Recent unprecedented skewness towards positive Indian Ocean Dipole occurrences and its impact on Australian rainfall
Recent unprecedented skewness towards positive Indian Ocean Dipole occurrences and its impact on Australian rainfall
复制标题
DOI：
10.1029/2009gl037604
复制
发表时间：
2009-06-06
影响因子：
5.2
通讯作者：
Sullivan, A.
中科院分区：
文献类型：
--
作者：
Cai, W.;Cowan, T.;Sullivan, A.
最近印度洋偶极子（pIOD）事件的高频率是全球变暖的结果吗？利用现有的观测和再分析，我们表明，pIOD发生增加约4每30年在20世纪世纪初到约10在过去的30年中，相比之下，负印度洋偶极子（nIOD）事件的数量从约10减少到两个在同一时期，分别。偏度测量，定义为pIODs和nIODs发生的差异，说明了该参数在世纪早期开始的系统趋势。1950年后，有更多的pIODs比nIODs，一致的平均环流变化的pIOD流行的季节。在澳大利亚东南部（SEA），这些变化可能占自1950年以来观察到的南半球冬季和春季降雨量减少的大部分。这些特征与预测的未来气候变化相一致，因此也与全球变暖的预期相一致。引文：Cai，W.，T.科万和A. Sullivan（2009），Recent unprecedented skewness towards positive Indian Ocean Dipole occurrences and its impact on Australian rainfall，Geophys.保留信函：36，L11705，doi：10.1029/2009GL037604。
Is the recent high frequency of positive Indian Ocean Dipole (pIOD) events a consequence of global warming? Using available observations and reanalyses, we show that the pIOD occurrences increase from about four per 30 years early in the 20th century to about 10 over the last 30 years; by contrast, the number of negative Indian Ocean Dipole (nIOD) events decreases from about 10 to two over the same periods, respectively. A skewness measure, defined as the difference in occurrences of pIODs and nIODs, illustrates a systematic trend in this parameter commencing early in the 20th century. After 1950, there are more pIODs than nIODs, with consistent mean circulation changes in the pIOD-prevalent seasons. Over southeastern Australia (SEA), these changes potentially account for much of the observed austral winter and spring rainfall reduction since 1950. These features are consistent with projected future climate change and hence with what is expected from global warming. Citation: Cai, W., T. Cowan, and A. Sullivan (2009), Recent unprecedented skewness towards positive Indian Ocean Dipole occurrences and its impact on Australian rainfall, Geophys. Res. Lett., 36, L11705, doi: 10.1029/2009GL037604.