Tropospheric ozone Tropospheric ozone Ozone (O) is a trace gas of the troposphere, with an average concentration of 20-30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. . Ozone is also an important constituent of the stratosphere, where the ozone layer exists. The troposphere is the lowest layer of the Earth's atmosphere. It extends from the ground up to a variable height of approximately 14 kilometers above sea level. Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. It's concentration increases as height above sea level increases, with a maximum
Layer by Layer there are many variant techniques for the final layer, depending on whether the corner or edge pieces are solved first. The CFOP speedcubing technique, developed by Jessica Fridrich and others in the 1980s, similarly divides the puzzle into layers to be solved. However the method uses far more algorithms and shortcuts than the beginners' methods. Layer by Layer The Layer by Layer method is a method of solving the 3x3x3 Rubik's Cube. Many beginners' methods use this approach, but it also forms the basis of the CFOP speedcubing technique. The Layer by Layer Method was pioneered by David Singmaster in