Homogeneous daily solar (GLOBAL) radiation data for station Mikołajki (Poland) for the period 1991-2015

Ground-based measurements of global solar radiation are often subject to various errors which are very difficult to detect. This is why quality control procedures and homogenisation of data are essential and should be performed prior to further analyses. We present homogeneous global solar radiation data set, without any gaps, for 16 ground-based stations located in Poland for the period 1991-2015. The data set was prepared with a modification of bias-based quality control (BQC) method (developed by Urraca, and presented in 2017), tailored specially for detecting single erroneous daily values (mostly caused by a failure of the measuring equipment), and very long periods of small errors (mostly caused by a miscalibration of the measuring equipment). The values on the days considered as erroneous were replaced with debiased SIS SARAH-2 values. In many situations the data were visually checked to make sure that the prepared set constitutes the best possible climatology of actinometric data in Poland.