Topological correlations in Bénard-Marangoni convective structures

Cerisier, P.; Rahal, Samir; Rivier, N.

doi:10.1103/physreve.54.5086

Cited by 45 publications

(43 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Only the variance of the neighbor number distribution σ 2 tends to be slightly larger for the open-cell case. The Sc network parameters are, however, distinctly different from Voronoi networks derived from randomly placed points, as well as being different from observational results for solar granulation (26) and experimental Bénard-Marangoni convection (27). This indicates that Sc convection is shaped neither by randomness nor by rules generic to natural convection.…”

Section: Resultscontrasting

confidence: 61%

“…Nonhexagonal cells are arranged such that larger cells are surrounded by smaller ones. Although qualitatively in agreement, the parameter values for Sc do not seem universal to natural convection, as they differ from those of Bénard-Marangoni convection (27) and solar granulation (26). Future studies based on heuristic network models could reveal the system specifics behind these differences.…”

Section: Discussionmentioning

confidence: 74%

See 1 more Smart Citation

Network approach to patterns in stratocumulus clouds

Glassmeier

Feingold

2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Stratocumulus clouds (Sc) have a significant impact on the amount of sunlight reflected back to space, with important implications for Earth's climate. Representing Sc and their radiative impact is one of the largest challenges for global climate models. Sc fields self-organize into cellular patterns and thus lend themselves to analysis and quantification in terms of natural cellular networks. Based on large-eddy simulations of Sc fields, we present a first analysis of the geometric structure and self-organization of Sc patterns from this network perspective. Our network analysis shows that the Sc pattern is scale-invariant as a consequence of entropy maximization that is known as Lewis's Law (scaling parameter: 0.16) and is largely independent of the Sc regime (cloud-free vs. cloudy cell centers). Cells are, on average, hexagonal with a neighbor number variance of about 2, and larger cells tend to be surrounded by smaller cells, as described by an AboavWeaire parameter of 0.9. The network structure is neither completely random nor characteristic of natural convection. Instead, it emerges from Sc-specific versions of cell division and cell merging that are shaped by cell expansion. This is shown with a heuristic model of network dynamics that incorporates our physical understanding of cloud processes.louds reflect incoming sunlight back to space and thus play an important role in modulating energy flows in the climate system. The description of shallow clouds in current global circulation models remains a challenge, however (1-3); due to computational constraints, the small scales of cloud processes cannot explicitly be resolved, and their subgrid-scale variability needs to be diagnosed (parameterized) from grid-scale mean quantities. The representation of stratocumulus (Sc) clouds, in particular, is one of the largest uncertainties for future climate projections (4, 5).Sc clouds cover extensive parts of the subtropical oceans with an intricate tapestry of shape and structure. Satellite images reveal hexagonal cells that are reminiscent of patterns arising from Rayleigh-Bénard convection (6). Indeed, Sc fields can be considered a form of Rayleigh-Bénard convection in moist atmospheric air (7); atmospheric flow is driven by a temperature difference over the depth of the planetary boundary layer, and adiabatic cooling in upwelling regions leads to condensation and cloud formation (Fig. 1). In the absence of rain, Sc fields are arranged as approximately stationary cloudy cells separated by cloud-free rings of downwelling air (closed cells, Fig. 1A) (8). The formation of rain means that cloudy updraft regions develop into regions of negatively buoyant air (cold pools) as a result of sedimentation and evaporation of rain (Fig. 1B), (9-11). Cold pools correspond to horizontally divergent flow at the surface and are bounded by convergent rings of upwelling air that are caused by the impingement of neighboring cold pools. Cold pools thus form cloud-free cells surrounded by cloudy rings and organize into patterns of open...

show abstract

Section: Resultscontrasting

confidence: 61%

Section: Discussionmentioning

confidence: 74%

Network approach to patterns in stratocumulus clouds

Glassmeier

Feingold

2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The parameter a versus parameter σ from the literature[2,4,7,[15][16][17][18][19][20][21][22][23][24][25][26].…”

unclassified

On the Aboav–Weaire law

Vincze

Zsoldos

Szász

2004

Journal of Geometry and Physics

View full text Add to dashboard Cite

“…For estimating gradT, a temperature measurement of the liquid was performed using an infrared thermometer (Model PT-3S, Optex, Japan), an effective device for the estimation. 11 The gradient of the temperature (gradT) was then roughly calculated to be 2 × 10 3 K m -1 . The thermal Marangoni number, 8 MT = -∂σ/∂T gradTd 2 (ρκν) -1 , was then calculated to be MT = 2400.…”

Section: Resultsmentioning

confidence: 99%