Solar coronal mass ejections (CMEs) show a large variety in their kinematic properties. CMEs originating in active regions and accompanied by strong flares are usually faster and accelerated more impulsively than CMEs associated with filament eruptions outside active regions and weak flares. It has been proposed more than two decades ago that there are two separate types of CMEs, fast (impulsiv...

We describe a method with which to measure the magnetic field orientation of coronal mass ejections (CMEs) using Faraday rotation (FR). Two basic FR profiles, Gaussian-shaped with a single polarity or N-shaped with polarity reversals, are produced by a radio source occulted by a moving flux rope, depending on its orientation. These curves are consistent with Helios observations, providing evide...

The LASCO and EIT instruments on the SOHO spacecraft have provided an unprecedented set of observations for studying the physics of coronal mass ejections (CMEs). They provide the ability to view the pre-event corona, the initiation of the CME and its evolution from the surface of the Sun through 30 R ⊙. An example of the capability of these instruments is provided in a description of a single ...

On 2012 September 30–October 1 the Earth underwent a two-step geomagnetic storm. We examine the Sun-toEarth characteristics of the coronal mass ejections (CMEs) responsible for the geomagnetic storm with combined heliospheric imaging and in situ observations. The first CME, which occurred on 2012 September 25, is a slow event and shows an acceleration followed by a nearly invariant speed in the...

With the assumption of radial motion and uniform longitudinal distribution of coronal mass ejections (CMEs), we propose a method to eliminate projection effects from the apparent observed CME latitude distribution. This method has been applied to SOHO LASCO data from 1996 January to 2006 December. As a result, we find that the real CME latitude distribution had the following characteristics: (1...

Forbes & Lin derived simple equations to link the properties of magnetic reconnection in the corona to observed signatures of solar flares. We measured the photospheric magnetic fields and the flare ribbon separation speeds then applied these equations to derive two physical terms for the magnetic reconnection rates: the rate of magnetic flux change ’rec involved in magnetic reconnection in the...

Previous attempts to produce three-dimensional (3-D) reconstructions of coronal mass ejections (CMEs) have required either modeling efforts or comparisons with secondary associated eruptions near the solar surface. This is because coronagraphs are only able to produce sky-plane-projected images of CMEs and it has hence been impossible to overcome projection effects by using coronagraphs alone. ...

We report on the spatial relationship between solar flares and coronal mass ejections (CMEs) observed during 1996-2005 inclusive. We identified 496 flare-CME pairs considering limb flares (distance from central meridian ≥ 45◦) with soft X-ray flare size ≥ C3 level. The CMEs were detected by the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SO...

We propose a new model for the initiation of a solar coronal mass ejection (CME). The model agrees with two properties of CMEs and eruptive Ñares that have proved to be very difficult to explain with previous models : (1) very low-lying magnetic Ðeld lines, down to the photospheric neutral line, can open toward inÐnity during an eruption ; and (2) the eruption is driven solely by magnetic free ...