Gulkana


Index

Map of area
Gulkana station history
Gulkana temperature history (uncorrected)


Map of Area



Selection from USGS Gulkana A-3 quadrangle, original 1949 updated 1975. Squares are sections, 1 mile on a side; contours in feet.

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Gulkana Station History

The Copper River Basin is a nearly closed basin, floor elevations around 1500' - 2000', at the junction of the Copper and Chitina Rivers. The basin is bounded by the Talkeetna Mountains on the west, the Alaska Range on the north, the Wrangell-St Elias Range on the east, and the Chugach Range on the south. The Copper River drains to the Pacific through a narrow canyon in the Chugach Range. During glacial times, this canyon was filled with ice and an ice- dammed lake filled the basin. Since then, the rivers have cut into the lake sediments and generally flow below the level of the basin floor.

There is only a single long-term station, Gulkana, in the Basin. Division average temperatures published in the Alaska Climatological Data show a strong positive temperature trend, but this is an artifact. The plot for each year is based on whatever stations happen to be active that year, and there has been a systematic trend to drop the colder stations and bring in warmer ones. The straight Gulkana record, while showing some warming since 1976, shows little overall trend since the early 40's.

Gulkana is located toward the east side of the Copper River Basin, west of and above the Copper River. Current coordinates 62 degrees 9' N, 145 degrees 27' W, elevation 1572 feet. Brief periods of record in 1907 and 1909-1920 9 miles N and downhill from present site, at 62 degrees 18' N, 145 degrees 28', elevation 1370 feet. Given north to south direction of river flow, the early location was probably down in the river valley. Station was reestablished 9 miles south and 202 feet higher at the Gulkana Airport 11/9/1942. Became an AMOS station and HO6 hygrothermometer added 9/27/73.

Observation time 1 pm in 1907, 4 pm 1909-1920. Observation time midnight 11/9/1942-9/1/1971, switched to 6 am 9/1/71. Switch to 9 pm 5/99/80.

Observer currently automated FAA (FSS/AMOS), formerly USWB (1967-1973) and CAA (1942-1967).

Length of record somewhat short, as early observations were at a different site. Site continuity since 1942 good except for time of observation and switch to AMOS. Data completeness good except missing three months in 1973.
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Gulkana Temperature History


Plot of mean annual temperature history at Gulkana

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Geophysical InstituteInt'l Arctic Research Center