واکاوی همدیدی اثر تغییرات اقلیمی بر ویژگی های پوشش برف زاگرس میانی در ارتباط با الگوهای گردشی جو

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری دانشگاه یزد

2 عضو هیات علمی دانشگاه یزد

3 دانشیار آب و هواشناسی، دانشگاه یزد، یزد، ایران

چکیده

یکی از عوامل موثر در فرایند تغییر اقلیم تغییرات عمده در مقدار برف و باران است. در این پژوهش از داده های روزهای همراه با برف در طول دوره آماری (2018-1989)، استفاده شد. سپس به دلیل اهمیت در مطالعه پوشش برف، نقشه های ارتفاع ژئوپتانسیل تراز 500 و 850 هکتوپاسکال، سرعت و جهت بادهای سطح زمین، نقشه رطوبت نسبی سطح زمین، نقشه آب قابل بارش، نقشه امگای تراز 500 و 850 هکتوپاسکال و نقشه فشار سطح دریا،با استفاده از تکنیک تحلیل عاملی و روش خوشه بندی سلسله مراتبی وارد چهار الگوی همدیدی حاکم بر روزهای برفی شناسایی و تعیین گردید . نتایج نشان داد که الگوی اول و سوم با مجموع 5/64 درصد الگوی غالب بارش برف در زاگرس میانی می باشند که عمدتاً به دلیل استقرار مرکز پرفشار در دریای مدیترانه و دریای سیاه و قرارگیری منطقه مورد مطالعه در جلو ناوه عمیق در سطح بالا است. همچنین در غالب مواقع بارش برف سنگین یک سردچال در تراز 850 هکتوپاسکال شکل می گیرد که منطقه را تحت تاثیر قرار می دهد و در بیشتر مواقع ناوه ای قوی در شرق اروپا قرار گرفته است که از غرب دریای خزر تا جنوب دریای سرخ کشیده می شود.بررسی سایر الگوها نشان می دهد که مرکز پرارتفاع جنب حاره ای غرب مدیترانه و فلات تبت تقویت می شود و با جابه جایی به عرض های جغرافیایی بالاتر به ایجاد پشته های قوی با محور شمالی- جنوبی در اروپا و آسیا کمک می کند. تاوه قطبی در چنین مواقعی با محور شمالی- جنوبی یا شمال شرقی- جنوب غربی به عرض های پایین از جمله شمال خزر و غرب ایران امتداد می یابد و موجب ریزش هوای سرد در منطقه می شود. در مجموع در بررسی الگوها مشاهده شد که برای ریزش برف سنگین نفوذ تاوه قطبی به عرض های پایین ضروری است

کلیدواژه‌ها


عنوان مقاله [English]

Synopsis analysis of the effect of climate change on the characteristics of the snow cover of Middle Zagros in relation to atmospheric circulation patterns

نویسندگان [English]

  • moslem seidy shahivandi 1
  • kamal omidvar 2
  • gholamali mozafari 2
  • Ahmad Mazidi 3
1 PHDstudent of yazd univerity
2 Department of Geography,Yazd University
3 Associate Professor of Climatology, Yazd University, Yazd, Iran
چکیده [English]

