On May 22nd, 1997, our institute celebrated the formal opening of the new aerosol and cloud chamber facility AIDA. After about two years of construction and technical runs, the first scientific campaign started on May 11th, 1997, and investigated heterogeneous chemistry on soot aerosols. Since then, a number of 5 to 10 campaigns was conducted every year, covering topics of trace gas chemistry, heterogeneous chemistry, aerosol formation, aerosol optical properties, polar stratospheric cloud formation as well as formation, growth, morphology and radiative properties of ice crystals in tropospheric clouds. The aerosol-cloud research with AIDA is also the topic of a recent KIT podcast (in German). We are grateful to all our national and international collaboration partners who contributed and still contribute to many of the AIDA campaigns.
The first experimental determination of HDO/H2O isotopic fractionation factors for ice deposition in simulated cirrus clouds for temperatures betwen 190-233 K could be achieved in the AIDA aerosol and cloud chamber (Lamb et al., PNAS 2017). In collaboration between the University of Chicago, PTB, and KIT unique measurement techniques for water isotopes were developed and applied for dedicated cirrus cloud simulation experiments. A detailed box model analysis including wall effects resulted in equilibrium fractionation factors and kinetic isotope effects with a weaker temperature dependence than extrapolations of previous work suggested. These results are fundamental for inferring processes on Earth and other planets from water isotopic measurements.
During the INUIT-CLACE campaign in January and February 2017, international teams collaborate at the Jungfraujoch Research Station (3571 m, Switzerland) to investigate aerosol-cloud processes and cloud microphysics in the mixed-phase cloud regime. KIT contributes single particle mass spectrometer measurements of aerosol particles and cloud ice residuals, as well as measurements of ice nucleating particle (INP) concentrations by taking aerosol filter samples for later offline INP analysis with an immersion freezing method.
Between December 2016 and 2020 the EU invests ~9 Mio € to further integrate 16 simulation chamber and 4 calibration facilities. This includes the AIDA aerosol and cloud chamber facility of KIT. Trans national access to these facilities is substantially supported. For details contact us or see: www.eurochamp.org.
Scientists of IMK-AAF, in cooperation with researchers of the KIT Laboratory of Electron Microscopy (LEM) and University College London (UCL) have succeeded in identifying the unique features on K-Feldspar responsible for its high ice nucleation efficiency. As reported in Science magazine (DOI: 10.1126/science.aai8034), they combined electron microscopy observations with molecular modeling to determine for the first time the atomic nature of this important inorganic ice nucleating particle. They showed that ice starts to grow on the specific crystal faces with (100) orientation that only occur at defects (steps, cracks, and crevices) on the surface of feldspar particles.
The KIT in-house development PHIPS-HALO was chosen as the only non-US instrument to participate in the NSF funded airborne campaign ARISTO taking place in Colorado, USA. ARISTO is a unique platform for testing innovative and novel technologies in the field of atmospheric research. This year’s platform, the C-130, is well-known for its capabilities to do research flights under harsh conditions. The first flight of the campaign was performed targeting ongoing forest fires in the Rocky Mountains area. The flight was a success for the whole payload and especially for the KIT PHIPS-HALO.
She received the award for her Master thesis “Influence of biodiesel fuel composition on morphology and microstructure of particles emitted from Diesel engines”. Her results are expected to be useful for the development of after treatment devices and the understanding of the atmospheric behaviour of soot particles as well as their health effects. (http://www.umweltstiftung-karlsruhe.de/sparkassen-umwelt-preis)
AeroTram findings of unexpected high annual averaged particle number concentrations near Leopoldshafen are investigated in a joint effort by IMK-TRO and IMK-AAF. A measurement container equipped with various gas and particle sensors including most advanced mass spectrometers is deployed near Leopoldshafen to identify the nature and potentially the origin of the high particle concentrations observed by the instrumented AeroTram (http://www.aero-tram.kit.edu/).
