Pacific Northwest Cooperative Ecosystem Studies Unit (CESU)

High-resolution hydrologic modeling of Glacier Bay National Park

Project ID: P15AC01065

Federal Agency: National Park Service

Partner Institution: Oregon State University

Fiscal Year: 2015

Initial Funding: $41,702

Total Funding: $41,702

Project Type: Research

Project Disciplines: Physical

National Park: Glacier Bay National Park & Preserve

Principal Investigator: Hill, David F

Agreement Technical Representative: Gende, Scott

Abstract: Freshwater runoff plays a first order role in controlling the spatial and temporal distribution of water column properties (salinity, temperature, density) in the waters of Glacier Bay National Park and Preserve (GBNPP). Runoff also strongly controls circulation patterns and residence times. These physical oceanographic processes are linked in many ways to ecological processes, demonstrating the broad impact of freshwater runoff on Glacier Bay. Streamflow is under sampled in Alaska in general and in GBNPP in particular. As a result, the hydrologic budget of Glacier Bay cannot be determined through monitoring alone, and a modeling campaign is needed.
Glacier Bay and Oregon State University will jointly develop a physical process-based hydrologic model for GBNPP that models snow and ice melt, and that routes runoff through the landscape to the coastline. The model will be highly resolved in space (100-500 m) and in time (daily step) allowing for estimates among and within seasons and years, and can accommodate individual rainfall events.

The model will ultimately be validated using physical oceanographic data collected by park staff. Since runoff is strongly controlled by the precipitation and weather data, we will make model runs using three different weather products (NARR [North American Regional Reanalysis], MERRA [Modem-Era Retrospective Analysis for Research and Applications], and PRISM [Parameter­ elevation Relationships on Independent Slopes Model]). The ensemble of data sets will help to quantify the uncertainty in runoff associated with uncertainty in forcing weather data.

Outcomes of this project will include a dataset in netcdf format covering the entire GBNPP watershed that specifies runoff on a daily time step for a 30-year hindcast period. ‘Derived’ products will also include files describing the runoff extracted only at coastline grid cells to allow for the specification of the runoff into Glacier Bay. These data files will be suitable for immediate inclusion into an oceanographic model of the bay by other interested parties. Finally, a number of visual materials will also be generated based on input from park management and interpretation staff, including images (at a given time step, for example) and movies (covering a year, or the entire model period) that demonstrate the rich behavior of snowfall, ice melt, and runoff.

Deliverables: