Atchmosphere.?

Question

Considering what you know about the athsmosphere. What is a temperature iversion, Where do they occur, and, What causes them?

Answer 1

Temperature inversion - a layer of dense cold air hugging the ground (it can be anywhere from 10 to over 1000 ft thick) , overlaid by a warmer, less dense warm air mass. Above this warm airmass, temperatures decrease as expected with increasing altitude.

Thin temperature inversions (a few feet in depth) occur on any calm clear night but most often in fall and winter. It requires clear skies, little or no wind and preferably dry ground. The ground cools rapidly, cooling the air immediately above it, which then fails to rise or mix with the rest of the air.

Answer 2

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.

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.

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.

Under certain conditions, the normal vertical temperature gradient is inverted such 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, more dense 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. 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 angle of 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.

A warmer air mass moving over a cooler one can "shut off" any convection which may be present in the cooler air mass. This is known as a capping inversion. However, if this cap is broken, either by extreme convection overcoming the cap, or by the lifting effect of a front or a mountain range, the sudden release of bottled-up convective energy---like the bursting of a balloon---can result in severe thunderstorms. Such capping inversions typically precede the development of tornadoes in the midwestern United States. In this instance, the "cooler" layer is actually quite warm, but is still more dense and usually cooler than the lower part of the inversion layer capping it.

Answer 3

First responder is correct. Temperature inversions occur frequently in the San Francisco area; warm air aloft from the hot central valley is undermined by cold moist air blowing in from the ocean through the Golden Gate. This leads to the standard summertime Bay Area weather forecast: Coastal low clouds and fog, extending inland nights and mornings, otherwise fair.

Answer 4

David is right about the temp part. They are most common in valleys where the cold air has a harder time escaping. We live on a 90 mile long lake in a valley and from higher up the mountain where there is clear blue sky and sunshine ; you can actually see the inversion layer. Down in the town in the valley it's another gloomy foggy smoggy day.