Indicator chemicals

Ozone layer above Switzerland

Ozone is a gas that has the property of absorbing a portion of the ultraviolet radiation emanating from the sun. It is present throughout the stratosphere at an altitude of between 10 and 40 km, where it forms the so-called ozone layer. The destruction of ozone molecules is not caused directly by the substances that deplete the ozone layer, but rather by their degradation products (chlorine, bromine), which are formed under the particularly intense UV radiation in the stratosphere. This indicator reflects the evolution of the ozone layer and is an indication of the efficiency of measures taken to preserve it and of the necessity of further intervention.

Assessment of the state
medium medium
Assessment of the trend
unsatisfactory unsatisfactory
Ozone column above Arosa 2018: 322.8 Ozone column above Arosa 2017: 309.7 Ozone column above Arosa 2016: 311 Ozone column above Arosa 2015: 314.5 Ozone column above Arosa 2014: 317.7 Ozone column above Arosa 2013: 321.8 Ozone column above Arosa 2012: 302.7 Ozone column above Arosa 2011: 301.5 Ozone column above Arosa 2010: 329.8 Ozone column above Arosa 2009: 316.1 Ozone column above Arosa 2008: 306.6 Ozone column above Arosa 2007: 312.9 Ozone column above Arosa 2006: 315.2 Ozone column above Arosa 2005: 312.6 Ozone column above Arosa 2004: 312.6 Ozone column above Arosa 2003: 317.7 Ozone column above Arosa 2002: 310.4 Ozone column above Arosa 2001: 315.9 Ozone column above Arosa 2000: 304.9 Ozone column above Arosa 1999: 315.1 Ozone column above Arosa 1998: 319.7 Ozone column above Arosa 1997: 304.9 Ozone column above Arosa 1996: 311.3 Ozone column above Arosa 1995: 305.1 Ozone column above Arosa 1994: 315.7 Ozone column above Arosa 1993: 299.6 Ozone column above Arosa 1992: 305.5 Ozone column above Arosa 1991: 327.6 Ozone column above Arosa 1990: 315.4 Ozone column above Arosa 1989: 318.7 Ozone column above Arosa 1988: 320.6 Ozone column above Arosa 1987: 324.9 Ozone column above Arosa 1986: 325.6 Ozone column above Arosa 1985: 316.4 Ozone column above Arosa 1984: 327.8 Ozone column above Arosa 1983: 313.1 Ozone column above Arosa 1982: 326.5 Ozone column above Arosa 1981: 326.4 Ozone column above Arosa 1980: 325.7 Ozone column above Arosa 1979: 332.6 Ozone column above Arosa 1978: 326.2 Ozone column above Arosa 1977: 331.5 Ozone column above Arosa 1976: 328.5 Ozone column above Arosa 1975: 320.6 Ozone column above Arosa 1974: 327 Ozone column above Arosa 1973: 330.5 Ozone column above Arosa 1972: 333.2 Ozone column above Arosa 1971: 331.9 Ozone column above Arosa 1970: 341.3 Ozone column above Arosa 1969: 336.6 Ozone column above Arosa 1968: 333.4 Ozone column above Arosa 1967: 322.3 Ozone column above Arosa 1966: 333.2 Ozone column above Arosa 1965: 331.5 Ozone column above Arosa 1964: 318.6 Ozone column above Arosa 1963: 332.5 Ozone column above Arosa 1962: 330.9 Ozone column above Arosa 1961: 320.1 Ozone column above Arosa 1960: 338.9 Ozone column above Arosa 1959: 336.1 Ozone column above Arosa 1958: 332 Ozone column above Arosa 1957: 320.8 Ozone column above Arosa 1956: 332.6 Ozone column above Arosa 1955: 331.6 Ozone column above Arosa 1954: 336.1 Ozone column above Arosa 1953: 329.2 Ozone column above Arosa 1952: 345.4 Ozone column above Arosa 1951: 337.9 Ozone column above Arosa 1950: 332 Ozone column above Arosa 1949: 325.7 Ozone column above Arosa 1948: 326.7 Ozone column above Arosa 1947: 336.6 Ozone column above Arosa 1946: 323.6 Ozone column above Arosa 1945: 332.2 Ozone column above Arosa 1944: 323.7 Ozone column above Arosa 1943: 326.6 Ozone column above Arosa 1942: 338.7 Ozone column above Arosa 1941: 349.5 Ozone column above Arosa 1940: 354.8 Ozone column above Arosa 1939: 324 Ozone column above Arosa 1938: 325.3 Ozone column above Arosa 1937: 333.1 Ozone column above Arosa 1936: 335.6 Ozone column above Arosa 1935: 327.3 Ozone column above Arosa 1934: 323.4 Ozone column above Arosa 1933: 343.2 Ozone column above Arosa 1932: 322.7
One Dobson Unit (DU) is defined as a layer of pure ozone that would be 0.01 mm thick if measured at ground level at a temperature of 0°C and a pressure of 1 atmosphere. Thus, if all the ozone contained in a column of air was brought down to the surface of the Earth, 330 DU would represent an ozone layer 3.3 mm thick

Data for the graph: Excel
Source: MeteoSwiss
Comment

Since the minimum level recorded in 1993 due to the temporary increase in the concentration of chlorine in the stratosphere following the eruption of Pinatubo, the average concentration of ozone over Arosa first tended to rise slightly each year. For the last ten years it has remained more or less stable. Due to the longevity of ozone depleting substances in the atmosphere, and their continued emission from existing stocks, in particular insulation foams and refrigeration systems, a return to the initial level is not expected before 2060, and will also depend on other related factors, such as climate change. In order to reach its 1980 level, the ozone concentration must rise by 5%. This corresponds to a linear increase of 0.075% per year between ca.1995 and 2060. Between 1995 and 2010, the increase should therefore have amounted to 1.15%. Since the ozone concentration remained more or less stable during this period, the target can deemed to have been missed by these 1.15%. As this value is lower than 2%, the state of the ozone layer above Switzerland can nevertheless not be assessed as completely negative.

International comparison

This indicator illustrates the global state of an environmental parameter at a given spot on our Planet. A comparison with data from other countries does not make sense, since dissimilarities between regions are more likely to be due to local variations in the Earth climatic system than to differences in the effects of ozone-depleting substances.

Method

The transparency of the atmosphere to solar UV radiation is measured using Dobson and Brewer spectrometers. These measurements are used to calculate the amount of ozone present in the air column above the Arosa observatory.

 
Last updated on: 26.03.2019

Further information

Links

inidkatoren_hirun

Indicators

Search and list of all indicators

https://www.bafu.admin.ch/content/bafu/en/home/themen/thema-chemikalien/chemikalien--daten--indikatoren-und-karten/chemikalien--indikatoren/indikator-chemikalien.pt.html/aHR0cHM6Ly93d3cuaW5kaWthdG9yZW4uYWRtaW4uY2gvUHVibG/ljL0FlbURldGFpbD9pbmQ9U1AwMTYmbG5nPWVuJlN1Ymo9Tg==.html