Chapter 6-B

Question 1

the primary dust sources

Answer 1

the Tigris and Euphrates River alluvial plain

Question 2

mean threshold velocity

Answer 2

10 m s−1

Question 3

About 86% of the high pressure systems are located in three main regions and the rest of %14 in other areas. These 14% consist of places of

Answer 3

anticyclones which are far from the mentioned region and their coordinates do not exist in the selected range. The high pressure systems extended from northern Africa to central Europe.

Question 4

These main areas consist of:

Answer 4

• 86% high pressure systems, 43% is located in the north of Africa and south of Mediterra- nean Sea.
  
  • the main place of anticyclones, which are centered in north of Libya.
  • This area extends from north of Egypt to south of Tunisia and center of Libya to center of Mediterranean Sea.
• Of the 86% high pressure systems, 25% of the high pressure system is positioned from south of Bulgaria and east of Greece to east of Spain and south of France (east to west) and from south to north of Italy (south to north).
• The third region of high pressure system in Shamal dusty days
  
  • In 18% Shamal dusty days, the high pressure system is placed on west of Ukraine
  • This area extended from east of Ukraine to east of Germany (east to west) and from Hungary to north of Poland (south to north).

Question 5

…………………………… also play an important role in dust transport

Answer 5

Along with the high pressure systems, low pressure systems

Question 6

About ………….of low pressure systems associated with the dust events are located in four areas. The remaining……………. are located

Answer 6

90%

10%

outside of the study domain.

Question 7

The low pressure areas extend from

Answer 7

north-west of the Persian Gulf to the Indian subcontinent.

Question 8

the areas of low pressure systems associated with the Shamal dust storms, which are:

Answer 8

• The region with the highest frequency of low pressure system is located in central to southern Iran
  
  • This area extends from Sistan- Bluchestan to Khuzestan of Iran (east to west) and from north of Persian Gulf and Hormuz strait to center of Iran (south to north).
  • In 44% of Shamal dusty days, the cyclone is positioned in SLP1.
• In 19% of Shamal dusty days, the cyclone is consist of some parts of south-east of Iran, south-west of Pakistan and south of Afghanistan.
• In 17% of Shamal dusty days, the low pressure system is placed on SLP3 area, which extends from west of Iran and north-east of Iraq to the center of Iraq
• In 10% This region extends on north-east of India subcontinent with less frequency of occurrence.

Question 9

The synoptic patterns are classified into three types. The

synoptic patterns classification is based on

Answer 9

positioning of high and low pressure systems.

Question 10

total number of shamal dust storms

Answer 10

12

Question 11

The three types of synoptic pattern are as follows:

Answer 11

• Type 1: 29% the extension of a high pressure system over northern Africa and Libya
• Type 2: 17% of the Shamal dust storms belongs to this category. The main feature of Type 2 is the extension of a high pressure system from south to south-east of Europe
• Type 3: 14% of the Shamal dust storms belongs to this category. The main feature of Type 3 is the extension of a high pressure system from center to east of Europe

Question 12

Type 1: 29% of the Shamal dust storms belongs to this category. The main feature of Type 1 is the extension of a high pressure system over northern Africa and Libya

wind direction

Answer 12

The wind direction over the Tigris and Euphrates alluvial plain is northwesterly and westerly over Syria and Iraq and the emitted dust is transported to west and center of Iran by the westerly winds associated with the low and high- pressure systems.

Question 13

Type 1: 29% of the Shamal dust storms belongs to this category. The main feature of Type 1 is the extension of a high pressure system over northern Africa and Libya (described in SHP1). The wind direction over the Tigris and Euphrates alluvial plain is northwesterly and westerly over Syria and Iraq and the emitted dust is transported to west and center of Iran by the westerly winds associated with the low and high- pressure systems. Because of the position of the cyclone

Answer 13

dust can be transported to east and north-east of Iran. The most destructive dust storms observed in Iran are associated with this synoptic pattern

Question 14

Type 2: 17% of the Shamal dust storms belongs to this category. The main feature of Type 2 is the extension of a high pressure system from south to south-east of Europe (described in SHP2). The wind direction

Answer 14

over the Tigris and Euphrates alluvial plain is northwesterly and northerly over Syria and north of Iraq. The wind direction changes from north-westerly to westerly in west of Iran and dust may be transport to west and center of Iran by the westerly winds.

Question 15

Type 2: 17% of the Shamal dust storms belongs to this category. The main feature of Type 2 is the extension of a high pressure system from south to south-east of Europe (described in SHP2). The wind direction over the Tigris and Euphrates alluvial plain is northwesterly and northerly over Syria and north of Iraq. The wind direction changes from north-westerly to westerly in west of Iran and dust may be transport to west and center of Iran by the westerly winds. A portion of the emitted dust may be

Answer 15

transported to the southeast of the Arabian Peninsula and southern Iran by the north-westerly winds.

Question 16

Type 3: 14% of the Shamal dust storms belongs to this category. The main feature of Type 3 is the extension of a high pressure system from center to east of Europe (described in SHP3). The wind direction

Answer 16

over Tigris and Euphrates alluvial plain is northwesterly and northerly over northern Iraq and dust is transported to the west, south-west and south of Iran by the north-westerly winds.

