Contribution of Inversion Management to Controlling the Threshold of Urban Air Quality Index (Case Study: Isfahan City)

Document Type : Full length article


1 PhD Candidate in Geography and Urban Planning, Faculty of Geography Sciences and Planning, University of Isfahan, Iran

2 Professor of Physical Geography, Faculty of Geography Sciences and Planning, University of Isfahan, Iran

3 Associate Professor of Physical Geography, Faculty of Geography Sciences and Planning, University of Isfahan, Iran

4 Assistant Professor of Geography and Urban Planning, Islamic Azad University, Najafabad Branch, Iran


Air inversion is a climatic phenomenon causing increases in the aggregation of pollutants in highly populated and industrial cities. Hence, changes exceeding the air quality threshold would have extensive problems for the citizens. Attention of managers to this problem is mainly referred to as polluting factors. However, in case this phenomenon exists during all the seasons and as the polluting factors have no great changes during the year, some factors can lead to exceed the air quality index from the threshold value. Hence, there can be an approach for reducing the continuity of this situation, if continuity of the inversion leads to such a condition.
The main problem in this study is whether there is the possibility of managing Esfahan air pollution in such a way for to prevent atmospheric pollution density to reach the critical threshold. Therefore, we try to find a model to control the air pollution crisis threshold by relying on the climatic management.
Materials and methods
The research method of this study is mainly relying on an analytical method and dependent on the principles of interpreting the data of climatic and atmospheric pollutants. The subject of air pollution critical thresholds is considered for analysis of the research purposes. Thus, these data are related to a 30-year statistics (1985-2015) from Meteorological Organization and balloon data including pressure, temperature, speed, wind direction, and rains, and the air pollution data from 14 pollution measurement stations belonging to Esfahan Environmental Organization. The analyses in various levels enabled us to find out the inversion conditions in different levels. Hence, only the levels of 1670, 1680, and 1860 m were selected due to formation of pressure and temperature among one hundred weather maps. Then, the cellular excitation index (C.E.=f/k) was calculated, where k=    and “f” is the Newton mass and the temperature and cellular pressure differences. The two indices showed the conditions and possibility of excitation of temperature and pressure closed cells for reducing the continuity of inversion time.
Results and discussion
Given the documentation data and extracted results, we have determined the inversion in the city of Esfahan in terms of the intensity, continuity, and altitude of the inversion in various levels. Thus, the temperature and pressure inversion conditions were investigated for different levels with regards to the balloon data. The inversion analysis for different levels became possible according to temperature and pressure closed cells. The analyses included 100 maps from different altitudes. According to the analysis results, two levels of 1670 m and 1680 m were for the temperature and the level of 1860 m was for the pressure in the closed cells. In fact, the above altitudes were the levels with temperature and pressure cells with the specific differences providing the possibility of excitation. The excitation conditions were finally calculated by the cellular excitation index. Threshold control models for November, December, and January in multiple basis are as follows:
- General model for November includes:
A.P.C*isf.Nov = (C.M**) V (U.M***)
A.P.Cisf.Nov = (C.E****) V (C.CO or C.SO2)
A.P.Cisf.Nov = (C.E) V (C.NO2 or C.O3)
*Air Pollution Control
** Climatic Management
*** Urban Management
**** Cell Excitability
- General model for December includes:
A.P.Cisf.Dec = (C.M) V (U.M)
A.P.Cisf.Dec = (C.E) V (C.CO or C.SO2)
A.P.Cisf.Dec = (C.E) V (C.NO2 or C.O3)
- General model for January includes:
A.P.Cisf.Jan = (C.M) V (U.M)
A.P.Cisf.Jan = (C.E) V (C.CO or C.SO2)
A.P.Cisf.Jan = (C.E) V (C.NO2 or C.O3)
Statistical analysis of the obtained information from the balloons and atmospheric profile indicate that the inversion phenomenon in Esfahan occurs in different days of the year. In other words, inversion phenomenon may not be considered as the main factor in emergence of pollution crisis, but its continuity in the condition is a factor for increasing the density of atmospheric pollutants to exceed the critical threshold (AQI 150). Hence, it can be stated that continuity of inversion condition can force the concentration of pollutants to exceed the permissible range.      
It can be concluded from the statement that occurrence of atmospheric pollution condition can be prevented by two different methods: (1) reducing inversion continuity, (2) management of urban pollutants. Thus, the following statements can be considered as the achievements of this study:

