By applying the above method, approximately 5851 tracks were detected, and they were divided into 3221 (or 55.1% of the whole tracks) long tracks and 2630 (or 44.9%) short tracks; i.e., most of the generated cyclones had long tracks.
The seasonal distribution of the detected tracks, as shown in Table 1, indicates that approximately 296 tracks were detected in winter, with more than 55% being long tracks; in spring, approximately 1722 tracks (or 29.43 of the total tracks) were detected, and more than 66% were long tracks. Furthermore, 2912 tracks (or 49.77% of the total detected tracks) were observed in summer, with more than 51% being long tracks, and 921 tracks were identified in autumn, with 46.69% long tracks and 53.31% short tracks. This seasonal distribution suggested that most of the cyclone tracks were generated in summer and spring, with ratios of 49.77% and 29.43%, or a total of approximately 79.2% of all tracks; similar findings were noted in previous studies (Raible et al. 2008; Varga et al. 2014) of the cyclone center density over the Saharan region, which reaches a maximum in summer. However, the current results are opposite to those for the seasonal Mediterranean (the closed northern water area in the Sahara region) (intense) cyclone peak, which occurs in winter (HMSO 1962; Flaounas et al. 2013&2015), but the results from (Maheras et al. 2001; Trigo et al. 2002) for the western (not eastern) Mediterranean were compatible with the current results. The contradiction of these results with those of previous studies (Prezerakos 1985; Trigo et al. 1999; Maheras et al. 2001; Trigo et al. 2002) for Saharan depressions that reached their maximum frequency in spring and not in summer arose because the current results considered the whole Saharan region, not only the northwest African or the Atlas depressions, as studied in these works.
Table 1
Seasonal/total distribution of the classified long- and short-track Saharan cyclones detected. The percentage of the total number is given in parentheses.
Season/Class | Total | Long | Short |
Winter | 296 (5.1%) | 163 (5.1%) | 133 (5.0%) |
Spring | 1722 (29.4%) | 1138 (35.3%) | 584 (22.2%) |
Summer | 2912 (49.8%) | 1490 (46.3%) | 1422 (54.1%) |
Autumn | 921 (15.7%) | 430 (13.3%) | 491 (18.7%) |
Total | 5851 | 3221 | 2630 |
The annual track distribution (Figure 1-a) shows that approximately 58% of years, or 31 years, have fewer tracks than the annual average, that is 61 tracks/year, with the lowest numbers in 1992 and 1993 (47 tracks) and 2015 (39 tracks). The lowest number of tracks in 1992 agrees with tracks that influenced Turkey (Karaca et al. 2000), but the highest number during the widespread drought in 1989 (76 tracks) contrasted with their results (Karabulut 2015). Approximately 42% of years have a more track than the annual average, with the highest numbers of tracks (80) observed in 1980 and 2018, in contrast with the annual distribution of tracks that influenced Turkey (Karaca et al. 2000). Moreover, this annual distribution displayed a concave shape, with the highest values in the 1970s and the first decade of the twenty-first century and lowest values in the 1980s-1990s. Additionally, approximately 47% of years had between 55 and 72 tracks per year, i.e., between the average and +/-10% of the average. Generally, the intersection period of the annual distribution of Saharan cyclones is similar to the annual winter distribution of mid-latitude but opposite to that of high-latitude cyclones in the North Atlantic (Wang et al. 2006).
The monthly distribution (Figure 1-b) indicated that from October (114 tracks) to March (248 tracks), the number of tracks was lower than the monthly track average (approximately 269 tracks/month); the lowest numbers of tracks were observed in December, November and January, with values of 18, 39 and 40, respectively. These results were consistent with the results of (Alpert et al. 1990b; Trigo et al. 1999) but in contrast with the monthly distribution of tracks that influenced Turkey (Karaca et al. 2000); this difference may have appeared because their study concentrated only on cyclones that reached Turkey.
In contrast, the months from April to September had the highest track numbers, with more tracks than the monthly average; the month with the most tracks was July, with 531 tracks, or approximately two times the monthly average (269 tracks), then coming May with 482 tracks. Of these months, September had the fewest tracks at 275, or approximately the monthly average. The results from (Trigo et al. 1999) were inconsistent with the current results, where the maximum number of cyclones occurred in May and was not high in July; this difference may be explained by the fact that their results depended on cyclones generated in only a small area, namely, the Atlas region.
