The halo appears foreshadowing a period without rain

Halo is an optical phenomenon of nature. And when it appeared, it was reported before a period of no rain that would take place in the locality, sometimes causing water shortage, prolonged drought.

Since ancient times, when science and technology has not developed, lack of information on climate and weather, to know the evolution of the weather, over the years, my father has learned many experiences to predict the weather. daily or many days from observing all kinds of plants and animals and insects living around. In fact, many types of plants and animals are very sensitive to changes in weather.

Specifically, there are frogs, eels, leeches, terrestrial species of birds with flutes, crows, insects including Dragonfly, Ants, Termites ., on plants with Chicken grass, Si roots. In addition, his father also observed the state of the sky, the stars, the sun and the moon to forecast storms and droughts, so there was a proverb of the proverb in the world . , the moon can rain . "

Photo by reader Li Wen Sheng (Taiwanese) taken in Vung Tau.

Halo is an optical phenomenon of nature. They only appear during the day or night in the summer and fall every year. Studies show that sun halo or moon halo is only one.

Clouds produce halo phenomena with the Latin name Cirrostratus (Vietnamese called cirrus cloud, abbreviated Cs), clear and pale clouds, filamentous (like hair), or smooth, covering the sky well In part, this type of cloud is structured by numerous small ice crystals. The height of the cloud bottom is about 7 km from the ground, the temperature in the cloud is minus 20 degrees Celsius.

The sun's halo, the moon is an optical phenomenon, because the light of the sun or the moon passing through ice crystals refracted or reflected produces circles, the defect is a semi-circle with the center being The sun or the moon.

Sun halo in Vung Tau.(Photo: Nguyen Tan Phuong) .

When the halo is produced by refracted sunlight, there are 7 colors including red, orange, yellow, green, blue, indigo, purple. The inner rim is red, the outer rim is purple (the color arrangement of the halo is opposite to the color of the rainbow).

Due to the weak moon light, when causing halo phenomenon with unknown, faint color, usually the halo is the main white color; most of them only observe the small halo, with a radius of about 22 degrees (this is the angle from the bright ring to the center), sometimes observing that the halo has an angle of 46 degrees, called a large halo, with a poor light of small halo.

When the halo appears, it is a warning period before the rain will take place locally. Many times cause water shortage, prolonged drought.