Articles | Volume 20, issue 4
Research article
 | Highlight paper
27 Feb 2020
Research article | Highlight paper |  | 27 Feb 2020

Ultra-clean and smoky marine boundary layers frequently occur in the same season over the southeast Atlantic

Sam Pennypacker, Michael Diamond, and Robert Wood

Data sets

Ultra-High Sensitivity Aerosol Spectrometer (AOSUHSAS). 2016-04-23 to 2017-11-01 Atmospheric Radiation Measurement (ARM)

Condensation Particle Counter (AOSCPCU). 2016-05-20 to 2017-11-03 Atmospheric Radiation Measurement (ARM)

MWR Retrievals (MWRRET1LILJCLOU). 2016-05-21 to 2017-11-01 Atmospheric Radiation Measurement (ARM)

Total Sky Imager (TSISKYCOVER). 2016-05-02 to 2017-10-31 Atmospheric Radiation Measurement (ARM)

Short summary
Using observations from instruments deployed to a small island in the southeast Atlantic, we study days when the atmospheric concentrations of particles near the surface are exceptionally low. Interestingly, these ultra-clean boundary layers occur in the same months as the smokiest boundary layers associated with biomass burning in Africa. We find evidence that enhancements in drizzle scavenging, on top of a seasonal maximum in cloudiness and precipitation, likely drive these conditions.
Final-revised paper