Arctic-boreal regions are exhibiting the symptoms of profound ecological shifts as they experience pronounced warming. Wildlife in high-latitudes are one such harbinger of change, and their populations are undergoing range-shifts, declines, and extinctions in response to their rapidly altering habitats. As the circumpolar and boreal north is snow-covered for up...
The topics in this dissertation center on the snow processes that dominate mountain environments in the Western U.S. and Alaska, particularly in locations lacking long-term observational datasets or locales that are difficult to access in-person. Some are currently glacierized or have been glaciated in the recent past. Each of the...
Snow water equivalent (SWE) is a critical measurement in hydrology and water resources management. Microwave remote sensing can estimate snow water equivalent (SWE). However, the algorithms used to estimate SWE require snow grain size information. Thus, determining snow grain size is pertinent to estimate SWE. Currently, there are several models...
Rising global temperatures are having lasting effects on mountain snow environments in the form of diminishing snowpacks, shorter accumulation seasons, and shifts in meltwater timing. Seasonal snowpack is a vital source of water for natural and human systems. In the forested mountain landscapes of the Pacific Northwest seasonal snowmelt feeds...
Cold-season storms are responsible for generating most of the snow that accumulates in mountainous watersheds across the western United States, but with overwhelming evidence of warming temperature trends, this seasonal snowpack is at risk for melt, The vast majority of snow trend studies utilize undifferentiated air temperature records – these...
Declines in glacier area and volume are widespread. These changes will have important hydrologic consequences since glaciers store tremendous amounts of fresh water and buffer seasonally low flows in many densely populated regions. In this thesis I focus on a region that is hydrologically vulnerable to glacier change, namely the...
In the mountains of the Western US, shifts in the timing and magnitude of snow water equivalent (SWE) over the past century are well documented and attributed to climate warming, but the magnitude of sensitivity depends on elevation. We modeled the spatial distribution of SWE and its sensitivity to climate...
As a result of a warming climate, subsequent declining snowpack, and a century of fire suppression, forest fires are increasing across the western United States. However, we still do not fully understand how forest fire effects snowpack energy balance, nor the volume and availability of snow melt and associated water...
Forest canopy cover presents a major challenge for remote sensing of fractional snow-covered area (ƒSCA). Snow cover is systematically underestimated where satellites sensors cannot penetrate the forest canopy. Current canopy adjustments scale observable ƒSCA with the vegetation fraction, assuming that snow cover distributions are similar between sub-canopy and open locations....
Mountain glaciers are receding worldwide with numerous consequences including changing hydrology and geomorphology. This study focuses on changes in glacier area on Mt. Hood, Oregon and Mt. Rainier, Washington where damaging debris flows have occurred in glaciated basins. Landsat imagery is used to map debris-free ice on a decadal time...