The scientific research at AAF is part of the exhibition "GLOBALE: Exo-Evolution" at Center for Art and Media (ZKM, Karlsruhe, Germany). From 31.10 2015 to 28.02.2016 two exhibits, “High speed video recordings of freely levitated freezing droplets” and “Ice crystals growing on feldspar mineral in electron microscope” can be seen in the ZKM, Atrium 8+9. The exhibits show high resolution video recordings of microphysical processes responsible for nucleation and growth of ice in atmospheric clouds. The exhibition opening takes place on Friday, October 30th, 2015 at 7:30 pm.
During September 2015, U.S. and German teams of atmospheric ice nucleation research collaborate at the Storm Peak Laboratory, Steamboat Springs, Colorado, to intercompare methods for sampling ice nucleating particles from ambient air. This activity called FIN03 is the final major experimental activity within the Fifth International Ice Nucleation Workshop (FIN). The KIT PhD student Thea Schiebel is participating in this activity as part of her 3 month visit to the Colorado State University which is supported by the KIT Graduate School for Climate and Environment (GRACE)
This workshop is the most comprehensive ever held concerning atmospheric ice nucleation studies. Three phases include intercomparison of single particle mass spectrometers (FIN01, Nov 2014) and of ice nucleation measurement methods (FIN02, Mar 2015), both held at the KIT AIDA cloud chamber, and intercomparison of methods for sampling ice nucleating particles from ambient air at Storm Peak Laboratory, Steamboat Springs (FIN03, Sep 2015). The FIN activities are supported by NSF, DOE-ASR and DFG (Research Unit INUIT).
The ongoing AIDA-2 project includes the construction of a new lab building, the renovation of the AIDA facility, the installation of an aerosol mass spectrometry lab, and the construction of a novel dynamic cloud chamber. Building construction and AIDA renovation are making good progress. Reopening of the AIDA facility is planned for September after the installation of a new liquid gas supply system.
Searching for the ice nucleating particle (INP) types in the atmosheric aerosol is still a major challenge of aerosol-cloud-climate research. Scientists from the Karlsruhe Institute of Technology, the Meteorological Research Institute in Tsukuba, Japan, and the University of Bielefeld have identified cellulose as an important source of atmospheric INPs, as reported in Nature Geoscience 8, 273-277 (2015) .
The effects of ultrafine particles, the smallest constituents of airborne particulate matter, on air quality, atmospheric processes, climate, and human health are by far not finally investigated to proven evidence. The 5th EFCA Ultrafine Particles Symposium will reflect the most recent scientific progress in the field and aims to contribute to the dialogue with policymakers in Europe. The symposium takes place on May 4 - 5 in Brussels, Belgium. It is co-organized by KIT and chaired by the head of IMK-AAF, Prof. Thomas Leisner.
From April 23rd, 2014 until May 23rd, 2014 IMK-AAF participates in the RACEPAC campaign (http://www.uni-leipzig.de/~racepac/index.html) located in Inuvik and Tuktuyaktuk, Northwest Territories, Canada.
For the first time, cloud researchers from the KIT AIDA team participated in laboratory cloud simulation experiments at the Meteorological Research Institute (MRI) in Tsukuba, Japan. From October 1- 11, 2013, they closely collaborated with Dr. Masataka Murakami and his team for ice nucleation studies at the MRI dymanic cloud chamber. These experiments nicely extend and complement ice nucleation studies which are performed within the DFG funded Research Unit INUIT (FOR 1525).
