Page 184 - 《高原气象》2026年第2期

高 原 气 象 45 卷
484

Research on Optical Properties and Radiative Effects of Aerosols

in a Typical City in Southwest China

1， 2
1
1， 4
ZHANG Xiaoling 1， 2， 3 ， LI Zhaoyang ， YUAN Zhihe ， YUAN Liang ， HE Yulu 1
（1. Plateau Atmosphere and Environment Key Laboratory of Sichuan Province， School of Atmospheric Sciences， Chengdu
University of Information Technology， Chengdu 610225， Sichuan， China；
2. Chengdu Plain Urban Meteorology and Environment Observation and Research Station of
Sichuan Province， Chengdu 610225， Sichuan， China；
3. Yunnan Natural Hazards Prevention Center， Chengdu University of Information Technology， Kunming 650034， Yunnan， China；
4. The Meteorological Service Center of Jiangxi Province， Nanchang 330096， Jiangxi， China）

Abstract： Using aerosol scattering and absorption coefficient observations in Chengdu city from March 2021 to
February 2022， combined with EAC-4， MERRA-2 reanalysis data， and the libRadtran radiative transfer model，
the aerosol optical parameters in different seasons and the radiative effects of total aerosols and absorbing carbo‐
naceous aerosols were investigated. The results showed significant seasonal variations in aerosol optical parame‐
ters： the single scattering albedo （SSA） at 550 nm reached its maximum value in winter （0. 91±0. 02）， while it
was the lowest in spring （0. 84±0. 04）. The asymmetry factor （ASY） at 550 nm followed the order of summer >
winter > spring > autumn. The mean total aerosol optical thickness （AOD） was higher in spring and winter
（about 0. 77）， but lower in summer and autumn （about 0. 50~0. 53）. Further analysis of the optical depth of
light-absorbing carbonaceous aerosols revealed that black carbon （BC） contributed the most in winter， whereas
the brown carbon （BrC） reached its peak in spring. The radiative transfer model calculation indicated that the an‐
nual average shortwave radiative forcing induced by total aerosols at the surface （BOA）， top of the atmosphere
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（TOA）， and within the atmosphere （ATM） was -107. 21±42. 49 W·m ， -32. 10±20. 40 W·m ， and 75. 10±40. 16
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W·m ， respectively. These indicated there were an overall cooling effect at the surface but a warming effect with‐
in the atmosphere for aerosol. Notably， BC exhibited distinct seasonal variations in radiative forcing： TOA forc‐
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ing of BC was the highest in winter （7. 18±1. 59 W·m ） and lowest in autumn （4. 48±1. 49 W·m ）. Additional‐
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ly， BC contributed 31. 3% of the annual mean atmospheric radiative forcing， highlighting its significant warm‐
ing effect. In contrast， the radiative forcing of BrC and its proportion relative to total aerosols were higher in
spring and lower in winter.
Key words： black carbon aerosols； brown carbon aerosols； optical properties； radiative effects； Chengdu area