H111-0016
Testing an Implementation of WRF-Hydro for the Chena River (AK) watershed
Friday, 11 December 2020
Poster
Vladimir A Alexeev1, Alec P Bennett1, Aubrey L Dugger2, Katrina E Bennett3, Carl Dierking4, Jessica E Cherry5, David P Streubel6, Emily Niebuhr7, Kevin Michael Sampson8, David Gochis9 and Yongxin Zhang10, (1)University of Alaska Fairbanks, Fairbanks, AK, United States, (2)University of California Santa Barbara, Santa Barbara, CA, United States, (3)Los Alamos National Laboratory, Los Alamos, NM, United States, (4)University of Alaska Fairbanks, Geographic Information Network of Alaska, Fairbanks, AK, United States, (5)National Weather Service, Alaska Pacific River Forecast Center, Anchorage, United States, (6)NWS Alaska River Forecast Ctr, Hage, United States, (7)National Weather Service, Anchorage, AK, United States, (8)National Center for Atmospheric Research, Research Applications Laboratory, Boulder, CO, United States, (9)NCAR, Boulder, CO, United States, (10)NCAR-Rsrch Applications Lab, Boulder, CO, United States
Abstract:
Dramatic changes in snow and permafrost are leading to shifts in the hydrology of Arctic river basins. These changes have numerous consequences and lead to reduced ability to provide skillful river forecasting and flood prediction. In this study, WRF-Hydro, configured similarly to the NOAA National Water Model, was implemented for the Chena River basin in the Interior boreal forest region of Alaska. WRF-Hydro was forced using air temperature and precipitation data from MERRA2, and evaluated against available observations to determine potential biases. Because the Chena is one of the more densely instrumented basins in Alaska, it is an ideal testbed for this study.
Snow and air temperature impact the state of permafrost and spring melt peak in the runoff, and are thus two of the most important variables in cold regions hydrology. Our study revealed that air temperature biases from MERRA2 appear to be related to the a) resolution of the topography and b) ability of the MERRA2 Reanalysis to simulate inversions in the winter. Snow products from several sources (NCEP/NCAR, ERA5, MERRA, MERRA2 reanalysis products, weather/snow stations, and MiRS SWE from various polar-orbiting satellites) were also evaluated for the Chena River basin. Snow products show significant disagreement, however, some products capture snowmelt conditions and end-of-winter snowpack better than others.
WRF-Hydro was also tested and calibrated with different soil configurations to determine the impact of a thicker soil column on runoff. After further improvements and calibration, the implementation of WRF-Hydro for Chena River can be used for river forecasting and flood prediction in the region. Results from these model experiments are also informing development activities for the new NOAA National Water Model implementation in South-Central Alaska, and potential future expansion into the Alaskan interior region.
