PCC 8th Annual Public Lecture (2009): "Understanding Variations in Mountain Snow in the Pacific Northwest: Impacts of climate change and importance of location"

Start Date/Time: Thursday, April 23, 2009, 7:00 PM
Location: UW Campus: Kane Hall, Room 120

Dr. Lundquist will discuss the complexity and under-sampling of mountains in the Pacific Northwest relative to other U.S. mountains, why ski resorts here are so successful despite their relatively low elevations, and why arguing about rates of snow melt or retreat is fundamentally difficult because of spatial and temporal variability.

From glacier-topped volcanic peaks, to hydropower and water resources, to avalanches and rain-on-snow floods closing major roads, snow is a prominent feature of Washington State. The amount of snow stored in the mountains of the Pacific Northwest has been declining since observations began in the mid-1900s, with rates of decline depending on location and time period. One of the causes of this decline is an increase in mean temperature over this period, which leads to more precipitation falling as rain and less as snow. This shifts runoff from summer snowmelt, when water is a resource, to winter floods, when water is a hazard. Understanding how temperature varies in the mountains would enable us to estimate the fractions of precipitation falling as rain and snow. However, the mountains of the Pacific Northwest contain some of the most complex topography in the United States, and there are very few measurements at high elevations. Moreover, station placement has been traditionally driven by logistics and ease of access. Inadvertently, many of the stations are, in fact, measuring atmospheric conditions unique to their location, such as cooler temperatures at mountain passes due to cold-air spilling over from east of the Cascades. Errors in our estimates of how temperature changes with elevation can cause hydrology models to vary from current conditions as much as, if not more than, the amounts forecast by future climate predictions. Detailed, local observations of temperature and streamflow suggest that although we are rapidly gaining confidence in predictions of global mean climate changes, we have much work to do to understand what this might mean to a specific river reach or mountain snow patch.

Jessica Lundquist has been a faculty member with the Department of Civil and Environmental Engineering since 2006. She is particularly interested in hydroclimatology and the relative importance of hydrologic processes at different basin scales, with a focus on mountain watersheds in the western United States. Dr. Lundquist is a member of the advisory board for the UW Program on Climate Change.

Free Lecture. Registration is NOT available.
Call 206-543-6521 for additional event information.

Location and Directions: Kane Hall is located on the north side of Red Square on the UW Seattle campus. View a map showing the location. Paid parking is available in the Central Plaza Garage below Kane Hall. The campus is served by many bus routes. See the Lecture Flyer

The lecture was recently highlighted in an article in the UW news- read it here