A survey on the synoptic patterns based on critical periods of air pollution in severe inversions of Tabriz, Iran

Document Type : Full length article


Department of Geography,Tabriz Branch, Islamic Azad University,Tabriz, Iran


Air pollution as one of the most important technological risks of contemporary era is mainly resulted from the emergence of large cities and fast growing industries. One of the main objectives of climatic and environmental studies is to survey atmospheric pollutions. Tabriz is one of the metropolises where air pollution is a problem. However, what is essential to consider the severity of air pollution in the city of Tabriz is the function of atmospheric processes that act widely. In this case temperature inversion is one of the most important factors. Weather condition of each single day is affected by synoptic conditions. Therefore, sometimes it can result in stability and tranquility in the atmospheric conditions and due to the concentration of pollutants in lower atmospheric layers and the lack of or poor atmospheric motions, the severity of pollution increases. Given the importance of weather stability in the occurrence of atmospheric problems, it seems essential to investigate the synoptic conditions of Tabriz city during critical air pollution periods and providing recommendations and preventive measures. For this reason, the present article aims to investigate the cause of severe and periodic air pollutions in Tabriz.
Materials and Methods
The daily data of Tabriz pollution over a 6 year period (2008-2013) were the data of current study (CO, PM10) that were collected from the Department of Environmental Protection, East Azerbaijan Province. Among these data, four successive pollution periods along with temperature inversion were selected by EXCEL filtering software. Then, the situation of pollutants regarding their healthiness and unhealthiness were studied using PSI index. Also in this article due to the direct effect of temperature inversion on intensity of pollutant concentrations and depth of temperature inversion, Skew-T maps were used to determine the pollution periods of Tabriz. According to the purpose of this study which was to identify the synoptic systems affecting air pollution in Tabriz, to identify synoptic patterns that influence the amount of pollutants in polluted days, daily synoptic maps at ground level and 500 hp of pollutant days were received from NCEP/NCAR and to investigate the synoptic patterns affecting sustainable and long-term periods of air pollution in Tabriz.
Results and Discussion
The study area is often influenced by synoptic patterns of mid-latitudes. The most important seasonal thermal systems that affects large sections of the country are Siberian high pressure and low pressure summer heat. During the cold season, Siberian high pressure is strengthened which can affect the frequency of large areas of Iran including Tabriz. In the most days of the year especially in cold season, due to shortness of the length of day and cold radiation at night, temperature inversion including radiation and subsidence can occur in the area. The local characteristics of the area especially lack of high speed winds in cold seasons, i.e., autumn and winter, can reduce the intensity of inversion layer. The concentration of pollutants has provided the situation for air pollution. When a high-pressure system constantly during successive days focuses on a special area, the intensity of temperature inversion reaches its peak. Then, with the arrival of a low pressure systems inversion fades away. In general, the main factor reinforcing inversion in high temperature is due to the continuity of high-pressure systems which can cause long-term pollutions.
In present study, we investigated the atmospheric patterns affecting air pollution in Tabriz during the statistical period of 2008-2013. The main objective of this study was to investigate the relationship between sea level and 500 hPa synoptic patterns with temperature inversion and prolonged periods of pollution. The results showed that the concentration of pollutants in most days was due to the intensity inversion layer in a way that when the intensity of temperature inversion reaches more than 5°C it has the greatest impact on the increase of the concentration of pollutants in all investigated periods. The findings also indicated a strong correlation between the function of strong and weak inversion layers with low pressure and high pressure systems in a way that strong inversion layer is always associated with high pressure systems. Results indicate that the Siberian high pressure has a significant role in the occurrence of pollutions in Tabriz city. The circulation system in more than half of the studied days can cause formation of high concentration of pollution in Tabriz. This synoptic system due to the establishment of cold weather on the Zagros and the combination of high pressure developed in the Zagros Mountains has created strong pressure. However, this system is more powerful when in middle levels of atmosphere in all phases the high altitude was 500 hPa level along with the stack system based on the region have developed and intensified the high pressure on the ground and caused the stability of clear weather and also caused the formation of a strong inversion layer and increase in the concentration of suspended particles in the atmosphere of the city of Tabriz.


