Halo

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yang domisili di medan, pada ngeliat "HALO" ini ga kemaren....?

Halo (optical phenomenon)

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Complex halo display around the sun

Halo around the sun at the South Pole featuring a parhelic circle, a 22° halo with two sundogs, and an upper tangent arc topped by a faint Parry arc.

A halo (ἅλως; also known as a nimbus, icebow or Gloriole) is an optical phenomenon that appears near or around the Sun or Moon, and sometimes near other strong light sources such as street lights. There are many types of optical halos, but they are mostly caused by ice crystals in cold cirrus clouds located high (5–10 km, or 3–6 miles) in the upper troposphere. The particular shape and orientation of the crystals is responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split up into colors because of dispersion, similarly to the rainbow.

Sometimes in very cold weather optical halos are formed by crystals close to ground level, called diamond dust. The crystals behave like jewels, refracting and reflecting sunlight between their faces, sending shafts of light in particular directions.

Atmospheric phenomena such as halos were used as an empirical means of weather forecasting before meteorology was developed.

Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow.