Atmospheric circulation variability in the North-Atlantic-European area since the mid-seventeenth century
Atmospheric circulation variability in the North-Atlantic-European area since the mid-seventeenth century
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十七世纪中叶以来北大西洋-欧洲地区的大气环流变化
DOI：
10.1007/s00382-002-0293-1
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发表时间：
2003
期刊：
影响因子：
4.6
通讯作者：
K. Sturm
中科院分区：
文献类型：
--
作者：
J. Jacobeit;H. Wanner;J. Luterbacher;C. Beck;A. Philipp;K. Sturm
基于Luterbacher等人客观重建的月平均海平面气压网格。用新指数描述了1659~1999年31年间1、7月份大气环流动力模式的变化。这些指数反映了大气环流的持续演变，不仅反映了主要动力模式的频率变化，而且反映了每一模式内部关于动力(涡度、强度)和气候性质(分别是每一模式发生期间的中欧温度和降水)的内部变化。结果表明模式内变化的重要性：1月的纬向环流模式在1800-1930年间从小冰期向现代条件过渡期间，主要改变了其动力和气候特征(朝向更高的指数)，其频率随长周期变化。在一月份的俄罗斯高压模式中，中欧上空从东风到西风的偏爱模式在1850年左右发生了变化。对于7月份，18世纪末西风模式的显著频率最大值与中欧夏季显著暖期相吻合，这是由于该模式发生期间涡度/温度的负/正偏差。7月份的长期演变表明，在过去50年中，反气旋条件普遍增加，朝着过去几个世纪内的一种独特现象加强。然而，考虑到冬季西风环流的低频变化，近几十年来冬季西风环流的强劲增加并不是什么特别的现象。
Based on monthly mean sea level pressure grids objectively reconstructed by Luterbacher et al. variations of dynamical modes of the atmospheric circulation for January and July are described by novel indices for running 31-year periods between 1659 and 1999. These indices reflect the continuous evolution of the atmospheric circulation not only with regard to frequency changes of major dynamical modes but also in terms of internal changes within each mode concerning both dynamic (vorticity, intensity) and climatic properties (Central European temperature and precipitation during occurrence of each mode, respectively). Results indicate the great importance of within-mode variations: the zonal circulation mode in January, varying in frequency with long-term cycles, primarily changed its dynamic and climatic properties (towards higher indices) during the transition from the Little Ice Age to modern conditions between 1800 and 1930. Within the Russian High mode of January a change in preference from easterly to westerly patterns above Central Europe occurred around 1850. For July, a striking frequency maximum of the westerly mode at the end of the eighteenth century coincided with a period of marked summer warmth in Central Europe due to negative/positive deviations in vorticity/temperature during occurrence of this mode. The long-term evolution in July indicates a general increase of anticyclonic conditions strengthening during the last 50 years towards a unique phenomenon within the last centuries. The strong increase in the winter-time westerly circulation during the last decades, however, does not appear extraordinary in view of the low-frequency variations of this mode.