The Role of Regional Scale Atmospheric Circulation on the Occurrence of Critical Air Pollution Episodes in Mashhad, Iran

Document Type : مقاله پژوهشی

Authors

• Soleyman Sadeghia ¹
• Abbas Mofidi ¹
• Mahin Jahanshiri ²
• Reza Doostan ¹

¹ Ferdowsi University of Mashhad

² Hakim Sabzevari

10.22067/geo.v3i2.23437

Abstract

1. Introduction
Air pollution is one of the most important environmental issues in Megacities which is seriously threatening human health. High concentration of air pollution is frequently seen over large cities of Iran in recent years. It is difficult to estimate the exact loss of lives and properties resulting by air pollution because of the lack of data, however there are reports that show the vast destructive effects of this phenomenon over the polluted cities. Air quality over the cities is determined with respect to both the total air pollution in a given area as it interacts with meteorological conditions such as humidity, temperature, and wind characteristics to produce an overall atmospheric condition. Air quality is determined by emission sources and weather situations; however, serious pollution episodes in the urban environment mainly result from certain weather conditions which pose difficulty for pollutant dispersion. Air pollution is influenced by meteorological factors through transport, chemical transformations, and removal via wet and dry processes. In this research, the role of regional atmospheric circulation on the occurrence of critical air pollution episodes in the Mashhad metropolitan is investigated. Also the synoptic and thermodynamic mechanisms which are dominated during the most polluted days over the city is identified.
2. Study Area
The study area is located in the valley of Kashaf-Rood River between two mountain ranges of Binalood and Hezar-masjed. Its geographical coordinates are 59º, 27', 0" E to 59º, 40', 30'' E and 36º, 22', 0'' N. The city benefits from the proximity of the mountains, having cool winters, pleasant springs, rather hot summers, and beautiful autumns. It is only about 250 km (160 mi) from Ashgabat, Turkmenistan. Mashhad is 999 m higher than the sea level. According to meteorological records, the average maximum temperature for the four seasons in Mashhad are: winter 8.3°C (52°F), spring 21° C (88°F), summer 33.2°C (92°F), and autumn 22.2°C (72°F). The average minimum temperature for the four seasons also is: winter -3.6°C (18.9), spring 7.3°C (45.2°F), summer 13°C (61.3°F), and autumn 5.7°C (42°F). Mashhad has a semi-arid climate with occasional rainfall in spring and autumn and light snow in the winter. The city only sees about 250 mm of precipitation per year, some of which occasionally falls in the form of snow. Mashhad also has wetter and drier periods with the bulk of the annual precipitation falling between the months of December and May. Summers are typically hot and dry, with high temperatures sometimes exceeding 35 °C (95 °F). Winters are typically cool to cold and somewhat damper, with overnight lows routinely dropping below freezing. Mashhad enjoys on average just less than 2900 hours of sunshine per year. Its population was 2,772,287 at the 2011 population census; so, the city is ranked as the second most populous city of Iran (http://en.wikipedia.org/ wiki/Mashhad).
3. Material and Methods
In this study, a combined synoptic analysis approach is employed to identify the role of regional atmospheric circulation pattern on the occurrence of high-polluted days over Mashhad. Four types of dataset including air-quality monitoring station data, reanalysis gridded data, upper air soundings data and a lograngian backward trajectory model (HYSPLIT) outputs are used to do this research. The air-quality monitoring station data is obtained from Khorasan-e-Razavi Environmental Protection Administration, while the upper air soundings data and reanalysis gridded data are obtained from National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). and Wyoming Weather Web, respectively. Also, the Hybrid Single-Particle lograngian integrated Trajectory (HYSPLIT) model is employed to determine the main sources of air parcels by using a backward trajectory approach. Using the Pollutant Standards Index (PSI). daily, seasonal and annual variations of Mashhad air quality is investigated for a 7-year (2005-2011) time period. Using PSI index, we first detected and extracted all very high-polluted days (PSI>200) over Mashhad. Then, a combined synoptic classification approach has been applied by using a set of manual synoptic classification, lograngian backward trajectory model outputs and thermodynamic diagrams.
