Electrostatic forces alter particle size distributions in atmospheric dust
<p>Large amounts of dust are lofted into the atmosphere from arid regions of the world before being transported up to thousands of kilometers. This atmospheric dust interacts with solar radiation and causes changes in the climate, with larger-sized particles having a heating effect, and smalle...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-03-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/20/3181/2020/acp-20-3181-2020.pdf |
| Summary: | <p>Large amounts of dust are lofted into the atmosphere from arid
regions of the world before being transported up to thousands of kilometers.
This atmospheric dust interacts with solar radiation and causes changes in the climate, with larger-sized particles having a heating effect, and
smaller-sized particles having a cooling effect. Previous studies on the
long-range transport of dust have found larger particles than expected,
without a model to explain their transport. Here, we investigate the effect
of electric fields on lofted airborne dust by blowing sand through a
vertically oriented electric field, and characterizing the size distribution
as a function of height. We also model this system, considering the
gravitational, drag, and electrostatic forces on particles, to understand
the effects of the electric field. Our results indicate that electric fields
keep particles suspended at higher elevations and enrich the concentration
of larger particles at higher elevations. We extend our model from the
small-scale system to long-range atmospheric dust transport to develop
insights into the effects of electric fields on size distributions of lofted
dust in the atmosphere. We show that the presence of electric fields and the
resulting electrostatic force on charged particles can help explain the
transport of unexpectedly large particles and cause the size distribution to
become more uniform as a function of elevation. Thus, our experimental and
modeling results indicate that electrostatic forces may in some cases be
relevant regarding the effect of atmospheric dust on the climate.</p> |
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| ISSN: | 1680-7316 1680-7324 |