As the Arctic sea ice continues to melt, an initiative led by the Woods Hole Oceanographic Institution is trying to predict out future changes to the Arctic and how this will affect the environment.
In 2004, John Toole and his research team at Woods Hole Oceanic Institute (WHOI) developed a new way to measure changes in the Arctic as part of the Arctic Observing Network, an international collaboration of scientists studying the Arctic polar climate and ecosystem. Computer models suggest significant impacts in this region will occur in the next few years, and it is of great concern to scientists to know how these shifts will affect ocean stratification and circulation, ecosystems, and global weather patterns.
“The Earth’s climate system is changing in response to the increase of carbon levels in the atmosphere. Computer models seem to suggest in the next 100 years or earlier, say by mid-century, the ice cover of the Arctic may disappear mid-summer each year, and some models suggests once it begins to disappear, it could go very quickly, perhaps over the course of ten years,” says Toole. “The Arctic may function more like the Antarctic in the future with a highly seasonal ice cover – little in mid-late summer, and a broad, thin coverage in winter.”
The instruments Toole’s research team developed, known as Ice-Tethered Profilers (ITPs), measure seawater properties in the Arctic daily and send those data back to WHOI. Autonomous profiling instruments actually date back to the 1970s. However, engineers at WHOI were able to design a new model with greater endurance and depth capability. This new model consists of a foam buoy float that sits atop the sea ice and supports a wire rope tether extending down into the ocean, with an underwater vehicle that profiles along the wire.
The ITP is important given that it is nearly impossible to collect data over long periods of time in an environment such as the Arctic.
“To be able to get sustained measurements over time you need to have autonomous measurements rather than having a person standing there to take the measurements. Most likely if you place a profiler there you will not receive it back, so it is important to get data in real time through satellites,” Toole explains.
Toole and his research team study data from approximately 60 Arctic profilers deployed since the program began, with individual units surviving anywhere from a few months to several years (ITPs are often lost during ice convergence events, or when units are dragged into shallow water by their supporting ice floe). Real-time data from the profilers are collected via satellite, routed through servers based at WHOI, and then made immediately available to researchers and the public on WHOI’s Web site. Toole’s team collaborates with fellow researchers from institutions across North America, Europe, and Asia.
Toole says that, so far, their data suggests that the Arctic Ocean is reflecting a greater concentration of freshwater now than in previous decades. This buoyant cap of relatively fresh water is influencing the Arctic now, and has the potential to flow south to impact the deep convection sites of the sub-polar North Atlantic. In this region, it could possibly alter the ocean’s overturning circulation and mid-latitude climate. Such epic transformations in the Arctic represent significant environmental, cultural, economic, and geo-political impacts, and could alter the fate of local communities, habitats, and the global climate.
Check back for Sierra Club Green Home’s follow up discussion with Toole and his research team about implications for these observed changes in the Arctic, the challenges the team faces in their expeditions to the Arctic to deploy the instruments, and what the future may hold for the Arctic.
A video interview with Senior Scientist John Toole discussing the ITP program can be viewed on WHOI’s Web site.