Recognition of patterns and synoptic analysis of rainstorm in western Iran based on thermodynamic instability indices: A case study of Ah-vaz

نوع مقاله : مقاله پژوهشی‌

نویسندگان

1 Professor, Department of Physical Geography, University of Mohaghegh Ardabili, Ardabil, Iran

2 Ph.D. in Climatology, Environmental Hazards, Marine Science Institute, Kish International Campus, University of Tehran, Tehran, Iran

چکیده

In this research, patterning of rainstorm (more than 10 mm) was conducted by instability indices in Ahvaz. At first, rainfall data from 2000 to 2015 was extracted and statistically examined. Instability indices for rainy days were calculated by the Skew-T diagram. Then, patterning was done by using hierarchical clustering, Ward method, and Euclidean distance. As the sample, one day was selected from each cluster and was synoptically analyzed. The results revealed 60 rainstorms for the respective period. More rainstorms occurred in January and December. Autumn and winter had the most frequent days of rainstorm, while it did not occur in the summer. The results of classification divided rainstorms into 4 patterns and more days were in the fourth class, while the least was in the second class. In the second and fourth classes, instability indices were severe and could predict possible rainstorms, but the first and third classes couldn’t predict because synoptic systems caused the occurrence of the rainstorm. In the second and fourth classes, rainstorms were convectional. The synoptic
analysis showed that every time rainstorm occurred in Ahvaz, a deep trough at 500 hPa was formed in the East Mediterranean and the area was in front of it. Also, at sea level pressure, a low-pressure system formed in Iraq and winds got humid by passing through the Persian Gulf and entered into the atmosphere of Ahvaz. Due to the unstable atmosphere, the air would rise to heights causing rainstorm.

کلیدواژه‌ها

عنوان مقاله [English]

Recognition of patterns and synoptic analysis of rainstorm in western Iran based on thermodynamic instability indices: A case study of Ah-vaz

نویسندگان [English]

  • Bromand Salahi 1
  • Mahmoud Behrouzi 2
1 Professor, Department of Physical Geography, University of Mohaghegh Ardabili, Ardabil, Iran
2 Ph.D. in Climatology, Environmental Hazards, Marine Science Institute, Kish International Campus, University of Tehran, Tehran, Iran
چکیده [English]

In this research, patterning of rainstorm (more than 10 mm) was conducted by instability indices in Ahvaz. At first, rainfall data from 2000 to 2015 was extracted and statistically examined. Instability indices for rainy days were calculated by the Skew-T diagram. Then, patterning was done by using hierarchical clustering, Ward method, and Euclidean distance. As the sample, one day was selected from each cluster and was synoptically analyzed. The results revealed 60 rainstorms for the respective period. More rainstorms occurred in January and December. Autumn and winter had the most frequent days of rainstorm, while it did not occur in the summer. The results of classification divided rainstorms into 4 patterns and more days were in the fourth class, while the least was in the second class. In the second and fourth classes, instability indices were severe and could predict possible rainstorms, but the first and third classes couldn’t predict because synoptic systems caused the occurrence of the rainstorm. In the second and fourth classes, rainstorms were convectional. The synoptic
analysis showed that every time rainstorm occurred in Ahvaz, a deep trough at 500 hPa was formed in the East Mediterranean and the area was in front of it. Also, at sea level pressure, a low-pressure system formed in Iraq and winds got humid by passing through the Persian Gulf and entered into the atmosphere of Ahvaz. Due to the unstable atmosphere, the air would rise to heights causing rainstorm.

کلیدواژه‌ها [English]

  • Rainstorm
  • instability indices
  • clustering
  • synoptic analysis
  • Ahvaz

