Document Type
Article
Publication Title
Journal of Geophysical Research
Publisher
American Geophysical Union
Publication Date
8-21-2007
Volume
34
Disciplines
Earth Sciences
Abstract
We assess changes in runoff timing over the last 55 years at 21 gages unaffected by human influences, in the headwaters of the Columbia-Missouri Rivers. Linear regression models and tests for significance that control for ‘‘false discoveries’’ of many tests, combined with a conceptual runoff response model, were used to examine the detailed structure of spring runoff timing. We conclude that only about one third of the gages exhibit significant trends with time but over half of the gages tested show significant relationships with discharge. Therefore, runoff timing is more significantly correlated with annual discharge than with time. This result differs from previous studies of runoff in the western USA that equate linear time trends to a response to global warming. Our results imply that predicting future snowmelt runoff in the northern Rockies will require linking climate mechanisms controlling precipitation, rather than projecting response to simple linear increases in temperature.
DOI
10.1029/2007GL031022
Rights
© 2007 by the American Geophysical Union
Recommended Citation
Moore, J. N., J. T. Harper, and M. C. Greenwood (2007), Significance of trends toward earlier snowmelt runoff, Columbia and Missouri Basin headwaters, western United States, Geophys. Res. Lett., 34, L16402, doi:10.1029/2007GL031022.
Comments
An edited version of this paper was published by AGU. Copyright (2007) American Geophysical Union.