Spring Dust Storm Research Articles

Influence of Spring Dust Storm on Atmospheric Particulate-Bound Mercury in a Typical Inland City of Northern China: Characteristics, Sources, and Risk Assessment

Influence of Spring Dust Storm on Atmospheric Particulate-Bound Mercury in a Typical Inland City of Northern China: Characteristics, Sources, and Risk Assessment

Quantifying the contribution of local drivers to observed weakening of spring dust storm frequency over northern China (1982–2017)

Recent studies have suggested that spring dust storm (SDS) events in northern China (NC) have exhibited substantial decline over the past 30 years. However, it is unclear which local factors are most responsible for the decline in SDS events, and the contribution of each dominant factor remains to be determined. This study utilized high-density DS records and collocated homogenized surface meteorological observations from 1982 to 2017, in conjunction with land surface products, to examine the local drivers that influence the long-term variation in SDS frequency (SDSF) over the entire NC area and its three dust-source areas: northwestern China (NWC), north-central China (NCC), and northeastern China (NEC). Results indicated that the observed SDSF averaged over NC, NWC, NCC, and NEC has decreased by 144.4 %, 109.3 %, 166.4 %, and 92.2 %, respectively, during 1982–2017. The variation in SDSF is largely explained by variation in wind speed (WS), precipitation, volumetric soil moisture, and surface bareness. A multivariable linear regression model incorporating these local drivers accounted for 81.0 %, 74.0 %, and 46.9 % of the variance in SDSF in NWC, NCC, and NEC, respectively. Statistical analyses on the local drivers suggested that weakening of WS was the dominant factor in the reduction in SDSF over recent decades, contributing 76.9 %, 54.7 %, and 33.6 % of the variation in NWC, NCC, and NEC, respectively. More importantly, we revealed that the interannual variation in regional SDSF was not only controlled by local drivers, but also influenced by cross-regional transport of dust aerosols emitted from upstream source areas.

Strong ozone intrusions associated with super dust storms in East Asia

As one of the largest dust source regions, China suffers from frequent dust storms in spring. During the super dust storm in March 2021, a rapid increase in nocturnal surface ozone concentration was observed along with elevated dust loading. Ground-based and satellite observations as well as reanalysis data of air quality and meteorology are integrated to shed light on the ozone anomaly. It is indicated that cold fronts and cyclones are conducive to both dust emissions and the downwards transport of stratospheric air, leading to simultaneously soaring ozone and particle concentrations near the surface. Statistically, in the past few years, under the influence of specific synoptic weather accompanied with Stratosphere-Troposphere Exchange (STE), dust was frequently uplifted to 8–12 km and the low-tropospheric ozone was elevated by approximately 6 ppb in northern China during spring dust storms. This work reveals strong ozone intrusions associated with dust storms, which have great impacts on atmospheric chemistry and regional climate.

Relationship between the East Atlantic teleconnection pattern and the spring dust storm in northern China. Part‐I: Impacts of components of the atmospheric circulation over Eurasia on dust storm dynamic power—Spring gales

AbstractSpring gale is a dynamic power for DSs (DSs), which presents a close connection with the DSs of northern China. Both display declining trends during the past 68 years (1954–2021). In this study, the influencing factors of spring gales and DSs around northern China and possible adjustment functions of the East Atlantic (EA) teleconnection pattern have been investigated. It was found that the major systems controlling spring gales include the North Polar vortex (NPV), mid–high‐latitude blocking highs (BHs), air pressure status of the Tibetan Plateau (TP) over the Eurasian continent, India–Burma trough (IBT) and western Pacific subtropical high (WPSH). Under synthetic atmospheric circulation conditions of an enlarged NPV, lower air pressure over the TP, a strong IBT, and a southeastward‐retreated WPSH, spring gales increase, and the frequency of DS occurrence is increased, and vice versa. Additionally, spring gales are also negatively affected by BHs. The most important is the Baikal BH, which has influence not only in previous seasons but also in the contemporary spring. Furthermore, the NPV and IBT have close negative correlation with the EA pattern, whereas the TP and WPSH have positive correlation with the EA pattern both in previous seasons and in the contemporary spring. A high‐pitched EA pattern results in a strong western current north of Lake Baikal, which may prohibit the expansion of the NPV in the sector of northern China. A shrunk NPV means infrequent cold air attacks and decreased gales and DSs.

