Connecting 3D Evolution of Coronal Mass Ejections to Their Source Regions

Abstract

Since Coronal Mass Ejections (CMEs) are the major drivers of space weather, it is crucial to study their evolution starting from the inner corona. In this work we use Graduated Cylindrical Shell (GCS) model to study the 3D evolution of 59 CMEs in the inner (< 3R ) and outer (> 3R ) corona using observations from COR-1 and COR-2 on-board Solar TErrestrial RElations Observatory (STEREO) spacecraft. We identify the source regions of these CMEs and classify them as CMEs associated with Active Regions (ARs), Active Prominences (APs), and Prominence Eruptions (PEs). We find 27 % of CMEs show true expansion and 31 % show true deflections as they propagate outwards. Using 3D kinematic profiles of CMEs, we connect the evolution of true acceleration with the evolution of true width in the inner and outer corona. Thereby providing the observational evidence for the influence of the Lorentz force on the kinematics to lie in the height range of 2.5 − 3 R . We find a broad range in the distribution of peak 3D speeds and accelerations ranging from 396 to 2465 km s −1 and 176 to 10922 m s −2 respectively with a long tail towards high values coming mainly from CMEs originating from ARs or APs. Further, we find the magnitude of true acceleration is be inversely correlated to its duration with a power law index of -1.19. We believe that these results will provide important inputs for the planning of upcoming space missions which will observe the inner corona and the models that study CME initiation and propagation.

Investigating Width Distribution of Slow and Fast CMEs in Solar Cycles 23 and 24

“…For this we included a total of 1,064 events that occurred during 2000-2002, 2008, 2009, and also from 2012 to 2014, which covers the maxima of cycle 23, the minima of cycle 24 and the maxima of cycle 24. Here, we have followed a similar method as reported in Majumdar et al (2020) and using the JHelioviewer software (Muller et al, 2009;Müller et al, 2017) to back-project the CMEs onto the solar disk. We further segregated the identified source regions of the CMEs into two broad categories, namely 1) Active Regions(ARs) and 2) Prominence Eruptions(PEs).…”

“…For a spatial association (see Gilbert et al, 2000;Majumdar et al, 2020) between a source region and a subsequent CME, we require that the latitude of the source region to be around ± 30°t o that of the PA of the center of the CME as reported in the CDAW catalog. In the case of a filament eruption, due to larger uncertainty of its spatial location, we look for an erupting filament around ± 40°around the PA of the CME converted to equivalent apparent latitude (lat PA ) by the following relation:…”

“…Recently, it has been reported that the CMEs evolve non selfsimilarly in the inner corona (see Cremades et al, 2020;Majumdar et al, 2020). In the CDAW catalog, the width of a CME is defined as the maximum angle subtended by a CME on the center of the Sun when the CME enters the LASCO C3 field of view (FOV) where the width appears to approach a constant value (Gopalswamy, 2004).…”

“…Moore et al (2007) showed that the strength of the magnetic field of the source region flare arcade producing a CME can be estimated from the final angular width of the CME and the angular width of the flare arcade. Recently Majumdar et al (2020) connected 3D profiles of width evolution to the 3D acceleration profiles of slow and fast CMEs and found that the vanishing of the initial impulsive acceleration phase and the ceasing of width expansion phase both tend to occur in a height range of 2.5-3 R ʘ , thus showing the observational evidence of the height of impact of Lorentz force on CME kinematics. So, it is evident that the width of a CME is an essential ingredient in the understanding of their kinematics, and is also an important parameter for the consideration of their space weather impact.…”

“…Apart from their radial propagation, CMEs are also known to exhibit lateral expansion that leads to an increase in their angular width as they propagate outwards (Kay et al, 2015;Cremades et al, 2020;Majumdar et al, 2020) and that it is the Lorentz force at their source region that is closely responsible for translating and expanding them (Subramanian et al, 2014). In this regard, Zhao et al (2017) reported on the importance of the angular width of a CME, in determining whether the corresponding interplanetary CME and the preceding shock will reach Earth.…”