DETAILS IN THE DEVILS: USING CONVECTIVE VORTICES TO MEASURE PLANETARY BOUNDARY LAYER CONDITIONS ON EARTH AND MARS

Dust-laden vortices (i.e., dust devils) in the buoyantly-unstable daytime convective boundary layer of Earth and Mars are thought to be the among the few visible markers of the structured turbulent eddies that comprise convective atmospheric motions. The spatial and temporal characteristics of dust devils are controlled by local environmental conditions, and so studying them has the potential to reveal much about the nature of convective structures and dust lifting processes.

We present preliminary results of a field campaign at Smith Creek Valley, Nevada, USA, conducted from 04-21 June 2019, during which several suites of instruments simultaneously monitored dust devil activity and measured the local meteorological conditions. Four cameras obtained time-lapse stereo images, from which a database of dust devils and their physical characteristics can be constructed. An instrumented weather tower provided measurements of eddy heat and momentum fluxes, wind and temperature profiles, and surface energy budget terms; a LIDAR ceilometer measured the vertical structure of the boundary layer. Changing local conditions were placed in a mesoscale and synoptic context using the North American Mesoscale Forecast System (NAM).

Preliminary results suggest that dust devil onset times, frequency, and size are highly sensitive to local meteorological conditions such as sensible heat flux, relative humidity, and mean near-surface wind speeds. With further analysis, we aim to identify correlations that allow future dust devil observations on Mars and in remote locations on Earth to constrain local meteorological conditions.