Quantifying black carbon light absorption enhancement with a novel statistical approach
Black carbon (BC) particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, <i>E</i><sub>abs</sub>, was quantifi...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-01-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/289/2018/acp-18-289-2018.pdf |
| _version_ | 1811283799426727936 |
|---|---|
| author | C. Wu C. Wu D. Wu D. Wu D. Wu J. Z. Yu J. Z. Yu J. Z. Yu |
| author_facet | C. Wu C. Wu D. Wu D. Wu D. Wu J. Z. Yu J. Z. Yu J. Z. Yu |
| author_sort | C. Wu |
| collection | DOAJ |
| description | Black carbon (BC) particles in the atmosphere can absorb more light
when coated by non-absorbing or weakly absorbing materials during
atmospheric aging, due to the lensing effect. In this study, the
light absorption enhancement factor, <i>E</i><sub>abs</sub>, was
quantified using a 1-year measurement of mass absorption
efficiency (MAE) in the Pearl River Delta region (PRD). A new
approach for calculating primary MAE (MAE<sub>p</sub>),
the key for <i>E</i><sub>abs</sub> estimation, is demonstrated using the
minimum <i>R</i> squared (MRS) method, exploring the inherent source
independency between BC and its coating materials. A unique feature
of <i>E</i><sub>abs</sub> estimation with the MRS approach is its
insensitivity to systematic biases in elemental carbon (EC) and <i>σ</i><sub>abs</sub>
measurements. The annual average <i>E</i><sub>abs550</sub> is found to be
1.50 ± 0.48 (±1 SD) in the PRD region, exhibiting a clear
seasonal pattern with higher values in summer and lower in
winter. Elevated <i>E</i><sub>abs</sub> in the summertime is likely
associated with aged air masses, predominantly of marine origin, along
with long-range transport of biomass-burning-influenced air masses
from Southeast Asia. Core–shell Mie simulations along with measured
<i>E</i><sub>abs</sub> and absorption Ångström exponent (AAE) constraints
suggest that in the PRD, the coating materials are unlikely to be
dominated by brown carbon and the coating thickness is higher in the
rainy season than in the dry season. |
| first_indexed | 2024-04-13T02:18:03Z |
| format | Article |
| id | doaj.art-609cfe3e240a4b24a1c6c1c84f805fef |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-13T02:18:03Z |
| publishDate | 2018-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-609cfe3e240a4b24a1c6c1c84f805fef2022-12-22T03:07:04ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-01-011828930910.5194/acp-18-289-2018Quantifying black carbon light absorption enhancement with a novel statistical approachC. Wu0C. Wu1D. Wu2D. Wu3D. Wu4J. Z. Yu5J. Z. Yu6J. Z. Yu7Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, ChinaGuangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Guangzhou 510632, ChinaInstitute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, ChinaGuangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Guangzhou 510632, ChinaInstitute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou 510080, ChinaDivision of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, ChinaAtmospheric Research Centre, Fok Ying Tung Graduate School, Hong Kong University of Science and Technology, Nansha, ChinaDepartment of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, ChinaBlack carbon (BC) particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, <i>E</i><sub>abs</sub>, was quantified using a 1-year measurement of mass absorption efficiency (MAE) in the Pearl River Delta region (PRD). A new approach for calculating primary MAE (MAE<sub>p</sub>), the key for <i>E</i><sub>abs</sub> estimation, is demonstrated using the minimum <i>R</i> squared (MRS) method, exploring the inherent source independency between BC and its coating materials. A unique feature of <i>E</i><sub>abs</sub> estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC) and <i>σ</i><sub>abs</sub> measurements. The annual average <i>E</i><sub>abs550</sub> is found to be 1.50 ± 0.48 (±1 SD) in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated <i>E</i><sub>abs</sub> in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomass-burning-influenced air masses from Southeast Asia. Core–shell Mie simulations along with measured <i>E</i><sub>abs</sub> and absorption Ångström exponent (AAE) constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.https://www.atmos-chem-phys.net/18/289/2018/acp-18-289-2018.pdf |
| spellingShingle | C. Wu C. Wu D. Wu D. Wu D. Wu J. Z. Yu J. Z. Yu J. Z. Yu Quantifying black carbon light absorption enhancement with a novel statistical approach Atmospheric Chemistry and Physics |
| title | Quantifying black carbon light absorption enhancement with a novel statistical approach |
| title_full | Quantifying black carbon light absorption enhancement with a novel statistical approach |
| title_fullStr | Quantifying black carbon light absorption enhancement with a novel statistical approach |
| title_full_unstemmed | Quantifying black carbon light absorption enhancement with a novel statistical approach |
| title_short | Quantifying black carbon light absorption enhancement with a novel statistical approach |
| title_sort | quantifying black carbon light absorption enhancement with a novel statistical approach |
| url | https://www.atmos-chem-phys.net/18/289/2018/acp-18-289-2018.pdf |
| work_keys_str_mv | AT cwu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT cwu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT dwu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT dwu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT dwu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT jzyu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT jzyu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach AT jzyu quantifyingblackcarbonlightabsorptionenhancementwithanovelstatisticalapproach |