scholarly journals Influence of Long-Range Transport Dust Particles on Local Air Quality: A Case Study on Asian Dust Episodes in Taipei during the Spring of 2002

2004 ◽  
Vol 15 (5) ◽  
pp. 881 ◽  
Author(s):  
Charles C.-K. Chou ◽  
Chuan-Yao Lin ◽  
Tze-Kuang Chen ◽  
Shih-Chieh Hsu ◽  
Shih-Chun Lung ◽  
...  
2014 ◽  
Vol 14 (1) ◽  
pp. 505-521 ◽  
Author(s):  
G. Y. Jeong ◽  
J. Y. Kim ◽  
J. Seo ◽  
G. M. Kim ◽  
H. C. Jin ◽  
...  

Abstract. Giant particles transported over long distances are generally of limited concern in atmospheric studies due to their low number concentrations in mineral dust and possible local origin. However, they can play an important role in regional circulation of earth materials due to their enormous volume concentration. Asian dust laden with giant particles was observed in Korea on 31 March 2012, after a migration of about 2000 km across the Yellow Sea from the Gobi Desert. Scanning electron microscopy (SEM) revealed that 20% of the particles exceeded 10 μm in equivalent sphere diameter, with a maximum of 60 μm. The median diameter from the number distribution was 5.7 μm, which was larger than the diameters recorded of 2.5 and 2.9 μm in Asian dust storms in 2010 and 2011, respectively, and was consistent with independent optical particle counter data. Giant particles (>10 μm) contributed about 89% of the volume of the dust in the 2012 storm. Illite–smectite series clay minerals were the major mineral group followed by quartz, plagioclase, K-feldspar, and calcite. The total phyllosilicate content was ~52%. The direct long-range transport of giant particles was confirmed by calcite nanofibers closely associated with clays in a submicron scale identified by high-resolution SEM and transmission electron microscopy. Since giant particles consisted of clay agglomerates and clay-coated quartz, feldspars, and micas, the mineral composition varied little throughout the fine (<5 μm), coarse (5–10 μm), giant-S (10–20 μm), and giant-L (>20 μm) size bins. Analysis of the synoptic conditions of the 2012 dust event and its migration indicated that the mid-tropospheric strong wind belt directly stretching to Korea induced rapid transport of the dust, delivering giant particles. Giant dust particles with high settling velocity would be the major input into the terrestrial and marine sedimentary and ecological systems of East Asia and the western Pacific. Analysis of ancient aeolian deposits in Korea suggested the common deposition of giant particles from Asian dust through the late Quaternary Period. The roles of giant particles should be reviewed with regard to regional circulation of mineral particles and nutrients.


2003 ◽  
Vol 18 (2) ◽  
pp. 121-141 ◽  
Author(s):  
J. J. Simpson ◽  
G. L. Hufford ◽  
R. Servranckx ◽  
J. Berg ◽  
D. Pieri

2013 ◽  
Vol 13 (8) ◽  
pp. 21041-21077 ◽  
Author(s):  
G. Y. Jeong ◽  
J. Y. Kim ◽  
J. Seo ◽  
G. M. Kim ◽  
H. C. Jin ◽  
...  

Abstract. Giant particles transported over long distances are generally of limited concern in atmospheric studies due to their low number concentrations in mineral dust and possible local origin. However, they can play an important role in regional circulation of earth materials due to their enormous volume concentration. Asian dust laden with giant particles was observed in Korea on 31 March 2012, after a migration of about 2000 km across the Yellow Sea from the Gobi Desert. Scanning electron microscopy (SEM) revealed that 20% of the particles exceeded 10 μm in equivalent sphere diameter, with a maximum of 60 μm. The median diameter from the number distribution was 5.7 μm, which was larger than the diameters recorded of 2.5 and 2.9 μm in Asian dust storms in 2010 and 2011, respectively, and was consistent with independent optical particle counter data. Giant particles (> 10 μm) contributed about 89% of the volume of the dust in the 2012 storm. Illite-smectite series clay minerals were the major mineral group followed by quartz, plagioclase, K-feldspar, and calcite. The total phyllosilicate content was ~ 52%. The direct long-range transport of giant particles was confirmed by calcite nanofibers closely associated with clays in a submicron scale identified by high-resolution SEM and transmission electron microscopy. Since giant particles consisted of clay agglomerates and clay-coated quartz, feldspars, and micas, the mineral composition varied little throughout the fine (< 5 μm), coarse (5–10 μm), giant-S (10–20 μm), and giant-L (> 20 μm) size bins. Analysis of the synoptic conditions of the 2012 dust event and its migration indicated that the mid-tropospheric strong wind belt directly stretching to Korea induced rapid transport of the dust, delivering giant particles. Giant dust particles with high settling velocity would be the major input into the terrestrial and marine sedimentary and ecological systems of East Asia and the western Pacific. Analysis of ancient aeolian deposits in Korea suggested the common deposition of giant particles from Asian dust through the late Quaternary period. The roles of giant particles should be reviewed with regard to regional circulation of mineral particles and nutrients.


