Researchers seem to be advancing in their understanding of reasons behind changes in snow-energy and mass-balance, based on a study done in British-Columbia’s Okanagan Basin. The main idea of this research is that snow-energy and mass-balance might be influenced by elevation and forest-covers, and to determine to what extent this is true the researchers used four sites in the well elevated Coldstream Basin, found within the larger Okanagan Basin. Among the measured aspects were snow depth and density, temperature and humidity, radiation, wind speed and direction, melt and vapour, as well as precipitation. These aspects were evaluated in the four sites, which were situated strategically based on elevation, with one forested and one open site per elevation level.
According to Jackson and Prowse, there was a “1-4% loss of peak SWE [snow water equivalent] at open sites, and 4-12% at the forested sites”. Sublimation (the transformation of a solid to a vapour without passing through the liquid state) and melt rates were higher in the open sites, and although researchers found that the snow was gone 2-5 days earlier on open sites than on forested sites, the open sites still kept a higher SWE than the forested ones. The snow density in the forested areas was notably smaller than the snow density in the open areas.
As for the influence of elevation on the snow water equivalent (amount of water contained in the snow), what was noticed was that a higher elevation led to a greater wind speed and that temperature varied depending on the elevation, but that humidity barely changed. There was a very noticeable difference in radiation from site to site, and the relations between them were not evident. Cold Mid and Cold Up (two sites on different elevations) were the only two sites with the same radiation. For the most part, Cold Mid (the middle-elevation site) seemed to be the least influenced site of all; it had the smallest loss of snow water equivalent due to sublimation, and the latent heat fluxes were less common on this site. Also observed, was the fact that the melting occurred mostly in lower altitude areas since they became warmer sooner.
Generally, melting occurred mostly in warm and high moisture environments, sublimation was caused by cold and dry air masses, and the recorded wind speeds were faster at the lower and higher sites than at the middle sites. The results found in this study were very similar to those found elsewhere, and they are helping build a strong base for future research on snow-energy and mass-balance. This study is a good start to better understanding the effects of climate change and tree cutting (causing more open spaces) on our freshwater resources.
References
Jackson, Scott I., Prowse, Terry D. “Spatial variation of snowmelt and sublimation in a high-elevation semi-desert basin of western Canada.” InterScience. 23, 2611 – 2627 (2009). DOI: 10.1002/hyp.7320.
Overall, I found your newspaper article very interesting and packed with lots of information about the study done. It had good direct quotes that highlighted the problem of increased snow melt. I also liked how you explained some of the less well known terms (such as snow water equivalent) in brackets so that the average reader could better understand the study. However there were still a couple things that confused me. It would have been helpful to define snow-energy and mass-balance before explaining the methods of research so that the reader knows exactly what is being studied. Also, I’m not sure how radiation affects the SWE. It is hard to condense a primary source into 500 words, but a bit more explanation would have been awesome. Finally, the conclusion was great to tie everything together and initiate more research.
ReplyDelete- Amy Adair
For the most part your article was interesting, however it was hard to understanding what you were really talking about.
ReplyDeleteYour Article contains a abundance of good information from the primary research, however I found it was hard to understand the information because of the way it was presented. I found the information needed to be explained in greater detail and the use of diction had to be more directed to a audience assumed to have a non scientific background.
On a good note, you had a very strong introduction and conclusion!
Kendra Bester