HR: 1340h
AN: GC23A-0987    [Abstracts]
TI: Study of permafrost dynamics within the Northern Eurasia Region by a coupling between permafrost and water balance models
AU: * Nicolsky, D J
EM: ftdjn@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AU: Romanovsky, V E
EM: ffver@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AU: Rawlins, M A
EM: rawlins@eos.sr.unh.edu
AF: Water Systems Analysis Group, University of New Hampshire, Morse Hall, University of New Hampshire, Durham, NH 03824, United States
AU: Marchenko, S S
EM: ffssm1@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AB: Thawing and freezing of Arctic soils is affected by many factors, with air temperature, vegetation, snow accumulation, and soil moisture among the most significant. Here we describe the coupling of a Permafrost Model and the pan-Arctic Water Balance Model (PWBM), developed at the University of Alaska Fairbanks and the University of New Hampshire, respectively. Additionally, we present resultant simulated soil temperature and moisture dynamics, depth of seasonal freezing and thawing, river run-off and water storage across the Northern Eurasia Region. The coupled models simulate the snow/ground temperature with a 5-layer snow and 23-layer soil model. In the soil model the layers thicken with depth and span a 60 meter thick column. The PWBM has two soil storage zones; a root zone that gains water from infiltration and loses water via evapotranspiration and horizontal and vertical drainage, and a deep zone that gains water via root zone vertical drainage and loses water via horizontal drainage. Forcing data (i.e. air temperature, precipitation) are taken from ERA40. We validate our model simulations by comparing soil moisture and thermal profiles with observational data collected within the Northern Eurasia Region. The coupling captures thresholds and non-linear feedback processes induced by changes in hydrology and sub- surface temperature dynamics, and hence helps us to study the spatial and temporal variability of permafrost dynamics as well as potential future alterations to permafrost and the terrestrial arctic water cycle. Through explicit coupling of the Permafrost Model with the PWBM we are able to simulate the temporal and spatial variability in soil water/ice content, active layer thickness, and associated large-scale hydrology that are driven by contemporary and future climate variability and change.
DE: 0702 Permafrost (0475)
DE: 0704 Seasonally frozen ground
DE: 0798 Modeling
DE: 1847 Modeling
DE: 1876 Water budgets
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting