Here you can find an example of a monthly dataset within BSRN. The corresponding zipped datafile can be downloaded here (PANGAEA download format with quality codes already inserted). The quality codes (see 'Example of erroneous data') and the SumSW calculation were inserted by using the BSRN Toolbox, "Comparisons" check with the "Iqbal 1983" algorithm. For more information see https://wiki.pangaea.de/wiki/BSRN_Toolbox#Example. The first figure shows a typical monthly time series of logical record 0100 with the downward oriented radiation fluxes (min, max and std dev was left out for a better view). Examples of sunny, cloudy, and mixed days are highlighted in yellow, blue and green, respectively. DIR = direct radiation, DIF = diffuse radiation, SWD = global radiation, LWD = long-wave down, T2 = air temperature at 2 m height, RH = relative humidity, PoPoPoPo = atmospheric pressure. The second figure shows a diagram of SumSW (calculated global radiation) vs. the measured SWD (short-wave down) radiation. Both are perfectly in line.
Example of erroneous data
Here is an example of a time series with ~three days of erroneous data due to instrumental problems. The corresponding zipped datafile can be downloaded here (PANGAEA download format with quality codes already inserted). Please note, that the data of the respective days were of course removed before uploading it to the BSRN server and PANGAEA, but the uncorrected file is shown here to highlight the importance of quality checks. The first figure shows the monthly time series as above, with one line depicting the quality flags of the BSRN Toolbox (Comparisons check). The error is hardly visible in the time series, but the quality flags clearly show it. The second figure again shows the calculated global (SumSW) vs. the measured global radiation (SWD). Here you can clearly see the outliers which represent the data points of the ~three days of instrument failure.