The "anti-gravity waterfall" flows backwards and rushes straight to the cliff! How beautiful is the rising air flow?

In May 1954, a well-known American actor was preparing to shoot a comedy, The Seven Year Itch. The film won numerous acclaims and was the highest-grossing film of 1955. After so many years, many people no longer remember the specific plot of the film, but a promotional photo taken for the film has since become a classic.

Marilyn Monroe stood on a subway vent, and as a train passed through the tunnel directly below, the air blew out of the vent and lifted her skirt. The photographer recorded this pose in the photo, which became one of the most famous shots of her career.

Rising air currents are actually very common in our daily lives. Just raise your head, open your mouth, and gently exhale upwards to create an updraft. Although the updrafts here are caused by a train passing by and may not seem so "natural", they are still amazing enough. However, when it comes to the beautiful scenery created by rising air currents, there are actually many more in nature.

I recently saw a piece of news on domestic social media: "An 'anti-gravity waterfall' flows backwards down a 470-meter-high cliff; a rare and spectacular scene was captured" [1, 2]. The seemingly exaggerated title left a deep impression on me.

The location of this news happened in Beinisvørð (no official Chinese translation, roughly translated as Beniswolfs), the southern island of the Faroe Islands. This archipelago is in the Atlantic Ocean, geographically located between Norway and Iceland. Because the shape of the coast is concave here, the strong winds from the North Atlantic are forced to form vortices here and climb along the cliffs, forming cyclones that drive water up over the high cliffs.

The most incredible thing about this phenomenon is that the cliff is really too high. It takes one atmosphere of pressure to support a 10-meter water column. If it really relies solely on atmospheric pressure, the cyclone needs to provide 48 atmospheres of pressure to throw the water that high . However, we can also see from the video screenshots that what is transported up are actually just some tiny water droplets, not a complete water column. However, these water vapors across the 470-meter cliff look really shocking.

This tornado is a bit like a water pump. Everyone is familiar with water pumps. Many people think that as long as the power of the water pump is high enough, the water can always be lifted to a high enough place. However, they often forget a more important factor. How high the water can be lifted has little to do with the power of the water pump, but has more to do with the flow rate. Within a certain range, the flow rate and the head are inversely proportional. The larger the flow rate, the smaller the head, and the smaller the flow rate, the greater the head. There is no simple functional relationship between the two. The energy of the tornado to provide water is not large. In order to pump the water so high, the natural water volume must be very small. Most of it is actually just some small water droplets in the waves.

A cross-section of a mature tropical cyclone in the Northern Hemisphere. It can be seen that the center of the cyclone is formed by rising air currents, but the central area is indeed descending. This is because the lateral air currents in the upper layers of the cyclone are transported outward, causing the higher layers of the atmosphere to be transported to the center of the cyclone, thus forming a sinking air current. This is also the reason why there are no clouds in the middle of the eye of the storm.

There are many natural phenomena closely related to rising air currents, such as tornadoes, typhoons, hurricanes, etc. , which are all caused by strong convection. Specifically speaking, typhoons are caused by the continuous rise in temperature of the ocean surface due to the sun's radiation, and the air rises, forming a cyclone under the action of the Coriolis force.

Strong updrafts can lead to many atmospheric phenomena [3]. For example, updrafts caused by high mountain terrain can form spectacular pileus clouds . The word pileus in the word pileus is Latin for hat. This type of cloud is also called a bamboo hat cloud because it forms at the top of a mountain and really looks like a bamboo hat...

Mountain cap clouds are static clouds that are formed over isolated peaks when the humid air is forced to rise due to the terrain, cools and condenses . The conditions for the formation of such clouds are not very strict, but because they do not exist for a long time, it is often difficult for people to see them. As taking photos becomes more and more convenient, more and more pictures are gradually being recorded.