مراجع

Bagheri, S., 1993, Synoptic investigation of flood producing pressure systems in North Iran (Doctoral dissertation, MS Thesis, Meteorology Department, Institute of Geophysics, and University of Tehran. (In Persian)
Barros, A. P. and Kuligowski, R. J, 1998, Orographic effects during a severe wintertime rainstorm in the Appalachian Mountains. Monthly Weather Review, 126(10), 2648-2672.
Beal, A., Hallak, R., Martins, L. D., Martins, J. A, Biz, G., Rudke, A. P and Tarley, C. R., 2020, Climatology of hail in the triple border Paraná, Santa Catarina (Brazil) and Argentina. Atmospheric Research, 234, 104747.‏
Bradley, A. A. and Smith, J. A., 1994, The hydro meteorological environment of extreme rainstorms in the southern plains of the United States. Journal of Applied Meteorology, 33(12), 1418-1431.
Cao, X. G., Wang, H., Zou, L. J., Chen, Y. L. and Zhang, J., 2011, Contrast Analysis on'010805'and'080825'Heavy Rainstorm in Shanghai [J]. Plateau Meteorology, 3, 022.
Changnon, S. A., 1999, Record flood-producing rainstorms of 17–18 July 1996 in the Chicago metropolitan area. Part III: Impacts and responses to the flash flooding. Journal of Applied Meteorology, 38(3), 273-280.
Changnon, S. A. and Westcott, N. E., 2002, Heavy rainstorms in Chicago: Increasing frequency, altered impacts, and future implications. JAWRA Journal of the American Water Resources Association, 38(5), 1467-1475.
Chantraket, P., Kirtsaeng, S., Detyothin, C., Nakburee, A. and Mongkala, K., 2015, Characteristics of Hailstorm over Northern Thailand during Summer Season. Environment Asia, 8(1),101-114
Chen, L. C. and Bradley, A. A., 2006, Spatial and temporal characteristics of extreme rainstorms over the central United States. In 20th Conf. on Hydrology (CD-Rom), American Meteorological Society, Atlanta, Preprints (Vol. 1).
Colquhoun, J. R., 1987, A decision tree method of forecasting thunderstorms, severe thunderstorms and tornadoes. Weather and forecasting, 2(4), 337-345.
Cummine, J., Murphy, B. P. and Ford, R. P., 2002, The 49th Parallel Severe Rainstorm-An example of elevated thunderstorms and their impact, June 8 to 11.
Dayan, U. and Morin, E., 2006, Flash flood–producing rainstorms over the Dead Sea: A review. Geological Society of America Special Papers, 401, 53-62.
Dayan, u., Nissen, K. and Ulbrich, U., 2015, Review Article: Atmospheric conditions inducing extreme precipitation over the eastern and western Mediterranean. Nat. Hazards Earth Syst. Sci., 15, 2525–2544.
Dong-hong, L. V., 2009, A Diagnostic Analysis of Continual Rainstorm Process in Taizhou Area during July 7-9, 2007 [J]. Journal of Anhui Agricultural Sciences, 3, 115.
Galway, J. G., 1956, The lifted index as a predictor of latent instability. Bull. Amer. Meteor. Soc., 43, 528-529.
George, J. J., 1960, Weather Forecasting for Aeronautics. Academic Press, 673 pp.
Hales, E., 1996, Severe weather forecasting. Personal SPC notes, Severe Weather Forecast.
Hansen, E. M., Schwarz, F. K., Riedel, J. T., 1981, Meteorology of important rainstorms in the Colorado River and Great Basin drainages. National Oceanic and Atmospheric Administration Hydro meteorological Report, (50).
Hervada-Salaa, C. and Jarauta-Bragulat, E., 2004, A program to perform Ward’s clustering method on several regionalized variables; Comput Geosci, 30, 881–886.
Jenamani, R. K., Bhan, S. C., Kalsi, S. R, 2006, Observational/forecasting aspects of the meteorological event that caused a record highest rainfall in Mumbai. Current Science, 1344-1362.
Kahana, R., Ziv, B., Enzel, Y. and Dayan, U., 2002, Synoptic climatology of major floods in the Negev Desert, Israel. International Journal of Climatology, 22(7), 867-882.
Li, L., Rong, L., Xia, Z., Huimin, F. and Hongxing, W., 2007, Analysis of the Stability and Energy Parameters in a Short-time Rainstorm [J]. Meteorological and Environmental Sciences, 4, 010.
Lu, J., Qie, X., Jiang, R., Xiao, X., Liu, D., Li, J. and Yi, X., 2021, Lightning activity during convective cell mergers in a squall line and corresponding dynamical and thermodynamical characteristics. Atmospheric Research, 256, 105555.‏
