Synoptic patterns of cold waves of recent decades in Iran (2004 - 2013)

Document Type : Full length article

Authors

1 University of Tehran

2 University of Sayyed Jamaleddin Asadabadi

Abstract

Introduction

Weather conditions have always affected the man’s life; so he is used to adopt his life with Weather conditions, one of which is the condition of Cold waves. Cold days and cold waves are examples of extreme-temperature that include unusual notable amount of minimum temperature. Reduction of minimum temperature depends on heating degree and wind speed. Cold waves can be considered as a natural disaster or a provider of ideal weather in summer. Thus, present paper tries to analyze cold wave that mitigates weather in the warm period of year, besides cold waves of cold period in ten years.

Materials and methods

To pattern the cold waves of Iran in a ten-year period of time (2004-2013) three-hour minimum data of European Centre for Medium-Range Weather Forecasts (ECMWF) with distance of 1 * 1 degree latitude and Longitude has been used. In present study, a cold day due to relative notion of Coldness in different time and places, is defined as a day in which standard score of minimum temperature is below -1. For this reason, minimum data of all days was separated by MATLAB software; then by using the standard score those day with Anomalies below -1 known as cold days were diagnosed. In the next step all the days (569 days) that had this characteristic by MATLAB and based on sea level pressure patterns correlation were divided into five different classes includes Spring, Summer, Autumn, late Autumn, early winter and winter And interpreted them synoptic patterns. In the next step wind speed and also minimum and maximum temperature difference thresholds was used to distinction between the Radiative cool waves from the advective cool waves, so that minimum and maximum temperature difference below 8 ° C and wind speed more than Breeze threshold was used as advective cool waves criteria.

Results and Discussion

By extracting 569 days of negative anomalies between 2004 and 2013 it became clear that 2013 with 124 days and 2006 with 20 days (with negative anomalies below -1) have the most and the least negative anomalies respectively, in the mentioned research period. August, which have 83 days of negative anomalies, also contained the highest anomaly in selected 10 years. Analyzing level pressure patterns correlation between five presented patterns showed that interclass correlation of late autumn and early winter was 0.94 and more than all other groups. The highest correlation between groups was also between fourth (late autumn and early winter pattern) and fifth classes (winter pattern). In the days which cold waves entered the country, wind speed never reached to high-speed level and never exceed of the average wind speed. This speed never reached the average wind speed in summer but the frequency of light wind was higher than other seasons. While the frequency of breeze flow in the second and cold half of year is more than the first or warm half of the year; low speed of waves produce more intensive and continues cold wave when it’s accompanied by cold weather. Cold waves of Iran are usually advection and enter country from north and through west flows. In spring pattern (first pattern) west systems cause reduction of temperature and mitigation of Iran weather especially in western and northern regions of country. Minimum and maximum temperature difference in northwest of Iran was lower than 5 ° C in this pattern, while it was observed in water areas only in the other patterns. The highest difference between daily minimum and maximum temperature has been recorded in the second class (summer pattern).

Conclusion

Flows from the high altitude subtropical East lead to cold advection air of higher altitudes toward east and north east of Iran. But withdrawal of subtropical high pressure was the main factor of cool waves in this pattern. Siberian high pressure has caused low difference of daily minimum and maximum temperature in northeast of Iran and Alborz mountains in the autumn pattern (third pattern). Wind speed in North of Iran was more than the other region. And also stability conditions was the most in this pattern. There was low differences between minimum and maximum in south of Zagros mountains that was due to advection of cold air by African high pressure. In late autumn and early winter pattern (forth pattern) a complete advective Pattern is ruling over country. The fifth class (winter pattern) is advective- Radiative

