Related Experiment Video
Updated: Jun 8, 2026
06:25
Using Computer Vision Libraries to Streamline Nuclei Quantification
Published on: June 6, 2025
Subsuns, Bottlinger's rings, and elliptical halos
Applied Optics
|October 12, 2010
Summary
Simulations using a Monte Carlo model explain subsuns, Bottlinger
Area of Science:
- Atmospheric optics
- Cloud physics
Background:
- Subsuns, Bottlinger's rings, and elliptical halos are rare atmospheric optical phenomena.
- These phenomena are associated with sunlight reflection from ice crystals in clouds.
- Previous explanations lacked comprehensive simulation and crystal habit considerations.
Purpose of the Study:
- To simulate subsuns, Bottlinger's rings, and elliptical halos using a Monte Carlo model.
- To investigate the role of ice crystal shape and orientation in producing these phenomena.
- To compare simulation results with observational data and meteorological conditions.
Main Methods:
- Monte Carlo ray-tracing simulations of sunlight reflection from ice crystals.
- Modeling of various ice crystal habits (plates, dendrites) and orientations (horizontal, gyrating).
- Comparison of simulated halo intensity and shape with photographic density scans.
Main Results:
- Simulations successfully reproduce subsuns, Bottlinger's rings, and elliptical halos.
- Subsuns and Bottlinger's rings are explained by single crystal reflections; elliptical halos require two.
- Crystal eccentricity increases with solar zenith angle; specific crystal habits (swinging/gyrating plates) are favored.
- Hybrid clouds with both horizontal and gyrating crystals may produce the most distinct elliptical halos.
Conclusions:
- The Monte Carlo model provides a robust framework for understanding these halo phenomena.
- Specific ice crystal types and orientations are crucial for the formation of subsuns, Bottlinger's rings, and elliptical halos.
- Meteorological conditions favoring gyrating and horizontal crystals support the observed occurrence of these halos.
Related Concept Videos
01:18Frost Circles for Different Conjugated Systems
The inscribed polygon method is consistent with Hückel’s 4n + 2 rule and helps to learn whether the given cyclic compound is aromatic or not. The compound is stable and aromatic if every bonding molecular orbital (MO) is completely filled with a pair of electrons. However, if the non-bonding or antibonding orbitals are filled with electrons, the compound is unstable and not aromatic. Consider the Frost circle diagrams for cycloalkenes containing 4 to 8 carbons.
01:18Structure of Benzene: Molecular Orbital Model
According to the molecular orbital (MO) model, benzene has a planar structure with a regular hexagon of six sp2 hybridized carbons. As shown in Figure 1, each carbon is bonded to three other atoms with C–C–C and H–C–C bond angles of 120°. The C–H bond length is 109 pm, and the C–C bond length is 139 pm which is midway between the single bond length of sp3 hybridized carbons (154 pm) and sp2 hybridized carbons (133 pm).
01:27Eccentricity of an Ellipse
An ellipse is a fundamental conic section defined by the constant sum of distances from any point on its curve to two fixed points, known as the foci. This geometric property can be physically demonstrated using a pencil, string, and two pins. By anchoring the string at both ends and maintaining it taut with a pencil, one can trace the outline of an ellipse.The shape and extent of the ellipse are determined by its eccentricity, e, defined as the ratio of the distance between the center and a...
01:08Hückel's Rule Diagram of π MOs: Frost Circle
The Frost circle or the inscribed polygon method is a graphical method for determining the relative energies of π molecular orbitals (MOs) for planar, fully conjugated, and monocyclic compounds. This method was first described by A. A. Frost and Boris Musulin in 1953.
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so that...
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so that...
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
01:18π Molecular Orbitals of the Allyl Cation and Anion
An allyl group is a three-carbon conjugated system where the sp³-hybridized allylic carbon is bonded to a CH=CH2 group via a single bond. Allyl anions can be obtained by treating propene with a strong base that can deprotonate methyl groups. Allyl cations are formed as intermediates during substitution reactions involving allylic halides. In both cases, the hybridization of the allylic carbon changes from sp3 to sp2, giving rise to a carbon chain with three sp2-hybridized carbons, each with an...