Untangling Climate and Wildfire Influences from Snow Water Equivalent Measurements on the Deer Park, Washington Snow Course

TitleUntangling Climate and Wildfire Influences from Snow Water Equivalent Measurements on the Deer Park, Washington Snow Course
Publication TypeConference Proceedings
Year of Conference2008
AuthorsDrake, E., DeSisto C., McDonald S., Evans S., Barry D., and Baccus B.
Conference Name76th Annual Western Snow Conference
Series TitleProceedings of the 76th Annual Western Snow Conference
Date PublishedApril 2008
PublisherWestern Snow Conference
Conference LocationHood River, OR
KeywordsDeer Park fire, Olympic National Park, snow course, SWE, PDO, ENSO, snowpack decline
Abstract

In 1988, the Deer Park Fire burned 170 acres within Olympic National Park, WA. The wildfire burned up to the southern end of the NRCS/NPS Deer Park Snow Course. The burn eliminated a forest stand downwind and down-slope of the snow course; this study reports on a potential decline in snow water equivalent (SWE) measured by the course as a result of this adjacent change in forest cover. Regional climate trends based on Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) were incorporated into the evaluation, allowing the wildfire's impacts to be isolated from climatic variability. A comparison of mean SWE values before (1949-1988) and after (1989-2007) the wildfire for every reporting month in every climate cycle showed a clear trend of a decline after the wildfire; these differences are statistically significant in April and May for all climate cycles except for positive PDO+negative ENSO. Overall, estimates of effect size of the difference between means were uniformly negative and as low as 2.9 for February 1 snowpack in warm, dry climate cycles and as high as 17.1 for May 1 snowpack in cool, wet climate cycles.

URLsites/westernsnowconference.org/PDFs/2008Drake.pdf