warmer-arabian-sea-led-to-intense-rain-in-august-ht

 

Context: An unusually warm Arabian Sea is likely to have contributed to intense bursts of monsoon rain in parts of India in August, which in particular led to flooding and landslides in many parts of the west coast, scientists said.

Analysis

  • Arabian Sea has been warming rapidly in recent decades. This makes the air above warmer, humid and unstable. As a result, the monsoon winds are exhibiting more fluctuations than earlier. So occasionally there are episodes where huge amount of moisture is dumped along the west coast of India in a few days’ time. 
  • This year again, the northern Arabian Sea was up to 2-3°C warmer than usual in August, and we saw several spurts of monsoon rains across the west coast.
  • There are several scientific papers that have concluded that the Arabian Sea is becoming warmer as a result of climate change. 
  • Rapid warming in the Arabian Sea has resulted in a rise in widespread extreme rains over Western Ghats and central India, since warming induces increased fluctuations in the monsoon winds, with ensuing episodes of enhanced moisture transport from the Arabian Sea towards the Indian subcontinent. 
  • Indian Ocean warming is also found to reduce rainfall over India during the onset phase and increase it during the withdrawal phase. 
  • Models also indicate that there will be higher SST (sea surface temperature) warming over Arabian Sea compared to Bay of Bengal.
  • Some scientists cautioned that SSTs may have been one of the factors. 
  • Low pressure areas formed over Bay of Bengal which strengthened the monsoon winds are an equally dominant factor.