Xitian Cai is a Postdoctoral Fellow in the Climate and Ecosystem Sciences Division. His research mainly focuses on studying the water, carbon, and nutrient cycles using land surface or Earth system models. He led the development of a dynamic terrestrial nitrogen model for the Noah-MP land surface model, which improves the model’s performance in carbon cycle modeling. He used a hyperresolution land surface model for SMAP (Soil Moisture Active Passive satellite) soil moisture validation and soil moisture network design. Since joining the Berkeley Lab, he has been participating in the Biogeochemistry–Climate Feedbacks Scientific Focus Area project. Currently, he is investigating and improving the representation of land use/land cover change effects in an Earth system model.