Climate characteristics of dust aerosol and its transport in major global dust source regions

2020 ◽  
Vol 209 ◽  
pp. 105415
Author(s):  
Jie Xiong ◽  
Tianliang Zhao ◽  
Yongqing Bai ◽  
Yu Liu ◽  
Yongxiang Han ◽  
...  
Keyword(s):  
Dust Aerosol ◽  
Dust Source ◽  
Source Regions

scholarly journals Estimating radiative forcing efficiency of dust aerosol based on direct satellite observations: case studies over the Sahara and Taklimakan Desert

2021 ◽  
Vol 21 (15) ◽  
pp. 11669-11687
Author(s):  
Lin Tian ◽  
Lin Chen ◽  
Peng Zhang ◽  
Lei Bi
Keyword(s):  
Radiative Forcing ◽  
Complex Refractive Index ◽  
Satellite Observations ◽  
Dust Aerosol ◽  
Taklimakan Desert ◽  
Dust Source ◽  
Dust Aerosols ◽  
Microphysical Properties ◽  
Source Regions ◽  
The Taklimakan Desert

Abstract. The direct radiative forcing efficiency of dust aerosol (DRFEdust) is an important indicator to measure the climate effect of dust. The DRFEdust is determined by the microphysical properties of dust, which vary with dust source regions. However, there are only sparse in situ measurements of them, such as the distribution of the dust aerosol particle size and the complex refractive index in the main dust source regions. Furthermore, recent studies have shown that the non-spherical effect of the dust particle is not negligible. The DRFEdust is often evaluated by estimating given microphysical properties of the dust aerosols in the radiative transfer model (RTM). However, considerable uncertainties exist due to the complex and variable dust properties, including the complex refractive index and the shape of the dust. The DRFEdust over the Taklimakan Desert and Sahara is derived from the satellite observations in this paper. The advantage of the proposed satellite-based method is that there is no need to consider the microphysical properties of the dust aerosols in estimating the DRFEdust. For comparison, the observed DRFEdust is compared with that simulated by the RTM. The differences in the dust microphysical properties in these two regions and their impacts on DRFEdust are analyzed. The DRFEdust derived from the satellite observation is -39.6±10.0 W m-2τ-1 in March 2019 over Tamanrasset in the Sahara and -48.6±13.7 W m-2τ-1 in April 2019 over Kashi in the Taklimakan Desert. According to the analyses of their microphysical properties and optical properties, the dust aerosols from the Taklimakan Desert (Kashi) scatter strongly. The RTM-simulated results (−41.5 to −47.4 W m-2τ-1 over Kashi and −32.2 to −44.3 W m-2τ-1 over Tamanrasset) are in good agreement with the results estimated by satellite observations. According to previous studies, the results in this paper are proven to be reasonable and reliable. The results also show that the microphysical properties of the dust can significantly influence the DRFEdust. The satellite-derived results can represent the influence of the dust microphysical properties on the DRFEdust, which can also validate the direct radiative effect of the dust aerosol and the DRFEdust derived from the numerical model more directly.

scholarly journals Variability in Dust Observed over China Using A-Train CALIOP Instrument

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hui Xu ◽  
Fengjie Zheng ◽  
Wenhao Zhang
Keyword(s):  
Soil Moisture ◽  
Correlation Coefficients ◽  
Dust Aerosol ◽  
Vegetation Coverage ◽  
Taklimakan Desert ◽  
Vertical Column ◽  
Dust Source ◽  
Dust Layer ◽  
Source Regions ◽  
Vertical Variations

Patterns of dust aerosol variation over China are analyzed using A-Train CALIOP and precipitation, soil moisture, and vegetation coverage datasets during the period of 2007 and 2014. Spatially, dust is mostly prominent over northwestern China, with the highest and most widespread dust activities being in Taklimakan Desert. Dust is generally distributed across the atmosphere up to 5 km altitude, with a peak of DAFOD around 3 km. The dust layer has a significant geographical and seasonal drifting, with higher altitude in spring and summer and dust source regions (between 3 km and 5 km). Additionally, single dust layer is more often observed in a vertical column. Temporally, high amounts of dust aerosol (C-DAFOD as high as 0.08) experienced in spring subsequently continuous decrease until the spring of next year. The correlation coefficients between the latitude averaged column integrated dust aerosol feature optical depth (C-DAFOD) and precipitation, soil moisture, and vegetation coverage are −0.65, −0.81, and −0.77, respectively. The correlation coefficients of seasonal mean C-DAFOD with the three factors are −0.15, −0.67, and −0.35, respectively. The analysis showed dust and the other three factors are negatively correlated. Overall, dust over China shows considerable spatial, temporal, and vertical variations.

