Crucial Role of Mixed-Layer in Tropical Atlantic Multidecadal Variability

Abstract: Atlantic Multidecadal Variability (AMV) has been associated with climate variations in many regions worldwide. However, the mechanisms driving the development of AMV remain unclear. Modelling studies reveal that global teleconnections from AMV are sensitive to how the tropical branch is represented. Nevertheless, there has been limited attention to understanding how decadal Sea Surface Temperature (SST) anomalies develop in this region. In this study, we present a quantitative examination of the generation of tropical AMV using SST restoring experiments. In contrast to the generally proposed mechanisms such as wind-flux-SST or cloud feedback, our research provides new insights into the dominant and crucial role of upper ocean dynamics, particularly regarding the mixed layer depth. Given the sensitivity of tropical AMV to global implications, accurately simulating upper ocean dynamics in coupled climate models becomes imperative.

Biography: Balaji Senapati is a Postdoctoral Research Scientist at the University of Reading. He did his PhD jointly supervised by Prof. Mihir Kumar Dash and Prof. Swadhin Kumar Behera (APL, JAMSTEC) at IIT Kharagpur, India. Balaji discovered a new ocean-atmosphere coupled wave in the Southern Hemisphere and worked extensively on its generation dynamics and impact during his PhD. Now, he primarily works on the dynamics of the tropical Atlantic Multidecadal Variability.