Climate reconstructions from ice cores: New techniques to understand the information preserved in the South Pole ice core

Abstract

Polar ice cores preserve information about past changes in climate and ice dynamics. Studying changes that have occurred in the past improves understanding of Earth's climate system. Large climate changes, such as the most recent glacial-interglacial transition, provide opportunities to detect a strong signal in changes within the climate system. In this thesis I develop new techniques for interpreting information from ice-core records in order to create robust reconstructions of past climate change. The South Pole ice-core record spans the last 54 ka, encompassing the entirety of the last glacial-interglacial change. I make use of high-resolution data from the South Pole ice core to apply new techniques for interpreting ice-core water-isotope data. I use a novel inverse approach to simultaneously constrain records of temperature, accumulation, and ice-sheet vertical strain from multiple ice-core measurements. The temperature reconstruction improves upon previous ice-core estimates for deglacial warming in East Antarctica and reconciles a longstanding discrepancy between data and model estimates of Antarctic temperature change. I use a simple climate model to examine the physical processes underlying large changes in climate. This thesis improves our understanding of Antarctic climate change over glacial-interglacial transitions.