Sun pillar at sunset 07/01/2022

July

2022

фотографии

1 July 2022 23:52

In St. Petersburg on July 1, 2022, at sunset, a halo in the form of a column of light was observed.

Solar pillars of light typically occur in the winter when light is scattered by ice crystals.

But at high altitudes it is always cold; in the tropopause the air temperature is -60°C at any time of the year. Even in hot summer.

Height, meters	Temperature, °C
0	+25
1000	+10
2000	+7
3000	+4
4000	-3
5000	-7
6000	-14
7000	-20
8000	-26
9000	-35
10000	-43
11000	-60
12000	-67

Sun pillars are formed when heavy ice crystals fall from cirrus clouds. Such flat or cylindrical “snowflakes”, in the complete absence of wind, fall in an orderly manner, as if gliding and gliding horizontally. The sunlight reflected by them at a small viewing angle forms an illusion against the sky: a bright light vertical stripe, a “solar pillar”. Sun pillars are a fairly common atmospheric phenomenon if there are powerful cirrus clouds in the sky. The altitude of formation of ice cirrus clouds ranges from 4 to 20 kilometers (but at the latitude of St. Petersburg 60N - the average altitude is 7000 m). The reason for their occurrence is the formation of ice crystals on particles of stone or metal dust when warm and dry air rises. The thickness of cirrus clouds ranges from 100 meters to several kilometers (average 1500 m). As mentioned above, ice crystals drop from Cirrus clouds. Cirrus clouds freely transmit light (reflect only 9° solar radiation), but retain infrared radiation (up to 50%), contributing to the formation of the greenhouse effect, increasing the temperature under the clouds by 10°.