پیش بینی مسیر حرکتی ذرات گرد و غبار با استفاده از HYSPLIT و مدل WRF-Chem در حوزه جازموریان (مطالعه موردی گرد و غبار 7 و 8 اکتبر 2018)

Introduction

Dust storms are always known as one of the natural hazards that affect various sectors such as health, agriculture, transportation, etc. and have very wide consequences, especially reduced soil fertility, damage to crops, drying of cover. Natural plant causes disorders of communication systems, disorders of mechanical systems and an increased risk of respiratory diseases. In general, the main source of dust storms, or in other words, the main origin of dust storms is located in arid regions of the world such as East Asia, Middle East, Latin America, Australia, parts of Europe, East and South Africa, North America. In addition to the internal centers of the country, the main effective centers are the centers located in Iraq, Syria, the Arabian Peninsula and Afghanistan. In order to manage dust storms, forecasting and routing this phenomenon is of great importance. The lowest and highest range of dust suspended particles is from a few nanometers to 100 microns. Large particles usually move by rolling, medium particles by jumping, fine particles such as clay particles due to their lightness rise to a high height above the ground and remain suspended in the air for a long time and descend after a long distance. In suspension motion, very fine soil particles, after rising from the ground due to their extraordinary lightness and high specific surface area, remain suspended in the air for a long time and in the presence of favorable atmospheric currents, sometimes travel hundreds or thousands of kilometers and up to more than a few altitudes. They extend a thousand meters above the ground.



Materials and methods

Jazmourian basin is the most important basin in the southeast of Iran, which is located in Kerman, Sistan and Baluchestan provinces with the latitude coordinates of 33 ْ 26 to 36 ْ 29 north and the longitude of 16 ْ 56 to 26 ْ 26 east and with an area of 69374 square kilometers. After statistical study of the phenomenon of "dust" and the factors affecting it in the Jazmourian basin, the severe and widespread occurrence of "dust" in the Jazmourian basin is investigated. First, in order to investigate the "dust" mass in the region, the true color image of the Madis sensor of the Tera and Aqua satellites and the optical depth values of the airships are examined. Then, to investigate the prevailing atmospheric currents in the region, the HYSPLIT model is implemented as a matrix and in a leading way. In implementing the HYSPLIT model, GDAS meteorological data with a horizontal separation of 0.5 degrees have been used. Using the output of this model, it is possible to investigate the transfer of "dust" particles from this area.



Results and discussion

The True Color Composite and the light depth of the Aqua satellite sensor on October 7 and 8, 2018 show that the AOD values in the whole region are high every 2 days. Also, the True Color Composite of the MADIS sensor of the Aqua satellite shows the high values of "dust" concentration in the Jazmorian region. And they have gone to the Persian Gulf region. Particle optical depth values at UTC06 on October 8, 2018 show that AOD values on the North Sea of Oman have increased significantly and reached 1. Also, the amount of this quantity has reached 1 in the southern half of Jazmourian region, but it has reached 0.7 in a large part. Particle optical depth values at UTC12 on October 8, 2018 show that AOD values on the north of the Oman Sea have increased and reached 1.2. Also, the amount of this quantity has reached 1 in the southern half of Jazmorian region, but has reached 0.7 in a large part of Jazmorian region. Also, the values of the optical depth of the particles at UTC18 on October 8, 2018 show that the AOD values on a large part of the Oman Sea remain 1.2. But the amount of this quantity has decreased in the southern half of Jazmourian region and has reached 0.7 only in a small part of Jazmourian region.

Conclusion

Dust from these areas can directly affect the provinces of Kerman, Sistan and Baluchestan, as well as Hormozgan. Therefore, it is very important to study the path of particles as well as the dust collection centers. In this study, the beginning of the dust storm from October 7 to 8, 2018 was selected for simulation and navigation. The results showed that the southern parts of Jazmourian basin (wetland area and its surroundings) can be used as a critical dust center in these areas. Particles from these areas also move towards the Sea of Oman, which affects most of Hormozgan province and southern Sistan, and is also important for navigation and navigation systems.

Keywords: Dust Particles, Numerical Routing, Jazmourian Basin