Atmosphere of Earth (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. From highest to lowest, the five main layers are: The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at
Vienna Convention for the Protection of the Ozone Layer layer. One of the outcomes of the Vienna Convention was the creation of a panel of governmental atmospheric experts known as the Meeting of Ozone Research Managers, which assesses ozone depletion and climate change research and produces a report for the Conference of Parties (COP). Additionally, the COP utilizes the data assessed to suggest new policies aimed at limiting CFC emissions. Currently, the COP meets every three years and coordinates with the timing of a similar meeting rendered under the Montreal Protocol. The Ozone Secretariat functions as an administrator of the COP, Montreal Meeting of Parties (MOP), and Open-Ended Working