There are numerous groups within the wider scientific community that will be users of the CDRs generated within SPIN. A key user of the merged ozone data sets that will be generated within SPIN will be the new SPARC initiative on past changes in the vertical distribution of ozone. At the time of writing the 2010 WMO/UNEP ozone assessment it became clear that the long-term vertically resolved ozone database that had been available for prior assessments, specifically the merged SAGE and SAGE II database, was no longer available as a result of the termination of the SAGE II instrument in 2005. This resulted in the assessment community being unable to make statements on how ozone had changed in the most recent 5 years. This new SPARC initiative aims to address this data gap and to coordinate activities that will lead to the availability of suitable long-term, vertically resolved ozone databases in time for the 2014 WMO/UNEP ozone assessment. WP17 of SPIN, and WP22 which builds off WP17, will deliver merged ozone databases in direct support of this SPARC initiative. Connections between SPIN and the SPARC activity are fostered through numerous links, e.g. J. Tamminen, who is a key participant in WP17 and WP22 of SPIN, is co-leader of the ‘long-term satellite records’ working group within the SPARC initiative, M. Van Roozendael (the Science Leader for both SPIN and the ozone_CCI) is co-cleader of the ‘Last decade (satellite)’ working group within the SPARC initiative, and G.Bodeker, the Project Manager for SPIN, is co-leader of the working group looking at the different approaches to combining vertically resolved ozone databases.

The WCRP Observation and Assimilation Panel (WOAP) is also playing a key role in the development of satellite-based CDRs. Through SPARC, researchers active in SPIN have links to the WOAP community and will ensure that SPIN outputs are, where possible, tailored to meet the needs of the WOAP community. In particular the requirements for the development of CDRs of ECVs as detailed in the Guideline for the Generation of Datasets and Products Meeting GCOS Requirements (GCOS-143) will inform the process for establishing CDRs within SPIN.