What is sea surface temperature rise? How does it affect the formation of tropical cyclones?

Introduction

Sea Surface Temperature (SST) rise refers to the increase in the temperature of the ocean's surface due to factors such as global warming, increased greenhouse gas emissions, and natural climate variability like El Niño. According to the IPCC Sixth Assessment Report (2021), the global average SST has risen by approximately 0.13°C per decade since 1901.

Value Addition Block — Key Factors Driving SST Rise

Impact of SST Rise on Tropical Cyclone Formation

1. Enhanced Cyclone Intensity

• Warmer SSTs provide more latent heat energy, which fuels the intensification of tropical cyclones.
• Example: The 2020 Atlantic hurricane season saw a record 30 named storms, attributed to unusually warm SSTs.

2. Increased Cyclone Frequency in Certain Regions

• SST rise can shift cyclone activity to regions where conditions become more favorable.
• Example: The Arabian Sea has seen a rise in cyclone frequency due to warming waters, as noted by the India Meteorological Department (IMD).

3. Prolonged Cyclone Lifespan

• Warmer SSTs reduce the dissipation of cyclones, allowing them to sustain their strength for longer durations.
• Example: Cyclone Amphan (2020) maintained its intensity over the Bay of Bengal due to elevated SSTs (~32°C).

4. Increased Rainfall and Storm Surges

• Warmer SSTs enhance moisture availability, leading to heavier rainfall and more destructive storm surges.
• Example: Cyclone Tauktae (2021) caused widespread flooding in western India.

5. Geographical Shifts in Cyclone Formation

• Rising SSTs can alter wind patterns and ocean currents, leading to cyclones forming in previously unaffected areas.
• Example: Cyclones in the South Atlantic, such as Cyclone Catarina (2004), are linked to anomalous SST rise.

Challenges and Way Forward

• Challenges: SST rise exacerbates the vulnerability of coastal regions, disrupts marine ecosystems, and increases economic losses.
• Way Forward:
  • Strengthen early warning systems and disaster preparedness.
  • Implement global climate agreements like the Paris Accord to limit warming.
  • Promote blue carbon ecosystems (e.g., mangroves, seagrasses) to mitigate SST rise.

Conclusion

The rise in sea surface temperatures is a critical driver of tropical cyclone formation and intensification, posing significant risks to coastal communities and ecosystems. Addressing this challenge requires a combination of mitigation efforts to curb global warming and adaptation strategies to enhance resilience, aligning with SDG 13 (Climate Action).