Hydrologic Modeling in the Far North: needs, challenges, and progress Hydrologic Modeling in the Far North: needs, challenges, and progress Jessica Cherry International Arctic Research Center (IARC) and Institute of Northern Engineering, University of Alaska Fairbanks (UAF) & Northern Science Services Bob Bolton, IARC and Scenarios Network for Alaska Planning (SNAP) at UAF Katrina Bennett, IARC Stephanie McAfee, SNAP Support Acknowledged from the JAMSTEC-IARC Cooperative Agreement, the U.S. Department of Energy, the Alaska Climate Science Center, and the National Science Foundation

Needs for Hydrologic Projection in Alaska Communities: many Alaskans live in environmentally sensitive communities, with tenuous water supplies, near rivers that are subject to flooding J. Cherry

Needs for Hydrologic Projection in Alaska Municipal, Rural, and Resource Land Managers: many agencies are increasingly accountable for anticipating future changes to their management areas. May or may not have the staff expertise to interpret and make use of projections.

Needs for Hydrologic Projection in Alaska Technical experts: such as engineers, scientists (including NOAA’s WFO/RFC) are potentially most aware of the model shortcomings, but are obligated to provide best available information for their end-users. J. Cherry

Challenges for Hydrologic Projection in Alaska Climate Change is most amplified in the Arctic Climate Models do a poor job of representing many cryospheric processes such as permafrost dynamics, glacial change, river ice, changes in subsurface water storage, etc The historical observations in this region are particularly sparse and short Our technology for measuring solid precipitation works poorly and changes are difficult to detect

Challenges for Hydrologic Projection in Alaska Roles of Empirical and Process-based Models: The latter may be particularly important for getting the mechanisms correct, i.e. getting projections right for the right reasons ‘Tipping points’ are significant in the Arctic The former may provide better short-term projections, as measured by prediction of historical events, because historical record may inadequately sample key mechanisms Doing both gives credibility to projections, esp. when true uncertainties are difficult to quantify

Progress in Hydrologic Projection in Alaska Three approaches highlighted here: Downscaled climate products and derived hydrologic fields Improvement of cryospheric components of process-based, empirical, and complex models Reducing uncertainty in observational record

Progress in Hydrologic Projection in Alaska: downscaled climate products and derived hydrologic fields Scenarios Network for Alaska and Arctic Planning: Statistically downscaled projections of temperature and precipitation for 5 IPCC models that perform best in Alaska available (AR4 done, AR5 in the works), 2km, 800 m, scenarios: B1, A1B, A2, Method: Delta using PRISM Gridded, downscaled historical data available, 2 km, 800 m Additional model parameters are being downscaled (wind) Parameters that are not directly (or poorly) represented in the climate models are being derived (PET, snowfall, vegetation, permafrost distributions, growing season, etc.) Selected periods of dynamical downscaling available from WRF runs

MODEL Δ ( minus ) OBS PET (Hamon) ENSEMBLE Figure: S. McAfee

MODEL Δ ( minus ) OBS P-PET (Hamon) ENSEMBLE Figure: S. McAfee

Progress in Hydrologic Projection in Alaska: improvement of cryospheric components Slide: B. Bolton

Spring snow melt period Growing season Autumn Timing, Magnitude and Pathways Slide: B. Bolton & J. Cable

Slide: B. Bolton & J. Cable

NWS River Forecast Center Hydrologic Modeling Framework: Flood Early Warning System/ Community Hydrologic Prediction System Progress in Hydrologic Projection in Alaska: Reducing uncertainty in observational record Slide: K. Bennett

MODIS Snow Cover Extent April 1 st, 2011 Slide: K. Bennett

MODIS Snow Cover Extent May 23 rd, 2011 Slide: K. Bennett

SNOW-17/ SAC-SMA - RFC SNOW-17, snow air temperature index model SACramento Soil Moisture Accounting model, medium complexity, conceptual water balance model, run in lumped mode Anderson, 2006 Burnash et al Burnash, 1976 Slide: K. Bennett

UAF-managed Total Precipitation ‘Hot Plate’ Sensor Network: alternative for environments where gauges perform poorly = potential future hot plate installations Bar AtqOlik Tlk Umt Fox ATQASUK BARROW Used for in situ studies and validation of models J. Cherry WRF model comparison = other IARC snow research sites w/o TPS Poker Flat Kougarok

~5 m/s ~10 m/s Images: J. Cherry, M. Itomlenskis (ARSC summer intern) X & Y Velocity fields MIT wind tunnel testing of ‘Hot Plate’, IR measurement, algorithm development, CFD modeling

J. Cherry

Digital Surface Models from Structure from Motion Algorithms

RECAP: Needs, Challenges, Progress in Hydrologic Projection in Alaska Progress highlighted here: Downscaled climate products and derived hydrologic fields Improvement of cryospheric components of process-based, empirical, and complex models Reducing uncertainty in observational record Challenges: Climate Change is most amplified in the Arctic Climate Models do a poor job of representing many cryospheric processes such as permafrost dynamics, glacial change, river ice, changes in subsurface water storage, etc The historical observations in this region are particularly sparse and short Our technology for measuring solid precipitation works poorly and changes are difficult to detect Needs highlighted here: Communities Municipal, Rural, and Resource Land Managers Technological Experts

Questions?

SPRING (April-May) SUMMER (June- July) AUTUMN (Aug-Sept) Priestley-Taylor ( __ ) Hamon (…) Figure: S. McAfee