Non-stationary and non-linear influence of ENSO and Indian Ocean Dipole on the variability of Indian monsoon rainfall and extreme rain events
Non-stationary and non-linear influence of ENSO and Indian Ocean Dipole on the variability of Indian monsoon rainfall and extreme rain events
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DOI：
10.1007/s00382-014-2288-0
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发表时间：
2015-07-01
期刊：
影响因子：
4.6
通讯作者：
Badiger, Shrinivas
中科院分区：
文献类型：
--
作者：
Krishnaswamy, Jagdish;Vaidyanathan, Srinivas;Badiger, Shrinivas
厄尔尼诺南方涛动（ENSO）和印度洋偶极子（IOD）被广泛认为是印度季风（IM）和极端降雨事件（ERE）年际变化的主要驱动因素。我们使用动态线性回归和广义加性模型评估这些联系的时变强度和非线性。我们的结果表明，IOD 的演变独立于 ENSO，近几十年来，与 ENSO 相比，IOD 对 IM 和 ERE 的影响有所增强，而 ENSO 与 IM 的关系似乎正在减弱且更加不确定。目前，IOD 单位的变化对 IM 的影响相对较大。 ENSO 仅对低于 100 毫米日 (-1) 阈值的 ERE 产生积极影响。此外，IOD 和 IM 总量与 ERE 频率（> 100 mm day(-1)）之间存在非线性正相关关系。对这一复杂系统建模的改进可以提高 IM 和 ERE 的预测准确性。
The El Nino Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are widely recognized as major drivers of inter-annual variability of the Indian monsoon (IM) and extreme rainfall events (EREs). We assess the time-varying strength and non-linearity of these linkages using dynamic linear regression and Generalized Additive Models. Our results suggest that IOD has evolved independently of ENSO, with its influence on IM and EREs strengthening in recent decades when compared to ENSO, whose relationship with IM seems to be weakening and more uncertain. A unit change in IOD currently has a proportionately greater impact on IM. ENSO positively influences EREs only below a threshold of 100 mm day(-1). Furthermore, there is a non-linear and positive relationship between IOD and IM totals and the frequency of EREs (> 100 mm day(-1)). Improvements in modeling this complex system can enhance the forecasting accuracy of the IM and EREs.