3-1 Cyclogenesis areas
The spatial distribution of the Saharan cyclone regions, as shown in Figure 2-a, includes three main generation areas: the Atlas area (the area between 10° W-10° E and 15° N to 32.5° N, labeled “ATLAS” in the figure), the South Saharan area (the area between 10° E-37.5° E and 15° N to 22.5° N, labeled “STHSH” in the figure), and the North Saharan area (the area between 10° E-37.5° E and 22.5° N to 35.0° N, labeled “NTHSH” in the figure). These cyclogenesis areas were classified as main Saharan dust sources (Prospero et al. 2002; Israelevich et al. 2002) or as main high-frequency cyclone regions (Wernli and Schwierz 2006).
Approximately 61.87% of the long Saharan cyclone tracks (or 1993 cyclones) were generated in the Atlas area, and approximately 31.08% (or 1001 cyclones) and 7.05% (or 227 cyclones) were generated in the southern and northern Saharan areas, respectively (Table 2). This result is similar to the findings of Raible et al. (2008) for Northern Hemisphere (NH) cyclone centers and Trigo et al. (2002) for Mediterranean basin cyclone sources. Additionally, the results indicate that the lowest number of long-track Saharan cyclones is generated in the northern Saharan area north of 22.5° N, while the Atlas area, which is classified as the primary source of dust for the Mediterranean region (Alpert et al. 1990-a&b; Israelevich et al. 2002; Hannachi et al. 2011) and is responsible for generating a low-level shallow vortex (Horvath et al. 2006b), is associated with the highest number of generated long-track Saharan cyclones.
Table 2
Seasonal/total numbers of Saharan cyclones generated in the main cyclogenesis areas
Areas/Season | Winter | Spring | Summer | Autumn | Total |
Atlas (ATLAS) | 84 | 717 | 949 | 243 | 1993 |
South Sahara (STHSH) | 50 | 290 | 491 | 170 | 1001 |
North Sahara (NTHSH) | 29 | 131 | 51 | 16 | 227 |
The seasonal distribution of long tracks (Table 2) indicated the corresponding cyclones generated in the Atlas area accounted for 84 (or 4.21%), 717 (or 35.98%), 949 (47.62%) and 243 (or 12.19%) of all cyclones in the winter, spring, summer and autumn seasons, respectively. These seasonal distributions suggest that most of the cyclones in this area are generated in summer and spring (or 83.6% of the cyclones generated in the two seasons), while the lowest number of cyclones is generated in winter. Of the south-Saharan cyclones (Table 2), the distribution of the generated tracks indicates that 78.02% of cyclones occurred in spring and summer, while 5.00% of cyclones occurred in winter, an increase over the corresponding value in the Atlas area. Of the north-Saharan cyclones, as shown in Table 2, the distribution of the generated tracks suggests that 57.71% of cyclones occurred in spring, and only 7.05% occurred in autumn. Additionally, the ratio of the number of cyclones generated in the northern Sahara area in winter reached more than 56% of that in summer (twenty-nine winter cyclones compared to 51 summer cyclones).
3-2 Cyclolysis areas
The generated cyclones terminate in four main areas, as shown in Figure 2-b: the North African area, Mediterranean area, Arabian Peninsula and Red Sea area and eastern area. Approximately 2393 cyclones (74.29% from total generated cyclones) terminated in these four regions, and approximately 828 cyclones (or 25.71%) were not classified in any one of these areas (Table 3).
Table 3
Seasonal/total numbers of Saharan cyclone tracks that terminate in the main cyclolysis areas
Area/Season | Winter | Spring | Summer | Autumn | Total |
North Africa (NRTREG) | 9 | 149 | 196 | 29 | 383 |
Mediterranean (MEDREG) | 48 | 189 | 124 | 58 | 419 |
AP and Red Sea (APSREG) | 13 | 188 | 261 | 118 | 580 |
Eastern Area (ESTREG) | 67 | 407 | 423 | 114 | 1011 |
The North African area (the area from 10° E to 35° E and from 22.5° N to 32.5° N, labeled “NRTREG” in Figure 2-b) was influenced by 383 cyclones (11.89% of the long cyclonic tracks, or 16.01% of the tracks classified as associated with cyclolysis regions), including 9 (or 2.29%), 149 (or 38.90%), 196 (or 51.17%) and 29 (or 7.57%) in winter, spring, summer and autumn, respectively, as shown in Table 3.
