Analysis of the convective available potential energy by precipitation over Iraq using ECMWF data for the period of 1989–2018

The rain is the most common type of precipitation in our atmosphere and when liquid droplet falls to the earth surface. The source of precipitation is water vapor, which is always present in the atmosphere in varying amounts; there are three major types of rain can be distinguished depending on the different factors that cause the airlifting and formation of clouds and rain falling as well as meteorology factors (Niwas, Singh, Singh, Khichar & Singh, 2006): Convectional rainfall: this type of rainfall occurs due to the ground surface heating. When the land warms up, it heats the air above it. This causes the air to expand and – rise. As the air rises it cools and condenses. If this process continues then rain will fall. Convectional rainfall occurs for a very short duration but occurs in the form of heavy showers. This type of rain is often accompanied by lightning and thunder. It is called ascending/rising rain because it is the result of a rising process of the atmosphere, which is exposed to thermal heating and clouds resulting from this type cumulus and cumulonimbus (Saxena & Gupta, 2017). Cyclonic/Frontal rainfall: this type of rainfall occurs when a warm and moist air mass (warm front) meets a cold and dry air mass (cold front). When both masses come together, warmer air is forced to rise over cold air. The moist warm air condenses as it cool, which causes cloud and rain. When there are condensation nuclei and when the atmosphere arrives at saturation – Scientifi c Review – Engineering and Environmental Sciences (2020), 29 (2), 196–211 Sci. Rev. Eng. Env. Sci. (2020), 29 (2) Przegląd Naukowy – Inżynieria i Kształtowanie Środowiska (2020), 29 (2), 196–211 Prz. Nauk. Inż. Kszt. Środ. (2020), 29 (2) http://iks.pn.sggw.pl DOI 10.22630/PNIKS.2020.29.2.17