Investigate of Precipitable Water in dusty conditions using satellite images (Case study: Southwest of Iran)

Subject Areas : Applications in earth’s climate change

Tahereh Ensafimoghaddam ¹ , Taher Safarrad ²

1 - Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran
2 - Assistant Professor of Climatology, Department of Geography and Urban Planning, Faculty of Humanities and Social Sciences, Mazandaran University, Babolsar, Iran

Received: 2021-12-14 Accepted : 2022-04-11 Published : 2023-05-22

Keywords: Precipitable water vapor, MODIS, satellite remote sensing, MOD06, Aerosols,

Abstract :

While the Greenhouse gases impacts of Powerhouse، cars، and other man-made particulate matter on air quality and public health، well known، their impact on climate is not fully understood. Scientists have shown that aerosols can lower surface temperatures either directly، by reflecting sunlight skyward، or indirectly، by increasing the reflectivity of clouds، but until now have not figured out the role airborne particles play in shaping the distribution of rain and snowfall around the world. Suspended dust particles, especially in urban and industrial areas, act as a reducing agent for rainfall. Large fine dust (larger than 1 micron) can increase rainfall. But very fine dust particles in the upper atmosphere can suppress heavy rainfall. The current study aimed at investigating atmospheric precipitable water capacity and its relationship with periods of dust occurrences data in South west of Iran during (1986 –2016). In this paper، MODIS surface classification data was used to consider this influence. In this paper، the effect of dust occurances on rainfall studied by using classified data of MODIS/Terra Calibrated Radiances (MOD06). The results of this study by examining remote sensing data such as the amount of atmospheric precipitable water content and the occurrences of dust in some selected cases، showed that over time when dust rises، the amount of atmospheric precipitable water content which indicates the potential for rainfall، significantly reduced.The results of this study showed that one of the effects of dust events in southwestern Iran، there was a decrease in rainfall during a period of thirty years(1986-2016) and dust can significantly to act as reducing agent or rain suppressor in study region. On the other hand، in this study، in proof of dust reducing effect on atmospheric precipitable water content، the high performance of the MOD06 product appeared in the southwestern region of Iran.