Format:
Online-Ressource
ISSN:
1680-7324
Content:
Abstract BC), demonstrating the strong absorbing marine boundary layer in the south-eastern Atlantic. Here we investigate the monthly variations of critical optical properties of BB aerosols, i.e. SSA and MACBC, during the BB seasons and the driving factors behind these variations. Both SSA and MACBC increase from June to August and decrease in September and October. The average SSA during the BB seasons is 0.81 at 529 nm wavelength, with the highest mean ∼ ∼ E abs BC shows similar trends with SSA, with the average during the whole of the BB seasons at ∼ ∼ E abs ∼ Δ BC/Δ CO, equal to BC/Δ CO as the BC background concentration is considered to be 0) is well correlated with SSA and MACBC, providing a simple way to estimate the aerosol optical characteristics in the south-eastern Atlantic. The exponential function we proposed can approximate SSA and MACBC with BC/Δ CO, and when BC/Δ CO is small it can capture the rapid growth of SSA as BC/Δ CO decreases. BC/Δ CO is influenced by combustion conditions and aerosol scavenging. From the analysis of the location of BB, the primary source fuel, the water content in the fuel, combined with the mean cloud cover and precipitation in the transport areas of the BB plume, we conclude that the increase in BC/Δ CO from June to August is likely to be caused by burning becoming more flaming. The reduction in the water content of fuels may be responsible for the change in the burning conditions from June to August. The decrease in BC/Δ CO in September and October may be caused by two factors, one being a lower proportion of flaming conditions, possibly associated with a decrease in mean surface wind speed in the burning area, and the other being an increase in precipitation in the BB transport pathway, leading to enhanced aerosol scavenging, which ultimately results in an increase in SSA and MACBC.
In:
volume:22
In:
number:13
In:
year:2022
In:
pages:8767-8785
In:
extent:19
In:
Atmospheric chemistry and physics, Katlenburg-Lindau : EGU, 2001-, 22, Heft 13 (2022), 8767-8785 (gesamt 19), 1680-7324
Language:
English
DOI:
10.5194/acp-22-8767-2022
URN:
urn:nbn:de:101:1-2022071405280283237994
URL:
https://doi.org/10.5194/acp-22-8767-2022
URL:
https://nbn-resolving.org/urn:nbn:de:101:1-2022071405280283237994
URL:
https://d-nb.info/1262473764/34
URL:
https://acp.copernicus.org/articles/22/8767/2022/acp-22-8767-2022.pdf
URL:
https://acp.copernicus.org/articles/22/8767/2022/