Detailed Analysis of Climate Data in the Greater Yellowstone Area

Phil Farnes, Snowcap Hydrology

During his 50-year career, Phil Farnes has worked to ensure the quality of climate data in the Greater Yellowstone Area (GYA). Before scientists draw conclusions about climate change or its effects on ecological processes, it is important to screen the data for accuracy. Human errors and equipment malfunctions can lead to incorrect measurements, and the trends recorded at some weather stations are due to changes in equipment type or location rather than actual climate change. These errors can be detected with mathematical techniques and examination of each station's operational history.  

Farnes has conducted studies that distinguish between anthropogenic (human-caused) climate change and natural variability in the GYA. He found that average snow pack in Montana declined 15% during the twentieth century, while average temperatures increased by 1.4°C and total precipitation increased by 2%. The magnitude of change depends on the length of the weather record analyzed in each region, and significant spatial and temporal variability underly these trends. Even though the changes observed to date are statistically significant, they remain within the range of natural variability. Long-term measurements, accurate models, and logical analysis are needed to separate the effects of anthropogenic climate change from natural variability in the GYA. Estimates of future climate changes need to be based on more than just an extension of current trend lines.  

Farnes' collaborative work with researchers in other fields has been significant. He has contributed to investigations of the relationship between snow melt and bear denning behavior, the effects of snow pack on animal migrations, the effects of snow melt and temperature on salmon flies, changes in runoff due to fire, and parameters that influence forage production in mountain environments. He developed a winter severity index for ungulates and has studied climatic variables that influence production of whitebark pine cones (a key food source for bears) and western larch cones. He helped develop an accurate precipitation map for Montana and the GYA that was important to improving computer models that forecast snow water equivalent and runoff.  

When he was a Supervisory Hydrologist for the Soil Conservation Service (now Natural Resources and Conservation Service), Farnes was responsible for the installation and maintenance of SNOTEL stations (automated weather stations). Many of these stations now have over 25 years of records. These data have permitted researchers to look at climatic parameters at specific mountain elevations and locations rather than extrapolating data from valley stations. Many new relationships and understandings are now emerging that were not previously possible when using the valley data.