In situ Remnants of Solar Surface Structures from Jensen-Shannon Scalogram

Abstract The heliosphere is permeated with highly structured solar wind originating from the sun [7]. One of the primary science objectives of Parker Solar Probe (PSP) is to determine the structures and dynamics of the plasma and magnetic fields at the sources of the solar wind [18]. However, establishing the connection between in situ measurements and structures and dynamics in the solar atmosphere is challenging: most of the magnetic footpoint mapping techniques have significant uncertainties in the source localization of a plasma parcel observed in situ [39; 4; 5], and the PSP plasma measurements suffer from a limited field of view [26; 36]. Therefore it lacks a universal tool to self-contextualize the in situ measurements. Here we develop a novel time series visualization method named Jensen-Shannon Scalogram. Utilizing this method, by analyzing the magnetic magnitude data from both PSP and Ulysses [10], we successfully identify in situ remnants of solar atmospheric and magnetic structures spanning more than seven orders of magnitude, from years to seconds, including polar and mid-latitude coronal holes, [35; 5; 14] as well as structures compatible with super-granulation [9], “jetlets” [40; 48] and very small scale flaring activity [13]. Furthermore, computer simulations of Alfv´enic turbulence support key features of the observed magnetic magnitude distribution. Building upon these discoveries, the Jensen-Shannon Scalogram therefore not only enables us to reveal the fractal fine structures in the solar wind time series from both PSP and decades-old data archive, but will also serve as a general-purpose data visualization method applicable to all time series.