Implementing irrigation techniques in CESM2

Several recent studies have highlighted the importance of irrigation-induced changes in climate. Earth system models are a common tool to address this question, and to this end, irrigation is increasingly being represented in their land surface modules. Despite this evolution, currently, none of them considers different irrigation techniques. Here we develop and test a new parameterization that represents irrigation activities in the Community Land Model version 5 (CLM5) and considers three main irrigation techniques (surface, sprinkler and drip irrigation). Using global maps of the areas equipped by different irrigation systems, we will employ version 2 of the Community Earth System Model (CESM2) and its improved irrigation representation to detect the impacts of irrigation on climate. Two control experiments are designed, one with the new irrigation scheme and another with the original one. We will conduct an evaluation by comparing the simulated results against observed surface fluxes and meteorological variables. Subsequently, the differences between the experiments will be analyzed to quantify the impacts of irrigation on climate. We anticipate that our results will uncover whether considering different irrigation schemes is of value for exploring irrigate-induced impacts on climate.