AMT Atmospheric Measurement Techniques AMT Atmos. Meas. Tech. 1867-8548 Copernicus Publications Göttingen, Germany 10.5194/amt-7-65-2014 Propagation of radiosonde pressure sensor errors to ozonesonde measurements Stauffer R. M. https://orcid.org/0000-0002-8583-7795 1 Morris G. A. 2 Thompson A. M. https://orcid.org/0000-0002-7829-0920 1 3 Joseph E. 4 Coetzee G. J. R. 5 Nalli N. R. 6 Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania, USA Department of Physics and Astronomy, Valparaiso University, Valparaiso, Indiana, USA NASA/Goddard Space Flight Center, Greenbelt, Maryland, USA Department of Physics and Astronomy, Howard University, Washington, DC, USA South African Weather Service, Pretoria, South Africa I.M. Systems Group, Inc., NOAA/NESDIS/STAR, College Park, Maryland, USA 10 01 2014 7 1 65 79 Copyright: © 2014 R. M. Stauffer et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://amt.copernicus.org/articles/7/65/2014/amt-7-65-2014.html The full text article is available as a PDF file from https://amt.copernicus.org/articles/7/65/2014/amt-7-65-2014.pdf

Several previous studies highlight pressure (or equivalently, pressure altitude) discrepancies between the radiosonde pressure sensor and that derived from a GPS flown with the radiosonde. The offsets vary during the ascent both in absolute and percent pressure differences. To investigate this problem further, a total of 731 radiosonde/ozonesonde launches from the Southern Hemisphere subtropics to northern mid-latitudes are considered, with launches between 2005 and 2013 from both longer term and campaign-based intensive stations. Five series of radiosondes from two manufacturers (International Met Systems: iMet, iMet-P, iMet-S, and Vaisala: RS80-15N and RS92-SGP) are analyzed to determine the magnitude of the pressure offset. Additionally, electrochemical concentration cell (ECC) ozonesondes from three manufacturers (Science Pump Corporation; SPC and ENSCI/Droplet Measurement Technologies; DMT) are analyzed to quantify the effects these offsets have on the calculation of ECC ozone (O<sub>3</sub>) mixing ratio profiles (O<sub>3MR</sub>) from the ozonesonde-measured partial pressure. Approximately half of all offsets are > ±0.6 hPa in the free troposphere, with nearly a third > ±1.0 hPa at 26 km, where the 1.0 hPa error represents ~ 5% of the total atmospheric pressure. Pressure offsets have negligible effects on O<sub>3MR</sub> below 20 km (96% of launches lie within ±5% O<sub>3MR</sub> error at 20 km). Ozone mixing ratio errors above 10 hPa (~ 30 km), can approach greater than ±10% (> 25% of launches that reach 30 km exceed this threshold). These errors cause disagreement between the integrated ozonesonde-only column O<sub>3</sub> from the GPS and radiosonde pressure profile by an average of +6.5 DU. Comparisons of total column O<sub>3</sub> between the GPS and radiosonde pressure profiles yield average differences of +1.1 DU when the O<sub>3</sub> is integrated to burst with addition of the McPeters and Labow (2012) above-burst O<sub>3</sub> column climatology. Total column differences are reduced to an average of −0.5 DU when the O<sub>3</sub> profile is integrated to 10 hPa with subsequent addition of the O<sub>3</sub> climatology above 10 hPa. The RS92 radiosondes are superior in performance compared to other radiosondes, with average 26 km errors of −0.12 hPa or +0.61% O<sub>3MR</sub> error. iMet-P radiosondes had average 26 km errors of −1.95 hPa or +8.75 % O<sub>3MR</sub> error. Based on our analysis, we suggest that ozonesondes always be coupled with a GPS-enabled radiosonde and that pressure-dependent variables, such as O<sub>3MR</sub>, be recalculated/reprocessed using the GPS-measured altitude, especially when 26 km pressure offsets exceed ±1.0 hPa/±5%.

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