• 01.34 Sciences

Accepting PhD Students

PhD projects

- Isotopic fingerprints of carbonyl sulfide (COS) in atmosphere and biosphere (DTP ENVEast Competition Funding, hosted at UEA; UK and EU students only) - Plug and play monitoring – developing novel solutions for marine observations with divers as citizen scientists (CDT NEXUSS Competition Funding, hosted at UEA; UK and EU students only) - Observing the biological carbon pump with autonomous underwater vehicles (CDT NEXUSS Competition Funding, hosted at NOCS; UK and EU students only) - Understanding controls on oxygen deficits in UK waters using a community ecosystem model and isotopic tools (Fully Funded NERC CASE Studentship, hosted at PML; UK and EU students only)

If you made any changes in Pure these will be visible here soon.

Personal profile

Academic Background

Kaiser Group website: https://kaiserlab.org

Nitrate isotope analysis: We offer nitrogen (15N/14N) and oxygen (18O/16O, 17O/16O) isotopic analyses of nitrate (NO3–) as analytical service, see here for more information.

PhD opportunities

Apply for an @ARIES_DTP PhD project 'What causes ozone depletion events and bromine explosions in the polar atmosphere?', involving the Roland von Glasow Air-Sea-Ice Chamber and fieldwork possibilities with the British Antarctic Survey. Deadline: 12 January 2021.

Other PhD Positions

Click here for other current PhD opportunities in the School of Environmental Sciences.  However, feel free to email me to discuss projects outside these areas and alternative sources of funding.

Professional Activities

Awards

  • Certificate of Appreciation for valuable contribution and dedicated service in the peer review of manuscripts submitted to ACS journals, December 2011
  • Editors’ Citation for Excellence in Refereeing 'Global Biogeochemical Cycles' 2010
  • Editors’ Citation for Excellence in Refereeing 'Global Biogeochemical Cycles' 2008
  • Royal Society Wolfson Research Merit Award 2006-2011
  • Harry Hess Fellowship, Department of Geosciences, Princeton University 2003-2005
  • Gary Comer Postdoctoral Fellowship in Abrupt Climate Change 2003-2005
  • PhD thesis 'summa cum laude', Johannes Gutenberg University Mainz 2002
  • Outstanding Student Paper Award, AGU Spring Meeting, Washington 2002

Enterprise and Engagement Activities

  • Royal Society Summer Science Exhibition 01-07 July 2013
  • Science in Norwich, Forum 02 June 2013
  • Glider demo at Notre Dame High School, Norwich 21 June 2013
  • Press release on Science paper 4 September 2010
  • Interview BBC Radio Norfolk 10 August 2010 GOPINA glider mission
  • Glider demo at Wymondham High School, Norfolk 17 March 2010

Complete list of publications: UEA EPrints Digital Repository

Selected publications:

  • Kaiser, J. (2011) Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements. Biogeosciences, 8, 1793-1811, doi:10.5194/bg-8-1793-2011
  • Kaiser, J. (2008) Reformulated 17O correction of mass spectrometric stable isotope measurements in carbon dioxide and a critical appraisal of historic `absolute' carbon and oxygen isotope ratios Geochimica et Cosmochimica Acta, 72(5), 1312-1334, doi:10.1016/j.gca.2007.12.011
  • Kaiser, J., Hastings, M.G., Houlton, B.Z., Röckmann, T., Sigman, D.M. (2007). Triple oxygen isotope analysis of nitrate using the denitrifier method and thermal decomposition of N2O. Analytical Chemistry, 79(2), 599-607. doi:10.1021/ac061022s
  • Savarino, J. Kaiser, S. Morin, D.M. Sigman, and M.H. Thiemens (2006). Nitrogen and oxygen isotope constraints on the origin of atmospheric nitrate in coastal Antarctica. Atmospheric Chemistry and Physics, 7(8), 1925-1945, doi:10.5194/acp-7-1925-2007
  • Kaiser, J., A. Engel, R. Borchers, and T. Röckmann (2006). Probing stratospheric transport and chemistry with new balloon and aircraft observations of the meridional and vertical N2O isotope distribution. Atmospheric Chemistry and Physics, 6, 3535-3556, doi:10.5194/acp-6-3535-2006
  • Kaiser, J., M.K. Reuer, B. Barnett, B., and M.L. Bender (2005). Marine productivity estimates from continuous O2/Ar ratio measurements by membrane inlet mass spectrometry. Geophysical Research Letters, 32 (19), L19605, doi:10.1029/2005GL023459
  • Kaiser, J., T. Röckmann, and C.A.M. Brenninkmeijer (2004). Contribution of mass-dependent fractionation to the oxygen isotope anomaly of atmospheric nitrous oxide. Journal of Geophysical Research, 109 (D3), D03305, doi:10.1029/2003JD004088
  • Kaiser, J., C.A.M. Brenninkmeijer, and T. Röckmann (2002). Intramolecular 15N and 18O fractionation in the reaction of N2O with O(1D) and its implications for the stratospheric N2O isotope signature. Journal of Geophysical Research, 107 (D14), 4214, doi:10.1029/2001JD001506

