Ozone layer breakdown of ozone in the stratosphere results in reduced absorption of ultraviolet radiation. Consequently, unabsorbed and dangerous ultraviolet radiation is able to reach the Earth’s surface at a higher intensity. Ozone levels have dropped by a worldwide average of about 4 percent since the late 1970s. For approximately 5 percent of the Earth's surface, around the north and south poles, much larger seasonal declines have been seen, and are described as "ozone holes". The discovery of the annual depletion of ozone above the Antarctic was first announced by Joe Farman, Brian Gardiner and Jonathan Shanklin, in a paper which appeared
Free convective layer (MPL). Free convective layer In atmospheric sciences, the free convective layer (FCL) is the layer of conditional or potential instability in the troposphere. It is a layer of positive buoyancy (PBE) and is the layer where deep, moist convection (DMC) can occur. On an atmospheric sounding, it is the layer between the level of free convection (LFC) and the equilibrium level (EL). The FCL is important to a variety of convective processes and to severe thunderstorm forecasting. It is the layer of instability, the "positive area" on thermodynamic diagrams where an ascending air parcel is warmer than its environment. Integrating