The Mediterranean area (the area from 10° E to 37.5° E and from 32.5° N to 45° N, labeled “MEDREG” in Figure 2-b) was influenced by 419 cyclones (13.01% of the long tracks, or 17.51% of the tracks classified as associated with cyclolysis tracks), as shown in Table 3. This area was classified as a cyclone center by the NH (Raible et al. 2008) and was considered a generation area for eastern Mediterranean cyclones/rain (Alpert et al. 1990a&b; Kahanaet al. 2002; Rubin et al. 2007). Any discrepancies among results are potentially because the authors considered the existence of cyclones but did not consider cyclonic tracking. These cyclonic tracks include a maximum of 189 (or 45.11%) in spring (Table 3) and a minimum of 48 (11.46%) in winter (Table 3). The maximum number in this region was found in spring, not in summer, as in the North African area, although winter was the season with the fewest cyclones in both areas.
The Arabian Peninsula and Red Sea area (the area from 35° E to 57.5° E and from 15° N to 32.5° N, labeled “ARSREG” in Figure 2-b) was influenced by 580 cyclones (18.01% of the long-track cyclones, or 24.24% of the tracks classified as cyclolysis tracks), as shown in Table 3, with a maximum number of 261 cyclones in summer (or 45.0% of the area cyclones) and a minimum number of 13 cyclones in winter (or 2.24% of the area cyclones). Additionally, 306 cyclones formed in spring and autumn (or 32.41% and 20.34% in spring and autumn, respectively). This area was previously classified as a generation area for Mediterranean cyclones (Alpert et al. 1990a&b) because cyclones were detected in the area, but the tracks from the initial sources were not considered.
The Eastern area (the area from 37.5° E to 60° E and from 32.5° N to 50° N, labeled “ESTREG” in Figure 2-b) was influenced by 1011 cyclones (31.39% of the long-track cyclones, or 42.25% of the tracks classified as being associated with cyclolysis regions), as shown in Table 3. However, this area, especially around the Black and Caspian Seas, was considered a generation region for the Middle East (Alpert et al. 1990a&b) or an active cyclonic region linked with synoptic systems over Europe and the Mediterranean (Trigo et al. 2002). A highly seasonal distribution (Table 3) was found, with 423 cyclones (or 41.84% of the area cyclones) in summer and 407 cyclones (or 40.26% of the area cyclones) in spring; the minimum number of 67 cyclones was found in winter (6.63% of all cyclones in the area). This distribution indicated that more than 82% of the cyclones in the eastern area occur in spring and summer and only 11.3% occur in autumn.
3-3 Contributions of cyclogenesis in cyclolysis areas
The Atlas area was where 1261 (or 52.7%) of the cyclone tracks that reached the main cyclolysis areas (Table 4) formed, while the South Sahara and North Sahara areas were where 920 (or 38.4%) and 212 (or 8.9%) of these cyclones originated, respectively.
Table 4
Numbers of Saharan cyclones that move from cyclogenesis areas to cyclolysis areas
Cyclogenesis /Cyclolysis | Mediterranean (MEDREG) | North Africa (NRTREG) | AP and Red Sea (APSREG) | Eastern Region (ESTREG) |
Atlas (ATLAS) | 299 | 293 | 213 | 456 |
South Sahara (STHSH) | 71 | 87 | 350 | 412 |
North Sahara (NTHSH) | 49 | 3 | 17 | 143 |
In detail, Table 4 shows that 456 cyclones (or 45.1%) formed in the Atlas area and that 412 cyclones (or 40.8%) formed in the South Sahara area and moved to the eastern area, while only 143 cyclones (or 14.1%) formed in the North Sahara area. Most of the cyclones, approximately 299 (or 71.4%) and 293 (or 76.5%), that were generated in the Atlas area reached the Mediterranean and North African areas, respectively. Additionally, few cyclones from the Atlas, South Sahara and North Sahara areas, or 213 (or 10.69% from Atlas-generated cyclones), 71 (or 7.1% from South Sahara-generated cyclones) and 3 (or 1.32% from North Sahara-generated cyclones), reached the Arabian Peninsula and Red Sea area, Mediterranean and North African areas, respectively.
3-4 Affected regions
The most affected areas, i.e., the area influenced at least one time by any tracks, were identified based on long tracks, and four regions were highly influenced by Saharan cyclones (Figure 2-c): the South Sahara (labeled STHEF in the figure), North Sahara (labeled NRTEF in the figure), Mediterranean (labeled METEF in the figure) and Arabian Peninsula (labeled ARPEF in the figure) regions.
