In early 2011, a joint initiative was started under the auspices of SPARC, the International Ozone Commission (IO3C), the ozone focus area of the Integrated Global Atmospheric Chemistry Observations (IGACO-O3) programme, and the Network for Detection of Atmospheric Composition Change (NDACC). To aid digestion, an acronym of acronyms, SI2N, was adopted. Reports on the two workshops were published in SPARC Newsletters 37 and 39 (Harris et al., 2011, 2012 – http://www.sparc-climate.org/publications/).The main objective of SI2N is to assess and extend the current knowledge and understanding of measurements of the vertical distribution of ozone, with the aim of providing input to the next WMO/UNEP Scientific Assessment of Ozone Depletion anticipated for 2014. It is effectively a follow-up of the SPARC/IOC/GAW Ozone Profile Assessment (http://www.sparc-climate.org/publications/).

Guidelines for submissions:

• Anything which was or could have been considered for the last Ozone Assessment will not be included.
• Papers published prior to 2011 will be assessed using the following criteria.
• The content of the paper must still be valid and not superceded by more recent work.
• Datasets or technical advances (e.g. algorithm developments) will be looked on more favourably than interpretative papers such as trend analyses (since we assume they will updated if not by the same group.)
• Comparisons with model data or use in model runs can be included as long as they are using current datasets that will be used in SI2N.
• If a paper can be reasonably updated, then that is the preferable option.