Mini-DOAS measurements during HALO phase II missions WISE, CAFE, EmerGe, and CoMet, and retrieval, interpretation and dissemination of the data collected during previous HALO missions
Final Report Abstract
Within the framework of the SPP-1294 phase II, the novel mini-DOAS (Differential Optical Absorption Spectroscopy) instrument was successfully deployed and operated on the HALO aircraft during a total of 6 research missions, namely: 1. the EMeRGe Europe mission in summer 2017, 2. the WISE mission in fall 2017, 3. the EMeRGe Asia mission in spring 2018, 4. the CoMet mission in spring 2018, 5. the CAFÉ-Africa mission in summer 2018, and 6. the SOUTHTRAC mission in fall 2019. Re-occurring data transmission problems of the aircraft’s Basis HALO Measurement and Sensor System (Bahamas) to correctly submit on-line data to our instrument in real-time (i.e., the clock, and the aircraft’s location and attitude data, all of which are necessary to command the instrument and in particular limb receiving telescopes and to identify the measured data) led us to a refinement of the mini-DOAS instrument in summer 2019. Thereby a new ARINC (Aeronautical Radio Incorporated) input port was added to our electronics and directly connected to aircrafts avionics, from which the relevant data of the aircraft (e.g., the GPS clock, 3-D location, and attitude) could directly be received and processed in real-time. This novel complementary data connection, in addition to earlier refinements, improved the operational availability of the HALO instrument to nearly 100% (from previously 90 – 95%). To this end, the instrument successfully collected data in about 686 flight hours, corresponding to 122,592 (UV) and 483,837 (visible) skylight limb spectra during the six campaigns. Significant progress has been made within the present project to develop suitable retrieval methods, tools and software to infer absolute concentrations from the remotely sensed quantities (i.e., mostly slant column amounts of the targeted species) from the air-borne UV/vis/nearIR limb measurements under all skies. These include (a) a versatile radiative transfer Monte Carlo model (McArtim) with which Jacobian (and Hesse) matrices can be calculated, (b) a novel Mie scattering code based on Green's dyadic technique (GDT) matrix approach with which the light scattering of irregular shaped solid small particles (c.f. cirrus ice particles) can be calculated to a high accuracy, and (c) an inversion code and scaling method to infer absolute concentrations at flight level of the targeted species from the limb measurements. To date 60% to 70% of the measured limb and ~5% of the nadir data have been finally processed and the retrieved concentrations of the targeted gases (O3, O4, SO2, NO2, HONO, BrO, IO, OClO, CH2O, C2H2O2 and CH3H4O2*) are stored on the HALO data base. A small fraction (10 – 15%) of the processed data could already be interpreted and partly disseminated in the peer reviewed literature. With respect to the large amount of data collected during the past missions and insights gained from those data which already been retrieved, much more new scientific aspects may eventually arise when fully analysing the data. At the same time when considering how much time it may take to interpret and finally disseminate all these exciting data, it can fairly be concluded that the potential of collected data could to date at most be scientifically exploited by 10 – 15%. A better rate of utilisation and exploitation of the data would, however, require additional funding than presently available to employ PhD students and post-docs for the processing, interpretation and dissemination of the results. Therefore, it needs to be seen whether this (large and widening) gap in available data and the potential new and exciting science they bear can be closed in future projects.
Publications
- A New Differential Optical Absorption Spectroscopy Instrument to Study Atmospheric Chemistry from a High-Altitude Unmanned Aircraft, Atmos. Meas. Tech., 10, 1017-1042, 2017
Stutz, J., Werner, B., Spolaor, M., Scalone, L., Festa, J., Tsai, C., Cheung, R., Colosimo, Tricoli, U., Raecke, R., Hossaini, R., Chipperfield, 15 Feng, W., Gao, R.-S., Hintsa, Elkins, Moore, Daube, B., Pittman, J., Wofsy, S., and Pfeilsticker, K.
