Author's Personal Copy Dynamics of Atmospheres and Oceans Impact of Interactive Westerly Wind Bursts on Ccsm3 Author's Personal Copy
Author's Personal Copy Dynamics of Atmospheres and Oceans Impact of Interactive Westerly Wind Bursts on Ccsm3 Author's Personal Copy
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通讯作者：
H. Lopez;B. Kirtman;E. Tziperman;G. Gebbie;H. Lopez
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作者：
H. Lopez;B. Kirtman;E. Tziperman;G. Gebbie;H. Lopez
在大多数情况下，作者被允许将他们的文章版本（例如Word或Tex格式）发布到他们的个人网站或机构存储库。我们鼓励需要更多关于爱思唯尔存档和稿件政策信息的作者访问：西风爆发或事件（WWBs或wes）通常被视为随机过程，独立于任何海洋强迫。最近的一些工作和观测表明，这些事件可以被视为状态相关噪声，因为它们受到海温变率的调制。这可能会影响厄尔Niño南方涛动（ENSO）的可预测性。在本研究中，我们研究了参数化wbs对社区气候系统模式3.0和4.0 （CCSM3和CCSM4）中ENSO变率的影响。wbs的参数化是基于50年的大气再分析资料和热带太平洋海温的观测估计得出的。为了研究wbs的影响，进行了三个实验。在第一个实验中，模型被集成了几百年，没有规定的水涨船高事件（即控制）。在第二种情况下，引入了与状态无关的wwb事件。换句话说，wbs的发生、位置、持续时间和规模是随机确定的（在一定范围内）。这些风事件总是正的（东的），没有西的对应，完全独立于状态变量的异常，可以被认为是加性噪声。对于第三种情况，wbs被引入，但作为乘法噪声或状态相关强迫，由海温异常调制。Niño 3.4指数的统计矩表明，与控制和不依赖状态的运行相比，依赖状态的运行产生了更大的El Niño南方涛动（ENSO）事件，并且对强冷事件的偏倚减少了。控制和状态无关的WWB模拟之间的差异非常小，这表明爆发的确定性成分负责重塑ENSO事件。海洋变量与Niño 3.4指数的滞后相关表明ENSO事件具有较大的时间相干性。这与SSTA复合材料一起，也表明随着实验从控制到依赖状态的WWBs的进展，向更自我维持的机制转变。总体而言，参数化的wbs有能力改变CGCM中的ENSO状态，证明了年际时间尺度上次季节变率的重要性。WWB的快速变化（随机）分量为…
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t Westerly wind bursts or events (WWBs or WWEs) are commonly viewed as stochastic processes, independent of any oceanic forcing. Some recent work and observations have suggested that these events can be viewed as state-dependent noise in that they are modulated by the SST variability. This potentially affects the predictability of the El Niño Southern Oscillation (ENSO). In this study, we examine the impact of parameterized WWBs on ENSO variability in the Community Climate System Model version 3.0 and 4.0 (CCSM3 and CCSM4). The WWBs parameterization is derived based on 50 years of atmospheric reanalysis data and observed estimates of tropical Pacific SST. To study the impact of WWBs three experiments are performed. In the first experiment, the model is integrated for several hundred years with no prescribed WWBs events (i.e. the control). In the second case, state-independent WWBs events are introduced. In other words, the occurrence, location , duration, and scale of the WWBs are determined (within bounds) randomly. These wind events are always positive (eastward) without a westward counterpart and are totally independent of the anomalies in the state variables, and can be thought of as additive noise. For the third case, the WWBs are introduced but as multiplicative noise or state-dependent forcing, modulated by SST anomalies. The statistical moments for the Niño 3.4 index shows that the state-dependent case produced larger El Niño Southern Oscillation (ENSO) events and the bias toward stronger cold events is reduced as compared to the control and the state-independent runs. There is very little difference between the control and the state-independent WWB simulations suggesting that the deterministic component of the burst is responsible for reshaping the ENSO events. Lag-lead correlation of ocean variables with Niño 3.4 index suggests larger temporal coherence of the ENSO events. This, along with SSTA composites, also suggest a shift toward a more self sustained mechanism as the experiments progress from the control to the state dependent WWBs. Overall, the parameterized WWBs have the capability to modify the ENSO regime in the CGCM, demonstrating the importance of sub-seasonal variability on interannual time scales. The fast varying (stochastic) component of WWB is …