Question 17

Frontal dust storm

Answer 17

About 86% of the high and low pressure systems are grouped into a distinct region. The rest 14% are located outside of the study domain.

Question 18

The low pressure system is placed between 28oE to 48oE and 32oN to 43oN (FLP). This region extends

Answer 18

east to west from north-west of Iran to west of Turkey and south to north from north of Jordan and east of Mediterranean Sea to center of Black Sea.

Question 19

The low pressure system is placed between 28oE to 48oE and 32oN to 43oN (FLP). This region extends east to west from north-west of Iran to west of Turkey and south to north from north of Jordan and east of Mediterranean Sea to center of Black Sea. The corresponding high pressure system is

Answer 19

placed between 51oE to 67oE and 18oN to 33oN (FHP). This region extends east to west from south and south-west of Pakistan to west of Qatar and south to north from east of Oman to west of Afghanistan and east of Iran.

Question 20

About 82% of the frontal dust storms are associated with

Answer 20

this distinct synoptic pattern.

Question 21

About 82% of the frontal dust storms are associated with this distinct synoptic pattern.

This pattern generates

Answer 21

prefrontal dust storms in southern Iraq, Kuwait and the Khuzestan Plain of Iran.

Question 22

This pattern generates prefrontal dust storms in southern Iraq, Kuwait and the Khuzestan Plain of Iran. The most famous postfrontal dust storm is a

Answer 22

Winter Shamal dust storm that occurs in central and northern Iraq.

Question 23

This pattern generates prefrontal dust storms in southern Iraq, Kuwait and the Khuzestan Plain of Iran. The most famous postfrontal dust storm is a Winter Shamal dust storm that occurs in central and northern Iraq. Due to

Answer 23

the direction of frontal winds, the emitted dust can be transported north-eastwards to western and central Iran and in some severe cases; the dust plume reaches the south coast of the Caspian Sea.

Question 24

According to the synoptic analysis, the frontal edge extends from

Answer 24

south-east of Red Sea to north- west of Persian Gulf in 68% of the analyzed frontal dust storms.

Question 25

Synoptic scale dust storms in the Middle East were classified in two main categories:

Answer 25

Shamal (Summer Shamal) and

frontal dust storms.

Question 26

Shamal is

Answer 26

the main type of synoptic dust storms in this region. The highest frequency of Shamal is in June and July.

Question 27

The high pressure systems associated with

Answer 27

68% of the dust storms are located between 0oE to 30oE and 27oN to 45oN extending east to west from north of Egypt to east of Spain and south of France and south to north from center of Libya to north of Italy.

Question 28

The high pressure systems associated with 68% of the dust storms are located between 0oE to 30oE and 27oN to 45oN extending east to west from north of Egypt to east of Spain and south of France and south to north from center of Libya to north of Italy. Also, low pressure systems in

Answer 28

67% of dust storms located between 50oE to 70oE and 23oN to 43oN (SLPM) extending from center of Pakistan to north-west of Persian Gulf (east to west) and from north-east of Oman to north-east of Iran and south-east of Turkmenistan (south to north)

Question 29

Three main patterns for Shamal dust storm were identified.

Answer 29

About 60% of Shamal dust storms can be classified in these three main types

Question 30

This analysis confirms that the Shamal dust storm incorporates with

Answer 30

Anticyclones over north of Africa to east of Europe and Monsoon trough over Iraq, south of Iran and Pakistan and India subcontinent.

Question 31

This analysis confirms that the Shamal dust storm incorporates with Anticyclones over north of Africa to east of Europe and Monsoon trough over Iraq, south of Iran and Pakistan and India subcontinent. In other words,

Answer 31

the Monsoon trough is the main low pressure systems with special affects in formation of destructive dust storms.

Question 32

The main region of dust sink of Tigris and Euphrates alluvial plain extends from

Answer 32

center of Iraq and south-west of Iran to south and center of Pakistan.

Question 33

The highest frequency of frontal dust storm is in

Answer 33

March and April

Question 34

The highest frequency of frontal dust storm is in March and April. High and low pressure system placement in frontal dust storm was analyzed and regions with 86% of high and low Pressure system positioning were distinguished. Due to this classification, high pressure systems in 86% of frontal dust storms are located

Answer 34

extending from south and south-west of Pakistan to west of Qatar (east to west) and from east of Oman to west of Afghanistan and east of Iran (south to north).

Question 35

Due to this classification, high pressure systems in 86% of frontal dust storms are located between 51oE to 67oE longitude and 18oN to 33oN latitude (FHP) extending from south and south-west of Pakistan to west of Qatar (east to west) and from east of Oman to west of Afghanistan and east of Iran (south to north). Also, the low pressure systems in 86% of dust storms located bet- ween

Answer 35

This region extends from north-west of Iran to west of Turkey (east to west) and from north of Jordan and east of Mediter- ranean Sea to center of Black sea (south to north).

Question 36

The analysis shows the main dust sink for frontal dust storms in Tigris and Euphrates alluvial plain is extended from

Answer 36

center of Iraq to west, center and north of Iran and south coast of Caspian Sea.