Our research group investigates physical processes in the lower and middle atmosphere by means of optical spectroscopy, photochemical and radiative transfer modelling, and mathematical inversion techniques. The primary focus of our research is the photochemistry of ozone, and our central experimental method is Differential Optical Absorption Spectrometry (DOAS) in the UV/VIS/NIR, with which the detection of many relevant trace gases (O3, NO2, HONO, BrO, IO, OClO, CH2O, C2H2O2 ...) as well as water in all three phases is possible. A more recent application of our skills in radiative transfer modelling and inversion is in the monitoring of global radiation and the derivation of corresponding optical properties (aerosol and cloud optical depth) of the atmosphere using photovoltaic installations.
To date (April 2019), the group has authored125 peer-reviewed publications in international journals and contributed to various international assessment reports, for example the UNEP/WMO assessment reports on stratospheric ozone published in 2002, 2006, 2010, 2014 and 2018.
Physics and Chemistry of the Atmosphere
The primary research focus of our group is the photochemistry of ozone, which we investigate using Differential Optical Absorption Spectrometry (DOAS) in the UV/VIS/NIR. This allows the detection of many relevant trace gases (O3, NO2, HONO, BrO, IO, OClO, CH2O, C2H2O2 ...) as well as water in all three phases. The measurements are taken with optical grating spectrometers using either direct sunlight or scattered skylight, and different observation platforms such as aircraft (Falcon, HALO, Geophysica), unmanned air vehicles (UAV), or high altitude balloons are used. The spatial and temporal reconstruction of concentration fields of the targeted trace gases is performed either with traditional inversion techniques assisted by radiative transport calculations, or more recently by employing the scaling method to a (scaling) gas of which the atmospheric concentration is known.
Our measurements contribute to the following overarching scientific objectives:
- The photochemistry and budget of atmospheric halogens (Cl, Br, I) and their role in the destruction of stratospheric ozone, with air-borne measurements of BrO, IO, and OClO often performed with complementary measurements of a suite of halogenated source gases, including short-lived species and product gases (HCl, ClONO2, ClO, BrONO2 ...).
- Detection of all three phases of water in mixed-phased clouds and cirrus clouds.
- The photochemistry of volatile organic compounds, with specific emphasis on formaldehyde (CH2O) and the carbonyl compounds glyoxal (C2H2O2) and methylglyoxal (C3H4O2), which are either directly emitted by biomass burning or from cities, or photo-chemically formed in the oxidation of CH4 (CH2O) or in the oxidation of VOCs (CH2O, C2H2O2, and C3H4O2).
- The photochemistry of NOx and NOy species and their contribution to atmospheric oxidation capacity. Our measurements of NO2 and HONO often complement measurements of other NOx and NOy species (NO, HNO3, PAN …).
Solar Radiation and Renewable Energy
A second, more recent research objective that builds on our skills in atmospheric radiative transfer modelling and inversion techniques addresses the deposition of solar radiation at the ground and its relation to the generation of electricity using solar photovoltaic (PV) installations. In this regard a particularly exciting aspect is the relationship between atmospheric conditions (aerosol abundance and cloud cover) and electricity production, both in the forward (i.e. from atmospheric conditions to global radiation and PV power) and backward (i.e. from PV power to global radiation and thus to atmospheric conditions) sense.
The initial goal of the MetPVNet project is to use a physically-motivated forward model to calibrate individual PV installations under clear sky conditions – the measured PV power from several well-understood PV systems can then be used to reconstruct the corresponding atmospheric conditions under all sky conditions and to compare these results with the reanalysed weather from weather prediction models. In a second step, the power from a larger ensemble of PV installations will be used to reconstruct the aerosol and cloud cover for a greater area, commensurate with the electricity grid of a distribution network operator. In a final step, the actual PV power will be compared with meteorology-based PV power predictions, and machine learning tools will be used to improve PV power forecasts.
Current group members
|Prof. Dr. Klaus Pfeilsticker||Group leader||229 / R422||6401|
|Dr. James Barry||Postdoc||229 / R320||6314|
|Flora Kluge||PhD student||229 / R442||6316|
|Meike Rotermund||PhD Student||229 / R414||6315|
|Ben Schreiner||PhD Student||229 / R442||6316|
|Dominique Lörks||MSc Student|
|Franziska Schwab||MSc Student||229 / R438||6556|
|Sreedev Sreekumar||MSc Student||229 / R414||6315|
|Dirk Böttcher||BSc Student||229 / R416|
Alumni (PhD and Masters)
- Oliver-Alex Aderhold
- Nadine Bauer
- Hartmut Bösch
- André Butz
- Tina Buchmann
- Marcel Dorf
- Stefan Dorsch
- Tim Deutschmann
- Frank Erle
- Frieder Ferlemann
- Claudia Fensterer
- Richard Fitzenberger
- Oliver Funk
- Katja Großmann
- Katja Grunow
- Hartwig Harder
- Martin Hirsekorn
- Tilman Hüneke
- Rüdiger Huppert
- Christian Karl
- Mareike Kenntner
- Matthias Knecht
- Lena Kritten
- Sebastian Kreycy
- Aaron Lindner
- Andreas Lotter
- Sabrina Ludmann
- Ulrich Nägele
- Hartmut Osterkamp
- Krishna O'Brian
- Cristina Prados Román
- Rasmus Raecke
- Ulrike Reichl
- Marcel Reichert
- Christian von Savigny
- Matthias Schneider
- Thomas Scholl
- Benjamin Simmes
- Julia Schwärzle
- Ugo Tricoli
- Lisa Scalone
- Paul Vradelis
- Bodo Werner
- Frank Weidner
- Andreas Zahn
- SouthTRAC: HALO-Flüge in die Antarktis, polare Stratosphärenwolken und Biomassenverbrennung - the SOUTHTRAC campaign (2019).
- German HALO research aircraft to investigate ozone hole, Amazon fires and gravity waves - the SOUTHTRAC campaign (2019).
- Wettermessungen im Allgäu für die Wissenschaft - the second MetPVNet measurement campaign (2019).
- Die Kraft der Sonne durch präzisere Computermodelle besser nutzen - the first MetPVNet measurement campaign (2018).
- Investigating global air pollution - the CAFE-Africa campaign (2018).
- POLSTRACC Measurement Campaign: Strong Ozone Depletion above the Arctic Possible (2016).
- Coastal Waters Produce Halogenated Organic Molecules that Exacerbate Stratospheric Ozone Depletion - the SHIVA campaign (2012).
- First-Ever Climate Research Project with Unmanned Drone - the NASA-ATTREX project (2011).