I study how physical and biological processes contribute to the carbon cycle, and how the biological pump transfers carbon into the deep ocean. My current research interests include: developing and testing physical-biological models in several regions, the equatorial Pacific and the coast of Peru, the Gulf of Maine, and the Arabian Sea; studying the nutrient transport from the interior ocean to the surface by the ocean circulation and mixing processes; assimilating satellite information into the physical-biological models, such as sea surface temperature and surface ocean color. Much of my work has been interdisciplinary, emphasizing physical and biological oceanography. I am also interested in using the state of-the-art supercomputing power for the large scale ecosystem models.