Statistical Synoptic analysis of pervasive cooling waves in northwest Iran

Document Type : Full length article


1 PhD candidate in Climate Change, University of Zanjan

2 Assistant professor of Geography, University of Zanjan

3 Graduate in synoptic Meteorology, University of Zanjan


The amount of solar energy absorbed by earth surface features and converted into heat energy is measured as temperature. General temperature values are a function of elevation and latitude. Other secondary factors such as location of water bodies and land cover properties as local agents can form temperature structure of each location. One of the exceptional temperature situations representing minimum temperature values is cold waves. Given the general circulation pattern of the northern hemisphere, Iran is located in a place influenced by a variety of air masses. One of the important climatic phenomena prevailing in most of the country is cooling and freezing condition. Northwest Iran as a cold region is always experiencing losses by the extreme cooling events. Therefore, investigation about the patterns creating the extensive cooling waves can help us understand the behavior of the climatic phenomenon. 
Materials and methods
In order to examine the synoptic patterns of the cooling waves in northwest Iran as the purpose of this study, we have obtained the minimum temperature of 42 synoptic stations from Iran Meteorological Organization. We have selected the stations with longest period of data available. After sorting and quality control of the data and test of sufficiency of the sample stations, the minimum temperature has been interpolated by kriging method using scripting. In the procedure, a matrix 42*365 has been formed for the variables of each year. After the interpolation has been done, a matrix 5082*11323 has been formed for the 30 year statistical period and used as database in next stages of the research.
In this study, we have selected the days with cooling waves that have: (1) standard score less than -1.2, (2) spatial coherence, (3) 50% of spatial coverage, (4) the cooling waves in two successive days. Using these conditions, the days with the cooling waves have been selected for the Northwest Iran. After classification of sea level pressure data, suitable site has been selected to determine the representative days. Using scripting in MATLAB, we have calculated the correlations between the maps of different days for each class (2-6 groups), in 0.5 coefficient. We have used mean daily temperature data from 44 synoptic stations in northwest Iran from 1980 to 2010. The daily temperature data have been interpolated by kriging method using scripting in MATLAB, in the cells of 15x15 km and a total of 5082 cells. Using the defined threshold, up to 1196 cold days have been selected. They have been divided into four patterns combined by clustering program to draw the maps in Surfer. For more precise analysis of the cold waves in northwest Iran, other dynamic quantities including thermal blowing, atmospheric divergence and convergence, and prevailing meridian winds.   
Results and discussion  
The results of the cooling wave patterns have indicated that four synoptic patterns are influencing the cooling waves. These patterns are including low pressure belt of west Russia and North Africa with East Turkey high, East Europe low pressure, enormous high pressure of east Europe with Sudan low, Siberian high with European high pressure. The most severe cold waves occurred when the enormous high pressure of east Europe moved the high latitude cold air through a cyclone movement into the study area. As a result, a low was formed over north Europe and moved towards the east and lower latitude areas. This movement developed the high pressure on North Africa and Mediterranean Sea. It also brought Siberian high pressure over the region with a cold weather condition. There was also a negative pressure anomaly at the location of the low. The pattern formed in trough part suitable for overshooting of cold air. In this pattern, a progressive change can be observed in contours from Europe towards Iran. This provided suitable condition for descend of the cold air from northern Europe and cold air flows from higher latitudes towards Iran. In a comparative analysis of the effective patterns in cooling waves in northwest Iran, it can be argued that the influence of the patterns revealed that two patterns of east Europe low and the west Russia and north Europe low with east Turkey high have the greatest influence on creation of the cold wave in the region. This is due to extensive descending of the high latitude cold air into median and low atmospheric levels. Since the study area is located in the east part of the overshooting of warm air from low latitudes into the median atmospheric levels, the third pattern reduced the severity of the cooling wave. The fourth pattern moved parts of Siberian high and European low towards northwest areas and created a high with prevailing cold weather. This has the lightest severity of the cold wave because the cold air was not penetrated into median atmospheric levels.
This research has investigated the synoptic patterns of three days lasting cooling waves in northwest Iran in the last decades. The research has revealed some synoptic patterns for the cooling in the region. The results of the patterns have indicated that most of the prevailing cooling events in the northwest Iran are resulted from formation of Siberian high pressure near the earth surface. Arrangement of the two high pressure systems of Siberian high and western migrating highs have played the most important role in conducting the high latitude cold air into the northwest region. In most of the patterns, the most important phenomenon and the principal agent of cooling event is establishment of a deep trough over the region. In other cases, establishment of sub-polar low in northern Europe and Russia made the polar cold air masses to penetrate into lower latitudes and the northwest Iran. 


