ATMOSPHERIC RIVER (Syllabus: GS Paper 1 – Geography)

Context: California has experienced an exceptionally wet winter with 11 atmospheric rivers battering the state since late December .

Atmospheric River:

• About: A narrow corridor or filament of concentrated moisture in the atmosphere. Other names: For this phenomenon are tropical plume, tropical connection, moisture plume, water vapor surge, and cloud band.
• Total Atmospheric river: On an average the earth has four to five atmospheric river at any time.
• Size: Several thousand kilometers long and only a few hundred kilometers wide, and a single one can carry a greater flux of water than Earth's largest river, the Amazon Rive
• Formation:

oAtmospheric rivers usually begin over tropical regions. Warm temperatures cause ocean water to evaporate and rise into the atmosphere. Strong winds help to carry the water vapor through the atmosphere.

oAs atmospheric rivers move over land, the water vapor rises up farther into the atmosphere. It then cools into water droplets, which fall as precipitation.

• Impacts:

oHeavy rainfall leading to  flooding, landslides, and mudslides.

oDevelop drought-like conditions.

• Significance:

oNot all atmospheric rivers cause damage.

oMost are weak systems that often provide beneficial rain or snow that is crucial to the water supply.