Application of processed sattelite images for filling the air tempersture gaps ( Case Study : Mazandaran Province)

One of the main challenges in hydrological and meteorological studies is determination of the air temperature in in large scale and high altitudes regions with limted stations. The remote sensing images have been widely used for estimating air temperature providing large scacle,precise data. In this study, in order to evaluate the accuracy of TRMM satellite air temperature estimates, the monthly data of two years of 2012 and 2013 were used for calibration and the 2015 dataset for validation. 36 TRMM satellite images of monthly temperature were retrieved and compared with observations of of 24 meteorological stations in Mazandaran province The correlation coefficents of satellite temperature estimations and observation data in most months was more than 0.50. Also, the spatial distribution of TRMM satellite and froundbased were almost same For the accuracy evaluation the MBE and RMSE indices were used. The highest errors in 2012 and 2013 study years were correspond to February and December, respectively, with a RMSE value of 7.4 and 4.8 °Celsius, respectively, The lowest error were observed in July and September, i.e. 3.4 and 2.9 ° Celsius, respectively. Similariy, based on the MBE index, the highest and lowest error was belonged to December and April, with values of -3.4 and +0.1, respectively, and the highest and lowest error based on RMSE was observed in months of May and December, with the values of +5.1 and +2.5 degrees Celsius, respectively. The results of this study showed that the use of remote sensing can be recommended in the regions with limited weather stations.