Nitrous oxide (N2O) is the third-most important anthropogenic greenhouse gas and the most important currently emitted ozone-depleting substance. These impacts on the climate system and the long atmospheric lifetime of 125 years highlight the need to quantitatively understand the global N2O budget.
This project seeks to quantify recently discovered novel N2O sources and sinks in atmosphere and oceans, using concentration and flux measurements with modern laser spectroscopic analysers and cutting-edge isotopic techniques, as well as to assess the importance of these novel sources and sinks with the help of global biogeochemical models.
The student will use high-precision laser analysers to confirm surprisingly high N2O disequilibria in ocean surface waters. N2O supersaturations could reflect N2O production by nitrification in the well-lit euphotic
zone, a process that was traditionally thought to be inhibited by light, but has recently been hypothesized to be carried out by archaea. In contrast, unexpectedly large regions of N2O undersaturations have recently been suggested to be due to N2O fixation by diazotrophs. With the help of isotope labelling experiments, the student will investigate the importance of such N2O uptake.
Complementary to the fieldwork, laboratory experiments will investigate novel N2O production pathways. These will combine laser spectroscopy with natural abundance and artificially labelled isotope measurements, in particular of the 17O excess. Two denitrifier strains will be tested for their ability to denitrify organic nitrates to N2O. In addition, the student will work with a colleague in Denmark who has pioneered studies of UV-emissions of trace gases from plants.
Finally, the findings will be integrated into biogeochemical models to diagnose their relevance on a global scale.
Scientific training Oceanography, biogeochemical cycles and atmospheric chemistry; handling of gases, working with laser spectroscopic analysers and isotope ratio mass spectrometers, calibration, fieldwork at sea, kinetic measurements, microbiology, analysis of large datasets, calculation of air-sea fluxes; biogeochemical modelling
For more information on the supervisor for this project, please go here https://people.uea.ac.uk/j_kaiser
This is a PhD project.
This project will begin on 1 October.
The mode of study is full-time.
The studentship length is 3 years.
Acceptable first degree in Chemistry, Physics, Biological Sciences, Environmental Sciences, Natural Sciences, Oceanography
The standard minimum entry requirement is 2:1.