DATE: 8 October 2001 TO: LAII ATLAS Investigators, NSF FROM: Ken Hinkel and Fritz Nelson RE: Late summer 2001 field activities for NSF projects OPP-9529783, 9732051, 0094769, and 0095088
In mid-August, air and soil temperature data loggers were downloaded and serviced at Barrow, Atqasuk, West Dock, Betty Pingo, Deadhorse, Flux Study plots 95-3 and 95-4 in the Sagwon upland, Happy Valley, Imnavait Creek and Toolik Lake. Thaw depth and near-surface soil moisture were measured across the grids as part of the project's ongoing responsibilities for monitoring and modeling spatial and temporal patterns of soil thaw at many of the Alaskan CALM sites. In 2001, average grid thaw depth were similar to those experienced in 2000, and spatial patterns across the grids were consistent with those of previous years. In general, average thaw depths across the North Slope were about 10 cm below maximum averages experienced in 1998. Barrow experienced an unusually cool and cloudy summer, following a winter of heavier snowfall. Thaw depths at Barrow were reduced substantially from those of the previous year.
Costa Hill near Happy Valley was the subject of an intensive sampling program focused on relations between topographic parameters (slope gradient, slope orientation, profile curvature), microclimate, vegetation, and active-layer characteristics.
Series of targets and frost-defended benchmarks were installed in 1 ha areas in the Sagwon upland and near West Dock, using a nested, hierarchical sampling design. The targets will be monitored in subsequent years using differential GPS technology to determine the rate, magnitude, pattern, and variability of frost heave and ground subsidence. In collaboration with Ron Paetzold (NRCS) we installed equipment to conduct energy balance and ground thermal studies in the same areas. A major goal of this phase of our work is to determine the variability of the near-surface thermal regime at local and landscape scales.
The large drift along the Cakeater Road snow fence near Barrow did not melt out completely in 2001. About 50 cm of ice remained in late August as a remnant of the winter drift. The drift was over 4.3 m high in late April; by early June only 50 cm had ablated. This reflects an increase in volume by about 60% compared to previous years. Winter soil temperatures beneath the drift were elevated relative to the non-drifted control study areas, and were several degrees warmer than previous years.
In June, about 60 air and soil temperature loggers were installed in and around Barrow to monitor the urban heat island effect. Data were downloaded in August and are currently being processed and mapped. Loggers were also installed at new locations in the Foothills and the western portion of the Prudhoe Bay oil field.
Finally, we contributed to the Eisner-Bockheim thaw lake project, the field report for which was sent previously.