Search results
Results from the WOW.Com Content Network
Stable stratification of fluids occurs when each layer is less dense than the one below it. Unstable stratification is when each layer is denser than the one below it. Buoyancy forces tend to preserve stable stratification; the higher layers float on the lower ones. In unstable stratification, on the other hand, buoyancy forces cause convection ...
Within an unstable layer in the troposphere, the lifting of air parcels will occur, and continue for as long as the nearby atmosphere remains unstable. Once overturning through the depth of the troposphere occurs (with convection being capped by the relatively warmer, more stable layer of the stratosphere ), deep convective currents lead to ...
There are five types of air pollution dispersion models, as well as some hybrids of the five types: [1] Box model – The box model is the simplest of the model types. [2] It assumes the airshed (i.e., a given volume of atmospheric air in a geographical region) is in the shape of a box.
For example, air and water; both are fluids and if we consider them together then they can be seen as a stratified fluid system. Density variations in the atmosphere profoundly affect the motion of water and air. Wave phenomena in air flow over the mountains and occurrence of smog are the examples of stratification effect in the atmosphere.
Denser water is below lighter water, representing a stable stratification. The pycnocline is the layer where the rate of change in density is largest. Ocean stratification is generally stable because warmer water is less dense than colder water, and most heating is from the sun, which directly affects only the surface layer.
A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses." [1]: 6 Water is typically referred to as polluted when it is impaired by anthropogenic contaminants.
The six stability classes are referred to: A-extremely unstable B-moderately unstable C-slightly unstable D-neutral E-slightly stable F-moderately stable The resulting calculations for air pollutant concentrations are often expressed as an air pollutant concentration contour map in order to show the spatial variation in contaminant levels over ...
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 ...