Water Table Depth (WTD) NIMS grid Atqasuk, Alaska 2012

Water table depth (WTD) measurements were taken along the Networked Info-mechanical Systems (NIMS) grid in Atqasuk, Alaska during the summer of 2012. The NIMS grid is situated about 50 meters to the south of the International Tundra Experiment (ITEX) dry site. If a uniform representation of the water table within each plot was visible, then a WTD tube was placed there to measure the change in water table throughout the season. For instance if the plot was half saturated and half dry, then that plot was skipped and no tube was placed there. The exact location of WTD tubes are as follows: Between meters 0-1, 3-4, 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 32-33, 34-35, 36-37, 38-39, 40-41, 42-43, 44-45, 46-47 & 48-49. A total of 22 WTD tubes were installed into the NIMS grid in Atqasuk. Measurements were made every few days during the summer snow free period between mid June and mid August. WTD was calculated as the difference between the depth (cm) of the water table above or below the measuring tube (- Values = water above tube, + Values= water level below the height of the tube) and the height of the top of the measuring tube above the ground level. Measurements were not made (NA in data sheet) if there was persistent snow cover, interference or disturbance from other experimental infrastructure, or if water table depth tubes were dry to the upper surface of the permafrost.