Long-Term Monitoring Page 1


- Snow -

How can you tell how much water is in a snowpack? Scientists do this by taking a snow core like the one to the right, measuring its depth, and then weighing it for water content. In this way they can determine both the density of the snow and how much water is contained in it. Dense, heavy snow contains more water than light, fluffy snow. Both of these types of snow can look the same in terms of depth, but are very different hydrologically.

At the HBEF, technicians measure these "snow courses" once a week all winter long, all over the experimental watersheds. As you can see in the photo, this involves the use of snowmobiles and snowshoes - and a great deal of patience, energy, and tolerance for cold weather!

Examine the graph below. This graph shows data from 45 years of measuring water content present in the HBEF snowpack. Snow course 17 is on the north-facing slopes, and snow course 2 is on the south-facing side. These data indicate that:

  • Maximum snowpack water content varies from year to year

  • The north-facing slopes have a snowpack with higher water content (the snow is usually deeper on this side, too). Do you know why this is? Think about how the sun moves across the sky in New Hampshire.

  • On an annual basis, the north-facing and south-facing slopes exhibit similar patterns in terms of snowpack water content.

These data have helped scientists learn more about water cycles and overall watershed budgets at the HBEF.


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