| Using the NCEP/NCAR global daily reanalysis data and the ground observed daily data, by defining the persistent abnormal of the Northern Hemispheric mid-high Latitude atmospheric teleconnections during winter, which are Pacific/North American Pattern(PNA), Eurasian Pattern(EU), West Pacific Pattern(WP), West Atlantic Pattern(WA), and East Atlantic Pattern(EA), to analysis the characteristics of the persistent abnormal processes, the atmospheric circulation and it’s impact to China’s climate at the appropriate time.Results show that negative anomalies of EA and WP happens mainly in first half of winter, while the positive ones concentrated in the second half. The anomalies of WA, PNA, and EU indexes do not occurrence that centrally, but still can be summarized the multiple times for each index anomalies, which could serve as the focus forecast period.During WA index anomalies single characteristic show in the northern hemisphere atmospheric; while after the exception, EU pattern wave train increases. During and after EU, EA indexes separately anomalies, the atmosphere more than one at the same time: When negative anomaly instead. WP index anomalies, the northern hemisphere atmospheric only show the WP type wave train:positive anomaly, its circulation structure can prompt the prevailing easterly airstream in north China, abnormal after the eastern region in the north flow; Negative anomaly of reverse. PNA index significantly abnormal corresponding wind field structure is near the east China sea and the bay of Bengal two cyclonic circulation anomalies, the positive (negative) anomaly (block) cold air southward, but not obvious on the low-level wind field over the same period. The positive/negative anomaly index over the same period and later period, within the scope of our country have negative vapor flux divergence anomaly distribution, but in view of the influence of water vapor transmission, precipitation is conducive to the basic conditions, in the period of negative anomaly is anomalous water vapor condition is unfavorable to precipitation. WA, WP and EU index is positive and negative anomalies of the water vapor condition difference is bigger, the EA and the positive and negative anomalies caused by precipitation probability of PNA is similar.PNA index is the only one that positively correlated with the winter temperature distribution of the five characteristics index.1～3pentad after WA, WP index anomalies, northeast to the southeast of Inner Mongolia in central and northern China, and the temperature has significant effect in the southwest. EU abnormal index over the same period, most areas in China are affected, and has obvious temperature variation; After the exception, the northeast to Qinghai region in western and southern China have obvious difference in temperature. The west part in southwest of China syndrome after2～3at the end of the PNA abnormal temperature have significant differences.WA and EU indexes has a good negative correlation distribution with winter precipitation of our country, the anomaly rainfall caused by the significant differences of index also have good echo with high related area; EA and PNA index by the precipitation of related area and high index significantly caused by abnormal precipitation anomalies are all very limited, the distribution of degree is low.WA, EU index are negatively related to the winter precipitation distribution:WA index anomalies after1, near the southern bank of lower reaches of the Yellow River, Huanghuai plains is due to its significant difference area; EU index anomalies mainly caused during the same period in the middle and lower reaches of the Yellow River, abnormal after2pentad Yangtze River downstream precipitation caused by the significant differences. WP index anomalies, with precipitation in China is related, significant difference was found in south of the middle and lower reaches of the Yangtze river and the difference is larger. |
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