Enhanced Simulation of an Asian Dust Storm by Assimilating GCOM-C Observations

Dust aerosols have great effects on global and regional climate systems. The Global Change Observation Mission-Climate (GCOM-C), also known as SHIKISAI, which was launched on 23 December 2017 by the Japan Aerospace Exploration Agency (JAXA), is a next-generation Earth observation satellite that is used for climate studies. The Second-Generation Global Imager (SGLI) aboard GCOM-C enables the retrieval of more precious global aerosols. Here, the first assimilation study of the aerosol optical thicknesses (AOTs) at 500 nm observed by this new satellite is performed to investigate a severe dust storm in spring over East Asia during 28–31 March 2018. The aerosol observation assimilation system is an integration of the four-dimensional local ensemble transform Kalman filter (4D-LETKF) and the Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) coupled with the Non-Hydrostatic Icosahedral Atmospheric Model (NICAM). Through verification with the independent observations from the Aerosol Robotic Network (AERONET) and the Asian Dust and Aerosol Lidar Observation Network (AD-Net), the results demonstrate that the assimilation of the GCOM-C aerosol observations can significantly enhance Asian dust storm simulations. The dust characteristics over the regions without GCOM-C observations are better revealed from assimilating the adjacent observations within the localization length, suggesting the importance of the technical advances in observation and assimilation, which are helpful in clarifying the temporal–spatial structure of Asian dust and which could also improve the forecasting of dust storms, climate prediction models, and aerosol reanalysis.

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The impact of dust on sulfate aerosol, CN and CCN during an East Asian dust storm

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-365-2010 ◽

2010 ◽

Vol 10 (2) ◽

pp. 365-382 ◽

Cited By ~ 76

Author(s):

P. T. Manktelow ◽

K. S. Carslaw ◽

G. W. Mann ◽

D. V. Spracklen

Keyword(s):

Dust Storm ◽

East Asian ◽

Asian Dust ◽

Dust Storms ◽

Sulfate Aerosol ◽

Previous Model ◽

Condensation Nuclei ◽

Asian Dust Storm ◽

The Impact ◽

Mass Concentrations

Abstract. A global model of aerosol microphysics is used to simulate a large East Asian dust storm during the ACE-Asia experiment. We use the model together with size resolved measurements of aerosol number concentration and composition to examine how dust modified the production of sulfate aerosol and the particle size distribution in East Asian outflow. Simulated size distributions and mass concentrations of dust, sub- and super-micron sulfate agree well with observations from the C-130 aircraft. Modeled mass concentrations of fine sulfate (Dp<1.3 μm) decrease by ~10% due to uptake of sulfur species onto super-micron dust. We estimate that dust enhanced the mass concentration of coarse sulfate (Dp>1.0 μm) by more than an order of magnitude, but total sulfate concentrations increase by less than 2% because decreases in fine sulfate have a compensating effect. Our analysis shows that the sulfate associated with dust can be explained largely by the uptake of H2SO4 rather than reaction of SO2 on the dust surface, which we assume is suppressed once the particles are coated in sulfate. We suggest that many previous model investigations significantly overestimated SO2 oxidation on East Asian dust, possibly due to the neglect of surface saturation effects. We extend previous model experiments by examining how dust modified existing particle concentrations in Asian outflow. Total particle concentrations (condensation nuclei, CN) modeled in the dust-pollution plume are reduced by up to 20%, but we predict that dust led to less than 10% depletion in particles large enough to act as cloud condensation nuclei (CCN). Our analysis suggests that E. Asian dust storms have only a minor impact on sulfate particles present at climate-relevant sizes.

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A comprehensive characterisation of Asian dust storm particles: chemical composition, reactivity to SO<sub>2</sub>, and hygroscopic property

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-8899-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 8899-8925 ◽

Cited By ~ 2

Author(s):

Q. Ma ◽

Y. Liu ◽

C. Liu ◽

J. Ma ◽

H. He

Keyword(s):

Dust Storm ◽

Heterogeneous Reaction ◽

Cell Mass ◽

Asian Dust ◽

Dust Storms ◽

Source Distribution ◽

Dust Particles ◽

Uptake Coefficient ◽

Asian Dust Storm ◽

The Impact

Abstract. Mineral dust comprises of a significant fraction of the globe's aerosol loading. Yet it remains the largest uncertainty in future climate predictions due to the complexity in its components and physico-chemical properties. Multi-analysis methods, including SEM-EDX, FTIR, BET, TPD/mass, and Knudsen cell/mass, were used in the present study to characterise Asian dust storm particles. The morphology, element fraction, source distribution, true uptake coefficient of SO2 and hygroscopic behaviour were studied. The major components of Asian dust storm particles were found to consist of aluminosilicate, SiO2, and CaCO3, which were coated with organic compounds and inorganic nitrate. The dust storm particles have a low reactivity to SO2 (true uptake coefficient of 5.767×10−6) which limits the conversion of SO2 to sulfate during a dust storm period. The low reactivity also demonstrated that the heterogeneous reaction of SO2, in both dry and humid air conditions, had little effect on the hygroscopic behaviour of the dust particles. These results indicate that the impact of dust storms on atmospheric SO2 removal should not be overestimated.

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The impact of dust on sulfate aerosol, CN and CCN during an East Asian dust storm

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-14771-2009 ◽

2009 ◽

Vol 9 (4) ◽

pp. 14771-14823 ◽

Cited By ~ 2

Author(s):

P. T. Manktelow ◽

K. S. Carslaw ◽

G. W. Mann ◽

D. V. Spracklen

Keyword(s):

Dust Storm ◽

Cloud Condensation Nuclei ◽

East Asian ◽

Asian Dust ◽

Dust Storms ◽

Sulfate Aerosol ◽

Previous Model ◽

Asian Dust Storm ◽

The Impact ◽

Mass Concentrations

Abstract. A global model of aerosol microphysics is used to simulate a large East Asian dust storm during the ACE-Asia experiment. We use the model together with size resolved measurements of aerosol number concentration and composition to examine how dust modified the production of sulfate aerosol and the particle size distribution in East Asian outflow. Simulated size distributions and mass concentrations of dust, sub- and super-micron sulfate agree well with observations from the C-130 aircraft. Modelled mass concentrations of fine sulfate (Dp<1.3 μm) decrease by ~10% due to uptake of sulfur species onto super-micron dust. We estimate that dust enhanced the mass concentration of coarse sulfate (Dp<1.0 μm) by more than an order of magnitude, but total sulfate concentrations increase by less than 2% because decreases in fine sulfate have a compensating effect. Our analysis shows that the sulfate associated with dust can be explained largely by the uptake of H2SO4 rather than reaction of SO2 on the dust surface, which we assume is suppressed once the particles are coated in sulfate. We suggest that many previous model investigations significantly overestimated SO2 oxidation on East Asian dust, possibly due to the neglect of surface saturation effects. We extend previous model experiments by examining how dust modified existing particle concentrations in Asian outflow. Total particle concentrations modelled in the dust-pollution plume are reduced by up to 20%, but we predict that dust led to less than 10% depletion in particles large enough to act as cloud condensation nuclei. Our analysis suggests that E. Asian dust storms have only a minor impact on sulfate particles present at climate-relevant sizes.

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