Multidecadal Drought Cycles in the Great Basin Recorded by the Great Salt Lake: Modulation from a Transition-Phase Teleconnection
Multidecadal Drought Cycles in the Great Basin Recorded by the Great Salt Lake: Modulation from a Transition-Phase Teleconnection
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大盐湖记录的大盆地多年代干旱周期：过渡相遥相关的调制
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
T. Reichler
中科院分区：
文献类型：
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作者：
Shuang Wang;R. Gillies;T. Reichler
研究了大盐湖水位波动所揭示的与干旱年代际周期相关的气象条件。分析结合了仪器，代理和模拟数据集，包括二十世纪世纪再分析第2版，北美干旱地图集，和2000年的GFDL耦合模型，版本2.1（CM2.1）的控制模拟。谱相干分析的统计证据表明，大海盆的干湿循环与年代际太平洋振荡（IPO）的冷暖相之间存在6 ~ 9年的相移，海表温度和大气环流异常的诊断将这种相移归因于在IPO冷暖相之间的转换点上发展的一种独特的遥相关波列。这种遥相关波列形成了以阿拉斯加湾东南部为中心的周期性环流异常;这引导了整个大盆地的水分通量，随后驱动了大盆地和GSL流域的干湿状况。因此，IPO生命周期以四分之一阶段的方式调节当地的干旱-多雨。
This study investigates the meteorological conditions associated with multidecadal drought cycles as revealed by lake level fluctuation of the Great Salt Lake (GSL). The analysis combined instrumental, proxy, and simulation datasets, including the Twentieth Century Reanalysis version 2, the North American Drought Atlas, and a 2000-yr control simulation of the GFDL Coupled Model, version 2.1 (CM2.1). Statistical evidence from the spectral coherence analysis points to a phase shift amounting to 6‐9 yr between the wet‐dry cyclesin theGreatBasinandthewarm–coolphasesoftheinterdecadalPacificoscillation(IPO).Diagnosesof the sea surface temperature and atmospheric circulation anomaliesattribute such a phase shift to a distinctive teleconnectionwavetrainthatdevelopsduringthetransitionpoints betweentheIPO’swarmandcoolphases. This teleconnection wave train forms recurrent circulation anomalies centered over the southeastern Gulf of Alaska; this directs moisture flux across the Great Basin and subsequently drives wet‐dry conditions over the Great Basin and the GSL watershed. The IPO life cycle therefore modulates local droughts‐pluvials in a quarter-phase manner.