01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-04-0201 |
| Title of Abstract | Impact of the extreme Indian Ocean Dipole events on the Cold Pool characteristics over the Southern Bay of Bengal |
| Authors | Suprity Sethy*, Sandeep K K |
| Organisation | IIT Bhubaneswar |
| Address | salipur cuttack, odisha, India Pincode: 754202 E-mail: 24cl05008@iitbbs.ac.in |
| Country | India |
| Presentation | Poster |
| Abstract | The southern Bay of Bengal is characterized by the presence of a mini-cold pool during the summer monsoon. Several studies have reported that the sea surface temperature (SST) remains below 28°C within this pool and plays a crucial role in regulating convection, air⿿sea heat exchange, and monsoon onset and active-break cycles. In the present study, the impact of extreme Indian Ocean Dipole (IOD) on the maintenance and evolution of the mini-cold pool is investigated using satellite-derived and high-resolution ocean⿿atmosphere reanalysis products for the period 1996⿿2024. The temporal evolution of the Dipole Mode Index (DMI) was compared with SST anomalies over the southern Bay of Bengal cold pool (83°E⿿90°E, 4°N⿿10°N) to assess co-variability with positive and negative IOD phases through threshold-based classification. Analysis suggests that positive IOD phases are generally associated with above-average SST anomalies, reflecting warmer conditions during strong events (e.g., 1997⿿98, 2019, 2021⿿24). Conversely, negative IOD phases correspond to below-average anomalies, with pronounced cooling observed during prolonged events (e.g., 2002⿿07, 2015⿿19). Strong, prolonged phases produce more consistent SST anomalies, while shorter events exhibit higher variability within the cold-pool region. Atmospheric forcing parameters were analysed using the European Centre for Medium-Range Weather Forecasts fifth-generation reanalysis (ERA5) for the study period. Cold pool events during the last decade were further examined to discern the role of extreme IOD phases and the associated variability in the generation, evolution, and decay of such events. This event-wise analysis highlights that the magnitude of SST response depends on both the strength and duration of IOD events and the variability in atmospheric forcing and air⿿sea exchange processes. Understanding the causative factors of the southern Bay of Bengal cold pool is essential for improving regional climate prediction, anticipating extreme weather events, and assessing marine ecosystem responses in the northern Indian Ocean. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Southern Bay of Bengal, Mini-cold pool, summer monsoon, Convection, Air⿿sea heat exchange, Monsoon onset, active⿿break cycles, Indian Ocean Dipole (IOD), Dipole Mode Index (DMI), Atmospheric forcing |
| For Awards | no |