This data set contains percent soil moisture (by weight) (and/or water content if there is a moss/humus layers measured from aircraft using a terrestrial gamma ray instrument. There is also data that indicates the location of the aircraft at the time it collected the terrestrial gamma ray data for the various flight lines and bins. The location information contains a list of coordinates that indicate the path of the aircraft for each bin. The data were collected during four time periods from September 1993 to September 1994 over the Southern Study Area (SSA) and two time periods from February to August 1994 over the Northern Study Area (NSA).

This data set contains percent soil moisture ground measurements. These data were collected on the ground along the various flight lines flown in the Southern and Northern Study Areas (SSA and NSA) during 1994 by the gamma ray instrument. This data set contains information on the locations of field in-site measurements of soil moisture, depth of moss/humus layer, and water content of the moss/humus layer and contains information on soil conditions and vegetative cover around the sites.

Contains the measurements of soil moisture that were made at various sites on the ground by HYD-06.

Soil moistures measured by airborne gamma ray, averaged in segments or transects

The BOREAS HYD-01 team made measurements of volumetric soil moisture at the SSA and NSA tower flux sites in 1994 and at selected tower flux sites in 1995-97. Different methods were used to collect these measurements, including neutron probe and manual and automated TDR. In 1994, the measurements were made every other day at the NSA-OJP, NSA-YJP, NSA-OBS, NSA-Fen, SSA-OJP, SSA-YJP, SSA-Fen, SSA-YA, and SSA-OBS sites. In 1995-97, when automated equipment was deployed at NSA-OJP, NSA-YJP, NSA-OBS, SSA-OBS, and SSA-OA, the measurements were made as often as every hour.

Under-canopy precipitation measurements were made by the BOREAS HYD-01 science team in 1994, 1995, and 1996 at various flux tower sites in the NSA and SSA. In 1994, these data were collected at the NSA-OJP, NSA-YJP, SSA-OJP, and SSA-YJP sites. Starting in 1995 and ending in 1997, data were collected at the NSA-OBS, NSA-OJP, NSA-YJP, and SSA-OA. These data were collected to support HYD-01 research by measuring the amount of water that falls through the canopy and is intercepted by the ground or moss. These data coincide with volumetric soil moisture measurements made by HYD-01.

Gravimetric soil moisture data collected in conjunction w/ gamma ray soil study

Contains the HYD-08 mean gross precipitation measurements made at 2 gauges at the SSA-OBS.

Airborne soil moisture measurement is based on the difference between natural terrestrial gamma radiation flux measured for comparatively wet and dry soils. The presence of moisture in the soil causes an effective increase in the soil density resulting in an increased attenuation of the gamma flux for relatively wet soil and a correspondingly lower flux at the ground surface. As part of the FIFE experiment, natural terrestrial gamma radiation data over a network of 24 flight lines were collected. The data acquisition procedure was designed to accumulate and store spectral radiation data along a flight line from which estimates of soil moisture could be computed. Ground-based soil moisture measurements were used to make a one-time calibration of the natural terrestrial radioisotope signal over the flight line network. A time-series of airborne soil moisture measurements (to a depth of 20 cm) was compared to an extensive, independent data set of ground-based soil moisture measurements. Estimates for flight line segments were found to have an average RMS error of approximately 2.5 % soil moisture (Peck et al., 1990).

Contains the under canopy precipitation data that was collected in 1994, 1995, 1996 and 1997 by the HYD-01 group at the various tower sites.