Novel Pb Isotope Record Tracking the Impact of Policy and the Covid-19 Pandemic on Asian Pollution Emissions Deposited in Alaskan Ice Cores

Hanna Brooks, Michael Handley, Dominic Winski, Karl Kreutz, Jacob Chalif, Erich Osterberg

*With support from: Inga Kindstedt, Emma Erwin, Scott Braddock, and Liam Kirkpatrick

University of Maine; Dartmouth College; University of Washington

Novel Pb Isotope Record Tracking the Impact of Policy and the Covid-19 Pandemic on Asian Pollution Emissions Deposited in Alaskan Ice Cores

The Denali Ice Cores were recovered near the summit of Begguya, within the traditional homelands of six sovereign nations who have occupied the region for thousands of years before our study. Research conducted at the University of Maine occurs in the homeland of the Penobscot Nation, a member of the Wabanaki Tribal Nations.

Tracing Pb with cyrosphere records allows us to understand discrete regional, hemispheric, and global signals.

Brooks et al., unpublished

Long term changes in emission occur due to changes in culture, legislation, and technology.

Koffman et al., 2022

Long term changes in emission occur due to changes in culture, legislation, and technology.

Koffman et al., 2022

The project builds off previous work to examine the emerging story of the pollution deposited in the North Pacific from Asia.

Our dataset of 1,171 samples spans ~1,700 years of natural and anthropogenic variability.

Pb concentration data from across the North Pacific all record a rise post-1950. This is distinctly different from Greenland.

Brooks et al., unpublished

Brooks et al., unpublished;

McConnell et al., 2019

Pb concentration data from across the North Pacific all record a rise post-1950. This is distinctly different from Greenland.

Brooks et al., unpublished;

McConnell et al., 2019;

Osterberg et al., 2008

Pb concentration data from across the North Pacific all record a rise post-1950. This is distinctly different from Greenland.

Pb isotopes are distinctly different from other global regions.

Brooks et al., unpublished; Lee et al., 2011; Burn-Nunes et al., 2014; Gross et al., 2013; Wensman et al., 2022

Comparing the Pb ratio and concentration records allows for pinpointing of dust storms and volcanism.

Brooks et al., unpublished

Preliminary takeaways:

• The data shows unique trends, distinct from other global regions

• This is currently the only ice dataset from the North Pacific extending through the 2020s -- allowing for examination of changes through the Covid-19 pandemic.

• Large spikes in the data may reflect major dust storms or volcanic events.