Predicting the Interannual Variability of California's Total Annual Precipitation
Predicting the Interannual Variability of California's Total Annual Precipitation
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DOI：
10.1029/2020gl091465
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发表时间：
2021-04-16
影响因子：
5.2
通讯作者：
Schneider, Tapio
中科院分区：
文献类型：
--
作者：
Cheng, Rui;Novak, Lenka;Schneider, Tapio
了解和预测季节性和较长时间尺度的降水特征可以帮助加州为长期干旱和极端降水做好准备。我们发现，年际变化的总降水量在整个加州主要是由降水频率。如前所述，总降水量，降水频率与北太平洋急流的位置。这表明，加州降水频率主要是由喷流引导降水天气系统，而不是如何潮湿或充满活力的系统。反过来，急流的位置取决于厄尔尼诺-南方涛动（ENSO）和太平洋十年涛动（PDO）的状态。我们用它来构建一个回归模型，预测加州的年总降水量和降水频率的变化。在南加州冬季降水方差的20%是可预测的，在前一个夏天使用去相关ENSO和PDO指数。
Understanding and predicting precipitation characteristics on seasonal and longer timescales can help California prepare for long-term droughts and precipitation extremes. We find that interannual variations in total precipitation across California are primarily determined by precipitation frequency. As was shown previously for total precipitation, the precipitation frequency is linked to the North Pacific jet stream location. This indicates that California precipitation frequency is primarily controlled by where the jet guides precipitate weather systems rather than how moist or energetic the systems are. The jet's position, in turn, depends on the states of the El Nino-Southern Oscillation (ENSO) and of the Pacific Decadal Oscillation (PDO). We use this to construct a regression model that predicts variations in California's annual total precipitation and precipitation frequency. Up to 20% of the wintertime precipitation variance in Southern California is predictable using decorrelated ENSO and PDO indices in the previous summer.