Larry D. Hinzman University of Alaska Fairbanks Amanda Lynch University of Colorado Kenji Yoshikawa University of Alaska Fairbanks William Gutowski Iowa State University Philip Marsh National Hydrologic Research Center John Cassano University of Colorado Douglas L. Kane University of Alaska Fairbanks Matt A. Nolan University of Alaska Fairbanks Yuji Kodama Hokkaido University Richard Janowicz Indian and Northern Affairs Detection and attribution of changes in the hydrologic regimes of the Mackenzie, the Kuparuk and the Lena River Basins

The objectives of this research are to detect and document changes in the storage of freshwater in the Arctic regions of the Western Canadian, Alaskan, and Eastern Siberian Arctic, to ascribe those changes to their land cover or climate source, and assess the impacts of past and future variations in storage components on freshwater inputs into the Arctic Ocean. We intend to characterize the changing hydrologic regime spatially to facilitate accurate projections of future hydrologic conditions and to develop a numerical modeling capability that 1) accurately captures contemporary climatic and hydrologic dynamics, 2) projects reasonably accurate responses to future scenarios and 3) incorporates well documented algorithms that will be distributed to other modeling groups wishing to include dynamic land surface processes in arctic regions.

Objectives: - document changes in the storage of terrestrial freshwater in the Arctic regions of the Western Canada, Alaska, and Eastern Siberia - attribute the cause of those changes - accurately project future hydrologic conditions by validating and applying several spatially- distributed numerical models of atmosphere and surface hydrology - assess the impacts of past and possible future variations

Atmospheric Modeling with the pan-Arctic MM5 Pan-Arctic MM5 (PAM) –We will use an atmospheric model with Arctic specific physics –Includes NOAH land surface model Used in NCEP climate and weather prediction models Predicts soil moisture, soil and skin temperature, snowpack depth, snow water equivalent, and heat and moisture fluxes Includes explicit treatment of frozen ground –Polar specific model physics for clouds, turbulence, and sea ice Atmospheric physics from the Polar MM5 –Horizontal resolution of km Pan-Arctic and SHEBA domains - 50 km Mackenzie, Kuparuk, and Lena watersheds - 30 and 10 km

Atmospheric Modeling Lena Model Domain Mackenzie and Kuparuk Domains Smaller watershed domains –Indicated with red boxes in these plots –10 km horizontal resolution –Provide atmospheric forcing data for detailed hydrologic modeling with TopoFlow Large watershed domains –Mackenzie, Kuparuk, and Lena watersheds –30 km horizontal resolution

Atmospheric Modeling Initial Simulations –Sept Sept 1998 (SHEBA year) Increased data for model validation –Coordinated with ARCMIP International model intercomparison project Purpose of simulations –Model validation with a focus on: Snow cover Surface fluxes Atmospheric circulation SHEBA Domain Pan-Arctic Domain

Trail Valley Creek, NWT

Trail Valley Creek 63 Km 2 Tania Creek 8 Km 2 Wolf Creek 195 Km 2 Caribou-Poker Creeks 104 Km 2

Kuparuk River Watershed 8000 Km 2

Hulahula River Konngakut River McCall Glacier