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3 December, 2001

Bundled in six layers of clothes, bunny boots, and layers of hats The first snow measurements were taken near Council. Albedo measurements were taken across the tundra. Albedo is the ratio of outgoing solar radiation from the snow or ground to the incoming solar radiation from the atmosphere. An albedo measurement of 1 would mean that all of the incoming solar radiation would be reflected back into the atmosphere. An albedo measurement of 0 would mean that all of the radiation was being absorbed by the snow/ground. Because snow is white, it strongly reflects solar radiation. On the opposite end, something black strongly absorbs solar radiation. So a deep layer of snow would be very reflective and have a high albedo. On the other hand, snow also acts like a huge insulating blanket on the ground. The more snow cover on the ground, the warmer the ground will stay. The less snow on the ground, the cooler the ground will become. Shrub height on the tundra plays an essential role in snow cover and ground temperature. Taller shrubs trap more snow, making a deeper snow cover. This in turn keeps the ground warmer, leading to even taller shrubs. The albedo of tundra with tall shrubs is on the lower end of the 0-1 albedo scale. This is because the shrub tops are sticking out of the snow, and the dark branches absorb more solar radiation. In turn, the shrubs are causing the snow cover to be deeper, this causes the ground to be warmer because of the insulating blanket characteristics of the snow. Today we measured an albedo of 0.65 in an area where there were few shrubs, which is on the higher end of the scale. The shrub height was low in this area so much of the radiation was escaping back into the atmosphere. On another site with medium shrub heights, the albedo was 0.3 which means 70% of the radiation was absorbed into the ground.

The albedo measurements are taken by this cool looking UFO device. It hangs off a wire stretched between two poles. This complex instrument simply measures the amount of incoming and outgoing solar radiation. A probe is connected to the albedo instrument that collects all of the readings and saves the data on a data logger. These data that were saved on the data logger can be later transferred into the computer, for plotting using graphics programs and analyzed using statistical programs. In addition, the computer is used to store the data for later use.

Albedo measurements are important because it helps scientists understand the relationships between temperature changes, snow depth, and shrub height. If the shrub height changes, then the snow depth changes, and this in turn has an effect on the overall temperature of the ground. If temperatures at the North or South poles change this can change the overall global weather and climate patterns. So, albedo measurements and an understanding of their implications are important to the entire world!!!

High Temp: -5 F

Low Temp: -15 F

Jon and Matthew taking an albedo measurement.

A day of long, cold work!

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