TITLE
Daily Solar Radiation Data
PRINCIPAL INVESTIGATOR
Amey Bailey
USDA Forest Service
Hubbard Brook Experimental Forest
West Thornton, NH
Telephone: (603) 726-8902
BEGIN DATE
January 1956
END DATE
On-going
LOCATION
HBEF station headquarters
DATA DESCRIPTION
Daily solar radiation has been measured at HBEF Headquarters since 1960, using several different sensors.
SAMPLING DESIGN
Solar radiation has been recorded continuously by a Belfort pyrano--graph and later by a Weather Measure pyranograph. The instrument has been at its current Headquarter location since 1960 and before that at weather station 1, near weir 1. Since the installation of the automatic weather station in 1981, its LiCor pyranometer has replaced the pyranograph as the primary radiation sensor. The pyranograph is still maintained as a backup.
Solar radiation is now sampled by the LiCor sensor once minute and hourly means are calculated by a Campbell CR-21 Data logger. The data are dumped hourly to a data storage module, which is changed and downloaded monthly. Where LiCor data are not available, pyranograph data are used. The pyranograph chart is changed weekly. Because of rapid fluctuation, instantaneous readings cannot be obtained from the pyranograph on partly cloudy days. The pyranograph chart is digitized visually, using a digitizer, for each 2-hour increment throughout the day.
ACCESS
Public
DATA LOCATION
USDA Forest Service, Durham, NH
LAST UPDATED
May 24, 2001
CONTACT PERSON
John Campbell
PO Box 640
Durham, NH 03824
Telephone: (603) 868-7643
E-mail: jcampbell@lternet.edu
VARIABLES
| Column | Variable | Description | Units | Coded | Missing Value |
| 1 | Date | Sample date | yymmdd | n | none |
| 2 | HQ | Measured at Headquarters | MJ/M2 | n | 99.99 |
NOTES
Although all sensors appear to have been within about +- 5% of the true value, users should be aware that bias may exist in the radiation data and may change over time.
Beginning in 1987, zeros are embedded in the date.
DATA FILE NAME(S)
radYYYY.txt