Nitrogen is vital to all forms of life. These nitrogenous compounds support remarkable diversity of marine organisms. Nitrogen isotopes enable us to accurately determine nitrogen transformation rates in the marine environments; in particular, the microbial production of nitrous oxide (N2O). N2O is an atmospheric trace gas that has great impact on climate, and its production is associated with the growth and distribution of marine organisms. N2O can be used as an analytical proxy to understand complex ecological interactions in the ocean. Furthermore, N2O is a tracer of human activities. Recent development in the analytical power of N2O concentration and isotope can better characterize the human impact on the marine environments.
Dr Qixing Ji is an associate professor at the School of Marine Sciences, Sun Yat-Sen University. He obtained his Ph.D. degree from Princeton University in 2017. From 2017 to 2019, he worked as a post-doctoral researcher at GEOMAR Helmholtz Centre for Ocean Research Kiel, and served as visiting scholar at Bermuda Institute of Ocean Sciences. His research work includes nitrogen isotope tracing marine biogeochemical processes, nitrous oxide production in aquatic and sedimentary systems, and nitrogen isotope instrumentation. At present, he is investigating the coupling of nitrogen cycling processes and microbial interactions, as well as calibrating ocean biogeochemical models.