The tropopause is the boundary layer between the troposphere and the stratosphere in Earth's atmosphere. It is located at an altitude that varies from about 8 to 15 kilometers (5 to 9 miles) above sea level, depending on geographic location and weather conditions. The temperature in the tropopause remains relatively constant, marking a transition where the temperature stops decreasing with altitude. This layer plays a crucial role in weather patterns and the movement of air masses. It acts as a barrier that limits the vertical mixing of air, which helps to stabilize the atmosphere and influences the formation of clouds and storms in the troposphere.