A groundbreaking study conducted by researchers at Brown University has shed new light on the intricate forces both above and below the surface of the ocean that are influencing the movement and dispersal of sea ice in the rapidly warming Arctic Ocean. As the region warms at double the rate of the global average, understanding these complex dynamics is crucial for predicting future climate patterns and comprehending the impacts of climate change. This in-depth analysis not only examines the influence of local tidal currents on ice movement but also reveals the significant role that the makeup of the sea floor plays in triggering sudden changes.
By leveraging data from the largest-ever drifting sea-ice buoy array and two decades of satellite images, the research team explored how sea ice moves as it drifts from the Arctic Ocean through the Fram Strait and ultimately into the Greenland Sea. The study highlights the profound impact of the sea floor on the most abrupt transformations experienced by the sea ice, such as rapid increases in speed and altered motion patterns that cause the ice to compress or disintegrate. These findings provide valuable information for improving computer simulations used to forecast Arctic sea ice conditions and furnish a deeper understanding of how climate change is reshaping the Arctic.
The Arctic region, the most rapidly warming area on Earth, has long been recognized for its crucial role in global climate dynamics. The sea ice in this region acts as a reflective surface, bouncing sunlight back into space and regulating the amount of energy absorbed by the Earth. As the ice continues to melt, more sunlight is absorbed, leading to further warming. Furthermore, the retreat of Arctic ice is expected to have far-reaching consequences for weather patterns across the Northern Hemisphere, potentially resulting in extreme cold spells, heatwaves, and devastating floods. Therefore, delving deeper into the processes shaping this vital ecosystem is of paramount importance.
To obtain the data required for this study, researchers embarked on the Multidisciplinary drifting Observatory for the Study of Arctic Climate, the largest polar expedition in history. This ambitious expedition involved teams of scientists spending a year drifting with the sea ice aboard a massive German icebreaker in the Arctic Ocean. This vast amount of data was instrumental in uncovering the intricate relationship between the sea floor and sea ice behavior. The expedition also involved the deployment of 214 buoys, 108 of which transmitted GPS data to track their drift from the central Arctic through the Fram Strait and into the Greenland Sea.
The main focus of this study was to examine the impact of marginal ice zones in the Greenland Sea and Fram Strait. These zones, located at the boundary between ice-free ocean and the pack ice of the central Arctic, experience unique interactions between ocean currents and sea ice. By analyzing satellite measurements collected from 2003 to 2020, the researchers were able to place the buoy data within a historical context, confirming the notable changes in ice velocity and motion that can only be explained by the influence of the sea floor. One observation was the sudden increase in ice speed northeast of Svalbard, Norway, even in the absence of wind changes. This unexpected acceleration was attributed to the presence of the Transpolar Drift Stream transitioning into the fast-moving East Greenland Current due to the interplay between Earth’s rotation and the continental shelf’s edge. Consequently, these findings demonstrate the sea ice’s response to different ocean currents and emphasize the significant role of the sea floor in shaping its behavior.
Moving forward, the research team aims to collaborate with model developers to integrate the insights gained from this study into forecasting models of sea ice movement and destination. By doing so, they hope to enhance the accuracy of predictions and further refine our understanding of the changing physics of ice in a warming Arctic. Additionally, they plan to develop an ice floe tracking tool that can monitor the motion of individual ice pieces, providing valuable details that are often overlooked using conventional approaches. Ultimately, this research contributes to our broader comprehension of the Arctic environment and its response to climate change.
The study was led by Daniel Watkins, a postdoctoral researcher at Brown University, with the collaboration of Monica Martinez Wilhelmus, an assistant professor of engineering and a senior author on the study. The team also included Angela C. Bliss from NASA’s Goddard Space Flight Center and Jennifer K. Hutchings from Oregon State University. By pooling their expertise, these researchers have made significant strides in unraveling the complex dynamics of Arctic sea ice, paving the way for a deeper understanding of climate change’s impact on this critical region.