synoptic analysis of precipitation and Widespread spring thunderstorm in North - West Iran

Document Type : Full length article


1 PhD student of Climatology, University of Tehran, Tehran, Iran

2 Assistant Professor Department of Physical Geography, University of Tehran, Tehran, Iran

3 Professor Department of Physical Geography, University of Tehran, Tehran, Iran

4 Assistant Professor Department of Geography, Seyed Jamaluddin Asadabadi University, Asadabad, Iran


Extended Abstract
Identifying pressure patterns during thunderstorms and Widespread precipitation is important. One of the methods of studying the climate of a region is the study of atmospheric phenomena in relation to the pressure pattern prevailing in that region. Classification of atmospheric patterns is a useful tool for managing a huge and unlimited continuity of atmospheric patterns. Classifications by identifying a number of representative patterns called moment patterns, simplify the physical reality of the atmosphere. One of the purposes of synoptic classifications is to help describe the effects of atmospheric circulation on the surface climate, which is the main task of synoptic climatology. In this paper, atmospheric pressure patterns are studied using factor analysis method. Then, by drawing synoptic maps of each pattern, the characteristics of the desired pattern were examined.
The present study investigates the recognition of prevailing atmospheric patterns during precipitation and Widespread thunderstorms in northwestern Iran. To conduct this research, first rainfall and thunderstorm data were received daily from 18 synoptic stations with a common statistical period of 20 years (1993-1992) from the Meteorological Organization. Then, to determine the selected days, the days that were reported in 5 stations and more rain and thunderstorms were selected. Then 108 days were selected by principal component analysis (PCA). Six components out of the total components that explain more than 73% of the total variance were selected for the next analysis. Then, using Euclidean distance and ward’s method, a cluster analysis on the matrix, Factor scores were performed. Then the clustering tree was drawn and the observations were divided into 5 clusters. To analyze the atmosphere in the obtained patterns, re-analyzed data were prepared with a resolution of 2.5 * 2.5 degrees from the National Center for Environmental Prediction and Atmospheric Research, USA (NCEP / NCAR). Using these data, synoptic maps in each pattern were drawn and analyzed.
Results and discussion
Investigations showed no compression patterns with Widespread thunderstorms in March. Because this month has winter features, extensive local climbs are less common this month. Therefore, Widespread thunderstorms in this month and other cold months of the year are considered a random phenomenon. It can also be said that hot and cold fronts can not create Widespread thunderstorms without local thermal rise. In other words, in summer due to lack of sufficient humidity and in cold seasons due to lack of surface heating we do not see the occurrence of Widespread thunderstorms.
At the time of the occurrence of rains and Widespread thunderstorms in northwestern Iran, It is often located at the 500 hpa level of Trough in central Iraq to the eastern Mediterranean. Differences in the location, depth and extent of this trough have caused the patterns to differ from each other, resulting in differences in the occurrence of atmospheric events in the study area. In this study, pattern three had the highest number of events compared to the 5 extracted patterns. Patterns that are limited to April and the cold days of May are more widespread. Also, patterns that occur limited to June and hot days in May are less widespread. In the Deep trough and minor Trough pattern, the precipitation is mostly influenced by local moisture sources and moisture sources close to the study area (such as the Caspian Sea). Also, in these patterns, the sources of moisture in the lower levels of the atmosphere play a greater role in the occurrence of precipitation. At the time of the Deep Trough and Minor Trough patterns, it is the combination of western systems with local ascent that creates Widespread precipitation. These patterns are limited to May and June. During these months, the ground receives the energy it needs to climb locally. The integration of the local ascent with the western system strengthens it and creates Widespread thunderstorms and rainstorms.
