Numerical Archetypal Parameterization for Mesoscale Convective Systems

Abstract

Vertical shear commonly organizes atmospheric convection into coherent multiscale structures. The associated countergradient vertical transport of horizontal momentum by organized convection can enhance the wind shear and transport kinetic energy upscale. However, organized convection and its upscale effects are not represented by traditional mass-flux-based parameterizations. The present paper sets the archetypal dynamical models, originally formulated by the second author, into a parameterization context by utilizing a nonhydrostatic anelastic model with segmentally constant approximation (NAM–SCA). Using a two-dimensional framework as a starting point, NAM–SCA spontaneously generates propagating tropical squall lines in a sheared environment. High numerical efficiency is achieved through a novel compression methodology. The numerically generated archetypes produce vertical profiles of convective momentum transport that are consistent with the analytic archetype.

A Mechanism for the Southward Propagation of Mesoscale Convective Systems Over the Bay of Bengal

“…Organized MCSs are not represented in cumulus parameterization (Randall et al, ). Attempts are being made to include all the above mentioned processes in the parameterizations (Yano & Moncrieff, ) for model horizontal resolutions in the gray scale (5 to 30 km).…”

Investigation of Turbulent Entrainment‐Mixing Processes With a New Particle‐Resolved Direct Numerical Simulation Model

“…A long-standing problem in cloud physics is that observed droplet size distributions are generally much broader than those predicted by the classical uniform model (e.g., Howell, 1949;Hudson & Yum, 1997;Yum & Hudson, 2005). Understanding the issue of so-called spectral broadening has been a fundamental focus of cloud physics over the last decades, and a number of ideas have been proposed, including stochastic condensation theory that considers the growth of droplet populations as a stochastic process and relates the spectral broadening to turbulence-related fluctuations (Hsiu-chi, 1964;Khvorostyanov & Curry, 1999;McGraw & Liu, 2006;Sedunov, 1974), systems theory that applies statistical physics ideas to cloud physics (Liu et al, 1995;Liu & Hallett, 1997Liu & Daum, 2002;Yano & Moncrieff, 2016), turbulence-induced preferential concentration of droplets (Shaw et al, 1998), Despite their differences, virtually all the ideas tie the outstanding problems to turbulence-related processes that occur on sub-LES scales (e.g., < 100 m) such as turbulent entrainment-mixing processes and turbulencemicrophysics interactions. There are significant knowledge gaps on such sub-LES scale processes because of the limitations in observations and computer modeling.…”

“…A long‐standing problem in cloud physics is that observed droplet size distributions are generally much broader than those predicted by the classical uniform model (e.g., Howell, ; Hudson & Yum, ; Yum & Hudson, ). Understanding the issue of so‐called spectral broadening has been a fundamental focus of cloud physics over the last decades, and a number of ideas have been proposed, including stochastic condensation theory that considers the growth of droplet populations as a stochastic process and relates the spectral broadening to turbulence‐related fluctuations (Hsiu‐chi, ; Khvorostyanov & Curry, ; McGraw & Liu, ; Sedunov, ), systems theory that applies statistical physics ideas to cloud physics (Liu et al, ; Liu & Hallett, , ; Liu & Daum, ; Yano & Moncrieff, ), turbulence‐induced preferential concentration of droplets (Shaw et al, ), and turbulent entrainment‐mixing processes (Baker et al, ; Hicks et al, ; Lu, Liu, Niu, & Vogelmann, ; Telford & Chai, ; Su et al, ; Warner, ). Another outstanding problem is related to the formation of warm rain (Liu et al, ; McGraw & Liu, ).…”

Novel SnO2(ZnO:Sn)m superlattice nanoparticles for ultra-low ppb-level H2S detection

“…[3][4][5][6][7][8] In the selection of the ZnO-In 2 O 3 system, there exists a group of naturally grown superlattice compounds as In 2 O 3 (ZnO) m , composed of the alternate stacking of InO 2 − octahedral layers and (002) ZnO slabs with near-perfect periodicity. 9 Through first-principle calculations, Yan and co-workers further proposed the general rules for the superlattice formation mechanism for a more broad system of InMO 3 (ZnO) m , where M could be Ga, Fe, Al or other trivalent elements, like Sc, Y, Er, Tm, Yb and Lu, including the octahedron rule for the InO 2 − layers and the existence of an inversion domain boundary. 10 InMO 3 (ZnO) m compounds have been extensively studied in their bulk forms over the past decades, [11][12][13][14][15][16][17][18] which are relatively easy to prepare by co-sintering the designed oxide components.…”