scholarly journals Size dependence of wet removal of black carbon aerosols during transport from the boundary layer to the free troposphere

2012 ◽  
Vol 39 (13) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. Moteki ◽  
Y. Kondo ◽  
N. Oshima ◽  
N. Takegawa ◽  
M. Koike ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Size Dependence ◽  
Free Troposphere ◽  
Carbon Aerosols ◽  
Wet Removal ◽  
Black Carbon Aerosols

scholarly journals Black Carbon Aerosols in the Lower Free Troposphere are Heavily Coated in Summer but Largely Uncoated in Winter at Jungfraujoch in the Swiss Alps

2020 ◽  
Vol 47 (14) ◽  
Author(s):  
Ghislain Motos ◽  
Joel C. Corbin ◽  
Julia Schmale ◽  
Rob L. Modini ◽  
Michele Bertò ◽  
...  
Keyword(s):  
Black Carbon ◽  
Swiss Alps ◽  
Free Troposphere ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

scholarly journals The Semidirect Aerosol Effect: Comparison of a Single-Column Model with Large Eddy Simulation for Marine Stratocumulus

2005 ◽  
Vol 18 (1) ◽  
pp. 119-130 ◽  
Author(s):  
B. T. Johnson
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Radiative Forcing ◽  
General Circulation ◽  
Radiative Properties ◽  
Aerosol Effect ◽  
Large Eddy ◽  
Single Column ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Abstract Large eddy simulations (LES) show that the presence of black carbon aerosols in marine boundary layers leads to a marked reduction of stratocumulus liquid water path (LWP) by heating the cloud layer and suppressing convection in the boundary layer. The reduction of LWP leads to a positive radiative forcing known as the semidirect effect. In this study LES results are compared with results from the National Center for Atmospheric Research (NCAR) Single-Column Community Climate Model (SCCM). The SCCM represents clouds and boundary layer processes through simple parameterization schemes that are typical of general circulation models (GCMs) used for climate experiments. In a case study in which black carbon aerosols were introduced in a stratocumulus-capped boundary layer the SCCM gave a semidirect aerosol radiative forcing that was a factor of 5 smaller than the value obtained from the LES. The cloud response to absorbing aerosols was underestimated because of the way that cloud cover and cloud radiative properties were parameterized in the SCCM. Furthermore, the SCCM gave a poor representation of processes, such as entrainment and boundary layer decoupling, that are crucial to determining stratocumulus LWP. This study shows that GCMs may not include all the physical processes necessary to adequately capture the semidirect aerosol effect. Previous GCM estimates of the semidirect effect that have incorporated simple cloud parameterizations should, therefore, be treated with some caution.

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