Climate Forcing at the Arctic LTER Site

• Main Authors: Hobbie, John E., Bettez, Neil
• Format: Book Part
• Language: unknown
• Published: Oxford University Press 2003
• Subjects: Arctic; Arctic Ocean; Fairbanks; Haugan; Haugen; Northern Foothills; Brooks Range; Prudhoe Bay; Tundra; Alaska
• Online Access: http://dx.doi.org/10.1093/oso/9780195150599.003.0011

The Arctic LTER site is located at 68º38'N and 149º43'W, at an elevation of 760 m in the northern foothills of the Brooks Range, Alaska. The location, 208 km south of Prudhoe Bay, was chosen for accessibility to the Dalton Highway, which extends along the Trans-Alaska Oil Pipeline from north of Fairbanks to Prudhoe Bay on the Arctic Ocean (figure 5.1). The rolling foothills at the site are covered with low tundra vegetation (Shaver et al. 1986a), which varies from heaths and lichens in dry sites to sedge tussocks on moist hillslopes to sedge wetlands in valley bottoms and along lakes. Riparian zones often have willow thickets up to 2 m in height. Small lakes are frequent; the best studied such lake is the 25-m-deep Toolik Lake (O’Brien 1992), the center of the LTER research site. Some 14 km from Toolik Lake, the Dalton Highway crosses the fourth-order Kuparuk River, the location of much of the LTER stream research (Peterson et al. 1993). Climate records at Toolik Lake have been kept since the early 1970s when a pipeline construction camp was established. On completion of the road in 1975, climate stations were set up by the U.S. Army Cold Regions Research Laboratory (CRREL, climate reported in Haugan 1982 and Haugen and Brown 1980). Since 1987, the LTER project has maintained climate stations at Toolik Lake (http:// ecosystems.mbl.edu/arc/) whereas the Water Resources Center of the University of Alaska has continuous records beginning in 1985 from nearby Imnavait Creek. An automatic station at Imnavait now reports every few hours to the Natural Resources Conservation Service–Alaska of the U.S. Dept. of Agriculture. The characteristics of the climate in northern Alaska are summarized by Zhang et al. (1996), who pointed out the strong influence of the ocean during both summer and winter months. They reported that the mean annual air temperature is coldest at the coast (–12.4ºC), where there are strong temperature inversions in the winter, and warmest in the foothills (–8.0ºC). At Toolik Lake, snow covers the ...