Leaf Wax Proxy System Modeling (PSM) of Hydrogen Isotopic Fractionation

Presenter(s)

Allie Sheets

Abstract or Description

Paleoclimatology, the study of past Earth climates, uses proxies observable in the field to understand desired variables in Earth’s history. A proxy system explains how the original desired variable is affected by the environment, how the original variable’s signal is translated by a sensor, how the sensor is archived, and how an observation appears in the archive. Leaf waxes are an important proxy that retains the signal of hydrogen isotopic composition changes of water. Understanding how the wax system works helps us to understand changes in the paleo global water cycle. My research focuses on the understanding of the leaf waxy system as a whole, as well as how it is modelled. I built upon a previous wax proxy system model (PSM), which contained a single fractionation equation. To improve the concept model of leaf waxes, I intensively studied the current scientific literature. After identifying important variables, I incorporated two of them into the wax PSM: modes of transport and their respective rates. The current code, written in python, is adjustable depending on user preferences. The user can choose respective rates of transport as well as each mode’s percentage of transport load.