Indian ocean warming
From 1950 to 2020, the Indian Ocean had become warmer by 1.2 degrees Celsius, and climate models expect it to heat up a further 1.7 degrees Celsius to 3.8 degrees Celsius from 2020 to 2100.
While we are familiar with heat waves on land, “marine heatwaves”, their counterparts in the sea and linked to the rapid formation of cyclones, are expected to increase tenfold from the current average of 20 days per year to 220-250 days per year
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 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 zetta-joules per decade in the future.
Joule is a unit of energy and one zetta-joule is equal to one billion-trillion joules (10^21).
Consequences
Mostly attributable to global warming, the tropical Indian Ocean will likely be in a “near-permanent heatwave state” and accelerate coral bleaching, seagrass destruction, and loss of kelp forests, affecting the fisheries sector adversely
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 glacier and sea-ice melting
COMMENTS