Journal of Environmental Sciences, Journal Year: 2023, Volume and Issue: 138, P. 74 - 87
Published: March 5, 2023
Language: Английский
Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(10), P. 5887 - 5905
Published: May 23, 2024
Abstract. To investigate the optical characteristics and sources of brown carbon (BrC) in North China, where atmospheric aerosol loadings are high have severe impacts on Earth's climate system, we collected fine aerosols (PM2.5) at an urban site Tianjin over a 1-year period. We measured ultraviolet (UV) light absorption excitation emission matrix (EEM) fluorescence water-soluble BrC (WSBrC) water-insoluble but methanol-soluble (WI-MSBrC) PM2.5 using three-dimensional spectrometer. The average efficiency both WSBrC (Abs365, WSBrC) WI-MSBrC WI-MSBrC) 365 nm was found to be highest winter (10.4 ± 6.76 10.0 5.13 Mm−1, respectively) distinct from season season. averages index (FI) biological (BIX) were lower summer than other seasons opposite that humification (HIX), which implied secondary formation further chemical processing more intensive during period seasons. However, winter, higher HIX together with FI BIX suggested loading mainly influenced by primary emissions biomass burning coal combustion. Based EEM, types fluorophores divided into humic-like substances (HULIS), including low-oxygenated high-oxygenated species protein-like compounds (PLOM), though mostly PLOM WI-MSBrC. direct radiation range 300–400 accounted for ∼ 40 % (SFEAbs, 4.97 2.71 7.58 5.75 W g−1, 300–700 nm.
Language: Английский
Citations
2
The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 818, P. 151772 - 151772
Published: Nov. 19, 2021
Language: Английский
Citations
15
Atmospheric measurement techniques, Journal Year: 2022, Volume and Issue: 15(9), P. 2819 - 2838
Published: May 9, 2022
Abstract. Bioaerosols are usually defined as aerosols arising from biological systems such bacteria, fungi, and viruses. They play an important role in atmospheric physical chemical processes including ice nucleation cloud condensation. As such, their dispersion affects not only public health but also regional climate. Lidar is effective technique for aerosol detection pollution monitoring. It used to profile the vertical distribution of wind vectors. In this paper, a coherent Doppler lidar (CDWL) deployed Hefei, China, 11 20 March 2020. A wideband integrated bioaerosol sensor (WIBS) monitor variations local fluorescent bioaerosols. Three transport events captured. The WIBS data show that, during these events, several types particles exhibit abnormal increases concentration, number fractions total particles, whole aerosols. These attributed external bioaerosols instead Based on HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory model characteristics WIBS, possible sources, paths, components discussed. results prove influence high particulate matter (PM) particle composition. combination CDWL expands monitoring parameters provides potential method real-time events. addition, it helps understand relationships between phenomena at altitudes like virga variation surface bioaerosol. contributes further understanding long-range transport, roles processes, aerosol–cloud–precipitation interactions.
Language: Английский
Citations
11
Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(19), P. 12609 - 12630
Published: Oct. 10, 2023
Abstract. Brown carbon (BrC) aerosol could impact atmospheric radiative forcing and play a crucial role in photochemistry. In this study, fine particulate matter (PM2.5) filter samples were collected synchronously four major cities northwestern China during the winter season (December 2019–January 2020): Lanzhou (LZ), Xining (XN), Yinchuan (YC), Ürümqi (UR), which are represented as energy-producing heavy manufacturing China. The primary aim of study is to explore optical properties, sources, chemical processes water-soluble BrC (WS-BrC). average mass absorption efficiency at 365 nm (MAE365) WS-BrC these was 1.24 ± 0.19 m2 g−1 1.19 0.12 1.07 0.23 0.78 0.16 (UR). properties further investigated by an acid–base titration experiment. results showed that MAE365 values all increased with higher pH (2–11), while fluorescence intensities water extracts fluctuated values, being stronger under both highly acidic basic conditions. sensitivity variation most pronounced from YC LZ, indicating important contribution acid or base functional group compounds locations. Additionally, revealed significant photo-enhancement (LZ) photo-bleaching (YC UR) phenomena different cities. These suggest sources and/or varied among explored combination parallel factor analysis (PARAFAC) on excitation–emission matrix (EEM) spectra positive factorization (PMF) high-resolution organic (WSOA). Six PARAFAC components identified, including three humic-like substances (HULIS; two less oxygenated (LO) HULIS one (HO) HULIS), protein-like phenol-like (PLS), undefined substance. Four PMF factors OA (WS-POA), oxidized associated coal combustion-induced WSOA (LO-OOA), OAs resulting photochemical oxidation aqueous-phase transformations (HO-OOA1 HO-OOA2). WS-POA determined be source light absorption, accounting for 30 %–60 % based multiple linear regression models, it correlation PLS LO-HULIS components. loss found occur through its conversion LO-OOA HO-OOAs aqueous reactions, significantly correlated HO-HULIS component. can clearly illustrated integrating composition using Van Krevelen diagram EEM plot.
Language: Английский
Citations
6
Journal of Environmental Sciences, Journal Year: 2023, Volume and Issue: 138, P. 74 - 87
Published: March 5, 2023
Language: Английский
Citations
5