The influence of the Interdecadal Pacific Oscillation on Temperature and Precipitation over the Globe
The influence of the Interdecadal Pacific Oscillation on Temperature and Precipitation over the Globe
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DOI：
10.1007/s00382-015-2500-x
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发表时间：
2015-11-01
期刊：
影响因子：
4.6
通讯作者：
Dai, Aiguo
中科院分区：
文献类型：
--
作者：
Dong, Bo;Dai, Aiguo
年代际太平洋涛动（IPO）是一种40-60年的准振荡，主要出现在太平洋盆地，但它对澳大利亚、美国西南部等地区的地面温度（T）和降水（P）的影响也已被发现。在这里，全球分析IPO的影响T和P和调制ENSO的影响T和P在地球仪使用观测和再分析数据和模式模拟。自1920年以来，有两个暖（1924-1944和1977-1998）和两个冷（1945-1976和1999至今）的IPO阶段，其变化与北太平洋海平面气压（SLP）的突变、东太平洋和西太平洋T、P和大气环流的对比异常型有关。IPO解释了许多地区（如澳大利亚东北部、加拿大西部和印度北方）T和P的年代际变化的一半以上。在澳大利亚东部，非洲南部和美国西南部的IPO和当地P之间的显着相关性观察到的IPO也调制ENSO的影响，当地的T和P在大多数这些地区。印度北方上空的T与Nio3.4 ENSO指数在冷IPO阶段呈正相关，但在暖IPO阶段相关性变为负或不显著。在澳大利亚东北部，T与ENSO和P与ENSO的相关性在IPO冷阶段比在温暖阶段更强。在南部非洲的P与ENSO的相关性往往是负的，在IPO暖阶段，但变得更弱或不显着在IPO冷阶段。IPO引起的P异常可以用相关的异常环流来解释，其特征在于北太平洋的高SLP中心和反气旋流，以及印度尼西亚和西太平洋地区的负SLP异常和增加的风辐合。这些观察到的影响的IPO对区域T和P一般再现由观测到的海表温度强迫的大气模式。
The Interdecadal Pacific Oscillation (IPO) is a 40-60 year quasi-oscillation seen mostly in the Pacific basin, but its impacts on surface temperature (T) and precipitation (P) have been found over Australia, the Southwest U.S. and other regions. Here, a global analysis of IPO's impacts on T and P and its modulation of ENSO's influence on T and P over the globe is performed using observational and reanalysis data and model simulations. Since 1920, there are two warm (1924-1944 and 1977-1998) and two cold (1945-1976 and 1999-present) IPO phases, whose change is associated with abrupt shifts in North Pacific sea level pressure (SLP) and contrasting anomaly patterns in T and P and atmospheric circulation over the eastern and western Pacific. The IPO explains more than half of the interdecadal variations in T and P over many regions, such as northeastern Australia, western Canada and northern India. Significant correlations between the IPO and local P are observed over eastern Australia, southern Africa and the Southwest U.S. The IPO also modulates ENSO's influence on local T and P over most of these regions. T over northern India is positively correlated with Nio3.4 ENSO index during cold IPO phases but the correlation turns negative or insignificant during IPO warm phases. Over northeastern Australia, the T versus ENSO and P versus ENSO correlations are stronger during the IPO cold phases than during the warm phases. The P versus ENSO correlation over southern Africa tends to be negative during IPO warm phases but becomes weaker or insignificant during IPO cold phases. The IPO-induced P anomalies can be explained by the associated anomaly circulation, which is characterized by a high SLP center and anti-cyclonic flows over the North Pacific, and negative SLP anomalies and increased wind convergence over the Indonesia and western Pacific region during IPO cold phases. These observed influences of the IPO on regional T and P are generally reproduced by an atmospheric model forced by observed sea surface temperatures.