Comparison of Cone Model Parameters for Halo Coronal Mass Ejections

Na, Hyeonock; Moon, Yong‐Jae; Jang, Su-Jin; Lee, Kyoung‐Sun; Kim, Hae-Yeon

doi:10.1007/s11207-013-0293-9

Cited by 14 publications

(6 citation statements)

References 15 publications

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“…As with any coronagraph observations, significant plane of the sky projection effects occur in the speed (and also width) if the CME does not originate near the limb of the Sun relative to the observing spacecraft. Cone models have been developed to help correct for projection (e.g., Howard et al, 1982;Zhao, Plunkett and Liu, 2002;Xie, Ofman and Lawrence, 2004;Xue, Wang and Dou, 2005;Michalek, Gopalswamy and Yashiro, 2007;Na et al, 2013;Nicewicz and Michalek, 2014, and references therein) but have not been widely used in SEP studies (see however, Pan et al, 2011).…”

Section: Cme Catalogsmentioning

confidence: 99%

The Properties of Solar Energetic Particle Event-Associated Coronal Mass Ejections Reported in Different CME Catalogs

Richardson

Rosenvinge

Cane³

2015

Sol Phys

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We compare estimates of the speed and width of coronal mass ejections (CMEs) in several catalogs for the CMEs associated with ∼ 200 solar energetic particle (SEP) events in 2006-2013 that included 25 MeV protons. The catalogs used are: CDAW, CACTUS, SEEDS and CORIMP, all derived from observations by the LASCO coronagraphs on the SOHO spacecraft, the CACTUS catalog derived from the COR2 coronagraphs on the STEREO-A and -B spacecraft, and the DONKI catalog, which uses observations from SOHO and the STEREO spacecraft. We illustrate how, for this set of events, CME parameters can differ considerably in each catalog. The well-known correlation between CME speed and proton event intensity is shown to be similar for most catalogs, but this is largely because it is determined by a few large particle events associated with fast CMEs, and small events associated with slow CMEs. Intermediate particle events "shuffle" in position when speeds from different catalogs are used. Quadrature spacecraft CME speeds do not improve the correlation. CME widths also vary widely between catalogs, and are influenced by plane of the sky projection and how the width is inferred from the coronagraph images. The high degree of association (∼ 50%) between the 25 MeV proton events and "full halo" (360 owidth) CMEs as defined in the CDAW catalog is removed when other catalogs are considered. Using CME parameters from the quadrature spacecraft, the SEP intensity is correlated with CME width, which is also correlated with CME speed.

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Section: Cme Catalogsmentioning

confidence: 99%

The Properties of Solar Energetic Particle Event-Associated Coronal Mass Ejections Reported in Different CME Catalogs

Richardson

Rosenvinge

Cane³

2015

Sol Phys

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“…In this work, we consider three different cone types (an elliptical cone model, an ice cream cone model, and an asymmetric cone model) to determine 3‐D CME parameters such as radial velocity, angular width, and source location. We determine their cone model parameters using the elliptical and the ice cream cone models [ Na et al , ].…”

Section: Discussionmentioning

confidence: 99%

“…There are two differences in both methods (1) using the root‐mean‐square (RMS) error instead of the least squares fitting method to obtain the cone parameters and (2) having angular widths at different position angles. More detailed explanations of the models and how to derive CME 3‐D parameters using these models are well described by Na et al [].…”

Section: Model and Datamentioning

confidence: 99%

“…These halo CMEs were associated with IP shocks [ Gopalswamy et al , ], and their asymmetric cone model parameters were already obtained by Michalek et al []. We determine their cone model parameters using the elliptical and the ice cream cone models [ Na et al , ]. We also use Mount Wilson Observatory (MWO) magnetograms for initial magnetic fields of the WSA‐ENLIL cone model.…”

Section: Model and Datamentioning

confidence: 99%

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Comparison of interplanetary CME arrival times and solar wind parameters based on the WSA‐ENLIL model with three cone types and observations

et al. 2014

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to determine 3-D CME cone parameters (radial velocity, angular width, and source location), which are the input values of the WSA-ENLIL model. The mean absolute error of the CME-associated shock travel times for the WSA-ENLIL model using the ice-cream cone model is 9.9 h, which is about 1 h smaller than those of the other models. We compare the peak values and profiles of solar wind parameters (speed and density) with in situ observations. We find that the root-mean-square errors of solar wind peak speed and density for the ice cream and asymmetric cone model are about 190 km/s and 24/cm 3 , respectively. We estimate the cross correlations between the models and observations within the time lag of ± 2 days from the shock travel time. The correlation coefficients between the solar wind speeds from the WSA-ENLIL model using three cone types and in situ observations are approximately 0.7, which is larger than those of solar wind density (cc ∼0.6). Our preliminary investigations show that the ice cream cone model seems to be better than the other cone models in terms of the input parameters of the WSA-ENLIL model.

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“…In fact, despite the extensive use of simulations involving spherical CMEs by the space weather community for both scientific and prediction purposes, the definition of a “spherical” CME shape in 3‐D simulation models appears to be ambiguous. In works using simulations in support of observational evidences, this ambiguity seems to pass unnoticed, and the use of a generic spherical or “conical” CME shape is often mentioned—without reference to the shape implementation details (see, e.g., Mays et al, ; Na et al, ; Patsourakos et al, ; Vršnak et al, ). The aim of this work is to point out how the concept of “spherical shape” in CME models can be interpreted in different ways, i.e., can be implemented differently in 3‐D simulations.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Initial Shape of Coronal Mass Ejections on 3‐D MHD Simulations and Geoeffectiveness Predictions

et al. 2018

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Coronal mass ejections (CMEs) are the major space weather drivers, and an accurate modeling of their onset and propagation up to 1 AU represents a key issue for more reliable space weather forecasts. In this paper we use the newly developed EUropean Heliospheric FORecasting Information Asset (EUHFORIA) heliospheric model to test the effect of different CME shapes on simulation outputs. In particular, we investigate the notion of “spherical” CME shape, with the aim of bringing to the attention of the space weather community the great implications of the CME shape implementation details for simulation results and geoeffectiveness predictions. We take as case study an artificial Earth‐directed CME launched on 6 June 2008, corresponding to a period of quiet solar wind conditions near Earth. We discuss the implementation of the cone model used to inject the CME into the modeled ambient solar wind, running several simulations of the event and investigating the outputs in interplanetary space and at different spacecraft and planetary locations. We apply empirical relations to simulation outputs at L1 to estimate the expected CME geoeffectiveness in terms of the magnetopause stand‐off distance and the induced Kp index. Our analysis shows that talking about spherical CMEs is ambiguous unless one has detailed information on the implementation of the CME shape in the model. All the parameters specifying the CME shape in the model significantly affect simulation results at 1 AU as well as the predicted CME geoeffectiveness, confirming the pivotal role played by the shape implementation details in space weather forecasts.

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Comparison of Cone Model Parameters for Halo Coronal Mass Ejections

Cited by 14 publications

References 15 publications

The Properties of Solar Energetic Particle Event-Associated Coronal Mass Ejections Reported in Different CME Catalogs

The Properties of Solar Energetic Particle Event-Associated Coronal Mass Ejections Reported in Different CME Catalogs

Comparison of interplanetary CME arrival times and solar wind parameters based on the WSA‐ENLIL model with three cone types and observations

Effect of the Initial Shape of Coronal Mass Ejections on 3‐D MHD Simulations and Geoeffectiveness Predictions

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