Investigators and Program Directors
Ted Yoshinari
Research Scientist, Wadsworth Center, Inorganic and Nuclear Chemistry
Assistant Professor, School of Public Health, Environmental Health Sciences
Ph.D., Dalhousie University (1973)
E-mail: yoshinar@wadsworth.org
Research Interests
Research interests: global nitrogen cycle, microbial nitrification and denitrification, nitrogen isotope biogeochemistry of the ocean and groundwater.
Nitrous oxide (N2O) is an interesting gas in the natural environment:
- It is a natural agent that destroys ozone in the stratosphere.
- It is a greenhouse gas, which is increasing at a rate of 0.3% per year, although the major source is unknown.
- N2 is a major returning species in the nitrogen cycle, but N2O could be as much as 20% of the total nitrogen that returns to the atmosphere through denitrification.
N2O is mostly produced by two different microbial processes:
- nitrification, and
- denitrification.
Conventional approaches (i.e., concentration and flux measurements) cannot differentiate the origin of N2O produced by either one of the above two processes. It is generally known that the N2O produced by nitrification is isotopically lighter than that by denitrification. This is because N2O produced by nitrification is the metabolic end-product, while that by denitrification is an intemediat so that an isotopically heavy fraction of N2O is left after a small fraction of isotopically light N2O is reduced to N2. Thus, determination of dual isotopic signatures of N2O should be able to help identify the origin of N2O in the environment. Using the method recently developed, we have determined the isotopic composition of N2O in different environments. The results indicate that the determination of isotopic composition of N2O provides important information to unveil mechanisms of the nitrogen transformations in terrestrial and aquatic ecosystems as well as the global atmospheric N2O inventory.
Contact Information
Phone: (518) 474-2429
Fax: (518) 473-2895
E-mail: yoshinar@wadsworth.org.