How does atmospheric pressure generally change with increasing altitude in the troposphere?

Concept overview / definition Key idea: Most of the mass of the atmosphere is concentrated in the lower layers, so the air above you becomes thinner as you go up. As altitude increases, air density decreases and the “air column” above the point becomes smaller in mass, reducing its weight per unit area.

Why the correct option is correct If the air column above becomes shorter and less dense with height, its total weight reduces. Since pressure is the weight of the air column per unit area, pressure must decrease with altitude in the lower atmosphere, especially within the troposphere where these changes are pronounced.

Why the other options are incorrect Statements claiming pressure increases with altitude reverse the air-column logic. Statements claiming pressure remains constant ignore the changing density and mass distribution with height. Options that attribute pressure change only to humidity or only to wind are incomplete; these can influence weather but do not define the overall vertical pressure trend.

UPSC exam tip / common confusion Elimination: Think “less air above, less weight, less pressure.” In prelims, if altitude increases and nothing else is specified, the safest conceptual inference is decreasing pressure in the troposphere.