The STHEF region (the area from 00° E to 35° E and from 15° N to 23° N in Figure 2-c) was affected by 2076 cyclones (or approximately 64.45% of long-track cyclones), as shown in Table 5, and these cyclones were divided into 61 cyclones (or 2.94% of the cyclones that affected this region), 615 cyclones (or 29.62%), 1100 cyclones (or 52.99%) and 300 cyclones (or 14.45%) in winter, spring, summer and autumn, respectively.
Table 5
The seasonal/total numbers of cyclones that affect different regions
Area | South Area | Medit. Area | North Area | AP Area |
Winter | 61 | 103 | 98 | 21 |
Spring | 615 | 485 | 611 | 252 |
Summer | 1100 | 446 | 529 | 274 |
Autumn | 300 | 153 | 171 | 85 |
Total | 2076 | 1187 | 1409 | 632 |
The NRTEF region (the area from 00° E to17.5° E and from 24° N to 32.5° N in Figure 2-c) was affected by 1409 cyclones (or 43.74% of long-track cyclones), as shown in Table 5; this was the second most affected region by Saharan cyclones after the STHEF region. The seasonal effect in this region was highest in spring, with 611 cyclones, or 43.36% of the cyclones that affected the region, followed by 529 cyclones (or 37.54%) in summer.
The MEDEF region (the area from 20° E to 40° E and from 30° N to 37.5° N in Figure 2-c) was affected by 1187 cyclones (or 36.85% of the long-track cyclones), as shown in Table 5. The highest numbers of cyclones occurred in spring and summer, with 485 cyclones (or 40.86% of the cyclones that affected the region) and 446 cyclones (or 37.57%), respectively. However, the MEDEF region was weakly affected in winter and autumn, with 103 (or 8.68%) and 153 (or 12.89%) cyclones, respectively.
The ARPEF region (the area from 40° E to 50° E and from 25° N to 32.5° N in Figure 2-c) was the least affected area (Table 5); notably, only 632 cyclones (or 19.62% of the long-track cyclones) were observed in this area. Most of the cyclones were generated in summer and spring, with 274 cyclones (or 43.35%) and 252 cyclones (or 39.84%) in these seasons, respectively; thus, approximately 83.19% of all cyclones that affected the area occurred in these seasons.
3-5 Main routes
3-5-1 General description of main routes
By applying the route conditions, more than 90% of the long tracks were classified into five main routes (Table 6).
Table 6
Seasonal/total numbers (ratio, with respect to the total number of tracks along the route) of tracks for main routes
Route/Num. | South Sahara Route | North Sahara Route | Eastern Mediterranean Route | Northeast Egypt Route | Northern Route |
Winter (Ratio) | 11 (1.18%) | 26 (6.97%) | 29 (5.81%) | 4 (2.94%) | 81 (8.27%) |
Spring (Ratio) | 238 (25.43%) | 236 (63.27%) | 171 (34.27%) | 62 (45.59%) | 331 (33.78%) |
Summer (Ratio) | 535 (57.16%) | 82 (21.98%) | 224 (44.89%) | 62 (45.59%) | 435 (44.39%) |
Autumn (Ratio) | 152 (16.24%) | 29 (7.77%) | 75 (15.03%) | 8 (5.88%) | 133 (13.57%) |
Total Num. (Ratio) | 936 (29.06%) | 373 (11.58%) | 499 (15.49%) | 136 (4.22%) | 980 (30.43%) |
The first route (or the South Sahara route) passes directly eastward over Sahara and northeast over the Arabian Peninsula (AP) (Figure 3-a); this route encompassed 936 tracks, or 29.06% of all long tracks (Table 6). This route was noted for spring by (Alpert et al. 1990b).
The second route (or North Sahara route) passes directly eastward over northern Africa and the south Mediterranean, and some of the corresponding tracks are directed southeastward over the northern AP (Figure 3-b). This route encompasses 373 tracks, or 11.58% of all long tracks (Table 6), and includes the area known as the Saharan depression or Khamasin depression (Tantawy 1964; Alpert and Ziv 1989) or the Saharan spring cyclones track (Alpert et al. 1990a&b).
