Severe Dust Storm Research Articles

Spatial and Temporal Analysis of Severe Dust Storm in Iraq in May 2022

Dust storms are a common ecological occurrence in many world‘s countries, mainly in dry and semi-dry parts. Dust storms tremendously influence human health, the environment, the climate, and numerous social aspects. In this paper, spatial and temporal analysis, metrological triggers, and trajectory, dust exporting areas of a severe dust storm that occurred in Iraq on May 16, 2022, were investigated. The dust storm's backward trajectory was determined using HYSPLIT model, which is then compared with MODIS and Meteosat satellite images. The weather is then analyzed using the NCEP/NCAR Reanalysis model, and the approximate area of these sources was determined using Landsat 8 satellite image classification method. The results revealed that the HYSPLIT model trajectory of the dust storm agreed with MODIS and Meteosat satellite visuals. The primary dust storm sources and their areas are identified. The first source is from the shared border region between Syria (Rif-Dimasshq) and Jordan (north of Al-Ruwaished), with an area of about 775 km2. The second is from the northwestern regions of Iraq, specifically north of Anbar and south of Nineveh, with an area of about 905 km2.

Synoptic Conditions at Pressure Different Levels for the Dust Storm of May/ 2022 Over Iraq

This study examines the severe dust storm from May 12-16/2022,culminating on May 15, with a comprehensive analysis and explanation. The weather maps from the National Oceanic and Atmospheric Administration (NOAA) and the European Centre for Medium-Range Weather Forecasts (ECMWF) weather maps were used to identify systems and patterns that contributed to the storm's activity, continuity, and tracking as well as maps of pressure compounds and wind vectors in levels 1000 and 850 mbar that appear with the dust state for the same days accompanied by tracking patterns in the middle of the turbosphere 500 mbar to give a comprehensive analytical view of climate conditions at each level of pressure and higher systems supportive of their persistence on the surface. The northwesterly winds are the main factor that carries dust over long distances. The eastern desert in Syria, the Empty Quarter in the Kingdom of Saudi Arabia, the desert of western Iran, and the desert region of western Iraq are among the main sources of dust In its atmosphere. Based on weather maps of the surface and upper levels of storm days, the concentration of dust reached very high levels in Iraq's airspace and surrounding countries, including Egypt, Jordan, Lebanon, Palestine, and Syria. The intensity of the dust gradually decreased as the area was affected by wet westerly winds with relatively low temperatures and a relative increase in wind speeds due to the impact of the study area on the atmospheric decline centered around the Turkish island of Cyprus.

Morphology and chemical composition of mineral particles in a special dust storm with high relative humidity in North China

A special dust storm characterized by high PM10 mass concentrations (921.9 ± 632.3 μg m−3) and high relative humidity (RH; 60.1 % ± 11.1 %) was observed on March 22–24, 2023 at a coastal city of North China. Aerosol particles of PM10 were analyzed by a scanning electron microscope coupled with energy dispersive X-ray and an ion chromatograph. The results showed that individual mineral particles were dominated by clay minerals, followed by quartz, feldspar, and carbonate. Bulk water-soluble inorganic ions analysis showed that SO42- mass concentrations varied from 3.7 μg m−3 to 23.3 μg m−3 with an average value of 12.4 μg m−3. However, their mass ratios to PM10 were relatively stable, being 1.15–2.01 % with an average value of 1.49 % ± 0.25 %, similar to the value near the dust sources (Tengger Desert). Although S-containing individual mineral dust varied from 5.2 % to 70.7 %, the average weight ratio of S on individual mineral dust was 2.1 %, much lower than that of non-dust periods (11.0 %). The results suggested limited sulfate formation on mineral dust surfaces even under high RH. In contrast, NO3-, which was very limited in dust sources, varied from 0.21 % to 4.11 % of the total PM10 with an average value of 1.61 % ± 1.07 %. The research highlighted that nitrate formation has exceeded sulfate formation during severe dust storm episodes, which might because the atmospheric compositions in China have changed significantly with a high mass ratio of NO2/SO2 after the implementation of the strict emission control measures.

