon River. When atmospheric rivers reach land, they release this moisture, causing heavy snowfall and rainfall.
Atmospheric rivers are a very important part of the Earth’s climate. They are responsible for 90% of the movement of moisture from the tropics to the poles. This means that atmospheric rivers are a major factor in cloud formation and therefore have a significant effect on air temperature, sea ice and other components of the climate.
The moisture content of atmospheric rivers shape large parts of the world. Research indicates that they are responsible for more than half of the precipitation in parts of North America, France, Spain, Portugal, the United Kingdom, South America, Southeast Asia and the coasts of New Zealand. As such, they are important to plant and animal life, agriculture and as a source of water to people. But atmospheric rivers can also cause severe flooding due to heavy rainfall.
fast Facts
- DOE-sponsored research found that from 1979 to 2019, 24 atmospheric rivers hit the US West Coast each winter on average.
- The atmospheric rivers that create storms are the source of about 50 percent of the US West Coast’s water supply. They ended three-quarters of the drought in the Pacific Northwest from 1950 to 2010.
- In February 2022, the Australian city of Brisbane received nearly 80 percent of its normal annual rainfall in just six days from an atmospheric river. The floods submerged more than 15,000 homes in the city and killed nine people in northeastern Australia.
DOE’s Contribution to Atmospheric River Research
Understanding atmospheric rivers is essential for developing accurate models of Earth’s climate. The Department of Energy’s (DOE) Office of Science supports research on atmospheric rivers through its Biological and Environmental Research Program. The Atmospheric Radiation Measurement (ARM) Facility, a DOE Office of Science User Facility that provides the scientific community with observations of Earth’s atmosphere, performs detailed aircraft and ship measurements of atmospheric rivers during a large interstellar effort. To translate this research into climate and Earth system models such as the state-of-the-art Energy Exascale Earth System Model (E3SM), the Office of Science supports research on incorporating atmospheric rivers into computer simulations. To address the fundamental understanding of variability and change of atmospheric rivers, a DOE-led international team of researchers created the Atmospheric River Tracking Method Intercomparison Project (ARTMIP). The group has helped the scientific community make strong predictions of how atmospheric rivers and their effects will change in warmer climates. With DOE funding, ARTMIP has helped produce 14 scientific papers and organizes several meetings.