Main Subjects

اسماعیلی، ر. و خسروی، م. (1386). الگوهای همدید یخبندان‏های دیررس شمال‏ شرق کشور، مجموعه علوم جغرافیایی، 7ـ8: 53ـ75.
امام هادی، م. و علیجانی، ب. (1383). توده‏های هوای مؤثر بر ایران در دورة سرد سال، مجلة تحقیقات جغرافیایی، 628: 34ـ53.
جهان‏بخش اصل، س. و باباپور، ع. ا. (1382). بررسی و پیش‏بینی متوسط دمای ماهانة تبریز با استفاده از مدل آریما، تحقیقات فصل‏نامة جغرافیایی دانشگاه اصفهان، 3: 34-46.
جهان‏بخش، س.؛ رضائی، س.؛ قاسمی، ا.ر. و تدینی، م. (1390). تحلیل سینوپتیکی یخبندان‏های بهارة تبریز (مطالعة موردی: سرمای بهار 1382 و 1383)، فصل‏نامة تحقیقات جغرافیایی، 3: 17248ـ17272.
حبیبی، ف. (1385). تحلیل همدیدی و دینامیکی سامانه‏های بندالی، روش تشخیص سامانة بندال و تأثیر آن روی منطقة ایران، مجلۀ فیزیک زمین و فضا، 32: 69ـ89.
حلبیان، اح. و حسینعلی پورجزی، ف. (1391). شناسایی شرایط همدید بارش‏های حدی و فراگیر در کرانه‏های غربی خزر با تأکید بر الگوی ضخامت جوی، جغرافیا و پایداری محیط، 3: 101ـ122.
خلجی، م. (1387). پیش‏بینی سرمای دیررس بهاره و یخبندان زودرس پاییزه برای تعدادی ازگیاهان زراعی و باغی در استان چهارمحال و بختیاری، مجلة نهال و بذر، ش17: 126.
دارند، م. (1393). شناسایی امواج سرما و تحلیل زمانی- مکانی آن‏ها بر روی ایران‏زمین، جغرافیا و برنامه‏ریزی محیطی، 2: 268-253.
رحیمی، م. (1387). بررسی احتمال زمانی وقوع یخبندان‏های دیرس بهاره و زودرس پاییزه در البرز مرکزی، پایان‏نامة کارشناسی ارشد، گروه جغرافیا، دانشگاه تهران.
شاهرخوندی، م.؛ غیور، ح‏ع. و کاویانی، م‏ر. (1386). گردش بهنجار جو و پارامترهای شاخص مراکز عمل در فصل زمستان بر روی ایران، مجلة پژوهشی دانشگاه اصفهان، 22: 85ـ100.
صادقی، س.؛ حسین‏زاده، س‏ر.؛ دوستان، ر. و آهنگرزاده، ز. (1391). تحلیل همدیدی امواج سرمایی در شمال شرق ایران، جغرافیا و مخاطرات محیطی، 3: 107ـ123.
عزیزی، ق. (1383). ارزیابی سینوپتیکی یخبندان‏های بهاری در نیمة غرب ایران، فصل‏نامة مدرس علوم جغرافیایی، 2: 99ـ115.
عزیزی، ق. و یوسفی، ح. (1384). زمان‏یابی ورود پُرفشار سیبری به سواحل جنوبی دریای خزر، مجلة مدرس، 63-64: 149-165.
علیجانی، ب. (1381). اقلیم‏شناسی سینوپتیک، تهران: سمت.
علیجانی، ب. و براتی، غ‏‏ر. (1375). تحلیل سینوپتیک یخبندان فروردین 1366، فصل‏نامة تحقیقات جغرافیایی، 40: 121ـ135.
علیجانی، ب. و قویدل رحیمی، ی. (1384). مقایسه و پیش‏بینی تغییرات دمای سالانة تبریز با ناهنجاری‏های دمایی کرة زمین با استفاده از روش رگرسیون خطی و شبکة عصبی مصنوعی، مجلة جغرافیا و توسعه دانشگاه سیستان و بلوچستان، 6: 21ـ38.
علیجانی، ب. و هوشیار، م. (1387). شناسایی الگوهای سینوپتیکی سرماهای شدید شمال غرب ایران، پژوهش‏ها‏ی جغرافیای طبیعی، 65: 1-16.
