Reflection rainbow

(Section 3.2.3.5.5)

Reflection of sunlight from smooth water surfaces (such as lakes, or occasionally a calm sea or calm coastal waters) sends reflected sunlight upwards. The reflected sunlight can act as a light source for both primary and secondary “reflection rainbows”.

The source of the reflected sunlight is usually a body of smooth water behind the observer, but it can be in front, in which case, only the base of the reflection bow will be visible.

The arc of a reflection rainbow is centred opposite the Sun and at the same angular elevation (the anthelic point). This is the same elevation above the horizon as the centre of a normal rainbow is below it. Reflection bows appear at a steeper angle in the sky than the corresponding normal bows, which they intersect at the horizon.