Atmospheric circulation has a variety of patterns in terms of time and space, However, drastic changes in atmospheric factors and elements have caused anomalies in these patterns, which result in changes in temperature, humidity, pressure and precipitation in different parts of the world, one of which can be the snowfall in snow-covered areas. Snow cover has significant effects on climate, such as the effect of radiant energy in the region and atmospheric and thermal circulation, and any changes in climate may have long-term environmental and economic consequences for the time, amount and distribution of snow. Cold, rainy and snowy winters are a feature of the mountainous climate of the Central Zagros region of Iran, which is the gateway for various humid air masses to enter Iran from the Mediterranean and Eastern Europe. With this feature and being mountainous, the region is witnessing low temperatures and snowfall in the mountainous areas of this region. In this research, snowfall in the Middle Zagros, which is the source, the most important catchment area of the country and the source of the most important and largest rivers in Iran to the south and southwest of the country is investigated. This is especially necessary in the mountainous areas of the Zagros, where water from snowmelt plays an important role in runoff, which can be considered a pivotal operation in the field of water resources management and flood control in the Zagros. Therefore, the present study tries to investigate the relationship between changes in snow cover in the Middle Zagros region and changes in atmospheric circulation patterns using synoptic methods. The purpose of this study is to analyze the synoptic characteristics of the Middle Zagros snow cover in relation to atmospheric circulation patterns and to explain the spatial and temporal characteristics of this phenomenon using the statistics of synoptic stations in the study area. The results can help in forecasting and planning surface and groundwater resources as well as drought and prevent damage due to flooding of rivers in this region, most of which is due to snowmelt in the highlands of this region. The data required for the study include hourly and daily meteorological statistics of snowy days at synoptic stations in the three provinces of Ilam, Kermanshah and Lorestan, which were obtained from the Meteorological Organization. Geopotential altitude data of 500 and 850 and sea level were also obtained from the website of the National Center for Environmental Prediction and the National Meteorological Research Center (NCEP / NCAR). These statistics cover the long-term period (2018-1989). After extracting the snow day codes (including codes 70, 71, 72, 73, 74, 75), it was found that among the stations in the region, 14 stations had days with snow to be checked, which in terms of time distribution. And have a statistical period of 30 years and cover the entire Middle Zagros. In this study, after collecting statistics and data on snow-related days during the statistical period (1989-2018) in synonymous stations located in three provinces of Kermanshah, Ilam and Lorestan, as well as data on different atmospheric levels from the site of NCEP/NCAR center in Middle Zagros, they were processed using factor analysis and hierarchical clustering techniques and The results were analyzed and finally different snow-generating companion patterns in the study area were studied in detail. The results of studying circulatory coping patterns after analyzing the data at the levels of 500 and 850 hpa were entered using factor analysis technique and hierarchical clustering method, four models of companionship governing the snowy days of middle Zagros were identified and determined. These results showed that four distinct patterns for snowfall in middle Zagros can be identified. Accordingly, the first and third patterns with a total of 64.5% of the dominant pattern of snowfall in middle Zagros are mainly due to the establishment of high pressure center in the Mediterranean and Black Sea and the study area in the front of the deep landing at a high level Also, in most cases of heavy snowfall, a cold hole is formed at the level of 850 hpe which covers the study area and In most cases, a strong carrier is located in Eastern Europe or stretched diagonally from the west of the Caspian Sea to the south of the Red Sea. The study of patterns shows that the high-elevated center of the western Mediterranean and tibetan plateau is strengthened and by moving to higher latitudes, it helps to create strong graphs with north-south axis in Europe and Asia. The creation of these crypts and the existence of low-lying or cold centers in western Iran strengthens the eastern Mediterranean frigate and stretches to low latitudes and causes cold escape in the study area. On such days, the polar vortex fold extends to low latitudes such as the north of the Caspian and western Iran with the north-south or northeast-southwest axis, causing cold air to fall in the region. In the study of patterns and days of heavy snowfall, it is necessary to penetrate the polar vertex fold into low latitudes for heavy snowfall.

کلیدواژه‌ها [English]

