12 Topics.
0 of 5 Concepts Done
Asked in UPSC PrelimsUPSC 2003
What to Study: What share of the atmosphere is water vapour by volume, and in which three forms is water present? Know its two sources and the four processes that keep water moving between the atmosphere, oceans and continents. You should be able to explain why water vapour decreases with altitude and why it varies with latitude.
What to Study: What does absolute humidity measure, and in which unit is it expressed? Understand why its value differs from place to place on the earth's surface.
What to Study: How is relative humidity defined? Explain what happens to it when the air gets warmer or cooler while the moisture stays the same. Remember where it is greater and where it is least (oceans or continents), and be clear how it differs from absolute humidity.
What to Study: Learn what specific humidity measures and in which unit it is expressed. Be clear how it differs from absolute humidity (a volume-based measure) and from relative humidity (a measure against capacity). What happens to it when the temperature or pressure of the air changes but no moisture is added or removed?
What to Study: When is air said to be saturated, and what is the dew point? Understand how cooling moist air to its dew point leads to condensation. Also see why the dew point, compared with the freezing point, matters for dew and frost.