(See online at https://doi.org/10.5194/amt-10-1017-2017) - Depletion of ozone and reservoir species of chlorine and nitrogen oxide in the lower Antarctic polar vortex measured from aircraft, Geophys. Res. Lett., 44, 2017
Jurkat T., C. Voigt, S. Kaufmann, J.-U. Grooß, H. Ziereis, A. Dörnbrack, P. Hoor, H. Bozem, A. Engel, H. Bönisch, T. Keber, T. Hüneke, K. Pfeilsticker, K. Walker, C.D. Boone, P.F. Bernath, and H. Schlager
(See online at https://doi.org/10.1002/2017GL073270) - Potential of remote sensing of cirrus optical thickness by airborne spectral radiance measurements at different sideward viewing angles, Atmos. Chem. Phys., 17, 4283-4303, 2017
Wolf K., Ehrlich, A., Hüneke, T., Pfeilsticker, K., Werner, F., Wirth, M., and Wendisch, M
(See online at https://doi.org/10.5194/acp-17-4283-2017) - Probing the subtropical lowermost stratosphere and the tropical upper troposphere and tropopause layer for inorganic bromine, Atmos. Chem. Phys., 17, 1161-11, 2017
Werner, B., Stutz, J., Spolaor, M., Scalone, L., Raecke, R., Festa, J., Colosimo, S.F., Cheung, R., Tsai, C., Hossaini, R., Chipper_eld, M. P., Taverna, G. S., Feng, W., Elkins, J. W., Fahey, D. W., Gao, R.-S., Hintsa, E. J., Thornberry, T. D., Moore, F. L., Navarro, M. A., Atlas, E., Daube, B. C., Pittman, J., Wofsy, S., and Pfeilsticker, K.
(See online at https://doi.org/10.5194/acp-17-1161-2017) - The novel HALO mini-DOAS instrument: Inferring trace gas concentrations from air-borne UV/visible limb spectroscopy under all skies using the scaling method, AMT, 10, 4209-4234, 2017
Hüneke, T., Aderhold, O.-A., Bounin, J., Dorf, M., Gentry, E., Grossmann, K., Grooß, J.-U., Hoor, P., Jöckel, P., Kenntner, M., Knapp, M., Knecht, M., Lörks, D., Ludmann, S., Raecke, R., Reichert, M., Weimar, J., Werner, B., Zahn, A., Ziereis, H., and Pfeilsticker, K.
(See online at https://doi.org/10.5194/amt-10-4209-2017) - POLSTRACC: Airborne experiment for studying the Polar Stratosphere in a 2 Changing Climate with the high-altitude long-range research aircraft HALO, Bull. Amer. Meteor. Soc.
Oelhaf, Hermann, Björn-Martin Sinnhuber, Wolfgang Woiwode, Harald Bönisch, Heiko Bozem, Andreas Engel, Andreas Fix, Felix Friedl-Vallon, Jens-Uwe Grooß, Peter Hoor , Sören Johansson, Tina Jurkat-Witschas, Stefan Kaufmann, Martina Krämer, Jens Krause, Erik Kretschmer, Dominique Lörks, Andreas Marsing, Johannes Orphal, Klaus Pfeilsticker, Michael Pitts, Lamont Poole, Peter Preusse, Markus Rapp, Martin Riese, Christian Rolf, Jörn Ungermann, Christiane Voigt, C. Michael Volk, Martin Wirth, Andreas Zahn, and Helmut Ziereis
(See online at https://doi.org/10.1175/BAMS-D-18-0181.1) - CH4 and CO2 IPDA Lidar Measurements During the Comet 2018 Airborne Field Campaign, EPJ Web Conferences 237, 03005, 2020
Fix A, A. Amediek, C. Büdenbender, G. Ehret, C. Kiemle, M. Quatrevalet, M. Wirth, S. Wolff, H. Bovensmann, A. Butz, M. Galkowski, C. Gerbig, P. Jöckel, J. Marshall, J. Necki, K. Pfeilsticker, A. Roiger, J. Swolkien, M. Zöger and the CoMet team
(See online at https://doi.org/10.1051/epjconf/202023703005) - Profiling of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon: normalized excess mixing ratios and related emission factors in biomass burning plumes, Atmos. Chem. Phys., 20, 12363–12389, 2020
Kluge, F., Hüneke, T., Knecht, M., Lichtenstern, M., Rotermund, M., Schlager, H., Schreiner, B., and Pfeilsticker, K.
(See online at https://doi.org/10.5194/acp-20-12363-2020)