Possible Explanation for Interannual Variations in Trans-Pacific Transport of East Asian Dust

2021 ◽  
Author(s):  
Mingxing Wang ◽  
Yiran Peng ◽  
Tianliang Zhao
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Western North Pacific ◽  
East Asian ◽  
Dust Emission ◽  
Asian Dust ◽  
Dust Aerosol ◽  
Interannual Variations ◽  
Dust Source ◽  
Source Regions

<p>East Asian dust aerosols prevail during spring season and transport cross Pacific Ocean. Satellite retrieval data show that dust AOD in downwind plume region over Pacific is significantly high and extends northward and eastward in 2003 comparing to 2002. In this study, we investigate the possible mechanism behind the differences in dust plume over Pacific by analyzing aerosol observations from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) and MISR (Multi-angle Imaging SpectroRadiometer) satellite platforms and ERA-Interim reanalysis data of meteorological fields. Firstly, we derive dust aerosol optical depth (AOD) in spring of 2002 and 2003 from MISR data by referring to the climatological mass ratio of dust to total aerosol from CALIPSO aerosol retrievals during 2007-2016. Second, we illustrate the axis of dust plume over Pacific by mimicking the center-of-gravity method for dust distribution, which clearly demonstrates that the axis shifts more northward and eastward and dust AOD is noticeably higher in April to May of 2003 than 2002. Thirdly, we look into the relationships between dust AOD and meteorological fields. Our results show that stronger surface wind speed in Northwest China (the source regions of East Asian dust) leads to higher dust emission in spring of 2003 than 2002. The updraft velocity in dust source regions is also stronger in 2003, which favors the uplifting of emitted dust. The precipitation over Pacific shows similar pattern between 2002 and 2003, indicating that wet deposition of dust has similar impacts on the dust aerosol transported cross Pacific Ocean. Lastly, we found that stronger southerly wind prevails over western North Pacific in May of 2003 than 2002, where negative vorticity is observed and might be related to certain features of Rossby wave. It is likely responsible for the northward axis of dust plume over Pacific. Therefore we conclude that the stronger and more easterly extended dust plume over Pacific Ocean in 2003 is resulted from excessive dust emission and stronger uplift in dust source regions of East Asia. The stronger southerly winds cause to the further northward axis of dust plume over western North Pacific. In the current stage, we extend the above investigation for the past two decades, to explain the interannual variations of East Asian dust related to emission in source regions, Trans-Pacific transport, meteorological fields and climatic indices.</p>

scholarly journals Seasonal provenance changes in present-day Saharan dust collected in and off Mauritania

2017 ◽  
Vol 17 (16) ◽  
pp. 10163-10193 ◽  
Author(s):  
Carmen A. Friese ◽  
Johannes A. van Hateren ◽  
Christoph Vogt ◽  
Gerhard Fischer ◽  
Jan-Berend W. Stuut
Keyword(s):  
Environmental Changes ◽  
Saharan Dust ◽  
Local Source ◽  
Trade Wind ◽  
Back Trajectory ◽  
Dust Source ◽  
Western Sahara ◽  
Source Areas ◽  
Source Regions ◽  
Dust Sources

Abstract. Saharan dust has a crucial influence on the earth climate system and its emission, transport and deposition are intimately related to, e.g., wind speed, precipitation, temperature and vegetation cover. The alteration in the physical and chemical properties of Saharan dust due to environmental changes is often used to reconstruct the climate of the past. However, to better interpret possible climate changes the dust source regions need to be known. By analysing the mineralogical composition of transported or deposited dust, potential dust source areas can be inferred. Summer dust transport off northwest Africa occurs in the Saharan air layer (SAL). In continental dust source areas, dust is also transported in the SAL; however, the predominant dust input occurs from nearby dust sources with the low-level trade winds. Hence, the source regions and related mineralogical tracers differ with season and sampling location. To test this, dust collected in traps onshore and in oceanic sediment traps off Mauritania during 2013 to 2015 was analysed. Meteorological data, particle-size distributions, back-trajectory and mineralogical analyses were compared to derive the dust provenance and dispersal. For the onshore dust samples, the source regions varied according to the seasonal changes in trade-wind direction. Gibbsite and dolomite indicated a Western Saharan and local source during summer, while chlorite, serpentine and rutile indicated a source in Mauritania and Mali during winter. In contrast, for the samples that were collected offshore, dust sources varied according to the seasonal change in the dust transporting air layer. In summer, dust was transported in the SAL from Mauritania, Mali and Libya as indicated by ferroglaucophane and zeolite. In winter, dust was transported with the trades from Western Sahara as indicated by, e.g., fluellite.

