AlbedoLast Updated on 2010-05-08 03:53:22
Albedo is the fraction of Sun’s radiation reflected from a surface. The term has its origins from the Latin word albus, meaning “white”. It is quantified as the proportion, or percentage of solar radiation of all wavelengths reflected by a body or surface to the amount incident upon it. An ideal white body has an albedo of 100% and an ideal black body, 0%. Visually we can estimate the albedo of an object’s surface from its tone or color. This method suggests that albedo becomes higher as an object gets lighter in shade. The data in Table 1 verifies this fact. Light toned surfaces like snow do have high albedos. Low albedos are associated with surfaces that appear dark colored to our eyes. Some dark colored surfaces include black-top roads, coniferous forest, and dark soil. Table 1 also indicates that the albedo of water varies with Sun... More »
Pacific Coastal Mountain icefields and tundraLast Updated on 2008-08-21 20:38:14
The Pacific Coastal Mountain Icefields and Tundra ecoregion consists of a steep, very rugged range of mountains that stretches from the Kenai Penninsula along the Gulf of Alaska Coast and the Canadian/Alaskan border to the southern end of the Alaska panhandle. In Canada, this ecoregion encompasses the extreme southwestern corner of the Yukon Territory and parts of the coastal mountains in British Columbia south to Portland Inlet.
Elevations range from sea level to over 4,500 meters (m), and slopes generally are steeper than seven degrees, ranging to over 20 degrees. The landscape of this ecoregion is dominated by mountains of great height. Most peaks reach between 2,100 m and 3,050 m, but some are over 5000 m (Mount Logan is 5,959 m, and King Peak is 5,175 m). In this high, extreme northern part of the ecoregion, the Seward, Hubbard, and Malaspina glaciers are the... More »
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