FLYING RIVERS (Syllabus: GS Paper 1 – Geography)

Context: The warming of the Indian Ocean is fueling atmospheric rivers, leading to severe flooding across India. 

Flying Rivers(FRs)

• Definition: Flying rivers, also known as atmospheric rivers (ARs), are long, narrow regions in the atmosphere that transport most of the water vapor outside of the tropics.
• Dimensions: An average FR measures about 2,000 km in length, 500 km in width, and nearly 3 km in depth.
• Role in Extratropical Cyclones: FRs are part of a larger system of extratropical cyclones that move heat and moisture from the tropics towards the poles.
• Location: FRs are typically situated within the low-level jet, a region of strong winds in the lower atmosphere.
• Major Freshwater Transport Mechanisms: These are the largest transport mechanisms of freshwater on Earth, accounting for 90% of the moisture transfer from the tropics to the poles.
• Features:

o Several thousand kilometers long and only a few hundred kilometers wide.

o Single one can carry a greater flux of water than Earth's largest river, the Amazon Rive.

• Formation:

o These are 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.

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

• Impact on India: Seven of India's ten most severe monsoon floods between 1985 and 2020 were linked to ARs. Additionally, increased fog and haze in the Indo-Gangetic Plains have been connected to rising pollution and water vapor due to ARs.
• Effects on Snow Albedo: Declining snow albedo in the Hindukush-Karakoram-Himalayan mountain range is attributed to accelerated snow melting from increased rainfall.