What is an "inversion," the condition that occurs during summer months?

Question

During this period there is not enough fresh air, which causes illness and death to the elderly, or those with breathing difficulties, or is it too much heat, or the presence of some other condition, like trapped polluted vapor?

What causes an inversion,
and what elements are present
that an inversion is so life-
threatening?

Thank you

Answer 1

DC Bob answer was good but didn't quite go far enough to answer some of the questions that you asked.

Yes, normally an inversion is a layer within the lowest part of the atmosphere (troposphere or sometimes call the weather-sphere) where the temperature increases with height rather than the normal decreases with height. These layers can be just off the ground, or well aloft. The placement of each depends on the type of inversion.

There are several ways inversions can form. The most common one is a surface inversion where cool air next to the earths surface is colder than the warmer air just above. This type of inversion forms during clear nights with very light (calm) winds. This type of inversion will most often dissipate due to heating from the sun by mid morning with little ill affect.

The inversion caused by a large (many hundreds of miles across) stationary high pressure system is the one that causes the most problem. The high pressure will sit over an area and slowly settle causing a layer to warm due to compression.

A stagnate high pressure system keeps any winds from blowing the pollution away which builds up with time. The high pressure can persist for up to several weeks. Being high pressure, clouds have difficulty forming and the sunshine becomes the enemy by forming more toxic compounds from the pollution in the air.

Normally this occurs during the summer and the compression even warms the atmosphere more. So you have the combined problems of heat, lack of wind, and pollution. Anyone that is not healthy would have a problem with those combined elements.

Answer 2

Definition of Inversion
Generally, a departure from the usual increase or decrease in an atmospheric property with altitude. Specifically it almost always refers to a temperature inversion, i.e., an increase in temperature with height, or to the layer within which such an increase occurs. This occurs when warm air sits over cold air, possibly trapping moisture and pollutants in the surface air layer. An inversion is present in the lower part of a cap.

Explanation of Inversion and cause
If you assume the atmosphere is perfectly still, calculations show that the air will become steadily colder as you go to higher altitudes. This is something called the "adiabatic lapse rate" and is based on the fact that as air goes into lower pressure and expands, it also cools. If you then heat some air near the ground, it will become hotter than its surroundings and will start to rise. As it rises it cools, but it will still be hotter than the surrounding air, and so it keeps going up, until it mixes. A temperature inversion means that as you go up in altitude, the air suddenly becomes warmer instead of cooler as you would expect from the lapse rate. What happens is that either the air near the ground is made unusually cold, or the air at higher altitude is made unusually hot. The first case can occur when the sky is very clear at night and you get radiative cooling of the ground. The ground radiates heat to space and then cools the air by conduction. In cold climates with no wind, you can get situations where it might be -30 degrees C at one level and be 20 degrees C warmer on the tops of a nearby hill 100 meters high. The change in temperature is so abrupt it almost feels like you have entered the tropics, even though the temperature is still only -10C. When you have an inversion, the unusually warm air acts like a lid over the cold air layer. Smoke and car exhaust are trapped near the ground and can accumulate
to unhealthy levels.

Answer 3

In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to a temperature inversion, i.e., an increase in temperature with height, or to the layer within which such an increase occurs. [1]

An inversion can lead to pollution such as smog being trapped close to the ground, with possible adverse effects on health. 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.

Complete article at the URL below

This is my help from Washington, D.C. USA.

Answer 4

In Meteorology,inversion usually refers to the increase of temperature with height.Ground inversion(an inversion layer near the earth's surace) sometimes occurs due to the loss of heat by radiation of energy into space during late night, with clear sky,moist air and light wind.Due to this inversion layer, radiation fog will occur on the ground which will create breathing diffculties for people having asthma complaint.
Inversion layers at higher levels are often associated with anticyclones and sometimes with fronts.A sudden drop in moisture content in the higher levels sometimes causes inversion at that levels which I myself have noticed while taking upper air observations with balloon.This means absence of turbulence at that level and this inversion prevents cloud formation above that level.

Answer 5

An inversion occurs when a moist cooler air system moves in over a warm dry one. It usually causes air stagnation during which particulate matter, carbon dioxide, and carbon monoxide levels build up in the atmosphere lowering the oxygen level.

Answer 6

is occurs when you have cooler and warmer air mix.
cold air is dense, while warmer air rises. an inversion occurs when some force mixes this up, it can sometimes lead to severe weather