Long-range transport impact of a severe dust storm over the Yangtze River Basin region and its modeling sensitivity to dust emission scheme

Dust storms frequently occur in the spring over East Asia, affecting southern Mongolia and northeast China. An exceptionally powerful dust storm occurred in East Asia from March 14th to March 18th, 2021. To investigate the ability of climate models to simulate severe dust storms, we employed the Weather Research Forecast model coupled with chemistry (WRF-Chem) with Goddard Chemistry Aerosol Radiation and Transport (GOCART), SHAO and KOK dust emission schemes to simulate the evolution of this event and to characterize dust aerosols long-range transport. Results showed that this storm was caused by a Mongolian cyclone depicted at 850 hPa with a cold front, which swept dust aerosols southeastward across southern Mongolia to northeast China. Model evaluation with satellite-retrieved Aerosol Optical Depth (AOD) and observational PM10 concentrations revealed that the SHAO dust emission scheme performed better in simulating spatial and temporal distribution of AOD over the Gobi Desert (GD) but overestimated them over Taklimakan Desert (TD). In contrast, the GOCART dust emission scheme underestimated AOD over most areas except the Taklimakan Desert; the KOK dust emission scheme overestimated them over both TD and GD. Overall, the SHAO dust emission scheme had good performance in simulating the surface PM10 concentrations over the Yangtze River Basin (YRB) and depicted an increase in PM10 concentrations, which denoted the transport of dust aerosols over YRB. As a better description of the physical process of dust emission flux over the eastern region of the Gobi Desert, the SHAO dust emission scheme depicted well the spatial and temporal evolution of dust plume episodes, especially over northeast China and YRB. The significant differences in dust emission fluxes between the three dust emission schemes were attributed to the sensitivity of threshold friction velocity and erodibility factor. Thereunto, the SHAO dust emission scheme incorporated well soil particle size distribution and threshold velocity to produce the dust emission flux, which allowed higher dust emission flux over the eastern GD and under strong southwesterly transported dust aerosols to East Central China's region of North China Plain (NCP) and YRB. This study will help further the simulation of extreme dust events more accurately and the exploration of climate change's effect on dust events over East Asia.

Comparing annual extreme winds in Iran predicted by numerical weather forecasting and Gram-Charlier statistical model with meteorological observation data

Iran has been experiencing severe dust storms due to strong wind speeds that cause sand erosion. This erosion is particularly pronounced in the semi-arid and arid zones. Wind speed predictions using numerical weather forecasting (NWF) are indispensable; however, the applicability of NWF for predicting extreme annual wind speeds is not well known. To validate the NWF model, this study compared NWF-model-predicted 3-hour averaged wind speeds over one year and those observed at 390 weather stations. In addition, a statistical model was employed to estimate the probability densities of wind speeds for both the observational data and the NWF output. As an NWF model, the mesoscale Weather Research and Forecasting (WRF) model was utilized to simulate wind speeds. The results indicate that the observation data are consistent with the modeled datasets regarding the relationships among the mean, standard deviation, and skewness, whereas the WRF model tends to overestimate the mean wind speeds. In addition, the predictability of annual extreme wind speeds was determined using the peak factor. Moreover, skewness has emerged as an influential parameter for predicting extreme winds. Finally, the Gram-Charlier series model was utilized to estimate probability density functions of the wind speeds, demonstrating its effectiveness in capturing positively skewed distributions. The present analyses broaden the use of both NWF outputs and statistical methods to predict extreme wind speeds in Iran.

