Do all raindrops fall at terminal speed?
Article first published online: 13 JUN 2009
Copyright 2009 by the American Geophysical Union.
Geophysical Research Letters
Volume 36, Issue 11, June 2009
How to Cite
2009), Do all raindrops fall at terminal speed? Geophys. Res. Lett., 36, L11818, doi:10.1029/2008GL037111., , , and (
- Issue published online: 13 JUN 2009
- Article first published online: 13 JUN 2009
- Manuscript Accepted: 11 MAY 2009
- Manuscript Revised: 18 APR 2009
- Manuscript Received: 22 DEC 2008
- raindrops fall speeds;
- warm rain processes
 A unique relation between raindrop size and fall speed vt(D) is assumed throughout atmospheric science. Yet, our speed versus size measurements of millions of drops during natural rainfall events show that many intermediate sized raindrops fall up to an order of magnitude faster than expected. Furthermore, images of drop clusters reveal that these “super-terminal drops” are differently sized fragments of a recent break-up, moving with the speed of the parent drop and relaxing towards vt(D). Additional evidence of the break-up conjecture includes: (i) positive skewness in the distribution of fall speed deviations, (ii) strong size dependence of fall speed deviations and their maximum values and, (iii) preponderance of super-terminal drops in the presence of large raindrops (i.e., during periods of high rainfall rates).