In patterns closed low, blocking , the Eastern Mediterranean Trough, the Red Sea and the Mediterranean Sea are the most important sources of moisture, respectively. In the mentioned patterns, moisture sources at the levels of 700 and 500 hPa play the most important role in creating Widespread precipitation. During the occurrence of closed low, blocking and trough patterns in the eastern Mediterranean, the surface temperature decreases and the role of western systems becomes more prominent. From pattern one to pattern five, the surface temperature decreases, respectively. In the Deep Trough and Minor Trough patterns, the study area experiences a temperature of 295 degrees Kelvin. In the closed low pattern, a temperature of 287 degrees Kelvin is observed in the northern half of the study area; But in the blocking pattern, the temperature of 287 is transferred to the more southern parts. In the Trough pattern of the eastern Mediterranean, the temperature of 283 degrees Kelvin is seen in the northern parts of the study area. In other words, from model one to five in the study area, the surface temperature decreases and from one model to another, the surface temperature decreases. As a result, with decreasing temperature, the effect of local ascent compared to the first and second patterns has decreased and it can be said that a significant part of thunderstorms in addition to local ascent, is affected by the front systems passing through northwestern Iran; But fronts alone cannot create widespread thunderstorms without integrating with local thermal rise.
The result was that the closed low pattern had the highest and the Deep trough pattern had the lowest repetition. Deep trough and minor trough patterns have less geographical extent than other patterns. When occur patterns closed low, blocking and trough eastern Mediterranean, the study area experiences a lower surface temperature. Also, precipitation is more extensive in these patterns and the maximum vertical air flow is observed at the level of 700 and 500 hPa. Widespread thunderstorms are more likely to occur in the spring. In winter, due to the lack of surface heating, we do not see Widespread storms. In hot seasons, too, Widespread thunderstorms cannot occur due to lack of moisture. In other words, Widespread thunderstorms in northwestern Iran occur when a local ascent is combined with a dynamic ascent resulting from the passage of a low-pressure system through the study area.


Main Subjects

  1. جلالی،م.؛ دوستکامیان، م.؛ شیری کریم وندی، امین. (1397). بررسی و تحلیل همدیدی دینامیکی سازوکارهای بارش فراگیر زمستانه ایران، نشریه تحقیقات کاربردی علوم جغرافیایی، سال 19, شماره 55، صص 55-37.
  2. جلالی، م.؛ کمریان، و. (1397). تحلیل الگوهای فضایی توفان های تندری در شمال غرب ایران، فصلنامه ی علمی پژوهشی فضای جغرافیایی، سال 18، شماره 61، صص 81-63.
  3. حجازی زاده، ز.؛ جعفرپور، ز.؛ پروین، ن. (1386). بررسی و شناسایی الگوهای سینوپتیکی تراز 500 هکتوپاسکال مولد سیلاب‌های مخرب و فراگیر سطح حوضه آبریز دریاچه ارومیه. تحقیقات کاربردی علوم جغرافیایی (علوم جغرافیایی). سال 7, شماره 10،صص 125 -155.
  4. دوستان، ر.؛ میردریکوندی، م.(1392). تحلیل سینوپتیکی بارندگی‌های سنگین و فراگیر غرب ایران، دومین کنفرانس بین‌المللی مخاطرات محیطی،صص 17-10.
  5. ذوالفقاری، ح.؛ معصوم پور سماکوش، ج.؛ جلیلیان، آ.؛ فتح نیا، ا. (1392). تعیین الگوهای سینوپتیک و توده‌های هوای مؤثر بر فصول اقلیمی غرب ایران، پژوهش‌های جغرافیای طبیعی، سال 45، شماره 1، صص 53-70.
  6. رضایی بنفشه، م.؛ حسین‌علی‌پور گزی، ف.؛ جعفری شندی، ف.؛ علی محمدی، م. (1394). تحلیل همدید بارش‌های سنگین پهنه‌ شمال غرب ایران (با تأکید بر الگوهای ضخامت جو). نشریه علمی جغرافیا و برنامه‌ریزی، سال 19، شماره 53، صص117-135.‎
  7. رفیعایی، ا.؛ علیجانی، ب.؛ یزدانی، م. (1393). تحلیل همدیدی آغاز بارش‌های فراگیر زودرس دوره سرد سال در ایران. مجله ژئوفیزیک ایران، سال 8, شماره 3، صص35-55.