علیجانی، ب.؛ محمودی، پ.؛ ریگی چاهی، ا.‏ب. و خسروی، پ. (1389). بررسی تداوم روزهای یخبندان در ایران با استفاده از زنجیرة مارکوف، پژوهش‏های جغرافیای طبیعی، 73: 1-20.
فتاحی، ا. و صالحی پاک، ت. (1388). تحلیل الگوهای سینوپتیکی یخبندان‏های زمستانة ایران، جغرافیا و توسعه، 13: 127ـ136.
فرشادفر، ع‏ا. (1384). اصول و روش‏های آماری چندمتغیره، چ 3، انتشارات طاق‏بستان، دانشگاه رازی کرمانشاه.
قویدل رحیمی، ی. (1390). رابطة دماهای فرین پایین فراگیر دورة سرد آذربایجان با الگوهای گردشی تراز 500 هکتوپاسکا ل، فضای جغرافیایی، 35: 155ـ184.
قویدل رحیمی، ی. (1391). نگاشت و تفسیر سینوپتیک اقلیم با استفاده از نرم‏افزار Grads، تهران: انتشارات سهادانش.
کاویانی، م‏ر. و علیجانی، ب. (1391). مبانی آب و هواشناسی، تهران: سمت.
کریمی، ص.؛ نگارش، ح.؛ طاوسی، ت. و علیجانی، ب. (1391). تحلیل همدید امواج سرماهای فراگیر ایران (مطالعة موردی موج سرمای دی و بهمن 1383 استان چهارمحال و بختیاری)، جغرافیا و توسعه، 29: 55ـ76.
گندمکار، ا. (1387). تحلیل سینوپتیکی یخبندان‏های بهارة نجف‏آباد، مجلة علمی- پژوهشی فضای جغرافیایی، دانشگاه آزاد اسلامی واحد اهر، 23: 137ـ165.
لشکری، ح. و کیخسروی، ق. (1389). تحلیل سینوپتیکی موج سرمای 8ـ15 دی‏ماه 1385 در ایران، مجلة مدرس علوم انسانی، 14: 155ـ177.
مارتین، جاناتان ‏ای (1388). دینامیک جو در عرض میانه، ترجمة سیدابوالفضل مسعودیان، دانشگاه اصفهان، اصفهان: انتشارات سمت.
مرادی، م. (1390). مقدمه‏ای بر هواشناسی دینامیکی (1)، سیدباقر حسینی، نشر آب و هوا، تهران
مسعودیان، ا. (1390). مبانی آب و هوای ایران، مشهد: نشر شریعة توس.
مسعودیان، ا. (1392). آب‏وهوای ایران، چ2، انتشارات دانشگاه شریعة توس.
مسعودیان، ا. و دارند، م. (1390 الف). تحلیل همدید سرماهای فرین ایران، جغرافیا و توسعه، 22: 165ـ185.
مسعودیان، ا. و دارند، م. (1390 ب). شناسایی و پهنه‏بندی نواحی دمای فرین سرد ایران، مطالعات جغرافیایی مناطق خشک، 2: 43ـ54.
مسعودیان، ا. و دارند، م. (1392). ارتباط دو الگوی دریای شمال- خزر (Ncp) و شرق اروپا- شمال شرق ایران (Enei) با بسامد رخداد سرماهای فرین دورة سرد سال ایران، فیزیک زمین و فضا، 2: 171ـ186.
مسعودیان، ا. و محمدی، ب. (1389). تحلیل فراوانی تابع هم‏گرایی شار رطوبت در زمان رخداد بارش‏های ابرسنگین ایران، مجموعه مقالات چهارمین کنگرة بین‏المللی جغرافیدانان جهان اسلام، ایران، زاهدان.
منتظری، م. و مسعودیان، ا. (1389). شناسایی الگوهای فرارفت دمایی ایران در سال‏های سرد، پژوهش‏های جغرافیای طبیعی، 74: 79ـ94.
میرموسوی، س‏ح. و حسین بابایی، م. (1390). مطالعة توزیع زمانی‏- مکانی احتمال وقوع یخبندان در استان زنجان، مجلة جغرافیا و برنامه‏ریزی محیطی، 3: 167ـ184.
یارنال، ب. (1390). اقلیم‏شناسی همدید و کاربردهای آن در مطالعات محیطی، برگردان سید ابوالفضل مسعودیان، چ2، دانشگاه اصفهان، اصفهان.
Alijani, B. (2002). Synoptic Climatology, Thran, Samt Publishing.
Alijani, B. and Barati, Gh. (1996). Synoptic Analysis of Freezing, Farvardin, 1366, Quarterly Journal of Geographic Research, 40: 121-135.
