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This is a catalog of Earthdirected coronal mass ejections (CMEs) observed by STEREO. It features:
Please contact Dr. Ying Liu at liuxying@ssl.berkeley.edu if you have any questions. Collaborations are welcome! Please note that the analysis requires significant amount of time and efforts. If you think that the movies and results are helpful, and especially if you want to include some of them in your presentations and publications, we would greatly appreciate if you check with us for collaborations and coauthorships. More events will be added. Please stay tuned. 2007 November 15 CME Movies: Animations made of composite images of COR1, COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 40 degrees in longitude. Movies in the AVI format are also available. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. Three consecutive CMEs are observed during the time period. The second track corresponds to the 2007 November 15 CME. The vertical dashed line indicates the arrival time of the CMEdriven shock at the Earth, and horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from geometric triangulation (scatter) and track fitting (dashed lines). The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. Features 1, 2 and 3 correspond to the 2007 November 14, 15 and 16 CMEs, respectively. Note that, for the 2007 November 15 CME, the propagation angle is scaled by the right axis (red). Only the November 15 CME is Earthdirected. In situ data: Measurements at STEREO A, B and WIND/ACE. The vertical dotted lines show the predicated arrival times of four features at 1 AU from track fitting (see time elongation map). The 2007 November 15 CME (2nd feature) is responsible for the in situ signatures at 1 AU. In situ reconstruction: Reconstructed cross section of the magnetic cloud at ACE and STEREO B. Black contours show the distribution of the vector potential, and the color shading indicates the value of the axial magnetic field. The field configuration is lefthanded. The in situ reconstruction gives an axis elevation angle of 1.4 degrees and azimuthal angle of 106.7 degrees at ACE/WIND, and an elevation angle of 33.8 degrees and azimuthal angle of 91.8 degrees at STEREO B (RTN). Reference: Liu, Y., A. Thernisien, J. G. Luhmann, A. Vourlidas, J. A. Davies, R. P. Lin, and S. D. Bale, Reconstructing Coronal Mass Ejections with Coordinated Imaging and In Situ Observations: Global Structure, Kinematics, and Implications for Space Weather Forecasting, 2010, Astrophys. J., 722, 1762 (pdf) 2008 December 12 CME Movies: Animations made of composite images of EUVI, COR1, COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 86.3 degrees in longitude. Movies in GIF and AVI formats are also available. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The CME produces two tracks in the map, one corresponding to the CME leading edge and the other the trailing edge. The vertical dashed lines show the magnetic cloud interval observed at WIND. The horizontal line marks the elongation angle of the Earth. Kinematics: Propagation direction, radial distance and velocity of the CME leading and trailing edges in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. In situ data: Measurements at WIND and ACE. The hatched area shows the arrival times (with uncertainties) of the CME leading and trailing edges predicted by the geometric triangulation technique. The horizontal lines mark the corresponding predicted velocities at 1 AU. In situ reconstruction: Reconstructed cross section of the magnetic cloud at WIND. Black contours show the distribution of the vector potential, and the color shading indicates the value of the axial magnetic field. The field configuration is lefthanded. The in situ reconstruction gives an axis elevation angle of 6.4 degrees and azimuthal angle of 94.9 degrees at WIND (RTN). References: Liu, Y., J. A. Davies, J. G. Luhmann, A. Vourlidas, S. D. Bale, and R. P. Lin, Geometric Triangulation of Imaging Observations to Track Coronal Mass Ejections Continuously Out to 1 AU, 2010, Astrophys. J. Lett., 710, L82 (pdf) Liu, Y., A. Thernisien, J. G. Luhmann, A. Vourlidas, J. A. Davies, R. P. Lin, and S. D. Bale, Reconstructing Coronal Mass Ejections with Coordinated Imaging and In Situ Observations: Global Structure, Kinematics, and Implications for Space Weather Forecasting, 2010, Astrophys. J., 722, 1762 (pdf) 2010 February 7 CME Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 135.9 degrees in longitude. Movies in GIF and AVI formats are also available. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The vertical dashed line shows the arrival time of a shocklike structure preceding the ICME at the Earth. The horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. The data gap is due to singularities in the calculation scheme of the geometric triangulation method (the singularities occur because the longitudinal separation of STEREO A and B is very large); data with unusually large error bars are removed. In situ data: Measurements at WIND. A shocklike structure is observed ahead of the ejecta. The red hatched area shows the arrival time (with uncertainties) of the CME leading edge predicted by the geometric triangulation technique. The horizontal red line marks the corresponding predicted velocity at 1 AU. In situ reconstruction: The ICME does not look like a traditional magnetic cloud. Reconstruction with the GradShafranov (GS) method shows a complex structure. The resulting axis elevation angle from the GS method is \theta = 45 degrees and axis azimuthal angle \phi = 275 degrees at WIND (GSE). Minimum variance analysis (MVA) of the magnetic field within the same time interval gives \theta = 20 degrees and \phi = 170 degrees. 2010 February 12 CME Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 136.2 degrees in longitude. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The vertical dashed line shows the arrival time of the CMEdriven shock at the Earth. The horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. The data gap is due to singularities in the calculation scheme of the geometric triangulation method (the singularities occur because the longitudinal separation of STEREO A and B is very large); data with unusually large error bars are removed. In situ data: Measurements at WIND. The red hatched area shows the arrival time (with uncertainties) of the CME predicted by the geometric triangulation technique. The predicted arrival time is coincident with the shock observed at WIND. The predicted radial velocity at 1 AU is about 95 km/s higher than observed. A possible explanation is that, at distances close to 1 AU where the CME is too weak to be observed in HI2 by both spacecraft, the CME propagates into a slow solar wind region and then is slowed down. The predication is made with the data where the CME is observed by both spacecraft. In situ reconstruction: Reconstructed cross section at WIND. Black contours show the distribution of the vector potential, and the color shading indicates the value of the axial magnetic field. The magnetic field configuration is lefthanded. The in situ reconstruction with the GradShafranov (GS) method gives an axis elevation angle \theta = 31 degrees and azimuthal angle \phi = 93 degrees at WIND (GSE). Minimum variance analysis (MVA) of the magnetic field within the same time interval gives \theta = 6 degrees and \phi = 73 degrees. 2010 March 14 CME Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 138 degrees in longitude. Movies in MPG and AVI formats are available. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. The data gap is due to singularities in the calculation scheme of the geometric triangulation method. The singularities occur because the longitudinal separation of STEREO A and B is very large; data with unusually large error bars are removed. In situ data: Measurements at WIND. The red hatched area shows the arrival time (with uncertainties) of the CME leading edge predicted by the geometric triangulation technique. The horizontal red line marks the corresponding predicted velocity at 1 AU. A small ejecta (shaded region) is observed with a depressed proton temperature and slightly enhanced magnetic field. Only the latter half interval shows a rotation of the magnetic field. It is likely that the Earth cuts through the event at the flank. In situ reconstruction: TBD 2010 April 3 CME Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 138.8 degrees in longitude. Movies in GIF and AVI formats are also available. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The vertical dashed lines show the arrival times of CMEdriven shocks at the Earth. The 2010 April 3 CME corresponds to the first track in the map (and the first shock). The horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. The data gap is due to singularities in the calculation scheme of the geometric triangulation method (the singularities occur because the longitudinal separation of STEREO A and B is very large); data with unusually large error bars are removed. In situ data: Measurements at WIND. The red hatched area shows the arrival time (with uncertainties) of the CME leading edge predicted by the geometric triangulation technique. The horizontal red line marks the corresponding predicted velocity at 1 AU. In situ reconstruction: The ICME does not look like a traditional magnetic cloud. Reconstruction with the GradShafranov (GS) method shows a complex structure. Application