  • Synoptic Analysis
  • Snow
  • Cluster Analysis
  • Aactor Analysis
  • Middle Zagros
  1. Abhari, Maryam (2005), Synoptic Analysis of Heavy Snow and Its Impact on Haraz Road Avalanches, M.Sc. Thesis, Shahid Beheshti University.
  2. Azizi, G., Rahimi, M., Mohammadi, H., & Khoshakhlagh, F. (2017). Spatio-temporal variations of snow cover in the southern slope of central Alborz. Physical Geography Research, 49(3), 381-393 .
  3. Babaian Iman, Najafi Nik, Zahra, Zabol Abbasi, Fatemeh, Habibi, Nokhandan, Mojbad, Adab, Majid, Blousi, Sharareh, (2009), Climate change assessment in the period 2039-2010 using the exponential scale of circulation model data General Atmosphere, Journal of Geography and Development. .
  4. Bednorz, E, (2008). Synoptic reasons for heavy snowfalls in the Polish- German Lowlands , International Journal of Cimatoligy,, 31(8), pp1108-1118.
  5. Dargahian, Fatemeh, Alijani, Bahlol (2019), synoptic and dynamic investigation of snowfall in Iran in 2012 with an emphasis on the phenomenon of blocking, Journal of Natural Environment Hazards, number 12, pp 19-36.
  6. Derksen, C., Walker, A., & Goodison, B. (2005). Evaluation of passive microwave snow water equivalent retrievals across the boreal forest/tundra transition of western Canada. Remote sensing of environment, 96(3-4), 315-327..
  7. Esteban, P Jones. PD, Martin.J, and Masem.M,2005, Atmosphere circulation patterns related to heavy snowfall days in Andorra, Pyrenees, International Journal of Climatology, No 25, pp 319-329.
  8. Fahiminejad, Elham, Hijazizadeh, Zahra, Alijani, Bahloul, Ziaian Parviz (2012), Synoptic analysis of the snowstorm in Gilan province (February 2005), Regional Development Geography Journal, No. 19,pp 281-302.
  9. Falahati, F., Alijani, B. & Saliqeh, M. (2018). Investigating the effect of climate change on snow cover with the approach of water resources management in the coming decades (Case study: Basin of watershed leading to Amir Kabir dam. Scientific Journal of Rescue and Relief, 9(3),pp68-79.
  10. Fatahi, Ebrahim, Shiravand, Hangameh, Investigation of atmospheric circulation patterns on days with heavy snow in western Iran, Journal of Environmental Hazard Analysis, first year, serial number 1, 2013, 97-107.
  11. S, Hu, Q, (2007), chang in winter snowfall precipitation ratio the contiguous United States. Journal of Geophysical research atmospheres, 112(D15)
  12. Ghorbanizadeh Kharazi, Hossein. Saghafian, Bahram. Hagh Neghdar, Amin. (2007). Preliminary study of the effect of Enso phenomenon. Precipitation, snow level and temperature on the average flow of Karun River in Shaloo Bridge hydrometric station. The first regional conference of Behbahan water, Islamic Azad University, Behbahan branch.
  13. Hendrikx, J., Hreinsson, E, O, (2012) The potential impact of climate change on seasonal snow in New Zealand: part II industry valerabli and future snowmaking potential, Theoretical and Applied climatology, 110(4), pp, 619-630.
  14. Huang, Xiaodong, Deng, Jie, Wang, Wei, Feng, Qisheng, Liang, Tiangang, 2017, Impact of climate and elevation on snow cover using integrated remote sensing snow products in Tibetan Plateau, Remote Sensing of Environment, Volume 190, PP 274–288.
  15. Karandish, Fatemeh., Ebrahimi, Kiomars., Porhemat, Jahangir. (2008). Calibration of snowmelt parameters in estimating flood hydrograph - Karun Basin, Shaloo Bridge. The Second National Conference on Hydropower, Tehran, Iran Water and Power Resources Development Company.
  16. Kashki, Abdolreza, Haji Mohammadi, Hassan (2016). Investigating atmospheric synoptic systems during heavy snow events in the northern provinces of Iran, Journal of Water Resources Research, 13th year, number 2, 170-181.
  17. Klein, Geoffrey, Vitesse, Yann, Rixen, Christian, Marty, Christoph, Rebetez, Martine, 2016, Shorter snow cover duration since 1970 in the Swiss Alps due to earlier snowmelt more than to later snow onset, Climatic Change, Volume 139, pp 637– 649.
  18. Lashkari, Hassan, Naghizadeh, Habibeh, Moradi, Mohammad, Najafi, Mohammad Saeed (2013), Analysis of basic synoptics of snowfall in northwestern Iran, Journal of Climatological Research, Fifth Year, No. 19 ,pp11-22.
  19. Laternser, M., schaneebeli, M.(2003). Long-term snow climate trends of the Swiss Alps(1931-99). International Journal of climatology, 23(7),733-750.
  20. Lehning, M., Bartelt, P., Brown, B., Fierz, C (2000). A physical SNOW- PACK model for the Swiss avalanche warning: Part III: Meterological focing, thin Layer formation and evaluation. Cold Regions Science and Technology,35(3), 169-184.
  21. Miller, N. L., Bashford, K. E., Strem., E. (2003). Potential impacts of climate change on California hydroloyl. Climatology, 110(4), 619-630.
  22. Mimmack, G.M., Mason, S.J., Galpin, J.S. (2001). Distance Metrics in hierarchical cluster analysis: defining regions. Journal of Climate, 14: 2790- 2797.
  23. Mirmousavi, Seyyed Hossein, Sabour, Lyal (2013) Study The trend of changes in snowfall in the northwestern region of Iran. Geography and environmental planning, year 25, number 3, pp. 119-136.
  24. Momenpour, Forough, Negah, Samaneh, Hadinjad Sabouri, Shabnam,Farid Mojtahedi, Nima and Asadi Eskoui, Ibrahim (2013)Analyzing thmechanism of the hazard of heavy snow in JalgahiGyalen in the last half century,geography and environmental.no,9, pp. 17-36.
  25. Montazeri, Majid, Fanai, Razieh, (2017), Identifying Iran's Snowy Regions by Cluster Analysis, Journal of Natural Environment Hazards, Volume 7, Number 16, pp 241-258.
  26. Mostafaei, Jalal, Kalantari, Mustafa. (2004). Cluster analysis. Associate Thesis in Statistics, Faculty of Statistics and Informatics, Iranian Education Evaluation Organization, Tehran.
  27. Petkova, N., Brown, R., Koleva, E., Alexandrov, V. (2005). Snow cover change in Bulgarian Mountainous regions, 1931-2000. Hrevaski Meteor- OLISKI CASOPIS, 40(40), 662-665.
  28. Rezaei, P. and Janbaz Ghobadi, Gh.R. (2012). The Synoptic Analysis of Snow in Guilan Plain. J. Basic. Appl. Sci. Res., 2(5)4722-4732.
  29. Safari, Hedieh, Salahi, Boroumand (2010), Synoptic statistical analysis of heavy snowfalls in Kermanshah, Fifth National Conference on Geology and Environment.
  30. Shakiba, Amineh, Sadeghi, Soleiman, Doostan, Reza,(2016). The Synoptic Activity Centers and Pressure Patterns of Heavy Snowfall in Northwest of Iran. Journal of Geography and Environmental Hazards. 4(16)87.magiran.com/p154854.
  31. Sen, P. K (1968). Estimates of the regression coefficients based on Kendall’s tau. Journal of the American Statistical Association, 63:1379–1389.
  32. Simona, F., Silvia, T., Fiorella, A.,Mattia, F., Diego, G., Cristina, P.M., Secondo, B.(2015). How Snow and Its Physical Properties Change in a changing Climate Alpine Context? In Engineering Geology for Society and Territory- Volume 1 (pp.57-60). Springer International Publishing.