A detection algorithm for Asian dust aerosol over China Seas based on MODIS observations

Abstract The transport of dust aerosol in East Asia is affected by the East Asian winter monsoon (EAWM) and westerly circulation both for modern and geological periods. There are obvious seasonal changes in the intensity and range of EAWM and westerly jet; however, their impacts and relative contributions to East Asian dust transmission are still unclear. In this study, we use Regional Climate Model 4 (RegCM4) to simulate the changes in the East Asian dust cycle under present conditions, assessing the effects of EAWM and westerly jet on dust transport. The results show that the dust at the upper level is mainly transported by the westerly circulation, while that of the lower layer is mainly transported by the EAWM. In March, the westerly jet is located on the south side of the Tibet Plateau and the high-level dust aerosol is transmitted eastward to the northern Pacific. Low-level dust is transmitted to the southeastern China with the influence of EAWM. With the northward shift of the westerly jet, the control range of the westerly winds increases in May and their correlations are weakened. In contrary, the impact of EAWM on the lower layer dust is enhanced. Due to the strengthened interaction between the westerly winds and the EAWM, they can both affect the middle-level dust transmission. The effect of EAWM is sensitive to the dust particle sizes. Under the action of EAWM, fine-grained dust is transmitted far away, while coarse-grained dust is limited to the vicinity of the source area. Once the dust is carried to the westerly layer, the influence of westerly winds on the transmission of different particle sizes dust is similar.

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A Simulated Climatology of Asian Dust Aerosol and Its Trans-Pacific Transport. Part II: Interannual Variability and Climate Connections

Journal of Climate ◽

10.1175/jcli3606.1 ◽

2006 ◽

Vol 19 (1) ◽

pp. 104-122 ◽

Cited By ~ 86

Author(s):

S. L. Gong ◽

X. Y. Zhang ◽

T. L. Zhao ◽

X. B. Zhang ◽

L. A. Barrie ◽

...

Keyword(s):

Interannual Variability ◽

El Niño ◽

North China ◽

El Nino ◽

Asian Dust ◽

Dust Aerosol ◽

The North ◽

Source Regions ◽

The Pacific ◽

Dust Loading

Abstract A 44-yr climatology of spring Asian dust aerosol emission, column loading, deposition, trans-Pacific transport routes, and budgets during 1960–2003 was simulated with the Northern Aerosol Regional Climate Model (NARCM). Interannual variability in these Asian dust aerosol properties simulated by the model and its climate connections are analyzed with major climatic indices and records in ground observations. For dust production from most of the source regions, the strongest correlations were with the surface wind speed in the source region and the area and intensity indices of the Asian polar vortex (AIAPV and IIAPV, respectively). Dust emission was negatively correlated with precipitation and surface temperatures in spring. The strength of the East Asian monsoon was not found to be directly related to dust production but rather with the transport of dust from the Asian subcontinent. The interannual variability of dust loading and deposition showed similar relations with various climate indices. The correlation of Asian dust loading and deposition with the western Pacific (WP) pattern and Atmospheric Circulation Index (ACI) exhibited contrasting meridional and zonal distributions. AIAPV and IIAPV were strongly correlated with the midlatitude zonal distribution of dust loading and deposition over the Asian subcontinent and the North Pacific. The Pacific–North American (PNA) pattern and Southern Oscillation index (SOI) displayed an opposite correlation pattern of dust loading and deposition in the eastern Pacific, while SOI correlated significantly with dust loading over eastern China and northeast Asia. The Pacific decadal oscillation (PDO) was linked to variations of dust aerosol and deposition not only in the area of the eastern North Pacific and North America but also in the Asian dust source regions. The anomalies of transport flux and its divergence as well as dust column loading were also identified for eight typical El Niño and eight La Niña years. A shift of the trans-Pacific transport path to the north was found for El Niño years, which resulted in less dust storms and dust loading in China. In El Niño years the deserts in Mongolia and western north China closer to the polar cold air regions contributed more dust aerosol in the troposphere, while in La Niña years the deserts in central and eastern north China far from polar cold regions provided more dust aerosol in the troposphere. On the basis of the variability of Asian dust aerosol budgets, the ratio of inflow to North America to the outflow from Asia was found to be correlated negatively with the PNA index and positively with the WP index.

