V. Balaji et Jl. Redelsperger, SUB-GRIDSCALE EFFECTS IN MESOSCALE DEEP CONVECTION - INITIATION, ORGANIZATION AND TURBULENCE, Atmospheric research, 40(2-4), 1996, pp. 339-381
Deep convection shows a tendency toward organized long-lived mesoscale
cloud systems. These dynamically self-sustaining systems form an impo
rtant element of atmospheric variability on the mesoscale and down to
dissipative scales. As it is not possible to resolve all scales of mot
ion involved in mesoscale cloud systems, the representation and modell
ing of organized mesoscale deep convection necessarily requires a rupt
ure of the mesoscale spectrum and a separate representation of smaller
scales. It is proposed here that a natural point for this rupture is
the scale of initiation of deep convection, linked to the tropospheric
scale height, O(10 km). Smaller scale motions that must be represente
d as sub-gridscale effects include the effects of turbulent motions; c
ondensation and precipitation at sub-gridscales; the organization of t
he troposphere and planetary boundary layer on the convective scale, I
t will be shown that the initiation and organization of deep convectio
n can be understood in a systematic manner by examining mechanisms by
which convective-scale motions appear through transitions from forced
motions at other scales.