2.2 Angular width

The angular width of CMEs projected in the plane of the sky ranges widely from ∼ 2° to 360° (Yashiro et al., 2004Jump To The Next Citation Point), with a significant fraction in the low end (e.g., < 20°) and a small fraction in the high end (e.g., > 120°). The CMEs with the angular width less than ∼ 10° can be called narrow CMEs (Wang et al., 1998Jump To The Next Citation Point), and others are sometimes called normal CMEs (Yashiro et al., 2004Jump To The Next Citation Point, see Figure 1View Image). Note that halo CMEs, with an apparent angular width of or close to 360°, are simply due to that the CMEs, probably with an angular width of tens of degrees, propagate near the Sun-Earth line, either toward or away from the Earth.
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