Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Deep convective clouds with sustained supercooled liquid water down to -37.5 °C


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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Cloud microstructure and composition as a function of temperature.


  1. Sassen, K. Highly supercooled cirrus cloud water: confirmation and climatic implications. Science 227, 411–413 (1985).

    Article  ADS  CAS  Google Scholar 

  2. Heymsfield, J. A. & Miloshevich, L. M. Homogeneous ice nucleation and supercooled liquid water in orographic wave clouds. J. Atmos. Sci. 50, 2335–2353 (1993).

    Article  ADS  Google Scholar 

  3. 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).

    Article  ADS  Google Scholar 

  4. Pruppacher, H. R. & Klett, J. D. Microphysics of Clouds and Precipitation 2nd edn (Kluwer Academic, Norwell, Massachusetts, 1997).

    Google Scholar 

  5. 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).

    Article  ADS  CAS  Google Scholar 

  6. Pruppacher, H. R. A new look at homogeneous ice nucleation in supercooled water drops. J. Atmos. Sci. 52, 1924–1933 (1995).

    Article  ADS  Google Scholar 

  7. 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).

    Article  ADS  Google Scholar 

  8. Sassen, K. in Nucleation and Atmospheric Aerosols (eds Fukuta, N. & Wagner, P. E.) 287–290 (Deepak, Hampton, Virginia, 1992).

    Google Scholar 

  9. Houghton, H. G. Physical Meteorology (MIT Press, Cambridge, Massachusetts, 1985).

    Google Scholar 

  10. 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).

  11. Williams, E. R., Zhang, R. & Rydock, J. Mixed-phase microphysics and cloud electrification. J. Atmos. Sci. 48, 2195–2203 (1991).

    Article  ADS  Google Scholar 

  12. 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).

    Article  ADS  Google Scholar 

Download references


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.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Daniel Rosenfeld.

Rights and permissions

Reprints and Permissions

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).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing