Although much of the concern about possible global warming has focused on changes in temperatures, some climatologists, geographers, and other atmospheric scientists have noted that substantial changes in the amount, form, and timing of precipitation also may occur. The extent and duration of snow cover is one measure by which changing precipitation and temperature patterns may be identified, and snow cover is a variable for which many nations have historical data that extends over decades. Analyses of these historical data are essential to help identify natural variability in snow cover, a pattern that must be distinguished if changes in snowfall resulting from human activities or other factors are to be identified. This project will integrate into a single, coherent database the daily measurements of snow cover and related variables for roughly 1,000 observation stations in the United States, Soviet Union, Canada, China, and several European nations. Records in the USA and USSR extend back to the early years of the 20th Century. These integrated data will be statistically analyzed to test hypotheses about the spatial and temporal variability of snow cover and to differentiate random variability from long-term trends. The most valuable contribution of this project will be the integration of historical data into a single database, which will be available for use by this investigator and by other scientists for a wide range of inquiries into climatic variability and change. The project also will provide analyses of fundamental variations in snow cover across the Northern Hemisphere during the 20th Century, thereby enhancing general understandings of changing climatic patterns over the last 100 years.
