Oscillation propagation features of the atmosphere around the Qinghai-Xizang Plateau during the spring season of typical strong and weak monsoon years

Abstract

The interaction between the low-frequency atmospheric oscillation (Madden-Julian Oscillation, MJO) and the diabatic heating over the Qinghai-Xizang Plateau (QXP) from March to June is analyzed. The results show that there are respectively two and one wave trains around the QXP during the onset of the South China Sea monsoon in strong and weak monsoon years. The locations and strength of the wave train propagation differ between the strong and weak monsoon years. Because diabatic heating of the QXP prevents the low-frequency oscillation, the wave train of interaction between the diabatic heating and the zonal wind MJO propagates along the west and east of the QXP in the strong monsoon years. The distribution of the wave train interaction between the diabatic heating and the zonal wind MJO traverses the QXP and coincides with the location of the southern and northern upper-level jet streams, showing that they are remarkably correlated. An interesting and notable phenomenon is that the interaction between diabatic heating and the zonal wind MJO over the QXP suddenly disappears during the monsoon onset in weak monsoon years.