Chennai: Experts are closely monitoring a low-pressure system off the north Tamil Nadu-south Andhra Pradesh coast, which is projected to develop into the year’s first cyclone.
This potential cyclone is set to draw considerable energy from the Bay of Bengal, where sea surface temperatures (SST) have remained unusually high since April. Marine heatwaves, characterised by prolonged periods of elevated ocean temperatures, are not uncommon in the Bay of Bengal. Over the past three years, regions spanning the Andamans, Tamil Nadu, and Andhra Pradesh have experienced frequent marine heatwaves, defined by SSTs exceeding 1°C above normal. Typically, the Bay of Bengal’s SST ranges between 28°C and 30°C.
This year, the frequency of days with SSTs more than one degree above normal has tripled along the coasts of Lakshadweep, Kerala, and Karnataka, and doubled along the Andamans compared to the previous two years. Researchers at the Indian National Centre for Ocean and Information Services (INCOIS), who have been tracking these phenomena using weather buoys for the past three years, noted that in the last three months, marine heatwave conditions persisted longer over parts of the Arabian Sea than the Bay of Bengal. Last week, INCOIS issued an advisory in response to these developments.
Marine heatwaves, which involve extremely high sea surface temperatures lasting at least five days, are predominantly caused by changes in ocean currents, atmospheric patterns, and climate change. The current marine heatwave conditions in the Bay of Bengal are a significant concern due to their potential to rapidly intensify cyclones. Elevated SSTs provide additional energy to cyclonic systems, potentially increasing their intensity and the associated risks to coastal communities. The implications of these marine heatwaves are far-reaching. Elevated SSTs not only heighten the risk of more powerful cyclones but also pose a threat to marine ecosystems and the livelihoods of coastal populations dependent on fishing and tourism. As the climate continues to change, the frequency and duration of marine heatwaves are expected to rise, further exacerbating these risks.
Authorities and local communities are urged to remain vigilant and prepare for the potential impacts of an intensified cyclone season. The situation calls for enhanced monitoring and early warning systems to mitigate the adverse effects on vulnerable coastal regions. The phenomenon underscores the pressing need for robust climate action and adaptation strategies to address the escalating threat posed by marine heatwaves and their impact on weather patterns and coastal resilience. As India braces for the cyclone season, the ongoing marine heatwave in the Bay of Bengal serves as a stark reminder of the intricate linkages between climate change and extreme weather events.
