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Atmospheric Trace Species

Head of department: Dr. Hans Schlager

Trace gases and aerosols play a key role in atmospheric physics and chemistry via homogeneous and heterogeneous chemical reactions, phase transitions, and interaction with radiation. The department investigates the distribution of trace species in the atmosphere from the troposphere to the mesosphere and the processes involved. This includes the characterization of natural and anthropogenic emissions (e.g. NOx from lightning, emissions of jet engines, methane from oil extraction facilities) and the investigation of transport and transformation processes. For this purpose, in-situ measurement techniques for trace gases, ions, and aerosols are developed and deployed from different platforms (research aircraft, Lufthansa in-service aircraft, balloons, rockets, UAVs). In addition, accompanying model simulations are performed.

DLR research aircraft HALO, a platform used by the department Atmospheric Trace Species (Photo: DLR, CC-BY 3.0).

Current reasearch activities focus on:

• Determination of emissions from air traffic, in particular from alternative fuels and modern jet engine technologies
• Measurements of emissions and their dispersion and transformation of major populations centers and megacities in Europe and Asia
• Investigation of the transport of trace species by deep convection in Europe and in the tropics, in particular in the region of the Asian monsoon
• Studies of aerosol microphysics and aerosol-cloud-interaction in polluted and remote regions
• Validation of satellite data and investigations on the detection of greenhouse gases by satellite remote sensing
• Performance of  model simulations on the dispersion, microphysics, and transformation of gas and particle emissions to support the interpretation of the field studies 

For this purpose, the following in situ measurement systems are applied

• Mass spectrometer for trace gases (e.g. SO₂, inorganic and organic acids) and mesospheric ions
• Chemiluminescence detectors for nitrogen oxides (NO_x, NO_y)
• UV and IR absorption photometer for ozone (O₃) and carbon dioxide (CO₂)
• Vacuum UV fluorescence detector for carbon monoxide (CO),
• Quantum cascade laser and cavity ring down spectrometer for methane (CH₄) and carbon dioxide (CO₂) 
• Optical particle counter and condensation nuclei counter for nucleation and accumulation mode aerosol
• Absorption photometer for soot

The department also hosts the young investigator’s group “Greenhouse gases” which focusses on in-situ measurements and remote sensing of CH₄, CO₂, and N₂O.   

In addition, the department performs coordination and service activities, e.g. maintaining of the HALO database, chair of the international SPARC/IGAC activity ACAM (Atmospheric Composition and the Asian Monsoon).