In April 2013 50 scientists from 6 different countries participated with 36 different hygrometers in a blind refereed intercomparison including traceable references. The intercomparison covered conditions simulating the UT/LS (186-233 K, 0.2-1300 ppmv) with static periods and dynamic changes including ice clouds. AquaVIT-2 will help reducing instrument uncertainties in order to better quantify the important role of atmospheric water vapor in weather and climate systems.http://www.imk-aaf.kit.edu/621.php
Together with the Teramobile Collaboration the interaction of fs- laser filaments with clouds was investigated. As detailed in a recent article in the Proceedings of the National Academy of Science of the United States http://dx.doi.org/10.1073/pnas.1222190110, the laser induced plasma channels did not influence ice nucleation in mixed phase clouds but had a remarkably strong effect on ice clouds at temperatures below the limit of homogeneous freezing. Read more: http://www.kit.edu/visit/pi_2013_13037.php
The effects of ultrafine particles, the smallest constituents of airborne particulate matter, on air quality, atmospheric processes, climate, and human health are by far not finally investigated to proven evidence. The 4th EFCA Ultrafine Particles Symposium will reflect the most recent scientific progress in the field and aims to contribute to the dialogue with policymakers in Europe. The symposium takes place on May 16 - 17 in Brussels, Belgium. It is co-organized by KIT and chaired by the head of IMK-AAF, Prof. Thomas Leisner.
The joint NSF/DFG project ISOCLOUD investigates the water isotope fractionation by combining AIDA cloud simulation experiments with process modelling studies. In October 2012, the project partners achieved simulta- neous measurements of H2O, HDO, and H2(18)O both in the gas phase and the condensed phase. First results show the HDO fractionation to be in agreement with Rayleigh distillation assumptions. In March 2013, further AIDA experiments are planned to measure fractionation factors in cold cirrus clouds.
18.01.2013. Within the DFG-funded project ISI a team from IMK-AAF is currently investigating the microphysical properties of cloud droplet and ice particles at the high altitude research station Jungfraujoch in Switzerland. The aim of the study is to improve the current understanding of the formation processes and structure of mixed-phase clouds.
In an extensive review article (Hoose and Möhler, ACP 2012), results on ice nucleation by various aerosols, such as dust, soot, organic acids and biological particles, from AIDA and many other laboratory studies are compiled and intercompared. The aim is to provide an easily accessible overview of historic and recent results in this active field of research. One of the figures of this article has also been adapted for the draft of the "Clouds and Aerosols" chapter of the IPCC Fifth Assessment Report (AR5).
The interdisciplinary workshop "Challenges and chances of new Unmanned Aerial Systems (UAS)" took place on September 13-15, 2012, in Karlsruhe and was organized by the IMK-AAF in cooperation with the IPF and FBTA. The workshop received startup funding from the KIT Competence Area “Earth and Environment”. The participants from various fields such as atmospheric, environmental and geo science, photogrammetry, mathematics, computer science and civil engineering discussed recent develop- ments in sensor and UAS technology and evaluated the opportunities arising from new cooperations.
Nine partners of the DFG-funded project ACRIDICON (Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems) and the AIDAmobile team join on mount Zugspitze during a three week, ground based field campaign starting 17.09.2012. Instruments designed for future missions aboard the High Altitude and LOng Range Research Aircraft HALO will be installed both on the summit and at the environmental research station UFS to characterize cloud microphysical and radiative properties and aerosol-cloud interaction.
IMK-AAF scientists and their AIDA facility participated in the Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) demonstrating that chemical conversions induced by hydroxyl radicals, the dominant atmospheric oxidant, significantly increase the concentration of first-generation biogenic secon- dary organic aerosol (SOA). The principal findings from MUCHACHAS have now been published in the Proceedings of the National Academy of Sciences of the USA (link to PNAS paper).
Ice particles in Arctic boundary layer clouds are in the focal point of the German scientific expedition VERDI. The main goal of VERDI is to understand the role of these clouds in the strong warming observed in the Artic over the last decades. The clouds are probed by a novel set of instruments onboard the Polar 5 research aircraft, which is operated by the Alfred Wegener Institute (AWI). VERDI is based in Inuvik, NWT, Canada, for research flights over the Beaufort Sea.
The formation of the ice phase in tropospheric clouds has multiple impacts on the hydrological cycle and the climate system. Many aspects of ice nucleation induced by a minor subgroup of the atmospheric aerosol system, so-called ice nuclei, remain unclear and will be addressed by the Research Unit INUIT, which was recently established by the German Research Foundation (DFG). In two projects, the IMK-AAF will contribute comprehensive laboratory and modeling studies on ice nucleation.
