| Abstract Submission No. | ABS-08-0037 |
| Title of Abstract | Contrasting sea level trends in the Arabian Sea and the Bay of Bengal using satellite altimetry |
| Authors | Kavita Krishnamurthy* |
| Organisation | Manipal Institute of Technology, MAHE |
| Address | Flat No. 5, D15 Urals CHS, Godrej Hill, Barave Road Kalyan (West), Maharashtra, India Pincode: 421301 E-mail: krishnamurthy.kavita@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Multidecadal sea level variations and the factors influencing the same in the North Indian Ocean and its sub-domains, the Arabian Sea and the Bay of Bengal, are analysed from 1993 to 2018 using satellite altimetry, ocean, and atmospheric numerical model datasets. In the Arabian Sea, sea level trends are negative from 1993 to 2003 (-1.3 mm/yr), positive from 2004 to 2014 (4.8 mm/yr), and higher from 2015 to 2020 (7.1 mm/yr). The Bay of Bengal Sea level trends remained positive from 1993 to 2003 (2.4 mm/yr), escalated from 2004 to 2014 (6.2 mm/yr), and dropped after 2015 till 2020 (-5.3 mm/yr). Steric sea level, prominently the thermosteric component, dominates total sea level anomalies, indicating thermal expansion as the main factor impacting sea level variations. Unlike the Bay of Bengal, halosteric sea level does not positively impact total sea level variability in the Arabian Sea. Ocean heat content and its rate of change in both basins agree with the sea level with a time lag, the latter being regulated by meridional heat transport across 9°N. Heat is lost from the Arabian Sea till 2001, beyond which it is retained, supporting sea level observations from thermal expansion. In the Bay of Bengal, positive heat transport anomalies show retention of heat from the beginning. Net surface heat fluxes play a minimum role in the total rate of change of heat content and are controlled by turbulent fluxes. Loss and retention of energy in both basins is further supported by increasing wind stress in both basins until 2000 and reduced variations thereafter. Basin stratification patterns explain the effect of wind stress and give grounds for further analysis of sea level variations in the Arabian Sea and the Bay of Bengal. |
| Keywords | sea level, heat content, Arabian Sea, Bay of Bengal, wind stress |
| For Awards | yes |