Advection, moistening, and shallow‐to‐deep convection transitions during the initiation and propagation of Madden‐Julian Oscillation
Advection, moistening, and shallow‐to‐deep convection transitions during the initiation and propagation of Madden‐Julian Oscillation
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马登-朱利安振荡发起和传播过程中的平流、湿润以及浅层到深部的对流转变
DOI：
10.1002/2014ms000335
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发表时间：
2014
影响因子：
6.8
通讯作者：
C. Long
中科院分区：
文献类型：
--
作者：
S. Hagos;Zhe Feng;K. Landu;C. Long
利用2011年Amie/Dynamo印度洋上的观测资料和一个高分辨率的区域模式模拟，研究了与Madden-Julian振荡(MJO)的启动和向东传播有关的导致快速浅到深对流转换的过程。通过跟踪数千个单独模式模拟降水特征的深度演变，在大尺度和对流尺度上量化了在探测到深对流之前观测到的对流层中层水汽积累的作用和控制过程。浅-深对流转换的频率对这种中层水汽和大范围的抬升很敏感。这种抬升伴随着赤道平流引起的大范围干燥的减弱，导致了水汽的积聚，导致了MJO的发生。对流尺度的水汽变率和抬升、大尺度纬向平流起次要作用。
Using observations from the 2011 AMIE/DYNAMO field campaign over the Indian Ocean and a high‐resolution regional model simulation, the processes that lead to the rapid shallow‐to‐deep convection transitions associated with the initiation and eastward propagation of the Madden‐Julian Oscillation (MJO) are examined. By tracking the evolution of the depth of several thousand individual model simulated precipitation features, the role of and the processes that control the observed midtropospheric moisture buildup ahead of the detection of deep convection are quantified at large and convection scales. The frequency of shallow‐to‐deep convection transitions is found to be sensitive to this midlevel moisture and large‐scale uplift. This uplift along with the decline of large‐scale drying by equator‐ward advection causes the moisture buildup leading to the initiation of the MJO. Convection scale moisture variability and uplift, and large‐scale zonal advection play secondary roles.