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Key Points in Linking Dynamic Ecosystem Models with Permafrost and Hydrology Models

Key Points in Linking Dynamic Ecosystem Models with Permafrost and Hydrology Models. A. David McGuire (UAF), Eugenie Euskirchen (UAF), and Shuhua Yi (UAF). Arctic System Model Workshop, August 6 and 7, 2007. Interactions of Northern High Latitude Terrestrial Regions with

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Key Points in Linking Dynamic Ecosystem Models with Permafrost and Hydrology Models

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  1. Key Points in Linking Dynamic Ecosystem Models with Permafrost and Hydrology Models A. David McGuire (UAF), Eugenie Euskirchen (UAF), and Shuhua Yi (UAF) Arctic System Model Workshop, August 6 and 7, 2007

  2. Interactions of Northern High Latitude Terrestrial Regions with the Earth’s Climate System Regional Climate Global Climate Exchange of carbon-based greenhouse gases (CO2 and CH4) Delivery of freshwater to Arctic Ocean Water and energy exchange Impacts Northern High Latitude Terrestrial Regions

  3. Snow cover 12, 13 5, 6, 7 I III 10, 11 V 16 1, 2, 3, 4 8, 9 Climate warming A   Physiology Structure      composition, vegetation shifts enzymes, stomates 14 15 CO2, SH B II Physiological feedbacks: (1) higher decomposition CO2 (2) reduced transpiration SH (3) drought stress: CO2 (4) PF melting: CH4 (5) longer production period: CO2 (6) NPP response to N min: CO2 (7) NPP response to T: CO2 IV Disturbance fire, insects C E Land Use Permafrost warming, thawing logging, drainage, reindeer herding Response time D Structural feedbacks: (8) shrub expansion:  (9) treeline advance: , CO2 (10) forest degradation but CO2, SH (11) light to dark taiga:  but CO2, SH (12) more deciduous forest: , SH (13) fire / treeline retreat:  fast (seconds to months) intermediate (months to years) slow (years to decades) Biotic control Physical feedbacks Mediating processes Physical feedbacks: (14) increased, then reduced heat sinkGH,SH (15) watershed drainage SH (16) earlier snowmelt • Mechanisms: • : albedo GH: ground heat flux • SH: sensible heat flux • CO2, CH4: atmospheric concentration From McGuire, Chapin, Walsh, and Wirth. 2006. Integrated regional changes in arctic climate feedbacks: Implications for the global climate system. Annual Review of Environment and Resources 31:61-91.

  4. Terrestrial Research Focus Areas at IARC • Physical Feedbacks Involving Permafrost Responses • Feedbacks Involving Carbon and Water Responses • Feedbacks Involving Snow Responses • Feedbacks Involving Responses of Vegetation • Composition and Structure

  5. Coupled Climate-Carbon Cycle Model Intercomparison (C4MIP) Biospheric Carbon-Climate Feedback Atm. CO2 difference (ppm) 20 - 220 ppm Up to +1.5°C • All soils treated as mineral soils • No C-hydrology dynamics in peatlands • No C-thawing dynamics in permafrost • No Nitrogen-Phosphorus limitations • Most models don’t have fire • Most don’t have vegetation dynamics Friedlingstein et al. 2006; IPCC SRES 2000

  6. Feedbacks Involving Carbon and • Water Cycle Responses • Some Key Issues: • - vulnerability to fire and permafrost thaw • - delivery of carbon from high latitude terrestrial • ecosystems to marine environments • - dynamic simulation of wetlands

  7. Vulnerability to CO2 and CH4 releaseZhuang et al. 2006. Geophysical Research Letters. • Permafrost thawing (MIT IGSM Scenarios) • Fire disturbance increase(~1% yr-1)

  8. Methane Consumption and Emission Module (MCEM) Hydrological Module (HM) Water Table and Soil Moisture Profile Soil Thermal Module (STM) Soil Temperature Profile Active Layer Depth 40 35 20 10 0 –1 Terrestrial Ecosystem Model (TEM) Source Sink Labile carbon Vegetation Characteristics (g CH4 m-2 year-1)