Inverse modeling of the 2021 spring super dust storms in East Asia

Abstract. Last spring, super dust storms reappeared in East Asia after being absent for one and a half decades. The event caused enormous losses in both Mongolia and China. Accurate simulation of such super sandstorms is valuable for the quantification of health damage, aviation risks, and profound impacts on the Earth system, but also to reveal the climatic driving force and the process of desertification. However, accurate simulation of dust life cycles is challenging, mainly due to imperfect knowledge of emissions. In this study, the emissions that lead to the 2021 spring dust storms are estimated through assimilation of MODIS AOD and ground-based PM10 concentration data simultaneously. With this, the dust concentrations during these super storms could be reproduced and validated with concentration observations. The multi-observation assimilation is also compared against emission inversion that assimilates AOD or PM10 concentration measurements alone, and the added values are analyzed. The emission inversion results reveal that wind-blown dust emissions originated from both China and Mongolia during spring 2021. Specifically, 19.9×106 and 37.5×106 t of particles were released in the Chinese and Mongolian Gobi, respectively, during these severe dust events. By source apportionment it was revealed that the Mongolian Gobi poses more severe threats to the densely populated regions of the Fenwei Plain (FWP) and the North China Plain (NCP) located in northern China than does the Chinese Gobi. It was estimated that 63 % of the dust deposited in FWP was due to transnational transport from Mongolia. For NCP, the long-distance transport dust from Mongolia contributes about 69 % to the dust deposition.

Analysing the Pollutants Dispersion in Erbil City-Kurdistan with Support of Statistical Analysis.

Analysing the Pollutants Dispersion in Erbil City-Kurdistan with Support of Statistical Analysis.

Effect of Climate Change on Spring Massive Sand/Dust Storms in Iraq

Sand and Dust storms are considered a major natural disaster that cause many damages to society and environment in Iraq and surrounded deserted regions. Two spring sand/dust storms on May in two different years were synoptically analyzed. These sand/dust storms were compared in terms of dust surface concentration from NMMB/BSC-Dust model, sea level pressure, surface wind vector, satellite vegetation index and stations rainfall. The findings of this sand/dust storms comparison indicate that Iraq in spring may be affected by two types of wind one dust storm initiated by Shamal which have long occurred in this region and caused frequent dust storms in spring and second by Al-Khamsian. Dust storm in 2012 is massive than sand/dust storm in 2018 where the highest dust surface concentration is reached to (7700 μg/m3) in 22 May 2012 and about (3100 μg/m3) in 11 May 2018. Increase in vegetation cover over Iraq in 2018 was about 23% more than in 2012. Rainfall level in season (2017-2018) was higher than in rainfall season (2011-2012) in Iraqi dust sources regions. Low pressure gradient, less strong wind, rise in rainfall level and enhancement in vegetation cover are contributed to decrease the storm concentration of 2018 roughly by half.

Increasing spring dust storms in the future over the Taklimakan Desert, Northwest China: implications from changes in circulation pattern frequency in CMIP6

Dust storms over the Taklimakan Desert (TD), Northwest China, not only influence human health but also affect regional climate through direct effects of dust aerosols on solar and longwave radiation. The Coupled Model Intercomparisons Project Phase 5 (CMIP5) models project a decrease in dust storms because of a decrease in dust emissions over the TD in the future under warming scenarios. However, inaccurate simulations of dust emissions cause the CMIP5 models to simulate dust storms poorly. Here we analyzed typical circulation patterns that initiate dust storms over the TD and examined changes in the frequency of typical circulation patterns derived from the CMIP6 models in an extreme warming scenario. The results show that there will be an increase in typical circulation pattern frequency in the latter half of the 21st century compared with 1958–2014, implying an increase in dust storms over the TD in the future under the extreme warming scenario. The increase in dust storms over the TD may be related to an increase in synoptic activities in the future from the Middle Asia to the TD, which is caused by a southern movement of subtropical westerly jet stream under the extreme warming scenario.

