In situ measurement of dust devil dynamics: Toward a strategy for Mars

Abstract

An intensive 3‐day dust devil investigation was conducted near Eloy, Arizona, during June of 2001. The goal was to evaluate strategies for observing dust devils on Mars by studying the physics of terrestrial dust devils. As part of this campaign, an instrumented vehicle outfitted with wind, temperature, and pressure sensors was used to intercept and penetrate numerous dust devils. Defined analysis of meteorological fields was only possible with knowledge of the whole body motion of a dust devil. One such data set analyzed revealed a dust devil structure characterized by a tangential wind proportional to radius, r, inside the warm, low‐pressure core of a dust devil, and proportional to r−1/2 outside the core. We discuss the implications for optimum measurement strategies.

Willy-willies in the Australian landscape: The role of key meteorological variables and surface conditions in defining frequency and spatial characteristics

“…The role played by local environmental conditions in their initiation and maintenance has received little attention, with the focus of research being on the internal structure and rotation of the vortices (Barcilon and Drazin, 1972;Balme et al, 2003;Ives, 1947;Ryan and Carroll, 1970;Sinclair, 1973;Tratt et al, 2003).…”

Field Measurements of Terrestrial and Martian Dust Devils

“…In addition to vehicle disturbance of measurements (e.g. visible in Tratt et al 2003) and often rather poorly-documented distance histories, the tendency to chase the biggest, slowest devils leads to strong selection biases, which make it difficult to estimate the characteristics of the dust devil population. Technological developments in flash memory in the late 2000s allowed inexpensive data acquisition (Lorenz 2012b) with compact and low-power systems that could be deployed for months, sampling at > 1 Hz without requiring operator visits to download data or replace power supplies.…”

“…Wide range of temperature excursions measured-probably due to variations in sensor type; excursions of 1-5 • C common; larger excursions of > 20 • C reported Metzger (1999); Tratt et al (2003); Sinclair (1964); Sinclair (1973) Core pressure excursion (DP)…”

“…These impending Mars missions lead to several field campaigns in Arizona and Nevada (e.g. Tratt et al 2003;Renno et al 2004;etc. ) during which, again, the measurements were principally vehicle-borne.…”

Thermoconvective instabilities to explain the main characteristics of a dust devil-like vortex

“…They are common atmospheric phenomena on Earth [3][4][5][6][7][8] but also in the atmosphere of other planets such as Mars [9][10][11]. The conditions under which dust devils appear are a surface interface region particle loaded and a strong horizontal thermal gradient on areas with anomalously high soil temperature [2,12].…”