U.S. Fish and Wildlife Service | WildREACH Workshop Abstracts

U.S. Fish and Wildlife Service - WildREACH Workshop

Measurements and Modeling of Soil Water Distributions in Time and Space, Barrow, Alaska

Anna Liljedahl¹, Larry Hinzman², Sergei Marchenko³, Svetlana Berezovskaya⁴, Robert Busey⁵, Robert Busey^6
1International Arctic Research Center, University of Alaska, Fairbanks, PO Box 757340, Fairbanks, AK, 99775, USA, Phone 9074741951, ftakl@uaf.edu
²International Arctic Research Center, University of Alaska, Fairbanks, PO Box 757340, Fairbanks, AK, 99775, USA, Phone 9074747331, lhinzman@iarc.uaf.edu
³Geophysical Institute, University of Alaska, Fairbanks, 903 Koyukuk Dr., Fairbanks, AK, 99775, USA, Phone 9074747698, ffssm1@uaf.edu
⁴Water and Environmental Researh Center, University of Alaska, Fairbanks, PO Box 755860, Fairbanks, AK, 99775, USA, Phone 9074742714, sveta.berezovskaya@uaf.edu
⁵International Arctic Research Center, University of Alaska, Fairbanks, PO Box 757340, Fairbanks, AK, 99775, USA, Phone 9074742792, fnrcb1@uaf.edu
⁶International Arctic Research Center, University of Alaska, Fairbanks, PO Box 757340, Fairbanks, AK, 99775, USA, Phone 9074742792, fnrcb1@uaf.edu

Soil moisture is tightly linked to several biological and physical processes. Soil moisture varies drastically on a micro-scale (<1 m) especially in a polygonal landscape, while many coupled models today work on a regional scale (>1 km). We examine fine-scale spatial resolution of soil moisture and temperatures through field measurements and modeling with the larger goal of projecting future soil moisture distribution at the coast of northern Alaska. Here, we present measured variations in soil temperature, snow depth and soil moisture and compare model simulations of snow cover and soil temperatures to field measurements. During a single year, we found spatial variations in ground surface temperatures across one polygon measuring up to 12°C in winter time and even larger in summer time. By combining a blowing snow model (SnowModel) and an analytical soil thermal regime model (GIPL 1.1) we successfully simulated spatial features across the polygon, but overall values were slightly underestimated. In the near future, we will use output from the two models in a hydrological model to simulate sub-meter scale soil water distributions. The hydrological model, TopoFlow, will be validated against field measurements and later used as a tool to project future scenarios of today’s wetlands at the coastal Arctic region. The low hydraulic gradients, limited hydraulic storage capacity, short summers and efficient recharge of soil during snowmelt maintain the extensive wetlands currently seen in the Arctic. With a topography mainly defined by polygons over ice-rich permafrost, changes occurring at the micro-scale may have implications on the wide-spread persistence of Arctic wetlands.