64 research outputs found
Numerical Simulation of Tehran Dust Storm on 2 June 2014: A Case Study of Agricultural Abandoned Lands as Emission Sources
No full textOn 2 June 2014, at about 13 UTC, a dust storm arrived in Tehran as a severe hazard that caused injures, deaths, failures in power supply, and traffic disruption. Such an extreme event is not considered as common for the Tehran area, which has raised the question of the dust storm’s origin and the need for increasing citizens’ preparedness during such events. The analysis of the observational data and numerical simulations using coupled dust-atmospheric models showed that intensive convective activity occurred over the south and southwest of Tehran, which produced cold downdrafts and, consequently, high-velocity surface winds. Different dust source masks were used as an input for model hindcasts of the event (forecasts of the past event) to show the capability of the numerical models to perform high-quality forecasts in such events and to expand the knowledge on the storm’s formation and progression. In addition to the proven capability of the models, if engaged in operational use to contribute to the establishment of an early warning system for dust storms, another conclusion appeared as a highlight of this research: abandoned agricultural areas south of Tehran were responsible for over 50% of the airborne dust concentration within the dust storm that surged through Tehran. Such a dust source in the numerical simulation produced a PM10 surface dust concentration of several thousand μm/m3, which classifies it as a dust source hot-spot. The produced evidence indivisibly links issues of land degradation, extreme weather, environmental protection, and health and safety.The study was initially proposed within the framework of the WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). For the conversion of the dust source mask of Iran into the geo-referenced, we thank Bojan Spasojevic and Dimitrije Kostic. The communications that allowed the interconnectivity of the researchers who contributed to this study were supported by InDust CA16202. The authors from Faculty of Agriculture, University of Belgrade, were supported for their scientific work in 2021 by the contract on financing between the Faculty of Agriculture and the Ministry of Education, Science and Technological Development of RS (451-03-9/2021-14/200116).Peer Reviewed"Article signat per 15 autors/es: Ana Vukovic Vimic , Bojan Cvetkovic,Theodore M. Giannaros, Reza Shahbazi,Saviz Sehat Kashani ,Jose Prieto ,Vassiliki Kotroni ,Konstantinos Lagouvardos ,Goran Pejanovic ,Slavko Petkovic ,Slobodan Nickovic ,Mirjam Vujadinovic Mandic ,Sara Basart ,Ali Darvishi Boloorani andEnric Terradellas "Postprint (published version
Saharan dust and ice nuclei over Central Europe
No full textSurface measurements of aerosol and ice nuclei (IN) at a Central European mountain site during an episode of dust transport from the Sahara are presented. Ice nuclei were sampled by electrostatic precipitation on silicon wafers and were analyzed in an isothermal static vapor diffusion chamber. The transport of mineral dust is simulated by the Eulerian regional dust model DREAM. Ice nuclei and mineral dust are significantly correlated, in particular IN number concentration and aerosol surface area. The ice nucleating characteristics of the aerosol as analyzed with respect to temperature and supersaturation are similar during the dust episode than during the course of the year. This suggests that dust may be a main constituent of ice nucleating aerosols in Central Europe
Remote Sensing and Modeling of Atmospheric Dust and Studying Its Impact on Environment, Weather, and Climate
No full textAn overview of the 2015 volume of Advances in Meteorology, which was co-edited by Chapman faculty member Dr. Hesham El-Askary
A hemispheric dust storm affecting the Atlantic and Mediterranean in April 1994: Analyses, modeling, ground‐based measurements and satellite observations
No full textOne of the largest recorded dust tranpsort events originating from the great Sahara desert during April 1994 affected the entire region extending from the Caribbean to the Eurasian continent. This hemispherical transport of airborne dust took place during a series of storms that developed during the first three weeks of April in a background of low-index circulation. These repeated events are studied through the combined analyses and interpretation of atmospheric data, ground-based aerosol measurements, visibility observations, AVHRR and Meteosat visible band satellite data, and the results of Eta model simulations, including an aerosol transport component. The observations produce a consistent picture of the temporal and spatial development of the dust events, whose main features are used in parts to verify the model results. The rate of dust suspension from some areas of the western Sahara desert exceeded 1.5 mg m(-2) h(-1) and the maximum column integrated dust load reached 2 g m(-2) during April 3-5 1994, when the first major suspension event produced two simultaneous pulses of dust moving in opposite directions across the subtropical Atlantic Ocean and the eastern Mediterranean Sea. These dust suspensions were created by surface winds resulting from subsidence on the northeastern side of a blocking anticyclone in the Atlantic region and subsequent winds of an intense developing cyclone in the Mediterranean-African region. In the following period, maximum dust loads of 4.5 and 2.5 g m(-2) occurred on April 12 and 17, respectively, when new cyclones transported dust across the Mediterranean from Africa to Europe. The generation of the two dust pulses during the first even and the recurrent cyclone transport in the following period is shown to be the result of a large-scale, anomalous atmospheric circulation connected with blocking in the Atlantic Ocean and the interactions of tipper air jets downstream of the blocking. The particular state of the hemispheric circulation during the studied period corresponded to the positive phase of the North Atlantic Oscillation (NAO). While previous statistical evidence has consistently linked dust transport in the region with the NAO signatures, we show the same connection on the basis of this case study
An illustration of the transport and deposition of mineral dust onto the eastern Mediterranean
No full textInternational audienc
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