Association of Asian dust storms and PM2.5 with clinical visits for respiratory diseases in children

East Asia dust storms originated in China, bringing abundant suspended particulate matters (PMs), are investigated to examine the association between their arrivals and clinical visits for respiratory diseases (RCV – Respiratory disease Clinical Visit). Taiwan, located in the downwind with a well-documented health database from the National Health Insurance, is selected for the study. Children under the age of 17 years, because of their regular daily activities and outdoor exposures, who are diagnosed with respiratory disease, are our targeted population. We conducted a case-crossover design and used the conditional regression analysis to explore the relationship between the dust storms and RCV, for cases between 2000 and 2012, when severe dust storms were mostly recorded. In total, 2,253,092 patients were recruited. The analysis shows that the coming of dust storms significantly affects the condition of RCV in children. After adjusting for temperature, relative humidity, and air pollutant concentrations, dust storm in springtime is associated with an increase in RCV. In contrast, dust storm impact in wintertime is associated with a decrease in RCV. In addition, PM2.5 concentrations associated positively with RCV among children, especially in the southern region of Taiwan in springtime and in the central and southern regions of Taiwan in wintertime. In short, the results showed that the occurrence of dust storms affects the RCV in children. PM2.5 exposure is also responsible for the increase in children's RCV.

Dust storms from the Taklamakan Desert significantly darken snow surface on surrounding mountains

Abstract. The Taklamakan Desert (TD) is a major source of mineral dust emissions into the atmosphere. These dust particles have the ability to darken the surface of snow on the surrounding high mountains after deposition, significantly impacting the regional radiation balance. However, previous field measurements have been unable to capture the effects of severe dust storms accurately, and their representation on regional scales has been inadequate. In this study, we propose a modified remote-sensing approach that combines data from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite and simulations from the Snow, Ice, and Aerosol Radiative (SNICAR) model. This approach allows us to detect and analyze the substantial snow darkening resulting from dust storm deposition. We focus on three typical dust events originating from the Taklamakan Desert and observe significant snow darkening over an area of ∼ 2160, ∼ 610, and ∼ 640 km2 in the Tien Shan, Kunlun, and Qilian mountains, respectively. Our findings reveal that the impact of dust storms extends beyond the local high mountains, reaching mountains located approximately 1000 km away from the source. Furthermore, we observe that dust storms not only darken the snowpack during the spring but also in the summer and autumn seasons, leading to increased absorption of solar radiation. Specifically, the snow albedo reduction (radiative forcing) triggered by severe dust deposition is up to 0.028–0.079 (11–31.5 W m−2), 0.088–0.136 (31–49 W m−2), and 0.092–0.153 (22–38 W m−2) across the Tien Shan, Kunlun, and Qilian mountains, respectively. This further contributes to the aging of the snow, as evidenced by the growth of snow grain size. Comparatively, the impact of persistent but relatively slow dust deposition over several months during non-event periods is significantly lower than that of individual dust events. This highlights the necessity of giving more attention to the influence of extreme events on the regional radiation balance. This study provides a deeper understanding of how a single dust event can affect the extensive snowpack and demonstrates the potential of employing satellite remote sensing to monitor large-scale snow darkening.

Simulation and synoptic investigation of a severe dust storm originated from the Urmia Lake in the Middle East

Dried lake beds are one of the largest sources of dust in the world, causing environmental problems in the surrounding areas. In this study, the desiccated Urmia Lake was the primary source of dust for all nearby synoptic stations during the April 24-25, 2017 dust episode. Synoptic analysis revealed that the heavy dust storm was triggered by a strong Black Sea cyclone and a low-pressure system over central Iraq in conjunction with a vast high-pressure system. HYSPLIT-based trajectory analysis showed that high PM10 recorded over the Urmia Lake region on April 23-26, 2017, influenced western Azerbaijan, the south of the Caspian Sea, southwestern Kazakhstan, northwestern Uzbekistan, and western Turkmenistan. The dustiest air masses (PM10 > 400 µg m–3) affected the south of the Caspian Sea and western Azerbaijan. Furthermore, the WRF-Chem model was run to evaluate the spatial distribution of dust particles in the study region. The vertical profile revealed that the simulated dust concentration ascended to 5 km from the lake. The WRF-Chem dust schemes accurately simulated dust propagation and the vertical dust profile over Urmia Lake; however, the AFWA and GOCART dust schemes showed that PM10 fluctuating changes were earlier than the measured surface PM10 at five stations around Urmia Lake on April 23-26, 2017. Furthermore, the maximum amount anticipated by the model simulation was 12 h earlier than the maximum surface mass concentration of measured PM10 at the stations throughout the period.

