Identification of the Thresholds of Extreme Values and Synoptic Analysis of PM10 Pollution in the Atmosphere of Ahvaz

Document Type: Original Research Paper

Authors

1 Department of Physical Geography, Tarbiat Modares University, Tehran, Iran

2 Department of Climatology, the University of Tabriz, Tabriz, Iran

Abstract

Ahvaz can be regarded as one of the most polluted cities in the world in terms of air pollution. Successive years of drought and weather conditions in recent years have resulted in particulate matter (PM10) concentration in Ahvaz. In this study, using probability distribution techniques, an appropriate threshold to identify the PM10 maximum extreme concentrations (MEC) has been detected. Based on log-logistics probability distribution, which has the best fit to the data of PM10 concentration in Ahvaz, the 0.99 percentile threshold which is specified by 1516 μg/m³ is known as the primary PM10 concentrations in Ahvaz air. Based on the mentioned threshold, 24 days in which the PM10 concentration was equal to or more than the threshold were selected for synoptic analysis. Analysis of the circulation of weather types showed that two weather types circulations at 500 hPa level provide the climatic conditions for the occurrence of (MEC) caused by PM10 concentration ≥1516 μg/m³ in Ahvaz in the first type (which is for hot days). Under such condition, the closed high pattern of 500 hPa level is accompanied by the ground low pressures. In the second type (which is for cold and transitional days) the closed high pattern of 500 hPa level is accompanied by the ground high pressures. In addition, this study showed that the (MEC) of PM10 in both models fed with several different sources at different levels and due to being multi-source, storms can create MEC.

Keywords


Draxler, R.R., Giillette, D.A., Kirkp Patrick, J.S. and Heller, R.J. (2001). Estimating PM10 air concentrations from dust storms in Iraq, Kuwait and Saudi Arabia. Atmos. Environ., 35: 4315-4330.
Farajzadeh, M. (2015). Climate hazards of Iran, Samt Publication Co, Tehran, Iran. 339P.
Hamidi, M., Kavianpou, R., M.R. and Shao, Y. (2013). Synoptic analysis of dust storms in the Middle East, Asia-Pacific. J. Atmos. Sci., 49(3): 279-286.
Kabatas, B., Unal, A., Pierce, R.B. and Pozzoli, L. (2014). The contribution of Saharan dust in PM10 concentration levels in Anatolian Peninsula of Turkey. Sci. Total. Environ., 489: 413-421.
Natsagdorj, L., Jugder, D. and Chung, Y.S. (2003). Analysis of dust storms observed in Mongolia during 1937–1999. Atmos. Environ. 37: 1401–1411.
Pope, C.A. (2000). Epidemiology of fine particulate air pollution and human health: Biologic mechanisms and who’s at risk. Environ. Health Persp, 108 (SUPPL. 4): 713-723.
Pourshahbaz, H. (2015). The statistical and synoptic analysis of maximum extreme values of PM10 in Ahvaz, MSc dissertation, Department of Physical Geography, Tarbiat Modares University.
Sadeghi, S. and Khaksar, S. (2014). Neural network model for short term prediction of PM10 pollution in Ahvaz city. J. Environ. Res., (in Persian)., 9: 177-186.
Saniei, R., Zanghiabadi, A., Sharifikia, M. and Ghavidel, Y. (2016). Air quality classification and its temporal trend in Tehran, Iran. 2002-2012, J. Geosp. Health., 11 (2):1-12.
Shahsavani, A., Naddafi, K., Jafarzade Haghighifard, N., Mesdaghinia, A., Yunesian, M. Nabizadeh, R., …and Goudarzi, G. (2012). The evaluation of PM10, PM2.5, and PM1 concentrations during the Middle Eastern Dust (MED) events in Ahvaz, Iran, from April through September 2010. J. Arid. Environ., 77: 72-83.
Tavousi, T., Khosravi, M. and Raeisipour, K. (2011). Synoptic analysis of dust systems in Khuzestan province. Geography and Development (in Persian)., 20: 97-118.
Tian, G., Qiao, Z. and Xu, X. (2014). Characteristics of particulate matter (PM10) and its relationship with meteorological factors during 2001–2012 in Beijing. Environ. Pollut., 192: 266-274.
Triantafyllou, A.G. (2001). PM10 pollution episodes as a function of synoptic climatology in a mountainous industrial area. Environ. Pollut., 112: 491-500.
Weihong, Q. Lingshen, Q. and Shaoyin, S. (2002). Variations of the Dust Storm in China and its Climatic Control. J. Climate., 15: 1216–1229.
Wang, W. and Fang, Z.Y. (2006). Numerical simulation and synoptic analysis of dust, emission and transport in East Asia. Global Planet Change., 52: 57-7.
Yao, L. and Lu, N. (2014). Spatiotemporal distribution and short-term trends of particulate matter concentration over China, 2006-2010. Environ. Sci. Pollut. Res., 21:9665-75.