These are the tab-delimited text files available for download until the
searcheable database is ready.


Common things for all files:

The first row contains the column labels.
The second row contains units or other relevant info about the data.
First column, second row shows the year.

The first column is the julian day for that year.
The second column is the time of day (eg. 1230 = 12:30PM).
The data are averaged over a 30-min period, the time shows the *end* of that period.
Following that are the data columns.
The last column shows the julian day + decimal time, useful for indexing
in a database. Please note that the decimal time is calculated using the
*beginning* of each time period, so that day 1, time 0000 to 0030 = 1.00,
and day 1, time 2330 to 2400 = 1.979, not 2.00!

Specifics:

Soil moisture data files for the six experimental rings (r1 - r6):
Each ring has four sensors (tdr1 - trd4).
Data columns show percent volumetric soil moisture content integrated over
the 30 cm vertical rod (eg. .125 = 12.5%) for each sensor.

Precipitation, Net radiation, and PAR data files (1998, rings 4 and 5):
First four columns show precipitation (mm) and net radiation (W/m^2).
Ring 4 measures overstory precipitation (po), and ring 5 measures throughfall (pt).
The last data column shows PAR (millimol/m^2*s).

Air temperature, Relative Humidity, SVP, and VPD (r1 - r6):
Data columns are organised by ring number.
For each ring there is:
- Temperature (Degrees C)
- Relative humidity (absolute values)
- SVP (Saturated Vapor Pressure - kPa)
- VPD (Vapor Pressure Deficit - kPa)
measurements are done at 2/3 of canopy height

Soil temperature
measured via thermistors at one point at 10-12 cm depth in each ring

For 1997, the T-RH-SVP-VPD-files also contain the precip and net-rad data.


References and Specifications:

Temperature and relative humidity:
Vaisala sensor distributed from Campbell Sci. Inc. Model HMP35C:
	Temperature +/- 0.4 deg C @ -24 deg to 48 deg C
	rel. humidity +/- 2 % 0 to 90 %; +/- 3% >90%

soil moisture content:
Campbell Sci. Model CS615 accuracy +/- 2%; since no temperature correction is used,
additional +/- 0.8% measurement error. The probe consists of two 30 cm long metal rods, where
the soil moisture content is integrated, thus encompassing the total root volume of the site.

precipitaion:
Tipping Buckets by Texas Instruments distributed from Campbell Sci. Model TM 525MM:
	< 10 mm/hr +/- 1%; 10-20 mm/hr +/- 3%; 20-30 mm/hr +/- 5%

net radiation: Radiation and Energy Balance System Inc. Model REBS Q*7.1:
	not corrected for wind speed -1.6 % to + 4.3 % measurement error

photosynthetic active radiation (PAR): LiCor Inc. Model LI 190SZ +/- 5%

soil temperature: thermistors by Siemens Type M 841/S1 +/- 0.4 % from -40 deg C
to + 100 deg C

Companies:
Campbell Scientific Inc. 815 W. 1800 N., Logan, Utah 84321-1784
LiCor Inc. 4421 Superior Street P.O. Box 4425, Lincoln, Nebraska 68504
Radiation & Energy Balance Systems Inc. PO Box 15512, Seattle, Washington
98115-0512
Siemens GmbH, Nuernberg, Germany

Changes:

Nov 4, 1998: Cleaned up data in the Soil moisture file for August - R6,
sensor #3
Nov 18, 1998: Corrected the units for PAR - mmol is correct, was umol.
Nov 24, 1998: Added more files for 1997, redesigned the headers for soil moisture,
renamed files for better directory listing.
Dec 3, 1998: All published files are now clean, all available data has been
published through the end of October, 1998.
May 16, 2000: The edc00mar file has been reposted with a correction of a leap-year
error in the time stamp.


Please send your questions/suggestions/requests/complaints to
yavor@acpub.duke.edu