4. Results and Discussion
Investigating the temporal variations of five air pollutants over Mashhad, it is seen that Carbon monoxide is apparently shown a decreasing trend among all air pollutants. While Ozone and Sulfur dioxide experience an increasing trend during the study period. Also, it’s seen that the PM10 shows the most monthly, seasonal and annual values among the others. Moreover, it is revealed that those pollutants with low concentration are showing more seasonal variations in Mashhad.
Using combined synoptic classification approach it is indicated that the days with highest level of air pollution in Mashhad can be classified into four main atmospheric circulation patterns including: combined Siberian high-subtropical high, migrating anticyclone, subtropical high and extra-tropical cyclone patterns. In combined Siberian high-subtropical high pattern, a simultaneous domination of Siberian high in lower atmosphere and subtropical high in middle troposphere has been caused an atmospheric stability and high levels of air pollution during cold period of the year. In this pattern, formation and coexistence of a shallow inversion layer in the lower atmosphere and another upper inversion layer in mid-troposphere show coincident roles of Siberian high and subtropical high in increasing the concentration of air pollution to higher level. In mitigating anticyclone pattern, by crossing a Rossby wave over the area, a strong mid-tropospheric ridge over the Oral Mountains and the Caspian Sea will dominate. The eastward inclination of this ridge has been caused an anticylonic circulation in a region from Caspian Sea to northern Khorasan in lower atmosphere. In this pattern, a few thin inversion layers form at the same time below 400hPa level. Rapid temperature drop between the inversion layers indicate the strength and weakness of air subsidence in this pattern. The subtropical high pattern has caused a high level of air pollution over Mashhad only in warm period of the year and it shows a distinct pattern of subsidence inversion type in the vertical profile of atmosphere. The Low-pressure pattern has identified by passing of a rather deep trough over the northern Iran in mid-troposphere and the formation and eastward movement of a cyclone in the lower atmosphere. In general, this pattern is not associated with a distinct and strong inversion layer in vertical profile of the atmosphere, while the thermodynamic diagrams show baroclinic instability through the atmosphere. In this pattern the days with very high levels of air pollution have been caused by lifting, transportation and distribution of dust and particles to the study area due to instability and vast ascend of air as well as lack of suitable moisture feeding into the low pressure.
5. Conclusion
The results indicate that the middle atmospheric circulations play the most important role in creating extremely high air pollution episodes in Mashhad. The results also demonstrate that the importance of each atmospheric circulation pattern differs from one season to another season. In other words, while in cold period of the year the occurrence of extremely high air pollution episodes has strongly related to extra-tropical atmospheric circulation patterns (i.e. mitigating anticyclone and low-pressure patterns). in warm period, all of high polluted days have mainly related to subtropical atmospheric circulation pattern. However, the subtropical ridge is the most important and also the most frequent pattern which should be consider among 4 main atmospheric circulation patterns. Implication of a combined synoptic classification approach by combining manual synoptic classification, backward trajectory analysis and investigating atmospheric thermodynamic conditions provide a better understanding of dominant mechanisms in extreme air pollution episodes over northeast of Iran. This approach was successful and effective and it has created reasonable and reliable results.

