1. Finding and Identifying Particles in Snow



    Students from many locations will find, identify and report the various kinds of particles they find in snow.

    Research question

    What kind of particles can be found in snow?


    Small container to collect fresh snow





    Why use data from multiple participants?

    One student or team of students can do this project. But the results will be much more interesting and even of interest to professional scientists if many students from different cities, regions and countries participate. Especially interesting will be comparing the findings from urban and rural areas.

    Investigation Protocol

    Follow these steps to examine freshly fallen snow:

    1. Carefully examine freshly fallen snow.

    ●How deep is it?

    ●Does the snow cover the ground or previously fallen snow?

    ●Does it appear very white and clean or is it slightly discolored?

    ●Do you see anything in the snow, such as small black specks?

    ●Are there any insects or spiders in the snow?

    ●Are there animal tracks in the snow?

    Write this information in your notebook.

    2. Photograph an area of fresh snow when the sun is shining. Hold the camera so that the top of the picture shows the sky and any trees or buildings and the bottom of the picture shows the snow. You might want to include some friends in the picture. You might want to ask one of them to take a picture of you standing in the snow.

    3. Take a close-up photo of the snow. First print the date on a small, white card and place the card on the snow. Hold the camera very near the card paper and move it away until the date is perfectly in focus. The snow around the card will be in focus, too. Then take a picture of the card with the snow around it. For best results, the snow should not be shadowed by you or the camera. Later enlarge your photo to see if any small particles are in the snow.

    4. Use a magnifying lens to carefully examine the surface of the snow. What do you see? Look very carefully to see if any tiny, dark objects, insects or spiders are in the snow. Record what you see in your notebook.

    5. Collect a thin layer from the upper few centimeters of freshly fallen snow. One way is to pull the straight edge of a clean plastic container across the top of the snow. Or you can drag a ruler across the snow and then collect the snow along the ruler with the container. Take the snow indoors and allow it to melt. Place one drop of melted snow on a white plate and examine it with a magnifying lens. Describe what you see in your notebook. Hint: Very large particles are probably plant material. Small black particles are probably carbon (soot) from fires.

    The photo above shows snow covered with plant matter and black carbon from smoke. The snow below is much cleaner.

    6. Place a drop of melted snow on a microscope slide. Carefully place a cover slip over the drop. Use tissue paper to remove excess water from the edge of the slide and cover slip. Use a microscope to examine the thin layer of water between the slide and cover slip. Describe what you see in your notebook. What do you see?

    The photo above of a drop of melted snow made through a microscope shows a large, black carbon particle below a brown soil particle.

    Safety tips

    Wear warm clothing when studying snow. If the sun is shining wear sunglasses to protect your eyes from the ultraviolet sunlight reflected by the snow. Avoid studying snow that is close to roads or hazards. When using a microscope be very careful to avoid cutting your fingers if you use a glass microscope slide and especially a thin glass cover slip. If you have never used a microscope slide and cover slip, ask a teacher for help. This photo made through a microscope shows a large, black carbon particle below a brown soil particle.

    Report Form Before filling in the Report Form, please read the Investigation Protocol