The stratosphere is the second major layer of Earth's atmosphere, located above the troposphere and below the mesosphere. It extends from about 10 to 50 kilometers above the Earth's surface. The stratosphere contains the ozone layer, which plays a crucial role in protecting life on Earth by absorbing most of the Sun's harmful ultraviolet radiation. Research in the stratosphere focuses on understanding the dynamics and chemistry of this layer of the atmosphere, including studying the formation and depletion of the ozone layer, the impact of human activities on stratospheric ozone, and the effects of climate change on the stratosphere. Scientists use a variety of methods, including satellite observations, ground-based measurements, and computer models, to study the stratosphere and its complex interactions with other parts of the Earth's atmosphere.