Keywords

• Regional atmospheric circulation
• Air Pollution
• PSI
• HYSPLIT model
• Mashhad

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References

اصیلیان، حسن، قانعیان، محمد تقی، و غنی زاده، قادر، (1386)، آلودگی هوا، تهران، نشر میترا، 199 ص.

انتظاری ، علیرضا، (1384)، مطالعه آماری و سینوپتیکی آلودگی هوای تهران، رساله دکتری جغرافیای طبیعی-گرایش اقلیم شناسی، گروه جغرافیا، دانشگاه تربیت معلم تهران.

بیدختی، عباسعلی و شرعی پور، زهرا، (1388)، شرایط هواشناختی جو بالا و وضعیت حاد آلودگی هوا (مطالعه موردی: شهر تهران)، محیط شناسی،52: 14-1.

جهانشیری، مهین، (1389)، بررسی آماری و سینوپتیکی آلودگی هوای مشهد، پایان نامه کارشناسی ارشد جغرافیای طبیعی-اقلیم شناسی، به راهنمایی علیرضا انتظاری، دانشگاه حکیم سبزواری، سبزوار.

حجازی جویباری، آزاده، (1387)، بررسی آلودگی هوا و ارزیابی کیفیت هوا در اصفهان، پایان نامه کارشناسی ارشد فیزیک، به راهنمایی اسماعیل حسن زاده، دانشگاه اصفهان، اصفهان.

حسین پور، زینب، (1390)، تحلیل همدیدی آلودگی هوای شهر تهران با تاکید بر ذرات معلق (PM10)، پایان نامه کارشناسی ارشد جغرافیای طبیعی- اقلیم شناسی، دانشکده جغرافیای دانشگاه تهران به راهنمایی علی اکبر شمسی پور.

حسین زاده، سیدرضا، دوستان، رضا، حقیقت ضیابری، سیدمرضیه، و حقیقت ضیابری، سید مریم، (1392)، بررسی الگوهای همدید مؤثر بر آلودگی هوا در کلان شهر مشهد، جغرافیا و توسعه ناحیه ای، 21: 81-101.

ذوالفقاری، حسن، صحرایی، جلیل، شاقبادی، فریاد، و جلیلیان، آذر، (1393)، تحلیلی بر جنبه های سینوپتیکی-دینامیکی آلودگی هوا در کرمانشاه، مجله جغرافیا و مخاطرات محیطی، 9: 96-75.

روزنامه شهرآرا، (1391)، طرح جامع کاهش آلودگی هوای مشهد؛ دستورالعمل هست، بودجه نیست! دوشنبه 22مهر، شماره 969، ص 2.

رنجبر سعادت آبادی، عباس و محمدیان، لیلا، (1389)، مطالعه میانگین الگوهای همدیدی بر اساس رخداد غلظت های مختلف آلاینده CO در فصول تابستان و پائیز در تهران، پژوهش های جغرافیای طبیعی، 72: 128-111.

سایت تابناک، (1391)، مصاحبه با مشاور وزیر بهداشت جناب آقای آقاجانی، گزارش شماره 295767: 16دی ماه 1391، (http://www.tabnak.ir/fa/news/295767).

صفوی، سید یحیی و علیجانی، بهلول، (1385)، بررسی عوامل جغرافیایی در آلودگی هوای تهران، پژوهش های جغرافیایی، 58: 112-99.

عزتیان، ویکتوریا، (1386)، بررسی تأثیر عوامل هواشناسی بر روی شاخص کیفیت هوا در شهر اصفهان، رساله دکتری جغرافیای طبیعی-اقلیم شناسی، گروه جغرافیای دانشگاه اصفهان به راهنمایی جواد خوشحال دستجردی.

عطایی، هوشمند، و هاشمی نسب، سادات، (1390)، شناسایی و تجزیه و تحلیل الگوهای تراز میانی جو مؤثر در آلودگی هوای شهر اصفهان، مجله پژوهش و برنامه ریزی شهری، 2 (4): 112-97.

علیجانی، بهلول، (1381)، اقلیم شناسی سینوپتیک، انتشارات سمت، صص20-5.

علیجانی، بهلول، (1382)، شناسایی تیپ های هوایی مؤثر برآلودگی هوای تهران، سومین کنفرانس منطقه ای و اولین کنفرانس ملی تغییر اقلیم، 29 مهر تا 1 آبان، دانشگاه اصفهان.

