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Not just frozen water: Measuring snow’s nitrogen pulse

Not just frozen water: Measuring snow’s nitrogen pulse. Sarah J. Nelson, University of Maine Hannah Webber, SERC Institute Ivan Fernandez, University of Maine. “Snow on the ground is a dynamic medium.” - Mark Williams, UC Boulder

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Not just frozen water: Measuring snow’s nitrogen pulse

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  1. Not just frozen water:Measuring snow’s nitrogen pulse Sarah J. Nelson, University of Maine Hannah Webber, SERC Institute Ivan Fernandez, University of Maine

  2. “Snow on the ground is a dynamic medium.” - Mark Williams, UC Boulder See: http://snobear.colorado.edu/Markw/Intro/Snow/MtnSnowpack/snowpack.html

  3. Snowfall: • Freshly fallen snow. • For example, 2.5 inches of snow fell in Bangor on Feb. 27, 2010.

  4. Snowfall: Protocol 9

  5. Snowpack: • Accumulated snow on the ground. • E.g., Snowpack was 36 inches on Feb. 26, 2010. www.arts.monash.edu.au

  6. Snowpack: Protocol 9

  7. Snow Water Equivalent(SWE): • “the amount of water contained within the snowpack. • It can be thought of as the depth of water that would theoretically result if you melted the entire snowpack instantaneously.” www.or.nrcs.usda.gov/Snow/about/swe.html

  8. Snow water equivalent: Protocol 10

  9. Snow Density: • the ratio of the volume of meltwater that can be derived from a sample of snow to the original volume of the sample. • E.g., 1.2" water equivalent divided by 15" of snow = .08 density (= 8%).

  10. We will measure snow melt: Surface runoff produced from melting snow

  11. How much water?

  12. Stream stage: Protocol 8 ga.water.usgs.gov/edu/measureflow.html

  13. How much nitrogen through the snowmelt period?

  14. Nitrogen in stream water: Protocol 7

  15. Snowmeltis surface runoff, but • By the time it’s in the stream, was are also measuring what has moved through the watershed (some soil signal, existing water in the stream) • Other protocols deal with soils and watershed characteristics – these give students’ questions some dimension!

  16. Acadia Learning is a joint effort of the Schoodic Education and Research Center (SERC) Institute at Acadia National Park, the University of Maine, and Maine Sea Grant. • It is supported by: • National Science Foundation (DEB 1056692) • Maine Department of Education • National Oceanic and Atmospheric Administration • Private donors

  17. Watershed scale: snow cover • Which places have snow, and how patchy is it? www.nohrsc.nws.gov/interactive/html/map.html

  18. Density & SWE math • Snow Density = Snow Depth / SWE • Density must be in decimal form. For example:  25% = 0.25 • Density is usually specified in kilogram per cubic meter (kg/m3). • The density of water is 1000 kg/m3 and snow density is usually measured as a ratio to this. • So snow which is 100 kg/m3 is specified as 100/1000, or 10% (of the density of water). www.avalanche-center.org/Education/glossary

  19. What’s in that snow? • Like rain, needs a condensation nucleus to form • Then particles and gases can glom on as snow forms, grows, travels Snow crystal photos – check out: http://www.its.caltech.edu/~atomic/snowcrystals/class/class.htm

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