ICUC9 - 9 th International Conference on Urban Climate jointly with 12 th Symposium on the Urban Environment Monitoring of Air pollution and black cloud influence on Aerosol optical properties over Nile Delta based on Moderate Resolution Imaging Spectroradiometer (MODIS) and climatic data from 2002-2012 Hossam Ismael Geography and GIS department, Faculty of Arts, Assiut University, New Valley Branch. Egypt hossam_geography@yahoo.com hosam.ismael@artnv.au.edu.eg Abstract The Study area is the most affected region in the world by climate change impacts according to the fourth report of the Intergovernmental Panel on Climate Change 4th Report of IPCC, 2007. This report presents a scenario of destruction of the settlement centers in Nile Delta, Port Said in the east and Alexandria in the west (10 million people are at risk), besides, losing more than 86 square kilometers of the northern lakes, about 200,000 acres of the most valuable agricultural land as a result of high temperature and the consequent rise in average sea level. In Egypt, air pollutants (e.g. SO2 and CO2) gave rise to high concentrations of air pollutants especially in Nile delta, due to bio mass fire which is called 'Black Cloud' phenomenon. The main aim of this study is to Monitoring of Air pollution and black cloud influence on Aerosol optical properties over Nile Delta based on Moderate Resolution Imaging Spectroradiometer (MODIS) and climatic data from 2002-2012. To achieve this aim the study will use the HYDRA visualization software with the characteristics of the MODIS climatic data. Results obtained from MODIS data are validated by using the previously mentioned data sets to reveal the nature and the characteristics of the climate change. Fire, dust Detection with MODIS, AIRS, and AOD analysis clearly indicates large amounts of aerosols that form the black cloud events over various locations within the Nile delta region. Also the results agree with the observed values in the study area, and highly required for many applications related to integrated remote sensing techniques with actual field measurements and data Meteorological Authority in different periods to reduce the risk of climate. 1-Introduction: The Nile delta is suffering from high ambient concentrations of atmospheric pollutants including particulates (PM), carbon monoxide, nitrogen oxides, ozone and sulfur dioxide (Abu- Allaban et al., 2007, Abu- Allaban et al., 2002, El-Metwally et al., 2008). Pollution in this area is represented in what is called “Black cloud” over Nile delta. The existence of this black cloud could be attributed to many reasons among which are biomass burning, local emission and long rang of transport during the fall season. Several studies have been conducted to investigate this phenomenon using ground-based and satellite air quality data as compared to other megacities (Abu- Allaban et al., 2002, 2007, 2009; Alfaro and Wahab, 2006; El-Askary and Kafatos, 2008; El-Askary, 2006, 2008, 2010); El- Metwally et al., 2008; Favez et al., 2008; Kanakidou et al., 2011; Mahmoud et al., 2008; and Marey et al., 2010; Prasad et al., 2010 and Zakey et al., 2004). Marey et al. (2010) have used a multi- sensor approach using the Moderate Resolution Imaging Spectrometer (MODIS) and the Multi-angle Imaging Spectro Radiometer (MISR) with meteorological data and trajectory analysis to examine the reasons for the black cloud formation over Cairo. MODIS fire detection has identified the aerosol source which is burning the agricultural waste after harvest season in the Nile Delta region. Prasad et al. (2010) suggest that the long range of dust transport at high altitude (2.5-6 km) from the Western desert and its deposition over the Nile Delta region is one of the major contributors to air pollution episodes during this season. Nile delta and Great Cairo have witnessed different seasonal climate systems that are highly influenced by sand and dust storms coming from the western desert as well as local, increasing anthropogenic activities (El-Askary et al, 2010). As a result, it is characterized by a complicated meteorology that varies in the different times of the year. This study suggests that the pollution during the black cloud episode is the worst on human beings in addition to its effect on the local climate. During winter the climate is generally cold, humid and rainy; while during the summer season the weather is hot and dry (Zakey et al, 2008). Several studies have been conducted to examine the main reasons for the increasing pollution levels in Cairo and Nile delta using ground-based and satellite air quality data (Zakey et al., 2004; Abu-Allaban et al., 2002, 2007; Alfaro and Wahab, 2006; El-Askary and Kafatos, 2008; Favez et al., 2008; Mahmoud et al., 2008; and El-Metwally et al., 2008; Marey et al., 2010 and Prasad et al., 2010). However, the genesis of the fall episodes (the black cloud season) is still under discussion and needs more investigations. In order to acquire further synoptic information and visualization of the aerosol and clouds characteristics, it is useful to analyze satellite data as well, since these data provide horizontal and vertical covering with fairly high (e.g. daily and monthly) temporal resolution. (Marey et al, 2010, 2011) utilized data from several satellite instruments to examine the most likely reasons for the black cloud formation over Nile delta. The impacts of pollution on aerosol optical properties and the long range of dust transport have been widely studied over Asia and other regions. Recent studies, using different sensors over optical and microwave spectra, have analyzed aerosol optical properties during dust and pollution events over Northern India and East Asia (Uno et al. 2001, Carmichael et al. 2002, Di Girolamo et al. 2004, Singh et al. 2004, El-Askary et al. 2006).