Methods
TRIHOP (TRacer In-situ quantum cascade laser absorption spectrometer/ Hydrogen and Organic Peroxide monitor)
TRIHOP consists of an IR-laser absorption spectrometer for in situ measurements of HCHO, CO, and CH4 employing three quantum cascade lasers and a wet chemical dual-enzyme monitor (modified Aero-Laser AL2021CA) for the detection of H2O2 and organic peroxides, ROOH. Both instruments are integrated into one rack that has been deployed successfully on the HALO (High Altitude LOng range) research aircraft during the TACTS/ESMVal, OMO and CAFE-Africa missions.
Schiller, C.L., H. Bozem, C. Gurk, U. Parchatka, R. Königstedt, G.W. Harris, J. Lelieveld and H. Fischer, TRISTAR: Application of a Quantum Cascade TDLAS for sensitive trace gas measurements of CO, CH4, N2O and HCHO, Applied Physics B, 419-430, 2008.
Tadic, I., U. Parchatka, R. Königstedt, and H. Fischer, In-flight stability of quantum cascade laser based infrared absorption spectroscopy measurements of atmospheric carbon monoxide, Appl. Phys. B, 123, 146, 2017.
NOAH (Nitrogen Oxides Analyser on Halo)
NOAH is a modified commercial instrument (ECO-Physics CLD 790 SR) for the detection of NO and NO2. Quantitative measurements of NO are based on the chemiluminescence of NO2* in the reaction of NO with O3. NO2 is detected as NO after photolytic conversion in a blue light converter (DMT). The instrument is mounted in a HALO rack and has been successfully deployed during CAFE-Africa, on research ships (Commandor Iona, Marion Dufresne) and during various ground-based campaigns.
Hosaynali Beygi, Z., Fischer, H., Harder, H. D., Martinez, M., Sander, R., Williams, J., Brookes, D. M., Monks, P. S., and Lelieveld, J.: Oxidation photochemistry in the Southern Atlantic boundary layer: unexpected deviations of photochemical steady state, Atmos. Chem. Phys., 11, 8497-8513, doi:10.5194/acp-11-8497-2011, 2011.
ATTILA (Airborne Tropospheric Tracer In-situ Laser Absorption)
ATTILA is the latest version of various compact single laser quantum cascade laser spectrometer, consisting of two IR-laser absorption spectrometers for CO and CH4 measurements for deployment on HALO.
Kormann, R., R. Königstedt, U. Parchatka, J. Lelieveld, and H. Fischer, QUALITAS – A mid-infrared spectrometer for sensitive trace gas measurements based on quantum cascade lasers in CW operation, Rev. Sci. Instrum., 76, 075102, doi: 10.1036/1.1931233, 2005.
Li, J., U. Parchatka, R. Königstedt, and H. Fischer, Real-time measurements of atmospheric CO using a continuous-wave room temperature quantum cascade laser based spectrometer, Opt. Express, 20, 7590-7601, 2012.
Additional instrumentation:
AL4021 (AEROLASER, Garmisch Partenkirchen, Germany): Hantzsch detector for HCHO
AL2021A (AEROLASER, Garmisch Partenkirchen, Germany): Dual enzyme monitor for the detection of H2O2
HPLC: Custom made combination of a dual enzyme monitor with a high liquid chromatography system for the detection of hydroperoxides