The third route (or eastern Mediterranean route) passes generally northeast over Sahara and east/northeast over the Mediterranean and Middle East, and only a few tracks pass southeast over the Arabian Gulf (Figure 3-c). This route encompasses 499 tracks, or 15.49% of all long tracks, as shown in Table 6. This route is considered one of three main winter NH storm paths (Wernli and Schwierz 2006), or one of the four main passes that influence Turkey (Karaca et al. 2000). Both the HMSO (1962) and Alpert and Ziv (1989) suggested that this route in spring contributes to approximately 43% of the North African cyclones that reach the eastern coast of the Mediterranean.
The fourth route (or the northeast Egypt route) passes northeastward over Egypt and the Middle East and southeast over the region around the Arabian Gulf (Figure 3-d). This route encompasses 136 tracks, or 4.22% of all long tracks (Table 6). This route was mentioned by (Alpert and Ziv 1989; Awad and Mashat 2014) as a track for African dust.
The fifth route (or northern route) generally passes directly northward or near northward (Figure 3-e) and encompasses 980 tracks, or approximately 30.43% of all long tracks (Table 6). The cyclones from this route were considered as the main Saharan cyclones influenced Mediterranean (HMSO 1962; Prezerakos 1985; Prezerakos et al. 1990; Thorncroft and Flocas 1997; Horvath et al. 2006a&b; Bou Karam et al. 2010).
Generally, more than 31.29% of annual Saharan cyclones influence the eastern Mediterranean, the results are usually consistent with those of the HMSO (1962), showing that 58% of the cyclones that enter the Mediterranean region and 34.5% of cyclones that enter the Red Sea region originate from the Saharan region (Romem et al. 2007), if the influence of tracks that reach the whole Mediterranean and Red Sea regions at least one time is considered.
3-5-2 Seasonal and monthly variations in the main routes and their lifespans
The total monthly distribution of classified tracks, as shown in Figure 4-a, displays two high numbers of tracks, one in August, with 485 tracks, or 16.59% of the classified tracks, and the other in May, with 431 tracks, or 14.74% of the classified tracks. Furthermore, the lowest numbers of tracks were observed in November, December and January, with 34, 16 and 34 long classified tracks, accounting for less than 1.2% of classified tracks in each month. This situation contrasts with the monthly distribution of Mediterranean cyclones (the water area northern Sahara), where for example Alpert and Ziv (1989) suggested that the low numbers of cyclones in warm months was explained by the dominance of the subtropical high in warm months.
In particular, along the South Sahara route, RT1 in Figure 4-b, no tracks were observed in December or January, and the highest number of tracks occurred in July, with 217, or 23.18% of the tracks along that route.
December, with one track, was the month with the fewest tracks along the North Sahara route, RT2 as shown in Figure 4-b. The highest number of tracks occurred in April, with 96 tracks, or 25.74% of the tracks along that route, as shown in Table 6. This high number was explained (Elfandy 1940; Alpert and Ziv 1989) by the thermal gradient between the cold African continent and the warm Mediterranean water.
Generally, the seasonal distribution of route tracks (Table 6) suggests that the lowest number of tracks occurs in winter, while spring had the highest numbers for North Sahara and the eastern Mediterranean and most tracks occurred in summer along other routes.
The lifespan distribution indicates that more than 66% of tracks along the South Sahara route have lifespans between two and three days, as shown by RT1 in Figure 4-c; only approximately 16% of tracks have lifespans longer than three days, and approximately 17% of tracks have lifespans of one day or less.
For the North Sahara route, RT2 in Figure 4-c, more than 63% of tracks have lifespans between two and four days, more than 20% of tracks have lifespans of one day or less, and more than 16% of tracks have lifespans between four and 7 days.
Approximately 41% of the tracks along the Eastern Mediterranean route, RT3 in Figure 4-c, have lifespans of one day or less, more than 46% of tracks have a lifespan between two and three days, and only approximately 12% of tracks have a lifespan between four and seven days.
Most of the tracks, approximately 76%, along the northeast Egypt route, RT4 in Figure 4-c, have lifespans between two and four days, 18% of tracks have a lifespan of a day or less, and only 5% of tracks have lifespans of 5 to 6 days.
On the northern route, RT5 in Figure 4-c, more than 79% of tracks have a lifespan of two days, and more than 20% of tracks have a lifespan between three and six days.
