In fact, most of the ozone molecules present 2 in the atmosphere at any time have been made by this same two-step splitti- plus-combination process, although the initiating cause usually begins with very energetic solar ultraviolet (UV) radiation rather than lightning. Many thousands of years later, the modern history of ozone began with its synthesis in the laboratory of H. F. Schonbein in 1840 (Nolte 1999), although the positive con?rmation of its three-oxygen atom chemical formula came along sometime later. Scienti?c interest in high- altitude stratospheric ozone dates back to 1881 when Hartley measured the spectrum of ozone in the laboratory and found that its ability to absorb UV light extended only to 293nm at the long wavelength end (Hartley 1881a).