Share of Inversion Management in Controlling the Threshold of Urban Air Quality Index Case Study: City of Isfahan

  Air inversion is a climatic phenomenon causing increasing in the aggregation of pollutants in highly populated and industrial cities, such that crossing from the air quality threshold would have extensive problems for the citizens. Attention of managers to this problem is mainly referred to polluting factors such as traffic. However, it should be seen that in case this phenomenon exists during all the seasons and if the polluting factors have no great changes during the year, what factor can lead in crossing the air quality index from the threshold value, and, will there 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 the atmosphere pollution density not to tend towards the critical threshold. In case the answer is positive, how can a model be presented for controlling the air pollution crisis threshold by relying on the climatic management? The research method in this paper is mainly relying on an analytical method and depends on the principles of interpreting climatic and atmospheric pollutants data. The subject of air pollution critical thresholds is considered for approaching the research aims. Thus, the used data were related to a 30-year data (1985-2015) from Meteorological Organization and balloon data including pressure, temperature, speed, wind direction, and rains, and the air pollution data were from 14 pollution measurement stations belonging to Esfahan Environmental Organization. The analyses in various levels enabled us to find out about the inversion conditions in different levels. Hence, only the 1670, 1680, and 1860 m levels were selected due to formation of pressure and temperature closed cells among one hundred produced weather maps. Then, the cellular excitation index (C.E.=f/k) was calculated, where k= D/(Δt,p) and “f” is the Newton mass, and the temperature and cellular pressure differences were calculated by using this formula. The two indices showed the conditions and possibility of excitation of temperature and pressure closed cells for reducing the continuity of inversion time. Regarding the documentation data and extracted results, the inversion in the city of Esfahan was analyzed, and the intensity, continuity, and altitude of the inversion in various high levels were determined. Thus, the temperature and pressure inversion conditions were investigated for different levels with regards to the balloon data, and inversion analysis for different levels became possible according to temperature and pressure closed cells. The analyses included 100 maps from different altitudes that according to the analysis, the two 1670 m and 1680 m were for the temperature and the 1860 m level was for the pressure in the closed cells. In fact, the above altitudes were the levels having temperature and pressure closed cells with specific differences, providing the possibility of excitation. Afterwards, the excitation conditions were calculated by calculating the cellular excitation index. Statistical analysis of the obtained information from the balloons and atmospheric profile indicate that the inversion phenomenon in Esfahan region occurs in different days of the year, and the considered point regarding the research questions is the continuity of inversion time. In other words, inversion phenomenon may not be considered as the main factor in emergence of pollution crisis, but the continuity of this of this condition is the factor for increasing the density of atmospheric pollutants and crossing from critical threshold (AQI 150). Hence, it can be stated that continuity of inversion condition leads to exceeding of the pollutants density from the permissible range.
It can be concluded from the statement that occurrence of atmospheric pollution condition can be prevented by two different Reducing inversion continuity
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
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)