Mahović, N. S., Plačko-Vršnak, D. and Drvar, D. M., 2012, Synoptic and Mesoscale Analysis of Hailstorms over Croatia on 22 and 23 June 2007. Hrvatski meteorološki časopis, 47, 57-67.
Melcón, P., Merino, A., Sánchez, J. L., López, L. and García-Ortega, E., 2017, Spatial patterns of thermodynamic conditions of hailstorms in southwestern France. Atmospheric Research, 189, 111-126.‏
Miller, R. C., 1972, Notes on analysis and severe storm forecasting procedures of the Air Force Global Weather Central. Tech. Report 200(R), Headquarters, Air Weather Service, Scott Air Force Base, IL 62225, 190 pp.
Moncrieff, M. W. and Miller, M. J., 1976, the dynamics and simulation of tropical cumulonimbus and squall lines. Q.J.R. Roy. Meteorol. Soc, 102, 373-394.
Movahedi, S., heydari, B., Hashemi, S. K. and Ranjbar., F, 2012, The Identification of Climatic Regions in Khouzestan Province. Geographical Space. 12(4), 64-73. (In Persian)
Pablo Davilaa, L. F., Rivas Sorianoa, J., JiménezAlonsob, L. J. and MoraGarcíac, M., 2021, Synoptic patterns of severe hailstorm events in Spain, Atmospheric Research, 250, 105397. https://doi.org/10.1016/j.atmosres.2020.105397.
Peleg, N. and Morin, E., 2012, Convective rain cells: Radar‐derived spatiotemporal characteristics and synoptic patterns over the eastern Mediterranean. Journal of Geophysical Research: Atmospheres, 117(D15). (In Persian)
Punge, H. J. and Kunz, M., 2016, Hail observations and hailstorm characteristics in Europe: A review. Atmospheric Research, 176, 159-184.‏
Qin, N., Wang, J., Yang, G., Chen, X., Liang, H. and Zhang, J., 2015, Spatial and temporal variations of extreme precipitation and temperature events for the Southwest China in 1960–2009. Geoenvironmental Disasters, 2(1), 4.
Qingzhi, S., Chungui, Q. and Yuanyuan, G, 2009, Synoptic Analysis of the Super Rainstorm Process in Henan [J]. Meteorological and Environmental Sciences, 3, 13-23.
Raveh‐Rubin, S. and Wernli, H., 2015, Large‐scale wind and precipitation extremes in the Mediterranean: a climatological analysis for 1979–2012. Quarterly Journal of the Royal Meteorological Society, 141(691), 2404-2417.
Sabziparvar, A. A., Parandeh, A., Lashkari, H. and Yazdanpanah, H, 2010, Mid-level synoptic analysis of flood-generating systems in South-west of Iran (case study: Dalaki watershed river basin). Natural Hazards and Earth System Sciences, 10(11), 2269. (In Persian)
Salimi Sobhan, M., Hejazizadeh, Z., Fishing, F. and Ghaderi, F., 2019, Synoptic analysis and identification of moisture flux of days with hail in western Iran (Case study: Zab catchment, West Azerbaijan), Natural Geography Research, 110, 715-731.
Showalter, A. K., 1953, A stability index for thunderstorm forecasting. Bull. Amer. Meteor. Soc, 34(6), 250-252.
Teng, S., QU, Y., Wang, J., LI, B., Zhang, T. and Wang, R., 2007, Synoptic Diagnosis of a Sudden Rainstorm Process in Hexi Corrider [J]. Arid Meteorology, 3, 011.
Toker, E., Ezber, Y. and Sen, O. L., 2021, Numerical simulation and sensitivity study of a severe hailstorm over Istanbul. Atmospheric Research, 250, 105373.‏
Torri, D., Regüés, D., Pellegrini, S. and Bazzoffi, P., 1999, Within-storm soil surface dynamics and erosive effects of rainstorms. Catena, 38(2), 131-150.
Trefalt, S., Martynov, A., Barras, H., Besic, N., Hering, A. M., Lenggenhager, S. and Martius, O., 2018, A severe hail storm in complex topography in Switzerland-Observations and processes. Atmospheric research, 209, 76-94.‏
Van Delden, A., 2001, The synoptic setting of thunderstorms in Western Europe. Atmospheric research, 56(1), 89-110.
Yao, H., Li, X., Pang, H., Sheng, L. and Wang, W., 2020, Application of random forest algorithm in hail forecasting over Shandong Peninsula. Atmospheric Research, 244, 105093.‏
Zhao, Y. C. and Cui, C. G., 2010, A study of rainstorm process triggering Zhouqu extremely mudslide on 8 August 2010. Torrential Rain and Disasters, 3, 15-30.
مجله ژئوفیزیک ایران
دوره 16، شماره 4
بهمن 1401
صفحه 101-112

فایل ها

هم رسانی

ارجاع به این مقاله

آمار