DAYCENT and its land surface submodel: description and testing

A land surface submodel was developed for the daily version of the CENTURY ecosystem model (DAYCENT). The goal of DAYCENT to simulate soil N2O, NOx, and CH4 fluxes for terrestrial ecosystems determined the structure and processes represented in the land surface model. The land surface model was set up to simulate daily dynamics of soil water and temperature from a multi-layered soil system (0–1, 1–4, 4–15, 15–30 cm, etc.) and included surface runoff and above field capacity soil water dynamics during intense rainfall events and snowmelt into frozen soils. The comparison of the simulated soil water content (0–10 cm) with observed data from four sites was quite favorable (squared correlation coefficient—γ2=0.87, 0.65, 0.86 and 0.58) and the simulated results were comparable for the soil temperature model (r2=0.92 and 0.95 for minimum and maximum 10 cm soil temperatures). Detailed soil water and temperature data during snowmelt time periods and following rainfall events are needed to fully evaluate the performance of the water flow model.