Coronal Mass Ejection of 2000 July 14 Flare Event: Imaging from Near‐Sun to Earth Environment

Abstract

We report the results of our investigation of interplanetary e †ects caused by the large solar Ñare (X5.7/ 3B) that occurred on 2000 July 14. In association with this event a bright, fast, halo coronal mass ejection (CME) was observed. The analysis of multiwavelength, high-cadence images obtained from the Radioheliograph shows the on-disk signatures of the initiation of the CME at low-coronal NancÓ ay heights, ¹2The formation of the CME inferred from the radio data indicates a nearly developed R _ . halo at the low corona. The white-light images and CME follow-up measurements in the interplanetary medium also show, in agreement with the radio data, the propagation of the fully developed halo CME. The inference on the consequences of the CME in the inner heliosphere is from the interplanetary scintillation (IPS) observations obtained with the Ooty Radio Telescope and multiantenna system at the SolarTerrestrial Environment Laboratory. Scintillation measurements at Ooty on a grid of a large number of radio sources provided an opportunity to image the disturbance associated with the CME at di †erent distances from the Sun before its arrival at the near-Earth space. The scintillation data in particular also played a crucial role in understanding the radial evolution of the speed of the CME in the inner heliosphere. The "" speed-distance ÏÏ plot indicates a two-level deceleration : (1) a low decline in speed at distances within or about 100 solar radii and (2) a rapid decrease at larger distances from the Sun. The linear increase in the size of the CME with radial distance is also brieÑy discussed. The expansion of the CME, formation of the halo in the low corona, and its speed history in the interplanetary medium suggest a driving energy, which is likely supplied by the twisted magnetic Ñux rope system associated with the CME.

Dynamics of coronal mass ejections in the interplanetary medium

“…The acceleration in the interplanetary medium of CMEs is well-established (Gopalswamy et al 2000(Gopalswamy et al , 2001Manoharan et al 2001;Manoharan 2006;Howard 2007). This acceleration has been explained by an increase of the ICME mass (snowplough model Tappin 2006) or due to Lorentz force (Chen 1996;Howard 2007), although it is more common to attribute this acceleration to drag forces (Vršnak 2001;Cargill 2004).…”

“…Using scintillation data (IPS), Manoharan et al (2001) and Manoharan (2006) have found that ICMEs show a low decline in speed below 100 R (0.36 AU) and a rapid decrease after this distance. This behavior agree with the concavity of the curves in Figs.…”

Flux‐Rope Coronal Mass Ejection Geometry and Its Relation to Observed Morphology

“…2 of Li et al [2001], Fig. 5 of Manoharan et al [2001], Figs. 3 and 8 of Yurchyshyn et al [2001], and Fig.…”

CME Propagation Characteristics from Radio Observations

“…The radial profiles of some of the events indicate that the internal energy of the CME supports the propagation, i.e., the expansion (Manoharan et al, 2000;. Further, IPS data have been useful to quantify the force of interaction experienced by CMEs in the IP medium before their arrival at the near-Earth environment (Manoharan et al, 2001;Manoharan, 2006). In other words, the CMEs moving with speeds less than the background solar-wind speed are accelerated (or aided by the ambient wind).…”

“…The propagation signatures of a CME in the space outside the LASCO field of view can be obtained from the remote-sensing Interplanetary Scintillation (IPS) technique (e.g., Manoharan et al 2001;Tokumaru et al 2005). The IPS method exploits the scattering of radiation from distant radio sources (quasars, galaxies, etc.)…”