Meteorological Institute

Department / Institute
Meteorological Institute
Subject area
Remote sensing of air pollutants
Name of Supervisor
Prof. Mark Wenig
Number of open positions
Project title
Air quality monitoring using MAX DOAS
Language requirements
fluent in English
Academic requirements
Master in Physics or Meteorology or a related discipline with a focus on environmental science

Project description

Air quality monitoring has become a very important issue within the last couple of years due to recent events. The ‘Dieselgate’ has raised public concern and the frequent exceedances of the World Health Organization emission standards in many German cities have drawn the public attention towards air quality improvement efforts and regulations.

The concentration of atmospheric pollutants are easy to measure at a limited number of sampling points, but in order to identify different sources, more comprehensive measurement techniques are needed. Different source types like traffic, residential heating, power plants, etc. can only be distinguished if the spatial and temporal variability of pollutant concentration within the city can be analyzed. This can be achieved using a measurement network or remote sensing concept that can scan different parts of the city.

We developed a NO2 measurement system consisting of several scanning remote sensing instruments. The measurement method is called differential optical absorption spectroscopy (DOAS) which can be applied in a variety of setups. We combine long-path DOAS instruments that measure along different measurement paths using retro reflectors that are installed at different locations in Munich within the field of view of the scanning spectrometers on the roof of the institute building at the center of Munich. Another DOAS type instrument, called Multi-Axis DOAS (MAX-DOAS) is used to scan the sky at different angles, analyze the sunlight that has been scattered and partly absorbed in the atmosphere in order to derive vertical profile information of gases and aerosols. One instrument is installed at the roof of the institute’s building to continuously monitor the distribution of atmospheric pollutants within the city center, whereas the other instrument can be installed on the roof the measurement bus for mobile measurements.

The goal of this PhD projectis to analyze the MAX DOAS data in combination with the additional sensor data from the other instruments in order to analyze the distribution of NO2 in Munich. Additionally, the mobile MAX DOAS will be used on measurement campaigns. Part of the thesis will be organizing new measurement campaign, but also to analyze the data from past campaigns. This includes mobile measurements on the highway, monitoring locations in the outskirts of Munich for comparison with the city center measurements, but also a campaign where we installed the MAX DOAS on a zeppelin. The derived profile information has tobe validated using alternative measurement techniques, e.g. in-situ sensors on a drone.