A Comparison of Reconstruction Methods for the Estimation of Coronal Mass Ejections Kinematics Based on Secchi/Hi Observations

Abstract

A study of the kinematics and arrival times of CMEs at Earth, derived from time-elongation maps (J-maps) constructed from STEREO/Heliospheric Imager (HI) observations, provides an opportunity to understand the heliospheric evolution of CMEs in general. We implement various reconstruction techniques, based on the use of time-elongation profiles of propagating CMEs viewed from single or multiple vantage points, to estimate the dynamics of three geo-effective CMEs. We use the kinematic properties, derived from analysis of the elongation profiles, as inputs to the Drag Based Model for the distance beyond which the CMEs cannot be tracked unambiguously in the J-maps. The ambient solar wind into which these CMEs, which travel with different speeds, are launched, is different. Therefore, these CMEs will evolve differently throughout their journey from the Sun to 1 AU. We associate the CMEs, identified and tracked in the J-maps, with signatures observed in situ near 1 AU by the WIND spacecraft. By deriving the kinematic properties of each CME, using a variety of existing methods, we assess the relative performance of each method for the purpose of space weather forecasting. We discuss the limitations of each method, and identify the major constraints in predicting the arrival time of CMEs near 1 AU using heliospheric imager observations.

Connecting Speeds, Directions and Arrival Times of 22 Coronal Mass Ejections From the Sun to 1 Au

“…We conclude that predicting CME speeds and arrival times with heliospheric images gives more accurate results than using projected initial speeds from coronagraph measurements. These improvements are on the order of 12 hr for the arrival times (Colaninno et al 2013), and our results are consistent with those found with other space weather models in the STEREO era (see also Gopalswamy et al 2013;Mishra & Srivastava 2013;Mishra et al 2014). Independent of the specific methods used, we can derive an average of the CME IP propagation speed when we track a CME out to 1 AU.…”

Interplanetary and Geomagnetic Consequences of Interacting CMEs of 13 – 14 June 2012

“…On the basis of earlier studies regarding the relative performance of the reconstruction methods (Lugaz, 2010;Liu et al, 2013;Mishra, Srivastava, and Davies, 2014), we applied the stereoscopic self-similar expansion (SSSE) method to the J-maps of the interacting CMEs in the present study. The SSSE method is expected to yield better results as the CMEs were observed in HI field of view of both STEREO-A and B.…”

“…To implement the SSSE method, we require an appropriate value of the cross-sectional angular half width (λ) of the CMEs as an input. Earlier studies have also revealed that use of different values of λ with the SSSE method give different estimates of the kinematics of CMEs Mishra, Srivastava, and Davies, 2014). It has been observed that for CMEs that are Earth-directed when STEREO spacecraft are behind the Sun, the SSSE method should be implemented with a value of λ as 90 • (Liu et al, , 2014Mishra, Srivastava, and Singh, 2015;Vemareddy and Mishra, 2015).…”

Testing the current paradigm for space weather prediction with heliospheric imagers

“…Setting this parameter to zero replicates the FP geometry while setting it to 90 ∘ replicates the HM geometry; intermediate values approximate the CME cross section as a self-similar expanding circle of constant half width (as discussed by Davies et al [2012]). As a result, some studies have set the half width to a value that represents a compromise between the two extremes; Möstl et al [2014] used 45 ∘ , Rollett et al [2016] used 35 ∘ , while Barnard et al [2015a] and Mishra et al [2014] used 30 ∘ . Such techniques can be applied to CMEs observed from a single spacecraft or to simultaneous observations from two spacecraft with distinct viewpoints [Lugaz, 2010;Liu et al, 2010Liu et al, , 2013.…”

“…Because of these difficulties, additional refinements have been introduced including approaches that combine standard analysis of -t profiles from J-map with other models, such as a drag force model [Tucker-Hood et al, 2015;Mishra et al, 2014Mishra et al, , 2015Rollett et al, 2016]. Others have attempted to constrain the CME direction such that the distance-time and velocity-time profiles were most consistent with in situ measurements of the arrival time and velocity [Rollett et al, 2012].…”