Multifractal cross‐correlation analysis between CME and Planetary K‐index time series

Abstract This research aims to examine the multiscale‐multifractal correlation properties between the geomagnetic storm and coronal mass ejection (CME) occurrences by analyzing the CME linear speed and Planetary K‐index time series data. The relevant data for both CME and geomagnetic storm occurrences were obtained from the Solar and Heliospheric Observatory mission's LASCO and the NOAA Space Weather Prediction Center, respectively, for the same period (February 1999 to December 2007). We performed MultiFractal cross‐correlation Detrended Fluctuation Analysis (MFXDFA) and Multifractal cross‐correlation Detrending Moving average Analysis (MFXDMA) to investigate and quantify the possible cross‐correlation between the two natural events. The MFXDFA technique is also compared to the backward MFXDMA algorithm's performance. The change in the degree of cross‐correlation over time has been investigated, and the findings are quantitatively analyzed. The existence of significant power‐law cross‐correlations has been discovered within all scaling orders. Furthermore, we also find evident persistence of cross‐correlation with substantial Hurst exponents. In addition, it has been observed that long‐term cross‐correlation has a more considerable degree of multifractality and persistence than short‐term cross‐correlation.