• Project
  • Host
  • How to Apply


Project Highlights:

  • Modelling of aircraft measurements taken during the WINTER 2015 campaign to clarify the wintertime chemical processes.
  • Development of state-of-the-art computer models.
  • How do slower chemical process and meteorological patterns in winter affect the formation and transport of pollutants with respect to summer?

Atmospheric chemical transformations, which play a large role in controlling the formation of pollutants and climate forcers, have strong seasonal dependencies. In the warmer and more photochemically active summer months, strong oxidant formation leads to the rapid production of multiple secondary pollutants such as ozone and organic aerosol. In winter, primary pollutants react far more slowly and consequently spread over wider geographic areas downwind of sources.

The large majority of ambient measurements in polluted regions in the past years have focused on understanding emissions, transformation and transport under warm summertime conditions. However, the differences in chemistry and meteorology between summer and winter are significant and can cause important variations in the formation of pollutants, emissions patterns, and secondary aerosol formation, including their geographic distributions and export to remote regions.

In order to investigate these issues, NOAA (National Oceanic and Atmospheric Administration), NCAR (National Center for Atmospheric Research) and University of Washington (Seattle) conducted a field campaign in February-March 2015 using the NSF/NCAR C130 research aircraft, which flew several flights over the Northeastern United States and into the Western Atlantic Ocean.

This project aims to analyse the data from the WINTER 2015 campaign using highly detailed chemistry and transport modelling, focusing in particular on the chemical processes involving halogens, nitrogen oxides and ozone. The objective is to interpret the observations and understand the differences between winter and summer and the implications for the formation of pollutants in urban-influenced atmospheres.

The NSF/NCAR C130 research aircraft and particle composition data from the WINTER 2015 campaign (Guo et al., J. Geophys. Res., 2016).


The project will involve the upgrade, development and use of the state-of-the-art 1D MISTRA model (https://archive.uea.ac.uk/~fkd06bju/mistra.html). The model contains a detailed description of chemical and microphysical processes and will be adapted to follow the flight paths of the C130 aircraft and reproduce the observations during the research flights.

Dispersion modelling – with the Met Office NAME model – will be used to track the source (and potential emissions from those areas) of the air masses encountered during the flights originating from North America.

Training and Skills

The student will based in the Atmospheric Chemistry Group in Leicester (approx 20 people) and will benefit from the group’s extensive expertise in atmospheric chemistry, data analysis and modelling.

Basic computer skills are required. Programming skills are desirable, but not necessary as long as there is willingness to learn. The student will be extensively trained in programming and in modelling, as well as in data analysis and database management techniques.

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes.


Year 1: General training in Atmospheric chemistry and environmental science topics with lectures at Leicester University. The NCAS Introduction to Atmospheric Science, Atmospheric Measurement and the Introduction to Scientific Computing courses will be attended. Access to and introduction to the WINTER 2015 campaign dataset will be introduced at an early stage. In-house training on the MISTRA models will allow the student to carry out their own model simulations and experiments in the areas of interest. Training on the NAME dispersion model will be carried out.

Year 2: Upgrade and development of the MISTRA model. Analysis and modelling of the ambient data using MISTRA and NAME, followed by analysis of the model results and comparison with the measurements. A research trip to the USA will allow the student to exchange information with the American partners of the project

Year 3: Synthesis and integration of the dataset and model results from the first two years to build a comprehensive picture of wintertime chemical processes in the North American continental outflow.

Partners and collaboration (including CASE)

Dr Zoë Fleming works for the National Centre for Atmospheric science (NCAS, which is a NERC centre), with colleagues based at various Universities around the UK so the student would be encouraged to work collaboratively with these and Dr Sommariva’s networks. All supervisors have strong links with national and international researchers. In particular, partners in this project are the research groups at NOAA and NCAR (Boulder, CO) and at the University of Washington (Seattle, WA). The student will have the opportunity to visit these groups in order to access the datasets and discuss the campaign and the data with the researchers involved in the measurements.

Further Details

Please contact Dr Zoë Fleming

National Centre for Atmospheric Science,

Department of Chemistry

University of Leicester


email: zf5@le.ac.uk for further information