Environmental controls on cloud populations in the Madden-Julian Oscillation during AMIE/DYNAMO

 
Poster PDF

Authors

Samson M Hagos — Pacific Northwest National Laboratory
Zhe Feng — Pacific Northwest National Laboratory
Chuck N. Long — NOAA- Earth System Research Laboratory
Kiranmayi Landu — Pacific Northwest National Laboratory
L. Ruby Leung — Pacific Northwest National Laboratory

Category

Modeling

Description

Analysis of radar reflectivity data collected by Spol-Ka-Pol, SMART-R, and the Ka-band ARM zenith radar (KAZR) revealed that cloud populations evolving from isolated shallow clouds, to deep convective cores, to wide convective cores, and finally to broad stratiform regions during the passage of each of the two Madden-Julian Oscillation episodes observed during the AMIE/DYNAMO field campaign. We used cloud-permitting regional model simulations, which correctly capture the salient features of these episodes, to examine the large-scale environmental processes that determine the timing of these transitions. Specifically we tested the “stretched building block hypothesis” on the organization of convection by the large-scale environment and the role of environmental wind shear and cold-pool dynamics.