Tree-Ring Data from Subantarctic Forests: Indices of Southern Hemisphere Atmosphere-Ocean Climate Variability

Past instrumental and proxy records of climate are relatively scarce for the middle to high latitudes of the Southern Hemisphere. Yet this highly oceanic region is a key to larger-scale climatic change, in ways that are fundamentally different from comparable northern latitudes. Climatically-sensitive, absolutely-dated annual tree-ring chronologies have been developed for time-spans ranging from recent centuries to the past millennium for the three forested land areas at southern middle latitudes: Tierra del Fuego, Tasmania and New Zealand. However this data has yet to be fully exploited in large-scale studies of climate change. Prior research has demonstrated the value of using tree-ring data as indicators of past atmosphere-ocean interaction at sites around the globe. This award supports the utilization of these southern tree- ring records to model and reconstruct indices of atmospheric and oceanic parameters of climatic variability in the subantarctic sector. These new data will allow us to evaluate the Little Ice Age and Medieval Warm Epoch at these latitudes, and how recent and possible future greenhouse warming relates to past patterns of natural climate variability for this part of the Southern Hemisphere.