01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-02-0004 |
| Title of Abstract | The changes in La Niña induced summertime interannual variability of sea level anomaly along the western boundary of the Bay of Bengal |
| Authors | Arnab Mukherjee*, Supriyo Ghosh |
| Organisation | National Centre for Polar and Ocean Research (NCPOR) |
| Address | Headland Sada, Vasco Da Gama South Goa, Goa, India Pincode: 403804 E-mail: arnab@ncpor.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | In this study, interannual variability and associated dynamics of sea level anomaly (SLA) along the western boundary of the Bay of Bengal (WBoB) during the summer (June⿿September) seasons of La Niña years between 1998⿿2016 have been investigated using satellite observations and a linear, continuously stratified (LCS) model. To quantify interannual variability along WBoB, regions have been divided into three parts, which include northern (NBoB), central (CBoB), and southern (SBoB). Satellite observation shows negative interannual SLA at all three regions of WBoB during summertime La Niña years of 1998, 1999, and 2007, which became positive during summertime La Niña years of 2010, 2011, and 2016. The LCS model simulates reasonably well the observed interannual SLA variability along WBoB, depending on the forcing mechanisms and La Niña episode. Using dedicated boundary experiments on the LCS model, it has been observed that the interannual variability of SLA during summertime La Niña events is significantly dominated by remote forcing from the Equatorial Indian Ocean (EIO) and the interior BoB. The maximum dominant forcing for negative interannual SLA during summertime La Niña years of 1998 and 2007 originates from the EIO. However, negative interannual SLA during the summertime La Niña year of 1999 is mostly dominated by interannual SLA forced by the interior BoB. The LCS model also shows that positive interannual SLA during summertime La Niña years of 2010, 2011, and 2016 are significantly dominated by remote forcing from both the interior BoB and EIO via constructive interference. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Satellite altimeter, Interannual sea level anomaly, Western boundary of Bay of Bengal, Linear wind-driven model, La Niña |
| For Awards | no |