Key Considerations in Linking Permafrost, Ecosystems and Run-off William J. Gutowski, Jr. Dept. of Geological & Atmospheric Sciences Iowa State University Readiness of Existing Models for Coupling Land-Atmosphere Water & Energy Cycles

Complexity of Arctic terrain 1.A range of “permanent” land surface types (forest, tundra, wetlands, glaciers) 2.Seasonal variation: snow cover, freeze/thaw of soil and water bodies 3.Mix of hydrological landscapes (unorganized flow  major rivers)

Are the fluxes (couplings) well modeled? Ecosystems Permafrost Surface Water (snow cover, albedo) (ponding, wet soil) (water availability, nutrients) Atmosphere

Issue: Resolution of Observations Borehole Locations

Issue: Horizontal Resolution of Model Borehole Locations ~ 0.5˚ grid Great Bear Lake Mackenzie River

Issue: Vertical Resolution of Model Active Layer Depth Over Permafrost (31 stations in Siberia; Frauenfeld et al., 2004)

Issue: Vertical Resolution of Model Active Layer Depth Over Permafrost (31 stations in Siberia; Frauenfeld et al., 2004) 10 cm 40 cm 100 cm 200 cm NOAH LSM (Chen and Dudhia, 2001)

Issue: Standard Landcover Types 1) Broadleaf-evergreen trees 2) Broadleaf-deciduous trees 3) Broadleaf and needleleaf trees 4) Needleleaf-evergreen trees 5) Needleleaf-deciduous trees (larch) 6) Broadleaf trees with groundcover 7) Groundcover only 8) Broadleaf shrubs with groundcover 9) Broadleaf shrubs with bare soil 10) Dwarf trees/shrubs with groundcover (tundra) 11) Bare soil 12) Cultivations 13) Wetland 14) Dry coastal complex 15) Water 16) Glacial Sufficient Detail? Both specified as “12) Cultivations”  Need “Data Rich” Approach

Further Challenges to Modeling Movement of water and heat in frozen soilMovement of water and heat in frozen soil Runoff sensitivity to presence/absence of permafrostRunoff sensitivity to presence/absence of permafrost Annual cycle of river ice Annual cycle of river ice Change in landscape structure (e.g., slumping with permafrost decline) Change in landscape structure (e.g., slumping with permafrost decline) Change in wetlands (slow, disorganized flow) Change in wetlands (slow, disorganized flow) Ecosystem evolution as permafrost and runoff change (dynamic vegetation modeling) Ecosystem evolution as permafrost and runoff change (dynamic vegetation modeling) Permafrost evolution as ecosystems change Permafrost evolution as ecosystems change

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