Dr. Ren's main interests lie in climate diagnostics, dynamic data assimilation and fluid mechanics, as well as land surface modeling of ecosystem responses to a warming climate, glacier/ice sheet dynamic modeling, natural hazards such as storm-triggered landslides, frozen soil thawing and refreezing processes and soil nutrient fluctuations. He has coded a scalable, extensible and adaptable geo-fluid model (SEGMENT), which offers a unified approach for a disparate set of poorly understood phenomena in geophysical flows/movements such as glacier sudden surge and which is also is capable of describing nutrient content between different vegetation types.