Correction of the Observatoire Haute Provence electrochemical concentration cell (ECC) ozonesonde 1991–2023 data record

Abstract. The Observatoire Haute Provence (OHP) station is one of the few long-term measuring stations for vertical ozone profiles in southern Europe. Since 1991, vertical ozone distribution has been monitored by the OHP weekly electrochemical concentration cell (ECC) ozonesonde. In this study, we have corrected the ECC datasets for the period 2002–2007. The correction of the ECC has been carried out using comparisons with other ozone-measuring instrument at the same station, stratospheric lidar, and with collocated satellite observations of the ozone vertical profile by Microwave Limb Sounder (MLS). Median ozone concentration of the ECC for the period 2002–2007 was -3.4 % lower than that of the stratospheric lidar and MLS. The ECC internal pump temperature showed a sudden drop of 16 K at 25 km for the period 2002–2007 compared to the period 1991–2001. Considering the long-term trends of the ECC current and stratospheric lidar ozone concentration at 25 km as well as the ECC pump speed trend, we show that the observed ECC pump temperature between 2002 and 2007 is too low by –10 K at 25 km. The ECC pump temperature for the period 2002–2007 has been corrected accordingly by 0 K at 0 km and 10 K at 30 km and the bias at 25 km with the stratospheric lidar and MLS have been reduced to -0.5 %.