Basic Convective and Mesoscale Research
Other Agency – Martian Dust Devils
Funding Agency: NSF and CIMMS Task I
Objectives
Analyze Martian dust devil characteristics as determined by Mars Orbiter
Camera (MOC) images and make comparisons with terrestrial dust devils;
gain insight into dust devil formation and maintenance dynamics, and
their role in boundary layer processes, by comparison of their characteristics
in two different atmospheres.
Accomplishments
Collaborative
efforts with Dr. Ken Edgett and Dr. Bruce Cantor at Malin Space Science
Systems (MSSS) have resulted in a paper on Martian dust devils in press
at the Journal of Geophysical Research. In this paper, observations
of dust devils and dust devil tracks from Mars Orbiter Camera images
are described. Recent data from the Mars Rover Thermal Emission Spectrometer
are used to determine a representative temperature profile that might
be typical of Martian dust devil environments in order to make estimates
of tangential wind speeds given the physical dimensions determined
from the MOC images. The ubiquitous dust devil tracks that mark the
Martian surface are described.
An LES of the Martian boundary layer has been conducted to simulate Martian dust devils (see figure below). The vortex detection algorithm again will be used to quantify the simulated vortices and the results will be compared to the observations given in Fisher et al. (2005). A paper authored by Kanak is planned for these results, for submission to Journal of Geophysical Research – Planets.
This project is ongoing.
Publications
Cantor, B. A., K. M. Kanak, and K. E. Edgett, 2006: Mars Orbital Camera
observations of Martian dust devils and their tracks (September 1997
to January 2006) and evaluation of theoretical vortex models. J. Geophys.
Res.-Planets, 111, E12002, doi:10.1029/2006JE002700.
Top: sub-domain of XY cross-section at t = 4580 s and z =21 m of vertical vorticity with every other wind vector overlain. Maximum vector length is 11 m s-1. Maximum value (red) is 0.198 s-1, minimum value (gray) is -0.32 s-1, and the contour interval is 0.037 s-1.
Bottom: sub-domain XZ cross-section at t = 4580 s and Y = 1820 m of vertical vorticity. Cross-section is taken along the black line in (a). Maximum value (red) is 0.18 s-1, minimum value (grey) is - 0.33 s-1 and the contour interval is 0.066 s-1. Zero values are denoted by yellow.