An introduction to the snowpack project

Brief description

This activity introduces the snowpack project to your students. The readings explore different aspects of climate change and snowpack and give a broader overview of changing climate and the role snowpack plays in Maine’s ecosystems.

Background for Teachers

About 25 percent of our water for the state falls in the form of snow. Once snow falls, if conditions are right, snow can stay on the ground (or on top of older snow) and to accumulate into a snowpack. Sometimes snowfall will melt, especially early in the winter or if there is a “thaw”, and snowpack accumulation must start again. Snowpack, that accumulation of snow, is an important factor on the winter landscape. Snowpack protects tree roots from freezing, and provides cover for organisms that need shelter through the winter. In the spring, when the snowpack melts, the meltwater feeds streams and rivers, and provides water and nutrients to plants that are beginning to bud and leaf out. Snowpack also re-charges aquifers that we rely on for drinking water and provides the flow rates that returning diadromous (sea-run) fish need for migrating into freshwater in the spring. We don’t necessarily think about snowpack and fish migration or snowpack and community resilience, and the subnivean (under the snow) is hidden to us for the winter and thus may go un-noticed, yet, these are the broader contexts in which this project is framed.

This introductory activity sets the larger stage for the snowpack research that your students will be undertaking. For this activity students read excerpts from Maine’s Climate Future report, a USGS fact sheet on changing springtime stream flow, an Audubon article on the subnivean, and a NOAA article on the Flood of 1936. Students will then use information from the readings to think about how snowpack will affect different parts of the ecosystem (including humans) and report to the rest of the class.

Diadromous fish

Maine’s diadromous fish migrate into Maine’s freshwaters in the spring. Diadromous fish rely on a variety of cues that tell them when to migrate into freshwater streams in the spring, including length of daylight, water temperature and stream flow rates. A primary concern for fisheries scientists and managers is a gradual decoupling of these signals due to climate change, which could lead to asynchrony (mis-matched timing) in cues. Amount of daylight in spring is a constant over years, but if water temperature increases and streamflow is reduced or is earlier because of reduced snowpack (Hodgkins & Dudley, 2006), then fish migration may be improperly timed or difficult due to lack of sufficient streamflow (Wilson, 2012; NMFS, 2012). Maine’s 11 species of diadromous fish are:

  • Sea lamprey (Petromyzon marinus)
  • Shortnose sturgeon (Acipenser brevirostrum)
  • Atlantic sturgeon (Acipenser oxyrhynchus)
  • Alewife (Alosa pseudoharengus)
  • Blueback herring (Alosa aestivalis)
  • American shad (Alosa sapidissima)
  • Atlantic salmon (Salmo salar)
  • Brook trout (Salvelinus fontinalis)
  • Rainbow smelt (Osmerus mordax)
  • American eel (Anguilla rostrata)
  • Atlantic tomcod (Microgadus tomcod)
  • Striped bass (Morone saxatilis)

Each species has its own set of migratory cues, but a change in the timing, volume or duration of the spring melt from snowpack will affect all of them.

Figure 1 from Jacobson, G.L., I.J. Fernandez, P.A. Mayewski, and C.V. Schmitt (editors). 2009. Maine's Climate Future: An Initial Assessment. Orono, ME: University of Maine.

Coastal Reslience

Snow fall and snowpack affects coastal and inland resilience- (resilience is defined as ‘building the ability of a community to "bounce back" after hazardous events such as hurricanes, coastal storms (in the case of coastal communities), and flooding – rather than simply reacting to impacts’ (NOAA definition, for more see: Changes in the timing and intensity of late winter storms or the spring thaw are both changes that communities living on the coast and along waterways of any size are now developing those “bounce back” plans. (for an example of the need for resilience see: and and the March, 1936 flooding)  

The Subnivean Environment

As snowpack builds, it acts as a blanket and when it’s thick enough it can keep the space just above the ground at a constant 0 degrees C. This becomes a refuge for organisms that do not migrate or hibernate. This blanket also insulates tree roots and a rich diversity of microbes that thrive in the subnivean (the interface between soil and snow).  When there is little snowpack (either because it has not snowed or because of a melt) or the density of the snowpack increases (becoming more like an ice layer, through settling and changes in the character of the snow) the insulation provided by the snow blanket decreases and temperatures become more variable, reflecting the air temperatures.

For this exercise students do not need to know definitively how deep the snow needs to be to offer a thermal benefit, the exact flow regime needed for any species of diadromous fish, or specific coastal town plans for managing change in a changing climate.  They do need to consider how change in one part of the ecosystem can affect what might seem, at first, to be a completely unrelated part of the same system.

Figure 2: image by Marco Cibola from


Students understand:

  • The nature of the project with which they are getting involved.
  • The role snowpack plays in the yearly hydrologic cycle.
  • How a changing climate could affect snowpack.
  • Changing snowpack affects organisms and communities that depend on snowpack and snowmelt, even those that seem unrelated.


  • Students identify the importance of snowpack to towns and other human infrastructure, subnivean organisms, and diadromous fish.
  • Students can state how a changing climate could change snowfall and snowpack in Maine.

Where does this lesson happen in the Project?

This is the first lesson in the project.

Getting Ready

Ask your students to tell you anything they can about snowfall and snowpack, or anything they do for recreation in the winter. Introduce the word snowpack (the accumulation of snow on the ground through the entire winter season). Brainstorm, asking how snowpack affects the natural world. List all student information on a board.

Explain that, for this project, the students will be conducting their own research on snowfall and snowpack while contributing data to a larger weather and climate database. They’ll need to learn about snowpack and changing climate before developing their own questions and experimental designs.


  • Readings
  • “Changes in Streamflow Timing in New England During the 20th Century” a USGS fact sheet
  • “Flood of March 1936” a NOAA article on the flood of 1936
  • "Packed to the Hilt" an Audubon magazine archived article
  • Excerpts from Maine’s Climate Future (pp. 9-15 and pp. 23-25)
  • Worksheets based on each of the readings.
  • Student Question Worksheet

Student Prerequisites

  • Students should be able to describe the four seasons in Maine
  • Students should understand that precipitation in Maine comes in different forms.
  • Students should understand why we have seasons. (Be sure they understand that seasons happen because of the tilt of the Earth, not distance from the sun—a common misconception).

Time needed

One class period

Doing the Activity

  • Spilt the class into three groups.
  • Assign all students the excerpts from the Maine’s Climate Future report.
  • Page 23 through 25: Freshwater ecosystems
  • Page 9 through 15: Maine’s Climate Yesterday, Today, And Tomorrow

(Maine’s Climate Future is a 74-page report prepared in 2009. The report is available online: and in Supplemental Materials on the website.)



Students explain the outcomes they have defined from the climate ‘models’ to the class, have students write down the questions that they have about the snowfall and snowpack as they relate to their own setting (home or school).


Have students explain one of the graphs from Maine’s Climate Future to their parents, siblings or peers.

Lesson Extensions and Supplements


  • Visit (National Snow Analyses) then use a model developed by NOHRSC, a NOAA scientist group working to model snowfall and snowpack across the US.

Have students predict when and where there will be snow, enter dates, and use the model to check their predictions. Example: My birthday is October 19. Say I want to see snow on my birthday. I could guess that I’d better go to northern Alaska to see snow on my birthday. Or, ask, has there ever been snow in Arizona? Use the model to see how likely that would be.

  • Students call their town and ask about changes their own town managers have made to adapt to a changing winter landscape (more sand and salt or changing to brine solution to combat ice instead of snow, lower plowing budget, perhaps). Have there been any large floods in the past several springs? How does the town manage flood waters or blocked culverts in the spring?

Additional reading:

Maine: Confronting climate change in the U.S. Northeast (an article from the Union of Concerned Scientists)

The subnivium: a deteriorating seasonal refugium (a 2013 journal article from Frontiers in Ecology and the Environment, available through the University of Maine's LIbrary system)


Borrow and Watch:

You can borrow Great Flood of 1936: The Connecticut River Story a 75-minute long DVD on the 1936 flood from Northeast Historic Film (



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