Marine heatwaves

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Context:

An analysis led by scientists at the Indian Institute of Tropical Meteorology (ITM), Pune highlights increased instances of marine heatwaves in the Indian Ocean.

Details of the study

From 1950 to 2020, the Indian Ocean became warmer by 1.2 degrees Celsius, and climate models expect it to heat a further 1.7 degrees Celsius to 3.8 degrees Celsius from 2020 to 2100.
Marine waves are expected to increase tenfold from the current average of 20 days per year to 220-250 days per year.
The tropical Indian Ocean will likely be in a "near-permanent heatwave state" and accelerate coral bleaching, sea-grass destruction, and loss of kelp forests, affecting the fisheries sector adversely.
The heating of the ocean was not merely restricted to the surface but went deeper and increased the overall "heat content" of the ocean.
The heat content of the Indian Ocean, when measured from the surface to a depth of 2,000 metres, is currently increasing at the rate of 4.5 zetta-joules per decade, and is predicted to increase at a rate of 16-22 zet-ta-joules per decade in the future.
The future increase in heat content is comparable to adding the energy equivalent of one Hiroshima atomic bomb detonation every second, all day, every day, for a decade.
Rising heat content contributes to sea-level rise also. Heat causes the volume of water to increase, called the thermal expansion of water, and this is responsible for more than half of the sea-level rise in the Indian Ocean - larger than the changes arising from glaciers and sea ice melting.

Note: Joule is a unit of energy and one zetta-joule is equal to one billion-tril-lion joules (10^21).

Articles on Marine heatwaves:

https://www.iasgyan.in/daily-current-affairs/marine-heat-waves

https://www.iasgyan.in/daily-current-affairs/marine-heatwaves#:~:text=Marine%20heat%20waves%20(MHWs),weeks%2C%20months%20or%20even%20years.

https://www.iasgyan.in/daily-current-affairs/marine-heat-waves-25

Source:

The Hindu

PRACTICE QUESTION

Q) Analyze the projected increase in temperature, frequency of marine waves, and its impacts on coral reefs, sea-grass, and fisheries due to marine heatwaves. Evaluate the significance of rising heat content in terms of sea-level rise and propose mitigation strategies.(250 words)