EAPSI: Assessing New Zealand's changing hydrologic record and paleoclimate

Miller Daniel R, Hadley MA

Investigators

Abstract

Future impacts from climate change can be better understood by placing modern climate trends into perspective through extension of the short instrumental records of climate variability. Although researchers tend to focus on extremes of temperature associated with global warming in these analyses, precipitation changes (and related hydrological extremes) are likely to be an important consequence of anthropogenic climate change, due to changes in global wind patterns that control rainfall patterns and the hydrology of regions. This is especially evident in the Southern Hemisphere, where the strength and positioning of the Southern Hemisphere westerly winds have a large influence on storm tracks and therefore precipitation changes over terrestrial mid-latitude regions, such as in Southern New Zealand. This projects aims to create high-resolution paleoclimate and paleoenvironmental records in collaboration with Dr. Christopher Moy at the University of Otago, New Zealand. These records will be used to reconstruct past changes in precipitation of the region. In order to create a comprehensive record of climate variability and to accurately place the magnitude of modern hydrologic change occurring in New Zealand in a longer perspective, this project will use a multi-proxy analysis of sediment cores obtained from fjords in Southwestern New Zealand to perform a comprehensive paleoclimate reconstruction. This multi-proxy analysis will include X-Ray Fluorescence analysis, bulk density, organic biomarker analysis and magnetic susceptibility analysis. This project will contribute to constructing a pan-Pacific paleoclimate synthesis, which should identify past shift and strength changes within the South Pacific and provide a useful constraint in climate studies throughout the Southern Ocean. This will then be used to evaluate global carbon cycle models and potentially constrain the westerly wind influence on Holocene atmospheric CO2 concentrations. This NSF EAPSI award is funded in collaboration with the Royal Society of New Zealand.