Near-Earth Interplanetary Coronal Mass Ejections Since January 1996

This list of near-Earth interplanetary coronal mass ejections (ICMEs), believed to be the interplanetary manifestations of the coronal mass ejections seen near the Sun by coronagraphs, is based on, and updated from, Cane and Richardson, Interplanetary coronal mass ejections in the near-Earth solar wind during 1996–2002, JGR [2003], and Richardson and Cane, Near-Earth Interplanetary Coronal Mass Ejections During Solar Cycle 23 (1996--2009): Catalog and Summary of Properties, Solar Physics, [2010].
Data description/Footnotes (a) The time of the associated geomagnetic storm sudden commencement (typically related to the arrival of a shock at Earth) if reported in the NGDC file storm2.ssc (currently only to 2011) or the Service International des Indices Geomagnetique. Some other SSCs have been identified using abrupt increases in the 1-minute SYM-H geomagnetic index. Otherwise, 'A' indicates the time of shock passage at ACE (e.g., in the ACE List of Disturbances and Transients or the Kasper/Stevens/CfA Shock list), 'W' indicates the time of a shock at the WIND spacecraft (from the Kasper/Stevens list or inspection of Wind plasma/field data), and 'S' indicates the time of a possible shock identified by the SOHO CELIAS/MTOF/PM \"Shockspotter\" program. If no shock or SC is reported or evident from these sources, the estimated arrival time of the disturbance (which in some cases is the ICME leading edge) is given to the nearest hour. Typical features we look for are increases in the solar wind speed, magnetic field strength and density that are more gradual than those associated with shocks. (b) Estimated start and end times of the ICME based primarily on plasma and magnetic field observations. See Cane and Richardson, JGR, (2003) for additional information on the methods used to identify ICMEs. The times are estimated to ~ the nearest hour. (c) Start and end times of the associated interval of abnormal solar wind composition/charge states (e.g., enhanced O7/O6, Mg/O, Fe charge states) estimated from ACE/SWICS data in hours relative to the start and end times of the ICME based on plasma/field observations as in (b). See Richardson and Cane, Solar Physics, (2010) for further details. A positive (negative) value means that the compositional signature starts after (before) the ICME leading edge or ends after (before) the ICME trailing edge. 'ns' indicates that there is no clear compositional/charge state signature, while 'nc' means that there is no change or the boundary is not clear in the compositional data (for example, between two adjacent ICMEs with similarly elevated ion charge states). No SWICS data are available until February, 1998. (d) Start and end times of the magnetic clouds reported by Lepping or Huttunen et al. Ann Geophys. (2005) 23:1-17 (see also (l)) in hours relative to the ICME leading or trailing edges. In a few cases, there are 2 magnetic clouds reported during the interval of interest. Magnetic clouds are structures associated with a subset of ICMEs defined by Burlaga and co-workers as having enhanced (> 10 nT) magnetic fields that rotate smoothly through a large angle, low proton temperatures, and low plasma beta (e.g., Klein and Burlaga [1982]; Lepping et al. [1990]). (e) Evidence of BiDirectional suprathermal Electron strahls (BDE) in ACE/SWEPAM Observations. If data are unavailable from SWEPAM (data commence on 10/22/97), observations from the 3-D P instrument on WIND are referred to. \"SEP\" indicates that an intense solar energetic particle event was in progress at the time of ICME passage and electron flows therefore cannot be determined. (f) Evidence of Bidirectional energetic Ion Flows (BIF) in 0.5 -4.0 MeV ion observations from the IMP 8 Goddard Medium Energy instrument. '...' indicates no data, low particle intensities, or when IMP 8 was inside the Earth's bow shock. (g) The \"quality\" of the boundary times (`1' indicating the most reliable) based on assessment of the various data sets, including plasma, magnetic field and solar wind composition/charge states. 'W' indicates that the overall ICME signatures are particularly weak. (h) Increase in solar wind speed at the upstream disturbance (shock/wave) estimated from 1 hour averaged solar wind data. 'S' indicates that a forward fast shock has been reported in the ACE List of Disturbances and Transients or CfA Interplanetary Shock Database (including ACE and WIND observations). (i) Mean ICME speed, based on solar wind speed observations during the period from (b) to (c) above. (j) Maximum solar wind speed during the period from the disturbance (a) to the trailing edge of the ICME (c). (k) Mean magnetic field strength in the ICME, based on the interval from (b) to (c), to the nearest 1 nT. (l) '2' indicates that a magnetic cloud has been reported in association with the ICME (see (d) above) or (occasionally, or for recent events) that by our assessment, the ICME has the clear features of a magnetic cloud but a magnetic cloud may not have...