In oceanography, a Halocline is a strong, vertical salinity gradient. Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification.
CMEs that appear to surround the occulting disk of the coronagraph. The CME can originate from the front or back side of the Sun, and therefore are travelling either towards or away from the observer.
About 70% of Earth directed halo CMEs are geoeffective.
A faint ring of enhanced emission seen around most or all of the edge of the occulting disk of a coronagraph. Indicative of a spatially large CME on the front side (Earthward) or back side of the Sun
. The source region is usually nearer to solar central meridian than the limbs. Full halo CMEs from the front side of the Sun almost always result in geomagnetic storms at Earth, especially when accompanied by a solar proton event.