B03: Characterization of Arctic mixed-phase clouds by airborne in-situ measurements and remote sensing
In phase I, the project successfully combined airborne remote sensing of the vertical column and the radiative impact of clouds with in–situ microphysical measurements of cloud and aerosol properties during the ACLOUD and AFLUX campaigns. The ability of novel airborne instrumentation including a multi–channel microwave radiometer, an imaging spectrometer for reflected spectral solar radiation, active profiling by radar and lidar as well as a counterflow virtual impactor (CVI), was demonstrated and identified cloud characteristics that are relevant for the role of clouds in Arctic amplification. Clouds were about 10 % more frequent (80 %) and higher (median cloud top 1.3 km) over ocean than over sea ice. Frequent precipitation was detected (50% of observed clouds) with the majority of them being mixed–phase clouds. Their small-scale cloud phase distribution differed in warm and cold air masses. Furthermore, different potential sources of cloud forming particles were identified over sea ice and open water (above or below cloud).
As the completed campaigns represent only a snapshot of Arctic conditions, we aim to extend these measurements by two major campaigns to systematically investigate seasonal and regional differences of cloud and aerosol properties and their contribution to Arctic amplification. MOSAiC-ACA (Svalbard) in spring and summer 2020 is embedded in the framework of MOSAiC and uses the Polar 5&6 aircraft to characterise Arctic boundary layer clouds. These measurements will primarily address seasonal differences and built the bridge between the ground-based observations of Polarstern and Ny–Ålesund and satellite observations. HALO-(AC)³ (Kiruna) in spring 2021 will make use of the HALO aircraft to track transformations of cloud characteristics along air mass pathways from the Arctic circle into the central Arctic. The observed cloud and aerosol properties will be linked to each other and categorised for warm/cold air masses, above sea ice/open ocean, spring/summer, central Arctic/lower latitudes, and above/within/below cloud (aerosol only) to identify changes of aerosol-cloud interaction under different conditions, which are expected to occur more/less frequently due to Arctic amplification. Therefore, the data set will be used to explain observed precipitation properties and to derive measurement–based estimates of the cloud radiative forcing.
Changes of cloud properties and cloud forming particles along air mass transitions are in the same order as those due to seasonal variability.
For testing this hypothesis the work in phase II aims to answer the questions:
- How cloud properties change in air mass transformations (Q1)?
- Does the source of cloud forming aerosol particles change in air mass transformations (Q2)?
- Are there seasonal and regional differences of Q1 and Q2?
- What are the effects of Q1 and Q2 on precipitation and cloud radiative forcing?
Achievements phase I
Within B03, Arctic mixed–phase clouds were observed with a set of unique remote sensing (Mech et al., 2019) and in–situ instruments during ACLOUD (Wendisch et al., 2019) and AFLUX. A comprehensive characterisation of the horizontal and vertical variability of cloud properties was performed. Ambient and cloud forming aerosol particles were separated and analysed for their physical and chemical properties. Surprisingly, mixed–phase clouds and precipitating snow were frequently observed in a rather high temperature range between –13 ◦C and 0 ◦C. It was shown, that the vertical distribution of ice particles in clouds differs in cold and warm air masses (Knudsen et al., 2018a). Also, the in–situ observations identified larger cloud particle residuals over open ocean and smaller over sea ice, which indicates different pathways of cloud forming particles into the cloud: below-cloud mixing of large sea salt dominated over the open ocean and cloud top entrainment of smaller tropospheric particles over closed sea ice (Wendisch et al., 2019).
