TY - JOUR
T1 - Diabatic divergence profiles in western Pacific mesoscale convective systems
AU - Mapes, B. E.
AU - Houze, R. A.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1995
Y1 - 1995
N2 - Heating in the atmosphere can be expressed as diabatic divergence δd, which is nearly equal to the actual horizontal divergence δ in tropical convection. High-quality δ profile measurements from airborne Doppler radar "purls' in ten mesoscale convective systesm (MCS) observed during TOGA-COARE are examined, and the mean profile is compared with rawinsonde array measurements. Young convective features have strong near-surface convergence, while older cells with better-developed downdrafts and stratiform precipitation areas have their peak convergence aloft. In the mean, then, surface flow is only weakly convergent or even divergent, so that the main convergence into MCSs is deep and peaked aloft, with a sharp "melting convergence' at 0°C. Simple linear models of Hadley and Walker circulations forced by observed MCS δd profiles illustrate the importance of the elevated convergence peak to large-scale circulations, particularly to low-level wind fields. -from Authors
AB - Heating in the atmosphere can be expressed as diabatic divergence δd, which is nearly equal to the actual horizontal divergence δ in tropical convection. High-quality δ profile measurements from airborne Doppler radar "purls' in ten mesoscale convective systesm (MCS) observed during TOGA-COARE are examined, and the mean profile is compared with rawinsonde array measurements. Young convective features have strong near-surface convergence, while older cells with better-developed downdrafts and stratiform precipitation areas have their peak convergence aloft. In the mean, then, surface flow is only weakly convergent or even divergent, so that the main convergence into MCSs is deep and peaked aloft, with a sharp "melting convergence' at 0°C. Simple linear models of Hadley and Walker circulations forced by observed MCS δd profiles illustrate the importance of the elevated convergence peak to large-scale circulations, particularly to low-level wind fields. -from Authors
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U2 - 10.1175/1520-0469(1995)052<1807:DDPIWP>2.0.CO;2
DO - 10.1175/1520-0469(1995)052<1807:DDPIWP>2.0.CO;2
M3 - Article
AN - SCOPUS:0029412928
VL - 52
SP - 1807
EP - 1828
JO - Journals of the Atmospheric Sciences
JF - Journals of the Atmospheric Sciences
SN - 0022-4928
IS - 10
ER -