Sea Surface Temperature (SST) rise refers to the sustained increase in ocean surface temperatures driven by anthropogenic greenhouse gas emissions and global climate change. Global ocean surface temperatures have risen by roughly 0.9°C since the pre-industrial era, altering marine ecosystems and atmospheric circulations.

Phenomenon of Sea Surface Temperature Rise

• Ocean Heat Absorption: The world’s oceans absorb over 90% of excess heat trapped by greenhouse gases, warming surface water layers down to several hundred meters.
• Reduction of Ocean Albedo: Melting polar sea ice exposes darker ocean water, absorbing more solar radiation and accelerating surface water warming through feedback loops.
• Stratification of Water Layers: Thermal expansion and surface warming create a stable, warm upper layer, limiting vertical mixing with colder deep waters and concentrating heat in the upper ocean.

Impact on the Formation and Intensification of Tropical Cyclones

• Lowering the Threshold for Cyclogenesis: Tropical cyclones require a minimum threshold SST of roughly 26.5°C to 27°C to initiate. Elevated baseline SSTs lengthen the seasonal window and expand the geographical areas where cyclogenesis can occur.
• Rapid Intensification (RI): Warmer surface waters provide a continuous source of sensible and latent heat, allowing low-pressure systems to intensify rapidly into Severe and Super Cyclonic storms within short timeframes (e.g., Super Cyclone Amphan in the Bay of Bengal, which intensified rapidly due to abnormally warm waters).
• Increased Atmospheric Moisture Capacity (Clausius-Clapeyron Law): For every 1°C increase in temperature, air holds roughly 7% more moisture. This expands the precipitable water available to cyclone updrafts, causing intense coastal rainfall and severe inland flooding.
• Sustained Landfall Intensity: Warmer seas create deeper warm oceanic layers that delay the typical cold-water upwelling caused by cyclone winds, allowing storms to maintain structural intensity further inland after landfall (e.g., Cyclone Idai).
• Shifting Cyclone Tracks: Rising SSTs are altering regional storm dynamics, making basins that historically saw fewer storms—such as the Arabian Sea—experience more frequent and severe cyclones (e.g., Tauktae, Biparjoy).

Rising sea surface temperatures are driving more intense, rapidly intensifying, and moisture-heavy tropical cyclones. Addressing these risks requires improved satellite forecasting alongside resilient coastal adaptation infrastructure.