North Atlantic atmospheric circulation indices: Links with summer and winter temperature and precipitation in north-west Europe, including persistence and variability
North Atlantic atmospheric circulation indices: Links with summer and winter temperature and precipitation in north-west Europe, including persistence and variability
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DOI：
10.1002/joc.8364
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发表时间：
2024-01-17
期刊：
影响因子：
--
通讯作者：
Wei，Hua-Liang
中科院分区：
文献类型：
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作者：
Simpson，Ian;Hanna，Edward;Wei，Hua-Liang
欧洲西北部季节性天气的变化基本上是由急流变化决定的。北大西洋涛动（NAO）已被很好地研究，作为一个关键的代表，这种急流的变化，但其他环流指数也很重要。在这里，500 hPa位势高度（GPH）的前三个主成分经验正交函数（EOFs），大致对应于NAO，东大西洋型（EA）和斯堪的纳维亚型（SCA），以及急流速度和纬度，与欧洲（重点是西北欧）的温度和降水异常以及持续性和变率的测量相关。在盛夏（7月和8月），所有三个主要的EOFs显着相关的极端温度在大面积的北方欧洲。在冬季，欧洲西北部的大部分地区，气温和降水都与急流速度呈正相关，降水与EOF 3呈负相关。在某些关系中存在一些非平稳性，特别是冬季降水与EOF 1之间，以及7月/8月降水与EOF 2之间。除了单变量相关性外，当结合两个或三个环流指数时，还使用多个相关系数来确定显著相关的区域。多重相关分析表明，结合这三个EOFs产生显着的相关性与温度和降水在欧洲大部分地区。这些分析提供了利用季节性预报的范围，以便根据对大气环流异常的预测和缩小尺度来预测可能的温度和降水异常。改进温度和降水的季节性预报，包括持久性和可变性预报，将对农业食品、运输、能源供应和保险等用户有用。
Variability in seasonal weather in north‐west Europe is substantially determined by jet stream variability. The North Atlantic Oscillation (NAO) has been well studied as a key representation of this jet stream variability, but other circulation indices are also important. Here the first three principal component empirical orthogonal functions (EOFs) of 500 hPa geopotential height (GPH), which broadly correspond to the NAO, the East Atlantic pattern (EA) and Scandinavian pattern (SCA), as well as jet speed and latitude, are correlated with temperature and precipitation anomalies over Europe with a focus on north‐west Europe, as well as measures of persistence and variability. In high summer (July and August), all three of the principal EOFs are significantly correlated with extreme temperatures in large areas of northern Europe. In winter, for much of north‐west Europe, both temperatures and precipitation are positively correlated with the jet speed, and precipitation is negatively correlated with EOF3. There is some non‐stationarity in some of the relationships, notably between winter precipitation and EOF1, and between July/August precipitation and EOF2. In addition to single variate correlations, multiple correlation coefficients are also used to determine areas of significant correlation when combining two or three of the circulation indices. The multiple correlation analyses show that combining the three EOFs produces significant correlations with temperature and precipitation over much of Europe. These analyses provide scope for using seasonal forecasts to predict likely temperature and precipitation anomalies based on predicting the atmospheric circulation anomalies and downscaling them. Improved seasonal forecasts of temperature and precipitation, including persistence and variability, will be useful to a number of users, such as agrifood, transport, energy supply and insurance.