Regional Characteristics Of Two Types Of Rossby Wave Breakup And Their Associated Stratospheric-tropospheric Exchange Differences

Based on the daily potential vorticity(PV)data on the 330 K isentropic surface of ERA-Interim from 1979 to 2018,this paper used the improved Rossby wave breaking(RWB)identification method to statistically analyze the characteristics of RWB events in different types,seasons,and regions in the extratropical zones of Northern Hemisphere.For different types of typical RWB events,the Hysplit4 trajectory analysis are used to discuss the transport path of particles in the tongue area of high and low PV and the amount of stratosphere-troposphere mass exchange(STE)after wave breaking.The results show that:1)According to the frequency with which the grid points are located in the RWB area,the high frequency regions of cyclonic wave breaking(CWB)are located over the North Pacific and North Atlantic respectively in winter,spring and autumn,while the high frequency region of anticyclonic wave breaking(AWB)is located over the east coast of the North Atlantic.In summer,the two types of RWB show three high-frequency regions,which are located over the North Pacific,North Atlantic and Eurasia;According to the analysis of the centroid position of RWB,the recognition times of CWB(AWB)over the North Atlantic is the most in summer(winter),and the recognition times of CWB(AWB)over the North Atlantic is the least in winter(summer);2)Compared with the standarsized area of high and low PV tongues,CWB is mainly transported to the equator in all regions,and the North Atlantic is the region with the largest net transported to the equator in summer.AWB in the North Atlantic is mainly transported to the pole in winter,but due to the scale difference of different events,the cumulative net transport of all AWB events is symmetrical.In other seasons,AWB in each region is mainly transported to the equator,and the North Pacific contributes the most in summer;3)The average scale of RWB is maximum in winter and minimum in summer;The durations of the two types of RWB are concentrated in 1-4 days,and the number of occurrences decreases rapidly with the increase of duration;From the perspective of interannual variability of winter and summer,the probability of occurrence of CWB in winter and AWB in summer in the North Pacific region,CWB and AWB in summer in the North Atlantic region are significantly increased;4)Four typical case studies show that the occurrence of wave breaking is accompanied by the development of blocking high.Taking winter and summer as examples,the composite analysis shows that when the blocking high develops strongly in the middle troposphere of the North Atlantic in winter and the Eurasian continent(North Pacific in winter)in summer,the RWB at the tropospause is more represented by AWB(CWB).5)With the onset of RWB as the initial time,the material transport to the equator(invasion from stratosphere to troposphere)is reflected in the later stage(foward 6-48 hours)within 48 hours after the two equatorial CWB and AWB events.After about 12 hours,showing a net amount of transportation to the equator,and the maximum amount is about1.54×10¹³kg and 7.80×10¹²kg,respectively;Within 48 hours after the occurrence of the two polar CWB and AWB events,the material transport to the pole(invasion from troposphere to the stratosphere)is reflected in the early stage(foward 0-12 hours).About 24 hours ago,showing a net amount of material transport to the pole,and the maximum is about 1.48×10¹³kg and 9.96×10¹²kg,respectively.