Document Type
Article
Journal/Book Title/Conference
Geophysical Research Letters
Volume
45
Issue
15
Publisher
AGU
Publication Date
8-11-2018
First Page
7596
Last Page
7605
Abstract
Groundwater flow regimes in the seasonally thawed soils in areas of continuous permafrost are relatively unknown despite their potential role in delivering water, carbon, and nutrients to streams. Using numerical groundwater flow models informed by observations from a headwater catchment in arctic Alaska, United States, we identify several mechanisms that result in substantial surface‐subsurface water exchanges across the land surface during downslope transport and create a primary control on dissolved organic carbon loading to streams and rivers. The models indicate that surface water flowing downslope has a substantial groundwater component due to rapid surface‐subsurface exchanges across a range of hydrologic states, from unsaturated to flooded. Field‐based measurements corroborate the high groundwater contributions, and river dissolved organic carbon concentrations are similar to that of groundwater across large discharge ranges. The persistence of these groundwater contributions in arctic watersheds will influence carbon export to rivers as thaw depth increases in a warmer climate.
Recommended Citation
Neilson, B. T., Cardenas, M. B., O'Connor, M. T., Rasmussen, M. T., King, T. V., & Kling, G. W. (2018). Groundwater flow and exchange across the land surface explain carbon export patterns in continuous permafrost watersheds. Geophysical Research Letters, 45, 7596–7605. https://doi.org/10.1029/2018GL078140
