# DOI: https://doi.org/10.5880/Kp.0001 # LICENCE: CC BY 4.0, please cite: # Matzka, J., Bronkalla, O., Tornow, K., Elger, K. and Stolle, C., 2021. # Geomagnetic Kp index. V. 1.0. GFZ Data Services, # https://doi.org/10.5880/Kp.0001 # Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., # 2021. The geomagnetic Kp index and derived indices of geomagnetic activity. # Space Weather, https://doi.org/10.1029/2020SW002641 # The Kp index was introduced by Bartels (1949) and is produced by Geomagnetic # Observatory Niemegk, GFZ German Research Centre for Geosciences. International Quietest Days Most Disturbed Days Month Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 D1 D2 D3 D4 D5 Jan 1972 6 14 13 7 8 9 12 5 3K 31A 23 16 22 28 26 Feb 1972 29 9 12 22 27 28 26K 6 5 23 24 17 13 25* 14* Mar 1972 12 10 14 19 21 20 5 15 13A 11A 7 30 29 24 16 Apr 1972 25 26 3 24 9K 10 16 11K 17 8K 29 28 18 21* 4* May 1972 7 19 21 8 20 24 25 22 4 5K 28 15 2* 1* 16* Jun 1972 30 12 11 10 9 13 21 1 8 25 18 17 19* 27* 4* Jul 1972 5 21 14 13 29 6 4 30 28 1 25 24* 26* 7* 23* Aug 1972 23 24 3 13 2 25K 16 31A 17 30K 5 4 6 9 27 Sep 1972 21 20 5 22 1 7 3 12 4 19K 14 13 17 29 15 Oct 1972 5 17 6 3 8K 9 2 25 10 4A 19 14 13 29 31 Nov 1972 5 13 14 10 30 24 12K 4 8A 9A 1 2 16 20 15* Dec 1972 5 21 10 27 6 11 9 4 25 20 16 13 15 23 30*