Articles | Volume 22, issue 1
Research article
03 Jan 2022
Research article |  | 03 Jan 2022

New investigations on homogeneous ice nucleation: the effects of water activity and water saturation formulations

Manuel Baumgartner, Christian Rolf, Jens-Uwe Grooß, Julia Schneider, Tobias Schorr, Ottmar Möhler, Peter Spichtinger, and Martina Krämer

Related authors

Impact of formulations of the homogeneous nucleation rate on ice nucleation events in cirrus
Peter Spichtinger, Patrik Marschalik, and Manuel Baumgartner
Atmos. Chem. Phys., 23, 2035–2060,,, 2023
Short summary
On numerical broadening of particle-size spectra: a condensational growth study using PyMPDATA 1.0
Michael A. Olesik, Jakub Banaśkiewicz, Piotr Bartman, Manuel Baumgartner, Simon Unterstrasser, and Sylwester Arabas
Geosci. Model Dev., 15, 3879–3899,,, 2022
Short summary
High homogeneous freezing onsets of sulfuric acid aerosol at cirrus temperatures
Julia Schneider, Kristina Höhler, Robert Wagner, Harald Saathoff, Martin Schnaiter, Tobias Schorr, Isabelle Steinke, Stefan Benz, Manuel Baumgartner, Christian Rolf, Martina Krämer, Thomas Leisner, and Ottmar Möhler
Atmos. Chem. Phys., 21, 14403–14425,,, 2021
Short summary
In situ observation of new particle formation (NPF) in the tropical tropopause layer of the 2017 Asian monsoon anticyclone – Part 2: NPF inside ice clouds
Ralf Weigel, Christoph Mahnke, Manuel Baumgartner, Martina Krämer, Peter Spichtinger, Nicole Spelten, Armin Afchine, Christian Rolf, Silvia Viciani, Francesco D'Amato, Holger Tost, and Stephan Borrmann
Atmos. Chem. Phys., 21, 13455–13481,,, 2021
Short summary
In situ observation of new particle formation (NPF) in the tropical tropopause layer of the 2017 Asian monsoon anticyclone – Part 1: Summary of StratoClim results
Ralf Weigel, Christoph Mahnke, Manuel Baumgartner, Antonis Dragoneas, Bärbel Vogel, Felix Ploeger, Silvia Viciani, Francesco D'Amato, Silvia Bucci, Bernard Legras, Beiping Luo, and Stephan Borrmann
Atmos. Chem. Phys., 21, 11689–11722,,, 2021
Short summary

Related subject area

Subject: Clouds and Precipitation | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Above-cloud concentrations of cloud condensation nuclei help to sustain some Arctic low-level clouds
Lucas J. Sterzinger and Adele L. Igel
Atmos. Chem. Phys., 24, 3529–3540,,, 2024
Short summary
Contrail formation on ambient aerosol particles for aircraft with hydrogen combustion: a box model trajectory study
Andreas Bier, Simon Unterstrasser, Josef Zink, Dennis Hillenbrand, Tina Jurkat-Witschas, and Annemarie Lottermoser
Atmos. Chem. Phys., 24, 2319–2344,,, 2024
Short summary
Effects of intermittent aerosol forcing on the stratocumulus-to-cumulus transition
Prasanth Prabhakaran, Fabian Hoffmann, and Graham Feingold
Atmos. Chem. Phys., 24, 1919–1937,,, 2024
Short summary
Cloud properties and their projected changes in CMIP models with low to high climate sensitivity
Lisa Bock and Axel Lauer
Atmos. Chem. Phys., 24, 1587–1605,,, 2024
Short summary
Water isotopic characterisation of the cloud–circulation coupling in the North Atlantic trades – Part 2: The imprint of the atmospheric circulation at different scales
Leonie Villiger and Franziska Aemisegger
Atmos. Chem. Phys., 24, 957–976,,, 2024
Short summary

Cited articles

Baumgartner, M. and Spichtinger, P.: Homogeneous nucleation from an asymptotic point of view, Theor. Comput. Fluid Dynam., 33, 83–106,, 2019. a, b
Berkemeier, T., Shiraiwa, M., Pöschl, U., and Koop, T.: Competition between water uptake and ice nucleation by glassy organic aerosol particles, Atmos. Chem. Phys., 14, 12513–12531,, 2014. a, b
Bullock, G. and Molinero, V.: Low-density liquid water is the mother of ice: on the relation between mesostructure, thermodynamics and ice crystallization in solutions, Faraday Discuss., 167, 371–388,, 2013. a
Bunz, H., Benz, S., Gensch, I., and Krämer, M.: MAID: a model to simulate UT/LS aerosols and ice clouds, Environ. Res. Lett., 3, 035001,, 2008. a
Carslaw, K. S., Clegg, S. L., and Brimblecombe, P.: A Thermodynamic Model of the System HCl-HNO3-H2SO4-H2O, Including Solubilities of HBr, from <200 to 328 K, J. Phys. Chem., 99, 11557–11574,, 1995. a, b, c, d
Short summary
An important mechanism for the appearance of ice particles in the upper troposphere at low temperatures is homogeneous nucleation. This process is commonly described by the Koop line, predicting the humidity at freezing. However, laboratory measurements suggest that the freezing humidities are above the Koop line, motivating the present study to investigate the influence of different physical parameterizations on the homogeneous freezing with the help of a detailed numerical model.
Final-revised paper