SE Asia Cyclones and its Impact
Context:
A recent study by the World Weather Attribution (WWA) group highlights that rising global temperatures and rapid urbanization exacerbated the impact of floods triggered by Cyclone Senyar and Cyclone Ditwah in Southeast and South Asia.
These storms caused over 1,600 deaths across Sri Lanka, Indonesia, Malaysia, and Thailand.
The Cyclones:
Cyclone Ditwah struck Sri Lanka on November 27.
Cyclone Senyar made landfall in Indonesia on November 26 and Malaysia on November 27.
Cyclone Senyar was particularly unusual as it formed near the equator in the Strait of Malacca.
This is a rare occurrence for tropical cyclones.
Role of Sea Surface Temperatures (SST):
The study notes that at the time of the cyclones, sea surface temperatures (SSTs) in the North Indian Ocean were 0.2 degrees Celsius higher than the 1991-2020 average.
Without the 1.3°C rise in global temperatures since the mid-1800s, SSTs would have been about one degree colder.
Warmer oceans provide more energy for tropical storm development and evaporation, fueling heavier rainfall.
Impact of Climate Change:
A warmer atmosphere holds more moisture.
For every 10 Celsius rises in temperature, the atmosphere can hold about 7% more moisture.
Extreme rainfall events in the Malacca Strait region have increased by 9% to 50%, and in Sri Lanka by 28% to 160% due to global warming.
Deforestation (loss of sponge effect) and urbanization in flood-prone areas further intensified the disaster.