Using three cameras and two high powered flash lamps, the HYdrometeor Detection and Ranging using stereO-Photography (HYDROP) experiment, we made the first determination of the sizes and positions of raindrops (diameters >0.2 mm) in a significant volume (approx. 10 m3). Analyzing six three dimensional reconstructions---with 11000--22000 raindrops each and with nominal rain rates in the range of 8--15 mm/hr.---we performed the first direct investigation of the continuum limit of a large number of particles in cloud/rain physics. Since the mean interparticle distance was 7--8 cm and the largest sphere has a radius of the order 2 m, our range of scales is only roughly a factor of 10. Nevertheless, we were able to show clear evidence that a non-trivial multiscaling limit was obtained at least for one rain event out of the two studied; the q th moment of the liquid water density in a radius r was found to scale with a nonlinear (but convex) exponent K(q), characteristic of multifractals. In contrast, when the particle positions were randomized, clear convergence to the classical (homogeneous) continuum was observed with K(q) = 0. By raising the raindrop volumes to a power n = 1/3, in order to improve convergence towards the continuum limit, the universal multifractal parameters of this quantity derived from the field of liquid water content were estimated to be alpha = 1.95 +/- 0.1, C1 = 0.05 +/- 0.01 and H = -0.01 +/- 0.01.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36003 |
| Date | January 1999 |
| Creators | Desaulniers-Soucy, Nicolas. |
| Contributors | Lovejoy, Shaun (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001686941, proquestno: NQ55321, Theses scanned by UMI/ProQuest. |
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