scholarly journals Long-range transport of giant particles in Asian dust identified by physical, mineralogical, and meteorological analysis

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.

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.


2018 ◽  
Author(s):  
Yan Yu ◽  
Olga V. Kalashnikova ◽  
Michael J. Garay ◽  
Michael Notaro

Abstract. Asian dust, primarily emitted from the Taklamakan and Gobi Deserts, has been reported to reach remote destinations, such as North America. However, the relative contribution of the Taklamakan and Gobi Deserts to dust loadings through long-range transport remains unaddressed in any observational study. Here, the climatology of Asian dust activation and transport is investigated using stereo observations of dust sources from the Multiangle Imaging SpectroRadiometer (MISR) instrument combined with observation-initiated trajectory modeling. MISR-derived dust injection height and dust plume motion vectors confirm the peak of dust activation and transport potential in spring over the Gobi Desert and in both spring and summer over the Taklamakan Desert. The long-range transport patterns of Asian dust, including the influence on North America through trans-Pacific transport, are assessed using extensive forward trajectories initiated by MISR dust plume observations. The trajectory analysis reveals latitude-dependent influence of dust from the Taklamakan and Gobi deserts, with Taklamakan dust dominantly affecting to the south of 50° N and Gobi dust primarily affecting to the north of 50° N in North America. The Asian dust activation and transport exhibit substantial seasonal and interannual variability, motivating future studies on the potential drivers.


2004 ◽  
Vol 15 (5) ◽  
pp. 881 ◽  
Author(s):  
Charles C.-K. Chou ◽  
Chuan-Yao Lin ◽  
Tze-Kuang Chen ◽  
Shih-Chieh Hsu ◽  
Shih-Chun Lung ◽  
...  

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.


Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 313
Author(s):  
Catherine N. Liu ◽  
Sen Chiao ◽  
Ju-Mee Ryoo

The study investigates the effect of aerosol long-range transport on precipitation over Northern California during atmospheric river (AR) events in the 2017 cold season (January–April). ARs in 2017 were one of the strongest to date, and the intense precipitation associated with the ARs resulted in flooding, destruction of property, and contamination of water supplies. The Aerosol Optical Depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data shows Asian dust traveling across the Northern Pacific Ocean along with AR events. Aerosol measurements in California, provided by the Interagency Monitoring of Protected Visual Environments (IMPROVE), show that more Asian dust tends to be observed over the coast, while non-Asian/localized dust is observed inland. A mixture of Asian and localized dust is observed over the mountains, although higher amounts of both are observed in the spring (March–April). Back trajectory analysis confirms that Asian aerosols are transported along the air parcels, and each AR event has its own transport pattern in terms of horizontal advection and vertical lifting. Correlation between precipitation and aerosols is low. This suggests that aerosols contribute little to the decrease of local precipitation during the 2017 AR events.


2016 ◽  
Author(s):  
Leonardo A. Mingari ◽  
Estela A. Collini ◽  
Arnau Folch ◽  
Walter Báez ◽  
Emilce Bustos ◽  
...  

Abstract. On the 13 June 2015, the London Volcanic Ash Advisory Centre (VAAC) warned the Buenos Aires VAAC about a possible volcanic eruption from the Nevados Ojos del Salado volcano (6879 m), located in the Andes mountain range on the border between Chile and Argentina. A volcanic ash cloud was detected by the SEVIRI instrument on board the Meteosat Second Generation (MSG) satellites from 14:00 UTC on 13 June. Further studies concluded that the phenomenon was caused by remobilization of ancient pyroclastic deposits (circa 4.5 Ka Cerro Blanco eruption) from the Bolsón de Fiambalá (Fiambalá Basin) in northwestern Argentina. In this paper, we provide the first comprehensive description of the dust episode through observations and numerical simulations. We have investigated the spatio-temporal distribution of aerosols and the emission process over complex terrain to gain insight into the key role played by the orography and the condition that triggered the long-range transport episode. Numerical simulations of windblown dust were performed using the WRF-ARW/FALL3D modeling system with meteorological fields downscaled to a spatial resolution of 2 km in order to resolve the complex orography of the area. Results indicated that favourable conditions to generate dust uplifting occurred in northern Fiambalá Basin, where orographic effects caused strong surface winds. According to short-range numerical simulations, dust particles were confined to near-ground layers around the emission areas. On the other hand, dust aerosols were injected up to 5–6 km high in central and southern regions of the Fiambalá Basin, where intense ascending airflows are driven by horizontal convergence. Long-range transport numerical simulations were also performed to model dust cloud spreading over northern Argentina. Results of simulated vertical particle column mass were compared with the MSG-SEVIRI retrieval product. We tested two numerical schemes: with the default configuration of the FALL3D model, we found difficulties to simulate transport through orographic barriers, whereas an alternative configuration, using a numerical scheme to more accurately compute the horizontal advection in abrupt terrains, substantially improved the model performance.


2001 ◽  
Vol 106 (D16) ◽  
pp. 18361-18370 ◽  
Author(s):  
I. G. McKendry ◽  
J. P. Hacker ◽  
R. Stull ◽  
S. Sakiyama ◽  
D. Mignacca ◽  
...  

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