علیجانی، بهلول، (1384)، رابطه بین توزیع فشار و تراکم آلاینده ها در تهران، پژوهش های جغرافیایی، 51: 151-141.

علیجانی، بهلول و نجفی نیک، زهرا، (1388)، بررسی الگوهای سینوپتیکی اینورژن در مشهد با استفاده از تحلیل عاملی، مجله جغرافیا و توسعه ناحیه ای، 12: 12-1.

علیجانی، بهلول، مفیدی، عباس، جعفرپور، زین العابدین، و بیدختی، عباسعلی، (1390)، الگوهای گردش جو بارش های تابستانه جنوب شرق ایران در ماه جولای1994، مجله فیزیک زمین و فضا، 37 (3): 227-205.

فهیمی فرد، سید محمد، و افشار، فهیمه، (1389)، بررسی و اندازه گیری آلودگی هوای شهر مشهد، دومین کنفرانس برنامه ریزی و مدیریت شهری، 29 و 30 اردیبهشت ماه، دانشگاه فردوسی مشهد، 14 صفحه.

قربانی، محمد، و فیروز زارع، علی، (1388)، ارزش‎گذاری ویژگی‏های مختلف آلودگی هوا در مشهد، مجله تحقیقات اقتصادی، 89: 241-215.

قسامی، طاهره، بیدختی، عباسعلی، صداقت کردار، عبدالله، و صحرائیان، فاطمه، (1386)، بررسی شرایط همدیدی حاکم در چند دوره بحرانی آلودگی هوای شهر تهران، علوم و تکنولوژی محیط زیست، 9 (3): 238-229.

کریمی، صادق، (1391)، بررسی پیوند بین گردش اتمسفری در مقیاس همدید و تغییرات غلظت ازون تروپوسفری در کلانشهر تهران، رساله دکتری جغرافیای طبیعی-اقلیم شناسی، گروه جغرافیای دانشگاه سیستان و بلوچستان.

گلریز ضیائی، زهرا، صادقی، حمید، معتمدی، محمد، و ژاله رجبی، میترا، (1390)، پیش بینی، ارزشگذاری و ترسیم نقشه آلودگی هوای شهر مشهد؛ مطالعه موردی گاز منوکسید کربن، اولین کنفرانس اقتصاد شهری ایران, مشهد، 2 و 3 آذر ماه.

لشکری، حسن و هدایت، پریسا، (1385)، تحلیل الگوی اینورژن شدید شهر تهران، پژوهش های جغرافیایی، 56: 82-65.

مفیدی (1386) تحلیل گردش جو تابستانه بر روی جنوب غرب آسیا و ارتباط آن با بارش های تابستانه جنوب شرق ایران، رساله دکتری جغرافیای طبیعی-گرایش اقلیم شناسی، دانشگاه تربیت معلم تهران، گروه جغرافیا، 165ص.

موسوی، محمد، بحرپیما، سارا، و رضازاده، رضا، (1382)، بررسی آلودگی هوای ناشی ازسه نیروگاه موجود در شهر مشهد با استفاده از مدل گوس، چهارمین همایش ملی انرژی، کمیته ملی انرژی جمهوری اسلامی ایران، تهران، 9 صفحه.

منصوری، نبی الله، و علی نژاد، جواد، (1388)، بررسی کارآیی سیستم های کنترل کننده ذرات معلق و تعیین میزان انتشار در کارخانجات آسفالت مشهد، علوم و تکنولوژی محیط زیست ،11 (1): 9-1.

مهندسان مشاور فرنهاد، (1387)، طرح توسعه و عمران (جامع) کلانشهر مشهد مقدس؛ مطالعات پایه محیط طبیعی، وزارت مسکن و شهرسازی، شهرداری مشهد، 167ص.

واثقی، الهه، و زیبایی، منصور، (1387)، پیش بینی آلودگی هوای شیراز، محیط شناسی، سال سی و چهارم، 47: 72-65.

