Abstract: IAGA 2013, aout 2013, Merida, Mexique.
The planetary three-hour range Kp index was introduced by J. Bartels in 1949. Kp is the average of standardized K-index from 13 observatories between 44° and 60° northern or southern geomagnetic latitude: 11 of them are located in North America and Europe and 2 in Australia and New Zealand. Such a distribution of the Kp observatories results in a UT dependent statistical bias in the estimate of planetary geomagnetic activity, since the geomagnetic activity intensity varies with Local Time. In this paper, we took advantage of the recent developments on sectorial indices to better characterize the description of planetary geomagnetic activity provided by Kp.