  8. شکیبا، ا.؛ صادقی، س.؛ دوستان، ر. (1394). مراکز فعالیت و الگوهای سینوپتیکی بارش برف سنگین در شمال غرب ایران. جغرافیا و مخاطرات محیطی،سال 4، شماره 4، صص 87-104.‎
  9. عزیزی، ق.، گرامی، م، ص.؛ شریفی، ل. (1396). تحلیل فضایی توفان‌های تندری در گستره کشور ایران، نشریه تحقیقات کاربردی علوم جغرافیایی، سال 17، شماره 47، صص 243-259.
  10. علیجانی، ب. (1376). تعیین فصول طبیعی در ایران، مجله پژوهش‌های جغرافیایی، شماره 35، صفحه 21-33.
  11. علیجانی، ب. (1391). آب و هواشناسی ایران، چاپ یازدهم، انتشارات دانشگاه پیام نور، تهران.
  12. علیجانی، ب. (1381)، اقلیم‌شناسی سینوپتیک، انتشارات سمت، تهران.
  13. فتاحی، ا.؛ قناد، ه. (1390). تحلیل الگوهای سینوپتیکی توفان های گردوخاک در منطقه جنوب غرب ایران، فصلنامه علمی پژوهشی جغرافیا، سال 4، شماره 12، صص 49-62.
  14. گرامی، م. ص. (1394). بررسی سازوکار وقوع بارش‌های بهاره در شمال غرب ایران، پایان‌نامه کارشناسی ارشد اقلیم شناسی، دانشگاه فردوسی مشهد، استاد راهنما، عباس مفیدی، صفحه 32.
  15. گرامی، م، ص.؛ مفیدی، ع.؛ زرین، آ. (1394). تحلیل فضایی ارتباط بین وقوع بارش‌های بهاره در شمال غرب ایران و مؤلفه‌های مقیاس منطقه‌ای گردش جو، کنفرانس ملی آبیاری و زهکشی ایران، همایش آب و هواشناسی،23-24 اردیبهشت، دانشگاه فردوسی مشهد.
  16. Alijani, B.; O’Brien, J. and Yarnal, B. (2008). Spatial analysis of precipitation intensity and concentration in Iran. Theoretical and Applied Climatology,Vol. 94, No. 1, PP. 107-124.
  17. Alijani, B. (2003). Synoptic Climatology, Fifth Edition, Samt Publications, Tehran.
  18. Alijani, B. (1998). Determining the natural seasons of Iran, Geographical Research Quarterly, Vol. 34, No. 1, PP. 21-33.
  19. Alijani, B. (2013). Iranian Meteorological Book, Eleventh edition, Payame Noor University Press.
  20. Azizi, G.; Gerami, M. S. and Sharifi, L. (2017). Spatial Analysis of thunder storm in Iran. Researches in Geographical Sciences, Vol. 17, No. 47, PP. 241-257.
  21. Barry, R. G. and Carleton, A.M. (2013). Synoptic and dynamic climatology. Routledge.
  22. Bednorz, E. (2008). Synoptic conditions of snow occurrence in Budapest, Meteorologische Zeitschrift, Vol. 17, No. 1, PP. 39-46.
  23. Cassano, E. N.; Lynch, A. H.; Cassano, J. J. and Koslow, M. R. (2010). Classification of synoptic patterns in the western Arctic associated with extreme events at Barrow, Alaska, Climate Research, Vol. 30, No. 2, PP. 83-97.
  24. Changnon, S. A. and Changnon, D. (2001). Long-term fluctuations in thunderstorm activity in the United States. Climatic Change, Vol. 50, No. 4, PP. 489-503.
  25. Dayan, U.; Tubi, A. and Levy, I. (2012). On the importance of synoptic classification methods with respect to environmental phenomena. International Journal of Climatology, Vol. 32, No. 5, PP. 681-694.
  26. Donat, M. G.; Leckebusch, G. C.; Pinto, J. G. and Ulbrich, U. (2015). Examination of wind storms over Central Europe with respect to circulation weather types and NAO phases. International Journal of Climatology, Vol. 30, No. 9, PP. 1289-1300.