Alijani, B. and Ghavidel, R. (2005). Comparison and prediction of annual temperature changes of Tabriz with temperature abnormalities of the Earth using linear regression and artificial neural network, Geography and Development Magazine, Sistan and Baluchestan University, 6: 21-38.
Alijani, B. and Hooshyar, M. (2006). Identification of Synoptic Patterns of Serious Serum in Northwest of Iran, Natural Geographic Research, 65: 1-16.
Alijani, B.; Mahmoudi, P.; Rigi, C.; Allah, S. and Khosravi, P. (2010). Investigating the continuation of glacial days in Iran using the Markov chain, Natural geographic research, 73: 1-20.
Ashcroft, L.C.; Pezza, A.B. and Simmonds, I. (2009). Cold Events Over Southern Australia: Synoptic Climatology and Hemispheric Structure, Journal of Climate, 22: 6679-6698.
Azizi, Gh. (2004). Synoptic Estimation of Spring Frosts in the Midwest of Iran, Quarterly Journal of Geosciences, 2: 99-115.
Azizi, Gh. and Yousefi, H. (2005). Timing of the entry of Siberian highway to the southern shores of the Caspian Sea, Modarres Magazine, 63-64: 149-165.
Bonsal, B.R.; Zhang, X.; Vincent, L.A. and Hogg, W.D. (2001). Characteristics of daily and extreme temperature over Canada, Journal of climate, Vol. 14.
Darand, M. (1393). Identification of cold waves and their temporal and spatial analysis of Iran, Geography and environmental planning, 2: 268-253
Esmaeili, R. and Khosravi, M. (2007). Patterns of late northwest frost of the country, Geosciences Collection, 7-8: 75-53.
Farshadfar, E. (2005). Multivariate Statistical Principles and Methods, Third Edition, Tahibastan Publications, Razi University of Kermanshah.
Fatahi, E. and Salehi Pak, T. (2009). Synoptic Pattern Analysis of Iran's Winter Frosts, Geography and Development, 13: 112-136.
Gandmkar, A. (2008). Synoptic analysis of spring frosts of Najaf Abad, Journal of Geospatial Research, Islamic Azad University, Ahar Branch, 23: 137-165.
Ghavidel Rahimi, Y. (1391). Synoptic Mapping and Interpretation of the Climate Using Grads Software, Tehran, Sohadanesh Publications.
Ghavidel Rahimi, Y. (2010). Relationship of Farin Low Temperatures in the Cold Period of Azerbaijan with Circulation Patterns of 500 HPA, Journal of Geographical Space, 35: 155-184.
Ghavidel Rahimi, Y. (2011). The Relationship of Low Cold Temperatures in the Cold Period of Azerbaijan with Circulation Patterns of 500 Hectopacca L, Geographical Space, 35: 155-184.
Ghil, M. and Vautard, R. (1991). Interdecadal Oscillations and the Warming Trend in Global Temperature Time Series, Science, 199: 1065-1068.
Habibi, F. (2006). Synthesis and Dynamic Analysis of bolo-king Systems, Diagnostic Method of Bandal System and Its Influence on Iran, Journal of Physics of Earth & Space, 32:69-89.
Halabian, AH. and HosseinAli Pourjazi, F. (2012). Identification of the Contiguous and Predictable Conditions in the Western Caspian Sea with Emphasis on Pattern of Atmospheric Thickness, Geography and Environmental Sustainability, 3:101-122.
Imam Hadi, M. and Alijani, B. (2004). Air Mass Effect on Iran in the Cold Period, Geographic Journal, 628: 53-34.
Jahanbakhsh Asl, S. and Babapour, AA. (2003). Estimation and prediction of average monthly temperature of Tabriz using Arima Model, Geographical Quarterly Journal of Isfahan University, 3: 34-46.
Jahanbakhsh, S.; Rezaei, S.; Ghasemi, A. and Tedini, M. (2011). Synoptic Analysis of Tabriz's Spring Frosts (Case Study: Cold Spring, 2003 and 2004), Geographical Quarterly, 3: 17248-17272.
Yang, J., Ren, C., & Jiang, Z. (2008). Characteristics of extreme temperature event and its response to regional warming in Northwest China in past 45 years. Chinese Geographical Science18(1), 70-76.
Jones, P.D. and Hegerl, G.C. (1998). Comparisons of Two Methods of Removing Anthropogenically Related Variability from the Near-surface Observational Temperature Field, J. Geophys. Res., 103 (D12), 13, 777-13, 786.
