EGU21-8233
https://doi.org/10.5194/egusphere-egu21-8233
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Impact of surface roughness on dust occurrence frequency over arid regions

Martina Klose1,2, Carlos Pérez García-Pando2,3, Paul Ginoux4, and Ron L. Miller5
Martina Klose et al.
  • 1Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research (IMK-TRO), Department Troposphere Research, Karlsruhe, Germany (martina.klose@kit.edu)
  • 2Barcelona Supercomputing Center (BSC), Barcelona, Spain
  • 3ICREA, Catalan Institution for Research and Advanced Studies, Barcelona, Spain
  • 4Geophysical Fluid Dynamics Laboratory (GFDL), Princeton, NJ, USA
  • 5NASA Goddard Institute for Space Studies (GISS), New York, NY, USA

Soil dust aerosol created by wind erosion of arid and semi-arid surfaces dominates climate effects over large areas of the Earth. To represent the dust cycle, Global Earth System Models (ESMs) typically prescribe preferential dust sources phenomenologically using empirical source scaling functions. While this approach has helped to compensate for a lack or inaccuracy of soil and surface input data to models, it potentially limits progress in the representation of the global dust cycle, because such strong empirical constraints make models less sensitive to parameters known to affect dust emission, and thus potentially insensitive to changes in climate. Here we investigate the link between surface roughness due to non-erodible elements such as vegetation, pebbles and rocks, and the spatial patterns of dust activity. Using two different satellite-based methods to represent roughness within an atmospheric dust transport model, we evaluate the impact of surface roughness on the spatial distribution of dust optical depth occurrence frequency observed from satellite by both reducing the atmospheric momentum available for particle entrainment and protecting the surface from dust emission. We test the variability of our results across conceptually different parameterizations of dust emission and drag partition. Our results suggest that the spatial patterns of dust activity are largely determined by surface roughness, not only in semi-arid, but also in arid regions, where green vegetation is sparse or absent. 

How to cite: Klose, M., Pérez García-Pando, C., Ginoux, P., and Miller, R. L.: Impact of surface roughness on dust occurrence frequency over arid regions, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8233, https://doi.org/10.5194/egusphere-egu21-8233, 2021.

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