On the basis of vertical distribution of temperature, the atmosphere is classified into four characteristic regions, namely troposphere, stratosphere, mesosphere and thermosphere. Environmental or Normal Lapse Rate: The lapse rate refers to the rate at which temperature decreases with an increase in altitude in the atmosphere. There are different lapse rates in different layers of the atmosphere: 1. Troposphere (Negative Lapse Rate): In the troposphere, which is the lowest layer(8-17KM) of the atmosphere where weather phenomena occur, the lapse rate is called the environmental lapse rate (ELR). On average, the ELR is about 0.64°C /100 m or 6.5°C per kilometer (or 3.5°F per 1,000 feet) of altitude gained. However, it can vary due to various factors such as atmospheric stability, moisture content, and geographical location. In the upper limits of the troposphere, the temperature decreases to about –56°C. The upper boundary of the troposphere is known as tropopause. The trans...