Role within (AC)³
Prof. Dr. Susanne Crewell
University of Cologne
Institute for Geophysics and Meteorology (IGM)
Ehrlich, A., M. Wendisch, C. Lüpkes, M. Buschmann, H. Bozem, D. Chechin, H.-C. Clemen, R. Dupuy, O. Eppers, J. Hartmann, A. Herber, E. Jäkel, E. Järvinen, O. Jourdan, U. Kästner, L.-L. Kliesch, F. Köllner, M. Mech, S. Mertes, R. Neuber, E. Ruiz-Donoso, M. Schnaiter, J. Schneider, J. Stapf, and M. Zanatta, 2019: A comprehensive in situ and remote sensing data set from the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign, Earth Syst. Sci. Data, https://doi.org/10.5194/essd-11-1853-2019
Mech, M., L.-L. Kliesch, A. Anhäuser, T. Rose, P. Kollias and S. Crewell, 2019: Microwave Radar/radiometer for Arctic Clouds MiRAC: First insights from the ACLOUD campaign, Atmos. Meas. Tech., 12, 5019–5037, doi:10.5194/amt-12-5019-2019
Wendisch, M., A. Macke, A. Ehrlich, C. Lüpkes, M. Mech, D. Chechin, K. Dethloff, C. Barrientos, H. Bozem, M. Brückner, H.-C. Clemen, S. Crewell, T. Donth, R. Dupuy, C. Dusny, K. Ebell, U. Egerer, R. Engelmann, C. Engler, O. Eppers, M. Gehrmann, X. Gong, M. Gottschalk, C. Gourbeyre, H. Griesche, J. Hartmann, M. Hartmann, B. Heinold, A. Herber, H. Herrmann, G. Heygster, P. Hoor, S. Jafariserajehlou, E. Jäkel, E. Järvinen, O. Jourdan, U. Kästner, S. Kecorius, E.M. Knudsen, F. Köllner, J. Kretzschmar, L. Lelli, D. Leroy, M. Maturilli, L. Mei, S. Mertes, G. Mioche, R. Neuber, M. Nicolaus, T. Nomokonova, J. Notholt, M. Palm, M. van Pinxteren, J. Quaas, P. Richter, E. Ruiz-Donoso, M. Schäfer, K. Schmieder, M. Schnaiter, J. Schneider, A. Schwarzenböck, P. Seifert, M.D. Shupe, H. Siebert, G. Spreen, J. Stapf, F. Stratmann, T. Vogl, A. Welti, H. Wex, A. Wiedensohler, M. Zanatta, S. Zeppenfeld, 2019: The Arctic Cloud Puzzle: Using ACLOUD/PASCAL Multi-Platform Observations to Unravel the Role of Clouds and Aerosol Particles in Arctic Amplification, Bull. Amer. Meteor. Soc., 100 (5), 841–871, doi:10.1175/BAMS-D-18-0072.1
Knudsen, E.M., B. Heinold, S. Dahlke, H. Bozem, S. Crewell, I. V. Gorodetskaya, G. Heygster, D. Kunkel, M. Maturilli, M. Mech, C. Viceto, A. Rinke, H. Schmithüsen, A. Ehrlich, A. Macke, C. Lüpkes, M. Wendisch, 2018: Meteorological conditions during the ACLOUD/PASCAL field campaign near Svalbard in early summer 2017, Atmos. Chem. Phys., 18, 17995-18022, doi:10.5194/acp-18-17995-2018
Wendisch, M. and A. Ehrlich, 2018: Arktische Verstärkung und Wolken, promet, 102, 21-32
Schäfer, M., K. Loewe, A. Ehrlich, C. Hoose, M. Wendisch, 2018: Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus, Atmos. Chem. Phys., 18, 13115-13133,
Ehrlich, A., Bierwirth, E., Istomina, L., and Wendisch, M., 2017: Combined retrieval of Arctic liquid water cloud and surface snow properties using airborne spectral solar remote sensing, Atmos. Meas. Tech., 10, 3215-3230, doi:10.5194/amt-10-3215-2017
Data supplement is available here.
Franz Kanngießer, 2017: Beobachtungen von Glorien über arktischen Grenzschichtwolken zur Identifikation der Wolkenphase und Ableitung deren Häufigkeit, Master Thesis, University of Leipzig
Directional, Horizontal Inhomogeneities of Cloud Optical Thickness Fields Retrieved from Ground-Based and Airborne Spectral Imaging, Atmos. Chem. Phys., 17, 2359-2372, 2017,
Data supplement is available here.
Wendisch, M., M. Brückner, J. P. Burrows, S. Crewell, K. Dethloff, K. Ebell, Ch. Lüpkes, A. Macke, J. Notholt, J. Quaas, A. Rinke, and I. Tegen, 2017: Understanding causes and effects of rapid warming in the Arctic. Eos, 98, doi:10.1029/2017EO064803
Korolev, A., G. McFarquhar; P. Field; C. Franklin; P. Lawson; Z. Wang; E. Williams; S. Abel; D. Axisa; S. Borrmann; J. Crosier; J. Fugal; M. Krämer; U. Lohmann; O. Schlenczek, M. Wendisch, 2017: Ice Formation and Evolution in Clouds and Precipitation: Measurement and Modeling Challenges, Baumgardner, D., McFarquhar, G., and Heymsfield, A. (Eds.), Chapter 5: Mixed-Phase Clouds: Progress and Challenges, AMS Meteorological Monographs, 58, pp 5.1-5.50, doi:10.1175/AMSMONOGRAPHS-D-17-0001.1
Cziczo, D. J., Ladino, L., Boose, Y., Kanji, Z. A., Kupiszewski, P., Lance, S., Mertes, S., Wex., H., 2017: Ice Formation and Evolution in Clouds and Precipitation: Measurement and Modeling Challenges, Baumgardner, D., McFarquhar, G., and Heymsfield, A. (Eds.), Chapter 8: Measurements of Ice Nucleating Particles and Ice Residuals, AMS Meteorological Monographs, 58, 8.1-8.13, doi:10.1175/AMSMONOGRAPHS-D-16-0008.1
Noth, R., 2016: Atmosphärische Heizraten in bewölkten und unbewölkten Bedingungen aus Flugzeugmessungen in der Arktis, Bachelor Thesis, University of Leipzig