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This is a great activity for introducing weather data and what we can learn from ice cores. In this activity, developed by Eric Carpenter, students study graphs of wind, temperature and snowfall, and make their own simulated ice cores. 

Overview:

In this activity learners will first examine a set of weather data from McMurdo station. The data includes snow accumulation, average wind speeds, temperature, and average solar radiation. After noting significant trends in the data, including the precipitation events, low temperatures and significant amounts of solar radiation, learners will be asked to identify these trends in a simulated snowpack core or snow tube. Scientist across the state, and around the world, use data to understand the snowpack, the water it contains, and to predict the amount of water that will be available when the snow melts. Key events in the data, as well as structural changes in the snow itself, are represented in the tubes including: snow compaction in the lower levels, formation of layers of ice from radiation driven melting and refreezing events, and the deposition of fine grained sediments during wind events. A method for creating snow tubes based on this data is included in the ‘Preparation’ section of this guide and basic instructions for making snow tubes from local data is included in the section titled ‘Grade Level Adaptations and Local Variations’.

Time Needed:

• 10-15 minutes    

Learning Objectives:

Learners will: 

• Interpret trends and patterns in sample weather data
• Match trends in the weather data to physical characteristics of the snow tubes
• Identify and describe physical changes to the snow and the snowpack over time

Learner Engagement: 

• Having the learners describe the typical weather conditions in high mountain environments (we share that the Colorado alpine is a good proxy for arctic and antarctic environments)
• Share their experiences with snow, snowpack and high mountain environments
• Share their understandings of the processes that impact the formation of the snowpack

Guiding Questions: 

• What role do snow and ice play in Colorado’s water supply? 
• What role do precipitation, wind, temperature and solar radiation play in the development and longevity of the snowpack?
• What physical changes occur when snow is compressed into glacial ice? 

Common Misconceptions:

• Once snow falls, it remains in a relatively stable state until it melts. 
• Layers of ice and crust formation in the snowpack are attributed to high temperatures, not the role of temperate and solar radiation combined.
• Snow must first melt into water before evaporating, which discounts the process called sublimation. 

Prerequisite Knowledge and Skills:

• Familiarity with the metric system
• The ability to interpret graphs and complex sets of data

Materials for the Teacher:

• Master data sheets and instructions for creating snow tubes
• Watertight clear plastic tubes, graduated cylinders or similar materials
• Snow, crushed or shaved ice
• Fine grained sand or dirt
• Access to water, a freezer and a cooler/ice for storage
• 2-3 cm sections of snow tubes or prepared ice sections
• A tool for compressing the snow and ice inside the tube

Materials for the Class: 

• 1 or 2 sets of data sheets for each team
• 1 or 2 snow tubes for each team
• Paper or hand towels to clean up an water or debris

Safety and Logistics:

Sharing roles, data sheets and access to the snow tubes are central to the success of this activity. Be sure have students immediately clean up water and debris to limit the rick of slips and falls. 

Set Up:

• Using the provided tubes, or other materials, create three 0.5 cm and two 1.0 cm thick layers of ice for each set that will easily slide into the tubes. This is best accomplished in advance by filling the tube with a small amount of water, allowing it to freeze, then storing the ice layers in a freezer while you make more. 
• Create a tool from a rod, dowel or other material wrapped with tape that fits snugly inside the tube and can be used to compact the snow and ice layers.  
• Review and print the master data sheets and prepare data sheets for each team. 
• Create a set of snow tubes, following the chart in Appendix 1 by:
  • Adding an amount of snow that will result in the compressed depth found in the chart. Small amounts of water can be added to the lower layers to accentuate their compressed nature and ice-like consistency.
  • Slipping the layers of ice into the tube and pressing them onto the layers below.  
  • Sprinkling a small amount (1 g) of fine sand or dirt onto the snow or ice layers. 

Procedures:

• Begin by distributing the weather data sheets and describing the collection location, collection date, data types and units. 
• Go through the data sheets having learners note significant events and trends including:
• The precipitation events measure centimeters of snow, but not the consistency of the snow which can vary from fine powder to heavy, wet snow.
• The wind speed is measured in meters per second and represents an average for the day, not the highest wind speeds measured. Though there are often significant amounts of wind on the ridge, but there are only a few times when the average is above 30 meters/second or over 65 miles per hour.
• The temperature on the ridge, measured in degrees C, rarely reaches the melting and freezing point of water.
• Anyone who has been high in the mountains can relate to the power of the sun at those elevations. This powerful force is limited by cloud cover, mountain fogs, and is the primary melting agent for surface snow. It is also the engine for sublimation, which is the process that turns solid snow and ice directly into water vapor.
• Next, pass out the snow tubes and instruct the students that there task is to use the data to find out which end of the tube represents the end of the month, or the top of the snow layers.  
• Once the bulk of the students have had time to examine the tubes, have them describe the relationships between: 
  • Snow compression at the bottom of the tube
  • Ice layers and the likely events that lead to their formation
  • The presence of wind driven dust and debris on the snow
• Finally, share that the end of the tube with the lighter snow and dust as the top layer represents the end on the month. 

Assessment:

Have the students focus their attention on the layers that have ice, wind deposited dust, then ice again and have them describe the likely causal agents using the data. Conclude by posing the Guiding Questions to the group in either a written or discussion format.  

Grade Level Adaptations and Local Variations:

This activity can be easily adapted to many locations by changing the weather data and snow tubes to match local conditions. Higher level learners can use measurements and math to calculate the amount of compression for the snow layers, compare data from across the state or nation, as well as yearly data for the same sites,  or use the methods described in the next activity to calculate the water weight equivalence of one or all of the snow and ice layers in the tube.