Arctic Oscillation (enso), The Polar Ice Northeast Winter Temperatures Interdecadal Variations

The interdecadal relationship of AO, arctic sea ice and winter air temperature in Northeast China between 1950s to the early 20th century are investigated by using monthly mean air temperature data at 160 stations in China, AO indices, the NCEP/NCAR reanalysis data and the monthly mean sea ice intensity data from UK/GISST of Hadley center of English. The main results are:(1) In recent 50 years, winter air temperature in Northeast China and AO bears clear interdecadal variabilities respectively and they show significant, positive interdecadal relationship. When winter AO indices display a low(high) phase, winter air temperature in Northeast China displays a continued cold(warm) winter phase. In the bottom of atmosphere, winter AO influences winter air temperature in Northeast China by influencing the intensity of Siberia High. In middle troposphere annualar mode influences winter air temperature in middle troposphere in Northeast China by influencing the intensity of East Asia trough and the ridge in north of Baikal. In lower stratosphere annualar mode influences winter air temperature in Northeast China in lower stratosphere by influencing the intensity of polar vortex and the trough in the east of Asia(2) The key region of arctic sea-ice that influence winter air temperature in Northeast China is in Greenland Sea-Barents Sea..The key period time is from June to AugustThe arctic sea-ice in key region manifests significant interdecadal feature and important negative relationship with air temperature in Northeast China.(3) The artic sea-ice in key region in summer has significant, negative interdecadal relationship with winter AO in the same year. From ground to the lower stratosphere ?the influences of artic sea-ice to AO exhibits equivalent barotropicity and behaves strongest in Jannuary in the following year and persists till April.It manifests better continuity from autumn to winter to spring.(4) From ground to the lower stratosphere , the possible mechanism that artic sea-ice in the key region in summer influences winter air temperature in Northeast China is: When the artic sea-ice displays a more-ice(less-ice) period, the SLP field in the same year displays a negative (positive) AO period. So the Siberia High is strengthened (weakened), the low pressure near Japan sea is strengthened (weakened), the winter monsoon is strengthened (weakened), Northeast China displays a continued cold(warm) winter period. When the artic sea-ice displays a more-ice(less-ice) period, middle troposphere manifests low index (high index)phase of annualar mode, the East Asia trough is strengthened (weakened), the ridge in north of Baikal is strengthened (weakened), the circulation develops along the meridional(latitudinal) way, the north wind is strengthened(weakened),and the air temperature in middle stratosphere in NortheastChina is descended(ascended). When the artic sea-ice displays a more-ice(less-ice) period, lower stratosphere shows low(high) index state of annualar mode, Asia polar votex is weakened (strengthened),the trough in the east of Asia is strengthened (weakened), circulation develops along the meridional(latitudinal) way, north wind in lower stratosphere is strengthened(weakened), and air temperature in lower stratosphere in Northeast China is descended(ascended).