Breakthrough Study Examines Ice Cores to Determine Frequent Weather Patterns
University of Colorado Boulder researchers and a team of international scientists have collaborated to reveal 11,000 years of Earth’s climatic history by studying Antarctic ice cores, according to a January 2023 report in Science Daily.
Published on January 11, 2023, in Nature, the study is the first of its kind to determine seasonal temperature records dating to the onset of the period known as the Holocene. Though scientists have long studied polar ice cores for atmospheric data over extended periods of time, this was the first study to determine annual summer and winter temperatures—a frequency never before achieved.
How did they do it? The team relied on recent technological developments and a few innovations of their own. Tyler Jones, lead author on the study, and assistant research professor and fellow at the Institute of Arctic and Alpine Research (INSTAAR), said that the research team’s goal was to “push the boundaries of what is possible with past climate interpretations.”
“For us,” he said, "that meant trying to understand climate at the shortest timescales—in this case seasonally, from summer to winter, year-by-year, for many thousands of years."
According to Science Daily, the study also validates one aspect of a long-standing theory that has not been previously proven: how seasonal temperatures in polar regions respond to what are known as Milankovitch cycles, hypothetical “collective effects of changes in Earth's position relative to the sun due to slow variations of its orbit and axis.”
"I am particularly excited that our result confirms a fundamental prediction of the theory used to explain Earth's ice-age climate cycles: that the intensity of sunlight controls summertime temperatures in the polar regions, and thus melt of ice, too," said Kurt Cuffey, a co-author on the study and professor at the University of California, Berkeley.
This new access to more highly detailed data on past climate patterns should also help researchers study the impacts of anthropogenic greenhouse gas emissions on Earth’s present and future climate. By understanding naturally occurring planetary cycles, scientists can do a better job of identifying human influences on climate and temperatures.
"This research is something that humans can really relate to because we partly experience the world through the changing seasons—documenting how summer and winter temperature varied through time translates to how we understand climate," said Jones.
Study co-authors Bruce Vaughn, a chief scientist on the project and manager of the Stable Isotope Lab, and Bradley Markle, assistant professor at INSTAAR and the Department of Geology, collected the West Antarctica ice that was shipped for analysis.
Next on the team's agenda is an attempt to analyze ice cores from similar locales, such as the South Pole and northeast Greenland, where ice cores have previously been drilled.