Start Date/Time: Thursday, March 06, 2014, 3:30 PM
Ending Date/Time: Thursday, March 06, 2014, 4:30 PM
Location: MORE 220
Special CEE Seminar, co-sponsored by the Program on Climate Change
Speaker: Charles Luce, USDA Forest Service, Boise ID, Research Research Development.
Title: High and Dry: Declining Precipitation in the Mountains of the Pacific Northwest
Declining flows in Pacific Northwest streams have been noted by several authors, but the causality has been unclear, because precipitation data at NOAA cooperative observer (COOP) climate stations in the region have shown little to no change. Closer examination, however, reveals that COOP stations may not reflect precipitation in the mountains, whereas observed stream flow declines are likely driven by mountain precipitation declines. Decreases in winter westerlies across the region from 1950-2012 are hypothesized to have driven these declines, as winter (Nov-Mar) westerlies are strongly correlated to high elevation precipitation but weakly correlated with low elevation precipitation. Climate projections show weakened westerlies across the region under enhanced greenhouse forcing, highlighting an additional stressor relevant for climate change impacts on hydrology.
Link to the paper "The Missing Mountain Water: Slower Westerlies Decrease Orographic Enhancement in the Pacific Northwest USA" by Luce: https://www.sciencemag.org/content/342/6164/1360.abstract