Snow Depth

1. Snow Depth • Property with potentially largest variation in space

2. Snow Depth • Property with potentially largest variation in space • Measure vertical to earth’s surface

3. Snow Depth • Property with potentially largest variation in space • Measure vertical to earth’s surface

4. Snow Depth • Property with potentially largest variation in space • Measure vertical to earth’s surface

5. Snow Depth • Property with potentially largest variation in space • Measure vertical to earth’s surface

6. SWE measurement • Mass of water over a unit area • Weigh cylindrical snow sample • Typically the Mt. Rose or Federal Sampler is used • A gravimetric technique

7. SWE measurement • Clean the snow tube of debris, snow, etc. cutter/teeth snow tube

8. SWE measurement • Clean the snow tube • Tare the snow tube cutter/teeth scale snow tube

9. SWE measurement • Clean the snow tube • Tare the snow tube scale snow tube

10. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube vertically

11. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube vertically • Rotate tube into snowpack

12. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube vertically • Rotate tube into snowpack • Twist sharply at bottom

13. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube perpendicular • Rotate tube into snowpack • Twist sharply at bottom • Pull out vertically

14. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube perpendicular • Rotate tube into snowpack • Twist sharply at bottom • Pull out vertically • If an entire column has been removed, weigh tube with core

15. SWE measurement • Clean the snow tube • Tare the snow tube • Insert tube perpendicular • Rotate tube into snowpack • Twist sharply at bottom • Pull out vertically • If an entire column has been removed, weigh tube with core

16. Snowpack Density • Average density = SWE / depth

17. Snowpack Density Stratified densities from snow pits • Dig a pit to the bottom • Include a stairway • Cut a straight face along the southern wall • Measure total depth • From top or bottom, measure densities at 10cm intervals • Concurrently measure temperature

18. Snowpack Density • Kelly Cutter density sample extracter:

19. Snowpack Density • Kelly Cutter density sample extracter:

20. Snowpack Density • Kelly Cutter density sample extracter:

21. Snowpack Density 5. From top or bottom, measure densities at 10cm intervals • Clean wedge-shaped sample extracter (Kelly cutter) • Tare sample extracter • Insert sampler vertically to sample wall with bottom parallel to the ground • Slide plate along open side of sampler • Pull sampler and plate from wall • Remove excess snow from bottom and side of sampler • Weigh sampler and sample • Density = mass / volume

22. Snowpack Density • Line up sampler perpendicular face of pit wall PLAN VIEW

23. Snowpack Density • Insert sampler perpendicular PLAN VIEW

24. Snowpack Density • Insert sampler perpendicular PLAN VIEW

25. Snowpack Density • Insert sampler perpendicular • Do not push into snow wall PLAN VIEW

26. Snowpack Density • Slide lid along open face PLAN VIEW

27. Snowpack Density • Slide lid along open face PLAN VIEW

28. Snowpack Density • Slide lid along open face PLAN VIEW

29. Snowpack Density • Extract sampler perpendicular PLAN VIEW

30. Snowpack Density • Extract sampler perpendicular PLAN VIEW

31. Snowpack Density • Volume of Kelly cutter = 1 L  Mass of sample = density

32. Shallow Snowpacks • Less snow, potential for greater relative variation • Take measurement large cores • eg. MSC sampler with F = 7.8 cm • Smaller stratified samplers • eg. 250 – 500 ml Kelly cutter