October 17, 2012
Earth Climate Modeling Works On Mars Too
Lee Rannals for redOrbit.com - Your Universe Online
According to a new study, scientific modeling methods that predicated climate change on Earth can also be used on Mars as well.
Researchers from Planetary Science Institute in Tucson report they have found that an unusual concentration of glacial features on Mars matches predictions made by global climate computerized models, in terms of age and location.
"Some public figures imply that modeling of global climate change on Earth is 'junk science,' but if climate models can explain features observed on other planets, then the models must have at least some validity," said PSI Senior Scientist William K. Hartmann.
Hartmann presented PSI's report at the annual meeting of the Division of Planetary Sciences of the American Astronomical Society.
The team combined four different aspects of Martian geological mapping and Martian climate science in recent years.
They found that the climate models, the presence of glaciers, the ages of the glacial surface layers, and radar conformation of ice in the same general area all gave consistent results.
Astronomers as early as 1993 analyzed the changing tilt of Mars' rotational axis and found that during high-tilt Martian episodes, the axis tilt can exceed 45 degrees. Under these conditions, the summer hemisphere is strongly tilted toward the sun, and the planet's polar cap in the hemisphere evaporates, which increases water vapor and the chances for snowfall in the winter hemisphere.
French and American researchers applied the global climate computer models to study this effect between 2001 and 2006. The programs were originally developed for Earth to estimate climate effects, but the scientists were able to apply Martian topography, atmosphere and gravity to it in order to run Mars calculations.
These previous researchers' calculations indicated a strong concentration of winter snow and ice in a mid-latitude southern region of Mars.
The Planetary Science Institute scientists found independently an unusual concentration of glacial features in a 40-mile-wide crater named "Greg."
Their analysis shows the surface layers of the glaciers formed at the same time as the predicted climate extremes.
"The bottom line is that the global climate models indicate that the last few intense deposits of ice occurred about 5 million to 15 million years ago, virtually centered on Greg crater, and that's just where the spacecraft data reveal glaciers whose surface layers date from that time," Hartmann said in a press release.
"If global climate models indicate specific concentration of ice-rich features where and when we actually see them on a distant planet, then climate modeling should not be sarcastically dismissed," Hartmann continued. "Our results provide an important, teachable refutation of the attacks on climate science on our home planet."