Circumhorizontal Arc
This incredible optical phenomenon is an ice halo formed by the refraction of sunlight or moonlight in plate-shaped ice crystals suspended in the atmosphere, usually in cirrus or cirrostratus clouds. The arc in its full form generally appears to be a rainbow spectrum running parallel to the horizon.
Meeting of the Waters
The Meeting of the Waters, also known as Encontro das Águas, is the confluence between the blackwater Rio Negro and the pale whitewater Amazon River. It is one of the main tourist attractions of Manaus, Brazil. This phenomenon is caused by differences in temperature, speed, and the dissolved sediments in the two rivers' waters.
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