Observation and study of consecutive dust storms in the Taklimakan desert from March 16 to 27, 2022, using reanalysis models and lidar

A series of severe dust storms hit the Taklimakan desert between March 16 and 27, 2022, significantly deteriorating air quality throughout China. This study presents a comprehensive analysis of the vertical structure of aerosols during these dust storms, as well as their causes and impacts on China's regional and city-scale air quality, utilizing data from reanalysis models, coherent Doppler wind lidar, and air quality monitoring stations. During dust storms, intense wind layers increase dust emissions, resulting in reduced lidar detection ranges and signal strengths. In addition, lower temperatures prevail due to sunlight absorption and scattering. Moreover, high-speed winds at high altitudes increase dust particles that serve as cloud condensation nuclei, leading to increased humidity, decreased temperature, and precipitation. The Taklimakan desert's trough serves as a wind convergence zone, which promotes favorable conditions for the initiation of dust storms. Due to the steep pressure gradients, strong winds enter the Taklimakan desert through the gap between its mountains in the east, coming from northern Xinjiang and Inner Mongolia via the Hexi corridor, which facilitates the lifting and transport of dust aerosols. Dust is transported long distances from the Taklimakan desert to the eastern coasts, impacting numerous cities along the way. The emissions from these dust storms swept across most Chinese provinces. Even though each dust storm was over in the Taklimakan desert, its effects on China's air quality continued for several days. The coarse PM concentrations (PM10–2.5) in Hotan, Kashgar, Aksu, Korla, Hami, Xining, Yinchuan, Taiyuan, and Beijing spiked to levels around 14, 36, 11, 6, 7, 12, 11, 12, and 6 times higher than their 2022 averages, respectively. This study provides valuable insights into the causes and effects of the Taklimakan desert dust storms, helping authorities develop effective mitigation plans.

The effect of dust storms on air quality and public health in the city of Hillah

Dust storms, which have become frequent events, pose great risks to health and the environment. There are three factors responsible for generating them: strong winds, lack of rain, and lack of vegetation cover. AirQ+ software developed by the World Health Organization, was used to assess the health risks resulting from short-term exposure to PM2.5 measured using Continuous Particulate Monitor BAM-1020 for a period of two years from Jan 2021 to Jan 2023. The frequency and intensity of dust storms were recorded during the summer and spring of 2022, with high concentrations. The concentrations of the pollutant PM2.5 range during storm days (213.89 - 674.48 μg/m3), where short-term exposure causes an increase in the risk of respiratory illnesses and cardiovascular diseases. The most severe dust storms (674.48 μg/m3) caused a rise in the risk relative to 3.395 for respiratory diseases and 1.801 for cardiovascular disease. The great danger of dust storms is evident by comparing them with corresponding days for the year 2021, where the relative risk did not exceed 1.03for respiratory diseases and 1.01) for cardiovascular diseases. In general, air quality was classified using the concentrations obtained, where the concentrations of PM2.5 increased strongly, especially during the dry months, and the sand and dust storms that happened in 2022 caused the air quality to become dangerous by 2%, very unhealthy by 6%, and unhealthy by 8%. As for the other pollutants (SO2, NO2, and CO), they did not rise much beyond the allowable limit, and it has no direct relationship with dust storms, i.e. they did not increase with their increase. Several health and safety precautions and environmental control techniques can be used to lessen the effects of sand and dust storms. Although it is unreasonable to take action to stop or prevent widespread sand and dust storms from occurring, management measures can be taken to lessen their effects.

