Ds. Decroix et al., CELLULAR CONVECTION EMBEDDED IN THE CONVECTIVE PLANETARY BOUNDARY-LAYER SURFACE-LAYER, Journal of wind engineering and industrial aerodynamics, 67-8, 1997, pp. 387-401
Cellular convection was first studied in the laboratory by Benard [Ann
. Chim. Phys. 23 (1901) 62-144] and Rayleigh [Phil. Mag. Ser. 6 (1916)
529-546] investigated these motions from a theoretical perspective. H
e defined a dimensionless number, now called the Rayleigh number, whic
h is the ratio of convective transport to molecular transport, and fou
nd that if a certain critical value is exceeded, cellular convection o
ccurs. Mesoscale cellular convection (MCC) is a common occurrence in t
he planetary boundary layer. Agee [Dyn. Atmos. Oceans 10 (1987) 317-34
1] discussed the similarities and differences of MCC and classical Ray
leigh-Benard convection. A similar cellular pattern can be seen in the
convective boundary layer (CBL) surface layer. It is known that in th
e CBL, air near the surface converges into thermals producing updrafts
. This produces a 'spoke' type pattern similar to the mesoscale cellul
ar or Rayleigh-Benard convection. This paper will focus on applying Ra
yleigh-Benard convection criteria, using a linearized perturbation met
hod, to the CBL surface layer produced by Large Eddy Simulation (LES).
We will investigate the length scales of turbulence in the CBL surfac
e layer and compare them to those predicted from linear theory. Simila
rities and differences will be discussed between the LES produced surf
ace layer and classical Rayleigh-Benard convection theory.