An Analytical Model for Daily-Periodic Slope Winds. Part 1: Surface Radiation Budget

This article presents an analytical model for calculating representative daily-periodic cycles of net surface radiation on a slope with any angle alpha$$ \alpha $$ (0 degrees <=alpha <= 90 degrees$$ {0}<^>{\circ}\le \alpha \le 9{0}<^>{\circ } $$) and orientation, at any latitude and elevation (up to 2500 m), and for all seasons. Starting from the basic equations for estimating the daytime direct and diffuse components of the incoming solar radiation at the Earth's surface under clear-sky conditions, a Fourier series expansion is derived to get an overall daily-periodic expression, that is, covering both daytime and nighttime, which does not require data from observations, differently from most models available in the literature. Among various possible applications, this formulation is preliminary to evaluating the radiation and energy budgets driving daily-periodic wind systems on a simple slope, as reproduced by the model presented in Part 2.The article presents an analytical model for evaluating representative daily-periodic cycles of net surface radiation on a slope with any angle alpha$$ \alpha $$ (0 degrees <=alpha <= 90 degrees$$ {0}<^>{\circ}\le \alpha \le 9{0}<^>{\circ } $$) and orientation, at any latitude and elevation (up to 2500 m), and for all seasons. Starting from the basic equations for estimating the daytime direct and diffuse components of the incoming solar radiation at the Earth's surface under clear-sky conditions, a Fourier series expansion is derived to get an overall daily-periodic expression, that is, covering both daytime and nighttime, which does not require data from observations, differently from most models available in the literature. Among other possible applications, this formulation is preliminary to evaluating the radiation and energy budgets, driving daily-periodic wind systems on a simple slope according to the model presented in Part 2. image