TY - JOUR
T1 - Impact of particle number and mass size distributions of major chemical components on particle mass scattering efficiency in urban Guangzhou in southern China
AU - Tao, Jun
AU - Zhang, Zhisheng
AU - Wu, Yunfei
AU - Zhang, Leiming
AU - Wu, Zhijun
AU - Cheng, Peng
AU - Li, Mei
AU - Chen, Laiguo
AU - Zhang, Renjian
AU - Cao, Junji
N1 - Publisher Copyright:
© Author(s) 2019.
PY - 2019/7/4
Y1 - 2019/7/4
N2 - To grasp the key factors affecting particle mass scattering efficiency (MSE), particle mass and number size distribution, PM2.5 and PM10 and their major chemical compositions, and the particle scattering coefficient (bsp) under dry conditions were measured at an urban site in Guangzhou, southern China, during 2015-2016. On an annual average, 10±2 %, 48±7% and 42±8% of PM10 mass were in the condensation, droplet and coarse modes, respectively, with mass mean aerodynamic diameters (MMADs) of 0.78±0.07 in the droplet mode and 4.57±0.42 μm in the coarse mode. The identified chemical species mass concentrations can explain 79±3 %, 82±6% and 57±6% of the total particle mass in the condensation, droplet and coarse mode, respectively. Organic matter (OM) and elemental carbon (EC) in the condensation mode, OM, (NH4)2SO4, NH4NO3, and crustal element oxides in the droplet mode, and crustal element oxides, OM, and CaSO4 in the coarse mode, were the dominant chemical species in their respective modes. The measured bsp can be reconstructed to the level of 91±10% using Mie theory with input of the estimated chemically resolved number concentrations of NaCl, NaNO3, Na2SO4, NH4NO3, (NH4)2SO4, K2SO4, CaSO4, Ca(NO3)2, OM, EC, crustal element oxides and unidentified fraction. MSEs of particle and individual chemical species were underestimated by less than 13% in any season based on the estimated bsp and chemical species mass concentrations. Seasonal average MSEs varied in the range of 3.5±0.1 to 3.9±0.2m2g-1 for fine particles (aerodynamic diameter smaller than 2.1 μm), which was mainly caused by seasonal variations in the mass fractions and MSEs of the dominant chemical species (OM, NH4NO3),NH4)2SO4) in the droplet mode. MSEs of the dominant chemical species were determined by their lognormal sizedistribution parameters, including MMADs and standard deviation (σ) in the droplet mode.
AB - To grasp the key factors affecting particle mass scattering efficiency (MSE), particle mass and number size distribution, PM2.5 and PM10 and their major chemical compositions, and the particle scattering coefficient (bsp) under dry conditions were measured at an urban site in Guangzhou, southern China, during 2015-2016. On an annual average, 10±2 %, 48±7% and 42±8% of PM10 mass were in the condensation, droplet and coarse modes, respectively, with mass mean aerodynamic diameters (MMADs) of 0.78±0.07 in the droplet mode and 4.57±0.42 μm in the coarse mode. The identified chemical species mass concentrations can explain 79±3 %, 82±6% and 57±6% of the total particle mass in the condensation, droplet and coarse mode, respectively. Organic matter (OM) and elemental carbon (EC) in the condensation mode, OM, (NH4)2SO4, NH4NO3, and crustal element oxides in the droplet mode, and crustal element oxides, OM, and CaSO4 in the coarse mode, were the dominant chemical species in their respective modes. The measured bsp can be reconstructed to the level of 91±10% using Mie theory with input of the estimated chemically resolved number concentrations of NaCl, NaNO3, Na2SO4, NH4NO3, (NH4)2SO4, K2SO4, CaSO4, Ca(NO3)2, OM, EC, crustal element oxides and unidentified fraction. MSEs of particle and individual chemical species were underestimated by less than 13% in any season based on the estimated bsp and chemical species mass concentrations. Seasonal average MSEs varied in the range of 3.5±0.1 to 3.9±0.2m2g-1 for fine particles (aerodynamic diameter smaller than 2.1 μm), which was mainly caused by seasonal variations in the mass fractions and MSEs of the dominant chemical species (OM, NH4NO3),NH4)2SO4) in the droplet mode. MSEs of the dominant chemical species were determined by their lognormal sizedistribution parameters, including MMADs and standard deviation (σ) in the droplet mode.
UR - https://www.scopus.com/pages/publications/85068473292
U2 - 10.5194/acp-19-8471-2019
DO - 10.5194/acp-19-8471-2019
M3 - 文章
AN - SCOPUS:85068473292
SN - 1680-7316
VL - 19
SP - 8471
EP - 8490
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 13
ER -