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1

Dust storm in the Middle East and south-west Asia is a natural hazard and the ............................ plain has been recognized as the main dust source in this area 

Tigris-Euphrates alluvial

2

Dust storms in the region can be grouped into two main categories, i.e., 

  • the Shamal dust storms and
  • the frontal dust storms. 

3

frequency of patterns

  • For 68% of the Shamal dust storms, a high pressure system is situated between 0oE to 30oE and 27oN to 45oN, and a low pressure system between 50oE to 70oE and 23oN to 43oN.
  • For 86% of the frontal dust storms, a high is located between 51oE to 67oE and 18oN to 33oN and a low between 28oE to 48oE and 32oN to 43oN. 

4

Three main patterns for Shamal dust storms are identified, which represent about 

60% of the Shamal dust storms

5

Three main patterns for Shamal dust storms are identified, which represent about 60% of the Shamal dust storms. This analysis confirms that the Shamal is related to 

the anticyclones located over northern Africa to Eastern Europe and the monsoon trough over Iraq, southern Iran, Pakistan and the Indian Subcontinent.  

6

This analysis confirms that the Shamal is related to the anticyclones located over northern Africa to Eastern Europe and the monsoon trough over Iraq, southern Iran, Pakistan and the Indian Subcontinent. The analysis also shows that the main dust sink for the frontal dust storms in Tigris and Euphrates alluvial plain extends from

center of Iraq to west and center of Iran and, in most severe cases, to northern Iran and the southern coast of the Caspian Sea. 

7

Mineral dust aerosol is involved in many important pro- cesses in Earth’s climate system including 

  • radiative forcing,
  • nutrient transport,
  • land-use change, and
  • ecosystem health 

8

Dust storms and suspended dust pose serious environmental pro- blems in 

south-west Asia and natural hazards in the Middle East region. 

9

Major dust storms occur over the Middle East region nearly every 

spring and summer and cause destructive effects in some countries like Iraq, Saudi Arabia and Iran. 

10

Model simulations suggest that the dust emission from this region contributes to about .............. of the global total emission. 

20%

11

The Tigris-Euphrates alluvial plain has been recognized as 

he main dust source in the Middle East. 

12

he Tigris-Euphrates alluvial plain has been recognized as the main dust source in the Middle East. The dust originating from this area can be transported over 

large distances because the dust particles from this area mainly consist of fine sedi- ments from the Tigris and Euphrates rivers 

13

The Tigris-Euphrates alluvial plain has been recognized as the main dust source in the Middle East. The dust originating from this area can be transported over large distances because the dust particles from this area mainly consist of fine sedi- ments from the Tigris and Euphrates rivers. Therefore, the dust storms from the Middle East also have important impacts on 

the neighboring countries like Iran. 

14

The dust originating from this area can be transported over large distances because the dust particles from this area mainly consist of fine sedi- ments from the Tigris and Euphrates rivers. Therefore, the dust storms from the Middle East also have important impacts on the neighboring countries like Iran. The dust activities have intensified in the  

Mesopotamian area in recent years, partly due to the development of the dam construction projects on Tigris and Euphrates rivers. 

15

Construction of new dams decrease 

the humidity and water content of soil in the downstream areas, which consequently lessen the threshold friction velocity of the soil and its resistance against wind erosion.  

16

The seasonal variation of dust activity in the Middle East is 

complex and differs for different regions 

17

The seasonal variation of dust activity in the Middle East is complex and differs for different regions. Over much of the Middle East, dust is active  

all year long, but it decreases in the winter months. 

18

Over much of the Middle East, dust is active all year long, but it decreases in the winter months. Dust activity increases in 

March and April 

19

Over much of the Middle East, dust is active all year long, but it decreases in the winter months. Dust activity increases in March and April, peaks in 

June and July and weakens in September 

20

The MODIS satellite images between 2003 and 2011 show that nearly 

60 dust storms occurred in the Middle East, which are reported as natural hazards in the area by NASA 

21

The MODIS satellite images between 2003 and 2011 show that nearly 60 dust storms occurred in the Middle East, which are reported as natural hazards in the area by NASA. Amongst these, 12 severe dust storms were considered for synoptic analysis of the dust storms in this area. The distinguished feature of these selected dust storms is that, 

 their dust plumes were spread and covered the western to central part of Iran. 

22

The MODIS satellite images between 2003 and 2011 show that nearly 60 dust storms occurred in the Middle East, which are reported as natural hazards in the area by NASA. 

The rest of 48 dust storms were just spread over 

Iraq and a smaller part of Iran.

In four of the selected cases, the dust plumes reached the north-eastern to eastern part of Iran and affected the Caspian Sea region.  

23

The analysis of the MODIS satellite images shows that the dust storms from the Tigris- Euphrates alluvial plain may affect  

more than 10 countries in the Middle East. 

24

The Middle East, largely made up of the  

Arabian Plateau and the Tigris-Euphrates Basin, is an area of active wind erosion. 

25

The Arabian Plateau 

slopes down from the southwest high terrains (1,500-3,000 m) bordering the Red Sea towards the northeast flat lands (50-200 m) adjacent to the Persian Gulf.  

26

Arabian Peninsula 

Two dust areas have been identified 

The first covers the Tigris-Euphrates River alluvial plain in Iraq and Kuwait, the low-lying flat lands in the east of the peninsula along the Persian Gulf and the Ad Dahna and the Rubal Khali deserts (Shao, 2008). The alluvial plains have the highest frequency of dust storms in the Middle East (Safar, 1980).

The second dust area is found off the Oman coast, and the number of daily dust-storms in this area is rather low and thus is eliminated from this study. 

27

In this paper, the land surface is divided into  

non erodible areas which are not prone for dust emission, and potential dust source regions which can be used for dust emission in numerical models.

The potential dust source regions are defined on the basis of remotely sensed leaf area index (LAI), topography (H) and surface type (S).  

28

It should be mentioned that alluvial plains as a source of 

fine sediment for dust are usually placed above the sea level but not very high to face mountains 

29

Therefore, as the most part of the present study area located in Iran and Arabian plateau with high altitude, critical height topography of 

500 m, 700 m and 900 m were selected for this investigation, which cover most of the potential dust sources. 

30

The climate in the Middle East is mainly affected by four systems:  

(a) The Siberian anticyclone in winter over central Asia;

(b) The Polar anticyclone in summer over east of Europe and Mediterranean Sea;

(c) The monsoon cyclones in summer over the India Subcontinent, south and southeast of Iran and southeast of Arabian peninsula;

(d) The depressions travelling from north of Africa and south and east of Mediterranean sea across the Middle East and southwest of Asia in the non- summer seasons (spring and winter).