Saturday, March 1, 2014

Snow water equivalent measurement

Snow water equivalent measurement:





Historical photograph (circa 1907) of Dr. James E. Church - Courtesy of the Western Snow Conference
Photo of Dr. James Church--l
ikely in the vicinity of Mt. Rose


Our information about the amount of water in a snowpack comes from at least two sources--the Natural Resources Conservation Service's Snow Telemetry (SNOTel) system and snow surveys (see http://www.wcc.nrcs.usda.gov/snotel/SNOTEL_brochure.pdf).  Dr. James Church, a professor of classic languages at the University of Nevada, developed techniques for measuring the water content of snowpacks based on the mass of a core extracted using a tube.  The technique is based on the mass of a cubic centimeter of frozen water, which is slightly less than the mass of a cubic centimeter of liquid water. 
Church developed the Mt. Rose sampler--a coring tool with a scale that translates mass into inches of water.  See a photo below of Church at work (courtesy of the Natural Resources Conservation Service's Snow Measurement web site (http://www.wcc.nrcs.usda.gov/snowcourse/sc-hist.html).




The Mt. Rose sampler is in common use for estimating the water content of the snowpack in snow courses.  Snow courses consist of many cores taken in a line for some distance.  Nevada's Mt. Rose Ski Resort has one of the original snow courses from early surveying work and a SNOTel site.  For recent data from the Mt. Rose Ski Resort snow course see http://1.usa.gov/1gJ0RM4.









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