Impacts of Shallow Convection on MJO Simulation: A Moist Static Energy and Moisture Budget Analysis
Impacts of Shallow Convection on MJO Simulation: A Moist Static Energy and Moisture Budget Analysis
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DOI：
10.1175/jcli-d-12-00127.1
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发表时间：
2013-04
影响因子：
4.9
通讯作者：
Qiongqiong Cai;G. Zhang;Tianjun Zhou
中科院分区：
文献类型：
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作者：
Qiongqiong Cai;G. Zhang;Tianjun Zhou
从湿静能(MSE)和水汽收支两个方面考察了浅对流在Madden-Julian振荡(MJO)模拟中的作用。使用NCAR社区大气模式3.0版(CAM3.0)进行了两个试验：“CTL”运行和“NSC”运行与CTL运行相同，只是在20°S到20°N之间700百帕以下的浅对流被禁用。虽然在这两个模拟中都合理地再现了出射长波辐射、850百帕风的平均状态和比湿度的垂直结构的主要特征，但在NSC运行中，水汽和云更多地局限于行星边界层。虽然与再分析数据相比，CTL运行提供了更好的MJO生命周期模拟，但NSC显示的MJO信号要弱得多。再分析资料和模拟结果均表明，MSE演化过程中存在以水汽异常为主的充放电机制。然而，在NSC中，MSE和水分的发展是值得注意的。
AbstractThe role of shallow convection in Madden–Julian oscillation (MJO) simulation is examined in terms of the moist static energy (MSE) and moisture budgets. Two experiments are carried out using the NCAR Community Atmosphere Model, version 3.0 (CAM3.0): a “CTL” run and an “NSC” run that is the same as the CTL except with shallow convection disabled below 700 hPa between 20°S and 20°N. Although the major features in the mean state of outgoing longwave radiation, 850-hPa winds, and vertical structure of specific humidity are reasonably reproduced in both simulations, moisture and clouds are more confined to the planetary boundary layer in the NSC run. While the CTL run gives a better simulation of the MJO life cycle when compared with the reanalysis data, the NSC shows a substantially weaker MJO signal. Both the reanalysis data and simulations show a recharge–discharge mechanism in the MSE evolution that is dominated by the moisture anomalies. However, in the NSC the development of MSE and moisture anom...