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FEDERAL-STATE COOPERATIVE SNOW COVER SURVEYS FEDERAL, STATE, AND PRIVATE AGENCIES SURVEY NOTES Snow Surveying is completely explained in Miscellaneous Publication No. 380, United States Department of Agriculture Brief Directions and Suggestions for Snow Cover Sampling (1) The usefulness of snow cover surveying depends primarily on the care and honesty of the men actually doing the field work. (2) The work of the snow cover surveyor is often laborious, especially in stormy weather, and men willing to undertake such work can usually be depended upon to do their best and record the results faithfully. DIRECTIONS FOR USING THE SNOW SAMPLER A. Care of Sampler. (1) In transporting sampler, extreme care should be used to guard it against injury; it can be easily dented. • (2) When sampling on steep slopes do not cling to the sampler to avoid sliding down hill; the tube is easily bent. (3) Keep the sampler covered inside and out with a thin coating of shellac or paraffin. The inside coating can be applied by pulling through a swab soaked or wet with shellac.l This coating not only prevents corrosion but tends to keep moist snow from adhering to the tube. (4) Since ice and rock sound and feel alike when struck by the sampler, be careful to determine what the substance is; ice will not blunt the cutter, rocks will. (~ (5) Keep the cutter sharp and the orifice true to its original diameter (1 1/2 `inches inside in case the Mt. Rose ~teel Tube is used; and 1.485 in case the improved Utah Aluminum Tube is used.) B. Measuring for Samples • Always start measurements for sampling from the initial point as shown by the sketch map of the course and follow the spacing for samples as indicated. Note any irregular spacing between samples. Care should be used in spacing by tape measurements, so that the samples taken different years on the same course will be at the same spots. (1) Plunging the tube should be avoided. In driving, a steady downthrust is preferable to twisting, because with the latter a small amount of snow enters the slots. However, a minimum amount of twisting aids in the driving and also facil- itiates the quick cutting of the thinner crusts. Plunging should be entirely un- •necessary. In case the sampler sticks or freezes down, a light twist will usual- ~y4.r~lease it. (2) The presence of temperatures below 32 degrees F. in the snow, while the temperature of the air is above freezing, often causes the snow to adhere firmly to the orifice of the cutter after a depth of from 10 to 12 feet has been reached. This difficulty can be met in three ways. (a) Withdraw the sampler when cutter becomes clogged and clean cutter and tube thoroughly. Push the tube rapidly through the snow without stopping until bottom is reached but do not plunge tube. Repeat until a complete core is ob- tained.3 (b) In case sampling is being done in the foret, keep the sampler in the .shade as much as possible to keep it cold. (_ (c) The best method of all is to sample when the temperature of the air is at or below freezing, or late in the season when the temperature of the deep snow has risen to 32 degrees F. At these times sampling is easy and rapid.