Relationships between daily solar irradiance and maximum temperature in Iraq

This study investigates the relation between daily solar irradiance (SI) and maximum air temperature (Tmax) over six cities in Iraq (Basra, Shanafiya, Baghdad, Rutba, Kirkuk, and Shakhan) using NASA POWER data for the period 2014-2023. Results revealed that in the arid southern provinces such as Basra, the annual mean SI exceeds 5.6 kWh m-2day-1 and Tmax frequently exceeds 48°C during the summer months while in the northern provinces lower SI and Tmax values were observed. The seasonal variation indicated peak values of SI during June while peak values of Tmax were observed in July-August. A strong relationship between SI and Tmax were obtained with R2 of 0.75 to 0.82 at different locations.