Normally, the temperature decreases with the increase in height from the Earth's surface, because 1. the atmosphere can be heated upwards only from the Earth's surface 2. there is more moisture in the upper atmosphere 3. the air is less dense in the upper atmosphere Select the correct answer using the codes given below :

1. The phenomenon described is the typical decrease in temperature with increasing height in the troposphere, known as the Environmental Lapse Rate. 2. Statement 1 is correct. The atmosphere is largely transparent to incoming solar radiation but absorbs outgoing longwave (terrestrial) radiation from the Earth's surface. Thus, the primary heating of the troposphere occurs from the bottom upwards. As altitude increases, the distance from the primary heat source (Earth's surface) increases, contributing to lower temperatures. 3. Statement 2 is incorrect. Generally, moisture content (water vapor) is concentrated in the lower layers of the atmosphere and decreases with altitude. The presence of moisture contributes to heat absorption, so less moisture in the upper atmosphere would contribute to lower temperatures, not higher ones. 4. Statement 3 is correct. Atmospheric pressure and density decrease rapidly with height. The air is less dense in the upper atmosphere, meaning there are fewer molecules per unit volume to absorb and retain heat energy. This lower density contributes significantly to the decrease in temperature with altitude.