Hong Kong sky-gazers were treated to a spectacular sight as the city sizzled on Sunday – a so-called 22-degree halo around the sun.
Although not particularly rare, the bright glowing halo, in vivid blue skies, prompted a flurry of stunning pictures uploaded to Facebook and Twitter. “Amazing” exclaimed one netizen, “beautiful” said another.
A 22-degree halo is caused by light passing through billions of hexagonal ice crystals in cirrostratus or cirrus clouds between three and five miles above the Earth. The phenomenon can also be observed around the moon, which is sometimes known as a winter halo.
According to the website weather.com: “Scientifically, halos are called 22-degree halos because two refractions bend the light by 22 degrees from its original direction. This means that the halo can be seen when your eye makes a 22-degree angle with the sun or moon.”
Hong Kong Observatory said today the outlook for the coming week was for the very hot weather to continue. Temperatures are expected to peak at around 33 degrees Celsius tomorrow and may climb a little higher mid-week.