0.1635
900 319 0030
x

Rising Indian Ocean

iasparliament Logo
May 16, 2017

How is global warming affecting oceans?

  • There are two broad mechanisms at work.
    • Heat trapped in the atmosphere due to rising sea levels makes water expand.
    • Melting ice sheets begin to add water to the world’s oceans.
  • NASA’s satellite data shows that the seas on average have risen 85 mm since 1993, adding about 3.5 mm annually.

What is peculiar about the Indian Ocean?

  • The Indian Ocean has been rising rapidly, particularly since 200.
  • It was specific to a smaller stretch called the North Indian Ocean, which consists of the Bay of Bengal, the Arabian Sea and a large part of the Indian Ocean until the 5 degree S latitude.
  • North Indian Ocean sea levels actually dipped between 1993 and 2004, at about 0.3 mm per year, but after 2004, the rise was 6 mm annually.
  • Such a fluctuating trend hasn’t been observed for the Pacific Ocean and the Atlantic Ocean.

Why did this happen?

  • The North Indian Ocean is surrounded by land on all sides, except an outlet on the southern side.
  • This influences the rate at which heat is absorbed and flushed out from within the system.
  • Wind flows, which led to warm water welling up on the Indian Ocean surface, changed directions every decade and probably influenced sea level patterns.

What does this imply?

  • This means a rise in average global temperature doesn’t mean a concurrent rise in sea levels everywhere.
  • Every year in the last decade has broken temperature records that have held for over a century.
  • But researchers believe that North Indian Ocean levels may see a fall over the next decade (like seen between 1993 and 2004).

What should be done?

  • These points to a need for more research to understand the inherent variability of the Indian Ocean.
  • This could help sharpen monsoon forecasts and predicting coastal erosion patterns.
  • Better understanding of sea level undulations could also inform future reports by the Intergovernmental Panel on Climate Change.

 

Source: The Hindu

Login or Register to Post Comments
There are no reviews yet. Be the first one to review.

ARCHIVES

MONTH/YEARWISE ARCHIVES

Free UPSC Interview Guidance Programme