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Connections matter: Updraft merging in organized tropical deep convection
Author(s) -
Glenn I. B.,
Krueger Steven K.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl074162
Subject(s) - deep convection , convection , merge (version control) , entrainment (biomusicology) , meteorology , atmospheric sciences , environmental science , climatology , geology , dropsonde , tropical cyclone , geography , physics , computer science , rhythm , acoustics , information retrieval
Abstract When tropical cumulus convection is organized, the spacing between updrafts is reduced, and deep convective cloud tops are higher. The relative importance of various processes through which organization increases cloud top heights is not well understood. It is likely that decreased spacing between updrafts in organized convection increases the frequency of convective updraft merging. What is the relative importance of merging in determining an updraft parcel's detrainment height? We investigated updraft parcel merging in organized deep convection using results from a large eddy simulation. We used Lagrangian parcel trajectories (LPTs) to locate merging events. LPTs that merge reach detrainment heights 1.5 km higher on average than LPTs which do not merge. Merged LPTs are more buoyant than nonmerged LPTs, implying less dilution due to entrainment. Using mutual information analysis, we found that merging, cloud base vertical velocity, and cloud base area are about equally important in determining parcel detrainment height.