Observations of black carbon aerosols characteristics over an urban environment: Radiative forcing and related implications

2017 ◽  
Vol 603-604 ◽  
pp. 319-329 ◽  
Author(s):  
Samina Bibi ◽  
Khan Alam ◽  
Farrukh Chishtie ◽  
Humera Bibi ◽  
Said Rahman
Keyword(s):  
Urban Environment ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Black carbon aerosols over a high altitude station, Mahabaleshwar: Radiative forcing and source apportionment

2020 ◽  
Vol 11 (8) ◽  
pp. 1408-1417
Author(s):  
M.P. Raju ◽  
P.D. Safai ◽  
S.M. Sonbawne ◽  
P.S. Buchunde ◽  
G. Pandithurai ◽  
...  
Keyword(s):  
High Altitude ◽  
Black Carbon ◽  
Source Apportionment ◽  
Radiative Forcing ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Distribution and direct radiative forcing of black carbon aerosols over Korean Peninsula

2012 ◽  
Vol 58 ◽  
pp. 45-55 ◽  
Author(s):  
Min Young Kim ◽  
Seung-Bok Lee ◽  
Gwi-Nam Bae ◽  
Seung Shik Park ◽  
Kyung Man Han ◽  
...  
Keyword(s):  
Black Carbon ◽  
Korean Peninsula ◽  
Radiative Forcing ◽  
Direct Radiative Forcing ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Scavenging efficiency of rainfall on black carbon aerosols over an urban environment

2005 ◽  
Vol 6 (3) ◽  
pp. 148-151 ◽  
Author(s):  
K. Madhavi Latha ◽  
K. V. S. Badarinath ◽  
P. Manikya Reddy
Keyword(s):  
Urban Environment ◽  
Black Carbon ◽  
Scavenging Efficiency ◽  
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.

scholarly journals Black carbon fractal morphology and short-wave radiative impact: a modelling study

2011 ◽  
Vol 11 (8) ◽  
pp. 23103-23137
Author(s):  
M. Kahnert ◽  
A. Devasthale
Keyword(s):  
Optical Properties ◽  
Fractal Dimension ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Homogeneous Sphere ◽  
Radiative Impacts ◽  
Radiative Impact ◽  
Sphere Approximation ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Abstract. We investigate the impact of the morphological properties of freshly emitted black carbon aerosols on optical properties and on radiative forcing. To this end, we model the optical properties of fractal black carbon aggregates by use of numerically exact solutions to Maxwell's equations within a spectral range from the UVC to the mid-IR. The results are coupled to radiative transfer computations, in which we consider six realistic case studies representing different atmospheric pollution conditions and surface albedos. The spectrally integrated radiative impacts of black carbon are compared for two different fractal morphologies, which brace the range of recently reported experimental observations of black carbon fractal structures. We also gauge our results by performing corresponding calculations based on the homogeneous sphere approximation, which is commonly employed in climate models. We find that at top of atmosphere the aggregate models yield radiative impacts that can be as much as 2 times higher than those based on the homogeneous sphere approximation. An aggregate model with a low fractal dimension can predict a radiative impact that is higher than that obtained with a high fractal dimension by a factor ranging between 1.1–1.6. Although the lower end of this scale seems like a rather small effect, a closer analysis reveals that the single scattering optical properties of more compact and more lacy aggregates differ considerably. In radiative flux computations there can be a partial cancellation due to the opposing effects of differences in the optical cross sections and asymmetry parameters. However, this cancellation effect can strongly depend on atmospheric conditions and is therefore quite unpredictable. We conclude that the fractal morphology of black carbon aerosols and their fractal parameters can have a profound impact on their radiative forcing effect, and that the use of the homogeneous sphere model introduces unacceptably high biases in radiative impact studies. We emphasise that there are other potentially important morphological features that have not been addressed in the present study, such as sintering and coating of freshly emitted black carbon by films of organic material.

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