Author profiles

Key Responsibilities

  • Director, Centre for Ocean and Atmospheric Sciences, University of East Anglia
  • Head, Sector Atmosphere, Ocean and Climate Sciences, School of Environmental Sciences
  • Executive Group, School of Environmental Sciences
  • Study Abroad Coordinator, School of Environmental Sciences
  • Adviser, School of Environmental Sciences
  • SCI PGR Faculty Appeals and Complaints Panel
  • Module Organiser, ENV-5015A Atmospheric Chemistry and Global Change
  • Module Organiser, ENV-6032Y Year Abroad
  • Module Organiser, ENV-6033B Semester Abroad

Specialisms

  • Atmospheric chemistry: nitrous oxide, nitrate, nitrogen oxides, halocarbons, stable isotopes (13C, 15N, 17O, 18O, 37Cl), polar firn air and ice measurements, stratospheric chemistry and transport
  • Marine biogeochemistry: net and gross biological productivity (oxygen, oxygen/argon, oxygen triple isotopologues), air-sea exchange of greenhouse and related gases (nitrous oxide, methane, carbon dioxide, carbon monoxide), benthic and pelagial nitrogen cycling
  • Terrestrial biogeochemistry: Arctic lakes (Greenland, Svalbard), freshwater, lagoons

Career

Biography

I study global chemical, physical and biological processes in the Earth's atmosphere and oceans, and their variations through time under natural and anthropogenic influences, by integrating fieldwork, laboratory studies and modelling into a coherent framework, often involving the use of stable isotopes.

This approach has been applied to nitrous oxide (N2O), nitrate, oxygen, nitrogen, argon and CO2. I have led studies on the isotopic composition of atmospheric N2O, emphasizing position-dependent 15N/14N isotope ratio measurements and the fate of N2O in stratospheric photolysis and photo-oxidation. I developed analytical methods to accurately measure N2O isotopes in troposphere, stratosphere, polar firn air and ice. This work allowed reconstruction of past changes and demonstrated increasing agricultural influences on atmospheric N2O. In laboratory experiments, I studied temperature- and wavelength-dependent isotope effects in N2O photolysis. I discovered that during photolysis the central nitrogen position always becomes more enriched in 15N than the terminal one, but that during photo-oxidation the opposite position-dependent fractionation occurs. This pattern allowed me to distinguish photolysis and photo-oxidation in the stratosphere.

I am also interested in rare isotope signatures, such as oxygen isotope anomalies (17O-excess, Δ(17O)) and multiply-substituted isotopologues (clumped isotopes) such as 15N15NO. The small 17O-excess of atmospheric N2O motivated me to consider how best to characterise such anomalies. My review of data reduction practices for CO2 isotope measurements revealed systematic uncertainties in global carbon budget calculations.

The N2O work led on to the first online gas chromatography-isotope ratio mass spectrometric method to measure Δ(17O) of nitrate, which drastically reduced sample sizes and enabled seawater analyses. Δ(17O) combined with nitrogen isotope ratios were used to understand the annual cycle of nitrate in coastal Antarctica, uncovering stratospheric influences and re-evaporation from surface snow. Low sample size requirements make this technique suitable for ice core studies of past changes in the atmospheric oxidation capacity.

I have also developed a sea-going membrane inlet mass spectrometer (MIMS). The instrument continuously measures dissolved oxygen, nitrogen, argon and CO2. Oxygen/argon ratios allow separation of physical and biological effects on gas concentrations and provide net community production estimates on unprecedentedly fine scales.

More recent work included studies of N2O and nitrate in marine and terrestrial environments as well as measurements of the chlorine (37Cl/35Cl) and carbon (13C/12C) of volatile organic compounds. As a member of the UEA Glider Group, I have been involved with deployments of oxygen sensors (optodes) on autonomous float (NAB 2008) and glider (GOPINA) platforms, in order to provide vital data on the oceanic carbon cycle and biological productivity estimates in a changing climate.

Teaching Interests

  • ENV-5015A Atmospheric Chemistry and Global Change
  • ENV-7024A Stable Isotope Geochemistry
  • ENV-5037Y Year Abroad (BSc degrees)
  • ENV-6032Y Year Abroad (MSci degrees)

Education/Academic qualification

Doctor rerum naturalium, Johannes Gutenberg University Mainz

Award Date: 1 Jan 2002

Master of Chemistry, University of Bremen

Award Date: 1 Jan 1998

Network

Recent external collaboration on country/territory level. Dive into details by clicking on the dots or