UPSC CSE Prelims 2024
Statement 1 is correct. Water vapour is a gaseous constituent of the atmosphere. Its distribution is highly variable, but it generally decreases significantly with increasing altitude. The majority of atmospheric water vapour is concentrated in the lower layers, primarily the troposphere. This is due to the decrease in temperature with altitude, which reduces the air's capacity to hold moisture.
Statement 2 is incorrect. The percentage of water vapour is not maximum at the poles; it is typically at its minimum in these regions. Water vapour concentration is highest in tropical and equatorial areas, especially over warm oceans and rainforests, owing to higher temperatures and greater evaporation. Conversely, colder temperatures at the poles result in reduced evaporation and lower atmospheric water vapour content.