A diatom–conductivity transfer function for reconstructing past changes in the Southern Hemisphere westerly winds over the Southern Ocean

• Published in: Journal of Quaternary Science
• Main Authors: SAUNDERS, KRYSTYNA M., HODGSON, DOMINIC A., MCMURTRIE, SHELLEY, GROSJEAN, MARTIN
• Other Authors: 50 degrees South Trust, Swiss National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Antarctic; Campbell Island; Southern Ocean; Antarc*
• Online Access: http://dx.doi.org/10.1002/jqs.2788; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.2788; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.2788

ABSTRACT Sub‐Antarctic islands are ideally placed to reconstruct past changes in Southern Hemisphere westerly wind behaviour. They lie within their core belt (50–60°S) and the strong winds deliver sea salt ions to the islands resulting in a west to east conductivity gradient in their water bodies. This means that the stronger (or weaker) the winds, the higher (or lower) the conductivity values measured in the water bodies. A survey of the water chemistry and diatom assemblages of lakes and ponds on sub‐Antarctic Campbell Island (52°32′S, 169°8′E) revealed that, similar to other sub‐Antarctic islands, conductivity was the most important, statistically significant ecological variable explaining turnover in diatom community structure. Based on this, a diatom–conductivity transfer function was developed (simple weighted averaging with inverse deshrinking: R 2 = 0.86, R 2 jack = 0.66, RMSEP = 0.25 log 10 μS cm −1 ). This transfer function will be applied to lake sediment cores from the western edge of the Campbell Island plateau to reconstruct past conductivity/sea spray and therefore directly reconstruct changes in Southern Hemisphere westerly wind strength within their core belt.