Martian Mixed Layer during Pathfinder Mission

Details Martian Mixed Layer during Pathfinder Mission Martian Mixed Layer during Pathfinder Mission

Sep 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008epsc.conf..248m&link_type=abstract

European Planetary Science Congress 2008, Proceedings of the conference held 21-25 September, 2008 in Münster, Germany. Online a

Statistics

Scientific paper

In situ measurements of the Martian Planetary Boundary Layer (MPBL) encompass only the sur- face layer. Therefore, in order to fully address the MPBL, it becomes necessary to simulate somehow the behaviour of the martian mixed layer. The small-scale processes that happen in the MPBL cause GCM's ([1], [2]) to describe only partially the turbulent statistics, height, convective scales, etc, of the surface layer and the mixed layer. For this reason, 2D and 3D martian mesoscale models ([4], [5]), and large eddy simulations ([4], [6], [7], [8]) have been designed in the last years. Although they are expected to simulate more accurately the MPBL, they take an extremely expensive compu- tational time. Alternatively, we have derived the main turbu- lent characteristics of the martian mixed layer by using surface layer and mixed layer similarity ([9], [10]). From in situ temperature and wind speed measurements, together with quality-tested simu- lated ground temperature [11], we have character- ized the martian mixed layer during the convective hours of Pathfinder mission Sol 25. Mean mixed layer turbulent statistics like tem- perature variance < σ >, horizontal wind speed variance < σu,v >, vertical wind speed variance < σw >, viscous dissipation rate < ǫ >, and turbu- lent kinetic energy < e > have been calculated, as well as the mixed layer height zi, and the convective scales of wind w and temperature θ . Our values, obtained with negligible time cost, match quite well with some previously obtained results via LES's ([4] and [8]). A comparisson between the above obtained mar- tian values and the typical Earth values are shown in Table 1. Convective velocity scale w doubles its counterpart terrestrial typical value, as it does the mean wind speed variances < σu,v > and < σw >. On the other hand, the temperature scale θ and the mean temperature variance < σ > are virtu- ally around one order higher on Mars. The limitations of these results concern the va- lidity of the convective mixed layer similarity. This theory neglects the effect of the radiation heating which is negligible under fair weather conditions on Earth. However, it is relevant under martian conditions due to the absorption of solar radiation by dust. Supported both by [11] and the low dust optical depth (≃ 0.3 for the PF summer), the con- vective heating of the mixed layer domiantes the radiation heating (around three times higher), al- lowing us to estimate these values via mixed layer similarity.

Affiliated with

Also associated with

No associations

Rating

Martian Mixed Layer during Pathfinder Mission does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Martian Mixed Layer during Pathfinder Mission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Martian Mixed Layer during Pathfinder Mission will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1793149