CWOP Solar Radiation Data

About one fifth of active CWOP members send solar radiation data along with other weather data and most use this Solar Radiation Sensor. Each of these Davis sensors has been "calibrated against a secondary standard which is calibrated periodically against an Eppley Precision Spectral Pyranometer in natural daylight". Click here for information on solar radiation measurements.

All of the solar radiation data received by CWOP since 2009 have been archived. The raw data packets used to get the solar radiation data in the archive are available for download as daily text files compressed by gzip. The NOAA SurfRad data discussed below are also included in these files.

NOAA operates the SurfRad Network with these Eppley Precision Spectral Pyranometers to monitor solar radiation at seven sites around the US 48-state area. The downwelling solar radiation data from these sites are available to compare with CWOP solar radiation data. The NOAA SurfRad data have IDs that start with the letters of "Surf Rad Calibration (SRC...) and are: SRCBON Bondville, IL; SRCTBL Boulder, CO; SRCDRA Desert Rock, NV; SRCFPK Fort Peck, MT; SRCGWN Goodwin Creek, MS; SRCPSU Penn State, PA; and SRCSXF Sioux Falls, SD. The raw data packets used to get the solar radiation data in the archive are available for download as daily text files compressed by gzip. After download, the gunzip command has to be used to view the text files. The report linked above has a script for downloading the files. The NOAA SurfRad data discussed above are also included in these files.

The units are: time, decimal UTC hours; solar radiation, Watts per square meter; wind, miles per hour and degrees from true north; and temperature, degrees F. Note that only raw packets with non-zero values of solar radiation are listed. The SurfRad data files start and end at 0000z. All other data files start and end one hour earlier.

Technical reports are prepared occasionally to describe the archive of solar radiation observations. The Technical Reports map the global distribution of reporting stations, describe ways to parse and represent it, and present the breakout of stations by technology in use, daily frequency of reporting, and station age. Six Year Technical Report download. Ten Year Technical Report download. Twelve-Year Technical Report download.

How the solar data have been collected into an Amazon Web Services database is described by Paper 12.1 in the Innovative Measurements Session from the 2016 AMS Annual Meeting. There is a related poster from the 31st Conference on Climate Variability and Change presented at the 2018 AMS Annual Meeting. Also, a way to view CWOP solar radiation data via a Redshift database.