scholarly journals CUACE/Dust – an integrated system of observation and modeling systems for operational dust forecasting in Asia

2007 ◽  
Vol 7 (4) ◽  
pp. 10323-10342 ◽  
Author(s):  
S. L. Gong ◽  
X. Y. Zhang
Keyword(s):  
East Asia ◽  
Atmospheric Chemistry ◽  
Monitoring Network ◽  
Integrated System ◽  
Dust Aerosol ◽  
China Meteorological Administration ◽  
Source Regions ◽  
Operational Forecasts ◽  
Forecasting System ◽  
Aerosol Module

Abstract. An integrated sand and dust storm (SDS) forecasting system – CUACE/Dust (the Chinese Unified Atmospheric Chemistry Environment for Dust) has been developed, which consists of a comprehensive dust aerosol module with emission, dry/wet depositions and other atmospheric dynamic processes, and a data assimilation system (DAS) using observational data from the CMA (China Meteorological Administration) ground dust monitoring network and retrieved dust information from a Chinese geostationary satellite – FY-2C. This is the first time that a combination of surface network observations and satellite retrievals of the dust aerosol has been successfully used in the real time operational forecasts in East Asia through a DAS. During its application for the operational SDS forecasts in East Asia for spring 2006, this system captured the major 31 SDS episodes observed by both surface and satellite observations. Analysis shows that the seasonal mean threat score (TS) for 0–24 h forecast over the East Asia in spring 2006 increased from 0.22 to 0.31 by using the DAS, a 41% enhancement. The time series of the forecasted dust concentrations for a number of representative stations for the whole spring 2006 were also evaluated against the surface PM10 monitoring data, showing a very good agreement in terms of the SDS timing and magnitudes near source regions where dust aerosols dominate. This is a summary paper for a special issue of ACP featuring the development and results of the forecasting system.

scholarly journals Identification and Characterization of Dust Source Regions Across North Africa and the Middle East Using MISR Satellite Observations

2018 ◽  
Vol 45 (13) ◽  
pp. 6690-6701 ◽  
Author(s):  
Yan Yu ◽  
Olga V. Kalashnikova ◽  
Michael J. Garay ◽  
Huikyo Lee ◽  
Michael Notaro
Keyword(s):  
Middle East ◽  
North Africa ◽  
Satellite Observations ◽  
Dust Source ◽  
Source Regions ◽  
Identification And Characterization

scholarly journals Performance of KMA-ADAM3 in Identifying Asian Dust Days over Northern China

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 593
Author(s):  
Sang-Boom Ryoo ◽  
Jinwon Kim ◽  
Jeong Hoon Cho
Keyword(s):  
Dust Emission ◽  
Northern China ◽  
Asian Dust ◽  
Probability Of Detection ◽  
Soil Types ◽  
Dust Source ◽  
Aerosol Model ◽  
Dust Generation ◽  
Source Regions ◽  
Dust Events

Recently, the Korea Meteorological Administration developed Asian Dust Aerosol Model version 3 (ADAM3) by incorporating additional parameters into ADAM2, including anthropogenic particulate matter (PM) emissions, modification of dust generation by considering real-time surface vegetation, and assimilations of surface PM observations and satellite-measured aerosol optical depth. This study evaluates the performance of ADAM3 in identifying Asian dust days over the dust source regions in Northern China and their variations according to regions and soil types by comparing its performance with ADAM2 (from January to June of 2017). In all regions the performance of ADAM3 was markedly improved, especially for Northwestern China, where the threat score (TS) and the probability of detection (POD) improved from 5.4% and 5.5% to 30.4% and 34.4%, respectively. ADAM3 outperforms ADAM2 for all soil types, especially for the sand-type soil for which TS and POD are improved from 39.2.0% and 50.7% to 48.9% and 68.2%, respectively. Despite these improvements in regions and surface soil types, Asian dust emission formulas in ADAM3 need improvement for the loess-type soils to modulate the overestimation of Asian dust events related to anthropogenic emissions in the Huabei Plain and Manchuria.

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