Suggestions for Future Work

The primary objectives of this paper are to provide an updated summary of available chemistry data from Antarctica and make recommendations for future efforts. The observed variability across Antarctica clearly shows the need for an improved understanding of the mechanisms that ultimately control the chemistry of a snow or ice sample. By making this data set available, we invite and encourage the wider science community to participate in this continent-wide effort

Based on our findings and on previous papers, we aim for the following research outputs as the next step for the ITASE Chemistry Synthesis Group:

• Investigation of the snow chemistry signal migration and spatial variability of significant climate events and oscillating and non-oscillating climate drivers
• This can be achieved by intercontinental comparison of snow chemistry variability contrasting e.g. El Niño with La Niña years, high index Antarctic Oscillation years with low index years, and the snow chemistry signal before, during and after volcanic eruptions
• Furthermore, cross–correlation of snow chemistry data with reanalysis data, such as NCEP/NCAR and ERA-40 will allow us to link characteristic geographic chemistry patterns to typical climate modes, establishing transfer functions, and to identify Antarctic teleconnections and their variability through time.
• Tuning general circulation models to reconstruct snow chemistry patterns in reoccurring synoptic and meso-scale climate events using contemporary chemistry data as a training set will allow us to use these models in reverse, to output climate events using chemistry data further back in time
• Investigation of the relationship between atmospheric aerosol loading and contemporary snow chemistry.
• Quantification of contemporary aerosol precipitation and deposition efficiency by linking surface snow chemistry concentration with atmospheric aerosol loading measurements can be established in collaboration with the ITASE Atmospheric Chemistry Synthesis Group. Furthermore, this will assist in investigating the processes that lead to post-depositional ion concentration changes. It is important to compare samples of similar age as well as of similar snow depths.
• Investigation of dry versus wet deposition is particularly important when comparing coastal sites with the Antarctic interior. Here progress can be achieved in collaboration with the ITASE/ISMASS Mass Balance Synthesis Group and the ITASE Atmospheric Chemistry Synthesis Group
• Incorporate new analytical techniques allowing the measurement of trace elements and their isotopic signatures, as well as organic acids, and particles
• Laboratory inter-comparison
• We suggest a laboratory inter-comparison in order to demonstrate the compatibility of snow chemistry data across all laboratories.
• Data Availability
• The data described here are made available through the ITASE Synthesis Groups web page. The data set will be updated as new data and data sets are provided.

Acknowledgements

We would like to thank SCAR, the national Antarctic programmes, and the national funding sources for their support. Two anonymous reviewers made helpful comments that improved this manuscript.