ASOPOS

Since 2004, the WMO/GAW-sponsored ASOPOS (Assessment of Standard Operating Procedures (SOPs) of OzoneSondes) team of experts has been evaluating ozonesonde records and the results of field and laboratory experiments that intercompare instruments. The first ASOPOS Guidebook on “best practices” was published in 2014: WMO/GAW Report 201, 2014. At the urging of the ozone trends community, the ASOPOS team has been working on a new set of recommendations that are being published as the ASOPOS 2.0 Report. Important aspects of the new report: 1) the measurement principles of the ozonesonde instrument, 2) the uncertainty chain of the parameters affecting the measurement, 3) new recommendations on sonde preparation steps and 4) revised data processing protocols. Newly added sections give expanded guidelines on data quality indicators and the rationale for recording of enhanced metadata. With the adoption of these SOP’s, 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. The new ASOPOS 2.0 Report is published as GAW Report No. 268.

For the implementation of the ASOPOS 2.0 recommendations into the global ozonesonde network a series of six webinars have been prepared which can be downloaded from here.