2010 ◽  
Vol 10 (12) ◽  
pp. 5391-5408 ◽  
Author(s):  
J. Jung ◽  
Y. J. Kim ◽  
K. Y. Lee ◽  
M. G. -Cayetano ◽  
T. Batmunkh ◽  
...  

Abstract. As a part of the IGAC (International Global Atmospheric Chemistry) Mega-cities program, aerosol physical and optical properties were continuously measured from March 2007 to March 2008 at an urban site (37.57° N, 126.94° E) in Seoul, Korea. Spectral optical properties of long-range transported Asian dust and pollution aerosols have been investigated based on the year long measurement data. Optically measured black carbon/thermally measured elemental carbon (BC/EC) ratio showed clear monthly variation with high values in summer and low values in winter mainly due to the enhancement of light attenuation by the internal mixing of EC. Novel approach has been suggested to retrieve the spectral light absorption coefficient (babs) from Aethalometer raw data by using BC/EC ratio. Mass absorption efficiency, σabs (=babs/EC) at 550 nm was determined to be 9.0±1.3, 8.9±1.5, 9.5±2.0, and 10.3±1.7 m2 g−1 in spring, summer, fall, and winter, respectively with an annual mean of 9.4±1.8 m2 g−1. Threshold values to classify severe haze events were suggested in this study. Increasing trend of aerosol single scattering albedo (SSA) with wavelength was observed during Asian dust events while little spectral dependence of SSA was observed during long-range transport pollution (LTP) events. Satellite aerosol optical thickness (AOT) and Hysplit air mass backward trajectory analyses as well as chemical analysis were performed to characterize the dependence of spectral optical properties on aerosol type. Results from this study can provide useful information for studies on regional air quality and aerosol's effects on climate change.


2018 ◽  
Vol 18 (7) ◽  
pp. 1734-1745 ◽  
Author(s):  
Leila Droprinchinski Martins ◽  
Ricardo Hallak ◽  
Rafaela Cruz Alves ◽  
Daniela S. de Almeida ◽  
Rafaela Squizzato ◽  
...  

2017 ◽  
Author(s):  
Zhe Jiang ◽  
Helen Worden ◽  
John R. Worden ◽  
Daven K. Henze ◽  
Dylan B. A. Jones ◽  
...  

Abstract. Decreases in surface emissions of nitrogen oxides (NOx = NO + NO2) in North America have led to substantial improvements in air-quality over the last several decades. Here we show that satellite observations of tropospheric nitrogen dioxide (NO2) columns over the contiguous United States (US) do not decrease after about 2009, while surface NO2 concentrations continue to decline through to the present. This divergence, if it continues, could have a substantial impact on surface air quality due to mixing of free-tropospheric air into the boundary layer. Our results show only limited contributions from local effects such as fossil fuel emissions, lightning, or instrument artifacts, but we do find a possible relationship of NO2 changes to decadal climate variability. Our analysis demonstrates that the intensity of transpacific transport is stronger in El Niño years and weaker in La Niña years, and consequently, that decadal-scale climate variability impacts the contribution of Asian emissions on North American atmospheric composition. Because of the short lifetime, it is usually believed that the direct contribution of long-range transport to tropospheric NOx distribution is limited. If our hypothesis about transported Asian emissions is correct, then this observed divergence between satellite and surface NOx could indicate mechanisms that allow for either NOx or its reservoir species to have a larger than expected effect on North American tropospheric composition. These results therefore suggest more aircraft and satellite studies to determine the possible missing processes in our understanding of the long-range transport of tropospheric NOx.


Sign in / Sign up

Export Citation Format

Share Document