Open AccessThe environment of aggregated deep convection
Author(s) -
Tsai WeiMing,
Wu ChienMing
Publication year - 2017
Publication title -
journal of advances in modeling earth systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.03
H-Index - 58
ISSN - 1942-2466
DOI - 10.1002/2017ms000967
Subject(s) - convection , precipitation , wind shear , atmospheric convection , environmental science , deep convection , atmospheric sciences , relative humidity , meteorology , mechanics , geology , wind speed , physics
In this study, the environment of aggregated deep convection is investigated using a vector vorticity equation cloud‐resolving model (VVM). Idealized experiments are performed under various environmental moisture with or without imposed vertical wind shear. Convective aggregation is then evaluated through diagnosing the 3‐D size of an individual cloud from the model output using a six‐connected segmentation method. The aggregated convection is recognized by a distinct mode with larger size in the cloud‐size distribution. The results suggest that aggregated convection tends to develop when column relative humidity (CRH) is larger than 80% (67%) in nonshear (shear) cases. In addition, the degree of aggregation further increases with the increase of CRH. This aggregation process may be caused by an increasing probability of multicellular cloud structure under a moister environment. The results also suggest that there are at least five convective cores of such system. Analyses of precipitation distribution suggest that the most extreme instantaneous grid point precipitation mainly occurs within the largest convective clusters.