Trans-Boundary Dust Transport of Dust Storms in Northern China: A Study Utilizing Ground-Based Lidar Network and CALIPSO Satellite

During 14–16 March 2021, a large-scale dust storm event occurred in the northern region of China, and it was considered the most intense event in the past decade. This study employs observation data for PM2.5 and PM10 from the air quality monitoring station, the HYSPLIT model, ground-based polarized Lidar networks, AGRI payload data from Fengyun satellites and CALIPSO satellite Lidar data to jointly explore and scrutinize the three-dimensional spatial and temporal characteristics of aerosol transport. Firstly, by integrating meteorological data for PM2.5 and PM10, the air quality is assessed across six stations within the Lidar network during the dust storm. Secondly, employing a backward trajectory tracking model, the study elucidates sources of dust at the Lidar network sites. Thirdly, deploying a newly devised portable infrared 1064 nm Lidar and a pulsed 532 nm Lidar, a ground-based Lidar observation network is established for vertical probing of transboundary dust transport within the observed region. Finally, by incorporating cloud imagery from Fengyun satellites and CALIPSO satellite Lidar data, this study revealed the classification of dust and the height distribution of dust layers at pertinent sites within the Lidar observation network. The findings affirm that the eastward movement and southward compression of the intensifying Mongolian cyclone led to severe dust storm weather in western and southern Mongolia, as well as Inner Mongolia, further transporting dust into northern, northwestern, and northeastern parts of China. This dust event wielded a substantial impact on a broad expanse in northern China, manifesting in localized dust storms in Inner Mongolia, Beijing, Gansu, and surrounding areas. In essence, the dust emanated from the deserts in Mongolia and northwest China, encompassing both deserts and the Gobi region. The amalgamation of ground-based and spaceborne Lidar observations conclusively establishes that the distribution height of dust in the source region ranged from 3 to 5 km. Influenced by high-pressure systems, the protracted transport of dust over extensive distances prompted a gradual reduction in its distribution height owing to sedimentation. The comprehensive analysis of pertinent research data and information collectively affirms the precision and efficacy of the three-dimensional aerosol monitoring conducted by the ground-based Lidar network within the region.

The Lower Atmospheric Characteristics of Dust Storms Using Ground-Based Sensor Data: A Comparative Analysis of Two Cases in Jinan, China

Two severe dust storm (DS) events (15–17 March and 28–29 March) hit northern China in 2021 consecutively. The lower atmospheric vertical dynamic and thermal structures during the two cases were compared using the ground-based sensor data from the microwave radiometer and radar wind profiler, combined with the environmental and meteorological observations data in Jinan, China. It was found that both cases occurred under the background of cold vortexes over northeastern China. The dust was transported through the cold air on the northwest route. During the dust period, 2–3 km was the west or northwest airflow, and below 2 km was the northeast wind. The variation in the dynamic structure determined the duration of the DS. During the DS maintenance phase, the vertical wind shear (VWS) below 3 km measured approximately 10 m∙(s∙km)−1. The increased VWS during the dust intrusion period facilitated the transportation of dust. In contrast, the more significant VWS was not conducive to the maintenance of DS, and the shift to south wind control in the upper middle layer indicated the weakening of DS. In both cases, we observed a cliff-like decrease in relative humidity as a prominent indicator of dust outbreaks, occurring approximately 2–5 h beforehand. The diurnal difference between the vertical temperature and relative humidity during the dust maintenance period was found to be insignificant.

Atmospheric environment characteristic of severe dust storms and its impact on sulfate formation in downstream city