Air Weather Service., 1990. The Use of the Skew-T, log P Diagram in Analysis and Forecasting. Technical report, AWS/TR-79/006, Scott Air Force Base, Illinois 62225-5008, 164 pp.

Aliakbari Bidokhti, A.A., and Shareipoor, Z., 2009. Meteorological conditions of upper atmosphere and critical air pollution periods; (case study: Tehran). Journal of Environmental studies 35 (52), 1-14.

Alijani, B., 2002. Synoptic Climatology. 1st edition, SAMT Publication, Tehran, 5-20.

Alijani, B., 2003. Identification of weather types related to Tehran air pollution. Proceeding of 3rd regional and 1st national conference on Climate Change, October 21, 2003, University of Isfahan, Isfahan.

Alijani, B., 2005. The relationships between pressure distribution and pollutants concentration in Tehran city. Geographical Research 51, 141-151.

Alijani, B., and Najafi-e-Neek, Z., 2009. Investigation of Synoptic patterns related to occurrence of temperture Inversion in Mashhad using Factor Analysis. Geography and Regional Development 12, 1-12.

Alijani, B., Mofidi, A., Aliakbari Bidokhti, A.A., and Jafarpour, Z., 2012. Atmospheric Circulation patterns of summer rainfalls in the Southeast of Iran during July 1994. Journal of Earth and Space Physics 37(3), 205-227.

Aseeliyan, H., Ghaneiyan, M.T., and Ghanizadeh, Gh., 2007. Air Pollution. Mitra Publication, Tehran, 199p.

Ataei, H., and Hashemi-Nasab, S., 2011. Identification and Analysis of mid-troposphere pressure patterns related to Isfahan city Air pollution. Journal of Research and Urban Planning, 2(4). 97-112.

Baker, J., 2010. A cluster of long range air transport pathway and associated pollutant concentration within the UK. Atmos. Environ., 44, 563-571.

Cheng, C.S., Campbell, M., Li, Q., Li, G., Auld, H., Day, N., Pengelly, D., Gingrich, S., and Yap, D., 2007. A synoptic climatological approach to assess climatic impact on air quality in south-central Canada, Part I: historical analysis. Water, Air, and Soil Pollution, 182, 131–148.

Chen, Z.H., Cheng, S.Y., and Li, J.B., Guo, X.R., Wang, W.H., and Chen, D.S., 2008. Relation between atmospheric pollution processes and synoptic pressure patterns in northern China. Atmos. Enviorn., 42, 6078-6087.

Cheng, W.L., Pai, J.L., Tsuang, B.J., and Chen, C.L., 2001. Synoptic patterns in relation to ozone concentrations in west-central Taiwan. Meteorol. Atmos. Phys., 78, 11–21.

Comrie, A.C., 1990. The climatology of surface ozone in rural areas: a conceptual model. Progress in Physical Geography 14, 295–316.

Comrie, A.C., and B. Yarnal, 1992. Relationships between synoptic-scale atmospheric circulation and ozone concentrations in metropolitan Pittsburgh, Pennsylvania. Atmos. Environ., Part B, 26, 301–312.

Comrie, A.C., 1996. An All-Season Synoptic Climatology of Air Pollution in the U.S.-Mexico Border Region. The Professional Geographer 48 (3), 237-251.

Davis, R. E., Kalkstein, L. S., 1990. Using a spatial synoptic climatological classification to assess changes in atmospheric pollution concentrations. Phys. Geogr., 11, 320-342.

Davis, RE., Normile, CP., Sitka, L., Hondula, DM., Knight, DB., Gawtry, SP., and Stenger, PJ., 2010. A comparison of trajectory and air mass approaches to examine ozone variability. Atmos. Environ., 44(1), 64-74.

Dayan, U., and Levy, I., 2002. Relationship between synoptic-scale atmospheric circulation and ozone concentrations over Israel, J. Geophys. Res., 107(D24), 4813, doi:10.1029/2002JD002147.

