Intense storms sweeping across the Southern Ocean are enabling this vast body of water to absorb more atmospheric heat than previously understood. New research from the University of Gothenburg reveals that current climate models may significantly underestimate the effect of these storms, potentially skewing future climate projections.
The Southern Ocean, encircling the Antarctic continent, is a critical player in regulating Earth’s climate. It acts as a global climate moderator by distributing heat, carbon, and nutrients across the world’s oceans. Notably, it absorbs over 75 percent of the excess heat generated by human activities, making its role in mitigating climate change indispensable.
Storms Enhance Heat Absorption
According to a study published in Nature Geoscience, researchers have identified that storms are pivotal in determining how effectively the Southern Ocean exchanges heat with the atmosphere. The study highlights that intense winds associated with these storms churn the ocean, bringing colder deep waters to the surface and pushing warmer surface waters downward. This process results in cooler surface temperatures, allowing the ocean to absorb more atmospheric heat.
“Our research shows that summers with stronger storm activity generate lower surface temperatures across the Southern Ocean. Hence, a stormy ocean can absorb more heat from the atmosphere than in calm weather,” explains Marcel du Plessis, a researcher in oceanography at the University of Gothenburg and the study’s lead author.
Implications for Climate Models
The findings carry significant implications for climate models, which are essential tools for policymakers. Current models tend to underestimate the strength and impact of Southern Ocean storms, leading to projections of an overly warm ocean.
“That is why our findings are important, because a better representation of storm processes is essential for more accurate future climate projections,” says Marcel du Plessis.
The research team utilized advanced autonomous underwater and surface robots to measure ocean temperature, salinity, and atmospheric conditions. These observations were combined with multi-year model and satellite data to unravel the complex interactions between storms and ocean heat exchange.
Historical Context and Future Research
The study is groundbreaking in its ability to link Southern Ocean storms to changes in ocean warming and climate variability over the past two decades. This understanding is crucial for predicting future climate patterns.
“This is the first time we can clearly link Southern Ocean storms to changes in ocean warming and our climate variability over the past 20 years,” notes Sebastiaan Swart, Professor of Oceanography at the University of Gothenburg. “Such results mean we can better understand how the ocean is warming today and thereby predict how our Earth’s climate may change in the future.”
While the impact of storms is most pronounced during the Antarctic summer, different processes occur in the winter, presenting a new frontier for researchers to explore. Understanding these seasonal variations will be the next challenge in comprehending the Southern Ocean’s role in climate dynamics.
Looking Ahead
The research underscores the importance of accurately representing storm processes in climate models to improve the reliability of climate projections. As the world grapples with the impacts of climate change, understanding the mechanisms that regulate Earth’s climate becomes increasingly critical.
Future research will focus on winter storm processes and their implications for ocean heat uptake. As scientists continue to unravel the complexities of the Southern Ocean, their findings will be vital for shaping global climate policy and strategies for mitigating climate change.
