As early as 2014, scientists captured images from space of a massive pool of bright blue meltwater, dotted with icebergs, sitting atop a glacier in Alaska. The concerning news is that as the planet warms, such "melt ponds" are becoming increasingly common in the Arctic, significantly accelerating the rate of ice loss in the region, reports Live Science.
This striking melt pond is scattered with hundreds of tiny icebergs and measures about 700 meters in width at its broadest point. The vivid blue color of the pool gives the impression of great depth; however, scientists believe this is merely an illusion. A 2022 study revealed that the average depth of such melt ponds is approximately 22 centimeters. Nonetheless, the exact depth of the pond in the photograph remains unknown.
The icy lagoon was discovered and recorded by the Multiple Altimeter Beam Experimental Lidar (MABEL) on board NASA's ER-2 aircraft—a specialized research plane capable of flying twice as high as commercial flights. The aircraft surveyed the area as part of a broader study of melt ponds in the Arctic and captured hundreds of similar photographs. However, this pond was one of the largest identified by the researchers.
Melt ponds are known to form in late spring and early summer when the heat causes snow to melt, resulting in water pooling in depressions. Scientists note that these features have always existed in the Arctic, but have become significantly more prevalent in recent years. The increase in their numbers is believed to be linked to climate change driven by human activity.
Researchers are also concerned about the rise of melt ponds in the Arctic, as the dark blue "puddles" absorb substantially more sunlight than snow and ice. Consequently, the ponds warm up more quickly, leading to increased melting of the surrounding ice. This "positive feedback" could ultimately trigger an uncontrollable reaction, where the rate of melting accelerates exponentially.
Scientists have concluded that the number of melt ponds that appear each summer serves as a good predictor of the minimum extent of Arctic sea ice for the year. However, despite the importance of monitoring these melt ponds, some researchers argue that we still do not understand them sufficiently to make such predictions.
In a 2023 article, a group of scientists claimed that observations of melt ponds in the Arctic are quite limited, making it difficult to forecast their impacts and understand their role in accelerating ice melt in the region. Unfortunately, this increases uncertainty regarding the role of melt ponds in the climate crisis. Nevertheless, scientists agree that these gaps can be filled by enhancing aerial observations of the Arctic.