Diem, J.E., Hursey, M.A., Morris, I.R., Murray, A.C., and Rodriguez, R.A., 2010. Upper-Level Atmospheric Circulation Patterns and Ground-Level Ozone in the Atlanta Metropolitan Area. J. Appl. Meteorol., Climatol., 49, 2185-2196.

Doswell, C. A., III, and E. N. Rasmussen, 1994. The effect of neglecting the virtual temperature correction on CAPE calculations. Wea. Forecasting, 9, 625–629.

Draxler RR., and Rolph GD., 2011. HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory). Model access via NOAA ARL READY Website (http://ready.arl.noaa.gov/HYSPLIT. php). NOAA Air Resources Laboratory, Silver Spring, MD.

Entezari, A., 2005. Statistical and Synoptic study of Tehran air pollution. PhD dissertation of Physical geography, Department of Geography, Tarbiat Moallem University, Tehran.

Ezzatiyan, V., 2007. Investigating the influence of meteorological factors on air quality conditions in Isfahan city. PhD dissertation of climatology, Faculty of Geography, University of Isfahan. Isfahan.

Fahimi-Fard, S.M., and Afshar, F., 2010. Investigation and measurement of air pollution in the Mashhad city. Proceeding of 1st National Conference on Urban Planning and Management, May 19-20, 2010, Ferdowsi University of Mashhad, Mashhad, 14p.

Farnahad Architecture and Urbanism Consulting, 2008. Comprehensive plan for development of holly Mashhad metropolitan, basic environmental studies. Funded by Ministry of Urban planning and Construction, Mashhad Municipality, 167p.

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(3-4), 265-277.

Greene, J.S., Kalkstein, L.S., Ye, H., 1999. Relationships between synoptic climatology and atmospheric pollution at 4 US cities, Theor. Appl. Climatol., 62, 163–174.

Ghassami, T., Aliakbari Bidokhti, A.A., Sedaghat-Kerdar, A., and Sahraeyan, F., 2007. Investigation of Synoptic conditions during several critical episodes of air pollution in Tehran. Journal of Environmental Science and Technology, 9 (3), 229-238.

Ghorbani, M., and Firooz-Zare, A., 2009. Evaluating the different characteristics of air pollution in Mashhad, Economic Research Journal, 89, 215-241.

Golriz Ziaee, Z., Sadeghi, H., Motamedi, M., Jaleh-Rajabi, M., (2011). Prediction, Evaluation and mapping of Mashhad air pollution distribution, Case study; CO pollutant. Proceeding of 1st Iranian conference on Urban Economies, November 23-24, 2011, Mashhad.

Heidorn, K. C., and Yap, D., 1986. A synoptic climatology for surface ozone concentrations in southern Ontario 1976– 1981, Atmos. Environ., 20, 695–703.

Hejazi-Jooybari, A., (2008). Air pollution investigation and air quality evaluation in Isfahan. MS. Thesis of Physics, Department of Physics, University of Isfahan. Isfahan.

Hoseinpoor, z., 2011. Synoptic analysis of air pollution in Tehran (with emphasis on suspended particles PM10). MA. Thesis of climatology. Faculty of geography, Tehran University, Tehran.

Hosseinzadeh, SR., Doostan, R., Haghighat Zeyabari, SM., and Haghighat Zeyabari, SM., 2013. Investigating the synoptic patterns of air pollution in Mashhad metropolis, Geography and Regional Development 21, 81-101.

Hu, Y., Chang, M.E., Russell, A.G., and Odman, M.T., (2010). Using synoptic classification to evaluate an operational air quality forecasting system in Atlanta. Atmospheric Pollution Research, 1, 280–287, DOI:10.5094/APR.2010.035.

Jahanshiri, M., 2010. A Synoptic and Statistical investigation of Mashhad air pollution. MA. Thesis of climatology, Faculty of Geography and Environmental sciences, Hakim Sabzevari University, Sabzevar.