Karimi, S.; Negaresh, H.; Tavoshi, T. and Alijani, B. (2012). Synthesis analysis of the waveforms of the all-encompassing regions of Iran (Case of the cold wave in February and February 2004 in Chaharmahal va Bakhtiari province), Geography and Development, 29: 56-56.
Kaviani, MR. and Alijani, B. (1391). Meteorological Principles, Tehran: Samt Publications.
Khalaji, M. (2008). Forecast of late spring frost and early autumn frost for some agricultural and garden plants in Chaharmahal va Bakhtiari province, Journal of Seedlings and Seeds, 17: 126.
Klain Tank, A.M.G., Konnen, G.P. and Selten, F.M. (2005). Signals of anthropogenic influence on European warming as seen in the trend patterns of daily temperature variance, Int. J. Climato, 25: 1-16.
Lashkari, H. and Keikhosrowi, Q. (2010). Synoptic Analysis of Cold Wave, January 8-15, 2009 in Iran, Modares Journal of Humanities, 14: 155-177.
Martin, Jonathan A. (2009). Baro dynamics in the Middle, Massoudian translation, Seyyed Abolfazl, First edition, Isfahan University, Isfahan Publication.
Masoudian, A. (1390). Iran's Climatic Basis, Mashhad: Shariah Toos Publishing.
Masoudian, A. and Mohammad, D. (2011b). Identification and zoning of cold-tempered Farin temperature regions of Iran, Geographical studies of arid regions, 2: 43-54.
Masoudian, A. and Mohammadi, B. (2010). Frequency Analysis of the Convergence Function of Moisture Flow during the Atmospheric Accidents of Iran, Proceedings of the Fourth International Congress of Geographers of the Islamic World, Iran, Zahedan.
Masoudian, A. and Mohmand, M. (1392). Relationship between two patterns of the North-Caspian Sea (Ncp) and East-Europe-Northeast of Iran (Enei) with the frequency of the incidence of the Farin Periods in the cold season of Iran, Physics of Earth and Space, 2: 171-186.
Massoudian, A. (1392). Iran's climate, Second edition, Sharia University of Toos Publications.
Massoudian, A. and Mohammad, D. (2011a). Coordinated analysis of Farin Iran, Geography and Development, 22: 165-185.
Mirmosavi, H. and Hossein Babaei, M. (2011). Study of temporal-spatial distribution of probability of freezing in Zanjan province, Journal of Geography and Environmental Planning, 3: 184-167.
Montazeri, M. and Masudian, A. (2010). Identification of Temporal Temperatures in Cold Years, Natural Geographic Research, 74: 79-94.
Moradi, M. (2011). Introduction to Dynamic Meteorology (1), Seyyed Baqer Hosseini, publish climate, Tehran.
Onate, J.J. and Pou, A. (1996). Temperature variations in Spain since 1901: A preliminary analysis, Int. J. Climatol, 16:805–815.
Rahimi, M. (2008). Investigation of the probability of occurrence of frosty periods of spring and early spring in central Alborz, MSc dissertation, Department of Geography, Tehran University.
Sadeghi, S.; Hosseinzadeh, S.; Friends, R. and Ahangarzadeh, Z. (2012). Co-analyzes of cold waves in northeastern Iran, Geography and environmental hazards, 3: 107- 123.
Santer, B.D.; Taylor, K.E.; Wigley, T.M.L.; Penner, J.E.; Jones, P.D. and Cubasch, U. (1995). Towards the Detection and Attribution of an Anthropogenic Effect on Climate, Climate Dynamics, 12: 79-100.
Schlesinger, M.E. and Ramankutty, N. (1994). An oscillation in the global climate system of period 65-70 years, Nature, 360: 330-333.
Shahkhorvandi, M.; Ghayour, Hi. and Kaviani, MR. (2007). Normal flow of barley and parameters of the centers of action in winter in Iran, Isfahan University of Medical Sciences, 22: 85-100.
Stott, P.;  Stone, D. and Allen, M. (2004). Human contribution to the European heat wave of 2003, Nature, 432: 610-614.
Vatkins, S.C. (1991). The Annual Period of Freezing Temperatures in Centurial England 1850-1959, International Journal of Climatology, 11: 889-896.
Vithkeich, V.I. (1963). Agicultuar metrological, Jerusalem, pp. 183-305.
Yarnal, B. (2011). Climatology and its Applications in Environmental Studies, Translated by Seyyed Abolfazl Masoudian, Second Edition, Isfahan University Isfahan.
Yue, S. and Hashino, M. (2003). Temperature trends in Japan: 1900–1996, Theor. Appl. Climatol., 75: 15-27.