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
Radius of outermost closed isobar objectively determined that tropical cyclones in the northwest Pacific Ocean are the largest on earth on average, with North Atlantic tropical cyclones roughly half their size. Radius of outermost closed isobar The radius of outermost closed isobar (ROCI) is one of the quantities used to determine the size of a tropical cyclone. It is determined by measuring the radii from the center of the storm to its outermost closed isobar in four quadrants, which is then averaged to come up with a scalar value. It generally delimits the outermost extent of a tropical cyclone's wind circulation. Use of this measure