Articles | Volume 16, issue 24
Atmos. Chem. Phys., 16, 15517–15528, 2016
Atmos. Chem. Phys., 16, 15517–15528, 2016

Research article 15 Dec 2016

Research article | 15 Dec 2016

Surface renewal as a significant mechanism for dust emission

Jie Zhang1,2, Zhenjiao Teng2, Ning Huang1,2, Lei Guo2, and Yaping Shao3 Jie Zhang et al.
  • 1Key Laboratory of Mechanics on Disaster and Environment in Western China (Lanzhou University), Ministry of Education, Lanzhou 730000, China
  • 2School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China
  • 3Institute for Geophysics and Meteorology, University of Cologne, 50937 Cologne, Germany

Abstract. Wind tunnel experiments of dust emissions from different soil surfaces are carried out to better understand dust emission mechanisms. The effects of surface renewal on aerodynamic entrainment and saltation bombardment are analyzed in detail. It is found that flow conditions, surface particle motions (saltation and creep), soil dust content and ground obstacles all strongly affect dust emission, causing its rate to vary over orders of magnitude. Aerodynamic entrainment is highly effective, if dust supply is unlimited, as in the first 2–3 min of our wind tunnel runs. While aerodynamic entrainment is suppressed by dust supply limits, surface renewal through the motion of surface particles appears to be an effective pathway to remove the supply limit. Surface renewal is also found to be important to the efficiency of saltation bombardment. We demonstrate that surface renewal is a significant mechanism affecting dust emission and recommend that this mechanism be included in future dust models.

Short summary
In spite of the tremendous efforts, many questions remain unanswered regarding dust emission mechanisms. A series of wind tunnel experiments are carried out on dust emissions from different soil surfaces to better understand relevant mechanisms. Here are some interesting results that demonstrate the importance of surface renewal mechanism, which was normally neglected in previous research and is strongly recommended to be considered in future dust models.
Final-revised paper