  27. Doostan, R. and Mirdirikvand, M. (2015). Synoptic analysis of heavy and pervasive rainfall in western Iran, Published at the Second International Conference on Environmental Hazards,
  28. Fattahi, E. and GHannad, H. (2011). Analysis of synoptic patterns of dust storms in the southwestern region of Iran, Geography, Vol. 4, No. 12, PP. 49-62.
  29. Fleig, A. K.; Tallaksen, L. M.; Hisdal, H.; Stahl, K. and Hannah, D. M. (2016). Inter-comparison of weather and circulation type classifications for hydrological drought development. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 35, No. 9-12, PP. 507-515.
  30. Gaetani, M.; Pohl, B.; Douville, H. and Fontaine, B. (2016). West African Monsoon influence on the summer Euro‐Atlantic circulation. Geophysical Research Letters, Vol. 38, No. 9, PP. 123-145.
  31. García, C.; Martí, G.; Oller, P.; Moner, I.; Gavaldà, J.; Martínez, P. and Peña, J. C. (2009). Major avalanches occurrence at regional scale and related atmospheric circulation patterns in the Eastern Pyrenees. Cold Regions Science and Technology, Vol. 59, No. 2-3, PP. 106-118.
  32. Ghavidel Rahimi, Y. (2011). The use of atmospheric instability indices for the detection and dynamic analysis thunderstorms 5 may 2011 in Tabriz, Quarterly geographical space, Vol. 9, No. 34, PP. 182-208.
  33. Gerami, M.S. (2016). Investigation of the mechanism of occurrence of spring precipitation in northwestern Iran, Master Thesis of Ferdowsi University of Mashhad, Supervisor Abbas Mofid.
  34. Gerami, M.S.; Mofidi, A. and Zarrin, A. (2016). Spatial analysis of the relationship between the occurrence of spring precipitation in northwestern Iran and the components of the Atmospheric Regions Scale, Iranian National Conference on Irrigation and Drainage, Meteorological Conference, Mashhad Ferdowsi University.
  35. Hagen, M. and Finke, U. (2000). Motion characteristics of thunderstorms in southern Germany, Meteorological Applications, Vol. 6, PP. 227-239.
  36. Hejazizadeh, Z.; Jafarpoor, Z. and Parvin, N. (2008). Investigation and identification of synoptic patterns at the level of 500 hectopascals of destructive and pervasive floods in the catchment area of Lake Urmia, Researches in Geographical Sciences, Vol. 7, No. 5, PP. 125-155.
  37. Huth, R.; Beck, C. and Kučerová, M. (2016). Synoptic‐climatological evaluation of the classifications of atmospheric circulation patterns over Europe. International Journal of Climatology, Vol. 36, No. 7, PP. 2710-2726.
  38. Huth, R.; Beck, C.; Philipp, A.; Demuzere, M.; Ustrnul, Z.; Cahynová, M. ... and Tveito, O. E. (2008). Classifications of atmospheric circulation patterns: recent advances and applications. Annals of the New York Academy of Sciences, Vol. 1146, No. 1, PP. 105-152.
  39. Jalali, M.; Doustkamian, M. and Shiri karim vandi, A. (2019). The studying and synoptic analysis of mechanical in mechanism of widespread winter precipitation of Iran, Researches in Geographical Sciences, Vol. 19, No. 55, PP. 37-55.
  40. Jalali, M. and Kamarian, V. (2018). The Analysis of Spatial Patterns of Thunderstorms in the North West of Iran, Geographical space, Vol. 18, No. 61, PP. 41-62.
  41. Kassomenos, P. (2010). Synoptic circulation control on wild fire occurrence. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 35, No. 9-12, PP. 544-552.
  42. Lericos, T.P.; Fuelberg, H.E.; Watson, A.I. and Holle, R.L. (2002). Warm season lightning distributions over the Florida Peninsula as related to synoptic patterns, Weather and Forecasting , Vol.17, PP. 83-98.
  43. López, R. E. and Holle, R. L. (1999). The distribution of lightning as a function of low-level wind flow in central Florida. NOAA Tech. Memo. ERL ESG-28, National Severe Storms Laboratory, Norman, OK, 43 pp.
