Study On The Effect Of Polar Vortex Changes On Ozone In Eurasia

This paper mainly uses the data provided by the European Center from 1979 to2018 to calculate three indexes(AO/NAM,PVI,PVA)that can represent the changes in polar vortex and combine with isentropic potential vortices to summarize and analyze the polar vortex changes.At the same time,the variation trend of ozone over Eurasia in recent years is studied.By calculating the correlation coefficient,it is found that the variation of polar vortex has a certain effect on the ozone over Eurasia.After the discussion from the wind field,temperature field and individual cases,the main conclusions are summarized as follows:(1)The AO/NAM index,PVI index,and PVA index all change the most in winter.The intensity of the stratospheric polar vortices may be transmitted down to the troposphere,but there will still be abnormal frequency variations and failure to transmit down.(2)As for the selection method of the southern boundary characteristic contour line of the polar vortex,the location of the maximum westerly wind in each year and each month(year-month exact method)can be used to more accurately represent it,making the contour line position closer to the location of the maximum westerly wind.(3)The change of isentropic potential vortex center position in January can replace the change of isentropic potential vortex center position in winter,and the polar vortex center tends to Eurasia continent in February.(4)The stratified ozone changes in the European and Asian parts of Eurasia continent are negative anomaly in the stratosphere and positive anomaly in the troposphere,and the relationship between stratosphere ozone content and troposphere ozone content is mostly in reverse phase.(5)In strong polar vortex years,the ozone over Eurasia has a negative-positive-negative anomalous convex structure from polar to equatorial.In the weak polar vortex years,there is a positive-negative-positive ozone anomaly concave structure in the middle high latitude of Eurasia continent.(6)The downward transport of ozone anomaly is significantly hindered by the tropopause.Temperature downtransfer is an important reason why ozone downtransfer is hindered by tropopause.Whether ozone and temperature anomalies can be transmitted to the troposphere depends on the strong and irregular amplitude fluctuation of PVI and PVA phases in the late winter.