Kalkstein, L. S., and Corrigan, P. R., 1986. A synoptic climatological approach for geographical analysis: assessment of sulfur dioxide concentrations. Annals of the Association of American Geographers, 76, 381-395.

Kalkstein, L.S., Nichols, M.C., Barthel, D.C., and Greene, S.J., 1996. A new spatial synoptic classification: Application to air-mass analysis, Int. J. Climatol., 16, 983-1004.

Kalnay, E., and 21-Co-Authors, 1996. The NCEP/NCAR 40-year reanalysis project, Bull. Amr. Met. Soc., 77, 437-471.

Karimi, S., 2012. Investigating the relation between Synoptic scale atmospheric circulation and the variations of tropospheric Ozone concentration in Tehran Metropolitan. PhD dissertation of climatology, Faculty of Geography and Regional Planning, Sistan and Baluchistan University, Zahedan.

Keim, B. D., Meeker, L.D., and Slater, J.F., 2005. Manual synoptic climate classification for the east coast of New England (USA) with an application to PM2.5 concentration, Climate Res., 28, 143–153.

Kistler, R., and 16-CoAuthors, 2001. The NCEP/NCAR 50-Year Reanalysis Project, Bull. Amr. Met. Soc., 82, 246-267.

Lam, K. C., and S. Cheng, 1998. A synoptic climatological approach to forecast concentrations of sulfur dioxide and nitrogen oxides in Hong Kong, Environ. Pollution 101, 183–191.

Lashkari, H., and Hedayat, P., 2006.The analysis of synoptic patterns of severe Inversions in Tehran. Geographical Research 56, 65-82.

Mansouri, N., and Ali-Nejad, J., 2009. Investigation on dust control systems and determination of emission rate in Mashhad asphalt plants. Journal of Environmental Science and Technology 11 (1). 1-9.

McGregor, G. R., and Bamzelis, D., 1995. Synoptic typing and its application to the investigation of weather air pollution relationships, Birmingham, United Kingdom, Theor. Appl. Climatol., 51 (4), 223-236.

Mofidi, A., 2007. The Analysis of Summer Atmospheric Circulation over Southwest Asia and its Relation to Summer Rainfall in Iran Plateau, PhD. Dissertation of Physical geography (climatology). Department of Geography, Kharazmi University, Tehran, 165p.

Moncrieff, M. W., and Miller, M. J., 1976. The dynamics and simulation of tropical cumulonimbus and squall lines. Quart. J. Roy. Meteor. Soc., 102; 373–394.

Mosavi, M., Bahr-Peyma, S., and Reza-Zadeh, R., (2003). Investigation of air pollution resulted by three power plants in Mashhad using Goss model. Proceeding of 4th national meeting of energy, Islamic Republic of Iran national committee of energy, Tehran, 9 pages.

National Weather Service Training Center (NWSTC). 2000. Skew-T, Log P Diagram and Sounding Analysis, RTM –230, Kansas City, MO 64153, 45 pp.

Nilsson, E. D., Paatero, J., and Boy, M., (2001). Effects of air masses and synoptic weather on aerosol formation in the continental boundary layer. Tellus B, 53, 462-478.

O'Hare, G.P., and Wilby, R.L., 1995. Ozone pollution in the United Kingdom: an analysis using Lamb circulation types, Geographical Journal, 161, 1–20.

Ranjbar Saadat-Abadi, A., and Mohammadian, L., 2010. Investigation of predominant Synoptic patterns related to different CO pollutant concentrations in Summer and Autumn seasons in Tehran. Physical Geography Research Quarterly, 72, 111-128.

Ranjbar Saadat-Abadi, A., Mohammadian, L., and Vazifeh, A., 2012. Controls on air pollution over a semi-enclosed basin, Tehran: A synoptic climatological approach, Iranian Journal of Science & Technology, A4, 501-510.