  44. Lykoudis, S. P.; Kostopoulou, E. and Argiriou, A. A. (2014). Stable isotopic signature of precipitation under various synoptic classifications. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 35, No. 9-12, PP. 530-535.
  45. Martin-Vide, J.; Sanchez-Lorenzo, A.; Lopez-Bustins, A. J.; Cordobilla, M.; J. GarciaManuel, A. and Raso, J. M. (2008). Torrential rainfall in northeast of the Iberian Peninsula: synoptic patterns and WeMO influence Advances in Science and Research, Vol. 2, PP.99-105.
  46. Mohammadpour, K.; Sciortino, M. and Kaskaoutis, D. G. (2021). Classification of weather clusters over the Middle East associated with high atmospheric dust-AODs in West Iran. Atmospheric Research,Vol. 259, PP. 105682.
  47. Mojarrad, F.; Koshki, S.; Masompour, J. and Miri, M. (2018). Analysis of Thunderstorm Instability Indexes in Iran using Reanalysis Data. jsaeh. Vol. 4, No. 4, PP.33-48.
  48. Pineda, N.; Esteban, P.; Trapero, L.; Soler, X. and Beck, C. (2015). Circulation types related to lightning activity over Catalonia and the Principality of Andorra. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 35, No. 9-12, PP. 469-476.
  49. Rafiaei, A.; Alijani, B. and Yazdani, M. (2014). Synoptic analysis of the onset of the earliest widespread winter precipitation in Iran (except the Caspian Sea coastal region). Iranian Journal of Geophysics,Vol. 8, No. 3, pp. 36-48.
  50. Ramos, A. M.; Ramos, R.; Sousa, P.; Trigo, R. M.; Janeira, M. and Prior, V. (2017). Cloud to ground lightning activity over Portugal and its association with circulation weather types. Atmospheric Research, Vol. 101, No. 1-2, PP. 84-101.
  51. Rasilla, D. F.; García-Codron, J. C.; Carracedo, V. and Diego, C. (2010). Circulation patterns, wildfire risk and wildfire occurrence at continental Spain. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 35, No. 9-12, PP. 553-560.
  52. Raziei, T.; Bordi, I.; Pereira, L. S.; Corte‐Real, J. and Santos, J. A. (2012). Relationship between daily atmospheric circulation types and winter dry/wet spells in western Iran. International Journal of Climatology, Vol. 32, No.7, PP. 1056-1068.
  53. Rezaee Banafshe, M.; Hossein Alipour Ghazi, H.; Jaffari Shendi, F. and Alimohammadi, M. (2015). Synoptic Analysis of Heavy Rainfall in Northwest of Iran (With an Emphasis on Patterns of Atmospheric Thickness). Geography and Planning,Vol. 19, No. 53, PP. 117-135.
  54. Shakiba, A.; Sadeghib, S. and Doostan, R. (2016). The Synoptic Activity Centers and Pressure Patterns of Heavy Snowfall in Northwest of Iran, Journal of Geography and Environmental Hazards, Vol.4, No. 4, PP. 87-104.
  55. Tomás, C.; De Pablo, F. and Rivas Soriano, L. (2004). Circulation weather types and cloudto-ground flash density over the Iberian Peninsula. International Journal of Climatology, Vol. 24, No.1, PP. 109-123.
  56. Wilks, D.S. (2011). Statistical methods in the atmospheric sciences(Vol. 100). Academic press.
  57. Yarnal, B. (1993). Synoptic Climatology in Environmental Analysis. A Primer. Belhaven Press: London.
  58. Yarnal, B.; Comrie, A. ; Frakes, B. and Brown, D. P. (2001). Developments and prospects in synoptic climatology. International Journal of Climatology: A Journal of the Royal Meteorological Society, Vol. 21, No. 15, PP. 1923-1950.
  59. Zolfaghari, H.; Masoompour Samakosh, J.; Jalilian, A. and Fathnia, A. (2013). Studying and Determining of Synoptic Patterns of Climatic Seasons in the West of Iran. Physical Geography Research Quarterly, Vol. 45, No. 1, PP. 53-70.