pISSN 0705-3797 eISSN 2586-1298
HOME Article View

Article

Episodes 2024; 47(3): 497-510

Published online September 1, 2024

https://doi.org/10.18814/epiiugs/2024/02403s06

Copyright © International Union of Geological Sciences.

Developing a Hybrid Wavelet-Artificial Neural Network model for simulating high-resolution Antarctic ice core CO2 concentration records during 9–120 thousand years ago

Nasrin Salehnia1,2, Jinho Ahn1,2*

1 School of Earth and Environmental Science, Seoul National University, Seoul, South Korea
2 Center for Cryospheric Sciences, Seoul National University, Siheung, South Korea

Correspondence to:*E-mail: jinhoahn@gmail.com

Received: January 3, 2024; Revised: April 16, 2024; Accepted: April 16, 2024

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The most reliable archive of atmospheric CO2 information comprises ice core records spanning the last 800 ka (thousand years ago). The connection between temperature and greenhouse gases, as deduced from ice core records, may help better simulate CO2 variations. This research aimed to explore the model methods to precisely predict the atmospheric CO2 concentrations and fill the CO2 data gaps with CH4 concentration and temperature proxies (δD and δ18O) from Antarctica ice cores, employing Artificial Neural Network (ANN) and Wavelet Transform (WT) techniques. This study was divided into three sections to examine various timescales and resolutions. First, coarse-resolution CO2 records from the Vostok and EPICA Dronning Maud Land cores from 70–120 ka were used. Second, the models were applied to the Dome Fuji core for 9–120 ka. Finally, a high-resolution West Antarctic Ice Sheet (WAIS) Divide ice core record, focusing on the 9–70 ka, was employed. The results showed that between 70–120 ka, the hybrid method surpasses the traditional ANN approach. The hybrid method maintained superior performance in the last phase by utilizing high-resolution WAIS record. The results indicated improved accuracy (r=0.98), reinforcing the notion that hybrid methods yield better outcomes than those relying solely on AI methods.