Snow Depth and Snow Water Equivalent: A 30-Year New Hampshire Climatology and Analysis of Spatial Variability Underneath the Canopy of the White Mountain National Forest
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Authors
Baron, Stephen L.
Date
21-May
Type
text
Language
en_US
Keywords
Alternative Title
Abstract
Electronic Thesis or Dissertation
Description
Snow water equivalent (SWE) measurements are critical for creating flood and drought outlooks in the spring. These data are abundantly collected throughout the winter and spring months and reported to organizations like the National Weather Service to use in their products. Organizations such as the National Weather Service use snow data to look at how it has behaved in the past in order to predict how it might look in the future. Unfortunately, the current collection and archival of snow data by the National Weather Service from numerous organizations in New Hampshire is not streamlined. Various file formats and delivery methods are used, which is no conducive to archive and perform data analyses useful for operational flood-related products. Furthermore, metadata for snow sites is neither complete nor all in one file. This project took historical data from the New England division of the U.S. Army Corps of Engineers and New Hampshire Department of Environmental Services, and systematically organized, quality assured, and conglomerated them. Thirty-five high-fidelity snow sites were identified that can be used to create 30-year climatological products. A subset of products, such as yearly max SWE and snow depth within the climatological period were also created.
<p>In a second snowpack research project, field operations were preformed to attempt to analyze the variability of SWE and snow depth underneath canopy covers of varying closure values during the 2019-2020 snow season. Six snowboards were placed in areas that were visually deemed to fall into three categories of overhead canopy cover: Full Cover, Partial Cover, and No Cover. The canopy closure values were quantified by using image analysis software on photographs of the overhead canopy. Initial analyses of the data showed that snow depth behaved inversely with canopy closure with the boards under full canopy receiving less snow depth on average than the other boards. The SWE, however, behaved close to a direct relationship with canopy closure. The boards in areas under full canopy recorded more SWE on average than the other boards. Snow depth behaved anomalously during periods of high wind suggesting wind drifting is a significant factor on snow depth. The SWE is most affected by wind in the early season and largely driven by temperature and/or increased solar radiation in the late season as meltwater from intercepted snow can easily drip down to the surface.