Deep within the vast oceans lie colossal undersea mountains called seamounts, reaching heights of thousands of meters. These seamounts play a crucial role in stirring up deep sea currents, which in turn influence how the ocean stores heat and carbon. An international team, led by the University of Cambridge, conducted a study using numerical modeling to delve into the significance of underwater turbulence around seamounts on ocean circulation.
The research findings shed light on the fact that the intense turbulence around seamounts is a major contributor to ocean mixing at a global scale. Surprisingly, this vital process is missing from the climate models commonly used in policymaking. Dr. Ali Mashayek from Cambridge’s Department of Earth Science, who spearheaded the study, emphasized the importance of incorporating seamount-induced turbulence into climate models to enhance the accuracy of forecasts regarding the ocean’s response to global warming.
The ocean is often likened to a massive giant conveyor belt, with warm water from the tropics gradually making its way towards the poles, where it eventually cools and descends deep into the ocean’s abyss. This process is essential for transporting stored carbon, heat, and nutrients. However, the return flow of cold, heavy water to the surface is a complex mechanism that has puzzled scientists for years. The study highlights how seamounts contribute to ocean circulation by aiding in this crucial process.
Seamounts, which are essentially underwater mountains, act as barriers for deep sea currents. As water flows over the steep slopes of seamounts, it generates spiraling wake vortices that propel water towards the surface. This turbulent flow around seamounts churns up the ocean, similar to stirring milk into coffee. The resulting mixing helps bring deep and heavy water to the surface, completing a cycle that sustains the ocean’s circulation.
While deep-sea turbulence around seamounts has been observed in the past, its significance in ocean circulation on a global scale was not fully understood until now. According to Dr. Mashayek and his team, the stirring around seamounts contributes to about a third of ocean mixing worldwide. This contribution is even more substantial, accounting for around 40%, in the Pacific Ocean due to the abundance of seamounts in that region. The Pacific Ocean, which stores a vast amount of heat and carbon, plays a critical role in global climate dynamics.
The study findings have important implications for understanding how seamounts impact ocean circulation and the storage of heat and carbon. By enhancing mixing, seamounts may influence the timescale of carbon storage in the ocean, potentially accelerating climate change. The research underscores the need to incorporate the physics of seamount-induced turbulence into climate models to improve predictions on the ocean’s response to climate change.
Moving forward, Dr. Mashayek and his colleagues plan to integrate the dynamics of seamount-induced turbulence into climate models. This crucial step will enable more accurate forecasts of how climate change could alter the ocean’s carbon and heat storage. By gaining a better understanding of deep ocean circulation, scientists can unravel how the ocean is adapting to the challenges posed by climate change. The study marks a significant advancement towards achieving a realistic representation of ocean dynamics in the face of a changing climate.
Leave a Reply