THE RELATIONSHIP BETWEEN LARGE-SCALE LOW-LEVEL JET OVER EAST ASIA AND MONSOON AS WELL AS CROSS-EQUATORIAL CURRENTS IN SUMMER

A review regarding the investigation of the background circulation of large-scale low-level jet (LLJ) over East Asia is given,which indicates the important effect of the monsoon westerlies on LLJ and the relationship between LLJ and cross-equatorial currents.The data of the Global Analyses provided by ECMWF are used to investigate the relationship between LLJ and monsoon as well as cross-equatorial currents.It indicates that a large amount of momentum of the monsoon westerlies is transferred downstream to the LLJ area,strengthening the jet speed.Most of LLJs over Asia are connected with the cross-equatorial currents in the Eastern Hemisphere.The cross-equatorial currents near 80°E are the main currents connected with the LLJ in May.However,once the Somalia jet is established,it becomes the main flow together with cross-equatorial currents near 105°E to influence the LLJ over East Asia.