How do spatial patterns vary with weather and climate?

A realistic quantification of how temperatures vary over mountain terrain is crucial for models of basin-scale snowmelt and spring streamflow. Recent work with Nick Pepin at the University of Portsmouth, UK [Pepin and Lundquist, 2008] examining high elevation temperature records across the globe has demonstrated that temperature trends vary between mountain ranges and within a mountain range and are greatly affected by local topography.

• For example, Lundquist and Cayan [2007] showed that decadal-scale changes in atmospheric circulation patterns appear to have changed the temperature contrast across the east and west sides of the Sierra Nevada range. Specifically, weakening westerly winds were associated with less long-term warming on the east slope than the west slope of the Sierra Nevada.
• Our group is currently working with networks of near-surface air temperature sensors, using deployment strategies detailed in Lundquist and Huggett [2008], in the Sierra Nevada, CA, Rocky Mountains, CO, North Cascades, WA, and Pyrenees, France, to come up with general methods for mapping temperature patterns through space and time, based on knowledge of local topography and large-scale atmospheric circulation patterns.
• These sensors were deployed in Mt. Rainier National Park and North Cascades National Park in 2006-2007 and revealed that lapse rates in the state of Washington vary from the typical "standard atmosphere" lapse rates that were being used in hydrologic models, as detailed in Minder et al. [2010].

• A technique for mapping areas prone to cold-air pooling is detailed in a recent paper in the Journal of Geophysical Research [Lundquist et al., 2008]. This technique has been used in studies of pika habitat, and we are currently investigating its potential application in determining wolverine habitat.
• Work with Nick Pepin and Chris Daly (Oregon State University) has revealed that cold air pool locations tend to be decoupled with the free atmosphere, but that does not mean that they have been sheltered from recent warming trends. Rather, due to circulation changes, they may either experience more or less temperature change than nearby hilltop locations (paper under review).