Short-term changes in snowpack due to weather Sean Sutherland  University of Colorado, Boulder  EBIO 4100, Winter Ecology Spring 2011  Mountain Research Station  Nederland, CO 9500 ft.

Background  The snowpack is largely affected by the winter time weather patterns that include the cold, wind and some radiation from the sun, trees and rocks and all of this impacts subnivean life (Marchand 1989).

Hypothesis  Are you able to see changes in the snowpack layers over solely one week?  Is this change (if any) correlated with the winter weather processes?

Questions  What does the weather record say about the metamorphosis of the snowpack?  What does this particular snowpack mean for subnivean life?  What benefits and downfalls are associated with these animals both above and below the snowpack?

Methods and Location Location  -Lodgepole, Aspen Forest North of C1 Meteorological Station (3022 meters/9912 feet).  Open clearing on North side of path, undisturbed.  Scarce amount of noticed animal activity due to new snow on first dig. Methods  Two snow pits, one on 2/5 and 2/12, used snow pit kit.  Recorded Weather for week between dig dates.  Measured densities and temperatures every 10 cm with the height of the pack.  Examined different layers in each pack.

Limitations  Time was a factor on the first dig.  Weather on first dig (lots of snow!)  Issues with scale.

Pit One 2/5/11Time of Dig:12:45 pm - Air temperature: -6 degrees C - Cloudiness/Insolation: mostly cloudy - Precipitation: Heavy Snow, periods of lighter snowfall - Southwest winds - Surface Hardness: Powder, soft, sink to knees with no floatation.

Pit Two 2/12/11 Time of Dig: 12:30 pm -Air Temperature: -3 degrees C -Cloudiness/Insolation: Mostly sunny, clear skies with few clouds -Precipitation: None -Westerly Winds (Orographic) -Surface Hardness: Soft, Sink to knees

Wind Speed for 2/5-2/12

Peak Wind Gust

Temperature 2/5-2/12

Subnivean Life

Lesson Points  Winter Processes both above and below the snowpack impact the layers directly.  Impact in correlation with insulative properties of snow.  General trends of temperature, depth and density within layers of a pack.  Subnivean habitat is dependent on snowpack conditions (Casselman 2008).

Citations  General Sources:  Halfpenny, J.C., and Roy Douglas. Ozanne. Winter: an Ecological Handbook. Boulder, CO: Johnson, Print.  Marchand, P.J. Life in the Cold: an Introduction to Winter Ecology. Hanover, NH: University of New England, Print.  C1 Meteorological Site, Niwot Ridge

Citations  Specific References:  Casselman, Bill. "Subnivian." Web..  CAIC: Colorado Avalanche Information Center. Web. 19 Feb  "National Oceanic Atmospheric Association." NOAA - National Oceanic and Atmospheric Administration. Web. 19 Feb  "Snowpack." Forest Service National Avalanche Center. Web. 19 Feb  "Subnivean (Life Under the Snow)." Maynard Life Outdoors. Web. 19 Feb