Atmospheric Rivers

Overview

According to a new study
published in ‘Science Advances’ of the University of California,
atmospheric rivers have shifted by about 6 to 10 degrees towards both
poles in the last four decades. This situation is affecting the global
climate pattern and accelerating the effects of climate change.

What are atmospheric rivers:

• Atmospheric rivers are
  relatively long and narrow areas in the atmosphere that transport most
  of the water vapor outside the tropical regions. They are like rivers in
  the sky. Although atmospheric rivers come in many sizes, those with the
  highest water vapour and the strongest winds can cause heavy rainfall
  and flooding. Atmospheric rivers are often
  found in the extreme tropical North Pacific and Atlantic, Southeastern
  Pacific and South Atlantic oceans, often causing landfall on the western
  coasts of North and South America. Atmospheric rivers usually form
  in tropical regions. Warm temperatures cause sea water to evaporate and
  rise into the atmosphere. Strong winds help carry the water vapour into
  the atmosphere.
  
• As atmospheric rivers pass over
  land, the water vapour spreads far into the atmosphere. After some time,
  these water droplets cool down and are received as rain.

• Major findings of the study:

  According to the study, one of the main reasons for the shift of
  atmospheric rivers towards the poles is the change in sea surface
  temperature in the Pacific region. According to experts, climate change has also made monsoon
  rainfall more irregular in India. After a long period of drought,
  torrential rain is suddenly falling at a place in a very short time.

  Major implications of the study:

  1. In subtropical regions, where atmospheric rivers are decreasing, this may result in prolonged drought and water shortage. California and southern Brazil depend on atmospheric rivers for rainfall to recharge reservoirs and for agriculture. Without this moisture, these regions could face water shortages, putting pressure on communities, agriculture and ecosystems.

  2. Atmospheric
  rivers flowing poleward could cause more intense rainfall, flooding and
  landslides in high latitudes. Effects could be seen along the US coast,
  in the Pacific Northwest, Europe and even in polar regions.

  3. Current
  changes reflect changes caused primarily by natural processes, but
  human-induced global warming also plays a role. Global warming is also
  projected to increase the overall frequency and intensity of atmospheric
  rivers in the future.

  
  

  
  

  
  

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