Sun halos appearing in some provinces: Can signal prolonged heat

According to Mr. Dang Vu Tuan Son, Chairman of the Vietnam Association of Astronomy and Cosmology (VACA), on May 21, a circle appeared around the Sun in some localities, an optical phenomenon also known as a 22-degree halo. of the Sun, is not a rare phenomenon.

At noon on May 21, many localities in the Northern region such as Quang Ninh, Hai Phong, Hanoi, Hai Duong,. many people discovered a bright circle surrounding the Sun.

Mr. Dang Vu Tuan Son said that the above phenomenon is called the 22 degree halo of the Sun or solar halo . Some places also call this phenomenon by another name, halo. However, according to Mr. Son's explanation, this is an emotional and inaccurate call.

Solar halos occur during certain times and conditions, such as in the upper layers of the earth's atmosphere, the weather is very dry, with little water vapor but many ice crystals.

'Light from the Sun or Moon when passing through ice crystals is scattered and forms a halo surrounding the Sun with a radius of 22 degrees from the Sun, hence the name 22 degree halo' , Mr. Son said.

Sun halos appear in some localities.

Also according to the President of the Vietnam Association of Astronomy and Cosmology, our folk have an experienced saying: 'The moon halo is dry, the moon is bright, it is rainy' with the meaning of signaling hot weather when the halo appears on the Moon. , but this experience is also not entirely accurate.

Solar halos appear less frequently than lunar halos , but are not too rare and do not affect daily life. However, this phenomenon can also signal the coming short period of prolonged hot weather and little rain.

The Sun's halo only appears in some localities, while in other places it is not visible. This is explained by experts as only in places with certain atmospheric conditions, when the air is dry and the upper layer contains a lot of sunlight. New ice crystals appear. Places with clouds and lots of water vapor will not see this phenomenon.