IMK-AAF disclosed its pioneering Particle Habit Imaging and Polar Scattering (PHIPS) probe in the Journal of Atmospheric Measurement Techniques (October 12, 2011). Developed for the German research aircraft HALO, it simultaneously measures the 3-D morphology and corre- sponding optical and micro- physical parameters of individual cloud particles. The paper outlines the concept and design of PHIPS and dis- cusses preliminary results of two ice cloud campaigns con- ducted in the AIDA chamber.
New sampling inlets and continuous aerosol measurements have been installed at the environmental research station Schneefernerhaus (UFS) in summer 2011. The IMK-AAF investigated aerosol - cloud interactions in warm clouds with focus on bioaerosol, soot, water budget in cooperation with the IMK-IFU on three plattforms (UFS, Zugspitze, and ultralight research aircraft) during a 2-week summer campaign.
The International Workshop on Ice Nucleation in Tropospheric Clouds (IN2clouds) was organized by the IMK-AAF within the framework of the Helmholtz Virtual Institute on Aerosol- Cloud Interactions. The workshop took place in Ettlingen on May 23-25, 2011, offering the opportunity to discuss recent and ongoing research activities in the field of aerosol-cloud-climate interactions among the VI-ACI project partners and invited experts from Europe, Israel, U.S.A. and Japan.
The Small Ice Detector (SID3) of IMK-AAF has been successfully deployed on board the NASA WB-57F aircraft during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) in April 2011. SID3 single particle data will give unique contributions to the question on the microphysical nature of the smallest ice crystals and how important these particles are for the radiative forcing.
On February 25th, FameLab Baden-Württemberg took place in Karlsruhe for the first time: FameLab is a compe-tition where students have only 3 minutes to explain a complex scientific subject and convince the audience with their creative performance. Among the participants was Isabelle Steinke, PhD student at IMK-AAF. Learn more about what experiments at the AIDA cloud chamber have in common with Germany’s Next Topmodel: http://www.youtube.com/watch?v=jgsv_xEsfYY
The nucleation and growth of pristine ice crystals attached to a frozen water droplet levitated in the Electro-Dynamic Balance (EDB, also known as “Paul trap”) has been recently observed at IMK-AAF. The newly developed environmental EDB allows for controlling the humidity and temperature profiles inside the trap, thus providing a unique tool for studying the evolution of single ice crystals.
Organic aerosols are ubiquitous in the atmos-phere. At low temperatures they are known to become glassy, that is, amorphous, non-crystalline solids. AIDA cloud chamber experiments demonstrate heterogeneous nucleation of ice on glassy citric acid particles (Murray et al., Nature Geoscience 2010).
In the first global modelling study of heterogeneous ice nucleation by biological particles, Hoose et al. (http://iopscience.iop.org/1748-9326/5/2/024009/fulltext) show that typical atmospheric bacteria, fungal spores and pollen concentrations are too low to make a significant impact for cloud ice and precipitation formation. The research is featured in a news article on environmentalresearchweb. org.
Dr. Corinna Hoose and her Young Investigators Group “Aerosol effects on cloud ice, precipitation and climate“ will work on improved parameterizations for aerosol-cloud interactions in numerical models on different scales. A special focus is on cloud ice formation.
IMK-AAF participates in the new Marsilius Project “The Global Governance of Climate Engineering” which focuses on options and risks in dealing with climate change by technological means. The Marsilius Kolleg was recently established at the University of Heidelberg as a Centre for Advanced Study to promote interdisciplinary dialogue and research.
More about the Climate Engineering Project
The IMK-AAF Atmospheric Nanoscience Group joins a three week measurement campaign at the synchrotron source BESSY II in Berlin. Research objective is the identification of polymorphs of nanometric ironoxide cloud nucleation seeds. Nanoaerosols ablated from meteorites are expected to play a crucial role in the formation of mesospheric noctilucent clouds.
In February, IMK-AAF conducted a feasibility study at the environmental research station Schneefernerhaus (UFS). The aim of the study was to show that the UFS is well suited to measure aerosol - cloud interactions in natural clouds.