Mineralogical similarities and differences of dust storm particles at Beijing from deserts in the north and northwest

Dust storm particles have been one of the important contributors to global aerosol loading, affecting human health and climate system. Beijing, a megapolitan city, experienced two severe dust storms in spring of 2015, with maximum hourly-mean PM10 mass concentrations exceeding 1000 μg/m3. The first dust storm (Dust 1) was from east area of Gobi Desert about 850 km in the north of Beijing and the second (Dust 2) was from west area of Gobi Desert about 1500 km in the northwest of Beijing. Morphologies and elemental compositions of dust particles were identified using high-resolution electron microscopy. The statistical analysis showed that the number fractions of mineral dust particles during the two dust storm episodes were 85.3% and 95.4%, respectively. Clay minerals were the most abundant among mineral particles, with a number fraction larger than 50%, followed by quartz particles (17.3% and 14.8%) and feldspar. Feldspar and carbonate particles accounted for 14.8% and 3.4% of mineral particles in Dust 1, and 9.9% and 13.6% in Dust 2, with the difference due to the different source areas. When the dust storms directly migrated to Beijing, the occurrence of S-containing mineral particles and the relative weight ratio of S in individual mineral particles were extremely low, indicating limited production of sulfate on the dust-storm particles in the atmosphere, regardless of the differences of source areas, migration paths, and mineralogical components. After the peaks of dust storms passed, the occurrence of S on the mineral particles were much higher, although the relative weight ratios of S in the mineral particles was still very small. This result suggests that most of the mineral particles underwent heterogeneous reactions, but the reaction rates were low.

Retrievals of aerosol layer height during dust events over the taklimakan and gobi desert

This study retrieves and evaluates aerosol layer height (ALH) during spring dust storm events observed over the Taklimakan and Gobi Desert. A novel strategy is proposed to identify single- or multi-layered aerosol scenarios in wide-swath passive sensor images from Ozone Mapping and Profiler Suite (OMPS) and Moderate Resolution Imaging Spectroradiometer (MODIS), aided by profiles of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and use different sets of look-up tables (LUTs) to retrieve ALH accordingly. The strategy combines the advantage of two independent methods–the ability to expand three-dimensional atmospheric structure using the spectral radiance matching (SRM) method, and the ability to estimate ALH over a long distance using the aerosol single-scattering albedo and height estimation (ASHE) method. From 2012 to 2016, ALH during 4 severe dust storms is retrieved over the Taklimakan and Gobi Desert. Analysis shows that the average height and occurrence frequency retrieved fall in the same range with results from previous studies. Comparisons with ALH inferred from CALIOP profiles indicate that the combined ASHE-SRM method has improved the overall performance. The estimated ALH correlates well (R = 0.68) with those measured by CALIOP, except for areas with potential cloud contamination, but slightly overestimated over the multi-layered area; the mean absolute difference (MAD) is 1.34±1.02 km. The reason of general overestimation is exanimated with a case study of dust storm occurred on April 23, 2012. With additional ALH information retrieved over broad area, the ASHE-SRM method has great potential to improving our understanding of aerosols and related impacts.

