The American space agency NASA is gearing up to test a new way to measure the effects of climate change. They are doing so by strapping metallic headgear to seals in waters around Antarctica. The project can also provide for research in deep-sea currents that can help scientists draw a clear and expansive picture of fluctuating climatic patterns.
Equipped with a specialised sensor reminiscent of a small hat, the seal can go deep into the ocean and swim through large tracts of water to lend a view of life at the antipodes of our planet. Such a technique can save on expensive equipment like deep-sea drones or hi-tech underwater cameras and submarines. The seal’s interaction with the aquatic environment can increase the quality of data generated.
Seals often dive down even further than whales in their pursuit of the fish and squid that they eat. In fact, elephant seals native to waters around the Antarctic, which are being used by NASA and their associated scientists, have been known to dive as deep as 7,000 feet down. As the aim of the scientists is to get a decent idea of what is happening in the intensely cold waters of the Antarctic Circumpolar Current, which is responsible for regulating temperature across the whole of the southern hemisphere, the best way to go about it is to capture a seal.
Lia Siegelman, a visiting scientist at NASA’s Jet Propulsion Laboratory in California, has been using seals to gather oceanic data. A tagged seal swam more than 4,800 km on a three-month voyage, much of it through the turbulent, eddy-rich waters of the Antarctic Circumpolar Current. The seal made around 80 dives at depths ranging from 500 to 1,000 metres per day during this time. All the while, it collected a continuous stream of data that has provided new insight into how heat moves vertically between ocean layers in this volatile region — insight that brings scientists one step closer to understanding how much heat from the Sun the ocean there is able to absorb. They also tracked her movements with a satellite.
(This 3D schematic shows how a tagged elephant seal collects data by swimming long distances and diving to great depths through turbulent waters near Antarctica. Satellite data are used to identify characteristics of the waters through which the seals swim. The blue represents cold, dense water; the red areas are less dense and typically warmer.)
New model for better studying of climate patterns
Lia Siegelman, said, “I hope this will encourage physicists and biologists to use those very rich data from seals.” She added that the seal experiment had changed the team’s understanding of what’s going on with our deep-sea temperature.
Siegelman continued, “Most current modelling studies indicate that the heat would move from the surface to the ocean interior in these cases, but with the new observational data provided by the seal, we found that that’s not the case. This could be an important implication for our climate and the ocean’s role in offsetting the effects of global warming by absorbing most of the heat.”
Although their results are significant, Siegelman says more research is needed to fully understand and quantify the long-term effects these fronts may have on the global ocean and our climate system.
(With inputs from agencies)