A new analysis of the changing character of runoff, river discharge and other hydrological cycle elements across the North Slope of Alaska reveals significant increases in the proportion of subsurface runoff and cold season discharge, changes the authors say are “consistent with warming and thawing permafrost.”
First author and lead climate modeler Michael Rawlins, associate professor of geosciences at the University of Massachusetts Amherst and associate director of its Climate Systems Research Center, says warming is expected to shift the Arctic from a surface water-dominated system to a groundwater-dominated system, with deeper water flow paths through newly thawed soils.
“Our model estimates of permafrost thaw are consistent with the notion that permafrost region ecosystems are shifting from a net sink to a net source of carbon,” he says.
Freshwater and riverborne nutrients, mainly dissolved organic carbon, are transported to coastal estuaries and lagoons that lie at the land-sea interface, he explains. Field measurements of river discharge and other hydrological cycle elements in this region are sparse, which requires a modeling approach to quantify the land-ocean flows and their changing character. Details of this investigation into Arctic watersheds between Utqiagvik (formerly Barrow) and just west of the Mackenzie River over the period 1981-2010 are in the current issue of the open access journal, The Cryosphere.
Read more at University of Massachusetts Amherst
Photo: A caribou atop cliff bluffs that are eroding into a coastal lagoon along the Beaufort Sea on the North Slope of Alaska. Photo courtesy: UMass Amherst/M. Rawlins