Keywords


خسروی. ی.؛ دوستکامیان. م.؛ طاهریان، ا. و شیری کریم‏وند، ا. (1397). بررسی و تحلیل فرارفت دمایی امواج سرمایشی ایران، تحقیقات کاربردی علوم جغرافیایی، 18(5): 17-37.
خوش‏اخلاق، ف.؛ داوودی، م.؛ روستا، ا. و حقیقی، ا. (1391). تحلیل همدیدی سرماهای شدید شمال خراسان، نشریة پژوهش‏های اقلیمشناسی، 9: 1-12.
خوشحال دستجردی، ج.؛ یزدان‏پناه، ح. و حاتمی، ب. (1388). شناسایی الگوهای گردشی پدیدة یخبندان با کاربرد تحلیل مؤلفه‏های مبنا و تحلیل خوشه‏ای (مطالعة موردی: استان فارس)، فصل‏نامة جغرافیای طبیعی، 4: 33-45.
دارند، م. و مسعودیان، ا. (1394). شناسایی و تحلیل الگوهای ناهنجاری ضخامت سرماهای فرین ایران‏زمین (طی بازة زمانی 1340 تا 1383)، فصل‏نامة تحقیقات جغرافیایی، 118: 105-120.
دوستکامیان. م و طاهریان زاد. ا. (1396). تحلیل آماری- همدید امواج سرمایشی و فراگیر شمال ‏غرب ایران، پژوهش‏های جغرافیای طبیعی، 39(۴): 699-717.
زرین. آ. و مفیدی. ع. (1390). آیا پُرفشار جنب‏حاره‏ای تابستانه بر روی ایران زبانه‏ای از پُرفشار جنب‏حاره‏ای آزور است، یازدهمین کنگرة انجمن جغرافیدانان ایران- ۲۴ و ۲۵ شهریورماه ۱۳۹۰- دانشگاه شهید بهشتی.
صادقی، س.؛ حسین‏زاده، ر.؛ دوستان، ر. و آهنگرزاده، ز. (1391). تحلیل همدیدی امواج سرمایی در شمال شرق ایران، جغرافیا و مخاطرات محیطی، 3: 107-123.
علیجانی، ب و هوشیار، م. (1387). شناسایی الگوهای سینوپتیکی سرماهای شدید شمال غرب ایران، پژوهشهای جغرافیای طبیعی (پژوهش‏های جغرافیایی)، 65: 1-16.
قویدل ‏رحیمی، ی. (1390). رابطة دماهای فرین پایین فراگیر دورة سرد آذربایجان با الگوهای گردشی تراز 500 هکتوپاسکال، فصل‏نامة علمی- پژوهشی فضای جغرافیایی، 35: 155-184.
قویدل رحیمی، ی.؛ فرج‏زاده، م. و مطلبی‏زاده، س. (1395). تحلیل آماری و سینوپتیک امواج سرمایی منطقة شمال غرب ایران، نشریة تحقیقات کاربردی علوم جغرافیایی، 40: 29-46.
کاظمی‏زاد، م. (1380). محاسبة سرعت باد به روش میانگین برداری (وکتور)، آموزش جغرافیا، 59: 53-55.
کریمی، ص.؛ نگارش، ح.؛ طاووسی، ت. و علیجانی، ب. (1391). تحلیل همدید امواج سرماهای فراگیر ایران، جغرافیا و توسعه، 29: 55- 76.
لشکری، ح. (1387). تحلیل سینوپتیکی موج سرمای فراگیر 1382 در ایران، پژوهش‏های جغرافیایی، 66: 1-18.
لشکری، ح. و یارمحمدی، ز. (1393). تحلیل همدیدی استقرار پُرفشار سیبری و مسیرهای ورودی آن به کشور ایران در فصل سرد، پژوهش‏های جغرافیای طبیعی، 2: 199-218.
مسعودیان، س.ا. (1390). آب‏وهوای ایران، مشهد: شریعة توس.
مفیدی، ع. (1386). تحلیل گردش جو تابستانه بر روی ایران و ارتباط آن با بارشهای تابستانة فلات ایران، رسالة دکتری، دانشگاه تربیت معلم، دانشکده علوم جغرافیایی، تهران.
نوحی، ک.؛ صحرائیان، ف.؛ پدارم، م. و صداقت‏کردار، ع. (1387). تعین طول دورة بدون یخبندان با استفاده از تاریخ‏های آغاز و خاتمة یخبندان‏های فرارفتی و تابشی در نواحی زنجان، قزوین و تهران، علوم و فنون کشاورزی و منابع طبیعی، 48: 449-460.
یارنال، ب. (1390). اقلیمشناسی همدید و کاربرد آن در مطالعات محیطی، ترجمة س.ا. مسعودیان، اصفهان: دانشگاه اصفهان.
یوسفی، ح. و عزیزی، ق. (1384). زمان‏یابی ورود پُرفشار سیبری به سواحل جنوبی دریای خزر، فصل‏نامة مدرس علوم انسانی، 9(۴): ۱۹۴-213.
Al Senafi, F. and Anis, A. (2015). Shamals and climate variability in the Northern Arabian/Persian Gulf from 1973 to 2012, Int. J. Climatol., 35: 4509-4528. doi:10.1002/joc.4302.
Alijani, B. and Hooshyar, M. (2008). Synoptic pattern identification of extreme cold air in North West of Iran, Physical Geography Research quarterly, 65: 1-16.
Bitan, A. and Saaroni, H. (1992). The horizontal and vertical extension of the Persian Gulf trough, International Journal of Climatology, 12: 733-747. 10.1002/joc.3370120706.
Cony, M.; Hernandez, H. and Del, T. (2008). Influnce of synoptic scale in the generation of extremely cold days in Europe, Atmosfera, 21: 389-401.
Darand, M. and Masodian, A. (2015). Identification and analysis of thickness anomaly patterns of extreme cold air in Iran, Geographical Research, 118: 105-120.
Doostkamian, M. and TaherianZad, A. (2017). Statistical-Synoptical analysis of the cooling waves in the North-West of Iran, Physical Geography Research, 39(4): 699-717.
Ghvidel, Y. (2011). Relation of extreme cold air in Azarbayejan with 500 hPa patterns, Geographic Space, 35: 155-184.
