We Know the Arctic is Warming -- What Will Changing River Flows do to its Environment?

Scientists at the University of Massachusetts Amherst recently combined satellite data, field observations and sophisticated numerical modeling to paint a picture of how 22.45 million square kilometers of the Arctic will change over the next 80 years. As expected, the overall region will be warmer and wetter, but the details—up to 25% more runoff, 30% more subsurface runoff and a progressively drier southern Arctic, provides one of the clearest views yet of how the landscape will respond to climate change. The results were published in the journal The Cryosphere.

The Arctic is defined by the presence of permafrost—the permanently frozen layer on or under the Earth’s surface. It’s that permafrost that drives everything from seasonal runoff to the freshwater dumping into coastal lagoons to the amounts of soil carbon that wind up flowing into the ocean. But the Arctic is warming two-and-a-half to four times faster than the global average, which means that massive amounts of carbon-rich soils in permafrost regions are thawing, releasing their carbon to rivers and the atmosphere every year. The thawing is also intensifying the Arctic’s water cycle—the continuous loop of precipitation, runoff and evaporation that, in part, determines a region’s environment.

The upper part of the permafrost that thaws each summer is called the active layer, and it has been of particular interest to Michael Rawlins, associate professor in the Department of Earth, Geographic and Climate Sciences at UMass Amherst and the paper’s lead author. As the Arctic warms, the active layer is getting thicker, and Rawlins wanted to know how that thickening, combined with warming and an intensified water cycle, would affect the terrestrial Arctic environment.

Read more at: University of Massachusetts - Amherst

Mike Rawlins collecting data on Arctic streams. (Photo Credit: UMass Amherst)