Atmospheric Rivers (ARs)



Published on 05 Mar 2025

• Rivers in the sky or atmospheric rivers are becoming more intense and can be linked with devastating floods, heat stress and are also a cause for the recent Wayanad event.

 AR triggers when the water vapour forms a band or a column in the lower part of the atmosphere which moves from the tropics to the cooler latitudes.

• It comes down as rain or snow, devastating enough to cause floods or deadly avalanches.

• These invisible “rivers in the sky” carry some 90% of the total water vapour that moves across the Earth’s mid-latitudes.

• They can also be responsible for the increasing humid heat during the summer months.

• A 2023 study showed that 70% of all major floods in India in the last 35 years were associated with ARs.

• ARs are identified and measured using a metric called Vertically integrated water vapour transport (IVT).

Keywords:

Atmospheric Rivers flood heat stress avalanche Vertically integrated water vapour transport climate change climate