Water plays a major role for our planet not only in its liquid form at the surface. In the atmosphere too,it considerably affects our lives as well as weather and climate. Clouds and rainfall are one example. Water vapor, the gaseous form of water, or also plays a prominent role on soil. It is the most important greenhouse gas in the atmosphere,without it the soil would be a frozen planet. For climate variations, water vapor is particularly important in the stratosphere at altitudes between 15 and 50 kilometers. How much of the gas actually reaches the stratosphere mainly depends on the temperature at the transition between the lowest atmospheric layer, or the troposphere,and the overlying stratosphere. This boundary layer is called the tropopause.
Source: phys.org