Main Subjects

جهان‌بخش اصل، س. و روشنی، ر. (1393). بررسی شرایط الگوی سینوپتیکی حاکم بر وضعیت‌های وارونگی دمای بسیار شدید شهر تبریز، مجلة جغرافیا و برنامه‌ریزی، 18(48): 81 ـ 96.
حسین‏زاده، س.‌ر.؛ دوستان، ر. و حقیقت ضیابری، س.‌م. (1392). بررسی الگوهای همدید مؤثر بر آلودگی هوا در کلان‌شهر مشهد، مجلة جغرافیاوتوسعةناحیهای، 11(21): 81 ـ 101.
ذوالفقاری، ح.؛ صحرایی، ج.؛ شاقبادی، ف. و جلیلیان، آ. (1393). تحلیلی بر جنبه‌های سینوپتیکی- دینامیکی آلودگی هوا در کرمانشاه، مجلة جغرافیاومخاطراتمحیطی، 9: 75 ـ 96.
روشنی، ر. (۱۳۹۰). بررسی تأثیر پُرفشارها در وقوع اینورژن‌های بسیار شدید و تداوم آلودگی‌های شهر تبریز در سال 2008، همایشملیتغییراقلیموتأثیرآنبرکشاورزیومحیطزیست، ارومیه، مرکز تحقیقات کشاورزی و منابع طبیعی استان آذربایجان غربی.
صادقی، س.؛ مفیدی، ع.؛ جهانشیری، م. و دوستان، ر. (1393). نقش الگوهای گردش مقیاس منطقه‌ای جو بر وقوع روزهای بسیار آلوده در شهر مشهد، مجلة جغرافیاومخاطراتمحیطی، 3(10): 1 ـ 35.
عابدینی، ی.؛ نوروززاده، ف. و صدایی، ی. (1391). تعیین آلودگی هوای شهر تبریز با استفاده از شاخص PSI، اولینهمایشملیحفاظتوبرنامهریزیمحیطزیست، دانشگاه آزاد اسلامی، واحد همدان.
علیجانی، ب. و هوشیار، م. (1378). شناسایی الگوهای سینوپتیکی سرماهای شدید شمال غرب ایران، پژوهشهایجغرافیایطبیعی، 65: 1 ـ 16.
قسامی، ط.؛ بیدختی، ع.ا.؛ صداقت‌کردار، ع. و صحراییان، ف. (1386). بررسی شرایط همدیدی حاکم در چند دورة بحرانی آلودگی هوای شهر تهران، مجلة علوموتکنولوژیمحیطزیست، 9(3): 229 ـ 238.
نوروززاده، ف. (1391). بررسی آلودگی هوا و منابع آلایندة هوا در سطح شهر تبریز، پایان‏نامة کارشناسی ارشد، دانشکدة علوم انسانی و اجتماعی، دانشگاه زنجان.
هدایت، پ. (1381). بررسی سینوپتیکی سیستم‌های اقلیمی مؤثر بر آلودگی هوای شهر تهران و بیماری‌های قلبی و ریوی، پایان‏نامة کارشناسی ارشد، دانشکدة علوم زمین، دانشگاه شهید بهشتی.
یارنال، ب. (1385). اقلیمشناسیهمدیدوکاربردآندرمطالعاتمحیطی، ترجمة سید ابوالفضل مسعودیان، اصفهان: دانشگاه اصفهان.
Alijani, B. and Hushyar, M. (1999). Identifying synoptic patterns of severe colds in North West of Iran, Physical Geography Research, 65:1-16.
Abedini, Y.; Norozzadeh, F. and Sadaie, Y. (2013). Determination of air pollution in the city of Tabriz using SPI index, First National Conference on Environmantal Protection and Planning, Islamic Azad University Hamedan Branch.
Barry, R. (1997). Synoptic Climatology, in J.E Oliver and R.W. Fairbrdge (eds), The Encyclopedia of Climatology, New York: Van Nostrand Reinhold Book.
Bei, N.; Li, G.; Huang, R.; Cao, J.; Meng, N.; Feng, T.; Liu, S.; Zhang, T.; Zhang, Q. and Molina, L.T. (2016). Typical synoptic situations and their impacts on the wintertime air pollution in the Guanzhong basin, China, Journal Atmospheric Chemistry and Physics, NO.0:1-34.
Ccoyllo, S.O.R. and Andrade, M.F. (2002). The influence of meteorological conditions on the behavior of pollutants concentrations in São Paulo, Brazil, Environmental Pollution, 116(2): 257-263.
Chen, Z.C.; SY, L.; Guo, J.; Wang, X. and Chen, W. (2008). Relationship between atmospheric pollution processes and synoptic pressure patterns in northern China, Atmospheric Environment, 42: 6078-6087.
