Unravelling the mysteries of air quality above polar snow and ice using the isotopic fingerprints of reactive nitrogen

(FREY_UBAS20ARIES)

Unravelling the mysteries of air quality above polar snow and ice using the isotopic fingerprints of reactive nitrogen

(FREY_UBAS20ARIES)

Project Description

Supervisors

Dr Markus Frey, BAS

Professor Jan Kaiser, School of ENV (UEA)

Scientific background:

Climate and environment in polar and high-altitude regions are particularly sensitive to anthropogenic perturbation. Understanding the natural processes in the background atmosphere is essential to assess the human contribution to environmental change. Examples are the nitrogen oxides NO and NO2, which alter concentrations of ozone (O3), a pollutant and greenhouse gas, and the hydroxyl radical (OH), which is responsible for the removal of many other atmospheric pollutants (e.g. CO, CH4). Nitrous acid gas (HONO) is a particularly reactive nitrogen species, related to NO and NO2, which has been observed previously at surprisingly high levels in air above snow, suggesting a large snowpack source may be present. The aim of this project is to quantify HONO emissions with an optical technique (LOPAP instrument) and to use isotopic techniques (15N/14N, 18O/16O and 17O/16O ratios) to trace reactive nitrogen formation and loss processes in polar regions.

Research methodology:

You will use a combination of state-of-the art methods and instruments to measure the concentration, fluxes and isotopic composition of reactive nitrogen species (HONO, NOx, HNO3, NO3– separated using filters and annular denuders) above snow and ice in lab experiments at BAS Cambridge and the UEA Roland von Glasow Air-Sea-Ice Chamber, and potentially in the field at a station operated by BAS in coastal Antarctica. You will interpret your observations with a numerical air-snow model to quantitatively understand the composition of the atmosphere above snow, to study the relationship between HONO and NOx as well as their conversion to HNO3 and NO3–, with the ultimate goal to improve global chemistry-climate models.

Training:

You will be part of dynamic research teams at BAS and UEA, which are working on a wide range of environmental topics in the polar regions. You will receive full training in the relevant instruments and sampling techniques, modelling and fieldwork. You will attend an atmospheric sciences summer school and receive support to publish results in peer-reviewed journals and at international conferences.

Qualifications:

Degree in chemistry, physics or related Earth/Environmental Science, with experience in experimental work and good numerical skills (e.g. knowledge of Matlab, Python or equivalent).

References

  • 1. Legrand, M., Preunkert, S., Frey, M., Bartels-Rausch, T., Kukui, A., King, M. D., Savarino, J., Kerbrat, M., and Jourdain, B.: Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?, Atmos. Chem. Phys., 14, 9963–9976, doi:10.5194/acp-14-9963-2014, URL http://www.atmos-chem-phys.net/14/9963/2014/, 2014.
  • 2. Kaiser, J., Hastings, M. G., Houlton, B. Z., Röckmann, T., and Sigman, D. M.: Triple oxygen isotope analysis of nitrate using the denitrifier method and thermal decomposition of N2O, Anal. Chem., 79, 599-607, 10.1021/ac061022s, 2007.
  • 3. Frey, M. M., Roscoe, H. K., Kukui, A., Savarino, J., France, J. L., King, M. D., Legrand, M., and Preunkert, S.: Atmospheric nitrogen oxides (NO and NO2) at Dome C, East Antarctica, during the OPALE campaign, Atmos. Chem. Phys., 15, 7859–7875, doi:10.5194/acp-15-7859-2015, 2015.
  • 4. Chai, J., and Hastings, M. G.: Collection method for isotopic analysis of gaseous nitrous acid, Anal. Chem., 90, 830-838, 10.1021/acs.analchem.7b03561, 2018.
  • 5. Grannas, A. M., Jones, A. E., Dibb, J., Ammann, M., Anastasio, C., Beine, H. J., Bergin, M., Bottenheim, J., Boxe, C. S., Carver, G., Chen, G., Crawford, J. H., Dominé, F., Frey, M. M., Guzmán, M. I., Heard, D. E., Helmig, D., Hoffmann, M. R., Honrath, R. E., Huey, L. G., Hutterli, M., Jacobi, H. W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P. B., Simpson, W. R., Sodeau, J. R., von Glasow, R., Weller, R., Wolff, E. W., and Zhu, T.: An overview of snow photochemistry: evidence, mechanisms and impacts, Atmos. Chem. Phys., 7, 4329–4373, doi:10.5194/acp-7-4329-2007, 2007.

Key Information

  • This project has been shortlisted for funding by the ARIES NERC Doctoral Training Partnership, and will involve attendance at mandatory training events throughout the course of the PhD.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship - UK and EU nationals who have been resident in the UK for 3 years are eligible for a full award.
  • Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses in the subject area (see https://www.aries-dtp.ac.uk/supervisors/additional-funding/).
  • This studentship will start on 1st October 2020, and the closing date for applications is 12:00 on 7th January 2020.
  • Shortlisted applicants will be interviewed on 18/19 February 2020.
  • For further information, please contact the supervisor.

Studentship Open for Applications

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