How did scientist determine the layers of the atmosphere?

Scientists determined the layers of the atmosphere by analyzing changes in temperature, pressure, and composition at various altitudes. They used instruments such as weather balloons, satellites, and aircraft to collect data on atmospheric conditions. These measurements revealed distinct changes in temperature and gas concentrations, allowing scientists to categorize the atmosphere into layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Additionally, studies of atmospheric phenomena, such as the behavior of auroras and the propagation of radio waves, further confirmed the existence of these layers.