The sea surface temperature anomalies （SSTAs） associated with the Victoria mode （VM） can persist into the following season and then influence climate variability in the tropical Pacific. This paper demonstrates th...The sea surface temperature anomalies （SSTAs） associated with the Victoria mode （VM） can persist into the following season and then influence climate variability in the tropical Pacific. This paper demonstrates the connection between the preceding boreal winter VM and precipitation in the following spring over the southeastern United States （SE USA） and the Gulf of Mexico （GM）. The results indicate that a positive （negative） preceding winter VM is usually followed by increased （reduced） precipitation over the SE USA and GM during the following spring. The corresponding mechanism is similar, but slightly different to, the seasonal footprinting mechanism. For positive VM cases, the preceding-winter VM-related SSTAs appear to persist into the following spring via air- sea interactions, which then induce low-level convergence and vigorous ascending motion, leading to an adjustment of the zonal and meridional circulation. This adjustment can then influence the local Hadley cell by weakening the downward branch. These anomalous patterns of vertical airflow enhance spring precipitation over the SE USA and GM under suitable moisture conditions. Hence, this work demonstrates that the preceding-winter VM has the potential to regulate precipitation over the SE USA and GM in the following spring.展开更多
基金the China Special Fund for Meteorological Research in the Public Interest[grant number GYHY201506013]the National Basic Research Program of China[973 Program,grant number 2012CB955200]+2 种基金the National Natural Science Foundation of China for Excellent Young Scholars[grant number 41522502]the National Natural Science Foundation of China[grant number 41475037]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA11010303]
文摘The sea surface temperature anomalies （SSTAs） associated with the Victoria mode （VM） can persist into the following season and then influence climate variability in the tropical Pacific. This paper demonstrates the connection between the preceding boreal winter VM and precipitation in the following spring over the southeastern United States （SE USA） and the Gulf of Mexico （GM）. The results indicate that a positive （negative） preceding winter VM is usually followed by increased （reduced） precipitation over the SE USA and GM during the following spring. The corresponding mechanism is similar, but slightly different to, the seasonal footprinting mechanism. For positive VM cases, the preceding-winter VM-related SSTAs appear to persist into the following spring via air- sea interactions, which then induce low-level convergence and vigorous ascending motion, leading to an adjustment of the zonal and meridional circulation. This adjustment can then influence the local Hadley cell by weakening the downward branch. These anomalous patterns of vertical airflow enhance spring precipitation over the SE USA and GM under suitable moisture conditions. Hence, this work demonstrates that the preceding-winter VM has the potential to regulate precipitation over the SE USA and GM in the following spring.