Climatology of Iraqi dust events during 1980–2015

Mesopotamia in Iraq is exposed to dust events of different intensity because of adjacent extended desert or semi-desert areas. This study investigates the spatial–temporal distributions of dust events (including suspended dust, rising dust and dust storms) in Iraq by analysing dust observations based on visibility from seven meteorological stations supplied by the Iraqi Meteorological Organization (IMO) during 1980–2015. The annual and seasonal evaluation of all dust event frequencies is examined. The findings show that Iraq has been exposed to the maximum number of dust events in spring and summer seasons over the past 35 years. The dust was more active in summer compared with other seasons for the northern region of Iraq, while the south and central parts of Iraq are exposed to the largest frequency of dust storms in spring and summer. The cities near desert areas (e.g. Nasiriya, Basra and Baghdad) suffer from the greatest frequency of dust storms compared to the northern and eastern regions. According to the annual average during 1980–2015, the frequency of major dust storm activity in Nasiriya was 7.8 days, in Baghdad 3.1 days) and in Basra 2.3 days. Suspended dust is more frequent in Iraq compared with rising dust or dust storms. There was a greater frequency of dust events associated with high temperatures and wind speeds in the central and southern areas during summer. All three types of dust events show similar time trend distributions with three periods: increased frequency of dust between 1980 and 1993, decreased frequency during 1993–2001 and increased again from 2001.

Forest Roles in Particle Removal during Spring Dust Storms on Transport Path.

The transpacific transport of mineral dust often occurs in spring, and a large amount of aeolian dust is deposited in the Asian continent and north Pacific. Moreover, a heterogeneous reaction occurs when dust particles are mixed with man-made pollution gases and particles. In the present study, atmospheric PM10 and PM2.5 concentrations were investigated, and a scanning electron microscope and an X-ray energy spectrometer were used to analyze the effects of dust resistance and capture by forests. It showed that (1) the PM2.5 and PM10 concentrations during a dust storm, on sunny days, and during light pollution periods, were higher in the non-forest covered area (NFC area) than in the forest covered area (FC area), except during heavy pollution events; which suggests that the forests have a strong effect on dust resistance; (2) the PM reduction efficiency of forests was highest on sunny days, followed by light pollution periods, heavy pollution periods, and during the dust storm; (3) after the dust storm, TSP captured by leaves significantly increased, especially for the broadleaved tree species; and the particulates number in the grooves on leaves’ surface increased particularly sharply. This study will help improve the dust resistance and retention efficiency of forest shelterbelt projects during dust storms.

Spatial analysis of spring dust storms hazard in Iran

In this research, monthly data on the frequency of dust storms of 44 synoptic stations of Iran during a 50-year period from 1968 to 2017 and methods of Ward’s hierarchical cluster analysis, linear regression, Mann–Kendall test, and kriging geostatistic were used. After calculating the frequency of occurrence of dust storms and its related statistical characteristics, suitable probability distribution function was fitted with dust storm data and then, using cluster analysis, the classification of different regions of the country into homogeneous groups was done and by using the kriging method, the zoning of dust storms was performed. After examining the descriptive statistics of spring dust storms in Iran, it was found that the probability distribution of dust storm data occurrence is proportional to the probability distribution of the normal 3-parameter log normal. According to the results of cluster analysis, different regions of the country were clustered into five homogeneous regions comprising of (1) southeast regions, (2) southern and central regions, (3) western regions, (4) eastern and middle regions, and (5) the northern regions. In investigating the trend of time variations of dust storms, it was revealed that the frequency time series of dust storms in Iran had an increasing trend and these results were confirmed by Mann–Kendall statistics. After zoning, it was found that the main focus of this phenomenon was concentrated in the southeast and southern parts of the country.

Occurrence and Reverse Transport of Severe Dust Storms Associated with Synoptic Weather in East Asia

The range and time of the environmental effects of Asian dust are closely dependent on the pathways and the speed of dust plume movement. In this study, the occurrence and movement of two dust storms in China in May 2017 were examined by using open space- and ground-based measurement data and the backward trajectories of dust plumes. Results from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data showed that the dust storms were caused by the rapid coupling development of Mongolian cyclones and Asian highs. After the dust plumes arrived at the Southeastern China in the first dust event, the stable weather conditions and the Asian high slowed down the movement of the plumes, leading to the gradual diffusion of dust particles. Moreover, the Asian high in the first event and the Huabei low (a low-pressure system in North China Plain) in the second altered the movement direction of the dust plumes from southward to northward, which we denote as the “dust reverse transport (DRT)”. The DRT occurred only within the lower troposphere even though dust plumes could extended to 5–10 km in vertical direction. Statistical results of 28 spring dust events occurred in 2015–2018 showed that all these dust storms were triggered by Mongolian cyclones and/or Asian highs, and approximately 39% moved as the DRT, indicating about one third of severe spring dust storms could influence larger areas or longer time than the remained ones.

