[meteorite-list] Science of Global Climate Modeling Confirmed by Discoveries on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 17 Oct 2012 15:05:52 -0700 (PDT)
Message-ID: <201210172205.q9HM5qKZ000059_at_zagami.jpl.nasa.gov>

NEWS RELEASE FROM THE PLANETARY SCIENCE INSTITUTE

FROM:
Alan Fischer
Public
Information Officer
Planetary Science Institute
520-382-0411
520-622-6300
fischer at psi.edu

Science of Global Climate Modeling Confirmed by Discoveries on Mars

Oct. 16, 2012, Tucson, Ariz. and Reno, Nev. -- Scientific modeling methods
that predicted climate change on Earth have been found to be accurate on Mars
as well, according to a paper presented at an international planetary
sciences conference Tuesday.

An international team of researchers from the Planetary Science Institute in
Tucson, working with French colleagues, found that an unusual concentration of
glacial features on Mars matches predictions made by global climate
computerized models, in terms of both age and location.
  
PSI Senior Scientist William K. Hartmann led the team, which included Francois
Forget (Universit?? Paris), who did the Martian climate modeling, and Veronique
Ansan and Nicolas Mangold (Universit?? de Nantes) and Daniel Berman (PSI), all
of who analyzed spacecraft measurements regarding the glaciers.
  
"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 team leader
Hartmann.
  
Hartmann presented the report, "Science of Global Climate Modeling: Confirmation
from Discoveries On Mars," at the annual meeting of the Division of Planetary
Sciences of the American Astronomical Society in Reno, Nev.
  
The scientific team reached their conclusions by combining four different
aspects of Martian geological mapping and Martian climate science in recent
years. They noted that the climate models, the presence of glaciers,
the ages of the glacial surface layers, and radar confirmation of ice
in same general area, all gave consistent results - that the glaciers
formed in a specific region of Mars, due to unusual climate circumstances,
just as indicated by the climate model.

The work has a long background. As early 1993, astronomers analyzed the changing
tilt of Mars' rotational axis and found that during high-tilt Martian episodes,
the axis tilt can exceed 45 degrees. Under this extreme condition, the summer
hemisphere is strongly tilted toward the sun, and Mars' polar ice cap in that
hemisphere evaporates, increasing water vapor in the Martian air, thus
increasing the chances for snowfall in the dark, cold, winter hemisphere.
The last such episodes happened on Mars 5 million to 20 million years ago.

By 2001-2006, various French and American researchers applied the
global climate computer models to study this effect. The computer programs
were originally developed for planet Earth to estimate climate effects,
from hurricane paths to CO2 greenhouse warming. Planetary scientists simply
applied the Martian topography, atmosphere, and gravity, in order to run
the computer calculations for Mars. The calculations indicated a strong
concentration of winter snow and ice in a mid-latitude southern region
of Mars, just east of a huge Martian impact basin named Hellas.

At the same time, the PSI scientists independently discovered an unusual
concentration of glacial features in a 40-mile-wide crater named "Greg"
centered in the same region. Their analysis showed that the surface layers
of the glaciers formed at the same time as the predicted climate extremes,
about 5 million to 20 million years ago.
  
"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. "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. Our results provide
an important, teachable refutation of the attacks on climate science on our
home planet."


Images and maps supporting the paper are available at
http://www.psi.edu/news/hartmanndps.html

A web-based photo tour of Greg Crater is available at
http://www.psi.edu/~hartmann/Greg_crater.html



CONTACT:
William
K. Hartmann
Senior Scientist
hartmann at psi.edu

PSI INFORMATION:
Mark V.
Sykes
Director
520-622-6300
sykes at psi.edu
Received on Wed 17 Oct 2012 06:05:52 PM PDT