Browsing by Subject "snow cover"

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    Assessing Historical Trends in Snowpack Variability Across the Northern Rocky Mountains Using Remote Sensing and Dendrochronology Approaches
    (2013-06) Crawford, Christopher
    Mountain snowpack across the western United States is declining because of warming spring temperatures during the modern period. Earlier snowmelt has been documented for numerous localities throughout the American West using ground-based snow-water-equivalent measurements and gauged streamflow. This research uses historical satellite imagery, tree-ring records, and instrumental climate observations from the northern Rocky Mountain (NRM) region to evaluate the climatic controls on mountain snowpack spatiotemporal variability, assess historical spring snowmelt trends, and contextualize modern climatic change with pre-instrumental climate variability. A suite of methodological approaches is employed to develop and calibrate satellite, tree-ring, and instrumental climate records using time-series analysis techniques. Together, these NRM region climate records suggest that precipitation in the form of mountain snowpack extent varies on interannual to decadal timescales. Of more importance, spring mountain snowpack appears to be decreasing in areal extent during the 20th and early 21st centuries driven largely by modern spring warming.
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    Snow Cover and Winter Soil Temperatures at St. Paul, Minnesota
    (Water Resources Research Center, University of Minnesota, 1971-06) Baker, Donald
    The objectives of this study of winter soil temperatures under a sod cover were to show the configuration of the soil isotherm patterns, in particular that of OC, and to determine which soil thermal characteristics can be estimated by the snow cover. The temperature data were obtained at the University of Minnesota Agricultural Experiment Station plots on the St. Paul campus with copper-constantan thermocouples during the winter of 1961-62 through 1968-69. Based upon the depth and persistence of the snow cover there were in effect 3 kinds of winters: one with deep and persistent snow cover, one with very little snow cover and all other winters. There was a close relationship between the kinds of winters and the maximum depth to which the OC isotherm penetrated, and a fair relationship to the rate of movement of the OC isotherm into the soil. The combination of type of winter (snow depth and duration) with cumulative heating degree days proved to be a simple and effective means of predicting the maximum freezing depth.