Orbital Observations of Dust Lofted by Daytime Convective Turbulence

Over the past several decades, orbital observations of lofted dust have revealed the importance of mineral aerosols as a climate forcing mechanism on both Earth and Mars. Increasingly detailed and diverse data sets have provided an ever-improving understanding of dust sources, transport pathways, and sinks on both planets, but the role of dust in modulating atmospheric processes is complex and not always well understood. We present a review of orbital observations of entrained dust on Earth and Mars, particularly that produced by the dust-laden structures produced by daytime convective turbulence called “dust devils”. On Earth, dust devils are thought to contribute only a small fraction of the atmospheric dust budget; accordingly, there are not yet any published accounts of their occurrence from orbit. In contrast, dust devils on Mars are thought to account for several tens of percent of the planet’s atmospheric dust budget; the literature regarding martian dust devils is quite rich. Because terrestrial dust devils may temporarily contribute significantly to local dust loading and lowered air quality, we suggest that martian dust devil studies may inform future studies of convectively-lofted dust on Earth

Cryopreservation of organs: NMR follow-up of cryoprotectant perfusion in rabbit kidneys.

International audienc

Introduction

Mineral dust is a key player in the Earth system with important impacts on the global energy and carbon cycles, acting on timescales of minutes to millennia. Megatons of dust are lifted each year into the atmosphere by strong near-surface winds over the world's arid regions. Such winds can be generated by short-lived small-scale dust devils, cold outflow from thunderstorms up to continental-scale dust storms. The tiny dust particles can be lifted to great heights and transported thousands of kilometres across the globe. Once airborne, dust affects radiation and clouds and thereby also precipitation. Dust also alters chemical processes in the atmosphere and deteriorates air quality and visibility for aviation. Dust is removed from the atmosphere by gravitational settling, turbulence or precipitation. Deposition on plants, snow and ice changes the amount of reflected solar radiation. Iron and other nutrients contained in dust fertilise both terrestrial and marine ecosystems. Dust deposits in glaciers, soils and ocean or lake sediments constitute an important archive of past environmental changes. For the first time, this book gives a detailed account of the state of the art in the fascinating, highly interdisciplinary and dynamically evolving area of dust research including results from field campaigns, laboratory, aircraft, satellite, modelling and theoretical studies. This chapter gives a short introduction into the topic, placing several recent developments in dust research into a historical context