نتایج جستجو برای: introduction dust storms
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Background and objectives: Dust storm is a natural event that occurs in arid and semi-arid and There are many adverse consequences. according to the increased number and duration of dust storms and their effects on the environment and human health, present article is to Analysis of dust and dust storms in Iran,Investigation Internal and external origin of dust storms in Iran using sate...
introduction the dust storms are one of the climatic hazards in the dry climates of the world. they cause many damages to the environment and humans. one of the aspects of a study to understand the origin of this phenomenon is the formation of foci in the recent years in the areas of research. it has been done in the central regions. the dust storms have gained global scale. this has demonstrat...
1- Introduction In middle and lower troposphere, the main control factor of weather and climate over the Middle East is a local to regional scale thermal forcing including forcing from high mountains. In this regard, regional scale atmospheric circulation associated with surface forcing has an important role in the occurrence of summer dust storms over the area. Southwest of Iran experiences a...
introduction one of the factors that affect the climate of arid and semi-arid areas is dust storm. numerical models are new methods for evaluation of dust storms which can also be used for forecasting dust storms. weather patterns that lead to dust outbreaks can be simulated using computer models that support a wide range of simulations related to the long-range transport, dispersion, and depos...
The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust stor...
Dust storms in arid and semi-arid regions have harmful impacts on the environment, the economy, and the health of local and global communities. In this study, the frequency of annual dust events in twenty-five stations and five climatic variables including rainfall, maximum annual wind speed, average annual wind speed, maximum annual temperature, and average annual temperature in arid regions o...
In drylands, both dust storms and ephemeral salt lakes (playas) are common. Observations using remote sensing and ground studies have shown that these playas can be major sources of saline dust storms. Some basins have recently become desiccated as a result of water abstraction by humans, and these have become significant sources of dust. The timing and amounts of dust emissions depends on such...
iran is facing dust storms every year and frequently. this phenomenon has affected, especially in recent years, various aspects of people's lives. the aim of this research is iran’s seasonal clustering in terms of dust storms frequency with visibility less than 1000 and 500 m for the period of 1987–2008. for this purpose, we used the data of 87 synoptic stations that had suitable spatial d...
Study of physical and chemical characteristics of dust storms in Iran is necessary. In this regard, 10 samples from Khozestan dust storms in 1387 and 1388 were collected for XRD and SEM studies. XRD result show that mineralogical composition of these dust particles can be divided into three groups: (1) Carbonate group (calcite mineral), (2) Silicate group (quartz mineral) and (3) Clay group (Ka...
Introduction: Different regions have various dust production; and the increase of dust storms illustrates the arid ecosystem dominance in each region. Analyzing and identifying of dust storms and its association with climatic parameters is one of the crucial approaches to reduce the caused damage of this phenomenon. Since besides determining the portion of each climate variables in intensifying...
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