52 citations · 114 across the 10 of their papers we have counts for
10 papers
The ratio between the number of sunspot and the number of sunspot groups
K. Georgieva, A. Kilcik, Yu. Nagovitsyn +1
Data from three solar observatories, Learmonth, Holloman, and San Vito, are used to study the variations in the average number of sunspots per sunspot group. It is found that the d…
About the recalibration of the sunspot record
Katya Georgieva, Ali Kilcik, Yury Nagovitsyn +1
In 2015 the calculation of the International (Zurich) sunspot number was cancelled, and it was replaced by a new "recalibrated" series. A new data series was proposed also for the…
Temporal Offsets between Maximum CME Speed Index and Solar, Geomagnetic, and Interplanetary Indicators during Solar Cycle 23 and the Ascending Phase of Cycle 24
A. Özgüç, A. Kilcik, K. Georgieva +1
On the basis of morphological analysis of yearly values of the maximum CME (coronal mass ejection) speed index, the sunspot number and total sunspot area, sunspot magnetic field, a…
What causes geomagnetic activity during sunspot minimum
Boian Kirov, Simeon Asenovski, Katya Georgieva +1
The average geomagnetic activity during sunspot minimum has been continuously decreasing in the last four cycles. The geomagnetic activity is caused by both interplanetary disturba…
Solar magnetic fields and terrestrial climate
Katya Georgieva, Yury Nagovitsyn, Boian Kirov
Solar irradiance is considered one of the main natural factors affecting terrestrial climate, and its variations are included in most numerical models estimating the effects of nat…
Why the sunspot cycle is double peaked
Katya Georgieva
Many sunspot cycles are double peaked. In 1967 Gnevyshev suggested that actually all cycles have two peaks generated by different physical mechanisms, but sometimes the gap between…