01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-04-0390 |
| Title of Abstract | Seasonal Variability of Wave States and Their Influence on Air-Sea Fluxes in the Northern Indian Ocean |
| Authors | Hyodae Seo*, Siddhant Kerhalkar, Cesar Sauvage, Amit Tandon |
| Organisation | University of Hawaiʻi at Mānoa |
| Address | 1000 Pope Road Honolulu, HI, United States Pincode: 96822 E-mail: hyodae@hawaii.edu |
| Country | United States |
| Presentation | Poster |
| Abstract | The Northern Indian Ocean (NIO) exhibits pronounced intra-seasonal and seasonal variability in sea surface temperature (SST), air⿿sea fluxes, and wave dynamics. Recent studies (e.g., Sauvage et al., 2023; Raj et al., 2025) have demonstrated that mixed sea states and wind⿿wave misalignment can significantly alter air⿿sea momentum exchange, suggesting that conventional bulk flux formulations may not always be applicable under such conditions. These processes may, in turn, influence SST and upper-ocean thermal structure, particularly in regions with strong thermal, vorticity, and stratification gradients such as the Arabian Sea mini-warm pool. To investigate the spatiotemporal characteristics of wave states in the NIO, we analyze long-term OMNI mooring records from the Arabian Sea together with observations from a fleet of autonomous wave gliders deployed in the Bay of Bengal during the 2024 EKAMSAT field campaign. The results reveal that mixed sea states⿿combinations of locally generated wind waves and remotely generated swell⿿and wind⿿wave misalignment are persistent features across seasons. Comparisons with state-of-the-art wave reanalyses indicate that these features are systematically underrepresented, particularly during the Spring Intermonsoon and Southwest Monsoon periods. Given that mixed-sea conditions often violate the wave⿿wind equilibrium assumption embedded in the COARE flux algorithm, we assess the sensitivity of air⿿sea fluxes and the upper-ocean thermal structure of the NIO mini⿿warm pool (characteristic of the Spring Intermonsoon) to alternative parameterizations proposed by Sauvage et al. (2023). The analysis highlights the strong coupling between wave state and upper-ocean thermodynamics in the NIO, underscoring their implications for sub-seasonal to seasonal monsoon prediction. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Northern Indian Ocean (NIO) , SST, air⿿sea fluxes, wave dynamics, EKAMSAT |
| For Awards | no |