The Impact of Seamounts on Ocean Circulation and Global Climate

The world’s oceans are vast and complex systems that play a crucial role in regulating our planet’s climate. Recent research conducted by an international team led by the University of Cambridge has shed light on the importance of undersea mountains, known as seamounts, in influencing ocean circulation and mixing. This groundbreaking study has significant implications for our understanding of how the ocean stores heat and carbon, and how it may respond to global warming in the future.

Undersea Mountains: Nature’s Turbulent Giants

Seamounts are colossal underwater mountains that can reach heights of thousands of meters. These geological formations disrupt deep-sea currents, creating intense turbulence around them. This turbulence serves as a major contributor to ocean mixing on a global scale, a process that has been largely missing from current climate models used in policymaking. Dr. Ali Mashayek, the lead researcher of the study, emphasized the importance of incorporating seamount-induced turbulence into climate models to improve our forecasts of how the ocean will respond to climate change.

The ocean is like a massive conveyor belt, with warm water from the tropics slowly moving towards the poles, where it cools, sinks, and takes with it stored carbon, heat, and nutrients. The return flow of cold, heavy water to the surface is essential to maintain the ocean’s circulation. Seamounts act as obstacles that stir up the ocean, pulling deep and heavy water towards the surface. This process helps complete the circuit of ocean circulation, keeping the global ocean currents flowing.

The research findings indicate that seamounts contribute significantly to ocean mixing globally, with an estimated one-third of ocean mixing attributed to the turbulence around these underwater mountains. In the Pacific Ocean, where seamounts are more abundant, the contribution to ocean mixing is even higher at around 40%. The Pacific Ocean is the largest store of heat and carbon, making the role of seamounts in this region particularly critical. By enhancing mixing, seamounts may shorten the timescale of carbon storage, potentially accelerating climate change.

The study’s results support the idea that seamounts could be the “stirring rods of the ocean,” as proposed by oceanographer Walter Munk in the 1960s. Incorporating the physics of seamount-induced turbulence into climate models will be crucial for improving our understanding of how climate change could impact the ocean’s carbon and heat storage. By integrating this new knowledge into climate models, researchers hope to provide more accurate forecasts of the ocean’s response to ongoing environmental changes. Dr. Mashayek and his team are optimistic that this research brings us a step closer to a more realistic representation of deep ocean circulation and its role in global climate dynamics.

The study highlights the critical importance of seamounts in shaping ocean circulation and mixing processes. These undersea mountains, with their turbulent wake vortices, play a significant role in driving the global ocean currents and influencing how the ocean stores heat and carbon. By integrating the effects of seamount-induced turbulence into climate models, we can improve our predictions of how the ocean will respond to climate change and mitigate its potential impacts on our planet’s climate system.