• Physics 15, s153
Some icicles develop floor ripples as they develop. Researchers now clarify the expansion mechanism, however a full rationalization stays elusive.
Icicles might sound an unlikely supply of sustained inspiration, however they’ve occupied Stephen Morris on and off for greater than a decade (see Synopsis: Freeze Body). One characteristic that has eluded description is the horizontal floor ripples that generally develop as an icicle grows. Morris and his colleague John Ladan, each on the College of Toronto, have now recognized the mechanism by which such ripples kind on lab-grown icicles . Morris notes, nevertheless, that the reason for the underlying instability stays unknown.
In earlier experiments, Morris and colleagues found two vital clues about icicle ripples: they solely develop when an icicle types from water that accommodates impurities, and their formation requires that water flows down the icicle’s floor in discrete rivulets reasonably than as a steady layer of fluid.
Within the newest experiment, Morris and Ladan grew icicles utilizing water with numerous impurity concentrations. They then melted every icicle from two instructions to show an axial cross part of the icicle’s core. This sectioning revealed that rippled icicles comprise a collection of chevron-like inside constructions that connect with the ripples on the floor. These chevrons are every composed of a collection of crescent-shaped inclusions of liquid water through which the dissolved impurity is concentrated.
The duo thinks that these chevrons document the method by which flowing water accumulates on the higher surfaces of ripples earlier than freezing. Morris hopes that their end result will encourage experiments and modeling by different teams, which could uncover why the ripples kind within the first place and what determines their wavelength.
Marric Stephens is a Corresponding Editor for Physics Journal primarily based in Bristol, UK.
- J. Ladan and S. W. Morris, “Sample of inclusions inside rippled icicles,” Phys. Rev. E 106, 054211 (2022).