In the most intensive dominating days of air inversion, pressure and temperature cellular nuclei provide the possibility to manage the continuity duration of air inversion by exciting the cells,
Regarding the intensity of inversion phenomenon exceeding quality index from the permissible range can be avoided in November and December by controlling the inter-city traffic control, and in January by controlling the industrial pollutants.


Main Subjects

ادارة کل حفاظت محیط زیست استان اصفهان (1392). برنامة جامع کنترل کیفی هوای اصفهان.
ادارة کل مدیریت بحران استانداری اصفهان (1391). طرح جامع خطرپذیری و مدیریت بحران استان اصفهان- بحران‏های جوی: آلودگی هوا، وارونگی دما، و گرد و غبار.
جهان‏بخش اصل، س. و روشنی، ر. (1392). بررسی وضعیت و شدت وارونگی‏های سطح پایین‏ شهر تبریز طی دورة 2004 تا 2008، فصل‏نامة تحقیقات جغرافیایی، 28(4): 45ـ54.
درویش‏محمدی، م. (1391). توپوکلیما و پدیدة وارونگی (مطالعة موردی: شهر اصفهان- 1389)، پایان‏نامة کارشناسی ارشد رشتة جغرافیای طبیعی، دانشگاه اصفهان.
شفقی، س. (1381). جغرافیای اصفهان، اصفهان: انتشارات دانشگاه اصفهان.
عزیزی، ق.؛ شمسی‏پور، ع.ا.؛ مهدیان ماه‏فروزی، م. و میری، م. (1392). تأثیرپذیری شدت جزیرة گرمایی شهری تهران از الگوهای همدیدی جو، فصل‏نامة محیط‏شناسی، 4: 55ـ66.
کریمی، م. و درخشان، ح. (1384). بررسی وارونگی دمایی (وارونگی) در شهر اصفهان، مجموعه مقالات دوازدهمین اجلاس ژئوفیزیک ایران، ص 1ـ6.
کیخسروی، ق. و لشکری، ح. (1393). تحلیل رابطه بین ضخامت و ارتفاع وارونگی و شدت آلودگی هوا در شهر تهران، فصل‏نامة جغرافیا و برنامه‏ریزی، 49: 231ـ257. 
مهدیان ماه‏فروزی، م.؛ شمسی‏پور، ع. ا. و عزیزی، ق. (1394). اثرات گسترش فضای سبز بر الگوی جزیرة گرمایی شهری (مطالعة موردی: بوستان ولایت)، فصل‏نامة پژوهش‏های جغرافیای برنامه‏ریزی شهری، 3(1): 85ـ99.
Amarsaikhan, D.; Battsengel, V.; Nergui, B.; Ganzorig1, M. and Bolor, G. (2014). A Study on Air Pollution in Ulaanbaatar City, Mongolia, Journal of Geoscience and Environment Protection, 2: 123-128.
Azizi, G.; Shamsipour, A.; Mahdian Mahforouzi, M. and Miri, M. (2013). Effectiveness of the Urban Heat Islands of Tehran from the Climatic Synoptical Models, Environment Seasonal Magazine, 4: 55-66.
Darvish Mohamadi, M. (2010). Topoclima and Inversion (Case Study: Isfahan City), M.A Thesis in Major of Physical Geography, University of Isfahan, Supervisor: Dr. Ramesht, M.H., PP. 1-88.
Devasthale, A.; Willen, U.; Karlsson, K.G. and Jones, C.G. (2010). Quantifying the Clear-Sky Temperature Inversion Frequency and Strength over the Arctic Ocean during Summer and Winter Seasons from AIRS Profiles, The Journal of Atmospheric Chemistry and Physics, 10: 2835-2858.
Esfahan Province Environment Conservation General Office (2013). Comprehensive Plan for Esfahan Air Quality Control.
Esfahan Province General Governor’s Crisis Management General Office (2012). Comprehensive Risk Taking and Crisis Management of Esfahan Province – Climatic Crises: Air Pollution, Temperature and Dust Inversion.