This study comprehensively investigated the impact of dust storms (DSs) on downstream cities, by selecting representative DS events. In this paper, we discussed the characteristics of meteorological conditions, air pollutants, PM2.5 components, and their influence on sulfate formation mechanisms. During DSs, strong winds, reaching speeds of up to 10 m/s, led to significant increases in PM10 and PM2.5, with maximum concentrations of 2684.5 and 429 μg/m3, respectively. Primary gaseous pollutants experienced substantial reductions, with decline rates of 48.1, 34.9, 36.8, and 9.0 % for SO2, NO2, NH3, and CO, respectively. Despite a notable increase in PM2.5 concentrations, only 7.6 % of the total mass of PM2.5 was attributed to ionic and carbonaceous components, a much lower value than observed before the DSs (77.3 %). Concentrations of Fe, Ti, and Mn exhibited increases by factors of 6.5–14.1, 10.4–17.0, and 1.6–4.7, respectively. In contrast to the significant decrease of >76.2 % in nitrogen oxidation ratio (NOR), sulfur oxidation ratio (SOR) remained at a relatively high level, displaying a strong positive correlation with high concentrations of Fe, Mn, and Ti. Quantitative analysis revealed an average increase of 0.187 and 0.045 μg/m3 in sulfate from natural sources and heterogeneous generation, respectively. The heterogeneous reaction on mineral dust was closely linked to atmospheric humidity, radiation intensity, the form of metal existence, and concentrations of it. High concentrations of titanium dioxide and iron‑manganese oxides in mineral dust promoted heterogeneous oxidation of SO2 through photocatalysis during the daytime and metal ion catalysis during the nighttime. This study establishes that the metal components in mineral dust promote heterogeneous sulfate formation, quantifies the yield of sulfate generated as a result, and provides possible mechanisms for heterogeneous sulfate formation.

Impact of a severe dust storm on aerosol properties and their radiative forcing over the Indian subcontinent during winter

The impact of a severe dust storm that originated over the Arabian Peninsula (AP) and travelled to the Indian subcontinent during 20–26 January 2022 is examined. According to the event's synoptic analysis, the Gulf of Oman, adjacent areas of Oman and Iran had strong mid-lower tropospheric westerlies because of the configuration of north-south cyclonic and anticyclonic circulation patterns generated by a sizable north-south pressure gradient. A strong westerly wind component continued down to surface level and brought large quantities of dust from the desert region of the Middle East to the Indian subcontinent. Overall, 90% of the monitoring locations over the Indian subcontinent (mostly the western region) exceeded the national tolerable level of 100 μg m−3 (PM10), with peaks as high as 650 μg m−3. Changes in optical and physical properties of aerosols varied in accordance with the dust loading, in which absorption aerosol optical depth denotes a 10% increase in absorbing aerosols. Due to the excessive cooling effect, the near-surface air temperature dropped by −6 °C from its daily climatology over a sizable zone of high aerosol loading. Additionally, the dust storm prolonged the winter's harshness by lowering temperatures (from pre-dust days) in some of the most severely afflicted areas to 10–12 °C. Changes in wind patterns at mid- and low levels have resulted in a temperature inversion (∼ 2.5 km), which prevented trapped dust particles from being diluted, which in turn increased the likelihood of a more significant decline in air quality and affecting human health/wealth.

Temporal evolution of dust in the atmosphere of Baluchestan, southeast Iran, studied by handheld sun-photometer, space-borne lidar, and synoptic data

The atmospheric aerosol parameters in the vicinity of Iranshahr County in Baluchestan, located in the southeast of Iran (27.00-27.40 °N, 60.09-61.09 °E), were investigated using a Calitoo handheld sunphotometer, space-borne CALIOP-CALIPSO lidar, and synoptic station measurements. The findings indicate the prevalence of dust aerosols throughout the year, with a pronounced presence during the summer season. The Aerosol Optical Depth (AOD), as determined by Calitoo measurements at 540 nm between April and October 2022, peaked in July with a maximum value of 0.63 ± 0.20. During this month, the Angstrom exponent reached the value of 0.44 ± 0.21, providing further evidence of severe dust storm activities in the region. An analysis of the level 2 aerosol profile data obtained from CALIOP measurements spanning a decade (2013-2022) has been presented. The results derived from the vertical profiles of extinction coefficient, depolarization ratio, and AODs are consistent with those measured by Calitoo. The monthly-averaged AOD at 532 nm exhibited its maximum and minimum values in July and January, registering at 0.83 ± 0.36 and 0.09 ± 0.13, respectively. As indicated by prior research, the primary atmospheric system responsible for dust events in the area is the north and northwesterly “120-days” or the Levar wind. Synoptic measurements of horizontal visibility indicated a significant reduction during the Levar wind period, which extends from April to late August.

