One of the strangest atmospheric phenomena must be the parhelion. It is an atmospheric phenomenon caused by the sun, although it can also be considered a phenomenon of astronomical origin. It usually appears under certain unique environmental conditions and for a short time.
In this article, we're going to tell you what a parhelion is, how it forms, and what effects it has.
What is parhelion
It is a type of atmospheric phenomenon that is caused by the sun. They are two small glows that form on both sides of the sun when there is a certain type of cloud. The types of clouds that are needed for parhelion to occur are those of the cirrus typeThese clouds have a filament-like appearance, and some of them resemble cotton balls. For this type of atmospheric phenomenon to occur, these clouds must exist, since they contain ice crystals that act like tiny prisms. These tiny ice crystals are responsible for refracting the sun's rays. This means they will deflect part of the sun's rays elsewhere, forming the parhelion.
These environmental conditions occur very rarely, so it could be said that this phenomenon is like seeing a sun behind a cloud, but less bright than the actual sun. When this phenomenon occurs, both parhelia are not always visible. Often, cirrus clouds are present only on one side of the sun, and only one parhelia is formed. They are merely brighter points in an iridescent halo surrounding the sun. It is very rare for the entire halo to be visible.
As expected, this is an atmospheric phenomenon that doesn't always have the same appearance. Sometimes the parhelion appears as a round, luminous spot. With this type of shape, the sun appears less bright. On the other hand, on other occasions, we can find a more vertically elongated appearance or it breaks down into the colors of the rainbow. Only occasionally can we see some smaller fragments of the rainbow. I don't confuse these fragments with the rainbow, since the parhelion always appears next to the sun, while the rainbow appears on the side of the sky opposite the sun. It is also interesting to mention the phenomenon of three suns, which has similarities to the parhelion.
When does the parhelion appear
Until now, when nothing is known about this atmospheric phenomenon, nothing is taken into account. However, once we learn of the existence of the parhelion, we begin to pay attention to this phenomenon. It can be seen more frequently than we think. It is usually seen at dusk or in the morning when the sun is below the horizon.
Parhelion usually appears exactly at an inclination of 22 degrees from the sun, due to the angle at which light rays are refracted. This phenomenon can be observed by observing the sky, doing the following: first, place your arm fully extended forward and open your hand. When you cover the sun with your hand, we can see that the parhelion should be approximately where the tip of your little finger indicates. You could say we're measuring the sky with the palm of your hand. If there are cirrus clouds in that area, the parhelion may be forming. It can be found either to the right or left of the sun, or both.
The word parhelio comes from the Greek para-HeliosThis can be interpreted as being similar to the sun. Although much less common, a lunar parhelion can sometimes be found. The effect is the same, and the way to capture it is the same. The problem with this is that it can only be seen when there is a full moon, and cirrus clouds must be present in the position to refract the moon's limited light.
History
Although it's not very long, this phenomenon seems to have been documented since ancient times. An example of this is its mention in the first book of The Republic. Here we find various characters engaged in a philosophical conversation. In this conversation, we can see one of the characters asking about an atmospheric phenomenon observed in the city of Rome. This phenomenon was called Parhelion and refers to a phenomenon in which "two suns" can be seen with the naked eye.
Today we know that this is not true since They are just ice crystals that are responsible for refracting the sunlight.
Many people are unsure why this phenomenon occurs more frequently in winter. It's not surprising that in the middle of winter, temperatures can reach -20 degrees Celsius in many places around the world, such as the northern United States. These areas experience frigid environments with extreme environmental conditions that are perfect for this type of phenomenon. The formation of parhelion requires the formation of ice crystals in cirrus clouds. To learn more about the relationship between this phenomenon and other similar ones, you can consult the article on the solar halo.
However, these halos have nothing to do with rainbows, as we mentioned before. They always appear next to the sun, while rainbows appear on the opposite side.
Implications and effects
What this optical phenomenon implies in the sky. It is what we ask ourselves a lot. The fact that a parhelion appears in the sky anticipates certain meteorological changes that can occur as the weather is approaching. And it is that if we see a parhelion it is possible that looming in storms that will deliver short-term rainfall. Many of the farmers in the areas of the world where this type of phenomenon can be seen more frequently are those who consider the parhelion as a sign of the arrival of bad weather. Cirrus clouds in many places are formed only in the days before the appearance of storms.
Other times, when the halo has a more oval shape, it can be predicted that the weather will worsen in a period of 12-24 hours.
I hope that with this information you can learn more about parhelion in its characteristics.