Producing K indices by the interactive method based on the traditional hand-scaling methodology — preliminary results

•We proposed an interactive method that simulate the hand-scaling of K indices.•The method incorporates a subjective choice for creating non-K variations.•Our method performed well for both very low (K  =0) and high (K≥5K≥5) levels of the geomagnetic activity.

This paper reports on an interactive computer method for producing K indices. The method is based on the traditional hand-scaling methodology that had been practised at Hurbanovo Geomagnetic Observatory till the end of 1997. Here, the performance of the method was tested on the data of the Kakioka Magnetic Observatory. We have found that in some ranges of the K-index values our method might be a beneficial supplement to the computer-based methods approved and endorsed by IAGA. This result was achieved for both very low (K  =0) and high (K≥5K≥5) levels of the geomagnetic activity. The method incorporated an interactive procedure of selecting quiet days by a human operator (observer). This introduces a certain amount of subjectivity, similarly as the traditional hand-scaling method.