Description of the long-term ozone data series obtained from different instrumental techniques at a single location: the Observatoire de Haute-Provence (43.9 degrees N, 5.7 degrees E)

A description of the long-term data series of stratospheric ozone at the Ob servatoire de Haute-Provence is presented. At this station, data sets with temporal length of a decade or more are provided in the framework of the Ne twork for Detection of Stratospheric Change by ground-based experiments: Do bson spectrophotometer (in both column and Umkehr mode), lidar and ozoneson des. The data time series obtained from these various instruments operated simultaneously at a single site and complemented by SAGE II spaceborne meas urements are first described with respect to instrumental uncertainties, sa mpling rate and time evolution. These data series are then compared to each other in terms of sampling rate and average vertical profiles. The differe nce between the mean ozone profiles of the data sets can partly be explaine d by the different sampling rate of the instruments. Using the overlap and the complementarity of the various data sets, a preliminary estimate of the long-term evolution of ozone over the last decade over Southern France is conducted. Trend values for both total column and vertical profiles are der ived using the multi-regression statistical model AMOUNTS O-3. In the 25-40 km altitude range, a similar ozone decrease frost -4%/decade to -10%/decad e is observed from lidar, Umkehr and SAGE II data series in good agreement with previous estimates. In the lower stratosphere (15-25 km), large negati ve trends in the ozone vertical profile are observed. In addition, the nega tive trend of -5.4%/decade in total ozone inferred from the Dobson measurem ents over the period 1983-1995 is in good agreement with the integrated tre nd profile.