Snow and climate change research in two mountain catchments, Glacier National Park, Montana

Snow is a dominant driver of many mountain ecosystem processes, determining forest growth, basin hydrology and glacier dynamics in many temperate mountain ranges. A 14-year research program in the Northern Rocky Mountains, USA, has focused on how mountain ecosystem processes in Glacier National Park, Montana have responded to changes in climate patterns. Modeling and monitoring the spatial and temporal variability in seasonal snowpacks has been focused on two catchments, each approximately 450km2. We have conducted intensive snow surveys across these two catchments since 1993 and have over 10,000 monthly measurements of snow water equivalence (SWE) and snow depths. Because some of the oldest Natural Resource Conservation Service (NRCS) snow courses (dating back to 1922) and SNOTEL sites (dating back to 1969) are located in our catchments, our spatially extensive snow datasets complement the single site snow records from SNOTEL installations and NRCS snow courses. Snow chemistry has been investigated for five seasons at multiple sites and elevations to determine spatial variability of major ion concentrations and loadings in addition to a 10-year single site record to track interannual variability. Backcountry stream gages and water chemistry sampling sites monitor snowmelt in both catchments to augment long-term historical records from USGS gages. Snow avalanche research has provided several hundred snowpack profiles, a history of avalanche magnitude and frequency, and an ongoing forecasting program for natural avalanche releases. Glaciers and perennial snowfields have been mapped, monitored and modeled in the catchments and four high-elevation backcountry weather stations have provided climatic data for up to 10 years. The integrated research program has produced or modified models of snow distribution, snowpack seasonal evolution, decadal-scale variability, and catchment-scale water balance. These snow oriented products are scaled up to mountain ecosystem models that address impacts of climatic change for western mountain regions.