DefinePK

Abstract

In this study, spatial and temporal variations of aerosol optical depth (AOD) in selected regions in Iraq, namely, Mosul, Baghdad, Rutbah, and Basrah, were investigated with spatial resolution of 1° × 1° over Iraq (28.5°–38.5°N, 38.5°– 48.25°E); data have been retrieved from January 2003 to December 2015 by Moderate Resolution Imaging Spectroradiometer (MODIS) were analyzed which can lead to modifications in the microphysics of clouds as well. The highest values for mean seasonal AOD were observed in summer and spring, and the maximum recorded AOD values ranged from 0.324 ± 0.191 to 0.378 ± 0.189. By contrast minimum AOD values ranging from 0.195 ± 0.097 to 0.216 ± 0.111 were found in winter and autumn respectively, besides analyzed the relationship between AOD and Ångström exponent (AE) that consider a perfect indicator of the size of an aerosols particles. Furthermore, the relationships between AOD and four cloud parameters, namely, cloud fraction (CF), water vapor (WV), cloud optical depth (COD) and cloud effective radius (CER) have been investigated by employing spatial correlation maps for their data values. The analysis showed a strong negative correlation between AOD and AE particularly in the middle region (Baghdad) and western region (Rutbah). The correlation between AOD and CF showed a weak negative correlation and be close to zero in the western region. The correlation between AOD and WV was positive (~ 0.4) especially in the strip joint between a northern and middle region. AOD showed a negative relationship with COD in the whole of Iraq. AOD and CER presented a positive relation along the arid desert region extended from west northern region to the west southern region passing western region of Iraq. All mentioned correlations performed on the four study regions are based on the large-scale atmospheric variations.