![]() The West Antarctic Ice Sheet (WAIS) Divide ice core, the longest ice core ever drilled by U.S. These slender, cylindrical columns of ice, drilled from ancient ice sheets (mostly in Antarctica and Greenland), provide valuable long-term data trapped in time about everything from past atmospheric concentrations of greenhouse gases to past temperatures of the air and oceans. Scientists around the world have long studied Earth's past climate using ice cores gathered from the poles. "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. By knowing which planetary cycles occur naturally and why, researchers can better identify the human influence on climate change and its impacts on global temperatures. These more highly detailed data on long-term climate patterns of the past also provide an important baseline for other scientists, who study the impacts of human-caused greenhouse gas emissions on our present and future climate. "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. ![]() Serbian scientist Milutin Milankovitch hypothesized a century ago that the collective effects of changes in Earth's position relative to the sun - due to slow variations of its orbit and axis - are a strong driver of Earth's long-term climate, including the start and end of ice ages (prior to any significant human influence on the climate). The study also validates one aspect of a long-standing theory about Earth's climate that has not been previously proven: how seasonal temperatures in polar regions respond to Milankovitch cycles. "The goal of the research team was to push the boundaries of what is possible with past climate interpretations, and for us 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," said Tyler Jones, lead author on the study, and assistant research professor and fellow at the Institute of Arctic and Alpine Research (INSTAAR). Published today in Nature, the study is the very first seasonal temperature record of its kind, from anywhere in the world.
0 Comments
Leave a Reply. |