THE KAURI-CLIMATE CONNECTION: A NEW ZEALAND TREE-RING PROXY RECORD OF PACIFIC CLIMATE VARIABILITY AND PALAEOENVIRONMENTAL CHANGE DURING THE QUATERNARY

The El Niño-Southern Oscillation (ENSO) is one of the most important sources of global-scale natural climate variability, and is intimately connected to New Zealand climate. Lingering questions about this climate phenomenon ask the following: A.) How stable are the observed 20th century teleconnections? B.) Is there an evolving character of ENSO on a decadal to millennial scale? C.) Is ENSO a late Holocene phenomenon only? Answers to the aforementioned queries require a data set that extends beyond the scope of modern instrumental records, and emphasise the need for high-resolution climate proxies. Annually resolved proxy climate record sources include ice cores, corals, tree-rings, and laminated lacustrine sediments to name a few, all of which can lengthen modern climate records from centuries to millennia. Agathis australis(kauri) tree-ring sequences from the far north of New Zealand may be useful in this regard. It has been demonstrated that the growth patterns of these trees have a strong correlation with the Southern Oscillation Index (SOI), with decadal scale growth variations associated with ENSO superposed on centennial scale trends. The longevity of kauri makes it a prime candidate for the creation of lengthy modern era time series (>1000y BP to present). In addition, abundant subfossil specimens have been combined into multiple site chronologies that cover large segments of time (>2000 years) for the Holocene and the pre-last glacial maximum. We present progress of this research to date, which includes the construction of master chronologies, the use of terrestrial geologic records to provide contextual constraints for climate analysis exercises, and some preliminary findings of observed climate variability on decadal through millennial time scales for the late Quaternary.