Variations in Summer Temperature Patterns near Barrow, Alaska: Analysis and Ecological Interpretation

Abstract

Twenty-six yr (1950-1975) of daily mean temperature and wind direction records for May-Sept. at Barrow, Alaska [USA], were examined for seasonal patterns in variability. Cumulative deviations from average daily mean temperature were calculated to compare differences among years in temperature regimes. Seven yr deviated more than 100 cumulative degrees Celsius by the end of Aug., while 5 yr remained close to the 26 yr average. Early May and late July-Aug. were more variable among years than June and early July. This related to a decrease in the predictability of wind direction in Aug. and to a concomitant increase in the sensitivity of temperature to wind direction. Within a given year, temperatures during the latter half of the summer were more predictable from one 15 day period to the next than were temperatures in June. These seasonal patterns in temperature variability foreshorten the length of the active period for tundra organisms and have important implications for life-history processes.