Center for Cloud Ice Nucleation


The Center for Cloud Ice Nucleation (CCIce) is situated at the Karlsruhe Institute of Technology (KIT) and is hosted by the Institute of Meteorology and Climate Research - Department Atmospheric Aerosol Research (IMK-AAF). Here, the large atmospheric simulation chamber AIDA (Aerosol Interaction and Dynamics in the Atmosphere) is employed for cloud studies, instrument inter-comparison or calibration. Atmospheric online-measurements are realized via PM10 inlets installed at the institute’s roof top. The department’s building also houses a chemical laboratory, a workshop and generous lab-space.
For calibration and inter-comparisons of ice nucleating particle (INP) online-instrumentation, CCIce uses a dedicated mobile cloud chamber, the Portable Ice Nucleation Chamber PINE. Offline-derived INP immersion freezing spectra are measured using the Ice Nucleation Spectrometer of the Karlsruhe Insitute of Technology INSEKT freezing assay. A dedicated cloud chamber for INP instrument calibration and inter-comparison will be available soon.

CCIce is currently being set-up and will be fully operational in 2026. The infrastructure implementation is funded by the German Federal Ministry of Education and Research (BMBF) within the ACTRIS-D project in the course of the strategy „Forschung für Nachhaltigkeit" (FONA).


Main Task

INPs are a very rare subgroup of atmospheric aerosols with the ability to trigger the ice formation in clouds. This is often the first step in the formation of precipitation and also influences the radiative properties of the cloud. There is currently scarce data on the long-term regional availability of INPs and their seasonal dependencies. In addition, global warming will most probably influence INP concentrations and their ice nucleation activity. For the fundamental understanding of cloud physical processes and a refined prediction of future climate and weather conditions, ACTRIS aims to measure and provide high quality long-term data on INP concentrations in various environments.

Within CIS, the measurement of INPs provide specializing requirements for observational and exploratory platforms. The serviced variables are:

  • Ice nucleating particle number concentration
  • Ice nucleating particle number temperature spectrum

Both can be measured on-line via direct atmospheric measurement (e.g., using PINE) or off-line by post-analysis of aerosol samples (e.g., using INSEKT). The technical requirements for ACTRIS National Facilities (NFs) are currently under development and will be provided here soon.


The Center for Cloud Ice Nucleation (CCIce) will provide guidance on the set-up and required infrastructure for CIS associated facilities. Also, QA/QC measurement and data guidelines and tools will be available soon. We organize trainings and workshops for ACTRIS NFs and ACTRIS users, as well as INP instrument inter-comparisons and calibrations. CCIce will guide NFs in the labelling process and conduct technical and quality audits and is responsible for implementing the quality assurance measures.

CCIce also offers access to its facility to users from industry and research facilities. The access to ACTRIS facilities is managed by Service Access Management Unit of the ACTRIS Head Office (SAMU, Link).


Dr. Kristina Höhler

Leader of the Central Facility for Cloud in Situ Measurements (CIS)
Head of the Center for Cloud Ice Nucleation (CCIce)
Karlsruhe Institute of Technology (KIT)



Dr. Ottmar Möhler

Leader of the National Facility AIDA cloud simulation chamber
Deputy Head of the Center for Cloud Ice Nucleation (CCIce)
Karlsruhe Institute of Technology (KIT)