Deceleration of Madden-Julian Oscillation Speed in NICAM AMIP‐Type Simulation Associated With Biases in the Walker Circulation Strength
Deceleration of Madden-Julian Oscillation Speed in NICAM AMIP‐Type Simulation Associated With Biases in the Walker Circulation Strength
复制标题
丽音 AMIP 型模拟中与沃克循环强度偏差相关的 Madden-Julian 振荡速度的减速
DOI：
10.1029/2022gl098628
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发表时间：
2022
影响因子：
5.2
通讯作者：
Daisuke
中科院分区：
文献类型：
--
作者：
Miura;Hiroaki;Kodama;Chihiro;Takasuka;Daisuke
本文分析了全球云解析模式（非流体静力二十面体大气模式）与平板海洋大气模式比对方案30年模拟的Madden-Julian涛动（MJO）事件的东移速度，并与观测结果进行了比较。模拟重现了观测到的MJO在嵌入较强的Walker环流时减速的趋势，在较暖的西太平洋与较冷的印度洋和东太平洋之间具有较大的纬向梯度的背景海表温度状态下，MJO减速的趋势会增强。然而，模拟的MJO事件在El Niño事件期间不成比例地发生，并且显示出缓慢的偏差。这些偏差与对西部沃克环流细胞强度的高估有关，在El Niño事件期间部分抵消了这一点。我们的研究结果强调了准确地再现平均大气环流对于在长期模拟中真实再现MJO的重要性。
The eastward movement speed of Madden–Julian Oscillation (MJO) events simulated in a 30‐year simulation on a global cloud resolving model, nonhydrostatic icosahedral atmospheric model, following the atmospheric model intercomparison project protocol with a slab ocean was analyzed and compared with the observation. The simulation reproduced the observed tendency of the MJO to decelerate when it is embedded within the stronger Walker circulation, intensified by background sea surface temperature states with larger zonal gradients between the warmer western Pacific and the cooler Indian Ocean and eastern Pacific. However, the simulated MJO events occurred disproportionately during El Niño events and displayed a slow bias. These biases were associated with an overestimation of the western Walker circulation cell strength, which was partially counteracted during El Niño events. Our results highlight the importance of accurately reproducing the mean atmospheric circulation for the realistic reproduction of the MJO in long term simulations.