Mountain cap clouds can also be found above very high cumulus clouds.[4]

Why can mountain cap clouds exist stably? The premise for the existence of this type of cloud is the existence of stable airflows with high humidity in the upper atmosphere. When cumulus clouds continue to develop and move upward, or when high mountains lie across the path of the original air flow, the original stable air flow is forced to rise, causing the water vapor to reach the dew point and begin to condense. Eventually, beautiful mountain cap clouds are formed. Although mountain cap clouds appear to be stationary, they are actually in a dynamic balance at all times. Clouds are continuously formed and transported backwards on the windward side because of the rising air flow; clouds on the leeward side decrease due to the height. [5]

Sarychev Peak's plume and cap cloud were captured from the International Space Station during its 2009 eruption NASA/JPL

As mentioned above, the existence of this kind of cap cloud only requires the airflow to rise in height, and there are many conditions that can meet this condition. For example, when a volcano erupts or a nuclear bomb explodes, the rapidly rising volcanic ash and mushroom cloud can also form this kind of cap cloud. In some wonderful places in nature, violence and beauty are always mixed together in a special way.

Beautiful updrafts on the beach in Panama City, Florida, USA

Sometimes, artificial updrafts created by high-rise buildings can also create beautiful clouds. This scene was recorded by someone on a helicopter at the beach in Panama City, Florida, USA[6]. The warm and humid air from the Gulf of Mexico rises with the apartment building. As in all the previous examples, it is cold at high altitudes, and the temperature drops, causing the water vapor in the air to condense. The slight cooling caused by the change in altitude is enough to make the air reach saturation point, thus forming a cool fog .

Since the helicopter landing pad was located near the fog, it was impossible to take off smoothly and shoot this rare scene from the air. Moreover, this phenomenon forms very quickly, "it only takes 2-3 minutes for a small wisp of fog on the top of the building to cover the entire building." Only when a helicopter returns from the outside when the fog is forming can the above scene be shot.

In fact, whether it is a mountain cap cloud or a spectacular cloud on the beach, the formation principle is roughly the same. This type of cloud actually has a more common name - lenticular cloud . Its biggest feature is its smooth disc-like shape . In the past, it was not mistaken for an alien spaceship or an unidentified flying object. It looks like a UFO no matter how you look at it.

Stratocumulus lenticularis

Lenticular clouds can form in a variety of conditions. In addition to the terrain-related formation processes mentioned above, they can also form due to the rise of warm air at a cold front, or due to the convergence of high-altitude downdrafts and ground-level updrafts. Depending on the type of cloud, lenticular clouds can form in two forms: lenticular stratocumulus and lenticular altocumulus, which are thicker and thinner in appearance, respectively. [6]

In some popular articles on the Internet, you can often see some photoshopped lenticular cloud pictures, such as "The king of the sky covers the earth, the pagoda suppresses the river monster" . Although lenticular clouds are indeed very cool, you should never believe in such fake photos that are too cool. From the principle of formation, we know that lenticular clouds are usually one or two discs, and it is impossible for so many to be piled up.

A widely circulated image of a processed lenticular cloud. Originally, it should have only one layer, but after post-processing, the cloud layer was artificially superimposed to five layers. You know what, the image on the left really looks a bit like the childhood animation "Magic Hero Legend", that is, the Creation Mountain in the Dragon Ball.

There are still "double-layer pagodas", but they are really rare. The photo below clearly shows the double-layer lenticular cloud structure. The original author was Jim George who took it in Puyallup, WA, USA in 2004. He was woken up by his son that morning and told him that he had to look outside the house before he used his camera to record the scene. It has been almost 16 years since then, and there are still so few photos of double-layer lenticular clouds circulating on the Internet, which shows how rare they are.

one more thing

Having said so much, can we also create a beautiful updraft on ourselves?

The answer is of course, yes, I guarantee you will have the best temperament++

References:

[1] "Anti-gravity waterfall flows backwards down a 470-meter-high cliff. This rare and spectacular scene was captured on camera."

[2] Incredible footage shows water flowing upwards - after waves were caught in a 'sea vortex', Joe Gamp, Yahoo News

[3] When cumulus clouds are building, sometimes there is a smooth cloud that looks bowed and rides horizontally above and over the building cumulus. What is this and what causes this cloud formation? - Quora

[4] Pileus capping cumulus in MD, Community Cloud Atlas

[5] [Exploring the Clouds] Look, this cloud looks like a UFO~, Mobei, Zhihu column: Atmospheric Signs

[6] Florida waterfront condos literally create their own weather, Scott Sistek, Katu

[7] Weather photographers lament: 'Hey! That's *my* photo!'