NOTICE: The quantum sensor that measures photosynthetically active radiation (PAR) at the Penn State SURFRAD station lost approximately 4% sensitivity on 22 Sept. 2013. That sensor was replaced on 14 Nov. 2013 after which the PAR measurements increased to more normal values. On 21 Nov. 2013, the QC values of the Penn State SURFRAD PAR measurements over the affected period (22-Sept to 14-Nov. 2013) were set to bad (1), however, the PAR values were kept in the data files, i.e., not set to missing.
NOTICE: The clock in the Table Mountain SURFRAD station data logger drifted linearly from late October 2012 to 5 May 2013. On 5 May 2013 the clock time was found to be fast by nearly four minutes, and the problem was fixed. A linear correction has been applied to the time in all Table Mountain raw data files for that period and those files have been reprocessed. The new time-corrected data files were uploaded to the SURFRAD FTP site on 15 August 2013.
NOTICE: The station pressure at Penn State drifted by about 0.4 mb per year between 11-April-2003 and 18-June-2012. Those data have been corrected and new Penn State SURFRAD daily files have been generated with corrected pressure for the affected period.
NOTICE: The README file that describes the SURFRAD data files has been updated. Please download the latest version from any of the individual station FTP data directories, e.g., ftp://aftp.cmdl.noaa.gov/data/radiation/surfrad/Bondville_IL.