of the GS method to the first half of data, where the magnetic field has the clearest rotation, gives an axis elevation angle \theta = 46 degrees and an azimuthal angle \phi = 265 degrees at WIND (GSE). Minimum variance analysis (MVA) of the magnetic field within the same time interval gives \theta = 58 degrees and \phi = 225 degrees; when the magnetic field is normalized, MVA yields \theta = 45 degrees and \phi = 180 degrees. Note that all the results here are obtained from the first half of the ICME interval. Reference: Liu, Y., J. G. Luhmann, S. D. Bale, and R. P. Lin, Solar Source and Heliospheric Consequences of the 2010 April 3 Coronal Mass Ejection: A Comprehensive View, 2011, Astrophys. J., 734, 84 (pdf) 2010 April 8 CME Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CME from STEREO A and B. The two spacecraft are separated by about 139 degrees in longitude. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The vertical dashed lines show the arrival times of CMEdriven shocks at the Earth. The 2010 April 8 CME corresponds to the second track in the map (and the second shock). The horizontal line marks the elongation angle of the Earth. Kinematics: CME propagation direction, radial distance and velocity in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. The data gap is due to singularities in the calculation scheme of the geometric triangulation method (the singularities occur because the longitudinal separation of STEREO A and B is very large); data with unusually large error bars are removed. In situ data: Measurements at WIND. The red hatched area shows the arrival time (with uncertainties) of the CME leading edge predicted by the geometric triangulation technique. The horizontal red line marks the corresponding predicted velocity at 1 AU. In situ reconstruction: The GradShafranov reconstruction shows, more or less, a fluxrope structure, which is righthanded. The resulting axis elevation angle is \theta = 20 degrees and axis azimuthal angle \phi = 250 degrees at WIND (GSE). 2010 July 30  August 1 CMEs Movies: Animations made of composite images of COR2, HI1 and HI2. They show two views of the CMEs from STEREO A and B. The two spacecraft are separated by about 150 degrees in longitude. Timeelongation map: J map constructed from running difference images of COR2, HI1 and HI2 along the ecliptic plane. The vertical dashed line shows the observed arrival time of a shock at the Earth. The horizontal line marks the elongation angle of the Earth. Note a data gap for STEREO B. Kinematics: CME propagation direction and radial distance in the ecliptic plane derived from the geometric triangulation method. The propagation direction is converted to an angle with respect to the SunEarth line; positive if it is west of the SunEarth line and negative if east. In situ data: Measurements at Wind. Three ICMEs (shaded areas) and a shock are observed at the Earth with clear signatures of CMECME interactions. The shock is propagating into the first one, which causes enhanced density, temperature and magnetic field strength in the first ICME due to shock compression. The horizontal line marks the predicted arrival time (with uncertainties) and speed of the shock at the Earth. Both the predicted arrival time and speed are consistent with the in situ measurements. In situ reconstruction: TBD Reference: Liu, Y. D., et al., Interactions between Coronal Mass Ejections Viewed in Coordinated Imaging and In Situ Observations, 2012, Astrophys. J. Lett., 746, L15 (pdf) Relevant References Geometric triangulation technique of imaging observations: Liu, Y., J. A. Davies, J. G. Luhmann, A. Vourlidas, S. D. Bale, and R. P. Lin, Geometric Triangulation of Imaging Observations to Track Coronal Mass Ejections Continuously Out to 1 AU, 2010, Astrophys. J. Lett., 710, L82 (pdf) Liu, Y., A. Thernisien, J. G. Luhmann, A. Vourlidas, J. A. Davies, R. P. Lin, and S. D. Bale, Reconstructing Coronal Mass Ejections with Coordinated Imaging and In Situ Observations: Global Structure, Kinematics, and Implications for Space Weather Forecasting, 2010, Astrophys. J., 722, 1762 (pdf) GradShafranov method of in situ reconstruction: Hau, L.N., and B. U. \"{O}. Sonnerup, Twodimensional coherent structures in the magnetopause: Recovery of static equilibria from singlespacecraft data, 1999, J. Geophys. Res., 104, 6899 Hu, Q., and B. U. \"{O}. Sonnerup, Reconstruction of magnetic clouds in the solar wind: Orientations and configurations, 2002, J. Geophys. Res., 107, 1142 Liu, Y., J. G. Luhmann, K. E. J. Huttunen, R. P. Lin, S. D. Bale, C. T. Russell, and A. B. Galvin, Reconstruction of the 2007 May 22 Magnetic Cloud: How Much Can We Trust the FluxRope Geometry of CMEs? 2008, Astrophys. J. Lett., 677, L133 (pdf)