Ghvidel, Y.; Farajzadeh, M. and Motallebizad, S. (2016). Statistical and synoptic analysis of cold wave in North West of Iran, Applied Research of Geographic Sciences, 40: 29-46.
Glossary of meteorology. American meteorological society. http://glossary.ametsoc.org.
Karimi, S.; Negaresh, H.; Tavoosi, T. and Alijani, B. (2012). Synoptic analysis of cold wave in Iran, Geography and Development, 29: 55-76.
Kazemizad, M. (2001). Wind speed calculation using vector score, Geography instruction, 59: 53-55.
Khoshakhlagh, F.; Davoodi, M.; Roosta, I. and Haghighi, E. (2012). Synoptic analysis of extreme cold air in North of Khorasan, Journal of Climate Research, 9: 1-12.
Khoshhal, J.; Yazdanpanah, H.; Hatami, Kh. and Bigloo, B. (2009). Patterns identification of frost phenomenon using principal component analysis and clustering analysis (case study: Fars Province), Journal of Physical Geography, 4: 33-45.
Khosravi, Y.; Doostkamian, M.; TaherianZad, A. and Shiri Karivand, A. (2018). Investigation and Analysis of Temperature Advection of Cooling Waves in Iran, Applied Research of Geographic Sciences, 18(5): 17-37.
Lashkari, H. (2008). Synoptic analysis of 2003 cold wave in Iran, Geography Resarch, 66: 1-18.
Lashkari, H. and Yarmoradi, Z. (2014). Synoptic analysis of Siberian high pressure and its entrance paths to Iran in cold season, Physical Geography Research Quarterly, 2: 199-218.
Marengo, A. and Nobre, C. (1997). Climate impact of "Friagens" in forested and Deforested areas of the Amazon basin, Centre for Weather Forecasting and Climate Research (CPTEC), National Institute for Space Research (INPE), 36: 1553-1566.
Masoodian, S.A. (2011). Climate of Iran, Mashhad: Sharia Toos.
Mofidi, A. (2007). The analysis of the summer atmospheric circulation over Iran and its relation to the summer rainfall of the Iranian plateau, Ph.D. Thesis in, Tarbiat Moalem University, Tehran.
Nohi, K.; Sahraeian, F.; Pedram, M. and Sedghat Kerdar, A. (2008). Specification of the duration of period without frost using start and end dates of advective and radiative frost in Zanjan, Qazvin and Tehran, Journal of Science and Technology of Agriculture and Natural Resources, 48: 449-460.
Salighe, M.; Alijani, B. and Cheraghi, M. (2012). Synoptic analysis of cold and warm wave at selected stations in sought west of Iran, Kharazmi University, Master's Thesis.
Samra, J.S.; Gurbachan, S. and Ramakrishna, Y.S. (2003). Cold wave of 2002-03 Impact on agriculture, Central Research Institute for Dryland Agriculture, 1-49.
Sedaghi, S.; Hoseinzadeh, R.; Doostan, R. and Ahangarzadeh, Z. (2012). Synoptic analysis of cold wave in north east of Iran, Geography and Environmental Hazards, 3: 107-123.
Sofroni, V.; Putuntica, A.; Sfica, L. and Ichim, P. (2013). The Cold wave of the 25 Janury – 18 February 2012 priod on the Territori of the Republic of Moldova, Present Enviroment and Sustainable Development, 7: 5-11.
Takashi, H. (1990). Migration of the cold air mass related to rain belt formation of the chienese continent and atmospheric circulation systems during the baiu season (In Japanese), Geographical review of japan, 64: 10-24.
Vavrus, S.; Walsh, J.E.; Chapman, W.L. and Portis, D. (2006). The behavior of extreme cold air outbreaks under greenhouse warming, International Journal of Climatology, 2: 1133-1147.
Yarnal, B. (1993). Synoptic climatology in environmental analysis: a primer, London: waily.
Zarrin, A. and Mofidi, A. (2011). Is the tropical high pressure on Iran a tributary of the Azores high pressure? 11th Congress of the Iranian Geographers Association, University of Shahid Beheshti, 24th and 25th of September 2011.
 Zhang, Y.; Sperber, K. and Boyle, J. (1996). Climatology of East Asian Winter Monsoon and Cold Surges, Results from the 1979-1995 NCEP/NCAR Reanalysis, Program for Climate Pattern Diagnosis and Intercomparison, PCMDI Report, 38: 1-14.