Scientific Sponsorship Statement - SSSHIS.TXT for Historical Total Ozone Data 1952-1957 (Issued 2004-11-17) Oxford 1952-1957 Arhus 1952-1957 Vigna di Valle 1954-1957 Aldergrove 1952-1957 Camborne 1952-1957 Fairbanks (College) 1952-1957 Lerwick 1952-1957 Magny les Hameaux 1955-1957 Cagliari/Elmas 1954-1957 General Methodology. The data are from Dobson spectrophotometers. For all European sites we used the reduced total ozone valued as archived by the International Ozone Commission (ref. 1). Later revisions of earlier data found within the same archival source were included. The data were digitised from paper and adjusted for changes in the absorption coefficients. The Fairbanks (College) data were available in original form and were re-calculated using Bass-Paur absorption coefficients and changing h from 22 to 19 km. Calibration of the instrument in 1953 revealed a separation in the optical wedge. The wegde was later replaced. Several tests with respect to accuracy and precision were performed on a day-to-day basis using local (NCEP/NCAR) 100 hPa temperature and 300 hPa geopotential height as reference series. Form this analysis, two types of outliers were determined and correspondingly flagged. The same analysis was performed in a recent period using TOMS overpass data. The ratio r of the correlation coefficients in the older and recent periods were then used to assess the precision (excellent: r>0.9, very good: 0.9>r>0.85, good: 0.85>r>0.8, fair: 0.8>r>0.75). For testing the accuracy, all series were extended to 1963 using corresponding total ozone data stored at WOUDC. Apart from meteorological reference series, the total ozone series from Arosa was used as a reference. After first tests indicated that the Oxford series is not significantly inhomogeneous, we also used the latter series as reference series. Confidence intervals for the tests were obtained from Monte Carlo simulations. In addition, tests for a change in the seasonality were performed, and standardized difference series were explored visually. This procedure led to the identification of a number of unplausible periods (flagged) and the detection of several step inhomogeneities. The inhomogeneities were corrected for by assuming by assuming a seasonally dependent error (as is expected for changes in the extraterrestrial constants or the wedge calibration), if possible. The methodology is and some station information is described in ref. 2 and ref. 3. Results. Århus, 1466 daily means, precision: fair, accuracy: fair, outliers flagged, offset corrected Aldergrove, 1427 daily means, precision: excellent, accuracy: n. d., outliers flagged Cagliari, 786 daily means, precision: poor, accuracy: good, outliers flagged, implausible period flagged, offset corrected Camborne, 1606 daily means, precision: good, accuracy: fair, outliers flagged, offset corrected Hemsby, 938 daily means, precision: very good, accuracy: n. d., outliers flagged, implausible period flagged Lerwick, 1396 daily means, precision: excellent, accuracy: fair, outliers flagged, offset corrected Magny les Hameaux, 449 daily means, precision: very good, accuracy: poor, outliers flagged Messina, 1074 daily means, precision: poor, accuracy: poor, outliers flagged Oxford, 1806 daily means, precision: excellent, accuracy: good, outliers flagged Reykjavik, 574 daily means, precision: poor, accuracy: poor, outliers flagged Vigna di Valle, 1162 daily means, precision: very good, accuracy: good, outliers flagged, implausible period flagged Santa Maria, 1213 daily means, precision: poor, accuracy: n. d., outliers flagged Uccle, 278 daily means, precision: poor, accuracy: n. d., outliers flagged Fairbanks (College), 394 daily means, precision: fair, accuracy: fair, low sun rejected, 1954 data need further assessment (n. d. = not determined) References Ref. 1 Normand, C. W. B. (1961) (ozone data tables). In: Air Ministry Branch, Ozone values (International Ozone Commission). (Report MO 19/3/9 Part I (formerly MO 15/90) of UK MetOffice), 31 Jan. 1961 (unpublished) Ref. 2 Brönnimann, S., J. Staehelin, S. F. G. Farmer, J. C. Cain, T. M. Svendby and T. Svenøe (2003) Total ozone observations prior to the IGY. I: A history. Quarterly Journal of the Royal Meteorological Society, Vol. 129, p. 2797–2817. Ref. 3 Brönnimann, S., J. C. Cain, J. Staehelin and S. F. G. Farmer (2003) Total ozone observations prior to the IGY. II: Data and quality. Quarterly Journal of the Royal Meteorological Society, Vol. 129, p. 2819–2843.