Since 2004, WMO/GAW in collaboration with NDACC, SHADOZ and GRUAN have sponsored the ASOPOS (Assessment of Standard Operating Procedures (SOPs) of OzoneSondes) team of experts who evaluate regularly the long term ozonesonde records and the results of field and laboratory experiments that intercompare various ozonesonde instruments. A couple of years ago, the ASOPOS team re-evaluated the first ASOPOS Report (WMO/GAW Report 201, 2014) and produced an updated set of recommendations that are recently published as the ASOPOS 2.0 Report “Ozonesonde Measurement Principles and Best Operational Practices” (GAW Report No. 268, 2021; https://library.wmo.int/idurl/4/57720).
Important aspects of this newest WMO/GAW Report 268 are: 1) detailed measurement principles of the ozonesonde instrument; 2) the uncertainty chain of parameters affecting the ozone measurement; 3) new recommendations on sonde preparation steps; 4) revised data processing protocols. Newly added sections give guidelines on data quality indicators and the rationale for recording of enhanced metadata. With the adoption of these SOPs, the global ozonesonde community has the potential to achieve the 5% uncertainty level in tropospheric and stratospheric ozone requested by the satellite and trends communities.
To this end, it is essential that the ASOPOS 2.0 recommendations for best ozonesonde practices be implemented in the operation of the global networks of GAW, NDACC, SHADOZ and GRUAN. Therefore, the ASOPOS panel prepared a series of six, relatively short (around 20 minutes), webinars addressing key topics and practical issues of the WMO/GAW Report 268. These webinars are available as videos, and as PowerPoint (pptx with voice) and pdf presentations, and can be obtained at:
https://www.wccos-josie.org/en/asopos
To interact with the ozonesonde managers, operators, and data users about these webinars and the practical implementation at their stations or in the time series, a series of regional, interactive, online meetups are being set up. The first was organized on 28 June 2024, covering the Central European ozonesonde sites. It drew 15 dedicated participants, and there was excellent exchange of common practices between the stations, and how preparation of ozonesondes might be improved in the future. The regional meetup also paved the way for follow-up communication, via e-mail, with individual sites.
We are looking forward to organize the remaining regional meetups in the fall of this year!
Fig. 1. Cover of the WMO-GAW Report No; 268 on “Ozonesonde Measurement Principles and Best Operational Practices”, available at https://library.wmo.int/idurl/4/57720
Fig. 2: Title slide of one of the six webinars, prepared by two of the NDACC Sonde Working Group representatives.