Sun Halo Seen Across Trinidad and Tobago

Sun Halos, and halos in general, are a sign of high, thin cirrus clouds drifting 6 kilometers (20,000 feet) or more above our heads. These clouds contain millions of tiny ice crystals. The halos you see are caused by both refraction, or splitting of light, and also by reflection, or glints of light from these ice crystals. The crystals have to be oriented and positioned just so with respect to your eye, in order for the halo to appear.

That’s why, like rainbows, halos around the sun – or moon – are personal. Everyone sees their own particular halo, made by their own particular ice crystals, which are different from the ice crystals making the halo of the person standing next to you.

The familiar separation of the colors of white light in a prism is a result of dispersion, the variation of the index of refraction of light with wavelength. Since hexagonal ice crystals make up a section of a a 60° prism, they separate the colors of white light. (Hyperphysics)

The prism effect of light passing through these six-sided ice crystals also separates the light into its various color frequencies, making the halo look like a very pale rainbow, with red on the inside and blue on the outside. A 22° halo may be visible on as many as 100 days per year—much more frequently than rainbows.

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There’s an old weather saying: ring around the moon means rain soon. There’s truth to this saying, because high cirrus clouds often come before showers. Notice in the below photos that the sky looks fairly clear. 

Moisture is increasing at mid and upper levels of the atmosphere, due to a deep mid to upper level trough over Eastern Columbia and Western Venezuela advecting a deep tropical plume of moisture across the Southern Windwards. This increase in moisture and favorable upper level conditions is forecast to create favorable conditions for increased cloudiness overnight, and isolated to scattered showers tomorrow (Thursday 25th April 2019) and even the isolated thunderstorm. See latest forecasts for more information.

Photos of the Sun Halo Across Trinidad and Tobago

What is that dot in everyone’s photos?

It is simply the bright light of a relatively small object that reflects inside the glass of your camera lens. It often appears as a dot, and many times it will have a partial circle or oval with a glow around the dot. It might also be tinted blue or purple or even green!

Bright lights like the sun often leave a reflection and other artifacts inside a camera lens, as a dot. These are called lens artifacts or lens flares and they happen in all photography. It’s more noticeable when any part of your lens is flat- like the outside of a camera phone lens, or the flat lens filter many photographers use on DSLRs and even film cameras.

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A more technical explanation: The lens elements in a camera contains anti-reflection coatings (thin films). Although they are intended to remove all internal reflections, they are not perfect. Their effectiveness generally depends on incident angle and wavelength. When you photograph an intense source of light, such as the sun, the little bit of light that is reflected is enough to show up in the photograph and the color is an indication of the wavelength dependence of the particular coating. (Stackexchange)

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