Hubbard Brook Experimental Forest: Daily Solar Radiation Measurements, 1959 - present

Daily solar radiation has been measured at Hubbard Brook Experimental
Forest Headquarters since 1959, using several different sensors.
Radiation was recorded continuously first by a Belfort pyranograph and
later by a Weather Measure pyranograph. The pyranograph has been at
its current Headquarter location since 1960 and before that at weather
station 1, near weir 1. With the installation of the automatic weather
station in 1981, a LiCor pyranometer was collocated with the
pyranograph and used as the primary radiation sensor. After the LiCor
sensor came online the pyranograph charts were only read for the
purpose of gapfilling. The pyranograph remained in operation until
2005 for this purpose but was discontinued when the charts were no
longer available. In April, 2018 the LiCor sensor was exchanged for an
Apogee SP230 light sensor. Data checking was done on the entire record
and values flagged when changes were made to previously posted,
erroneous or missing data. These data were gathered as part of the Hubbard Brook Ecosystem Study
(HBES). The HBES is a collaborative effort at the Hubbard Brook
Experimental Forest, which is operated and maintained by the USDA
Forest Service, Northern Research Station.