Active Layer Thickness site «Barrow, CRREL Plots» (at site «Barrow», United States) inactive

SITE DESCRIPTION

In 1962, 10 x 10 meter plots were randomly distributed across a 2-km long transect characteristic of the ice-wedge dominated Arctic Coastal Plain. Plots were subdivided into 2 x 2 m squares and the active layer measured at 20 border points during the thaw season and at all 36 grid points in late August and/or early September. Data from a total of 42 plots are available at variable sampling intervals, with a standard set of 20 plots at the end of the thaw season (400 points per sample date). Summary and descriptive statistics for each plot on each date of measurement are reported.

Map of plots and further details on sampling design are provided in USA CREEL STUDY AREA.doc

Summary statistics by plot are believed to be accurate reflections of the position of the seasonal thawing front, owing to the ice-bonded nature of the substrate and the number of replications at each plot. Values reflecting observations made in late summer and early fall may be slightly greater than actual (thermally defined) thaw depth values because some refreezing may have occurred from the bottom of the active layer.

Soil temperatures are available from 1963-66, and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

Soil moisture content data are available from 1963 only and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

Snow depth measurements are available from 1963-64, and and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

These data were collected at each study plot site to characterize the active soil layer at Barrow and to determine the relationships these physical properties have at permafrost sites in the Arctic. Please refer to each subdirectory for detailed descriptions of the sampling techniques used to collect the data and the data format for each data set.

For additional soil temperature, soil moisture, and snow cover data refer to site U1 Barrow 1 km grid.

The U1 air temperature is in close proximity to CREEL plot 34,

U1-2 soil temperature, and soil moisture installations are located in close proximity to CREEL plot 42. The data also available (http://soils.usda.gov/survey/scan/alaska/Barrow2/ )

The environment at Barrow was described in a series of papers including of the Tundra Biome Program during the 1970s (Brown et al., 1980). The Barrow CRREL grid is located about 5 km east of the village of Barrow on the outer Arctic Coastal Plain. The site is situated on reworked silts of marine origin. A series of nineteen, 10m plots are located in the southeast section of the 1 km grid (U1).

SAMPLING DESIGN AND METHOD:

Soil thaw was measured by inserting a metal probe in the soil to the point of resistance. The sample intervals are varied from year to year. During the summers in 1960s and 1997 outer 20 points of each plot   were probed and at the time of estimated maximum thaw, all 36 plot points were measured. In years 1993-1996 only interior 16 points were probed. For map of the study area and sampling design, please check USA CREEL STUDY AREA.doc

DATA

Soil temperatures are also available from 1963-66, and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

Soil moisture content data are also available from 1963 only and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

Snow depth measurements are also available from 1963-64, and are located at NSIDC web site http://nsidc.org/data/docs/fgdc/ggd222_activlayer_barrow/data.html

For additional soil temperature, soil moisture, and snow cover data refer to site U1 Barrow 1 km grid.

The U1 air temperature is in close proximity to CREEL plot 34,

U1-2 soil temperature, and soil moisture installations are located in close proximity to CREEL plot 42. The data also available (http://soils.usda.gov/survey/scan/alaska/Barrow2/ )