December 05, 2022
For a long time, we didn’t know very much about the weather in the Southern Hemisphere: most of the ways we observe weather are land-based, and the Southern Hemisphere has much more ocean than the Northern Hemisphere does.
But with the advent of satellite-based global observing in the 1980s, we could quantify just how extreme the difference was. The Southern Hemisphere has a stronger jet stream and more intense weather events.
“You can’t put the Earth in a jar,” Professor Tiffany Shaw explained, “so instead we use climate models built on the laws of physics and run experiments to test our hypotheses.”
Shaw, graduate student Osamu Miyawaki (now at the National Center for Atmospheric Research), and colleagues used a numerical model of Earth’s climate built on the laws of physics that reproduced the observations. Then they removed different variables one at a time, and quantified each one’s impact on storminess. Shaw and her colleagues found two major culprits: ocean circulation and the large mountain ranges in the Northern Hemisphere. The study also found that this storminess asymmetry has increased since the beginning of the satellite era in the 1980s. The increase was shown to be qualitatively consistent with climate change forecasts from physics-based models.
The results have been published in the Proceedings of the National Academy of Sciences.
October 27, 2022
A group with the University of Chicago and the Field Museum of Natural History tested an instrument made by Thermo Fisher Scientific on a piece of a Martian meteorite nicknamed ‘Black Beauty’ and were able to quickly and precisely date it by probing it with a tiny laser beam—a significant improvement over past techniques, which involved far more work and destroyed parts of the sample.
“We are very excited by this demonstration study, as we think that we will be able to employ the same approach to date rocks that will be returned by multiple space missions in the future,” said Nicolas Dauphas, the Louis Block Professor of Geophysical Sciences at the University of Chicago and first author on a study laying out the results. “The next decade is going to be mind-blowing in terms of planetary exploration.”
UChicago-affiliated scientists on the paper included Nicolas Dauphas, Timo Hopp, Zhe Zhang, Phillip Heck, Bruce L.A. Charlier, and Andrew Davis.
October 20, 2022
Postdoctoral researcher Timo Hopp (now at the Max Planck Institute for Solar System Research) and Louis Block Professor Nicolas Dauphas analyzed iron isotopes from samples returned by the Hayabusa-2 spacecraft from asteroid Ryugu. They found that asteroid Ryugu formed in a reservoir that was different from the source regions of other carbonaceous asteroids. The distinct isotopic composition of Ryugu may reflect its formation at great distances from the Sun, ultimately owing its presence in the inner Solar System to excitation by Uranus and Neptune. "We are probably sampling some of the material that was in the outer disk when the sun was born," said Dauphas. The results have been published in Science Advances , and are summarized in a UChicago News article.