Flocas, H.; Kelessis, A.; Helmis, C.; Petrakakis, M.; Zoumakis, M. and Pappas, K. (2009). Synoptic and local scale atmospheric circulation associated with air pollution episodes in an urban Mediterranean area, Theor Appl Climatol, 95: 265-277.
Gasami, T.; Bidokhti, A.A.; Sedagat Kerdar, A. and Sahrayiyan, F. (2007). Investigating prevailing Synoptic conditions in several critical periods of air pollution in Tehran, Journal of Environmental Research, 9(3): 229-238.
Hedayat, P. (2002). A synoptic survey on climatic systems affecting air pollution in Tehran and heart and lung diseases, MS Thesis, Department of Earth Sciences, University of Martyr Beheshti.
HosseinZadeh, S.; Dostan, R.; Hagigat Ziyabari, S.M. and Hagigat Ziyabari, S.M. (2013). Investigating the synoptic patterns affecting air pollution in the metropolis of Mashhad,Journal of Geography and Regional Development, year 11th, 21: 81-101.
Jahanbakhsh Asl, S. and Roshani, R. (2015). Investigating the synoptic patterns of very severe temperature inversion conditions in Tabriz , Journal of Geography and planning, 18(48): 81-96.
Juneng, L.; Talib Latif, M. and Tangang, F. (2011). Factors influencing the variations of PM10 aerosol dust in Klang Valley, Malaysia during the summer, Atmospheric Environment, 45: 4370-4378.
Landsberg, H.E. (1980). The Urban Climate, Academic Press, PP. 288.
Makra, L.; Mika, J.; Bartzokas, A.; Be´czi, R.; Borsos, E. and Su¨meghy, Z. (2006). An objective classification system of air mass types for Szeged, Hungary, with special interest in air pollution levels, Meteorol Atmos Phys, 92: 115-137.
Norozzadeh, F. (2011). Investigating the pollution and Source of air pollution inTabriz, Master's thesis, Faculty of Humanities and Social Sciences, University of Zanjan.
Roshani, R. (2011). Investigating the effect of pressure on the occurrence of severe inversions and continuity of pollution in the city of Tabriz (2008), The National Conference on climate change and its impact on agriculture and the environment, Urmia, West Azerbaijan Province Research Center for Agriculture and Natural Resources
Sadegi, R.; Mofidi, A.; Jahanshiri, M. and Dostan, R. (2014). Investigating the role of regional scale atmospheric circulation patterns on heavily polluted days in the city of Mashhad, Journal of Geography and Environmental Hazards, 3(10): 1-35.
Yarnal, B. (2006). Synoptic climatology and its application inEnvironmental studies, translation: SA Masoodian, 1st publication, Isfahan, Isfahan University.
Yarnal, B. (1993).Synoptic Climatology in Enviromental Analysis, London, A Primer Belhaven Press.
Zulfaqari, H.; Sahraii, J.; Shaqbady, F. and Jalileans, A. (2014). Investigating the Synoptic - dynamics aspects of air pollution in Kermanshah, Journal of Geography and Environmental hazards, 9: 75-96.