[Baps] Fwd: TODAY, 4pm, Haller Hall (Geo102): EPS colloquium series with Dr. Robin Wordsworth (U of Chicago)

[Sarah Stewart-Mukhopadhyay]

---------- Forwarded message ----------
From: *Cappo, Sabinna*
Date: Monday, April 29, 2013
Subject: TODAY, 4pm, Haller Hall (Geo102): EPS colloquium series with Dr.
Robin Wordsworth (U of Chicago)
To: "Cappo, Sabinna" <scappo at fas.harvard.edu>




              The Department of Earth and Planetary Sciences

Harvard University



*April 29th Colloquium Series Presents*



                    *Dr. Robin Wordsworth*

*From University of Chicago*

*
*

*"3D Modeling of the Martian Climate during the Late Noachian**"*



 *Abstract:*
The image of early Mars as warm and wet, with rivers, oceans and
potentially microbial life, has captured the imagination of scientists ever
since images of fluvial erosion were first sent back by spacecraft.
However, the environmental conditions that caused these features remain
poorly understood, in large part because of the climate challenges raised
by Mars’ orbital distance and the faintness of the young Sun. Various
solutions have been proposed over the years, but most previous modeling of
early Mars warming mechanisms has been limited to simple 1D climate
calculations.

  Here I discuss new 3D GCM simulations that were performed to investigate
the Martian climate during the late Noachian (~3.8 Ga). The simulations
incorporate self-consistent representations of the cycles of both CO2 and
water, including correlated-k radiative transfer for atmospheric gases and
clouds. Results show that a pure CO2-H2O greenhouse alone is incapable of
warming early Mars above global mean temperatures of around 240 K, even
when the climate effects of CO2 clouds are taken into account.
Nonetheless, for atmospheric pressures greater than a fraction of a bar,
adiabatic cooling causes water ice transport to the valley network regions
under a wide range of conditions. In addition, an extended water ice cap
forms on the southern pole, approximately corresponding to the location of
the Noachian/Hesperian era Dorsa Argentea Formation. I suggest that when
combined with episodic warming events, this generic transport mechanism may
be sufficient to account for most of the fluvial geology without the need
to invoke additional long-term warming mechanisms or an early warm, wet
Mars. Finally, in light of these results I discuss what Mars can teach us
about the potential diversity of exoplanet climates and planetary
habitability in general.





Monday, April 29th, 2013

4:00 p.m., Haller Hall (Geo-Museum 102)



*Reception to follow at Hoffman Lab 4th floor*
 *
*



-- 
Sarah T. Stewart-Mukhopadhyay
Professor of Earth & Planetary Sciences, Harvard University
617.863.0423, www.shock.eps.harvard.edu<http://www.fas.harvard.edu/~planets/sstewart/>
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