In cirrus1 and orographic wave clouds2, highly supercooled water has been observed in small quantities (less than 0.15 g m-3). This high degree of supercooling was attributed to the small droplet size and the lack of ice nuclei at the heights of these clouds1,2. For deep convective clouds, which have much larger droplets near their tops and which take in aerosols from near the ground, no such measurements have hitherto been reported. However, satellite data suggest that highly supercooled water (down to -38 °C) frequently occurs in vigorous continental convective storms3. Here we report in situ measurements in deep convective clouds from an aircraft, showing that most of the condensed water remains liquid down to -37.5 °C. The droplets reach a median volume diameter of 17 µm and amount to 1.8 g m-3, one order of magnitude more than previously reported2. At slightly colder temperatures only ice was found, suggesting homogeneous freezing. Because of the poor knowledge of mixed-phase cloud processes4, the simulation of clouds using numerical models is difficult at present. Our observations will help to understand these cloud processes, such as rainfall, hail, and cloud electrification, together with their implications for the climate system.
This is a preview of subscription content, access via your institution
Open Access articles citing this article.
Communications Earth & Environment Open Access 19 August 2021
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Sassen, K. Highly supercooled cirrus cloud water: confirmation and climatic implications. Science 227, 411–413 (1985).
Heymsfield, J. A. & Miloshevich, L. M. Homogeneous ice nucleation and supercooled liquid water in orographic wave clouds. J. Atmos. Sci. 50, 2335–2353 (1993).
Rosenfeld, D. & Lensky, I. M. Spaceborne sensed insights into precipitation formation processes in continental and maritime clouds. Bull. Am. Meteorol. Soc. 79, 2457–2476 (1998).
Pruppacher, H. R. & Klett, J. D. Microphysics of Clouds and Precipitation 2nd edn (Kluwer Academic, Norwell, Massachusetts, 1997).
Jeffery, C. A. & Austin, P. H. Homogeneous nucleation of supercooled water: results from a new equation of state. J. Geophys. Res. 102, 25269–25279 (1997).
Pruppacher, H. R. A new look at homogeneous ice nucleation in supercooled water drops. J. Atmos. Sci. 52, 1924–1933 (1995).
Heymsfield, J. A. & Miloshevich, L. M. Evaluation of liquid water measuring instruments in cold clouds, sampled during FIRE. J. Atmos. Ocean. Technol. 6, 378–388 (1989).
Sassen, K. in Nucleation and Atmospheric Aerosols (eds Fukuta, N. & Wagner, P. E.) 287–290 (Deepak, Hampton, Virginia, 1992).
Houghton, H. G. Physical Meteorology (MIT Press, Cambridge, Massachusetts, 1985).
Sukarnjanaset, W., Sudhikoses, P., Tantipubthong, N., Woodley, W.L. & Rosenfeld, D. Cloud water, rainwater, temperature and draft relationships in Thai supercooled convective clouds. Preprint, Conf. on Cloud Physics/14th Conf. on Planned and Inadvertent Weather Modification J24–J27 (American Meteorological Society, Boston, Massachusetts, 1998).
Williams, E. R., Zhang, R. & Rydock, J. Mixed-phase microphysics and cloud electrification. J. Atmos. Sci. 48, 2195–2203 (1991).
Petersen, W. A. & Rutledge, S. A. On the relationship between cloud-to-ground lightning and convective rainfall. J. Geophys. Res. D 103, 14025–14040 (1996).
We thank P. Sweeney, of Weather Modification, Inc., for providing the WMI Lear jet at no charge; we also thank R. Tilbury and S. Gordon for piloting the aircraft through the vigorous Texas clouds, and K. Bosch for technical support.
About this article
Cite this article
Rosenfeld, D., Woodley, W. Deep convective clouds with sustained supercooled liquid water down to -37.5 °C. Nature 405, 440–442 (2000). https://doi.org/10.1038/35013030
This article is cited by
Natural Hazards (2023)
Identifying Supercooled Liquid Water in Cloud Based on Airborne Observations: Correlation of Cloud Particle Number Concentration with Icing Probability and Proportion of Spherical Particles
Journal of Meteorological Research (2022)
Intraseasonal variability and possible causes of large-scale and convective precipitations over the Gangetic plain of India
Theoretical and Applied Climatology (2022)