A study titled ‘Future projections for the tropical Indian Ocean’ predict accelerated warming of Indian Ocean

Posted 30 Apr 2024

2 min read

Key findings of study:
- Climate models predicts accelerated warming of Indian Ocean (IO) at a rate of 1.7°C–3.8°C per century from 2020–2100, compared to 1.2°C per century from 1950–2020.
- Maximum warming is in the Arabian Sea (northwestern IO).
- Marine heatwaves are expected to increase from 20 days per year to 220–250 days per year, pushing tropical IO into near-permanent heatwave state.
- In high emission scenario, study expects minimum average temperature in IO basin to stay above 28°C by 2100, which remained around 26°C-28°C during 1980-2020.
Impact of warming Indian Ocean:
- Thermal expansion due to increased heat content contributing to sea level rise.
- Marine heatwaves may lead to habitat destruction (coral bleaching, seagrass destruction, loss of kelp forests) and rapid intensification of cyclones.
- Increase in frequency of extreme Indian Ocean Dipole (IOD) events.
  - IOD is marked by temperature differences in IO.
  - During Positive IOD, warm waters are pushed to Western IO while during Negative IOD, warm waters are pushed to Eastern IO.
  - Positive IOD is favourable for rainfall in Indian sub-continent.
- Others: Increased Ocean acidification and decline in net primary productivity etc.