Elevated Soil Temperature and Water Table Manipulation Data from Barrow, Alaska, 1999-2001

Summary

This data set contains elevated soil temperature and water table manipulation measurements taken at a tundra site near Barrow, Alaska, USA. Eighteen 60-cm diameter polycarbonate cylinders were installed into the ground at the end of the 1998 growing season when thaw depth was at its seasonal maximum to isolate plots of tundra. The cylinders were organized into three blocks of six for three replicates of the six treatments to be tested. The six factors tested include: control, elevated water table, lowered water table, elevated soil temperature, elevated soil temperature and elevated water table, and elevated soil temperature and lowered water table. Temperature data were collected from June 1999, until September 2001.

Measurements were taken as part of the Land-Atmosphere-Ice Interactions Arctic Transitions in the Land-Atmosphere System (LAII-ATLAS) program. The research project was funded by the Arctic System Sciences (ARCSS) Program, grant number OPP-9732105.

Data are available for ordering through NCAR.

Citing These Data:

Oechel, W. 2003. Elevated Soil Temperature and Water Table Manipulation Data from Barrow, Alaska, 1999-2001. Boulder, CO: National Center for Atmospheric Research, ARCSS Data Archive.

Overview Table

Category	Description
Data format	Comma-delimited text file
Spatial coverage	Data were collected near Barrow, Alaska, USA, located at 71.32º N, 156.62º W
Temporal coverage and resolution	Dates of collection were between 1999-06-09 and 2001-09-01
File size	Data file is 20.24 MB; column heading definition file is 8 KB
Parameter(s)	Soil temperature, water table depth

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Acquisition and Processing
4. Document Information

1. Contacts and Acknowledgments:

Investigator(s) Name and Title:

Walter C. Oechel
Department of Biology
San Diego State University
San Diego, CA 92182

2. Detailed Data Description:

Format:

barrow_soiltmp_manip.txt: comma-delimited text file of soil temperatures at various sites

barrow_soil_definitions.txt: ASCII text file that describes the column headings for barrow_soiltmp_manip.txt.

Column Headings

The barrow_soil_definitions.txt file describes column headings in the data file. The data file (barrow_soiltmp_manip.txt) contains 111 columns. The first three columns are unnumbered and are Year, Julian Day, and Hour. The remaining columns (numbered 1 - 108) contain probe descriptions. Below is an example of the column headings for columns 1 through 3.

1	2	3
1-1-1c H	1-1-5c H	1-1-15c H
plot 1-1, 1 cm depth, center, heated	plot 1-1, 5 cm depth, center, heated	plot 1-1, 15 cm depth, center, heated

File Size:

barrow_soiltmp_manip.txt: 20.24 MB
barrow_soil_definitions.txt: 8 KB

Spatial Coverage:

Data were collected near Barrow, Alaska, USA, located at 71.32º N, 156.62º W.

Temporal Coverage:

Data were collected between 1999-06-09 and 2001-09-01.

Temporal Resolution:

Measurements were collected once every half hour.

Parameter or Variable:

Parameter Description:

The parameters measured in this data set are soil temperature and water table depth. The six factors tested include: control, elevated water table, lowered water table, elevated soil temperature, elevated soil temperature and elevated water table, and elevated soil temperature and lowered water table. See the barrow_soil_definitions.txt file for a complete description.

Unit of Measurement:

The unit of measurement for temperature is degrees Celsius, measured at various depths (cm).

Sample Data Record:

Sample data from columns Year, Julian Day, Hour, and 1-6.

Year	Julian Day	Hour	1	2	3	4	5	6
1999	190	1930	14.38	12.75	8.07	5.509	12.99	8.86
1999	190	2000	12.76	12.05	8.08	5.502	12.81	8.87
1999	190	2030	8.86	10.91	8.16	5.533	12.54	9.14

3. Data Acquisition and Processing:

Sensor or Instrument Description:

Eighteen 60 cm-diameter polycarbonate cylinders were installed into the ground at the end of the 1998 growing season when thaw depth was at its seasonal maximum to isolate plots of tundra and were organized into three blocks of six for three replicates of the six treatments to be tested.

There are six type-t thermocouples in each plot, four in the center and two at the edge. The depths of the center probes are 1 cm, 5 cm, 15 cm, and 25 cm. The probes at the edge of the plots are at 5 cm and 15 cm depth. Data were collected in half-hour intervals by a 23X datalogger (Campbell Scientific, Inc.). Blank areas in the data are due to power failure or other loss beyond investigator control. Soil heating was accomplished by the use of silicone rubber heaters (Omegalux, Inc., 5.0 W m-2) affixed to the inner surface of the cylinders. Heating treatments are maintained so that soil temperature was 5ºC warmer than ambient soil temperatures during the 1999 season and 3ºC warmer than ambient during the 2000 and 2001 seasons. Water table drainage was maintained through the use of float switch activated water pumps (Rule Inc., 500 gph) within perforated PVC pipe water wells in each plot. In elevated water table treatments, water was pumped into identical wells from an outside reservoir.