2023-08-16 13:02:09
A large storm dominates the featureless surface of Saturn in an image taken by the Cassini spacecraft on February 25, 2011 – NASA/JPL/SPACE SCIENCE INSTITUTE
MADRID, 16 Ago. (EUROPA PRESS) –
Like Jupiter with its Great Red Spot, Saturn also has long-duration megastorms, and with impacts deep in the atmosphere persisting for centuries.
A study published in the journal Science Advances by scientists at the University of California, Berkeley, and the University of Michigan, Ann Arbor, observed the planet’s radio emissions, finding deep in the atmosphere the side effects of megastorms that They happened hundreds of years ago.
Megastorms occur approximately every 20 to 30 years on Saturn and are similar to hurricanes on Earth, though significantly larger. But unlike hurricanes on Earth, no one knows what causes megastorms in Saturn’s atmosphere. it is composed mainly of hydrogen and helium with traces of methane, water and ammonia.
“Understanding the mechanisms of the largest storms in the solar system places hurricane theory in a larger cosmic context, challenging our current knowledge and pushing the boundaries of terrestrial meteorology“said andin a statement lead author Cheng Li, a former fellow at Berkeley who is now an assistant professor at the University of Michigan.
Imke de Pater, professor emeritus of astronomy and of Earth and planetary sciences at UC Berkeley, has been studying gas giants for more than four decades to better understand their composition and what makes them unique, using the Karl G. Jansky Very Large Array in New Mexico to probe radio emissions from the depths of the planet.
“At radio wavelengths, we probe below the cloud layers visible on giant planets. Since chemical reactions and dynamics will alter the composition of a planet’s atmosphere, observations below these cloud layers are required to limit the true atmospheric composition of the planet, a key parameter for planet formation models,” he said. “Radio observations help characterize dynamic, physical, and chemical processes, including heat transport, cloud formation and convection in the atmospheres of giant planets on both a global and local scale“.
As reported in the new study, de Pater, Li, and UC Berkeley graduate student Chris Moeckel found something surprising about the planet’s radio emissions: anomalies in the concentration of ammonia gas in the atmosphere, that connected with the past occurrences of megastorms in the northern hemisphere of the planet.
According to the team, the ammonia concentration is lowest at medium altitudes, just below the top layer of the ammonia ice cloud, but has become richer at lower altitudes, 100 to 200 kilometers deeper in the atmosphere. They believe that ammonia is transported from the upper to the lower atmosphere through processes of precipitation and re-evaporation. Furthermore, that effect can last for hundreds of years.
The study further revealed that although both Saturn and Jupiter are made of hydrogen gas, the two gas giants are remarkably different. Although Jupiter has tropospheric anomalies, they have been linked to its zones (whitish bands) and belts (dark bands) and are not caused by storms as they are on Saturn. The considerable difference between these neighboring gas giants challenges what scientists know about the formation of megastorms on gas giants and other planets. and can inform how they are found and studied on exoplanets in the future.
#Megastorms #Saturn #leave #effects #centuries