Record Details

Spatial and temporal variability of freshwater discharge into the Gulf of Alaska

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Field Value
Title Spatial and temporal variability of freshwater discharge into the Gulf of Alaska
Names Hill, D. F. (creator)
Bruhis, N. (creator)
Calos, S. E. (creator)
Arendt, A. (creator)
Beamer, J. (creator)
Date Issued 2015-02-05 (iso8601)
Note This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292169-9291/.
Abstract A study of the freshwater discharge into the Gulf of Alaska (GOA) has been carried out. Using
available streamgage data, regression equations were developed for monthly flows. These equations
express discharge as a function of basin physical characteristics such as area, mean elevation, and land
cover, and of basin meteorological characteristics such as temperature, precipitation, and accumulated
water year precipitation. To provide the necessary input meteorological data, temperature and precipitation
data for a 40 year hind-cast period were developed on high-spatial-resolution grids using weather station
data, PRISM climatologies, and statistical downscaling methods. Runoff predictions from the equations were
found to agree well with observations. Once developed, the regression equations were applied to a network
of delineated watersheds spanning the entire GOA drainage basin. The region was divided into a northern
region, ranging from the Aleutian Chain to the Alaska/Canada border in the southeast panhandle, and a
southern region, ranging from there to the Fraser River. The mean annual runoff volume into the northern
GOA region was found to be 792 ± 120 km³ yr⁻¹. A water balance using MODIS-based evapotranspiration
rates yielded seasonal storage volumes that were consistent with GRACE satellite-based estimates. The
GRACE data suggest that an additional 57 ± 11 km³ yr⁻¹ be added to the runoff from the northern region,
due to glacier volume loss (GVL) in recent years. This yields a total value of 849 ± 121 km³ yr⁻¹. The ease of
application of the derived regression equations provides an accessible tool for quantifying mean annual values,
seasonal variation, and interannual variability of runoff in any ungaged basin of interest.
Genre Article
Identifier Hill, D. F., Bruhis, N., Calos, S. E., Arendt, A., & Beamer, J. (2015). Spatial and temporal variability of freshwater discharge into the Gulf of Alaska. Journal of Geophysical Research: Oceans, 120(2), 634-646. doi:10.1002/2014JC010395

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