The Ohio State University researchers are using dust trapped in glacier ice in Tibet to document past changes in the Earth's complex climate system, and perhaps one day help predict future changes.
Their findings indicated that the dust composition in samples collected from different areas and depths of the same glacier can vary greatly, implying that a complete dust record may reveal more secrets than scientists realize.
Desert dust collected from glacier ice helps document climate change
Alberto Restifo/Unsplash
Strong winds can cause a slew of chain reactions in the atmosphere, affecting everything from human health and marine biochemistry to the carbon dioxide balance, as per ScienceDaily.
The impact of these microparticles on the surrounding atmosphere is largely determined by their size, shape, and chemical composition.
In a new study published in the Journal Geosciences, researchers worked to better understand how dust affects and is affected by climate by examining dust particles trapped inside ancient ice, or what Emilie Beaudon, co-author of the study and a senior research associate at the Byrd Polar and Climate Research Center, refers to as "cryo-dust."
Ice cores, which are cylinders of ice drilled from glaciers and ice caps, have long been used as comprehensive archives of the Earth's climate system due to their preservation.
Aerosols accumulate within each new layer of ice as it accumulates over seasons and years, eventually providing researchers with very detailed records of the planet's tumultuous climate history.
Scientists can learn about what the world looked like at the time by using natural time capsules, such as greenhouse gas concentrations, and volcanic, solar, and biological activity.
The ice used in this study was collected from the Guliya Ice Cap in Northwestern Tibet, which is home to one of the Northern Hemisphere's largest atmospheric dust source regions, second only to the Sahara Desert.
Because the region is influenced by westerly winds, much of the dust that accumulates there is blown to major cities in East Asia, according to Beaudon.
For example, in 2021, China experienced its largest dust storm in a decade, forcing entire cities to seek shelter, and prompting scientific concerns about the effects of climate change on the frequency and intensity of such events.
However, scientists lack sufficient data to determine how Central Asian desert dust is transported over long distances, as well as how it changes over time.
According to the researcher, one of the only ways to provide a long-term perspective on the Central Asian dust cycle is to examine a dust record from a Tibetan ice core.
A team of researchers from the United States and China assisted in drilling for ice cores from various locations at the Guliya ice cap in 2015, before shipping these cores back to the Ohio State lab.
Beaudon's team studied microparticles collected on filters from melted ice as well as those trapped in typical ice subsamples to investigate the area's dust record.
The scientist noticed that the encased dust was not uniform; rather, each deposit was an unusual assortment of different colors, sizes, and layers.
Beaudon's team also attempted to determine whether the majority of the particles in the ice originated in the Taklimakan desert near the Guliya ice cap, or if they were transported there from other distant locations.
"With these preliminary samples, we wanted to demonstrate that there is actual variability in their geochemistry and mineralogy," she explained.
Overall, the study notes that the particularly old Guliya glacial dust archive is a prime candidate for deeper exploration, implying that Beaudon's work opens up many research avenues by using additional ice core samples to develop higher-resolution dust records, including studying the microbial populations that exist inside the ice and feed on the nutrients cryo-dust carries within it.
What effects do melting glaciers have on sea level rise?
Melting glaciers contribute to rising sea levels, which increases coastal erosion and storm surge as warming air and ocean temperatures produce more frequent and intense coastal storms, such as hurricanes and typhoons, as per WWF.
The Greenland and Antarctic ice sheets, in particular, are the largest contributors to global sea level rise.
Greenland's ice sheet is melting four times faster than it was in 2003, accounting for 20% of the current sea-level rise.
The amount and rate at which these Greenland and Antarctic ice sheets melt in the future will largely determine how much ocean levels rise.
If greenhouse gas emissions continue to rise, the current rate of melting on the Greenland ice sheet will more than double by the end of the century.
Alarmingly, if all of Greenland's ice melted, global sea levels would rise by 20 feet.
The Arctic is warming twice as fast as anywhere else on the planet, and sea ice there is declining by more than 10% every 10 years.
As this ice melts, darker patches of the ocean begin to emerge, eliminating the effect that previously cooled the poles, creating warmer air temperatures, and disrupting normal patterns of ocean circulation.
