22 March, 2002

Climate: Sunny
High 35
Low -3

The Science Behind Sun Cups

Before we proceed with this new topic, recall thermal conductivity changes from yesterday's journal. Variations in thermal conductivity depend on changes of snow density, which can be affected by warmer temperatures and flooding.

As far as snow cover on Jalpertia pond, snow depth and surface textures are two evident changes. Due to warmer temperatures and gust winds, snow depth decreases and surface textures present more detail and deviation.

With more than 12 hours of daylight, sun cups (cup-like grooves) will extend snow surface area especially near dark-colored vegetation -- excellent solar radiant material. Often times, air gaps are found

near vegetation (see Picture #6.)

For homework tomorrow, we will have a quiz on native trees. Study the identification chart (March 19th journal.)

1. Irregular patterns - possibly caused by wind.

2. 33.5 Mile pond

3. Uniform pattern on Jalpertia pond - possibly caused by wind AND sun.

4. MST pond

5. Extended sun cup exposing more surface area

6. Air gap near vegetation from solar radiation.