Pacific northwest climate7/5/2023 Polissar helped design the research, was involved in taking cores from some other lakes nearby, and helped the team develop the methods used to construct the long-term climate record. “Even without anthropogenic climate change and global warming, we still need to deal with this,” he said. Polissar said the influence of global climate change will increase the uncertainty for the future. It will shift back to wet eventually, but probably not to the extremes seen during most of the 20th century.” “Now the cycle has changed and is trending drier, which is actually normal. “Western states happened to build dams and water systems during a period that was unusually wet compared to the past 6,000 years,” he said. Lead researcher Mark Abbott, a Pitt professor of geology and planetary science, said those unusually wet years coincide with the period when western U.S. At the same time, they reported, the wet cycle stretching from the 1940s to approximately 2000 was the dampest in 350 years. The team attributed this recent deviation to the irregular pressure and temperature changes brought on by El Niño/La Niña. The researchers analyzed a sediment core from Castor Lake in north central Washington to plot the region’s drought history since around 4,000 BCE and found that wet and dry cycles during the past millennium have grown longer. “This was in my backyard, so it was a personal interest.” “We live in unusual times – that was really what I found so striking,” Polissar said. Measurement of oxygen isotope ratios (red) and grayscale (black) arranged to show drought cycle duration and intensity with 20th century wet period indicated.įor Lamont-Doherty Assistant Research Professor Pratigya Polissar, who participated in the project and grew up in Seattle, the research carries a personal message.
0 Comments
Leave a Reply. |