PhD student: Measurements of nitrogen oxides and total odd nitrogen in the atmosphere aboard commercial aircraft
For a research project at the Institute of Energy and Climate Research – Troposphere, IEK-8, we are seeking a
PhD student (Chemistry, Physics, Meteorology or equivalent degree)
for a 3 year position.
With 4400 staff members Forschungszentrum Jülich is the largest interdisciplinary research center in Germany focusing its research in the fields of health, environment and energy, and information technology. At IEK-8:Troposphere simulation chamber experiments, experimental field studies, and model calculations are used to investigate the processes that control the chemical transformation and spatial distribution of trace compounds, and their ultimate removal from the atmosphere. About 60 scientists, engineers, technicians and doctoral students are currently working at the institute in the field of atmospheric chemistry.
Nitrogen oxides (NOx) play an important role in atmospheric chemistry, particularly in the photochemistry related to ozone and hydroxyl radicals (OH). Knowledge of the distribution of NOx in the free troposphere is a prerequisite for studying the budgets of OH and hence of many trace gases that are related to air quality and climate change, whereas measurements of total odd-nitrogen (NOy, i.e., the sum of NO and its atmospheric oxidation products) have proven useful for studying transport processes and the budget of odd-nitrogen in the troposphere and stratosphere.
The distribution and variability of nitrogen oxides particularly in the upper troposphere and lower stratosphere (UT/LS) is still not well known although these uncertainties have strong implications on the pathways for recycling of NOx from, e.g. HNO3 and organic nitrates. The different sources of NOy to the UT/LS include lightning and emissions by aircraft (in the form of NOx), uplifting of surface emissions (variable NOx/NOy ratio) and downward transport from the stratosphere (mainly HNO3).
Regular airborne measurements are the only means of obtaining highly resolved information on the distribution of reactive nitrogen compounds in the UT/LS. This kind of routine measurements is accomplished by operating autonomous instruments on a fleet of long-range aircraft of internationally operating airlines in the framework of the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System). Forschungszentrum Jülich is coordinating IAGOS and was a key partner in the predecessor project MOZAIC (Measurements of Ozone, Water Vapour, Carbon Monoxide and Nitrogen Oxides by In-service Airbus Aircraft); see www.iagos.org for details.
Science and Experiments within the PhD thesis
In the context of IAGOS we have an immediate opening for a three-year PhD-position to investigate the horizontal and vertical distribution of nitrogen oxides (NOx and NOy) in the troposphere and lower stratosphere from measurements made routinely on board of passenger aircraft.
- calibration and validation of the NOx and NOy measurements made in IAGOS from laboratory studies and field experiments in order to assess the data quality
- analysis of the distribution of nitrogen oxides from the observations and establishment of a climatology of NOx and NOy for comparison with data from regional chemistry transport models and remote sensing
- investigation of possible sources of nitrogen oxides, as well as their atmospheric chemistry and transport
- laboratory evaluation of novel instruments based on optical techniques (optional)
International collaboration during this PhD thesis is ensured by the strong involvement in the European Research Infrastructure IAGOS and the European collaborative project IGAS (IAGOS for the GMES Atmospheric Service).
- M. Sc. (or equivalent) in physics, chemistry, or a comparable discipline with a good final grade (in the German system 2.0 or better
- Scientific interest in atmospheric physics
- technical and organizational skills
- willingness to communicate research results and to interact within an interdisciplinary and international research environment are expected
- Experience in experimental laboratory work and software programming is advantageous but not necessary
- Fluent knowledge of English language is required
Equal opportunity is a cornerstone of our staff policy. Applications from disabled persons are welcomed. Payment of the PhD fellow will be based on salary grade 13/2 Collective Agreement for the Civil Service (TVöD). Depending on the candidate's profile and the subject of his/her PhD thesis an additional allowance may be granted.
Please send your application - quoting the reference number - with the relevant documentation to:
Mr. K. Beumers
Institut für Energie und Klimaforschung
Forschungszentrum Jülich GmbH