Safavi, S.Y., and Alijani, B., 2006. Investigation of geographical factors impact on Tehran air pollution. Geographical research, 58, 99-112.

Schwarzhoff, P.J., and Reid, P.D., 2000. Classification of meteorological patterns associated with the ozone categories in Kelowna, British Columbia, J. Appl. Meteorol., 39, 463–470.

Shahgedanova, M., Burt, T.P., and Davies, T.D., 1998. Synoptic Climatology of Air Pollution in Moscow, Theor. Appl. Climatol., 61(1-2), 85-102.

Shahr-Ara Newspaper, 2012. Comprehensive plan for reducing the air pollution in Mashhad. Report no. 969, Monday Oct 13, 2012, Page 2.

Sindosi, O.A, Katsoulis, B.D, and Bartzokas, A., (2003). An objective definition of air mass types affecting Athen, Greece; the corresponding atmospheric pressure pattern s and air pollution levels, Enviornmental technology, 24(8), 947-962.

Sando, T.R., 2011. A climatology of air pollution in the Kansas city metropolitan area, M.A. thesis, Kansas State University, http://krex.kstate.edu/dspace/ bitstream/handle/2097/ 11987/ThomasSando 2011.pdf? sequence=3

Sheridan, SC., 2002. The redevelopment of a weather-type classification scheme for North America. Int. J. Climatol., 22, 51–68.

Stunder, B.J.B., 1997. NCEP Model Output –FNL ARCHIVE DATA, TD-6141, Prepared for National Climatic Data Center (NCDC). This document and archive grid domain maps are also available at http://www.arl.noaa.gov/ss/transport/archives.html.

Taabnak, 2012. Interview with Counselor of Health Minister Mr. Aghajani. Report no. 295767, January 5, 2013, http://www.tabnak.ir/fa/news/295767.

Tanner, P.A., and Law, P.T., 2002. Effects of synoptic weather systems upon the air quality in an Asian megacity, Water, Air, & Soil Pollution, 136, 105–124.

United States Environmental Protection Agency (US-EPA). 1978. Rapid techniques for calculating the pollutant standards index (PSI). EPA--600/4-78-002, 68 pp.

United States Environmental Protection Agency (US-EPA). (1998). Guideline for Reporting of Daily Air Quality-Pollutant Standards Index (PSI). EPA Draft, Office of Air Quality Planning and Standards, North Carolina 27711, 28 pp.

Vaseghi, E., and Zibaei, M., 2008. Prediction of Shiraz air pollution. Journal of Environmental Sciences, 47, 65-72.

Wang, L.-L., Wang, Y.-S., and Li, Y.-Y., 2010. Synoptic typing and its application for evaluating climatic impact on air quality in Urumqi, Atmos, Oceanic Sci. Lett., 3 (6), 312–318.

World Health Organization (WHO). 2011. The Top 10 Most Air Polluted Cities in the World, written by M. L. Goldberg, UN Dispatch, 26 Sep. 2011, Available at http://www.undispatch.com/the-top-10-most-air-polluted-cities-in-the-world-are.

Yarnal, B., (1993). Synoptic Climatology in Environmental Analysis, Belhaven press, 1-18.

Yarnal, B., Comrie, A.C., Frakes, B., and Brown, D.P., 2001. Developments and prospects in synoptic climatology, Int. J. Climatol., 21, 1923–1950.

Yuen, C.Y., et al., 1998 Synoptic weather patterns associated with Nox pollution episodes in Hong Kong urban areas, Proceedings of the air & Waste management Association’s Annual Meeting & Exhibition, 9p.

Ziomas, I., Melas, D., and Zerefos, C.S., 1995. Forecasting peak pollutant levels from meteorological variables, Atmos. Environ., 29, 3703–3711.

Zolfaghari, H., Sahraei, J., Shahghobadi, F., and Jalilian, A., 2014. Analysis on synoptic and dynamical aspects of air pollution in Kermanshah city, Geography and Environmental Hazards 9, 75-96.