Surface ozone levels at the end of the nineteenth century in South America

Abstract

Records of surface ozone data collected twice a day by means of the Schönbein method at Villa Colon, Montevideo, Uruguay, during the years 1883–1885 and at Cordoba, Argentina, during the years 1886–1892 have been converted to present‐day concentrations. Most of the uncertainties suffered from the original technique are removed by a two‐step procedure, in particular a conversion algorithm for humidity and a linear regression constructed by simultaneous readings of Schönbein and a quantitative method. The relative error of this procedure, previously applied to the Moncalieri data series, is 33%. Within these limitations we can state that one century ago the surface ozone levels at that latitude of the southern hemisphere were comparable to those of Moncalieri and Montsouris. Furthermore, the recent levels observed in remote areas at that latitude are approximately twice as large as a century ago.

Global distribution and trends of tropospheric ozone: An observation-based review

“…Bojkov (1986) applied his derived Montsouris regression to measurements from eleven Schönbein ozonoscopes across Michigan, and found lower ozone values compared to the method of Linvill et al (1980). Several years later Bojkov's analysis was shown to be incorrect by Marenco et al (1994) who demonstrated that an error in Bojkov's regression equation led to ozone estimates that were too high by a factor of three, further increasing the discrepancy between the Linvill et al (Anfossi et al, 1991);Montevideo, Uruguay (1883-1885 and Cordoba, Argentina (1886-1892 (Sandroni et al 1992); Athens, Greece (1901-1940 (Cartalis and Varotsos, 1994); five Southern Hemisphere (SH) and seven NH sites with varying time series between 1872 and 1928 (Pavelin et al, 1999); Malta in the Mediterranean Sea (Nolle et al, 2005);andZagreb, Croatia (1889-1900) (Lisac et al, 2010). Due to the uncertainty in the Elementa: Science of the Anthropocene • 2: 000029 • doi: 10.12952/journal.elementa.000029 absolute ozone mixing ratios derived from Schönbein measurements (Marenco et al, 1994;Pavelin et al, 1999;Staehelin and Schnadt Poberaj, 2008), those values are not summarized here.…”

Change in global aerosol composition since preindustrial times

“…Comparison with the few existing measurements during the preindustrial period (Volz and Kley, 1988;Anfossi et al, 1991;Sandroni et al, 1992;Marenco et al, 1994;Sandroni and Anfossi, 1994;Pavelin et al, 1999) indicates that the model may overestimate ozone concentrations (within a factor of two and in some cases above a factor of 3), with only 3 occasions (over wintertime Japan) of calculated O 3 concentration above 30 ppbv. These high O 3 levels are mainly associated with strong stratospheric influx of ozone in the troposphere in the northern hemisphere during the winter and spring periods.…”

Anthropogenic forcing on tropospheric ozone and OH since preindustrial times

“…However, biomass burning takes place principally in the tropics. As will be discussed in section 4, nineteenth century observations of 03 in South America [Sandroni et al, 1992] imply a much weaker tropical biomass burning source than that of today. Following Crutzen and Zimmermann [1991], we assume in our standard simulation that preindustrial biomass burning emissions are 10% of the present-day value and retain the same geographic distribution.…”