SFB 641:  The Tropospheric Ice Phase - TROPICE

• Subject Area: Geosciences ; Geosciences
• Term: from 2004 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5486032

The tropospheric ice phase comprises the large variety of frozen particles in clouds and precipitation: ice crystals, graupel, snowflakes, hail stones. In clean air that contains no particles ice crystals can only form at temperatures below -40°Celsius. However, it can be initiated at higher temperature by so called "ice nuclei", i.e. aerosol particles having specific physico-chemical properties. The sources, properties and concentration distribution of these ice nuclei and their spatial distribution are only poorly known.About 80% of the global precipitation is produce in clouds that contain ice particles. Therefore, we need to understand the detailed process of precipitation formation that involve the ice phase in order to be able to make quantitative prediction of precipitation.The formation and spatial distribution of the ice phase has also an considerable effect on the energy budget of the atmosphere, on the radiation budget in particular at the top of convective clouds and cirrus clouds as well as on the transport and distribution of trace substances. These scientific questions will be investigated in 14 projects that are grouped in the two areas of the Collaborative Research Centre: "Formation and Characterisation of the Ice Phase" and "Tropospheric Effects of the Ice Phase". During the first period of funding work packages concentrate on development and testing of new observation methods, process studies in the laboratory and the development of numerical models.The new experimental techniques will be deployed during co-ordinated field campaigns that aim at the observation of the concentration and composition of ice particles, in particular on the new German "High Altitude and LOng range research aircraft" (HALO). Process studies of the interactive processes between the ice phase and its atmospheric environment are further issues of the research programme. The results will be used to validate the newly developed or improved numerical models.The Collaborative Research Centre will organise regular workshops in order to foster the communication between and co-ordination of relevant research activities. The participating scientists will seek the co-operation with colleagues from other national and international research institutes. The long-term goal is the accomplishment of a comprehensive assessment of the global distribution and characterisation of the ice phase and its role in the troposphere.

• DFG Programme: Collaborative Research Centres
• International Connection: Switzerland

Completed projects

• A01 - In Situ IN (Ice Nuclei) Measurements (Project Heads Bundke, Ulrich ;  Jaenicke, Ruprecht ;  Pöschl, Ulrich )
• A02 - Composition and distribution of ice nuclei in continental air masses and in mineral dust after long-range transport (Project Heads Bingemer, Heinz ;  Schütz, Lothar ;  Weinbruch, Stephan )
• A03 - Mass spectrometric in situ analysis of the chemical composition of ice nuclei and ice particle residuals (Project Heads Borrmann, Stephan ;  Curtius, Joachim )
• A04 - Einfluss organischer Verbindungen auf die Eiskeimfähigkeit des Aerosols (Project Heads Moortgat, Ph.D., Geert K. ;  Williams, Jonathan )
• A05 - Holographische in-situ Messungen der mikrophysikalischen Größen atmosphärischer Partikel in vereisten Wolken (Project Head Vössing, Hermann-Josef )
• A07 - Tomographische und spektroskopische Charakterisierung der Phasenverteilung von Fremdstoffen in Eispartikeln (Project Head Kersten, Michael )
• A08 - Einschluss von Fremdmolekülen bei der Bildung der troposphärischen Eisphase: Berechnung von Struktur und Energie der Einschlüsse (Project Head Schmidt, Martin U. )
• B01 - Bedeutung der troposphärischen Eisphase für die globale Dynamik (Project Head Wirth, Volkmar )
• B02 - Modelling and prediction of Central European snow- and ice storms - the role of ice microphysics (Project Head Wernli, Heini )
• B03 - Einfluss der Eisphase auf die Dynamik von tropischen Orkanen (Project Heads Frisius, Thomas ;  Herbert, Fritz )
• B04 - The Influence of Ice in Deep Convection on Tropospheric Trace Gases and Aerosols (Project Head Lawrence, Mark G. )
• B05 - Untersuchungen zum Einfluss der Partikeleigenschaften auf den Strahlungstransport in unterkühlten und vereisten Wolken (Project Head Borrmann, Stephan )
• B07 - Wind tunnel studies about riming of ice particles. II: Influence of turbulence and retention of water-soluble organics (Project Heads Diehl, Karoline ;  Mitra, Subir Kumar )
• B08 - Partitioning of volatile organic compounds (VOCs) between gas phase, ice phase and quasi liquid layer (Project Head Püttmann, Wilhelm )
• B09 - Spatial Inhomogeneities of Cirrus: Effects on Atmospheric Radiation (Project Heads de Reus, Marian ;  Spichtinger, Peter ;  Wendisch, Manfred )
• C01 - Central Administrative PRoject Of the SFB (CAPROS) (Project Heads Bingemer, Heinz ;  Borrmann, Stephan )

• Applicant Institution: Goethe-Universität Frankfurt am Main
• Participating University: Johannes Gutenberg-Universität Mainz; Technische Universität Darmstadt
• Participating Institution: Eidgenössische Technische Hochschule Zürich (ETH) ; Institut für Atmosphäre und Klima; Max-Planck-Institut für Chemie (Otto-Hahn-Institut)
• Spokesperson: Professor Dr. Stephan Borrmann
• Deputy: Professor Dr. Ulrich Schmidt