Reconstruction of New Zealand climate indices back to AD 1731 using dendroclimatic techniques: Some preliminary results

Reconstructions of temperature and zonal and meridional flow over New Zealand are presented for the period back to AD 1731. The reconstructions have made use of ring-width chronologies from five endemic species (three different genera); the first time multispecies reconstructions have been attempted in New Zealand. The chronologies were standardized using techniques that attempted to maintain as much of the low-frequency variance in the tree-ring series as possible, so that long-term climatic trends could be detected. In independent periods verification, the reconstructions of temperature explain between 30 and 33 per cent of the variance, whereas zonal and meridional flow reconstructions explain 31–43 per cent and 18–39 per cent of the variance, respectively.