The transboundary contribution of PM10 in Korea depended on the dipole surface temperature pattern in the East Asian region during April of 2021

During the spring of 2021, rapid surface cooling in the Arctic area expanded to most of the East Asian region, featuring surface-temperature dipole patterns of the colder west (Mongolia and northern-central China) and the warmer east (eastern-northeastern China, the Yellow Sea, and Korea). Despite the decreasing trend of dusty days within Korea, a notable rise in the occurrence of transboundary mineral dust-induced dusty days was observed in contributing to an increase in PM10 levels in the spring of 2021. This study investigated the PM10 source apportionment of anthropogenic dust, mineral dust, and biomass burning in the East Asian region and its transboundary impact on Korea, within the context of the surface-temperature dipole pattern observed in April of 2021. Source apportionment of PM10 was determined through a comparative analysis between baseline and sensitivity experiments conducted by means of a WRF-Chem simulation. In these sensitivity simulations, emissions from each source were systematically excluded to assess their individual contributions. PM10 Base refers to baseline simulations, PM10 Anthro to anthropogenic emissions, PM10 Dust to mineral dust, and PM10 Biomass to biomass burning. The colder west pattern was linked to increased synoptic-scale cyclonic activity, marked by higher positive potential vorticity, causing a sudden surge in severe dust storms over Mongolia and northern China. PM10 Base levels were most elevated in the higher terrain of Mongolia, comprising predominantly PM10 Dust (95%). However, the dominance of atmospheric-warming-induced anticyclones, represented by enhanced negative potential vorticity, prevailed over the lower terrain in the warmer east regions, obstructing the transboundary dispersion of PM10 Base to Korea. Nevertheless, Korea experienced a transboundary contribution of PM10 Dust, reaching 35%. In addition, the source apportionments indicated a PM10 Anthro ratio of 55% in eastern China and a PM10 Biomass ratio of 35% in northeastern China, contributing 25% and 5% respectively to Korea. During April 14–30, 2021, the dipole pattern evolved further to the significantly colder west (Mongolia and China) and the moderately warmer east (the Yellow Sea and Korea). The transboundary contributions of PM10 Anthro, PM10 Dust, and PM10 Biomass were intensified as a composite mixture within Korea, an outcome attributed to the intermittent cyclones and subsequent anticyclones.

Aeolian dust and hydro-biological characteristics: Decoding dust storm impacts on phytoplankton in the northern Arabian Gulf

Aeolian dust is an essential source of growth-limiting nutrients for marine phytoplankton. Despite being at the core of the Global Dust Belt, the response of the Arabian Gulf ecosystem to such atmospheric forcing is rarely documented. Here, the hydro-biological effect of mineral dust was studied in the northern Arabian Gulf (NAG) off Kuwait through monthly water sampling (December 2020 to December 2021), dust-storm follow-up sampling, and mineral dust and nutrient addition in-situ experiments. The multivariate analysis of oceanographic data revealed pronounced hydro-biological seasonality. The mineral dust deposition during two severe dust storm events in March and June 2021 showed a spatially varying effect of dust on coastal waters. The dust storms elevated the surface dissolved iron levels by several magnitudes, increased the dissolved inorganic nitrogen and phosphorous levels, changed their stoichiometry, and offset the hydrobiological seasonality. In the microcosms, dust input temporarily reduced phytoplankton phosphorous limitation in a dose-dependent manner when mesozooplankton (copepods) grazing was minimal. The microphytoplankton response to mineral dust inputs was comparable to that with nitrogen and phosphorous treatment. While Both treatments increased diatom size structure and biomass, the abundance of single-celled diatoms was comparatively higher in dust treatment. Multivariate analysis indicated that dust deposition alters the hydrographical properties of the surface ocean during dust storm events. The effects, though transient, were traceable for 3–16 days post-storm in coastal waters. The response of the summer phytoplankton to these changes, if delayed or muted, should be interpreted with caution given the summer water column stratification, the high nitrogen: phosphorous ratio and the low phosphorous solubility of aerosol dust, and the complex pelagic microbial food web interactions in the NAG. This study thus underlines the importance of a multivariate approach in documenting the ecological implications of Aeolian dust storms on marine environments closer to the dust source regions.