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Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-15501-2016 ◽

2016 ◽

Vol 16 (24) ◽

pp. 15501-15516 ◽

Cited By ~ 25

Author(s):

Jianrong Bi ◽

Jianping Huang ◽

Brent Holben ◽

Guolong Zhang

Keyword(s):

Optical Properties ◽

Climate Models ◽

Complex Refractive Index ◽

Asian Dust ◽

Global Climate Models ◽

Dust Aerosol ◽

Asymmetry Factor ◽

Anthropogenic Aerosol ◽

Sensing Applications ◽

Central Asian

Abstract. Asian dust particulate is one of the primary aerosol constituents in the Earth–atmosphere system that exerts profound influences on environmental quality, human health, the marine biogeochemical cycle, and Earth's climate. To date, the absorptive capacity of dust aerosol generated from the Asian desert region is still an open question. In this article, we compile columnar key absorption and optical properties of mineral dust over East and Central Asian areas by utilizing the multiyear quality-assured datasets observed at 13 sites of the Aerosol Robotic Network (AERONET). We identify two types of Asian dust according to threshold criteria from previously published literature. (1) The particles with high aerosol optical depth at 440 nm (AOD440 ≥  0.4) and a low Ångström wavelength exponent at 440–870 nm (α < 0.2) are defined as Pure Dust (PDU), which decreases disturbance of other non-dust aerosols and keeps high accuracy of pure Asian dust. (2) The particles with AOD440 ≥  0.4 and 0.2 < α < 0.6 are designated as Transported Anthropogenic Dust (TDU), which is mainly dominated by dust aerosol and might mix with other anthropogenic aerosol types. Our results reveal that the primary components of high AOD days are predominantly dust over East and Central Asian regions, even if their variations rely on different sources, distance from the source, emission mechanisms, and meteorological characteristics. The overall mean and standard deviation of single-scattering albedo, asymmetry factor, real part and imaginary part of complex refractive index at 550 nm for Asian PDU are 0.935 ± 0.014, 0.742 ± 0.008, 1.526 ± 0.029, and 0.00226 ± 0.00056, respectively, while corresponding values are 0.921 ± 0.021, 0.723 ± 0.009, 1.521 ± 0.025, and 0.00364 ± 0.0014 for Asian TDU. Aerosol shortwave direct radiative effects at the top of the atmosphere (TOA), at the surface (SFC), and in the atmospheric layer (ATM) for Asian PDU (α < 0.2) and TDU (0.2 < α < 0.6) computed in this study, are a factor of 2 smaller than the results of Optical Properties of Aerosols and Clouds (OPAC) mineral-accumulated (mineral-acc.) and mineral-transported (mineral-tran.) modes. Therefore, we are convinced that our results hold promise for updating and improving accuracies of Asian dust characteristics in present-day remote sensing applications and regional or global climate models.

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Optical properties of Asian dust aerosol by SeaWiFS and contemporaneous ground observation data

10.1117/12.509460 ◽

2003 ◽

Author(s):

Hiroshi Kobayashi ◽

Hajime Fukushima ◽

Toshiyuki Murayama ◽

Yuichiro Hagihara ◽

Sachio Ohta

Keyword(s):

Optical Properties ◽

Asian Dust ◽

Dust Aerosol ◽

Observation Data ◽

Ground Observation

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Air Quality in East Asia during the heavy haze event period of 10 to 15 January 2013

International Journal of Energy and Environment ◽

10.46300/91012.2021.15.1 ◽

2021 ◽

Vol 15 ◽

pp. 1-9

Author(s):

Soon-Ung Park ◽

Jeong Hoon Cho

Keyword(s):

Eastern China ◽

Northern China ◽

Asian Dust ◽

Dust Aerosol ◽

Anthropogenic Aerosols ◽

The Public ◽

Inorganic Aerosols ◽

Source Regions ◽

Haze Event ◽

Aerosol Modeling

A prolonged heavy haze event that has caused for the Environmental Protection Bureau (EPB) in Beijing to take emergency measures for the protection of the public health and the reduction of air pollution damages in China has been analyzed with the use of the Aerosol modeling System (AMS) to identify causes of this event. It is found that the heavy haze event is associated with high aerosols and water droplets concentrations. These high aerosol concentrations are mainly composed of anthropogenic aerosols, especially secondary inorganic aerosols formed by gas-to-particle conversion of gaseous pollutants in the eastern part of China whereas those in the northeastern parts of China are composed of the mixture of the anthropogenic aerosols and the Asian dust aerosol originated from the dust source regions of northern China and Mongolia. These high aerosol concentrations are found to be subsequently transported to the downwind regions of the Korean Peninsula and Japan causing a prolonged haze event there. It is also found that the Asian dust aerosol originated from northern China and Mongolia and the anthropogenic aerosols produced by chemical reactions of pollutants in the high emissions region of eastern China can cause significantly adverse environmental impacts in the whole Asian region by increased atmospheric aerosol loadings that may cause respiration diseases and visibility reduction and by excess deposition of aerosols causing adverse impacts on terrestrial and marine eco-systems.

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