Consider the following scenario: You and some friends are backcountry skiing in

Question

Consider the following scenario: You and some friends are backcountry skiing in the Green Mountains of Vermont in January. There is a deep snowpack, and you’re having a great time. On the way into the mountains, your group crossed a stream several times using bridges built for carrying skiers. The stream level was very close to the bottom of the bridges because of a warm spell that was occurring. After a few hours of skiing high in the mountains, it’s time to leave. Unfortunately, it has started to rain, so everyone pulls out their rain jackets, puts them on, and starts heading down. You are concerned that the bridges crossing the swollen stream may be flooded by the time you reach them. NOW, with reference to this scenario answer the following questions: a) Discuss the factors that will affect the amount of snow an area will receive b) Explain the process of snow melt. c) Explain the factors that must be taken into account in calculating snow melt. What is it that ultimately determines how much snow melts? (i.e. what number or factor do we actually try to calculate?) Be sure and discuss the differences (and reasons for them) between snow melt rates with and without rainfall. d) Explain how you might go about determining the amount of water in the winter snow pack of a watershed. Why is this important to know? e) Discuss what processes might be causing the stream to rise and whether you think the bridges will be flooded or not. Explain your reasoning. f) Now change locations. Snow melt is very important in the western US. i) Why is the role that it plays different from the eastern US? ii) Dust deposition causes snowmelt to occur earlier. Explain this AND what effect earlier snowmelt my have on water supplies in areas that rely on snowmelt as a major water source. g) What long term effect might occur over the next 50 years (due to climate change) in areas that rely on snow melt for water supply? Cite ONE example in your discussion.

Explanation / Answer

a) The factors affecting the amount of snow a an area will receive:

1. The latitudinal location

As you move away from the Equator, the seasonal variation is higher across the summer and winter seasons. In the case of Vermont, around 40-45 degrees North. During the winter, the distance from the sun is higher in this region, and hence the amount of sunlight and the hotness of the region is less.

2. Air Pressure & Winds/ Frontal Activity

Solar radiation heats the planet, bit it does not do it evenly. The movement of air happens between areas of low pressure to the areas of high pressure (laterally meaning, from the colder areas to the warmer areas), resulting in winds.When there is air circulation, and resultant air rising, it causes condensation. Depending upon the moisture content of the rising air, and the ambient temperature of the location, the precipitation happens, in the form of snow, or rains.

In the case of Vermont, the prevailing Northwesterly flow of wind in the winter season which brings in a lot of cold dry air from the north, warm moist air from the sub tropics, cool damp air from the North Atlantic interact to produce low pressure storm systems and lot of unpredictable weather variations. The frontal activity of the region causes rainfall during summers, and snowfall during the winters.

3. Moisture Content/ Amount of Water availble

The presence of water in the air is a very significant factor for producing snow. The presence of vast water bodies next to a location adds water to the atmosphere due to evaporation, similarly, there is a constant generation of air movement between land and sea, due to the temperature differntial between land and water bodies.

The greatest influence of the south-east Vermont, and the Green Mountain range is the presence of the Atlantic Ocean.

4. Elevation from the Mean Sea Level

Another factor which influences the amount of precipitation in the form of snow at a given location is the elevation from the Mean Sea Level. Higher the elevation, higher the probability of receiving precipitation in the form of snow. The temperatures of higher altitude will be lower than the locations of the same latitude at the Mean Sea Level. Hence, there is more probability of condensation and precipitation.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.