EUREKA!

EUREKA!

NEW FINDINGSAND RESEARCH

Erratic Weather

What causes jet stream volatility?

For a change, climate change does not seem to be to blame. In their recent study published in AGU Advances, Jacob Chalif, Adv ’21, and earth sciences prof Erich Osterberg show that volatility in the polar jet stream during the past 125 years— before climate change was a significant influence—was frequently just as wavy as it is today, if not more so. Contrary to popular belief, recent waviness in the jet stream, which brings Arctic air south and regulates most of the weather in the Northern Hemisphere, may not be linked to global warming. “Climate change is intensifying these storms through a different process,” Osterberg says. “We must rapidly reduce the production of new greenhouse gas emissions worldwide, but we must also identify the correct mechanisms driving extreme weather to inform better solutions.”

Early Agriculture

Evidence found of raised gardening beds.

>» A drone equipped with a laser flown over more than 300 acres in northern Michigan has revealed what may be the largest intact remains of an ancient Native American agricultural site in the eastern United States. The study—led by anthropology profs Madeleine McLeester and Jesse Casana and published in Science—found evidence of subtle features of farming, including parallel rows of raised gardening beds that ancestors of the Menominee tribe in Wisconsin may have used to grow crops, such as corn, beans, and squash, centuries before Europeans arrived. The researchers say it was a shock to find this level of investment in an agricultural system, which would require enormous human labor, and at such a vast scale that far north, especially during the Little Ice Age.

Nancy Schoeffler