In radiative-convective equilibrium simulations, convective self-aggregation (CSA) is the spontaneous organization into segregated cloudy and cloud-free regions. Evidence exists for how CSA is stabilized, but how it arises favorably on large domains is not settled. Using large-eddy simulations, we link the spatial organization emerging from the interaction of cold pools (CPs) to CSA. We systematically weaken simulated rain evaporation to reduce maximal CP radii, Rmax , and find reducing Rmax causes CSA to occur earlier. We further identify a typical rain cell generation time and a minimum radius, Rmin, around a given rain cell, within which the formation of subsequent rain cells is suppressed. Incorporating Rmin and Rmax , we propose a toy model that captures how CSA arises earlier on large domains: when two CPs of radii ri, rj ∈ [Rmin, Rmax] collide, they form a new convective event. These findings imply that interactions between CPs may explain the initial stages of CSA
Nissen S.B. and Haerter J.O. (2021) Circling in on Convective Self‐Aggregation. Journal of Geophysical Research Atmospheres 126(20): e2021JD035331. 10.1029/2021JD035331
@article{Nissen2021,
Title = {Circling in on Convective Self‐Aggregation},
Author = {Nissen, Silas Boye and Haerter, Jan O.},
Editor = {},
Journal = {Journal of Geophysical Research Atmospheres},
Year = {2021},
Pages = {e2021JD035331},
Volume = {126},
Doi = {10.1029/2021JD035331},
Abstract = {In radiative-convective equilibrium simulations, convective self-aggregation (CSA) is the spontaneous organization into segregated cloudy and cloud-free regions. Evidence exists for how CSA is stabilized, but how it arises favorably on large domains is not settled. Using large-eddy simulations, we link the spatial organization emerging from the interaction of cold pools (CPs) to CSA. We systematically weaken simulated rain evaporation to reduce maximal CP radii, Rmax , and find reducing Rmax causes CSA to occur earlier. We further identify a typical rain cell generation time and a minimum radius, Rmin, around a given rain cell, within which the formation of subsequent rain cells is suppressed. Incorporating Rmin and Rmax , we propose a toy model that captures how CSA arises earlier on large domains: when two CPs of radii ri, rj ∈ [Rmin, Rmax] collide, they form a new convective event. These findings imply that interactions between CPs may explain the initial stages of CSA},
}
TY - JOUR
AU - Nissen, Silas Boye
AU - Haerter, Jan O.
TI - Circling in on Convective Self‐Aggregation
T2 - Journal of Geophysical Research Atmospheres
PY - 2021
SP - e2021JD035331
VL - 126
DO - 10.1029/2021JD035331
AB - In radiative-convective equilibrium simulations, convective self-aggregation (CSA) is the spontaneous organization into segregated cloudy and cloud-free regions. Evidence exists for how CSA is stabilized, but how it arises favorably on large domains is not settled. Using large-eddy simulations, we link the spatial organization emerging from the interaction of cold pools (CPs) to CSA. We systematically weaken simulated rain evaporation to reduce maximal CP radii, Rmax , and find reducing Rmax causes CSA to occur earlier. We further identify a typical rain cell generation time and a minimum radius, Rmin, around a given rain cell, within which the formation of subsequent rain cells is suppressed. Incorporating Rmin and Rmax , we propose a toy model that captures how CSA arises earlier on large domains: when two CPs of radii ri, rj ∈ [Rmin, Rmax] collide, they form a new convective event. These findings imply that interactions between CPs may explain the initial stages of CSA
ER -
