<p>Saharan cyclones occurring from 1967 to 2019 were detected using mean sea level pressure (MSLP); their tracks were mapped on the basis of nearest neighbor cyclonic positions and classified as long or short tracks depending on the area influenced by the cyclones. Additionally, the detected long tracks were objectively classified into five main routes: two directed eastward, two directed northeastward, and one directed northward, accounting for approximately 41.6%, 19.7%, and 30.4% of the total long tracks, respectively. For long tracks in particular, this study identified three cyclogenesis areas, where more than 99% of cyclones originated, and more than 61% of the cyclones were found to originate in the Atlas region. Moreover, this analysis identified four cyclolysis areas, where approximately 74% of the cyclones terminated. In particular, more than 66% of these cyclones terminated in the eastern study region. Furthermore, statistical analysis indicated that Saharan cyclones were common in the spring and summer, with these seasons accounting for ~ 35.3% and 46.3% of the total cyclones, respectively. In detail, the highest percentages occur in spring in the northern Saharan region and in summer in the southern Saharan region, with ~ 49.1% and 57.7%, respectively. Temporally, the monthly distribution indicated that most of the cyclones moving along the five main routes occurred in warm months, namely, May to August. Approximately 85% of these cyclones had a lifespan of three days, whereas only 1% lasted more than five days.</p>

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Variability in Saharan cyclone tracks, I: climatology study

  • Abdulhaleem H. Labban,
  • Adel M. Awad

摘要

Saharan cyclones occurring from 1967 to 2019 were detected using mean sea level pressure (MSLP); their tracks were mapped on the basis of nearest neighbor cyclonic positions and classified as long or short tracks depending on the area influenced by the cyclones. Additionally, the detected long tracks were objectively classified into five main routes: two directed eastward, two directed northeastward, and one directed northward, accounting for approximately 41.6%, 19.7%, and 30.4% of the total long tracks, respectively. For long tracks in particular, this study identified three cyclogenesis areas, where more than 99% of cyclones originated, and more than 61% of the cyclones were found to originate in the Atlas region. Moreover, this analysis identified four cyclolysis areas, where approximately 74% of the cyclones terminated. In particular, more than 66% of these cyclones terminated in the eastern study region. Furthermore, statistical analysis indicated that Saharan cyclones were common in the spring and summer, with these seasons accounting for ~ 35.3% and 46.3% of the total cyclones, respectively. In detail, the highest percentages occur in spring in the northern Saharan region and in summer in the southern Saharan region, with ~ 49.1% and 57.7%, respectively. Temporally, the monthly distribution indicated that most of the cyclones moving along the five main routes occurred in warm months, namely, May to August. Approximately 85% of these cyclones had a lifespan of three days, whereas only 1% lasted more than five days.