In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to an inversion of the air temperature lapse rate, in which case it is called a temperature inversion. Normally, air temperature decreases with an increase in altitude, but during an inversion warmer air is held above cooler air.
An inversion traps air pollution, such as smog, close to the ground. An inversion can also suppress convection by acting as a "cap.". If this cap is broken for any of several reasons, convection of any moisture present can then erupt into violent thunderstorms. Temperature inversion can notoriously result in freezing rain in cold climates.
Usually, within the lower atmosphere (the troposphere) the air near the surface of the Earth is warmer than the air above it, largely because the atmosphere is heated from below as solar radiation warms the Earth's surface, which in turn then warms the layer of the atmosphere directly above it, e.g., by thermals (convective heat transfer). Air temperature also decreases with an increase in altitude because higher air is at lower pressure, and lower pressure results in a lower temperature, following the ideal gas law and adiabatic lapse rate.
Under the right conditions, the normal vertical temperature gradient is inverted so that the air is colder near the surface of the Earth. This can occur when, for example, a warmer, less-dense air mass moves over a cooler, denser air mass. This type of inversion occurs in the vicinity of warm fronts, and also in areas of oceanic upwelling such as along the California coast in the United States. With sufficient humidity in the cooler layer, fog is typically present below the inversion cap. An inversion is also produced whenever radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the sun is very low in the sky. This effect is virtually confined to land regions as the ocean retains heat far longer. In the polar regions during winter, inversions are nearly always present over land.
An inversion can develop aloft as a result of air gradually sinking over a wide area and being warmed by adiabatic compression, usually associated with subtropical high-pressure areas. A stable marine layer may then develop over the ocean as a result. As this layer moves over progressively warmer waters, however, turbulence within the marine layer can gradually lift the inversion layer to higher altitudes, and eventually even pierce it, producing thunderstorms, and under the right circumstances, tropical cyclones. The accumulated smog and dust under the inversion quickly taints the sky reddish, easily seen on sunny days.
Temperature inversions stop atmospheric convection (which is normally present) from happening in the affected area and can lead to high concentrations of atmospheric pollutants. Cities especially suffer from the effects of temperature inversions because they both produce more atmospheric pollutants and have higher thermal masses than rural areas, resulting in more frequent inversions with higher concentrations of pollutants. The effects are even more pronounced when a city is surrounded by hills or mountains since they form an additional barrier to air circulation. During a severe inversion, trapped air pollutants form a brownish haze that can cause respiratory problems. The Great Smog of 1952 in London, England, is one of the most serious examples of such an inversion. It was blamed for an estimated 10,000 to 12,000 deaths.
Sometimes the inversion layer is at a high enough altitude that cumulus clouds can condense but can only spread out under the inversion layer. This decreases the amount of sunlight reaching the ground and prevents new thermals from forming. As the clouds disperse, sunny weather replaces cloudiness in a cycle that can occur more than once a day.
As the temperature of air increases, the index of refraction of air decreases, a side effect of hotter air being less dense. Normally this results in distant objects being shortened vertically, an effect that is easy to see at sunset when the sun is visible as an oval. In an inversion, the normal pattern is reversed, and distant objects are instead stretched out or appear to be above the horizon, leading to the phenomenon known as a Fata Morgana or mirage.
Very high frequency radio waves can be refracted by inversions, making it possible to hear FM radio or watch VHF low-band television broadcasts from long distances on foggy nights. The signal, which would normally be refracted up and away into space, is instead refracted down towards the earth by the temperature-inversion boundary layer. This phenomenon is called tropospheric ducting. Along coastlines during Autumn and Spring, due to multiple stations being simultaneously present because of reduced propagation losses, many FM radio stations are plagued by severe signal degradation disrupting reception.In higher frequencies such as microwaves, such refraction causes multipath propagation and fading.
When an inversion layer is present, if a sound or explosion occurs at ground level, the sound wave is refracted by the temperature gradient (which affects sound speed) and returns to the ground. The sound, therefore, travels much better than normal. This is noticeable in areas around airports, where the sound of aircraft taking off and landing often can be heard at greater distances around dawn than at other times of day, and inversion thunder which is significantly louder and travels further than when it is produced by lightning strikes under normal conditions.
The shock wave from an explosion can be reflected by an inversion layer in much the same way as it bounces off the ground in an air-burst and can cause additional damage as a result. This phenomenon killed two people in the Soviet RDS-37 nuclear test when a building collapsed.
The goal of this exercise was to envision the negative things that could happen in life. For example, the Stoics would imagine what it would be like to lose their job and become homeless or to suffer an injury and become paralyzed or to have their reputation ruined and lose their status in society.
The Stoics believed that by imagining the worst case scenario ahead of time, they could overcome their fears of negative experiences and make better plans to prevent them. While most people were focused on how they could achieve success, the Stoics also considered how they would manage failure. What would things look like if everything went wrong tomorrow? And what does this tell us about how we should prepare today?
This way of thinking, in which you consider the opposite of what you want, is known as inversion. When I first learned of it, I didn't realize how powerful it could be. As I have studied it more, I have begun to realize that inversion is a rare and crucial skill that nearly all great thinkers use to their advantage. 2
Jacobi believed that one of the best ways to clarify your thinking was to restate math problems in inverse form. He would write down the opposite of the problem he was trying to solve and found that the solution often came to him more easily.
Inversion is a powerful thinking tool because it puts a spotlight on errors and roadblocks that are not obvious at first glance. What if the opposite was true? What if I focused on a different side of this situation? Instead of asking how to do something, ask how to not do it.
Great thinkers, icons, and innovators think forward and backward. They consider the opposite side of things. Occasionally, they drive their brain in reverse. This way of thinking can reveal compelling opportunities for innovation.
Nirvana turned the conventions of mainstream rock and pop music completely upside down. Where hair metal bands like Poison and Def Leppard spent millions to produce and promote each record, Nirvana recorded Nevermind for $65,000. Where hair metal was flashy, Nirvana was stripped-down and raw. 5
Inversion is often at the core of great art. At any given time there is a status quo in society and the artists and innovators who stand out are often the ones who overturn the standard in a compelling way.
This type of inverse logic can be extended to many areas of life. For example, ambitious young people are often focused on how to achieve success. But billionaire investor Charlie Munger encourages them to consider the inverse of success instead.
You can learn just as much from identifying what doesn't work as you can from spotting what does. What are the mistakes, errors, and flubs that you want to avoid? Inversion is not about finding good advice, but rather about finding anti-advice. It teaches you what to avoid.
This strategy is not only effective, but often safer than chasing success. For example, some people take drugs or mental stimulants in an effort to increase their productivity. These methods might work, but you also run the risk of possible side effects.
Meanwhile, there is very little danger in leaving your phone in another room, blocking social media websites, or unplugging your television. Both strategies deal with the same problem, but inversion allows you to attack it from a different angle and with less risk.
What behaviors might ruin a marriage? Lack of trust. Not respecting the other person. Not letting each person have time to be an individual. Spending all of your time on your kids and not investing in your relationship together. Not having open communication about money and spending habits. Inverting a good marriage can show you how to avoid a bad one.
Before you worry too much about how to make more money make sure you have figured out how to not lose money. If you can manage to avoid these problems, you'll be far ahead of many folks and save yourself a lot of pain and anguish along the way.
And yet inversion is a key tool of many great thinkers. Stoic practitioners visualize negative outcomes. Groundbreaking artists invert the status quo. Effective leaders avoid the mistakes that prevent success just as much as they chase the skills that accelerate it. 041b061a72