Fortelli, A.; Scafetta, N. and Mazzarella, A. (2016). Influence of Synoptic and local Atmospheric Patterns on PM10 air- Pollution levels: a Model Application to Naples (Italy), Meteorological Observatory, Department of Earth Sciences, Environment and Georesources, University of Naples, PP.10 – 80.
Goldreich, Y. )2009). Updating the Urban Topoclimatology – A Review, the 7th International Conference on Urban Climate , 29 June-3 July 2009, Yokohama, Japan, PP. 1-4.
Jahanbakhsh Asl, S. and Roshani, R. (2013). Analyzing the Conditions and Intensity of Low Level Inversions of the City of Tabriz during 2004 to 2008, Geographical Research Seasonal Magazine, Edition Year: 20(4): 45-54.
Karimi, M. and Derakhshan, H. (2005). The Study of Temperature Inversion in Isfahan, Collection of Articles Twelfth Conference of Geophysics in Iran, PP. 1-6.
Keykhosravi, G. and Lashkari, H. (2014). Analysis of the Relation between Thickness and Altitude of Inversion and Intensity of Air Pollution in Tehran, Geography and Planning Seasonal Magazine, 49: 231-257.
Lauvaux, T.; Natasha, L.; Aijun, D.; Scott, J.; Richardson, M.; Cambaliza, O.; Kenneth, J.; Brian, G.; Kevin, R.; Jianhua, H.; Darragh, O.; Yang Song, A.; Tomohiro, O.; Risa, P.; Igor,  R. and Sarmiento, D. (2016). High-Resolution Atmospheric Inversion of Urban CO2 Emissions during the Dormant Season of the Indianapolis Flux Experiment, Journal of Geophysical Research: Atmospheres.
Leukauf, D.; Gohm, A.; Mathias W. and Johannes, S. (2015). The Impact of the Temperature Inversion Breakup on the Exchange of Heat and Mass in an Idealized Valley: Sensitivity to the Radiative Forcing, Journal of Applied Meteorology and Climatology, 54: 2199.
Mahdian Mahforouzi, M.; Shamsipour, A.A. and Azizi, G. (2015). Effects of Green Space Expansion on the Patterns of Urban Heat Island(Case Study: Velayat Urban Park), Geographical Urban Planning Research Seasonal Magazine, 3(1): 85-99.
Mastic, A.; Musemic, R. and Dzaferovic, E. (2016). Temperature Inversion Measurements in Sarajevo Valley Using Unmanned Aerial Vehicles, Proceedings of the 27 th, DAAAM International Symposium, pp. 423-427, Vienna, Austria.
Pei, H. and Shiliang, W. (2016). Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality, Scientific RepoRts, Doi: 10.1038/srep23792 1- 2016.
Rendon, A.; Juan, F. and Palaclo, C. (2014). Temperature Inversion Breakup with Impacts on Air Quality in Urban Valleys Influenced by Topographic Shading, Journal of Applied Meteorology and Climatology, 54: 302.
Shafaghi, S. (2002). Geography of Isfahan, Printing one , University of Isfahan Press.
Thadathil, P. and Gosh., A.K. (1992). Surface Layer Temperature Inversion in the Arabian sea during Winter, Journal of Oceanography, 48: 293-304.