  9. Soil temperature Vegetation type;Snow pack; Soil moisture Terrestrial Ecosystem Model (TEM) couples biogeochemistry and soil thermal dynamics

  10. Snow Moss Moss growth Fire disturbance Moisture update Temperature update Peat Mineral Thawing front

  11. Decadal patterns of simulated soil temperature in top 10 cm of of mineral soil in black spruce forests of interior Alaska for Different topographic positions (Yi, McGuire, and Kasischke). Field observations and modeling have shown that permafrost in black spruce stands on different topographic positions have been warming since the mid-1960s, which means that over this time period, deeper duff layers in black spruce forests have become warmer and drier.

  12. 34 cm Control of depth to permafrost and soil temperature by the forest floor in Black spruce/Feathermoss Communities C.T. Dyrness 1982 USDA, Forest Service, Pacific Northwest Forest and Range Experiment Station, Research Note: PNW-396 28 cm 25 cm 12 cm Site: Washington Creek Fire Ecology Experimental Area, north of Fairbanks 0 cm

  13. Effects of Org Thickness onactive layer depth (S. Yi) 0 cm : moss 0 cm : peat 6 cm : moss 14 cm : peat 0 cm : moss 14 cm : peat 0 cm : moss 9 cm : peat Thawing front Freezing front DFCC site

  14. Kougarok burn site (k2) • Biome: Tussock Tundra • Lat: 65.25 oN • Lon: 164.38 oW • Elev: 110 m • Aspect: south • Slope: 3 o • Fire History: 1971, 2002

  15. K2 soil profiles After Fire • Upper organic layer • Thick : 0 cm • Porosity : 90 • Lower organic layer • Thick: 5 cm • Porosity : 80 • Mineral • Sand :20, Silt: 58, Clay :22 Before Fire • Upper organic layer • Thick : 4 cm • Porosity : 90 • Lower organic layer • Thick: 10 cm • Porosity : 80 • Mineral • Sand :20, Silt: 58, Clay :22 Run from 1901 to 2006. The initial soil structure uses the one before fire. At July 2002, top two organic layers are removed, and only 5 cm organic layer is left. No other changes have been made at fire event.

  16. Soil Temperature Simulation fire X-axis: doy Y-axis: temperature (degc)

  17. Soil Moisture Simulation --surface fire X-axis: doy Y-axis: soil wetness (%)

  18. Soil Moisture Simulation --shallow layer fire X-axis: doy Y-axis: soil wetness (%)

  19. Soil Moisture Simulation --deep layer fire X-axis: doy Y-axis: soil wetness (%)

  20. Implementation of fire disturbance Slope Aspect Elevation Moss Burn depth Soil temperature Moisture Active layer depth Peat Other issues affecting burn depth Mineral Thawing front

  21. Implementation of moss growth and organic matter conversion Vegetation biomass Moss biomass Moss thickness above below live dead fibric mesic humic mineral

  22. Observations and model predictions at the Alaska-Canada scale, 1960-2005 (R2 = 0.82 (p<0.0001) for period 1960-2002)

  23. Delivery of Carbon to Marine Environments Shaded area = Modified TEM CO2 (g) CO2 (g) fire GPP abvR soilR Soil Inorganic Carbon Vegetation Chemical Weathering rootR HCO3- CO3-2 CO2(g) CO2(aq) harvest Soil Organic Matter RH leachCO2 leachALK evadeCO2 CO2 (g) CO2(aq) Alkalinity POC erodePOC leachDOC DOC Stream Export

  24. Comparison of TEM Estimated DOC Leaching Rates during the 1990s to Measured DOC Export from Arctic Rivers *includes rivers draining directly into the Arctic Ocean, the Arctic Archipeligo, Hudson Bay, and the Bering strait D. Kicklighter, J. Melillo, and A.D. McGuire

  25. Dynamic simulation of wetlands in the Yukon River Drainage Basin using a TOPMODEL approach Depth to water table (DTW) (m) of 1990’s July M. Stieglitz, D. Kicklighter, J. Melillo, and A.D. McGuire

