Treatment Missing Data of Daily and Monthly Air Temperature in Some Iraqi cities by Using Curve Fitting

Climate change has become fast and entered a new stage and began to affect all regions of the world. so, the climate must be analyzed and studied accurately. In order to do this, should be available a continuous database without interruptions, to improve the accuracy of forecasts. Therefore, this research aims to treat the missing temperature data for the stations (Baghdad, Hilla, Basra, Nasiriya, and Samawa) by using the curve fitting method. In the monthly treatment for the period (1980-2020), it was observed that the highest match between the real and the treatment values ​​using the Gaussian function and the sine wave function was recorded in the summer months at (100%), and the lowest match was recorded in the winter months. The daily treatment period (2010-2020) recorded the highest match at (97%) in the summer, and the lowest match was recorded in the winter months. In order for the treated values ​​to be close to the real values, it is recommended to use this method for months from April to October. In the winter months, it should be used with caution.