Statistical Alignment and Dating of the Soluble Iron Signal in the EGRIP Ice Core

Abstract

Ice cores are collected in paleoclimatic studies in order to analyze their physical and chemical properties with the purpose of reconstructing important aspects of the past climate. During the campaigns of the East Greenland Ice-core Project (EGRIP), ice core samples were drilled and collected from the northeastern part of the Greenland Ice Sheet with the aim of producing a paleoclimate record of the last 50,000 years.

This thesis will focus on the soluble iron signal obtained from the EGRIP ice core during the transition from the Last Glacial Termination to the Early Holocene. This transition occurred 11.7 thousand years before 2000 CE (ka b2k) and marks the last, most abrupt climate warming without anthropogenic influences. The aim is to produce the first continuous record of soluble iron over this time period in order to see the effect of the climate warming on soluble iron and to study its evolution in relation to other climate signals found within the ice core.

The first part of the thesis consists of the necessary steps to clean, combine, and homogenize soluble iron concentrations obtained from different chemical analysis sessions of the ice core. The prepared data then will be consolidated into a single data set for statistical analysis.

In the second part of the thesis, cross-correlation methods for irregular time series data are applied in order to align the soluble iron signal with other climate signals from the ice core, namely conductivity, acidity, dust, and total iron. This alignment with existing data will allow the soluble iron signal to be converted to both depth and temporal scales. This will enable the production of the first high-resolution record of iron solubility in the Arctic over this time period and give the opportunity to understand and interpret its environmental and climate implications.

This thesis has been developed in collaboration with the CNR Institute of Polar Sciences.