1961-90 HIGH RESOLUTION TEMPERATURE, PRECIPITATION, AND SOLAR RADIATION CLIMATOLOGIES FOR ITALY

This PhD thesis focuses on the construction of monthly 30-arc-second resolution temperature, precipitation, and solar radiation 1961-90 climatologies for Italy and on the superimposition of the information of the secular anomaly records to these climatologies. The minimum, mean, and maximum temperature climatologies are based on a quality-checked new 1961-90 dataset for Italy that includes 1,493 TM records and 1,138 TN-TX records; they have been obtained by means of a Multiple Linear Regression model, plus local and global improvements and a Geographical Inverse Distance Gaussian Weighting of the residuals. The final monthly average MAE is 0.65 °C for TM, 0.91 °C for TN, 0.81 °C for TX. The precipitation climatologies are based on a quality-checked new 1961-90 dataset for Italy that includes more than 4,000 precipitation totals; they have been obtained by means of a PRISM model. The relative MAE for yearly total precipitation is approximately 10%. Further work is under development in order to improve both the database and the models. Examples of new reconstructed temperature and precipitation secular records for 1851-2010 are shown and the methodology used to obtain a secular record for each grid point is described. The solar radiation climatologies are obtained by means of a solar radiation model based on a quality-checked new dataset for Italy that includes more than 150 sunshine duration records. The solar radiation model is created on the basis of astronomical parameters, shading effects, albedo tables and turbidity Linke’s factor: monthly 1961-90 grids for direct, diffuse, reflected, absorbed, and global radiation are obtained. The final monthly average relative MAE is 4.6%.