Heavy Dust Storm Research Articles

Performance Evaluation of mm-Wave Based System in GFDM- 5G and Beyond Channel Model with Dust Storm Scenario

Telecommunication has made tremendous improvements in terms of bandwidth, requiring good frequency location, high data rates, and wideband spectrum availability. One solution to these requirements is the millimeter wave frequency band of 30 GHz. However, communication in this band is facing new challenges due to climate effects such as humidity, dust storms, and temperature. For fifth-generation (5G) mobile networks and beyond, Generalized Frequency Division Multiplexing (GFDM) has been proposed as a compelling candidate to substitute Orthogonal Frequency Division Multiplexing (OFDM). The GFDM's ability to adapt the block size and type of pulse shaping filters enables it to meet various crucial requirements, including low latency, low Out-Of-Band(OOB) radiation, and high data rates. This paper evaluated the overall GFDM performance and investigated the Bit Error Rate (BER) across a Rayleigh channel under various weather conditions. The simulation results show that GFDM outperforms the current OFDM candidate system. Also, GFDM offers better resistance to the Rayleigh channel with moderate and heavy dust storms in terms of BER.

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.

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

In order to address the growing demands for both enhanced security levels and increased transmission capacity, this research proposes a novel approach for free space optical (FSO) transmission. The proposed design incorporates an identity column shift matrix (ICSM) code to ensure robust security. Additionally, capacity enhancement is achieved through the utilization of a 4-level quadrature amplitude modulation (4-QAM) scheme in conjunction with an orthogonal frequency division multiplexing (OFDM) modulator. The performance of the system is evaluated across three channels, each transmitting data at a rate of 20 Gb/s, while operating in an FSO channel that is subjected to varying atmospheric attenuation effects and atmospheric turbulence. Real meteorological data from three different cities [Alexandria, Egypt; Jeddah, Kingdom of Saudi Arabia (KSA); and Hyderabad, India], situated across two continents, are incorporated to demonstrate the practicality of implementing the proposed model in real-world environments. The experimental results reveal that an increase in atmospheric turbulence leads to a higher bit error rate (BER) and lower received optical power (ROP), resulting in degraded data reception. Furthermore, the study examines the impact of weather conditions, indicating that the longest and shortest propagation ranges of 12.5 and 0.286 km, respectively, are achieved under clear weather and heavy dust storms. These conditions yield an ROP of −9.5 dBm and a log (BER) of approximately −2.5. Conversely, in the presence of strong turbulence, the performance further deteriorates. The proposed model demonstrates its ability to transmit a message signal over a distance of 0.8375 km, with a log (BER) of −2.6 under weak atmospheric turbulence. However, under strong atmospheric turbulence at the same distance, the log (BER) increases to −0.5. Regarding specific cities, the FSO range for transmitting information signals is found to be 9.58 km in Jeddah, which decreases to 6.58 km in Alexandria and 5.17 km in Hyderabad due to the increased atmospheric attenuation in these cities.

Use of dens by the desert fox in the desertic environment

The study was carried out on the use of dens by the desert fox in the desertic environment at Jajiwal Dhora and Guda Bhakri study sites in Jodhpur district of Rajasthan. Dens played a vital role in protecting desert fox and their pups from adverse environmental conditions. During study period total 104 dens were recorded out of them, 42 were resting dens and 62 were breeding dens. At Jajiwal Dhora study site 72 dens were observed and at Guda Bhakari study site 32 dens were noted. The desert fox used the dens for pup rearing, resting and saving themselves from different climatic factors such as heavy rain, dust storms, warm air and coldness. Desert fox use the den according to the seasonal changes. Northern-facing dens were mainly used during summer, while southern-facing dens were used in winter. The rodents, birds and bushes dominated areas and agricultural fields were mainly preferred by the desert fox for digging the dens. Direct observation, questionnaire and interview methods were used for the investigation.

Hybrid Methods’ Integration for Remote Sensing Monitoring and Process Analysis of Dust Storm Based on Multi-Source Data

Dust storms are of great importance to climate change, air quality, and human health. In this study, a complete application frame of integrating hybrid methods based on multi-source data is proposed for remote sensing monitoring and process analysis of dust storms. In the frame, horizontal spatial distribution of dust intensity can be mapped by optical remote sensing products such as aerosol optical depth (AOD) from MODIS; the vertical spatial distribution of dust intensity by LIDAR satellite remote sensing products such as AOD profile from CALIPSO; geostationary satellite remote sensing products such as Chinese Fengyun or Japanese Himawari can achieve high-frequency temporal distribution information of dust storms. More detailed process analysis of dust storms includes air quality analysis supported by particulate matter (PM) data from ground stations and the dust emission trace and transport pathways from HYSPLIT back trajectory driven by meteorological data from the Global Data Assimilation System (GDAS). The dust storm outbreak condition of the source location can be proved by precipitation data from the WMO and soil moisture data from remote sensing products, which can be used to verify the deduced emission trace from HYSPLIT. The proposed application frame of integrating hybrid methods was applied to monitor and analyze a very heavy dust storm that occurred in northern China from 14–18 March 2021, which was one of the most severe dust storms in recent decades. Results showed that the dust storm event could be well monitored and analyzed dynamically. It was found that the dust originated in western Mongolia and northwestern China and was then transmitted along the northwest–southeast direction, consequently affected the air quality of most cities of northern China. The results are consistent with the prior research and showed the excellent potential of the integration of the hybrid methods in monitoring dust storms.

6G enabling FSO communication system employing integrated PDM-OAM-OCDMA transmission: impact of weather conditions inIndia.

Currently, free space optics (FSO) transmission has gained attention due to its capability to deliver high data rates with a high level of security. In addition, using multiplexing techniques with FSO makes it capable of handling the excessive increase in traffic data and supporting the 5G and 6G wireless network requirements. Accordingly, in this paper, a novel, to the best of our knowledge, FSO system integrating three multiplexing techniques-orbital angular momentum (OAM) (four OAM beams are used) polarization-division multiplexing (two polarization states are used), and optical code division multiple access (four channels assigned with permutation vector codes are used)-is proposed. Additionally, the effects of rainy, foggy, dusty weather and the real weather for four different Indian cities that have different geographical locations are studied and investigated. The system performance is evaluated based on the bit error rate (BER), quality factor (Q-factor), maximum FSO range, and eye diagram opening. The simulation results show successful transmission of 320Gbps overall capacity with a maximum achievable FSO range of 7km under clear weather. On the other hand, the shortest FSO range of 0.105km is achieved when there are heavy dust storms. As for the Indian cities, Srinagar (hilly area of India) achieves the shortest FSO link, which is 4.2km while the largest range of 7km is observed for Chennai city (coastal area of India). All these ranges are evaluated for a log(BER) value <-7. Consequently, this proposed transmission model is suggested for use in 6G applications of FSO communication systems.

6G Network Architecture Using FSO-PDM/PV-OCDMA System with Weather Performance Analysis

This paper presents a novel 160 Gbps free space optics (FSO) communication system for 6G applications. Polarization division multiplexing (PDM) is integrated with an optical code division multiple access (OCDMA) technique to form a PDM-OCDMA hybrid. There are two polarization states: one is X-polarization generated from adjusting the azimuthal angle of a light source at 0° while the other is Y-polarization which is generated by adjusting the azimuthal angle of a light source at 90°. Each polarization state is used for the transmission of four independent users. Each channel is assigned by permutation vector (PV) codes and carries 20 Gbps data. Four different weather conditions are considered for evaluating the performance of our proposed model. These weather conditions are clear air (CA), foggy conditions (low fog (LF), medium fog (MF), and heavy fog (HF)), dust storms (low dust storm (LD), moderate dust storm (MD), heavy dust storm (HD)), and snowfall (wet snow (WS) and dry snow (DS)). Bit error rate (BER), Q-factors, maximum propagation range, channel capacity, and eye diagrams are used for evaluating the performance of the proposed model. Simulation results assure successful transmission of 160 Gbps overall capacity for eight channels. The longest FSO range is 7 km which occurred under CA while the minimum is achieved under HD, which is 0.112 km due to large attenuation caused by HD. Within fog conditions, the maximum propagation distances are 1.525 km in LF, 1.05 km in MF, and 0.85 km in HF. Likewise, under WS and DS, the proposed system can support transmission distances of 1.15 km and 0.28 km, respectively. All these transmission distances are achieved at BER less than 10−5.

Characterizing a Heavy Dust Storm Event in 2021: Transport, Optical Properties and Impact, Using Multi-Sensor Data Observed in Jinan, China

On 15 March 2021, the strongest sandstorm of the last 10 years occurred in China. The MODIS, MPL lidar, EDM 180, ADI 2080 and Meteorological observation instruments were used to observe the dust in Jinan, China, while the HYSPLIT model was also employed to find the source. It was found that the dust originated from Mongolia and the Gobi desert and was transported to Jinan at night on 14th March, lasting until the 18th. Multi-layer dust was observed, of which the dust below the height of 1 km was strongest with the VDR about 0.2 and the maximum extinction coefficient up to 3 km−1. The values of AOD and AE were greater than 2 and less than 0.25, respectively. The mass concentrations of PM10 and PM2.5 increased rapidly, and were up to 573 µg/m3 and 3406 µg/m3, respectively. Additionally, the mass concentration ratio decreased rapidly, with a minimum of 17%. The particle size of the dust was mainly distributed between 0.58–6.50 micros due to larger particles increasing dramatically; simultaneously, both the proportion and the value for calcium ions in PM2.5 went up. The dust had an obvious impact on the vertical structure of the air temperature, resulting in occurrence of a strong inversion layer.

Dust Aerosol Vertical Profiles in the Hinterland of Taklimakan Desert During Summer 2019

Dust aerosol vertical profiles are very essential to accurately evaluate their climate forcing and trans-subcontinental transportation to downstream areas. We initiated a joint comprehensive field experiment to investigate the vertical profiles and optical characteristics of dust aerosol in the hinterland of Taklimakan Desert (TD) during summer 2019. After smoothing the raw signals, the CHM15k ceilometer could distinctly detect a moderate intensity of dust layer, cloud layer, and subsequent rainfall process. The results showed that dust events frequently occurred in TD during the entire period; the overall mean PM2.5, PM10, PM2.5/PM10, and Ångström exponent are 110.4 ± 121.0 μg/m3, 317.2 ± 340.0 μg/m3, 0.35 ± 0.07, and 0.28 ± 0.12, respectively, suggesting that dust particles are predominant aerosol types in TD. There was an obvious summertime dust stagnation layer persistently hanged over the desert at 1.5–3.0-km height. A deep and intense daytime convective structure was also detected by the ceilometer, with maximum aerosol mixing layer height of ∼3 km that appeared at 12:00 UTC, which was in favor of lifting the ground-generated dust particles into the upper atmosphere. The normalized range-corrected signal log10(RCS), aerosol extinction σ(z), and backscattering coefficient β(z) of the ceilometer were higher than 6.2, 0.5 km−1, and 0.01 km−1 sr−1 for heavy dust storms, respectively, and the corresponding vertical optical range was smaller than 1.0 km. The aerosol lidar ratio was equal to 50 sr, which was greatly different from those of clear-sky cases. The retrieved σ(z) values were about 2.0, 0.5, 0.14, and 0.10 km−1 at 200-m height, respectively, under strong dust storm, blowing dust, floating dust, and clear-sky conditions. This indicated that the aerosol extinction coefficients under dust events were about 3–10 times greater than those of clear-sky cases. The statistics of the aerosol optical parameters under different dust intensities in TD were very helpful to explore and validate dust aerosols in the application of climate models or satellite remote sensing.

Impact of dust radiation effect on simulations of temperature and wind – A case study in Taklimakan Desert

Dust significantly influences the radiation budget by absorbing and scattering solar radiation, changing the heating/cooling rates, and reducing radiation incoming to change the atmospheric thermal and dynamics conditions, this subsequently affects the accuracy of weather forecasting itself. However, the currently operational numerical models for weather prediction systems rarely consider dust aerosol's impact. Two sets of experiments based on the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) were conducted in this study to simulate a heavy dust storm (6–9 June 2020) over Taklimakan Desert while considering the radiative effects of dust (called DUST) and ignoring them (NoDUST). The simulations were associated with in-situ measurements and MODIS aerosol optical to evaluate the dust effect. The results show that the overestimation of SW radiation reduced significantly in DUST compared with NoDUST, dust-induced radiative forcing had a net warming effect on the atmosphere (47.8 W/m2) and a cooling effect on the surface (−62.6 W/m2). The surface radiation budget also improved in DUST, which accompanied the considerable reduction in SW radiation in the sensible heat flux to 57 W/m2, which was better agree with measurements. The interactions of dust radiation significantly adjusted the stability of the boundary layer and lowered its height. Further, the verification indicated that the warm biases in the 2 m temperature and the overestimation of wind speed reduced by 20.6% and 6.6%, respectively. The atmospheric temperature and wind speed in vertical dimension layers were verified by radio-sounding, indicating that the dust radiation effect helped to alleviate forecasting bias. Thus, the effect of dust radiation should be considered in the operational weather forecasting system to improve forecasting accuracy, particularly in arid and semi-arid areas dust-affected.

Characteristics of clouds, precipitation, and latent heat in midlatitude frontal system mixed with dust storm from GPM satellite observations and WRF simulations

A heavy dust storm originating in Mongolia and Inner Mongolia traveled to Northeast China and met a midlatitude frontal system on May 3, 2017. The potential ice nuclei (IN) effects of mineral dust aerosols on the vertical structure of clouds, precipitation, and latent heat (LH) were studied using Global Precipitation Mission (GPM) satellite observations and Weather Research and Forecasting (WRF) model simulations. The WRF simulations correctly captured the main features of the system, and the surface rain rate distribution was positively correlated with data retrieved from the GPM Microwave Imager. Moreover, the correlation coefficient increased from 0.31 to 0.54 with increasing moving average window size. The WRF-simulated rainfall vertical profiles are generally comparable to the GPM Dual-Frequency Precipitation Radar (DPR) observations, particularly in low layers. The joint probability distribution functions of the rain rate at different altitudes from the WRF simulation and GPM observations show high positive correlation coefficients of ~0.80, indicating that the assumptions regarding the raindrop size distribution in the WRF model and DPR retrieval were consistent. Atmospheric circulation analysis and aerosol optical depth observations from the Himawari-8 satellite indicated that the dust storm entered only a narrow strip of the northwest edge of the frontal precipitation system. The WRF simulations showed that in carefully selected areas of heavy dust, dust can enhance the heterogeneous ice nucleation process and increase the cloud ice, snowfall, high-altitude precipitation rate, and LH rate in the upper layers. This effect is significant at temperatures of −15 °C to −38 °C and requires dust number concentrations exceeding 10&lt;sup&gt;6&lt;/sup&gt; m&lt;sup&gt;−&lt;/sup&gt;&lt;sup&gt;3&lt;/sup&gt;. It is important to accurately classify the dusty region in this type of case study. In the selected vertical cross section, the WRF-simulated and DPR-retrieved LH have comparable vertical shapes and amplitudes. Both results reflect the structure of the tilted frontal surface, with positive LH above it and negative LH below it. The simulated area-averaged LH profiles show positive heating in the entire column, which is a convective-dominated region, and this feature is not significantly affected by dust. DPR-based LH profiles show stratiform-dominated or convective-dominated shapes, depending on the DPR retrieval product.

Terahertz wireless communications in space

The New Space Era has increased communication traffic in space by new space missions led by public space agencies and private companies. Mars colonization is also targeted by crewed missions in the near future. Due to increasing space traffic near Earth and Mars, the bandwidth is getting congested. Moreover, the downlink performance of the current missions is not satisfactory in terms of delay and data rate. Therefore, to meet the increasing demand in space links, Terahertz band (0.1-10 THz) wireless communications are proposed in this study. In line with this, we discuss the major challenges that the realization of THz band space links pose and possible solutions. Moreover, we simulate Mars-space THz links for the case of a clear Mars atmosphere, and a heavy dust storm to show that even in the worst conditions, a large bandwidth is available for Mars communication traffic.

Comparison of the influence of Martian and Earth's atmospheric environments on terahertz band electromagnetic waves

SummaryTerahertz waves have wide application prospects in space communication because of their strong penetration ability, wide band, and strong directional antenna. Therefore, it is necessary to study the propagation characteristics of terahertz waves in space, such as in the environment on Mars. In space near Mars, the terahertz link is mainly affected by the absorption attenuation of its atmosphere and the scatter attenuation of heavy dust storms. In this paper, the absorption of 0.1–1 THz waves in the Martian atmosphere is analyzed. The absorption coefficient is calculated based on the theory of atmospheric radiative transfer and the HITRAN database. The influence of temperature, pressure, and altitude on the absorption coefficient is analyzed, and the calculation results are compared with those of Earth's atmosphere. The size distribution of Martian dust particles is then fitted by lognormal distribution, and the transmission characteristics of terahertz waves with different wavelengths are studied based on Mie theory. The research results show the transparent window positions of the attenuation peaks of water vapor and oxygen, which are the main factors of atmospheric transmission attenuation in the 0.1–1 THz band. The attenuation of Martian dust is affected by the size parameter, and it decreases with the visibility of the dust storm. The results provide a reference for terahertz communications in a Martian atmospheric environment and clarify the range of Martian atmospheric fading and dust fading.

Шороон шуурга болох үеийн агаар мандлын тогтворшлын параметрүүд

Although many studies investigated the spatial distribution, duration and frequency of dust storm in Mongolia, there are a few studies were undertaken it in terms of physical process that underpinned the current study on the subject. The study examines whether it is possible to acquire the distribution of dust storms in a relatively simple way by estimating the atmospheric stability during a dust storm. In order to achieve the main purpose of the study, the atmospheric stability parameters such as Brunt-Vaisala frequency (N), Gradient Richardson Number (Ri), and Eady Growth Rate (σ_E) were evaluated on 3 different cases of heavy dust storms which are occurred from March to May 2020, covered almost all over Mongolia, using reanalysis data produced by the European Centre for Medium-Range Weather Forecasts and radiosonde data from “Dalanzadgad” an aerological station in Dalanzadgad, Umnugovi. Differential equations of N, Ri, and σ_E are solved using the finite difference method. The results of the study revealed that both Ri and σ_E stability parameters can be identified well the distribution of dust storm, while a linear relationship between a dust storm and N as well as the buoyancy component of Ri was not found. In addition, in the study, a simplified method to compute the Ri parameter based on power function was acquired by the wind shear. It was difficult to make statistical analyses in the results of the study based on few cases between March and May in 2020. Therefore, it is necessary to consider more cases in the future, to undertake statistical analysis.&#x0D; &#x0D; &#x0D;

New Gaussian Plume Equation for the Impacts of Dust Storms on Radionuclide Transport

ABSTRACT Potential impacts of dust storms on radionuclide atmospheric dispersion have been the focus of great attention lately by countries that opted to build nuclear power plants in arid regions. The Gaussian point source dispersion equations have been modified to incorporate the rate of scavenging of gaseous radioactive plumes emitted from nuclear power plants due to adsorption by nanoaerosols that come from dust storms. The radionuclide-nanoaerosol interaction has been built based on the flux-matching theory assumptions: the size of a particle has the same order of magnitude of the mean free path of the molecules of air, and the adsorption coefficient is time-dependent. A correction factor (λr) has been introduced to the Gaussian plume equation to represent the fraction of the remaining radionuclides in the atmosphere at any distance downwind. A case study involving iodine-131 was used to apply the modified equations and to estimate the correction factor for different dust storms. The fraction of the adsorbed radionuclides on the atmospheric nanoaerosols (1 – λr) varies from less than 0.1 during a dust storm that has a density of 10 µg m–3 to more than 0.9 during a heavy dust storm of 1000 µg m–3 of density. Therefore, 90 percent of the transported radionuclide plume can be adsorbed by the atmospheric nanoparticles during the heavy dust events, while less than 10 percent can be adsorbed on the atmospheric nanoaerosols in normal days. These findings pose new challenges since radionuclides can be carried by nanoaerosols to farther distances than what is normally expected.

In situ continuous observation of hourly elements in PM2.5 in urban beijing, China: Occurrence levels, temporal variation, potential source regions and health risks

Elements in fine particles (PM2.5) have adverse impacts on ecosystems and human health. Using an online multi-heavy metal analyzer, one-year continuous hourly measurements were performed for thirteen elements, namely, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Ba, Hg and Pb, from June 1, 2016, to May 31, 2017, in urban Beijing. The total concentrations of 13 elements were in the range of 114–136,574 ng/m3, with a mean concentration of 2534 ± 5563 ng/m3. The four dominated elements were K (900 ± 3554 ng/m3), Fe (738 ± 1485 ng/m3), Ca (493 ± 1473 ng/m3) and Zn (174 ± 189 ng/m3). The annual mean concentrations of Cr and As exceeded the guideline values of the World Health Organization and the Chinese National Ambient Air Quality Standard. In the absence of firework-burning episodes and heavy dust storms, K, Cr, Mn, Cu, Zn, As, Se, Hg and Pb showed higher concentrations in autumn and winter, whereas lower concentrations were observed in spring and summer. The higher concentrations of Ca, Fe, and Ba observed in spring were associated with the frequent occurrence of dust. All elements showed higher concentrations on weekends than on weekdays. The diel patterns of Fe, Ba, Ca, Cu, Zn, Ni and Mn showed higher concentrations during peak traffic periods, whereas those of As, Cr, Hg, K, Pb and Se showed lower concentrations in the daytime but higher ones in the nighttime. The potential source function (PSCF) identified that neighboring provinces were the major source regions for most elements, whereas Ni mainly came from Shandong and the eastern ocean in spring and summer. Health risks of PM2.5 elements (Cr, Mn, Ni, As, Ba and Pb) via the inhalation pathway were estimated. Mn (As) and As posed the highest noncarcinogenic and carcinogenic risks to human health, respectively. Overall, this work can provide more detailed information on the characteristics of elements for the science community and be used in other receptor modelling and health risk assessment studies.

Detection of New Dust Sources in Central/East Asia and Their Impact on Simulations of a Severe Sand and Dust Storm

AbstractInformation regarding dust concentrations and size distributions is very important for determining air quality and aerosol–radiation–cloud interactions. Only by using a correct erosion database can the sectional dust emission scheme resolve detailed size distributions and determine where and how dust will be emitted. In this paper, the bias and reasons for dust emission in China Meteorological Administration Unified Atmospheric Chemistry Environment–Dust, an operational dust forecasting model, are analyzed using a heavy sand and dust storm episode. We used 18 years of routine sand and dust storm phenomena recorded at meteorological stations to retrieve and update the desertification details in the MBA sectional dust emission scheme adopted in China Meteorological Administration Unified Atmospheric Chemistry Environment–Dust. New desertification details include decreased erodibility in the area adjacent to Uzbekistan, Turkmenistan, and southern Kazakhstan, where Kyzylkum, Karakum, and Aralkum are located in central Asia, and in the Chinese deserts of Onqin Daga, Mu Us, and Gurbantungut. New desertification also results in increased erodibility in northern Mongolia. Comparisons show that the new desertification database decreases overestimation of dust emission in central Asia, including western Mongolia. It improves the underestimation of dust emission in northern Mongolia and the Gobi desert in southeast Mongolia, and the Taklimakan desert in China. Consequently, it corrects the overestimated dust cloud in the source area and in areas impacted by dust transportation. The timing, quantitative mass concentrations, and dust size distributions determined here are all more reasonable and rational than those of the original case.

Radiative impact of a heavy dust storm over India and surrounding oceanic regions

Efficient management of frequently occurring destructive dust storms requires an in-depth understanding of the extent of impacts of such events. Due to limited availability of observational data, it is difficult to understand/estimate the impact of dust aerosols on the Earth's radiation budget in detail. This study, applies a regional model, Weather Research and Forecasting model with chemistry (WRF-Chem), to investigate the impact of an intense dust storm that originated over the Arabian peninsula during 01–02 April 2015 and transported towards the Indian subcontinent by the westerly winds. Two identical numerical experiments are designed, each for 15 days, one with and another without dust aerosols, to estimate the impact of the dust storm over the Indian subcontinent and adjoining regions. WRF-Chem model reproduced the spatial, temporal as well as the vertical distribution of dust plume reasonably well.Model results show significant changes in aerosol optical, physical and radiative properties due to the dominance of coarse mode aerosols in the atmosphere during the dust storm. Analysis of vertical profiles of particulate matter (PM10) concentration reveals the presence of dust aerosols extending from the surface to altitudes as high as 3–4 km during the dust storm period. The dust storm induced a cooling effect at the surface via reduction in shortwave (SW) radiative flux. A substantial decrease in temperature is also seen at 850 hPa due to dust, indicating a significant impact of dust layer on the atmospheric temperature profile. Atmospheric heating due to dust aerosols in the SW region is found to be compensated up to a large extent by longwave (LW) cooling effect of dust. The net dust induced radiative perturbation at the top of the atmosphere (TOA) over different regions is negative and varied from −2.49 to −0.34 Wm-2, while it is in the range of −0.62 to + 0.32 Wm-2 at the surface.

Mineralogical and Chemical Characterization of Settleable Dustfall in Sulaimani City, Kurdistan Region, Iraq

Airborne particulate matter has now become an important global environmental issue because of its many diverse effects on overall health and environmental degradation. Because of its unique complexity, solutions to this problem are challenging. The main objectives of this study were to assess the mineralogical composition and selected chemical properties of atmospheric settleable particulate materials from 15 locations in Sulaimani City, Kurdistan Region, Iraq, sampled between August 2009 and March 2010. In addition, representative samples from a heavy dust storm that affected the region on February 22, 2010, were collected from 3 locations within the city. Organic carbon, total carbonate (CaCO3 equivalent), and total free iron contents, along with pH, were determined in all samples. Mineralogical analysis of the collected samples was performed by x-ray diffraction. Carbonates made up the largest fraction of the identified minerals and were predominantly in an active form. The following abundant minerals occurred in all the studied dust samples in decreasing amounts: calcite, clay minerals, quartz, feldspar, and dolomite. The clay fraction was composed (in descending order of abundance) of palygorskite, illite, muscovite, chlorite, and smectite. Samples from the dust storm event contained gypsum minerals that were not present in the other samples and had the highest percentage of dolomite of all samples, indicating that settleable particulate matter from the meteorological dust storm had a different source than local dust.

Calipso recordings and monitoring dust storms over the open seas in south of the iran plateau

Open seas in the south of the Iran plateau are under the influence of heavy dust storms which are originating either from the Tigris and Euphrates basin, the Arabian Peninsula or Hamoun lake. We have used the recordings of the CALIPSO satellite to investigate the seasonal variations as well as the origins of the dust storms over the region. CALIPSO data set shows dust activities are frequent during May to September in the interested region and the Hamoun lake has considerable impacts on it.