- School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Odisha, 752050, India (s21es09001@iitbbs.ac.in)
Climatic modes like ENSO and IOD influence wind systems, which in turn can significantly impact the wave dynamics of a region. This study focuses on the changes in seasonal characteristics of waves induced by ENSO and IOD over the Bay of Bengal (BoB). We used monthly ERA-5 dataset of wind and wave parameters for 1980–2020. Based on Niño3.4 and dipole mode index, different phase of ENSO and IOD were selected. During the monsoon season, it was found that El Niño and La Niña increase significant wind wave height (Hsw) in the coastal regions, while they reduce the significant swell height (Hss) over the entire basin. However, the nIOD and pIOD enhance both the Hss and Hsw, albeit in different regions of the BoB. In post-monsoon season, when El Niño and La Niña are comparatively more active, they show similar features as pIOD and nIOD respectively. Reduced significant wave height (Hs), Hsw, and Hss in the entire BoB were noticed in the presence of El Niño and pIOD. However, these parameters were found to increase during La Niña and nIOD, especially in the eastern BoB. During winter, the signatures of the waves were much similar to those of post-monsoon but the magnitudes were comparatively low. During pre-monsoon of the next year, El Niño and pIOD showed signatures with increased Hss in the western BoB, whereas Hsw activity increased over the whole BoB. In presence of La-Niña and nIOD, a basin-wide increment in Hs, Hss, and Hsw is noticed. The aforementioned changes during different seasons were even more pronounced when El Niño & pIOD and La Niña & nIOD co-occurred. All these features noted in Hs, Hss, and Hsw during different seasons were found to co-vary with the spatial wind patterns, indicating winds to be a primary driver of these wave activities.
How to cite: Sahu, S., Gupta, H., Deogharia, R., and Sil, S.: Seasonal Wave Characteristics in the Presence of ENSO and IOD over the Bay of Bengal, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15317, https://doi.org/10.5194/egusphere-egu25-15317, 2025.