Generally, previous results indicated that approximately 85% of tracks have lifespans of less than 3 days; notably, the typical lifespan of extratropical cyclone tracks is less than 2 days (Nielsen and Dole 1992; Trigo et al. 1999; Hanson et al. 2004). Moreover, the results show that less than 13% of the cyclone tracks have lifespans of greater than three days to five days, and only approximately 1% of route tracks have lifespans longer than five days. These results are consistent with the findings of Hannachi et al. (2011) for spring Saharan cyclones; additionally, according to a classification used in a study by (Raible et al. 2008), only approximately 14% of cyclones that have lifespan greater than three days can be classified as strong cyclones.
Furthermore, the longest lifespan for easterly routes (South/North Sahara) is nine days, and the lifespan of northerly routes (Northern and Northeast Mediterranean/Egypt) is shorter at six days.
3-5-3 Cyclogenesis and cyclolysis regions for main routes
The main area of cyclogenesis for the South Sahara route, as shown in Figure 5-a, delimited from 15o N to 20o N and distributed in three regions, namely, those between 5o W and 7.5o E, 10o E and 22.5o E, and 27.5o E and 32.5oE, were the sources of 323, 277 and 127 tracks (or 34.51%, 29.59% and 13.57% of the total tracks along the route), respectively. The cyclolysis areas were concentrated in four regions (Figure 5-b): local areas over Chad between 17.5°E and 22.5° E and three water areas over the Red Sea, around the Arabian Gulf and around the Caspian Sea.
The main cyclogenesis area for the North Sahara route, as shown in Figure 5-c, is the Atlas region, which was the source of 246 tracks (or 65.95% of the total tracks along the route), and some sparse areas in northern Africa contributing to the formation of 79 cyclone tracks (or 21.18% of the total tracks along the route). The local cyclolysis area (Figure 5-d) is located over the Sirte region in Libya, and the main termination area is the area around the Caspian Sea; in addition, less concentrated cyclolysis areas can be observed over Iraq and the Arabian Gulf. The Caspian Sea was previously mentioned as a cyclolysis area for western Saharan cyclones in spring (Hannachi et al. 2011). On the other hand, the area around the Black and Caspian Seas was considered a cyclonic center by (Alpert et al. 1990a; Maheras et al. 2001; Campins et al. 2010), which authors not considered the tracks on their consideration.
For the eastern Mediterranean route, as shown in Figure 5-e, the southern Atlas region and the zone from 15° N to 20° N and 2.5°E to 20° E represent the main cyclogenesis areas, with109 tracks and 199 tracks (or 21.84% and 39.88% from total tracks of the route), respectively, forming in each area. The three main cyclolysis areas for this route (Figure 5-f) include the eastern Mediterranean, Black Sea, and Caspian Sea, with a less notable area over the Arabian Gulf. The Black Sea was previously mentioned as a cyclolysis area for Mediterranean cyclones (Trigo 2006; Romem et al. 2007), or for western Saharan cyclones in spring (Hannachi et al. 2011).
Generally, the Atlas region appeared as the source of the most cyclones that influenced the Mediterranean region, as previously indicated by (Alpert et al. 1990a&b; Hannachi et al. 2011)
Northern Sudan is the main cyclogenesis area for the Northeast Egypt route (Figure 5-g), and 64 cyclone tracks (or 47.06% of the total tracks along the route) formed there; Chad is a less frequent cyclogenesis area, with 43 associated tracks (or 31.62% of the total tracks along the route). Two cyclolysis areas for this route (Figure 5-h) are dense, and they are located near the Caspian Sea, while less frequent cyclolysis areas are located over the Arabian Gulf.
The cyclogenesis areas for the northern route (Figure 5-j) are the Atlas region and the area between 15° N and 20° N and between 2.5° E and 32.5° E; notably, 372 tracks and 348 tracks (or 37.96% and 35.51% of the total tracks along the route), respectively, originated in these areas. The Atlas contribution is comparable to the value of 46% proposed by Egger et al. (1995) for cyclones that originate in the Atlas region and travel along routes to the Mediterranean. The main cyclolysis area for this route, as shown in Figure 5-k, is located near southeastern Libya and Algeria. Furthermore, less frequent cyclolysis areas are located over the Mediterranean, the Adriatic Sea, the eastern Mediterranean, Iraq, Turkey and the Black Sea, as mentioned above (Maheras et al. 2001; Romem et al. 2007). Considering only the Atlas region, all (Prezerakos 1985; Prezerakos et al. 1990) were considered it as a source of Saharan cyclones influenced south Balkans area.