Photo taken on Wednesday shows a solar halo appearing in the sky above Qianling Mountain in Beijing. (Photos: VCG) A solar halo is an atmospheric optical phenomenon caused by sunlight being refracted or reflected by ice crystals as it passes through cirrostratus clouds.

Photo taken on Wednesday shows a solar halo appearing in the sky above Qianling Mountain in Beijing. A solar halo is an atmospheric optical phenomenon caused by sunlight being refracted or reflected by ice crystals as it passes through cirrostratus clouds.

Photo taken on Wednesday shows a solar halo appearing in the sky above Qianling Mountain in Beijing. A solar halo is an atmospheric optical phenomenon caused by sunlight being refracted or reflected by ice crystals as it passes through cirrostratus clouds.

Photo taken on Wednesday shows a solar halo appearing in the sky above Qianling Mountain in Beijing. A solar halo is an atmospheric optical phenomenon caused by sunlight being refracted or reflected by ice crystals as it passes through cirrostratus clouds.