How is turbulence organized in the dry convective atmosphere? A study utilizing large-eddy simulation

Turbulence in unstable atmospheres often self-organize into cellular structures. While many studies have examined their shape, size, flux characteristics, and implications for observations and boundary layer parameterization, the mechanisms driving their formation remain inadequately understood, e.g., why their horizontal dimensions are roughly one boundary layer height? This study aims to address this gap by investigating the dynamics of cellular structures in an idealized dry, surface-homogeneous free convective atmosphere boundary layers, using large eddy simulation for obtaining data. Key content include: (1) modifying subgrid parameters to simulate idealized conditions and investigating their influence on self-organized structures; (2) analyzing velocity and temperature budget within updrafts and downdrafts to identify the factors driving cellular structures and their interrelations; and (3) modeling the process by which downdrafts reach the surface, are heated, and rise as updrafts. Preliminary results suggest that the surface heating process plays a critical role in determining the horizontal shape of cellular structures. This study provides new insights into the fundamental dynamics of turbulent self-organization, potentially contributing to improved parameterizations and understanding of convective boundary layers.