Simulating hydro-meteorological variables across a range of temporal scales with a weather generator

Long continuous series of meteorological variables are required for many ecological, hydrological, agricultural, and geomorphological applications. They are also needed for water resource management or in studies of crop and ecosystem responses to climate forcing. Observational time series are often too short or discontinuous to achieve these purposes or to make feasible modeling approaches. This study presents an application of a new weather generator, Advanced WEather Generator (AWE-GEN), capable of simulating a wide range of hydro-climatic variables at the hourly time scale. The generator operates at the point scale and reproduces precipitation, cloudiness, air temperature, vapor pressure, wind speed, atmospheric pressure, and solar radiation partitioned into the diffuse and direct beam components as well as into visible and near-infrared spectral bands. In the presented analysis, the time series of meteorological variables observed at the station of Firenze University and the long-term observations of annual precipitation at a neighbouring location are used. Forty years of hourly meteorological variables are reproduced using only eight years of hourly observations. The developed tool satisfactorily reproduces climate characteristics at the location of interest. The satisfactory simulation of higher order statistics, including extremes, is verified. A comparison of the observed and simulated climatic variables demonstrates an excellent performance of AWE-GEN in matching statistics across a wide range of temporal scales, including inter-annual variability of precipitation.