01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-05-0190 |
| Title of Abstract | Subsurface Drivers and Teleconnections of Marine Heatwaves in the Seychelles-Chagos Thermocline Ridge |
| Authors | Saranya JS*, Panini Dasgupta, SungHyun Nam |
| Organisation | Future Innovation Institute, Seoul National University |
| Address | Seoul National University Seoul, Seoul, Korea, Rep. Pincode: 08826 E-mail: saranyaozhoor@gmail.com |
| Country | Korea, Rep. |
| Presentation | Oral |
| Abstract | Marine heatwaves (MHWs), extended periods of unusually warm sea surface temperatures are intensifying globally under climate change, cascading impacts on marine ecosystems and regional climate. This study investigates the characteristics and drivers of MHWs in the Seychelles-Chagos Thermocline Ridge (SCTR; 50° to 75°E, 5° to 12°S), an important open-ocean upwelling zone in the southwestern tropical Indian Ocean. Analysis of daily optimum interpolated SST data (1982 to 2024) identifies 98 MHW events and shows a marked increase (3 days per year) in annual MHW days. K-means clustering of event duration and intensity reveals three distinct types with differing thermocline dynamics: long-lived, intense events (Cluster 1, 9%) linked to rapid thermocline shoaling and strong subsurface warming; short-lived, weak events (Cluster 2, 52%) driven mainly by surface heat flux anomalies; and moderate events (Cluster 3, 39%) characterized by subsurface heat buildup and pronounced upper-ocean stratification. Thermocline shoaling emerges as a key mechanism facilitating vertical heat emergence and MHW initiation. Notably, Cluster 1 events coincide with enhanced rainfall over southern India and East Asia, indicating far-reaching atmospheric teleconnections. These results underscore the importance of incorporating subsurface processes into MHW monitoring, particularly in upwelling systems such as the SCTR. |
| Are you part of IIOE-2 endorsed project | yes |
| Endorsed Project Number | IIOE2-EP20 |
| Keywords | Marine Heatwaves, Extreme Rainfall, Seychelles-Chagos Thermocline Ridge, Clustering |
| For Awards | yes |
| Date Of Birth | 13-03-1997 |
| ECSN Registration Number | IIOE2-ECSN-057 |