Ozonesonde Quality Assurance: The JOSIE–SHADOZ (2017) Experience

Abstract

The ozonesonde is a small balloon-borne instrument that is attached to a standard radiosonde to measure profiles of ozone from the surface to 35 km with ∼100-m vertical resolution. Ozonesonde data constitute a mainstay of satellite calibration and are used for climatologies and analysis of trends, especially in the lower stratosphere where satellites are most uncertain. The electrochemical concentration cell (ECC) ozonesonde has been deployed at ∼100 stations worldwide since the 1960s, with changes over time in manufacture and procedures, including details of the cell chemical solution and data processing. As a consequence, there are biases among different stations and discontinuities in profile time series from individual site records. For 22 years the Jülich (Germany) Ozonesonde Intercomparison Experiment (JOSIE) has periodically tested ozonesondes in a simulation chamber designated the World Calibration Centre for Ozonesondes (WCCOS) by WMO. During October–November 2017 a JOSIE campaign evaluated the sondes and procedures used in Southern Hemisphere Additional Ozonesondes (SHADOZ), a 14-station sonde network operating in the tropics and subtropics. A distinctive feature of the 2017 JOSIE was that the tests were conducted by operators from eight SHADOZ stations. Experimental protocols for the SHADOZ sonde configurations, which represent most of those in use today, are described, along with preliminary results. SHADOZ stations that follow WMO-recommended protocols record total ozone within 3% of the JOSIE reference instrument. These results and prior JOSIEs demonstrate that regular testing is essential to maintain best practices in ozonesonde operations and to ensure high-quality data for the satellite and ozone assessment communities.

A Post‐2013 Dropoff in Total Ozone at a Third of Global Ozonesonde Stations: Electrochemical Concentration Cell Instrument Artifacts?

“…Possible changes in behavior of the pump, pump motor, or batteries at low stratospheric pressures and temperatures are obvious candidate factors and have been considered, but preliminary results have not identified significant differences. Both Type1 and Type2 ozonesondes, four different sensing SSTs, and varying preparation procedures were tested in the 2017 JOSIE‐SHADOZ experiment (Thompson et al, 2019), and a preliminary analysis did not reveal any signs of the dropoff in those data. In‐depth analysis of the 80 profiles from JOSIE‐SHADOZ should help identify the causes and magnitudes of contributing factors like SST to the ECC O 3 dropoff.…”

“…Hypothesized causes for these findings, for example, hardware changes in the 2011–2016 period (the company manufacturing Type1 ECCs changed ownership twice) or the non‐standard SST supplied by NOAA to the above‐mentioned sites, were tested along with other variables in a new series of chamber tests (JOSIE; Jülich Ozonesonde Intercomparison Experiments) in late 2017. Initial results from the 80 chamber profiles in JOSIE‐SHADOZ could not explain the dropoff behavior (Thompson et al, 2019), and the cause remained unsolved.…”

Taehwa Research Forest: a receptor site for severe domestic pollution events in Korea during 2016

“…However, during this same time period, the observed trend has increased near the petrochemical and industrial regions to the west and southwest of the SMA. Therefore, due to the complexities and heterogeneity of emissions within the SMA (Vellingiri et al, 2015), it is important to assess chemical gradients that may occur among sites with varying distances from emission sources (Ryu et al, 2013;Iqbal et al, 2014;Jeon et al, 2014;Lee et al, 2014), including sites that may be rural pollution receptor sites.…”

The NASA Wallops Flight Facility Digital Ozonesonde Record: Reprocessing, Uncertainties, and Dual Launches

“…Journal of Geophysical Research: Atmospheres et al, 1998;Deshler et al, 2008;Hilsenrath et al, 1986;Johnson et al, 2002;Smit et al, 2007;Thompson et al, 2019).…”

“…The Deshler et al () study was a multisonde photometer intercomparison campaign (Balloon Experiment on Standards for Ozone Sondes) conducted in April 2004 that evaluated sonde type and sensing solution under actual flight conditions. Thompson et al () is an assessment of the JOSIE 2017 campaign that focused on ozonesonde performance under tropical conditions. The ASOPOS (Assessment for Standards in Operating Procedures for Ozone Sondes) panel, composed of ozonesonde experts, was established to consolidate and evaluate the JOSIE and other ozonesonde experiments to establish consistency in the trends derived from sounding data among multiple stations and to ensure homogeneity in the data quality of a station data record (Smit & ASOPOS, ).…”