Tracer-tracer Relations as a Tool for Research on Polar Ozone Loss

Ozone was discovered by Christian Friedrich Sch¨onbein in 1839. Sch¨onbein himself believed that ozone plays an important role in the Earth system and suggested (in 1853) that long-term ozone measurements in the atmosphere should be performed on an international scale: “Geneigt zu glauben, das atm. Ozon spiele im Haushalte der Erde eine wichtige Rolle, halte ich es f¨ur w¨unschenswerth, dass m¨oglichst zahlreiche, sowohl grosse Zeitr¨aume als bedeutende L¨anderstrecken umfassende, untereinander vergleichbare Beobachtungen ¨uber die Ver¨anderungen des Ozongehaltes der Atmosph¨are angestellt werden. . . 2” (in a letter to Justus von Liebig, Kahlbaum and Thon, 1900, p. 10). Indeed numerous measurements were made during the second half of the 19th century using a method that Sch¨onbein had developed (for a detailed discussion of the early measurements of atmospheric ozone see e.g., Crutzen, 1988; London and Liu, 1992; Sonnemann, 1992). This early interest in ozone was motivated to a large extent by the fact that ozone, at that time, was considered an indicator of clean, healthy air and that ozone-poor air was thought to promote sickness. Measurement series of ozone were performed in spas with the intention of demonstrating how beneficial to health a stay would be (Lender, 1872). This view persisted for many decades and was held by leading scientists in the field; as late as 1946 Regener stated “Anwesenheit von Ozon ist ein Indikator f¨ur gute Luft3”. Today, of course, it is known that high concentrations of tropospheric ozone are detrimental to human health and similarly harmful to other living systems. ...