The North Atlantic Sea Surface Temperature Tripole In All Seasons And Its Relationship With Interannual Variability Of Temperature In China

Based on Hadley Sea Surface Temperature(SST),NCEP/NCAR reanalysis data,the OAFlux dataset from the Woods Hole Oceanographic Research Institute,the monthly mean temperature data of 160 stations in China by the National Climate Center of the China Meteorological Administration,we analyze the spatiotemporal characteristics of the interannual variability of the North Atlantic Sea Surface Temperature Anomaly(SSTA)in each season.Based on this,the North Atlantic SST Tripole(NAT)and its relationship with NAO and ENSO is analyzed.Furthermore,we also discuss the influence of the NAT on the interannual changes of temperature in China.The results show that:(1)The first mode of the interannual variability of the North Atlantic SSTA in winter,spring,and summer and the second mode in fall is the NAT,the structure is most obvious in spring.The first mode in fall is the North Atlantic Horseshoe SSTA.(2)The formation of the NAT in winter and spring is affected by the local air-sea interaction,which is mainly dominated by NAO during the same period.The formation of the NAT in summer and fall is due to the continuity of the NAT in spring from the spring to the fall season.(3)Winter ENSO has a regulating effect on the North Atlantic SST in winter,spring and summer.The main effect is the low latitude SST in the North Atlantic in all seasons.It has the most significant effect on the North Atlantic SST in the late spring.(4)The spring NAT is significantly positively correlated with the interannual variability of temperature in Northeast of China in spring.In spring,the NAT positive phase stimulates a North Atlantic-Eurasian teleconnection wave train,which reduces the potential height of the polar region and increases the height of the mid-high latitude potential,causing the weakening of the East Asian trough.It is conducive to the Northeast region temperature rise.At the same time,the northerly position of the polar front westerly jet and the difference of sea level pressure between the sea and land in Northeast Asia decreases cause a weakening of the meridional activity of the mid-high latitude atmosphere,which is not conducive to the cold air from Arctic down to the Northeast of China and is conducive to the warming of the Northeast region of China,vice versa.(5)The summer NAT is significantly negatively correlated with the interannual variability of temperature in the Southwest of China during the same period in summer.In summer,the NAT positive phase stimulates the northern hemisphere mid-high latitude Eurasian teleconnection wave train,which causes the potential height reduction in East Asia and produces anomalous cyclonic circulation.In the middle and lower troposphere,the Southwest of China is affected by the Northwest airflow in the Southwest of the abnormal cyclone,which is conducive to the southward and accumulation of cold air.There is cold advection transport in the Southwest region of China.In the abnormal updraft on the South side of the jet stream,this configuration will cause the temperature in the area to decrease,vice versa.