Researcher Explores Ancient Climate Data Preserved in Antarctic Ice Core

A climate modeler from the University of Canterbury is contributing to a global research effort that involves studying a 764-meter ice core preserving over 80,000 years of vital climate data.

Dr. Abhijith Ulayottil Venugopal, a Postdoctoral Fellow affiliated with the School of Physical and Chemical Sciences at Te Whare Wānanga o Waitaha | University of Canterbury (UC), played a crucial role in the Roosevelt Island Climate Evolution (RICE) project, which brings together scientists from nine different nations under New Zealand’s leadership.

The primary objective of the RICE project is to explore the stability of the Ross Ice Shelf and the West Antarctic Ice Sheet in the context of a warming climate. This research aims to provide insights into the potential consequences for global sea level changes.

To facilitate this investigation, a deep ice core was extracted from Roosevelt Island in the Ross Dependency between 2011 and 2013, with support from Antarctica New Zealand and the US Antarctic Programme (USAP). The data derived from this ice core is anticipated to enhance climate models used for projecting future climate changes and to help identify irreversible thresholds.

Dr. Venugopal’s research focuses on the influence of Westerly wind patterns on the Southern Ocean, particularly how these patterns impact the release of CO2 from deep ocean currents. His collaborative study, titled “Antarctic evidence for an abrupt northward shift of the Southern Hemisphere westerlies at 32ka BP,” involving researchers from New Zealand (GNS Science and VUW), the United States, Germany, and Denmark, has been published in the journal Nature Communications.

By analyzing the ice core, Dr. Venugopal’s team has uncovered a critical insight: shifts in the Westerly wind belt can significantly alter ocean currents, affecting the amount of carbon dioxide released into the atmosphere, with global implications.

Roosevelt Island’s “grounded ice dome” forms as snow accumulates over millennia, providing a precise historical record of temperature, dust composition, and gas concentrations in the atmosphere over distinct time periods. Dr. Venugopal highlights that the ice core samples from the island constitute an unparalleled archive of Earth’s atmospheric and climatic history.

This study has revealed, for the first time, a sudden equatorward shift in the Westerly wind position 32,000 years ago during the last ice age. It contributes to the broader scientific community’s ongoing efforts to investigate past time intervals for insights into significant climate drivers, such as the Southern Hemisphere Westerlies.

The findings underscore that when the climate reaches critical thresholds, the atmospheric response can be rapid, occurring within human timescales. Given that future Westerly wind behavior is closely linked to greenhouse gas emissions, this research holds promise for anticipating regional and global consequences.

Dr. Giuseppe Cortese, a co-author of the study from GNS Science, emphasizes that shifts in the position and strength of the Westerly wind system also respond to current warming trends, affecting global climate systems and New Zealand’s climate, temperature, precipitation, and storms.

Professor Nancy Bertler, the Chief Scientist of RICE from Te Herenga Waka—Victoria University of Wellington (VUW) and GNS Science, notes the timeliness of this study as Antarctica experiences unprecedented and concerning extreme climate events with potentially global repercussions that current models have not yet captured or predicted. Dr. Venugopal’s findings are instrumental in enhancing climate models and future projections.

From October 2nd to 8th, the Days of Ice festival in Christchurch will celebrate Antarctic exploration and scientific investigation, highlighting the special connection that Ōtautahi—one of the world’s five Antarctic Gateway cities—shares with the frozen continent.

Dr. Venugopal recognizes the significance of such initiatives in communicating science to a broader audience. His interest in science communication led to the translation of the documentary “Thin Ice: The Inside Story of Climate Science,” with subtitles added to enable its screening in his home country, India. This effort aims to provide students in tropical climates with a better understanding of how Antarctica influences global climate dynamics.

Source: University of Canterbury

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