Unformatted text preview: pse rate > saturated lapse rate).
2. (a) What is an atmospheric temperature inversion? Give one example of how it forms. (2
ANS An atmospheric temperature inversion is a situation where the air temperature
steadily increases from ground level as you increase in height, the opposite of what
An example of its formation would be cold winds (katabatic) spilling off a cold mountain
top and becoming trapped in the bottom of a valley, displacing warmer air that then rises
above it. Another example would be when warm air moves over an area of existing cold
air and then stays there, or vice versa. Others possible.
(b) Explain how such an inversion results in the formation of a blanket layer of pollution above a
city like Los Angeles or Tehran. (2 marks)
ANS Local warming at ground level can result in a parcel of air detaching itself from the
ground. It rises as its resulting density is lower than that of the surrounding air. As it rises
it cools adiabatically. At a certain point its temperature (and density) will meet that of the
surrounding air, as it is warmer the higher you go within an inversion, and so the
temperatures and densities and pressures eventually match. At that point it has no
remaining buoyancy. The now risen air is then trapped and other air rising will join it,
levelling out at the same altitude and resulting in the blanket layer.
An unsaturated warm air m...
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This document was uploaded on 01/17/2014.
- Fall '14