Study of the strongest dust storm occurred in Uzbekistan in November 2021

We studied and reconstructed a severe Central Asian dust storm of November 4, 2021, through high-resolution TROPOMI UVAI spaceborne observations, ground-based aerosol measurements, and Lagrangian particle modeling. The dust storm was caused by the front part of a cold polar anticyclone front from the Ural-Volga regions, which struck the central and eastern parts of Uzbekistan under favorable atmospheric conditions. Two plumes spread out, causing a thick haze to blanket the region. The most severe dust storm effects hit the capital of Uzbekistan (Tashkent) and the Fergana Valley, where the thick atmospheric dust layer dropped the visibility to 200 m. PM10 concentrations reached 18,000 µg/m3 (260-fold exceedance of the local long-term average). The PM2.5 concentrations remained above 300 µg/m3 for nearly ten days, indicating an extremely long-lasting event. The dust storm was caused by an extremely strong summer heatwave of 2021 in Kazakhstan with unprecedentedly high temperatures reaching 46.5 °C. The long-lasting drought dried up the soil down to 50 cm depth, triggering the soil cover denudation due to drying out vegetation and losing its moisture. This event was the worst since 1871 and considering the increasing aridity of Central Asia, the onset of potentially recurring severe dust storms is alarming.

Investigation of the characteristics of atmospheric and meteorological parameters of a severe dust storm in the Mumbai during January 2022

In recent years, India has experienced frequent dust storms, which have a significant impact on local climatic conditions. This research focuses on a significant dust storm event that took place in January 2022 across the Arabian Sea and its effects on the Mumbai region. The study utilizes a combination of ground-based measurements and satellite observations of optical parameters to investigate different atmospheric and meteorological parameters. The analysis of aerosol optical characteristics observed through Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI) data indicates significant variations during the dust storm day in comparison to pre- and post-dust storm days. There is a huge surge in the Aerosol Optical Depth (AOD) values Ångström Exponent (AE) values decrease. This confirms the presence of coarser particles in the affected region. The elevated values of the Aerosol Index (AI) on dusty days shows the presence of UV-absorbing aerosols. The ground-based measurements obtained by Central Pollution Control Board (CPCB) in the Mumbai region shows a rapid surge in the PM concentrations during the dust storm day. This study also highlights the change in the meteorological conditions associated with the occurrence of dust storm. The back trajectory analysis shows that most of the air-mass parcels transported from the Arabian Sea. The findings of this study collectively emphasize the substantial impact of dust storms on local atmospheric chemistry and the climatic system.

Sensitivity study and comparative evaluation of WRF-Chem over Iran: Available and embedded dust emission schemes

In this study, a severe dust storm has been simulated using the WRF-Chem model to investigate the accuracy of different dust emission schemes in estimating dust concentration in Tehran, the capital of Iran. First, by comparing the results of the GOCART, AFWA, UOC-2001, UOC-2004, and UOC-2011 dust emission schemes in WRF-Chem model, it is observed that the GOCART and AFWA schemes have the best performance compared to the in-situ measurements. The GOCART scheme with a better prediction of the trend of the dust concentration profile, and the AFWA scheme with a better prediction of the dust concentration peak value, are selected as the preferred schemes for this region. In the following, by using a two-way nested grid and embedding a new computational code for calculating the dust emission into the numerical model, an attempt has been made to increase the accuracy of the numerical model, especially in Tehran. Compared to the base model, the new dust emission scheme has decreased the overestimation of peak dust concentrations from observations by 24.9% and has enhanced the correlation coefficient by 0.12. Finally, by focusing on identifying dust sources, it is observed that external sources, namely Iraq and eastern Syria dry lands, have a significant influence on dust emissions. It is shown that the amount of mineral dust originating from these areas on February 20 and 21 is 1.5–1.9 Mg/km2. Also, the total dust particles lifted from the entire computing domain and Iran are 95.1 and 1.3 Tg, respectively.