Evolution of aerosol chemistry in Xi'an during the spring dust storm periods: Implications for heterogeneous formation of secondary organic aerosols on the dust surface

TSP and 9-stage size-segregated samples were simultaneously collected in Xi'an during the spring of 2013 and analyzed for organic aerosols (OA) on a molecular level. n-Alkanes were the dominant compound class during the whole campaign, followed by fatty acids. High molecular weight (HMW) n-alkanes and fatty acids dominated in the coarse mode particles (>1.1 μm) during the dust event, indicating they were mostly originated from surface soil and plants in the upwind regions. Low-volatile anthropogenic compounds such as benzo(e)pyrene (BeP) and bisphenol A (BPA) dominated in the fine mode particles during the whole campaign. In contrast, semi-volatile anthropogenic compounds such as phenanthrene (Phe) and di-n-butyl phthalates (DBP) showed a bimodal size distribution with a significant increase in the coarse mode during the dust event due to their vaporization from the fine mode particles and the subsequent adsorption on the dust surface. Secondary organic aerosols (SOA) in Xi'an during the dust storm period were predominantly enriched on the coarse particles, which can be ascribed to the adsorption and subsequent oxidation of gas-phase hydrophilic organics on the aqueous-phase of hygroscopic dust surface (e.g., mirabilite). Our work suggested an important role of multiphase reaction in evolution of aerosol chemistry during the dust long-range transport process.

Primary biogenic and anthropogenic sources of organic aerosols in Beijing, China: Insights from saccharides and n-alkanes

Sugars and n-alkanes are important organic constituents of atmospheric fine particulate matter (PM2.5). For better understanding their sources and seasonal variations in urban atmosphere, sugar compounds (anhydrosugars, sugars and sugar alcohols) and homologue n-alkanes (C18–C37) were studied in PM2.5 samples collected from September 2013 to July 2014 in Beijing, China. In general, all measured compounds showed the lowest levels in summer. Higher concentrations of sugar compounds and n-alkanes were observed in winter, probably due to elevated combustion emissions (e.g., coal, biofuel and agricultural residue burning) and stable meteorological conditions during heating season. Levoglucosan was the major sugar species in all seasons particularly in autumn and winter, highlighting the significant contribution of biomass burning to fine organic aerosols throughout the whole year especially in cold seasons. Plant waxes contributed to n-alkanes the most in late spring (54.5%) and the least in winter (11.6%); while fossil fuel combustion had the largest contribution in winter (385 ng m−3). The weak odd-carbon predominance of n-alkanes in wintertime aerosols also suggests fossil fuel combustion as the important source of organic aerosols in the heating season. Soil resuspension, fossil fuel combustion and biomass burning, and secondary sources are the main sources of OC in PM2.5 at Beijing. The seasonal variation in source contributions indicates that meteorological condition is a key factor in controlling PM2.5 levels. Furthermore, dust storms in spring can strongly enhance the atmospheric level of fine organic matter in Beijing.