  26. Feedbacks Involving Snow Responses • Retrospective Studies of Carbon and Energy Feedbacks • Vulnerability of Climate System to Changes in Snow

  27. -Examine patterns in snowmelt, snow return, and the duration of the snow free season as they impact atmospheric heating -Perform analyses for the 1910 –1940 and 1970 - 2000 time periods over the arctic-boreal land area above 50º N at a half-degree latitude by longitude spatial resolution E. Euskirchen and A.D. McGuire

  28. Between 1970 -2000, the number of days of snow covered ground decreased by an estimated 2.5 days per decade across the pan-Arctic. Change in the duration of snow covered ground (anomaly): Days per year shorter Days per year longer <- 0.4 -0.4 - -0.3 -0.3 - -0.2 -0.2 - -0.05 -0.05 - 0.01 0.01 - 0.1 >0.1 1970 -2000 From Euskirchen et al. in press.

  29. Changes in atmospheric heating due to changes in the snow season, 1970-2000 -0.25 - -3 3 - 5 0.1 - -0.1 -1 - -0.25 2 - 3 0.5 - 1 0.25 - 0.5 0.1- 0.25 1 - 2 Cooling Heating W m-2 decade-1 Across the pan-Arctic, an overall reduction in the duration of snow covered ground by ~2.5 days per decade resulted in atmospheric heating of ~1.0 W m-2 per decade. 1970 -2000 • Heating magnified in 1970-2000 period • Spring more important than autumn • Tundra important (high albedo contrast) From Euskirchen et al. in press.

  30. Feedbacks Involving Responses of Vegetation Composition and Structure

  31. Energy budget feedbacks to regional summer climate • Feedbacks from vegetation change • Tussock to shrub transition: 3.9 W/m2 • Tussock to forest transition: 5.0 W/m2 • 2% change in solar constant: 4.6 W/m2 • (glacial to interglacial change) • Doubling atmospheric CO2: 4.4 W/m2 Chapin and McFadden

  32. Upper Boundary Conditions Soil Temps. at Different Depths Prescribed Temperature Heat balance surface Snow Cover Heat Conduction Snow Depth Moss Depth Organic Soil Depth Mineral Soil Depth Moss & litter Heat Conduction Frozen Ground Organic Soil Moving phase plane Thawed Ground Mineral Soil Prescribed Temperature Frozen Ground Lower boundary Lower Boundary Conditions Soil temperature Vegetation type;Snow pack; Soil moisture Soil thermal model coupled to TEM Multiple vegetation pools MVP – TEM includes leaf, wood, and root components Dynamic vegetation model E. Euskirchen and A.D. McGuire DVM - TEM

  33. Dynamic Vegetation Model coupled to the Terrestrial Ecosystem Model Changes in plant productivity between 2003 – 2100 in northern Alaska: Large variation among the plant functional types in the shrub tundra, represented with the error bars. 60 Boreal forest Shrub tundra Sedge tundra 40 20 0 Warming of 12°C (SRES A2 Scenario) Warming of 6°C (SRES B2 Scenario) Warming of 2°C (SRES B1 Scenario) E. Euskirchen and A.D. McGuire Mean (± standard deviation) percent change in plant net primary productivity between 2002 - 2100

  34. Estimated Cumulative Area Burned for Interior Alaska CRU A2 Hadley B2 Hadley A2 PCM B2 PCM Area Burned (km^2)

  35. A2 Hadley (Most Area Burned) Single Replicate 2000 2050 1950 black spruce white spruce deciduous

  36. Estimated Change in Summer Energy Budget CRU A2 Hadley B2 Hadley A2 PCM B2 PCM

  37. Changes in surface albedo in response to fire Grey line = Recent burn Black line = Control Liu et al., 2005

  38. Coupling of DVM-TEM with CCSM3.0 • Coupling of DVM/TEM and frozen soil/permafrost module within CCSM Mölders, Euskirchen, and McGuire

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