Differential Column Measuring System for Assessing Urban Emissions (using FTIR Spectrometers)

• Subject Area: Atmospheric Science, Oceanography and Climate Research
• Term: Funded in 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 422614568

It is evident that the present global warming is due to anthropogenic greenhouse gas (GHG) emissions. Hence, monitoring and reducing emissions of CO2 and CH4 is essential. Nowadays, most cities rely on bottom-up methods to calculate total emissions. Since these estimates are not based on direct measurements, they can have large uncertainties and are not able to identify and localize unknown emission sources.With this project my group and I will build a mesoscale monitoring network to measure CO2, CH4, CO, NO2, and O3 concentrations using the novel technique of differential column measurements. This method captures the difference in the column amounts downwind and upwind of the city, and therefore directly represents the particle mass loading within an urban domain.By means of this proposal, the existing measurement system consisting of two stationary FTIR spectrometers (in the east and west of Munich) is to be expanded to include an additional identical measurement system to ensure that emissions can not only be measured in the west-eastern, but also in the north-southern wind directions.With the help of this second measurement system, the sensor network is expanded and will thus become the World's first stationary differential column network for measuring greenhouse gas emissions in any wind direction. This will allow us to accurately measure GHG emission rates for Munich’s urban areas over time, and will also yield information about the internal generation and redistribution. In addition to the stationary use, the requested system can also be used mobile to characterize possible emission sources. We will answer key questions such as: "What is the real, measured trend of CO2, CH4 and NO2 emissions in Munich over several years?", "Where are the emission hotspots?" or "How accurate are the bottom-up estimates?"To this end, my group will not only expand the fully automated sensor network but also develop suitable methods for modelling (inversion model), which reproduces the atmospheric transport of the particles and thus answers the questions raised above. It will be a unique pilot project worldwide and will provide ground-breaking scientific results.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Differentielles Säulenmesssystem
• Instrumentation Group: 1830 Fourier-Transform-IR-Spektrometer
• Applicant Institution: Technische Universität München (TUM)
• Leader: Professorin Dr.-Ing. Jia Chen