01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-05-0374 |
| Title of Abstract | Subsurface Structure of the Marine Heatwaves in the Bay of Bengal |
| Authors | Kalyan Vavalapalli * |
| Organisation | Andhra university |
| Address | 985 kovvada Bhimavaram, Andhra Pradesh, India Pincode: 534202 E-mail: kalyanvavilapalli7@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Marine Heatwaves (MHWs) in the Bay of Bengal (BoB) are becoming more frequent and intense under climate change, with major ecological and climatic implications. Using NOAA OISST (1991⿿2020) and Argo float profiles, this study examined 2018 MHW events with focus on two subregions: Region 1 (14°N⿿16°N; 88°E⿿90°E, high intensity) and Region 2 (6°N⿿8°N; 88°E⿿90°E, low intensity). Hovmöller analyses revealed strong MHWs between 8°N⿿18°N during March, May, and October, propagating west⿿east, with prolonged March⿿June events linked to solar heating and shorter October events influenced by rainfall and runoff. Vertical structure showed Region 1 characterized by high SSTs (up to 32 °C), deeper thermocline, strong stratification, and shallow MLDs, favoring persistent MHWs, while Region 2 exhibited weaker stratification, deeper MLDs (~74 m in June), and stronger vertical mixing, limiting intensity. Isotherm analysis indicated deeper d20 (~157 m) and stratified subsurface structure in Region 1 versus shallower, more stable profiles in Region 2. T⿿S diagrams confirmed freshwater-driven stratification in Region 1 and salinity-controlled mixing in Region 2. Collectively, results show that MHW intensity and persistence in the BoB are strongly regulated by subsurface structure, freshwater fluxes, and vertical mixing, with unusual June 2018 events linked to monsoon breaks and enhanced insolation. Multi-year analyses are needed to assess interannual variability and the roles of ENSO, IOD, and monsoon extremes in modulating MHWs. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Marine Heatwaves (MHWs), Thermocline, Mixed Layer Depth (MLD), Stratification, Vertical mixing |
| For Awards | yes |
| Date Of Birth | 12-02-2003 |
| ECSN Registration Number | IIOE2-ECSN-0224 |