On the impacts of the Indian summer monsoon on ENSO in a coupled GCM
On the impacts of the Indian summer monsoon on ENSO in a coupled GCM
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DOI：
10.1256/qj.02.214
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发表时间：
2003-10
影响因子：
8.9
通讯作者：
R. Wu;B. Kirtman
中科院分区：
文献类型：
--
作者：
R. Wu;B. Kirtman
本文利用两个耦合的大气环流模式模拟研究了印度夏季风(ISM)对厄尔尼诺-南方涛动(ENSO)演变的影响。第一次模拟使用海洋-陆地-大气研究中心的异常耦合模式，第二次模拟采用一种新的耦合策略--交互集合，旨在提高边界强迫的信噪比。将与ENSO相关和不相关的季风变率的影响用NINO3.4区(170°W-120°W，5°S-5°N)的海温(SST)和印度夏季风降水(IMR)的异常组合来区分。研究发现，与ENSO相关的季风变率对暖事件有显著影响。在交互集合模拟中，弱(强)季风增强(减弱)持续的暖事件。季风的影响表现在赤道中西部太平洋表层纬向风应力异常上。在异常耦合模拟中，季风与ENSO的关系很难探测到。持续的冷事件只受到季风变化的微弱影响。与ENSO无关的季风变化也在次年冬季引起赤道中太平洋明显的海温异常。在相互作用集合模式中，弱(强)季风引起明显的暖(冷)海温异常。
This study explores the impacts of the Indian summer monsoon (ISM) on the El Niño–Southern Oscillation (ENSO) evolution by utilizing two coupled general‐circulation model simulations. The first simulation uses the Center for Ocean–Land–Atmosphere Studies anomaly‐coupled model and the second simulation employs a new coupling strategy, interactive ensembles, that is designed to increase the signal‐to‐noise ratio of boundary forcing. The effects of monsoon variability related and unrelated to ENSO are separated through composites in terms of both sea surface temperature (SST) over the Niño‐3.4 area (170°W–120°W,5°S–5°N) and Indian summer monsoon rainfall (IMR) anomalies. It is found that ENSO‐related monsoon variability has significant impacts on warm events. In the interactive‐ensemble simulation, a weak (strong) monsoon enhances (weakens) an ongoing warm event. The monsoon impacts are manifested in the surface zonal wind‐stress anomalies in the western central equatorial Pacific. In the anomaly‐coupled simulation, the monsoon–ENSO relationship is difficult to detect. The ongoing cold events are only weakly affected by monsoon variability. Monsoon variability that is unrelated to ENSO also induces noticeable SST anomalies in the equatorial central Pacific in the following winter. In the interactive‐ensemble model, a weak (strong) monsoon induces noticeable warm (cold) SST anomalies.