PEroxy rAdicals measured by OF-Cavity Enhanced spectroscopy in the free troposphere with a focus on the upper troposphere / lower stratosphere (PEACE)

• Antragsteller: Professor Dr. John Philip Burrows
• Fachliche Zuordnung: Physik und Chemie der Atmosphäre
• Förderung: Förderung von 2007 bis 2018
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 47489505

The importance of peroxy radicals, RO2* (=I[HO2]+[RO2]) in atmospheric chemistry is well established. RO2* are short lived species, which generate longer lived radiatively active (e.g. ozone, O3) and chemically or toxicologically important pollutants (e.g. O3, peroxyacetyl nitrate, CH3CO.O2.NO2, PAN, aldehydes, acids etc.). Following vertical and long-range transport, these in turn play a significant role in the chemistry of the earth’s atmosphere both regionally and globally. As a result of their low concentrations, measurements of RO2* even at the ground are sparse. Thus our ability to test our understanding of RO2* chemistry and its consequences has been limited. The overarching scientific objective of PEACE addresses this deficit by the optimization of a new measurement technique and by making and analyzing measurements of RO2* in combination with other key species in the boundary layer, the free troposphere and the UT/LS region. The role of RO2* in determining O3 abundance will be one important focus, utilizing the unique capability of the new research aircraft HALO (High Altitude Long Range). In-situ measurements of RO2* from the boundary layer to the UT/LS provide unique information about these processes. Within PEACE the new RO2* detection instrument PerCEAS (Peroxy radical Cavity Enhanced Absorption Spectrometer) will be optimised for flight on HALO, prior its participation in the HALO-OMO (Oxidative Mechanisms Observations) and SHIVA/HOx-NOx-XOx (Stratospheric ozone: Halogen Impacts in a Varying Atmosphere) measurement campaigns. In addition HALO-PerCEAS will be improved to enable the speciation of RO2* and the direct detection of nitrogen dioxide, NO2. The instrument will also be adapted to measure the radical precursor, glyoxal (CHO.CHO), a key temporary reservoir, formed in both biogenic and anthropogenic emissions and biomass burning.

• DFG-Verfahren: Infrastruktur-Schwerpunktprogramme
• Teilprojekt zu: SPP 1294: Bereich Infrastruktur - Atmospheric and Earth system research with the "High Altitude and Long Range Research Aircraft" (HALO)