Modeling of Atmospheric Regional Circulation for Event of Most Severe Spring Dust Storms on West of Iran

Modeling of Atmospheric Regional Circulation for Event of Most Severe Spring Dust Storms on West of Iran

Cycling and Budgets of Organic and Black Carbon in Coastal Bohai Sea, China: Impacts of Natural and Anthropogenic Perturbations

AbstractOrganic carbon (OC) cycling in coastal seas that connect terrestrial and open oceanic ecosystems is a dynamic and disproportionately important component of oceanic and global carbon cycles. However, OC cycling in coastal seas needs to be better constrained, particularly for geochemically important black carbon (BC). In this study, we conducted multimedium sampling campaigns, including atmospheric deposition, river water, seawater, and sediments in coastal Bohai Sea (BS) in China. We simultaneously quantified particulate OC (POC), particulate BC (PBC), dissolved OC (DOC), and dissolved BC (DBC) and investigated the cycling and budgets of OC and BC. The cycling and budgets of each individual particulate phase (i.e., POC versus PBC) and dissolved phase (i.e., DOC versus DBC) displayed similar patterns, but there were some distinct differences between the particulate and dissolved phases. In the particulate phases, atmospheric and riverine delivery dominated exogenous inputs (>80%), sequestration to sediments dominated removal (~70%), and exchanges in the Bohai Strait resulted in net export. In the dissolved phases, exchanges in the Bohai Strait dominated both import and export and were in a relatively dynamic equilibrium. We found that both natural perturbations, such as spring dust storms, and anthropogenic activity, exerted significant impacts on BS carbon cycling. The integration of regional and global source‐to‐sink process databases made it clear that future BC studies should calculate PBC and DBC fluxes independently. Continuous field observational studies, more details of the biogeochemical processes involved, and consistent BC quantification methods are urgently needed to elucidate coastal OC and BC cycling.

Short-term effects of air pollution on daily hospital admissions for cardiovascular diseases in western China

Controlling the confounding factors on cardiovascular diseases, such as long-time trend, calendar effect, and meteorological factors, a generalized additive model (GAM) was used to investigate the short-term effects of air pollutants (PM10, SO2, and NO2) on daily cardiovascular admissions from March 1st to May 31st during 2007 to 2011 in Lanzhou, a heavily polluted city in western China. The influences of air pollutants were examined with different lag structures, and the potential effect modification by dust storm in spring was also investigated. Significant associations were found between air pollutants and hospital admissions for cardiovascular diseases both on dust event days and non-dust event days in spring. Air pollutants had lag effects on different age and gender groups. Relative risks (RRs) and their 95% confidence intervals (CIs) associated with a 10μg/m3 increase were 1.14 (1.04~1.26) on lag1 for PM10, 1.31 (1.21~1.51) on lag01 for SO2, and 1.96 (1.49~2.57) on lag02 for NO2 on dust days. Stronger effects of air pollutants were observed for females and the elderly (≥60years). Our analysis concluded that the effects of air pollutants on cardiovascular admissions on dust days were significantly stronger than non-dust days. The current study strengthens the evidence of effects of air pollution on health and dust-exacerbated cardiovascular admissions in Lanzhou.

The dual effect of vegetation green-up date and strong wind on the return period of spring dust storms

Vegetation phenology changes have been widely applied in the disaster risk assessments of the spring dust storms, and vegetation green-up date shifts have a strong influence on dust storms. However, the effect of earlier vegetation green-up dates due to climate warming on the evaluation of dust storms return periods remains an important, but poorly understood issue. In this study, we evaluate the spring dust storm return period (February to June) in Inner Mongolia, Northern China, using 165 observations of severe spring dust storm events from 16 weather stations, and regional vegetation green-up dates as an integrated factor from NDVI (Normalized Difference Vegetation Index), covering a period from 1982 to 2007, by building the bivariate Copula model. We found that the joint return period showed better fitting results than without considering the integrated factor when the actual dust storm return period is longer than 2years. Also, for extremely severe dust storm events, the gap between simulation result and actual return period can be narrowed up to 0.4888years by using integrated factor. Furthermore, the risk map based on the return period results shows that the Mandula, Zhurihe, Sunitezuoqi, Narenbaolige stations are identified as high risk areas. In this study area, land surface is extensively covered by grasses and shrubs, vegetation green-up date can play a significant role in restraining spring dust storm outbreaks. Therefore, we suggest that Copula method can become a useful tool for joint return period evaluation and risk analysis of severe dust storms.