Spatial distribution, sources, and direct radiative effect of carbonaceous aerosol along a transect from the Arctic Ocean to Antarctica

Guangmei Wu; Ye Hu; Chongshui Gong; Danhe Wang; Fan Zhang; Imali Kaushalya Herath; Zhenlou Chen; Guitao Shi

doi:10.1016/j.scitotenv.2024.170136

Spatial distribution, sources, and direct radiative effect of carbonaceous aerosol along a transect from the Arctic Ocean to Antarctica

Sci Total Environ. 2024 Mar 15:916:170136. doi: 10.1016/j.scitotenv.2024.170136. Epub 2024 Jan 17.

Authors

Guangmei Wu¹, Ye Hu¹, Chongshui Gong², Danhe Wang¹, Fan Zhang¹, Imali Kaushalya Herath¹, Zhenlou Chen¹, Guitao Shi³

Affiliations

¹ Key Laboratory of Geographic Information Science, School of Geographic Sciences and State Key Lab of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
² Institute of Arid Meteorology, China Meteorological Administration, Lanzhou 730020, China.
³ Key Laboratory of Geographic Information Science, School of Geographic Sciences and State Key Lab of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China; Key Laboratory of Spatial-temporal Big Data Analysis and Application of Natural Resources in Megacities, Ministry of Natural Resources, Shanghai, China. Electronic address: gtshi@geo.ecnu.edu.cn.

PMID: 38242463
DOI: 10.1016/j.scitotenv.2024.170136

Abstract

Carbonaceous aerosols (CA) have a high impact on air quality and climate. However, the composition and spatial variability of CA in the marine boundary layer (MBL) remain understudied, especially in the remote regions. Here, atmospheric organic carbon (OC) and elemental carbon (EC) measurements using DRI Model 2001 Thermal/Optical Carbon Analyzer in the MBL were performed during the Chinese Antarctic (2019-2020) and Arctic (2021) research expedition, spanning about 160 latitudes. Due to varying intensities of atmospheric transport from the continents, a significant latitudinal gradient in OC and EC was observed. OC exhibited the highest concentration over the coastal East Asia (CEA), with a mean of 4324 ng m^-3 (358-18027 ng m^-3), followed by the Arctic Ocean (AO). Similar OC levels were detected over the Southern Ocean (SO) and the Antarctic Ice Sheet (AIS). Similarly, the highest EC was also observed over CEA, with a mean of 867 ng m^-3 (71-3410 ng m^-3), followed by AO and SO, while the lowest EC appeared over the AIS, with a mean of 30 ng m^-3 (2-70 ng m^-3). The lower Char-EC/Soot-EC ratios over AO and CEA compared to SO and AIS indicated that fossil fuel combustion contributed more to EC over AO and CEA, while biomass burning played a more significant role in EC levels over SO and AIS. The high OC/EC ratio over AIS was associated with an extremely low EC level and the formation of secondary OC over AIS. SBDART model results suggested that EC had a net warming effect on the atmospheric column, with the highest direct radiative effects (DRE) over AO (5.50 ± 0.15 W m^-2, corresponding a heating rate of 0.15 K day^-1) and the lowest DRE over SO (1.35 ± 0.04 W m^-2, corresponding a heating rate of 0.04 K day^-1).

Keywords: Antarctica; Carbonaceous aerosol; Direct radiative effect; Latitudinal gradient; The Arctic Ocean; The Southern Ocean.